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  • richardmitnick 10:02 am on October 3, 2020 Permalink | Reply
    Tags: "Searching for the chemistry of life", , , , DESY, DNA base pairs, DNA-Deoxyribonucleic Acid, , The nucleobases adenine (A); cytosine (C); guanine (G) and thymine (T).   

    From DESY and From Helmholtz Association of German Research Centres: “Searching for the chemistry of life” 


    From DESY

    and

    From Helmholtz Association of German Research Centres

    2020/10/02

    Study shows possible new way to create DNA base pairs.

    1
    From the mixture of all four nucleobases, A:T pairs emerged at about 100 degrees Celsius and G:C pairs formed at 200 degrees Celsius. Credit: Ruđer Bošković Institute, Ivan Halasz.

    In the search for the chemical origins of life, researchers have found a possible alternative path for the emergence of the characteristic DNA pattern: According to the experiments, the characteristic DNA base pairs can form by dry heating, without water or other solvents. The team led by Ivan Halasz from the Ruđer Bošković Institute and Ernest Meštrović from the pharmaceutical company Xellia presents its observations from DESY’s X-ray source PETRA III [below] in the journal Chemical Communications.

    “One of the most intriguing questions in the search for the origin of life is how the chemical selection occurred and how the first biomolecules formed,” says Tomislav Stolar from the Ruđer Bošković Institute in Zagreb, the first author on the paper. While living cells control the production of biomolecules with their sophisticated machinery, the first molecular and supramolecular building blocks of life were likely created by pure chemistry and without enzyme catalysis. For their study, the scientists investigated the formation of nucleobase pairs that act as molecular recognition units in the Deoxyribonucleic Acid (DNA).

    Our genetic code is stored in the DNA as a specific sequence spelled by the nucleobases adenine (A), cytosine (C), guanine (G) and thymine (T). The code is arranged in two long, complementary strands wound in a double-helix structure. In the strands, each nucleobase pairs with a complementary partner in the other strand: adenine with thymine and cytosine with guanine.

    “Only specific pairing combinations occur in the DNA, but when nucleobases are isolated they do not like to bind to each other at all. So why did nature choose these base pairs?” says Stolar. Investigations of pairing of nucleobases surged after the discovery of the DNA double helix structure by James Watson and Francis Crick in 1953. However, it was quite surprising that there has been little success in achieving specific nucleobase pairing in conditions that could be considered as prebiotically plausible.

    “We have explored a different path,” reports co-author Martin Etter from DESY. “We have tried to find out whether the base pairs can be generated by mechanical energy or simply by heating.” To this end, the team studied methylated nucleobases. Having a methyl group (-CH3) attached to the respective nucleobases in principle allows them to form hydrogen bonds at the Watson-Crick side of the molecule. Methylated nucleobases occur naturally in many living organisms where they fulfil a variety of biological functions.

    In the lab, the scientists tried to produce nucleobase pairs by grinding. Powders of two nucleobases were loaded into a milling jar along with steel balls, which served as the grinding media, while the jars were shaken in a controlled manner. The experiment produced A:T pairs which had also been observed by other scientists before. Grinding however, could not achieve formation of G:C pairs.

    In a second step, the researchers heated the ground cytosine and guanine powders. “At about 200 degrees Celsius, we could indeed observe the formation of cytosine-guanine pairs,” reports Stolar. In order to test whether the bases only form the known pairs under thermal conditions, the team repeated the experiments with mixtures of three and four nucleobases at the P02.1 measuring station of DESY’s X-ray source PETRA III. Here, the detailed crystal structure of the mixtures could be monitored during heating and formation of new phases could be observed.

    2
    Artist’s impression of young Earth. Credit: NASA GSFC CC BY 2.0.

    At about 100 degrees Celsius, we were able to observe the formation of the adenine-thymine pairs, and at about 200 degrees Celsius the formation of Watson-Crick pairs of guanine and cytosine,” says Etter, head of the measuring station. “Any other base pair did not form even when heated further until melting.” This proves that the thermal reaction of nucleobase pairing has the same selectivity as in the DNA.

    “Our results show a possible alternative route as to how the molecular recognition patterns that we observe in the DNA could have been formed,” adds Stolar. “The conditions of the experiment are plausible for the young Earth that was a hot, seething cauldron with volcanoes, earthquakes, meteorite impacts and all sorts of other events. Our results open up many new paths in the search for the chemical origins of life.” The team plans to investigate this route further with follow-up experiments at P02.1.

    See the full article here.

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    desi

    DESY is one of the world’s leading accelerator centres. Researchers use the large-scale facilities at DESY to explore the microcosm in all its variety – from the interactions of tiny elementary particles and the behaviour of new types of nanomaterials to biomolecular processes that are essential to life. The accelerators and detectors that DESY develops and builds are unique research tools. The facilities generate the world’s most intense X-ray light, accelerate particles to record energies and open completely new windows onto the universe. 
That makes DESY not only a magnet for more than 3000 guest researchers from over 40 countries every year, but also a coveted partner for national and international cooperations. Committed young researchers find an exciting interdisciplinary setting at DESY. The research centre offers specialized training for a large number of professions. DESY cooperates with industry and business to promote new technologies that will benefit society and encourage innovations. This also benefits the metropolitan regions of the two DESY locations, Hamburg and Zeuthen near Berlin.

    DESY Petra III interior

    DESY Petra III

    DESY/FLASH

    H1 detector at DESY HERA ring

    DESY DORIS III


    DESY LUX beamline

    The Helmholtz Association

    The Helmholtz Association of German Research Centers was created in 1995 to formalise existing relationships between several globally-renowned independent research centres. The Helmholtz Association distributes core funding from the German Federal Ministry of Education and Research (BMBF) to its, now, 19 autonomous research centers and evaluates their effectiveness against the highest international standards.

     
  • richardmitnick 7:40 am on August 19, 2020 Permalink | Reply
    Tags: "World record: Plasma accelerator operates right around the clock", , , , DESY, , The LUX beamline,   

    From DESY- “World record: Plasma accelerator operates right around the clock” 


    From DESY

    2020/08/19

    Milestone towards first practical applications of this innovative accelerator technology.

    A team of researchers at DESY has reached an important milestone on the road to the particle accelerator of the future. For the first time, a so-called laser plasma accelerator has run for more than a day while continuously producing electron beams. The LUX beamline [below], jointly developed and operated by DESY and the University of Hamburg, achieved a run time of 30 hours. “This brings us a big step closer to the steady operation of this innovative particle accelerator technology,” says DESY’s Andreas R. Maier, the leader of the group. The scientists are reporting on their record in the journal Physical Review X. “The time is ripe to move laser plasma acceleration from the laboratory to practical applications,” adds the director of DESY’s Accelerator Division, Wim Leemans.

    Physicists hope that the technique of laser plasma acceleration will lead to a new generation of powerful and compact particle accelerators offering unique properties for a wide range of applications. In this technique, a laser or energetic particle beam creates a plasma wave inside a fine capillary. A plasma is a gas in which the gas molecules have been stripped of their electrons. LUX uses hydrogen as the gas.

    “The laser pulses plough their way through the gas in the form of narrow discs, stripping the electrons from the hydrogen molecules and sweeping them aside like a snow plough,” explains Maier, who works at the Centre for Free-Electron Laser Science (CFEL), a joint enterprise between DESY, the University of Hamburg and the Max Planck Society. “Electrons in the wake of the pulse are accelerated by the positively charged plasma wave in front of them – much like a wakeboarder rides the wave behind the stern of a boat.”

    This phenomenon allows laser plasma accelerators to achieve acceleration strengths that are up to a thousand times greater than what could be provided by today’s most powerful machines. Plasma accelerators will enable more compact and powerful systems for a wide range of applications, from fundamental research to medicine. A number of technical challenges still need to be overcome before these devices can be put to practical use. “Now that we are able to operate our beamline for extended periods of time, we will be in a better position to tackle these challenges,” explains Maier.

    During the record-breaking nonstop operation, the physicists accelerated more than 100,000 electron bunches, one every second. Thanks to this large dataset, the properties of the accelerator, the laser and the bunches can be correlated and analysed much more precisely. “Unwanted variations in the electron beam can be traced back to specific points in the laser, for example, so that we now know exactly where we need to start in order to produce an even better particle beam,” says Maier. “This approach lays the foundations for an active stabilisation of the beams, such as is deployed on every high performance accelerator in the world,” explains Leemans.

    According to Maier, the key to success was combining expertise from two different fields: plasma acceleration and know-how in stable accelerator operation.“ Both are available at DESY, which is unparalleled in the world in this respect,” Maier emphasises. According to him, numerous factors contributed to the accelerator’s stable long-term operation, from vacuum technology and laser expertise to a comprehensive and sophisticated control system. “In principle, the system could have kept running for even longer, but we stopped it after 30 hours,” reports Maier. “Since then, we have repeated such runs three more times.”

    “This work demonstrates that laser plasma accelerators can generate a reproducible and controllable output. This provides a concrete basis for developing this technology further, in order to build future accelerator-based light sources at DESY and elsewhere,” Leemans summarises.

    Scientists from the University of Hamburg, the European ELI-Beamlines Project, the Max Planck Research School for Ultrafast Imaging & Structural Dynamics (IMPRS-UFAST) and DESY were all involved in the research.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    desi

    DESY is one of the world’s leading accelerator centres. Researchers use the large-scale facilities at DESY to explore the microcosm in all its variety – from the interactions of tiny elementary particles and the behaviour of new types of nanomaterials to biomolecular processes that are essential to life. The accelerators and detectors that DESY develops and builds are unique research tools. The facilities generate the world’s most intense X-ray light, accelerate particles to record energies and open completely new windows onto the universe. 
That makes DESY not only a magnet for more than 3000 guest researchers from over 40 countries every year, but also a coveted partner for national and international cooperations. Committed young researchers find an exciting interdisciplinary setting at DESY. The research centre offers specialized training for a large number of professions. DESY cooperates with industry and business to promote new technologies that will benefit society and encourage innovations. This also benefits the metropolitan regions of the two DESY locations, Hamburg and Zeuthen near Berlin.

    DESY Petra III interior

    DESY Petra III

    DESY/FLASH

    H1 detector at DESY HERA ring

    DESY DORIS III

    DESY LUX beamline

     
  • richardmitnick 2:14 pm on August 17, 2020 Permalink | Reply
    Tags: "Strange gamma-ray heartbeat puzzles scientists", , , , , DESY   

    From DESY: “Strange gamma-ray heartbeat puzzles scientists” 


    From DESY

    2020/08/17

    Cosmic gas cloud blinks in sync with wobbling black hole.

    Scientists have detected a mysterious gamma-ray heartbeat coming from a cosmic gas cloud. The inconspicuous cloud in the constellation Aquila is beating with the rhythm of a neighbouring precessing black hole, indicating a connection between the two objects, as the team led by DESY Humboldt Fellow Jian Li and ICREA Professor Diego F. Torres from the Institute of Space Sciences (IEEC-CSIC) reports in the journal Nature Astronomy. Just how the black hole powers the cloud’s gamma-ray heartbeat over a distance of about 100 light years remains enigmatic.

    1
    The microquasar SS 433 (background) sways with a period of 162 days. The inconspicuous gas cloud Fermi J1913+0515 (foreground), about 100 light years away, pulsates with the same rhythm, suggesting a direct connection. But how exactly the microquasar drives this ‘heartbeat’ of the gas cloud is still puzzling. Credit: DESY, Science Communication Lab.

    The research team, comprising scientists from Germany, Spain, China and the U.S., rigorously analysed more than ten years of data from the US space administration NASA’s Fermi gamma-ray space telescope, looking at a so-called micro quasar.

    NASA/Fermi LAT


    NASA/Fermi Gamma Ray Space Telescope

    The system catalogued as SS 433 is located some 15 000 lightyears away in the Milky Way and consists of a giant star with about 30 times the mass of our sun and a black hole with about 10 to 20 solar masses. The two objects are orbiting each other with a period of 13 days, while the black hole sucks matter from the giant star.

    “This material accumulates in an accretion disc before falling into the black hole, like water in the whirl above the drain of a bath tub,” explains Li. “However, a part of that matter does not fall down the drain but shoots out at high speed in two narrow jets in opposite directions above and below the rotating accretion disk.” This setting is known from active galaxies called quasars with monstrous black holes with millions of solar masses at their centres that shoot jets tens of thousands of lightyears into the cosmos. As SS 433 looks like a scaled-down version of these quasars, it has been dubbed a micro quasar.

    The high-speed particles and the ultra-strong magnetic fields in the jet produce X-rays and gamma rays.

    “The accretion disc does not lie exactly in the plane of the orbit of the two objects. It precesses, or sways, like a spinning top that has been set up slanted on a table,” says Torres. “As a consequence, the two jets spiral into the surrounding space, rather than just forming a straight line.”

    The precession of the black hole’s jets has a period of about 162 days. Meticulous analysis revealed a gamma-ray signal with the same period from a position located relatively far from the micro quasar’s jets, which has been labelled as Fermi J1913+0515 by the scientists. It is located at the position of an unremarkable gas enhancement. The consistent periods indicate the gas cloud’s emission is powered by the micro quasar.

    “Finding such an unambiguous connection via timing, about 100 light years away from the micro quasar, not even along the direction of the jets is as unexpected as amazing,” says Li. “But how the black hole can power the gas cloud’s heartbeat is unclear to us.” Direct periodic illumination by the jet seems unlikely. An alternative that the team explored is based on the impact of fast protons (the nuclei of hydrogen atoms) produced at the ends of the jets or near the black hole, and injected into the cloud, where these subatomic particles hit the gas and produce gamma rays. Protons could also be part of an outflow of fast particles from the edge of the accretion disc. Whenever this outflow strikes the gas cloud, it lights up in gamma rays, which would explain its strange heartbeat. “Energetically, the outflow from the disc could be as powerful as that of the jets and is believed to precess in solidarity with the rest of the system,” explains Torres.

    Further observations as well as theoretical work are required to fully explain the strange gamma-ray heartbeat of this unique system beyond this initial discovery. “SS 433 continues to amaze observers at all frequencies and theoreticians alike,” emphasises Li. “And it is certain to provide a testbed for our ideas on cosmic-ray production and propagation near micro quasars for years to come.”

    Scientists from DESY (Germany), ICE (Spain), Nanjing University (China), the U.S. Naval Research Laboratory (USA) and Purple Mountain observatory (China) contributed to this research.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    desi

    DESY is one of the world’s leading accelerator centres. Researchers use the large-scale facilities at DESY to explore the microcosm in all its variety – from the interactions of tiny elementary particles and the behaviour of new types of nanomaterials to biomolecular processes that are essential to life. The accelerators and detectors that DESY develops and builds are unique research tools. The facilities generate the world’s most intense X-ray light, accelerate particles to record energies and open completely new windows onto the universe. 
That makes DESY not only a magnet for more than 3000 guest researchers from over 40 countries every year, but also a coveted partner for national and international cooperations. Committed young researchers find an exciting interdisciplinary setting at DESY. The research centre offers specialized training for a large number of professions. DESY cooperates with industry and business to promote new technologies that will benefit society and encourage innovations. This also benefits the metropolitan regions of the two DESY locations, Hamburg and Zeuthen near Berlin.

    DESY Petra III interior

    DESY Petra III

    DESY/FLASH

    H1 detector at DESY HERA ring

    DESY DORIS III

     
  • richardmitnick 11:10 am on July 1, 2020 Permalink | Reply
    Tags: "Binary star as a cosmic particle accelerator", , , , , , DESY, , , Very high-energy gamma radiation   

    From DESY: “Binary star as a cosmic particle accelerator” 

    From DESY

    2020/07/01

    Specialized telescope provides evidence of very high-energy gamma radiation from Eta Carinae.

    With a specialised telescope in Namibia a DESY-led team of researchers has proven a certain type of binary star as a new kind of source for very high-energy cosmic gamma-radiation. Eta Carinae is located 7500 light years away in the constellation Carina (the ship’s keel) in the Southern Sky and, based on the data collected, emits gamma rays with energies all the way up to 400 gigaelectronvolts (GeV), some 100 billion times more than the energy of visible light.

    1
    Eta Carinae. NASA

    The team headed by DESY’s Stefan Ohm, Eva Leser and Matthias Füßling is presenting its findings, made at the gamma-ray observatory High Energy Stereoscopic System (H.E.S.S.), in the journal Astronomy & Astrophysics. [see also in Astronomy and Astrophysics] specially created multimedia animation explains the phenomenon. “With such visualizations we want to make the fascination of research tangible,” emphasises DESY’s Director of Astroparticle Physics, Christian Stegmann.


    Animation: DESY, Science Communication Lab; Sound by Alva Noto.

    Eta Carinae is a binary system of superlatives, consisting of two blue giants, one about 100 times, the other about 30 times the mass of our sun. The two stars orbit each other every 5.5 years in very eccentric elliptical orbits, their separation varying approximately between the distance from our Sun to Mars and from the Sun to Uranus. Both these gigantic stars fling dense, supersonic stellar winds of charged particles out into space. In the process, the larger of the two loses a mass equivalent to our entire Sun in just 5000 years or so. The smaller one produces a fast stellar wind travelling at speeds around eleven million kilometres per hour (about one percent of the speed of light).

    A huge shock front is formed in the region where these two stellar winds collide, heating up the material in the wind to extremely high temperatures. At around 50 million degrees Celsius, this matter radiates brightly in the X-ray range. The particles in the stellar wind are not hot enough to emit gamma radiation, though. “However, shock regions like this are typically sites where subatomic particles are accelerated by strong prevailing electromagnetic fields,” explains Ohm, who is the head of the H.E.S.S. group at DESY.

    H.E.S.S. Čerenkov Telescope Array, located on the Cranz family farm, Göllschau, in Namibia, near the Gamsberg searches for cosmic rays, altitude, 1,800 m (5,900 ft)

    When particles are accelerated this rapidly, they can also emit gamma radiation. In fact, the satellites “Fermi”, operated by the US space agency NASA, and AGILE, belonging to the Italian space agency ASI, already detected high-energy gamma rays of up to about 10 GeV coming from Eta Carinae in 2009.

    NASA/Fermi LAT


    NASA/Fermi Gamma Ray Space Telescope

    Italian Space Agency AGILE Spacecraft

    Subatomic hailstorm

    Different models have been proposed to explain how this gamma radiation is produced,” Füßling reports. “It could be generated by accelerated electrons or by high-energy atomic nuclei.” Determining which of these two scenarios is correct is crucial: very energetic atomic nuclei account for the bulk of the so-called Cosmic Rays, a subatomic cosmic hailstorm striking Earth constantly from all directions. Despite intense research for more than 100 years, the sources of the Cosmic Rays are still not exhaustively known. Since the electrically charged atomic nuclei are deflected by cosmic magnetic fields as they travel through the universe, the direction from which they arrive at Earth no longer points back to their origin. Cosmic gamma rays, on the other hand, are not deflected. So, if the gamma rays emitted by a specific source can be shown to originate from high-energy atomic nuclei, one of the long-sought accelerators of cosmic particle radiation will have been identified.

    “In the case of Eta Carinae, electrons have a particularly hard time getting accelerated to high energies, because they are constantly being deflected by magnetic fields during their acceleration, which makes them lose energy again,” says Leser. “Very high-energy gamma radiation begins above the 100 GeV range, which is rather difficult to explain in Eta Carinae to stem from electron acceleration.” The satellite data already indicated that Eta Carinae also emits gamma radiation beyond 100 GeV, and H.E.S.S. has now succeeded in detecting such radiation up to energies of 400 GeV around the time of the close encounter of the two blue giants in 2014 and 2015. This makes the binary star the first known example of a source in which very high-energy gamma radiation is generated by colliding stellar winds.

    “The analysis of the gamma radiation measurements taken by H.E.S.S. and the satellites shows that the radiation can best be interpreted as the product of rapidly accelerated atomic nuclei,” says DESY’s PhD student Ruslan Konno, who has published a companion study, together with scientists from the Max Planck Institute for Nuclear Physics in Heidelberg. “This would make the shock regions of colliding stellar winds a new type of natural particle accelerator for cosmic rays.” With H.E.S.S., which is named after the discoverer of Cosmic Rays, Victor Franz Hess, and the upcoming Čerenkov Telescope Array (CTA), the next-generation gamma-ray observatory currently being built in the Chilean highlands, the scientists hope to investigate this phenomenon in greater detail and discover more sources of this kind.

    Čerenkov Telescope Array, http://www.isdc.unige.ch/cta/ at Cerro Paranal, located in the Atacama Desert of northern Chile searches for cosmic rays on Cerro Paranal at 2,635 m (8,645 ft) altitude, 120 km (70 mi) south of Antofagasta; and at at the Instituto de Astrofisica de Canarias (IAC), Roque de los Muchachos Observatory in La Palma, Spain

    Cosmic road trip

    Thanks to detailed observations of Eta Carinae at all wavelengths, the properties of the stars, their orbits and stellar winds have been determined relatively accurately. This has given astrophysicists a better picture of the binary star system and its history. To illustrate the new observations of Eta Carinae, the DESY astrophysicists have produced a video animation together with the animation specialists of the award-winning Science Communication Lab [above]. The computer-generated images are close to reality because the measured orbital, stellar and wind parameters were used for this purpose. The internationally acclaimed multimedia artist Carsten Nicolai, who uses the pseudonym Alva Noto for his musical works, created the sound for the animation.

    “I find science and scientific research extremely important,” says Nicolai, who sees close parallels in the creative work of artists and scientists. For him, the appeal of this work also lay in the artistic mediation of scientific research results: “particularly the fact that it is not a film soundtrack, but has a genuine reference to reality,” emphasizes the musician and artist. Together with the exclusively composed sound, this unique collaboration of scientists, animation artists and musician has resulted in a multimedia work that takes viewers on an extraordinary journey to a superlative double star some 7500 light years away.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    desi

    DESY is one of the world’s leading accelerator centres. Researchers use the large-scale facilities at DESY to explore the microcosm in all its variety – from the interactions of tiny elementary particles and the behaviour of new types of nanomaterials to biomolecular processes that are essential to life. The accelerators and detectors that DESY develops and builds are unique research tools. The facilities generate the world’s most intense X-ray light, accelerate particles to record energies and open completely new windows onto the universe. 
That makes DESY not only a magnet for more than 3000 guest researchers from over 40 countries every year, but also a coveted partner for national and international cooperations. Committed young researchers find an exciting interdisciplinary setting at DESY. The research centre offers specialized training for a large number of professions. DESY cooperates with industry and business to promote new technologies that will benefit society and encourage innovations. This also benefits the metropolitan regions of the two DESY locations, Hamburg and Zeuthen near Berlin.

    DESY Petra III interior

    DESY Petra III

    DESY/FLASH

    H1 detector at DESY HERA ring

    DESY DORIS III

     
  • richardmitnick 1:38 pm on March 20, 2020 Permalink | Reply
    Tags: , "Tiny double accelerator recycles energy", A miniature double particle accelerator that can recycle some of the laser energy fed into the system to boost the energy of the accelerated electrons a second time., Center for Free-Electron laser Science (CFEL), DESY   

    From DESY via phys.org: “Tiny double accelerator recycles energy” 

    DESY
    From DESY

    via


    phys.org

    1
    Proof of concept for cascaded terahertz accelerator using long pulses. The mini-accelerator uses terahertz radiation that can be recycled for a second stage of acceleration. Credit: DESY, Science Communication Lab.

    A team of DESY scientists has built a miniature double particle accelerator that can recycle some of the laser energy fed into the system to boost the energy of the accelerated electrons a second time. The device uses narrowband terahertz radiation which lies between infrared and radio frequencies in the electromagnetic spectrum, and a single accelerating tube is just 1.5 centimetres long and 0.79 millimetres in diameter. Dongfang Zhang and his colleagues from the Center for Free-Electron laser Science (CFEL) at DESY present their experimental accelerator in the journal Physical Review X.

    The miniature size of the device is possible due to the short wavelength of terahertz radiation. “Terahertz-based accelerators have emerged as promising candidates for next-generation compact electron sources,” explains Franz Kärtner, Lead Scientist at DESY and head of the CFEL group that built the device. Scientists have successfully experimented with terahertz accelerators before, which could enable applications where large particle accelerators are just not feasible or necessary. “However, the technique is still in an early stage, and the performance of experimental terahertz accelerators has been limited by the relatively short section of interaction between the terahertz pulse and the electrons,” says Kärtner.

    For the new device, the team used a longer pulse comprising many cycles of terahertz waves. This multicycle pulse significantly extends the interaction section with the particles. “We feed the multicycle terahertz pulse into a waveguide that is lined with a dielectric material”, says Zhang. Within the waveguide, the pulse’s speed is reduced. A bunch of electrons is shot into the central part of the waveguide just in time to travel along with the pulse. “This scheme increases the interaction region between the terahertz pulse and the electron bunch to the centimetre range—compared to a few millimetres in earlier experiments,” reports Zhang.

    The device did not produce a large acceleration in the lab. However, the team could prove the concept by showing that the electrons gain energy in the waveguide. “It is a proof of concept. The electrons’ energy increased from 55 to about 56.5 kilo electron volts,” says Zhang. “A stronger acceleration can be achieved by using a stronger laser to generate the terahertz pulses.”

    The set-up is mainly designed for the non-relativistic regime, meaning the electrons have speeds that are not so close to the speed of light. Interestingly, this regime enables a recycling of the terahertz pulse for a second stage of acceleration. “Once the terahertz pulse leaves the waveguide and enters the vacuum, its speed is reset to the speed of light,” explains Zhang. “This means, the pulse overtakes the slower electron bunch in a couple of centimetres. We placed a second waveguide at just the right distance that the electrons enter it together with the terahertz pulse which is again slowed down by the waveguide. In this way, we generate a second interaction section, boosting the electrons’ energies further.”

    In the lab experiment, only a small fraction of the terahertz pulse could be recycled this way. But the experiment shows that recycling is possible in principle, and Zhang is confident that the recycled fraction can be substantially increased. Nicholas Mattlis, senior scientist and the team leader of the project in the CFEL group, emphasises: “Our cascading scheme will greatly lower the demand on the required laser system for electron acceleration in the non-relativistic regime, opening new possibilities for the design of terahertz-based accelerators.”

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    About Science X in 100 words

    Science X™ is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004 (Physorg.com), Science X’s readership has grown steadily to include 5 million scientists, researchers, and engineers every month. Science X publishes approximately 200 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Science X community members enjoy access to many personalized features such as social networking, a personal home page set-up, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.
    Mission 12 reasons for reading daily news on Science X Organization Key editors and writersinclude 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

    desi

    DESY is one of the world’s leading accelerator centres. Researchers use the large-scale facilities at DESY to explore the microcosm in all its variety – from the interactions of tiny elementary particles and the behaviour of new types of nanomaterials to biomolecular processes that are essential to life. The accelerators and detectors that DESY develops and builds are unique research tools. The facilities generate the world’s most intense X-ray light, accelerate particles to record energies and open completely new windows onto the universe. 
That makes DESY not only a magnet for more than 3000 guest researchers from over 40 countries every year, but also a coveted partner for national and international cooperations. Committed young researchers find an exciting interdisciplinary setting at DESY. The research centre offers specialized training for a large number of professions. DESY cooperates with industry and business to promote new technologies that will benefit society and encourage innovations. This also benefits the metropolitan regions of the two DESY locations, Hamburg and Zeuthen near Berlin.

    DESY Petra III interior


    DESY Petra III

    DESY/FLASH

    H1 detector at DESY HERA ring

    DESY DORIS III

     
  • richardmitnick 2:13 pm on November 21, 2019 Permalink | Reply
    Tags: , , , , , DESY, H.E.S.S. Čerenkov Telescope Array located on the Cranz family farm Göllschau in Namibia near the Gamsberg,   

    From DESY: “Gamma-Ray Bursts with record energy” 

    DESY
    From DESY

    2019/11/20

    First detection of the cosmic monster explosions with ground-based gamma-ray telescopes.

    The strongest explosions in the universe produce even more energetic radiation than previously known: Using specialised telescopes, two international teams have registered the highest energy gamma rays ever measured from so-called gamma-ray bursts, reaching about 100 billion times as much energy as visible light. The scientists of the H.E.S.S. and MAGIC telescopes present their observations in independent publications in the journal Nature.

    A very-high-energy component deep in the γ-ray burst afterglow; The H.E.S.S. collaboration Nature

    Teraelectronvolt emission from the γ-ray burst GRB 190114C; The MAGIC collaboration Nature

    These are the first detections of gamma-ray bursts with ground-based gamma-ray telescopes. DESY plays a major role in both observatories, which are operated under the leadership of the Max Planck Society.

    H.E.S.S. Čerenkov Telescope Array, located on the Cranz family farm, Göllschau, in Namibia, near the Gamsberg searches for cosmic rays, altitude, 1,800 m (5,900 ft)

    MAGIC Čerenkov telescopes at the Observatorio del Roque de los Muchachos (Garfia, La Palma, Spain)), Altitude 2,396 m (7,861 ft)

    Gamma-ray bursts (GRB) are sudden, short bursts of gamma radiation happening about once a day somewhere in the visible universe. According to current knowledge, they originate from colliding neutron stars or from supernova explosions of giant suns collapsing into a black hole. “Gamma-ray bursts are the most powerful explosions known in the universe and typically release more energy in just a few seconds than our Sun during its entire lifetime – they can shine through almost the entire visible universe,” explains David Berge, head of gamma-ray astronomy at DESY. The cosmic phenomenon was discovered by chance at the end of the 1960s by satellites used to monitor compliance with the nuclear test ban on Earth.

    Since then, astronomers have been studying gamma-ray bursts with satellites, as Earth’s atmosphere very effectively absorbs gamma rays. Astronomers have developed specialised telescopes that can observe a faint blue glow called Čerenkov light that cosmic gamma rays induce in the atmosphere, but these instruments are only sensitive to gamma rays with very high energies. Unfortunately, the brightness of gamma-ray bursts falls steeply with increasing energy. Čerenkov telescopes have identified many sources of cosmic gamma rays at very high energies, but no gamma-ray bursts. Satellites, on the other hand, have much too small detectors to be sensitive to the low brightness of gamma-ray bursts at very high energies. So, it was effectively unknown, if the monster explosions emit gamma rays also in the very-high-energy regime.

    Scientists have tried for many years, to catch a gamma-ray burst with Čerenkov telescopes. Then suddenly, between summer 2018 and January 2019, two international teams of astronomers, both involving DESY scientists, detected gamma rays from two GRB events for the first time from the ground. On 20 July 2018, faint afterglow emission of GRB 180720B in the gamma-ray regime was observed with the 28-metre telescope of the High-Energy Stereoscopic System H.E.S.S. in Namibia. On 14 January 2019, bright early emission from GRB 190114C was detected by the Major Atmospheric Gamma Imaging Čerenkov (MAGIC) telescopes on La Palma, and immediately announced to the astronomical community.

    Both observations were triggered by gamma-ray satellites of the US space agency NASA that monitor the sky for gamma-ray bursts and send automatic alerts to other gamma-ray observatories upon detection. “We were able to point to the region of origin so quickly that we could start observing only 57 seconds after the initial detection of the explosion,” reports Cosimo Nigro from the MAGIC group at DESY, who was in charge of the observation shift at that time. “In the first 20 minutes of observation, we detected about thousand photons from GRB 190114C.”

    MAGIC registered gamma-rays with energies between 200 and 1000 billion electron volts (0.2 to 1 teraelectronvolts). “These are by far the highest energy photons ever discovered from a gamma-ray burst,” says Elisa Bernardini, leader of the MAGIC group at DESY. For comparison: visible light is in the range of about 1 to 3 electron volts.

    The rapid discovery allowed to quickly alert the entire observational community. As a result, more than twenty different telescopes had a deeper look at the target. This allowed to pinpoint the details of the physical mechanism responsible for the highest-energy emission, as described in the second paper led by the MAGIC collaboration. Follow-up observations placed GRB 190114C at a distance of more than four billion light years. This means, its light travelled more than four billion years to us, or about a third of the current age of the universe.

    GRB 180720B, at a distance of six billion light years even further away, could still be detected in gamma rays at energies between 100 and 440 billion electron volts long after the initial blast. “Surprisingly, the H.E.S.S. telescope observed a surplus of 119 gamma quanta from the direction of the burst more than ten hours after the explosion event was first seen by satellites,” says Stefan Ohm, head of the H.E.S.S. group at DESY.

    “The detection came quite unexpected, as gamma-ray bursts are fading fast, leaving behind an afterglow which can be seen for hours to days across many wavelengths from radio to X-rays, but had never been detected in very-high-energy gamma rays before,” adds DESY theorist Andrew Taylor, who contributed to the H.E.S.S. analysis. “This success is also due to an improved follow-up strategy in which we also concentrate on observations at later times after the actual star collapse.”

    The detection of gamma-ray bursts at very high energies provides important new insights into the gigantic explosions. “Having established that GRBs produce photons of energies hundreds of billion times higher than visible light, we now know that GRBs are able to efficiently accelerate particles within the explosion ejecta,” says DESY researcher Konstancja Satalecka, one of the scientists coordinating GRB searches in the MAGIC collaboration. “What’s more, it turns out we were missing approximately half of their energy budget until now. Our measurements show that the energy released in very-high-energy gamma-rays is comparable to the amount radiated at all lower energies taken together. That is remarkable!”

    To explain how the observed very-high-energy gamma rays are generated is challenging. Both groups assume a two-stage process: First, fast electrically charged particles from the explosion cloud are deflected in the strong magnetic fields and emit so-called synchrotron radiation, which is of the same nature as the radiation that can be produced in synchrotrons or other particle accelerators on Earth, for example at DESY. However, only under fairly extreme conditions would the synchrotron photons from the explosion be able to reach the very high energies observed. Instead, the scientists consider a second step, where the synchrotron photons collide with the fast particles that generated them, which boosts them to the very high gamma-ray energies recorded. The scientists call the latter step inverse Compton scattering.

    Observation of inverse Compton emission from a long γ-ray burst; The MAGIC CollaborationNature

    “For the first time, the two instruments have measured gamma radiation from gamma-ray bursts from the ground,” concludes Berge. “These two groundbreaking observations have established gamma-ray bursts as sources for terrestrial gamma-ray telescopes. This has the potential to significantly advance our understanding of these violent phenomena.” The scientists estimate that up to ten such events per year can be observed with the planned Čerenkov Telescope Array (CTA), the next generation gamma-ray observatory. The CTA will consist of more than 100 individual telescopes of three types that will be built at two locations in the northern and southern hemispheres. DESY is responsible for the construction of the medium-sized telescopes and will host CTA’s Science Data Management Centre on its campus in Zeuthen. CTA observations are expected to start in 2023 at the earliest.

    ________________________________________
    Background information

    The detection of the very high-energy gamma rays on Earth was achieved with specialised telescopes that do not observe the cosmic gamma rays directly, but rather their effect on Earth’s atmosphere: When an energetic cosmic gamma ray hits Earth’s atmosphere, it shatters molecules and atoms.

    This process creates an avalanche of particles called an air shower.

    Cosmic rays produced by high-energy astrophysics sources (ASPERA collaboration – AStroParticle ERAnet)

    The shower particles are so energetic that they move faster through the air than light – although not faster than light in a vacuum, which according to Albert Einstein’s theory of relativity is the absolute upper speed limit. The result is a bluish glow, a kind of optical counterpart to the supersonic bang. This Čerenkov light, named after its discoverer, can be observed by Čerenkov telescopes such as those of the H.E.S.S. and MAGIC observatories or the planned CTA.

    The H.E.S.S. observations were first announced at the CTA science symposium in May 2019. The MAGIC observations were distributed in an Astronomers’ Telegram (ATel) on 14 January 2019.

    The H.E.S.S. consortium consists of more than 250 researchers from 41 institutes in 12 countries. The MAGIC consortium brings together 280 members from 37 institutes in 12 countries. The MAGIC group at DESY is partially funded by a grant from the Helmholtz Association for excellent women researchers.

    ________________________________________

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    desi

    DESY is one of the world’s leading accelerator centres. Researchers use the large-scale facilities at DESY to explore the microcosm in all its variety – from the interactions of tiny elementary particles and the behaviour of new types of nanomaterials to biomolecular processes that are essential to life. The accelerators and detectors that DESY develops and builds are unique research tools. The facilities generate the world’s most intense X-ray light, accelerate particles to record energies and open completely new windows onto the universe. 
That makes DESY not only a magnet for more than 3000 guest researchers from over 40 countries every year, but also a coveted partner for national and international cooperations. Committed young researchers find an exciting interdisciplinary setting at DESY. The research centre offers specialized training for a large number of professions. DESY cooperates with industry and business to promote new technologies that will benefit society and encourage innovations. This also benefits the metropolitan regions of the two DESY locations, Hamburg and Zeuthen near Berlin.

    DESY Petra III interior


    DESY Petra III

    DESY/FLASH

    H1 detector at DESY HERA ring

    DESY DORIS III

     
  • richardmitnick 2:37 pm on October 28, 2019 Permalink | Reply
    Tags: A decisive function for the young field of multi-messenger astronomy (MMA)., DESY, New insights into high-energy phenomena such as supernova explosions; colliding neutron stars and active black holes., The satellite will search for the origin of the heavy chemical elements., The UV camera which DESY is developing and building will be the heart of the telescope., ULTRASAT satellite, ULTRASAT will study the sky in the ultraviolet range (220 to 280 nanometres wavelength) of the electromagnetic spectrum.,   

    From DESY: “UV Satellite Will Open New View on Exploding Stars and Black Holes” 

    DESY
    From DESY

    2019/10/28

    DESY to build 100-megapixel camera for Israeli space telescope.

    A new space telescope will open up an unprecedented view of the universe in ultraviolet light: The ULTRASAT satellite will provide fundamental new insights into high-energy phenomena such as supernova explosions, colliding neutron stars and active black holes, all of which can also generate gravitational waves and act as cosmic particle accelerators. On Monday in Rehovot, Israel, the President of the Helmholtz Association, Otmar D. Wiestler, and the Director of the Helmholtz centre DESY, Helmut Dosch, agreed with the Weizmann Institute of Science on a cooperation for German participation in the Israeli-led project. DESY will build the 100-megapixel UV camera for the space telescope. For the project, DESY is working with the German Aerospace Center DLR, which also is a member of the Helmholtz Association.

    Weizmann Institute Campus

    “Helmholtz has had many excellent scientific collaborations with Israeli partners for decades. Together with the Weizmann Institute of Science, we are now taking another important step in the field of astrophysics. I am extremely pleased about this,” said Helmholtz President Otmar D. Wiestler. “The cooperation on the ULTRASAT space telescope has the potential to create a completely new basis for the detection of gravitational waves and related astrophysical events, at the highest international level.”

    DESY Director Helmut Dosch added: “We have a long and fruitful cooperation with a number of Israeli partners. We are now continuing this success story with our participation in Weizmann Institute of Science’s challenging satellite project.” DESY’s Research Director for Astroparticle Physics, Christian Stegmann, emphasised: “ULTRASAT offers us unique insights into the high-energy universe. With the camera for the telescope, DESY will be able to combine and contribute its outstanding expertise in detector development for astroparticle physics and X-ray physics.”

    ULTRASAT will study the sky in the ultraviolet range (220 to 280 nanometres wavelength) of the electromagnetic spectrum and have a particularly large field of view of 225 square degrees – about 1200 times as large as the full moon appears in our sky. “This unique configuration will help us answer some of the big questions in astrophysics,” said Eli Waxman, principal investigator of ULTRASAT at the Weizmann Institute of Science.

    2
    Collage of the satellite with typical observation targets like supernova explosions (top left), merging neutron stars (bottom left) and active black holes (top right). Photomontage: DESY, with material from NASA and Weizmann Institute of Science

    For example, the satellite will search for the origin of the heavy chemical elements. Apart from the lightest elements like hydrogen and helium, the elements were almost exclusively created by nuclear fusion in the cosmos. Stars produce their energy from this nuclear fusion, but this only works up to iron. The fusion of heavier elements such as lead or gold costs energy. Their synthesis takes place in the most powerful processes in the universe, such as the explosion of a star as a supernova or the collision of two neutron stars – the nuclei of burnt-out suns that have collapsed under their own weight to such an extent that they have a density like a gigantic atomic nucleus. Every gold atom on Earth and in the rest of the cosmos comes from an exploding sun or from a neutron star crash.

    “We want to understand exactly how the elements are produced and how they are distributed,” explains David Berge, Lead Scientist at DESY. Both, supernova explosions and neutron star collisions can be followed particularly well in UV light, as Berge points out. “The direct phase of a supernova in the first minutes, hours and days is mainly seen in the UV. During this time, the UV light contains characteristic signatures that indicate the predecessor star.” Later, a shockwave breaks out of the hot fireball, within which charged subatomic particles are also accelerated to high energies. “The satellite can therefore help us to understand the origin of such cosmic particle accelerators,” says Berge. “We also want to find out which type of star explodes in which kind of supernova.”

    ULTRASAT is particularly sensitive to high-energy phenomena. “Everything that gets extremely hot shines brightly in the UV light,” reports DESY researcher Rolf Bühler, project manager for the UV camera. This includes active black holes, which absorb matter from their environment and also accelerate particles, and colliding neutron stars. The observation of neutron star crashes can not only provide information about element synthesis in the cosmos, but is also of great importance for gravitational wave research. “If gravitational waves are registered by merging neutron stars, their position can so far only be coarsely resolved on the basis of the gravitational wave data,” explains Bühler. “ULTRASAT can orient itself to the target region within a maximum of 30 minutes and, thanks to its large field of view, can then determine the exact position almost immediately.”

    3
    Infographic: DESY, Sven Stein

    The satellite thus has a decisive function for the young field of multi-messenger astronomy (MMA), which studies the universe via various messengers such as cosmic particles, gravitational waves and electromagnetic radiation and forms a new area of research at DESY. With its large field of view, the satellite will have a particularly large section of the sky in view and will thus also be able to detect unknown objects that suddenly flare up in the UV range.

    With a total weight of only 160 kilograms and a volume of less than one cubic metre, ULTRASAT (Ultraviolet Transient Astronomy Satellite) is a small scientific satellite. The Weizmann Institute of Science and the Israeli Space Agency ISA share funding and management. The launch is scheduled for 2023. The space telescope will then collect data for three years. It will be put in a high orbit about 35,000 kilometres above Earth’s surface. This guarantees that disturbances from the ultraviolet background radiation, which Earth’s atmosphere reflects from the sun, are negligible and allows large areas of the sky to be surveyed. UV radiation can only be observed from orbit because it is largely absorbed and reflected by the atmosphere.

    The UV camera, which DESY is developing and building, will be the heart of the telescope. It will have a UV-sensitive sensor area of nine by nine centimetres and a resolution of 100 megapixels. With these parameters, the developers are breaking new ground: A UV space camera with such a resolution and sensitivity has never been built before. For the camera, DESY experts in astroparticle physics work together with specialists in detector development from the field of research with synchrotron radiation. With this project, DESY is contributing about 5 million euros to the satellite, which will cost about 70 million euros in total.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    desi

    DESY is one of the world’s leading accelerator centres. Researchers use the large-scale facilities at DESY to explore the microcosm in all its variety – from the interactions of tiny elementary particles and the behaviour of new types of nanomaterials to biomolecular processes that are essential to life. The accelerators and detectors that DESY develops and builds are unique research tools. The facilities generate the world’s most intense X-ray light, accelerate particles to record energies and open completely new windows onto the universe. 
That makes DESY not only a magnet for more than 3000 guest researchers from over 40 countries every year, but also a coveted partner for national and international cooperations. Committed young researchers find an exciting interdisciplinary setting at DESY. The research centre offers specialized training for a large number of professions. DESY cooperates with industry and business to promote new technologies that will benefit society and encourage innovations. This also benefits the metropolitan regions of the two DESY locations, Hamburg and Zeuthen near Berlin.

    DESY Petra III interior


    DESY Petra III

    DESY/FLASH

    H1 detector at DESY HERA ring

    DESY DORIS III

     
  • richardmitnick 11:43 am on October 28, 2019 Permalink | Reply
    Tags: ALPS-II, , , , DESY,   

    From DESY: “Dark Matter search enters new chapter” 

    DESY
    From DESY

    2019/10/27

    First magnet installed for the ALPS-II experiment at DESY.

    1
    Artist’s impression of the ALPS II experiment. Image: DESY, Scicom Lab

    1
    The ALPS I experiment laboratory surrounded by superconducting HERA dipole magnet.

    The international ALPS II (“Any light particle search”) collaboration installed the first of 24 superconducting magnets today, marking the start of the installation of a unique particle physics experiment to look for dark matter. Located at the German research centre DESY in Hamburg, it is set to start taking data in 2021 by looking for dark matter particles that literally make light shine through a wall, thus providing clues to one of the biggest questions in physics today: what is the nature of dark matter?

    “It is very exciting to see the project that many of us have been working on for so many years finally taking shape in the tunnel,” ALPS-II spokesman Axel Linder from DESY said. “When installation and commissioning proceed as planned we will be able to start the search in the first half of 2021.”

    Dark matter is one of the greatest mysteries in physics. Observations and calculations of the motion of stars in galaxies, for example, show that there must be more matter in the Universe than we can account for with matter particles known today. In fact, dark matter must make up 85 % of all the matter in the Universe. However, currently we don’t know what it is. But we know that it does not interact with regular matter and is essentially invisible, so that it is called “dark”.

    There are several theories that try to explain the nature of dark matter and the particles it may consist of. One of these theories states that dark matter consists of very light-weight particles with very specific properties. One example is the axion which was originally postulated to explain aspects of the strong interaction, one of the fundamental forces of nature. There are also puzzling astrophysical observations such as discrepancies in the evolution of stellar systems, which might also be explained by the existence of axions or axion-like particles.

    This is where ALPS II comes in. It is designed to create and detect those axions. A strong magnetic field can make axions switch to photons and vice versa. “This bizarre property was already exploited in the initial ALPS I experiment which we ran from 2007 to 2010. Despite its limited size, it achieved the world-wide best sensitivities for these kinds of experiments,” said Benno Willke, the leader of the ALPS and of the laser development group at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute) and at the Institute for Gravitational Physics at Leibniz Universität of Hannover.

    ALPS II is being set up in a straight tunnel section of DESY’s former particle physics accelerator HERA.

    DESY HERA , 1992 to 2007

    Twenty-four superconducting accelerator magnets, twelve on either side of a wall, house two 120-metre-long optical cavities. A powerful and intricate laser system produces light that is amplified by the cavity inside the magnetic field and will, to a very small fraction, convert into dark matter particles. A light-blocking barrier – a wall – separates the second compartment of ALPS II, but this wall is no hurdle for axions and similar particles that can easily pass through it. In the second cavity dark matter particles would convert back into light. The tiny signal will be picked up by dedicated detection systems.

    The more than 1,000-fold improvement in sensitivity of ALPS II is made possible by the increased length of the magnet strings but also by significant advances in optical technologies. “These advances emerged from the work on gravitational wave interferometers such as GEO600 and LIGO, and nicely show how technological advances in one area enable progress in others,” said Co-Spokesperson Guido Mueller from the University of Florida in Gainesville.

    ALPS II is also an example of recycling in research: it does not only reuse a stretch of tunnel that once housed DESY’s flagship particle accelerator, but it also reuses the very magnets that drove protons around the ring until 2007. These magnets needed to be reengineered to fit the ALPS purposes: the slight bend needed in an accelerator ring had to be removed to allow photons to propagate through them.

    The ALPS II collaboration consists of some 25 scientists from these institutes: DESY, the Max Planck Institute for Gravitational Physics (Albert Einstein Institute) and the Institute for Gravitational Physics at Leibniz Universität of Hannover, the Johannes Gutenberg-Universität Mainz, the University of Florida in Gainesville, and Cardiff University. Beyond that, the collaboration is supported by partners worldwide like the National Metrology Institute (PTB) in Germany and the National Institute of Standards and Technology in the USA. The experiment is mainly funded by DESY, the Heising-Simons Foundation, the US National Science Foundation, the German Volkswagen Stiftung and German Research Foundation (DFG).

    At DESY, ALPS II might be just the first experiment within a new strategic approach to tackle dark matter. “International collaborations are preparing the IAXO experiment to search for axions emitted by the Sun as well as the MADMAX detector, which will look directly for axions as constituents of the local dark matter surrounding us”, explained Joachim Mnich, DESY’s director for particle physics.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    desi

    DESY is one of the world’s leading accelerator centres. Researchers use the large-scale facilities at DESY to explore the microcosm in all its variety – from the interactions of tiny elementary particles and the behaviour of new types of nanomaterials to biomolecular processes that are essential to life. The accelerators and detectors that DESY develops and builds are unique research tools. The facilities generate the world’s most intense X-ray light, accelerate particles to record energies and open completely new windows onto the universe. 
That makes DESY not only a magnet for more than 3000 guest researchers from over 40 countries every year, but also a coveted partner for national and international cooperations. Committed young researchers find an exciting interdisciplinary setting at DESY. The research centre offers specialized training for a large number of professions. DESY cooperates with industry and business to promote new technologies that will benefit society and encourage innovations. This also benefits the metropolitan regions of the two DESY locations, Hamburg and Zeuthen near Berlin.

    DESY Petra III interior


    DESY Petra III

    DESY/FLASH

    H1 detector at DESY HERA ring

    DESY DORIS III

     
  • richardmitnick 7:52 am on September 24, 2019 Permalink | Reply
    Tags: Buckminsterfullerenes-buckyballs, DESY,   

    From SLAC and DESY: “Breaking up buckyballs is hard to do” 

    From SLAC National Accelerator Lab

    DESY
    From DESY

    4

    September 23, 2019
    Ali Sundermier

    How molecular footballs burst in an X-ray laser beam.

    As reported in Nature Physics, an international research team observed how soccer ball-shaped molecules made of carbon atoms burst in the beam of an X-ray laser. The molecules, called buckminsterfullerenes – buckyballs for short ­– consist of 60 carbon atoms arranged in alternating pentagons and hexagons like the leather coat of a soccer ball. These molecules were expected to break into fragments after being bombarded with photons, but the researchers watched in real time as buckyballs resisted the attack and delayed their break-up.

    1
    An illustration shows how soccer ball-shaped molecules called buckyballs ionize and break up when blasted with an X-ray laser. A team of experimentalists and theorists identified chemical bonds and charge transfers as crucial factors that significantly delayed the fragmentation process by about 600 millionths of a billionth of a second. (Greg Stewart/SLAC National Accelerator Laboratory)

    2
    Computer simulated evolution of a C60 molecule at 0, 60 and 240 femto seconds after the X-ray flash. Credit: DESY, Zoltan Jurek

    “Buckyballs are well suited as a simple model system for biomolecules,” explains Robin Santra, who is a lead scientist at DESY at the Center for Free-Electron Laser Science (CFEL) and a physics professor at the Universität Hamburg. “Since they consist of only one type of atom and have a symmetrical structure, they can be well represented in theory and experiment. This is a first step before the investigation of molecules from different types of atoms.”

    The team was led by Nora Berrah, a professor at the University of Connecticut, and included researchers from the Department of Energy’s SLAC National Accelerator Laboratory and the Deutsches Elektronen-Synchrotron (DESY) in Germany. The researchers focused their attention on examining the role of chemical effects, such as chemical bonds and charge transfer, on the buckyball’s fragmentation.

    Using X-ray laser pulses from SLAC’s Linac Coherent Light Source (LCLS) [below], the team showed how the bursting process, which takes only a few hundred femtoseconds, or millionths of a billionth of a second, unfolds over time. The results will be important for the analysis of sensitive proteins and other biomolecules, which are also frequently studied using bright X-ray laser flashes, and they also strengthen confidence in protein analysis with X-ray free-electron lasers (XFELs).

    “This investigation uncovered for the first time the persistence of the molecular structure, which thwarted fragmentation over a timescale of hundreds of femtoseconds” Berrah says. “With the dawn of several new XFELs in the world, the findings lay the foundation for a deeper understanding of XFEL-induced radiation damage, which will have a strong impact on biomolecular imaging.”

    What follows then is not an actual explosion,” explains the scientist. “Instead, the buckyballs dissolve comparatively slowly. Carbon atoms gradually evaporate – with many more neutral ones than electrically charged ones, which was surprising.” Since the fragmentation of the buckyballs on this time scale is not explosive but happens gradually, the researchers speak of the evaporation of the atoms. The experimental data could only be meaningfully interpreted with the help of theoretical modelling of the process.

    “Typically, about 25 neutral and only 15 electrically charged carbon atoms fly out of the molecule,” Santra explains. “The rest form fragments of several atoms.” The whole process takes about 600 femtoseconds. This is still unimaginably short by human standards, but extremely long for structural analysis with X-ray lasers. “In the typically 20 femtoseconds of an X-ray laser flash, the atoms move a maximum of 0.1 nanometers – that is in the range of individual atom diameters and smaller than the measurement accuracy of structural analysis.” One nanometer is one millionth of a millimeter.

    For the structural analysis of proteins, researchers usually grow small crystals from the biomolecules. The bright X-ray laser flash is then diffracted at the crystal lattice and generates a typical diffraction pattern from which the crystal structure and with it the spatial structure of the individual proteins can be calculated. The spatial structure of a protein reveals details about its exact function. The protein crystals are very sensitive and evaporate through the X-ray laser flash. However, previous investigations had shown that the crystal remains intact long enough to generate the diffraction image before evaporation and thus to reveal its spatial structure.

    The new study now confirms that this is also the case with individual molecules that are not bound in a crystal lattice. “Our findings with buckyballs are likely to play a role in most other molecules,” Santra emphasises. Since many biomolecules are notoriously difficult to crystallise, researchers hope to be able to determine the structure of ensembles of non-crystallised proteins or even individual biomolecules with X-ray lasers in the future. The results obtained now lay the foundation for a deeper understanding and quantitative modelling of the radiation damage in biomolecules induced by X-ray laser flashes, the scientists write.

    The study also involved researchers from Imperial College London; University of Gothenburg in Sweden; University of Texas; Synchrotron SOLEIL in France; Kansas State University; Tohoku University in Japan; State University of New York at Potsdam; and Max Planck Institute for Nuclear Physics, Max Born Institute and University of Hamburg, all in Germany.

    See the full article here .
    See the full DESY article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    desi

    DESY is one of the world’s leading accelerator centres. Researchers use the large-scale facilities at DESY to explore the microcosm in all its variety – from the interactions of tiny elementary particles and the behaviour of new types of nanomaterials to biomolecular processes that are essential to life. The accelerators and detectors that DESY develops and builds are unique research tools. The facilities generate the world’s most intense X-ray light, accelerate particles to record energies and open completely new windows onto the universe. 
That makes DESY not only a magnet for more than 3000 guest researchers from over 40 countries every year, but also a coveted partner for national and international cooperations. Committed young researchers find an exciting interdisciplinary setting at DESY. The research centre offers specialized training for a large number of professions. DESY cooperates with industry and business to promote new technologies that will benefit society and encourage innovations. This also benefits the metropolitan regions of the two DESY locations, Hamburg and Zeuthen near Berlin.

    DESY Petra III interior


    DESY Petra III

    DESY/FLASH

    H1 detector at DESY HERA ring

    DESY DORIS III

    SLAC/LCLS


    SLAC/LCLS II projected view


    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.

     
  • richardmitnick 4:25 pm on July 16, 2019 Permalink | Reply
    Tags: , DESY, , , , ,   

    From U Wisconsin IceCube Collaboration: A Flock of Articles on NSF Grant to Upgrade IceCube 

    U Wisconsin ICECUBE neutrino detector at the South Pole

    From From U Wisconsin IceCube Collaboration

    From U Wisconsin: “UW lab gears up for another Antarctic drilling campaign”

    With news that the National Science Foundation (NSF) and international partners will support an upgrade to the IceCube neutrino detector at the South Pole, the UW–Madison lab that built the novel drill used to bore mile-deep holes in the Antarctic ice is gearing up for another drilling campaign.

    The UW’s Physical Sciences Laboratory (PSL), which specializes in making customized equipment for UW–Madison researchers, will once again lead drilling operations. The $37 million upgrade announced this week (July 16, 2019) will expand the IceCube detector by adding seven new strings of 108 optical modules each to study the basic properties of neutrinos, phantom-like particles that emanate from black holes and exploding stars, but that also cascade through Earth’s atmosphere as a result of colliding subatomic particles.

    1
    “It takes a crew of 30 people to run this 24/7. It’s the people that make it work,” says Bob Paulos, director of the Physical Sciences Lab. Photo: Bryce Richter

    See the full article here .

    From U Wisconsin: “IceCube: Antarctic neutrino detector to get $37 million upgrade”

    2
    The IceCube Neutrino Observatory is located at NSF’s Amundsen-Scott South Pole Station. Management and operation of the observatory is through the Wisconsin IceCube Particle Astrophysics Center at UW–Madison. Raffaela Busse, IceCube / NSF

    IceCube, the Antarctic neutrino detector that in July of 2018 helped unravel one of the oldest riddles in physics and astronomy — the origin of high-energy neutrinos and cosmic rays — is getting an upgrade.

    This month, the National Science Foundation (NSF) approved $23 million in funding to expand the detector and its scientific capabilities. Seven new strings of optical modules will be added to the 86 existing strings, adding more than 700 new, enhanced optical modules to the 5,160 sensors already embedded in the ice beneath the geographic South Pole.

    The upgrade, to be installed during the 2022–23 polar season, will receive additional support from international partners in Japan and Germany as well as from Michigan State University and the University of Wisconsin–Madison. Total new investment in the detector will be about $37 million.

    See the full article here .

    From Niels Bohr Institute: “A new Upgrade for the IceCube detector”

    3
    Illustration of the IceCube laboratory under the South Pole. The sensors detecting neutrinos are attached to the strings lowered into the ice. The upgrade will take place in the Deep Core area. Illustration: IceCube/NSF

    Neutrino Research:

    The IceCube Neutrino Observatory in Antarctica is about to get a significant upgrade. This huge detector consists of 5,160 sensors embedded in a 1x1x1 km volume of glacial ice deep beneath the geographic South Pole. The purpose of the installation is to detect neutrinos, the “ghost particles” of the Universe. The IceCube Upgrade will add more than 700 new and enhanced optical sensors in the deepest, purest ice, greatly improving the observatory’s ability to measure low-energy neutrinos produced in the Earth’s atmosphere. The research in neutrinos at the Niels Bohr Institute, University of Copenhagen is led by Associate Professor Jason Koskinen

    See the full article here .

    From Michigan State University: “Upgrade for neutrino detector, thanks to NSF grant”

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    The IceCube Neutrino Observatory, the Antarctic detector that identified the first likely source of high-energy neutrinos and cosmic rays, is getting an upgrade. Courtesy of IceCube

    The IceCube Neutrino Observatory, the Antarctic detector that identified the first likely source of high-energy neutrinos and cosmic rays, is getting an upgrade.

    The National Science Foundation is upgrading the IceCube detector, extending its scientific capabilities to lower energies, and bridging IceCube to smaller neutrino detectors worldwide. The upgrade will insert seven strings of optical modules at the bottom center of the 86 existing strings, adding more than 700 new, enhanced optical modules to the 5,160 sensors already embedded in the ice beneath the geographic South Pole.

    The upgrade will include two new types of sensor modules, which will be tested for a ten-times-larger future extension of IceCube – IceCube-Gen2. The modules to be deployed in this first extension will be two to three times more sensitive than the ones that make up the current detector. This is an important benefit for neutrino studies, but it becomes even more relevant for planning the larger IceCube-Gen2.

    The $37 million extension, to be deployed during the 2022-23 polar field season, has now secured $23 million in NSF funding. Last fall, the upgrade office was set up, thanks to initial funding from NSF and additional support from international partners in Japan and Germany as well as from Michigan State University and the University of Wisconsin-Madison.

    See the full article here .

    From U Wisconsin IceCube: “The IceCube Upgrade: An international effort”

    The IceCube Upgrade project is an international collaboration made possible not only by support from the National Science Foundation but also thanks to significant contributions from partner institutions in the U.S. and around the world. Our national and international collaborators play a huge role in manufacturing new sensors, developing firmware, and much more. Learn more about a few of our partner institutions below.

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    The Chiba University group poses with one of the new D-Egg optical detectors. Credit: Chiba University

    Chiba University is responsible for the new D-Egg optical detectors, 300 of which will be deployed on the new Upgrade strings. A D-Egg is 30 percent smaller than the original IceCube DOM, but its photon detection effective area is twice as large thanks to two 8-inch PMTs in the specially designed egg-shaped vessel made of UV-transparent glass. Its up-down symmetric detection efficiency is expected to improve our precision for measuring Cherenkov light from neutrino interactions. The newly designed flasher devices in the D-Egg will also give a better understanding of optical characteristics in glacial ice to improve the resolution of arrival directions of cosmic neutrinos.

    See the full article here .

    From DESY: “Neutrino observatory IceCube receives significant upgrade”

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    Deep down in the perpetual ice of Antarctica IceCube watches out for a faint bluish glow that indicates a rare collision of a cosmic neutrino within the ice. Artist’s concept: DESY, Science Communication Lab

    Particle detector at the South Pole will be expanded to comprise a neutrino laboratory

    The international neutrino observatory IceCube at the South Pole will be considerably expanded in the coming years. In addition to the existing 5160 sensors, a further 700 optical modules will be installed in the perpetual ice of Antarctica. The National Science Foundation in the USA has approved 23 million US dollars for the expansion. The Helmholtz Centres DESY and Karlsruhe Institute of Technology (KIT) are supporting the construction of 430 new optical modules with a total of 5.7 million euros (6.4 million US dollars), which will turn the observatory into a neutrino laboratory. IceCube, for which Germany with a total of nine participating universities and the two Helmholtz Centres is the most important partner after the USA, had published convincing indications last year of a first source of high-energy neutrinos from the cosmos.

    See the full article here .

    See the full articles above .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition
    IceCube is a particle detector at the South Pole that records the interactions of a nearly massless sub-atomic particle called the neutrino. IceCube searches for neutrinos from the most violent astrophysical sources: events like exploding stars, gamma ray bursts, and cataclysmic phenomena involving black holes and neutron stars. The IceCube telescope is a powerful tool to search for dark matter, and could reveal the new physical processes associated with the enigmatic origin of the highest energy particles in nature. In addition, exploring the background of neutrinos produced in the atmosphere, IceCube studies the neutrinos themselves; their energies far exceed those produced by accelerator beams. IceCube is the world’s largest neutrino detector, encompassing a cubic kilometer of ice.

    IceCube employs more than 5000 detectors lowered on 86 strings into almost 100 holes in the Antarctic ice NSF B. Gudbjartsson, IceCube Collaboration

    Lunar Icecube

    IceCube DeepCore annotated

    IceCube PINGU annotated


    DM-Ice II at IceCube annotated

     
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