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  • richardmitnick 12:01 pm on May 15, 2018 Permalink | Reply
    Tags: Dark Matter experiments, , SNOLAB, SuperCDMS (Cryogenic Dark Matter Search), ,   

    From Sanford Underground Research Facility: “SD Mines develops radon reduction system for LZ, SuperCDMS” 

    SURF logo
    Sanford Underground levels

    From Sanford Underground Research Facility

    May 14, 2018
    Constance Walter

    1
    Radon reduction researchers pictured with the machine they designed from left): SD Mines physics graduate student Joseph Street, Richard Schnee, Ph.D., along with lab technicians David Molash and Christine Hjelmfelt. Charles Michael Ray, SD Mines

    In the coming months, researchers will begin building the LUX-ZEPLIN dark matter experiment in a surface cleanroom at the Sanford Underground Research Facility (Sanford Lab).

    LBNL Lux Zeplin project at SURF

    Once the detector is assembled, a team will carefully move the highly sensitive physics equipment to its home on the 4850 Level of Sanford Lab.

    But before that can happen, there’s some work that needs to be done to ensure the experiment remains free of backgrounds that could interfere with the results. That’s where Dr. Richard Schnee and a team from the South Dakota School of Mines & Technology come in. Schnee, who is head of the physics department at SD Mines and a collaborator with LZ, heads up the SD Mines team that designed a radon reduction system for the experiment.

    “Our detectors need very low levels of radon,” Schnee said. While the radon levels at the 4850 Level are safe for humans, they are too high for sensitive experiments like LZ, which go deep underground to escape cosmic radiation, Schnee explained. “We will take regular air from the facility and the systems will reduce the levels by 1,000 times or more.”

    LZ, a second-generation dark matter experiment, will continue the search for WIMPs—weakly interacting massive particles—begun by its much smaller predecessor LUX (Large Underground Xenon), which was named the most sensitive of its kind in 2013 and again in 2016.

    U Washington Large Underground Xenon at SURF, Lead, SD, USA

    LZ will hold 10 tons of liquid xenon, making it approximately 30 times larger and 100 times more sensitive than LUX.

    LZ is designed so that if a dark matter particle collides with a xenon atom, it will produce a flash of light followed by a second flash of light when the electrons produced in the liquid xenon chamber drift to its top. The light pulses, picked up by a series of about 500 photo multiplier tubes lining the massive tank—over four times more than were installed in LUX—will carry the telltale fingerprint of the particles that created them.

    Additionally, LZ will include a component not present in LUX—nine acrylic tanks filled with a liquid scintillator will form a veto system around the experiment, allowing researchers to better recognize a WIMP if they see one.

    The system designed by the SD Mines team focuses specifically on filtering out radon particles to produce the ultra-pure air needed for the acrylic tanks and other components of LZ located in the same water tank that held LUX. The team is also helping ensure the parts used to build the experiments are relatively free of radon.

    “The real problem for these super sensitive dark mater detectors are the radon daughters that are radioactive,” Schnee said. Even miniscule amounts of radioactive particles could contaminate and throw off the experiments—so the work of Schnee and his team is critical.

    “We are very excited to have SD Mines as a partner in producing a major component for LZ, a world-leading dark matter experiment,” said Mike Headley, executive director the South Dakota Science and Technology Authority.

    LZ is in a global race to discover dark matter. One competitor, SuperCDMS (Cryogenic Dark Matter Search), which will be located at SNOLab in Canada, is using germanium to search for WIMPs. And SD Mines is designing a radon reduction system for that experiment as well, Schnee said.

    SNOLAB, a Canadian underground physics laboratory at a depth of 2 km in Vale’s Creighton nickel mine in Sudbury, Ontario


    SNOLAB, Sudbury, Ontario, Canada.

    LBNL SuperCDMS, at SNOLAB (Vale Inco Mine, Sudbury, Canada)


    LBNL SuperCDMS, at SNOLAB (Vale Inco Mine, Sudbury, Canada)


    LBNL Super CDMS, at SNOLAB (Vale Inco Mine, Sudbury, Canada)

    SNOLab is the deepest underground laboratory in North America at 6,800 feet deep. Although the experiments are competitors, Schnee said they actually complement each other as they are searching for dark matter in different areas. To use a metaphor, if dark matter were a lost child in a large cornfield, LZ would be looking in one part of the field, and SuperCDMS would be looking in another. Both projects will begin operations in the early 2020s. SD Mines is one of 26 institutions working on the SuperCDMS and one of 37 institutions working on LZ.

    Headley attributes the expanding role of SD Mines’ in research at Sanford Lab and other international experiments to the Ph.D. program in South Dakota. SD Mines and the University of South Dakota offer a joint program and each graduated Ph.D. students in 2017.

    “With the implementation of the Ph.D. program in 2012, South Dakota institutions are attracting high-quality professors and students,” Headley said. “It’s impressive to see them deliver such an important component for LZ, but also on other experiments around the world.”

    To learn more about the physics program at SD Mines, go to http://www.sdsmt.edu; to read the full press release about SD Mines work on LZ and SuperCDMS, go to https://www.sdsmt.edu/Research/.

    You can learn more about LZ at http://lz.lbl.gov/detector/and SCDMS at https://supercdms.slac.stanford.edu.

    See the full article here .

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    About us.
    The Sanford Underground Research Facility in Lead, South Dakota, advances our understanding of the universe by providing laboratory space deep underground, where sensitive physics experiments can be shielded from cosmic radiation. Researchers at the Sanford Lab explore some of the most challenging questions facing 21st century physics, such as the origin of matter, the nature of dark matter and the properties of neutrinos. The facility also hosts experiments in other disciplines—including geology, biology and engineering.

    The Sanford Lab is located at the former Homestake gold mine, which was a physics landmark long before being converted into a dedicated science facility. Nuclear chemist Ray Davis earned a share of the Nobel Prize for Physics in 2002 for a solar neutrino experiment he installed 4,850 feet underground in the mine.

    Homestake closed in 2003, but the company donated the property to South Dakota in 2006 for use as an underground laboratory. That same year, philanthropist T. Denny Sanford donated $70 million to the project. The South Dakota Legislature also created the South Dakota Science and Technology Authority to operate the lab. The state Legislature has committed more than $40 million in state funds to the project, and South Dakota also obtained a $10 million Community Development Block Grant to help rehabilitate the facility.

    In 2007, after the National Science Foundation named Homestake as the preferred site for a proposed national Deep Underground Science and Engineering Laboratory (DUSEL), the South Dakota Science and Technology Authority (SDSTA) began reopening the former gold mine.

    In December 2010, the National Science Board decided not to fund further design of DUSEL. However, in 2011 the Department of Energy, through the Lawrence Berkeley National Laboratory, agreed to support ongoing science operations at Sanford Lab, while investigating how to use the underground research facility for other longer-term experiments. The SDSTA, which owns Sanford Lab, continues to operate the facility under that agreement with Berkeley Lab.

    The first two major physics experiments at the Sanford Lab are 4,850 feet underground in an area called the Davis Campus, named for the late Ray Davis. The Large Underground Xenon (LUX) experiment is housed in the same cavern excavated for Ray Davis’s experiment in the 1960s.
    LUX/Dark matter experiment at SURFLUX/Dark matter experiment at SURF

    In October 2013, after an initial run of 80 days, LUX was determined to be the most sensitive detector yet to search for dark matter—a mysterious, yet-to-be-detected substance thought to be the most prevalent matter in the universe. The Majorana Demonstrator experiment, also on the 4850 Level, is searching for a rare phenomenon called “neutrinoless double-beta decay” that could reveal whether subatomic particles called neutrinos can be their own antiparticle. Detection of neutrinoless double-beta decay could help determine why matter prevailed over antimatter. The Majorana Demonstrator experiment is adjacent to the original Davis cavern.

    Another major experiment, the Long Baseline Neutrino Experiment (LBNE)—a collaboration with Fermi National Accelerator Laboratory (Fermilab) and Sanford Lab, is in the preliminary design stages. The project got a major boost last year when Congress approved and the president signed an Omnibus Appropriations bill that will fund LBNE operations through FY 2014. Called the “next frontier of particle physics,” LBNE will follow neutrinos as they travel 800 miles through the earth, from FermiLab in Batavia, Ill., to Sanford Lab.

    Fermilab LBNE
    LBNE

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  • richardmitnick 2:31 pm on May 11, 2018 Permalink | Reply
    Tags: Arthur B. McDonald Canadian Astroparticle Physics Research Institute, , , , , , , , SNOLAB   

    From Perimeter Institute: “New centre for astroparticle physics launches in Canada” 

    Perimeter Institute

    From Perimeter Institute

    May 10, 2018

    Perimeter Institute is among 13 partner organizations contributing to a new national hub of astroparticle physics at Queen’s University in Kingston, Ontario.

    Queen’s University has officially launched the Arthur B. McDonald Canadian Astroparticle Physics Research Institute, a national research network dedicated to understanding some of the universe’s deepest mysteries.

    The namesake of the institute, Arthur B. McDonald, is the 2015 Nobel laureate in physics for his pioneering neutrino work at SNOLAB, and is a member of Perimeter Institute’s Board of Directors.

    SNOLAB, a Canadian underground physics laboratory at a depth of 2 km in Vale’s Creighton nickel mine in Sudbury, Ontario

    SNOLAB, Sudbury, Ontario, Canada.

    The newly announced institute is the result of a $63.7 million investment from the Government of Canada’s Canada First Research Excellence Fund given to Queen’s University in 2016.

    Perimeter Institute is among the five affiliated research organizations and eight universities in partnership with the McDonald Institute. Together, the partners aim to facilitate the exchange of research and ideas at the intersections of cosmology and particle physics.

    “Although the dimensions of the particles we are studying are minute, the implications of these discoveries are monumental and fundamental to the very properties of science and our understanding of the formation and evolution of the universe,” said McDonald Institute Scientific Director Tony Noble at the May 8 launch in Kingston.

    Perimeter Faculty Chair Luis Lehner said partnering with the McDonald Institute will facilitate “collaborative research in pursuit of answers to some of the deepest mysteries in science, and mutually strengthen the training and educational outreach activities of both institutes.”

    Over the past year and a half, the McDonald Institute has appointed a scientific director and recruited 13 new faculty members (out of 15 designated positions) from around the world.

    In addition to advancing research into areas such as the mysteries surrounding dark matter and neutrino science, the McDonald Institute has a mandate for scientific outreach and to develop unique undergraduate and graduate student programming and opportunities.

    Visit http://www.mcdonaldinstitute.ca for more information.

    See the full article here .

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    About Perimeter

    Perimeter Institute is the world’s largest research hub devoted to theoretical physics. The independent Institute was founded in 1999 to foster breakthroughs in the fundamental understanding of our universe, from the smallest particles to the entire cosmos. Research at Perimeter is motivated by the understanding that fundamental science advances human knowledge and catalyzes innovation, and that today’s theoretical physics is tomorrow’s technology. Located in the Region of Waterloo, the not-for-profit Institute is a unique public-private endeavour, including the Governments of Ontario and Canada, that enables cutting-edge research, trains the next generation of scientific pioneers, and shares the power of physics through award-winning educational outreach and public engagement.

     
  • richardmitnick 9:01 am on May 7, 2018 Permalink | Reply
    Tags: , , Construction Begins on One of the World’s Most Sensitive Dark Matter Experiments, , , , , SNOLAB, SuperCDMS SNOLAB experiment,   

    From SLAC Lab: “Construction Begins on One of the World’s Most Sensitive Dark Matter Experiments” 


    From SLAC Lab

    May 7, 2018

    Press Office Contact: Andrew Gordon,
    agordon@slac.stanford.edu
    (650) 926-2282

    Written by Manuel Gnida

    1
    The future SuperCDMS SNOLAB experiment will hunt for weakly interacting massive particles (WIMPs), hypothetical components of dark matter. If a WIMP (white trace) strikes an atom inside the experiment’s detector crystals (gray), it will cause the crystal lattice to vibrate (blue). The collision will also send electrons (red) through the crystal that enhance the vibrations. (Greg Stewart/SLAC National Accelerator Laboratory)

    2
    The future SuperCDMS SNOLAB experiment will hunt for weakly interacting massive particles (WIMPs), hypothetical components of dark matter. This photo shows one of the experiment’s detector crystals within its protective copper housing. (Andy Freeberg/SLAC National Accelerator Laboratory)

    3
    SLAC’s Paul Brink handles the SuperCDMS SNOLAB engineering tower. (Chris Smith/SLAC National Accelerator Laboratory)

    4
    A SuperCDMS SNOLAB detector, fabricated at Texas A&M University. (Matt Cherry/SuperCDMS collaboration/SLAC National Accelerator Laboratory)

    5
    Dan Bauer (left) and Mark Ruschman in Fermilab’s Lab G , where the SuperCDMS SNOLAB project is preparing to test the cryogenics system for the new experiment. (Reidar Hahn/Fermi National Accelerator Laboratory)

    6
    Fermilab’s Mark Ruschman tests prototypes for the SuperCDMS SNOLAB cryogenics system. (Reidar Hahn/Fermi National Accelerator Laboratory)

    The SuperCDMS SNOLAB project, a multi-institutional effort led by SLAC, is expanding the hunt for dark matter to particles with properties not accessible to any other experiment.

    SNOLAB, Sudbury, Ontario, Canada.

    The U.S. Department of Energy has approved funding and start of construction for the SuperCDMS SNOLAB experiment, which will begin operations in the early 2020s to hunt for hypothetical dark matter particles called weakly interacting massive particles, or WIMPs. The experiment will be at least 50 times more sensitive than its predecessor, exploring WIMP properties that can’t be probed by other experiments and giving researchers a powerful new tool to understand one of the biggest mysteries of modern physics.

    The DOE’s SLAC National Accelerator Laboratory is managing the construction project for the international SuperCDMS collaboration of 111 members from 26 institutions, which is preparing to do research with the experiment.

    “Understanding dark matter is one of the hottest research topics – at SLAC and around the world,” said JoAnne Hewett, head of SLAC’s Fundamental Physics Directorate and the lab’s chief research officer. “We’re excited to lead the project and work with our partners to build this next-generation dark matter experiment.”

    With the DOE approvals, known as Critical Decisions 2 and 3, the researchers can now build the experiment. The DOE Office of Science will contribute $19 million to the effort, joining forces with the National Science Foundation ($12 million) and the Canada Foundation for Innovation ($3 million).

    “Our experiment will be the world’s most sensitive for relatively light WIMPs – in a mass range from a fraction of the proton mass to about 10 proton masses,” said Richard Partridge, head of the SuperCDMS group at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), a joint institute of SLAC and Stanford University. “This unparalleled sensitivity will create exciting opportunities to explore new territory in dark matter research.”

    An Ultracold Search 6,800 Feet Underground

    Scientists know that visible matter in the universe accounts for only 15 percent of all matter. The rest is a mysterious substance, called dark matter. Due to its gravitational pull on regular matter, dark matter is a key driver for the evolution of the universe, affecting the formation of galaxies like our Milky Way. It therefore is fundamental to our very own existence.

    But scientists have yet to find out what dark matter is made of. They believe it could be composed of dark matter particles, and WIMPs are top contenders. If these particles exist, they would barely interact with their environment and fly right through regular matter untouched. However, every so often, they could collide with an atom of our visible world, and dark matter researchers are looking for these rare interactions.

    7
    The centerpiece of the SuperCDMS SNOLAB experiment will be four detector towers (left), each containing six detector packs. The towers will be mounted inside the SNOBOX (right), a vessel in which the detector packs will be cooled to almost absolute zero temperature. (Greg Stewart/SLAC National Accelerator Laboratory)

    In the SuperCDMS SNOLAB experiment, the search will be done using silicon and germanium crystals, in which the collisions would trigger tiny vibrations. However, to measure the atomic jiggles, the crystals need to be cooled to less than minus 459.6 degrees Fahrenheit – a fraction of a degree above absolute zero temperature. These ultracold conditions give the experiment its name: Cryogenic Dark Matter Search, or CDMS. The prefix “Super” indicates an increased sensitivity compared to previous versions of the experiment.

    The collisions would also produce pairs of electrons and electron deficiencies that move through the crystals, triggering additional atomic vibrations that amplify the signal from the dark matter collision. The experiment will be able to measure these “fingerprints” left by dark matter with sophisticated superconducting electronics.

    The experiment will be assembled and operated at the Canadian laboratory SNOLAB – 6,800 feet underground inside a nickel mine near the city of Sudbury. It’s the deepest underground laboratory in North America. There it will be protected from high-energy particles, called cosmic radiation, which can create unwanted background signals.

    8
    The SuperCDMS dark matter experiment will be located at the Canadian laboratory SNOLAB, 2 kilometers (6,800 feet) underground inside a nickel mine near the city of Sudbury. It’s the deepest underground laboratory in North America. There it will be protected from high-energy particles, called cosmic radiation, which can create unwanted background signals. (Greg Stewart/SLAC National Accelerator Laboratory; inset: SNOLAB)

    “SNOLAB is excited to welcome the SuperCDMS SNOLAB collaboration to the underground lab,” said Kerry Loken, SNOLAB project manager. “We look forward to a great partnership and to supporting this world-leading science.”

    Over the past months, a detector prototype has been successfully tested at SLAC. “These tests were an important demonstration that we’re able to build the actual detector with high enough energy resolution, as well as detector electronics with low enough noise to accomplish our research goals,” said KIPAC’s Paul Brink, who oversees the detector fabrication at Stanford.

    Together with seven other collaborating institutions, SLAC will provide the experiment’s centerpiece of four detector towers, each containing six crystals in the shape of oversized hockey pucks. The first tower could be sent to SNOLAB by the end of 2018.

    “The detector towers are the most technologically challenging part of the experiment, pushing the frontiers of our understanding of low-temperature devices and superconducting readout,” said Bernard Sadoulet, a collaborator from the University of California, Berkeley.

    A Strong Collaboration for Extraordinary Science

    In addition to SLAC, two other national labs are involved in the project. Fermi National Accelerator Laboratory is working on the experiment’s intricate shielding and cryogenics infrastructure, and Pacific Northwest National Laboratory is helping understand background signals in the experiment, a major challenge for the detection of faint WIMP signals.

    9
    Slideshow of SuperCDMS SNOLAB photos. For more images, visit the SuperCDMS SNOLAB photostream on Flickr.

    A number of U.S. and Canadian universities also play key roles in the experiment, working on tasks ranging from detector fabrication and testing to data analysis and simulation. The largest international contribution comes from Canada and includes the research infrastructure at SNOLAB.

    “We’re fortunate to have a close-knit network of strong collaboration partners, which is crucial for our success,” said KIPAC’s Blas Cabrera, who directed the project through the CD-2/3 approval milestone. “The same is true for the outstanding support we’re receiving from the funding agencies in the U.S. and Canada.”

    Fermilab’s Dan Bauer, spokesperson of the SuperCDMS collaboration said, “Together we’re now ready to build an experiment that will search for dark matter particles that interact with normal matter in an entirely new region.”

    SuperCDMS SNOLAB will be the latest in a series of increasingly sensitive dark matter experiments. The most recent version, located at the Soudan Mine in Minnesota, completed operations in 2015.

    “The project has incorporated lessons learned from previous CDMS experiments to significantly improve the experimental infrastructure and detector designs for the experiment,” said SLAC’s Ken Fouts, project manager for SuperCDMS SNOLAB. “The combination of design improvements, the deep location and the infrastructure support provided by SNOLAB will allow the experiment to reach its full potential in the search for low-mass dark matter.”

    For more information on the SuperCDMS SNOLAB project and the SuperCDMS collaboration, check out this website:

    SuperCDMS SNOLAB Website

    See the full article here .

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    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 12:50 pm on March 20, 2018 Permalink | Reply
    Tags: , Beyond the WIMP: Unique Crystals Could Expand the Search for Dark Matter, , , , SNOLAB,   

    From LBNL: “Beyond the WIMP: Unique Crystals Could Expand the Search for Dark Matter” 

    Berkeley Logo

    Berkeley Lab

    Glenn Roberts Jr.
    geroberts@lbl.gov
    (510) 486-5582

    1
    A computerized simulation of the large-scale distribution of dark matter in the universe. An overlay graph (in white) shows how a crystal sample intensely scintillates, or glows, when exposed to X-rays during a lab test. This and other properties could make it a good material for a dark matter detector. (Credit: Millennium Simulation, Berkeley Lab)

    A new particle detector design proposed at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) could greatly broaden the search for dark matter – which makes up 85 percent of the total mass of the universe yet we don’t know what it’s made of – into an unexplored realm.

    While several large physics experiments have been targeting theorized dark matter particles called WIMPs, or weakly interacting massive particles, the new detector design could scan for dark matter signals at energies thousands of times lower than those measurable by more conventional WIMP detectors.

    The ultrasensitive detector technology incorporates crystals of gallium arsenide that also include the elements silicon and boron. This combination of elements causes the crystals to scintillate, or light up, in particle interactions that knock away electrons.

    This scintillation property of gallium arsenide has been largely unexplored, said Stephen Derenzo, a senior physicist in the Molecular Biophysics and Integrated Bioimaging Division at Berkeley Lab and lead author of a study published March 20 in the Journal of Applied Physics that details the material’s properties.

    “It’s hard to imagine a better material for searching in this particular mass range,” Derenzo said, which is measured in MeV, or millions of electron volts. “It ticks all of the boxes. We are always worried about a ‘Gotcha!’ or showstopper. But I have tried to think of some way this detector material can fail and I can’t.”

    The breakthrough came from Edith Bourret, a senior staff scientist in Berkeley Lab’s Materials Sciences Division who decades earlier had researched gallium arsenide’s potential use in circuitry. She gave him a sample of gallium arsenide from this previous work that featured added concentrations, or “dopants,” of silicon and boron.

    Derenzo had previously measured some lackluster performance in a sample of commercial-grade gallium arsenide. But the sample that Bourret handed him exhibited a scintillation luminosity that was five times brighter than in the commercial material, owing to the silicon and boron that imbued the material with new and enhanced properties. This enhanced scintillation meant it was far more sensitive to electronic excitations.

    “If she hadn’t handed me this sample from more than 20 years ago, I don’t think I would have pursued it,” Derenzo said. “When this material is doped with silicon and boron, this turns out to be very important and, accidentally, a very good choice of dopants.”

    Derenzo noted that he has had a longstanding interest in scintillators that are also semiconductors, as this class of materials can produce ultrafast scintillation useful for medical imaging applications such as PET (positron emission tomography) and CT (computed tomography) scans, for example, as well as for high-energy physics experiments and radiation detection.

    The doped gallium arsenide crystals he studied appear well-suited for high-sensitivity particle detectors because extremely pure crystals can be grown commercially in large sizes, the crystals exhibit a high luminosity in response to electrons booted away from atoms in the crystals’ atomic structure, and they don’t appear to be hindered by typical unwanted effects such as signal afterglow and dark current signals.

    Some of the larger WIMP-hunting detectors – such as that of the Berkeley Lab-led LUX-ZEPLIN project now under construction in South Dakota, and its predecessor, the LUX experiment – incorporate a liquid scintillation detector. A large tank of liquid xenon is surrounded by sensors to measure any light and electrical signals expected from a dark matter particle’s interaction with the nucleus of a xenon atom. That type of interaction is known as a nuclear recoil.

    2
    A crystal of gallium arsenide. (Credit: Wikimedia Commons)

    In contrast, the crystal-based gallium arsenide detector is designed to be sensitive to the slighter energies associated with electron recoils – electrons ejected from atoms by their interaction with dark matter particles. As with LUX and LUX-ZEPLIN, the gallium arsenide detector would need to be placed deep underground to shield it from the typical bath of particles raining down on Earth.

    It would also need to be coupled to light sensors that could detect the very few infrared photons (particles of light) expected from a low-mass dark matter particle interaction, and the detector would need to be chilled to cryogenic temperatures. The silicon and boron dopants could also possibly be optimized to improve the overall sensitivity and performance of the detectors.

    Because dark matter’s makeup is still a mystery – it could be composed of one or many particles of different masses, for example, or may not be composed of particles at all – Derenzo noted that gallium arsenide detectors provide just one window into dark matter particles’ possible hiding places.

    While WIMPs were originally thought to inhabit a mass range measured in billions of electron volts, or GeV, the gallium arsenide detector technology is well-suited to detecting particles in the mass range measured in millions of electron volts, or MeV.

    Berkeley Lab physicists are also proposing other types of detectors to expand the dark matter search, including a setup that uses an exotic state of chilled helium known as superfluid helium to directly detect low-mass dark matter particles.

    “Superfluid helium is scientifically complementary to gallium arsenide since helium is more sensitive to dark matter interactions with atomic nuclei, while gallium arsenide is sensitive to dark matter interacting with electrons,” said Dan McKinsey, a faculty senior scientist at Berkeley Lab and physics professor at UC Berkeley who is a part of the LZ Collaboration and is conducting R&D on dark matter detection using superfluid helium.

    LBNL LZ project at SURF, Lead, SD, USA

    SURF-Sanford Underground Research Facility


    SURF Above Ground

    SURF Out with the Old


    SURF An Empty Slate


    SURF Carving New Space


    SURF Shotcreting


    SURF Bolting and Wire Mesh


    SURF Outfitting Begins


    SURF circular wooden frame was built to form a concrete ring to hold the 72,000-gallon (272,549 liters) water tank that would house the LUX dark matter detector


    SURF LUX water tank was transported in pieces and welded together in the Davis Cavern


    SURF Ground Support


    SURF Dedicated to Science


    SURF Building a Ship in a Bottle


    SURF Tight Spaces


    SURF Ready for Science


    SURF Entrance Before Outfitting


    SURF Entrance After Outfitting


    SURF Common Corridior


    SURF Davis


    SURF Davis A World Class Site


    SURF Davis a Lab Site


    SURF DUNE LBNF Caverns at Sanford Lab

    FNAL DUNE Argon tank at SURF

    U Washington LUX Xenon experiment at SURF


    SURF Before Majorana


    U Washington Majorana Demonstrator Experiment at SURF

    “We don’t know whether dark matter interacts more strongly with nuclei or electrons – this depends on the specific nature of the dark matter, which is so far unknown,” he said.

    Another effort would employ gallium arsenide crystals in a different approach to the light dark matter search based on vibrations in the atomic structure of the crystals, known as optical phonons. This setup could target “light dark photons,” which are theorized low-mass particles that would serve as the carrier of a force between dark matter particles – analogous to the conventional photon that carries the electromagnetic force.

    Still another next-gen experiment, known as the Super Cryogenic Dark Matter Search experiment, or SuperCDMS SNOLAB, will use silicon and germanium crystals to hunt for low-mass WIMPs.

    LBNL SuperCDMS, at SNOLAB (Vale Inco Mine, Sudbury, Canada)

    LBNL SuperCDMS, at SNOLAB (Vale Inco Mine, Sudbury, Canada)


    LBNL Super CDMS, at SNOLAB (Vale Inco Mine, Sudbury, Canada)

    SNOLAB, a Canadian underground physics laboratory at a depth of 2 km in Vale’s Creighton nickel mine in Sudbury, Ontario

    SNOLAB, a Canadian underground physics laboratory at a depth of 2 km in Vale’s Creighton nickel mine in Sudbury, Ontario

    “These would be complementary experiments,” Derenzo said of the many approaches. “We need to look at all of the possible mass ranges. You don’t want to be fooled. You can’t exclude a mass range if you don’t look there.”

    Stephen Hanrahan, a staff scientist in Berkeley Lab’s Molecular Biophysics and Integrated Bioimaging Division; and Gregory Bizarri, a senior lecturer in manufacturing at Cranfield University in the U.K., also participated in this study. The work was supported by Advanced Crystal Technologies Inc.

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  • richardmitnick 10:48 am on October 17, 2017 Permalink | Reply
    Tags: Carleton U, , DEAP-3600 experiment, Ottawa Citizen, SNOLAB   

    From Carleton U via Ottawa Citizen: “Dark matter: Carleton physicist gets $3.35M to help unravel mysteries of the universe” 

    Carleton University
    1
    Carleton University experimental physicist Mark Boulay has been warded $3.35 million for a new lab. Tony Caldwell

    A Carleton University experimental physicist has been awarded $3.35 million to build a lab to help gain insight into the nature of neutrinos and dark matter. The elusive answers to those questions could lead to nothing less than a better understanding of how the universe was formed.

    Neutrinos are much smaller than other known particles, and are very difficult to detect. The actually mass of the neutrino is not known. A measurement that would shed light on its mass and the origin of that mass would offer some insight into the formation of the universe.

    Dark matter is even more mysterious.

    Dark Matter Research

    Universe map Sloan Digital Sky Survey (SDSS) 2dF Galaxy Redshift Survey

    Scientists studying the cosmic microwave background hope to learn about more than just how the universe grew—it could also offer insight into dark matter, dark energy and the mass of the neutrino.

    Dark matter cosmic web and the large-scale structure it forms The Millenium Simulation, V. Springel et al

    Dark Matter Particle Explorer China

    DEAP Dark Matter detector, The DEAP-3600, suspended in the SNOLAB deep in Sudbury’s Creighton Mine

    LUX Dark matter Experiment at SURF, Lead, SD, USA

    ADMX Axion Dark Matter Experiment, U Uashington

    It has never been observed, but scientists have known for a long time that it’s out there because its gravitational effects can be seen — galaxies move faster than expected, for example.

    Dark matter outweighs conventional matter by five-to-one, said Mark Boulay, who is the Canada Research Chair in Particle Astrophysics and Subatomic Physics. Essentially, most of the matter in the universe is invisible.

    “There’s a large amount of mass that goes unaccounted for. We know that there’s matter out there, but we haven’t directly seen it,” he said.

    The $3.35 million in funding from the Canada Foundation for Innovation will be used to develop and build detectors that use liquified noble gases to identify extremely rare subatomic processes.

    Boulay has been leading the DEAP-3600 experiment in SNOLAB, an underground laboratory in a mine two kilometres under the surface of the earth near Sudbury.

    SNOLAB, a Canadian underground physics laboratory at a depth of 2 km in Vale’s Creighton nickel mine in Sudbury, Ontario

    SNOLAB, a Canadian underground physics laboratory at a depth of 2 km in Vale’s Creighton nickel mine in Sudbury, Ontario

    One hypothesis suggests that dark matter consists of Weakly Interacting Massive Particles, known as WIMPs. The rock overburden at SNOLAB filters out cosmic rays that would interfere with WIMP detection. The DEAP-3600 experiments searches for dark matter particle interactions using a detector containing 3,600 kilograms of liquid argon.

    Dark matter research is one of the highest-profile areas of particle physics — and it’s highly competitive. The detectors being developed for the Carleton lab will support the study of neutrinos and dark matter at SNOLAB. The lab will be used by researchers at Carleton and others in its network, which includes TRIUMF, Canada’s national laboratory for particle and nuclear physics, as well as the University of British Columbia, McGill University and Université de Sherbrooke.

    “In my field we’ve been looking to demonstrate conclusively the existence of this particle. We’ve been looking for two or three decades. We haven’t found it yet. We don’t know what the mass of the particle is, or how likely it is to interact with other matter,” said Boulay. “We understand that we have a lot of work ahead of us.”

    He estimates it will take a year to construct the first set of prototype detectors for the lab at Carleton. The lab will occupy about 2,000 square feet of space in the Herzberg building.

    “We want to be able to define future programs — what detectors we will be able to build in the next 20 years,” said Boulay. “We’re at the leading edge of what’s possible, and we want to push that.”

    See the full article here .

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    Situated on unceded Algonquin territory beside the historic Rideau Canal, an official UNESCO World Heritage Site, Carleton University was founded by the community in 1942 to meet the needs of veterans returning from the Second World War.

    What defines Carleton?

    We strive for innovation in research, teaching and learning.
    Our location in Ottawa, the nation’s capital, connects us to the world.
    We encourage hands-on experience in the classroom.
    We offer exceptional student support.

     
  • richardmitnick 4:11 pm on September 1, 2017 Permalink | Reply
    Tags: , , DEAP3600, , SNOLAB, ,   

    From TRIUMF: “New results surface from world’s most sensitive argon dark matter experiment” 

    TRIUMF

    31. August 2017

    1

    Argon in its natural form is a colourless, odorless, and non-flammable gas. It is also utterly unreactive – chemists and physicists have long wielded argon to formulate nonreactive and inert conditions. These qualities earned this noble gas its name, derived from the Greek word for ‘inactive.’

    What use, then, is a 3600-kilogram sphere of liquid argon, buried under two kilometers of Ontario bedrock?

    If you ask Dr. Pietro Giampa, a newly-joined TRIUMF scientist and recipient of the Otto Hausser Postdoctoral Fellowship, the simple answer (accompanied by a knowing smile) is: “Possibly changing our entire understanding of physics beyond the Standard Model, but also potentially the entire universe.” He delivers this response with the ease of repetition, a common trait among dark matter physicists. And while it may seem like a lofty claim, for Giampa and a dedicated team of particle physicists, astrophysicists, and astronomers at SNOLAB in Sudbury, ON, the proof may very well be in the depths of liquid argon.

    SNOLAB, Sudbury, Ontario, Canada.

    Deeper understanding

    The sphere of argon is a dark matter detector, and the central component of a state-of-the-art system called DEAP-3600: ‘Dark Matter Experiment using Argon Pulse-shape’ (with the argon weighing in at just over 3600 kilograms). Giampa and the DEAP-3600 team are working to characterize the fundamental properties of dark matter, a nebulous substance that makes up 23% of the mass of our universe and which we know next to nothing about.

    DEAP-3600 is in search of a host of particles widely considered the most viable candidates for dark matter: weakly interacting massive particles, or WIMPs. WIMPs behave similarly to the building-block particles of our universe like protons and neutrons, except that they don’t interact via any forces other than the electroweak and gravitational. This means that most WIMPs pass through our world without any interaction with atoms, subatomic particles, or nearly anything else.

    DEAP-3600 works by listening for collisions between dark matter and the nuclei of argon atoms. The impacts will be faint, and the apparatus can only listen in on one bandwidth at a time. Theoretical models beyond the Standard Model point to a WIMP of mass 100 gigaelectronvolts (GeV) or greater, a range DEAP is uniquely capable of investigating.

    Essentially, the detector provides a small sphere of space where collision events between WIMPs and the nuclei of argon atoms can be quietly recorded. Inactive argon, which undergoes no radioactive decay unless perturbed, is the perfect target for incoming dark matter particles; situating the argon sphere 2070 meters below Earth’s surface only heightens DEAP’s senses, eliminating the white noise of WIMP-like cosmic rays and muons. With a sufficiently large detector space and a sufficiently sensitive detection apparatus, there’s a chance that we’ll bear witness to the first WIMP ever observed as it glances off an argon atom.

    2
    DEAP-3600 takes a long, hard listen; silence.

    The DEAP team’s first results have surfaced: a new paper published by the group on August 1st, 2017 describes preliminary results from the experiment, and conclusions gleaned from just four and a half days of data-taking immediately following the completion of the detector system in August 2016. The paper details an extremely sensitive system, and a similarly sensitive, high-performance mathematical model for discriminating between the energy signals of WIMPs of different masses near the 100 GeV range.

    The experiment didn’t observe any dark matter-argon collisions during its initial monitoring period, but this absence of signal is itself a telling sign. While the number of potential WIMP-argon collisions is as large as the diversity of WIMP masses, it is finite – by ruling out different masses of WIMPs, Giampa and the DEAP team are honing in on the mass of the WIMP that may interact with an argon nucleus.

    Finding such a particle would be a boon for the field of particle physics. While WIMPS were chosen because they fit snugly into current theoretical models as potential dark matter particles, their discovery would have vast ramifications that extend beyond our current understanding of particle physics. Our entire concept of the universe would undergo a dramatic, tectonic shift.

    With this lofty goal as their north star, the DEAP team (including TRIUMF scientists Pierre-Andre Amadruz, Ben Smith, Thomas Lidner, and TRIUMF team leader Fabrice Retiere) will continue their search, re-calibrating and tuning into different bandwidths of potential collisions. Further data-taking has been ongoing since August 2016, and it’s possible that more results will surface soon.

    “We’re very excited to have proven the precision and sensitivity of the detector apparatus. While we’re but one of the many experiments around the world investigating the identity of dark matter, we can’t help but think that we are now one step closer to making this remarkable discovery.” – Dr. Pietro Giampa

    To keep tabs on the DEAP team or to learn more about the experiment, visit: http://deap3600.ca/

    See the full article here .

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    Stem Education Coalition
    Triumf Campus
    Triumf Campus
    World Class Science at Triumf Lab, British Columbia, Canada
    Canada’s national laboratory for particle and nuclear physics
    Member Universities:
    University of Alberta, University of British Columbia, Carleton University, University of Guelph, University of Manitoba, Université de Montréal, Simon Fraser University,
    Queen’s University, University of Toronto, University of Victoria, York University. Not too shabby, eh?

    Associate Members:
    University of Calgary, McMaster University, University of Northern British Columbia, University of Regina, Saint Mary’s University, University of Winnipeg, How bad is that !!

     
  • richardmitnick 3:28 pm on February 28, 2017 Permalink | Reply
    Tags: , , PICO collaboration, SNOLAB   

    From FNAL: “New world-leading limit on dark matter search from PICO experiment” 

    FNAL II photo

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    February 27, 2017
    Andre Salles
    Fermilab Office of Communication
    asalles@fnal.gov
    630-840-6733

    Editor’s note: The PICO-60 detector was originally called “COUPP-60,” with COUPP standing for “Chicagoland Observatory for Underground Particle Physics.” It was designed and built by Fermilab in collaboration with the University of Chicago and Indiana University, South Bend. Work began at Fermilab in 2005, and, after extensive testing, the detector was moved to SNOLAB in 2012.

    1
    A team of Fermilab scientists installs the PICO-60 dark matter detector at SNOLAB. Photo: Fermilab

    “We’ve been working on this for a long time,” said Fermilab’s project manager Andrew Sonnenschein of the below result. “This is by far our most satisfying result yet, because the techniques we used to reject background events from sources other than dark matter worked flawlessly. Bubble chambers are finally living up to their full potential as dark matter detectors. Now the dark matter just needs to show up.”

    Read the original SNOLAB press release on the SNOLAB website.

    The PICO Collaboration is excited to announce that the PICO-60 dark matter bubble chamber experiment has produced a new dark matter limit after analysis of data from the most recent run. This new result is a factor of 17 improvement in the limit for spin-dependent WIMP-proton cross-section over the already world-leading limits from PICO-2L run-2 and PICO-60 CF3I run-1 in 2016.

    The PICO-60 experiment is currently the world’s largest bubble chamber in operation; it is filled with 45 Liters of C3F8 (octafluoropropane) and is taking data in the ladder lab area of SNOLAB. The detector uses the target fluid in a superheated state such that a dark matter particle interaction with a fluorine nucleus causes the fluid to boil and creates a tell tale bubble in the chamber.

    The PICO experiment uses digital cameras to see the bubbles and acoustic pickups to improve the ability to distinguish between dark matter particles and other sources when analysing the data.

    The superheated detector technology has been at the forefront of spin-dependent (SD) searches, using various refrigerant targets including CF3I, C4F10 and C2ClF5, and two primary types of detectors: bubble chambers and droplet detectors. PICO is the leading experiment in the direct detection of dark matter for spin-dependent couplings and is developing a much larger version of the experiment with up to 500 kg of active mass.

    2
    Inside the PICO-60 detector, installed at SNOLAB in Sudbury, Ontario. Photo: SNOLAB

    About PICO

    17 participating institutions: University of Alberta; University of Chicago; Czech Technical University; Fermilab; Indiana University South Bend; Kavli Institute for Cosmological Physics; Laurentian University; Université de Montréal; Northeastern Illinois University (NEIU); Northwestern University; Universidad Nacional Autonoma de Mexico; Pacific Northwest National Laboratory; Queen’s University at Kingston; Saha Institute of Nuclear Physics, India; SNOLAB; Universitat Politecnica de Valencia; Virginia Tech.

    The PICO Collaboration (formed from the merger of two existing groups, PICASSO and COUPP) uses bubble chambers and superheated fluid to search for dark matter. The PICO-60 detector consists of a fused-silica jar sealed to flexible, stainless steel bellows, all immersed in a pressure vessel filled with hydraulic fluid. Eight lead zirconate (PZT) piezoelectric acoustic transducers mounted to the exterior of the bell jar record the acoustic emissions from bubble nucleation and four 2-megapixel resolution fast CMOS cameras are used to photograph the chamber. The PICO-60 detector was built at Fermilab in Batavia, IL and installed underground at SNOLAB in 2012.

    The PICO bubble chambers are made insensitive to electromagnetic interactions by tuning the operating temperatures of the experiment, while the alpha decays are discriminated from dark matter interactions by their sound signal, making these detectors very powerful tools in the search for dark matter.

    PICO is operating two detectors deep underground at SNOLAB: PICO-60, a bubble chamber with 52 kg of C3F8 and PICO-2L, another bubble chamber with 2.9 kg of C3F8.

    The paper is available on the arXiv.

    About SNOLAB

    SNOLAB is Canada’s leading edge astroparticle physics research facility located 2 km (6800 ft) underground in the Vale Creighton Mine. The SNOLAB facility was created by an expansion of the underground research areas next to the highly successful Sudbury Neutrino Observatory (SNO) experiment. The entire laboratory is operated as an ultra-clean space to limit local radioactivity. With greater depth and cleanliness than any other international laboratory, it has the lowest background from cosmic rays providing an ideal location for measurements of rare processes that would be otherwise unobservable.

    Learn more

    PICO website

    SNOLAB

    For more information, please contact:
    Samantha Kuula
    Communications officer, SNOLAB
    Phone: 705-692-7000 ext. 2222
    Email: Samantha.Kuula@snolab.ca
    Website: http://www.snolab.ca

    French language contact:
    Guillaume Giroux
    Postdoctoral fellow, Queen’s University
    Email: ggiroux@owl.phy.queensu.ca
    Phone: 613-533-6000 ext. 79203

    U.S. contact:
    Andrew Sonnenschein
    Project manager, PICO-60
    Fermi National Accelerator Laboratory
    Email: sonnensn@fnal.gov
    Phone: 630-840-2883

    See the full article here .

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    Fermilab Campus

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world
    collaborate at Fermilab on experiments at the frontiers of discovery.

     
  • richardmitnick 4:55 pm on February 16, 2017 Permalink | Reply
    Tags: , Dark Matter Physics, SNOLAB   

    From CERN Courier: “Funding injection for SNOLAB” 

    CERN Courier

    1
    DEAP-3600 detector at SNOLAB

    The SNOLAB laboratory in Ontario, Canada, has received a grant of $28.6m to help secure its next three years of operations. The facility is one of 17 research facilities to receive support through Canada’s Major Science Initiative (MSI) fund, which exists to secure state-of-the-art national research facilities.

    SNOLAB, which is located in a mine 2 km beneath the surface, specialises in neutrino and dark-matter physics and claims to be the deepest cleanroom facility in the world. Current experiments located there include: PICO and DEAP-3600, which search for dark matter using bubble-chamber and liquid-argon technology, respectively; EXO, which aims to measure the mass and nature of the neutrino; HALO, designed to detect supernovae; and a new neutrino experiment SNO+ based on the existing SNO detector.

    4
    EXO. U. MD

    The new funds will be used to employ the 96-strong SNOLAB staff and support the operations and maintenance of the lab’s facilities.

    See the full article here .

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    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS
    CERN ATLAS New

    ALICE
    CERN ALICE New

    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

    LHC

    CERN LHC Map
    CERN LHC Grand Tunnel

    CERN LHC particles

     
  • richardmitnick 1:48 pm on May 2, 2013 Permalink | Reply
    Tags: , , , SNOLAB   

    From Fermilab: “New dark matter detector begins search for invisible particles” 


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    May 2, 2013
    Science contacts:
    Hugh Lippincott, Fermilab, 609-558-6313, hugh@fnal.gov .
    Juan Collar, University of Chicago, 773-702-4253, collar@uchicago.edu

    “Scientists this week heard their first pops in an experiment that searches for signs of dark matter in the form of tiny bubbles.

    bubbles
    This is an image of the first particle interactions seen in the COUPP-60 detector, located half a mile underground at SNOLAB in Ontario, Canada. Photo: SNOLAB

    Scientists will need further analysis to discern whether dark matter caused any of the COUPP-60 experiment’s first bubbles.

    ‘Our goal is to make the most sensitive detector to see signals of particles that we don’t understand,’ said Hugh Lippincott, a postdoc with the Department of Energy’s Fermi National Accelerator Laboratory who has spent much of the past several months leading the installation of the one-of-a-kind detector in a laboratory a mile and a half underground.

    COUPP-60 is a dark-matter experiment funded by DOE’s Office of Science. Fermilab managed the assembly and installation of the experiment’s detector.

    The COUPP-60 detector is a jar filled with purified water and CF3I—an ingredient found in fire extinguishers. The liquid in the detector is kept at a temperature and pressure slightly above the boiling point, but it requires an extra bit of energy to actually form a bubble. When a passing particle enters the detector and disturbs an atom in the clear liquid, it provides that energy.

    Dark-matter particles, which scientists think rarely interact with other matter, should form individual bubbles in the COUPP-60 tank.

    ‘The events are so rare, we’re looking for a couple of events per year,’ Lippincott said.”

    See the full article here.

    Fermilab Campus

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics.


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  • richardmitnick 1:46 pm on December 12, 2012 Permalink | Reply
    Tags: , , , SNOLAB   

    From Fermilab: “Going deep for detector R&D” 


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Wednesday, Dec. 12, 2012

    ed
    Erik Ramberg, assistant head for detector research, wrote this column

    “Sometimes you have to go to the ends of the Earth to get what you need. Last week for one Fermilab project this saying was more literal than figurative. The DAMIC (Dark Matter In CCDs) experiment saw a very successful culmination of several years of detector research.

    The latest episode for the DAMIC experiment played out in one of the more exotic laboratories in the world: the Sudbury Neutrino Observatory Lab [SNOLAB], located 6,800 feet underground in an active nickel mine in Ontario, Canada. This laboratory provides the right conditions for DAMIC and other dark-matter experiments. The extreme depth filters out cosmic rays, which could mimic dark matter interactions, and the highly specialized SNOLAB crew keeps the laboratory in clean-room conditions…”

    sl

    “…DAMIC uses charged coupled devices—the CCDs that have been used for many years in digital cameras. But these are not your average CCDs. They are the high-tech ones also used in the Dark Energy Camera [DECam], which Fermilab installed on the Blanco telescope in Chile. The detectors were developed and fabricated at Berkeley Lab and were tested and installed in the camera here at Fermilab…”

    decam
    view of the DECam, also showing the arrangement of the CCD array (CTIO)

    See the full article here.

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics.


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