Science.gov

Sample records for nuclear astrophysical studies

  1. Studying Nuclear Astrophysics at NIF

    SciTech Connect

    Boyd, R; Bernstein, L; Brune, C

    2009-07-01

    The National Ignition Facility's primary goal is to generate fusion energy. But the starlike conditions that it creates will also enable NIF scientists to study astrophysically important nuclear reactions. When scientists at the stadium-sized National Ignition Facility attempt to initiate fusion next year, 192 powerful lasers will direct 1.2 MJ of light energy toward a two-mm-diameter pellet of deuterium ({sup 2}H, or D) and tritium ({sup 3}H, or T). Some of that material will be gaseous, but most will be in a frozen shell. The idea is to initiate 'inertial confinement fusion', in which the two hydrogen isotopes fuse to produce helium-4, a neutron, and 17.6 MeV of energy. The light energy will be delivered to the inside walls of a hohlraum, a heavy-metal, centimeter-sized cylinder that houses the pellet. The container's heated walls will produce x rays that impinge on the pellet and ablate its outer surface. The exiting particles push inward on the pellet and compresses the DT fuel. Ultimately a hot spot develops at the pellet's center, where fusion produces {sup 4}He nuclei that have sufficient energy to propagate outward, trigger successive reactions, and finally react the frozen shell. Ignition should last several tens of picoseconds and generate more than 10 MJ of energy and roughly 10{sup 19} neutrons. The temperature will exceed 10{sup 8} K and fuel will be compressed to a density of several hundred g/cm{sup 3}, both considerably greater than at the center of the Sun. The figure shows a cutaway view of NIF. The extreme conditions that will be produced there simulate those in nuclear weapons and inside stars. For that reason, the facility is an important part of the US stockpile stewardship program, designed to assess the nation's aging nuclear stockpile without doing nuclear tests. In this Quick Study we consider a third application of NIF - using the extraordinary conditions it will produce to perform experiments in basic science. We will focus on

  2. Nuclear astrophysics

    SciTech Connect

    Haxton, W.C.

    1992-01-01

    The problem of core-collapse supernovae is used to illustrate the many connections between nuclear astrophysics and the problems nuclear physicists study in terrestrial laboratories. Efforts to better understand the collapse and mantle ejection are also motivated by a variety of interdisciplinary issues in nuclear, particle, and astrophysics, including galactic chemical evolution, neutrino masses and mixing, and stellar cooling by the emission of new particles. The current status of theory and observations is summarized.

  3. Nuclear astrophysics

    SciTech Connect

    Haxton, W.C.

    1992-12-31

    The problem of core-collapse supernovae is used to illustrate the many connections between nuclear astrophysics and the problems nuclear physicists study in terrestrial laboratories. Efforts to better understand the collapse and mantle ejection are also motivated by a variety of interdisciplinary issues in nuclear, particle, and astrophysics, including galactic chemical evolution, neutrino masses and mixing, and stellar cooling by the emission of new particles. The current status of theory and observations is summarized.

  4. Underground nuclear astrophysics studies with CASPAR

    NASA Astrophysics Data System (ADS)

    Robertson, Daniel; Couder, Manoel; Greife, Uwe; Strieder, Frank; Wiescher, Michael

    2016-02-01

    The drive of low-energy nuclear astrophysics laboratories is to study the reactions of importance to stellar burning processes and elemental production through stellar nucleosynthesis, over the energy range of astrophysical interest. As laboratory measurements approach the stellar burning window, the rapid drop off of cross-sections is a significant barrier and drives the need to lower background interference. The natural background suppression of underground accelerator facilities enables the extension of current experimental data to lower energies. An example of such reactions of interest are those thought to be sources of neutrons for the s-process, the major production mechanism for elements above the iron peak. The reactions 13C(α,n)16O and 22Ne(α,n)25Mg are the proposed initial focus of the new nuclear astrophysics accelerator laboratory (CASPAR) currently under construction at the Sanford Underground Research Facility, Lead, South Dakota

  5. Nuclear astrophysics

    SciTech Connect

    Penionzhkevich, Yu. E.

    2010-08-15

    The International Year of Astronomy 2009 (IYA2009) was declared by the 62nd General Assembly of the United Nations and was also endorsed by UNESCO. Investigations in the realms of particle and nuclear physicsmake a large contribution in the development of our ideas of the properties of the Universe. The present article discusses some problems of the evolution of the Universe, nucleosyntheses, and cosmochronology from the point of view of nuclear and particle physics. Processes occurring in the Universe are compared with the mechanisms of the production and decay of nuclei, as well as with the mechanisms of their interaction at high energies. Examples that demonstrate the potential of nuclearphysics methods for studying cosmic objects and the properties of the Universe are given. The results that come from investigations into nuclear reactions induced by beams of radioactive nuclei and which make it possible to take a fresh look at the nucleosynthesis scenario in the range at light nuclei are presented.

  6. Nuclear Structure and Nuclear Astrophysics Studies with Fast Heavy-Ion Beams

    NASA Astrophysics Data System (ADS)

    Motobayashi, Tohru

    Collaboration between France and Japan on studies with fast RI (radioactive isotope) beams and related technical developments started in 1980s, when the GANIL accelerators and RIKEN cyclotron complex started operation and RI beam production technique was developed. Several examples of collaboration on nuclear physics and nuclear astrophysics experiments including related technical development are discussed.

  7. Nuclear astrophysics studies by SAMURAI spectrometer in RIKEN RIBF

    NASA Astrophysics Data System (ADS)

    Yoneda, K.

    2012-11-01

    SAMURAI is a spectrometer which is now being constructed at RIKEN RI Beam Factory. This spectrometer is characterized by a large angular-and momentum-acceptance enabling, for example, multi-particle coincidence measurements. Here brief descriptions of SAMURAI spectrometer and physics topics relevant to nuclear astrophysics are presented.

  8. Nuclear astrophysics studies by SAMURAI spectrometer in RIKEN RIBF

    SciTech Connect

    Yoneda, K.

    2012-11-12

    SAMURAI is a spectrometer which is now being constructed at RIKEN RI Beam Factory. This spectrometer is characterized by a large angular-and momentum-acceptance enabling, for example, multi-particle coincidence measurements. Here brief descriptions of SAMURAI spectrometer and physics topics relevant to nuclear astrophysics are presented.

  9. The Nuclear Astrophysics Explorer

    NASA Technical Reports Server (NTRS)

    Matteson, J. L.; Teegarden, B. J.; Gehrels, N.; Mahoney, W. A.

    1989-01-01

    The Nuclear Astrophysics Explorer was proposed in 1986 for NASA's Explorer Concept Study Program by an international collaboration of 25 scientists from nine institutions. The one-year feasibility study began in June 1988. The Nuclear Astrophysics Explorer would obtain high resolution observations of gamma-ray lines, E/Delta E about 1000, at a sensitivity of about 0.000003 ph/sq cm s, in order to study fundamental problems in astrophysics such as nucleosynthesis, supernovae, neutron star and black-hole physics, and particle acceleration and interactions. The instrument would operate from 15 keV to 10 Mev and use a heavily shielded array of nine cooled Ge spectrometers in a very low background configuration. Its 10 deg FWHM field of view would contain a versatile coded mask system which would provide two-dimensional imaging with 4 deg resolution, one-dimensional imaging with 2 deg resolution, and efficiendt measurements of diffuse emission. An unshielded Ge spectrometer would obtain wide-field measurements of transient gamma-ray sources. The earliest possible mission would begin in 1995.

  10. The Nuclear Astrophysics Explorer

    NASA Technical Reports Server (NTRS)

    Matteson, J. L.; Teegarden, B. J.; Gehrels, N.; Mahoney, W. A.

    1989-01-01

    The Nuclear Astrophysics Explorer was proposed in 1986 for NASA's Explorer Concept Study Program by an international collaboration of 25 scientists from nine institutions. The one-year feasibility study began in June 1988. The Nuclear Astrophysics Explorer would obtain high resolution observations of gamma-ray lines, E/Delta E about 1000, at a sensitivity of about 0.000003 ph/sq cm s, in order to study fundamental problems in astrophysics such as nucleosynthesis, supernovae, neutron star and black-hole physics, and particle acceleration and interactions. The instrument would operate from 15 keV to 10 Mev and use a heavily shielded array of nine cooled Ge spectrometers in a very low background configuration. Its 10 deg FWHM field of view would contain a versatile coded mask system which would provide two-dimensional imaging with 4 deg resolution, one-dimensional imaging with 2 deg resolution, and efficiendt measurements of diffuse emission. An unshielded Ge spectrometer would obtain wide-field measurements of transient gamma-ray sources. The earliest possible mission would begin in 1995.

  11. CASPAR - Nuclear Astrophysics Underground

    NASA Astrophysics Data System (ADS)

    Strieder, Frank; Robertson, Daniel; Couder, Manoel; Greife, Uwe; Wells, Doug; Wiescher, Michael

    2015-10-01

    The work of the LUNA Collaboration at the Laboratori Nationali del Gran Sasso demonstrated the research potential of an underground accelerator for the field of nuclear astrophysics. Several key reactions could be studied at LUNA, some directly at the Gamow peak for solar hydrogen burning. The CASPAR (Compact Accelerator System for Performing Astrophysical Research) Collaboration will implement a high intensity 1 MV accelerator at the Sanford Underground Research Facility (SURF) and overcome the current limitation at LUNA. The installation of the accelerator in the recently rehabilitated underground cavity at SURF started in Summer 2015 and first beam should be delivered by the end of the year. This project will primarily focus on the neutron sources for the s-process, e.g. 13C(α , n) 16O and 22Ne(α , n) 25Mg , and lead to unprecedented measurements compared to previous studies. A detailed overview of the science goals of CASPAR will be presented.

  12. The Array for Nuclear Astrophysics Studies with Exotic Nuclei (anasen)

    NASA Astrophysics Data System (ADS)

    Matos, M.; Blackmon, J. C.; Gardiner, H. E.; Linhardt, L. E.; Macon, K. T.; Mondello, L. L.; Baby, L.; Johnson, E.; Koshchiy, E.; Rogachev, G.; Wiedenhöver, I.; Bardayan, D. W.

    2013-03-01

    Experimental information about most reactions involving short-lived nuclei is limited. New facilities aim to provide wider access to unstable isotopes, but the limited intensities require more efficient and selective techniques and devices. The Array for Nuclear Astrophysics Studies with Exotic Nuclei (ANASEN) is a charged-particle detector array designed primarily for studies of reactions important in the αp- and rp- processes with proton-rich exotic nuclei. The array consists of 40 silicon-strip detectors backed with CsI scintillators. The detectors cover an area of about 1300 cm2 providing essentially complete solid angle coverage for the reactions of interest with good energy and position resolution. ANASEN also includes a position-sensitive annular gas proportional counter that allows it to be used as an active gas target/detector. ANASEN is designed for direct measurement of (α,p) re-actions in inverse kinematics as well as for studies of proton elastic and inelastic scattering, (p, γ) reactions and transfer reactions. The array is being developed by Louisiana State University and Florida State University. Presently it is located at the RESOLUT radioacitve ion beam facility at FSU, where the first experiments are being performed. In the future, the array will be used at the ReA3 facility at the National Superconducting Cyclotron Laboratory.

  13. Nuclear physics and astrophysics

    SciTech Connect

    Schramm, D.N.; Olinto, A.V.

    1992-09-01

    We have investigated a variety of research topics on the interface of nuclear physics and astrophysics during the past year. We have continued our study of dihyperon states in dense matter and have started to make a connection between their properties in the core of neutron stars with the ongoing experimental searches at Brookhaven National Laboratory. We started to build a scenario for the origin of gamma-ray bursts using the conversion of neutron stars to strange stars close to an active galactic nucleous. We have been reconsidering the constraints due to neutron star cooling rates on the equation of state for high density matter in the light, of recent findings which show that the faster direct Urca cooling process is possible for a range of nuclear compositions. We have developed a model for the formation of primordial magnetic fields due to the dynamics of the quark-hadron phase transition. Encouraged by the most recent observational developments, we have investigated the possible origin of the boron and beryllium abundances. We have greatly improved the calculations of the primordial abundances of these elements I>y augmenting the reaction networks and by updating the most recent experimental nuclear reaction rates. Our calculations have shown that the primordial abundances are much higher than previously thought but that the observed abundances cannot be explained by primordial sources alone. We have also studied the origin of the boron and beryllium abundances due to cosmic ray spallation. Finally, we have continued to address the solar neutrino problem by investigating the impact of astrophysical uncertainties on the MSW solution for a full three-family treatment of MSW mixing.

  14. The Nuclear Astrophysics Explorer

    NASA Technical Reports Server (NTRS)

    Matteson, James L.; Teegarden, B. J.; Gehrels, Neil; Mahoney, William A.

    1990-01-01

    The Nuclear Astrophysics Explorer (NAE) is a concept for a possible future NASA Explorer mission which would obtain high resolution, E/Delta E about 500, observations of gamma-ray lines in order to study many fundamental problems in astrophysics. It operates from 15 keV to 10 MeV with a 3-sigma sensitivity of about 3 x 10 to the -6th ph/sq cm-s in a 10 to the 6th s observation. This is 100 times below the presently known gamma-ray line fluxes. The NAE uses a heavily shielded array of nine cooled Ge detectors in a very low background configuration. Its 10-deg field of view contains a versatile coded mask system which provides 2D imaging with 4-deg resolution, 1D imaging with 2-deg resolution and efficient measurements of emission from diffuse and point sources. The late 1990s is the earliest the NAE mission could begin. The scientific motivation, instrument concept, mission concept and expected results, and status and plans for the NAE are presented.

  15. Studies on Nuclear Astrophysics and Exotic Structure at the Low-Energy RI Beam Facility CRIB

    NASA Astrophysics Data System (ADS)

    Yamaguchi, H.; Kahl, D.; Hayakawa, S.; Sakaguchi, Y.; Nakao, T.; Wakabayashi, Y.; Hashimoto, T.; Teranishi, T.; Kubono, S.; Cherubini, S.; Mazzocco, M.; Signorini, C.; Gulino, M.; Di Pietro, A.; Figuera, P.; La Cognata, M.; Lattuada, M.; Spitaleri, C.; Torresi, D.; Lee, P. S.; Lee, C. S.; Komatsubara, T.; Iwasa, N.; Okoda, Y.; Pierroutsakou, D.; Parascandolo, C.; La Commara, M.; Strano, E.; Boiano, C.; Boiano, A.; Manea, C.; Sánchez-Benítez, A. M.; Miyatake, H.; Watanabe, Y. X.; Ishiyama, H.; Jeong, S. C.; Imai, N.; Hirayama, Y.; Kimura, S.; Mukai, M.; Kim, Y. H.; Lin, C. J.; Jia, H. M.; Yan, L.; Yang, Y. Y.; Kawabata, T.; Kwon, Y. K.; Binh, D. N.; Khiem, L. H.; Duy, N. N.

    Studies on nuclear astrophysics, resonant structure, and nuclear reaction are going on at CRIB (CNS Radioactive Ion Beam separator), a low-energy RI beam separator operated by Center for Nuclear Study (CNS), the University of Tokyo. Two major methods used at CRIB to study nuclear reactions of astrophysical relevance are the resonant scattering, and direct measurements of (α,p) reactions using a thick-gas target. Several experiments for decay measurements and reaction mechanism are also performed using low-energy RI beams at CRIB. Some of the results from recent experiments at CRIB are discussed.

  16. Activation Experiments for Nuclear Astrophysics

    SciTech Connect

    Sonnabend, K.; Mueller, S.; Pietralla, N.; Savran, D.; Schnorrenberger, L.; Hasper, J.; Zilges, A.

    2009-01-28

    The study of ({gamma},n) reactions can be used to constrain the theoretical predictions of the neutron capture cross sections of short-lived branching points in the s process. The usability of the activation technique to study these ({gamma},n) reactions is discussed as one example of an activation experiment in nuclear astrophysics. Two photon sources using bremsstrahlung and laser-Compton backscattered photons where such experiments were carried out are compared.

  17. Nuclear Astrophysics and Structure Studies Using Low-energy RI Beams at CRIB

    SciTech Connect

    Yamaguchi, H.; Hashimoto, T.; Hayakawa, S.; Binh, D. N.; Kahl, D.; Kubono, S.

    2010-05-12

    CRIB (CNS Radioactive Ion Beam separator) is a low-energy RI beam separator at the Center for Nuclear Study (CNS) of the University of Tokyo. Using the RI beams at CRIB, Many measurements on proton and alpha resonance scatterings, (alpha,p) reactions, and others were peformed in recent years, mainly for studying astrophysical reactions and exotic nuclear structure. Among them, the results on the {sup 7}Be+p and {sup 7}Li+alpha resonance scatterings are presented.

  18. Nuclear and particle astrophysics

    SciTech Connect

    Glendenning, N.K.

    1990-10-31

    We discuss the physics of matter that is relevant to the structure of compact stars. This includes nuclear, neutron star matter and quark matter and phase transitions between them. Many aspects of neutron star structure and its dependance on a number of physical assumptions about nuclear matter properties and hyperon couplings are investigated. We also discuss the prospects for obtaining constraints on the equation of state from astrophysical sources. Neuron star masses although few are known at present, provide a very direct constraint in as much as the connection to the equation of state involves only the assumption that Einstein's general of theory of relativity is correct at the macroscopic scale. Supernovae simulations involve such a plethora of physical processes including those involved in the evolution of the precollapse configuration, not all of them known or understood, that they provide no constraint at the present time. Indeed the prompt explosion, from which a constraint had been thought to follow, is now believed not to be mechanism by which most, if any stars, explode. In any case the nuclear equation of state is but one of a multitude on uncertain factors, and possibly one of the least important. The rapid rotation of pulsars is also discussed. It is shown that for periods below a certain limit it becomes increasingly difficult to reconcile them with neutron stars. Strange stars are possible if strange matter is the absolute ground state. We discuss such stars and their compatibility with observation. 112 refs., 37 figs., 6 tabs.

  19. The CASPAR underground accelerator facility for the study of low energy nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Robertson, Daniel; Couder, Manoel; Greife, Uwe; Strieder, Frank; Wiescher, Michael

    2016-09-01

    The drive of nuclear astrophysics is to push the limits of reaction measurements into the burning regime of astrophysical interest. As current laboratory experiments approach the stellar burning window, the rapid drop off of cross-sections is a significant barrier and drives the need for higher intensity accelerators, more robust and isotopically enriched target material and lower background interference. The natural background suppression of underground accelerator facilities enables the extension of current experimental data to the lower energies needed. The CASPAR facility is the first and only underground accelerator facility in the US, focused on the study of low energy reactions of nuclear astrophysical interest. Support provided by NSF Grant No. PHY 1419765, JINA-CEE Grant No. PHY 1430152 and the South Dakota Science and Technology Authority.

  20. Underground Nuclear Astrophysics in China

    NASA Astrophysics Data System (ADS)

    Liu, Weiping

    2016-10-01

    Underground Nuclear Astrophysics in China (JUNA) will take the advantage of the ultra-low background in Jinping underground lab. High current accelerator with an ECR source and detectors will be set up. We plan to study directly a number of nuclear reactions important to hydrostatic stellar evolution at their relevant stellar energies, such as 25Mg(p,γ)26Al, 19F(p,α)16O, 13C(α,n)16O and 12C(α,γ)16O.

  1. The Promise of Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Fuller, George

    2015-10-01

    The field of nuclear astrophysics stands at the intersection of some of the most exciting thrusts in nuclear theory and experiment, many-body physics, neutrino and particle physics, gravitation and astronomy. In fact, key facilities like FRIB for studying nuclear properties and reactions, JLAB and RHIC for uncovering fundamental aspects of QCD, and a variety of neutrino experiments are poised to leverage the fruits of a coming expansion of observational astrophysics capabilities. This will allow unprecedented insights into grand questions: Where do the nuclei come from?; How did the structures we see form?; What can the extreme conditions of the early universe, massive stars and violent stellar collapse/explosion and compact object mergers tell us about the nature of strongly interacting matter and neutrino physics?; What is the nature of Dark Matter? I will argue here that the advent of 30m-class optical telescopes, high precision cosmic microwave background polarization experiments, next generation orbiting X-ray and gamma-ray observatories, and gravitational wave astronomy (e.g., Advanced LIGO observations of compact object in-spiral events), combined with advances in nuclear theory and experiment, promises an intriguing future. (I would like to acknowledgement support from NSF, the University of California, LANL and DOE)

  2. Nuclear Astrophysical studies using low-energy RI beams at CRIB

    SciTech Connect

    Yamaguchi, H.; Wakabayashi, Y.; Hayakawa, S.; Binh, D. N.; Kahl, D.; Kurihara, Y.; Kubono, S.; Niikura, M.; Teranishi, T.; He, J. J.; Kwon, Y. K.; Nishimura, S.; Togano, Y.; Iwasa, N.; Khiem, L. H.

    2009-05-04

    CRIB (CNS Radioactive Ion Beam separator) is a low-energy RI beam separator at the Center for Nuclear Study (CNS) of the University of Tokyo, used for various studies covering nuclear-astrophysical topics. An application of the RI beam at CRIB for the astrophysical studies is a new measurement of the proton resonance scattering on {sup 7}Be. The measurement was performed up to the excitation energy of 6.8 MeV, ans the excitation function above 3.5 MeV was successfully measured for the first time, providing important information about the reaction rate of {sup 7}Be(p,{gamma}){sup 8}B, which is the key reaction in the solar {sup 8}B neutrino production. A preliminary result of the {sup 7}Be+p experiment is presented.

  3. A new low-energy radioactive beam line for nuclear astrophysics studies in China

    NASA Astrophysics Data System (ADS)

    He, J. J.; Xu, S. W.; Ma, P.; Wang, J. S.; Yang, Y. Y.; Ma, J. B.; Zhang, L. Y.; Li, L.; Yu, X. Q.; Jin, S. L.; Hu, J.; Kubono, S.; Chen, S. Z.; Zhang, N. T.; Liu, M. L.; Lei, X. G.; Sun, Z. Y.; Zhang, Y. H.; Zhou, X. H.; Xu, H. S.; Xiao, G. Q.

    2012-07-01

    A gas-target system has been newly developed and installed at a Radioactive Ion Beam Line in Lanzhou (RIBLL), which makes RIBLL capable of delivering intense, low-energy RIBs for nuclear astrophysics studies. A 1.7×104-pps intensity 22Na RI beam has been achieved in a commissioning run. With further improvements, a 105-pps intensity of some RI beams with mass A<30 (close to the line of β-stability) can be expected in the near future. Some detection equipment including Germanium and Silicon arrays (or balls) available (or to be constructed) at IMP are briefly introduced. A new low-energy radioactive beam line in China is now ready for nuclear astrophysics studies.

  4. Advances in instrumentation for nuclear astrophysics

    SciTech Connect

    Pain, S. D.

    2014-04-15

    The study of the nuclear physics properties which govern energy generation and nucleosynthesis in the astrophysical phenomena we observe in the universe is crucial to understanding how these objects behave and how the chemical history of the universe evolved to its present state. The low cross sections and short nuclear lifetimes involved in many of these reactions make their experimental determination challenging, requiring developments in beams and instrumentation. A selection of developments in nuclear astrophysics instrumentation is discussed, using as examples projects involving the nuclear astrophysics group at Oak Ridge National Laboratory. These developments will be key to the instrumentation necessary to fully exploit nuclear astrophysics opportunities at the Facility for Rare Isotope Beams which is currently under construction.

  5. Nuclear astrophysics and electron beams

    SciTech Connect

    Schwenk, A.

    2013-11-07

    Electron beams provide important probes and constraints for nuclear astrophysics. This is especially exciting at energies within the regime of chiral effective field theory (EFT), which provides a systematic expansion for nuclear forces and electroweak operators based on quantum chromodynamics. This talk discusses some recent highlights and future directions based on chiral EFT, including nuclear structure and reactions for astrophysics, the neutron skin and constraints for the properties of neutron-rich matter in neutron stars and core-collapse supernovae, and the dark matter response of nuclei.

  6. Nuclear astrophysics at DRAGON

    SciTech Connect

    Hager, U.

    2014-05-02

    The DRAGON recoil separator is located at the ISAC facility at TRIUMF, Vancouver. It is designed to measure radiative alpha and proton capture reactions of astrophysical importance. Over the last years, the DRAGON collaboration has measured several reactions using both radioactive and high-intensity stable beams. For example, the 160(a, g) cross section was recently measured. The reaction plays a role in steady-state helium burning in massive stars, where it follows the 12C(a, g) reaction. At astrophysically relevant energies, the reaction proceeds exclusively via direct capture, resulting in a low rate. In this measurement, the unique capabilities of DRAGON enabled determination not only of the total reaction rates, but also of decay branching ratios. In addition, results from other recent measurements will be presented.

  7. Nuclear astrophysics lessons from INTEGRAL.

    PubMed

    Diehl, Roland

    2013-02-01

    Measurements of high-energy photons from cosmic sources of nuclear radiation through ESA's INTEGRAL mission have advanced our knowledge: new data with high spectral resolution showed that characteristic gamma-ray lines from radioactive decays occur throughout the Galaxy in its interstellar medium. Although the number of detected sources and often the significance of the astrophysical results remain modest, conclusions derived from this unique astronomical window of radiation originating from nuclear processes are important, complementing the widely-employed atomic-line based spectroscopy. We review the results and insights obtained in the past decade from gamma-ray line measurements of cosmic sources in the context of their astrophysical questions.

  8. Computational Infrastructure for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Smith, M. S.; Lingerfelt, E. J.; Scott, J. P.; Nesaraja, C. D.; Hix, W. R.; Bardayan, D. W.; Blackmon, J. C.; Chae, K.; Guidry, M. W.; Hard, C. C.; Sharp, J. E.; Kozub, R. L.; Meyer, R. A.

    2004-12-01

    The Computational Infrastructure for Nuclear Astrophysics is a platform-independent, online suite of computer codes developed by the ORNL Nuclear Data Project that makes a rapid connection between laboratory nuclear physics results and astrophysical models. It enables users to evaluate cross sections, process them into thermonuclear reaction rates, and parameterize (with a few percent accuracy) these rates that vary by up to 30 orders of magnitude over the temperatures of interest. Users can then properly format these rates for input into astrophysical computer simulations, create and manipulate libraries of rates, as well as run and visualize sample post-processing nucleosynthesis calculations. For example, we have developed animated nuclide charts that show how predicted abundances (represented by a user-defined color scale) change in time. With this unique suite, users can within a very short time quantify the astrophysical impact of a newly measured or calculated cross section, or a newly created customized reaction rate library, and then document and share their results with the scientific community. The suite has a straightforward interface with a "Windows Wizard" motif whereby users progress through complicated calculations in a step-by-step fashion. Users can upload their own files for processing and save their work on our server, as well as work with files that other users wish to share. These tools are currently being used to investigate novae and X-ray bursts. The suite is available through nucastrodata.org, a website that also hyperlinks available nuclear data sets relevant for nuclear astrophysics research. New features are continually being added to this software, which is funded by the U.S. Department of Energy Low Energy Nuclear Physics and Nuclear Data Programs. ORNL is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.

  9. Advances IN Explosive Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Lotay, Gavin

    2016-09-01

    Breathtaking results from the Planck satellite mission and Hubble space telescope have highlighted the key role modern Astronomy is playing for our understanding of Big Bang Cosmology. However, not so widely publicized is the similar wealth of observational data now available on explosive stellar phenomena, such as X-ray bursts, novae and Supernovae. These astronomical events are responsible for the synthesis of almost all the chemical elements we find on Earth and observe in our Galaxy, as well as energy generation throughout the cosmos. Regrettably, understanding the latest collection of observational data is severely hindered by the current, large uncertainties in the underlying nuclear physics processes that drive such stellar scenarios. In order to resolve this issue, it is becoming increasingly clear that there is a need to explore the unknown properties and reactions of nuclei away from the line of stability. Consequently, state-of-the-art radioactive beam facilities have become terrestrial laboratories for the reproduction of explosive astrophysical events. In this talk, both direct and indirect methods for studying key astrophysical reactions using radioactive beams will be discussed.

  10. Indirect methods in nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Bertulani, C. A.; Shubhchintak; Mukhamedzhanov, A.; Kadyrov, A. S.; Kruppa, A.; Pang, D. Y.

    2016-04-01

    We discuss recent developments in indirect methods used in nuclear astrophysics to determine the capture cross sections and subsequent rates of various stellar burning processes, when it is difficult to perform the corresponding direct measurements. We discuss in brief, the basic concepts of Asymptotic Normalization Coefficients, the Trojan Horse Method, the Coulomb Dissociation Method, (d,p), and charge-exchange reactions.

  11. Nuclear Clusters in Astrophysics

    NASA Astrophysics Data System (ADS)

    Kubono, S.; Binh, Dam N.; Hayakawa, S.; Hashimoto, H.; Kahl, D.; Wakabayashi, Y.; Yamaguchi, H.; Teranishi, T.; Iwasa, N.; Komatsubara, T.; Kato, S.; Khiem, Le H.

    2010-03-01

    The role of nuclear clustering is discussed for nucleosynthesis in stellar evolution with Cluster Nucleosynthesis Diagram (CND) proposed before. Special emphasis is placed on α-induced stellar reactions together with molecular states for O and C burning.

  12. Transfer reactions in nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Bardayan, D. W.

    2016-08-01

    To a high degree many aspects of the large-scale behavior of objects in the Universe are governed by the underlying nuclear physics. In fact the shell structure of nuclear physics is directly imprinted into the chemical abundances of the elements. The tranquility of the night sky is a direct result of the relatively slow rate of nuclear reactions that control and determines a star’s fate. Understanding the nuclear structure and reaction rates between nuclei is vital to understanding our Universe. Nuclear-transfer reactions make accessible a wealth of knowledge from which we can extract much of the required nuclear physics information. A review of transfer reactions for nuclear astrophysics is presented with an emphasis on the experimental challenges and opportunities for future development.

  13. Development of an inertial confinement fusion platform to study charged-particle-producing nuclear reactions relevant to nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Gatu Johnson, M.; Zylstra, A. B.; Bacher, A.; Brune, C. R.; Casey, D. T.; Forrest, C.; Herrmann, H. W.; Hohenberger, M.; Sayre, D. B.; Bionta, R. M.; Bourgade, J.-L.; Caggiano, J. A.; Cerjan, C.; Craxton, R. S.; Dearborn, D.; Farrell, M.; Frenje, J. A.; Garcia, E. M.; Glebov, V. Yu.; Hale, G.; Hartouni, E. P.; Hatarik, R.; Hohensee, M.; Holunga, D. M.; Hoppe, M.; Janezic, R.; Khan, S. F.; Kilkenny, J. D.; Kim, Y. H.; Knauer, J. P.; Kohut, T. R.; Lahmann, B.; Landoas, O.; Li, C. K.; Marshall, F. J.; Masse, L.; McEvoy, A.; McKenty, P.; McNabb, D. P.; Nikroo, A.; Parham, T. G.; Paris, M.; Petrasso, R. D.; Pino, J.; Radha, P. B.; Remington, B.; Rinderknecht, H. G.; Robey, H.; Rosenberg, M. J.; Rosse, B.; Rubery, M.; Sangster, T. C.; Sanchez, J.; Schmitt, M.; Schoff, M.; Séguin, F. H.; Seka, W.; Sio, H.; Stoeckl, C.; Tipton, R. E.

    2017-04-01

    This paper describes the development of a platform to study astrophysically relevant nuclear reactions using inertial-confinement fusion implosions on the OMEGA and National Ignition Facility laser facilities, with a particular focus on optimizing the implosions to study charged-particle-producing reactions. Primary requirements on the platform are high yield, for high statistics in the fusion product measurements, combined with low areal density, to allow the charged fusion products to escape. This is optimally achieved with direct-drive exploding pusher implosions using thin-glass-shell capsules. Mitigation strategies to eliminate a possible target sheath potential which would accelerate the emitted ions are discussed. The potential impact of kinetic effects on the implosions is also considered. The platform is initially employed to study the complementary T(t,2n)α, T(3He,np)α and 3He(3He,2p)α reactions. Proof-of-principle results from the first experiments demonstrating the ability to accurately measure the energy and yields of charged particles are presented. Lessons learned from these experiments will be used in studies of other reactions. The goals are to explore thermonuclear reaction rates and fundamental nuclear physics in stellar-like plasma environments, and to push this new frontier of nuclear astrophysics into unique regimes not reachable through existing platforms, with thermal ion velocity distributions, plasma screening, and low reactant energies.

  14. Development of an inertial confinement fusion platform to study charged-particle-producing nuclear reactions relevant to nuclear astrophysics

    DOE PAGES

    Gatu Johnson, M.; Zylstra, A. B.; Bacher, A.; ...

    2017-03-28

    Here, this paper describes the development of a platform to study astrophysically relevant nuclear reactions using inertial-confinement fusion implosions on the OMEGA and National Ignition Facility laser facilities, with a particular focus on optimizing the implosions to study charged-particle- producing reactions. Primary requirements on the platform are high yield, for high statistics in the fusion product measurements, combined with low areal density, to allow the charged fusion products to escape. This is optimally achieved with direct-drive exploding pusher implosions using thin-glass-shell capsules. Mitigation strategies to eliminate a possible target sheath potential which would accelerate the emitted ions are discussed. Themore » potential impact of kinetic effects on the implosions is also considered. The platform is initially employed to study the complementary T(t,2n)α, T(3He,np)α and 3He(3He,2p)α reactions. Proof-of-principle results from the first experiments demonstrating the ability to accurately measure the energy and yields of charged particles are presented. Lessons learned from these experiments will be used in studies of other reactions. Ultimately, the goals are to explore thermonuclear reaction rates and fundamental nuclear physics in stellarlike plasma environments, and to push this new frontier of nuclear astrophysics into unique regimes not reachable through existing platforms, with thermal ion velocity distributions, plasma screening, and low reactant energies.« less

  15. Nuclear Astrophysics Studies with the Method of Continuum-Discretized Coupled-Channels

    SciTech Connect

    Ogata, K.; Yahiro, M.; Hashimoto, S.; Iseri, Y.; Kan, M.; Kamimura, M.

    2010-05-12

    The method of continuum-discretized coupled-channels (CDCC) is applied to two nuclear astrophysics studies. One is the determination of the astrophysical factor S{sub 17}(0) for the {sup 7}Be(p,gamma){sup 8}B reaction from the analysis of {sup 8}B breakup by {sup 208}Pb at 52 A MeV. We obtain S{sub 17}(0) = 20.9{sub -1.9}{sup +2.0} eV b, which is significantly larger than the previous one, S{sub 17}(0) = 18.9+-1.8 eV b, determined from an analysis with the virtual photon theory. The difference between the two values is found to be due to the contributions from nuclear breakup and higher-order processes. The other application of CDCC is the re-evaluation of the triple-alpha reaction rate by directly solving the three-body Schroedinger equation. The resonant and nonresonant processes are treated on the same footing. An accurate description of the alpha-alpha nonresonant states significantly quenches the Coulomb barrier between the first two alpha-particles and the third alpha-particle. Consequently, the alpha-alpha nonresonant continuum states give a markedly larger contribution at low temperatures than that reported in previous studies. We find an increase in triple-alpha reaction rate by 26 orders of magnitude around 10{sup 7} K compared with the rate of NACRE.

  16. Nuclear Astrophysics at DANCE

    SciTech Connect

    Reifarth, R.; Bredeweg, T.A.; Esch, E.-I.; Haight, R.C.; Kronenberg, A.; O'Donnell, J.M.; Rundberg, R.S.; Schwantes, J.M.; Ullmann, J.L.; Vieira, D.J.; Wouters, J.M.; Alpizar-Vicente, A.; Hatarik, R.; Greife, U.

    2005-05-24

    One of the most interesting nuclear physics challenges is obtaining a detailed understanding of the nucleosynthesis processes of the elements. Knowledge about the stellar sites, and how they are governed by stellar evolution and cosmology are crucial in understanding the overall picture. Information on reaction rates for neutron- and charged-particle-induced reactions have a direct impact on existing stellar models. Except for the stable isotopes, very few neutron-induced reactions in the energy range of interest have been measured to date. DANCE measurements on stable and unstable isotopes will provide many of the missing key reactions that are needed to understand the nucleosynthesis of the heavy elements.

  17. Nuclear astrophysics of supernovae

    SciTech Connect

    Cooperstein, J.

    1988-01-01

    In this paper, I'll give a general introduction to Supernova Theory, beginning with the presupernova evolution and ending with the later stages of the explosion. This will be distilled from a colloquium type of talk. It is necessary to have the whole supernova picture in one's mind's eye when diving into some of its nooks and crannies, as it is quite a mess of contradictory ingredients. We will have some discussion of supernova 1987a, but will keep our discussion more general. Second, we'll look at the infall and bounce of the star, seeing why it goes unstable, what dynamics it follows as it collapses, and how and why it bounces back. From there, we will go on to look at the equation of state (EOS) in more detail. We'll consider the cases T = 0 and T > 0. We'll focus on /rho/ < /rho//sub 0/, and then /rho/ > /rho//sub 0/ and the EOS of neutron stars, and whether or not they contain cores of strange matter. There are many things we could discuss here and not enough time. If I had more lectures, the remaining time would focus on two more questions of special interest to nuclear physicists: the electron capture reactions and neutrino transport. If time permitted, we'd have some discussion of the nucleosynthetic reactions in the explosion's debris as well. However, we cannot cover such material adequately, and I have chosen these topics because they are analytically tractable, pedagogically useful, and rather important. 23 refs., 14 figs., 3 tabs.

  18. A Deuterated Neutron Detector Array For Nuclear (Astro)Physics Studies

    NASA Astrophysics Data System (ADS)

    Almaraz-Calderon, Sergio; Asher, B. W.; Barber, P.; Hanselman, K.; Perello, J. F.

    2016-09-01

    The properties of neutron-rich nuclei are at the forefront of research in nuclear structure, nuclear reactions and nuclear astrophysics. The advent of intense rare isotope beams (RIBs) has opened a new door for studies of systems with very short half-lives and possible fascinating properties. Neutron spectroscopic techniques become increasingly relevant when these neutron rich nuclei are used in a variety of experiments. At Florida State University, we are developing a neutron detector array that will allow us to perform high-resolution neutron spectroscopic studies with stable and radioactive beams. The neutron detection system consists of 16 deuterated organic liquid scintillation detectors with fast response and pulse-shape discrimination capabilities. In addition to these properties, there is the potential to use the structure in the pulse-height spectra to extract the energy of the neutrons and thus produce directly excitation spectra. This type of detector uses deuterated benzene (C6D6) as the liquid scintillation medium. The asymmetric nature of the scattering between a neutron and a deuterium in the center of mass produces a pulse-height spectrum from the deuterated scintillator which contains useful information on the initial energy of the neutron. Work supported in part by the State of Florida and NSF Grant No. 1401574.

  19. Future of Nuclear Data for Astrophysics

    SciTech Connect

    Smith, Michael Scott

    2005-01-01

    Nuclear astrophysics is an exciting growth area in nuclear science. Because of the enormous nuclear data needs of this field, it has an exciting potential to boost nuclear data activities in the twenty-first century. Furthermore, the tremendous interest of the general public in astrophysics makes this area of work an excellent vehicle for wide exposure of nuclear data activities. Unfortunately, decreasing data evaluation manpower, the difficulty of processing nuclear data into formats compatible with astrophysical models, and a lack of a coherent future plan have brought about a crisis in nuclear data for nuclear astrophysics. It is imperative to take action now before the situation worsens - especially before new future facilities begin operation. A number of specific actions are proposed to help ensure that nuclear data is rapidly incorporated into astrophysical models in the future.

  20. White Paper on Nuclear Astrophysics and Low Energy Nuclear Physics - Part 1. Nuclear Astrophysics

    SciTech Connect

    Arcones, Almudena; Escher, Jutta E.; Others, M.

    2016-04-04

    This white paper informs the nuclear astrophysics community and funding agencies about the scientific directions and priorities of the field and provides input from this community for the 2015 Nuclear Science Long Range Plan. It summarizes the outcome of the nuclear astrophysics town meeting that was held on August 21 - 23, 2014 in College Station at the campus of Texas A&M University in preparation of the NSAC Nuclear Science Long Range Plan. It also reflects the outcome of an earlier town meeting of the nuclear astrophysics community organized by the Joint Institute for Nuclear Astrophysics (JINA) on October 9 - 10, 2012 Detroit, Michigan, with the purpose of developing a vision for nuclear astrophysics in light of the recent NRC decadal surveys in nuclear physics (NP2010) and astronomy (ASTRO2010). The white paper is furthermore informed by the town meeting of the Association of Research at University Nuclear Accelerators (ARUNA) that took place at the University of Notre Dame on June 12 - 13, 2014. In summary we find that nuclear astrophysics is a modern and vibrant field addressing fundamental science questions at the intersection of nuclear physics and astrophysics. These questions relate to the origin of the elements, the nuclear engines that drive life and death of stars, and the properties of dense matter. A broad range of nuclear accelerator facilities, astronomical observatories, theory efforts, and computational capabilities are needed. With the developments outlined in this white paper, answers to long-standing key questions are well within reach in the coming decade.

  1. Nuclear Astrophysics at LNL: The 10B(p, α )7Be Reaction Studied at the AN2000 Accelerator

    NASA Astrophysics Data System (ADS)

    Caciolli, Antonio

    The National Laboratory of Legnaro (LNL) has a wealth of experience in Nuclear Physics measurements. Recently a new effort to perform Nuclear Astrophysics studies has been initiated. This effort started with the collaboration of LNL with the LUNA (Laboratory for Underground Nuclear Astrophysics) collaboration for the study of targets. In 2014 the study of 10B(p, α )7Be was performed in order to give a precise normalisation to the indirect measurements. As a matter of fact, a normalization problem was raised in previous works due to discrepancies in the results of different experimental datasets. At LNL the cross section was determined by measuring the activated samples at the low counting facility of the LNL laboratory. The analysis of that experiment is now complete and a detailed report of the obtained results will be presented in this contribution.

  2. White paper on nuclear astrophysics and low energy nuclear physics Part 1: Nuclear astrophysics

    DOE PAGES

    Arcones, Almudena; Bardayan, Dan W.; Beers, Timothy C.; ...

    2016-12-28

    This white paper informs the nuclear astrophysics community and funding agencies about the scientific directions and priorities of the field and provides input from this community for the 2015 Nuclear Science Long Range Plan. It also summarizes the outcome of the nuclear astrophysics town meeting that was held on August 21–23, 2014 in College Station at the campus of Texas A&M University in preparation of the NSAC Nuclear Science Long Range Plan. It also reflects the outcome of an earlier town meeting of the nuclear astrophysics community organized by the Joint Institute for Nuclear Astrophysics (JINA) on October 9–10, 2012more » Detroit, Michigan, with the purpose of developing a vision for nuclear astrophysics in light of the recent NRC decadal surveys in nuclear physics (NP2010) and astronomy (ASTRO2010). Our white paper is informed informed by the town meeting of the Association of Research at University Nuclear Accelerators (ARUNA) that took place at the University of Notre Dame on June 12–13, 2014. In summary we find that nuclear astrophysics is a modern and vibrant field addressing fundamental science questions at the intersection of nuclear physics and astrophysics. These questions relate to the origin of the elements, the nuclear engines that drive life and death of stars, and the properties of dense matter. A broad range of nuclear accelerator facilities, astronomical observatories, theory efforts, and computational capabilities are needed. Answers to long standing key questions are well within reach in the coming decade because of the developments outlined in this white paper.« less

  3. White paper on nuclear astrophysics and low energy nuclear physics Part 1: Nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Arcones, Almudena; Bardayan, Dan W.; Beers, Timothy C.; Bernstein, Lee A.; Blackmon, Jeffrey C.; Messer, Bronson; Brown, B. Alex; Brown, Edward F.; Brune, Carl R.; Champagne, Art E.; Chieffi, Alessandro; Couture, Aaron J.; Danielewicz, Pawel; Diehl, Roland; El-Eid, Mounib; Escher, Jutta E.; Fields, Brian D.; Fröhlich, Carla; Herwig, Falk; Hix, William Raphael; Iliadis, Christian; Lynch, William G.; McLaughlin, Gail C.; Meyer, Bradley S.; Mezzacappa, Anthony; Nunes, Filomena; O'Shea, Brian W.; Prakash, Madappa; Pritychenko, Boris; Reddy, Sanjay; Rehm, Ernst; Rogachev, Grigory; Rutledge, Robert E.; Schatz, Hendrik; Smith, Michael S.; Stairs, Ingrid H.; Steiner, Andrew W.; Strohmayer, Tod E.; Timmes, F. X.; Townsley, Dean M.; Wiescher, Michael; Zegers, Remco G. T.; Zingale, Michael

    2017-05-01

    This white paper informs the nuclear astrophysics community and funding agencies about the scientific directions and priorities of the field and provides input from this community for the 2015 Nuclear Science Long Range Plan. It summarizes the outcome of the nuclear astrophysics town meeting that was held on August 21-23, 2014 in College Station at the campus of Texas A&M University in preparation of the NSAC Nuclear Science Long Range Plan. It also reflects the outcome of an earlier town meeting of the nuclear astrophysics community organized by the Joint Institute for Nuclear Astrophysics (JINA) on October 9-10, 2012 Detroit, Michigan, with the purpose of developing a vision for nuclear astrophysics in light of the recent NRC decadal surveys in nuclear physics (NP2010) and astronomy (ASTRO2010). The white paper is furthermore informed by the town meeting of the Association of Research at University Nuclear Accelerators (ARUNA) that took place at the University of Notre Dame on June 12-13, 2014. In summary we find that nuclear astrophysics is a modern and vibrant field addressing fundamental science questions at the intersection of nuclear physics and astrophysics. These questions relate to the origin of the elements, the nuclear engines that drive life and death of stars, and the properties of dense matter. A broad range of nuclear accelerator facilities, astronomical observatories, theory efforts, and computational capabilities are needed. With the developments outlined in this white paper, answers to long standing key questions are well within reach in the coming decade.

  4. White paper on nuclear astrophysics and low energy nuclear physics Part 1: Nuclear astrophysics

    SciTech Connect

    Arcones, Almudena; Bardayan, Dan W.; Beers, Timothy C.; Bernstein, Lee A.; Blackmon, Jeffrey C.; Messer, Bronson; Brown, B. Alex; Brown, Edward F.; Brune, Carl R.; Champagne, Art E.; Chieffi, Alessandro; Couture, Aaron J.; Danielewicz, Pawel; Diehl, Roland; El-Eid, Mounib; Escher, Jutta E.; Fields, Brian D.; Fröhlich, Carla; Herwig, Falk; Hix, William Raphael; Iliadis, Christian; Lynch, William G.; McLaughlin, Gail C.; Meyer, Bradley S.; Mezzacappa, Anthony; Nunes, Filomena; O’Shea, Brian W.; Prakash, Madappa; Pritychenko, Boris; Reddy, Sanjay; Rehm, Ernst; Rogachev, Grigory; Rutledge, Robert E.; Schatz, Hendrik; Smith, Michael S.; Stairs, Ingrid H.; Steiner, Andrew W.; Strohmayer, Tod E.; Townsley, Dean M.; Wiescher, Michael; Zegers, Remco G. T.; Zingale, Michael

    2016-12-28

    This white paper informs the nuclear astrophysics community and funding agencies about the scientific directions and priorities of the field and provides input from this community for the 2015 Nuclear Science Long Range Plan. It also summarizes the outcome of the nuclear astrophysics town meeting that was held on August 21–23, 2014 in College Station at the campus of Texas A&M University in preparation of the NSAC Nuclear Science Long Range Plan. It also reflects the outcome of an earlier town meeting of the nuclear astrophysics community organized by the Joint Institute for Nuclear Astrophysics (JINA) on October 9–10, 2012 Detroit, Michigan, with the purpose of developing a vision for nuclear astrophysics in light of the recent NRC decadal surveys in nuclear physics (NP2010) and astronomy (ASTRO2010). Our white paper is informed informed by the town meeting of the Association of Research at University Nuclear Accelerators (ARUNA) that took place at the University of Notre Dame on June 12–13, 2014. In summary we find that nuclear astrophysics is a modern and vibrant field addressing fundamental science questions at the intersection of nuclear physics and astrophysics. These questions relate to the origin of the elements, the nuclear engines that drive life and death of stars, and the properties of dense matter. A broad range of nuclear accelerator facilities, astronomical observatories, theory efforts, and computational capabilities are needed. Answers to long standing key questions are well within reach in the coming decade because of the developments outlined in this white paper.

  5. Underground Nuclear Astrophysics Experiment JUNA in China

    NASA Astrophysics Data System (ADS)

    Liu, W. P.

    Underground Nuclear Astrophysics Experiment in China (JUNA) will take the advantage of the ultra-low background in Jinping underground lab. A 400 kV high current accelerator with an ECR source and γ , neutron and charged particle detectors will be set up. We plan to study directly a number of nuclear reactions important to hydrostatic stellar evolution near their Gamow window energies such as 25Mg(p, γ )26Al, 19F(p, α )16O, 13C(α , n)16O, and 12C(α , γ )16O, by the end of 2019.

  6. FOREWORD: Nuclear Physics in Astrophysics V

    NASA Astrophysics Data System (ADS)

    Auerbach, Naftali; Hass, Michael; Paul, Michael

    2012-02-01

    the conference dinner banquet at the Dan hotel. An excursion to the 'Red Canyon' in the Eilat Mountains on Wednesday afternoon was one of the social highlights of the conference. A total number of 140 scientists attended NPA5 and about 30 accompanying persons; about 25% of these were young participants (less than 36 years old). 23 participants were from Israel, and 27 were from outside of Europe (including two from Africa). The subjects covered at the conference in Eilat concentrated mainly on the spirit of the original idea - to probe experimental and theoretical activity in nuclear structure and reactions that is directly related to the physics of the Universe. There were also sessions of general interest in astrophysics, as well as a poster session on Tuesday evening featuring 40 posters. The topics included: Nuclear Structure - Theory and Experiment Big-Bang Nucleosynthesis and Formation of First Stars Stellar Reactions and Solar Neutrinos Explosive Nucleosynthesis, Radioactive Beams and Exotic Nuclei-New Facilities and Future Possibilities for Astrophysics Neutrino Physics - the Low and High-Energy Frontiers Rare events, Dark Matter, Double beta-decay, Symmetries The conference started with an excellent exposé of the progress made in the discovery of super-heavy elements and the study of their properties. The progress in this field is enormous, and this subject should be communicated to more general audiences. The role of the nuclear equation of state and of the precise determination of nuclear masses in nucleosynthesis was emphasized in several talks. The role of neutrinos in astrophysics was discussed extensively in several sessions. One of the highlights of this was the presentation about the IceCube and DeepCore detectors operating deep in the Antarctic ice. These facilities are able to detect cosmogenic neutrinos in a wide energy range, from 10 GeV to 1010 GeV. The subject of solar neutrinos was discussed in a number of talks. Topics related to properties

  7. Underground Nuclear Astrophysics - from LUNA to CASPAR

    NASA Astrophysics Data System (ADS)

    Strieder, Frank; Caspar Collaboration

    2015-04-01

    It is in the nature of astrophysics that many of the processes and objects are physically inaccessible. Thus, it is important that those aspects that can be studied in the laboratory are well understood. Nuclear reactions are such quantities that can be partly measured in the laboratory. These reactions influence the nucleosynthesis of the elements in the Big Bang as well as in all objects formed thereafter, and control the associated energy generation and evolution of stars. Since 20 years LUNA (Laboratory for Underground Nuclear Astrophysics) has been measuring cross sections relevant for hydrogen burning in the Gran Sasso Laboratory and demonstrated the research potential of an underground accelerator facility. Unfortunately, the number of reactions is limited by the energy range accessible with the 400 kV LUNA accelerator. The CASPAR (Compact Accelerator System for Performing Astrophysical Research) Collaboration will implement a high intensity 1 MV accelerator at the Sanford Underground Research Facility (SURF) and overcome the current limitation at LUNA. This project will primarily focus on the neutron sources for the so-called s-process, e.g. 13 C(α , n) 16 O and 22 Ne(α , n) 25 Mg , and lead to unprecedented measurements compared to previous studies.

  8. Fundamental Interactions, Nuclear Masses, Astrophysics, and QCD

    SciTech Connect

    Gagliardi, C. A.

    2008-01-24

    During his long and varied career, Robert Tribble has made important contributions in many areas of nuclear physics. He has set new limits on the existence of second-class currents, lepton-flavor violation, and right-handed interactions. He optimized the use of the ({sup 4}He,{sup 8}He) reaction to determine nuclear masses and study charge-dependent effects in nuclei. He has developed a new indirect procedure to determine astrophysical reaction rates and applied it to study important nuclear reactions that occur in our sun, in massive stars, and in novae. He has explored anti-quark distributions in nucleons and nuclei, and the polarization of gluons in the nucleon. A brief overview of Bob Tribble's many accomplishments is presented.

  9. Physics with post accelerated beams: nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Murphy, A. St J.

    2017-05-01

    In this article, recent studies so far conducted with post accelerated beams at the ISOLDE facility in the area of nuclear astrophysics are reviewed. Two experiments in particular are highlighted, that each feature novelty and innovation. Three future experiments are also briefly presented. Collectively, these works advance our understanding of big bang nucleosynthesis, quiescent and explosive burning in novae and x-ray bursts, and core-collapse supernovae, both in terms of the underlying explosion mechanism and gamma-ray satellite observable radioisotopes.

  10. Reactor neutrons in nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Reifarth, René; Glorius, Jan; Göbel, Kathrin; Heftrich, Tanja; Jentschel, Michael; Jurado, Beatriz; Käppeler, Franz; Köster, Ulli; Langer, Christoph; Litvinov, Yuri A.; Weigand, Mario

    2017-09-01

    The huge neutron fluxes offer the possibility to use research reactors to produce isotopes of interest, which can be investigated afterwards. An example is the half-lives of long-lived isotopes like 129I. A direct usage of reactor neutrons in the astrophysical energy regime is only possible, if the corresponding ions are not at rest in the laboratory frame. The combination of an ion storage ring with a reactor and a neutron guide could open the path to direct measurements of neutron-induced cross sections on short-lived radioactive isotopes in the astrophysically interesting energy regime.

  11. PREFACE: Nuclear Physics in Astrophysics III

    NASA Astrophysics Data System (ADS)

    Bemmerer, D.; Grosse, E.; Junghans, A. R.; Schwengner, R.; Wagner, A.

    2008-01-01

    The Europhysics Conference `Nuclear Physics in Astrophysics III' (NPA3) took place from 26 31 March 2007 in Dresden, Germany, hosted by Forschungszentrum Dresden-Rossendorf. The present special issue of Journal of Physics G: Nuclear and Particle Physics contains all peer-reviewed contributions to the proceedings of this conference. NPA3 is the third conference in the Nuclear Physics in Astrophysics series of conferences devoted to the interplay between nuclear physics and astrophysics. The first and second editions of the series were held in 2002 and 2005 in Debrecen, Hungary. NPA3 has been organized under the auspices of the Nuclear Physics Board of the European Physical Society as its XXI Divisional Conference. The conference marks the 50th anniversary of the landmark paper B2FH published in 1957 by E M Burbidge, G R Burbidge, W A Fowler and F Hoyle. A public lecture by Claus Rolfs (Ruhr-Universität Bochum, Germany) commemorated the progress achieved since 1957. NPA3 aimed to bring together experimental and theoretical nuclear physicists, astrophysicists and astronomers to address the important part played by nuclear physics in current astrophysical problems. A total of 130 participants from 71 institutions in 26 countries attended the conference, presenting 33 invited and 38 contributed talks and 25 posters on six subject areas. The astrophysical motivation and the nuclear tools employed to address it are highlighted by the titles of the subject areas: Big Bang Nucleosynthesis Stellar Nucleosynthesis and Low Cross Section Measurement Explosive Nucleosynthesis and Nuclear Astrophysics with Photons Nuclei far from Stability and Radioactive Ion Beams Dense Matter in Neutron Stars and Relativistic Nuclear Collisions Neutrinos in Nuclear Astrophysics The presentations and discussions proved that Nuclear Astrophysics is a truly interdisciplinary subject. The remarkable progress in astronomical observations achieved in recent years is matched by advances in

  12. The Trojan Horse Method in Nuclear Astrophysics

    SciTech Connect

    Spitaleri, C.

    2010-11-24

    The Trojan Horse Method allows for the measurements of cross section in nuclear reaction between charged particles at astrophysical energies. The basic features of the method are discussed in the non resonant reactions case. A review of applications aimed to extract the bare nucleus astrophysical S{sub b}(E) factor for two body processes are presented. The information on electron screening potential U{sub e} were obtained from comparison with direct experiments of fusion reactions.

  13. Nuclear and Particle Astrophysics at CIPANP 2003

    NASA Astrophysics Data System (ADS)

    Baltz, Edward A.; Stone, James

    2004-02-01

    In the nuclear and particle astrophysics session of CIPANP 2003 we heard talks on a number of topics, focused for the most part into four broad areas. Here we outline the discussions of the standard cosmological model, dark matter searches, cosmic rays, and neutrino astrophysics. The robustness of theoretical and experimental programs in all of these areas is very encouraging, and we expect to have many questions answered, and new ones asked, in time for CIPANP 2006.

  14. A laser application to nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Barbui, M.; Bang, W.; Bonasera, A.; Hagel, K.; Schmidt, K.; Zheng, H.; Burch, R.; Barbarino, M.; Natowitz, J. B.; Dyer, G.; Quevedo, H. J.; Gaul, E.; Bernstein, A. C.; Donovan, M.; Kimura, S.; Mazzocco, M.; Consoli, F.; De Angelis, R.; Andreoli, P.; Ditmire, T.

    2014-05-01

    In the last decade, the availability in high-intensity laser beams capable of producing plasmas with ion energies large enough to induce nuclear reactions has opened new research paths in nuclear physics. We studied the reactions 3He(d,p)4He and d(d,n)3He at temperatures of few keV in a plasma, generated by the interaction of intense ultrafast laser pulses with molecular deuterium or deuterated-methane clusters mixed with 3He atoms. The yield of 14.7 MeV protons from the 3He(d,p)4He reaction was used to extract the astrophysical S factor. Results of the experiment performed at the Center for High Energy Density Science at The University of Texas at Austin will be presented.

  15. A laser application to nuclear astrophysics

    SciTech Connect

    Barbui, M.; Hagel, K.; Schmidt, K.; Zheng, H.; Burch, R.; Barbarino, M.; Natowitz, J. B.; Bang, W.; Dyer, G.; Quevedo, H. J.; Gaul, E.; Bernstein, A. C.; Donovan, M.; Bonasera, A.; Kimura, S.; Mazzocco, M.; Consoli, F.; De Angelis, R.; Andreoli, P.; Ditmire, T.

    2014-05-09

    In the last decade, the availability in high-intensity laser beams capable of producing plasmas with ion energies large enough to induce nuclear reactions has opened new research paths in nuclear physics. We studied the reactions {sup 3}He(d,p){sup 4}He and d(d,n){sup 3}He at temperatures of few keV in a plasma, generated by the interaction of intense ultrafast laser pulses with molecular deuterium or deuterated-methane clusters mixed with {sup 3}He atoms. The yield of 14.7 MeV protons from the {sup 3}He(d,p){sup 4}He reaction was used to extract the astrophysical S factor. Results of the experiment performed at the Center for High Energy Density Science at The University of Texas at Austin will be presented.

  16. Comparison of two HPGe counting system used in activation studies for nuclear astrophysics

    SciTech Connect

    Szücs, T.; Kiss, G. G.; Fülöp, Zs.

    2014-05-09

    The activation method is a widely used technique to measure charged-particle induced cross sections for astrophys-ical applications. This two step technique is used for example to measure alpha-induced cross sections in γ-process related studies. The first step – in which a target is irradiated with a proton/alpha beam – is followed by the determination of the produced activity. Especially in p-process related studies in the heavier mass range, the produced radioactive nuclei decays mainly with electron-capture, resulting intense x-rays. The activity of the reaction products hence can be determine via the counting of these x-rays, and not only by counting the usually much weaker γ-rays. In this paper we compare the minimum detectable activity (MDA) of two High Purity Germanium (HPGe) detectors used for x- and γ-ray counting in activation experiments.

  17. Neutrinos and Nuclear Astrophysics at LUNA

    NASA Astrophysics Data System (ADS)

    Gustavino, Carlo; LUNA Collaboration

    2016-04-01

    Nuclear astrophysics plays an important role in understanding open issues of neutrino physics. As an example, the two key reactions of the solar p-p chain 3He(3He, 2p)4He and 3He(4He, γ)7Be have been studied at low energy with LUNA, providing an accurate experimental footing for the Standard Solar Model and consequently to study the neutrino mixing parameters. The LUNA collaboration is now studying the D(p, γ)3He reaction at Big Bang Nucleosynthesis (BBN) energies. The poor knowledge of this reaction is the main source of the uncertainty of the primordial abundance of deuterium in BBN calculations. In turn, the abundance of deuterium depends on the number of relativistic species existing in the early Universe, making the comparison between observed an calculated abundance of deuterium a powerful tool to constrain the existence of light sterile neutrinos or any other type of ;dark radiation;.

  18. Selected topics in nuclear astrophysics

    SciTech Connect

    Martinez-Pinedo, Gabriel

    2013-06-10

    In this lectures after a brief introduction to stellar reaction rates and its implementation in nuclear networks, I discuss the nuclear physics aspects of core collapse supernova and explosive nucleosynthesis and their significance for the production of heavy elements by the rapid neutron capture process and potentially also by the recently discovered {nu}p process.

  19. Advancing Underground Nuclear Astrophysics with CASPAR

    NASA Astrophysics Data System (ADS)

    Robertson, Daniel; Couder, Manoel; Greife, Uwe; Strieder, Frank; Wells, Doug; Wiescher, Michael

    2015-04-01

    The advancement of experimental nuclear astrophysics techniques and the requirement of astrophysical network models for further nuclear data over greater energy ranges, has led to the requirement for the better understanding of nuclear reactions in stellar burning regimes. For those reactions of importance to stellar burning processes and elemental production through stellar nucleosynthesis, the energy range of astrophysical interest is always problematic to probe. As reaction measurements approach the burning window of interest, the rapid drop off in cross-section hampers laboratory investigation. The natural background suppression of underground accelerator facilities enables the extension of current experimental data to lower energies. An example of such reactions of interest are those thought to be sources of neutrons for the s-process, the major production mechanism for elements above the iron peak. The reactions 13 C(α,n)16 O and 22 Ne(α,n)25 Mg are the proposed initial focus of the new nuclear astrophysics accelerator laboratory (CASPAR) currently under construction at the Sanford Underground Research Facility, Lead, SD. With thanks to funding provided by South Dakota Science and Technology Authority and the NSF under Grant Number PHY-1419765.

  20. Nuclear astrophysics and the Trojan Horse Method

    NASA Astrophysics Data System (ADS)

    Spitaleri, C.; La Cognata, M.; Lamia, L.; Mukhamedzhanov, A. M.; Pizzone, R. G.

    2016-04-01

    In this review, we discuss the new recent results of the Trojan Horse Method that is used to determine reaction rates for nuclear processes in several astrophysical scenarios. The theory behind this technique is shortly presented. This is followed by an overview of some new experiments that have been carried out using this indirect approach.

  1. Nuclear Cluster Aspects in Astrophysics

    NASA Astrophysics Data System (ADS)

    Kubono, Shigeru

    2010-03-01

    The role of nuclear clustering is discussed for nucleosynthesis in stellar evolution with Cluster Nucleosynthesis Diagram (CND) proposed before. Special emphasis is placed on α-induced stellar reactions together with molecular states for O and C burning.

  2. Nuclear Data for Astrophysics: Resources, Challenges, Strategies, and Software Solutions

    SciTech Connect

    Smith, Michael Scott; Lingerfelt, Eric J; Nesaraja, Caroline D; Hix, William Raphael; Roberts, Luke F; Koura, Hiroyuki; Fuller, George M; Tytler, David

    2008-01-01

    One of the most exciting utilizations of nuclear data is to help unlock the mysteries of the Cosmos -- the creation of the chemical elements, the evolution and explosion of stars, and the origin and fate of the Universe. There are now many nuclear data sets, tools, and other resources online to help address these important questions. However, numerous serious challenges make it important to develop strategies now to ensure a sustainable future for this work. A number of strategies are advocated, including: enlisting additional manpower to evaluate the newest data; devising ways to streamline evaluation activities; and improving communication and coordination between existing efforts. Software projects are central to some of these strategies. Examples include: creating a virtual ''pipeline'' leading from the nuclear laboratory to astrophysics simulations; improving data visualization and management to get the most science out of the existing datasets; and creating a nuclear astrophysics data virtual (online) community. Recent examples will be detailed, including the development of two first-generation software pipelines, the Computational Infrastructure for Nuclear Astrophysics for stellar astrophysics and the bigbangonline suite of codes for cosmology, and the coupling of nuclear data to sensitivity studies with astrophysical simulation codes to guide future research.

  3. Nuclear properties for astrophysical applications

    SciTech Connect

    Moeller, P.; Nix, J.R.; Kratz, K.L.

    1994-09-23

    We tabulate the ground-state odd-proton and odd-neutron spins, proton and neutron pairing gaps, binding energies, neuton separation energies, quantities related to {beta}-delayed one, two and three neutron emission probabilities, {beta}-decay Q values and half-lives with respect to Gamow-Teller decay, proton separation energies, and {alpha}-decay Q values and half-lives. The starting point of the calculations is a calculation of nuclear ground-states and (information based on the finite-range droplet model and the folded-Yukawa single-particle model published in a previous issue of ATOMIC DATA AND NUCLEAR DATA TABLES. The {beta}-delayed neutron-emission probabilities and Gamow-Teller {beta}-decay rates are obtained from a QRPA model that uses single-particle levels and wave-functions at the calculated nuclear ground-state shape as the starting point.

  4. Current progress of nuclear astrophysics experiments at CIAE

    SciTech Connect

    Liu Weiping; Li Zhihong; Su Jun; Bai Xixiang; Wang Youbao; Lian Gang; Guo Bing; Zeng Sheng; Yan Shengquan; Wang Baoxiang; Shu Nengchuan; Chen Yongshou

    2006-07-12

    This paper described current progress of nuclear astrophysical studies using the unstable ion beam facility GIRAFFE. We measured the angular distributions for some low energy reactions, such as 11C(d,n)12N, 8Li(d,p)9Li and 17F(d,n)18Ne in inverse kinematics, and indirectly derived the astrophysical S-factors or reaction rates of 11C(p,{gamma})12N, 8Li(n,{gamma})9Li, 8B(p,{gamma})9C at astrophysically relevant energies.

  5. Nuclear Astrophysics with the Trojan Horse Method

    NASA Astrophysics Data System (ADS)

    Spitaleri, Claudio

    2015-04-01

    In stars nuclear reactions take place at physical conditions that make very hard their measurements in terrestrial laboratories. Indeed in astrophysical environments nuclear reactions between charged nuclei occur at energies much lower than the Coulomb barrier and the corresponding cross section values lie in the nano or picobarn regime, that makes their experimental determination extremely difficult. This is due to the very small barrier Coulomb penetration factor, which produces an exponential fall off of the cross section as a function of energy. Additionally, the presence of the electron screening needs to be properly taken into account when dealing with cross section measurements at low-energies. The Trojan Horse Method (THM) represents an independent experimental technique, allowing one to measure astrophysical S(E)-factor bared from both Coulomb penetration and electron screening effects. The main advantages and the most recent results are here shown and discussed.

  6. Neutron detection in nuclear astrophysics experiments: study of organic liquid scintillators

    NASA Astrophysics Data System (ADS)

    Ciani, Giovanni Francesco

    2016-02-01

    In order to study the nuclear reaction 13 C(α,n)16 O, crucial for the nucleosynthesis of heavy nuclei (A>58), the LUNA collaboration at Laboratori Nazionali del Gran Sasso, is looking for the best neutron detector to use in the set up. One of the possibilities is to use detectors based on cell filled with Organic Liquid Scintillator BC501A. These detectors are sensible to fast neutron, but also to gamma rays. A Pulse Shape Discrimination process using the Zero Crossing method has been performed to select only signals from neutrons. Comparing the neutron spectra after the Pulse Shape Discrimination and the spectrum from a GEANT4 simulations, the efficiency of the BC501A, in function of the neutron energy and varying the light threshold, has been evaluated.

  7. Nuclear Astrophysics Animations from the Nuclear Astrophysics Group at Clemson University

    DOE Data Explorer

    Meyer, Bradley; The, Lih-Sin

    The nuclear astrophysics group at Clemson University in South Carolina develops on-line tools and computer programs for astronomy, nuclear physics, and nuclear astrophysics. They have also done short animations that illustrate results from research with some of their tools. The animations are organized into three sections. The r-Process Movies demonstrate r-Process network calculations from the paper "Neutrino Capture and the R-Process" Meyer, McLaughlin, and Fuller, Phys. Rev. C, 58, 3696-3710 (1998). The Alpha-Rich Freezeout Movies are related to the reference: Standard alpha-rich freezeout calculation from The, Clayton, Jin, and Meyer 1998, Astrophysical Journal, "Reaction Rates Governing the Synthesis of 44Ti" At the current writing, the category for Low Metallicity s-Process Movies has only one item called n, p, 13C, 14N, 54Fe, and 88Sr Time evolution in convective zone.

  8. Bubble chambers for experiments in nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    DiGiovine, B.; Henderson, D.; Holt, R. J.; Raut, R.; Rehm, K. E.; Robinson, A.; Sonnenschein, A.; Rusev, G.; Tonchev, A. P.; Ugalde, C.

    2015-05-01

    A bubble chamber has been developed to be used as an active target system for low energy nuclear astrophysics experiments. Adopting ideas from dark matter detection with superheated liquids, a detector system compatible with γ-ray beams has been developed. This detector alleviates some of the limitations encountered in standard measurements of the minute cross-sections of interest to stellar environments. While the astrophysically relevant nuclear reaction processes at hydrostatic burning temperatures are dominated by radiative captures, in this experimental scheme we measure the time-reversed processes. Such photodisintegrations allow us to compute the radiative capture cross-sections when transitions to excited states of the reaction products are negligible. Due to the transformation of phase space, the photodisintegration cross-sections are up to two orders of magnitude higher. The main advantage of the new target-detector system is a density several orders of magnitude higher than conventional gas targets. Also, the detector is virtually insensitive to the γ-ray beam itself, thus allowing us to detect only the products of the nuclear reaction of interest. The development and the operation as well as the advantages and disadvantages of the bubble chamber are discussed.

  9. Reaction Rate Parameterization for Nuclear Astrophysics Research

    NASA Astrophysics Data System (ADS)

    Scott, J. P.; Lingerfelt, E. J.; Smith, M. S.; Hix, W. R.; Bardayan, D. W.; Sharp, J. E.; Kozub, R. L.; Meyer, R. A.

    2004-11-01

    Libraries of thermonuclear reaction rates are used in element synthesis models of a wide variety of astrophysical phenomena, such as exploding stars and the inner workings of our sun. These computationally demanding models are more efficient when libraries, which may contain over 60000 rates and vary by 20 orders of magnitude, have a uniform parameterization for all rates. We have developed an on-line tool, hosted at www.nucastrodata.org, to obtain REACLIB parameters (F.-K. Thielemann et al., Adv. Nucl. Astrophysics 525, 1 (1987)) that represent reaction rates as a function of temperature. This helps to rapidly incorporate the latest nuclear physics results in astrophysics models. The tool uses numerous techniques and algorithms in a modular fashion to improve the quality of the fits to the rates. Features, modules, and additional applications of this tool will be discussed. * Managed by UT-Battelle, LLC, for the U.S. D.O.E. under contract DE-AC05-00OR22725 + Supported by U.S. D.O.E. under Grant No. DE-FG02-96ER40955

  10. Indirect Methods For Nuclear Astrophysics With Radioactive Nuclear Beams

    NASA Astrophysics Data System (ADS)

    Trache, Livius

    2010-03-01

    For a good understanding of nucleosynthesis and energy production in stars through reliable modeling, we need nuclear data. To obtain them is the goal of nuclear physics for astrophysics, using direct and indirect measurements. In this lecture indirect methods for nuclear astrophysics are reviewed. In particular, methods applied to extract reaction rates for H-burning in stars are treated. The Coulomb dissociation is first briefly touched, for completeness. Then I go to one-nucleon transfer reactions (the ANC method), breakup reactions at intermediate energies and decay spectroscopy (β-decay and β-delayed proton-decay). They involve the use of radioactive nuclear beams. I chose for exemplification different experiments of our Texas A&M group, each involving a different method. The experiments were done at large energies to extract selected nuclear structure information. That is in turn used to evaluate the cross sections at low energies and the reaction rates for nuclear astrophysics. I will show the specificities of each method, their complementarities and redundancies, insisting on their peculiarities when used with radioactive beams.

  11. Few-body models for nuclear astrophysics

    SciTech Connect

    Descouvemont, P.; Baye, D.; Aoyama, S.; Arai, K.

    2014-04-15

    We present applications of microscopic models to nuclear reactions of astrophysical interest, and we essentially focus on few-body systems. The calculation of radiative-capture and transfer cross sections is outlined, and we discuss the corresponding reaction rates. Microscopic theories are briefly presented, and we emphasize on the matrix elements of four-body systems. The microscopic extension of the R-matrix theory to nuclear reactions is described. Applications to the {sup 2}H(d, γ){sup 4}He, {sup 2}H(d, p){sup 3}H and {sup 2}H(d, n){sup 3}He reactions are presented. We show the importance of the tensor force to reproduce the low-energy behaviour of the cross sections.

  12. Some nuclear data needs in astrophysics

    SciTech Connect

    Mathews, G.J.; Bauer, R.W.; Bloom, S.D.; Haight, R.C.; Howard, W.M.; Takahashi, K.; Ward, R.A.

    1985-05-01

    In this paper we discuss a number of astrophysical environments and how improved nuclear data could facilitate a better understanding of them. One area of interest includes proton and alpha-particle reactions with unstable nuclei which are necessary for understanding the nucleosynthesis and energy generation in hot hydrogen-burning environments. Efforts underway at LLNL and elsewhere to develop the technology for the measurement of these reaction rates are discussed. Heavy-element nucleosynthesis in the late stages of red-giant stars and supernovae requires a complete network of neutron capture rates and beta-decay rates for nuclei near and far from stability. Experimental and theoretical efforts at LLNL to supply the input data and to model the nucleosynthetic environments will be outlined. Suggestions are made as to which nuclear data are most critical for the various scenarios. 42 refs., 11 figs., 1 tab.

  13. Art as a Vehicle for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Kilburn, Micha

    2013-04-01

    One aim of the The Joint Institute for Nuclear Astrophysics (JINA) is to teach K-12 students concepts and ideas related to nuclear astrophysics. For students who have not yet seen the periodic table, this can be daunting, and we often begin with astronomy concepts. The field of astronomy naturally lends itself to an art connection through its beautiful images. Our Art 2 Science programming adopts a hands-on approach by teaching astronomy through student created art projects. This approach engages the students, through tactile means, visually and spatially. For younger students, we also include physics based craft projects that facilitate the assimilation of problem solving skills. The arts can be useful for aural and kinetic learners as well. Our program also includes singing and dancing to songs with lyrics that teach physics and astronomy concepts. The Art 2 Science programming has been successfully used in after-school programs at schools, community centers, and art studios. We have even expanded the program into a popular week long summer camp. I will discuss our methods, projects, specific goals, and survey results for JINA's Art 2 Science programs.

  14. Use of NIF in Nuclear Astrophysics: Examples of Experiments

    SciTech Connect

    Boyd, Richard N.

    2008-04-17

    The National Ignition Facility, the world's largest laser, is scheduled for completion in 2009, and will beginning performing experiments in basic science about the same time. NIF is expected to produce temperatures and densities well above those at the core of the Sun, so it appears to have the capability to study thermally averaged cross sections involving a variety of light nuclei, many of which are of interest to nuclear astrophysics. Most of these reactions are affected, in some instances dominated, by compound nuclear states. This paper first describes some of the basic parameters of NIF, then discusses several experiments in nuclear astrophysics, some of which might be performed at NIF, and some of which could not be performed at any other facility in existence.

  15. Nuclear astrophysics in the laboratory and in the universe

    SciTech Connect

    Champagne, A. E. Iliadis, C.; Longland, R.

    2014-04-15

    Nuclear processes drive stellar evolution and so nuclear physics, stellar models and observations together allow us to describe the inner workings of stars and their life stories. This Information on nuclear reaction rates and nuclear properties are critical ingredients in addressing most questions in astrophysics and often the nuclear database is incomplete or lacking the needed precision. Direct measurements of astrophysically-interesting reactions are necessary and the experimental focus is on improving both sensitivity and precision. In the following, we review recent results and approaches taken at the Laboratory for Experimental Nuclear Astrophysics (LENA, http://research.physics.unc.edu/project/nuclearastro/Welcome.html )

  16. Indirect measurements of nuclear astrophysics reactions at CIAE

    SciTech Connect

    Liu Weiping; Li Zhihong; Bai Xixiang; Wang Youbao; Lian Gang; Guo Bing; Zeng Sheng; Yan Shengquan; Wang Baoxiang; Su Jun; Shu Nengchuan; Chen Yongshou

    2006-11-02

    This paper described the nuclear astrophysical studies using the unstable ion beam facility GIRAFFE, by indirect measurements. We measured the angular distributions for some single proton or neutron transfer reactions, such as 7Be(d,n)8B, 11C(d,n)12N, 8Li(d,n)9Be, 8Li(d,p)9Li and 13N(d,n)14O in inverse kinematics, and derived the astrophysical S-factors or reaction rates of 7Be(p,{gamma})8B, 11C(p,{gamma})12N, 8Li(n,{gamma})9Li, 13N(p,{gamma})14O by asymptotic normalization coefficient, spectroscopic factor, and R-matrix approach at astrophysically relevant energies.

  17. Applications of the Trojan Horse method in nuclear astrophysics

    SciTech Connect

    Spitaleri, Claudio

    2015-02-24

    The study of the energy production in stars and related nucleosyntesis processes requires increasingly precise knowledge of the nuclear reaction cross section and reaction rates at interaction energy. In order to overcome the experimental difficulties, arising from small cross-sections involved in charge particle induced reactions at astrophysical energies, and from the presence of electron screening, it was necessary to introduce indirect methods. Trough these methods it is possible to measure cross sections at very small energies and retrieve information on electron screening effect when ultra-low energy direct measurements are available. The Trojan Horse Method (THM) represents the indirect technique to determine the bare nucleus astrophysical S-factor for reactions between charged particles at astrophysical energies. The basic theory of the THM is discussed in the case of non-resonant.

  18. Applications of the Trojan Horse method in nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Spitaleri, Claudio

    2015-02-01

    The study of the energy production in stars and related nucleosyntesis processes requires increasingly precise knowledge of the nuclear reaction cross section and reaction rates at interaction energy. In order to overcome the experimental difficulties, arising from small cross-sections involved in charge particle induced reactions at astrophysical energies, and from the presence of electron screening, it was necessary to introduce indirect methods. Trough these methods it is possible to measure cross sections at very small energies and retrieve information on electron screening effect when ultra-low energy direct measurements are available. The Trojan Horse Method (THM) represents the indirect technique to determine the bare nucleus astrophysical S-factor for reactions between charged particles at astrophysical energies. The basic theory of the THM is discussed in the case of non-resonant.

  19. Nuclear Mass Measurement and Evaluation Relevant to Astrophysics

    NASA Astrophysics Data System (ADS)

    Wang, Meng

    Nuclear mass data are crucial input for the astrophysics models. Thanks to the developments of radioactive nuclear beam facilities and novel mass spectrometers, the experimental knowledge of nuclear masses has been continuously expanding to the exotic nuclei far from the stability which play a critical role in astrophysics. The recent progress and future perspective of mass measurement relevant to astrophysics will be discussed. By evaluating all available experimental data from nuclear reactions, radioactive decays and direct mass measurements, the Atomic Mass Evaluation (AME) serve the research community with reliable source for comprehensive information related to the nuclear masses. The next AME version is envisioned to be published at the end of 2016.

  20. Recent Nuclear Astrophysics Data Activities in the US

    SciTech Connect

    Bardayan, D.W.; Blackmon, J.C.; Browne, E.; Firestone, R.B.; Hale, G.M.; Hoffman, R.D.; Ma, Z.; McLane, V.; Norman, E.B.; Shu, N.; Smith, D.L.; Smith, M.S.; Van Wormer, L.A.; Woosley, S.E.; Wu, S.-C.

    1999-08-30

    Measurements in nuclear physics laboratories form the empirical foundation for new, realistic, sophisticated theoretical models of a wide variety of astrophysical systems. The predictive power of these models has, in many instances, a strong dependence on the input nuclear data, and more extensive and accurate nuclear data is required for these models than ever before. Progress in astrophysics can be aided by providing scientists with more usable, accurate, and significant amounts of nuclear data in a timely fashion in formats that can be easily incorporated into their models. A number of recent data compilations, evaluations, calculations, and disseminations that address nuclear astrophysics data needs will be described.

  1. Nuclear Astrophysics at IFIN-HH

    NASA Astrophysics Data System (ADS)

    Livius, Trache

    2016-04-01

    I will present the possibilities and some results of doing nuclear astrophysics research in IFIN-HH Bucharest-Magurele. There are basically two lines of experimental activities: (1) direct measurements with beams from the local accelerators, in particular with the new 3 MV Tandetron accelerator. This facility turns out to be competitive for reactions induced by a-particles and light ions. Extra capabilities are given by the ultra-low background laboratory we have in a salt mine about 2.5 hrs. driving north of Bucharest; (2) indirect measurements done with beams at international facilities, in particular at those providing Rare Ion Beams. Completely new and unique opportunities will be provided by ELI-NP, under construction in our institute.

  2. Nuclear astrophysics with radioactive ions at FAIR

    NASA Astrophysics Data System (ADS)

    Reifarth, R.; Altstadt, S.; Göbel, K.; Heftrich, T.; Heil, M.; Koloczek, A.; Langer, C.; Plag, R.; Pohl, M.; Sonnabend, K.; Weigand, M.; Adachi, T.; Aksouh, F.; Al-Khalili, J.; AlGarawi, M.; AlGhamdi, S.; Alkhazov, G.; Alkhomashi, N.; Alvarez-Pol, H.; Alvarez-Rodriguez, R.; Andreev, V.; Andrei, B.; Atar, L.; Aumann, T.; Avdeichikov, V.; Bacri, C.; Bagchi, S.; Barbieri, C.; Beceiro, S.; Beck, C.; Beinrucker, C.; Belier, G.; Bemmerer, D.; Bendel, M.; Benlliure, J.; Benzoni, G.; Berjillos, R.; Bertini, D.; Bertulani, C.; Bishop, S.; Blasi, N.; Bloch, T.; Blumenfeld, Y.; Bonaccorso, A.; Boretzky, K.; Botvina, A.; Boudard, A.; Boutachkov, P.; Boztosun, I.; Bracco, A.; Brambilla, S.; Briz Monago, J.; Caamano, M.; Caesar, C.; Camera, F.; Casarejos, E.; Catford, W.; Cederkall, J.; Cederwall, B.; Chartier, M.; Chatillon, A.; Cherciu, M.; Chulkov, L.; Coleman-Smith, P.; Cortina-Gil, D.; Crespi, F.; Crespo, R.; Cresswell, J.; Csatlós, M.; Déchery, F.; Davids, B.; Davinson, T.; Derya, V.; Detistov, P.; Diaz Fernandez, P.; DiJulio, D.; Dmitry, S.; Doré, D.; Dueñas, J.; Dupont, E.; Egelhof, P.; Egorova, I.; Elekes, Z.; Enders, J.; Endres, J.; Ershov, S.; Ershova, O.; Fernandez-Dominguez, B.; Fetisov, A.; Fiori, E.; Fomichev, A.; Fonseca, M.; Fraile, L.; Freer, M.; Friese, J.; Borge, M. G.; Galaviz Redondo, D.; Gannon, S.; Garg, U.; Gasparic, I.; Gasques, L.; Gastineau, B.; Geissel, H.; Gernhäuser, R.; Ghosh, T.; Gilbert, M.; Glorius, J.; Golubev, P.; Gorshkov, A.; Gourishetty, A.; Grigorenko, L.; Gulyas, J.; Haiduc, M.; Hammache, F.; Harakeh, M.; Hass, M.; Heine, M.; Hennig, A.; Henriques, A.; Herzberg, R.; Holl, M.; Ignatov, A.; Ignatyuk, A.; Ilieva, S.; Ivanov, M.; Iwasa, N.; Jakobsson, B.; Johansson, H.; Jonson, B.; Joshi, P.; Junghans, A.; Jurado, B.; Körner, G.; Kalantar, N.; Kanungo, R.; Kelic-Heil, A.; Kezzar, K.; Khan, E.; Khanzadeev, A.; Kiselev, O.; Kogimtzis, M.; Körper, D.; Kräckmann, S.; Kröll, T.; Krücken, R.; Krasznahorkay, A.; Kratz, J.; Kresan, D.; Krings, T.; Krumbholz, A.; Krupko, S.; Kulessa, R.; Kumar, S.; Kurz, N.; Kuzmin, E.; Labiche, M.; Langanke, K.; Lazarus, I.; Le Bleis, T.; Lederer, C.; Lemasson, A.; Lemmon, R.; Liberati, V.; Litvinov, Y.; Löher, B.; Lopez Herraiz, J.; Münzenberg, G.; Machado, J.; Maev, E.; Mahata, K.; Mancusi, D.; Marganiec, J.; Martinez Perez, M.; Marusov, V.; Mengoni, D.; Million, B.; Morcelle, V.; Moreno, O.; Movsesyan, A.; Nacher, E.; Najafi, M.; Nakamura, T.; Naqvi, F.; Nikolski, E.; Nilsson, T.; Nociforo, C.; Nolan, P.; Novatsky, B.; Nyman, G.; Ornelas, A.; Palit, R.; Pandit, S.; Panin, V.; Paradela, C.; Parkar, V.; Paschalis, S.; Pawłowski, P.; Perea, A.; Pereira, J.; Petrache, C.; Petri, M.; Pickstone, S.; Pietralla, N.; Pietri, S.; Pivovarov, Y.; Potlog, P.; Prokofiev, A.; Rastrepina, G.; Rauscher, T.; Ribeiro, G.; Ricciardi, M.; Richter, A.; Rigollet, C.; Riisager, K.; Rios, A.; Ritter, C.; Rodriguez Frutos, T.; Rodriguez Vignote, J.; Röder, M.; Romig, C.; Rossi, D.; Roussel-Chomaz, P.; Rout, P.; Roy, S.; Söderström, P.; Saha Sarkar, M.; Sakuta, S.; Salsac, M.; Sampson, J.; Sanchez, J.; Rio Saez, del; Sanchez Rosado, J.; Sanjari, S.; Sarriguren, P.; Sauerwein, A.; Savran, D.; Scheidenberger, C.; Scheit, H.; Schmidt, S.; Schmitt, C.; Schnorrenberger, L.; Schrock, P.; Schwengner, R.; Seddon, D.; Sherrill, B.; Shrivastava, A.; Sidorchuk, S.; Silva, J.; Simon, H.; Simpson, E.; Singh, P.; Slobodan, D.; Sohler, D.; Spieker, M.; Stach, D.; Stan, E.; Stanoiu, M.; Stepantsov, S.; Stevenson, P.; Strieder, F.; Stuhl, L.; Suda, T.; Sümmerer, K.; Streicher, B.; Taieb, J.; Takechi, M.; Tanihata, I.; Taylor, J.; Tengblad, O.; Ter-Akopian, G.; Terashima, S.; Teubig, P.; Thies, R.; Thoennessen, M.; Thomas, T.; Thornhill, J.; Thungstrom, G.; Timar, J.; Togano, Y.; Tomohiro, U.; Tornyi, T.; Tostevin, J.; Townsley, C.; Trautmann, W.; Trivedi, T.; Typel, S.; Uberseder, E.; Udias, J.; Uesaka, T.; Uvarov, L.; Vajta, Z.; Velho, P.; Vikhrov, V.; Volknandt, M.; Volkov, V.; von Neumann-Cosel, P.; von Schmid, M.; Wagner, A.; Wamers, F.; Weick, H.; Wells, D.; Westerberg, L.; Wieland, O.; Wiescher, M.; Wimmer, C.; Wimmer, K.; Winfield, J. S.; Winkel, M.; Woods, P.; Wyss, R.; Yakorev, D.; Yavor, M.; Zamora Cardona, J.; Zartova, I.; Zerguerras, T.; Zgura, M.; Zhdanov, A.; Zhukov, M.; Zieblinski, M.; Zilges, A.; Zuber, K.

    2016-01-01

    The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process flow and r-process, β-decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will offer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes.

  3. Studies in Nuclear Astrophysics with an Optical Readout TPC (O-TPC) at HIγS

    NASA Astrophysics Data System (ADS)

    Gai, Moshe; UConn-Yale-Duke-Weizmann-PTB-UCL Collaboration

    2012-02-01

    An Optical Readout Time Projection Chamber (O-TPC) operating with the gas mixture of CO2(80%) + N2(20%) at 100 torr with gamma beams from the HIγS facility of TUNL at Duke University were used to study the formation of carbon and oxygen during helium burning. Measurements were carried out with circularly polarized gamma-ray beams at energies: Eγ = 9.08, 9.38, 9.58, 9.78, 10.08, 10.38 and 10.68 MeV. We have begun the process of extracting complete angular distributions for the 16O(γ, α)12C reaction and the 12C(γ, 3α) reaction (eventually with energy bins of approximately 100 keV) in order to determine the values of SE1, SE2 and the mixing phase phi12 of the 16O(γ, α)12C reaction. The rate of carbon formation at high temperatures (T > 3 GK) was suggested to increase due to contributions from a higher lying 2+ state. We have measured an angular distribution of (essentially) pure E2 transition at Eγ = 9.78 MeV of the 12C(γ, 3α) reaction, providing conclusive evidence for the elusive 2+2 state in 12C.

  4. From dripline to dripline: Nuclear astrophysics in the laboratory

    NASA Astrophysics Data System (ADS)

    Meisel, Zach

    2016-08-01

    For the better part of a century the field of nuclear astrophysics has aimed to answer fundamental questions about nature, such as the origin of the elements and the behavior of high-density, low-temperature matter. Sustained and concerted efforts in nuclear experiment have been key to achieving progress in these areas and will continue to be so. Here I will briefly review recent accomplishments and open questions in experimental nuclear astrophysics.

  5. Trojan horse particle invariance: The impact on nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Pizzone, R. G.; Spitaleri, C.; Bertulani, C. A.; Mukhamedzhanov, A. M.; Blokhintsev, L. D.; La Cognata, M.; Lamia, L.; Spartá, R.; Tumino, A.

    2014-05-01

    In the current picture of nuclear astrophysics indirect methods and, in particular, the Trojan Horse Method cover a crucial role for the measurement of charged particle induced reactions cross sections of astrophysical interest, in the energy range required by the astrophysical scenarios. To better understand its cornerstones and its applications to physical cases many tests were performed to verify all its properties and the possible future perspectives. The key to the method is the quasi-free break-up and some of its properties will be investigated in the present work. In particular, the Trojan Horse nucleus invariance will be studied and previous studies will be extended to the cases of the binary d(d, p)t and 6Li(d,α)4He reactions, which were tested using different quasi-free break-up's, namely 6Li and 3He. The astrophysical S(E)-factor were then extracted with the Trojan Horse formalism applied to the two different break-up schemes and compared with direct data as well as with previous indirect investigations. The very good agreement confirms the independence of binary indirect cross section on the chosen spectator particle also for these reactions.

  6. Trojan horse particle invariance: The impact on nuclear astrophysics

    SciTech Connect

    Pizzone, R. G.; La Cognata, M.; Spitaleri, C.; Bertulani, C. A.; Mukhamedzhanov, A. M.; Blokhintsev, L. D.; Lamia, L.; Spartá, R.; Tumino, A.

    2014-05-02

    In the current picture of nuclear astrophysics indirect methods and, in particular, the Trojan Horse Method cover a crucial role for the measurement of charged particle induced reactions cross sections of astrophysical interest, in the energy range required by the astrophysical scenarios. To better understand its cornerstones and its applications to physical cases many tests were performed to verify all its properties and the possible future perspectives. The key to the method is the quasi-free break-up and some of its properties will be investigated in the present work. In particular, the Trojan Horse nucleus invariance will be studied and previous studies will be extended to the cases of the binary d(d, p)t and {sup 6}Li(d,α){sup 4}He reactions, which were tested using different quasi-free break-up's, namely {sup 6}Li and {sup 3}He. The astrophysical S(E)-factor were then extracted with the Trojan Horse formalism applied to the two different break-up schemes and compared with direct data as well as with previous indirect investigations. The very good agreement confirms the independence of binary indirect cross section on the chosen spectator particle also for these reactions.

  7. Thermonuclear Reaction Rate Parameterization for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Sharp, Jacob; Kozub, Raymond L.; Smith, Michael S.; Scott, Jason; Lingerfelt, Eric

    2004-10-01

    The knowledge of thermonuclear reaction rates is vital to simulate novae, supernovae, X-ray bursts, and other astrophysical events. To facilitate dissemination of this knowledge, a set of tools has been created for managing reaction rates, located at www.nucastrodata.org. One tool is a rate parameterizer, which provides a parameterization for nuclear reaction rate vs. temperature values in the most widely used functional form. Currently, the parameterizer uses the Levenberg-Marquardt method (LMM), which requires an initial estimate of the best-fit parameters. The initial estimate is currently provided randomly from a preselected pool. To improve the quality of fits, a new, active method of selecting parameters has been developed. The parameters of each set in the pool are altered for a few iterations to replicate the input data as closely as possible. Then, the set which most nearly matches the input data (based on chi squared) is used in the LMM as the initial estimate for the final fitting procedure. A description of the new, active algorithm and its performance will be presented. Supported by the U. S. Department of Energy.

  8. Nuclear Reactions in Hot Astrophysical Plasmas with T > 1010 K

    NASA Astrophysics Data System (ADS)

    Kafexhiu, Ervin; Aharonian, Felix; Vila, Gabriela S.

    The importance of nuclear reactions in low-density astrophysical plasmas with ion temperatures T ≥1010 K has been recognized for more than thirty years. However, the lack of comprehensive data banks of relevant nuclear reactions and the limited computational power have not previously allowed detailed theoretical studies. Recent developments in these areas make it timely to conduct comprehensive studies on the nuclear properties of very hot plasmas formed around compact relativistic objects such as black holes and neutron stars. Such studies are of great interest in the context of scientific programs of future low-energy cosmic γ-ray spectrometry. In this work, using the publicly available code TALYS, we have built a large nuclear network relevant for temperatures exceeding 1010 K. We have studied the evolution of the chemical composition and accompanying prompt gamma-ray emission of such high-temperature plasmas. We present the results on the abundances of light elements D, T, 3He, 4He, 6Li, 7Li, 9Be, 10B, 11B, and briefly discuss their implications on the astrophysical abundances of these elements.

  9. Nuclear Astrophysics with the Trojan Horse Method

    NASA Astrophysics Data System (ADS)

    Tumino, A.; Spitaleri, C.; Lamia, L.; Pizzone, R. G.; Cherubini, S.; Gulino, M.; La Cognata, M.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Spartá, R.

    2016-01-01

    The Trojan Horse Method (THM) represents the indirect path to determine the bare nucleus astrophysical S(E) factor for reactions between charged particles at astrophysical energies. This is done by measuring the quasi free cross section of a suitable three body process. The basic features of the THM will be presented together with some applications to demonstrate its practical use.

  10. Nuclear astrophysics at the Holifield Radioactive Ion Beam Facility

    NASA Astrophysics Data System (ADS)

    Blackmon, Jeff C.

    1996-01-01

    Reactions involving radioactive nuclei play an important role in explosive stellar events such as novae, supernovae, and X-ray bursts. The development of accelerated, proton-rich radioactive ion beams provides a tool for directly studying many of the reactions that fuel explosive hydrogen burning. The experimental nuclear astrophysics program at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory is centered on absolute cross section measurements of these reactions with radioactive ion beams. Beams of F-17 and F-18, important nuclei in the hot-CNO cycle, are currently under development at HRIBF. Progress in the production of intense radioactive fluorine beams is reported. The Daresbury Recoil Separator (DRS) has been installed at HRIBF as the primary experimental station for nuclear astrophysics experiments. The DRS will be used to measure reactions in inverse kinematics with the techniques of direct recoil detection, delayed-activity recoil detection, and recoil-gamma coincidence measurements. The first astrophysics experiments to be performed at HRIBF, mA the application of the recoil separator in these measurements, are discussed.

  11. Nuclear Data for Astrophysical Nucleosynthesis: A Japanese + LANL Activity

    SciTech Connect

    Chiba, Satoshi; Koura, Hiroyuki; Nakagawa, Tsuneo; Seki, Akiyuki; Maruyama, Toshiki; Kawano, Toshihiko; Tachibana, Takahiro; Kajino, Toshitaka; Oryu, Shinsho; Hayakawa, Takehito; Tanigawa, Tomonori; Watanabe, Yukinobu; Ohsaki, Toshiro; Murata, Toru; Sumiyoshi, Kohsuke

    2005-05-24

    There are many common features in nuclear data for energy applications and nuclear cosmology/astrophysics, especially the neutron-capture nucleosynthesis. Therefore it is a natural consequence to think that many of the tools that we have developed for the conventional nuclear-data applications can be applied for a development of a database for nuclear cosmology/astrophysics. However, there are also many features that are uncommon to these fields, so new development is necessary when we think about a database for nuclear cosmology and astrophysics. Such new development will then give us a new horizon for the conventional nuclear data activities as well. In this paper we will show the present status of our activities in this direction, putting emphasis on data relevant to neutron capture nucleosynthesis, namely s- and r-processes.

  12. Experiences and Prospects of Nuclear Astrophysics in Underground Laboratories

    NASA Astrophysics Data System (ADS)

    Junker, M.

    2016-01-01

    Impressive progress has been made in the course the last decades in understanding astrophysical objects. Increasing precision of nuclear physics data has contributed significantly to this success, but now a better understanding of several important findings is frequently limited by uncertainties related to the available nuclear physics data. Consequently it is desirable to improve significantly the quality of these data. An important step towards higher precision is an excellent signal to background ratio of the data. Placing an accelerator facility inside an underground laboratory reducing the cosmic ray induced background by six orders of magnitude is a powerful method to reach this goal, even though careful reduction of environmental and beam induced background must still be considered. Experience in the field of underground nuclear astrophysics has been gained since 20 years due to the pioneering work of the LUNA Collaboration (Laboratory for Underground Nuclear Astrophysics) operating inside the underground laboratories of the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. Based on the success of this work presently also several other projects for underground laboratories dedicated to nuclear astrophysics are being pursued worldwide. This contribution will give a survey of the past experience in underground nuclear astrophysics as well as an outlook on future developments.

  13. Experiences and prospects of nuclear astrophysics in underground laboratories

    SciTech Connect

    Junker, M.

    2014-05-09

    Impressive progress has been made in the course the last decades in understanding astrophysical objects. Increasing precision of nuclear physics data has contributed significantly to this success, but now a better understanding of several important findings is frequently limited by uncertainties related to the available nuclear physics data. Consequently it is desirable to improve significantly the quality of these data. An important step towards higher precision is an excellent signal to background ratio of the data. Placing an accelerator facility inside an underground laboratory reducing the cosmic ray induced background by six orders of magnitude is a powerful method to reach this goal, even though careful reduction of environmental and beam induced background must still be considered. Experience in the field of underground nuclear astrophysics has been gained since 20 years due to the pioneering work of the LUNA Collaboration (Laboratory for Underground Nuclear Astrophysics) operating inside the underground laboratories of the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. Based on the success of this work presently also several other projects for underground laboratories dedicated to nuclear astrophysics are being pursued worldwide. This contribution will give a survey of the past experience in underground nuclear astrophysics as well as an outlook on future developments.

  14. VI European Summer School on Experimental Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    The European Summer School on Experimental Nuclear Astrophysics has reached the sixth edition, marking the tenth year's anniversary. The spirit of the school is to provide a very important occasion for a deep education of young researchers about the main topics of experimental nuclear astrophysics. Moreover, it should be regarded as a forum for the discussion of the last-decade research activity. Lectures are focused on various aspects of primordial and stellar nucleosynthesis, including novel experimental approaches and detectors, indirect methods and radioactive ion beams. Moreover, in order to give a wide educational offer, some lectures cover complementary subjects of nuclear astrophysics such as gamma ray astronomy, neutron-induced reactions, short-lived radionuclides, weak interaction and cutting-edge facilities used to investigate nuclear reactions of interest for astrophysics. Large room is also given to young researcher oral contributions. Traditionally, particular attention is devoted to the participation of students from less-favoured countries, especially from the southern coast of the Mediterranean Sea. The school is organised by the Catania Nuclear Astrophysics research group with the collaboration of Dipartimento di Fisica e Astromomia - Università di Catania and Laboratori Nazionali del Sud - Istituto Nazionale di Fisica Nucleare.

  15. Direct Reactions for Nuclear Structure and Nuclear Astrophysics

    SciTech Connect

    Jones, Katherine Louise

    2014-12-18

    Direct reactions are powerful probes for studying the atomic nucleus. Modern direct reaction studies are illuminating both the fundamental nature of the nucleus and its role in nucleosynthetic processes occurring in the cosmos. This report covers experiments using knockout reactions on neutron-deficient fragmentation beams, transfer reactions on fission fragment beams, and theoretical sensitivity studies relating to the astrophysical r-process. Results from experiments on 108,106Sn at the NSCL, and on 131Sn at HRIBF are presented as well as the results from the nucleosynthesis study.

  16. Influences of the astrophysical environment on nuclear decay rates

    SciTech Connect

    Norman, E.B.

    1987-09-01

    In many astronomical environments, physical conditions are so extreme that nuclear decay rates can be significantly altered from their laboratory values. Such effects are relevant to a number of current problems in nuclear astrophysics. Experiments related to these problems are now being pursued, and will be described in this talk. 19 refs., 5 figs.

  17. Nuclear Mass Systematics With Neural Nets And Astrophysical Nucleosynthesis

    SciTech Connect

    Athanassopoulos, S.; Mavrommatis, E.; Gernoth, K. A.; Clark, J. W.

    2006-04-26

    We construct a neural network model that predicts the differences between the experimental mass-excess values {delta}Mexp and the theoretical values {delta}MFRDM given by the Finite Range Droplet Model of Moeller et al. This difficult study reveals that subtle regularities of nuclear structure not yet embodied in the best microscopic/phenomenological models of atomic-mass systematics do actually exist. By combining the FRDM and the above neural network model we construct a Hybrid Model with improved predictive performance in the majority of the calculations of the systematics of nuclear mass excess and of related quantities. Such systematics is of current interest among others in such astrophysical problems as nucleosynthesis processes and the justification of the present abundances.

  18. Felsenkeller shallow-underground accelerator laboratory for nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Bemmerer, D.; Cowan, T. E.; Gohl, S.; Ilgner, C.; Junghans, A. R.; Reinhardt, T. P.; Rimarzig, B.; Reinicke, S.; Röder, M.; Schmidt, K.; Schwengner, R.; Stöckel, K.; Szücs, T.; Takács, M.; Wagner, A.; Wagner, L.; Zuber, K.

    2015-05-01

    Favored by the low background in underground laboratories, low-background accelerator-based experiments are an important tool to study nuclear reactions involving stable charged particles. This technique has been used for many years with great success at the 0.4 MV LUNA accelerator in the Gran Sasso laboratory in Italy, proteced from cosmic rays by 1400 m of rock. However, the nuclear reactions of helium and carbon burning and the neutron source reactions for the astrophysical s-process require higher beam energies than those available at LUNA. Also the study of solar fusion reactions necessitates new data at higher energies. As a result, in the present NuPECC long range plan for nuclear physics in Europe, the installation of one or more higher-energy underground accelerators is strongly recommended. An intercomparison exercise has been carried out using the same HPGe detector in a typical nuclear astrophysics setup at several sites, including the Dresden Felsenkeller underground laboratory. It was found that its rock overburden of 45m rock, together with an active veto against the remaining muon flux, reduces the background to a level that is similar to the deep underground scenario. Based on this finding, a used 5 MV pelletron tandem with 250 μA upcharge current and external sputter ion source has been obtained and transported to Dresden. Work on an additional radio-frequency ion source on the high voltage terminal is underway. The project is now fully funded. The installation of the accelerator in the Felsenkeller is expected for the near future. The status of the project and the planned access possibilities for external users will be reported.

  19. PREFACE: Nuclear Physics in Astrophysics VI (NPA6)

    NASA Astrophysics Data System (ADS)

    2016-01-01

    The Nuclear Physics in Astrophysics VI conference was the 6th event of the NPA biannual conference series. Previous events of this series were held at the Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen, Hungary, in 2002 and 2005; at the Forschungszentrum Dresden-Rossendorf, Dresden, Germany, in 2007; at the Laboratori Nazionali del Gran Sasso (LNGS), L'Aquila, Italy, in 2009; and in Eilat, Israel, in 2011. This edition of the NPA conference series was organized by the European Physical Society (EPS) through its Nuclear Physics Division, corresponding to the 26th edition of the Topical Conferences of the EPS. As in previous editions, the goal of the NPA conference was to bring together the specialists in the fields of Nuclear Physics (theory and experiment) and Nuclear Astrophysics (theory and observation), providing the appropriate forum for review and discussion of the status and prospects of the field of Nuclear Astrophysics. During the discussions, special attention was given to the Nuclear Physics aspects that have an impact in Astrophysics.

  20. The Trojan Horse Method in nuclear astrophysics

    SciTech Connect

    Spitaleri, C.; Mukhamedzhanov, A. M.; Blokhintsev, L. D.; Cognata, M. La; Pizzone, R. G.; Tumino, A.

    2011-12-15

    The study of energy production and nucleosynthesis in stars requires an increasingly precise knowledge of the nuclear reaction rates at the energies of interest. To overcome the experimental difficulties arising from the small cross sections at those energies and from the presence of the electron screening, the Trojan Horse Method has been introduced. The method provides a valid alternative path to measure unscreened low-energy cross sections of reactions between charged particles, and to retrieve information on the electron screening potential when ultra-low energy direct measurements are available.

  1. The Trojan Horse Method in nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Spitaleri, C.; Mukhamedzhanov, A. M.; Blokhintsev, L. D.; Cognata, M. La; Pizzone, R. G.; Tumino, A.

    2011-12-01

    The study of energy production and nucleosynthesis in stars requires an increasingly precise knowledge of the nuclear reaction rates at the energies of interest. To overcome the experimental difficulties arising from the small cross sections at those energies and from the presence of the electron screening, the Trojan Horse Method has been introduced. The method provides a valid alternative path to measure unscreened low-energy cross sections of reactions between charged particles, and to retrieve information on the electron screening potential when ultra-low energy direct measurements are available.

  2. Storage ring mass spectrometry for nuclear structure and astrophysics research

    NASA Astrophysics Data System (ADS)

    Zhang, Y. H.; Litvinov, Yu A.; Uesaka, T.; Xu, H. S.

    2016-07-01

    In the last two and a half decades ion storage rings have proven to be powerful tools for precision experiments with unstable nuclides in the realm of nuclear structure and astrophysics. There are presently three storage ring facilities in the world at which experiments with stored radioactive ions are possible. These are the ESR in GSI, Darmstadt/Germany, the CSRe in IMP, Lanzhou/China, and the R3 storage ring in RIKEN, Saitama/Japan. In this work, an introduction to the facilities is given. Selected characteristic experimental results and their impact in nuclear physics and astrophysics are presented. Planned technical developments and the envisioned future experiments are outlined.

  3. Alpha resonant scattering for astrophysical reaction studies

    SciTech Connect

    Yamaguchi, H.; Kahl, D.; Nakao, T.; Wakabayashi, Y.; Kubano, S.; Hashimoto, T.; Hayakawa, S.; Kawabata, T.; Iwasa, N.; Teranishi, T.; Kwon, Y. K.; Binh, D. N.; Khiem, L. H.; Duy, N. G.

    2014-05-02

    Several alpha-induced astrophysical reactions have been studied at CRIB (CNS Radioactive Ion Beam separator), which is a low-energy RI beam separator at Center for Nuclear Study (CNS) of the University of Tokyo. One of the methods to study them is the α resonant scattering using the thick-target method in inverse kinematics. Among the recent studies at CRIB, the measurement of {sup 7}Be+α resonant scattering is discussed. Based on the result of the experiment, we evaluated the contributions of high-lying resonances for the {sup 7}Be(α,γ) reaction, and proposed a new cluster band in {sup 11}C.

  4. Nuclear Astrophysics and Neutron Induced Reactions: Quasi-Free Reactions and RIBs

    SciTech Connect

    Cherubini, S.; Spitaleri, C.; Crucilla, V.; Gulino, M.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Puglia, S.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Coc, A.; Kubono, S.; Binh, D. N.; Hayakawa, S.; Wakabayashi, Y.; Yamaguchi, H.; Burjan, V.; Kroha, V.; De Sereville, N.

    2010-08-12

    The use of quasi-free reactions in studying nuclear reactions between charged particles of astrophysical interest has received much attention over the last two decades. The Trojan Horse Method is based on this approach and it has been used to study a number of reactions relevant for Nuclear Astrophysics. Recently we applied this method to the study of nuclear reactions that involve radioactive species, namely to the study of the {sup 18}F+p{yields}{sup 15}O+{alpha} process at temperatures corresponding to the energies available in the classical novae scenario. Quasi-free reactions can also be exploited to study processes induced by neutrons. This technique is particularly interesting when applied to reaction induced by neutrons on unstable short-lived nuclei. Such processes are very important in the nucleosynthesis of elements in the sand r-processes scenarios and this technique can give hints for solving key questions in nuclear astrophysics where direct measurements are practically impossible.

  5. Nuclear Reactions for Astrophysics and Other Applications

    SciTech Connect

    Escher, J E; Burke, J T; Dietrich, F S; Scielzo, N D; Ressler, J J

    2011-03-01

    Cross sections for compound-nuclear reactions are required for many applications. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

  6. Nuclear astrophysics with gamma-ray line observations

    NASA Astrophysics Data System (ADS)

    Diehl, Roland

    Gamma-ray spectrometers with high spectral resolution have been operated in space since 2002. Major efforts to understand instrumental response and backgrounds are a requird before detailed science interpretations can be derived; by now, high-resolution line-shape studies have resulted in significant astrophysical constraints, not only through studies of solar-flare details, but also for nuclear processes in the Galaxy: 44Ti from the Cas A supernova could only be detected in the low-energy lines at 68 and 78 keV, the 1157 keV line from the same decay is not seen; this constrains 44Ti ejection in core collapse supernovae. Diffuse nucleosynthesis is studied through 26 Al, 60Fe, and positron annihilation gamma-ray measurements. The gamma-ray line from decay of radioactive 26Al could be measured at unpredecented spectroscopic precision. The new determination of the total mass of 26Al produced by stellar sources throughout the Galaxy yields 2.8 ±0.9 M , and the interstellar medium around 26Al sources appears characterized by velocities in the ~100 km s-1 region. 60Fe is clearly detected with SPI, its intensity ratio to 26Al of ~15% is on the lower side of predictions from massive-star and supernova nucleosynthesis models. Nucleosynthesis sources are probably minor contributors to Galactic positrons; this may be deduced from the bulge-centered spatial distribution of the annihilation gamma-ray emission, considering that nucleosynthesis sources are expected to populate mainly the disk part of the Galaxy. It is evident that new views at nuclear and astrophysical processes in and around cosmic sources are being provided through these space missions.

  7. Development of a new bremsstrahlung source for nuclear astrophysics

    SciTech Connect

    Makinaga, A.; Kato, K.; Kamiyama, T.; Yamamoto, K.

    2010-08-12

    Nuclear reaction rate for photodisintegration and their inverse, charged particle and neutron capture reactions, are important input quantities for stellar nucleosynthesis. In order to evaluate reaction rates precisely, both nuclear experiment and model prediction are needed. Recently, real photon-beam is used as powerful tools for astrophysics. In this work, current status of the development of a new bremsstrahlung {gamma}-ray source with the electron linear accelerator at Hokkaido University will be presented.

  8. Progress of Jinping Underground laboratory for Nuclear Astrophysics (JUNA)

    NASA Astrophysics Data System (ADS)

    Liu, WeiPing; Li, ZhiHong; He, JiangJun; Tang, XiaoDong; Lian, Gang; An, Zhu; Chang, JianJun; Chen, Han; Chen, QingHao; Chen, XiongJun; Chen, ZhiJun; Cui, BaoQun; Du, XianChao; Fu, ChangBo; Gan, Lin; Guo, Bing; He, GuoZhu; Heger, Alexander; Hou, SuQing; Huang, HanXiong; Huang, Ning; Jia, BaoLu; Jiang, LiYang; Kubono, Shigeru; Li, JianMin; Li, KuoAng; Li, Tao; Li, YunJu; Lugaro, Maria; Luo, XiaoBing; Ma, HongYi; Ma, ShaoBo; Mei, DongMing; Qian, YongZhong; Qin, JiuChang; Ren, Jie; Shen, YangPing; Su, Jun; Sun, LiangTing; Tan, WanPeng; Tanihata, Isao; Wang, Shuo; Wang, Peng; Wang, YouBao; Wu, Qi; Xu, ShiWei; Yan, ShengQuan; Yang, LiTao; Yang, Yao; Yu, XiangQing; Yue, Qian; Zeng, Sheng; Zhang, HuanYu; Zhang, Hui; Zhang, LiYong; Zhang, NingTao; Zhang, QiWei; Zhang, Tao; Zhang, XiaoPeng; Zhang, XueZhen; Zhang, ZiMing; Zhao, Wei; Zhao, Zuo; Zhou, Chao

    2016-04-01

    Jinping Underground laboratory for Nuclear Astrophysics (JUNA) will take the advantage of the ultra-low background of CJPL lab and high current accelerator based on an ECR source and a highly sensitive detector to directly study for the first time a number of crucial reactions occurring at their relevant stellar energies during the evolution of hydrostatic stars. In its first phase, JUNA aims at the direct measurements of 25Mg(p, γ)26Al, 19F(p, α)16O, 13C(α, n)16O and 12C(α, γ)16O reactions. The experimental setup, which includes an accelerator system with high stability and high intensity, a detector system, and a shielding material with low background, will be established during the above research. The current progress of JUNA will be given.

  9. Progress of Jinping Underground laboratory for Nuclear Astrophysics (JUNA)

    NASA Astrophysics Data System (ADS)

    Liu, WeiPing; Li, ZhiHong; He, JiangJun; Tang, XiaoDong; Lian, Gang; An, Zhu; Chang, JianJun; Chen, Han; Chen, QingHao; Chen, XiongJun; Chen, ZhiJun; Cui, BaoQun; Du, XianChao; Fu, ChangBo; Gan, Lin; Guo, Bing; He, GuoZhu; Heger, Alexander; Hou, SuQing; Huang, HanXiong; Huang, Ning; Jia, BaoLu; Jiang, LiYang; Kubono, Shigeru; Li, JianMin; Li, KuoAng; Li, Tao; Li, YunJu; Lugaro, Maria; Luo, XiaoBing; Ma, HongYi; Ma, ShaoBo; Mei, DongMing; Qian, YongZhong; Qin, JiuChang; Ren, Jie; Shen, YangPing; Su, Jun; Sun, LiangTing; Tan, WanPeng; Tanihata, Isao; Wang, Shuo; Wang, Peng; Wang, YouBao; Wu, Qi; Xu, ShiWei; Yan, ShengQuan; Yang, LiTao; Yang, Yao; Yu, XiangQing; Yue, Qian; Zeng, Sheng; Zhang, HuanYu; Zhang, Hui; Zhang, LiYong; Zhang, NingTao; Zhang, QiWei; Zhang, Tao; Zhang, XiaoPeng; Zhang, XueZhen; Zhang, ZiMing; Zhao, Wei; Zhao, Zuo; Zhou, Chao

    2016-02-01

    Jinping Underground lab for Nuclear Astrophysics (JUNA) will take the advantage of the ultralow background in Jinping underground lab, high current accelerator based on an ECR source and highly sensitive detector to study directly a number of crucial reactions to the hydrostatic stellar evolution for the first time at their relevant stellar energies. In its first phase, JUNA aims at the direct measurements of 25Mg(p,γ)26Al, 19F(p,α)16O, 13C(α,n)16O and 12C(α,γ)16O. The experimental setup, which include the accelerator system with high stability and high intensity, the detector system, and the shielding material with low background, will be established during the above research. The current progress of JUNA will be given.

  10. Accelerator Mass Spectrometry in Laboratory Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Nusair, O.; Bauder, W.; Gyürky, G.; Paul, M.; Collon, P.; Fülöp, Zs; Greene, J.; Kinoshita, N.; Palchan, T.; Pardo, R.; Rehm, K. E.; Scott, R.; Vondrasek, R.

    2016-01-01

    The extreme sensitivity and discrimination power of accelerator mass spectrometry (AMS) allows for the search and the detection of rare nuclides either in natural samples or produced in the laboratory. At Argonne National Laboratory, we are developing an AMS setup aimed in particular at the detection of medium and heavy nuclides, relying on the high ion energy achievable with the ATLAS superconducting linear accelerator and on gas-filled magnet isobaric separation. The setup was recently used for the detection of the 146Sm p-process nuclide and for a new determination of the 146Sm half-life (68.7 My). AMS plays an important role in the measurement of stellar nuclear reaction cross sections by the activation method, extending thus the technique to the study of production of long-lived radionuclides. Preliminary measurements of the 147Sm(γ,n)146Sm are described. A measurement of the 142Nd(α,γ)146Sm and 142Nd(α,n)145Sm reactions is in preparation. A new laser-ablation method for the feeding of the Electron Cyclotron Resonance (ECR) ion source is described.

  11. Indirect measurement of nuclear reactions of astrophysical interest

    SciTech Connect

    Liu, W. P.; Li, Z. H.; Bai, X. X.; Wang, Y. B.; Guo, B.; Lian, G.; Su, J.; Zeng, S.; Wang, B. X.; Yan, S. Q.; Li, Y. J.; Li, E. T.; Jin, S. J.

    2010-05-12

    Systematic indirect measurements of nuclear astrophysical reactions using the unstable ion beam facility GIRAFFE in CIAE were performed. We have measured the angular distributions of transfer reactions, such as {sup 8}Li(d,p){sup 9}Li, {sup 8}Li(d,n){sup 9}Be and {sup 8}Li(p,d){sup 7}Li in inverse kinematics, and derived the astrophysical S-factors or reaction rates for {sup 8}Li(n,gamma){sup 9}Li and {sup 8}Li(p,gamma){sup 9}Be by using asymptotic normalization coefficient (ANC) or spectroscopic factor methods.

  12. DIANA - A deep underground accelerator for nuclear astrophysics experiments

    SciTech Connect

    Winklehner, Daniel; Leitner, Daniela; Lemut, Alberto; Hodgkinson, Adrian; Couder, Manoel; Wiescher, Michael

    2013-04-19

    DIANA (Dakota Ion Accelerator for Nuclear Astrophysics) is a proposed facility designed to be operated deep underground. The DIANA collaboration includes nuclear astrophysics groups from Lawrence Berkeley National Laboratory, Michigan State University, Western Michigan University, Colorado School of Mines, and the University of North Carolina, and is led by the University of Notre Dame. The scientific goals of the facility are measurements of low energy nuclear cross-sections associated with sun and pre-supernova stars in a laboratory setup at energies that are close to those in stars. Because of the low stellar temperatures associated with these environments, and the high Coulomb barrier, the reaction cross-sections are extremely low. Therefore these measurements are hampered by small signal to background ratios. By going underground the background due to cosmic rays can be reduced by several orders of magnitude. We report on the design status of the DIANA facility with focus on the 3 MV electrostatic accelerator.

  13. Nuclear Astrophysics with rare isotopes at FRIB

    NASA Astrophysics Data System (ADS)

    Schatz, Hendrik

    2011-05-01

    The Facility for Rare Isotope Beams (FRIB) currently under construction at Michigan State University will be one of the worlds’ most powerful accelerators to produce rare isotopes. These isotopes live only fractions of seconds, but their properties are imprinted onto the composition of the visible universe and the nature of stellar explosions. FRIB will produce for the first time many of the rare isotopes that are part of the rapid neutron capture process, responsible for the origin of heavy elements; it will measure reaction rates that govern stellar explosions such as supernovae, novae, and X-ray bursts; and it will produce the same exotic nuclei that form the crust of neutron stars. I will discuss how data from FRIB, together with new observational data, promise to address many open questions at the intersection of nuclear physics and astronomy, including the chemical evolution of our Galaxy, the nuclear energy sources of stellar explosions, and the nature of neutron stars.

  14. EMPIRE: A Reaction Model Code for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Palumbo, A.; Herman, M.; Capote, R.

    2014-06-01

    The correct modeling of abundances requires knowledge of nuclear cross sections for a variety of neutron, charged particle and γ induced reactions. These involve targets far from stability and are therefore difficult (or currently impossible) to measure. Nuclear reaction theory provides the only way to estimate values of such cross sections. In this paper we present application of the EMPIRE reaction code to nuclear astrophysics. Recent measurements are compared to the calculated cross sections showing consistent agreement for n-, p- and α-induced reactions of strophysical relevance.

  15. The Trojan Horse method for nuclear astrophysics: Recent results on resonance reactions

    SciTech Connect

    Cognata, M. La; Pizzone, R. G.; Spitaleri, C.; Cherubini, S.; Romano, S.; Gulino, M.; Tumino, A.; Lamia, L.

    2014-05-09

    Nuclear astrophysics aims to measure nuclear-reaction cross sections of astrophysical interest to be included into models to study stellar evolution and nucleosynthesis. Low energies, < 1 MeV or even < 10 keV, are requested for this is the window where these processes are more effective. Two effects have prevented to achieve a satisfactory knowledge of the relevant nuclear processes, namely, the Coulomb barrier exponentially suppressing the cross section and the presence of atomic electrons. These difficulties have triggered theoretical and experimental investigations to extend our knowledge down to astrophysical energies. For instance, indirect techniques such as the Trojan Horse Method have been devised yielding new cutting-edge results. In particular, I will focus on the application of this indirect method to resonance reactions. Resonances might dramatically enhance the astrophysical S(E)-factor so, when they occur right at astrophysical energies, their measurement is crucial to pin down the astrophysical scenario. Unknown or unpredicted resonances might introduce large systematic errors in nucleosynthesis models. These considerations apply to low-energy resonances and to sub-threshold resonances as well, as they may produce sizable modifications of the S-factor due to, for instance, destructive interference with another resonance.

  16. The Trojan Horse method for nuclear astrophysics: Recent results on resonance reactions

    NASA Astrophysics Data System (ADS)

    La Cognata, M.; Spitaleri, C.; Cherubini, S.; Gulino, M.; Lamia, L.; Pizzone, R. G.; Romano, S.; Tumino, A.

    2014-05-01

    Nuclear astrophysics aims to measure nuclear-reaction cross sections of astrophysical interest to be included into models to study stellar evolution and nucleosynthesis. Low energies, < 1 MeV or even < 10 keV, are requested for this is the window where these processes are more effective. Two effects have prevented to achieve a satisfactory knowledge of the relevant nuclear processes, namely, the Coulomb barrier exponentially suppressing the cross section and the presence of atomic electrons. These difficulties have triggered theoretical and experimental investigations to extend our knowledge down to astrophysical energies. For instance, indirect techniques such as the Trojan Horse Method have been devised yielding new cutting-edge results. In particular, I will focus on the application of this indirect method to resonance reactions. Resonances might dramatically enhance the astrophysical S(E)-factor so, when they occur right at astrophysical energies, their measurement is crucial to pin down the astrophysical scenario. Unknown or unpredicted resonances might introduce large systematic errors in nucleosynthesis models. These considerations apply to low-energy resonances and to sub-threshold resonances as well, as they may produce sizable modifications of the S-factor due to, for instance, destructive interference with another resonance.

  17. Nuclear astrophysics experiments with stored, highly-charged ions at FRS-ESR at GSI

    SciTech Connect

    Scheidenberger, Christoph

    2010-08-12

    At the FRS-ESR complex of GSI a nuclear physics program with exotic nuclei has been established in last 18 years, which also addresses key questions and nuclear properties relevant in nuclear astrophysics. The paper summarizes production of exotic nuclei, lifetime studies of highly-charged ions, direct mass measurements and reactions at internal targets. A few comments on the analysis of two-body weak decays are given.

  18. Beta delayed neutrons for nuclear structure and astrophysics

    NASA Astrophysics Data System (ADS)

    Grzywacz, Robert

    2014-09-01

    Beta-delayed neutron emission (β xn) is a significant or even dominant decay channel for the majority of very neutron-rich nuclei, especially for those on the r-process path. The recent theoretical models predicts that it may play more significant role then previously expected for astrophysics and this realization instigated a renewed experimental interest in this topic as a part of a larger scope of research on beta-decay strength distribution. Because studies of the decay strength directly probe relevant physics on the microscopic level, energy-resolved measurements of the beta-decay strength distribution is a better test of nuclear models than traditionally used experimental observables like half-lives and neutron branching ratios. A new detector system called the Versatile Array of Neutron Detectors at Low Energy (VANDLE) was constructed to directly address this issue. In its first experimental campaign at the Holifield Radioactive Ion Beam Facility neutron energy spectra in key regions of the nuclear chart were measured: near the shell closures at 78Ni and 132Sn, and for the deformed nuclei near 100Rb. In several cases, unexpectedly intense and concentrated, resonant-like, high-energy neutron structures were observed. These results were interpreted within shell model framework which clearly indicated that these neutron emission is driven by nuclear structure effects and are due to large Gamow-Teller type transition matrix elements. This research was sponsored in part by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Cooperative Agreement No. DE-FG52-08NA28552.

  19. Nuclear Halos and Borromeans in the Primordial Nucleosynthesis Process and in Astrophysical Nuclear Reactions

    NASA Astrophysics Data System (ADS)

    Yilmaz, M.; Özer, O.

    2007-04-01

    Nuclear halo structures and Borromean nuclei have been intensely studied almost two decades. They have a cloud of neutrons and protons extended well beyond the surface of tightly bound core of neutrons and protons which is classically forbidden. Since the extended tail of the valance neutron wave-function of the neutron halos the cross-sections are much larger and their sizes become substantially much larger than the ordinary nuclei. Inferred expectations of halo and Borroeman nuclei in astrophysics due to their novel structures have been suggested to influence the astrophysical reactions, especially in the primordial furnace during the Standard Big Bang Nucleosynthesis (SBBN) process. It is seen that the large spatial extension directly implies that both elastic and absorption cross-sections are large for the reactions involving halo nuclei. The Trojan Horse Method (THM) and the Distorted Wave Born Approximation (DWBA) reaction cross-sections calculations are discussed for low energies.

  20. Nuclear Halos and Borromeans in the Primordial Nucleosynthesis Process and in Astrophysical Nuclear Reactions

    SciTech Connect

    Yilmaz, M.; Oezer, O.

    2007-04-23

    Nuclear halo structures and Borromean nuclei have been intensely studied almost two decades. They have a cloud of neutrons and protons extended well beyond the surface of tightly bound core of neutrons and protons which is classically forbidden. Since the extended tail of the valance neutron wave-function of the neutron halos the cross-sections are much larger and their sizes become substantially much larger than the ordinary nuclei. Inferred expectations of halo and Borroeman nuclei in astrophysics due to their novel structures have been suggested to influence the astrophysical reactions, especially in the primordial furnace during the Standard Big Bang Nucleosynthesis (SBBN) process. It is seen that the large spatial extension directly implies that both elastic and absorption cross-sections are large for the reactions involving halo nuclei. The Trojan Horse Method (THM) and the Distorted Wave Born Approximation (DWBA) reaction cross-sections calculations are discussed for low energies.

  1. Prospects of Optical Single Atom Detection for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Singh, Jaideep

    2015-10-01

    We will discuss the prospects of optically detecting single atoms captured in a cryogenic thin film of a noble gas such as neon. This proposed detection scheme, when coupled with a recoil separator, could be used to measure rare nuclear reactions relevant for nuclear astrophysics. In particular, we will focus on the 22Ne(α, n)25Mg reaction, which is an important source of neutrons for the s-process. Noble gas solids are an attractive medium because they are optically transparent and provide efficient, pure, stable, & chemically inert confinement for a wide variety of atomic and molecular species. Atoms embedded inside of noble gas solids have a fluorescence spectrum that is often significantly shifted from its absorption spectrum. This makes possible the detection of individual fluorescence photons against a background of intense excitation light, which can be suppressed using the appropriate optical filters. We will report on our efforts to optically detect single Yb atoms in solid Ne. Yb is an ideal candidate for initial studies because it emits a strong green fluorescence when excited by blue light and it has an atomic structure that very closely resembles that of Mg. This work is supported by funds from Michigan State University.

  2. The Joint Institute of Nuclear Astrophysics Virtual Journal

    NASA Astrophysics Data System (ADS)

    Ferguson, Ryan

    2008-10-01

    We have developed a weekly, online system for collecting and distributing scholarly articles of interest to researchers in nuclear astrophysics, a virtual journal (VJ), through the Joint Institute of Nuclear Astrophysics (JINA). The articles are gathered from a variety of well-known publications, and our database of both current and past issues is easily searchable by topics, chosen by the editors, or by keywords. Subscribers are notified of each new VJ issue through an email-list server. The VJ is a source for experimental and theoretical data for the JINA reaction rate database, and the references to review and popular level articles are a convenient way to introduce students to the literature. There are two related journals: the JINA VJ and the SEGUE VJ. Both the journals and support information are available at http://groups.nscl.msu.edu/jina/journals.

  3. Nuclear and particle physics, astrophysics and cosmology (NPAC) capability review

    SciTech Connect

    Redondo, Antonio

    2010-01-01

    The present document represents a summary self-assessment of the status of the Nuclear and Particle Physics, Astrophysics and Cosmology (NPAC) capability across Los Alamos National Laboratory (LANL). For the purpose of this review, we have divided the capability into four theme areas: Nuclear Physics, Particle Physics, Astrophysics and Cosmology, and Applied Physics. For each theme area we have given a general but brief description of the activities under the area, a list of the Laboratory divisions involved in the work, connections to the goals and mission of the Laboratory, a brief description of progress over the last three years, our opinion of the overall status of the theme area, and challenges and issues.

  4. Nuclear neutrino energy spectra in high temperature astrophysical environments

    NASA Astrophysics Data System (ADS)

    Misch, G. Wendell; Fuller, George M.

    2016-11-01

    Astrophysical environments that reach temperatures greater than ˜100 keV can have significant neutrino energy loss via both plasma processes and nuclear weak interactions. We find that nuclear processes likely produce the highest-energy neutrinos. The important weak nuclear interactions include both charged current channels (electron capture and emission and positron capture and emission) and neutral current channels (deexcitation of nuclei via neutrino pair emission). We show that, in order to make a realistic prediction of the nuclear neutrino spectrum, one must take nuclear structure into account; in some cases, the most important transitions may involve excited states, possibly in both parent and daughter nuclei. We find that the standard technique of producing a neutrino energy spectrum by using a single transition with a Q value and matrix element chosen to fit published neutrino production rates and energy losses will not accurately capture important spectral features.

  5. Nuclear astrophysics measurements with ELISSA at ELI-NP

    NASA Astrophysics Data System (ADS)

    Matei, C.; Balabanski, D. L.; Tesileanu, O.; Xu, Y.; La Cognata, M.; Spitaleri, C.

    2017-09-01

    ELISSA is a new silicon-strip detector array under development at the Extreme Light Infrastructure - Nuclear Physics facility in collaboration with INFN-LNS, Catania. ELI-NP will provide very intense, brilliant gamma beams, tunable from 200keV to 19.5MeV. Several reactions important for the astrophysical p-process, Big Bang Nucleosynthesis and supernova explosion have been selected for the first measurement campaigns starting in 2019.

  6. AZURE: An R-matrix code for nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Azuma, R. E.; Uberseder, E.; Simpson, E. C.; Brune, C. R.; Costantini, H.; de Boer, R. J.; Görres, J.; Heil, M.; Leblanc, P. J.; Ugalde, C.; Wiescher, M.

    2010-04-01

    The paper describes a multilevel, multichannel R-matrix code, AZURE, for applications in nuclear astrophysics. The code allows simultaneous analysis and extrapolation of low-energy particle scattering, capture, and reaction cross sections of relevance to stellar hydrogen, helium, and carbon burning. The paper presents a summary of R-matrix theory, code description, and a number of applications to demonstrate the applicability and versatility of AZURE.

  7. Theoretical nuclear structure and astrophysics. Progress report for 1996

    SciTech Connect

    Guidry, M.W.; Nazarewicz, W.; Strayer, M.R.

    1996-12-31

    This research effort is directed toward theoretical support and guidance for the fields of radioactive ion beam physics, gamma ray spectroscopy, computational and nuclear astrophysics, and the interface between these disciplines. The authors report substantial progress in all those areas. One measure of progress is publications and invited material. The research described here has led to more than 43 papers that are published, accepted, or submitted to refereed journals, and to 15 invited presentations at conferences and workshops.

  8. Wanted! Nuclear Data for Dark Matter Astrophysics

    SciTech Connect

    Gondolo, P.

    2014-06-15

    Astronomical observations from small galaxies to the largest scales in the universe can be consistently explained by the simple idea of dark matter. The nature of dark matter is however still unknown. Empirically it cannot be any of the known particles, and many theories postulate it as a new elementary particle. Searches for dark matter particles are under way: production at high-energy accelerators, direct detection through dark matter-nucleus scattering, indirect detection through cosmic rays, gamma rays, or effects on stars. Particle dark matter searches rely on observing an excess of events above background, and a lot of controversies have arisen over the origin of observed excesses. With the new high-quality cosmic ray measurements from the AMS-02 experiment, the major uncertainty in modeling cosmic ray fluxes is in the nuclear physics cross sections for spallation and fragmentation of cosmic rays off interstellar hydrogen and helium. The understanding of direct detection backgrounds is limited by poor knowledge of cosmic ray activation in detector materials, with order of magnitude differences between simulation codes. A scarcity of data on nucleon spin densities blurs the connection between dark matter theory and experiments. What is needed, ideally, are more and better measurements of spallation cross sections relevant to cosmic rays and cosmogenic activation, and data on the nucleon spin densities in nuclei.

  9. Wanted! Nuclear Data for Dark Matter Astrophysics

    NASA Astrophysics Data System (ADS)

    Gondolo, P.

    2014-06-01

    Astronomical observations from small galaxies to the largest scales in the universe can be consistently explained by the simple idea of dark matter. The nature of dark matter is however still unknown. Empirically it cannot be any of the known particles, and many theories postulate it as a new elementary particle. Searches for dark matter particles are under way: production at high-energy accelerators, direct detection through dark matter-nucleus scattering, indirect detection through cosmic rays, gamma rays, or effects on stars. Particle dark matter searches rely on observing an excess of events above background, and a lot of controversies have arisen over the origin of observed excesses. With the new high-quality cosmic ray measurements from the AMS-02 experiment, the major uncertainty in modeling cosmic ray fluxes is in the nuclear physics cross sections for spallation and fragmentation of cosmic rays off interstellar hydrogen and helium. The understanding of direct detection backgrounds is limited by poor knowledge of cosmic ray activation in detector materials, with order of magnitude differences between simulation codes. A scarcity of data on nucleon spin densities blurs the connection between dark matter theory and experiments. What is needed, ideally, are more and better measurements of spallation cross sections relevant to cosmic rays and cosmogenic activation, and data on the nucleon spin densities in nuclei.

  10. Progress of Jinping Underground laboratory for Nuclear Astrophysics experiment JUNA

    NASA Astrophysics Data System (ADS)

    Liu, Weiping

    2015-08-01

    Direct measurement of the cross sections for the key nuclear reactions in hydrostatic stellar evolution within Gamow window, which makes use of low background at deep underground laboratory, is crucial to solve key scientific questions in nuclear astrophysics. JUNA project aims at direct measurement of (α,γ), (α,n) reactions in hydrostatic helium burning and (p, γ), (p, α) reactions in hydrostatic hydrogen burning based on Jinping deep underground laboratory in China. The progress of experimental techniques, which include the accelerator system with high stability and high intensity, the detector system, and the shielding material with low background, will be presented.

  11. Recent Efforts in Data Compilations for Nuclear Astrophysics

    SciTech Connect

    Dillmann, Iris

    2008-05-21

    Some recent efforts in compiling data for astrophysical purposes are introduced, which were discussed during a JINA-CARINA Collaboration meeting on 'Nuclear Physics Data Compilation for Nucleosynthesis Modeling' held at the ECT* in Trento/Italy from May 29th-June 3rd, 2007. The main goal of this collaboration is to develop an updated and unified nuclear reaction database for modeling a wide variety of stellar nucleosynthesis scenarios. Presently a large number of different reaction libraries (REACLIB) are used by the astrophysics community. The 'JINA Reaclib Database' on http://www.nscl.msu.edu/{approx}nero/db/ aims to merge and fit the latest experimental stellar cross sections and reaction rate data of various compilations, e.g. NACRE and its extension for Big Bang nucleosynthesis, Caughlan and Fowler, Iliadis et al., and KADoNiS.The KADoNiS (Karlsruhe Astrophysical Database of Nucleosynthesis in Stars, http://nuclear-astrophysics.fzk.de/kadonis) project is an online database for neutron capture cross sections relevant to the s process. The present version v0.2 is already included in a REACLIB file from Basel university (http://download.nucastro.org/astro/reaclib). The present status of experimental stellar (n,{gamma}) cross sections in KADoNiS is shown. It contains recommended cross sections for 355 isotopes between {sup 1}H and {sup 210}Bi, over 80% of them deduced from experimental data.A ''high priority list'' for measurements and evaluations for light charged-particle reactions set up by the JINA-CARINA collaboration is presented. The central web access point to submit and evaluate new data is provided by the Oak Ridge group via the http://www.nucastrodata.org homepage. 'Workflow tools' aim to make the evaluation process transparent and allow users to follow the progress.

  12. Recent Efforts in Data Compilations for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Dillmann, Iris

    2008-05-01

    Some recent efforts in compiling data for astrophysical purposes are introduced, which were discussed during a JINA-CARINA Collaboration meeting on ``Nuclear Physics Data Compilation for Nucleosynthesis Modeling'' held at the ECT* in Trento/Italy from May 29th-June 3rd, 2007. The main goal of this collaboration is to develop an updated and unified nuclear reaction database for modeling a wide variety of stellar nucleosynthesis scenarios. Presently a large number of different reaction libraries (REACLIB) are used by the astrophysics community. The ``JINA Reaclib Database'' on http://www.nscl.msu.edu/~nero/db/ aims to merge and fit the latest experimental stellar cross sections and reaction rate data of various compilations, e.g. NACRE and its extension for Big Bang nucleosynthesis, Caughlan and Fowler, Iliadis et al., and KADoNiS. The KADoNiS (Karlsruhe Astrophysical Database of Nucleosynthesis in Stars, http://nuclear-astrophysics.fzk.de/kadonis) project is an online database for neutron capture cross sections relevant to the s process. The present version v0.2 is already included in a REACLIB file from Basel university (http://download.nucastro.org/astro/reaclib). The present status of experimental stellar (n,γ) cross sections in KADoNiS is shown. It contains recommended cross sections for 355 isotopes between 1H and 210Bi, over 80% of them deduced from experimental data. A ``high priority list'' for measurements and evaluations for light charged-particle reactions set up by the JINA-CARINA collaboration is presented. The central web access point to submit and evaluate new data is provided by the Oak Ridge group via the http://www.nucastrodata.org homepage. ``Workflow tools'' aim to make the evaluation process transparent and allow users to follow the progress.

  13. Trojan Horse technique to measure nuclear astrophysics rearrangement reactions

    NASA Astrophysics Data System (ADS)

    Spitaleri, Claudio

    2013-03-01

    The knowledge of nucleosynthesis and of energy production in stars requires an increasingly precise measurement of nuclear fusion reactions at the Gamow energy. Because of the Coulomb barrier reaction cross sections in astrophysics cannot be accessed directly at ultra -low energies, unless very favorable conditions are met. Moreover, the energies characterizing nuclear processes in several astrophysical contexts are so low that the presence of atomic electrons must be taken into account. Theoretical extrapolations of available data are then needed to derive astrophysical S(E)-factors. To overcome these experimental difficulties the Trojan Horse Method (THM) has been introduced. The method provides a valid alternative path to measure unscreened low-energy cross sections of reactions between charged particles, and to retrieve information on the electron screening potential when ultra-low energy direct measurements are available. While the theory has been discussed in detail in some theoretical works, present in the scientific literature, also in relation to different types of excitation functions (e.g. non-resonant and resonant), work on detailed methodology used to extract the events to be considered for the bare nucleus cross section measurements is still on going. In this work we will present some critical points in the application of THM that deserve to be discussed in more detail.

  14. Construction of the Solenoid Spectrometer for Nuclear AstroPhysics (SSNAP) at Notre Dame

    NASA Astrophysics Data System (ADS)

    Allen, Jacob; Bardayan, Dan; Blankstein, Drew; Hall, Matthew; Hall, Oscar; Kolata, James; O'Malley, Patrick; Becchetti, Frederick; Blackmon, Jeffery; Pain, Steven

    2016-09-01

    The study of nucleon transfer reactions gives information about many nuclei involved in astrophysical processes. The design and use of new detector systems improves our ability to accurately characterize these nuclei. The Solenoid Spectrometer for Nuclear AstroPhysics (SSNAP) is a new helical orbit spectrometer being designed at the University of Notre Dame to study transfer reactions with high-energy light ion beams from the FN tandem accelerator. SSNAP incorporates a series of position-sensitive silicon detectors to be set on-axis inside the second TwinSol solenoid. SSNAP will be sensitive to light ions produced in different reactions and the charged-particle decay products from the exotic nuclei produced. Results of initial testing and future plans with this detector system will be shown in this presentation. This work is supported by the National Science Foundation and the Joint Institute for Nuclear Astrophysics.

  15. A DUAL mission for nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    von Ballmoos, Peter; Alvarez, Jose; Barrière, Nicolas; Boggs, Steve; Bykov, Andrei; Del Cura Velayos, Juan Manuel; Frontera, Filippo; Hanlon, Lorraine; Hernanz, Margarita; Hinglais, Emmanuel; Isern, Jordi; Jean, Pierre; Knödlseder, Jürgen; Kuiper, Lucien; Leising, Mark; Pirard, Benoît; Prost, Jean-Pierre; da Silva, Rui M. Curado; Takahashi, Tadayuki; Tomsick, John; Walter, Roland; Zoglauer, Andreas

    2012-10-01

    DUAL will study the origin and evolution of the elements and explores new frontiers of physics: extreme energies that drive powerful stellar explosions and accelerate particles to macroscopic energies; extreme densities that modify the laws of physics around the most compact objects known; and extreme fields that influence matter in a way that is unknown on Earth. The variability of these extreme objects requires continuous all-sky coverage, while detailed study demands an improvement in sensitivity over previous technologies by at least an order of magnitude. The DUAL payload is composed of an All-Sky Compton Imager (ASCI), and two optical modules, the Laue-Lens Optic (LLO) and the Coded-Mask Optic (CMO). The ASCI serves dual roles simultaneously, both as an optimal focal-plane sensor for deep observations with the optical modules and as a sensitive true all-sky telescope in its own right for all-sky surveys and monitoring. While the optical modules are located on the main satellite, the All-Sky Compton Imager is situated on a deployable structure at a distance of 30 m from the satellite. This configuration not only permits to maintain the less massive payload at the focal distance, it also greatly reduces the spacecraft-induced detector background, and, above all it provides ASCI with a continuous all-sky exposure.

  16. MAX, a Laue diffraction lens for nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Barrière, N.; von Ballmoos, P.; Halloin, H.; Abrosimov, N.; Alvarez, J. M.; Andersen, K.; Bastie, P.; Boggs, S.; Courtois, P.; Courvoisier, T.; Harris, M.; Hernanz, M.; Isern, J.; Jean, P.; Knödlseder, J.; Skinner, G.; Smither, B.; Ubertini, P.; Vedrenne, G.; Weidenspointner, G.; Wunderer, C.

    2005-12-01

    The next generation of instrumentation for nuclear astrophysics will have to achieve a factor of 10 100 improvement in sensitivity over present technologies. With the focusing gamma-ray telescope MAX we take up this challenge: combining unprecedented sensitivity with high spectral and angular resolution, and the capability of measuring the polarization of the incident photons. The feasibility of such a crystal diffraction gamma-ray lens has recently been demonstrated with the prototype lens CLAIRE. MAX is a proposed mission which will make use of satellite formation flight to achieve 86 m focal length, with the Laue lens being carried by one satellite and the detector by the other. In the current design, the Laue diffraction lens of MAX will consist of 13740 copper and germanium (Ge1- x Si x , x ˜ 0.02) crystal tiles arranged on 36 concentric rings. It simultaneously focuses in two energy bands, each centred on one of the main scientific objectives of the mission: the 800 900 keV band is dedicated to the study of nuclear gamma-ray lines from type Ia supernovae (e.g. 56 Co decay line at 847 keV) while the 450 530 keV band focuses on electron-positron annihilation (511 keV emission) from the Galactic centre region with the aim of resolving potential point sources. MAX promises a breakthrough in the study of point sources at gamma-ray energies by combining high narrow-line sensitivity (better than 10-6 cm-2 s-1) and high energy resolution (E/dE ˜ 500). The mission has successfully undergone a pre-phase A study with the French Space Agency CNES, and continues to evolve: new diffracting materials such as bent or composite crystals seem very promising.

  17. Nuclear astrophysics: the unfinished quest for the origin of the elements

    NASA Astrophysics Data System (ADS)

    José, Jordi; Iliadis, Christian

    2011-09-01

    Half a century has passed since the foundation of nuclear astrophysics. Since then, this discipline has reached its maturity. Today, nuclear astrophysics constitutes a multidisciplinary crucible of knowledge that combines the achievements in theoretical astrophysics, observational astronomy, cosmochemistry and nuclear physics. New tools and developments have revolutionized our understanding of the origin of the elements: supercomputers have provided astrophysicists with the required computational capabilities to study the evolution of stars in a multidimensional framework; the emergence of high-energy astrophysics with space-borne observatories has opened new windows to observe the Universe, from a novel panchromatic perspective; cosmochemists have isolated tiny pieces of stardust embedded in primitive meteorites, giving clues on the processes operating in stars as well as on the way matter condenses to form solids; and nuclear physicists have measured reactions near stellar energies, through the combined efforts using stable and radioactive-ion beam facilities. This review provides comprehensive insight into the nuclear history of the Universe and related topics: starting from the Big Bang, when the ashes from the primordial explosion were transformed to hydrogen, helium and a few trace elements, to the rich variety of nucleosynthesis mechanisms and sites in the Universe. Particular attention is paid to the hydrostatic processes governing the evolution of low-mass stars, red giants and asymptotic giant-branch stars, as well as to the explosive nucleosynthesis occurring in core-collapse and thermonuclear supernovae, γ-ray bursts, classical novae, x-ray bursts, superbursts and stellar mergers.

  18. MAX-a gamma-ray lense for nuclear astrophysics.

    SciTech Connect

    von Ballmoos, P.; Halloin, H.; Skinner, G.; Smither, B.; Paul, J.; Abrosimov, N.; Alvarez, J.; Astier , P.; Bastie, P.; Barrett, D.; Bazzano, A.; Blanchard, A.; Boutonnet, A.; Brousse, P.; Cordier, B.; Courvoisier, T.; DiCocco, G.; Giuliani, A.; Hamelin, B.; Hernanz, M.; Jean, P.; Isern, J.; Knodlseder, J.; Laurent, P.; Lebrun, F.; Experimental Facilities Division; CESR; CEA-Saclay; Inst. fur Kristallzuchtung; IEEC; LPNHE; Inst. Laue-Langevin; IAS; LA-OMP; Alcatel Space Industries; ISDC; TESRE; Univ. Insurbia

    2004-01-01

    The mission concept MAX is a space borne crystal diffraction telescope, featuring a broad-band Laue lens optimized for the observation of compact sources in two wide energy bands of high astrophysical relevance. For the first time in this domain, gamma-rays will be focused from the large collecting area of a crystal diffraction lens onto a very small detector volume. As a consequence, the background noise is extremely low, making possible unprecedented sensitivities. The primary scientific objective of MAX is the study of type Ia supernovae by measuring intensities, shifts and shapes of their nuclear gamma-ray lines. When finally understood and calibrated, these profoundly radioactive events will be crucial in measuring the size, shape, and age of the Universe. Observing the radioactivities from a substantial sample of supernovae and novae will significantly improve our understanding of explosive nucleosynthesis. Moreover, the sensitive gamma-ray line spectroscopy performed with MAX is expected to clarify the nature of galactic microquasars (e{sup +}e{sup -} annihilation radiation from the jets), neutrons stars and pulsars, X-ray Binaries, AGN, solar flares and, last but not least, gamma-ray afterglow from gamma-burst counterparts.

  19. Studies of alpha-induced astrophysical reactions at CRIB

    SciTech Connect

    Yamaguchi, H.; Hashimoto, T.; Hayakawa, S.; Binh, D. N.; Kahl, D.; Kubono, S.

    2010-08-12

    CRIB (CNS Radioactive Ion Beam separator) is a low-energy RI beam separator at the Center for Nuclear Study (CNS) of the University of Tokyo. Using the RI beams at CRIB, many measurements on proton alpha resonance scatterings, ({alpha},p) reactions, and others were performed in recent years mainly for studying astrophysical reactions and exotic nuclear structure. Among them, the results on the {sup 7}Li+{alpha} resonance scatterings are presented.

  20. Investigating resonances above and below the threshold in nuclear reactions of astrophysical interest and beyond

    SciTech Connect

    La Cognata, M.; Kiss, G. G.; Mukhamedzhanov, A. M.; Spitaleri, C.; Trippella, O.

    2015-10-15

    Resonances in nuclear cross sections dramatically change their trends. Therefore, the presence of unexpected resonances might lead to unpredicted consequences on astrophysics and nuclear physics. In nuclear physics, resonances allow one to study states in the intermediate compound systems, to evaluate their cluster structure, for instance, especially in the energy regions approaching particle decay thresholds. In astrophysics, resonances might lead to changes in the nucleosynthesis flow, determining different isotopic compositions of the nuclear burning ashes. For these reasons, the Trojan Horse method has been modified to investigate resonant reactions. Thanks to this novel approach, for the first time normalization to direct data might be avoided. Moreover, in the case of sub threshold resonances, the Trojan Horse method modified to investigate resonances allows one to deduce the asymptotic normalization coefficient, showing the close connection between the two indirect approaches.

  1. Penetration Factor for Nuclear Fusion Reaction in Nonthermal Astrophysical Plasmas

    NASA Astrophysics Data System (ADS)

    Ki, Dai-Han; Jung, Young-Dae

    2011-02-01

    The nonthermal effects on the nuclear fusion reaction process are investigated in Lorentzian astrophysical plasmas. The closed expression of the classical turning point in Lorentzian plasmas is obtained by the Lambert W-function. Using the WKB analysis with the effective screening length, the closed expressions of the fusion penetration factor and the cross section for the nuclear fusion reaction in Lorentzian plasmas are obtained as functions of the spectral index, relative kinetic energy, and plasma parameters. It is shown that the nonthermal character of the Lorentzian plasma enhances the fusion penetration factor. In addition, the nonthermal effect on the penetration factor is found to be more significant in plasmas with higher densities. It would be expected that the fusion reaction rates of the p-p chain and the CNO cycle in nonthermal plasmas are always greater than those in thermal Maxwellian plasmas.

  2. Approximate penetration factors for nuclear reactions of astrophysical interest

    NASA Technical Reports Server (NTRS)

    Humblet, J.; Fowler, W. A.; Zimmerman, B. A.

    1987-01-01

    The ranges of validity of approximations of P(l), the penetration factor which appears in the parameterization of nuclear-reaction cross sections at low energies and is employed in the extrapolation of laboratory data to even lower energies of astrophysical interest, are investigated analytically. Consideration is given to the WKB approximation, P(l) at the energy of the total barrier, approximations derived from the asymptotic expansion of G(l) for large eta, approximations for small values of the parameter x, applications of P(l) to nuclear reactions, and the dependence of P(l) on channel radius. Numerical results are presented in tables and graphs, and parameter ranges where the danger of serious errors is high are identified.

  3. Research activities in nuclear astrophysics and related areas

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NASA/GRO grant NAG 5-2081, at the University of Chicago, has provided support for a broad program of theoretical research in nuclear astrophysics and related areas, with regard to gamma-ray and hard X-ray emission from classical nova explosions. This research emphasized the possible detection of 22Na gamma-ray line emission from nearby novae involving ONeMg white dwarfs, the detailed examination of 26Al production in novae, and the possible detection of the predicted early gamma ray emission from novae that arises from the decay of the short lived, positron emitting isotopes of CNO elements. Studies of nova related problems have consumed an increasing fraction of the Principal Investigator's research efforts over the past decade. Current research addresses problems associated with the standard model for the outbursts of the classical novae: the occurrence of thermonuclear runaways (TNR) in the accreted hydrogen rich envelopes on white dwarfs in close binary systems (see, e.g., the reviews by Truran 1982; and Shara 1989). Research in progress and planned for the next three years has three main objectives: (1) to gain an improved understanding of the early evolution of the light curves of, particularly, the fastest novae; (2) to gain an improved understanding of the relative importance of the various possible mechanisms of envelope hydrogen depletion (e.g. winds, common envelope driven mass loss, and nuclear burning) to the long term evolution of novae in outburst; and (3) to seek to provide a somewhat more definitive statement of the role of classical novae in nucleosynthesis. Our proposed 2-D studies of convection during the early phases of the TNR and our systematic attempt to incorporate an improved treatment of radiation hydrodynamics into the hydrodynamic code utilized in our calculations, are particularly relevant to the first of these objectives. Further 2-D studies of the effects of common envelope evolution are intended to provide more realistic constraints

  4. Recent astrophysical applications of the Trojan Horse Method to nuclear astrophysics

    SciTech Connect

    Spitaleri, C.; Cherubini, S.; Crucilla, V.; Gulino, M.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Tumino, A.; Fu, C.; Tribble, R.; Banu, A.; Al-Abdullah, T.; Goldberg, V.; Mukhamedzhanov, A.; Tabacaru, G.; Trache, L.

    2008-05-21

    The Trojan Horse Method (THM) is an unique indirect technique allowing to measure astrophysical rearrangement reactions down to astrophysical relevant energies. The basic principle and a review of the recent applications of the Trojan Horse Method are presented. The applications aiming to the extraction of the bare astrophysical S{sub b}(E) for some two-body processes are discussed.

  5. Nuclear astrophysics at the Holifield Radioactive Ion Beam Facility

    SciTech Connect

    Smith, M.S.

    1994-12-31

    The potential for understanding spectacular stellar explosions such as novae, supernovae, and X-ray bursts will be greatly enhanced by the availability of the low-energy, high-intensity, accelerated beams of proton-rich radioactive nuclei currently being developed at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory. These beams will be utilized in absolute cross section measurements of crucial (p, {gamma}) capture reactions in efforts to resolve the substantial qualitative uncertainties in current models of explosive stellar hydrogen burning outbursts. Details of the nuclear astrophysics research program with the unique HRIBF radioactive beams and a dedicated experimental endstation--centered on the Daresbury Recoil Separator--will be presented.

  6. Laboratory tests of low density astrophysical nuclear equations of state.

    PubMed

    Qin, L; Hagel, K; Wada, R; Natowitz, J B; Shlomo, S; Bonasera, A; Röpke, G; Typel, S; Chen, Z; Huang, M; Wang, J; Zheng, H; Kowalski, S; Barbui, M; Rodrigues, M R D; Schmidt, K; Fabris, D; Lunardon, M; Moretto, S; Nebbia, G; Pesente, S; Rizzi, V; Viesti, G; Cinausero, M; Prete, G; Keutgen, T; El Masri, Y; Majka, Z; Ma, Y G

    2012-04-27

    Clustering in low density nuclear matter has been investigated using the NIMROD multidetector at Texas A&M University. Thermal coalescence modes were employed to extract densities, ρ, and temperatures, T, for evolving systems formed in collisions of 47A MeV (40)Ar+(112)Sn, (124)Sn and (64)Zn+(112)Sn, (124)Sn. The yields of d, t, (3)He, and (4)He have been determined at ρ=0.002 to 0.03 nucleons/fm(3) and T=5 to 11 MeV. The experimentally derived equilibrium constants for α particle production are compared with those predicted by a number of astrophysical equations of state. The data provide important new constraints on the model calculations.

  7. Unscreened cross-sections for nuclear astrophysics via the Trojan Horse Method

    NASA Astrophysics Data System (ADS)

    Tumino, A.; Spitaleri, C.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Sergi, M. L.

    2014-12-01

    The bare nucleus astrophysical S(E) factor is the Nuclear Physics parameter to determine the reaction rates in stellar plasmas. Whilst not being accessed in direct measurements, it can be easily determined using the Trojan Horse Method, successful indirect technique for nuclear astrophysics. The basic features of the method will be discussed and some recent results will be presented.

  8. New Advances in the Trojan Horse Method as an Indirect Approach to Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Tumino, A.; Spitaleri, C.; Cherubini, S.; Gulino, M.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Spartà, R.

    2013-05-01

    With the introduction of the Trojan Horse Method, nuclear cross sections between charged particles at astrophysical energies can now be measured. Here the basic features of the method are recalled together with recent results relevant for Nuclear Astrophysics. New applications in connection with plasma physics and industrial energy production are discussed.

  9. 2nd Iberian Nuclear Astrophysics Meeting on Compact Stars

    NASA Astrophysics Data System (ADS)

    Perez-Garcia, M. Angeles; Pons, Jose; Albertus, C.

    2012-02-01

    ORGANIZING COMMITTEE Dr M Ángeles Pérez-García (Área Física Teórica-Universidad de Salamanca & IUFFYM) Dr J A Miralles (Universidad de Alicante) Dr J Pons (Universidad de Alicante) Dr C Albertus (Área Física Nuclear-Universidad de Salamanca & IUFFYM) Dr F Atrio (Área Física Teórica-Universidad de Salamanca & IUFFYM) PREFACE The second Iberian Nuclear Astrophysics meeting was held at the University of Salamanca, Spain on 22-23 September 2011. This volume contains most of the presentations delivered at this international workshop. This meeting was the second in the series following the previous I Encuentro Ibérico de Compstar, held at the University of Coimbra, Portugal in 2010. The main purpose of this meeting was to strengthen the scientific collaboration between the participants of the Iberian and the rest of the southern European branches of the European Nuclear Astrophysics network, formerly, COMPSTAR. This ESF (European Science Foundation) supported network has been crucial in helping to make a broader audience for the the most interesting and relevant research lines being developed currently in Nuclear Astrophysics, especially related to the physics of neutron stars. It is indeed important to emphasize the need for a collaborative approach to the rest of the scientific communities so that we can reach possible new members in this interdisciplinary area and as outreach for the general public. The program of the meeting was tailored to theoretical descriptions of the physics of neutron stars although some input from experimental observers and other condensed matter and optics areas of interest was also included. The main scientific topics included: Magnetic fields in compact stars Nuclear structure and in-medium effects in nuclear interaction Equation of state: from nuclear matter to quarks Importance of crust in the evolution of neutron stars Computational simulations of collapsing dense objects Observational phenomenology In particular, leading

  10. Screening in Low Energy Nuclear Reactions of Importance to Astrophysics

    NASA Astrophysics Data System (ADS)

    Miley, George H.; Hora, Heinz; Luo, Nie

    2004-05-01

    Recent experiments in the LUNAR (Laboratory for Underground Nuclear Astrophysics) project have shown anonymously high electron screening may occur during acceleration driven low energy (<400 kV) ion bombardment of solid targets [1]. These effects become particularly important for E/ Ue < 100 (here E= ion energy and Ue = electron-screening potential energy). Thus these effects become significant for the understanding of reactions involved in nucleosynthesis of the elements and the interpretation of astrophysical data [1]. Another example of the behavior is the surprising threshold behavior near 18 keV for deuterons stopping in 3He gas at energies below the Bragg peak [2]. As pointed out in ref [1], the theoretical explanation for these effects is still under debate. Several researchers have proposed variations of the Trojan Horse Method (THM) to explain these effects [3]. In this paper, we propose an alternate mechanism associated with electron charge accumulation around the target atoms arising from the solid-state structure of the host. This concept will be explained in terms of density functional calculations of charge density profiles in a target undergoing ion dynamic effects [4]. REFERENCES [1] F. Strieder, et al., Naturwissenschaften (2000)88:461-467 [2] A. Formicola, et al., (2000) Eur Phys J. A 8:443-446 [3] S. Typel and H H Wolter, (2000) Few-Body System 29:75-93 [4] G. Miley and H. Hora, (2000) Nuclear Reactions in Solids, APS mtg. Lansing, MI [5] G. Miley, A. Lipson, N. Luo, and H. Hora, (2003) IEEE NSS/MIC Conf., Portland, OR

  11. Theoretical Studies in Gamma-Ray Astrophysics

    NASA Technical Reports Server (NTRS)

    Lingenfelter, Richard E.

    1998-01-01

    These studies were stimulated by the reported COMPTEL detection of nuclear gamma ray line emission from the Orion star formation region. Although the observation have very recently been retracted, the detailed analyses that we carried out clearly showed that the low energy cosmic rays that would have been required to explain the reported fluxes were exceedingly restrictive and thus highly improbable. More importantly, these studies proved to be the trigger for very productive new work. In particular, they led us into carefully re-examining the problem of the origin of the light elements, Li, Be and B, where we showed that the light elements could, in fact, be produced primarily by Galactic cosmic rays and did not require an unobserved low energy cosmic ray source , as had been suggested. We further showed that the observed abundances of Be and B in old halo stars contradicted the common belief that the Galactic cosmic rays were accelerated out of the well mixed interstellar medium, and required instead that they be accelerated out of freshly synthesized matter from supernovae. This work, in turn, led us to propose a new origin of Galactic cosmic rays from the refractory grains in supernova enriched core of superbubbles, which is now the subject of our on-going research under a new grant from the Astrophysics Theory Program.

  12. Promising lines of research in the realms of laboratory nuclear astrophysics by means of powerful lasers

    SciTech Connect

    Belyaev, V. S. Zagreev, B. V.; Kedrov, A. Yu.; Lobanov, A. V.; Matafonov, A. P.; Bolshakov, V. V.; Savel’ev, A. B.; Mordvintsev, I. M.; Tsymbalov, I. N.; Shulyapov, S. A.; Pikuz, S. A.; Skobelev, I. Yu.; Filippov, E. D.; Faenov, A. Ya.; Krainov, V. P.

    2016-09-15

    Basic nuclear-astrophysics problems that can be studied under laboratory conditions at a laserradiation intensity of 10{sup 18} W/cm{sup 2} or more are specified. These are the lithium problem, the problem of determining neutron sources for s-processes of heavy-element formation, the formation of bypassed stable p-nuclei, and nuclear reactions involving isotopes used by astronomers for diagnostics purposes. The results of experiments at the Neodym laser facility are presented, and proposals for further studies in these realms are formulated.

  13. Progress Towards Optical Single Atom Detection for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Singh, Jaideep; Wenzl, Jennifer; Frisbie, Dustin; Parzuchowski, Kristen; Johnson, Maegan

    2016-09-01

    We are developing the technique of optically detecting individual atoms embedded in thin films of cryogenically frozen solids. Noble gas solids such as frozen neon are an attractive medium because they are optically transparent and provide efficient, pure, stable, & chemically inert confinement for a wide variety of atomic and molecular species. We propose to couple this new detection technique to a recoil separator with the goal of measuring rare nuclear reactions relevant for nuclear astrophysics. Because of the additional selectivity provided by the atomic transitions of the captured atom, this detection scheme would help loosen the often demanding beam rejection requirements imposed on recoil separators. Our initial focus is the 22Ne(α, n)25Mg reaction, which is an important source of neutrons for the s-process. We will describe our measurements of the atomic & optical parameters needed to optimize the optical layout as well as a promising design for a prototype detector. This work is generously supported by Michigan State University.

  14. Excitation of compound states in subsystems as an indirect tool in nuclear astrophysics. The theory of the Trojan Horse method

    SciTech Connect

    Mukhamedzhanov, A. M.

    2010-03-01

    Astrophysical reactions proceeding through compound states represent one of the crucial part of nuclear astrophysics. However, due to the presence of the Coulomb barrier, it is often very difficult or even impossible to obtain the astrophysical S(E) factor from measurements in the laboratory at astrophysically relevant energies. The Trojan Horse method (THM) provides a unique tool to obtain the information about resonant astrophysical reactions at astrophysical energies. Here the theory and application of the THM for the resonant reactions is addressed.

  15. Decay data of radionuclides along the valley of nuclear stability for astrophysical applications.

    PubMed

    Chechev, Valery P; Huang, Xiaolong

    2015-11-01

    Several directions of the demand for decay data in nuclear astrophysics are discussed for radionuclides near the valley of nuclear stability. The current half-life and gamma-ray intensity evaluation results are presented for some radionuclides of astrophysical interest. An extended list of such nuclides is offered for their nuclear characteristics to be further evaluated by the Decay Data Evaluation Project collaboration participants.

  16. Phenomenological correlations in nuclear structure: An opportunity for nuclear astrophysics and a challenge to theory

    SciTech Connect

    Casten, R.F.; Zamfir, N.V. |

    1992-12-01

    Though it often appears daunting in its complexity, nuclear data frequently exhibits remarkable simplicities when viewed from the appropriate perspectives. This realization, which is becoming more and more apparent, is one of the fruits of the vast amount of nuclear data that has been accumulated over many years but, surprisingly, has never been completely digested. This emerging, unified, and simple macroscopic phenomenology, aided by microscopic underpinnings and physical arguments, appears in many guises and often simplifies semi-empirical estimates of structure far from stability in the critical realms where nuclear astrophysics takes place and where it is in need for improved nuclear input. The generality of simple phenomenological relationships begs both for a sound theoretical basis and for the advent of Radioactive Nuclear Beams so that the reliability of their extrapolations can be assessed and tested. These issues will be discussed, and illustrated with a number of specific examples.

  17. Phenomenological correlations in nuclear structure: An opportunity for nuclear astrophysics and a challenge to theory

    SciTech Connect

    Casten, R.F. ); Zamfir, N.V. Clark Univ., Worcester, MA )

    1992-01-01

    Though it often appears daunting in its complexity, nuclear data frequently exhibits remarkable simplicities when viewed from the appropriate perspectives. This realization, which is becoming more and more apparent, is one of the fruits of the vast amount of nuclear data that has been accumulated over many years but, surprisingly, has never been completely digested. This emerging, unified, and simple macroscopic phenomenology, aided by microscopic underpinnings and physical arguments, appears in many guises and often simplifies semi-empirical estimates of structure far from stability in the critical realms where nuclear astrophysics takes place and where it is in need for improved nuclear input. The generality of simple phenomenological relationships begs both for a sound theoretical basis and for the advent of Radioactive Nuclear Beams so that the reliability of their extrapolations can be assessed and tested. These issues will be discussed, and illustrated with a number of specific examples.

  18. Looking at Low-Background Nuclear Astrophysics Measurements using CASPAR

    NASA Astrophysics Data System (ADS)

    Robertson, Daniel; Couder, Manoel; Griefe, Uwe; Jung, Hyo Soon; Setoodehnia, Kiana; Wiescher, Michael; Wells, Doug; Caspar Collaboration

    2014-09-01

    An accelerator laboratory (CASPAR) to be installed at the Sanford Underground Research Facility (SURF) is being constructed by a collaboration lead by South Dakota School of Mines and Technology. The study of alpha induced reactions of astrophysical interest in a quasi-background free environment is the goal of the laboratory. Specifically, neutron producing reactions for the s-process will be investigated. This process is responsible for the nucleosynthesis of half of the elements heavier than iron. An outline of CASPAR, its timeline and scientific goals will be presented. An accelerator laboratory (CASPAR) to be installed at the Sanford Underground Research Facility (SURF) is being constructed by a collaboration lead by South Dakota School of Mines and Technology. The study of alpha induced reactions of astrophysical interest in a quasi-background free environment is the goal of the laboratory. Specifically, neutron producing reactions for the s-process will be investigated. This process is responsible for the nucleosynthesis of half of the elements heavier than iron. An outline of CASPAR, its timeline and scientific goals will be presented. Funding provided by SDSTA.

  19. ^26Al Beam Production and its Application to Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Richard, Brad

    2012-10-01

    Presumably produced during the supernova stage of stellar evolution, ^26Al offers unique opportunities to better understand the processes of nucleosynthesis occurring in pre-SN phases of stellar evolution and within the Galactic disk. When decaying to ^26Mg, ^26Al emits a unique 1.8MeV gamma ray, detectable by satellite telescopes. The production and destruction pathways of ^26Al is a key portion of understanding the on-going stellar nucleosynthesis. In order to measure the cross-section of ^26Al(n, p) ^26Mg at the astrophysical relevant energies, an indirect method, called the Trojan Horse Method(THM), is utilized. The THM allows the study of neutron induced reactions at astrophysical energies via the d break-up. This method requires the three-body cross section for the ^26Al(d, p ^26Mg)H reaction to be measured at a beam of 60 MeV. This requires that the ^26Al secondary beam is produced by the MARS facility at Cyclotron institute of Texas A&M University from a primary ^26Mg beam (E 16MeV/u) impinging on a H2 target. ^26Al beam was then degraded to 2.25MeV/u energy by means of a Beryllium foil. The obtained results will be shown and discussed in details together with the features of the obtained intense and pure beam.

  20. Ab initio calculations of nuclear reactions important for astrophysics

    NASA Astrophysics Data System (ADS)

    Navratil, Petr; Dohet-Eraly, Jeremy; Calci, Angelo; Horiuchi, Wataru; Hupin, Guillaume; Quaglioni, Sofia

    2016-09-01

    In recent years, significant progress has been made in ab initio nuclear structure and reaction calculations based on input from QCD employing Hamiltonians constructed within chiral effective field theory. One of the newly developed approaches is the No-Core Shell Model with Continuum (NCSMC), capable of describing both bound and scattering states in light nuclei simultaneously. We will present NCSMC results for reactions important for astrophysics that are difficult to measure at relevant low energies, such as 3He(α,γ)7Be and 3H(α,γ)7Li and 11C(p,γ)12N radiative capture, as well as the 3H(d,n)4He fusion. We will also address prospects of calculating the 2H(α,γ)6Li capture reaction within the NCSMC formalism. Prepared in part by LLNL under Contract DE-AC52-07NA27344. Supported by the U.S. DOE, OS, NP, under Work Proposal No. SCW1158, and by the NSERC Grant No. SAPIN-2016-00033. TRIUMF receives funding from the NRC Canada.

  1. Radioactive targets for nuclear astrophysics research at LANSCE

    SciTech Connect

    Koehler, P.E.; O'Brien, H.A.; Gursky, J.C.

    1990-01-01

    During the past few years we have made measurements of (n,p) and (n,{alpha}) cross sections on several radioactive nuclei of importance to nuclear astrophysics. The measurements were made at the Manuel Lujan, Jr., Neutron Scattering Center (LANSCE) from thermal neutron energy to approximately 100 keV. Successful measurements have been completed on the radioisotopes {sup 7}Be, {sup 22}Na and {sup 36}Cl while preliminary data have been taken on targets of {sup 54}Mn and {sup 55}Fe. Similar measurements have also been made on the stable isotopes {sup 14}N, {sup 17}O and {sup 35}Cl. We are currently assembling a 4{pi} barium fluoride (BaF{sub 2}) detector which will allow us to expand our program to (n,{gamma}) measurements. The (n,{gamma}) (and in some cases future (n,p)) measurements will require targets with higher specific activity and greater chemical purity than we have so far been able to use. We discuss the fabrication techniques used for the samples produced so far, the requirements the future (n,{gamma}) targets must meet and our current plans for producing them, and the physics motivations for the measurements.

  2. A Photo Archive for the History of Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Clayton, D. D.

    2001-12-01

    A web site bearing this name has been created at Clemson University. (http://photon.phys.clemson.edu/wwwpages/PhotoArchive) Selected photographs (about 250) come from the author's personal photograph collection covering 45 years of research in nuclear astrophysics. The historiography will be described. Each photograph is accompanied by an accurate caption, including references to works being pursued at the time the photos were taken. The accuracy of the captions was itself a research effort, aided greatly by the author's three decades of daily diaries. Featured are the author's experiences with colleagues at Caltech (1956-67), Cambridge (1967-74), Rice University (1963-89), Heidelberg (1976-84) and Clemson University (1989-2001). Photographs may be used subject to the constraints and acknowledgements posted on the site. This entire collection has been given to the Center for the History of Physics, who will eventually also make the images available; however, old photographs are still being added. My captions may or may not be provided by CHP. Clemson University provided the time for this research project.

  3. Nuclear and Astrophysics Data from the T2 Group at Los Alamos National Laboratory (LANL)

    DOE Data Explorer

    The T-2 Nuclear Information Service provides access to a variety of nuclear data, including ENDF/B cross sections, radioactive decay data, astrophysics data, photoatomic data, charged particle data, thermal neutron data, and a Nuclear Data Viewer. The data are useful for both nuclear science and nuclear engineering. The codes area gives information on computer codes used in the T-2 Group's nuclear data work.

  4. The Lunar Occultation Observer (LOCO) - A Nuclear Astrophysics All-Sky Survey Mission Concept

    NASA Astrophysics Data System (ADS)

    Miller, R. S.; Bonamente, M.; Burgess, J. M.; Harmon, B. A.; Jenke, P.; Lawrence, D. J.; O'Brien, S.; Orr, M. R.; Paciesas, W. S.; Young, C. A.

    2008-07-01

    The Lunar Occultation Observer (LOCO) is a new lunar-based concept to probe the nuclear astrophysics regime. It will be a pioneering mission in high-energy astrophysics: the first to employ occultation as the principle detection and imaging method.

  5. Project Title: Nuclear Astrophysics Data from Radioactive Beam Facilities

    SciTech Connect

    Alan A. Chen

    2008-03-27

    The scientific aims of this project have been the evaluation and dissemination of key nuclear reactions in nuclear astrophysics, with a focus on ones to be studied at new radioactive beam facilities worldwide. These aims were maintained during the entire funding period from 2003 - 2006. In the following, a summary of the reactions evaluated during this period is provided. Year 1 (2003-04): {sup 21}Na(p,{gamma}){sup 22}Mg and {sup 18}Ne({alpha},p){sup 21}Na - The importance of the {sup 21}Na(p,{gamma}){sup 22}Mg and the {sup 18}Ne({alpha},p){sup 21}Na reactions in models of exploding stars has been well documented: the first is connected to the production of the radioisotope {sup 22}Na in nova nucleosynthesis, while the second is a key bridge between the Hot-CNO cycles and the rp-process in X-ray bursts. By the end of Summer 2004, our group had updated these reaction rates to include all published data up to September 2004, and cast the reaction rates into standard analytical and tabular formats with the assistance of Oak Ridge National Laboratory's computational infrastructure for reaction rates. Since September 2004, ongoing experiments on these two reactions have been completed, with our group's participation in both: {sup 21}Na(p,{gamma}){sup 22}Mg at the TRIUMF-ISAC laboratory (DRAGON collaboration), and 18Ne({alpha},p){sup 21}Na at Argonne National Laboratory (collaboration with Ernst Rehm, Argonne). The data from the former was subsequently published and included in our evaluation. Publication from the latter still awaits independent confirmation of the experimental results. Year 2 (2004-05): The 25Al(p,{gamma}){sup 26}Si and {sup 13}N(p,{gamma})14O reactions - For Year 2, we worked on evaluations of the {sup 25}Al(p,{gamma}){sup 26}Si and {sup 13}N(p,{gamma}){sup 14}O reactions, in accordance with our proposed deliverables and following similar standard procedures to those used in Year 1. The {sup 25}Al(p,{gamma}){sup 26}Si reaction is a key uncertainty in

  6. The Lunar Occultation Observer (LOCO) -- A Nuclear Astrophysics All-Sky Survey Mission Concept

    NASA Astrophysics Data System (ADS)

    Miller, R. S.; Bonamente, M.; Burgess, J. M.; Jenke, P.; Lawrence, D. J.; O'Brien, S.; Orr, M. R.; Paciesas, W. S.; Young, C. A.

    2009-03-01

    The Lunar Occultation Observer (LOCO) is a new γ-ray astrophysics mission concept expected to have unprecedented sensitivity in the nuclear regime. Operating in lunar orbit, LOCO will utilize lunar occultation imaging to survey and probe the cosmos.

  7. Laboratory studies of astrophysical molecules

    NASA Astrophysics Data System (ADS)

    Wang, Haiyan

    There is growing evidence that the molecules necessary for the evolution of life on earth arrived from the interstellar medium. The study of these molecules is therefore of great current interest. Two major types of signals from interstellar space, so-called unidentified interstellar infrared emission bands and the diffuse interstellar absorption bands, have intrigued and puzzled astrochemists for decades. This work has been concentrated on how to contribute to an understanding of the origins of these perplexing signals from space and help identify other molecules that may exist in outer space. Matrix isolation spectroscopy (infrared and ultraviolet-visible) combined with theoretical calculations has been employed throughout this research. Fourier transform infrared absorption spectroscopic measurements, aided by theoretical calculations and 13 C-isotope shifts, have led to the identification of eight heretofore unknown C n S m clusters: C 2 S, C 6 S, C 7 S, C 7 S 2 , C 9 S 2 , C 11 S 2 , C 13 S 2 , and C 15 S 2 . Infrared absorption studies of xenon polycarbon clusters aid in understanding the special electronic structure and reactivity of carbon clusters, which might be associated with the formation mechanism of Buckyball (C 60 ). Reaction of C3 with benzene and ammonia might be involved in the formation of more complex molecular structures, including polycyclic aromatic hydrocarbons (PAHs) and biomolecules such as the amino acids. High resolution vibrational and electronic spectra of neutral dibenzo [b,def]chrysene and its ions in 12 K argon matrices have been recorded. Spectral assignments were supported by high level theoretical calculations. A mixture of the neutral and ionic infrared spectra of dibenzo[b,def]chrysene resembles the unidentified IR bands in the reflection nebula NGC 7023. Anharmonic frequency calculations for neutral and cationic naphthalene, phenanthrene and anthracene using density functional theory have been carried out for the first time

  8. Relevance of β-delayed neutron data for reactor, nuclear physics and astrophysics applications

    NASA Astrophysics Data System (ADS)

    Kratz, Karl-Ludwig

    2015-02-01

    Initially, yields (or abundances) and branching ratios of β-delayed neutrons (βdn) from fission products (Pn-values) have had their main importance in nuclear reactor control. At that time, the six-group mathematical approximation of the time-dependence of βdn-data in terms of the so-called "Keepin groups" was generally accepted. Later, with the development of high-resolution neutron spectroscopy, βdn data have provided important information on nuclear-structure properties at intermediate excitation energy in nuclei far from stability, as well as in nuclear astrophysics. In this paper, I will present some examples of the βdn-studies performed by the Kernchemie Mainz group during the past three decades. This work has been recognized as an example of "broad scientific diversity" which has led to my nomination for the 2014 Hans A. Bethe prize.

  9. The TUNL Enge Split-Pole Spectrograph: a Facility Entirely Dedicated to Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Setoodehnia, Kiana; Longland, Richard; Marshall, Caleb; Portillo Chaves, Federico; Kowal, Katie; Seed, Caitlin

    The Enge split-pole spectrograph at the Triangle Universities Nuclear Laboratory (TUNL) is the only spectrometer of this kind currently operational in North America for conducting charged-particle spectroscopy experiments using stable beams. This spectrograph was out of service for a relatively long period of time. However, it is now being re-commissioned and upgraded to perform high resolution charged-particle spectroscopy measurements, as well as particle-γ coincidence measurements to study various astrophysically significant reactions. This review discusses the current upgrades to the beamline, the detector system, and outlines near future experimental perspectives.

  10. Development of a high-density gas-jet target for nuclear astrophysics and reaction studies with rare isotope beams. Final Report

    SciTech Connect

    Uwe, Greife

    2014-08-12

    The purpose of this project was to develop a high-density gas jet target that will enable a new program of transfer reaction studies with rare isotope beams and targets of hydrogen and helium that is not currently possible and will have an important impact on our understanding of stellar explosions and of the evolution of nuclear shell structure away from stability. This is the final closeout report for the project.

  11. Physics with gamma-beams and charged particle detectors: I) Nuclear structure II) Nuclear astrophysics

    SciTech Connect

    Gai, Moshe

    2015-02-24

    The Charged Particle Working Group (CPWG) is proposing to construct large area Silicon Strip Detector (SSD), a gas Time Projection Chamber detector read by an electronic readout system (eTPC) and a Bubble Chamber (BC) containing superheated high purity water to be used in measurements utilizing intense gamma-ray beams from the newly constructed ELI-NP facility at Magurele, Bucharest in Romania. We intend to use the SSD and eTPC detectors to address essential problems in nuclear structure physics, such as clustering and the many alpha-decay of light nuclei such as {sup 12}C and {sup 16}O. All three detectors (SSD, eTPC and BC) will be used to address central problems in nuclear astrophysics such as the astrophysical cross section factor of the {sup 12}C(α,γ) reaction and other processes central to stellar evolution. The CPWG intends to submit to the ELI-NP facility a Technical Design Report (TDR) for the proposed detectors.

  12. Physics with gamma-beams and charged particle detectors: I) Nuclear structure II) Nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Gai, Moshe

    2015-02-01

    The Charged Particle Working Group (CPWG) is proposing to construct large area Silicon Strip Detector (SSD), a gas Time Projection Chamber detector read by an electronic readout system (eTPC) and a Bubble Chamber (BC) containing superheated high purity water to be used in measurements utilizing intense gamma-ray beams from the newly constructed ELI-NP facility at Magurele, Bucharest in Romania. We intend to use the SSD and eTPC detectors to address essential problems in nuclear structure physics, such as clustering and the many alpha-decay of light nuclei such as 12C and 16O . All three detectors (SSD, eTPC and BC) will be used to address central problems in nuclear astrophysics such as the astrophysical cross section factor of the 12C (α,γ) reaction and other processes central to stellar evolution. The CPWG intends to submit to the ELI-NP facility a Technical Design Report (TDR) for the proposed detectors.

  13. Isotope production and target preparation for nuclear astrophysics data

    NASA Astrophysics Data System (ADS)

    Schumann, Dorothea; Dressler, Rugard; Maugeri, Emilio Andrea; Heinitz, Stephan

    2017-09-01

    Targets are in many cases an indispensable ingredient for successful experiments aimed to produce nuclear data. With the recently observed shift to study nuclear reactions on radioactive targets, this task can become extremely challenging. Concerted actions of a certain number of laboratories able to produce isotopes and manufacture radioactive targets are urgently needed. We present here some examples of successful isotope and target production at PSI, in particular the production of 60Fe samples used for half-life measurements and neutron capture cross section experiments, the chemical processing and fabrication of lanthanide targets for capture cross section experiments at n_TOF (European Organization for Nuclear Research (CERN), Switzerland) as well as the recently performed manufacturing of highly-radioactive 7Be targets for the measurement of the 7Be(n,α)4He cross section in the energy range of interest for the Big-Bang nucleosynthesis contributing to the solving of the cosmological Li-problem. The two future projects: "Determination of the half-life and experiments on neutron capture cross sections of 53Mn" and "32Si - a new chronometer for nuclear dating" are briefly described. Moreover, we propose to work on the establishment of a dedicated network on isotope and target producing laboratories.

  14. C+C Fusion Cross Sections Measurements for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Almaraz-Calderon, S.; Carnelli, P. F. F.; Rehm, K. E.; Albers, M.; Alcorta, M.; Bertone, P. F.; Digiovine, B.; Esbensen, H.; Fernandez Niello, J. O.; Henderson, D.; Jiang, C. L.; Lai, J.; Marley, S. T.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Paul, M.; Ugalde, C.

    2015-06-01

    Total fusion cross section of carbon isotopes were obtained using the newly developed MUSIC detector. MUSIC is a highly efficient, active target-detector system designed to measure fusion excitation functions with radioactive beams. The present measurements are relevant for understanding x-ray superbursts. The results of the first MUSIC campaign as well as the astrophysical implications are presented in this work.

  15. C+C Fusion Cross Sections Measurements for Nuclear Astrophysics

    DOE PAGES

    Almaraz-Calderon, S.; Carnelli, P. F. F.; Rehm, K. E.; ...

    2015-06-02

    Total fusion cross section of carbon isotopes were obtained using the newly developed MUSIC detector. MUSIC is a highly efficient, active target-detector system designed to measure fusion excitation functions with radioactive beams. The present measurements are relevant for understanding x-ray superbursts. The results of the first MUSIC campaign as well as the astrophysical implications are presented in this work.

  16. Nanostructured targets irradiation by ns-laser for nuclear astrophysics applications: first results

    NASA Astrophysics Data System (ADS)

    Muoio, A.; Altana, C.; Frassetto, M.; Lanzalone, G.; Malferrari, L.; Mascali, D.; Odorici, F.; Tudisco, S.

    2017-03-01

    The studies discussed in this work are related to a scientific program that aims to reproduce astrophysical-plasmas in laboratory in order to better understand the nuclear processes involved in the stellar burning. An experimental campaign aiming to investigate the effects of innovative nanostructured targets based on Ni, Fe and Co nanowires on laser energy absorption in the ns time domain has been carried out at the LENS (Laser Energy for Nuclear Science) laboratory of INFN-LNS, Catania. Nanowires structures are tuned to increase the light absorption in the visible and infrared range due possibly to plasmonic excitation driven by the incoming photons. Different diagnostics techniques permit to monitor the plasma and to determine its reproducibility. Targets were then irradiated by Nd:YAG 2J, 6 ns infrared laser (λ = 1064 nm) at different pumping energies. Some preliminary results will be illustrated.

  17. Constraining the astrophysical origin of the p-nuclei through nuclear physics and meteoritic data.

    PubMed

    Rauscher, T; Dauphas, N; Dillmann, I; Fröhlich, C; Fülöp, Zs; Gyürky, Gy

    2013-06-01

    A small number of naturally occurring, proton-rich nuclides (the p-nuclei) cannot be made in the s- and r-processes. Their origin is not well understood. Massive stars can produce p-nuclei through photodisintegration of pre-existing intermediate and heavy nuclei. This so-called γ-process requires high stellar plasma temperatures and occurs mainly in explosive O/Ne burning during a core-collapse supernova. Although the γ-process in massive stars has been successful in producing a large range of p-nuclei, significant deficiencies remain. An increasing number of processes and sites has been studied in recent years in search of viable alternatives replacing or supplementing the massive star models. A large number of unstable nuclei, however, with only theoretically predicted reaction rates are included in the reaction network and thus the nuclear input may also bear considerable uncertainties. The current status of astrophysical models, nuclear input and observational constraints is reviewed. After an overview of currently discussed models, the focus is on the possibility to better constrain those models through different means. Meteoritic data not only provide the actual isotopic abundances of the p-nuclei but can also put constraints on the possible contribution of proton-rich nucleosynthesis. The main part of the review focuses on the nuclear uncertainties involved in the determination of the astrophysical reaction rates required for the extended reaction networks used in nucleosynthesis studies. Experimental approaches are discussed together with their necessary connection to theory, which is especially pronounced for reactions with intermediate and heavy nuclei in explosive nuclear burning, even close to stability.

  18. Lunar occultation imaging in nuclear astrophysics: A new paradigm for future investigations

    NASA Astrophysics Data System (ADS)

    Orr, Matthew R.

    Nuclear astrophysics (~10-10000 keV) is one of the last electromagnetic regimes without a sensitive all-sky survey, and therefore there is tremendous potential for future discoveries. A mission dedicated to such a survey will enable studies ranging from a survey of accreting black holes, to probing star formation rates by observing supernovae and novae, as well as investigating the underlying processes that power Active Galactic Nuclei. The Lunar Occultation Observer (LOCO) addresses these goals using the Lunar Occultation Technique (LOT), an innovative imaging approach to an all-sky survey. Occultation imaging eliminates the need for a pixelated, or high spatial resolution, detector. As a result, this technique is relatively simple to implement, maximizes active detector area, and is highly cost effective. This work characterizes the performance of the LOT in relation to the detection of astrophysical point sources. Sensitivity, position resolution, and issues of source confusion are all examined. The performance of LOCO, as demonstrated by this work, is an improvement over both previous and current instruments. The broadband sensitivity of LOCO in the range of 10-600 keV is <2 mCrab after 1 year of mission operation. The line sensitivity of LOCO is ~4 x 10 -5 photons cm -2 s -1 at 847 keV after 10 6 s of mission operation. A source localization accuracy of ~0.5 arcmin, and a 99% confidence region of ~0.6 square arcminutes, is also achievable with LOCO. Observing approximately 90% of the sky per orbit, LOCO is also able to identify sources separated by ~3 arcmin. This broad sky exposure, combined with its improved sensitivity and position resolution, give LOCO the potential to make significant contributions to nuclear astrophysics. These performance measures make the Lunar Occultation Observer a viable candidate for a survey mission.

  19. Temperature-tuned Maxwell-Boltzmann neutron spectra for kT ranging from 30 up to 50 keV for nuclear astrophysics studies.

    PubMed

    Martín-Hernández, G; Mastinu, P F; Praena, J; Dzysiuk, N; Capote Noy, R; Pignatari, M

    2012-08-01

    The need of neutron capture cross section measurements for astrophysics motivates present work, where calculations to generate stellar neutron spectra at different temperatures are performed. The accelerator-based (7)Li(p,n)(7)Be reaction is used. Shaping the proton beam energy and the sample covering a specific solid angle, neutron activation for measuring stellar-averaged capture cross section can be done. High-quality Maxwell-Boltzmann neutron spectra are predicted. Assuming a general behavior of the neutron capture cross section a weighted fit of the spectrum to Maxwell-Boltzmann distributions is successfully introduced. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Hans A. Bethe Prize: Astrophysical, observational and nuclear-physics aspects of r-process nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Kratz, Karl-Ludwig

    2014-03-01

    Guided by the Solar System (S.S.) abundance peaks at A ~= 130 and A ~= 195, the basic mechanisms for the rapid neutron-capture process (the r-process) have been known for over 50 years. However, even today, all proposed scenarios and sites face problems with astrophysical conditions as well as with the necessary nuclear-physics input. In my talk, I will describe efforts in experimental and theoretical nuclear-structure data for modeling today's three groups of r-process ``observables'', i.e. the bulk S.S. isotopic abundances, the elemental abundances in metal-poor halo stars, and peculiar isotopic patterns measured in certain cosmic stardust grains. To set a historical basis, I will briefly recall our site-independent ``waiting-point'' model, with superpositions of neutron-density components and the use of the first global, unified nuclear input based on the mass model FRDM(1992). This approach provided a considerable leap forward in the basic understanding of the required astrophysical conditions, as well as of specific shell-structure properties far from stability. Starting in the early millenium, the above simple model has been replaced by more realistic, dynamical parameter studies within the high-entropy wind scenario of core-collapse supernovae, now with superpositions of entropy (S) and electron-fraction (Ye) components. Furthermore, an improved, global set of nuclear-physics data is used today, based on the new mass model FRDM(2012). With this nuclear and astrophysics parameter combination, a new fit to the S.S. r-abundances will be shown, and its improvements and remaining deficiencies in terms of underlying shell structure will be discussed. Concerning the abundance patterns in metal-poor halo stars, an interpretation of the production of ``r-rich'' (e.g. CS 22892-052) and ``r-poor'' (e.g. HD 122563) stars in terms of different (Ye), S combinations will be presented. Finally, for the third group of ``r-observables'', a possible origin of the anomalous Xe

  1. Trojan Horse Method: recent results in nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Spitaleri, C.; Lamia, L.; Gimenez Del Santo, M.; Burjan, V.; Carlin, N.; Li, Chengbo; Cherubini, S.; Crucilla, V.; Gulino, M.; Hons, Z.; Kroha, V.; Irgaziev, B.; La Cognata, M.; Mrazek, J.; Mukhamedzhanov, M.; Munhoz, M. G.; Palmerini, S.; Pizzone, R. G.; Puglia, M. R.; Rapisarda, G. G.; Romano, S.; Sergi, L.; Zhou, Shu-Hua; Somorjai, E.; Souza, F. A.; Tabacaru, G.; Szanto de Toledo, A.; Tumino, A.; Wen, Qungang; Wakabayashi, Y.; Yamaguchi, H.

    2015-07-01

    The accurate knowledge of thermonuclear reaction rates is important in understanding the energy generation, the neutrinos luminosity and the synthesis of elements in stars. The physical conditions under which the majority of astrophysical reactions proceed in stellar environments make it difficult or impossible to measure them under the same conditions in the laboratory. That is why different indirect techniques are being used along with direct measurements. The Trojan Horse Method (THM) is introduced as an independent technique to obtain the bare nucleus astrophysical S(E)-factor. As examples the results of recent the application of THM to the 2H(11B, σ08Be)n and 2H(10B, σ07Be)n reactions are presented.

  2. A Study of Mechanisms Producing Astrophysical Jets.

    DTIC Science & Technology

    1988-03-01

    Pacholczyk, Astrophysical Jets, D. Reidel, Dordrecht, 1983 6 Field, G. B., ed., The Redshift Controversy, Benjamin , Reading, 1973 7 F. D. Kuhn, ed...Feature Associated with the Seyfert Galaxy Markarian 915, Astrophysical Journal, around September, 1986 112 Narlikar, J. V., Noncosmological

  3. Building a Single Atom Microscope for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Frisbie, Dustin; Johnson, Maegan; Parzuchowski, Kristen; Wenzl, Jennifer; Singh, Jaideep

    2017-01-01

    The primary research goal of this project is to develop a new technique of optical single atom detection to measure rare nuclear reactions at low energies. The 22Ne(α, n)25Mg reaction is of particular interest, as it is thought to be a primary source of neutrons in the s-process of massive stars. Nuclear reaction products are captured in a cryogenically frozen film of noble gas, which can contain a variety of guest atoms. These solids are ideal to use because they are optically transparent and simple to grow and purify. The sample is illuminated by laser light and imaged to identify fluorescing atoms. The atomic transitions of captured atoms indicate which atoms are present; only atoms which are excited at the laser wavelength will fluoresce. This offers high selectivity during experiments. We began development with Yb, a very bright guest atom, being embedded in a host of solid neon in order to study the optical properties necessary for single atom detection. In addition, we study background effects from the laser exciting contaminants in our substrates. We present data that indicates the efficiency with which we can excite and collect fluorescence light with our apparatus, and use it to propose a strategy for the development of Mg single atom detection. This work is generously supported by Michigan State University.

  4. Nuclear physics and astrophysics. Progress report, July 15, 1991--June 15, 1992

    SciTech Connect

    Schramm, D.N.; Olinto, A.V.

    1992-09-01

    We have investigated a variety of research topics on the interface of nuclear physics and astrophysics during the past year. We have continued our study of dihyperon states in dense matter and have started to make a connection between their properties in the core of neutron stars with the ongoing experimental searches at Brookhaven National Laboratory. We started to build a scenario for the origin of gamma-ray bursts using the conversion of neutron stars to strange stars close to an active galactic nucleous. We have been reconsidering the constraints due to neutron star cooling rates on the equation of state for high density matter in the light, of recent findings which show that the faster direct Urca cooling process is possible for a range of nuclear compositions. We have developed a model for the formation of primordial magnetic fields due to the dynamics of the quark-hadron phase transition. Encouraged by the most recent observational developments, we have investigated the possible origin of the boron and beryllium abundances. We have greatly improved the calculations of the primordial abundances of these elements I>y augmenting the reaction networks and by updating the most recent experimental nuclear reaction rates. Our calculations have shown that the primordial abundances are much higher than previously thought but that the observed abundances cannot be explained by primordial sources alone. We have also studied the origin of the boron and beryllium abundances due to cosmic ray spallation. Finally, we have continued to address the solar neutrino problem by investigating the impact of astrophysical uncertainties on the MSW solution for a full three-family treatment of MSW mixing.

  5. Studies of High Energy Particle Astrophysics

    SciTech Connect

    Nitz, David F; Fick, Brian E

    2014-07-30

    This report covers the progress of the Michigan Technological University particle astrophysics group during the period April 15th, 2011 through April 30th, 2014. The principal investigator is Professor David Nitz. Professor Brian Fick is the Co-PI. The focus of the group is the study of the highest energy cosmic rays using the Pierre Auger Observatory. The major goals of the Pierre Auger Observatory are to discover and understand the source or sources of cosmic rays with energies exceeding 10**19 eV, to identify the particle type(s), and to investigate the interactions of those cosmic particles both in space and in the Earth's atmosphere. The Pierre Auger Observatory in Argentina was completed in June 2008 with 1660 surface detector stations and 24 fluorescence telescopes arranged in 4 stations. It has a collecting area of 3,000 square km, yielding an aperture of 7,000 km**2 sr.

  6. A comparative study via Monte Carlo simulation of new inorganic scintillator Cs2HfCl6 for applications in nuclear medicine, security and defense, and astrophysics

    NASA Astrophysics Data System (ADS)

    Chen, Henry; Raby, Paul

    2016-09-01

    Cs2HfCl6 (CHC) is one of the most promising recently discovered new inorganic single crystal scintillator that has high light output, non-hygroscopic, no self-activity, having energy resolution significantly better than NaI(Tl), even approaching that of LaBr3 yet can also potentially be at a much lower cost than LaBr3. This study attempts to use Monte Carlo simulation to examine the great potential offered by this new scintillator. CHC's detector performance is compared via simulation with that of 4 typical existing scintillators of the same size and same PMT readout. Two halide-scintillators: NaI(Tl) and LaBr3 and two oxide-scintillators: GSO and LSO were used in this simulation to compare their 122 keV and 511 keV gamma responses with that of CHC with both spectroscopy application and imaging applications in mind. Initial simulation results are very promising and consistent with reported experimental measurements. Beside detector energy resolution, image-quality measurement parameters commonly used to characterize imaging detectors as in nuclear medicine such as Light Response Function (LRF) which goes in parallel with spatial resolution and simulated position spectra will also be presented and discussed.

  7. Nuclear Incompressibility and the Asymmetry Term: Implications for Astrophysics and Physics with Exotic Nuclei

    SciTech Connect

    Fujiwara, M.

    2010-06-01

    The compressional-mode giant resonances, the isoscalar giant monopole resonance (GMR) and the isoscalar giant dipole resonance (ISGDR), in various isotopes have been investigated using inelastic scattering of 400-MeV alpha-particles at extremely forward angles, including 0 deg. Recently, the centroid energies of the giant monopole resonance (GMR) in the Sn isotope region are found to be significantly lower than the theoretical predictions. In addition, based on the GMR results, the asymmetry-term in the nuclear incompressibility has been determined as K{sub t}au = -550+-100 MeV. Constraints on interactions employed in nuclear structure calculations are discussed on the basis of the experimentally values for K{sub i}nfinity and K{sub t}au. The combination of these two values gives stringent constraints on the interactions used for nuclear structure calculations and for formations of equation of state (EOS) of nuclear matter. A short review of the current status of the experimental studies on the compressional-mode giant resonances is given, and a possible new experiment for astrophysics and physics with exotic nuclei is suggested.

  8. Nuclear physics and astrophysics. Progress report for period June 15, 1992--June 14, 1993

    SciTech Connect

    Schramm, D.N.; Olinto, A.V.

    1993-06-01

    The authors report on recent progress of research at the interface of nuclear physics and astrophysics. During the past year, the authors continued to work on Big Bang and stellar nucleosynthesis, the solar neutrino problem, the equation of state for dense matter, the quark-hadron phase transition, and the origin of gamma-ray bursts; and began studying the consequences of nuclear reaction rates in the presence of strong magnetic fields. They have shown that the primordial production of B and Be cannot explain recent detections of these elements in halo stars and have looked at spallation as the likely source of these elements. By looking at nucleosynthesis with inhomogeneous initial conditions, they concluded that the Universe must have been very smooth before nucleosynthesis. They have also constrained neutrino oscillations and primordial magnetic fields by Big Bang nucleosynthesis. On the solar neutrino problem, they have analyzed the implications of the SAGE and GALLEX experiments. They also showed that the presence of dibaryons in neutron stars depends weakly on uncertainties of nuclear equations of state. They have started to investigate the consequences of strong magnetic fields on nuclear reactions and implications for neutron star cooling and supernova nucleosynthesis.

  9. Imaging detector development for nuclear astrophysics using pixelated CdTe

    NASA Astrophysics Data System (ADS)

    Álvarez, J. M.; Gálvez, J. L.; Hernanz, M.; Isern, J.; Llopis, M.; Lozano, M.; Pellegrini, G.; Chmeissani, M.

    2010-11-01

    The concept of focusing telescopes in the energy range of lines of astrophysical interest (i.e., of energies around 1 MeV) should allow to reach unprecedented sensitivities, essential to perform detailed studies of cosmic explosions and cosmic accelerators. Our research and development activities aim to study a detector suited for the focal plane of a γ-ray telescope mission. A CdTe/CdZnTe detector operating at room temperature, that combines high detection efficiency with good spatial and spectral resolution is being studied in recent years as a focal plane detector, with the interesting option of also operating as a Compton telescope monitor. We present the current status of the design and development of a γ-ray imaging spectrometer in the MeV range, for nuclear astrophysics, consisting of a stack of CdTe pixel detectors with increasing thicknesses. We have developed an initial prototype based on CdTe ohmic detector. The detector has 11×11 pixels, with a pixel pitch of 1 mm and a thickness of 2 mm. Each pixel is stud bonded to a fanout board and routed to an front end ASIC to measure pulse height and rise time information for each incident γ-ray photon. First measurements of a 133Ba and 241Am source are reported here.

  10. An optical readout TPC (O-TPC) for studies in nuclear astrophysics with gamma-ray beams at HIγS1

    NASA Astrophysics Data System (ADS)

    Gai, M.; Ahmed, M. W.; Stave, S. C.; Zimmerman, W. R.; Breskin, A.; Bromberger, B.; Chechik, R.; Dangendorf, V.; Delbar, Th; France, R. H., III; Henshaw, S. S.; Kading, T. J.; Martel, P. P.; McDonald, J. E. R.; Seo, P.-N.; Tittelmeier, K.; Weller, H. R.; Young, A. H.

    2010-12-01

    We report on the construction, tests, calibrations and commissioning of an Optical Readout Time Projection Chamber (O-TPC) detector operating with a CO2(80%) + N2(20%) gas mixture at 100 and 150 Torr. It was designed to measure the cross sections of several key nuclear reactions involved in stellar evolution. In particular, a study of the rate of formation of oxygen and carbon during the process of helium burning will be performed by exposing the chamber gas to intense nearly mono-energetic gamma-ray beams at the High Intensity Gamma Source (HIγS) facility. The O-TPC has a sensitive target-drift volume of 30x30x21 cm3. Ionization electrons drift towards a double parallel-grid avalanche multiplier, yielding charge multiplication and light emission. Avalanche-induced photons from N2 emission are collected, intensified and recorded with a Charge Coupled Device (CCD) camera, providing two-dimensional track images. The event's time projection (third coordinate) and the deposited energy are recorded by photomultipliers and by the TPC charge-signal, respectively. A dedicated VME-based data acquisition system and associated data analysis tools were developed to record and analyze these data. The O-TPC has been tested and calibrated with 3.183 MeV alpha-particles emitted by a 148Gd source placed within its volume with a measured energy resolution of 3.0%. Tracks of alpha and 12C particles from the dissociation of 16O and of three alpha-particles from the dissociation of 12C have been measured during initial in-beam test experiments performed at the HIγS facility at Duke University. The full detection system and its performance are described and the results of the preliminary in-beam test experiments are reported.

  11. White paper on nuclear astrophysics and low-energy nuclear physics, Part 2: Low-energy nuclear physics

    DOE PAGES

    Carlson, Joe; Carpenter, Michael P.; Casten, Richard; ...

    2017-01-04

    In preparation for the 2015 NSAC Long Range Plan (LRP), the DNP town meetings on Nuclear Astrophysics and Low-Energy Nuclear Physics were held at the Mitchell Center on the campus of Texas A&M University August 21–23, 2014. Participants met in a number of topic-oriented working groups to discuss progress since the 2007 LRP, compelling science opportunities, and the resources needed to advance them. These considerations were used to determine priorities for the next five to ten years. In addition, approximately 270 participants attended the meetings, coming from US national laboratories, a wide range of US universities and other research institutionsmore » and universities abroad.« less

  12. White paper on nuclear astrophysics and low-energy nuclear physics, Part 2: Low-energy nuclear physics

    NASA Astrophysics Data System (ADS)

    Carlson, Joe; Carpenter, Michael P.; Casten, Richard; Elster, Charlotte; Fallon, Paul; Gade, Alexandra; Gross, Carl; Hagen, Gaute; Hayes, Anna C.; Higinbotham, Douglas W.; Howell, Calvin R.; Horowitz, Charles J.; Jones, Kate L.; Kondev, Filip G.; Lapi, Suzanne; Macchiavelli, Augusto; McCutchen, Elizabeth A.; Natowitz, Joe; Nazarewicz, Witold; Papenbrock, Thomas; Reddy, Sanjay; Riley, Mark A.; Savage, Martin J.; Savard, Guy; Sherrill, Bradley M.; Sobotka, Lee G.; Stoyer, Mark A.; Betty Tsang, M.; Vetter, Kai; Wiedenhoever, Ingo; Wuosmaa, Alan H.; Yennello, Sherry

    2017-05-01

    Over the last decade, the Low-Energy Nuclear Physics (LENP) and Nuclear Astrophysics (NAP) communities have increasingly organized themselves in order to take a coherent approach to resolving the challenges they face. As a result, there is a high level of optimism in view of the unprecedented opportunities for substantial progress. In preparation of the 2015 US Nuclear Science Long Range Plan (LRP), the two American Physical Society Division of Nuclear Physics town meetings on LENP and NAP were held jointly on August 21-23, 2014, at Texas A&M, College Station, in Texas. These meetings were co-organized to take advantage of the strong synergy between the two fields. The present White Paper attempts to communicate the sense of great anticipation and enthusiasm that came out of these meetings. A unanimously endorsed set of joint resolutions condensed from the individual recommendations of the two town meetings were agreed upon. The present LENP White Paper discusses the above and summarizes in detail for each of the sub-fields within low-energy nuclear physics, the major accomplishments since the last LRP, the compelling near-term and long-term scientific opportunities plus the resources needed to achieve these goals, along with the scientific impact on, and interdisciplinary connections to, other fields.

  13. Constraints on CEMP-no progenitors from nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Choplin, Arthur; Maeder, André; Meynet, Georges; Chiappini, Cristina

    2016-09-01

    Context. The CEMP-no stars are long-lived small mass stars presenting a very low iron content and overabundances of carbon with no sign or only very weak signs of s- or r-elements. Although the origin of this abundance pattern is still a matter of debate, it was very likely inherited from a previous massive star, which we call the source star. Aims: We rely on a recent classification of CEMP-no stars arguing that some of them are made of a material processed by hydrogen burning that was enriched in products of helium burning during the nuclear life of the source star. We examine the possibility of forming CEMP-no stars with this material. Methods: We study the nucleosynthesis of the CNO cycle and the Ne-Na Mg-Al chains in a hydrogen burning single zone while injecting the helium burning products 12C, 16O, 22Ne, and 26Mg. We investigate the impact of changing density, temperature and the injection rate. The nuclear reaction rates involving the creation and destruction of 27Al are also examined. Results: 14N, 23Na, 24Mg, and 27Al are formed when injecting 12C, 16O, 22Ne, and 26Mg in the hydrogen burning zone. The 12C/13C ratio is constant under various conditions in the hydrogen burning zone. The predicted [Al/Fe] ratio varies up to ~ 2 dex depending on the prescription used for the reaction rates involving 27Al. Conclusions: The experiments we carried out support the view that some CEMP-no stars are made of a material processed by hydrogen burning that comes from a massive star experiencing mild to strong rotational mixing. During its burning, this material was likely enriched in helium burning products. No material coming from the carbon-oxygen rich core of the source star should be added to form the daughter star, otherwise the 12C/13C ratio would be largely above the observed range of values.

  14. Study on astrophysical reactions using low-energy RI beams

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Hidetoshi

    2009-10-01

    In recent years, low-energy RI beams can be produced in a good intensity and they have been used for studying many astrophysical reactions. One of the facilities producing low-energy RI beams is CRIB (CNS Radio-Isotope Beam separator) [1,2], an RI-beam separator of Center for Nuclear Study, University of Tokyo. Taking CRIB as an example, recent improvements on the RI-beam production and experimental results on astrophysical studies are presented. Several experimental approaches have been taken for the studies on astrophysical reactions.The feature of each method are discussed based on real measurements performed at CRIB. One is the direct method, applied for measurements of reactions such as (α,p) [3]. Another is the measurement of proton/alpha resonance scattering using the thick target method in inverse kinematics, by which we can obtain information on the resonances relevant in astrophysical reactions [4,5]. A recent fruitful result was from a measurement of proton resonance scattering using a ^7Be beam [5]. The energy level structure of ^8B, revealed by the experiment, is especially of interest as it is related with the ^7Be(p,γ) ^8B reaction, responsible for the production of ^8B neutrinos in the sun. We successfully determined parameters of resonances in ^8B below 6.7 MeV, which may affect the ^7Be(p,γ)^8B reaction rate at the solar temparature. Indirect methods, such as ANC and the Trojan Horse Method, were also used in some of the measurements.[4pt] [1] S. Kubono et al., Eur. Phys. J. A13 (2002) 217.[0pt] [2] Y. Yanagisawa et al., Nucl. Instrum. Meth. Phys. Res., Sect. A 539 (2005) 74.[0pt] [3] M. Notani et al., Nucl. Phys. A 764 (2004) 113c.[0pt] [4] T. Teranishi et al., Phys. Lett. B 650 (2007) 129.[0pt] [5] H. Yamaguchi et al., Phys. Lett. B 672 (2009) 230.

  15. The Dresden Felsenkeller shallow-underground accelerator laboratory for nuclear astrophysics - Status and first physics program

    SciTech Connect

    Ilgner, Ch.

    2015-07-01

    Favored by the low background in underground laboratories, low-background accelerator-based experiments are an important tool to study nuclear reactions involving stable charged particles. This technique has been used for many years with great success at the 0.4 MV LUNA accelerator in the Gran Sasso laboratory in Italy, protected from cosmic rays by 1400 m of rock. However, the nuclear reactions of helium and carbon burning and the neutron source reactions for the astrophysical s-process require higher beam energies than those available at LUNA. Also the study of solar fusion reactions necessitates new data at higher energies. As a result, in the present NuPECC long range plan for nuclear physics in Europe, the installation of one or more higher-energy underground accelerators is strongly recommended. An intercomparison exercise using the same High-Purity Ge detector at several sites has shown that, with a combination of 45 m rock overburden, as can be found in the Felsenkeller underground site in Dresden, and an active veto against the remaining muon flux, in a typical nuclear astrophysics setup a background level can be achieved that is similar to the deep underground scenario as in the Gran- Sasso underground laboratory, for instance. Recently, a muon background study and geodetic measurements were carried out by the REGARD group. It was estimated that the rock overburden at the place of the future ion accelerator is equivalent to 130 m of water. The maximum muon flux measured was 2.5 m{sup -2} sr{sup -1} s{sup -1}, in the direction of the tunnel entrance. Based on this finding, a used 5 MV pelletron tandem accelerator with 250 μA up-charge current and external sputter ion source has been obtained and transported to Dresden. Work on an additional radio-frequency ion source on the high voltage terminal is in progress and far advanced. The installation of the accelerator in the Felsenkeller is expected for the near future. The status of the project and the

  16. Ex Luna Scientia! A New Paradigm for Nuclear Gamma-Ray Astrophysics

    NASA Astrophysics Data System (ADS)

    Miller, Richard Scott; Bonamente, M.; Ebbets, D.; Freelove, R.; Harwit, A.; Lawrence, D. J.; O'Brien, S.; Paciesas, W. S.; Young, C. A.

    2010-03-01

    The Lunar Occultation Observer (LOCO) is a new gamma-ray astrophysics mission concept being developed to probe the nuclear regime (( 0.1-10 MeV). LOCO will perform an all-sky survey of the Cosmos at nuclear energies, and will the have capability to address multiple high-priority science goals. Placed into lunar orbit, LOCO will utilize the Moon's unique environment to maximize performance relative to terrestrial-orbit endeavors with similar science goals. Specifically, LOCO will use the Moon to occult astrophysical sources as they rise and set along the lunar limb. The encoded temporal modulation will then be used to image the sky thereby enabling spectroscopic, time-variability, point- & extended-source analyses. This Lunar Occultation Technique (LOT) enables the excellent flux sensitivity, position, and energy resolution required of the next-generation nuclear astrophysics mission. In addition, occultation imaging eliminates the need for complex, position sensitive detectors. The LOCO concept is cost-effective, competitive, and has a straightforward and scaleable implementation. I will review the top-level mission concept, simulations and performance estimates, detector development efforts, mission implementation strategies and tradeoffs, as well as the astrophysics and secondary lunar science goals. This work was supported in part by National Aeronautics and Space Administration grants NNG06GF74G and National Science Foundation grant ATM-0421267. One author (RSM) also acknowledges support of the National Space Science & Technology Center through cooperative agreement grants NCC8-200 and NNM05AA22A.

  17. "Parking-garage" structures in nuclear astrophysics and cellular biophysics

    NASA Astrophysics Data System (ADS)

    Berry, D. K.; Caplan, M. E.; Horowitz, C. J.; Huber, Greg; Schneider, A. S.

    2016-11-01

    A striking shape was recently observed for the endoplasmic reticulum, a cellular organelle consisting of stacked sheets connected by helical ramps [Terasaki et al., Cell 154, 285 (2013), 10.1016/j.cell.2013.06.031]. This shape is interesting both for its biological function, to synthesize proteins using an increased surface area for ribosome factories, and its geometric properties that may be insensitive to details of the microscopic interactions. In the present work, we find very similar shapes in our molecular dynamics simulations of the nuclear pasta phases of dense nuclear matter that are expected deep in the crust of neutron stars. There are dramatic differences between nuclear pasta and terrestrial cell biology. Nuclear pasta is 14 orders of magnitude denser than the aqueous environs of the cell nucleus and involves strong interactions between protons and neutrons, while cellular-scale biology is dominated by the entropy of water and complex assemblies of biomolecules. Nonetheless, the very similar geometry suggests both systems may have similar coarse-grained dynamics and that the shapes are indeed determined by geometrical considerations, independent of microscopic details. Many of our simulations self-assemble into flat sheets connected by helical ramps. These ramps may impact the thermal and electrical conductivities, viscosity, shear modulus, and breaking strain of neutron star crust. The interaction we use, with Coulomb frustration, may provide a simple model system that reproduces many biologically important shapes.

  18. Nuclear interactions of high energy heavy ions and applications in astrophysics

    SciTech Connect

    Wefel, J.P.

    1992-01-23

    This program was established for the purpose of studying projectile fragmentation; (1) as a function of energy, focusing first on the intermediate energy region, < 1 GeV/nucleon, where there have been few previous measurements and no systematic studies, and (2) as a function of projectile mass, starting with light beams and proceeding to species as heavy as nickel (and possibly beyond). The intermediate energy region is important as the transition between the lower energy data, where the interaction appears to be dominated by collective effects and the decay of excited nuclei, and the highest energy results, where nucleon-nucleon interactions are fundamental, limiting fragmentation'' applies, and the nucleus may well break-up before any de-excitation. The mass dependence of projectile fragmentation is largely unknown since most detailed work has involved light ion beams. Nuclear structure effects, for example, may well be quite prominent for heavier beams. Furthermore, the nuclear excitation functions for the production of different fragment isotopes have immediate application to the astrophysical interpretation of existing isotopic datasets obtained from balloon and satellite measurements of galactic cosmic rays.

  19. Laser-Induced Fluorescence Measurements for Optical Single Atom Detection for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Parzuchowski, Kristen; Singh, Jaideep; Wenzl, Jennifer; Frisbie, Dustin; Johnson, Maegan

    2016-09-01

    We propose a new highly selective detector to measure rare nuclear reactions relevant for nuclear astrophysics. Our primary interest is the 22Ne(α , n) 25Mg reaction, which is a primary source of neutrons for the s-process. Our proposed detector, in conjunction with a recoil separator, captures the recoil products resulting from the reaction in a cryogenically frozen thin film of solid neon. The fluorescence spectra of the captured atoms is shifted from the absorption spectra by hundreds of nanometers. This allows for the optical detection of individual fluorescence photons against a background of intense excitation light. We will describe our initial studies of laser-induced fluorescence of Yb and Mg in solid Ne. Neon is an attractive medium because it is optically transparent and provides efficient, pure, stable, & chemically inert confinement for a wide variety of atomic and molecular species. Yb is used as a test atom because of its similar atomic structure to Mg and much brighter fluorescence signal. This work is supported by funds from Michigan State University.

  20. Theoretical nuclear structure and astrophysics. Progress report for 1993--1995

    SciTech Connect

    Guidry, M.W.; Nazarewicz, W.; Strayer, M.R.

    1995-12-31

    This research effort is directed toward theoretical support and guidance for the developing fields of radioactive ion beam (RIB) physics, computational and nuclear astrophysics, and the interface between these disciplines. The authors are concerned both with the application of existing technologies and concepts to guide the initial RIB program, and the development of new ideas and new technologies to influence the longer-term future of nuclear structure physics and astrophysics. The authors report substantial progress in both areas. One measure of progress is publications and invited material. The research described here has led to more than 70 papers that are published, accepted, or submitted to refereed journals, and to 46 invited presentations at conferences and workshops.

  1. Studying the stars on earth: astrophysics on intense lasers

    SciTech Connect

    Remington, B A

    1999-03-10

    Lawrence Livermore National Laboratory in Livermore, California, is now performing significant astrophysics experiments on its huge Nova laser facility, and a similar effort has started at the Gekko laser facility at Osaka University in Japan. Our experiments on the Nova and Gekko lasers so far encourage us that our astrophysics work is already leading to a better understanding of the hydrodynamics of supernovae and astrophysical jets. The ability of large inertial confinement fusion lasers to recreate star-like conditions in the laboratory greatly improves our understanding of the heavens; for the first time in our history, we can study the stars up close on Earth.

  2. Nuclear Astrophysics Programs with Low-Energy RI Beams at CRIB

    SciTech Connect

    Kubono, S.; Binh, Dam N.; Hayakawa, S.; Hashimoto, T.; Kahl, D. M.; Yamaguchi, H.; Wakabayashi, Y.; Teranishi, T.; Iwasa, N.; Komatsubara, T.; Kato, S.; Khiem, Le H.

    2010-04-30

    Nuclear astrophysics activities with CNS RI beam separator (CRIB) are reported together with the present status of the CRIB facility which is supported by the AVF upgrade project for the total development of the low-energy RIB facility. The activities include direct and indirect measurements of stellar reactions especially relevant to explosive burning processes such as nova and supernovae. Some recent results are discussed together with a scope of the facility.

  3. NUCLEAR ASTROPHYSICS PROJECT WITH A NEW LOW-ENERGY RIB SEPARATOR CRIB:. Study of a Critical Stellar Reaction 15O(α,γ)19Ne

    NASA Astrophysics Data System (ADS)

    Kubono, S.; Michimasa, S.; Teranishi, T.; Yanagisawa, Y.; Fulop, Z.; Liu, X.; Kumagai, K.; Abe, K.; Yun, C. C.; Watanabe, S.; Yamazaki, N.; Ohshiro, Y.; Kurokawa, M.; Strasser, P.; Hahn, K. I.; Kishida, T.; Imai, N.; Kato, S.; Fuchi, Y.; Tanaka, M. H.

    2003-04-01

    One of the critical stellar reactions for the onset of explosive hydrogen burning, 15O(α,γ)19Ne, is discussed with our recent experimental effort and a new possibility in our new RIB project. This reaction was investigated experimentally by indirect methods. Single particle nature of the threshold states was studied by the analog reactions, (d,t) and (d,3He) on 20Ne. The α-branching ratios for some states were also measured by a coincidence measurement of a triton and α from 19F(3He,t)19Ne*(α)15O(g.s.). Experimental plan for the problem was also discussed that uses a new low-energy RIB facility at CNS, called CRIB, which will come into operation soon.

  4. Nuclear Data for Astrophysics: Collections at NucAstroData.org

    DOE Data Explorer

    In May of 2003, Dr. Michael Smith, Physics Division, ORNL, published a paper announcing the launch of the new website NucAstroData.org and the rationale behind it. An excerpt from the abstract of that paper, found in volume 718, pages 339-346, of ScienceDirect - Nuclear Physics A, explains: "In order to address important astrophysics problems such as the origin of the chemical elements, the inner workings of our Sun, and the evolution of stars, crucial nuclear datasets are needed. Recent evaluation and dissemination efforts have produced a number of such datasets, many of which are online and readily available to the research community. Current international efforts in this field are, unfortunately, insufficient to keep pace with the latest nuclear physics measurements and model calculations. A dedicated effort is required to update and expand existing datasets. I discuss several strategies and new initiatives that would ensure a more effective utilization of nuclear data in astrophysics. These include launching a new web site, www.nucastrodata.org, to aid in locating available nuclear data sets, and an interactive online plotting program with an easy-to-use graphical user interface to over 8000 reaction rates." This website continues to be resource for the nuclear astrophysics community. NucAstroData provides both links to datasets around the world and a repository where researchers can upload their own data. Tools for generating and manipulating reaction rates, merging libraries of data, plotting data and performing other tasks are provided under the website's Infrastructure section and the menu selection for software leads to useful codes.

  5. High Energy Studies of Astrophysical Dust

    NASA Astrophysics Data System (ADS)

    Corrales, Lia Racquel

    Astrophysical dust---any condensed matter ranging from tens of atoms to micron sized grains---accounts for about one third of the heavy elements produced in stars and disseminated into space. These tiny pollutants are responsible for producing the mottled appearance in the spray of light we call the "Milky Way." However these seemingly inert particles play a strong role in the physics of the interstellar medium, aiding star and planet formation, and perhaps helping to guide galaxy evolution. Most dust grains are transparent to X-ray light, leaving a signature of atomic absorption, but also scattering the light over small angles. Bright X-ray objects serendipitously situated behind large columns of dust and gas provide a unique opportunity to study the dust along the line of sight. I focus primarily on X-ray scattering through dust, which produces a diffuse halo image around a central point source. Such objects have been observed around X-ray bright Galactic binaries and extragalactic objects that happen to shine through the plane of the Milky Way. I use the Chandra X-ray Observatory, a space-based laboratory operated by NASA, which has imaging resolution ideal for studying X-ray scattering halos. I examine several bright X-ray objects with dust-free sight lines to test their viability as templates and develop a parametric model for the Chandra HETG point spread function (PSF). The PSF describes the instrument's imaging response to a point source, an understanding of which is necessary for properly measuring the surface brightness of X-ray scattering halos. I use an HETG observation of Cygnus X-3, one of the brightest objects available in the Chandra archive, to derive a dust grain size distribution. There exist degenerate solutions for the dust scattering halo, but with the aid of Bayesian analytics I am able to apply prior knowledge about the Cyg X-3 sight line to measure the relative abundance of dust in intervening Milky Way spiral arms. I also demonstrate how

  6. NanoSIMS and more: New tools in nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Hoppe, P.

    2016-01-01

    Primitive Solar System materials contain nm- to μm-sized presolar grains that formed in the winds of evolved stars and in the ejecta of stellar explosions. These samples of stardust can be analysed in terrestrial laboratories with sophisticated analytical instrumentation in great detail. Of particular importance are coordinated studies of individual grains by Secondary Ion Mass Spectrometry (SIMS), Resonance Ionization Mass Spectrometry (RIMS) and Focused Ion Beam/Transmission Electron Microscopy (FIB/TEM) from which detailed information on isotopic compositions and mineralogies can be obtained. A key tool is the NanoSIMS 50 ion probe which permits to do isotope measurements of light and many intermediate-mass elements with spatial resolutions of <100 nm. A new type of RIMS instrument, “CHILI”, is currently under construction and is aimed to provide <100 nm resolution for isotope studies of intermediate-mass and heavy elements. Another promising analysis technique for future studies is Atom Probe Tomography (APT) which might be useful to create 3D-elemental and isotopic maps of presolar grains at the nanometer scale.

  7. Design of an intense ion source and LEBT for Jinping Underground Nuclear Astrophysics experiments

    NASA Astrophysics Data System (ADS)

    Wu, Q.; Sun, L. T.; Cui, B. Q.; Lian, G.; Yang, Y.; Ma, H. Y.; Tang, X. D.; Zhang, X. Z.; Zhang, Z. M.; Liu, W. P.

    2016-09-01

    The ongoing Jinping Underground Nuclear Astrophysics experiment (JUNA) will take the advantage of the ultralow background in China Jinping Underground Laboratory (CJPL), high current accelerator driven by on an ECR source and highly sensitive detector to study directly a number of important reactions for the first time within their relevant stellar energy range. A 2.45 GHz ECR ion source is one of its key components to provide 10 emA H+, 10 emA He+ and 2.0 emA He2+ beams for the study of (p,γ), (p,α), (α,p) and (α,γ) reactions in the first phase of the JUNA project. Ion beam is extracted from the source with energies up to 50 kV/q. The following low energy beam transport (LEBT) system transports and matches the ion beam from the exit of ion source to the acceleration tube (AT). The design status of the ECR ion source and LEBT system for the JUNA project are presented. The potential risks of the ion source are also discussed and analysed.

  8. The Underground Nuclear Astrophysics in the Precision Era of BBN: Present Results and Future Perspectives

    NASA Astrophysics Data System (ADS)

    Gustavino, C.

    2016-01-01

    The abundance of light isotopes such as D, 3He, 4He, 6Li and 7Li produced during Big Bang Nucleosynthesis (BBN) only depends on particle physics, baryon density and relevant nuclear processes. At BBN energies (0.01 ÷ 1 MeV) the cross section of many BBN processes is very low because of the Coulomb repulsion between the interacting nuclei. As low-energy measurements on earth's surface are predominantly hampered by the effects of cosmic rays in the detectors, it is convenient to study the relevant reactions with facilities operating deep underground. Starting from the present uncertainty of the relevant parameters in BBN (i.e. baryon density, observed abundance of isotopes and nuclear cross-sections), it will be shown that the study of several reactions of the BBN chain, with existing or proposed underground accelerator facilities, can improve the accuracy of BBN calculations, providing a powerful tool to constrain astrophysics, cosmology and particle physics. In particular, a precise measurement of D(p, γ)3He reaction at BBN energies is of primary importance to calculate the baryon density of universe with an accuracy similar to the one obtained by Cosmic Microwave Background (CMB) experiments, and to constrain the number of active neutrino species. For what concern the so called ’’Lithium problems”, i.e. the disagreement between computed and observed abundances of the 7Li and 6Li isotopes, it will be also shown the importance of a renewed study of the D(α, γ) 6Li reaction.

  9. On the investigation of resonances above and below the threshold in nuclear reactions of astrophysical interest using the Trojan Horse Method.

    NASA Astrophysics Data System (ADS)

    La Cognata, M.; Spitaleri, C.; Cherubini, S.; Gulino, M.; Indelicato, I.; Lamia, L.; Pizzone, R. G.; Romano, S.; Trippella, O.; Tumino, A.

    2017-07-01

    The occurrence of resonances in reactions of astrophysical interest might significantly enhance the astrophysical factor with respect to the direct reaction contribution, divert nucleosynthesis path and change the energy production, with significant impact on astrophysics. Moreover, the determination of resonance parameters, that is, energy, spin-parity and partial widths, allows one to perform nuclear structure studies leading, for instance, to determine the cluster structure of the state under investigation. However, nuclear reactions in stars take place at energies well below ~ 1 MeV owing to the typical temperatures characterising these environments. Therefore, the Coulomb barrier exponentially suppressing the cross section and the electron screening effect, due to the shielding of nuclear charges by atomic electrons, make it very difficult to provide accurate astrophysical factors. The THM is an indirect method allowing to overcome such difficulties. It makes use of quasi-free reactions with three particles in the exit channel, a + A → c + C + s, to deduce the cross section of the reaction of astrophysical interest, a + x → c + C, under the hypothesis that A shows a strong x + s cluster structure, right at astrophysical energies. By using a generalised R-matrix approach, the resonance parameters can be deduced from THM data allowing one to perform a full spectroscopic study of low-energy and sub-threshold resonances. In this work, we will discuss two examples of reactions of astrophysical interest, whose cross sections show a resonant behaviour: the19F(p, α)16O cross section that displays resonances at energies above the particle emission threshold and the13C(α, n)16O reaction, dominated by the -3 keV sub-threshold resonance due to the 6.356 MeV level in17O.

  10. Study of astrophysical collisionless shocks at NIF

    NASA Astrophysics Data System (ADS)

    Park, Hye-Sook; Higginson, D. P.; Huntington, C. M.; Pollock, B. B.; Remington, B. A.; Rinderknecht, H.; Ross, J. S.; Ryutov, D. D.; Swadling, G. F.; Wilks, S. C.; Sakawa, Y.; Spitkovsky, A.; Petrasso, R.; Li, C. K.; Zylstra, A. B.; Lamb, D.; Tzeferacos, P.; Gregori, G.; Meinecke, J.; Manuel, M.; Froula, D.; Fiuza, F.

    2016-10-01

    High Mach number astrophysical plasmas can create collisionless shocks via plasma instabilities and turbulence that are responsible for magnetic field generations and cosmic ray acceleration. Recently, many laboratory experiments were successful to observe the Weibel instabilities and self-generated magnetic fields using high-power lasers that generated interpenetrating plasma flows. In order to create a fully formed shock, a series of NIF experiments have begun. The characteristics of flow interaction have been diagnosed by the neutrons and protons generated via beam-beam deuteron interactions, the x-ray emission from the hot plasmas and proton probe generated by imploding DHe3 capsules. This paper will present the latest results from the NIF collisionless shock experiments. Prepared by LLNL under Contract DE-AC52-07NA27344.

  11. Intermediate Energies for Nuclear Astrophysics and the Development of a Position Sensitive Microstrip Detector System

    SciTech Connect

    Sobotka, Lee G.; Blackmon, J.; Bertulani, C.

    2015-12-30

    The chemical elements are made at astrophysical sites through a sequence of nuclear reactions often involving unstable nuclei. The overarching aim of this project is to construct a system that allows for the inverse process of nucleosynthesis (i.e. breakup of heavier nuclei into lighter ones) to be studied in high efficiency. The specific problem to be overcome with this grant is inadequate dynamic range and (triggering) threshold to detect the products of the breakup which include both heavy ions (with large energy and large deposited energy in a detector system) and protons (with little energy and deposited energy.) Early on in the grant we provided both TAMU and RIKEN (the site of the eventual experiments) with working systems based on the existing technology. This technology could be used with either an external preamplifier that was to be designed and fabricated by our RIKEN collaborators or upgraded by replacing the existing chip with one we designed. The RIKEN external preamplifier project never can to completion but our revised chip was designed, fabricated, used in a test experiment and performs as required.

  12. High Energy, High Resolution X-Ray Spectroscopy: Microcalorimeters For Nuclear Line Astrophysics

    NASA Astrophysics Data System (ADS)

    Silver, E.; Schnopper, H. W.; Jones, C.; Forman, W.; Romaine, S.; Madden, N.; Landis, D.; Beeman, J.; Haller, E. E.; Barbera, M.; Christensen, F.; Ramsey, B.; Woosley, S.; Diehl, R.

    2005-06-01

    We introduce focusing optics and microcalorimeter spectroscopy to nuclear line emission astrophysics with a balloon payload concept called, B-MINE. It is designed to probe the deepest regions of a supernova explosion by detecting 44Ti emission at 68 keV with spatial and spectral resolutions that are sufficient to determine the velocity distribution of the 44Ti emitting region. B-MINE has a thin plastic foil telescope multilayered to maximize the reflectivity in a 20 keV band centered at 68 keV and a microcalorimeter array optimized for the same energy band. This combination provides a reduced background, an energy resolution of 50 eV and a 3σ sensitivity in 106 s of 6 × 10-8 ph cm-2 s-1 at 68 keV. During the course of a long duration balloon flight, B-MINE could carry out a detailed study of the 44Ti emission line centroids and width in CAS A. Details of the spectrometer and simulated results are presented.

  13. TIME-OF-FLIGHT MASS MEASUREMENTS AND THEIR IMPORTANCE FOR NUCLEAR ASTROPHYSICS

    SciTech Connect

    Matos, M.; Shapira, Dan

    2009-01-01

    Atomic masses play an important role in nuclear astrophysics. The lack of experimental values for nuclides of interest has triggered a rapid development of new mass measurement devices around the world, including Time-of-Flight (TOF) mass measurements offering an access to the most exotic nuclides. Recently, the TOF-B rho technique that includes a position measurement for magnetic rigidity correction has been implemented at the NSCL. An experiment with a similar TOF-B rho technique is approved and planned at the next generation radioactive beam facility (RIBF) at RIKEN.

  14. Time-of-Flight Mass Measurements and Their Importance for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Matoš, M.; Estrade, A.; Amthor, A. M.; Bazin, D.; Becerril, A.; Elliot, T.; Famiano, M.; Gade, A.; Galaviz, D.; Lorusso, G.; Pereira, J.; Portillo, M.; Rogers, A.; Schatz, H.; Shapira, D.; Smith, E.; Stolz, A.; Wallace, M.

    2009-03-01

    Atomic masses play an important role in nuclear astrophysics. The lack of experimental values for nuclides of interest has triggered a rapid development of new mass measurement devices around the world, including Time-of-Flight (TOF) mass measurements offering an access to the most exotic nuclides. Recently, the TOF-Brho technique that includes a position measurement for magnetic rigidity correction has been implemented at the NSCL. An experiment with a similar TOF-Brho technique is approved and planned at the next generation radioactive beam facility (RIBF) at RIKEN.

  15. Nuclear Reaction Data File for Astrophysics (NRDF/A) in Hokkaido University Nuclear Reaction Data Center

    SciTech Connect

    Kato, Kiyoshi; Kimura, Masaaki; Furutachi, Naoya; Makinaga, Ayano; Togashi, Tomoaki; Otuka, Naohiko

    2010-06-01

    The activities of the Japan Nuclear Reaction Data Centre is explained. The main task of the centre is data compilation of Japanese nuclear reaction data in collaboration of the International Network of Nuclear Reaction Data Centres. As one of recent activities, preparation of a new database (NRDF/A) and evaluation of astronuclear reaction data are reported. Collaboration in the nuclear data activities among Asian countries is proposed.

  16. Nuclear Reaction Data File for Astrophysics (NRDF/A) in Hokkaido University Nuclear Reaction Data Center

    NASA Astrophysics Data System (ADS)

    Katō, Kiyoshi; Kimura, Masaaki; Furutachi, Naoya; Togashi, Tomoaki; Makinaga, Ayano; Otuka, Naohiko

    2010-06-01

    The activities of the Japan Nuclear Reaction Data Centre is explained. The main task of the centre is data compilation of Japanese nuclear reaction data in collaboration of the International Network of Nuclear Reaction Data Centres. As one of recent activities, preparation of a new database (NRDF/A) and evaluation of astronuclear reaction data are reported. Collaboration in the nuclear data activities among Asian countries is proposed.

  17. Studying astrophysical reactions with low-energy RI beams at CRIB

    NASA Astrophysics Data System (ADS)

    Yamaguchi, H.; Kahl, D.; Hayakawa, S.; Sakaguchi, Y.; Wakabayashi, Y.; Hashimoto, T.; Cherubini, S.; Gulino, M.; Spitaleri, C.; Rapisarda, G. G.; La Cognata, M.; Lamia, L.; Romano, S.; Kubono, S.; Iwasa, N.; Teranishi, T.; Kawabata, T.; Kwon, Y. K.; Binh, D. N.; Khiem, L. H.; Duy, N. N.; Kato, S.; Komatsubara, T.; Coc, A.; De Sereville, N.; Hammache, F.; Kiss, G.; Bishop, S.

    2016-05-01

    Studies on nuclear astrophysics, nuclear structure, and other interests have been performed using the radioactive-isotope (RI) beams at the low-energy RI beam separator CRIB, operated by Center for Nuclear Study (CNS), the University of Tokyo. A typical measurement performed at CRIB is the elastic resonant scattering with the inverse kinematics. One recent experiment was on the α resonant scattering with 7Li and 7Be beams. This study is related to the astrophysical 7Li/7Be(α,γ) reactions, important at hot p-p chain and νp-process in supernovae. There have also been measurements based on other experimental methods. The first THM measurement using an RI beam has been performed at CRIB, to study the 18F(p, α)15O reaction at astrophysical energies via the three body reaction 2H(18F, α15O)n. The 18F(p, α) 15O reaction rate is crucial to understand the 511-keV γ-ray production in nova explosion phenomena, and we successfully evaluated the reaction cross section at novae temperature and below experimentally for the first time.

  18. Ex luna, scientia: lunar occultation as a paradigm for nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Miller, Richard S.; Lawrence, David J.; Peplowski, Patrick N.; Goldsten, John O.; Ozimek, Martin T.; Scott, Christopher J.; Leary, James C.; Grant, Dave; Young, C. Alex

    2016-07-01

    Next-generation nuclear astrophysics investigations must address a demanding set of requirements to probe the matter and energy life-cycle in our Galaxy and throughout the Cosmos. Enhanced flux sensitivity and (near) all-sky monitoring are just two of these requirements; cost effectiveness and other programmatic restrictions pose additional challenges. These competing goals can be addressed with a paradigm change, i.e. performing investigations from lunar orbit and utilizing a new detection and imaging technique. We report on our development of the Moon as a platform for nuclear astrophysics utilizing the Lunar Occultation Technique (LOT). Here source fluxes are temporally modulated as they are repeatedly occulted by the Moon; the modulation, as observed by a suitably configured instrument in lunar orbit, enables the detection, imaging, and characterization of both point- and extended-sources, narrow-line and broadband sources. Key benefits include maximizing the ratio of sensitive-to-total deployed mass and the operational simplicity relative to other detection schemes. A mission based on the LOT, the Lunar Occultation Explorer (LOX), will be the first to employ occultation as the principle method to characterize the intensity, variability, and spectra of detected sources.

  19. STARLIB: A Next-generation Reaction-rate Library for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Sallaska, A. L.; Iliadis, C.; Champange, A. E.; Goriely, S.; Starrfield, S.; Timmes, F. X.

    2013-07-01

    STARLIB is a next-generation, all-purpose nuclear reaction-rate library. For the first time, this library provides the rate probability density at all temperature grid points for convenient implementation in models of stellar phenomena. The recommended rate and its associated uncertainties are also included. Currently, uncertainties are absent from all other rate libraries, and, although estimates have been attempted in previous evaluations and compilations, these are generally not based on rigorous statistical definitions. A common standard for deriving uncertainties is clearly warranted. STARLIB represents a first step in addressing this deficiency by providing a tabular, up-to-date database that supplies not only the rate and its uncertainty but also its distribution. Because a majority of rates are lognormally distributed, this allows the construction of rate probability densities from the columns of STARLIB. This structure is based on a recently suggested Monte Carlo method to calculate reaction rates, where uncertainties are rigorously defined. In STARLIB, experimental rates are supplemented with: (1) theoretical TALYS rates for reactions for which no experimental input is available, and (2) laboratory and theoretical weak rates. STARLIB includes all types of reactions of astrophysical interest to Z = 83, such as (p, γ), (p, α), (α, n), and corresponding reverse rates. Strong rates account for thermal target excitations. Here, we summarize our Monte Carlo formalism, introduce the library, compare methods of correcting rates for stellar environments, and discuss how to implement our library in Monte Carlo nucleosynthesis studies. We also present a method for accessing STARLIB on the Internet and outline updated Monte Carlo-based rates.

  20. STARLIB: A NEXT-GENERATION REACTION-RATE LIBRARY FOR NUCLEAR ASTROPHYSICS

    SciTech Connect

    Sallaska, A. L.; Iliadis, C.; Champange, A. E.; Goriely, S.; Starrfield, S.; Timmes, F. X.

    2013-07-15

    STARLIB is a next-generation, all-purpose nuclear reaction-rate library. For the first time, this library provides the rate probability density at all temperature grid points for convenient implementation in models of stellar phenomena. The recommended rate and its associated uncertainties are also included. Currently, uncertainties are absent from all other rate libraries, and, although estimates have been attempted in previous evaluations and compilations, these are generally not based on rigorous statistical definitions. A common standard for deriving uncertainties is clearly warranted. STARLIB represents a first step in addressing this deficiency by providing a tabular, up-to-date database that supplies not only the rate and its uncertainty but also its distribution. Because a majority of rates are lognormally distributed, this allows the construction of rate probability densities from the columns of STARLIB. This structure is based on a recently suggested Monte Carlo method to calculate reaction rates, where uncertainties are rigorously defined. In STARLIB, experimental rates are supplemented with: (1) theoretical TALYS rates for reactions for which no experimental input is available, and (2) laboratory and theoretical weak rates. STARLIB includes all types of reactions of astrophysical interest to Z = 83, such as (p, {gamma}), (p, {alpha}), ({alpha}, n), and corresponding reverse rates. Strong rates account for thermal target excitations. Here, we summarize our Monte Carlo formalism, introduce the library, compare methods of correcting rates for stellar environments, and discuss how to implement our library in Monte Carlo nucleosynthesis studies. We also present a method for accessing STARLIB on the Internet and outline updated Monte Carlo-based rates.

  1. Fundamental studies in X-ray astrophysics

    NASA Technical Reports Server (NTRS)

    Lamb, D. Q.; Lightman, A. P.

    1982-01-01

    An analytical model calculation of the ionization structure of matter accreting onto a degenerate dwarf was carried out. Self-consistent values of the various parameters are used. The possibility of nuclear burning of the accreting matter is included. We find the blackbody radiation emitted from the stellar surface keeps hydrogen and helium ionized out to distances much larger than a typical binary separation. Except for low mass stars or high accretion rates, the assumption of complete ionization of the elements heavier than helium is a good first approximation. For low mass stars or high accretion rates the validity of assuming complete ionization depends sensitivity on the distribution of matter in the binary system.

  2. Nuclear Astrophysics at the LENA facility: The γ-ray detection system.

    NASA Astrophysics Data System (ADS)

    Longland, Richard; Iliadis, Christian; Champagne, Arthur; Fox, Chris; Newton, Joe

    2006-10-01

    Details of the detection system used at The Laboratory for Experimental Nuclear Astrophysics is described, including methods for measuring weak capture-γ-ray resonances. γγ-coincidence techniques with a large solid angle NaI(Tl) annulus are described, as well as their effects on background count rates in the energy regions of interest at LENA. In order to reduce the background further, cosmic muon induced counts can be decreased with the aid of an anti-coincidence plastic scintillator shield. In order to create a compact detection system, a novel, wavelength shifting fibre method of light readout has been used. These techniques are shown to reduce background count rates significantly for cascade decays in our regions of interest, and are shown to have a significant improvement over our previous results.

  3. Progress of the Felsenkeller Shallow-Underground Accelerator for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Bemmerer, D.; Cavanna, F.; Cowan, T. E.; Grieger, M.; Hensel, T.; Junghans, A. R.; Ludwig, F.; Müller, S. E.; Rimarzig, B.; Reinicke, S.; Schulz, S.; Schwengner, R.; Stöckel, K.; Szücs, T.; Takács, M. P.; Wagner, A.; Wagner, L.; Zuber, K.

    Low-background experiments with stable ion beams are an important tool for putting the model of stellar hydrogen, helium, and carbon burning on a solid experimental foundation. The pioneering work in this regard has been done by the LUNA collaboration at Gran Sasso, using a 0.4 MV accelerator. In the present contribution, the status of the project for a higher-energy underground accelerator is reviewed. Two tunnels of the Felsenkeller underground site in Dresden, Germany, are currently being refurbished for the installation of a 5 MV high-current Pelletron accelerator. Construction work is on schedule and expected to complete in August 2017. The accelerator will provide intense, 50 µA, beams of 1H+, 4He+, and 12C+ ions, enabling research on astrophysically relevant nuclear reactions with unprecedented sensitivity.

  4. Laboratory Study of Angular Momentum Transport in Astrophysical Accretion Disks

    NASA Astrophysics Data System (ADS)

    Ji, Hantao

    2014-10-01

    Studying astrophysical processes in the lab becomes increasingly possible and exciting, as one of Stirling's favorite subjects throughout his scientific career. In this talk, I will describe experimental efforts to study mechanisms of rapid angular momentum transport required to occur in accretion disks to explain a wide range of phenomena from star formation, energetic activity of cataclysmic variables, to powering quasars, the most luminous steady sources in the Universe. By carefully isolating effects due to artificial boundaries, which are inherent to terrestrial experiments, certain astrophysical questions regarding hydrodynamic and magnetohydrodynamic stabilities are being addressed in the laboratory. Inspirations from Stirling as well as scientific exchanges with him will be mentioned during this talk as part of my scientific journey on this subject.

  5. Report on the workshop "Decay spectroscopy at CARIBU: advanced fuel cycle applications, nuclear structure and astrophysics". 14-16 April 2011, Argonne National Laboratory, USA.

    SciTech Connect

    Kondev, F.; Carpenter, M.P.; Chowdhury, P.; Clark, J.A.; Lister, C.J.; Nichols, A.L.; Swewryniak, D.

    2011-10-06

    A workshop on 'Decay Spectroscopy at CARIBU: Advanced Fuel Cycle Applications, Nuclear Structure and Astrophysics' will be held at Argonne National Laboratory on April 14-16, 2011. The aim of the workshop is to discuss opportunities for decay studies at the Californium Rare Isotope Breeder Upgrade (CARIBU) of the ATLAS facility with emphasis on advanced fuel cycle (AFC) applications, nuclear structure and astrophysics research. The workshop will consist of review and contributed talks. Presentations by members of the local groups, outlining the status of relevant in-house projects and availabile equipment, will also be organized. time will also be set aside to discuss and develop working collaborations for future decay studies at CARIBU. Topics of interest include: (1) Decay data of relevance to AFC applications with emphasis on reactor decay heat; (2) Discrete high-resolution gamma-ray spectroscopy following radioactive decya and related topics; (3) Calorimetric studies of neutron-rich fission framgents using Total ABsorption Gamma-Ray Spectrometry (TAGS) technique; (4) Beta-delayed neutron emissions and related topics; and (5) Decay data needs for nuclear astrophysics.

  6. The Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas jet target

    NASA Astrophysics Data System (ADS)

    Chipps, K. A.; Greife, U.; Bardayan, D. W.; Blackmon, J. C.; Kontos, A.; Linhardt, L. E.; Matos, M.; Pain, S. D.; Pittman, S. T.; Sachs, A.; Schatz, H.; Schmitt, K. T.; Smith, M. S.; Thompson, P.

    2014-11-01

    New radioactive ion beam (RIB) facilities will push further away from stability and enable the next generation of nuclear physics experiments. Of great importance to the future of RIB physics are scattering, transfer, and capture reaction measurements of rare, exotic, and unstable nuclei on light targets such as hydrogen and helium. These measurements require targets that are dense, highly localized, and pure. Targets must also accommodate the use of large area silicon detector arrays, high-efficiency gamma arrays, and heavy ion detector systems to efficiently measure the reaction products. To address these issues, the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) Collaboration has designed, built, and characterized a supersonic gas jet target, capable of providing gas areal densities on par with commonly used solid targets within a region of a few millimeters diameter. Densities of over 5×1018 atoms/cm2 of helium have been achieved, making the JENSA gas jet target the most dense helium jet achieved so far.

  7. Gamma ray beams for Nuclear Astrophysics: first results of tests and simulations of the ELISSA array

    NASA Astrophysics Data System (ADS)

    La Cognata, M.; Anzalone, A.; Balabanski, D.; Chesnevskaya, S.; Crucillà, V.; Filipescu, D. M.; Guardo, G. L.; Gulino, M.; Lattuada, D.; Matei, C.; Pizzone, R. G.; Romano, S.; Spitaleri, C.; Taffara, A.; Tesileanu, O.; Tumino, A.; Xu, Y.

    2017-03-01

    The Extreme Light Infrastructure-Nuclear Physics (ELI-NP) facility, under construction in Magurele near Bucharest in Romania, will provide high-intensity and high-resolution gamma ray beams that can be used to address hotly debated problems in nuclear astrophysics. For this purpose, a silicon strip detector array (named ELISSA) will be realized in a common effort by ELI-NP and INFN-LNS (Catania, Italy), in order to measure excitation functions and angular distributions over a wide energy and angular range. A prototype of ELISSA was built and tested at Laboratori Nazionali del Sud (INFN-LNS) in Catania with the support of ELI-NP. On this occasion, we carried out experiments with alpha sources and with a 11 MeV 7Li beam. Thanks to our approach, the first results of those tests show up a very good energy resolution (better than 1%) and very good position resolution, of the order of 1 mm. Below 1 MeV, a resolution of the order of 6 mm is found, still good enough for the measurement of angular distribution and the kinematical identification of the reactions induced on the target by gamma beams.

  8. Trojan Horse method and radioactive ion beams: study of 18F(p,α)15O reaction at astrophysical energies

    NASA Astrophysics Data System (ADS)

    Gulino, M.; Cherubini, S.; Rapisarda, G. G.; Kubono, S.; Lamia, L.; La Cognata, M.; Yamaguchi, H.; Hayakawa, S.; Wakabayashi, Y.; Iwasa, N.; Kato, S.; Komatsubara, H.; Teranishi, T.; Coc, A.; De Séréville, N.; Hammache, F.; Spitaleri, C.

    2013-03-01

    The Trojan Horse Method was applied for the first time to a Radioactive Ion Beam induced reaction to study the reaction 18F(p,α)15O via the three body reaction 18F(d,α 15O)n at the low energies relevant for astrophysics. The abundance of 18F in Nova explosions is an important issue for the understanding of this astrophysical phenomenon. For this reason it is necessary to study the nuclear reactions that produce or destroy 18F in Novae. 18F(p,α)15O is one of the main 18F destruction channels. Preliminary results are presented in this paper.

  9. A multidisciplinary study of planetary, solar and astrophysical radio emissions

    NASA Technical Reports Server (NTRS)

    Gurnett, D. A.; Calvert, W.; Fielder, R.; Goertz, C.; Grabbe, C.; Kurth, W.; Mutel, R.; Sheerin, J.; Mellott, M.; Spangler, S.

    1986-01-01

    Combination of the related fields of planetary, solar, and astrophysical radio emissions was attempted in order to more fully understand the radio emission processes. Topics addressed include: remote sensing of astrophysical plasma turbulence; Alfven waves; astrophysical shock waves; surface waves; very long base interferometry results; very large array observations; solar magnetic flux; and magnetohydrodynamic waves as a tool for solar corona diagnostics.

  10. Experimental study of the astrophysical γ -process reaction 124Xe(α ,γ )128Ba

    NASA Astrophysics Data System (ADS)

    Halász, Z.; Somorjai, E.; Gyürky, Gy.; Elekes, Z.; Fülöp, Zs.; Szücs, T.; Kiss, G. G.; Szegedi, N. T.; Rauscher, T.; Görres, J.; Wiescher, M.

    2016-10-01

    Background: The synthesis of heavy, proton rich isotopes in the astrophysical γ process proceeds through photodisintegration reactions. For the improved understanding of the process, the rates of the involved nuclear reactions must be known. The reaction 128Ba(γ ,α )124Xe was found to affect the abundance of the p nucleus 124Xe in previous rate variation studies. Purpose: Since the stellar rate for this reaction cannot be determined by a measurement directly, the aim of the present work was to measure the cross section of the inverse 124Xe(α ,γ )128Ba reaction and to compare the results with statistical model predictions used in astrophysical networks. Modified nuclear input can then be used to provide an improved stellar reaction rate. Of great importance is the fact that data below the (α ,n ) threshold was obtained. Studying simultaneously the 124Xe(α ,n )127Ba reaction channel at higher energy allowed to further identify the source of a discrepancy between data and prediction. Method: The 124Xe(α ,γ )128Ba and 124Xe(α ,n )127Ba cross sections were measured with the activation method using a thin window 124Xe gas cell and an α beam from a cyclotron accelerator. The studied energy range was between Eα=11 and 15 MeV close above the astrophysically relevant energy range. Results: The obtained cross sections are compared with Hauser-Feshbach statistical model calculations. The experimental cross sections are smaller than standard predictions previously used in astrophysical calculations. As a dominating source of the difference, the theoretical α width was identified. The experimental data suggest an α width lower by at least a factor of 0.125 in the astrophysically important energy range. Conclusions: An upper limit for the 128Ba(γ ,α )124Xe stellar rate was inferred from our measurement. The impact of this rate and lower rates was studied in two different models for core-collapse supernova explosions of 25 M⊙ stars. A significant contribution to

  11. The evaluation of half-lives and other decay data used in nuclear astrophysics and cosmochronology

    SciTech Connect

    Chechev, V. P.

    2011-12-15

    The current status of some decay data used in nuclear astrophysics and cosmochronology is presented. The half-life of {sup 79}Se has been evaluated as 3.6(3) Multiplication-Sign 10{sup 5} yr. The total energy of non-neutrino radiation released in act of {sup 37}Ar decay has been obtained being 2.709 (16) keV per disintegration. The recommended half-life values of the long-lived radionuclides (T{sub 1/2} Greater-Than-Or-Equivalent-To 10{sup 6} yr) of {sup 26}Al, {sup 40}K, {sup 53}Mn, {sup 60}Fe, {sup 87}Rb, {sup 93}Zr, {sup 98}Tc, {sup 107}Pd, {sup 129}I, {sup 135}Cs, {sup 146}Sm, {sup 176}Lu, {sup 182}Hf, {sup 187}Re, {sup 205}Pb, {sup 232}Th, {sup 235}U, {sup 238}U, {sup 244}Pu, and {sup 247}Cm are given based on the evaluations published until 2010.

  12. Telescope for x ray and gamma ray studies in astrophysics

    NASA Technical Reports Server (NTRS)

    Weaver, W. D.; Desai, Upendra D.

    1993-01-01

    Imaging of x-rays has been achieved by various methods in astrophysics, nuclear physics, medicine, and material science. A new method for imaging x-ray and gamma-ray sources avoids the limitations of previously used imaging devices. Images are formed in optical wavelengths by using mirrors or lenses to reflect and refract the incoming photons. High energy x-ray and gamma-ray photons cannot be reflected except at grazing angles and pass through lenses without being refracted. Therefore, different methods must be used to image x-ray and gamma-ray sources. Techniques using total absorption, or shadow casting, can provide images in x-rays and gamma-rays. This new method uses a coder made of a pair of Fresnel zone plates and a detector consisting of a matrix of CsI scintillators and photodiodes. The Fresnel zone plates produce Moire patterns when illuminated by an off-axis source. These Moire patterns are deconvolved using a stepped sine wave fitting or an inverse Fourier transform. This type of coder provides the capability of an instantaneous image with sub-arcminute resolution while using a detector with only a coarse position-sensitivity. A matrix of the CsI/photodiode detector elements provides the necessary coarse position-sensitivity. The CsI/photodiode detector also allows good energy resolution. This imaging system provides advantages over previously used imaging devices in both performance and efficiency.

  13. Precision Masses for Studies of the Astrophysical r Process

    SciTech Connect

    Clark, Jason; Savard, Guy

    2013-09-01

    Half of the elements heavier than iron (Z > 26) are thought to be created through the astrophysical r process, whereby nuclides are produced via a rapid series of nuclear reactions that are postulated to occur in high temperature and neutron density environments such as supernovae or merging neutron stars. The nucleosynthetic path that describes the sequence of reactions through the chart of nuclides strongly depends on the neutron-separation energies of the nuclei. Until recently, however, almost all of these neutron-rich nuclei were not within reach of accelerator facilities, and therefore simulations of the r process had to rely on mass models for input into the calculations. Now, with the advent of facilities such as CARIBU at Argonne National Laboratory, the masses of many nuclides along the r-process path can be determined precisely with Penning trap mass spectrometers coupled to these facilities. More than 70 nuclides have been measured with the Canadian Penning Trap mass spectrometer alone in the past year, which overlap and complement results from other Penning trap mass spectrometers, and first calculations with these new masses suggest the timescale of the r process through the tin isotopes is delayed much more strongly than mass models would suggest.

  14. Study of shock waves and related phenomena motivated by astrophysics

    DOE PAGES

    Drake, R. P.; Keiter, P. A.; Kuranz, C. C.; ...

    2016-04-01

    This study discusses the recent research in High-Energy-Density Physics at our Center. Our work in complex hydrodynamics is now focused on mode coupling in the Richtmyer-Meshkov process and on the supersonic Kelvin-Helmholtz instability. These processes are believed to occur in a wide range of astrophysical circumstances. In radiation hydrodynamics, we are studying radiative reverse shocks relevant to cataclysmic variable stars. Our work on magnetized flows seeks to produce magnetized jets and study their interactions. We build the targets for all these experiments, and simulate them using our CRASH code. We also conduct diagnostic research, focused primarily on imaging x-ray spectroscopymore » and its applications to scattering and fluorescence.« less

  15. Study of shock waves and related phenomena motivated by astrophysics

    SciTech Connect

    Drake, R. P.; Keiter, P. A.; Kuranz, C. C.; Malamud, G.; Manuel, M.; Stefano, C. A. Di; Gamboa, E. J.; Krauland, C. M.; MacDonald, M. J.; Wan, W. C.; Young, R. P.; Montgomery, D. S.; Stoeckl, C.; Froula, D. H.

    2016-04-01

    This study discusses the recent research in High-Energy-Density Physics at our Center. Our work in complex hydrodynamics is now focused on mode coupling in the Richtmyer-Meshkov process and on the supersonic Kelvin-Helmholtz instability. These processes are believed to occur in a wide range of astrophysical circumstances. In radiation hydrodynamics, we are studying radiative reverse shocks relevant to cataclysmic variable stars. Our work on magnetized flows seeks to produce magnetized jets and study their interactions. We build the targets for all these experiments, and simulate them using our CRASH code. We also conduct diagnostic research, focused primarily on imaging x-ray spectroscopy and its applications to scattering and fluorescence.

  16. Laboratory Studies of Simple Dust Analogs in Astrophysical Environments

    NASA Astrophysics Data System (ADS)

    Brucato, John R.; Nuth, Joseph A., III

    2010-02-01

    Laboratory techniques seek to understand and to place limits upon chemical and physical processes that occur in space. Dust can be modified by long-term exposure to high-energy cosmic rays, thus rendering crystalline material amorphous.It can be heated to high temperatures, thus making amorphous material crystalline. Dust may be coated by organic molecules, changing its spectral properties, or may act as a catalyst in the synthesis of both simple and complex molecules. We describe experimental studies to understand such processes and report studies that focus on the properties of simple oxide grains. We give an overview of the synthesis and characterization techniques most often utilized to study the properties of solids in the laboratory and have concentrated on those techniques that have been most useful for the interpretation of astrophysical data. We also discuss silicate catalysis as an important mechanism that may drive the formation of complex molecular compounds relevant for prebiotic chemistry.

  17. ULTRACAM — studying astrophysics on the fastest timescales

    NASA Astrophysics Data System (ADS)

    Dhillon, Vik; Marsh, Tom

    2001-01-01

    The history of observational astronomy has shown that major advances in the science almost always result when a new area of observational parameter space, such as wavelength coverage, angular resolution, sensitivity or sky coverage, becomes accessible for exploration. ULTRACAM is an ultra-fast, triple-beam CCD camera which has been designed to study one of the few remaining unexplored regions of observational parameter space — high temporal resolution. The camera, which has recently been funded in full (£292 k) by PPARC, will see first light during the summer of 2001 and will be used on the 4.2 m WHT, 2.5 m INT, 2.0 m Liverpool Telescope, 3.9 m AAT, 9.1 m SALT and the 1.9 m SAAO Radcliffe Telescope to study astrophysics on the fastest timescales.

  18. Study of shock waves and related phenomena motivated by astrophysics

    NASA Astrophysics Data System (ADS)

    Drake, R. P.; Keiter, P. A.; Kuranz, C. C.; Malamud, G.; Manuel, M.; Di Stefano, C. A.; Gamboa, E. J.; Krauland, C. M.; MacDonald, M. J.; Wan, W. C.; Young, R. P.; Montgomery, D. S.; Stoeckl, C.; Froula, D. H.

    2016-03-01

    This paper discusses the recent research in High-Energy-Density Physics at our Center. Our work in complex hydrodynamics is now focused on mode coupling in the Richtmyer- Meshkov process and on the supersonic Kelvin-Helmholtz instability. These processes are believed to occur in a wide range of astrophysical circumstances. In radiation hydrodynamics, we are studying radiative reverse shocks relevant to cataclysmic variable stars. Our work on magnetized flows seeks to produce magnetized jets and study their interactions. We build the targets for all these experiments, and simulate them using our CRASH code. We also conduct diagnostic research, focused primarily on imaging x-ray spectroscopy and its applications to scattering and fluorescence.

  19. Design of an adiabatic demagnetization refrigerator for studies in astrophysics

    NASA Technical Reports Server (NTRS)

    Castles, S.

    1983-01-01

    An adiabatic demagnetization refrigerator was designed for cooling infrared bolometers for studies in astrophysics and aeronomy. The design was tailored to the requirements of a Shuttle sortie experiment. The refrigerator should be capable of maintaining three bolometers at 0.1 K with a 90% cycle. The advantage are of operations the bolometer at 0.1K. greater sensitivity, faster response time, and the ability to use larger bolometer elements without compromising the response time. The design presented is the first complete design of an ADR intended for use in space. The most important of these specifications are to survive a Shuttle launch, to operate with 1.5 K - 2.0 K space-pumped liquid helium as a heat sink, to have a 90% duty cycle, and to be highly efficient.

  20. Studying astrophysical particle acceleration with laser-driven plasmas

    NASA Astrophysics Data System (ADS)

    Fiuza, Frederico

    2016-10-01

    The acceleration of non-thermal particles in plasmas is critical for our understanding of explosive astrophysical phenomena, from solar flares to gamma ray bursts. Particle acceleration is thought to be mediated by collisionless shocks and magnetic reconnection. The microphysics underlying these processes and their ability to efficiently convert flow and magnetic energy into non-thermal particles, however, is not yet fully understood. By performing for the first time ab initio 3D particle-in-cell simulations of the interaction of both magnetized and unmagnetized laser-driven plasmas, it is now possible to identify the optimal parameters for the study of particle acceleration in the laboratory relevant to astrophysical scenarios. It is predicted for the Omega and NIF laser conditions that significant non-thermal acceleration can occur during magnetic reconnection of laser-driven magnetized plasmas. Electrons are accelerated by the electric field near the X-points and trapped in contracting magnetic islands. This leads to a power-law tail extending to nearly a hundred times the thermal energy of the plasma and that contains a large fraction of the magnetic energy. The study of unmagnetized interpenetrating plasmas also reveals the possibility of forming collisionless shocks mediated by the Weibel instability on NIF. Under such conditions, both electrons and ions can be energized by scattering out of the Weibel-mediated turbulence. This also leads to power-law spectra that can be detected experimentally. The resulting experimental requirements to probe the microphysics of plasma particle acceleration will be discussed, paving the way for the first experiments of these important processes in the laboratory. As a result of these simulations and theoretical analysis, there are new experiments being planned on the Omega, NIF, and LCLS laser facilities to test these theoretical predictions. This work was supported by the SLAC LDRD program and DOE Office of Science, Fusion

  1. Recent Progresses in Ab-Initio Studies of Low-Energy Few-Nucleon Reactions of Astrophysical Interest

    NASA Astrophysics Data System (ADS)

    Marcucci, Laura E.

    2017-03-01

    We review the most recent theoretical studies of nuclear reactions of astrophysical interest involving few-nucleon systems. In particular, we focus on the radiative capture of protons by deuterons in the energy range of interest for Big Bang Nucleosynthesis. Related to this, we will discuss also the most recent calculation of tritium β -decay. Two frameworks will be considered, the conventional and the chiral effective field theory approach.

  2. Spheroidal and Torsional Modes of Quasistatic Shear Oscillations in the Solid Globe Models of Nuclear Physics and Pulsar Astrophysics

    NASA Astrophysics Data System (ADS)

    Bastrukov, Sergey; Chang, Hsiang-Kuang; Mişicu, Şerban; Molodtsova, Irina; Podgainy, Dima

    The past three decades of investigation on nuclear physics and pulsar astrophysics have seen gradual recognition that elastodynamic approach to the continuum mechanics of nuclear matter provides proper account of macroscopic motions of degenerate Fermi-matter constituting interior of the nuclear material objects, the densest of all known today. This paper focuses on one theoretical issue of this development which is concerned with oscillatory behavior of a viscoelastic solid globe in the regime of quasistatic, force-free, noncompressional oscillations less investigated in the literature compared to oscillations in the regime of standing shear waves. We show that in this case the problem of computing frequency and lifetime of spheroidal and torsional modes of nonradial shear vibrations damped by viscosity can be unambiguously resolved by working from the energy balance equation and taking advantage of the Rayleigh's variational method. The efficiency of this method is demonstrated by solid globe models of nuclear physics and pulsar astrophysics dealing with oscillations of a spherical mass of a viscoelastic Fermi-solid with homogeneous and nonhomogeneous profiles of the bulk density, the shear modulus, and the shear viscosity.

  3. The Trojan Horse method for nuclear astrophysics: Recent results for direct reactions

    NASA Astrophysics Data System (ADS)

    Tumino, A.; Spitaleri, C.; Cherubini, S.; Gulino, M.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Rapisarda, G. G.; Romano, S.

    2014-05-01

    The Trojan Horse method is a powerful indirect technique to determine the astrophysical factor for binary rearrangement processes A+x→b+B at astrophysical energies by measuring the cross section for the Trojan Horse (TH) reaction A+a→B+b+s in quasi free kinematics. The Trojan Horse Method has been successfully applied to many reactions of astrophysical interest, both direct and resonant. In this paper, we will focus on direct sub-processes. The theory of the THM for direct binary reactions will be shortly presented based on a few-body approach that takes into account the off-energy-shell effects and initial and final state interactions. Examples of recent results will be presented to demonstrate how THM works experimentally.

  4. The Trojan Horse method for nuclear astrophysics: Recent results for direct reactions

    SciTech Connect

    Tumino, A.; Gulino, M.; Spitaleri, C.; Cherubini, S.; Romano, S.; Cognata, M. La; Pizzone, R. G.; Rapisarda, G. G.; Lamia, L.

    2014-05-09

    The Trojan Horse method is a powerful indirect technique to determine the astrophysical factor for binary rearrangement processes A+x→b+B at astrophysical energies by measuring the cross section for the Trojan Horse (TH) reaction A+a→B+b+s in quasi free kinematics. The Trojan Horse Method has been successfully applied to many reactions of astrophysical interest, both direct and resonant. In this paper, we will focus on direct sub-processes. The theory of the THM for direct binary reactions will be shortly presented based on a few-body approach that takes into account the off-energy-shell effects and initial and final state interactions. Examples of recent results will be presented to demonstrate how THM works experimentally.

  5. Laboratory Studies Of Astrophysically-interesting Phosphorus-bearing Molecules

    NASA Astrophysics Data System (ADS)

    Ziurys, Lucy M.; Halfen, D. T.; Sun, M.; Clouthier, D. J.

    2009-05-01

    Over the past year, there has been a renewed interest in the presence of phosphorus-containing molecules in the interstellar medium. Recent observations have increased the number of known interstellar phosphorus-bearing species from two (PN, CP) to six with the identification of HCP, CCP, and PH3 in the carbon-rich circumstellar shell of IRC+10216 and PO in the oxygen-rich envelope of VY Canis Majoris. More species of this type may be present in the ISM, but laboratory rest frequencies, necessary for such detections, are not generally known for many potential molecules. To fill in this gap, we have been conducting measurements of the pure rotational spectra of phosphorus-containing molecules of astrophysical interest, using both millimeter/submm direct absorption and Fourier transform microwave (FTMW) spectroscopy. We have developed a new phosphorus source for this purpose. These methods cover the frequency ranges 65-850 GHz and 4-40 GHz, respectively. Our recent study of the CCP radical (X2Πr) using both of these techniques has resulted in its identification in IRC+10216. Rotational spectra of other molecules such as PCN, HPS, and CH3PH2 have been recorded. We will report on these species and additional new laboratory developments

  6. Investigation of resonances in 20Mg: Implications for astrophysics and nuclear forces

    NASA Astrophysics Data System (ADS)

    Randhawa, Jaspreet; Kanungo, Rituparna; Alcorta, Martin; Burbadge, Christina; Burke, Devin; Christian, Greg; Davids, Barry; Even, Julia; Hackman, Greg; Henderson, Jack; Ishimoto, Shigeru; Kaur, Satbir; Keefe, Matthew; Kruecken, Reiner; Lighthall, Jon; Moukaddam, Mohamad; Padilla-Rodal, Elizabeth; Smith, Jenna; Turko, Joseph; Workman, Orry

    2016-09-01

    18Ne(2p, γ)20Mg provides a possible pathway for breakout from the hot CNO cycles to the rp-process in type I X-ray bursts. This reaction rate is uncertain due to lack of any experimental information on the resonant states in 20Mg above proton emission threshold. Recent calculations using nuclear forces from chiral perturbation theory predict quite a different level structure for 20Mg with and without inclusion of three nucleon forces. These differences make study of 20Mg states important to constraint both nuclear theory and this reaction rate. We have investigated the excited states in 20Mg through inelastic deuteron scattering. The experiment was performed using the IRIS facility at TRIUMF, Canada. The 20Mg beam with an average intensity of 500 pps and energy of 8.5A MeV was directed at novel thin windowless solid deuteron target. Experiment and initial observations will be discussed.

  7. Astrophysics at RIA (ARIA) Working Group

    SciTech Connect

    Smith, Michael S.; Schatz, Hendrik; Timmes, Frank X.; Wiescher, Michael; Greife, Uwe

    2006-07-12

    The Astrophysics at RIA (ARIA) Working Group has been established to develop and promote the nuclear astrophysics research anticipated at the Rare Isotope Accelerator (RIA). RIA is a proposed next-generation nuclear science facility in the U.S. that will enable significant progress in studies of core collapse supernovae, thermonuclear supernovae, X-ray bursts, novae, and other astrophysical sites. Many of the topics addressed by the Working Group are relevant for the RIKEN RI Beam Factory, the planned GSI-Fair facility, and other advanced radioactive beam facilities.

  8. Laboratory study of methyl isocyanate ices under astrophysical conditions

    NASA Astrophysics Data System (ADS)

    Maté, B.; Molpeceres, G.; Timón, V.; Tanarro, I.; Escribano, R.; Guillemin, J. C.; Cernicharo, J.; Herrero, V. J.

    2017-10-01

    Methyl isocyanate has been recently detected in comet 67P/Churyumov-Gerasimenko (67P/CG) and in the interstellar medium. New physicochemical studies on this species are now necessary as tools for subsequent studies in astrophysics. In this work, infrared spectra of solid CH3NCO have been obtained at temperatures of relevance for astronomical environments. The spectra are dominated by a strong, characteristic multiplet feature at 2350-2250 cm-1, which can be attributed to the asymmetric stretching of the NCO group. A phase transition from amorphous to crystalline methyl isocyanate is observed at ˜90 K. The band strengths for the absorptions of CH3NCO in ice at 20 K have been measured. Deuterated methyl isocyanate is used to help with the spectral assignment. No X-ray structure has been reported for crystalline CH3NCO. Here we advance a tentative theoretical structure, based on density functional theory (DFT) calculations, derived taking the crystal of isocyanic acid as a starting point. A harmonic theoretical spectrum is then calculated for the proposed structure and compared with the experimental data. A mixed ice of H2O and CH3NCO was formed by simultaneous deposition of water and methyl isocyanate at 20 K. The absence of new spectral features indicates that methyl isocyanate and water do not react appreciably at 20 K, but form a stable mixture. The high CH3NCO/H2O ratio reported for comet 67P/CG, and the characteristic structure of the 2350-2250 cm-1 band, makes it a very good candidate for future astronomical searches.

  9. Sensitivity studies for the main r process: nuclear masses

    SciTech Connect

    Aprahamian, A.; Mumpower, M.; Bentley, I.; Surman, R.

    2014-04-15

    The site of the rapid neutron capture process (r process) is one of the open challenges in all of physics today. The r process is thought to be responsible for the creation of more than half of all elements beyond iron. The scientific challenges to understanding the origin of the heavy elements beyond iron lie in both the uncertainties associated with astrophysical conditions that are needed to allow an r process to occur and a vast lack of knowledge about the properties of nuclei far from stability. One way is to disentangle the nuclear and astrophysical components of the question. On the nuclear physics side, there is great global competition to access and measure the most exotic nuclei that existing facilities can reach, while simultaneously building new, more powerful accelerators to make even more exotic nuclei. On the astrophysics side, various astrophysical scenarios for the production of the heaviest elements have been proposed but open questions remain. This paper reports on a sensitivity study of the r process to determine the most crucial nuclear masses to measure using an r-process simulation code, several mass models (FRDM, Duflo-Zuker, and HFB-21), and three potential astrophysical scenarios.

  10. Recent applications of the the Trojan Horse method to nuclear astrophysics

    SciTech Connect

    Spitaleri, Claudio

    2012-11-20

    Light elements lithium, beryllium and boron (LiBeB) have been used in the last years as possible probes for stellar structure. They are mainly destroyed by (p,a) reactions and cross section measurements for such channels are then needed. The Trojan Horse Method (THM) allows one to extract the astrophysical S(E)-factor without the experience of tunneling through the Coulomb barrier. In this work a resume of the recent new results about the {sup 11}B(p,{alpha}{sub 0}){sup 8}Be and {sup 7}Li(p,{alpha}){sup 4}He reactions are shown.

  11. New Opportunity for Improved Nuclear Forensics, Radiochemical Diagnostics, and Nuclear Astrophysics: Need for a Total-Cross-Section Apparatus at the LANSCE

    SciTech Connect

    Koehler, Paul E.; Hayes-Sterbenz, Anna C.; Bredeweg, Todd Allen; Couture, Aaron J.; Engle, Jonathan; Keksis, August L.; Nortier, Francois M.; Ullmann, John L.

    2014-03-12

    Total-cross-section measurements are feasible on a much wider range of radioactive samples than (n,γ) cross-section measurements, and information extracted from the former can be used to set tight constraints on the latter. There are many (n,γ) cross sections of great interest to radiochemical diagnostics, nuclear forensics, and nuclear astrophysics which are beyond the reach of current direct measurement, that could be obtained in this way. Our simulations indicate that measurements can be made at the Manuel Lujan Jr. Neutron Scattering Center at the Los Alamos Neutron Science Center for samples as small as 10μg. There are at least 40 high-interest nuclides which should be measurable, including 88Y,167,168,170,171Tm, 173,174Lu, and189,190,192Ir.

  12. ANASEN: The array for nuclear astrophysics and structure with exotic nuclei

    NASA Astrophysics Data System (ADS)

    Koshchiy, E.; Blackmon, J. C.; Rogachev, G. V.; Wiedenhöver, I.; Baby, L.; Barber, P.; Bardayan, D. W.; Belarge, J.; Caussyn, D.; Johnson, E. D.; Kemper, K.; Kuchera, A. N.; Linhardt, L. E.; Macon, K. T.; Matoš, M.; Rasco, B. S.; Santiago-Gonzalez, D.

    2017-10-01

    An active target detector array, ANASEN, has been developed for nuclear reaction studies with rare isotope beams at low energies. It aims at measurements of the excitation functions for proton and α- particle elastic and inelastic scattering and direct measurements of (α, p) reactions with exotic nuclei in inverse kinematics. ANASEN is composed of three types of charged particle detectors. The length of the active area is 340 mm and the total covered area is 1300 cm2 (almost 3 π steradian solid angle coverage) providing high efficiency for experiments with low intensity radioactive beams. A mix of 78 conventional electronics channels (for Proportional Counter and CsI-detectors) and 480 dedicated high-density ASICs electronics channels for the silicon detector are used for readout.

  13. Theory and laboratory astrophysics

    NASA Technical Reports Server (NTRS)

    Schramm, David N.; Mckee, Christopher F.; Alcock, Charles; Allamandola, Lou; Chevalier, Roger A.; Cline, David B.; Dalgarno, Alexander; Elmegreen, Bruce G.; Fall, S. Michael; Ferland, Gary J.

    1991-01-01

    Science opportunities in the 1990's are discussed. Topics covered include the large scale structure of the universe, galaxies, stars, star formation and the interstellar medium, high energy astrophysics, and the solar system. Laboratory astrophysics in the 1990's is briefly surveyed, covering such topics as molecular, atomic, optical, nuclear and optical physics. Funding recommendations are given for the National Science Foundation, NASA, and the Department of Energy. Recommendations for laboratory astrophysics research are given.

  14. Energy–density functional plus quasiparticle–phonon model theory as a powerful tool for nuclear structure and astrophysics

    SciTech Connect

    Tsoneva, N.; Lenske, H.

    2016-11-15

    During the last decade, a theoretical method based on the energy–density functional theory and quasiparticle–phonon model, including up to three-phonon configurations was developed. The main advantages of themethod are that it incorporates a self-consistentmean-field and multi-configuration mixing which are found of crucial importance for systematic investigations of nuclear low-energy excitations, pygmy and giant resonances in an unified way. In particular, the theoretical approach has been proven to be very successful in predictions of new modes of excitations, namely pygmy quadrupole resonance which is also lately experimentally observed. Recently, our microscopically obtained dipole strength functions are implemented in predictions of nucleon-capture reaction rates of astrophysical importance. A comparison to available experimental data is discussed.

  15. Plans for Studies of (alpha,n) Reactions Relevant to Astrophysics via Inverse Reactions

    NASA Astrophysics Data System (ADS)

    Shima, T.; Nagai, Y.; Kii, T.; Kikuchi, T.; Baba, T.; Kobayashi, T.; Okazaki, F.

    1996-08-01

    (alpha,n) reactions in the keV energy region play important roles in astrophysical nucleosynthesis. In the primordial nucleosynthesis, it has been pointed out that a fluctuation of the baryon density distribution could be formed if the QCD phase transition from quark-gluon plasma to hadron gas occurred by first order. In that case the space was separated into the high density proton-rich zones and the low density neutron-rich ones, and in the neutron-rich zones nucleosynthesis could proceed beyond the mass gap at A = 8 via the reaction chains such as H-1(n,gamma)H-2(n,gamma)H-3(d,n)He-4(t,gamma)Li-7(n,gamma)Li-8(alpha,n)B- 11(n,ga mma)B-12(e(sup-)nu)C-12(n,gamma)C-13(n,gamma)C-14(n,gamma)C-15 ......, and so on. In the above nuclear reactions, the Li-8(alpha,n)B reaction plays quite a crucial role, because it can break through the mass gap at A = 8. (alpha,n) reactions of some light nuclei are also important as neutron sources for slow neutron capture process (s-process) of nucleosynthesis in stars. In low-mass and intermediate-mass (M < 10 Solar Mass) stars, neutrons are supposed to be supplied mainly by the C-13(alpha,n)O-16 reaction. On the other hand, the Ne-22(alpha,n)Mg-25 reaction is a candidate of the neutron source in massive stars with M > or = 10 Solar Mass. The contribution of the O-18(alpha,n)Ne-21 reaction to s-process in massive stars is still unknown. Since the temperatures of the above astrophysical sites correspond to the energy range of between a few ten and a few hundred keV, accurate data of the (alpha,n) reaction cross sections in the energy range are required for investigating nucleosynthesis. In order to measure these cross sections, not only direct (alpha,n) reactions but also inverse (n,alpha) reactions can be studied. In the following we would like to show experimental designs for studying several (alpha,n) reactions of astrophysical importance.

  16. Nuclear interactions in high energy heavy ions and applications in astrophysics. Technical progress report, 1 April 1992--31 March 1993

    SciTech Connect

    Wefel, J.P.; Guzik, T.G.

    1993-01-11

    The overall objective is to study the mechanisms and the energy dependence of heavy ion fragmentation by studying the reactions of heavy ion projectiles (e.g. {sup 4}He, {sup 16}O, {sup 20}Ne, {sup 28}Si, {sup 56}Fe) in a variety of targets (H, He, C, Si, Cu, Pb) and at a number of beam energies exceeding 0.1 GeV/nucleon. The results have application to questions in high-energy nuclear astrophysics. Most of the discussion is on low-energy {sup 16}O,{sup 28}Si data analysis. The description includes analysis procedures and techniques, detector calibrations, data selections and normalizations. Cross section results for the analysis are also presented. 83 figs., 6 tabs., 73 refs.

  17. Nuclear interactions in high energy heavy ions and applications in astrophysics. [Dept. of Physics and Astronomy, Louisiana State Univ. , Baton Rouge

    SciTech Connect

    Wefel, J.P.; Guzik, T.G.

    1993-01-11

    The overall objective is to study the mechanisms and the energy dependence of heavy ion fragmentation by studying the reactions of heavy ion projectiles (e.g. [sup 4]He, [sup 16]O, [sup 20]Ne, [sup 28]Si, [sup 56]Fe) in a variety of targets (H, He, C, Si, Cu, Pb) and at a number of beam energies exceeding 0.1 GeV/nucleon. The results have application to questions in high-energy nuclear astrophysics. Most of the discussion is on low-energy [sup 16]O,[sup 28]Si data analysis. The description includes analysis procedures and techniques, detector calibrations, data selections and normalizations. Cross section results for the analysis are also presented. 83 figs., 6 tabs., 73 refs.

  18. Measurements and analysis of alpha-induced reactions of importance for nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    de Messieres, Genevieve Escande

    2011-11-01

    Reactions during stellar helium burning are of primary importance for understanding nucleosynthesis. A detailed understanding of the critical reaction chain 4He(2alpha, gamma)12C( alpha, gamma)16O(alpha, gamma) 20Ne is necessary both because it is the primary energy source and because it determines the ratio of 12C to 16O produced, which in turn significantly effects subsequent nucleosynthesis. Also during Helium burning, the reactions 22Ne(alpha, n)25Mg and 22Ne(alpha, gamma )26Mg are crucial in determining the amount of neutrons available for the astrophysical s-process. This thesis presents new experimental results concerning the 16O(alpha, gamma) 20Ne, 22Ne(alpha, n)25Mg, and 22Ne(alpha, gamma)26Mg reaction rates. These results are then applied to the calculation of the associated stellar reaction rates in order to achieve better accuracy.

  19. Reactions with 8Li at RIBRAS (Radioactive Ion Beams in Brasil): Astrophysical and nuclear structure applications

    NASA Astrophysics Data System (ADS)

    Mendes, D. R., Jr.; Lépine-Szily, A.; Descouvemont, P.

    2012-02-01

    We present the results of the 8Li(p, α) 5He reaction of astrophysical interest, measured at the RIBRAS system. It was realized in inverse kinematics and using a thick CH2 polyethylene target. Using the thick target method the complete excitation function could be measured between Ecm = 0.2-2.5 MeV, which includes the Gamow peak energy region. The contribution of contaminating 12C(8Li,4He) 16N and 12C(7Li, 4He) 15N reactions is still under analysis. However, if the cross section is expected to be somewhat reduced, the subtraction of the contamination will not change the general feature of the excitation function.

  20. Astrophysics studies relevant to stellar x-ray bursts

    SciTech Connect

    He, J. J.; Hu, J.; Zhang, L. Y.; Xu, S. W.; Ma, P.; Chen, S. Z.; Chen, R. F.; Parikh, A.; Yamaguchi, H.; Kahl, D.; Nakao, T.; Su, J.; Guo, B.; Wakabayashi, Y.; Togano, Y.; Hayakawa, S.; Wang, H. W.; Tian, W. D.; Teranishi, T.; Moon, J. Y.; and others

    2014-05-02

    Two reactions of {sup 14}O(α,p){sup 17}F and {sup 18}Ne(α,p){sup 21}Na provide the pathways for breakout from the hot CNO cycles to the rp-process in type I X-ray bursts. To better determine their astrophysical reaction rates, resonance parameters of the compound nuclei {sup 18}Ne and {sup 22}Mg have been investigated by the resonant elastic scattering of {sup 17}F+p and {sup 21}Na+p, respectively. The {sup 17}F and {sup 21}Na radioactive ion beams were produced at the CNS Radioactive Ion Beam Separator and impinged on the thick proton targets. The excitation functions were obtained with a thick-target method over a wide excitation energy range. The resonance parameters in the compound nuclei {sup 18}Ne and {sup 22}Mg have been determined through an R-matrix analysis. New reaction rates of these two (α,p) reactions are recalculated. The astrophysical impact for the {sup 18}Ne(α,p){sup 21}Na reaction has been investigated through one-zone postprocessing X-ray burst calculations.

  1. Astrophysics studies relevant to stellar x-ray bursts

    NASA Astrophysics Data System (ADS)

    He, J. J.; Hu, J.; Zhang, L. Y.; Xu, S. W.; Parikh, A.; Yamaguchi, H.; Kahl, D.; Ma, P.; Chen, S. Z.; Su, J.; Wakabayashi, Y.; Togano, Y.; Hayakawa, S.; Wang, H. W.; Tian, W. D.; Chen, R. F.; Guo, B.; Nakao, T.; Teranishi, T.; Moon, J. Y.; Jung, H. S.; Hashimoto, T.; Chen, A. A.; Irvine, D.; Hahn, K. I.; Iwasa, N.; Yamada, T.; Komatsubara, T.; Lee, C. S.; Kubono, S.

    2014-05-01

    Two reactions of 14O(α,p)17F and 18Ne(α,p)21Na provide the pathways for breakout from the hot CNO cycles to the rp-process in type I X-ray bursts. To better determine their astrophysical reaction rates, resonance parameters of the compound nuclei 18Ne and 22Mg have been investigated by the resonant elastic scattering of 17F+p and 21Na+p, respectively. The 17F and 21Na radioactive ion beams were produced at the CNS Radioactive Ion Beam Separator and impinged on the thick proton targets. The excitation functions were obtained with a thick-target method over a wide excitation energy range. The resonance parameters in the compound nuclei 18Ne and 22Mg have been determined through an R-matrix analysis. New reaction rates of these two (α,p) reactions are recalculated. The astrophysical impact for the 18Ne(α,p)21Na reaction has been investigated through one-zone postprocessing X-ray burst calculations.

  2. Photo-nuclear astrophysics in NewSUBARU {gamma}-ray source

    SciTech Connect

    Hayakawa, Takehito

    2010-08-12

    A laser Compton scattering (LCS){gamma}-ray source has been installed at an electron storage ring NewSUBARU at SPring-8. We have studied the nuclear physics using this LCS g-ray source. The half-lives of unstable isotopes, {sup 184}Re and {sup 164}Ho{sup m}, produced by photo-induced reactions have been measured. These half-lives are shorter than previous recommended values by 7% and 3%, respectively. These changes of the half-lives affects to evaluation of cross-sections using the activation method. We have discussed a problem of the residual ratio of an isomer in {sup 180}Ta in supernova explosions. The unstable ground state and the metastable isomer are linked by ({gamma}, {gamma}') reactions. We have developed a new time-dependent model to calculate the isomer ratio in supernovae. The solar abundance of {sup 180}Ta is reproduced by the supernova neutrino process with the present calculated isomer ratio.

  3. Nuclear Lunar Logistics Study

    NASA Technical Reports Server (NTRS)

    1963-01-01

    This document has been prepared to incorporate all presentation aid material, together with some explanatory text, used during an oral briefing on the Nuclear Lunar Logistics System given at the George C. Marshall Space Flight Center, National Aeronautics and Space Administration, on 18 July 1963. The briefing and this document are intended to present the general status of the NERVA (Nuclear Engine for Rocket Vehicle Application) nuclear rocket development, the characteristics of certain operational NERVA-class engines, and appropriate technical and schedule information. Some of the information presented herein is preliminary in nature and will be subject to further verification, checking and analysis during the remainder of the study program. In addition, more detailed information will be prepared in many areas for inclusion in a final summary report. This work has been performed by REON, a division of Aerojet-General Corporation under Subcontract 74-10039 from the Lockheed Missiles and Space Company. The presentation and this document have been prepared in partial fulfillment of the provisions of the subcontract. From the inception of the NERVA program in July 1961, the stated emphasis has centered around the demonstration of the ability of a nuclear rocket to perform safely and reliably in the space environment, with the understanding that the assignment of a mission (or missions) would place undue emphasis on performance and operational flexibility. However, all were aware that the ultimate justification for the development program must lie in the application of the nuclear propulsion system to the national space objectives.

  4. The Coulomb Dissociation of {sup 8}B: A New Tool in Nuclear Astrophysics

    SciTech Connect

    Gai, Moshe

    2008-01-24

    The GSI1, GSI2 (as well as the RIKEN2 and the corrected GSI2) measurements of the Coulomb Dissociation (CD) of {sup 8}B are in good agreement with the most recent Direct Capture (DC) {sup 7}Be(p,{gamma}){sup 8}B reaction measurement performed at Weizmann and in agreement with the Seattle result. Yet it was claimed that the CD and DC results are sufficiently different and need to be reconciled. We show that these statements arise from a misunderstanding (as well as misrepresentation) of CD experiments. We recall a similar strong statement questioning the validity of the CD method due to an invoked large E2 component that was also shown to arise from a misunderstanding of the CD method. In spite of the good agreement between DC and CD data the slope of the astrophysical cross section factor (S{sub 17}) can not be extracted with high accuracy due to discrepancies among the most recent DC data as well as a discrepancies among the three reports of the GSI CD data. The slope is directly related to the d-wave component that dominates at higher energies. This d-wave component must be subtracted from measured data to extrapolate to zero energy. Hence the uncertainty of the measured slope leads to an additional downward uncertainty ({sub -3.0}{sup +0.0} eV-b) of the extrapolated zero energy cross section factor, S{sub 17}(0). Such an uncertainty is also consistent with the smaller value of S{sub 17}(0) extracted using the ANC method. This uncertainty must be alleviated by future experiments to allow a precise determination of S{sub 17}(0), a goal that so far has not be achieved in spite of strong statement(s) that appeared in the literature.

  5. Nuclear interactions of high energy heavy ions and applications in astrophysics. Final technical report

    SciTech Connect

    Wefel, J.P.; Guzik, T.G.

    1998-06-25

    Projectile fragmentation experiments have been conducted at the LBL Bevalac accelerator, utilizing both the B40 and the HISS facilities, to produce a dataset of 36 beam/energy combinations covering projectiles from {sup 4}He to {sup 58}Ni and various energies from 170--2100 MeV/nucleon. While some runs were subject to beam instabilities, magnet problems or low statistics, there remains a large dataset which is still being analyzed. The results will be used to investigate the physics of the intermediate energy fragmentation process and will find application in the astrophysics of cosmic ray propagation in the galaxy. An overview of the science goals and rationale is followed by presentation of the experimental techniques and apparatus that has been employed. Data analysis, including both detector subsystem and accelerator calibration, is discussed with emphasis on the unique features of the dataset and the analysis problems being addressed. Results from the experiments are presented throughout to illustrate the status of the analysis, e.g., momentum distribution widths. Total, Elemental and Isotopic cross sections from various beam/energy combinations are presented, including the first data on {sup 32}S fragmentation and the complete isotopic fragmentation cross sections for {sup 28}Si interacting in both Carbon and Hydrogen targets. The new results are compared to any existing data and to formulae used to predict unmeasured cross sections. The size and complexity of the dataset and the required detail of the analysis precluded finishing the full analysis under the subject grant. Plans for additional analysis are presented, and these will be carried out in coming years as time and resources permit.

  6. Influence of nuclear physics inputs and astrophysical conditions on the Th/U chronometer

    SciTech Connect

    Niu Zhongming; Sun Baohua; Meng Jie

    2009-12-15

    The productions of thorium and uranium are key ingredients in r-process nucleo-cosmochronology. With the combination of improved nuclear and stellar data, we have made a detailed investigation of the r-process abundance pattern in the very metal-poor halo stars based on the classical r-process approach. It is found that the results are almost independent of specified simulations to observed abundances. The influence from nuclear mass uncertainties on a Th/U chronometer can approach 2 Gyr. Moreover, the ages of the metal-poor stars HE 1523-0901, CS 31082-001, and BD +17 deg. 3248 are determined as 11.8{+-}3.7, 13.5{+-}2.9, and 10.9{+-}2.9 Gyr, respectively. The results can serve as an independent check for age estimates of the Universe.

  7. Role of clusters in nuclear astrophysics with Cluster Nucleosynthesis Diagram (CND)

    NASA Astrophysics Data System (ADS)

    Kubono, S.; Binh, Dam N.; Hayakawa, S.; Hashimoto, H.; Kahl, D.; Yamaguchi, H.; Wakabayashi, Y.; Teranishi, T.; Iwasa, N.; Komatsubara, T.; Kato, S.; Chen, A.; Cherubini, S.; Choi, S. H.; Hahn, I. S.; He, J. J.; Khiem, Le Hong; Lee, C. S.; Kwon, Y. K.; Wanajo, S.; Janka, H.-T.

    2013-04-01

    The role of nuclear clustering in stellar reactions is discussed, with Cluster Nucleosynthesis Diagram (CND) proposed before, for nucleosynthesis in stellar evolution and explosive stellar phenomena. Special emphasis is placed on α-induced stellar reactions. We report here the first experimental evidence that a cluster resonances dominate the (α,p) stellar reaction cross sections that is crucial for the vp-process in core-collapse supernovae.

  8. The universe in the laboratory - Nuclear astrophysics opportunity at the facility for antiproton and ion research

    SciTech Connect

    Langanke, K.

    2014-05-09

    In the next years the Facility for Antiproton and Ion Research FAIR will be constructed at the GSI Helmholtzze-ntrum für Schwerionenforschung in Darmstadt, Germany. This new accelerator complex will allow for unprecedented and pathbreaking research in hadronic, nuclear, and atomic physics as well as in applied sciences. This manuscript will discuss some of these research opportunities, with a focus on supernova dynamics and nucleosynthesis.

  9. X-ray spectroscopy diagnostics of a recombining plasma in laboratory astrophysics studies

    NASA Astrophysics Data System (ADS)

    Ryazantsev, S. N.; Skobelev, I. Yu.; Faenov, A. Ya.; Pikuz, T. A.; Grum-Grzhimailo, A. N.; Pikuz, S. A.

    2015-12-01

    The investigation of a recombining laser plasma is topical primarily because it can be used to simulate the interaction between plasma jets in astrophysical objects. It has been shown that the relative intensities of transitions of a resonance series of He-like multicharged ions can be used for the diagnostics of the recombining plasma. It has been found that the intensities of the indicated transitions for ions with the nuclear charge number Z n ~ 10 are sensitive to the plasma density in the range N e ~ 1016-1020 cm-3 at temperatures of 10-100 eV. The calculations performed for the F VIII ion have determined the parameters of plasma jets created at the ELFIE nanosecond laser facility (Ecole Polytechnique, France) in order to simulate astrophysical phenomena. The resulting universal calculation dependences can be used to diagnose different recombining plasmas containing helium-like fluorine ions.

  10. A Laboratory Astrophysical Jet to Study Canonical Flux Tubes

    NASA Astrophysics Data System (ADS)

    You, Setthivoine; von der Linden, Jens; Vereen, Keon; Carroll, Evan; Kamikawa, Yu; Lavine, Eric Sander

    2013-10-01

    A new research program aims to simulate a magnetically driven jet launched by an accretion disk in a laboratory experiment. The experiment replaces an accretion disk that would rotate at impractical speeds in the laboratory with three concentric annular electrodes, independently biased by two sets of pulsed power supplies to generate magnetized plasma shear flows. With three electrodes, the radial electric field can be set up to approximate the rotation profile of an accretion disk. The primary diagnostics include arrays of magnetic probes to measure 3D magnetic fields and arrays of lines-of-sight to measure 3D ion flows from vector tomography of ion Doppler spectral lines. The symmetry of fast gas puff sources is fine-tuned with a fast ion gauge to remove any anchoring effects of discrete gas holes on the azimuthal rotation of the plasma jet. The aim is to understand how magnetically driven astrophysical jets become long and collimated, how they become unstable or turbulent, and investigate the physics from a canonical flux tube point-of-view. A canonical flux tube is a fundamental tube of magnetic flux with helical flows. This work is supported by the US DOE Grant DE-SC0010340

  11. New Global Calculation of Nuclear Masses and Fission Barriers for Astrophysical Applications

    NASA Astrophysics Data System (ADS)

    Möller, P.; Sierk, A. J.; Bengtsson, R.; Ichikawa, T.; Iwamoto, A.

    2008-05-01

    The FRDM(1992) mass model [1] has an accuracy of 0.669 MeV in the region where its parameters were determined. For the 529 masses that have been measured since, its accuracy is 0.46 MeV, which is encouraging for applications far from stability in astrophysics. We are developing an improved mass model, the FRDM(2008). The improvements in the calculations with respect to the FRDM(1992) are in two main areas. (1) The macroscopic model parameters are better optimized. By simulation (adjusting to a limited set of now known nuclei) we can show that this actually makes the results more reliable in new regions of nuclei. (2) The ground-state deformation parameters are more accurately calculated. We minimize the energy in a four-dimensional deformation space (ɛ2, V3, V4, V6,) using a grid interval of 0.01 in all 4 deformation variables. The (non-finalized) FRDM (2008-a) has an accuracy of 0.596 MeV with respect to the 2003 Audi mass evaluation before triaxial shape degrees of freedom are included (in progress). When triaxiality effects are incorporated preliminary results indicate that the model accuracy will improve further, to about 0.586 MeV. We also discuss very large-scale fission-barrier calculations in the related FRLDM (2002) model, which has been shown to reproduce very satisfactorily known fission properties, for example barrier heights from 70Se to the heaviest elements, multiple fission modes in the Ra region, asymmetry of mass division in fission and the triple-humped structure found in light actinides. In the superheavy region we find barriers consistent with the observed half-lives. We have completed production calculations and obtain barrier heights for 5254 nuclei heavier than A = 170 for all nuclei between the proton and neutron drip lines. The energy is calculated for 5009325 different shapes for each nucleus and the optimum barrier between ground state and separated fragments is determined by use of an ``immersion'' technique.

  12. New Global Calculation of Nuclear Masses and Fission Barriers for Astrophysical Applications

    SciTech Connect

    Moeller, P.; Sierk, A. J.; Bengtsson, R.; Ichikawa, T.; Iwamoto, A.

    2008-05-21

    The FRDM(1992) mass model [1] has an accuracy of 0.669 MeV in the region where its parameters were determined. For the 529 masses that have been measured since, its accuracy is 0.46 MeV, which is encouraging for applications far from stability in astrophysics. We are developing an improved mass model, the FRDM(2008). The improvements in the calculations with respect to the FRDM(1992) are in two main areas. (1) The macroscopic model parameters are better optimized. By simulation (adjusting to a limited set of now known nuclei) we can show that this actually makes the results more reliable in new regions of nuclei. (2) The ground-state deformation parameters are more accurately calculated. We minimize the energy in a four-dimensional deformation space ({epsilon}{sub 2}, {epsilon}{sub 3}, {epsilon}{sub 4}, {epsilon}{sub 6},) using a grid interval of 0.01 in all 4 deformation variables. The (non-finalized) FRDM (2008-a) has an accuracy of 0.596 MeV with respect to the 2003 Audi mass evaluation before triaxial shape degrees of freedom are included (in progress). When triaxiality effects are incorporated preliminary results indicate that the model accuracy will improve further, to about 0.586 MeV.We also discuss very large-scale fission-barrier calculations in the related FRLDM (2002) model, which has been shown to reproduce very satisfactorily known fission properties, for example barrier heights from {sup 70}Se to the heaviest elements, multiple fission modes in the Ra region, asymmetry of mass division in fission and the triple-humped structure found in light actinides. In the superheavy region we find barriers consistent with the observed half-lives. We have completed production calculations and obtain barrier heights for 5254 nuclei heavier than A = 170 for all nuclei between the proton and neutron drip lines. The energy is calculated for 5009325 different shapes for each nucleus and the optimum barrier between ground state and separated fragments is determined by

  13. The Next Century Astrophysics Program

    NASA Technical Reports Server (NTRS)

    Swanson, Paul N.

    1991-01-01

    The Astrophysics Division within the NASA Office of Space Science and Applications (OSSA) has defined a set of major and moderate missions that are presently under study for flight sometime within the next 20 years. These programs include the: Advanced X Ray Astrophysics Facility; X Ray Schmidt Telescope; Nuclear Astrophysics Experiment; Hard X Ray Imaging Facility; Very High Throughput Facility; Gamma Ray Spectroscopy Observatory; Hubble Space Telescope; Lunar Transit Telescope; Astrometric Interferometer Mission; Next Generation Space Telescope; Imaging Optical Interferometer; Far Ultraviolet Spectroscopic Explorer; Gravity Probe B; Laser Gravity Wave Observatory in Space; Stratospheric Observatory for Infrared Astronomy; Space Infrared Telescope Facility; Submillimeter Intermediate Mission; Large Deployable Reflector; Submillimeter Interferometer; and Next Generation Orbiting Very Long Baseline Interferometer.

  14. Nuclear interactions of high energy heavy ions and applications in astrophysics. Technical progress report, 1 April 1991--31 March 1992

    SciTech Connect

    Wefel, J.P.

    1992-01-23

    This program was established for the purpose of studying projectile fragmentation; (1) as a function of energy, focusing first on the intermediate energy region, < 1 GeV/nucleon, where there have been few previous measurements and no systematic studies, and (2) as a function of projectile mass, starting with light beams and proceeding to species as heavy as nickel (and possibly beyond). The intermediate energy region is important as the transition between the lower energy data, where the interaction appears to be dominated by collective effects and the decay of excited nuclei, and the highest energy results, where nucleon-nucleon interactions are fundamental, ``limiting fragmentation`` applies, and the nucleus may well break-up before any de-excitation. The mass dependence of projectile fragmentation is largely unknown since most detailed work has involved light ion beams. Nuclear structure effects, for example, may well be quite prominent for heavier beams. Furthermore, the nuclear excitation functions for the production of different fragment isotopes have immediate application to the astrophysical interpretation of existing isotopic datasets obtained from balloon and satellite measurements of galactic cosmic rays.

  15. Spectroscopic Studies of the H_3^+ + H_2 Reaction at Astrophysically Relevant Temperatures

    NASA Astrophysics Data System (ADS)

    Tom, Brian A.; McGuire, Brett A.; Moore, Lauren E.; Wood, Thomas J.; McCall, Benjamin J.

    2009-06-01

    H_3^+ is the key precursor to ion chemistry in the interstellar medium. It has been employed as an astrophysical probe of conditions of temperature and density due to its ubiquity in a variety of environments. The distribution of ortho- and para- spin modifications of H_3^+ is particularly interesting in this regard. Consequently, it is important to understand the pathways through which changes to the H_3^+ spin distribution can occur. One possible pathway is the H_3^+ + H_2 → H_2 + H_3^+ reaction, which proceeds by proton hop and proton exchange and is governed by the conservation of nuclear spin. Cordonnier et al. studies this reaction at high temperature in a pulsed hollow cathode cell, but to facilitate the understanding of astronomical observations, we need lower temperature measurements. Recently, we have constructed a liquid nitrogen-cooled hollow cathode discharge source and coupled it with multipass absorption spectroscopy to measure the ortho:para ratio of H_3^+ in plasmas at a variety of para-H_2 enrichment levels at ˜160 K. Previously, we have reported experimental measurements of the branching ratio between proton hop and exchange in a hydrogenic plasma at ˜80 K. Together, these experiments have allowed us to explore the temperature dependence of this branching ratio and provide valuable information for the interpretation of astronomical observations. [1] M. Cordonnier et al., J Chem Phys, 113, 3181 (2000) [2] B. A. Tom, M. B. Wiczer, A. A. Mills, K. N. Crabtree, and B. J. McCall, ``Observation of nuclear spin selection rules in supersonically expanding plasmas containing H_3^+,'' 63rd International Symposium on Molecular Spectroscopy (2008).

  16. Nuclear spectroscopic studies

    SciTech Connect

    Bingham, C.R.; Guidry, M.W.; Riedinger, L.L.; Sorensen, S.P.

    1993-02-08

    The Nuclear Physics group at the University of Tennessee, Knoxville is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While our main emphasis is on experimental problems involving heavy-ion accelerators, we have maintained a strong collaboration with several theorists in order to best pursue the physics of our measurements. During the last year we have led several experiments at the Holifield Heavy Ion Research Facility and participated in others at Argonne National Laboratory. Also, we continue to be very active in the collaboration to study ultra-relativistic heavy ion physics utilizing the SPS accelerator at CERN in Geneva, Switzerland and in a RHIC detector R D project. Our experimental work is in four broad areas: (1) the structure of nuclei at high angular momentum, (2) heavy-ion induced transfer reactions, (3) the structure of nuclei far from stability, and (4) ultra-relativistic heavy-ion physics. The results of studies in these particular areas will be described in this document in sections IIA, IIB, IIC, and IID, respectively. Areas (1), (3), and (4) concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons, or very high temperature and density. Area (2) pursues the transfer of nucleons to states with high angular momentum, both to learn about their structure and to understand the transfer of particles, energy, and angular momentum in collisions between heavy ions. An important component of our program is the strong emphasis on the theoretical aspects of nuclear structure and reactions.

  17. Nuclear explosive safety study process

    SciTech Connect

    1997-01-01

    Nuclear explosives by their design and intended use require collocation of high explosives and fissile material. The design agencies are responsible for designing safety into the nuclear explosive and processes involving the nuclear explosive. The methodology for ensuring safety consists of independent review processes that include the national laboratories, Operations Offices, Headquarters, and responsible Area Offices and operating contractors with expertise in nuclear explosive safety. A NES Study is an evaluation of the adequacy of positive measures to minimize the possibility of an inadvertent or deliberate unauthorized nuclear detonation, high explosive detonation or deflagration, fire, or fissile material dispersal from the pit. The Nuclear Explosive Safety Study Group (NESSG) evaluates nuclear explosive operations against the Nuclear Explosive Safety Standards specified in DOE O 452.2 using systematic evaluation techniques. These Safety Standards must be satisfied for nuclear explosive operations.

  18. Astrophysics experiments with radioactive beams at ATLAS

    SciTech Connect

    Back, B. B.; Clark, J. A.; Pardo, R. C.; Rehm, K. E. Savard, G.

    2014-04-15

    Reactions involving short-lived nuclei play an important role in nuclear astrophysics, especially in explosive scenarios which occur in novae, supernovae or X-ray bursts. This article describes the nuclear astrophysics program with radioactive ion beams at the ATLAS accelerator at Argonne National Laboratory. The CARIBU facility as well as recent improvements for the in-flight technique are discussed. New detectors which are important for studies of the rapid proton or the rapid neutron-capture processes are described. At the end we briefly mention plans for future upgrades to enhance the intensity, purity and the range of in-flight and CARIBU beams.

  19. Studies of highly charged iron ions using electron beam ion traps for interpreting astrophysical spectra

    NASA Astrophysics Data System (ADS)

    Brown, G. V.; Beilmann, C.; Bernitt, S.; Clementson, J.; Eberle, S.; Epp, S. W.; Graf, A.; Hell, N.; Kelley, R. L.; Kilbourne, C. A.; Kubiček, K.; Leutenegger, M. A.; Mäckel, V.; Porter, F. S.; Rudolph, J. K.; Simon, M. C.; Steinbrügge, R.; Träbert, E.; Ullrich, J.; Crespo López-Urrutia, J. R.; Beiersdorfer, P.

    2013-09-01

    For over a decade, the x-ray astrophysics community has enjoyed a fruitful epoch of discovery largely as a result of the successful launch and operation of the high resolution, high sensitivity spectrometers on board the Chandra, XMM-Newton and Suzaku x-ray observatories. With the launch of the x-ray calorimeter spectrometer on the Astro-H x-ray observatory in 2014, the diagnostic power of high resolution spectroscopy will be extended to some of the hottest, largest and most exotic objects in our Universe. The diagnostic utility of these spectrometers is directly coupled to, and often limited by, our understanding of the x-ray production mechanisms associated with the highly charged ions present in the astrophysical source. To provide reliable benchmarks of theoretical calculations and to address specific problems facing the x-ray astrophysics community, electron beam ion traps have been used in laboratory astrophysics experiments to study the x-ray signatures of highly charged ions. A brief overview of the EBIT-I electron beam ion trap operated at Lawrence Livermore National Laboratory and the Max-Planck-Institut für Kernphysik's FLASH-EBIT operated at third and fourth generation advanced light sources, including a discussion of some of the results are presented.

  20. Cognitive and Social Structure of the Elite Collaboration Network of Astrophysics: A Case Study on Shifting Network Structures

    ERIC Educational Resources Information Center

    Heidler, Richard

    2011-01-01

    Scientific collaboration can only be understood along the epistemic and cognitive grounding of scientific disciplines. New scientific discoveries in astrophysics led to a major restructuring of the elite network of astrophysics. To study the interplay of the epistemic grounding and the social network structure of a discipline, a mixed-methods…

  1. Cognitive and Social Structure of the Elite Collaboration Network of Astrophysics: A Case Study on Shifting Network Structures

    ERIC Educational Resources Information Center

    Heidler, Richard

    2011-01-01

    Scientific collaboration can only be understood along the epistemic and cognitive grounding of scientific disciplines. New scientific discoveries in astrophysics led to a major restructuring of the elite network of astrophysics. To study the interplay of the epistemic grounding and the social network structure of a discipline, a mixed-methods…

  2. ISOLDE decay station for decay studies of interest in astrophysics and exotic nuclei

    NASA Astrophysics Data System (ADS)

    Fynbo, Hans; Kirseboom, Oliver S.; Tengblad, Olof

    2017-04-01

    We report on studies of the beta-decays of 31Ar, {}{20,21}Mg, and 16N performed at the ISOLDE decay station (IDS) at CERN. These studies illustrate how beta-decays measured with the IDS can be used to extract information of astrophysical interest, or to study the structure and decay mechanism of exotic nuclei. We discuss the specific implementation of the IDS designed for this type of studies including detector setups and data acquisition.

  3. Nuclear structure studies with gamma-ray beams

    DOE PAGES

    Tonchev, Anton; Bhatia, Chitra; Kelley, John; ...

    2015-05-28

    In stable and weakly bound neutron-rich nuclei, a resonance-like concentration of dipole states has been observed for excitation energies below the neutron-separation energy. This clustering of strong dipole states has been named the Pygmy Dipole Resonance (PDR) in contrast to the Giant Dipole Resonance (GDR) that dominates the E1 response. Understanding the PDR is presently of great interest in nuclear structure and nuclear astrophysics. High-sensitivity studies of E1 and M1 transitions in closed-shell nuclei using monoenergetic and 100% linearly-polarized photon beams are presented.

  4. Nuclear astrophysics from neutron cross-section measurements on radiactive samples

    SciTech Connect

    Koehler, P.E.; O'Brien, H.A.

    1988-01-01

    Reaction rates for both big-bang and stellar nucleosynthesis calculations can be obtained from the measurement of (n,p) (n, ..cap alpha..) and (n,..gamma..) cross sections for radioactive nuclei. In the past, large backgrounds associated with the sample activity limited these types of measurements to radioisotopes with very long half lives. The advent of the high-intensity neutron source at the Los Alamos Neutron Scattering CEnter (LANSCE) has greatly increased the number of nuclei which can be studied. Results of recent measurements on samples with half lives as short as fifty-three days are given. Plans for future measurements are discussed. 32 refs., 3 figs.

  5. Very Low Energy Protons From the Beta Decay of Proton Rich Nuclei For Nuclear Astrophysics

    SciTech Connect

    Simmons, E.; Trache, L.; Banu, A.; McCleskey, M.; Roeder, B.; Spiridon, A.; Tribble, R. E.; Saastamoinen, A.; Aysto, J.; Davinson, T.; Woods, P. J.; Lotay, G. J.

    2010-03-01

    We have developed a new experimental technique to measure very low energy protons from beta-delayed p-decay of proton-rich nuclei produced and separated with the MARS recoil spectrometer at TAMU. Recently we have investigated the beta-delayed p-decays of {sup 23}Al and {sup 31}Cl and obtained information on the resonances in the reactions {sup 22}Na(p,gamma){sup 23}Mg and {sup 30}P(p,gamma){sup 31}S, respectively. These reactions are important in explosive H-burning in Novae. A simple setup consisting of a telescope made of a thin double sided Si strip detector (p-detector) backed or sandwiched between two thick Si detectors (beta-detectors) was designed. We studied two different p-detectors and found that the thinner detectors with a small cell size are best to measure proton energies as low as 2-300 keV.

  6. Decay spectroscopy for nuclear astrophysics: β- and β-delayed proton decay

    NASA Astrophysics Data System (ADS)

    Trache, L.; Banu, A.; Hardy, J. C.; Iacob, V. E.; McCleskey, M.; Roeder, B. T.; Simmons, E.; Spiridon, A.; Tribble, R. E.; Saastamoinen, A.; Jokinen, A.; Äysto, J.; Davinson, T.; Lotay, G.; Woods, P. J.; Pollacco, E.

    2012-02-01

    In several radiative proton capture reactions important in novae and XRBs, the resonant parts play the capital role. We use decay spectroscopy techniques to find these resonances and study their properties. We have developed techniques to measure beta- and beta-delayed proton decay of sd-shell, proton-rich nuclei produced and separated with the MARS recoil spectrometer of Texas A&M University. The short-lived radioactive species are produced in-flight, separated, then slowed down (from about 40 MeV/u) and implanted in the middle of very thin Si detectors. This allows us to measure protons with energies as low as 200 keV from nuclei with lifetimes of 100 ms or less. At the same time we measure gamma-rays up to 8 MeV with high resolution HPGe detectors. We have studied the decay of 23Al, 27P, 31Cl, all important for understanding explosive H-burning in novae. The technique has shown a remarkable selectivity to beta-delayed charged-particle emission and works even at radioactive beam rates of a few pps. The states populated are resonances for the radiative proton capture reactions 22Na(p,γ)23Mg (crucial for the depletion of 22Na in novae), 26mAl(p,γ)27Si and 30P(p,γ)31S (bottleneck in novae and XRB burning), respectively. Lastly, results with a new detector that allowed us to measure down to about 80 keV proton energy are announced.

  7. Neutron Energy Spectra and Yields from the 7Li(p,n) Reaction for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Tessler, M.; Friedman, M.; Schmidt, S.; Shor, A.; Berkovits, D.; Cohen, D.; Feinberg, G.; Fiebiger, S.; Krása, A.; Paul, M.; Plag, R.; Plompen, A.; Reifarth, R.

    2016-01-01

    Neutrons produced by the 7Li(p, n)7Be reaction close to threshold are widely used to measure the cross section of s-process nucleosynthesis reactions. While experiments have been performed so far with Van de Graaff accelerators, the use of RF accelerators with higher intensities is planned to enable investigations on radioactive isotopes. In parallel, high-power Li targets for the production of high-intensity neutrons at stellar energies are developed at Goethe University (Frankfurt, Germany) and SARAF (Soreq NRC, Israel). However, such setups pose severe challenges for the measurement of the proton beam intensity or the neutron fluence. In order to develop appropriate methods, we studied in detail the neutron energy distribution and intensity produced by the thick-target 7Li(p,n)7Be reaction and compared them to state-of- the-art simulation codes. Measurements were performed with the bunched and chopped proton beam at the Van de Graaff facility of the Institute for Reference Materials and Measurements (IRMM) using the time-of-flight (TOF) technique with thin (1/8") and thick (1") detectors. The importance of detailed simulations of the detector structure and geometry for the conversion of TOF to a neutron energy is stressed. The measured neutron spectra are consistent with those previously reported and agree well with Monte Carlo simulations that include experimentally determined 7Li(p,n) cross sections, two-body kinematics and proton energy loss in the Li-target.

  8. Laboratory infrared studies of molecules of atmospheric and astrophysical interest

    NASA Technical Reports Server (NTRS)

    Rao, N. N.

    1982-01-01

    Nineteen reprints on the molecular species are compiled. Much of the work was done by using the Doppler-limited resolution provided by diode lasers. The diode laser was used as a source to a grating spectrometer which has been used earlier for high resolution studies. This technique provided many advantages. Wherever possible, the studies have been directed to intensity determinations of infrared bands.

  9. Frontiers in nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Bertulani, C. A.; Kajino, T.

    2016-07-01

    The synthesis of nuclei in diverse cosmic scenarios is reviewed, with a summary of the basic concepts involved before a discussion of the current status in each case is made. We review the physics of the early universe, the proton to neutron ratio influence in the observed helium abundance, reaction networks, the formation of elements up to beryllium, the inhomogeneous Big Bang model, and the Big Bang nucleosynthesis constraints on cosmological models. Attention is paid to element production in stars, together with the details of the pp chain, the pp reaction, 3He formation and destruction, electron capture on 7Be, the importance of 8B formation and its relation to solar neutrinos, and neutrino oscillations. Nucleosynthesis in massive stars is also reviewed, with focus on the CNO cycle and its hot companion cycle, the rp-process, triple- α capture, and red giants and AGB stars. The stellar burning of carbon, neon, oxygen, and silicon is presented in a separate section, as well as the slow and rapid nucleon capture processes and the importance of medium modifications due to electrons also for pycnonuclear reactions. The nucleosynthesis in cataclysmic events such as in novae, X-ray bursters and in core-collapse supernovae, the role of neutrinos, and the supernova radioactivity and light-curve is further discussed, as well as the structure of neutron stars and its equation of state. A brief review of the element composition found in cosmic rays is made in the end.

  10. The New Worlds Observer: The Astrophysics Strategic Mission Concept Study

    DTIC Science & Technology

    2009-08-01

    immediately with a near term program of technology demonstration. Keywords: Exoplanets , Coronagraphy, Astrobiology 1. INTRODUCTION The New...Worlds Observer (NWO) is a mission concept for direct observation and study of exoplanets all the way down to Earth-like objects. It’s goal is very...decade with the New Worlds Observer (NWO). Hundreds of giant exoplanets have now been detected and improvements in technology are moving the de

  11. Millimeter/submillimeter Studies of Ions and Radicals of Astrophysical Interest Using a Hollow Cathode Spectrometer

    NASA Astrophysics Data System (ADS)

    Cross, Trevor; Wehres, Nadine; Rad, Mary Lynn; Carroll, Anne; Widicus Weaver, Susanna L.

    2014-06-01

    Ions and radicals are important in astrochemical models because they act as key reaction intermediates in the interstellar medium. However, much laboratory work remains to determine the rotational spectra of most ions and radicals of astrophysical interest. This is especially true in the millimeter/submillimeter range, where small sample quantities limit spectral signal intensities. Hollow--cathode discharges have previously been used to create and study ions and radicals of astrophysical interest, but most of these instruments have been coupled with infrared spectrometers. We have developed a hollow--cathode spectrometer to investigate ions and radicals using (sub)millimeter spectroscopy. Spectrometer performance has been benchmarked using the N2H+ molecular ion, which has a known rotational spectrum. Initial results from these benchmarking studies, as well as new spectral results for other molecular targets, will be presented.

  12. Studies of high energy density physics and laboratory astrophysics driven by intense lasers

    NASA Astrophysics Data System (ADS)

    Zhang, J.

    2016-10-01

    Laser plasmas are capable of creating unique physical conditions with extreme high energy density, which are not only closely relevant to inertial fusion energy studies, but also to laboratory simulation of some astrophysical processes. In this paper, we highlight some recent progress made by our research teams. The first part is about directional hot electron beam generation and transport for fast ignition of inertial confinement fusion, as well as a new scheme of fast ignition by use of a strong external DC magnetic field. The second part concerns laboratory modeling of some astrophysical phenomena, including 1) studies of the topological structure of magnetic reconnection/annihilation that relates closely to geomagnetic substorms, loop-top X-ray source and mass ejection in solar flares, and 2) magnetic field generation and evolution in collisionless shock formation.

  13. Feasibility Study for a Plasma Dynamo Facility to Investigate Fundamental Processes in Plasma Astrophysics. Final report

    SciTech Connect

    Forest, Cary B.

    2013-09-19

    The scientific equipment purchased on this grant was used on the Plasma Dynamo Prototype Experiment as part of Professor Forest's feasibility study for determining if it would be worthwhile to propose building a larger plasma physics experiment to investigate various fundamental processes in plasma astrophysics. The initial research on the Plasma Dynamo Prototype Experiment was successful so Professor Forest and Professor Ellen Zweibel at UW-Madison submitted an NSF Major Research Instrumentation proposal titled "ARRA MRI: Development of a Plasma Dynamo Facility for Experimental Investigations of Fundamental Processes in Plasma Astrophysics." They received funding for this project and the Plasma Dynamo Facility also known as the "Madison Plasma Dynamo Experiment" was constructed. This experiment achieved its first plasma in the fall of 2012 and U.S. Dept. of Energy Grant No. DE-SC0008709 "Experimental Studies of Plasma Dynamos," now supports the research.

  14. Laboratory Studies of Thermal Energy Charge Transfer of Silicon and Iron Ions in Astrophysical Plasmas

    NASA Technical Reports Server (NTRS)

    Kwong, Victor H. S.

    1997-01-01

    The laser ablation/ion storage facility at the UNLV Physics Department is dedicated to the study of atomic processes in low temperature plasmas. Our current program is directed to the study of charge transfer of multiply charged ions and neutrals that are of importance to astrophysics at energies less than 1 eV (about 10(exp 4) K). Specifically, we measure the charge transfer rate coefficient of ions such as N(2+), Si(3+), Si(3+), with helium and Fe(2+) with molecular and atomic hydrogen. All these ions are found in a variety of astrophysical plasmas. Their electron transfer reactions with neutral atoms can affect the ionization equilibrium of the plasma.

  15. A Model Study of the Thermal Evolution of Astrophysical Ices

    NASA Technical Reports Server (NTRS)

    Loeffler, M. J.; Teolis, B. D.; Baragiola, R. A.

    2006-01-01

    We address the question of the evolution of ices that have been exposed to radiation from stellar sources and cosmic rays. We studied in the laboratory the thermal evolution of a model ice sample: a mixture of water, hydrogen peroxide, dioxygen, and ozone produced by irradiating solid H2O2 with 50 keV H(+) at 17 K. The changes in composition and release of volatiles during warming to 200 K were monitored by infrared spectroscopy, mass spectrometry, and microbalance techniques. We find evidence for voids in the water component from the infrared bands due to dangling H bonds. The absorption from these bands increases during heating and can be observed at temperatures as high as approx. 155 K. More O2 is stored in the radiolyzed film than can be retained by codeposition of O2 and H2O. This O2 remains trapped until approx. 155 K, where it desorbs in an outburst as water ice crystallizes. Warming of the ice also drastically decreases the intrinsic absorbance of O2 by annealing defects in the ice. We also observe loss of O3 in two stages during heating, which correlates with desorption and possibly chemical reactions with radicals stored in the ice, triggered by the temperature increase.

  16. First application of the Trojan horse method with a radioactive ion beam: Study of the 18F (p,α ) 15O reaction at astrophysical energies

    NASA Astrophysics Data System (ADS)

    Cherubini, S.; Gulino, M.; Spitaleri, C.; Rapisarda, G. G.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Romano, S.; Kubono, S.; Yamaguchi, H.; Hayakawa, S.; Wakabayashi, Y.; Iwasa, N.; Kato, S.; Komatsubara, T.; Teranishi, T.; Coc, A.; de Séréville, N.; Hammache, F.; Kiss, G.; Bishop, S.; Binh, D. N.

    2015-07-01

    Measurement of nuclear cross sections at astrophysical energies involving unstable species is one of the most challenging tasks in experimental nuclear physics. The use of indirect methods is often unavoidable in this scenario. In this paper the Trojan horse method is applied for the first time to a radioactive ion beam-induced reaction studying the 18F (p ,α )15O process at low energies relevant to astrophysics via the three-body reaction 2H (18F ,α15O ) n . The knowledge of the 18F (p,α ) 15O reaction rate is crucial to understand the nova explosion phenomena. The cross section of this reaction is characterized by the presence of several resonances in 19Ne and possibly interference effects among them. The results reported in literature are not satisfactory and new investigations of the 18F (p,α ) 15O reaction cross section will be useful. In the present work the spin-parity assignments of relevant levels have been discussed and the astrophysical S factor has been extracted considering also interference effects.

  17. Astrophysics and Space Science

    NASA Astrophysics Data System (ADS)

    Mould, Jeremy; Brinks, Elias; Khanna, Ramon

    2015-08-01

    Astrophysics and Space Science publishes original contributions and invited reviews covering the entire range of astronomy, astrophysics, astrophysical cosmology, planetary and space science, and the astrophysical aspects of astrobiology. This includes both observational and theoretical research, the techniques of astronomical instrumentation and data analysis, and astronomical space instrumentation. We particularly welcome papers in the general fields of high-energy astrophysics, astrophysical and astrochemical studies of the interstellar medium including star formation, planetary astrophysics, the formation and evolution of galaxies and the evolution of large scale structure in the Universe. Papers in mathematical physics or in general relativity which do not establish clear astrophysical applications will not longer be considered.The journal also publishes topical collections consisting of invited reviews and original research papers selected special issues in research fields of particular scientific interest. These consist of both invited reviews and original research papers.Conference proceedings will not be considered. All papers published in the journal are subject to thorough and strict peer-reviewing.Astrophysics and Space Science has an Impact Factor of 2.4 and features short editorial turnaround times as well as short publication times after acceptance, and colour printing free of charge. Published by Springer the journal has a very wide online dissemination and can be accessed by researchers at a very large number of institutes worldwide.

  18. Novel approaches to the study of particle dark matter in astrophysics

    SciTech Connect

    Argüelles, C. R.; Ruffini, R. Rueda, J. A.; Mavromatos, N. E.

    2015-12-17

    A deep understanding of the role of the dark matter in the different astrophysical scenarios of the local Universe such as galaxies, represent a crucial step to describe in a more consistent way the role of dark matter in cosmology. This kind of studies requires the interconnection between particle physics within and beyond the Standard Model, and fundamental physics such as thermodynamics and statistics, within a fully relativistic treatment of Gravity. After giving a comprehensive summary of the different types of dark matter and their role in astrophysics, we discuss the recent efforts in describing the distribution of dark matter in the center and halo of galaxies from first principles such as gravitational interactions, quantum statistics and particle physics; and its implications with the observations.

  19. Studying astrophysical collisionless shocks with counterstreaming plasmas from high power lasers

    NASA Astrophysics Data System (ADS)

    Park, Hye-Sook; Ryutov, D. D.; Ross, J. S.; Kugland, N. L.; Glenzer, S. H.; Plechaty, C.; Pollaine, S. M.; Remington, B. A.; Spitkovsky, A.; Gargate, L.; Gregori, G.; Bell, A.; Murphy, C.; Sakawa, Y.; Kuramitsu, Y.; Morita, T.; Takabe, H.; Froula, D. H.; Fiksel, G.; Miniati, F.; Koenig, M.; Ravasio, A.; Pelka, A.; Liang, E.; Woolsey, N.; Kuranz, C. C.; Drake, R. P.; Grosskopf, M. J.

    2012-03-01

    Collisions of high Mach number flows occur frequently in astrophysics, and the resulting shock waves are responsible for the properties of many astrophysical phenomena, such as supernova remnants, Gamma Ray Bursts and jets from Active Galactic Nuclei. Because of the low density of astrophysical plasmas, the mean free path due to Coulomb collisions is typically very large. Therefore, most shock waves in astrophysics are "collisionless", since they form due to plasma instabilities and self-generated magnetic fields. Laboratory experiments at the laser facilities can achieve the conditions necessary for the formation of collisionless shocks, and will provide a unique avenue for studying the nonlinear physics of collisionless shock waves. We are performing a series of experiments at the Omega and Omega-EP lasers, in Rochester, NY, with the goal of generating collisionless shock conditions by the collision of two high-speed plasma flows resulting from laser ablation of solid targets using ˜1016 W/cm2 laser irradiation. The experiments will aim to answer several questions of relevance to collisionless shock physics: the importance of the electromagnetic filamentation (Weibel) instabilities in shock formation, the self-generation of magnetic fields in shocks, the influence of external magnetic fields on shock formation, and the signatures of particle acceleration in shocks. Our first experiments using Thomson scattering diagnostics studied the plasma state from a single foil and from double foils whose flows collide "head-on". Our data showed that the flow velocity and electron density were 108 cm/s and 1019 cm-3, respectively, where the Coulomb mean free path is much larger than the size of the interaction region. Simulations of our experimental conditions show that weak Weibel mediated current filamentation and magnetic field generation were likely starting to occur. This paper presents the results from these first Omega experiments.

  20. High-Energy-Density, Laboratory-Astrophysics Studies of Jets and Bow Shocks

    SciTech Connect

    Foster, J M; Wilde, B H; Rosen, P A; Perry, T S; Khokhlov, A M; Coker, R F; Frank, A; Keiter, P A; Blue, B E; Drake, R P; Knauer, J P; Williams, R R

    2005-01-24

    Large-scale directional outflows of supersonic plasma, also known as ''jets'', are ubiquitous phenomena in astrophysics [1]. The interaction of such jets with surrounding matter often results in spectacular bow shocks, and intense radiation from radio to gamma-ray wavelengths. The traditional approach to understanding such phenomena is through theoretical analysis and numerical simulations. However, such numerical simulations have limited resolution, often assume axial symmetry, do not include all relevant physical processes, and fail to scale correctly in Reynolds number and perhaps other key dimensionless parameters. Additionally, they are frequently not tested by comparison with laboratory experiments. Recent advances in high-energy-density physics using large inertial-confinement-fusion devices now allow controlled laboratory experiments on macroscopic volumes of plasma of direct relevance relevant to astrophysics [2]. In this Letter we report the first results of experiments designed to study the evolution of supersonic plasma jets and the bow shocks they drive into a surrounding medium. Our experiments reveal both regular and highly complex flow patterns in the bow shock, thus opening a new window--complementary to computer simulations--into understanding the nature of three-dimensional astrophysical jets.

  1. Laboratory Studies of Thermal Energy Charge Transfer of Multiply Charged Ions in Astrophysical Plasmas

    NASA Technical Reports Server (NTRS)

    Kwong, Victor H. S.

    2003-01-01

    The laser ablation/ion storage facility at the UNLV Physics Department has been dedicated to the study of atomic and molecular processes in low temperature plasmas. Our program focuses on the charge transfer (electron capture) of multiply charged ions and neutrals important in astrophysics. The electron transfer reactions with atoms and molecules is crucial to the ionization condition of neutral rich photoionized plasmas. With the successful deployment of the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Chandra X-ray Observatory by NASA high resolution VUV and X-ray emission spectra fiom various astrophysical objects have been collected. These spectra will be analyzed to determine the source of the emission and the chemical and physical environment of the source. The proper interpretation of these spectra will require complete knowledge of all the atomic processes in these plasmas. In a neutral rich environment, charge transfer can be the dominant process. The rate coefficients need to be known accurately. We have also extended our charge transfer measurements to KeV region with a pulsed ion beam. The inclusion of this facility into our current program provides flexibility in extending the measurement to higher energies (KeV) if needed. This flexibility enables us to address issues of immediate interest to the astrophysical community as new observations are made by high resolution space based observatories.

  2. Radiative capture reactions in astrophysics

    DOE PAGES

    Brune, Carl R.; Davids, Barry

    2015-08-07

    Here, the radiative capture reactions of greatest importance in nuclear astrophysics are identified and placed in their stellar contexts. Recent experimental efforts to estimate their thermally averaged rates are surveyed.

  3. A space Fresnel imager concept assessment study led by CNES for astrophysical applications

    NASA Astrophysics Data System (ADS)

    Hinglais, Emmanuel

    2011-06-01

    In 2009, the Centre National d'Etudes Spatiales (CNES) carried out an assessment study on a "Fresnel telescope" concept based on a two-spacecraftformation flying configuration. This concept uses a binary Fresnel zone plate, and the principle of diffraction focusing, which allows high resolution optical imaging for astrophysics. In addition to CNES, the Laboratoire d'Astrophysique de Toulouse Tarbes (LATT) was deeply involved at two levels: through Research & Technology (R&T) studies to simulate and validate on a test bench the Fresnel concept performance, and through active participation in the CNES team for the optical aspects and to define the astrophysical fields of Fresnel-based space missions. The study was conducted within the technical limitations that resulted from a compromise between the R&T state of the art and the potential scientific domains of interest. The main technical limitations are linked to the size of the primary Fresnel array and to its usable spectral bandwidth. In this framework, the study covers ambitious architectures, correlating the technology readiness of the main critical components with the time-scale and programmatic horizons. The possible scientific topics arise from this range of missions. In this paper, I present a mission launched by a Soyuz, dedicated to astrophysics in the Ultra Violet (UV) band: 120 to 300 nm using a 4-m Fresnel array. It could be competitive in the next fifteen years, whereas a 10-m aperture mission in different bands; UV, visible or Infra Red (IR) (up to 6 μm) could be achievable in the future. Larger missions, using a primary array larger than 20 m, request technologies not yet available but that will probably be based on new inflatable structures with membranes, as already tested in the USA for other ends.

  4. A broad band X-ray imaging spectrophotometer for astrophysical studies

    NASA Technical Reports Server (NTRS)

    Lum, Kenneth S. K.; Lee, Dong Hwan; Ku, William H.-M.

    1988-01-01

    A broadband X-ray imaging spectrophotometer (BBXRIS) has been built for astrophysical studies. The BBXRIS is based on a large-imaging gas scintillation proportional counter (LIGSPC), a combination of a gas scintillation proportional counter and a multiwire proportional counter, which achieves 8 percent (FWHM) energy resolution and 1.5-mm (FWHM) spatial resolution at 5.9 keV. The LIGSPC can be integrated with a grazing incidence mirror and a coded aperture mask to provide imaging over a broad range of X-ray energies. The results of tests involving the LIGSPC and a coded aperture mask are presented, and possible applications of the BBXRIS are discussed.

  5. Concept study for a compact homodyne astrophysics spectrometer for exoplanets (CHASE)

    NASA Astrophysics Data System (ADS)

    Hosseini, Sona; Webster, Chris; Fischer, Debra; Shkolnik, Evgenya; Nikzad, Shouleh; Vasisht, Gautam; Traub, Wesley

    2016-07-01

    In this concept study, we are targeting to build a new instrument to sequentially observe exoplanet atmospheres and their parent's stellar spectra over a significant time in NUV and FUV. The Compact Homodyne Astrophysics Spectrometer for Exoplanets (CHASE) offers integrated spectra over a wide field-of-view (FOV 40arcsec) in high spectral resolution (R>105) in a miniaturized architecture using no (or a small < 1m) primary mirror. CHASE's wide FOV is compatible with the relaxed pointing requirements of current CubeSats and SmallSats which makes it readily qualifiable for space in a compact format and have the potential to enable major scientific breakthroughs.

  6. A study of graduate students in an astrophysics bridging year: Identifying contradictions in a complex system

    NASA Astrophysics Data System (ADS)

    Nwosu, Victoria; Allie, Saalih; Demaree, Dedra; Deacon, Andrew

    2013-01-01

    Black South African students who transfer from "Historically Black Universities" to the National Graduate Program in Astrophysics and Space Science at the University of Cape Town often struggle academically. While our previous studies focused on student epistemology and went some way towards understanding student under-performance it became clear that broader socio-cultural and systemic issues were playing critical roles. Using Cultural Historical Activity Theory (CHAT) as a theoretical perspective we (a) characterized the broader context as an Activity System and (b) identified the four main types of systemic contradictions as proposed by the theory.

  7. Experimental Studies of Hydrogenation and Other Reactions on Surfaces Under Astrophysically Relevant Conditions

    NASA Technical Reports Server (NTRS)

    Vidali, Gianfranco

    1998-01-01

    The goal of our project is to study hydrogen recombination reactions on solid surfaces under conditions that are relevant in astrophysics. Laboratory experiments were conducted using low-flux, cold atomic H and D beams impinging on a sample kept under ultra high vacuum conditions. Realistic analogues of interstellar dust grains were used. Our results show that current models for hydrogen recombination reactions have to be modified to take into account the role of activated diffusion of H on surfaces even at low temperature.

  8. Adsorption on and Desorption from Surfaces of Astrophysical Interest Studied by Atomic Beam Scattering

    NASA Astrophysics Data System (ADS)

    Shen, Liyong

    Molecular hydrogen formation in the interstellar medium is one of the most relevant, perhaps the most relevant, problem of astrophysics. Being the most abundant molecule, molecular hydrogen enters or triggers virtually all molecule-formation schemes in space. Many of these reactions occur in the gas phase with participation of ions. Catalytic reactions involving hydrogen and heavier species take place on surfaces of dust particles in the extreme conditions of several astrophysical environments. Up to now, most investigations of surface catalysis have been carried out only on materials and in temperature ranges that are not of great relevance to space applications. This thesis describes how surface science tools can be employed to study physical processes leading to formation of molecules at surfaces under astrophysically relevant conditions. An experiment has been carried out in our laboratory to investigate key reactions between gas-phase particles and atoms/molecules adsorbed on surfaces of dust grain analogues (graphite, silicate, etc.) by using molecular beam methods and surface science techniques. An apparatus to study key reactions on low temperature surfaces is described in detail, as well as measurement procedures and some results of astrophysical relevance. We report on experimental investigations of HD production on low temperature surfaces of silicates under conditions relevant to hydrogen recombination on dust grain surfaces in the interstellar medium. Following adsorption of H and D at thermal energies on a silicate surface (olivine) in the 5-15 K range, flash desorption experiments were conducted to yield desorption energies and order of desorption kinetics. We find that significant recombination occurs only at the lowest temperatures. On the basis of our experimental evidence, our measurements give lower values for the recombination efficiency (sticking probability S times the probability of recombination upon H-H encounter, γ) than model

  9. Neutrino Nuclear Responses For Neutrino Studies In Nuclear Femto Laboratories

    SciTech Connect

    Ejiri, H.

    2011-12-16

    Neutrinos are key particles for particle and astro-nuclear physics. Majorana neutrino masses and phases, solar and supernova neutrino productions and oscillations, and neutrino nuclear synthesis and fundamental weak interactions are well studied in nuclei as femto laboratories. Here neutrino nuclear responses are crucial for the neutrino studies. This reports briefly experimental studies of neutrino nuclear responses, charge exchange reactions on Ga to study nuclear responses for solar and {sup 51}Cr neutrinos, and {beta}{sup +} neutrino responses for {beta}{beta}-{nu} matrix elements and astro {nu} interactions by photon and muon probes.

  10. Experimental Studies of Light-Ion Nuclear Reactions Using Low-Energy RI Beams

    NASA Astrophysics Data System (ADS)

    Yamaguchi, H.; Kahl, D.; Hayakawa, S.; Sakaguchi, Y.; Abe, K.; Shimuzu, H.; Wakabayashi, Y.; Hashimoto, T.; Cherubini, S.; Gulino, M.; Spitaleri, C.; Rapisarda, G. G.; La Cognata, M.; Lamia, L.; Romano, S.; Kubono, S.; Iwasa, N.; Teranishi, T.; Kawabata, T.; Kwon, Y. K.; Binh, D. N.; Khiem, L. H.; Duy, N. N.; Kato, S.; Komatsubara, T.; Coc, A.; de Sereville, N.; Hammache, F.; Kiss, G.; Bishop, S.

    CRIB (CNS Radio-Isotope Beam separator) is a low-energy RI beam separator of Center for Nuclear Study (CNS), the University of Tokyo. Studies on nuclear astrophysics, nuclear structure, and other interests have been performed using the RI beams at CRIB, forming international collaborations. A striking method to study astrophyiscal reactions involving radioactive nuclei is the thick-target method in inverse kinematics. Several astrophysical alpha-induced reactions have been be studied with that method at CRIB. A recent example is on the α resonant scattering with a radioactive 7Be beam. This study is related to the astrophysical 7Be(α , γ ) reactions, important at hot p-p chain and ν p-process in supernovae. There have been measurements based on several indirect methods, such as the asymptotic normalization coefficient (ANC) and Trojan horse method (THM). The first THM measurement using an RI beam has been performed at CRIB, to study the 18F(p, α )15O reaction at astrophysical energies via the three body reaction 2H(18F, α 15O)n. The 18F(p, α )15O reaction rate is crucial to understand the 511-keV γ -ray production in nova explosion phenomena, and we successfully evaluated the reaction cross section at novae temperature and below experimentally for the first time.

  11. Conversion electron measurements of 195Au using ICEBall for Nuclear Structure and Astrophysics at the University of Notre Dame

    NASA Astrophysics Data System (ADS)

    Battaglia, Anthony; Tan, Wanpeng; Aprahamian, Ani; Bauder, William; Casarella, Clark; Gurdal, Gulhan; Long, Alexander; Nystrom, Andrew; Siegl, Kevin; Smith, Karl; Smith, Mallory

    2013-10-01

    The Internal Conversion Electron Ball Array (ICEBall) consists of six Si(Li) detectors and it was recently re-comissioned at the University of Notre Dame Nuclear Science Laboratory for spectroscopic studies of heavy nuclei. For the commissioning experiment, a 16 MeV bunched proton beam was used from the FN Tandem for a (p,2n) reaction to populate low spin states of 195Au. Both conversion electrons and gamma-rays were detected in coincidence between ICEBall and a single high-purity germanium detector. A total of 14 conversion coeffcients were measured. The results will be presented and compared to previous results. This work was supported by the National Science Foundation under contract number NSF PHY-1068192. M.P. Metlay, J.X. Saladin, I.Y. Lee, and O. Dietzsch, Nucl. Instrum. Meth. A, 336, 162 (1993).

  12. Studying counterstreaming high velocity plasma flows relevant to astrophysical collisionless shock

    NASA Astrophysics Data System (ADS)

    Ross, James Steven; Amendt, Peter; Divol, Laurent; Pollock, Brad; Remington, Bruce; Ryutov, Dmitri; rozmus, Wojciech; Turnbull, David; Froula, Dustin; morita, taichi; Sakawa, Youichi; Takabe, Hideke; Drake, R. Paul; Kuranz, Carolyn C.; Gregori, Gianluca; Meinecke, Jena; Koenig, Michel; Spitkovsky, Anatoly; Park, Hye-Sook

    2015-08-01

    In a broad range of low-density astrophysical plasmas the flow has a high Mach number, making the ion-ion collisional mean free path very large compared to the scale lengths of various observed astrophysical shocks. These shocks are believed to be “collisionless,” driven by plasma instabilities and self-generated magnetic fields. A series of experiments at the NIF and Omega laser facilities is underway to study the formation of collisionless shocks under scaled laboratory conditions, using high velocity counterstreaming and interpenetrating plasma flows. Double CH2, and CH/CD planar foils have been irradiated with a laser intensity of ~1016 W/cm2. The laser-ablated plasma between the two foils was characterized using a suite of diagnostics, including Thomson scattering and x-ray radiography. On the Omega laser facility clear interpenetration and instability growth are observed, although our experimental conditions reached only ~50 ion skin depths (c/wpi) and were insufficient to fully form a collisionless shock. Initial NIF experimental results using 50x more laser energy than the Omega experiments will be presented.

  13. Laboratory Spectral Studies of NH3 Ice Mixtures Relevant to Astrophysical Environments

    NASA Astrophysics Data System (ADS)

    White, Douglas; Mastrapa, R. M. E.; Gerakines, P. A.; Sandford, S. A.

    2012-05-01

    Small quantities of NH3 have been detected in interstellar environments such as icy grain mantles and cometary environments via infrared (IR) absorption spectroscopy in the range λ = 0.9-25 μm (e.g., Hagen et al., 1980; Crovisier, 1997; Lacy et al., 1998). In our presentation, we will describe spectral studies of some H2O-dominated ice mixtures containing small amounts (≤10%) of NH3. We also present spectral data collected at the University of Alabama at Birmingham Astrophysics Laboratory of H2O-dominated ice mixtures containing NH3 (White 2010). Positions and profiles of absorption features of NH3 are noted according to temperature and mixture, along with the profiles of H2O. Mixtures with other species such as CO2 are also investigated. These results may then be used to identify IR spectral signatures from NH3 and other species from observational data from ground- and space-based observatories. Crovisier, J. 1997, Earth Moon and Planets, 79, 125 Hagen, W., Allamandola, L. J., & Greenberg, J. M. 1980, A&A, 86, L3 Lacy, J. H., Faraji, H., Sandford, S. A., & Allamandola, L. J. 1998, The Astrophysical Journal Letters, 501, L105 White, D. W. 2010, PhD thesis, University of Alabama at Birmingham

  14. Molecular Astrophysics

    NASA Astrophysics Data System (ADS)

    Hartquist, T. W.

    2005-07-01

    Part I. Molecular Clouds and the Distribution of Molecules in the Milky Way and Other Galaxies: 1. Molecular clouds in the Milky Way P. Friberg and A. Hjalmarson; 2. Molecules in galaxies L. Blitz; Part II. Diffuse Molecular Clouds: 3. Diffuse cloud chemistry E. F. Van Dishoeck; 4. Observations of velocity and density structure in diffuse clouds W. D. Langer; 5. Shock chemistry in diffuse clouds T. W. Hartquist, D. R. Flower and G. Pineau des Forets; Part III. Quiescent Dense Clouds: 6. Chemical modelling of quiescent dense interstellar clouds T. J. Millar; 7. Interstellar grain chemistry V. Buch; 8. Large molecules and small grains in astrophysics S. H. Lepp; Part IV. Studies of Molecular Processes: 9. Molecular photoabsorption processes K. P. Kirby; 10. Interstellar ion chemistry: laboratory studies D. Smith, N. G. Adams and E. E. Ferguson; 11. Theoretical considerations on some collisional processes D. R. Bates; 12. Collisional excitation processes E. Roueff; 13. Neutral reactions at Low and High Temperatures M. M. Graff; Part V. Atomic Species in Dense Clouds: 14. Observations of atomic species in dense clouds G. J. Melnick; 15. Ultraviolet radiation in molecular clouds W. G. Roberge; 16. Cosmic ray induced photodissociation and photoionization of interstellar molecules R. Gredel; 17. Chemistry in the molecular cloud Barnard 5 S. B. Charnley and D. A. Williams; 18. Molecular cloud structure, motions, and evolution P. C. Myers; Part VI. H in Regions of Massive Star Formation: 19. Infrared observations of line emission from molecular hydrogen T. R. Geballe; 20. Shocks in dense molecular clouds D. F. Chernoff and C. F. McKee; 21. Dissociative shocks D. A. Neufeld; 22. Infrared molecular hydrogen emission from interstellar photodissociation regions A. Sternberg; Part VII. Molecules Near Stars and in Stellar Ejecta: 23. Masers J. M. Moran; 24. Chemistry in the circumstellar envelopes around mass-losing red giants M. Jura; 25. Atoms and molecules in supernova 1987a R

  15. Studies of nuclear processes at the Triangle Universities Nuclear Laboratory. Progress report, 1 September 1995--31 August 1996

    SciTech Connect

    Ludwig, E.J.

    1996-09-01

    The Triangle Universities Nuclear Laboratory (TUNL)--a collaboration of Duke University, North Carolina State University, and the University of North Carolina at Chapel Hill--has had a very productive year. This report covers parts of the second and third year of a three-year grant between the US Department of Energy and the three collaborating universities. The TUNL research program focuses on the following areas: precision test of parity-invariance violation in resonance neutron scattering at LANSCE/LANL; parity violation measurements using charged-particle resonances in A = 20--40 targets and the A = 4 system at TUNL; chaotic behavior in the nuclei {sup 30}P and {sup 34}Cl from studies of eigenvalue fluctuations in nuclear level schemes; search for anomalies in the level density (pairing phase transition) in 1f-2p shell nuclei using GEANIE at LANSCE/LANL; parity-conserving time-reversal noninvariance tests using {sup 166}Ho resonances at Geel, ORELA, or LANSCE/LANL; nuclear astrophysics; few-body nuclear systems; Nuclear Data evaluation for A = 3--20 for which TUNL is now the international center. Developments in technology and instrumentation are vital to the research and training program. Innovative work was continued in: polarized beam development; polarized target development; designing new cryogenic systems; designing new detectors; improving high-resolution beams for the KN and FN accelerators; development of an unpolarized Low-Energy Beam Facility for radiative capture studies of astrophysical interest. Preliminary research summaries are presented.

  16. Nuclear reaction studies

    SciTech Connect

    Alexander, J.M.; Lacey, R.A.

    1994-11-01

    Research focused on the statistical and dynamical properties of ``hot`` nuclei formed in symmetric heavy-ion reactions. Theses included ``flow`` measurements and the mechanism for multifragment disassembly. Model calculations are being performed for the reactions C+C, Ne+Al, Ar+Sc, Kr+Nb, and Xe+La. It is planned to study {sup 40}Ar reactions from 27 to 115 MeV/nucleon. 2 figs., 41 refs.

  17. Nuclear spectroscopic studies. Progress report

    SciTech Connect

    Bingham, C.R.; Guidry, M.W.; Riedinger, L.L.; Sorensen, S.P.

    1994-02-18

    The Nuclear Physics group at UTK is involved in heavy-ion physics including both nuclear structure and reaction mechanisms. During the last year experimental work has been in 3 broad areas: structure of nuclei at high angular momentum, structure of nuclei far from stability, and ultra-relativistic heavy-ion physics. Results in these areas are described in this document under: properties of high-spin states, study of low-energy levels of nuclei far from stability, and high-energy heavy-ion physics (PHENIX, etc.). Another important component of the work is theoretical interpretation of experimental results (Joint Institute for Heavy Ion Research).

  18. Direct capture in nuclear astrophysics: The cases of Oxygen-17(p,gamma)Fluorine-18 and Helium-3(alpha,gamma)Beryllium-7

    NASA Astrophysics Data System (ADS)

    Kontos, Antonios

    Direct radiative capture is a non-resonant one-step nuclear reaction mechanism that in principle does not involve the formation of a compound nucleus. In the absence of strong resonance inside the Gamow window, direct capture can be the dominant contribution to astrophysically important reaction rates. The present thesis studies two such reactions, 17O(p,gamma) 18F and 3He(alpha,gamma)7Be. 17O(p,gamma)18F influences hydrogen-burning nucleosynthesis in several stellar sites, such as red giants, asymptotic giant branch (AGB) stars, massive stars and classical novae. In the relevant temperature range for these environments (T9 = 0.01- 0.4), the main contributions to the rate of this reaction are the direct capture process, two low lying narrow resonances (ElabR = 70 and 193 keV) and the low energy tails of two broad resonances (ElabR = 587 and 714 keV). Previous measurements and calculations give contradictory results for the direct capture contribution which in turn increases the uncertainty of the reaction rate. In addition, very few published cross section data exist for the high energy region that might affect the interpretation of the direct capture and the broad resonances contributions in the lower energy range. In this work we present a measurement of the reaction at a wide proton energy range (Elab = 360 - 1625 keV) and at several angles (θ lab = 0°, 45°, 90°, 135°). 3He(alpha,gamma)7Be is important for the neutrino production in the sun's core and the production of 7Li during the big bang nucleosynthesis. Due to the low level density of 7Be, the reaction mechanism is almost entirely non-resonant at the relevant energies. Recent experiments have improved the uncertainty of the reaction but some discrepancies still exist. In the present work, a relatively wide energy window was measured, ECM = 0.300 -- 1.450 MeV, by detecting the prompt gamma-rays from the reaction. The use of a compact helium jet gas target ensured high gamma-ray detection efficiency

  19. Bio-inspired computational heuristics to study Lane-Emden systems arising in astrophysics model.

    PubMed

    Ahmad, Iftikhar; Raja, Muhammad Asif Zahoor; Bilal, Muhammad; Ashraf, Farooq

    2016-01-01

    This study reports novel hybrid computational methods for the solutions of nonlinear singular Lane-Emden type differential equation arising in astrophysics models by exploiting the strength of unsupervised neural network models and stochastic optimization techniques. In the scheme the neural network, sub-part of large field called soft computing, is exploited for modelling of the equation in an unsupervised manner. The proposed approximated solutions of higher order ordinary differential equation are calculated with the weights of neural networks trained with genetic algorithm, and pattern search hybrid with sequential quadratic programming for rapid local convergence. The results of proposed solvers for solving the nonlinear singular systems are in good agreements with the standard solutions. Accuracy and convergence the design schemes are demonstrated by the results of statistical performance measures based on the sufficient large number of independent runs.

  20. Studying astrophysical particle acceleration mechanisms with colliding magnetized laser-produced plasmas

    NASA Astrophysics Data System (ADS)

    Fox, W.; Deng, W.; Bhattacharjee, A.; Fiksel, G.; Nilson, P.; Haberberger, D.; Chang, P.-Y.; Barnak, D.

    2015-11-01

    Significant particle energization is observed to occur in many astrophysical environments, and in the standard models this acceleration occurs as a part of the energy conversion processes associated with collisionless shocks or magnetic reconnection. A recent generation of laboratory experiments conducted using magnetized laser-produced plasmas has opened opportunities to study these particle acceleration processes in the laboratory. Ablated plasma plumes are externally magnetized using an externally-applied magnetic field in combination with a low-density background plasma. Colliding unmagnetized plasmas demonstrated ion-driven Weibel instability while colliding magnetized plasmas drive magnetic reconnection. Both magnetized and unmagnetized colliding plasma are modeled with electromagnetic particle-in-cell simulations which provide an end-to-end model of the experiments. Using particle-in-cell simulations, we provide predictions of particle acceleration driven by reconnection, resulting from both direct x-line acceleration and Fermi-like acceleration at contracting magnetic fields lines near magnetic islands.

  1. Laboratory Studies of Thermal Energy Charge Transfer of Silicon and Iron Ions in Astrophysical Plasmas

    NASA Technical Reports Server (NTRS)

    Kwong, Victor H. S.

    1996-01-01

    Charge transfer at electron-volt energies between multiply charged atomic ions and neutral atoms and molecules is of considerable importance in astrophysics, plasma physics, and in particular, fusion plasmas. In the year covered by this report, several major tasks were completed. These include: (1) the re-calibration of the ion gauge to measure the absolute particle densities of H2, He, N2, and CO for our current measurements; (2) the analysis of data for charge transfer reactions of N(exp 2 plus) ion and He, H2, N2, and CO; (3) measurement and data analysis of the charge transfer reaction of (Fe(exp 2 plus) ion and H2; (4) charge transfer measurement of Fe(exp 2 plus) ion and H2; and (5) redesign and modification of the ion detection and data acquisition system for the low energy beam facility (reflection time of flight mass spectrometer) dedicated to the study of state select charge transfer.

  2. Relativistic Astrophysics

    NASA Astrophysics Data System (ADS)

    Jones, Bernard J. T.; Markovic, Dragoljub

    1997-06-01

    Preface; Prologue: Conference overview Bernard Carr; Part I. The Universe At Large and Very Large Redshifts: 2. The size and age of the Universe Gustav A. Tammann; 3. Active galaxies at large redshifts Malcolm S. Longair; 4. Observational cosmology with the cosmic microwave background George F. Smoot; 5. Future prospects in measuring the CMB power spectrum Philip M. Lubin; 6. Inflationary cosmology Michael S. Turner; 7. The signature of the Universe Bernard J. T. Jones; 8. Theory of large-scale structure Sergei F. Shandarin; 9. The origin of matter in the universe Lev A. Kofman; 10. New guises for cold-dark matter suspects Edward W. Kolb; Part II. Physics and Astrophysics Of Relativistic Compact Objects: 11. On the unification of gravitational and inertial forces Donald Lynden-Bell; 12. Internal structure of astrophysical black holes Werner Israel; 13. Black hole entropy: external facade and internal reality Valery Frolov; 14. Accretion disks around black holes Marek A. Abramowicz; 15. Black hole X-ray transients J. Craig Wheeler; 16. X-rays and gamma rays from active galactic nuclei Roland Svensson; 17. Gamma-ray bursts: a challenge to relativistic astrophysics Martin Rees; 18. Probing black holes and other exotic objects with gravitational waves Kip Thorne; Epilogue: the past and future of relativistic astrophysics Igor D. Novikov; I. D. Novikov's scientific papers and books.

  3. Astrophysics today

    SciTech Connect

    Cameron, A.G.W.

    1984-01-01

    Examining recent history, current trends, and future possibilities, the author reports the frontiers of research on the solar system, stars, galactic physics, and cosmological physics. The book discusses the great discoveries in astronomy and astrophysics and examines the circumstances in which they occurred. It discusses the physics of white dwarfs, the inflationary universe, the extinction of dinosaurs, black hole, cosmological models, and much more.

  4. Theoretical studies in nuclear reactions and nuclear structure. Progress report

    SciTech Connect

    Not Available

    1992-05-01

    Research in the Maryland Nuclear Theory Group focusses on problems in four basic areas of current relevance. Hadrons in nuclear matter; the structure of hadrons; relativistic nuclear physics and heavy ion dynamics and related processes. The section on hadrons in nuclear matter groups together research items which are aimed at exploring ways in which the properties of nucleons and the mesons which play a role in the nuclear force are modified in the nuclear medium. A very interesting result has been the finding that QCD sum rules supply a new insight into the decrease of the nucleon`s mass in the nuclear medium. The quark condensate, which characterizes spontaneous chiral symmetry breaking of the late QCD vacuum, decreases in nuclear matter and this is responsible for the decrease of the nucleon`s mass. The section on the structure of hadrons contains progress reports on our research aimed at understanding the structure of the nucleon. Widely different approaches are being studied, e.g., lattice gauge calculations, QCD sum rules, quark-meson models with confinement and other hedgehog models. A major goal of this type of research is to develop appropriate links between nuclear physics and QCD. The section on relativistic nuclear physics represents our continuing interest in developing an appropriate relativistic framework for nuclear dynamics. A Lorentz-invariant description of the nuclear force suggests a similar decrease of the nucleon`s mass in the nuclear medium as has been found from QCD sum rules. Work in progress extends previous successes in elastic scattering to inelastic scattering of protons by nuclei. The section on heavy ion dynamics and related processes reports on research into the e{sup +}e{sup {minus}} problem and heavy ion dynamics.

  5. Theoretical studies in nuclear reactions and nuclear structure

    SciTech Connect

    Not Available

    1992-05-01

    Research in the Maryland Nuclear Theory Group focusses on problems in four basic areas of current relevance. Hadrons in nuclear matter; the structure of hadrons; relativistic nuclear physics and heavy ion dynamics and related processes. The section on hadrons in nuclear matter groups together research items which are aimed at exploring ways in which the properties of nucleons and the mesons which play a role in the nuclear force are modified in the nuclear medium. A very interesting result has been the finding that QCD sum rules supply a new insight into the decrease of the nucleon's mass in the nuclear medium. The quark condensate, which characterizes spontaneous chiral symmetry breaking of the late QCD vacuum, decreases in nuclear matter and this is responsible for the decrease of the nucleon's mass. The section on the structure of hadrons contains progress reports on our research aimed at understanding the structure of the nucleon. Widely different approaches are being studied, e.g., lattice gauge calculations, QCD sum rules, quark-meson models with confinement and other hedgehog models. A major goal of this type of research is to develop appropriate links between nuclear physics and QCD. The section on relativistic nuclear physics represents our continuing interest in developing an appropriate relativistic framework for nuclear dynamics. A Lorentz-invariant description of the nuclear force suggests a similar decrease of the nucleon's mass in the nuclear medium as has been found from QCD sum rules. Work in progress extends previous successes in elastic scattering to inelastic scattering of protons by nuclei. The section on heavy ion dynamics and related processes reports on research into the e{sup +}e{sup {minus}} problem and heavy ion dynamics.

  6. Cognitive Astrophysics

    NASA Astrophysics Data System (ADS)

    Madore, Barry F.

    2012-09-01

    Cognitive Astrophysics works at the cusp between Cognitive Science and Astrophysics, drawing upon lessons learned in the Philosophy of Science, Linguistics and Artificial Intelligence. We will introduce and illustrate the concept of ``Downward Causation,'' common in philosophical discussions, but either unknown to or disdained by most physicists. A clear example operating on cosmological scales involving the origin of large-scale structure will be given. We will also make the case that on scales exceeding most laboratory experiments, self-gravitating matter can be considered to be in a ``fifth state'', characterized primarily by its negative specific heat, as first recognized by Lynden-Bell and Lynden-Bell (1977, MNRAS, 181, 405). Such systems increase their temperature as they lose energy. Numerous examples will be given and discussed.

  7. Astrophysical symmetries

    PubMed Central

    Trimble, Virginia

    1996-01-01

    Astrophysical objects, ranging from meteorites to the entire universe, can be classified into about a dozen characteristic morphologies, at least as seen by a blurry eye. Some patterns exist over an enormously wide range of distance scales, apparently as a result of similar underlying physics. Bipolar ejection from protostars, binary systems, and active galaxies is perhaps the clearest example. The oral presentation included about 130 astronomical images which cannot be reproduced here. PMID:11607715

  8. Nuclear spectroscopic studies. Progress report

    SciTech Connect

    Bingham, C.R.; Guidry, M.W.; Riedinger, L.L.; Sorensen, S.P.

    1993-02-08

    The Nuclear Physics group at the University of Tennessee, Knoxville is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While our main emphasis is on experimental problems involving heavy-ion accelerators, we have maintained a strong collaboration with several theorists in order to best pursue the physics of our measurements. During the last year we have led several experiments at the Holifield Heavy Ion Research Facility and participated in others at Argonne National Laboratory. Also, we continue to be very active in the collaboration to study ultra-relativistic heavy ion physics utilizing the SPS accelerator at CERN in Geneva, Switzerland and in a RHIC detector R&D project. Our experimental work is in four broad areas: (1) the structure of nuclei at high angular momentum, (2) heavy-ion induced transfer reactions, (3) the structure of nuclei far from stability, and (4) ultra-relativistic heavy-ion physics. The results of studies in these particular areas will be described in this document in sections IIA, IIB, IIC, and IID, respectively. Areas (1), (3), and (4) concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons, or very high temperature and density. Area (2) pursues the transfer of nucleons to states with high angular momentum, both to learn about their structure and to understand the transfer of particles, energy, and angular momentum in collisions between heavy ions. An important component of our program is the strong emphasis on the theoretical aspects of nuclear structure and reactions.

  9. Millimeter and Submillimeter Studies of O(^1D) Insertion Reactions to Form Molecules of Astrophysical Interest

    NASA Astrophysics Data System (ADS)

    Hays, Brian; Wehres, Nadine; Deprince, Bridget Alligood; Roy, Althea A. M.; Laas, Jacob; Widicus Weaver, Susanna L.

    2015-06-01

    While both the number of detected interstellar molecules and their chemical complexity continue to increase, understanding of the processes leading to their formation is lacking. Our research group combines laboratory spectroscopy, observational astronomy, and astrochemical modeling for an interdisciplinary examination of the chemistry of star and planet formation. This talk will focus on our laboratory studies of O(^1D) insertion reactions with organic molecules to produce molecules of astrophysical interest. By employing these reactions in a supersonic expansion, we are able to produce interstellar organic reaction intermediates that are unstable under terrestrial conditions; we then probe the products using millimeter and submillimeter spectroscopy. We benchmarked this setup using the well-studied O(^1D) + methane reaction to form methanol. After optimizing methanol production, we moved on to study the O(^1D) + ethylene reaction to form vinyl alcohol (CH_2CHOH), and the O(^1D) + methyl amine reaction to form aminomethanol (NH_2CH_2OH). Vinyl alcohol measurements have now been extended up to 450 GHz, and the associated spectral analysis is complete. A possible detection of aminomethanol has also been made, and continued spectral studies and analysis are underway. We will present the results from these experiments and discuss future applications of these molecular and spectroscopic techniques.

  10. Laboratory Astrophysics Studies with the COSmIC Facility: Interstellar and Planetary Applications.

    NASA Astrophysics Data System (ADS)

    Salama, Farid; Contreras, Cesar S.; Sciamma-O'Brien, Ella; Bejaoui, Salma

    2015-08-01

    We present and discuss the characteristics and the capabilities of the laboratory facility, COSmIC, that was developed at NASA Ames to generate, process and analyze interstellar, circumstellar and planetary analogs in the laboratory [1]. COSmIC stands for “Cosmic Simulation Chamber” and is dedicated to the study of neutral and ionized molecules and nano particles under the low temperature and high vacuum conditions that are required to simulate space environments. COSmIC integrates a variety of state-of-the-art instruments that allow forming, processing and monitoring simulated space conditions for planetary, circumstellar and interstellar materials in the laboratory. COSmIC is composed of a Pulsed Discharge Nozzle (PDN) expansion that generates a plasma in free supersonic jet expansion coupled to two high-sensitivity, complementary in situ diagnostics: a Cavity Ring Down Spectroscopy (CRDS) and laser induced fluorescence (LIF) systems for photonic detection and a Reflectron Time-Of-Flight Mass Spectrometer (ReTOF-MS) for mass detection [2].Recent laboratory astrophysics results that were obtained using COSmIC will be presented, in particular the progress that has been achieved in the domain of the diffuse interstellar bands (DIBs) and in monitoring, in the laboratory, the formation of dust grains and aerosols from their gas-phase molecular precursors in environments as varied as stellar/circumstellar outflows [3] and planetary atmospheres [4]. Plans for future, next generation, laboratory experiments on cosmic molecules and grains in the growing field of laboratory astrophysics will also be addressed as well as the implications of the current studies for astronomy.References:[1] Salama F., In Organic Matter in Space, IAU Symposium 251, Kwok & Sandford Eds.Cambridge University Press, Vol. 4, S251, p. 357 (2008) and references therein.[2] Ricketts C., Contreras C., Walker, R., Salama F., Int. J. Mass Spec, 300, 26 (2011)[3] Cesar Contreras and Farid Salama, The

  11. Exotic nuclei in astrophysics

    NASA Astrophysics Data System (ADS)

    Penionzhkevich, Yu. E.

    2012-07-01

    Recently the academic community has marked several anniversaries connected with discoveries that played a significant role in the development of astrophysical investigations. The year 2009 was proclaimed by the United Nations the International Year of Astronomy. This was associated with the 400th anniversary of Galileo Galilei's discovery of the optical telescope, which marked the beginning of regular research in the field of astronomy. An important contribution to not only the development of physics of the microcosm, but also to the understanding of processes occurring in the Universe, was the discovery of the atomic nucleus made by E. Rutherford 100 years ago. Since then the investigations in the fields of physics of particles and atomic nuclei have helped to understand many processes in the microcosm. Exactly 80 years ago, K. Yanski used a radio-telescope in order to receive the radiation from cosmic objects for the first time, and at the present time this research area of physics is the most efficient method for studying the properties of the Universe. Finally, the April 12, 1961 (50 years ago) launching of the first sputnik into space with a human being onboard, the Russian cosmonaut Yuri Gagarin, marked the beginning of exploration of the Universe with the direct participation of man. All these achievements considerably extended our ideas about the Universe. This work is an attempt to present some problems on the evolution of the Universe: the nucleosynthesis and cosmochronology from the standpoint of physics of particles and nuclei, in particular with the use of the latest results, obtained by means of radioactive nuclear beams. The comparison is made between the processes taking place in the Universe and the mechanisms of formation and decay of nuclei, as well as of their interaction at different energies. Examples are given to show the capabilities of nuclear-physics methods for studying cosmic objects and properties of the Universe. The results of

  12. The Fermilab Particle Astrophysics Center

    SciTech Connect

    Not Available

    2004-11-01

    The Particle Astrophysics Center was established in fall of 2004. Fermilab director Michael S. Witherell has named Fermilab cosmologist Edward ''Rocky'' Kolb as its first director. The Center will function as an intellectual focus for particle astrophysics at Fermilab, bringing together the Theoretical and Experimental Astrophysics Groups. It also encompasses existing astrophysics projects, including the Sloan Digital Sky Survey, the Cryogenic Dark Matter Search, and the Pierre Auger Cosmic Ray Observatory, as well as proposed projects, including the SuperNova Acceleration Probe to study dark energy as part of the Joint Dark Energy Mission, and the ground-based Dark Energy Survey aimed at measuring the dark energy equation of state.

  13. Experimental study of erosion of methane ice by energetic ions and some considerations for astrophysics

    SciTech Connect

    Lanzerotti, L.J.; Brown, W.L.; Marcantonio, K.J.

    1987-02-01

    The rate of erosion and polymerization of methane ice under bombardment by hydrogen and helium ions, relevant to surface processes on Pluto and possibly Charon and Triton, is studied experimentally as a function of ion energy and ice film thickness. For the thinnest films studied, erosion of the entire film is accomplished using MeV energy helium ions. Loss of both carbon and hydrogen is observed from thicker films, with the hydrogen-to-carbon content of the films decreasing with increasing irradiation exposures. The effective cross section for initial hydrogen loss is about 5 x 10 to the -16th sq cm. After a total incident dose of MeV He ions greater than about 10 to the 15th/sq cm, the loss rates decrease significantly and the effective cross section is about 10 to the -17th sq cm. Thus, the state of ultimate polymerization of a pure methane film in an astrophysical particle environment will depend critically on the thickness of the ice layer as well as on the ion composition of the radiation environment. 33 references.

  14. "Macroscopic fluctuations" of light beams as a novel tool for astrophysical studies

    NASA Astrophysics Data System (ADS)

    Kaminsky, A. V.; Rubinstein, I. A.; Shapovalov, S. N.; Tolokonnikova, A. A.; Kolombet, V. A.; Shnoll, S. E.

    2015-01-01

    The presented work expands on that published in Astrophysics and Space Science a decade ago. In the previous publication we described a wonderful phenomenon—synchronous change of the shape of the histograms obtained from measurements of dark current fluctuations in the two photomultipliers located more than two thousand kilometers apart from each other. This work was a part of our persistent continuous studies showing the regularities in changes shape of histograms, i.e. spectra of amplitude fluctuations of the rates of different processes, constructed for relatively short section of the experimental time series. These regularities are similar for the processes of completely different nature: biochemical reactions, radioactive decay (both α and β), Brownian motion, or noise in the electronic devices. The regularities manifest themselves in the periodicity of changes of the shape of histograms. Phenomenon of regular changes in histogram shapes was termed "macroscopic fluctuations" (MF). We have shown that MF are determined by diurnal rotation of the Earth, its movement around the Sun, as well as by mutual disposition of the Earth, the Moon and the Sun.

  15. High-Energy-Density Laboratory Astrophysics Studies of Jets and Bow Shocks

    NASA Astrophysics Data System (ADS)

    Foster, J. M.; Wilde, B. H.; Rosen, P. A.; Williams, R. J. R.; Blue, B. E.; Coker, R. F.; Drake, R. P.; Frank, A.; Keiter, P. A.; Khokhlov, A. M.; Knauer, J. P.; Perry, T. S.

    2005-11-01

    We present the first results from high-energy-density laboratory astrophysics experiments that explore the interaction of supersonic jets/outflows with an ambient medium. Our experiments were conducted on the Omega laser facility, a large Inertial Confinement Fusion facility. In our experiments, a laser pulse drives a supersonic jet into foam. High-resolution X-ray radiography reveals the resulting highly structured bow shock. These are the first laboratory astrophysics experiments to capture the behavior of both the jet and the bow shock. We discuss the astrophysical relevance of the flow processes that we observe in the experiments and in the accompanying numerical models. Scaling arguments suggest that our experiments are most directly relevant to active galactic nucleus jets and planetary nebula outflows, while future work may allow our experiments to extend into regimes relevant to radiative outflows from young stellar objects. Contains material © British Crown Copyright 2005/MOD, reprinted with permission.

  16. Nuclear accident dosimetry intercomparison studies.

    PubMed

    Sims, C S

    1989-09-01

    Twenty-two nuclear accident dosimetry intercomparison studies utilizing the fast-pulse Health Physics Research Reactor at the Oak Ridge National Laboratory have been conducted since 1965. These studies have provided a total of 62 different organizations a forum for discussion of criticality accident dosimetry, an opportunity to test their neutron and gamma-ray dosimetry systems under a variety of simulated criticality accident conditions, and the experience of comparing results with reference dose values as well as with the measured results obtained by others making measurements under identical conditions. Sixty-nine nuclear accidents (27 with unmoderated neutron energy spectra and 42 with eight different shielded spectra) have been simulated in the studies. Neutron doses were in the 0.2-8.5 Gy range and gamma doses in the 0.1-2.0 Gy range. A total of 2,289 dose measurements (1,311 neutron, 978 gamma) were made during the intercomparisons. The primary methods of neutron dosimetry were activation foils, thermoluminescent dosimeters, and blood sodium activation. The main methods of gamma dose measurement were thermoluminescent dosimeters, radiophotoluminescent glass, and film. About 68% of the neutron measurements met the accuracy guidelines (+/- 25%) and about 52% of the gamma measurements met the accuracy criterion (+/- 20%) for accident dosimetry.

  17. Propagation of Cosmic Rays: Nuclear Physics in Cosmic-ray Studies

    NASA Technical Reports Server (NTRS)

    Moskalenko, Igor V.; Strong, Andrew W.; Mashnik, Stepan G.

    2004-01-01

    The nuclei fraction in cosmic rays (CR) far exceeds the fraction of other CR species, such as antiprotons, electrons, and positrons. Thus the majority of information obtained from CR studies is based on interpretation of isotopic abundances using CR propagation models where the nuclear data and isotopic production cross sections in p- and alpha-induced reactions are the key elements. This paper presents an introduction to the astrophysics of CR and diffuse gamma-rays and dimsses some of the puzzles that have emerged recently due to more precise data and improved propagation models. Merging with cosmology and particle physics, astrophysics of CR has become a very dynamic field with a large potential of breakthrough and discoveries in the near fume. Exploiting the data collected by the CR experiments to the fullest requires accurate nuclear cross sections.

  18. Propagation of Cosmic Rays: Nuclear Physics in Cosmic-Ray Studies

    SciTech Connect

    Moskalenko, Igor V.; Mashnik, Stepan G.

    2005-05-24

    The nuclei fraction in cosmic rays (CR) far exceeds the fraction of other CR species, such as antiprotons, electrons, and positrons. Thus the majority of information obtained from CR studies is based on interpretation of isotopic abundances using CR propagation models where the nuclear data and isotopic production cross sections in p- and {alpha}-induced reactions are the key elements. This paper presents an introduction to the astrophysics of CR and diffuse {gamma}-rays and discusses some of the puzzles that have emerged recently due to more precise data and improved propagation models. Merging with cosmology and particle physics, astrophysics of CR has become a very dynamic field with a large potential of breakthrough and discoveries in the near future. Exploiting the data collected by the CR experiments to the fullest requires accurate nuclear cross sections.

  19. Use of exotic nuclear beams for nuclear structure studies

    SciTech Connect

    Sugimoto, K.

    1984-10-01

    Possible experiments are discussed for nuclear structure studies using, as secondary beams, projectile fragments produced by high-energy heavy-ion collisions. They are, specifically, (a) determination of nuclear sizes from measurements of the total interaction cross sections of nucleus-nucleus collisions, and (b) determination of static electromagnetic moments, ..mu..'s and Q's, of short-lived ..beta..-radioactive nuclei. 9 references.

  20. Calculations of Nuclear Astrophysics and Californium Fission Neutron Spectrum Averaged Cross Section Uncertainties Using ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0 and Low-fidelity Covariances

    SciTech Connect

    Pritychenko, B.

    2015-01-15

    Nuclear astrophysics and californium fission neutron spectrum averaged cross sections and their uncertainties for ENDF materials have been calculated. Absolute values were deduced with Maxwellian and Mannhart spectra, while uncertainties are based on ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0 and Low-Fidelity covariances. These quantities are compared with available data, independent benchmarks, EXFOR library, and analyzed for a wide range of cases. Recommendations for neutron cross section covariances are given and implications are discussed.

  1. Calculations of Nuclear Astrophysics and Californium Fission Neutron Spectrum Averaged Cross Section Uncertainties Using ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0 and Low-fidelity Covariances

    NASA Astrophysics Data System (ADS)

    Pritychenko, B.

    2015-01-01

    Nuclear astrophysics and californium fission neutron spectrum averaged cross sections and their uncertainties for ENDF materials have been calculated. Absolute values were deduced with Maxwellian and Mannhart spectra, while uncertainties are based on ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0 and Low-Fidelity covariances. These quantities are compared with available data, independent benchmarks, EXFOR library, and analyzed for a wide range of cases. Recommendations for neutron cross section covariances are given and implications are discussed.

  2. Nuclear Structure Studies with Polarized Radioactive Beams

    SciTech Connect

    Asahi, K.; Uchida, M.; Inoue, T.; Hatakeyama, M.; Kagami, S.; Hasama, Y.; Suzuki, K.; Ueno, H.; Nagatomo, T.; Yoshimi, A.; Kameda, D.; Ishihara, M.; Shimada, K.; Nagae, D.; Murata, J.; Narita, K.; Kawamura, H.

    2009-08-04

    Nuclear moment studies on nuclei far from the beta-stability line, performed by taking advantage of the projectile fragmentation reaction, are reviewed. A method to produce spin polarization/alignment in the projectile fragments was developed and utilized for the beta-NMR/NQR measurements. Several new findings in nuclear structure physics were obtained from the nuclear moment experiments done with these techniques.

  3. The X-Ray Surveyor mission concept study: forging the path to NASA astrophysics 2020 decadal survey prioritization

    NASA Astrophysics Data System (ADS)

    Gaskin, Jessica; Özel, Feryal; Vikhlinin, Alexey

    2016-07-01

    The X-Ray Surveyor mission concept is unique among those being studied for prioritization in the NASA Astrophysics 2020 Decadal Survey. The X-Ray Surveyor mission will explore the high-energy Universe; providing essential and complimentary observations to the Astronomy Community. The NASA Astrophysics Roadmap (Enduring Quests, Daring Visions) describes the need for an X-Ray Observatory that is capable of addressing topics such as the origin and growth of the first supermassive black holes, galaxy evolution and growth of the cosmic structure, and the origin and evolution of the stars that make up our Universe. To address these scientifically compelling topics and more, an Observatory that exhibits leaps in capability over that of previous X-Ray Observatories in needed. This paper describes the current status of the X-Ray Surveyor Mission Concept Study and the path forward, which includes scientific investigations, technology development, and community participation.

  4. The X-Ray Surveyor Mission Concept Study: Forging the Path to NASA Astrophysics 2020 Decadal Survey Prioritization

    NASA Technical Reports Server (NTRS)

    Gaskin, Jessica; Ozel, Feryal; Vikhlinin, Alexey

    2016-01-01

    The X-Ray Surveyor mission concept is unique among those being studied for prioritization in the NASA Astrophysics 2020 Decadal Survey. The X-Ray Surveyor mission will explore the high-energy Universe; providing essential and complimentary observations to the Astronomy Community. The NASA Astrophysics Roadmap (Enduring Quests, Daring Visions) describes the need for an X-Ray Observatory that is capable of addressing topics such as the origin and growth of the first supermassive black holes, galaxy evolution and growth of the cosmic structure, and the origin and evolution of the stars that make up our Universe. To address these scientifically compelling topics and more, an Observatory that exhibits leaps in capability over that of previous X-Ray Observatories in needed. This paper describes the current status of the X-Ray Surveyor Mission Concept Study and the path forward, which includes scientific investigations, technology development, and community participation.

  5. Particle astrophysics

    NASA Technical Reports Server (NTRS)

    Sadoulet, Bernard; Cronin, James; Aprile, Elena; Barish, Barry C.; Beier, Eugene W.; Brandenberger, Robert; Cabrera, Blas; Caldwell, David; Cassiday, George; Cline, David B.

    1991-01-01

    The following scientific areas are reviewed: (1) cosmology and particle physics (particle physics and the early universe, dark matter, and other relics); (2) stellar physics and particles (solar neutrinos, supernovae, and unconventional particle physics); (3) high energy gamma ray and neutrino astronomy; (4) cosmic rays (space and ground observations). Highest scientific priorities for the next decade include implementation of the current program, new initiatives, and longer-term programs. Essential technological developments, such as cryogenic detectors of particles, new solar neutrino techniques, and new extensive air shower detectors, are discussed. Also a certain number of institutional issues (the funding of particle astrophysics, recommended funding mechanisms, recommended facilities, international collaborations, and education and technology) which will become critical in the coming decade are presented.

  6. Particle astrophysics

    NASA Astrophysics Data System (ADS)

    Sadoulet, Bernard; Cronin, James; Aprile, Elena; Barish, Barry C.; Beier, Eugene W.; Brandenberger, Robert; Cabrera, Blas; Caldwell, David; Cassiday, George; Cline, David B.

    The following scientific areas are reviewed: (1) cosmology and particle physics (particle physics and the early universe, dark matter, and other relics); (2) stellar physics and particles (solar neutrinos, supernovae, and unconventional particle physics); (3) high energy gamma ray and neutrino astronomy; (4) cosmic rays (space and ground observations). Highest scientific priorities for the next decade include implementation of the current program, new initiatives, and longer-term programs. Essential technological developments, such as cryogenic detectors of particles, new solar neutrino techniques, and new extensive air shower detectors, are discussed. Also a certain number of institutional issues (the funding of particle astrophysics, recommended funding mechanisms, recommended facilities, international collaborations, and education and technology) which will become critical in the coming decade are presented.

  7. Astrophysics: An Integrative Course

    ERIC Educational Resources Information Center

    Gutsche, Graham D.

    1975-01-01

    Describes a one semester course in introductory stellar astrophysics at the advanced undergraduate level. The course aims to integrate all previously learned physics by applying it to the study of stars. After a brief introductory section on basic astronomical measurements, the main topics covered are stellar atmospheres, stellar structure, and…

  8. Astrophysics: An Integrative Course

    ERIC Educational Resources Information Center

    Gutsche, Graham D.

    1975-01-01

    Describes a one semester course in introductory stellar astrophysics at the advanced undergraduate level. The course aims to integrate all previously learned physics by applying it to the study of stars. After a brief introductory section on basic astronomical measurements, the main topics covered are stellar atmospheres, stellar structure, and…

  9. Astrophysics at n_TOF Facility

    NASA Astrophysics Data System (ADS)

    Tagliente, G.; Abbondanno, U.; Aerts, G.; Alvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Calviño, F.; Calviani, M.; Cano-Ott, D.; Capote, R.; Carrapiço, C.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillman, I.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Fujii, K.; Furman, W.; Goncalves, I.; Gonzalez-Romero, E.; Gramegna, F.; Guerrero, C.; Gunsing, F.; Heil, M.; Herrera-Martinez, A.; Jericha, E.; Käppeler, F.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Kossionides, E.; Krtička, M.; Lamboudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marrone, S.; Martinez, T.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P. M.; Mosconi, M.; Neves, F.; Oberhummer, H.; O'Brien, S.; Pancin, J.; Papachristodoulou, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Plag, R.; Plukis, A.; Poch, A.; Praena, J.; Pretel, C.; Quesada, J.; Reifarth, R.; Rubbia, C.; Rudolf, G.; Salgado, J.; Santos, C.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wiescher, M.; Wisshak, K.

    2010-08-01

    Heavy elements with Z>=30 are made by neutron capture reactions during stellar He burning and presumably in supernovae. This contribution deals mainly with the slow neutron capture (s) process which is responsible for about one half of the abundances in the mass region between Fe and Bi. The slow time scale implies that the reaction path of this process involves mostly stable isotopes which can be studied in detail in laboratory experiments. The neutron time of flight (n_TOF) facility at CERN is a neutron spallation source, its white neutron energy spectrum ranges from thermal to several MeV, covering the full energy range of interest for nuclear astrophysics, in particular for measurements of the neutron capture cross section required in s-process nucleosynthesis. This contribution gives an overview on the astrophysical program made at n_TOF facility, the results and the implications will be considered.

  10. The Madison plasma dynamo experiment: A facility for studying laboratory plasma astrophysics

    SciTech Connect

    Cooper, C. M.; Brookhart, M.; Collins, C.; Khalzov, I.; Milhone, J.; Nornberg, M.; Weisberg, D.; Forest, C. B.; Wallace, J.; Clark, M.; Flanagan, K.; Li, Y.; Nonn, P.; Ding, W. X.; Whyte, D. G.; Zweibel, E.

    2014-01-15

    The Madison plasma dynamo experiment (MPDX) is a novel, versatile, basic plasma research device designed to investigate flow driven magnetohydrodynamic instabilities and other high-β phenomena with astrophysically relevant parameters. A 3 m diameter vacuum vessel is lined with 36 rings of alternately oriented 4000 G samarium cobalt magnets, which create an axisymmetric multicusp that contains ∼14 m{sup 3} of nearly magnetic field free plasma that is well confined and highly ionized (>50%). At present, 8 lanthanum hexaboride (LaB{sub 6}) cathodes and 10 molybdenum anodes are inserted into the vessel and biased up to 500 V, drawing 40 A each cathode, ionizing a low pressure Ar or He fill gas and heating it. Up to 100 kW of electron cyclotron heating power is planned for additional electron heating. The LaB{sub 6} cathodes are positioned in the magnetized edge to drive toroidal rotation through J × B torques that propagate into the unmagnetized core plasma. Dynamo studies on MPDX require a high magnetic Reynolds number Rm > 1000, and an adjustable fluid Reynolds number 10 < Re < 1000, in the regime where the kinetic energy of the flow exceeds the magnetic energy (M{sub A}{sup 2}=(v/v{sub A}){sup 2}>1). Initial results from MPDX are presented along with a 0-dimensional power and particle balance model to predict the viscosity and resistivity to achieve dynamo action.

  11. NASA's Astrophysics Program

    NASA Astrophysics Data System (ADS)

    Hertz, Paul L.

    2013-04-01

    The environment in which NASA and other Government agencies are operating is constantly changing. It is significantly different from the environment assumed by the recent 2010 Decadal Survey. NASA has described its plans for responding to the Decadal Survey in its 2012 Astrophysics Implementation Plan (http://science.nasa.gov/astrophysics/documents/). The NASA Astrophysics Division plans to: Enable the science and priorities identified by the Decadal Survey with new activities as well as through ongoing missions, including large missions, medium missions, and Explorers; Invest in the Astrophysics Research Program for developing the science cases and technologies of new missions and for maximizing the scientific return from operating missions; Engage in effective international and interagency partnerships that leverage NASA resources and extend the reach of our science results; Conduct studies of WFIRST and candidate probes that derive from the activities prioritized in the Decadal Survey and are responsive to the Decadal Survey science questions; Be prepared to begin a strategic mission, subject to the availability of funds, which follows from the Decadal Survey and is launched after the James Webb Space Telescope.

  12. Surprises in astrophysical gasdynamics.

    PubMed

    Balbus, Steven A; Potter, William J

    2016-06-01

    Much of astrophysics consists of the study of ionized gas under the influence of gravitational and magnetic fields. Thus, it is not possible to understand the astrophysical universe without a detailed knowledge of the dynamics of magnetized fluids. Fluid dynamics is, however, a notoriously tricky subject, in which it is all too easy for one's a priori intuition to go astray. In this review, we seek to guide the reader through a series of illuminating yet deceptive problems, all with an enlightening twist. We cover a broad range of topics including the instabilities acting in accretion discs, the hydrodynamics governing the convective zone of the Sun, the magnetic shielding of a cooling galaxy cluster, and the behaviour of thermal instabilities and evaporating clouds. The aim of this review is to surprise and intrigue even veteran astrophysical theorists with an idiosyncratic choice of problems and counterintuitive results. At the same time, we endeavour to bring forth the fundamental ideas, to set out important assumptions, and to describe carefully whatever novel techniques may be appropriate to the problem at hand. By beginning at the beginning, and analysing a wide variety of astrophysical settings, we seek not only to make this review suitable for fluid dynamic veterans, but to engage novice recruits as well with what we hope will be an unusual and instructive introduction to the subject.

  13. Surprises in astrophysical gasdynamics

    NASA Astrophysics Data System (ADS)

    Balbus, Steven A.; Potter, William J.

    2016-06-01

    Much of astrophysics consists of the study of ionized gas under the influence of gravitational and magnetic fields. Thus, it is not possible to understand the astrophysical universe without a detailed knowledge of the dynamics of magnetized fluids. Fluid dynamics is, however, a notoriously tricky subject, in which it is all too easy for one’s a priori intuition to go astray. In this review, we seek to guide the reader through a series of illuminating yet deceptive problems, all with an enlightening twist. We cover a broad range of topics including the instabilities acting in accretion discs, the hydrodynamics governing the convective zone of the Sun, the magnetic shielding of a cooling galaxy cluster, and the behaviour of thermal instabilities and evaporating clouds. The aim of this review is to surprise and intrigue even veteran astrophysical theorists with an idiosyncratic choice of problems and counterintuitive results. At the same time, we endeavour to bring forth the fundamental ideas, to set out important assumptions, and to describe carefully whatever novel techniques may be appropriate to the problem at hand. By beginning at the beginning, and analysing a wide variety of astrophysical settings, we seek not only to make this review suitable for fluid dynamic veterans, but to engage novice recruits as well with what we hope will be an unusual and instructive introduction to the subject.

  14. Studies of nuclear processes at the Triangle Universities Nuclear Laboratory. Progress report, 1 September 1994--31 August 1995

    SciTech Connect

    Ludwig, E.J.

    1995-09-01

    The Triangle Universities Nuclear Laboratory (TUNL)--a collaboration of Duke University, North Carolina State University, and the University of North Carolina at Chapel Hill--has had a very productive year. This report covers the second year of a three-year grant between the US Department of Energy and the three collaborating universities. The TUNL research program focuses on the following areas of nuclear physics: parity violation in neutron and charged-particle resonances--the mass and energy dependence of the weak interaction spreading width; chaotic behavior in {sup 30}P from studies of eigenvalue fluctuations in nuclear level schemes; studies of few-body systems; nuclear astrophysics; nuclear data evaluation for A = 3--20, for which TUNL is now the international center; high-spin spectroscopy and superdeformation in nuclei, involving collaborations at Argonne National Laboratory. Developments in technology and instrumentation have been vital to the research and training program. In this progress report the author describes: a proposed polarized {gamma}-beam facility at the Duke Free Electron Laser Laboratory; cryogenic systems and microcalorimeter development; continuing development of the Low Energy Beam Facility. The research summaries presented in this progress report are preliminary.

  15. (Nuclear theory). [Research in nuclear physics

    SciTech Connect

    Haxton, W.

    1990-01-01

    This report discusses research in nuclear physics. Topics covered in this paper are: symmetry principles; nuclear astrophysics; nuclear structure; quark-gluon plasma; quantum chromodynamics; symmetry breaking; nuclear deformation; and cold fusion. (LSP)

  16. 77 FR 18271 - Terrestrial Environmental Studies for Nuclear Power Stations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-27

    ... COMMISSION Terrestrial Environmental Studies for Nuclear Power Stations AGENCY: Nuclear Regulatory Commission... revision to Regulatory Guide (RG) 4.11, ``Terrestrial Environmental Studies for Nuclear Power Stations... environmental studies and analyses supporting licensing decisions for nuclear power reactors. ADDRESSES: Please...

  17. A Comprehensive Stellar Astrophysical Study of the Old Open Cluster M67 with Kepler

    NASA Astrophysics Data System (ADS)

    Mathieu, Robert D.; Vanderburg, Andrew; K2 M67 Team

    2016-06-01

    M67 is among the best studied of all star clusters. Being at an age and metallicity very near solar, at an accessible distance of 850 pc with low reddening, and rich in content (over 1000 members including main-sequence dwarfs, a well populated subgiant branch and red giant branch, white dwarfs, blue stragglers, sub-subgiants, X-ray sources and CVs), M67 is a cornerstone of stellar astrophysics.The K2 mission (Campaign 5) has obtained long-cadence observations for 2373 stars, both within an optimized central superaperture and as specified targets outside the superaperture. 1,432 of these stars are likely cluster members based on kinematic and photometric criteria.We have extracted light curves and corrected for K2 roll systematics, producing light curves with noise characteristics qualitatively similar to Kepler light curves of stars of similar magnitudes. The data quality is slightly poorer than for field stars observed by K2 due to crowding near the cluster core, but the data are of sufficient quality to detect seismic oscillations, binary star eclipses, flares, and candidate transit events. We are in the process of uploading light curves and various diagnostic files to MAST; light curves and supporting data will also be made available on ExoFOP.Importantly, several investigators within the M67 K2 team are independently doing light curve extractions and analyses for confirmation of science results. We also are adding extensive ground-based supporting data, including APOGEE near-infrared spectra, TRES and WIYN optical spectra, LCOGT photometry, and more.Our science goals encompass asteroseismology and stellar evolution, alternative stellar evolution pathways in binary stars, stellar rotation and angular momentum evolution, stellar activity, eclipsing binaries and beaming, and exoplanets. We will present early science results as available by the time of the meeting, and certainly including asteroseismology, blue stragglers and sub-subgiants, and newly discovered

  18. Nuclear structure studies with intermediate energy probes

    SciTech Connect

    Lee, T.S.H.

    1993-10-01

    Nuclear structure studies with pions are reviewed. Results from a recent study of 1 p-shell nuclei using (e,e{prime}), ({pi}, {pi}{prime}), and ({gamma},{pi}) reactions are reported. Future nuclear structure studies with GeV electrons at CEBAF are also briefly discussed.

  19. Nuclear and neutron matter studies

    SciTech Connect

    Wiringa, R.B.; Akmal, A.; Pandharipande, V.R.

    1995-08-01

    We are studying nuclear and neutron matter with the new Argonne v{sub 18} NN and Urbana 3N potentials. We use variational wave functions and a diagrammatic cluster expansion with Fermi hypernetted and single-operator chain (FHNC/SOC) integral equations to evaluate the energy expectation value. Initial results show some interesting differences with our previous calculations with the older Argonne v{sub 14} potential. In particular, there are a number of diagrams involving L{center_dot}S and L{sup 2} terms which were small with the older model and were rather crudely estimated or even neglected. It appears that these terms are more important with the new potential and will have to be evaluated more accurately. Work on this subject is in progress. A simple line of attack is to just add additional diagrams at the three-body cluster level. A longer term approach may be to adapt some of the methods for evaluating nucleon clusters used in the few-body and closed shell nuclei described above.

  20. Nuclear Weapons Complex reconfiguration study

    SciTech Connect

    Not Available

    1991-01-01

    Shortly after assuming duties as Secretary of Energy, I reviewed the Nuclear Weapons Complex Modernization Report'' submitted to the Congress in January 1989 as required by the National Defense Authorization Act of 1988 and 1989. My review showed that several of the report's assumptions needed to be re-evaluated. During this eighteen-month review, dramatic world changes forced further reassessments of the future Nuclear Weapons Complex. These changes are reflected in the new report. The new report presents a plan to achieve a reconfigured complex, called Complex-21. Complex-21 would be smaller, less diverse, and less expensive to operated than the Complex of today. Complex-21 would be able to safely and reliability support nuclear deterrent stockpile objectives set forth by the President and funded by the Congress. It would be consistent with realities of the emerging international security environment and flexible enough to accommodate the likely range of deterrent contingencies. In addition, Complex-21 would be constructed and operated to comply with all applicable federal, state, and local laws, regulations, and orders. Achieving Complex-21 will require significant resources. This report provides and organized approach toward selecting the most appropriate configuration for Complex-21, satisfying environmental requirements, and minimizing costs. The alternative -- to continue to use piecemeal fixes to run an antiquated complex -- will be more expensive and provide a less reliable Nuclear Weapons Complex. As a consequence, implementation of the Complex-21 plan is considered necessary to ensure continued viability of our nuclear deterrent.

  1. Lunar nuclear power feasibility study

    NASA Technical Reports Server (NTRS)

    Erdman, C. A.; Tran, T.

    1984-01-01

    Based on review of literature and on limited examination of nuclear power systems now proposed for space applications, a nuclear fission reactor powered system should be seriously considered as the first large (order of 50 kWe or greater) power system to be placed on a lunar base. With relatively minor modifications, the major one being addition of a cooled side shield, the proposed 100 kWe product of the SP-100 Program could be adapted for use on a lunar base.

  2. Study of X-ray photoionized Fe plasma and comparisons with astrophysical modeling codes

    SciTech Connect

    Foord, M E; Heeter, R F; Chung, H; vanHoof, P M; Bailey, J E; Cuneo, M E; Liedahl, D A; Fournier, K B; Jonauskas, V; Kisielius, R; Ramsbottom, C; Springer, P T; Keenan, K P; Rose, S J; Goldstein, W H

    2005-04-29

    The charge state distributions of Fe, Na and F are determined in a photoionized laboratory plasma using high resolution x-ray spectroscopy. Independent measurements of the density and radiation flux indicate the ionization parameter {zeta} in the plasma reaches values {zeta} = 20-25 erg cm s{sup -1} under near steady-state conditions. A curve-of-growth analysis, which includes the effects of velocity gradients in a one-dimensional expanding plasma, fits the observed line opacities. Absorption lines are tabulated in the wavelength region 8-17 {angstrom}. Initial comparisons with a number of astrophysical x-ray photoionization models show reasonable agreement.

  3. Astrophysical blastwaves

    NASA Astrophysics Data System (ADS)

    Ostriker, Jeremiah P.; McKee, Christopher F.

    The authors present a general discussion of spherical, nonrelativistic blastwaves in an astrophysical context. A variety of effects has been included: expansion of the ambient medium, gravitation, and an embedded fluid of clouds capable of exchanging mass, energy, or momentum with the medium. The authors also consider cases of energy injection due either to a central source or to detonations. Cosmological solutions are extensively treated. Most attention is devoted to problems in which it is permissible to assume self-similarity, as in the prototype Sedov-Taylor blastwave. A general virial theorem for blastwaves is derived. For self-similar blastwaves, the radius varies as a power of the time, Rs~tη. The integral properties of the solution are completely specified by two dimensionless numbers measuring the relative importance of thermal and kinetic energy. The authors find certain exact kinematical relations and a variety of analytic approximations to determine these numbers with varying degrees of accuracy. The approximations may be based on assumptions about the internal density distributions (e.g., shell-like), pressure distribution, or velocity distribution. In many cases exact conditions from, for example, boundary conditions or other constraints may be used to determine unspecified parameters. One new set of exact integral constraints has been derived. The various approximation schemes are tested with known solutions. The authors find that for blastwaves in which the flow extends to the origin, the assumption that the internal velocity is linear with radius is reasonably accurate. For blastwaves in which an interior vacuum develops, the equally simple approximation of constant interior velocity is accurate. These lowest-order approximations are shown to give numerical coefficients in the relation R=const×tη which are accurate to about 1-2%. The higher-order approximations show an accuracy that in some cases equals that obtained, to date, by direct

  4. Nuclear Structure Studies at the Future FAIR facility

    SciTech Connect

    Rubio, Berta

    2010-04-26

    This article is intended to be an introduction to studies of nuclear structure at the future FAIR facility. It addresses interested readers not necessarily expert in the field. It outlines the physics aims and experiments to be carried out at FAIR in the field of nuclear structure and astrophysics. Starting with a brief description of what can be achieved in experiments with intense, high quality stable beams the article leads the reader to how beams of unstable radioactive nuclei will be produced and exploited at FAIR. The characteristics of the beams from the main separation device, the Super-FRS, are outlined and the limitations they impose on experiment are discussed. The various setups at the three experimental branches associated with the Super-FRS are described. The aims of the various experimental setups, how they complement each other and the physics they will address are all explained. The concept of the r-process of nucleosynthesis is outlined at the beginning and used as a running example of how useful it will be to be able to carry out experiments with beams of short-lived, exotic ions.

  5. Current Perspectives in High Energy Astrophysics

    NASA Technical Reports Server (NTRS)

    Ormes, Jonathan F. (Editor)

    1996-01-01

    High energy astrophysics is a space-age discipline that has taken a quantum leap forward in the 1990s. The observables are photons and particles that are unable to penetrate the atmosphere and can only be observed from space or very high altitude balloons. The lectures presented as chapters of this book are based on the results from the Compton Gamma-Ray Observatory (CGRO) and Advanced Satellite for Cosmology and Astrophysics (ASCA) missions to which the Laboratory for High Energy Astrophysics at NASA's Goddard Space Flight Center made significant hardware contributions. These missions study emissions from very hot plasmas, nuclear processes, and high energy particle interactions in space. Results to be discussed include gamma-ray beaming from active galactic nuclei (AGN), gamma-ray emission from pulsars, radioactive elements in the interstellar medium, X-ray emission from clusters of galaxies, and the progress being made to unravel the gamma-ray burst mystery. The recently launched X-ray Timing Explorer (XTE) and prospects for upcoming Astro-E and Advanced X-ray Astronomy Satellite (AXAF) missions are also discussed.

  6. Improvised Nuclear Device Case Study

    SciTech Connect

    Buddemeier, Brooke; Suski, Nancy

    2011-07-12

    Reducing the casualties of catastrophic terrorist attacks requires an understanding of weapons of mass destruction (WMD) effects, infrastructure damage, atmospheric dispersion, and health effects. The Federal Planning Guidance for Response to a Nuclear Detonation provides the strategy for response to an improvised nuclear device (IND) detonation. The supporting science developed by national laboratories and other technical organizations for this document significantly improves our understanding of the hazards posed by such an event. Detailed fallout predictions from the advanced suite of three-dimensional meteorology and plume/fallout models developed at Lawrence Livermore National Laboratory, including extensive global geographical and real-time meteorological databases to support model calculations, are a key part of response planning. This presentation describes the methodology and results to date, including visualization aids developed for response organizations. These products have greatly enhanced the community planning process through first-person points of view and description of the dynamic nature of the event.

  7. Microphysics of Astrophysical Flames

    NASA Astrophysics Data System (ADS)

    Dursi, L. J.; Zingale, M.; Caceres, A.; Calder, A. C.; Timmes, F. X.; Truran, J. W.; Rosner, R.; Lamb, D. Q.; Brown, E.; Ricker, P.; Fryxell, B.; Olson, K.; Riley, K.; Siegel, A.; Vladimirova, N.

    2003-03-01

    Type Ia supernovae are thought to begin with a deflagration phase, where burning occurs as a subsonic flame which accelerates and possibly undergoes a transition to a supersonic detonation. Both the acceleration and possible transition will depend on the microphysics of astrophysical flames, and their interaction with a turbulent flow in degenerate material. Here we present recent progress in studying the interactions of astrophysical flames and curvature and strain at the FLASH center; in particular, we discuss quantitative measurements of the effects of strain on burning rate of these flames, and implications for instability growth and quenching. This work was supported by the DOE ASCI/Alliances program at the University of Chicago under grant No. B341495 and the Scientific through Advanced Computing (SciDAC) program of the DOE, grant number DE-FC02-01ER41176 to the Supernova Science Center/UCSC.

  8. Electromagnetic studies of nuclear structure and reactions

    SciTech Connect

    Hersman, F.W.; Dawson, J.F.; Heisenberg, J.H.; Calarco, J.R.

    1990-06-01

    This report contains papers on the following topics: giant resonance studies; deep inelastic scattering studies; high resolution nuclear structure work; and relativistic RPA; and field theory in the Schroedinger Representation.

  9. Astrophysical data mining with GPU. A case study: Genetic classification of globular clusters

    NASA Astrophysics Data System (ADS)

    Cavuoti, S.; Garofalo, M.; Brescia, M.; Paolillo, M.; Pescape', A.; Longo, G.; Ventre, G.

    2014-01-01

    We present a multi-purpose genetic algorithm, designed and implemented with GPGPU/CUDA parallel computing technology. The model was derived from our CPU serial implementation, named GAME (Genetic Algorithm Model Experiment). It was successfully tested and validated on the detection of candidate Globular Clusters in deep, wide-field, single band HST images. The GPU version of GAME will be made available to the community by integrating it into the web application DAMEWARE (DAta Mining Web Application REsource, http://dame.dsf.unina.it/beta_info.html), a public data mining service specialized on massive astrophysical data. Since genetic algorithms are inherently parallel, the GPGPU computing paradigm leads to a speedup of a factor of 200× in the training phase with respect to the CPU based version.

  10. Occultations of Astrophysical Radio Sources as Probes of Planetary Environments: A Case Study of Jupiter and Possible Applications to Exoplanets

    NASA Astrophysics Data System (ADS)

    Withers, Paul; Vogt, Marissa F.

    2017-02-01

    Properties of planetary atmospheres, ionospheres, and magnetospheres are difficult to measure from Earth. Radio occultations are a common method for measuring these properties, but they traditionally rely on radio transmissions from a spacecraft near the planet. Here, we explore whether occultations of radio emissions from a distant astrophysical radio source can be used to measure magnetic field strength, plasma density, and neutral density around planets. In a theoretical case study of Jupiter, we find that significant changes in polarization angle due to Faraday rotation occur for radio signals that pass within 10 Jupiter radii of the planet and that significant changes in frequency and power occur from radio signals that pass through the neutral atmosphere. There are sufficient candidate radio sources, such as pulsars, active galactic nuclei, and masers, that occultations are likely to occur at least once per year. For pulsars, time delays in the arrival of their emitted pulses can be used to measure plasma density. Exoplanets, whose physical properties are very challenging to observe, may also occult distant astrophysical radio sources, such as their parent stars.

  11. The Experimental Study of Nuclear Astrophysics Reaction Rate of 93Zr(n,γ)94Zr

    NASA Astrophysics Data System (ADS)

    Gan, L.; Li, Z. H.; Su, J.; Yan, S. Q.; Guo, B.; Du, X. C.; Wu, Z. D.; Zeng, S.; Jin, S. J.; Wang, Y. B.; Bai, X. X.; Zhang, W. J.; Sun, H. B.; Li, E. T.

    The slow neutron capture (s-) process plays a very important role in the nucleosynthesis, which produces about half of the elements heavier than iron. 94Zr is mainly from 93Zr(n,γ)94Zr in the s-process, and the direct component of the 93Zr(n,γ)94Zr capture reaction can be derived from the neutron spectroscopic factor of 94Zr. As the existing neutron spectroscopic factors of 94Zr vary from each other up to 60%, a new work should be adopted to measure it exactly. In the present work, the angular distributions of 94Zr(13C,13C)94Zr, 94Zr(12C,12C)94Zr and 94Zr(12C,13C)93Zr were obtained using the highprecision Q3D magnetic spectrograph. In addition, distorted-wave Born approximation (DWBA) calculations of the transfer differential cross sections were performed. The calculated result displays a good agreement with the experiment data, and a value of 2.60±0.20 for the neutron spectroscopic factor of 94Zr was extracted, and the direct capture cross section versus neutron energy of 93Zr(n,γ)94Zr for the ground state of 94Zr was obtained too.

  12. Nuclear Power Options Viability Study. Volume 3. Nuclear discipline topics

    SciTech Connect

    Trauger, D B; White, J D; Bowers, H I; Braid, R B; Cantor, R A; Daniels, L; Davis, R M; Delene, J G; Gat, U; Hood, T C

    1986-09-01

    Innovative reactor concepts are described and evaluated in accordance with criteria established in the study. The reactors to be studied were chosen on the basis of three ground rules: (1) the potential for commercialization between 2000-2010, (2) economic competiveness with coal-fired plants, and (3) the degree of passive safety in the design. The concepts, classified by coolants, were light water reactors, liquid metal reactors, and high temperature reactors, and most were of modular design. All the concepts appear to be potentially viable in the time frame selected, but the information available is not adequate for a definitive evaluation of their economic competitiveness. This volume primarily reports in greater detail on several topics from the study. These are: Construction, Economics, Regulation, Safety and Economic Risk, Nuclear Waste Transportation and Disposal, and Market Acceptance. Although treated generically, the topics are presented in the context of the reactor concepts of the study.

  13. Nuclear-spectroscopy problems studied with neutrons

    NASA Astrophysics Data System (ADS)

    Raman, S.

    Nuclear spectroscopy with neutrons continues to have a major impact on the progress of nuclear science. Neutrons, being uncharged, are particularly useful for the study of low energy reactions. Recent advances in time-of-flight spectroscopy, as well as in the gamma ray spectroscopy following neutron capture, have permitted precision studies of unbound and bound nuclear levels and related phenomena. By going to new energy domains, by using polarized beams and targets, through the invention of new kinds of detectors, and through the general improvement in beam quantity and quality, new features of nuclear structure and reactions were obtained that are not only interesting per se but are also grist for old and new theory mills. The above technical advances have opened up opportunities for further discoveries.

  14. Nuclear-spectroscopy problems studied with neutrons

    SciTech Connect

    Raman, S.

    1982-01-01

    Nuclear spectroscopy with neutrons continues to have a major impact on the progress of nuclear science. Neutrons, being uncharged, are particularly useful for the study of low energy reactions. Recent advances in time-of-flight spectroscopy, as well as in the gamma ray spectroscopy following neutron capture, have permitted precision studies of unbound and bound nuclear levels and related phenomena. By going to new energy domains, by using polarized beams and targets, through the invention of new kinds of detectors, and through the general improvement in beam quantity and quality, new features of nuclear structure and reactions have been obtained that are not ony interesting per se but are also grist for old and new theory mills. The above technical advances have opened up new opportunities for further discoveries.

  15. Shell model study on the astrophysical neutron capture of 8Li

    NASA Astrophysics Data System (ADS)

    Ma, Hai-Liang; Dong, Bao-Guo; Yan, Yu-Liang; Zhang, Xi-Zhen

    2012-09-01

    The astrophysical important neutron capture of 8Li is investigated by combining the shell model and potential model. Three effective interactions, SFO, PSDMK2 and PSDWBP are used to calculate the spectroscopic factors and reaction widths. For the resonant capture from 8Li to the first continuum state of 9Li , the three effective interactions give similar neutron partial widths, and they are well compared with the experimental results. However, the calculated photon widths are over 5 times less than the previous estimate. This will make the substantial difference that, at high temperature, the direct capture mechanism still dominates. The calculated capture rates generally agree well with the experimental data. The uncertainty of calculated cross-sections and capture rates mainly results from the different prediction of spectroscopic factors for the three effective interactions. The total neutron capture rates in our calculations are less than 4300 cm3 mole-1 s-1 for T 9 < 5 which confirms that the main reaction flow will proceed through the reaction 8Li ( α, n) 11B in the stellar environments.

  16. Controls Astrophysics and Structures Experiment in Space (CASES) advanced studies and planning

    NASA Technical Reports Server (NTRS)

    Wu, S. T.

    1989-01-01

    The CASES (Controls, Astrophysics, and Structures Experiment in Space) program consists of a flight demonstration of CSI (Controls-Structures Interactions) technology on the Space Shuttle. The basis structure consists of a 32 m deployable boom with actuators and sensors distributed along its length. Upon deployment from the Orbiter bay, the CASES structure will be characterized dynamically and its deformations controlled by a series of experimental control laws; and cold gas thrusters at its tip will be used to orient the Orbiter to a fixed celestial reference. The scientific observations will consist of hard x-ray imaging, at high resolution, of the Sun and the Galactic center. The hard x-ray observations require stable (few arc min) pointing at these targets for one or more position-sensitive proportional counters in the Orbiter bay, which view the object to be imaged through an aperture-encoding mask at the boom tip. This report gives the concensus developed at the second CASES Science Working Group meeting, which took place at NASA Marshall Space Flight Center May 16-17, 1990. An earlier paper and scientific summaries are available and form the basis for the present discussion.

  17. FLARE STARS—A FAVORABLE OBJECT FOR STUDYING MECHANISMS OF NONTHERMAL ASTROPHYSICAL PHENOMENA

    SciTech Connect

    Oks, E.; Gershberg, R. E.

    2016-03-01

    We present a spectroscopic method for diagnosing a low-frequency electrostatic plasma turbulence (LEPT) in plasmas of flare stars. This method had been previously developed by one of us and successfully applied to diagnosing the LEPT in solar flares. In distinction to our previous applications of the method, here we use the latest advances in the theory of the Stark broadening of hydrogen spectral lines. By analyzing observed emission Balmer lines, we show that it is very likely that the LEPT was developed in several flares of AD Leo, as well as in one flare of EV Lac. We found the LEPT (though of different field strengths) both in the explosive/impulsive phase and at the phase of the maximum, as well as at the gradual phase of the stellar flares. While for solar flares our method allows diagnosing the LEPT only in the most powerful flares, for the flare stars it seems that the method allows revealing the LEPT practically in every flare. It should be important to obtain new and better spectrograms of stellar flares, allowing their analysis by the method outlined in the present paper. This can be the most favorable way to the detailed understanding of the nature of nonthermal astrophysical phenomena.

  18. Laboratory Studies of Charging Properties of Dust Grains in Astrophysical/Planetary Environments

    NASA Astrophysics Data System (ADS)

    Tankosic, D.; Abbas, M. M.

    2012-11-01

    Dust grains immersed in ambient plasmas and radiation, are charged and coupled to the plasma through electric and magnetic fields. Dust grains in various astrophysical/planetary environments are generally charged by: (a) photoelectric emissions with incident radiation at photon energies higher than the work function of the material and (b) sticking of low energy electrons and ions of the surrounding plasma or by secondary electron emissions induced by incident electrons/ions at sufficiently high energies. Consequenly, the particle charge is an important parameter that influences physical and dynamical processes in the interplanetary and interstellar medium, planetary rings, interstellar dust clouds, comets and the outer atmospheres of planets. The charging properties of individual micron-size dust grains are expected to be substantially different from the bulk materials. However, no viable models for calculation of the charging properties of individual micron size dust grains are available at the present time. Currently, very limited experimental data are available for charging of individual micron-size dust grains. In this paper we give a review of the results of the measurements on charging of analogs of the interstellar as well as Apollo 11 and 17 lunar dust grains carried out on the Electrodynamic Balance Facility at the NASA-MSFC.

  19. Theoretical study of the Stark broadening for Mg IV spectral lines of astrophysical interest

    NASA Astrophysics Data System (ADS)

    de Andrés-García, I.; You, C.; Alonso-Medina, A.; Colón, C.

    2016-11-01

    Emission lines of Mg IV have been detected in the Far Ultraviolet Spectroscopic Explorer (FUSE) spectrum of LS V +46°21 star and in the Space Telescope Imaging Spectrograph (STIS) spectrum of BD +28°4211 star. This fact justifies our interest in providing spectroscopic parameters of Mg IV. Stark broadening parameters for 169 spectral lines of Mg IV have been calculated by using the Griem semi-empirical approach. The matrix elements used in these calculations has been determined from 13 configurations of Mg IV: 2s12p6, 2s22p4ns (n = 3-5), 2s22p4nd (n = 3-5) and 2s22p45g for even parity and 2s22p5, 2s22p4np (n = 3, 4) and 2s22p4nf (n = 4, 5) for odd parity. Our calculations were made by using the Cowan code. Data are presented for an electron density of 1017 cm-3 and temperatures T = 1.0-10.0 (104 K). Also we present calculated values of transition probabilities for 30 spectral lines and radiative lifetimes corresponding to its upper levels. These values were analysed using the data found in the literature. Theoretical trends of the Stark broadening parameters versus the temperature for several lines of astrophysical interest are presented.

  20. Mass-23 nuclei in astrophysics

    NASA Astrophysics Data System (ADS)

    Fraser, P. R.; Amos, K.; Canton, L.; Karataglidis, S.; Svenne, J. P.; van der Kniff, D.

    2015-09-01

    The formation of mass-23 nuclei by radiative capture is of great interest in astrophysics. A topical problem associated with these isobars is the so-called 22Na puzzle of ONe white dwarf novae, where the abundance of 22Na observed is not as is predicted by current stellar models, indicating there is more to learn about how the distribution of elements in the universe occurred. Another concerns unexplained variations in elements abundance on the surface of aging red giant stars. One method for theoretically studying nuclear scattering is the Multi-Channel Algebraic Scattering (MCAS) formalism. Studies to date have used a simple collective-rotor prescription to model the target states which couple to projectile nucleons. While, in general, the target states considered all belong to the ground state rotor band, for some systems it is necessary to include coupling to states outside of this band. Herein we discuss an extension of MCAS to allow coupling of different strengths between such states and the ground state band. This consideration is essential when studying the scattering of neutrons from 22Ne, a necessary step in studying the mass-23 nuclei mentioned above.

  1. Neutron reactions in astrophysics

    NASA Astrophysics Data System (ADS)

    Reifarth, R.; Lederer, C.; Käppeler, F.

    2014-05-01

    The quest for the origin of matter in the Universe had been the subject of philosophical and theological debates over the history of mankind, but quantitative answers could be found only by the scientific achievements of the last century. A first important step on this way was the development of spectral analysis by Kirchhoff and Bunsen in the middle of the 19th century, which provided first insight in the chemical composition of the sun and the stars. The energy source of the stars and the related processes of nucleosynthesis, however, could be revealed only with the discoveries of nuclear physics. A final break-through came eventually with the compilation of elemental and isotopic abundances in the solar system, which reflect the various nucleosynthetic processes in detail. This review focuses on the mass region above iron, where the formation of the elements is dominated by neutron capture, mainly in the slow (s) and rapid (r) processes. Following a brief historic account and a sketch of the relevant astrophysical models, emphasis is put on the nuclear physics input, where status and perspectives of experimental approaches are presented in some detail, complemented by the indispensable role of theory.

  2. Comparative study of Gamow-Teller strength distributions in the odd-odd nucleus {sup 50}V and its impact on electron capture rates in astrophysical environments

    SciTech Connect

    Nabi, Jameel-Un; Sajjad, Muhammad

    2007-11-15

    Gamow-Teller (GT) strength transitions are an ideal probe for testing nuclear structure models. In addition to nuclear structure, GT transitions in nuclei directly affect the early phases of Type Ia and Type-II supernovae core collapse since the electron capture rates are partly determined by these GT transitions. In astrophysics, GT transitions provide an important input for model calculations and element formation during the explosive phase of a massive star at the end of its life-time. Recent nucleosynthesis calculations show that odd-odd and odd-A nuclei cause the largest contribution in the rate of change of lepton-to-baryon ratio. In the present manuscript, we have calculated the GT strength distributions and electron capture rates for odd-odd nucleus {sup 50}V by using the pn-QRPA theory. At present {sup 50}V is the first experimentally available odd-odd nucleus in fp-shell nuclei. We also compare our GT strength distribution with the recently measured results of a {sup 50}V(d, {sup 2}He){sup 50}Ti experiment, with the earlier work of Fuller, Fowler, and Newman (referred to as FFN) and subsequently with the large-scale shell model calculations. One curious finding of the paper is that the Brink's hypothesis, usually employed in large-scale shell model calculations, is not a good approximation to use at least in the case of {sup 50}V. SNe Ia model calculations performed using FFN rates result in overproduction of {sup 50}Ti, and were brought to a much acceptable value by employing shell model results. It might be interesting to study how the composition of the ejecta using presently reported QRPA rates compare with the observed abundances.

  3. Comparative study of Gamow-Teller strength distributions in the odd-odd nucleus V50 and its impact on electron capture rates in astrophysical environments

    NASA Astrophysics Data System (ADS)

    Nabi, Jameel-Un; Sajjad, Muhammad

    2007-11-01

    Gamow-Teller (GT) strength transitions are an ideal probe for testing nuclear structure models. In addition to nuclear structure, GT transitions in nuclei directly affect the early phases of Type Ia and Type-II supernovae core collapse since the electron capture rates are partly determined by these GT transitions. In astrophysics, GT transitions provide an important input for model calculations and element formation during the explosive phase of a massive star at the end of its life-time. Recent nucleosynthesis calculations show that odd-odd and odd-A nuclei cause the largest contribution in the rate of change of lepton-to-baryon ratio. In the present manuscript, we have calculated the GT strength distributions and electron capture rates for odd-odd nucleus V50 by using the pn-QRPA theory. At present V50 is the first experimentally available odd-odd nucleus in fp-shell nuclei. We also compare our GT strength distribution with the recently measured results of a V50(d, He2)Ti50 experiment, with the earlier work of Fuller, Fowler, and Newman (referred to as FFN) and subsequently with the large-scale shell model calculations. One curious finding of the paper is that the Brink's hypothesis, usually employed in large-scale shell model calculations, is not a good approximation to use at least in the case of V50. SNe Ia model calculations performed using FFN rates result in overproduction of Ti50, and were brought to a much acceptable value by employing shell model results. It might be interesting to study how the composition of the ejecta using presently reported QRPA rates compare with the observed abundances.

  4. Photoneutron reactions in astrophysics

    SciTech Connect

    Varlamov, V. V. Ishkhanov, B. S.; Orlin, V. N.; Peskov, N. N.; Stopani, K. A.

    2014-12-15

    Among key problems in nuclear astrophysics, that of obtaining deeper insight into the mechanism of synthesis of chemical elements is of paramount importance. The majority of heavy elements existing in nature are produced in stars via radiative neutron capture in so-called s- and r processes, which are, respectively, slow and fast, in relation to competing β{sup −}-decay processes. At the same time, we know 35 neutron-deficient so-called bypassed p-nuclei that lie between {sup 74}Se and {sup 196}Hg and which cannot originate from the aforementioned s- and r-processes. Their production is possible in (γ, n), (γ, p), or (γ, α) photonuclear reactions. In view of this, data on photoneutron reactions play an important role in predicting and describing processes leading to the production of p-nuclei. Interest in determining cross sections for photoneutron reactions in the threshold energy region, which is of particular importance for astrophysics, has grown substantially in recent years. The use of modern sources of quasimonoenergetic photons obtained in processes of inverse Compton laser-radiation scattering on relativistic electronsmakes it possible to reveal rather interesting special features of respective cross sections, manifestations of pygmy E1 and M1 resonances, or the production of nuclei in isomeric states, on one hand, and to revisit the problem of systematic discrepancies between data on reaction cross sections from experiments of different types, on the other hand. Data obtained on the basis of our new experimental-theoretical approach to evaluating cross sections for partial photoneutron reactions are invoked in considering these problems.

  5. Unstable Nuclei in Astrophysics - Proceedings of the International Workshop

    NASA Astrophysics Data System (ADS)

    Kubono, S.; Kajino, T.

    1992-01-01

    The Table of Contents for the full book PDF is as follows: * Preface * Opening Address * I. Explosive Nucleosynthesis in Supernovae and Novae * Explosive Nucleosynthesis in Type II Supernovae * The p-Process in Type II Supernovae * The r-Process in Supernovae * Effects of the 14N(e-, v) 14C(α, γ) 18O Reaction to the Core Mass at the Helium Flash for Low Mass Stars * II. Helium Burning, CNO Cycle and rp-Process * The 12C(α, γ) 16O Cross Section at Low Energies * Helium Burning in Some Astrophysical Scenarios * Measurement of the 1H(13N, γ) 14O Cross Section and Determination of the 14O(1-, T = 1; Eexc = 5.17 MeV) γ-Width * Production of Nuclei on the Proton Drip Line for 31 ≤ Z ≤ 38 * III. Primordial Nucleosynthesis * Signatures of Inhomogeneous Cosmologies; Intermediate-Mass Nucleosynthesis and Radioactive Nuclear Beams * Recent Advances in Primordial Nucleosynthesis * Capture Rates of the 7Li(n, γ)8Li and 12C(n, γ) 13C Reactions by Prompt γ-Ray Detection * Study of the Key Reaction 8Li(α, n) 11B for the Primordial Nucleosynthesis * A QCD Study of Primordial Strange Quark Matter in the Chromoelectric Flux Tube Model (Contributed) * IV. Elemental Abundances, and s- and r-Processes * Shell Structure of Neutron-Rich sd-Shell Nuclei and Its Astrophysical Implication * Half Lives of Long-Lived Tc Isotopes * Evaluation of the CI* and Other Carbonaceous Chondrites as the Solar Abundance Standard * New Generation Calculations of Beta Decay Far from Stability and Astrophysics * Nuclear Masses Far from Stability and Their Relation to r-Process Calculations * Fermion Dynamical Symmetries, Nuclear Masses, and Their Astrophysical Implications * Weak Interaction Rates of sd Shell Nuclei in Stellar Matter (Contributed) * V. New Method in Experimental Nuclear Astrophysics * Experimental Study on the Coulomb Breakup of 14O * Coulomb Dissociation for Nuclear Astrophysics * Some New Developments in Polarized Radioactive Beams * Radioactive Ion Beam Rates from Inverse

  6. Spectroscopic study of the radionuclide 21Na for the astrophysical 17F(α ,p )20Ne reaction rate

    NASA Astrophysics Data System (ADS)

    Cha, S. M.; Chae, K. Y.; Ahn, S.; Bardayan, D. W.; Chipps, K. A.; Cizewski, J. A.; Howard, M. E.; Kozub, R. L.; Kwak, K.; Manning, B.; Matos, M.; O'Malley, P. D.; Pain, S. D.; Peters, W. A.; Pittman, S. T.; Ratkiewicz, A.; Smith, M. S.; Strauss, S.

    2017-08-01

    The 24Mg(p ,α )21Na reaction was measured at the Holifield Radioactive Ion Beam Facility of the Oak Ridge National Laboratory to study the spectroscopy of the radionuclide 21Na. A 31-MeV proton beam from the 25 MV tandem accelerator bombarded isotopically enriched 24Mg targets. Recoiling 4He particles were identified by an annular silicon strip detector array. Two energy levels at Ex=6.594 and 7.132 MeV were observed for the first time. By comparing the experimentally obtained angular distributions and distorted wave Born approximation calculations, the spins and parities of 21Na energy levels were constrained. The astrophysically-important 17F(α ,p )20Ne reaction rate was also calculated for the first time using resonance parameters for 12 energy levels.

  7. Perspectives in astrophysical databases

    NASA Astrophysics Data System (ADS)

    Frailis, Marco; de Angelis, Alessandro; Roberto, Vito

    2004-07-01

    Astrophysics has become a domain extremely rich of scientific data. Data mining tools are needed for information extraction from such large data sets. This asks for an approach to data management emphasizing the efficiency and simplicity of data access; efficiency is obtained using multidimensional access methods and simplicity is achieved by properly handling metadata. Moreover, clustering and classification techniques on large data sets pose additional requirements in terms of computation and memory scalability and interpretability of results. In this study we review some possible solutions.

  8. Laboratory Astrophysics as Key to Understanding the Universe

    NASA Astrophysics Data System (ADS)

    van Dishoeck, Ewine F.

    2012-05-01

    Modern astrophysics is blessed with an increasing amount of high quality observational data on astronomical sources, ranging from our own solar system to the edge of the Universe and from the lowest temperature clouds to the highest energy cosmic rays. Spectra containing thousands of features of atoms, molecules, ice and dust are routinely obtained for stars, planets, comets, the ISM andstar-forming regions, and in the near future even for the most distant galaxies. Realistic models of exo-planetary atmospheres require information on billions of lines. Theories of jets from young stars benefit from plasma experiments to benchmark them. Stellar evolution theories and cosmology rely heavily on accurate rates for nuclear fusion reactions. The first stars could not have formed without the simplest chemical reactions taking place in primordial clouds. Particle physics is at the heart of finding candidates for the mysterious dark matter. There is no doubt that laboratory astrophysics, which includes theoretical calculations, remains at the foundation of the interpretation of observations and truly 'makes astronomy tick'. In this talk, several recent developments in determining these fundamental data will be presented which have resulted in significant advances in our understanding of astrophysical environments. Often, a comparatively minor investment in basic studies can greatly enhance the scientific return from missions. Examples will be taken from each of the 6 themes of the new Laboratory Astrophysics dvision of the AAS (www.aas.org/labastro/lawg_charter.php): atomic, molecular, solid matter, plasma, nuclear, and particle physics. Special attention will be given to recent results from infrared and millimeter facilities, including Herschel and ALMA, which reveal rich spectra of water and organic molecules in star- and planet forming zones. Their interpretation is greatly added by the application of ultra-high vacuum surface science techniques to astrophysical problems.

  9. 77 FR 38090 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-26

    ... the following topics: --Astrophysics Division Update --James Webb Space Telescope Update --Wide-Field Infrared Survey Telescope Report --X-ray and Gravitational Waves Studies Reports --Nuclear Spectroscopic Telescope Array Launch Update It is imperative that the meeting be held on these dates to accommodate the...

  10. Laboratory Studies of Charging Properties of Dust Grains in Astrophysical/Planetary Environments

    NASA Technical Reports Server (NTRS)

    Tankosic, D.; Abbas, M. M.

    2012-01-01

    Dust grains in various astrophysical environments are generally charged electrostatically by photoelectric emissions with UV/X-ray radiation, as well as by electron/ion impact. Knowledge of physical and optical properties of individual dust grains is required for understanding of the physical and dynamical processes in space environments and the role of dust in formation of stellar and planetary systems. In this paper we focus on charging of individual micron/submicron dust grains by processes that include: (a) UV photoelectric emissions involving incident photon energies higher than the work function of the material and b) electron impact, where low energy electrons are scattered or stick to the dust grains, thereby charging the dust grains negatively, and at sufficiently high energies the incident electrons penetrate the grain leading to excitation and emission of electrons referred to as secondary electron emission (SEE). It is well accepted that the charging properties of individual micron/submicron size dust grains are expected to be substantially different from the bulk materials. However, no viable models for calculation of the charging properties of individual micron size dust grains are available at the present time. Therefore, the photoelectric yields, and secondary electron emission yields of micron-size dust grains have to be obtained by experimental methods. Currently, very limited experimental data are available for charging of individual micron-size dust grains. Our experimental results, obtained on individual, micron-size dust grains levitated in an electrodynamic balance facility (at NASA-MSFC), show that: (1) The measured photoelectric yields are substantially higher than the bulk values given in the literature and indicate a particle size dependence with larger particles having order-of-magnitude higher values than for submicron-size grains; (2) dust charging by low energy electron impact is a complex process. Also, our measurements indicate that

  11. Theoretical study of the electronically excited radical cations of naphthalene and anthracene as archetypal models for astrophysical observations. Part II. Dynamics consequences.

    PubMed

    Ghanta, S; Reddy, V Sivaranjana; Mahapatra, S

    2011-08-28

    Nuclear dynamics is investigated theoretically from first principles by employing the ab initio vibronic models of the prototypical naphthalene and anthracene radical cations developed in Part I. This Part is primarily aimed at corroborating a large amount of available experimental data with a specific final goal to establish an unambiguous link with the current observations in astrophysics and astronomy. The detailed analyses presented here perhaps establish that these two prototypical polycyclic aromatic hydrocarbon radical cations are indeed potential carriers of the observed diffuse interstellar bands.

  12. Ion irradiation of ices relevant to astrophysics

    NASA Astrophysics Data System (ADS)

    Baratta, G. A.; Brunetto, R.; Leto, G.; Palumbo, M. E.; Spinella, F.; Strazzulla, G.

    Ices, silicates, and carbonaceous materials have been observed in different astrophysical environments such as the interstellar medium, circumstellar regions, comets, and solid surfaces of Solar System objects. In space these materials suffer from processing caused by cosmic rays, photons and thermal annealing. Our knowledge of the effects of processing on the evolution of solids in different astrophysical environments in mainly based on laboratory experiments. The Laboratory of Experimental Astrophysics in Catania (Italy) is equipped to study the effects of processing on astrophysical relevant materials. Here we briefly describe the experimental set up and discuss some recent results.

  13. High-Energy Astrophysics: An Overview

    NASA Technical Reports Server (NTRS)

    Fishman, Gerald J.

    2007-01-01

    High-energy astrophysics is the study of objects and phenomena in space with energy densities much greater than that found in normal stars and galaxies. These include black holes, neutron stars, cosmic rays, hypernovae and gamma-ray bursts. A history and an overview of high-energy astrophysics will be presented, including a description of the objects that are observed. Observing techniques, space-borne missions in high-energy astrophysics and some recent discoveries will also be described. Several entirely new types of astronomy are being employed in high-energy astrophysics. These will be briefly described, along with some NASA missions currently under development.

  14. Study Gives Good Odds on Nuclear Reactor Safety

    ERIC Educational Resources Information Center

    Russell, Cristine

    1974-01-01

    Summarized is data from a recent study on nuclear reactor safety completed by Norman C. Rasmussen and others. Non-nuclear events are about 10,000 times more likely to produce large accidents than nuclear plants. (RH)

  15. Study Gives Good Odds on Nuclear Reactor Safety

    ERIC Educational Resources Information Center

    Russell, Cristine

    1974-01-01

    Summarized is data from a recent study on nuclear reactor safety completed by Norman C. Rasmussen and others. Non-nuclear events are about 10,000 times more likely to produce large accidents than nuclear plants. (RH)

  16. Nuclear Plant Siting Study. Volume 1

    DTIC Science & Technology

    1976-06-01

    power plant outfalls. Most sensitive genera were Potomogeton, Chara, and Stellaria wlth Elodea and Frontinalis apparently somewhat less sensitive (Ref...ti :NUCLEAR POWER PLANT SITING STUDY for DEPARTENT OF THE ARMY OFFICE, CHIEF OF ENGINEERS . -,SHINGTON, D.C. VOLUME I OCT, Sbmitted by 0 D B $ k...MO1 (,L~ A SI~~.3 EII’S CATALOG N4UMBER 4. TITLE (and ubtltio) S. TYPE OF REPORT &PERIOD COVERED Final - Jul 75-Jun 76 (6Nuclear Plant Siting Study

  17. Nuclear Magnetic Resonance Technology for Medical Studies

    NASA Astrophysics Data System (ADS)

    Budinger, Thomas F.; Lauterbur, Paul C.

    1984-10-01

    Nuclear magnetic resonance proton imaging provides anatomical definition of normal and abnormal tissues with a contrast and detection sensitivity superior to those of x-ray computed tomography in the human head and pelvis and parts of the cardiovascular and musculoskeletal systems. Recent improvements in technology should lead to advances in diagnostic imaging of the breast and regions of the abdomen. Selected-region nuclear magnetic resonance spectroscopy of protons, carbon-13, and phosphorus-31 has developed into a basic science tool for in vivo studies on man and a unique tool for clinical diagnoses of metabolic disorders. At present, nuclear magnetic resonance is considered safe if access to the magnet environment is controlled. Technological advances employing field strengths over 2 teslas will require biophysical studies of heating and static field effects.

  18. High Energy Density Laboratory Astrophysics

    SciTech Connect

    Remington, B A

    2004-11-11

    High-energy-density (HED) physics refers broadly to the study of macroscopic collections of matter under extreme conditions of temperature and density. The experimental facilities most widely used for these studies are high-power lasers and magnetic-pinch generators. The HED physics pursued on these facilities is still in its infancy, yet new regimes of experimental science are emerging. Examples from astrophysics include work relevant to planetary interiors, supernovae, astrophysical jets, and accreting compact objects (such as neutron stars and black holes). In this paper, we will review a selection of recent results in this new field of HED laboratory astrophysics and provide a brief look ahead to the coming decade.

  19. Science with hot astrophysical plasmas

    NASA Astrophysics Data System (ADS)

    Kaastra, J. S.; Gu, L.; Mao, J.; Mehdipour, M.; Mernier, F.; de Plaa, J.; Raassen, A. J. J.; Urdampilleta, I.

    2017-08-01

    We present some recent highlights and prospects for the study of hot astrophysical plasmas. Hot plasmas can be studied primarily through their X-ray emission and absorption. Most astrophysical objects, from solar system objects to the largest scale structures of the Universe, contain hot gas. In general we can distinguish collisionally ionised gas and photoionised gas. We introduce several examples of both classes and show where the frontiers of this research in astrophysics can be found. We put this also in the context of the current and future generation of X-ray spectroscopy satellites. The data coming from these missions challenge the models that we have for the calculation of the X-ray spectra.

  20. Future Experiments in Astrophysics

    NASA Technical Reports Server (NTRS)

    Krizmanic, John F.

    2002-01-01

    The measurement methodologies of astrophysics experiments reflect the enormous variation of the astrophysical radiation itself. The diverse nature of the astrophysical radiation, e.g. cosmic rays, electromagnetic radiation, and neutrinos, is further complicated by the enormous span in energy, from the 1.95 Kappa relic neutrino background to cosmic rays with energy greater than 10(exp 20)eV. The measurement of gravity waves and search for dark matter constituents are also of astrophysical interest. Thus, the experimental techniques employed to determine the energy of the incident particles are strongly dependent upon the specific particles and energy range to be measured. This paper summarizes some of the calorimetric methodologies and measurements planned by future astrophysics experiments. A focus will be placed on the measurement of higher energy astrophysical radiation. Specifically, future cosmic ray, gamma ray, and neutrino experiments will be discussed.

  1. Extraterrestrial Studies Using Nuclear Interactions

    NASA Technical Reports Server (NTRS)

    Reedy, Robert C.

    2003-01-01

    Cosmogenic nuclides were used to study the recent histories of the aubrite Norton County and the pallasite Brenham using calculated production rates. Calculations were done of the rates for making cosmogenic noble-gas isotopes in the Jovian satellite Europa by the interactions of galactic cosmic rays and especially trapped Jovian protons. Cross sections for the production of cosmogenic nuclides were reported and plans made to measure additional cross sections. A new code, MCNPX, was used to numerically simulate the interactions of cosmic rays with matter and the subsequent production of cosmogenic nuclides. A review was written about studies of extraterrestrial matter using cosmogenic radionuclides. Several other projects were done. Results are reviewed here with references to my recent publications for details.

  2. Accelerator Experiments for Astrophysics

    SciTech Connect

    Ng, J

    2003-10-15

    Many recent discoveries in astrophysics involve phenomena that are highly complex. Carefully designed experiments, together with sophisticated computer simulations, are required to gain insights into the underlying physics. We show that particle accelerators are unique tools in this area of research, by providing precision calibration data and by creating extreme experimental conditions relevant for astrophysics. In this paper we discuss laboratory experiments that can be carried out at the Stanford Linear Accelerator Center and implications for astrophysics.

  3. Spent Nuclear Fuel Transport Reliability Study

    SciTech Connect

    Wang, Jy-An John; Wang, Hong; Jiang, Hao

    2016-01-01

    This conference paper was orignated and shorten from the following publisehd PTS documents: 1. Jy-An Wang, Hao Jiang, and Hong Wang, Dynamic Deformation Simulation of Spent Nuclear Fuel Assembly and CIRFT Deformation Sensor Stability Investigation, ORNL/SPR-2015/662, November 2015. 2. Jy-An Wang, Hong Wang, Mechanical Fatigue Testing of High-Burnup Fuel for Transportation Applications, NUREG/CR-7198, ORNL/TM-2014/214, May 2015. 3. Jy-An Wang, Hong Wang, Hao Jiang, Yong Yan, Bruce Bevard, Spent Nuclear Fuel Vibration Integrity Study 16332, WM2016 Conference, March 6 10, 2016, Phoenix, Arizona.

  4. Trade studies for nuclear space power systems

    NASA Technical Reports Server (NTRS)

    Smith, John M.; Bents, David J.; Bloomfield, Harvey S.

    1991-01-01

    As human visions of space applications expand and as we probe further out into the universe, our needs for power will also expand, and missions will evolve which are enabled by nuclear power. A broad spectrum of missions which are enhanced or enabled by nuclear power sources have been defined. These include Earth orbital platforms, deep space platforms, planetary exploration, and terrestrial resource exploration. The recently proposed Space Exploration Initiative (SEI) to the Moon and Mars has more clearly defined these missions and their power requirements. Presented here are results of recent studies of radioisotope and nuclear reactor energy sources, combined with various energy conversion devices for Earth orbital applications, SEI lunar/Mars rovers, surface power, and planetary exploration.

  5. Trade studies for nuclear space power systems

    NASA Technical Reports Server (NTRS)

    Smith, John M.; Bents, David J.; Bloomfield, Harvey S.

    1991-01-01

    As visions of space applications expand and as probes extend further and further out into the universe, the need for power also expands, and missions evolve which are enabled by nuclear power. A broad spectrum of missions which are enhanced or enabled by nuclear power sources are defined. These include earth orbital platforms, deep space platforms, planetary exploration and extraterrestrial resource exploration. The recently proposed Space Exploration Initiative (SEI) to the moon and Mars has more clearly defined these missions and their power requirements. This paper presents results of recent studies of radioisotope and nuclear-reactor energy sources combined with various energy-conversion devices for earth orbital applications, SEI lunar/Mars rover and surface power, and planetary exploration.

  6. High Energy Astrophysics Program

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This report reviews activities performed by members of the USRA (Universities Space Research Association) contract team during the six months during the reporting period (10/95 - 3/96) and projected activities during the coming six months. Activities take place at the Goddard Space Flight Center, within the Laboratory for High Energy Astrophysics. Developments concern instrumentation, observation, data analysis, and theoretical work in Astrophysics. Missions supported include: Advanced Satellite for Cosmology and Astrophysics (ASCA), X-ray Timing Experiment (XTE), X-ray Spectrometer (XRS), Astro-E, High Energy Astrophysics Science, Archive Research Center (HEASARC), and others.

  7. High Energy Astrophysics Program

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This report reviews activities performed-by members of the USRA contract team during the six months of the reporting period and projected activities during the coming six months. Activities take place at the Goddard Space Flight Center, visiting the Laboratory for High Energy Astrophysics. Developments concern instrumentation, observation, data analysis, and theoretical work in Astrophysics. Missions supported include: Advanced Satellite for Cosmology and Astrophysics (ASCA); X-ray Timing Experiment (XTE); X-ray Spectrometer (XRS); Astro-E; High Energy Astrophysics Science Archive Research Center (HEASARC), and others.

  8. Transient Astrophysics Probe

    NASA Astrophysics Data System (ADS)

    Camp, Jordan

    2017-08-01

    Transient Astrophysics Probe (TAP), selected by NASA for a funded Concept Study, is a wide-field high-energy transient mission proposed for flight starting in the late 2020s. TAP’s main science goals, called out as Frontier Discovery areas in the 2010 Decadal Survey, are time-domain astrophysics and counterparts of gravitational wave (GW) detections. The mission instruments include unique imaging soft X-ray optics that allow ~500 deg2 FoV in each of four separate modules; a high sensitivity, 1 deg2 FoV soft X-ray telescope based on single crystal silicon optics; a passively cooled, 1 deg2 FoV Infrared telescope with bandpass 0.6-3 micron; and a set of ~8 small NaI gamma-ray detectors. TAP will observe many events per year of X-ray transients related to compact objects, including tidal disruptions of stars, supernova shock breakouts, neutron star bursts and superbursts, and high redshift Gamma-Ray Bursts. Perhaps most exciting is TAP’s capability to observe X-ray and IR counterparts of GWs involving stellar mass black holes detected by LIGO/Virgo, and possibly X-ray counterparts of GWs from supermassive black holes, detected by LISA and Pulsar Timing Arrays.

  9. Nuclear Proliferation: A Unit for Study.

    ERIC Educational Resources Information Center

    Fernekes, William R.

    1990-01-01

    Using Argentina as a sample case study, presents a classroom unit designed to explain the implications for world peace of nuclear weapons development. Employs a policy analysis model to make an indepth examination of the values underlying all government policy decisions. Includes unit topics and procedures for the exercise. (NL)

  10. Nuclear Proliferation: A Unit for Study.

    ERIC Educational Resources Information Center

    Fernekes, William R.

    1990-01-01

    Using Argentina as a sample case study, presents a classroom unit designed to explain the implications for world peace of nuclear weapons development. Employs a policy analysis model to make an indepth examination of the values underlying all government policy decisions. Includes unit topics and procedures for the exercise. (NL)

  11. Nuclear gamma rays from energetic particle interactions

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Kozlovsky, B.; Lingenfelter, R. E.

    1978-01-01

    Gamma ray line emission from nuclear deexcitation following energetic particle reactions is evaluated. The compiled nuclear data and the calculated gamma ray spectra and intensities can be used for the study of astrophysical sites which contain large fluxes of energetic protons and nuclei. A detailed evaluation of gamma ray line production in the interstellar medium is made.

  12. Studies of nuclear processes; Progress report, 1 September 1992--31 August 1993

    SciTech Connect

    Ludwig, E.J.

    1993-09-01

    Results for the period 1 Sep 92 through 31 Aug 93 are presented in nearly a hundred brief papers, some of which present new but preliminary data. Activities reported may be grouped as follows: Fundamental symmetries in the nucleus (parity-mixing measurements, time reversal invariance measurements, signatures of quantum chaos in nuclei), Internucleon reactions (neutron -- proton interactions, the neutron -- neutron scattering length, reactions between deuterons and very light nuclei), Dynamics of very light nuclei (measurements of D states of very light nuclei by transfer reactions, nuclear reactions between very light nuclei, radiative capture reactions with polarized sources), The many-nucleon problem (nuclear astrophysics, high-spin spectroscopy and superdeformation, the nuclear mean field: Dispersive relations and nucleon scattering, configuration mixing in {sup 56}Co and {sup 46}Sc using (d,{alpha}) reactions, radiative capture studies, high energy resolution resonance studies at 100--400 keV, nuclear data evaluation for A=3--20), Nuclear instruments and methods (FN tandem accelerator operation, KN accelerator operation and maintenance, atomic beam polarized ion source, development of techniques for determining the concentration of SF{sub 6} in the accelerator insulating gas mixture, production of beams and targets, detector systems, updating of TeX, Psprint, and associated programs on the VAX cluster), and Educational Activities.

  13. Nuclear magnetic resonance studies of lens transparency

    SciTech Connect

    Beaulieu, C.F.

    1989-01-01

    Transparency of normal lens cytoplasm and loss of transparency in cataract were studied by nuclear magnetic resonance (NMR) methods. Phosphorus ({sup 31}P) NMR spectroscopy was used to measure the {sup 31}P constituents and pH of calf lens cortical and nuclear homogenates and intact lenses as a function of time after lens enucleation and in opacification produced by calcium. Transparency was measured with laser spectroscopy. Despite complete loss of adenosine triphosphate (ATP) within 18 hrs of enucleation, the homogenates and lenses remained 100% transparent. Additions of calcium to ATP-depleted cortical homogenates produced opacification as well as concentration-dependent changes in inorganic phosphate, sugar phosphates, glycerol phosphorylcholine and pH. {sup 1}H relaxation measurements of lens water at 200 MHz proton Larmor frequency studied temperature-dependent phase separation of lens nuclear homogenates. Preliminary measurements of T{sub 1} and T{sub 2} with non-equilibrium temperature changes showed a change in the slope of the temperature dependence of T{sub 1} and T{sub 2} at the phase separation temperature. Subsequent studies with equilibrium temperature changes showed no effect of phase separation on T{sub 1} or T{sub 2}, consistent with the phase separation being a low-energy process. {sup 1}H nuclear magnetic relaxation dispersion (NMRD) studies (measurements of the magnetic field dependence of the water proton 1/T{sub 1} relaxation rates) were performed on (1) calf lens nuclear and cortical homogenates (2) chicken lens homogenates, (3) native and heat-denatured egg white and (4) pure proteins including bovine {gamma}-II crystallin bovine serum albumin (BSA) and myoglobin. The NMRD profiles of all samples exhibited decreases in 1/T{sub 1} with increasing magnetic field.

  14. 76 FR 50274 - Terrestrial Environmental Studies for Nuclear Power Stations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-12

    ... COMMISSION Terrestrial Environmental Studies for Nuclear Power Stations AGENCY: Nuclear Regulatory Commission... Environmental Studies for Nuclear Power Stations.'' This guide provides technical guidance that the NRC staff... nuclear power reactors. DATES: Submit comments by October 11, 2011. Comments received after this date will...

  15. Overview of Opportunities in Underground Nuclear Physics

    NASA Astrophysics Data System (ADS)

    Smith, Nigel

    2016-09-01

    The field of deep underground nuclear physics is within an exciting and burgeoning phase, demonstrated by the recent award of the 2105 Nobel Prize in physics for the observation of neutrino oscillations and neutrino flavor change, with new detector systems in construction and deployment to further develop this scientific field. This talk will overview the current status of the fields within deep underground nuclear physics, focusing on the study of astrophysical neutrino sources, the intrinsic nature of the neutrino, and nuclear astrophysics. The opportunities available in these fields in the near-future will also be discussed.

  16. Space astronomy and astrophysics program by NASA

    NASA Astrophysics Data System (ADS)

    Hertz, Paul L.

    2014-07-01

    The National Aeronautics and Space Administration recently released the NASA Strategic Plan 20141, and the NASA Science Mission Directorate released the NASA 2014 Science Plan3. These strategic documents establish NASA's astrophysics strategic objectives to be (i) to discover how the universe works, (ii) to explore how it began and evolved, and (iii) to search for life on planets around other stars. The multidisciplinary nature of astrophysics makes it imperative to strive for a balanced science and technology portfolio, both in terms of science goals addressed and in missions to address these goals. NASA uses the prioritized recommendations and decision rules of the National Research Council's 2010 decadal survey in astronomy and astrophysics2 to set the priorities for its investments. The NASA Astrophysics Division has laid out its strategy for advancing the priorities of the decadal survey in its Astrophysics 2012 Implementation Plan4. With substantial input from the astrophysics community, the NASA Advisory Council's Astrophysics Subcommittee has developed an astrophysics visionary roadmap, Enduring Quests, Daring Visions5, to examine possible longer-term futures. The successful development of the James Webb Space Telescope leading to a 2018 launch is an Agency priority. One important goal of the Astrophysics Division is to begin a strategic mission, subject to the availability of funds, which follows from the 2010 decadal survey and is launched after the James Webb Space Telescope. NASA is studying a Wide Field Infrared Survey Telescope as its next large astrophysics mission. NASA is also planning to partner with other space agencies on their missions as well as increase the cadence of smaller Principal Investigator led, competitively selected Astrophysics Explorers missions.

  17. Minicourses in Astrophysics, Modular Approach, Vol. II.

    ERIC Educational Resources Information Center

    Illinois Univ., Chicago.

    This is the second of a two-volume minicourse in astrophysics. It contains chapters on the following topics: stellar nuclear energy sources and nucleosynthesis; stellar evolution; stellar structure and its determination; and pulsars. Each chapter gives much technical discussion, mathematical treatment, diagrams, and examples. References are…

  18. Astrophysical Institute, Potsdam

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Built upon a tradition of almost 300 years, the Astrophysical Institute Potsdam (AIP) is in an historical sense the successor of one of the oldest astronomical observatories in Germany. It is the first institute in the world which incorporated the term `astrophysical' in its name, and is connected with distinguished scientists such as Karl Schwarzschild and Albert Einstein. The AIP constitutes on...

  19. Herzberg Institute of Astrophysics

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    The Herzberg Institute of Astrophysics (HIA) is the Institute within the NATIONAL RESEARCH COUNCIL of Canada responsible for providing astronomical facilities, and developing related instrumentation and software for Canadian researchers. The Institute was established in 1975, and now operates 1.8 m and 1.2 m optical telescopes at the DOMINION ASTROPHYSICAL OBSERVATORY close to Victoria, BC, as we...

  20. Indirect study of 11B(p,α)8Be and 10B(p,α)7Be reactions at astrophysical energies by means of the Trojan Horse Method: recent results

    NASA Astrophysics Data System (ADS)

    Lamia, L.; Puglia, S. M. R.; Spitaleri, C.; Romano, S.; Del Santo, M. Gimenez; Carlin, N.; Munhoz, M. Gameiro; Cherubini, S.; Kiss, G. G.; Kroha, V.; Kubono, S.; La Cognata, M.; Li, Cheng-Bo; Pizzone, R. G.; Wen, Qun-Gang; Sergi, M. L.; Szanto de Toledo, A.; Wakabayashi, Y.; Yamaguchi, H.; Zhou, Shu-Hua

    2010-03-01

    Nuclear (p,α) reactions destroying the so-called “light-elements” lithium, beryllium and boron have been largely studied in the past mainly because their role in understanding some astrophysical phenomena, i.e. mixing-phenomena occurring in young F-G stars [A.M. Boesgaard et al., Astr. Phys. J, 991, 2005, 621]. Such mechanisms transport the surface material down to the region close to the nuclear destruction zone, where typical temperatures of the order of ˜106 K are reached. The corresponding Gamow energy E=1.22(Z keV [C. Rolfs and W. Rodney, “Cauldrons in the Cosmos”, The Univ. of Chicago press, 1988] is about ˜10 keV if one considers the “boron-case” and replaces in the previous formula Z=1, Z=5 and T=5. Direct measurements of the two 11B(p,α)8Be and 10B(p,α)7Be reactions in correspondence of this energy region are difficult to perform mainly because the combined effects of Coulomb barrier penetrability and electron screening [H.J. Assenbaum, K. Langanke and C. Rolfs, Z. Phys., 327, 1987, 461]. The indirect method of the Trojan Horse (THM) [G. Baur et al., Phys. Lett. B, 178, 1986, 135; G. Calvi et al., Nucl. Phys. A, 621, 1997, 139; C. Spitaleri et al., Phys. Rev. C, 493, 1999, 206] allows one to extract the two-body reaction cross section of interest for astrophysics without the extrapolation-procedures. Due to the THM formalism, the extracted indirect data have to be normalized to the available direct ones at higher energies thus implying that the method is a complementary tool in solving some still open questions for both nuclear and astrophysical issues [S. Cherubini et al., Astr. Phys. J, 457, 1996, 855; C. Spitaleri et al., Phys. Rev. C, 63, 2001, 005801; C. Spitaleri et al., Phys. Rev. C, 63, 2004, 055806; A. Tumino et al., Phys. Rev. Lett., 98, 2007, 252502; M. La Cognata et al., Phys. Rev. Lett., 101, 2007, 152501; M.L. Sergi et al., AIPC, 1016, 2008, 433; H.W. Becker, Z. Phys. A, 327, 1987, 341; T. Rauscher and G. Raimann, Phys. Rev

  1. Nuclear anxiety: a test-construction study

    SciTech Connect

    Braunstein, A.L.

    1986-01-01

    The Nuclear Anxiety Scale was administered to 263 undergraduate and graduate studies (on eight occasions in December, 1985 and January, 1986). (1) The obtained alpha coefficient was .91. This was significant at the .01 level, and demonstrated that the scale was internally homogeneous and consistent. (2) Item discrimination indices (point biserial correlation coefficients) computered for the thirty (30) items yielded a range of .25 to .64. All coefficients were significant at the .01 level, and all 30 items were retained as demonstrating significant discriminability. (3) The correlation between two administrations of the scale (with a 48-hour interval) was .83. This was significant at the .01 level, and demonstrated test-retest reliability and stability over time. (4) The point-biserial correlation coefficient between scores on the Nuclear Anxiety Scale, and the students' self-report of nuclear anxiety as being either a high or low ranked stressor, was .59. This was significant at the .01 level, and demonstrated concurrent validity. (5) The correlation coefficient between scores on the Nuclear Anxiety Scale and the Spielberger State-Trait Anxiety Inventory, A-Trait, (1970), was .41. This was significant at the .01 level, and demonstrated convergent validity. (6) The correlation coefficient between positively stated and negatively stated items (with scoring reversed) was .76. This was significant at the .01 level, and demonstrated freedom from response set bias.

  2. Theoretical Particle Astrophysics

    SciTech Connect

    Kamionkowski, Marc

    2013-08-07

    Abstract: Theoretical Particle Astrophysics The research carried out under this grant encompassed work on the early Universe, dark matter, and dark energy. We developed CMB probes for primordial baryon inhomogeneities, primordial non-Gaussianity, cosmic birefringence, gravitational lensing by density perturbations and gravitational waves, and departures from statistical isotropy. We studied the detectability of wiggles in the inflation potential in string-inspired inflation models. We studied novel dark-matter candidates and their phenomenology. This work helped advance the DoE's Cosmic Frontier (and also Energy and Intensity Frontiers) by finding synergies between a variety of different experimental efforts, by developing new searches, science targets, and analyses for existing/forthcoming experiments, and by generating ideas for new next-generation experiments.

  3. Study of a detector system for high-energy astrophysical objects using a combination of plastic scintillator and MPPC

    NASA Astrophysics Data System (ADS)

    Nakaoka, Tatsuya; Mizuno, Tsunefumi; Takahashi, Hiromitsu; Fukazawa, Yasushi

    2016-09-01

    We have investigated a hard X-ray detector system using a combination of a plastic scintillator and multi-pixel photon counters (MPPC). Photomultiplier tubes (PMTs) have typically been adopted to read scintillators because of their high gain and large photoelectric surface, and studies on PMT and scintillator systems are well advanced. However, PMTs have limitations; for example, they are relatively large in size, require high voltage to operate, and cannot be used in strong magnetic fields. On the other hand, MPPCs do not have such limitations and instead possess high quantum efficiency and a large compact size. Therefore, we have studied a detector system that combines an MPPC with a plastic scintillator. The system is primarily intended to be used for polarization measurements of high-energy astrophysical objects. We achieved an energy threshold of as low as ~5 keV while operating the detector at low temperature (-10 °C), reading the signal with short integration time (50 ns), and using a low-noise MPPC. We also confirmed that the light yield of our MPPC+plastic scintillator system is comparable to that obtained using a conventional PMT to read the scintillator signal. Herein, we report test results and future prospects.

  4. Nuclear Physics Meets the Sources of the Ultra-High Energy Cosmic Rays.

    PubMed

    Boncioli, Denise; Fedynitch, Anatoli; Winter, Walter

    2017-07-07

    The determination of the injection composition of cosmic ray nuclei within astrophysical sources requires sufficiently accurate descriptions of the source physics and the propagation - apart from controlling astrophysical uncertainties. We therefore study the implications of nuclear data and models for cosmic ray astrophysics, which involves the photo-disintegration of nuclei up to iron in astrophysical environments. We demonstrate that the impact of nuclear model uncertainties is potentially larger in environments with non-thermal radiation fields than in the cosmic microwave background. We also study the impact of nuclear models on the nuclear cascade in a gamma-ray burst radiation field, simulated at a level of complexity comparable to the most precise cosmic ray propagation code. We conclude with an isotope chart describing which information is in principle necessary to describe nuclear interactions in cosmic ray sources and propagation.

  5. Laboratory study of pulsed regimes of electron cyclotron instabilities in a mirror-confined plasma for astrophysical applications

    NASA Astrophysics Data System (ADS)

    Viktorov, Mikhail; Golubev, Sergey; Mansfeld, Dmitry; Izotov, Ivan; Gospodchikov, Egor; Shalashov, Alexander; Demekhov, Andrei

    2014-05-01

    We discuss the use of a mirror-confined plasma of the electron cyclotron resonance discharge for modeling of burst processes in the inner magnetosphere of the Earth associated with the implementation of the plasma cyclotron maser. Heating under the electron cyclotron resonance conditions allows to create two component plasma which is typical for the inner magnetosphere of the Earth. One of the most interesting electron cyclotron resonance manifestations is the generation of bursts of electromagnetic radiation that are related to the explosive growth of cyclotron instabilities of the magnetoactive plasma confined in magnetic traps of various kinds and that are accompanied by particle precipitations from the trap. We investigate several regimes of cyclotron maser which are realized in dense and rarefied plasma, in the presence and absence of a permanent powerful gyrotron microwave radiation as a source of nonequilibrium particles in the plasma. Using the new technique for detection of microwave radiation we studied the dynamical spectrum and the intensity of stimulated electromagnetic radiation from the plasma in a wide frequency band covering all types of cyclotron instabilities. Also possible applications for astrophysical plasma are discussed.

  6. Black-hole astrophysics

    SciTech Connect

    Bender, P.; Bloom, E.; Cominsky, L.

    1995-07-01

    Black-hole astrophysics is not just the investigation of yet another, even if extremely remarkable type of celestial body, but a test of the correctness of the understanding of the very properties of space and time in very strong gravitational fields. Physicists` excitement at this new prospect for testing theories of fundamental processes is matched by that of astronomers at the possibility to discover and study a new and dramatically different kind of astronomical object. Here the authors review the currently known ways that black holes can be identified by their effects on their neighborhood--since, of course, the hole itself does not yield any direct evidence of its existence or information about its properties. The two most important empirical considerations are determination of masses, or lower limits thereof, of unseen companions in binary star systems, and measurement of luminosity fluctuations on very short time scales.

  7. The new JENSA gas-jet target for astrophysical radioactive beam experiments

    NASA Astrophysics Data System (ADS)

    Bardayan, D. W.; Chipps, K. A.; Ahn, S.; Blackmon, J. C.; Browne, J.; Greife, U.; Jones, K. L.; Kontos, A.; Kozub, R. L.; Linhardt, L.; Manning, B.; Matoš, M.; O'Malley, P. D.; Montes, F.; Ota, S.; Pain, S. D.; Peters, W. A.; Pittman, S. T.; Sachs, A.; Schatz, H.; Schmitt, K. T.; Smith, M. S.; Thompson, P.

    2016-06-01

    To take full advantage of advanced exotic beam facilities, target technology must also be advanced. Particularly important to the study of astrophysical reaction rates is the creation of localized and dense targets of hydrogen and helium. The Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas-jet target has been constructed for this purpose. JENSA was constructed at Oak Ridge National Laboratory (ORNL) where it was tested and characterized, and has now moved to the ReA3 reaccelerated beam hall at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University for use with radioactive beams.

  8. Progress report on nuclear spectroscopic studies

    SciTech Connect

    Bingham, C.R.; Guidry, M.W.; Riedinger, L.L.; Sorensen, S.P.

    1994-02-18

    The Nuclear Physics group at the University of Tennessee, Knoxville (UTK) is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While the main emphasis is on experimental problems, the authors have maintained a strong collaboration with several theorists in order to best pursue the physics of their measurements. During the last year they have had several experiments at the ATLAS at Argonne National Laboratory, the GAMMASPHERE at the LBL 88 Cyclotron, and with the NORDBALL at the Niels Bohr Institute Tandem. Also, they continue to be very active in the WA93/98 collaboration studying ultra-relativistic heavy ion physics utilizing the SPS accelerator at CERN in Geneva, Switzerland and in the PHENIX Collaboration at the RHIC accelerator under construction at Brookhaven National Laboratory. During the last year their experimental work has been in three broad areas: (1) the structure of nuclei at high angular momentum, (2) the structure of nuclei far from stability, and (3) ultra-relativistic heavy-ion physics. The results of studies in these particular areas are described in this document. These studies concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons, or very high temperature and density. Another area of research is heavy-ion-induced transfer reactions, which utilize the transfer of nucleons to states with high angular momentum to learn about their structure and to understand the transfer of particles, energy, and angular momentum in collisions between heavy ions.

  9. Theoretical Astrophysics at Fermilab

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The Theoretical Astrophysics Group works on a broad range of topics ranging from string theory to data analysis in the Sloan Digital Sky Survey. The group is motivated by the belief that a deep understanding of fundamental physics is necessary to explain a wide variety of phenomena in the universe. During the three years 2001-2003 of our previous NASA grant, over 120 papers were written; ten of our postdocs went on to faculty positions; and we hosted or organized many workshops and conferences. Kolb and collaborators focused on the early universe, in particular and models and ramifications of the theory of inflation. They also studied models with extra dimensions, new types of dark matter, and the second order effects of super-horizon perturbations. S tebbins, Frieman, Hui, and Dodelson worked on phenomenological cosmology, extracting cosmological constraints from surveys such as the Sloan Digital Sky Survey. They also worked on theoretical topics such as weak lensing, reionization, and dark energy. This work has proved important to a number of experimental groups [including those at Fermilab] planning future observations. In general, the work of the Theoretical Astrophysics Group has served as a catalyst for experimental projects at Fennilab. An example of this is the Joint Dark Energy Mission. Fennilab is now a member of SNAP, and much of the work done here is by people formerly working on the accelerator. We have created an environment where many of these people made transition from physics to astronomy. We also worked on many other topics related to NASA s focus: cosmic rays, dark matter, the Sunyaev-Zel dovich effect, the galaxy distribution in the universe, and the Lyman alpha forest. The group organized and hosted a number of conferences and workshop over the years covered by the grant. Among them were:

  10. Adventures in theoretical astrophysics

    NASA Astrophysics Data System (ADS)

    Farmer, Alison Jane

    This thesis is a tour of topics in theoretical astrophysics, unified by their diversity and their pursuit of physical understanding of astrophysical phenomena. In the first chapter, we raise the possibility of the detection of white dwarfs in transit surveys for extrasolar Earths, and discuss the peculiarities of detecting these more massive objects. A population synthesis calculation of the gravitational wave background from extragalactic binary stars is then presented. In this study, we establish a firm understanding of the uncertainties in such a calculation and provide a valuable reference for planning the Laser Interferometer Space Antenna mission. The long-established problem of cosmic ray confinement to the Galaxy is addressed in another chapter. We introduce a new wave damping mechanism, due to the presence of background turbulence, that prevents the confinement of cosmic rays by the resonant streaming instability. We also investigate the spokes in Saturn's B ring, an electrodynamic mystery that is being illuminated by new data sent back from the Cassini spacecraft. In particular, we present assessments of the presence of charged dust near the rings, and the size of currents and electric fields in the ring system. We make inferences from the Cassini discovery of oxygen ions above the rings. In addition, the previous leading theory for spoke formation is demonstrated to be unphysical. In the final chapter, we explain the wayward motions of Prometheus and Pandora, two small moons of Saturn. Previously found to be chaotic as a result of mutual interactions, we account for their behavior by analogy with a parametric pendulum. We caution that this behavior may soon enter a new regime.

  11. Currents in Astrophysics and Cosmology

    NASA Astrophysics Data System (ADS)

    Fazio, Giovanni G.; Silberberg, Rein

    1993-10-01

    Part I. Cosmic Rays: 1. Galactic cosmic rays and galactic halo X-ray emission; 2. Highly luminous radiogalaxies as sources of cosmic rays; 3. Where is the cosmic-ray modulation boundary of the heliosphere?; 4. Origin of primary cosmic rays above 1 TeV; 5. Astrophysical discoveries derived from transient cosmic ray and solar flare particle earth-based investigations: the early years; Part II. X-Ray, Gamma-Ray and Neutrino Astronomy: 6. How X-ray astronomy has extended the horizon of physics; 7. Selected topics in high energy gamma-ray astrophysics; 8. Cosmic gamma rays, the origin of cosmic rays, and the structure of the galaxy: the IRAS connection: reminiscences; 9. Ultra-high-energy gamma-ray astronomy; 10. Recent gamma-ray burst studies by Ginga; 11. High-energy astrophysics in solar flares; 12. High-energy gamma radiation from supernova; 13. IMB detection of neutrinos from SN1987A: history and results; 14. High-energy neutrino astronomy: project DUMAND; Part III. Cosmology: 15. The cosmic quark-hadron phase transition; 16. Ponderable soliton stars from early universe; 17. Dark matter and the generation of cosmological structure; Part IV. Reminiscences and Poetic Black Holes: 18. Contributions of Maurice M. Shapiro and his group to cosmic-ray astrophysics; 19. From Jerusalem to heavenly realms - memoir of a cosmic journey; 20. Maury Shapiro and ERICE; 21. Black holes.

  12. Electromagnetic studies of nucleon and nuclear structure

    SciTech Connect

    Heisenberg, J.H.; Calarco, J.R.; Hersman, F.W.; Dawson, J.F.

    1993-06-01

    Important objectives of the group are the study of subatomic structure through experimental measurements and the interpretation of the data through modeling. The common theme that unifies the studies of strong interactions and hadronic systems is the effort to determine the electromagnetic response as completely as possible. The general approach is coincidence detection of exclusive final states and determination of the dependence on the spin variables using polarized beams and targets and outgoing nucleon polarimetry. Direct reaction and giant resonance studies of electron quasi-elastic scattering on {sup 12}C and {sup 16}O are reported, as well as work on nuclear structure models and instrumentation development.

  13. New Approach to Concept Feasibility and Design Studies for Astrophysics Missions

    NASA Technical Reports Server (NTRS)

    Deutsch, M. J.; McLaughlin, W.; Nichols, J.

    1998-01-01

    JPL has assembled a team of multidisciplinary experts with corporate knowledge of space mission and instrument development. The advanced Concept Design Team, known as Team X, provides interactive design trades including cost as a design parameter, and advanced visualization for pre-Phase A Studies.

  14. PREFACE: International Conference on Particle Physics and Astrophysics (ICPPA-2015)

    NASA Astrophysics Data System (ADS)

    2016-02-01

    The International Conference on Particle Physics and Astrophysics (ICPPA-2015) was held in Moscow, Russia, from October 5 to 10, 2015. The conference is organized by Center of Fundamental Research and Particle Physics of National Research Nuclear University ''MEPhI''. The aim of the Conference is to promote contacts between scientists and development of new ideas in fundamental research. We bring together experts and young scientists working on experimental and theoretical aspects of nuclear, particle, astroparticle physics and cosmology. The conference covers a wide range of topics such as accelerator physics, (astro) particle physics, cosmic rays, cosmology and methods of experimental physics - detectors and instruments. These directions are unified by development of the Standard Model (SM) which is evidently not complete. There are deviations from the Standard Model - neutrino oscillations, the dark matter existence. Together with strong interactions, they are main subjects of the Conference. New results from LHC collider as well as its future upgrade are discussed with the Higgs as the main point for discussion. Substantial development of experimental tools for astrophysical observations and new results from cosmic ray experiments is one of the main subjects of the conference. Various aspects of strong interaction are discussed. Among them: Charmonium and Bottomonium states, Flavor physics at Super B factories, Exotic Nuclei in Astrophysics. Another subject for discussion is the neutrino physics, promising and unique way to get new knowledge. In this content, several talks on BOREXINO experiment where new results in neutrino oscillations are presented. Special session is devoted to PAMELA experiment - 9 years in orbit and to the future GAMMA-400 gamma-ray telescope with following main scientific goals: indirect dark matter origin study by the gamma-ray astronomy methods, discrete astrophysical sources observations, diffuse background γ-emission analysis

  15. Laboratory Study of Magnetohydrodynamic and Hydrodynamic Instabilities in Rotating Flows Relevant to Astrophysical Disks

    NASA Astrophysics Data System (ADS)

    Ji, Hantao

    Efficient dissipation of the orbital energy of plasma occurs in accretion disks ranging from those in which planets form around protostars, to those around supermassive black holes in active galactic nuclei. Two mechanisms have been proposed for the turbulence that drives dissipation and angular-momentum transport in such disks: (1) a linear instability of magnetized and electrically conducting flow known as magnetorotational instability (MRI); and (2) nonlinear hydrodynamic shear-flow instability. Two laboratory apparatuses have been constructed at Princeton to study these mechanisms. The LiquidMetal MRI experiment is designed to study MRI and related MHD instabilities. The Hydrodynamic Turbulence Experiment (HTX) is designed to study nonlinear hydrodynamic transition. Both of these devices are novel in two respects: large Reynolds numbers (Regtrsim 10(6) ) and multiple independently driven rings on the axial boundaries to minimize secondary (Ekman) flows. We have demonstrated negligible angular momentum transport at Re ≤ 2× 10(6) in quasi-keplerian hydrodynamic flow with minimized Ekman circulation. This result, published in Nature, has generated significant interest among astrophysicists and fluid dynamicists. Recently, the MHD experiment has demonstrated robust nonaxisymmetric Shercliff-layer instabilities in strong axial magnetic fields. The latter result has paved a clear path towards first conclusive demonstration of MRI in the laboratory. Support is requested to continue fundamental laboratory studies with these devices. The proposed research will focus on experimental studies of the following major questions: (Q1) Why are quasi-keplerian flows resistant to turbulence? Can the turbulence found by other experiments be explained by differences in the boundary conditions or diagnostics used? Can nonlinear hydrodynamic transition occur in flow that is partially magnetized but too diffusive for MRI? (Q2) How do MRI, Shercliff-layer instabilities, and other

  16. Relativistic astrophysics. [studies of gravitational radiation in asymptotic de sitter space and post Newtonian approximation

    NASA Technical Reports Server (NTRS)

    Smalley, L. L.

    1975-01-01

    The coordinate independence of gravitational radiation and the parameterized post-Newtonian approximation from which it is extended are described. The general consistency of the field equations with Bianchi identities, gauge conditions, and the Newtonian limit of the perfect fluid equations of hydrodynamics are studied. A technique of modification is indicated for application to vector-metric or double metric theories, as well as to scalar-tensor theories.

  17. Physics, astronomy, and astrophysics: A numerical study of the black hole plus Brill wave spacetime

    NASA Astrophysics Data System (ADS)

    Bernstein, David Harold

    We investigate solutions of the vacuum Einstein equations in space-times containing a single Einstein-Rosen bridge. The physical and geometrical content of the Schwarzschild solution is analyzed in a number of different spacetime coordinate systems, some well known and some new. In addition, the accuracy of numerical schemes for solving the evolution equations is studied. The same numerical methods are then used to construct axisymmetric solutions which correspond to a Schwarzschild black hole in the presence of time symmetric gravitational radiation (which we call 'Brill waves'). The initial data, evolution of perturbations, and evolution of large amplitude waves are discussed in detail. The initial data is found to display some of the properties of similar data sets studied in the past. The perturbation solutions are shown to agree with known black hole perturbation theory results to within a few percent. Some new results about the apparent horizon in the perturbed Schwarzschild solution are displayed (e.g., the apparent horizon undergoes oscillations similar to that of a damped harmonic oscillator). In addition, traditional radiative variables used in numerical relativity are matched against the known radiative variables of perturbation theory and good agreement is reached in most cases. The large amplitude wave space times are then studied by examining the behavior of the apparent horizon and by investigating the nature of the waveforms as the amplitude is increased into the 'nonlinear' regime. It is found that the apparent horizon may undergo severe distortions by collision with a large amplitude wave. The total mass loss in radiation is studied and it is shown that in some cases a large amount of the initial radiation may escape to null infinity.

  18. A Cost-Benefit Study of Doing Astrophysics On The Cloud: Production of Image Mosaics

    NASA Astrophysics Data System (ADS)

    Berriman, G. B.; Good, J. C. Deelman, E.; Singh, G. Livny, M.

    2009-09-01

    Utility grids such as the Amazon EC2 and Amazon S3 clouds offer computational and storage resources that can be used on-demand for a fee by compute- and data-intensive applications. The cost of running an application on such a cloud depends on the compute, storage and communication resources it will provision and consume. Different execution plans of the same application may result in significantly different costs. We studied via simulation the cost performance trade-offs of different execution and resource provisioning plans by creating, under the Amazon cloud fee structure, mosaics with the Montage image mosaic engine, a widely used data- and compute-intensive application. Specifically, we studied the cost of building mosaics of 2MASS data that have sizes of 1, 2 and 4 square degrees, and a 2MASS all-sky mosaic. These are examples of mosaics commonly generated by astronomers. We also study these trade-offs in the context of the storage and communication fees of Amazon S3 when used for long-term application data archiving. Our results show that by provisioning the right amount of storage and compute resources cost can be significantly reduced with no significant impact on application performance.

  19. Infrared Spectroscopic Studies of Matrix-Isolated Molecules with Potential Astrophysical Significance

    NASA Astrophysics Data System (ADS)

    Wehlburg, Christine Marie

    1997-08-01

    Many of the molecules purported to exist in interstellar space can only be generated in high temperature processes or are ions that are difficult to produce at high enough concentrations for spectroscopic analysis. The molecules investigated in this study, specifically, were polycyclic aromatic hydrocarbon (PAH) ions, carbon chain water complexes and carbon chain anions. PAHs are the proposed carriers of the unidentified interstellar (UIR) emission. The infrared investigation of pentacene and tetracene ions was pursued to provide data concerning the possibility that PAH cations were the source of the UIR emission. In this study, infrared features corresponding to both cation and anions for both molecules were observed for the first time. The most intense features for the neutral molecules were the CH out-of-plane wagging modes while the most intense cationic and anionic features were in the CC stretch and CH bending regions. The relative intensities from theoretical calculations were in reasonable agreement with experimental values with the exception of an overestimation for the intensities of the CH stretch in both neutral pentacene and tetracene. Carbon chain water complexes are very weakly bound species that are observed when graphite is vaporized at low power. The infrared features increase in intensity and new ones appear after annealing a matrix containing carbon chain molecules and H2O. The current study involved assignment of infrared features at 1959.4 and 2014.4 cm-1 to C6ċ H2O and C9ċ H2O, respectively. Assignments were based on the fact that both bands increased relative to the C9 and C6 bands when the concentration of H2O increased. The band assignments were further justified by a 12,13C study for C6/cdotH2O and the agreement of the theoretical shift, relative to the asymmetric stretch band of C9, for C9ċ H2O. In addition a new feature at 1550.4 cm-1 was tentatively assigned to C4ċ H2O. Finally, an isotopic study of a feature at 1721.8 cm-1

  20. Nuclear thermal propulsion engine cost trade studies

    SciTech Connect

    Paschall, R.K. )

    1993-01-10

    The NASA transportation strategy for the Mars Exploration architecture includes the use of nuclear thermal propulsion as the primary propulsion system for Mars transits. It is anticipated that the outgrowth of the NERVA/ROVER programs will be a nuclear thermal propulsion (NTP) system capable of providing the propulsion for missions to Mars. The specific impulse (Isp) for such a system is expected to be in the 870 s range. Trade studies were conducted to investigate whether or not it may be cost effective to invest in a higher performance (Isp[gt]870 s) engine for nuclear thermal propulsion for missions to Mars. The basic cost trades revolved around the amount of mass that must be transported to low-earth orbit prior to each Mars flight and the cost to launch that mass. The mass required depended on the assumptions made for Mars missions scenarios including piloted/cargo flights, number of Mars missions, and transit time to Mars. Cost parameters included launch cost, program schedule for development and operations, and net discount rate. The results were very dependent on the assumptions that were made. Under some assumptions, higher performance engines showed cost savings in the billions of dollars; under other assumptions, the additional cost to develop higher performance engines was not justified.

  1. Studies in Low-Energy Nuclear Science

    SciTech Connect

    Brune, Carl R; Grimes, Steven M

    2006-03-30

    This report presents a summary of research projects in the area of low energy nuclear reactions and structure, carried out between 1 January 2003 and 31 December 2005 and supported by U.S. DOE grant number DE-FG03-03NA00074. Cross sections measured with high resolution have been subjected to an Ericson theory analysis to infer information about the nuclear level density. Other measurements were made of the spectral shape of particles produced in evaporation processes; these also yield level density information. A major project was the development of a new Hauser-Feshbach code for analyzing such spectra. Other measurements produced information on the spectra of gamma rays emitted in reactions on heavy nuclei and gave a means of refining our understanding of gamma-ray strength functions. Finally,reactions on light nuclei were studied and subjected to an R-matrix analysis. Cross sections fora network of nuclear reactions proceedingthrough a given compound nucleus shouldgreatly constrain the family of allowed parameters. Modifications to the formalism andcomputer code are also discussed.

  2. Final Report - Nucelar Astrophysics & Neutron Cross Section Measurements

    SciTech Connect

    Carlton, Robert F.

    2005-02-01

    This enduring research program of 28 years has taken advantage of the excellent research facility of ORELA at Oak Ridge National Laboratory. The fruitful collaborations include a number of scientists from ORNL and some from LASL. This program which has ranged from nuclear structure determinations to astrophysical applications has resulted in the identification and/or the refinement of the nuclear properties of more than 5,000 nuclear energy levels or compound energy states. The nuclei range from 30Si to 250Cf, the probes range from thermal to 50 MeV neutrons, and the studies range from capture gamma ray spectra to total and differential scattering and absorption cross sections.

  3. Laboratory IR Studies and Astrophysical Implications of C2H2-Containing Binary Ices

    NASA Technical Reports Server (NTRS)

    Knez, C.; Moore, M.; Ferrante, R.; Hudson, R.

    2012-01-01

    Studies of molecular hot cores and protostellar environments have shown that the observed abundance of gas-phase acetylene (C2H2) cannot be matched by chemical models without the inclusion of C2H2 molecules subliming from icy grain mantles. Searches for infrared (IR) spectral features of solid-phase acetylene are under way, but few laboratory reference spectra of C2H2 in icy mixtures, which are needed for spectral fits to observational data, have been published. Here, we report a systematic study of the IR spectra of condensed-phase pure acetylene and acetylene in ices dominated by carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), and water (H2O). We present new spectral data for these ices, including band positions and intrinsic band strengths. For each ice mixture and concentration, we also explore the dependence of acetylene's nu5-band position (743 cm-1, 13.46 micrometers) and FWHM on temperature. Our results show that the nu5 feature is much more cleanly resolved in ices dominated by non-polar and low-polarity molecules, specifically CO, CO2, and CH4, than in mixtures dominated by H2O-ice. We compare our laboratory ice spectra with observations of a quiescent region in Serpens.

  4. Laboratory IR Studies and Astrophysical Implications of C2H2-Containing Binary Ices

    NASA Technical Reports Server (NTRS)

    Knez, C.; Moore, M.; Ferrante, R.; Hudson, R.

    2012-01-01

    Studies of molecular hot cores and protostellar environments have shown that the observed abundance of gas-phase acetylene (C2H2) cannot be matched by chemical models without the inclusion of C2H2 molecules subliming from icy grain mantles. Searches for infrared (IR) spectral features of solid-phase acetylene are under way, but few laboratory reference spectra of C2H2 in icy mixtures, which are needed for spectral fits to observational data, have been published. Here, we report a systematic study of the IR spectra of condensed-phase pure acetylene and acetylene in ices dominated by carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), and water (H2O). We present new spectral data for these ices, including band positions and intrinsic band strengths. For each ice mixture and concentration, we also explore the dependence of acetylene's nu5-band position (743 cm-1, 13.46 micrometers) and FWHM on temperature. Our results show that the nu5 feature is much more cleanly resolved in ices dominated by non-polar and low-polarity molecules, specifically CO, CO2, and CH4, than in mixtures dominated by H2O-ice. We compare our laboratory ice spectra with observations of a quiescent region in Serpens.

  5. Irradiation of astrophysical ice grains by cosmic-ray ions: a REAX simulation study

    NASA Astrophysics Data System (ADS)

    Mainitz, Martin; Anders, Christian; Urbassek, Herbert M.

    2016-07-01

    Context. The impact of cosmic rays on ice grains delivers considerable energy, inducing chemical reactions and molecule ejection. Aims: We study the effects of cosmic ray impact on ice grains, including shock wave expansion, grain heating, molecule fragmentation, formation of chemical reaction products, sputtering and evaporation. Methods: Molecular-dynamics simulations using the REAX potential allow us to follow the processes occurring in the irradiated ice grain; the mechanical, thermal and chemical consequences are simulated. The ice grain consists of a mixture of water, carbon dioxide, methanol and ammonia. The case of 1 keV/nm energy deposition is studied as an example. Results: The ion track emits a shock wave into the ambient grain. Due to the strong heating, abundant molecule fragmentation is observed; several of the fragments either recombine or form new product molecules. Prompt sputtering from the ion track is followed by evaporation from the surface of the heated grain. We present mass spectra of the chemically transformed species in the grain and in the ejecta.

  6. Relativistic astrophysics around SMBHs : A Suzaku study of 3C120 and Mrk841

    NASA Astrophysics Data System (ADS)

    Reynolds, Christopher

    At the heart of every active galactic nucleus (AGN) is an accreting supermassive black hole. Any fundamental understanding of the AGN phenomenon (for example, the origin of the radio-quiet/radio-loud dichotomy within the AGN population) must begin with an understanding of relativistic processes close to accreting black holes. X-ray spectroscopy provides a powerful way to probe this region; X-ray reprocessing/reflection spectra from the inner accretion disk provides the cleanest probe to date of the inner accretion flow and the strong gravitational field of the supermassive black hole. X-ray reflection studies also provide the opportunity to constrain the spin of supermassive black holes, an important goal since the spin may be a significant source of energy. We have been awarded deep Suzaku observations of two nearby bright AGN, the broad line radio galaxy 3C120 and the Seyfert 1 galaxy Mrk841 (with on-source Suzaku exposure times of 300ks and 350ks awarded, respectively). These observations constitute the third and final year of our Suzaku Key Project, the Suzaku AGN Spin Survey. Here, we request funds to support the analysis and interpretation of these new datasets and the dissemination of the final results. We highlight the particular opportunities presented by these two objects. Our study of 3C120 will provide the best view yet of the central engine of a radio-loud AGN, allowing a fresh look at the jet- production mechanism. We are currently constructing a multi-observatory campaign around our Suzaku observation of 3C120; we have already secured radio monitoring data, will utilize public Fermi data, have a pending proposal for Chandra/HETG observations, and are in discussions with the NuSTAR team about a possible coordinated observation in their early science phase. The Mrk841 study will address another mystery in AGN physics, the origin of the soft X-ray excess. Our observation will provide a high-fidelity look at the spectrum from 0.5-50keV, allowing the

  7. Recent Studies of the Nuclear Interaction

    NASA Astrophysics Data System (ADS)

    Carlson, J.

    Recent studies of light p-shell nuclei reveal that so-called 'realistic' nuclear interactions, those based on the NN scattering data augmented with plausible models of the three-nucleon interaction, provide a good description or nuclei through A=8. However, significant discrepancies exist, primarily in the energies of neutron rich systems and in the L.S splittings in the spectra of these nuclei. We briefly describe the methods used in these studies, and describe improved models of the three-nucleon interaction.

  8. Experimental and theoretical studies of pressure broadened alkali-metal lines for astrophysical applications

    NASA Astrophysics Data System (ADS)

    Shindo, F.; Zhu, C.; Babb, J.; Yoshino, K.; Dalgarno, A.; Kirby, K.

    2006-05-01

    We are undertaking a program of experimental and theoretical studies of the pressure broadening of Na and K by He and H2. This work is motivated by the need for accurate absorption coefficients to validate models of atmospheric opacities which can be used to characterize properties such as gravity and effective temperature of brown dwarfs or predict spectra of irradiated extrasolar giant planets. Due to the collisions with gaseous H2 and He at high concentration in these objects with temperatures of around 1000 K, the profiles of Na and K lines (respectively at 590 nm and 770 nm) are strongly broadened by at least 100 nm. The design of our spectroscopic experiment allows us to collect absorption spectra of alkali vapors at temperatures around 900 K in the presence of buffer gas at pressures of several hundred torr. The atomic densities are measured precisely using the anomalous dispersion (``hook'') method. Investigating the spectral range 380-920 nm, we observed the broadening of the K 770 nm lines and we find the K 404 nm doublet exhibits a putative satellite feature on its blue wing. The theoretical calculations utilize accurate molecular potential energies and transition dipole moments and fully quantum-mechanical methods. Supported in part by NASA grant NAG5-12751

  9. Astrophysical payloads for picosatellites

    NASA Astrophysics Data System (ADS)

    Hudec, R.

    2017-07-01

    The recent progress in cubesatellite technology allows to consider scientific applications of these minsatellites including astrophysical research. Miniature X-ray and UV-payloads may serve as an example.

  10. Compressible Astrophysics Simulation Code

    SciTech Connect

    Howell, L.; Singer, M.

    2007-07-18

    This is an astrophysics simulation code involving a radiation diffusion module developed at LLNL coupled to compressible hydrodynamics and adaptive mesh infrastructure developed at LBNL. One intended application is to neutrino diffusion in core collapse supernovae.

  11. Transient Astrophysics Observatory (TAO)

    NASA Astrophysics Data System (ADS)

    Racusin, J. L.; TAO Team

    2016-10-01

    The Transient Astrophysics Observatory (TAO) is a NASA MidEx mission concept (formerly known as Lobster) designed to provide simultaneous wide-field gamma-ray, X-ray, and near-infrared observations of the sky.

  12. SPAN: Astronomy and astrophysics

    NASA Technical Reports Server (NTRS)

    Thomas, Valerie L.; Green, James L.; Warren, Wayne H., Jr.; Lopez-Swafford, Brian

    1987-01-01

    The Space Physics Analysis Network (SPAN) is a multi-mission, correlative data comparison network which links science research and data analysis computers in the U.S., Canada, and Europe. The purpose of this document is to provide Astronomy and Astrophysics scientists, currently reachable on SPAN, with basic information and contacts for access to correlative data bases, star catalogs, and other astrophysic facilities accessible over SPAN.

  13. Dominion Radio Astrophysical Observatory

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    The Dominion Radio Astrophysical Observatory began operating in 1959, and joined the NATIONAL RESEARCH COUNCIL in 1970. It became part of the Herzberg Institute of Astrophysics in 1975. The site near Penticton, BC has a 26 m radio telescope, a seven-antenna synthesis telescope on a 600 m baseline and two telescopes dedicated to monitoring the solar radio flux at 10.7 cm. This part of the Institu...

  14. Eta Carinae: An Astrophysical Laboratory to Study Conditions During the Transition Between a Pseudo-Supernova and a Supernova

    NASA Astrophysics Data System (ADS)

    McKinnon, Darren; Gull, T. R.; Madura, T.

    2014-01-01

    A major puzzle in the studies of supernovae is the pseudo-supernova, or the near-supernovae state. It has been found to precede, in timespans ranging from months to years, a number of recently-detected distant supernovae. One explanation of these systems is that a member of a massive binary underwent a near-supernova event shortly before the actual supernova phenomenon. Luckily, we have a nearby massive binary, Eta Carinae, that provides an astrophysical laboratory of a near-analog. The massive, highly-eccentric, colliding-wind binary star system survived a non-terminal stellar explosion in the 1800's, leaving behind the incredible bipolar, 10"x20" Homunculus nebula. Today, the interaction of the binary stellar winds 1") is resolvable by the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope (HST). Using HST/STIS, several three-dimensional (3D) data cubes (2D spatial, 1D velocity) have been obtained at selected phases during Eta Carinae's 5.54-year orbital cycle. The data cubes were collected by mapping the central 1-2" at 0.05" intervals with a 52"x0.1" aperture. Selected forbidden lines, that form in the colliding wind regions, provide information on electron density of the shocked regions, the ionization by the hot secondary companion of the primary wind and how these regions change with orbital phase. By applying various analysis techniques to these data cubes, we can compare and measure temporal changes due to the interactions between the two massive winds. The observations, when compared to current 3D hydrodynamic models, provide insight on Eta Carinae's recent mass-loss history, important for determining the current and future states of this likely nearby supernova progenitor.

  15. Laboratory Astrophysics White Paper

    NASA Technical Reports Server (NTRS)

    Brickhouse, Nancy; Federman, Steve; Kwong, Victor; Salama, Farid; Savin, Daniel; Stancil, Phillip; Weingartner, Joe; Ziurys, Lucy

    2006-01-01

    Laboratory astrophysics and complementary theoretical calculations are the foundations of astronomical and planetary research and will remain so for many generations to come. From the level of scientific conception to that of the scientific return, it is our understanding of the underlying processes that allows us to address fundamental questions regarding the origins and evolution of galaxies, stars, planetary systems, and life in the cosmos. In this regard, laboratory astrophysics is much like detector and instrument development at NASA and NSF; these efforts are necessary for the astronomical research being funded by the agencies. The NASA Laboratory Astrophysics Workshop met at the University of Nevada, Las Vegas (UNLV) from 14-16 February, 2006 to identify the current laboratory data needed to support existing and future NASA missions and programs in the Astrophysics Division of the Science Mission Directorate (SMD). Here we refer to both laboratory and theoretical work as laboratory astrophysics unless a distinction is necessary. The format for the Workshop involved invited talks by users of laboratory data, shorter contributed talks and poster presentations by both users and providers that highlighted exciting developments in laboratory astrophysics, and breakout sessions where users and providers discussed each others' needs and limitations. We also note that the members of the Scientific Organizing Committee are users as well as providers of laboratory data. As in previous workshops, the focus was on atomic, molecular, and solid state physics.

  16. Scaling Extreme Astrophysical Phenomena to the Laboratory

    SciTech Connect

    Remington, B A

    2007-11-01

    High-energy-density (HED) physics refers broadly to the study of macroscopic collections of matter under extreme conditions of temperature and density. The experimental facilities most widely used for these studies are high-power lasers and magnetic-pinch generators. The HED physics pursued on these facilities is still in its infancy, yet new regimes of experimental science are emerging. Examples from astrophysics include work relevant to planetary interiors, supernovae, astrophysical jets, and accreting compact objects (such as neutron stars and black holes). In this paper, we review a selection of recent results in this new field of HED laboratory astrophysics and provide a brief look ahead to the coming decade.

  17. NACRE: A European Compilation of Reaction Rates for Astrophysics

    SciTech Connect

    Carmen Angulo

    1999-12-31

    We report on the program and results of the NACRE network (Nuclear Astrophysics Compilation of Reaction rates). We have compiled low-energy cross section data for 86 charged-particle induced reactions involving light (1 {<=} Z {<=} 14) nuclei. The corresponding Maxwellian-averaged thermonuclear reactions rates are calculated in the temperature range from 10{sup 6} K to 10{sup 10} K. The web site, http://pntpm.ulb.ac.be/nacre.htm, including the cross section data base and the reaction rates, allows users to browse electronically all the information on the reactions studied in this compilation.

  18. NACRE: A European Compilation of Reaction rates for Astrophysics

    SciTech Connect

    Angulo, Carmen

    1999-11-16

    We report on the program and results of the NACRE network (Nuclear Astrophysics Compilation of REaction rates). We have compiled low-energy cross section data for 86 charged-particle induced reactions involving light (1{<=}Z{<=}14) nuclei. The corresponding Maxwellian-averaged thermonuclear reactions rates are calculated in the temperature range from 10{sup 6} K to 10{sup 10} K. The web site http://pntpm.ulb.ac.be/nacre.htm, including the cross section data base and the reaction rates, allows users to browse electronically all the information on the reactions studied in this compilation.

  19. Direct measurements of astrophysically important α-induced reactions

    NASA Astrophysics Data System (ADS)

    Avila, Melina

    2016-03-01

    Understanding stellar evolution is one of the primary objectives of nuclear astrophysics. Reaction rates involving α-particles are often key nuclear physics inputs in stellar models. For instance, there are numerous (α , p) reactions fundamental for the understanding of X-ray bursts and the production of 44Ti in core-collapse supernovae. Furthermore, some (α , n) reactions are considered as one of the main neutron sources in the s-process. However, direct measurements of these reactions at relevant astrophysical energies are experimentally challenging because of their small cross section and intensity limitation of radioactive beams. The active target system MUSIC offers a unique opportunity to study (α , p) and (α , n) reactions because its segmented anode allows the investigation of a large energy range in the excitation function with a single measurement. Recent results on the direct measurement of (α , n) and (α , p) measurements in the MUSIC detector will be discussed. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract Number DE-AC02-06CH11357. This research used resources of ANL's ATLAS facility, which is a DOE Office of Science User.

  20. Follow-up of GW150914 and multi-messenger studies of transient astrophysical sources with the ANTARES neutrino telescope

    NASA Astrophysics Data System (ADS)

    Coleiro, Alexis

    2017-03-01

    By constantly monitoring at least one complete hemisphere of the sky, neutrino telescopes are well designed to detect neutrinos emitted by transient astrophysical sources. In particular, the ANTARES telescope is currently the largest high-energy neutrino detector in the Northern Hemisphere. Searches for ANTARES neutrino candidates coincident with multi-wavelength and multi-messenger transient phenomena are performed by triggering optical, X-ray and radio observations immediately after the detection of an interesting ANTARES event and also by looking for neutrino emission spatially and temporally coincident with transient astrophysical events detected across the electromagnetic spectrum or with new messengers as gravitational-wave signals. The latest results of the multi-messenger analyses performed with ANTARES will be presented in this contribution. In particular, we will focus on the neutrino follow-up performed after the detection of the first gravitation-wave event, GW150914.

  1. Life origination and development hydrate theory (LOH-Theory) in the context of biological, physicochemical, astrophysical, and paleontological studies

    NASA Astrophysics Data System (ADS)

    Ostrovskii, V. E.; Kadyshevich, E. A.

    2014-04-01

    Till now, we formulated and developed the Life Origination Hydrate Theory (LOH-Theory) and Mitosis and Replication Hydrate Theory (MRHTheory) as the instruments for understanding the physical and chemical mechanisms applied by Nature for the living matter origination and propagation. This work is aimed at coordination of these theories with the paleontological and astrophysical knowledges and hypotheses of the Earth and Solar System remote histories.

  2. A multidisciplinary study of DPRK nuclear tests

    NASA Astrophysics Data System (ADS)

    Materni, Valerio; Bignami, Christian; Giuntini, Alessandra; Chiappini, Stefano; Carluccio, Roberto; D'Ajello Caracciolo, Francesca; Pignatelli, Alessandro; Stramondo, Salvatore; Console, Rodolfo; Chiappini, Massimo

    2013-04-01

    The Democratic People Republic of Korea announced two underground nuclear tests carried out in their territory respectively on October 9th, 2006 and May 25th, 2009. The scarce information on the precise location and the size of those explosions has stimulated various kinds of studies, mostly based on seismological observations, by several National Agencies concerned with the Nuclear Test Ban Treaty verification. We analysed the available seismological data collected through a global high quality network for the two tests. After picking up the arrival times at the various stations, a standard location program has been applied to the observed data. If we use all the available data for each single event, due to the different magnitude and different number of available stations, the locations appear quite different. On the contrary, if we use only the common stations, they happen to be only few km apart from each other and within their respective error ellipses. A more accurate relative location has been carried out by the application of algorithms such as Double Difference Joint Hypocenter Determination (DDJHD) and waveform alignment. The epicentral distance between the two events obtained by these methods is 2 km, with the 2006 event shifted to the ESE with respect to that of 2009. We then used a dataset of VHR TerraSAR-X satellite images to detect possible surface effects of the underground tests. This is the first ever case where these highly performing SAR data have been used to such aim. We applied InSAR processing technique to fully exploit the capabilities of SAR data to measure very short displacements over large areas. Two interferograms have been computed, one co-event and one post-event, to remove possible residual topographic signals. A clear displacement pattern has been highlighted over a mountainous area within the investigated region, measuring a maximum displacement of about 45 mm overall the relief. Hypothesizing that the 2009 nuclear test had been

  3. PREFACE: 2nd International Workshop on Theoretical and Computational Physics (IWTCP-2): Modern Methods and Latest Results in Particle Physics, Nuclear Physics and Astrophysics and the 39th National Conference on Theoretical Physics (NCTP-39)

    NASA Astrophysics Data System (ADS)

    Hoang, Trinh Xuan; Ky, Nguyen Anh; Lan, Nguyen Tri; Viet, Nguyen Ai

    2015-06-01

    This volume contains selected papers presented at the 2nd International Workshop on Theoretical and Computational Physics (IWTCP-2): Modern Methods and Latest Results in Particle Physics, Nuclear Physics and Astrophysics and the 39th National Conference on Theoretical Physics (NCTP-39). Both the workshop and the conference were held from 28th - 31st July 2014 in Dakruco Hotel, Buon Ma Thuot, Dak Lak, Vietnam. The NCTP-39 and the IWTCP-2 were organized under the support of the Vietnamese Theoretical Physics Society, with a motivation to foster scientific exchanges between the theoretical and computational physicists in Vietnam and worldwide, as well as to promote high-standard level of research and education activities for young physicists in the country. The IWTCP-2 was also an External Activity of the Asia Pacific Center for Theoretical Physics (APCTP). About 100 participants coming from nine countries participated in the workshop and the conference. At the IWTCP-2 workshop, we had 16 invited talks presented by international experts, together with eight oral and ten poster contributions. At the NCTP-39, three invited talks, 15 oral contributions and 39 posters were presented. We would like to thank all invited speakers, participants and sponsors for making the workshop and the conference successful. Trinh Xuan Hoang, Nguyen Anh Ky, Nguyen Tri Lan and Nguyen Ai Viet

  4. SciDAC Computational Astrophysics Consortium

    SciTech Connect

    Burrows, Adam

    2008-06-18

    Supernova explosions are the central events in nuclear astrophysics. The core-collapse variety is a major source for the universe's heavy elements. The neutron stars, pulsars, and stellar-mass black holes of high-energy astrophysics are their products. Given their prodigious explosion energies, they are the major agencies of change in the interstellar medium, driving star formation and the evolution of galaxies. Their gas remnants are the birthplaces of the cosmic rays. Such is their brightness that they can be used as standard candles to measure the size and geometry of the universe. Recently, there is evidence that gamma-ray bursts (GRBs) originate in a small fraction of core collapses, thereby connecting two of the most energetic phenomena in the universe. However, the mechanism by which core-collapse supernovae explode has not yet been unambiguously determined. Arguably, this is one of the great unsolved problems in modern astrophysics and its investigation draws on nuclear physics, particle physics, radiative transfer, kinetic theory, gravitational physics, thermodynamics, and the numerical arts. Hence, supernovae are unrivaled astrophysical laboratories. It is the quest for the mechanism and new insights our team has recently had that motivate this proposal.

  5. Nuclear Energy Response in the EMF27 Study

    SciTech Connect

    Kim, Son H.; Wada, Kenichi; Kurosawa, Atsushi; Roberts, Matthew

    2014-03-25

    The nuclear energy response for mitigating global climate change across eighteen participating models of the EMF27 study is investigated. Diverse perspectives on the future role of nuclear power in the global energy system are evident in the broad range of nuclear power contributions from participating models of the study. In the Baseline scenario without climate policy, nuclear electricity generation and shares span 0 – 66 EJ/ year and 0 - 25% in 2100 for all models, with a median nuclear electricity generation of 39 EJ/year (1,389 GWe at 90% capacity factor) and median share of 9%. The role of nuclear energy increased under the climate policy scenarios. The median of nuclear energy use across all models doubled in the 450 ppm CO2e scenario with a nuclear electricity generation of 67 EJ/year (2,352 GWe at 90% capacity factor) and share of 17% in 2100. The broad range of nuclear electricity generation (11 – 214 EJ/year) and shares (2 - 38%) in 2100 of the 450 ppm CO2e scenario reflect differences in the technology choice behavior, technology assumptions and competitiveness of low carbon technologies. Greater clarification of nuclear fuel cycle issues and risk factors associated with nuclear energy use are necessary for understanding the nuclear deployment constraints imposed in models and for improving the assessment of the nuclear energy potential in addressing climate change.

  6. Nuclear techniques in studies of condensed matter

    NASA Technical Reports Server (NTRS)

    Singh, Jag J.

    1987-01-01

    Nuclear techniques have played an important role in the studies of materials over the past several decades. For example, X-ray diffraction, neutron diffraction, neutron activation, and particle- or photon-induced X-ray emission techniques have been used extensively for the elucidation of structural and compositional details of materials. Several new techniques have been developed recently. Four such techniques are briefly reviewed which have great potential in the study and development of new materials. Of these four, Mossbauer spectroscopy, muon spin rotation, and positron annihilation spectroscopy techniques exploit their great sensitivity to the local atomic environments in the test materials. Interest in synchrotron radiation, on the other hand, stems from its special properties, such as high intensity, high degree of polarization, and high monochromaticity. It is hoped that this brief review will stimulate interest in the exploitation of these newer techniques for the development of improved materials.

  7. Hydrodynamic Instability, Integrated Code, Laboratory Astrophysics, and Astrophysics

    NASA Astrophysics Data System (ADS)

    Takabe, Hideaki

    This is an article for the memorial lecture of Edward Teller Medal and is presented as memorial lecture at the IFSA03 conference held on September 12th, 2003, at Monterey, CA. The author focuses on his main contributions to fusion science and its extension to astrophysics in the field of theory and computation by picking up five topics. The first one is the anomalous resisitivity to hot electrons penetrating over-dense region through the ion wave turbulence driven by the return current compensating the current flow by the hot electrons. It is concluded that almost the same value of potential as the average kinetic energy of the hot electrons is realized to prevent the penetration of the hot electrons. The second is the ablative stabilization of Rayleigh-Taylor instability at ablation front and its dispersion relation so-called Takabe formula. This formula gave a principal guideline for stable target design. The author has developed an integrated code ILESTA (1D & 2D) for analyses and design of laser produced plasma including implosion dynamics. It is also applied to design high gain targets. The third is the development of the integrated code ILESTA. The forth is on Laboratory Astrophysics with intense lasers. This consists of two parts; one is review on its historical background and the other is on how we relate laser plasma to wide-ranging astrophysics and the purposes for promoting such research. In relation to one purpose, I gave a comment on anomalous transport of relativistic electrons in Fast Ignition laser fusion scheme. Finally, I briefly summarize recent activity in relation to application of the author's experience to the development of an integrated code for studying extreme phenomena in astrophysics.

  8. Hydrodynamic Instability, Integrated Code, Laboratory Astrophysics, and Astrophysics

    NASA Astrophysics Data System (ADS)

    Takabe, Hideaki

    2016-10-01

    This is an article for the memorial lecture of Edward Teller Medal and is presented as memorial lecture at the IFSA03 conference held on September 12th, 2003, at Monterey, CA. The author focuses on his main contributions to fusion science and its extension to astrophysics in the field of theory and computation by picking up five topics. The first one is the anomalous resisitivity to hot electrons penetrating over-dense region through the ion wave turbulence driven by the return current compensating the current flow by the hot electrons. It is concluded that almost the same value of potential as the average kinetic energy of the hot electrons is realized to prevent the penetration of the hot electrons. The second is the ablative stabilization of Rayleigh-Taylor instability at ablation front and its dispersion relation so-called Takabe formula. This formula gave a principal guideline for stable target design. The author has developed an integrated code ILESTA (ID & 2D) for analyses and design of laser produced plasma including implosion dynamics. It is also applied to design high gain targets. The third is the development of the integrated code ILESTA. The forth is on Laboratory Astrophysics with intense lasers. This consists of two parts; one is review on its historical background and the other is on how we relate laser plasma to wide-ranging astrophysics and the purposes for promoting such research. In relation to one purpose, I gave a comment on anomalous transport of relativistic electrons in Fast Ignition laser fusion scheme. Finally, I briefly summarize recent activity in relation to application of the author's experience to the development of an integrated code for studying extreme phenomena in astrophysics.

  9. Astrophysical processes on the Sun

    PubMed Central

    Parnell, Clare E.

    2012-01-01

    Over the past two decades, there have been a series of major solar space missions, namely Yohkoh, SOHO, TRACE, and in the past 5 years, STEREO, Hinode and SDO, studying various aspects of the Sun and providing images and spectroscopic data with amazing temporal, spatial and spectral resolution. Over the same period, the type and nature of numerical models in solar physics have been completely revolutionized as a result of widespread accessibility to parallel computers. These unprecedented advances on both observational and theoretical fronts have led to significant improvements in our understanding of many aspects of the Sun's behaviour and furthered our knowledge of plasma physics processes that govern solar and other astrophysical phenomena. In this Theme Issue, the current perspectives on the main astrophysical processes that shape our Sun are reviewed. In this Introduction, they are discussed briefly to help set the scene. PMID:22665891

  10. Astrophysics teaching at Assam University, Silchar

    NASA Astrophysics Data System (ADS)

    Das, Himadri Sekhar

    The Department of Physics is established in 1996 and since, then, thirteen batches of students have completed their Master’s programmes in the subject. The Department introduced in the year 2001 Astrophysics as one special paper in PG level (in the second year). The syllabus of Astrophysics is designed to include courses from observational Astronomy to Theoretical Astrophysics and Cosmology. There are two theory papers (in third and fourth semesters), one practical paper (in third semester) and one project or dissertation paper (in fourth semester), each one carries 100 marks. The major instruments available in the department for carrying out the experimental work are Meade-16 inch telescope, Celestron-8 inch inches Telescope, Meade refracting telescopes (4 inches, 2 number), SSP-5, SSP-3 photometer, Sivo Fibre-fed Spectrometer, CCD (Meade 416 XT, ST-6), Goniometer, Limb darkening apparatus etc. The practical paper includes study of the variation of sunspots; measurement of the parallax of distant objects, on moon and on planets like Jupiter and Saturn, measurement of the magnitude of different stars, study of the light scattering properties of rough surfaces, analysis of the image by image processing software (IRAF) etc. The project papers are based on research oriented topics which covers latest trends in Astrophysics including solar system studies, Interstellar medium and star formation studies and some problems in gravito-optics. There are altogether 6 scholars who have been awarded PhD and 10 are registered for PhD in Astrophysics. Besides these, 8 scholars have been awarded M. Phil. in Astrophysics. The broad research area of Astrophysics includes light scattering properties of cosmic dust, star formation, gravito optics, polarization study of comets etc. The Astrophysics group is currently doing research in different fields and have very good publications in several peer reviewed journals of international status.

  11. Numerical Relativity and Astrophysics

    NASA Astrophysics Data System (ADS)

    Lehner, Luis; Pretorius, Frans

    2014-08-01

    Throughout the Universe many powerful events are driven by strong gravitational effects that require general relativity to fully describe them. These include compact binary mergers, black hole accretion, and stellar collapse, where velocities can approach the speed of light and extreme gravitational fields (ΦNewt/c2≃1) mediate the interactions. Many of these processes trigger emission across a broad range of the electromagnetic spectrum. Compact binaries further source strong gravitational wave emission that could directly be detected in the near future. This feat will open up a gravitational wave window into our Universe and revolutionize our understanding of it. Describing these phenomena requires general relativity, and—where dynamical effects strongly modify gravitational fields—the full Einstein equations coupled to matter sources. Numerical relativity is a field within general relativity concerned with studying such scenarios that cannot be accurately modeled via perturbative or analytical calculations. In this review, we examine results obtained within this discipline, with a focus on its impact in astrophysics.

  12. High Energy Astrophysics Mission

    NASA Technical Reports Server (NTRS)

    White, Nicholas E.; Ormes, Jonathan F. (Technical Monitor)

    2000-01-01

    The nature of gravity and its relationship to the other three forces and to quantum theory is one of the major challenges facing us as we begin the new century. In order to make progress we must challenge the current theories by observing the effects of gravity under the most extreme conditions possible. Black holes represent one extreme, where the laws of physics as we understand them break down. The Universe as whole is another extreme, where its evolution and fate is dominated by the gravitational influence of dark matter and the nature of the Cosmological constant. The early universe represents a third extreme, where it is thought that gravity may somehow be unified with the other forces. NASA's "Cosmic Journeys" program is part of a NASA/NSF/DoE tri-agency initiative designed to observe the extremes of gravity throughout the universe. This program will probe the nature of black holes, ultimately obtaining a direct image of the event horizon. It will investigate the large scale structure of the Universe to constrain the location and nature of dark matter and the nature of the cosmological constant. Finally it will search for and study the highest energy processes, that approach those found in the early universe. I will outline the High Energy Astrophysics part of this program.

  13. High Energy Astrophysics Mission

    NASA Technical Reports Server (NTRS)

    White, Nicholas E.; Ormes, Jonathan F. (Technical Monitor)

    2000-01-01

    The nature of gravity and its relationship to the other three forces and to quantum theory is one of the major challenges facing us as we begin the new century. In order to make progress we must challenge the current theories by observing the effects of gravity under the most extreme conditions possible. Black holes represent one extreme, where the laws of physics as we understand them break down. The Universe as whole is another extreme, where its evolution and fate is dominated by the gravitational influence of dark matter and the nature of the Cosmological constant. The early universe represents a third extreme, where it is thought that gravity may somehow be unified with the other forces. NASA's "Cosmic Journeys" program is part of a NASA/NSF/DoE tri-agency initiative designed to observe the extremes of gravity throughout the universe. This program will probe the nature of black holes, ultimately obtaining a direct image of the event horizon. It will investigate the large scale structure of the Universe to constrain the location and nature of dark matter and the nature of the cosmological constant. Finally it will search for and study the highest energy processes, that approach those found in the early universe. I will outline the High Energy Astrophysics part of this program.

  14. Nuclear morphometric analysis in gastrointestinal stromal tumors: a preliminary study.

    PubMed

    Ozdamar, Sükrü Oğuz; Bektaş, Sibel; Erdem Ozdamar, Sevim; Gedikoğlu, Gökhan; Doğan Gün, Banu; Bahadir, Burak

    2007-06-01

    Gastrointestinal stromal tumors are considered a specialized group of mesenchymal neoplasms. In this study, the histomorphologic and immunohistochemical features of gastrointestinal stromal tumors are compared with nuclear morphometric results. Morphometric nuclear parameters such as mean area, mean roundness factor, mean form ellipse, mean length and mean perimeter were evaluated in hematoxylin and eosin stained slides of 22 gastrointestinal stromal tumors (9 benign and 13 malignant) by using a computer-assisted image analysis system. Morphometric results were compared with tumor behavior and tumor size, the presence of necrosis, mitotic index, and immunohistochemical expressions of p53 and proliferating cell nuclear antigen. We found that tumor necrosis was correlated with mean nuclear roundness factor, mean nuclear form ellipse, mean nuclear length and mean nuclear perimeter (p<0.05). Mitotic index was also correlated with mean nuclear roundness factor and mean nuclear form ellipse (p<0.05). However, no correlation was found between morphometric features and gastrointestinal stromal tumor behavior, tumor size, or index of proliferating cell nuclear antigen and p53 expressions (p>0.05). In this preliminary study, the relative concordance of the morphometric results and general histomorphologic data exhibited the importance of nuclear morphometric analysis in gastrointestinal stromal tumors. Studies including larger series of cases investigating detailed nuclear morphometric analysis of gastrointestinal stromal tumors are needed.

  15. Houdini for Astrophysical Visualization

    NASA Astrophysics Data System (ADS)

    Naiman, J. P.; Borkiewicz, Kalina; Christensen, A. J.

    2017-05-01

    The rapid growth in scale and complexity of both computational and observational astrophysics over the past decade necessitates efficient and intuitive methods for examining and visualizing large data sets. Here, we discuss some newly developed tools used to import and manipulate astrophysical data into the three-dimensional visual effects software, Houdini. This software is widely used by visual effects artists, but a recently implemented Python API now allows astronomers to more easily use Houdini as a visualization tool. This paper includes a description of features, workflow, and various example visualizations. The project website, www.ytini.com, is aimed at a scientific audience and contains Houdini tutorials and links to the Python script Bitbucket repository to simplify the process of importing and rendering astrophysical data.

  16. B1:. Relativistic Astrophysics

    NASA Astrophysics Data System (ADS)

    Friedman, John L.

    2002-09-01

    This review summarizes the parallel session on relativistic astrophysics at GR16. Much of the work reported here involved the structure and stability of neutron stars and the astrophysics of accretion disks around neutron stars and black holes. A large part of the recent work in relativistic astrophysics is tied to numerical investigations of binary coalescence and gravitational waves, but these topics demanded sessions of their own; gravitational waves in the present session were mentioned in connection with neutron-star instability and in a talk on coupling of gravitational waves to radio waves. Two talks involved relativistic stellar systems and cosmology. Finally, several authors outlined advances involving gravitational collapse, cosmic censorship, and baby universes.

  17. Astrophysics with Microarcsecond Accuracy Astrometry

    NASA Technical Reports Server (NTRS)

    Unwin, Stephen C.

    2008-01-01

    Space-based astrometry promises to provide a powerful new tool for astrophysics. At a precision level of a few microarcsonds, a wide range of phenomena are opened up for study. In this paper we discuss the capabilities of the SIM Lite mission, the first space-based long-baseline optical interferometer, which will deliver parallaxes to 4 microarcsec. A companion paper in this volume will cover the development and operation of this instrument. At the level that SIM Lite will reach, better than 1 microarcsec in a single measurement, planets as small as one Earth can be detected around many dozen of the nearest stars. Not only can planet masses be definitely measured, but also the full orbital parameters determined, allowing study of system stability in multiple planet systems. This capability to survey our nearby stellar neighbors for terrestrial planets will be a unique contribution to our understanding of the local universe. SIM Lite will be able to tackle a wide range of interesting problems in stellar and Galactic astrophysics. By tracing the motions of stars in dwarf spheroidal galaxies orbiting our Milky Way, SIM Lite will probe the shape of the galactic potential history of the formation of the galaxy, and the nature of dark matter. Because it is flexibly scheduled, the instrument can dwell on faint targets, maintaining its full accuracy on objects as faint as V=19. This paper is a brief survey of the diverse problems in modern astrophysics that SIM Lite will be able to address.

  18. Topics in Particle Astrophysics

    NASA Astrophysics Data System (ADS)

    Falk, Toby David

    1994-01-01

    This dissertation consists of a study of two topics in particle astrophysics. In Part I, we examine the generation of microwave background radiation fluctuations due to an inflationary epoch in the early universe. In Chapter 1, we study the angular dependence of the three-point correlation function of microwave background fluctuations. We use the standard techniques of field theory in curved spacetime to compute, up to an overall constant, the three-point function of the inflaton field varphi and relate this to the three-point function of microwave background temperature fluctuations. In Chapter 2, we study the dependence of the size of the fluctuations on the coupling constant lambda in the inflaton potential, and in particular we show that some claims in the literature that upper bounds on the size of the fluctuations do not put an upper bound on lambda are false. In Part II, we calculate the relic density of two supersymmetric particles with an eye to studying their viability as dark matter candidates. In Chapters 3 and 4, we compute corrections to the annihilation rate for binos (B) due to sfermion mixing (Chapter 3) and some loop effects (Chapter 4). We find that the effect of sfermion mixing may be large, both on the relic density of binos and their present annihilation cross-section, which affects their prospects for detection. The effect of the loop graphs we calculate is generically small, but can be large for bino masses near half the Z mass. In Chapter 5, we do a thorough calculation of the relic density of massive (_sp{~}>500 GeV) sneutrinos (~nu). We find that the relic density may lie in the cosmologically interesting region 0.1 _sp{~ }< Omega h^2 _sp{~}< 1.0 for sneutrino masses between 1 TeV and 4 TeV. Direct detection experiments require m _{~nu} _sp{~}< 2200 GeV and Omega_{~nu }h^2 _sp{~ }< 0.4.

  19. Neutron Capture Reactions on Fe and Ni Isotopes for the Astrophysical s-process

    SciTech Connect

    Lederer, C.; Giubrone, G.; Massimi, C.; Žugec, P.; Barbagallo, M.; Colonna, N.; Domingo-Pardo, C.; Guerrero, C.; Gunsing, F.; Käppeler, F.; Tain, J.L.; Altstadt, S.; Andrzejewski, J.; Audouin, L.; Bečvář, F.; and others

    2014-06-15

    Neutron capture cross sections in the keV neutron energy region are the key nuclear physics input to study the astrophysical slow neutron capture process. In the past years, a series of neutron capture cross section measurements has been performed at the neutron time-of-flight facility n{sub T}OF at CERN focussing on the Fe/Ni mass region. Recent results and future developments in the neutron time-of-flight technique are discussed.

  20. The NASA Astrophysics Program

    NASA Technical Reports Server (NTRS)

    Zebulum, Ricardo S.

    2011-01-01

    NASA's scientists are enjoying unprecedented access to astronomy data from space, both from missions launched and operated only by NASA, as well as missions led by other space agencies to which NASA contributed instruments or technology. This paper describes the NASA astrophysics program for the next decade, including NASA's response to the ASTRO2010 Decadal Survey.

  1. The NASA Astrophysics Program

    NASA Technical Reports Server (NTRS)

    Zebulum, Ricardo S.

    2011-01-01

    NASA's scientists are enjoying unprecedented access to astronomy data from space, both from missions launched and operated only by NASA, as well as missions led by other space agencies to which NASA contributed instruments or technology. This paper describes the NASA astrophysics program for the next decade, including NASA's response to the ASTRO2010 Decadal Survey.

  2. Augmented Reality in astrophysics

    NASA Astrophysics Data System (ADS)

    Vogt, Frédéric P. A.; Shingles, Luke J.

    2013-09-01

    Augmented Reality consists of merging live images with virtual layers of information. The rapid growth in the popularity of smartphones and tablets over recent years has provided a large base of potential users of Augmented Reality technology, and virtual layers of information can now be attached to a wide variety of physical objects. In this article, we explore the potential of Augmented Reality for astrophysical research with two distinct experiments: (1) Augmented Posters and (2) Augmented Articles. We demonstrate that the emerging technology of Augmented Reality can already be used and implemented without expert knowledge using currently available apps. Our experiments highlight the potential of Augmented Reality to improve the communication of scientific results in the field of astrophysics. We also present feedback gathered from the Australian astrophysics community that reveals evidence of some interest in this technology by astronomers who experimented with Augmented Posters. In addition, we discuss possible future trends for Augmented Reality applications in astrophysics, and explore the current limitations associated with the technology. This Augmented Article, the first of its kind, is designed to allow the reader to directly experiment with this technology.

  3. Gamma-ray astrophysics

    NASA Technical Reports Server (NTRS)

    Stecker, F. W. (Editor); Trombka, J. I. (Editor)

    1973-01-01

    Conference papers on gamma ray astrophysics are summarized. Data cover the energy region from about 0.3 MeV to a few hundred GeV and theoretical models of production mechanisms that give rise to both galactic and extragalactic gamma rays.

  4. The Astrophysics Data System

    NASA Astrophysics Data System (ADS)

    Eichhorn, Guenther; Accomazzi, Alberto; Kurtz, Michael J.; Grant, Carolyn S.

    The NASA Astrophysics Data System has been very successful in providing the researcher and librarian the capability to effectively search the astronomical and space science literature from their desktop. It currently provides access to four searchable databases of scientific bibliographic references and a large archive of full-text documents which includes all the major astronomical journals.

  5. Astrophysics at n_TOF Facility at CERN

    NASA Astrophysics Data System (ADS)

    Tagliente, G.; Abbondanno, U.; Aerts, G.; Alvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Audouin, L.; Badurek, G.; Baumann, P.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Bisterzo, S.; Calviño, F.; Calviani, M.; Cano-Ott, D.; Capote, R.; Carrapiço, C.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillman, I.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrari, A.; Ferreira-Marques, R.; Fujii, K.; Furman, W.; Gallino, R.; Goncalves, I.; Gonzalez-Romero, E.; Gramegna, F.; Guerrero, C.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Jericha, E.; Käppeler, F.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Koehler, P.; Kossionides, E.; Krtička, M.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marrone, S.; Martinez, T.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P. M.; Mosconi, M.; Neves, F.; Oberhummer, H.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Pigni, M. T.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Praena, J.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wendler, H.; Wiescher, M.; Wisshak, K.

    2011-09-01

    The neutron time of flight (n_TOF) facility at CERN is a spallation neutron source with white neutron energy spectrum (from thermal to several GeV), covering the full energy range of interest for nuclear astrophysics, in particular for measurements of the neutron capture cross section required in s-process nucleosynthesis. This contribution presents an overview on the astrophysical program carried on at the n_TOF facility, the main results and their implications.

  6. Computational astrophysics: Pulsating stars

    NASA Astrophysics Data System (ADS)

    Davis, C. G.

    The field of computational astrophysics in pulsating star studies has grown considerably since the advent of the computer. Initially calculations were done on the IBM 704 with 32K of memory and now we use the CRAY YMP computers with considerably more memory. Our early studies were for models of pulsating stars using a 1D Lagrangian hydrodynamic code (SPEC) with radiation diffusion. The radiative transfer was treated in the equilibrium diffusion approximation and the hydrodynamics was done utilizing the approximation of artificial viscosity. The early calculations took many hours of 704 CPU time. Early in 1965 we decided to improve on the usual treatment of the radiative transfer used in our codes by utilizing the method of moments, the so-called variable Eddington approximation. In this approximation the material energy field is uncoupled from the radiation energy field and the angular dependence is introduced through the Eddington factor. A multigroup frequency dependent method may also be applied. The Eddington factor is determined by snapshots of the stars structure utilizing a y-line approximation. The full radiative transfer approximation appears necessary in order to understand the light curves for W Virginia stars and may be important for the light curves of RR Lyrae stars. A detailed radiative transfer method does not appear to be necessary for the understanding of Cepheid light curves. A recent improvement to our models for pulsating stars is in the use of an adaptive mesh scheme to resolve the sharp features in the nonlinear hydrodynamic structure. From these improved structures, better analysis of the radius, velocity, and light curves could be obtained.

  7. Magnetized Astrophysical Flows

    NASA Astrophysics Data System (ADS)

    Russo, Matthew

    2016-08-01

    This thesis combines two studies of astrophysical flows in which magnetic fields play a dominant role. The first concerns outflows from compact objects in which plasma is accelerated to highly relativistic speeds by strong, ordered magnetic fields. We generalize the theory of relativistic, ideal magnetohydrodynamic (MHD) outflows by including an intense radiation source as is likely to occur in gamma-ray bursts (GRBs). This represents a hybrid of the traditional fireball and electromagnetic models of GRBs, which posit respectively that the acceleration is accomplished by thermal pressure or magnetic stresses. We find that acceleration is more efficient and occurs over a larger range of radii than in a pure Poynting jet. We also uncover a distinct observational signature in the emitted spectrum when the Poynting flux exceeds the radiation energy flux due to the Compton up-scattering of photons within the relativistic flow. We then turn to study the accretion of magnetized protoplanetary disks (PPDs) in which the assumptions of ideal MHD begin to break down due to the low level of ionization. We develop a novel model that prescribes the profiles of the magnetic field and mass flux in PPDs by tying them to the field of a magnetized, radial protostellar wind. We find that the inner disk is more strongly magnetized and thus supports a higher accretion rate by both large scale stresses and turbulence driven by the magnetorotational instability (MRI). This leads to an inside-out clearing of the inner disk that stalls at a low column density when particles are lofted from the midplane to higher altitudes where they suppress MRI turbulence. We calculate the long-term evolution of such a disk and show that the migration of planets is significantly slowed (or reversed), perhaps alleviating one of the central problems concerning the formation of planetary systems.

  8. Distance Measurement Solves Astrophysical Mysteries

    NASA Astrophysics Data System (ADS)

    2003-08-01

    distance. "Our measurements showed that the pulsar is about 950 light-years from Earth, essentially the same distance as the supernova remnant," said Steve Thorsett, of the University of California, Santa Cruz. "That means that the two almost certainly were created by the same supernova blast," he added. With that problem solved. the astronomers then turned to studying the pulsar's neutron star itself. Using a variety of data from different telescopes and armed with the new distance measurement, they determined that the neutron star is between 16 and 25 miles in diameter. In such a small size, it packs a mass roughly equal to that of the Sun. The next result of learning the pulsar's actual distance was to provide a possible answer to a longstanding question about cosmic rays. Cosmic rays are subatomic particles or atomic nuclei accelerated to nearly the speed of light. Shock waves in supernova remnants are thought to be responsible for accelerating many of these particles. Scientists can measure the energy of cosmic rays, and had noted an excess of such rays in a specific energy range. Some researchers had suggested that the excess could come from a single supernova remnant about 1000 light-years away whose supernova explosion was about 100,000 years ago. The principal difficulty with this suggestion was that there was no accepted candidate for such a source. "Our measurement now puts PSR B0656+14 and the Monogem Ring at exactly the right place and at exactly the right age to be the source of this excess of cosmic rays," Brisken said. With the ability of the VLBA, one of the telescopes of the NRAO, to make extremely precise position measurements, the astronomers expect to improve the accuracy of their distance determination even more. "This pulsar is becoming a fascinating laboratory for studying astrophysics and nuclear physics," Thorsett said. In addition to Brisken and Thorsett, the team of astronomers includes Aaron Golden of the National University of Ireland, Robert

  9. Chaos and Complexity in Astrophysics

    NASA Astrophysics Data System (ADS)

    Regev, Oded

    2006-03-01

    Part I. Dynamical Systems - General: 1. Introduction to Part I; 2. Astrophysical examples; 3. Mathematical properties of dynamical systems; 4. Properties of chaotic dynamics; 5. Analysis of time series; 6. Regular and irregular motion in Hamiltonian systems; 7. Extended systems - instabilities and patterns; Part II. Astrophysical Applications: 8. Introduction to Part II; 9. Planetary, stellar and galactic dynamics; 10. Irregularly variable astronomical point sources; 11. Complex spatial patterns in astrophysics; 12. Topics in astrophysical fluid dynamics; References; Index.

  10. Questioning nuclear waste substitution: a case study.

    PubMed

    Marshall, Alan

    2007-03-01

    This article looks at the ethical quandaries, and their social and political context, which emerge as a result of international nuclear waste substitution. In particular it addresses the dilemmas inherent within the proposed return of nuclear waste owned by Japanese nuclear companies and currently stored in the United Kingdom. The UK company responsible for this waste, British Nuclear Fuels Limited (BNFL), wish to substitute this high volume intermediate-level Japanese-owned radioactive waste for a much lower volume of much more highly radioactive waste. Special focus is given to ethical problems that they, and the UK government, have not wished to address as they move forward with waste substitution. The conclusion is that waste substitution can only be considered an ethical practice if a set of moderating conditions are observed by all parties. These conditions are listed and, as of yet, they are not being observed.

  11. Progress report on nuclear spectroscopic studies

    SciTech Connect

    Bingham, C.R.; Riedinger, L.L.; Sorensen, S.P.

    1996-01-16

    The experimental program in nuclear physics at the University of Tennessee, Knoxville, is led by Professors Carrol Bingham, Lee Riedinger, and Soren Sorenseni who respectively lead the studies of the exotic decay modes of nuclei far from stability, the program of high-spin research, and our effort in relativistic heavy-ion physics. Over the years, this broad program of research has been successful partially because of the shared University resources applied to this group effort. The proximity of the Oak Ridge National Laboratory has allowed us to build extremely strong programs of joint research, and in addition to play an important leadership role in the Joint Institute for Heavy Ion Research (JIHIR). Our experimental program is also very closely linked with those at other national laboratories: Argonne (collaborations involving the Fragment Mass Analyzer (FMA) and {gamma}-ray arrays), Brookhaven (the RHIC and Phenix projects), and Berkeley (GAMMASPHERE). We have worked closely with a variety of university groups in the last three years, especially those in the UNISOR and now UNIRIB collaborations. And, in all aspects of our program, we have maintained close collaborations with theorists, both to inspire the most exciting experiments to perform and to extract the pertinent physics from the results. The specific areas discussed in this report are: properties of high-spin states; study of low-energy levels of nuclei far from stability; and high energy heavy-ion physics.

  12. Nuclear fragmentation studies for microelectronic application

    NASA Technical Reports Server (NTRS)

    Ngo, Duc M.; Wilson, John W.; Buck, Warren W.; Fogarty, Thomas N.

    1989-01-01

    A formalism for target fragment transport is presented with application to energy loss spectra in thin silicon devices. Predicted results are compared to experiments with the surface barrier detectors of McNulty et al. The intranuclear cascade nuclear reaction model does not predict the McNulty experimental data for the highest energy events. A semiempirical nuclear cross section gives an adequate explanation of McNulty's experiments. Application of the formalism to specific electronic devices is discussed.

  13. Experimental Studies of Nuclear Physics Input for γ -Process Nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Scholz, Philipp; Heim, Felix; Mayer, Jan; Netterdon, Lars; Zilges, Andreas

    The predictions of reaction rates for the γ process in the scope of the Hauser-Feshbach statistical model crucially depend on nuclear physics input-parameters as optical-model potentials (OMP) or γ -ray strength functions. Precise cross-section measurements at astrophysically relevant energies help to constrain adopted models and, therefore, to reduce the uncertainties in the theoretically predicted reaction rates. During the last years, several cross-sections of charged-particle induced reactions on heavy nuclei have been measured at the University of Cologne. Either by means of the in-beam method at the HORUS γ -ray spectrometer or the activation technique using the Cologne Clover Counting Setup, total and partial cross-sections could be used to further constrain different models for nuclear physics input-parameters. It could be shown that modifications on the α -OMP in the case of the 112Sn(α , γ ) reaction also improve the description of the recently measured cross sections of the 108Cd(α , γ ) and 108Cd(α , n) reaction and other reactions as well. Partial cross-sections of the 92Mo(p, γ ) reaction were used to improve the γ -strength function model in 93Tc in the same way as it was done for the 89Y(p, γ ) reaction.

  14. Sensitivity of (d, p) Reactions to High n-p Momenta and the Consequences for Nuclear Spectroscopy Studies.

    PubMed

    Bailey, G W; Timofeyuk, N K; Tostevin, J A

    2016-10-14

    Theoretical models of low-energy (d, p) single-neutron transfer reactions are a crucial link between experimentation, nuclear structure, and nuclear astrophysical studies. Whereas reaction models that use local optical potentials are insensitive to short-range physics in the deuteron, we show that including the inherent nonlocality of the nucleon-target interactions and realistic deuteron wave functions generates significant sensitivity to high n-p relative momenta and to the underlying nucleon-nucleon interaction. We quantify this effect upon the deuteron channel distorting potentials within the framework of the adiabatic deuteron breakup model. The implications for calculated (d, p) cross sections and spectroscopic information deduced from experiments are discussed.

  15. Studying the Sun's Nuclear Furnace with a Neutrino Detector Spacecraft in Close Solar Orbit

    NASA Astrophysics Data System (ADS)

    Solomey, Nickolas

    2016-05-01

    A neutrino based detector in close solar orbit would have a neutrino flux 10,000x or more larger flux than on Earth and a smaller detector able to handle high rates with exception energy resolution could be used. We have studied the idea of operating such an experiment in close solar orbits that takes it off the ecliptic plane and in a solar orbit where the distance from the Sun will change distance. This neutrino detector on a space craft could do Solar Astrophysics studying the Solar nuclear furnace, basic nuclear physics and elementary particle physics; some of these ideas are new unique science that can only be preformed from a spacecraft. The harsh environment provides many challenges but if such a detector could be made to work it can be the next major step in this science study. How a small segmented detector can operate and preform in this environment to detect solar neutrinos will be elaborated upon using a combination of signal strength, fast signal timing, shielding and segmentation.

  16. Computer simulation of astrophysical plasmas

    NASA Technical Reports Server (NTRS)

    Max, Claire E.

    1991-01-01

    The role of sophisticated numerical models and simulations in the field of plasma astrophysics is discussed. The need for an iteration between microphysics and macrophysics in order for astrophysical plasma physics to produce quantitative results that can be related to astronomical data is stressed. A discussion on computational requirements for simulations of astrophysical plasmas contrasts microscopic plasma simulations with macroscopic system models. An overview of particle-in-cell simulations (PICS) is given and two examples of PICS of astrophysical plasma are discussed including particle acceleration by collisionless shocks in relativistic plasmas and magnetic field reconnection in astrophysical plasmas.

  17. Transportation capabilities study of DOE-owned spent nuclear fuel

    SciTech Connect

    Clark, G.L.; Johnson, R.A.; Smith, R.W.; Abbott, D.G.; Tyacke, M.J.

    1994-10-01

    This study evaluates current capabilities for transporting spent nuclear fuel owned by the US Department of Energy. Currently licensed irradiated fuel shipping packages that have the potential for shipping the spent nuclear fuel are identified and then matched against the various spent nuclear fuel types. Also included are the results of a limited investigation into other certified packages and new packages currently under development. This study is intended to support top-level planning for the disposition of the Department of Energy`s spent nuclear fuel inventory.

  18. Computational astrophysical fluid dynamics

    NASA Technical Reports Server (NTRS)

    Norman, Michael L.; Clarke, David A.; Stone, James M.

    1991-01-01

    The field of astrophysical fluid dynamics (AFD) is described as an emerging discipline which derives historically from both the theory of stellar evolution and space plasma physics. The fundamental physical assumption behind AFD is that fluid equations of motion accurately describe the evolution of plasmas on scales that are large in comparison with particle interaction length scales. Particular attention is given to purely fluid models of large-scale astrophysical plasmas. The role of computer simulation in AFD research is also highlighted and a suite of general-purpose application codes for AFD research is discussed. The codes are called ZEUS-2D and ZEUS-3D and solve the equations of AFD in two and three dimensions, respectively, in several coordinate geometries for general initial and boundary conditions. The topics of bipolar outflows from protostars, galactic superbubbles and supershells, and extragalactic radio sources are addressed.

  19. Extreme Scale Computational Astrophysics

    NASA Astrophysics Data System (ADS)

    Shoemaker, Deirdre

    2009-11-01

    We live in extraordinary times. With increasingly sophisticated observatories opening up new vistas on the universe, astrophysics is becoming more complex and data-driven. The success in understanding astrophysical systems that are inherently multi-physical, nonlinear systems demands realism in our models of the phenomena. We cannot hope to advance the realism of these models to match the expected sophistication of future observations without extreme-scale computation. Just one example is the advent of gravitational wave astronomy. Detectors like LIGO are about to make the first ever detection of gravitational waves. The gravitational waves are produced during violent events such as the merger of two black holes. The detection of these waves or ripples in the fabric of spacetime is a formidable undertaking, requiring innovative engineering, powerful data analysis tools and careful theoretical modeling. I will discuss the computational and theoretical challenges ahead in our new understanding of physics and astronomy where gravity exhibits its strongest grip on our spacetime.

  20. Astrophysical terms in Armenian

    NASA Astrophysics Data System (ADS)

    Yeghikian, A. G.

    2015-07-01

    There are quite a few astrophysical textbooks (to say nothing about monographs) in Armenian, which are, however out of date and miss all the modern terms concerning space sciences. Many terms have been earlier adopted from English and, especially, from Russian. On the other hand, teachers and lecturers in Armenia need scientific terms in Armenian adequately reproducing either their means when translating from other languages or (why not) creating new ones. In short, a permanently updated astrophysical glossary is needed to serve as explanation of such terms. I am not going here to present the ready-made glossary (which should be a task for a joint efforts of many professionals) but instead just would like to describe some ambiguous examples with comments where possible coming from my long-year teaching, lecturing and professional experience. A probable connection between "iron" in Armenian as concerned to its origin is also discussed.