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  • richardmitnick 1:31 pm on November 16, 2015 Permalink | Reply
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    From ASU: “Forged in the hearts of stars” 

    ASU Bloc

    Arizona State University

    November 16th, 2015
    Nikki Cassis

    ASU and UNC researchers to study thermonuclear reaction rates to determine how much of certain elements exploding stars can produce

    We are all made from stars. And that’s not just a beautiful metaphor.

    Apart from hydrogen, as many have heard from the Carl Sagan and Neil DeGrasse Tyson Cosmos series, every ingredient in the human body is made from elements forged by stars.

    The calcium in our bones, the oxygen we breathe, the iron in our blood – all those are forged in the element factories of stars. Even the carbon in our apple pie.

    Stars are giant element furnaces. Their intense heat can cause atoms to collide, creating new elements – a process known as nuclear fusion. That process is what created chemical elements like carbon or iron – the building blocks that make up life as we know it.

    It sounds pretty simple, but it is a very intricate process. And there are still many uncertainties.

    Professors Sumner Starrfield and Frank Timmes, both from Arizona State University, and Professor Christian Iliadis, from the University of North Carolina at Chapel Hill, hope to resolve some of those uncertainties.

    “Broad brush we have a good idea that massive stars become one kind of supernova and binary stars with white dwarfs become another type of supernova. We know a lot about what may have caused the explosions but there are many unexplained parts that need to be worked out,” said Starrfield, Regents’ Professor in ASU’s School of Earth and Space Exploration.

    The team was awarded a NASA grant of nearly $700,000 to better understand how supernovae evolve to an explosion. The study is aimed at determining how much of certain elements a star can produce.

    Inside these element factories, how much carbon for our apple pies gets made, how much calcium is available to make our bones, depends on their nuclear reaction rates.

    For example, as shown in the recent movie The Martian, if you were trying to make water, you would take hydrogen and oxygen and some energy and put it together in a container and it would make water at a certain rate depending on the temperature of the container. Add more heat, and the reaction speeds up, producing more water.

    A similar thing happens inside stars – except it’s nuclear reactions releasing a factor of one million times more energy than a chemical reaction. Stars run on nuclear reactions. Smash together a carbon nucleus and a helium nucleus inside the furnace of a star, and out pops the oxygen we breathe. Speed up that reaction, and the star yields more oxygen.

    Researchers use computers and solve equations to predict how a star evolves. Part of that input into how stars evolve are nuclear reaction rates. One set rate has been used to arrive at an estimate of how much of a certain element a star can produce. But is that number optimal? Is it some super optimistically high value, or it pessimistically low?

    “What we will define is a meaningful range, given the uncertainties of what is measured here on Earth, of what actually comes out. At the end of the day, what we are going to know is the variation – how much variation is there in a star’s output. How much calcium or carbon comes out of the star?” said Timmes, an astrophysicist in ASU’s School of Earth and Space Exploration.

    Investigating the range of elements that a star can produce is based on what is measured in the terrestrial laboratory. This is where nuclear physicist Iliadis, who recently published a textbook on the nuclear physics of stars, fits in; he’s the experimentalist providing the data on the nuclear fusion reaction rates and their uncertainties.

    “It is not quite “The power of the Sun, in the palm of my hands”, as muttered by Dr. Octavius in Spiderman 2; nevertheless we do measure with our accelerator facilities the very same nuclear fusion reactions that occur in stars,” said Iliadis.

    But uncertainties are inherent in lab measurements. What you want to do is connect what you do in the lab with what you see in the night sky. And that’s Starrfield’s contribution – he’s an expert in dead and dying suns. He will use the reaction rates from Iliadis in new calculations of how different types of stars can become supernovae.

    This proposal ties in a tight loop experiments done here on earth with observations in the night sky. For over two decades Timmes has been doing modeling of stars; the models he creates will serve as the glue between what is measured on earth by Iliadis and what is seen in the dark night sky by Starrfield.

    The team is going to be checking roughly 50 of the most important nuclear reaction rates for producing elements that form the building blocks of life as we know it. And just as important, some of these reaction rates are useful in nuclear fusion experiments to produce clean power on Earth.

    As a star ages, hydrogen and then helium nuclei fuse to form heavier elements. These reactions continue in stars today as lighter elements are transformed into heavier ones.

    Late in life, most stars will explode, ejecting the elements they forged into interstellar space. If a star is heavy enough, or has a close companion, it will explode in a supernova that creates many heavy elements including iron and nickel. The explosion also disperses the different elements across the galaxy, scattering the stellar material that will eventually make up planets, including Earth.

    Starrfield will compare their calculations with observations of exploding stars and determine the amounts of chemical elements blown into space. “We are the results,” said Starrfield.

    See the full article here .

    Please help promote STEM in your local schools.

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    Stem Education Coalition

    ASU is the largest public university by enrollment in the United States.[11] Founded in 1885 as the Territorial Normal School at Tempe, the school underwent a series of changes in name and curriculum. In 1945 it was placed under control of the Arizona Board of Regents and was renamed Arizona State College.[12][13][14] A 1958 statewide ballot measure gave the university its present name.
    ASU is classified as a research university with very high research activity (RU/VH) by the Carnegie Classification of Institutions of Higher Education, one of 78 U.S. public universities with that designation. Since 2005 ASU has been ranked among the Top 50 research universities, public and private, in the U.S. based on research output, innovation, development, research expenditures, number of awarded patents and awarded research grant proposals. The Center for Measuring University Performance currently ranks ASU 31st among top U.S. public research universities.[15]

    ASU awards bachelor’s, master’s and doctoral degrees in 16 colleges and schools on five locations: the original Tempe campus, the West campus in northwest Phoenix, the Polytechnic campus in eastern Mesa, the Downtown Phoenix campus and the Colleges at Lake Havasu City. ASU’s “Online campus” offers 41 undergraduate degrees, 37 graduate degrees and 14 graduate or undergraduate certificates, earning ASU a Top 10 rating for Best Online Programs.[16] ASU also offers international academic program partnerships in Mexico, Europe and China. ASU is accredited as a single institution by The Higher Learning Commission.

    ASU Tempe Campus
    ASU Tempe Campus

  • richardmitnick 4:45 pm on November 25, 2013 Permalink | Reply
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    From PPPL- “Multinational achievement: PPPL collaborates on record fusion plasma in tokamak in China” 

    November 25, 2013
    John Greenwald

    A multinational team led by Chinese researchers in collaboration with U.S. and European partners has successfully demonstrated a novel technique for suppressing instabilities that can cut short the life of controlled fusion reactions. The team, headed by researchers at the Institute of Plasma Physics in the Chinese Academy of Sciences (ASIPP), combined the new technique with a method that the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) has developed for protecting the walls that surround the hot, charged plasma gas that fuels fusion reactions.

    Interior view of EAST tokamak(Photo by Institute of Plasma Physics, Chinese Academy of Sciences )

    The record-setting results of the tests, conducted on the Experimental Advanced Superconducting Tokamak (EAST) in Hefei, China, could mark a key step in the worldwide effort to develop fusion as a clean and abundant source of energy for generating electricity. “This is a very good example of multinational collaboration on EAST,” said ASIPP Director Jiangang Li. “I very much appreciate the effort of our collaborators.”

    First reporting the results was a paper published online in the November issue of the journal Nature Physics. U.S co-authors included PPPL physicists Jon Menard and Rajesh Maingi, who headed the wall-conditioning effort, and General Atomics physicist Gary Jackson, a plasma-control expert who helped draft the paper.

    The findings could hold particular promise for developers of future fusion facilities such as ITER, the international experiment under construction in France. Controlling instabilities that erupt at the edge of the plasma will be crucial to the success of the huge donut-shaped ITER tokamak, which is designed to demonstrate the feasibility of fusion power.

    The EAST experiments set a record for the duration of what is called an H-mode, or high-confinement plasma — the type that will be employed in ITER and other future tokamaks. To achieve this duration, the EAST team beamed what are known as “lower hybrid wave current drive” microwaves into the plasma. The antenna-launched beams reshaped the magnetic field lines confining the plasma and suppressed instabilities at the edge of the gas near the interior walls of the tokamak. Controlling these fast-growing instabilities, called “edge localized modes” (ELMs), produced a record life span of more than 30 seconds for the H-mode plasma.

    These results suggested a potent new method for suppressing ELMS to create an extended, or long-pulse, plasma. Many methods already exist. Among them are the use of external magnetic coils to alter the field lines that enclose the plasma, and the injection of pellets of deuterium fuel into the plasma during experiments.

    Contributing to the EAST results was the PPPL-designed wall treatment, which coated the plasma-facing walls of the tokamak with the metal lithium and inserted lithium granules into experiments to keep the coating fresh. The silvery metal absorbed stray plasma particles and kept impurities from entering the core of the plasma and halting fusion reactions. “When lithium has been used to coat the walls of fusion devices, higher plasma temperature, pressure, and confinement have been achieved,” PPPL physicists Menard and Maingi said in an interview.

    “This was good physics,” Jackson of General Atomics said of the experiments, noting that long-pulse plasmas will be required for fusion power plants to generate electricity.

    Combining microwave beams for ELMs suppression with the advanced lithium wall treatment could thus provide a fruitful new direction for fusion-energy development. This combination of techniques, the Nature Physics paper said, offers “an attractive regime for high-performance, long-pulse operations.”

    See the full article here.

    Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University.

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  • richardmitnick 4:24 am on August 13, 2013 Permalink | Reply
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    From Livermore Lab: “D2T3 to join the ranks at National Ignition Facility” 

    Lawrence Livermore National Laboratory

    Breanna Bishop, LLNL, (925) 423-9802, bishop33@llnl.gov

    “A new employee will soon be added to the roster of those working on Level 2 of the National Ignition Facility’s (NIF) Target Bay. His name is D2T3, and his duties will be a bit different than his colleagues.

    D2T3 — named for the hydrogen isotopes that serve as fuel for NIF’s fusion targets — is a radiation-detecting, remote controlled robot. Currently in testing and training mode, he will be fully deployed in September after three years of development.

    System Manager Casey Schulz successfully running D2T3 through his paces, negotiating obstacles in the Target Bay.

    D2T3 has found his place in the NIF duty roster due to the continuing success of the facility’s experiments. As NIF laser shots continue to yield higher and higher neutron yields — a marker of the facility’s ultimate goal, fusion ignition — the immediate environment of the Target Bay is inhospitable to humans. Currently, the area remains sealed for a number of hours based on radiation decay models before radiation technicians enter to verify that levels are safe. As a safety precaution, this wait is longer than models predict to provide a safety buffer.

    Camera faceoff between TID’s Matthew Story and D2T3 in TB Level 2.

    However, D2T3 doesn’t have the same constraints as his human colleagues. He can patrol the Target Bay immediately after a shot and measure the remaining radiation levels, providing an accurate and timely notification for when it is safe to re-enter the area. He also can provide real-time decay information, allowing for fine-tuning of the current models.

    ‘This is the first actual, non-tethered robot we’ve got,’ said Casey Schulz, a mechanical and robotics engineer who serves as the system manager for D2T3. ‘It expands the capability of NIF, improves efficiency and maintains the high level of safety we require. It’s logically the next step as we continue to reach higher and higher neutron yields.'”

    See the full article here.

    Operated by Lawrence Livermore National Security, LLC, for the Department of Energy’s National Nuclear Security
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  • richardmitnick 3:01 pm on February 22, 2013 Permalink | Reply
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    From Livermore Lab: “National Academies recommend high priority for work on Lawrence Livermore’s National Ignition Facility” 

    Lawrence Livermore National Laboratory

    Breanna Bishop

    A report issued by the National Research Council highlights the significant impact of successful development of inertial fusion energy (IFE), and recommends priorities for future research in this area.

    A view from the bottom of the chamber. Pulses from NIF’s high-powered lasers race toward the Target Bay at the speed of light. They arrive at the center of the target chamber within a few trillionths of a second of each other, aligned to the accuracy of the diameter of a human hair.

    As noted in this National Academies’ report, ‘The potential benefits of inertial confinement fusion energy (abundant fuel, minimal greenhouse gas emissions, limited high-level radioactive waste requiring long-term disposal) provide a compelling rationale for establishing inertial fusion energy R&D as part of the long-term U.S. energy R&D portfolio.’

    Research into IFE is a key objective of Lawrence Livermore National Laboratory’s National Ignition Facility (NIF) — the world’s premier research facility in this area of science and technology. The NIF was built by the National Nuclear Security Administration (NNSA) primarily to provide data in support of its defense programs, but also has broad applications in basic science and fusion energy.

    The National Academies state that ‘The National Ignition Facility, designed for stockpile stewardship applications, also is of great potential importance for advancing the technical basis for inertial fusion energy (IFE) research,’ and that the target physics programs on the NIF (and related facilities) ‘should receive continued high priority.'”

    See the full article here.

    Operated by Lawrence Livermore National Security, LLC, for the Department of Energy’s National Nuclear Security

    DOE Seal


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  • richardmitnick 9:32 am on June 5, 2012 Permalink | Reply
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    From M.I.T.: “NSE fusion program moves beyond plasma, towards practical power-plant issues” 

    “Nuclear fusion is a seemingly ideal energy source: carbon-free, fuel derived largely from seawater, no risk of runaway reactors and minimal waste issues. And the MIT Department of Nuclear Science and Engineering’s (NSE) long-standing fusion program is extending its leadership role in advancing the technology toward practical use.

    NSE’s Plasma Science and Fusion Center (PFSC), home of one of just three U.S. tokamak fusion reactors, has been a focal point of fusion research since its founding in 1976, developing substantial basic knowledge about creating and maintaining fusion reactions. And today, explains Professor Dennis Whyte, NSE’s fusion team is beginning a strategic pivot into the next stage of development, with a focus on interdisciplinary knowledge needed for the creation of functioning

    A tokamak

    ‘We’re basically making energy by creating a star,’ explains Whyte. ‘For power generation, the star has to turn on, and stay on for a year at a time, and we need a way to extract the energy it creates.’”

    See the full article here.

  • richardmitnick 3:24 pm on December 2, 2010 Permalink | Reply
    Tags: , Nuclear Fuson,   

    From MITNews: 

    A step toward fusion power

    David L. Chandler, MIT News Office

    “The long-sought goal of a practical fusion-power reactor has inched closer to reality with new experiments from MIT’s experimental Alcator C-Mod reactor, the highest-performance university-based fusion device in the world.

    The new experiments have revealed a set of operating parameters for the reactor — a so-called “mode” of operation — that may provide a solution to a longstanding operational problem: How to keep heat tightly confined within the hot charged gas (called plasma) inside the reactor, while allowing contaminating particles, which can interfere with the fusion reaction, to escape and be removed from the chamber.

    Photo of the interior of Alcator C-Mod during a test run shows the glowing hot plasma, which can reach more than 55 million degrees Celsius.
    Image: Plasma Science and Fusion Center

    Read the full (and very important) article here.

  • richardmitnick 7:27 am on November 12, 2010 Permalink | Reply
    Tags: Nuclear Fuson   

    From Sandia Lab: Nuclear Fusion – A Step Toward the Future 

    Sandia effort images the sea monster of nuclear fusion: the Rayleigh-Taylor instability

    More accurate simulations could lead to “break-even” fusion in foreseeable future

    “ALBUQUERQUE, N.M. — A new X-ray imaging capability has taken pictures of a critical instability at the heart of Sandia’s huge Z accelerator. The effort may help remove a major impediment in the worldwide, multidecade, multibillion dollar effort to harness nuclear fusion to generate electrical power from sea water.

    “These are the first controlled measurements of the growth of magneto-Rayleigh-Taylor [MRT] instabilities” in fast Z-pinches, said project lead Daniel Sinars.

    MRT instabilities are spoilers that arise wherever electromagnetic forces are used to contract (pinch) a plasma, which is essentially a cloud of ions. The pinch method is the basis of the operation of Z, a dark-horse contender in the fusion race.

    This is an optical photograph of an aluminum z-pinch target tube installed in the Z machine. Click on the thumbnail for a high-resolution image.

    A pinch contracts plasma so suddenly and tightly that hydrogen isotopes available from sea water, placed in a capsule within the plasma, should fuse.

    A pinch contracts plasma so suddenly and tightly that hydrogen isotopes available from sea water, placed in a capsule within the plasma, should fuse.

    That’s the intent.” – Read the rest of the article here.

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