Important plasma problems in astrophysics

International Nuclear Information System (INIS)

Kulsrud, R.M.

1995-01-01

In astrophysics, plasmas occur under very extreme conditions. For example, there are ultrastrong magnetic fields in neutron stars, relativistic plasmas around black holes and in jets, extremely energetic particles such as cosmic rays in the interstellar medium, extremely dense plasmas in accretion disks, and extremely large magnetic Reynolds numbers in the interstellar medium. These extreme limits for astrophysical plasmas make plasma phenomena much simpler to analyze in astrophysics than in the laboratory. An understanding of such phenomena often results in an interesting way, by simply taking the extreme limiting case of a known plasma theory. The author will describe one of the more exciting examples and will attempt to convey the excitement he felt when he was first exposed to it. However, not all plasma astrophysical phenomena are so simple. There are certain important plasma phenomena in astrophysics that have not been so easily resolved. In fact, a resolution of them is blocking significant progress in astrophysical research. They have not yet yielded to attacks by theoretical astrophysicists nor to extensive numerical simulation. The author will attempt to describe one of the more important of these plasma--astrophysical problems, and discuss why its resolution is so important to astrophysics. This significant example is fast, magnetic reconnection. Another significant example is the large-magnetic-Reynolds number magnetohydrodynamics (MHD) dynamos

Parametric instabilities in shallow water magnetohydrodynamics of astrophysical plasma in external magnetic field

Energy Technology Data Exchange (ETDEWEB)

Klimachkov, D.A., E-mail: klimachkovdmitry@gmail.com [Space Research Institute of Russian Academy of Science, 84/32, Profsoyuznaya str., Moscow, 117997 (Russian Federation); Petrosyan, A.S. [Space Research Institute of Russian Academy of Science, 84/32, Profsoyuznaya str., Moscow, 117997 (Russian Federation); Moscow Institute of Physics and Technology (State University), 9 Institutskyi per., Dolgoprudny, Moscow Region, 141700 (Russian Federation)

2017-01-15

This article deals with magnetohydrodynamic (MHD) flows of a thin rotating layer of astrophysical plasma in external magnetic field. We use the shallow water approximation to describe thin rotating plasma layer with a free surface in a vertical external magnetic field. The MHD shallow water equations with external vertical magnetic field are revised by supplementing them with the equations that are consequences of the magnetic field divergence-free conditions and reveal the existence of third component of the magnetic field in such approximation providing its relation with the horizontal magnetic field. It is shown that the presence of a vertical magnetic field significantly changes the dynamics of the wave processes in astrophysical plasma compared to the neutral fluid and plasma layer in a toroidal magnetic field. The equations for the nonlinear wave packets interactions are derived using the asymptotic multiscale method. The equations for three magneto-Poincare waves interactions, for three magnetostrophic waves interactions, for the interactions of two magneto-Poincare waves and for one magnetostrophic wave and two magnetostrophic wave and one magneto-Poincare wave interactions are obtained. The existence of parametric decay and parametric amplifications is predicted. We found following four types of parametric decay instabilities: magneto-Poincare wave decays into two magneto-Poincare waves, magnetostrophic wave decays into two magnetostrophic waves, magneto-Poincare wave decays into one magneto-Poincare wave and one magnetostrophic wave, magnetostrophic wave decays into one magnetostrophic wave and one magneto-Poincare wave. Following mechanisms of parametric amplifications are found: parametric amplification of magneto-Poincare waves, parametric amplification of magnetostrophic waves, magneto-Poincare wave amplification in magnetostrophic wave presence and magnetostrophic wave amplification in magneto-Poincare wave presence. The instabilities growth rates

Laboratory Astrophysics Prize: Laboratory Astrophysics with Nuclei

Science.gov (United States)

Wiescher, Michael

2018-06-01

Nuclear astrophysics is concerned with nuclear reaction and decay processes from the Big Bang to the present star generation controlling the chemical evolution of our universe. Such nuclear reactions maintain stellar life, determine stellar evolution, and finally drive stellar explosion in the circle of stellar life. Laboratory nuclear astrophysics seeks to simulate and understand the underlying processes using a broad portfolio of nuclear instrumentation, from reactor to accelerator from stable to radioactive beams to map the broad spectrum of nucleosynthesis processes. This talk focuses on only two aspects of the broad field, the need of deep underground accelerator facilities in cosmic ray free environments in order to understand the nucleosynthesis in stars, and the need for high intensity radioactive beam facilities to recreate the conditions found in stellar explosions. Both concepts represent the two main frontiers of the field, which are being pursued in the US with the CASPAR accelerator at the Sanford Underground Research Facility in South Dakota and the FRIB facility at Michigan State University.

Astrophysics at RIA (ARIA) Working Group

International Nuclear Information System (INIS)

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

2006-01-01

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

Model of magnetic reconnection in space and astrophysical plasmas

Energy Technology Data Exchange (ETDEWEB)

Boozer, Allen H. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)

2013-03-15

Maxwell's equations imply that exponentially smaller non-ideal effects than commonly assumed can give rapid magnetic reconnection in space and astrophysical plasmas. In an ideal evolution, magnetic field lines act as stretchable strings, which can become ever more entangled but cannot be cut. High entanglement makes the lines exponentially sensitive to small non-ideal changes in the magnetic field. The cause is well known in popular culture as the butterfly effect and in the theory of deterministic dynamical systems as a sensitive dependence on initial conditions, but the importance to magnetic reconnection is not generally recognized. Two-coordinate models are too constrained geometrically for the required entanglement, but otherwise the effect is general and can be studied in simple models. A simple model is introduced, which is periodic in the x and y Cartesian coordinates and bounded by perfectly conducting planes in z. Starting from a constant magnetic field in the z direction, reconnection is driven by a spatially smooth, bounded force. The model is complete and could be used to study the impulsive transfer of energy between the magnetic field and the ions and electrons using a kinetic plasma model.

Model of magnetic reconnection in space and astrophysical plasmas

International Nuclear Information System (INIS)

Boozer, Allen H.

2013-01-01

Maxwell's equations imply that exponentially smaller non-ideal effects than commonly assumed can give rapid magnetic reconnection in space and astrophysical plasmas. In an ideal evolution, magnetic field lines act as stretchable strings, which can become ever more entangled but cannot be cut. High entanglement makes the lines exponentially sensitive to small non-ideal changes in the magnetic field. The cause is well known in popular culture as the butterfly effect and in the theory of deterministic dynamical systems as a sensitive dependence on initial conditions, but the importance to magnetic reconnection is not generally recognized. Two-coordinate models are too constrained geometrically for the required entanglement, but otherwise the effect is general and can be studied in simple models. A simple model is introduced, which is periodic in the x and y Cartesian coordinates and bounded by perfectly conducting planes in z. Starting from a constant magnetic field in the z direction, reconnection is driven by a spatially smooth, bounded force. The model is complete and could be used to study the impulsive transfer of energy between the magnetic field and the ions and electrons using a kinetic plasma model.

Nuclear astrophysics at the Holifield Radioactive Ion Beam Facility

International Nuclear Information System (INIS)

Smith, M.S.

1994-01-01

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, γ) 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

UNDERSTANDING THE GEOMETRY OF ASTROPHYSICAL MAGNETIC FIELDS

Energy Technology Data Exchange (ETDEWEB)

Broderick, Avery E [Canadian Institute for Theoretical Astrophysics, 60 St. George St., Toronto, ON M5S 3H8 (Canada); Blandford, Roger D., E-mail: aeb@cita.utoronto.c [Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Rd., Menlo Park, CA 94309 (United States)

2010-08-01

Faraday rotation measurements have provided an invaluable technique for probing the properties of astrophysical magnetized plasmas. Unfortunately, typical observations provide information only about the density-weighted average of the magnetic field component parallel to the line of sight. As a result, the magnetic field geometry along the line of sight, and in many cases even the location of the rotating material, is poorly constrained. Frequently, interpretations of Faraday rotation observations are dependent upon underlying models of the magnetic field being probed (e.g., uniform, turbulent, equipartition). However, we show that at sufficiently low frequencies, specifically below roughly 13(RM/1 rad m{sup -2}){sup 1/4}(B/1 G){sup 1/2} MHz, the character of Faraday rotation changes, entering what we term the 'super-adiabatic regime' in which the rotation measure (RM) is proportional to the integrated absolute value of the line-of-sight component of the field. As a consequence, comparing RMs at high frequencies with those in this new regime provides direct information about the geometry of the magnetic field along the line of sight. Furthermore, the frequency defining the transition to this new regime, {nu}{sub SA}, depends directly upon the local electron density and magnetic field strength where the magnetic field is perpendicular to the line of sight, allowing the unambiguous distinction between Faraday rotation within and in front of the emission region. Typical values of {nu}{sub SA} range from 10 kHz (below the ionospheric cutoff, but above the heliospheric cutoff) to 10 GHz, depending upon the details of the Faraday rotating environment. In particular, for resolved active galactic nuclei, including the black holes at the center of the Milky Way (Sgr A*) and M81, {nu}{sub SA} ranges from roughly 10 MHz to 10 GHz, and thus can be probed via existing and up-coming ground-based radio observatories.

UNDERSTANDING THE GEOMETRY OF ASTROPHYSICAL MAGNETIC FIELDS

International Nuclear Information System (INIS)

Broderick, Avery E.; Blandford, Roger D.

2010-01-01

Faraday rotation measurements have provided an invaluable technique for probing the properties of astrophysical magnetized plasmas. Unfortunately, typical observations provide information only about the density-weighted average of the magnetic field component parallel to the line of sight. As a result, the magnetic field geometry along the line of sight, and in many cases even the location of the rotating material, is poorly constrained. Frequently, interpretations of Faraday rotation observations are dependent upon underlying models of the magnetic field being probed (e.g., uniform, turbulent, equipartition). However, we show that at sufficiently low frequencies, specifically below roughly 13(RM/1 rad m -2 ) 1/4 (B/1 G) 1/2 MHz, the character of Faraday rotation changes, entering what we term the 'super-adiabatic regime' in which the rotation measure (RM) is proportional to the integrated absolute value of the line-of-sight component of the field. As a consequence, comparing RMs at high frequencies with those in this new regime provides direct information about the geometry of the magnetic field along the line of sight. Furthermore, the frequency defining the transition to this new regime, ν SA , depends directly upon the local electron density and magnetic field strength where the magnetic field is perpendicular to the line of sight, allowing the unambiguous distinction between Faraday rotation within and in front of the emission region. Typical values of ν SA range from 10 kHz (below the ionospheric cutoff, but above the heliospheric cutoff) to 10 GHz, depending upon the details of the Faraday rotating environment. In particular, for resolved active galactic nuclei, including the black holes at the center of the Milky Way (Sgr A*) and M81, ν SA ranges from roughly 10 MHz to 10 GHz, and thus can be probed via existing and up-coming ground-based radio observatories.

The Future of Gamma Ray Astrophysics

CERN Multimedia

CERN. Geneva

2016-01-01

Over the past decade, gamma ray astrophysics has entered the astrophysical mainstream. Extremely successful space-borne (GeV) and ground-based (TeV) detectors, combined with a multitude of partner telescopes, have revealed a fascinating “astroscape" of active galactic nuclei, pulsars, gamma ray bursts, supernova remnants, binary stars, star-forming galaxies, novae much more, exhibiting major pathways along which large energy releases can flow. From  a basic physics perspective, exquisitely sensitive measurements have constrained the nature of dark matter, the cosmological origin of magnetic field and the properties of black holes. These advances have motivated the development of new facilities, including HAWC, DAMPE, CTA and SVOM, which will further our understanding of the high energy universe. Topics that will receive special attention include merging neutron star binaries, clusters of galaxies, galactic cosmic rays and putative, TeV dark matter.

Final Technical Report: Magnetic Reconnection in High-Energy Laser-Produced Plasmas

Energy Technology Data Exchange (ETDEWEB)

Germaschewski, Kai [Univ. of New Hampshire, Durham, NH (United States); Fox, William [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Bhattacharjee, Amitava [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

2017-04-06

This report describes the final results from the DOE Grant DE-SC0007168, “Fast Magnetic Reconnection in HED Laser-Produced Plasmas.” The recent generation of laboratory high-energy-density physics facilities has opened significant physics opportunities for experimentally modeling astrophysical plasmas. The goal of this proposal is to use these new tools to study fundamental problems in plasma physics and plasma astrophysics. Fundamental topics in this area involve study of the generation, amplification, and fate of magnetic fields, which are observed to pervade the plasma universe and govern its evolution. This project combined experiments at DOE laser facilities with kinetic plasma simulation to study these processes. The primary original goal of the project was to study magnetic reconnection using a new experimental platform, colliding magnetized laser-produced plasmas. However through a series of fortuitous discoveries, the work broadened out to allow significant advancement on multiple topics in laboratory astrophysics, including magnetic reconnection, Weibel instability, and collisionless shocks.

Safety of magnetic fusion facilities: Guidance

International Nuclear Information System (INIS)

1996-05-01

This document provides guidance for the implementation of the requirements identified in DOE-STD-6002-96, Safety of Magnetic Fusion Facilities: Requirements. This guidance is intended for the managers, designers, operators, and other personnel with safety responsibilities for facilities designated as magnetic fusion facilities. While the requirements in DOE-STD-6002-96 are generally applicable to a wide range of fusion facilities, this Standard, DOE-STD-6003-96, is concerned mainly with the implementation of those requirements in large facilities such as the International Thermonuclear Experimental Reactor (ITER). Using a risk-based prioritization, the concepts presented here may also be applied to other magnetic fusion facilities. This Standard is oriented toward regulation in the Department of Energy (DOE) environment as opposed to regulation by other regulatory agencies. As the need for guidance involving other types of fusion facilities or other regulatory environments emerges, additional guidance volumes should be prepared. The concepts, processes, and recommendations set forth here are for guidance only. They will contribute to safety at magnetic fusion facilities

Plasma in astrophysics

International Nuclear Information System (INIS)

Kulsrud, R.M.

1982-10-01

Two examples of plasma phenomena of importance to astrophysics are reviewed. These are examples where astrophysical understanding hinges on further progress in plasma physics understanding. The two examples are magnetic reconnection and the collisionless interaction between a population of energetic particles and a cooler gas or plasma, in particular the interaction between galactic cosmic rays and the interstellar medium

Magnetized and collimated millimeter scale plasma jets with astrophysical relevance

International Nuclear Information System (INIS)

Brady, Parrish C.; Quevedo, Hernan J.; Valanju, Prashant M.; Bengtson, Roger D.; Ditmire, Todd

2012-01-01

Magnetized collimated plasma jets are created in the laboratory to extend our understanding of plasma jet acceleration and collimation mechanisms with particular connection to astrophysical jets. In this study, plasma collimated jets are formed from supersonic unmagnetized flows, mimicking a stellar wind, subject to currents and magnetohydrodynamic forces. It is found that an external poloidal magnetic field, like the ones found anchored to accretion disks, is essential to stabilize the jets against current-driven instabilities. The maximum jet length before instabilities develop is proportional to the field strength and the length threshold agrees well with Kruskal-Shafranov theory. The plasma evolution is modeled qualitatively using MHD theory of current-carrying flux tubes showing that jet acceleration and collimation arise as a result of electromagnetic forces.

Deep Space Thermal Cycle Testing of Advanced X-Ray Astrophysics Facility - Imaging (AXAF-I) Solar Array Panels Test

National Research Council Canada - National Science Library

Sisco, Jimmy

1997-01-01

The NASA Advanced X-ray Astrophysics Facility - Imaging (AXAF-I) satellite will be exposed to thermal conditions beyond normal experience flight temperatures due to the satellite's high elliptical orbital flight...

Electric Currents along Astrophysical Jets

Directory of Open Access Journals (Sweden)

Ioannis Contopoulos

2017-10-01

Full Text Available Astrophysical black holes and their surrounding accretion disks are believed to be threaded by grand design helical magnetic fields. There is strong theoretical evidence that the main driver of their winds and jets is the Lorentz force generated by these fields and their associated electric currents. Several researchers have reported direct evidence for large scale electric currents along astrophysical jets. Quite unexpectedly, their directions are not random as would have been the case if the magnetic field were generated by a magnetohydrodynamic dynamo. Instead, in all kpc-scale detections, the inferred electric currents are found to flow away from the galactic nucleus. This unexpected break of symmetry suggests that a battery mechanism is operating around the central black hole. In the present article, we summarize observational evidence for the existence of large scale electric currents and their associated grand design helical magnetic fields in kpc-scale astrophysical jets. We also present recent results of general relativistic radiation magnetohydrodynamic simulations which show the action of the Cosmic Battery in the vicinity of astrophysical black holes.

Creating stars, supernovae, and the big bang in the laboratory: Nuclear Astrophysics with the National Ignition Facility

International Nuclear Information System (INIS)

Mathews, G.J.

1994-02-01

This talk has been prepared for the Symposium on Novel Approaches to Nuclear Astrophysics hosted by the ACS Division of Nuclear Chemistry and Technology for the San Diego ACS meeting. This talk indeed describes a truly novel approach. It discusses a proposal for the construction of the National Ignition Facility which could provide the most powerful concentration of laser energy yet attempted. The energy from such a facility could be concentrated in such a way as to reproduce, for the first time in a terrestrial laboratory, an environment which nearly duplicates that which occurs within stars and during the first few moments of cosmic creation during the big bang. These miniature versions of cosmic explosions may allow us to understand better the tumultuous astrophysical environments which have profoundly influenced the origin and evolution of the universe

Modeling the astrophysical dynamical process with laser-plasmas

International Nuclear Information System (INIS)

Xia Jiangfan; Zhang Jun; Zhang Jie

2001-01-01

The use of the state-of-the-art laser facility makes it possible to create conditions of the same or similar to those in the astrophysical processes. The introduction of the astrophysics-relevant ideas in laser-plasma experiments is propitious to the understanding of the astrophysical phenomena. However, the great difference between the laser-produced plasmas and the astrophysical processes makes it awkward to model the latter by laser-plasma experiments. The author addresses the physical backgrounds for modeling the astrophysical plasmas by laser plasmas, connecting these two kinds of plasmas by scaling laws. Thus, allowing the creation of experimental test beds where observations and models can be quantitatively compared with laser-plasma data. Special attentions are paid on the possibilities of using home-made laser facilities to model astrophysical phenomena

Plasma astrophysics

CERN Document Server

Kaplan, S A; ter Haar, D

2013-01-01

Plasma Astrophysics is a translation from the Russian language; the topics discussed are based on lectures given by V.N. Tsytovich at several universities. The book describes the physics of the various phenomena and their mathematical formulation connected with plasma astrophysics. This book also explains the theory of the interaction of fast particles plasma, their radiation activities, as well as the plasma behavior when exposed to a very strong magnetic field. The text describes the nature of collective plasma processes and of plasma turbulence. One author explains the method of elementary

Laboratory Plasma Source as an MHD Model for Astrophysical Jets

Science.gov (United States)

Mayo, Robert M.

1997-01-01

The significance of the work described herein lies in the demonstration of Magnetized Coaxial Plasma Gun (MCG) devices like CPS-1 to produce energetic laboratory magneto-flows with embedded magnetic fields that can be used as a simulation tool to study flow interaction dynamic of jet flows, to demonstrate the magnetic acceleration and collimation of flows with primarily toroidal fields, and study cross field transport in turbulent accreting flows. Since plasma produced in MCG devices have magnetic topology and MHD flow regime similarity to stellar and extragalactic jets, we expect that careful investigation of these flows in the laboratory will reveal fundamental physical mechanisms influencing astrophysical flows. Discussion in the next section (sec.2) focuses on recent results describing collimation, leading flow surface interaction layers, and turbulent accretion. The primary objectives for a new three year effort would involve the development and deployment of novel electrostatic, magnetic, and visible plasma diagnostic techniques to measure plasma and flow parameters of the CPS-1 device in the flow chamber downstream of the plasma source to study, (1) mass ejection, morphology, and collimation and stability of energetic outflows, (2) the effects of external magnetization on collimation and stability, (3) the interaction of such flows with background neutral gas, the generation of visible emission in such interaction, and effect of neutral clouds on jet flow dynamics, and (4) the cross magnetic field transport of turbulent accreting flows. The applicability of existing laboratory plasma facilities to the study of stellar and extragalactic plasma should be exploited to elucidate underlying physical mechanisms that cannot be ascertained though astrophysical observation, and provide baseline to a wide variety of proposed models, MHD and otherwise. The work proposed herin represents a continued effort on a novel approach in relating laboratory experiments to

LLNL superconducting magnets test facility

Energy Technology Data Exchange (ETDEWEB)

Manahan, R; Martovetsky, N; Moller, J; Zbasnik, J

1999-09-16

The FENIX facility at Lawrence Livermore National Laboratory was upgraded and refurbished in 1996-1998 for testing CICC superconducting magnets. The FENIX facility was used for superconducting high current, short sample tests for fusion programs in the late 1980s--early 1990s. The new facility includes a 4-m diameter vacuum vessel, two refrigerators, a 40 kA, 42 V computer controlled power supply, a new switchyard with a dump resistor, a new helium distribution valve box, several sets of power leads, data acquisition system and other auxiliary systems, which provide a lot of flexibility in testing of a wide variety of superconducting magnets in a wide range of parameters. The detailed parameters and capabilities of this test facility and its systems are described in the paper.

Nuclear Astrophysics Experiments at CIAE

International Nuclear Information System (INIS)

Liu Weiping; Li Zhihong; Bai Xixiang; Lian Gang; Guo Bing; Zeng, Sheng; Yan Shengquan; Wang Baoxiang; Shu Nengchuan; Wu Kaisu; Chen Yongshou

2005-01-01

This paper describes nuclear astrophysical studies using the unstable ion beam facility GIRAFFE. We measured the angular distributions for some low energy reactions, such as 7 Be(d, n) 8 B, 11 C(d, n) 12 N, 8 Li(d, n) 9 Be and 8 Li(d, p) 9 Li in inverse kinematics, and indirectly derived the astrophysical S-factors or reaction rates of 7 Be(p, γ) 8 B, 11 C(p, γ) 12 N, 8 Li(n, γ) 9 Li at astrophysically relevant energies

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Astrophysics and Astronomy. K. M. Hiremath. Articles written in Journal of Astrophysics and Astronomy. Volume 21 Issue 3-4 September-December 2000 pp 263-264 Session V – Vector Magnetic Fields, Prominences, CMEs & Flares. Emergence of Twisted Magnetic Flux Related Sigmoidal ...

Experimental studies of nuclear astrophysics

International Nuclear Information System (INIS)

He Jianjun; Zhou Xiaohong; Zhang Yuhu

2013-01-01

Nuclear astrophysics is an interdisciplinary subject combining micro-scale nuclear physics and macro-scale astrophysics. Its main aims are to understand the origin and evolution of the elements in the universe, the time scale of stellar evolution, the stellar environment and sites, the energy generation of stars from thermonuclear processes and its impact on stellar evolution and the mechanisms driving astrophysical phenomena, and the structure and property of compact stars. This paper presents the significance and current research status of nuclear astrophysics; we introduce some fundamental concepts, the nuclear physics input parameters required by certain astrophysics models, and some widely-used experimental approaches in nuclear astrophysics research. The potential and feasibility of research in this field using China’s current and planned large-scale scientific facilities are analyzed briefly. Finally, the prospects of the establishing a deep underground science and engineering laboratory in China are envisaged. (authors)

Generating Long Scale-Length Plasma Jets Embedded in a Uniform, Multi-Tesla Magnetic-Field

Science.gov (United States)

Manuel, Mario; Kuranz, Carolyn; Rasmus, Alex; Klein, Sallee; Fein, Jeff; Belancourt, Patrick; Drake, R. P.; Pollock, Brad; Hazi, Andrew; Park, Jaebum; Williams, Jackson; Chen, Hui

2013-10-01

Collimated plasma jets emerge in many classes of astrophysical objects and are of great interest to explore in the laboratory. In many cases, these astrophysical jets exist within a background magnetic field where the magnetic pressure approaches the plasma pressure. Recent experiments performed at the Jupiter Laser Facility utilized a custom-designed solenoid to generate the multi-tesla fields necessary to achieve proper magnetization of the plasma. Time-gated interferometry, Schlieren imaging, and proton radiography were used to characterize jet evolution and collimation under varying degrees of magnetization. Experimental results will be presented and discussed. This work is funded by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, grant number DE-NA0001840, by the National Laser User Facility Program, grant number DE-NA0000850, by the Predictive Sciences Academic Alliances Program in NNSA-ASC, grant number DEFC52-08NA28616, and by NASA through Einstein Postdoctoral Fellowship grant number PF3-140111 awarded by the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for NASA under contract NAS8-03060.

Highlights of the NASA particle astrophysics program

Energy Technology Data Exchange (ETDEWEB)

Jones, William Vernon, E-mail: w.vernon.jones@nasa.gov [Astrophysics Division DH000, Science Mission Directorate, NASA Headquarters, Washington DC (United States)

2014-07-01

The NASA Particle Astrophysics Program covers Origin of the Elements, Nearest Sources of Cosmic Rays, How Cosmic Particle Accelerators Work, The Nature of Dark Matter, and Neutrino Astrophysics. Progress in each of these topics has come from sophisticated instrumentation flown on long duration balloon (LDB) flights around Antarctica over the past two decades. New opportunities including Super Pressure Balloons (SPB) and International Space Station (ISS) platforms are emerging for the next major step. Stable altitudes and long durations enabled by SPB flights ensure ultra-long duration balloon (ULDB) missions that can open doors to new science opportunities. The Alpha Magnetic Spectrometer (AMS) has been operating on the ISS since May 2011. The CALorimetric Electron Telescope (CALET) and Cosmic Ray Energetics And Mass (CREAM) experiments are being developed for launch to the Japanese Experiment Module Exposed Facility (JEM-EF) in 2015. And, the Extreme Universe Space Observatory (EUSO) is planned for launch to the ISS JEM-EF after 2017. Collectively, these four complementary ISS missions covering a large portion of the cosmic ray energy spectrum serve as a cosmic ray observatory. (author)

Highlights of the NASA particle astrophysics program

International Nuclear Information System (INIS)

Jones, William Vernon

2014-01-01

The NASA Particle Astrophysics Program covers Origin of the Elements, Nearest Sources of Cosmic Rays, How Cosmic Particle Accelerators Work, The Nature of Dark Matter, and Neutrino Astrophysics. Progress in each of these topics has come from sophisticated instrumentation flown on long duration balloon (LDB) flights around Antarctica over the past two decades. New opportunities including Super Pressure Balloons (SPB) and International Space Station (ISS) platforms are emerging for the next major step. Stable altitudes and long durations enabled by SPB flights ensure ultra-long duration balloon (ULDB) missions that can open doors to new science opportunities. The Alpha Magnetic Spectrometer (AMS) has been operating on the ISS since May 2011. The CALorimetric Electron Telescope (CALET) and Cosmic Ray Energetics And Mass (CREAM) experiments are being developed for launch to the Japanese Experiment Module Exposed Facility (JEM-EF) in 2015. And, the Extreme Universe Space Observatory (EUSO) is planned for launch to the ISS JEM-EF after 2017. Collectively, these four complementary ISS missions covering a large portion of the cosmic ray energy spectrum serve as a cosmic ray observatory. (author)

Promising lines of investigations in the realms of laboratory astrophysics with the aid of powerful lasers

International Nuclear Information System (INIS)

Belyaev, V. S.; Batishchev, P. A.; Bolshakov, V. V.; Elkin, K. S.; Karabadzhak, G. F.; Kovkov, D. V.; Matafonov, A. P.; Raykunov, G. G.; Yakhin, R. A.; Pikuz, S. A.; Skobelev, I. Yu.; Faenov, A. Ya.; Fortov, V. E.; Krainov, V. P.; Rozanov, V. B.

2013-01-01

The results of work on choosing and substantiating promising lines of research in the realms of laboratory astrophysics with the aid of powerful lasers are presented. These lines of research are determined by the possibility of simulating, under laboratory conditions, problematic processes of presentday astrophysics, such as (i) the generation and evolution of electromagnetic fields in cosmic space and the role of magnetic fields there at various spatial scales; (ii) the mechanisms of formation and evolution of cosmic gamma-ray bursts and relativistic jets; (iii) plasma instabilities in cosmic space and astrophysical objects, plasma jets, and shock waves; (iv) supernova explosions and mechanisms of the explosion of supernovae featuring a collapsing core; (v) nuclear processes in astrophysical objects; (vi) cosmic rays and mechanisms of their production and acceleration to high energies; and (vii) astrophysical sources of x-ray radiation. It is shown that the use of existing powerful lasers characterized by an intensity in the range of 10 18 –10 22 W/cm 2 and a pulse duration of 0.1 to 1 ps and high-energy lasers characterized by an energy in excess of 1 kJ and a pulse duration of 1 to 10 ns makes it possible to perform investigations in laboratory astrophysics along all of the chosen promising lines. The results obtained by experimentally investigating laser plasma with the aid of the laser facility created at Central Research Institute of Machine Building (TsNIIMash) and characterized by a power level of 10 TW demonstrate the potential of such facilities for performing a number of experiments in the realms of laboratory astrophysics.

Study of aluminum emission spectra in astrophysical plasmas

International Nuclear Information System (INIS)

Jin Zhan; Zhang Jie

2001-01-01

High temperature, high density and strong magnetic fields in plasmas produced by ultra-high intensity and ultrashort laser pulses are similar to the main characteristics of astrophysical plasmas. This makes it possible to simulate come astrophysical processes at laboratories. The author presents the theoretic simulation of aluminum emission spectra in astrophysical plasmas. It can be concluded that using laser produced plasmas, the authors can obtain rich information on astrophysical spectroscopy, which is unobservable for astronomer

Exploring Astrophysical Magnetohydrodynamics in the Laboratory

Science.gov (United States)

Manuel, Mario

2014-10-01

Plasma evolution in many astrophysical systems is dominated by magnetohydrodynamics. Specifically of interest to this talk are collimated outflows from accretion systems. Away from the central object, the Euler equations can represent the plasma dynamics well and may be scaled to a laboratory system. We have performed experiments to investigate the effects of a background magnetic field on an otherwise hydrodynamically collimated plasma. Laser-irradiated, cone targets produce hydrodynamically collimated plasma jets and a pulse-powered solenoid provides a constant background magnetic field. The application of this field is shown to completely disrupt the original flow and a new magnetically-collimated, hollow envelope is produced. Results from these experiments and potential implications for their astrophysical analogs will be discussed.

Mirror Fusion Test Facility magnet system

International Nuclear Information System (INIS)

VanSant, J.H.; Kozman, T.A.; Bulmer, R.H.; Ng, D.S.

1981-01-01

In 1979, R.H. Bulmer of Lawrence Livermore National Laboratory (LLNL) discussed a proposed tandem-mirror magnet system for the Mirror Fusion Test Facility (MFTF) at the 8th symposium on Engineering Problems in Fusion Research. Since then, Congress has voted funds for expanding LLNL's MFTF to a tandem-mirror facility (designated MFTF-B). The new facility, scheduled for completion by 1985, will seek to achieve two goals: (1) Energy break-even capability (Q or the ratio of fusion energy to plasma heating energy = 1) of mirror fusion, (2) Engineering feasibility of reactor-scale machines. Briefly stated, 22 superconducting magnets contained in a 11-m-diam by 65-m-long vacuum vessel will confine a fusion plasma fueled by 80 axial streaming-plasma guns and over 40 radial neutral beams. We have already completed a preliminary design of this magnet system

Production of radiatively cooled hypersonic plasma jets and links to astrophysical jets

International Nuclear Information System (INIS)

Lebedev, S V; Ciardi, A; Ampleford, D J; Bland, S N; Bott, S C; Chittenden, J P; Hall, G N; Rapley, J; Jennings, C; Sherlock, M; Frank, A; Blackman, E G

2005-01-01

We present results of high energy density laboratory experiments on the production of supersonic radiatively cooled plasma jets with dimensionless parameters (Mach number ∼30, cooling parameter ∼1 and density contrast ρ j /ρ a ∼ 10) similar to those in young stellar objects jets. The jets are produced using two modifications of wire array Z-pinch driven by 1 MA, 250 ns current pulse of MAGPIE facility at Imperial College, London. In the first set of experiments the produced jets are purely hydrodynamic and are used to study deflection of the jets by the plasma cross-wind, including the structure of internal oblique shocks in the jets. In the second configuration the jets are driven by the pressure of the toroidal magnetic field and this configuration is relevant to the astrophysical models of jet launching mechanisms. Modifications of the experimental configuration allowing the addition of the poloidal magnetic field and angular momentum to the jets are also discussed. We also present three-dimensional resistive magneto-hydrodynamic simulations of the experiments and discuss the scaling of the experiments to the astrophysical systems

Nuclear physics in astrophysics. Part 2. Abstracts

International Nuclear Information System (INIS)

Gyuerky, Gy.; Fueloep, Zs.

2005-01-01

The proceedings of the 20. International Nuclear Physics Divisional Conference of the European Physical Society covers a wide range of topics in nuclear astrophysics. The topics addressed are big bang nucleosynthesis, stellar nucleosynthesis, measurements and nuclear data for astrophysics, nuclear structure far from stability, neutrino physics, and rare-ion-beam facilities and experiments. The perspectives of nuclear physics and astrophysics are also overviewed. 77 items are indexed separately for the INIS database. (K.A.)

Hydrodynamic instabilities in astrophysics and ICF

International Nuclear Information System (INIS)

Paul Drake, R.

2005-01-01

Inertial fusion systems and astrophysical systems both involve hydrodynamic effects, including sources of pressure, shock waves, rarefactions, and plasma flows. In the evolution of such systems, hydrodynamic instabilities naturally evolve. As a result, a fundamental understanding of hydrodynamic instabilities is necessary to understand their behavior. In addition, high-energy-density facilities designed for ICF purposes can be used to provide and experimental basis for understanding astrophysical processes. In this talk. I will discuss the instabilities that appear in astrophysics and ICF from the common perspective of the basic mechanisms at work. Examples will be taken from experiments aimed at ICF, from astrophysical systems, and from experiments using ICF systems to address issues in astrophysics. The high-energy-density research facilities of today can accelerate small but macroscopic amounts of material to velocities above 100 km/s, can heat such material to temperature above 100 eV, can produce pressures far above a million atmospheres (10''12 dybes/cm''2 or 0.1 TPascal), and can do experiments under these conditions that address basic physics issues. This enables on to devise experiments aimed directly at important process such as the Rayleigh Taylor instability at an ablating surface or at an embedded interface that is accelerating, the Richtmeyer Meshkov evolution of shocked interfaces, and the Kelvin-Helmholtz instability of shear flows. The talk will include examples of such phenomena from the laboratory and from astrophysics, and will discuss experiments to study them. (Author)

Safety of magnetic fusion facilities: Requirements

International Nuclear Information System (INIS)

1996-05-01

This Standard identifies safety requirements for magnetic fusion facilities. Safety functions are used to define outcomes that must be achieved to ensure that exposures to radiation, hazardous materials, or other hazards are maintained within acceptable limits. Requirements applicable to magnetic fusion facilities have been derived from Federal law, policy, and other documents. In addition to specific safety requirements, broad direction is given in the form of safety principles that are to be implemented and within which safety can be achieved

Facilities at Indian Institute of Astrophysics and New Initiatives

Science.gov (United States)

Bhatt, Bhuwan Chandra

2018-04-01

The Indian Institute of Astrophysics is a premier national institute of India for the study of and research into topics pertaining to astronomy, astrophysics and related subjects. The Institute's main campus in Bangalore city in southern India houses the main administrative set up, library and computer center, photonics lab and state of art mechanical workshop. IIA has a network of laboratories and observatories located in various places in India, including Kodaikanal (Tamilnadu), Kavalur (Tamilnadu), Gauribidanur (Karnataka), Leh & Hanle (Jammu & Kashmir) and Hosakote (Karnataka).

Mirror Fusion Test Facility magnet

International Nuclear Information System (INIS)

Henning, C.H.; Hodges, A.J.; Van Sant, J.H.; Hinkle, R.E.; Horvath, J.A.; Hintz, R.E.; Dalder, E.; Baldi, R.; Tatro, R.

1979-01-01

The Mirror Fusion Test Facility (MFTF) is the largest of the mirror program experiments for magnetic fusion energy. It seeks to combine and extend the near-classical plasma confinement achieved in 2XIIB with the most advanced neutral-beam and magnet technologies. The product of ion density and confinement time will be improved more than an order of magnitude, while the superconducting magnet weight will be extrapolated from the 15 tons in Baseball II to 375 tons in MFTF. Recent reactor studies show that the MFTF will traverse much of the distance in magnet technology towards the reactor regime. Design specifics of the magnet are given

The magnet measurement facility for the Advanced Photon Source

International Nuclear Information System (INIS)

Kim, S.H.; Doose, C.; Hogrefe, R.; Kim, K.; Merl, R.

1993-01-01

A magnet measurement facility has been developed to measure the prototype and production magnets for the Advance Photon Source. The measurement facility is semi-automatic in measurement control and data analysis. One dipole system and three rotating coil measurement systems for quadrupole and sextupole magnets and corresponding probe coils are described

Advances in instrumentation for nuclear astrophysics

Directory of Open Access Journals (Sweden)

S. D. Pain

2014-04-01

Full Text Available 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.

Safety of magnetic fusion facilities: Volume 2, Guidance

International Nuclear Information System (INIS)

1995-01-01

This document provides guidance for the implementation of the requirements identified in Vol. 1 of this Standard. This guidance is intended for the managers, designers, operators, and other personnel with safety responsibilities for facilities designated as magnetic fusion facilities. While Vol. 1 is generally applicable in that requirements there apply to a wide range of fusion facilities, this volume is concerned mainly with large facilities such as the International Thermonuclear Experimental Reactor (ITER). Using a risk-based prioritization, the concepts presented here may also be applied to other magnetic fusion facilities. This volume is oriented toward regulation in the Department of Energy (DOE) environment

Long-pulse magnetic field facility at Zaragoza

International Nuclear Information System (INIS)

Algarabel, P A; Moral, A del; Martin, C; Serrate, D; Tokarz, W

2006-01-01

The long-pulse magnetic field facility of the Laboratorio de Magnetismo - Instituto de Ciencia de Materiales de Aragon (Universidad de Zaragoza-CSIC) produces magnetic fields up to 31, with a pulse duration of 2.2s. Experimental set-ups for measurements of magnetization, magnetostriction and magnetoresistance are available. The temperature can be controlled between 1.4 and 335 K, being the inner bore of the He cryostat of 22.5 mm. Magnetization is measured using the mutual induction technique, the magnetostriction is determined with the strain-gage and the capacitive cantilever methods, and the magnetoresistance is measured by means of the aclock-in technique in the 4-probes geometry. An overview of the facility will be presented and the presently available experimental techniques will be discussed

SSC string test facility for superconducting magnets: Testing capabilities and program for collider magnets

International Nuclear Information System (INIS)

Kraushaar, P.; Burgett, W.; Dombeck, T.; McInturff, A.; Robinson, W.; Saladin, V.

1993-05-01

The Accelerator Systems String Test (ASST) R ampersand D Testing Facility has been established at the SSC Laboratory to test Collider and High Energy Booster (HEB) superconducting magnet strings. The facility is operational and has had two testing periods utilizing a half cell of collider prototypical magnets with the associated spool pieces and support systems. This paper presents a description of the testing capabilities of the facility with respect to components and supporting subsystems (cryogenic, power, quench protection, controls and instrumentation), the planned testing program for the collider magnets

Numerical simulation in astrophysics

International Nuclear Information System (INIS)

Miyama, Shoken

1985-01-01

There have been many numerical simulations of hydrodynamical problems in astrophysics, e.g. processes of star formation, supernova explosion and formation of neutron stars, and general relativistic collapse of star to form black hole. The codes are made to be suitable for computing such problems. In astrophysical hydrodynamical problems, there are the characteristics: problems of self-gravity or external gravity acting, objects of scales very large or very short, objects changing by short period or long time scale, problems of magnetic force and/or centrifugal force acting. In this paper, we present one of methods of numerical simulations which may satisfy these requirements, so-called smoothed particle methods. We then introduce the methods briefly. Then, we show one of the applications of the methods to astrophysical problem (fragmentation and collapse of rotating isothermal cloud). (Mori, K.)

Long-pulse magnetic field facility at Zaragoza

Science.gov (United States)

Algarabel, P. A.; del Moral, A.; Martín, C.; Serrate, D.; Tokarz, W.

2006-11-01

The long-pulse magnetic field facility of the Laboratorio de Magnetismo - Instituto de Ciencia de Materiales de Aragón (Universidad de Zaragoza-CSIC) produces magnetic fields up to 31, with a pulse duration of 2.2s. Experimental set-ups for measurements of magnetization, magnetostriction and magnetoresistance are available. The temperature can be controlled between 1.4 and 335 K, being the inner bore of the He cryostat of 22.5 mm. Magnetization is measured using the mutual induction technique, the magnetostriction is determined with the strain-gage and the capacitive cantilever methods, and the magnetoresistance is measured by means of the aclock-in technique in the 4-probes geometry. An overview of the facility will be presented and the presently available experimental techniques will be discussed.

A New ECR Ion Source for Nuclear Astrophysics Studies

Science.gov (United States)

Cesaratto, John M.

2008-10-01

The Laboratory for Experimental Nuclear Astrophysics (LENA) is a low energy facility designed to study nuclear reactions of astrophysical interest at energies which are important for nucleosysthesis. In general, these reactions have extremely small cross sections, requiring intense beams and efficient detection systems. Recently, a new, high intensity electron-cyclotron-resonance (ECR) ion source has been constructed (based on a design by Wills et al.[1]), which represents a substantial improvement in the capabilities of LENA. Beam is extracted from an ECR plasma excited at 2.45 GHz and confined by an array of permanent magnets. It has produced H^+ beams in excess of 1 mA on target over the energy range 100 - 200 keV, which greatly increases our ability to measure small cross sections. Initial measurements will focus on the ^23Na(p,γ)^24Mg reaction, which is of interest in a variety of astrophysical scenarios. The present uncertainty in the rate of this reaction is the result of an unobserved resonance expected at Elab =144 keV, which should be detectable using beams from the new ECR source. In collaboration with Arthur E. Champagne and Thomas B. Clegg, University of North Carolina, Chapel Hill and TUNL. [3pt] [1] J. S. C. Wills et al., Rev. Sci. Instrum. 69, 65 (1999).

Simulations of Laboratory Astrophysics Experiments using the CRASH code

Science.gov (United States)

Trantham, Matthew; Kuranz, Carolyn; Fein, Jeff; Wan, Willow; Young, Rachel; Keiter, Paul; Drake, R. Paul

2015-11-01

Computer simulations can assist in the design and analysis of laboratory astrophysics experiments. The Center for Radiative Shock Hydrodynamics (CRASH) at the University of Michigan developed a code that has been used to design and analyze high-energy-density experiments on OMEGA, NIF, and other large laser facilities. This Eulerian code uses block-adaptive mesh refinement (AMR) with implicit multigroup radiation transport, electron heat conduction and laser ray tracing. This poster will demonstrate some of the experiments the CRASH code has helped design or analyze including: Kelvin-Helmholtz, Rayleigh-Taylor, magnetized flows, jets, and laser-produced plasmas. This work is funded by the following grants: DEFC52-08NA28616, DE-NA0001840, and DE-NA0002032.

Global kinetic theory of astrophysical jets

International Nuclear Information System (INIS)

Chang, T.

1989-01-01

We suggest that an astrophysical plasma stream flowing outward from a central object aling an open magnetic field line with decreasing field strength generally will have anisotropic velocity distributions. I particular, the electron distribution function of this type of plasma streams will contain a 'thermally populated' region and a stretche out high energy tail (or 'jet-like') region collimated in the utward direction of the magnetic field line. Our argument is based on a global, collisional, kinetic theory. Because the 'kinetic jets' are always pointed aling the outward direction of the field lines, thy are automatically collimated and will assume whatever the peculiar geometries dictated by the magnetic field. This result should be useful in the understanding of the basic structures of such diverse astrophysical objects as the extragalactic radio jets, stellar winds, the solar wind, planetary polar winds, and galactic jets. (author). 8 refs.; 2 figs

The Toulouse pulsed magnet facility

International Nuclear Information System (INIS)

2006-01-01

The 'Laboratoire National des Champs Magnetiques Pulses' (LNCMP) is an international user facility providing access to pulsed magnetic fields up to and beyond 60 T. The laboratory disposes of 10 magnet stations equipped with long-pulse magnets operating in the 35-60 T range and a short-pulse system reaching magnetic fields in excess of 70 T. The experimental infrastructure includes various high and low-temperature systems ranging from ordinary flow-type cryostats to dilution refrigerators reaching 50 mK, as well as different types of high-pressure cells. Experimental techniques include magnetization, transport, luminescence, IR-spectroscopy and polarimetry. The LNCMP pursues an extensive in-house research program focussing on all technological and scientific aspects of pulsed magnetic fields. Recent technical developments include the implementation of 60 T rapid-cooling coils, an 80 T prototype, a pulsed dipole magnet for optical investigations of dilute matter and a transportable horizontal access magnet for small angle x-ray scattering experiments. Scientific activities cover a variety of domains, including correlated electron systems, magnetism, semiconductors and nanoscience

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

Energy Technology Data Exchange (ETDEWEB)

Arcones, Almudena [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Escher, Jutta E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Others, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

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.

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

International Nuclear Information System (INIS)

Arcones, Almudena; Bardayan, Dan W.

2016-01-01

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 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.

Tandem mirror magnet system for the mirror fusion test facility

International Nuclear Information System (INIS)

Bulmer, R.H.; Van Sant, J.H.

1980-01-01

The Tandem Mirror Fusion Test Facility (MFTF-B) will be a large magnetic fusion experimental facility containing 22 supercounducting magnets including solenoids and C-coils. State-of-the-art technology will be used extensively to complete this facility before 1985. Niobium titanium superconductor and stainless steel structural cases will be the principle materials of construction. Cooling will be pool boiling and thermosiphon flow of 4.5 K liquid helium. Combined weight of the magnets will be over 1500 tonnes and the stored energy will be over 1600 MJ. Magnetic field strength in some coils will be more than 8 T. Detail design of the magnet system will begin early 1981. Basic requirements and conceptual design are disclosed in this paper

Effective magnetic moment of neutrinos in strong magnetic fields

International Nuclear Information System (INIS)

Perez M, A.; Perez R, H.; Masood, S.S.; Gaitan, R.; Rodriguez R, S.

2002-01-01

In this paper we compute the effective magnetic moment of neutrinos propagating in dense high magnetized medium. Taking typical values of magnetic field and densities of astrophysical objects (such as the cores of supernovae and neutron stars) we obtain an effective type of dipole magnetic moment in agreement with astrophysical and cosmological bounds. (Author)

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... Home; Journals; Journal of Astrophysics and Astronomy. John McKean. Articles written in Journal of Astrophysics and Astronomy. Volume 32 Issue 4 December 2011 pp 557-566. LOFAR and APERTIF Surveys of the Radio Sky: Probing Shocks and Magnetic Fields in Galaxy Clusters · Huub Röttgering ...

Multi-scale Dynamical Processes in Space and Astrophysical Plasmas

CERN Document Server

Vörös, Zoltán; IAFA 2011 - International Astrophysics Forum 2011 : Frontiers in Space Environment Research

2012-01-01

Magnetized plasmas in the universe exhibit complex dynamical behavior over a huge range of scales. The fundamental mechanisms of energy transport, redistribution and conversion occur at multiple scales. The driving mechanisms often include energy accumulation, free-energy-excited relaxation processes, dissipation and self-organization. The plasma processes associated with energy conversion, transport and self-organization, such as magnetic reconnection, instabilities, linear and nonlinear waves, wave-particle interactions, dynamo processes, turbulence, heating, diffusion and convection represent fundamental physical effects. They demonstrate similar dynamical behavior in near-Earth space, on the Sun, in the heliosphere and in astrophysical environments. 'Multi-scale Dynamical Processes in Space and Astrophysical Plasmas' presents the proceedings of the International Astrophysics Forum Alpbach 2011. The contributions discuss the latest advances in the exploration of dynamical behavior in space plasmas environm...

A small electron beam ion trap/source facility for electron/neutral–ion collisional spectroscopy in astrophysical plasmas

Science.gov (United States)

Liang, Gui-Yun; Wei, Hui-Gang; Yuan, Da-Wei; Wang, Fei-Lu; Peng, Ji-Min; Zhong, Jia-Yong; Zhu, Xiao-Long; Schmidt, Mike; Zschornack, Günter; Ma, Xin-Wen; Zhao, Gang

2018-01-01

Spectra are fundamental observation data used for astronomical research, but understanding them strongly depends on theoretical models with many fundamental parameters from theoretical calculations. Different models give different insights for understanding a specific object. Hence, laboratory benchmarks for these theoretical models become necessary. An electron beam ion trap is an ideal facility for spectroscopic benchmarks due to its similar conditions of electron density and temperature compared to astrophysical plasmas in stellar coronae, supernova remnants and so on. In this paper, we will describe the performance of a small electron beam ion trap/source facility installed at National Astronomical Observatories, Chinese Academy of Sciences.We present some preliminary experimental results on X-ray emission, ion production, the ionization process of trapped ions as well as the effects of charge exchange on the ionization.

A plasma deflagration accelerator as a platform for laboratory astrophysics

Science.gov (United States)

Underwood, Thomas C.; Loebner, Keith T. K.; Cappelli, Mark A.

2017-06-01

The replication of astrophysical flows in the laboratory is critical for isolating particular phenomena and dynamics that appear in complex, highly-coupled natural systems. In particular, plasma jets are observed in astrophysical contexts at a variety of scales, typically at high magnetic Reynolds number and driven by internal currents. In this paper, we present detailed measurements of the plasma parameters within deflagration-produced plasma jets, the scaling of these parameters against both machine operating conditions and the corresponding astrophysical phenomena. Using optical and spectroscopic diagnostics, including Schlieren cinematography, we demonstrate the production of current-driven plasma jets of ∼100 km/s and magnetic Reynolds numbers of ∼100, and discuss the dynamics of their acceleration into vacuum. The results of this study will contribute to the reproduction of various types of astrophysical jets in the laboratory and indicate the ability to further probe active research areas such as jet collimation, stability, and interaction.

Role of Magnetic Reconnection in Heating Astrophysical Plasmas

Science.gov (United States)

Hammoud, M. M.; El Eid, M.; Darwish, M.; Dayeh, M. A.

2017-12-01

The description of plasma in the context of a fluid model reveals the important phenomenon of magnetic reconnection (MGR). This process is thought to be the cause of particle heating and acceleration in various astrophysical phenomena. Examples are geomagnetic storms, solar flares, or heating the solar corona, which is the focus of the present contribution. The magnetohydrodynamic approach (MHD) provides a basic description of MGR. However, the simulation of this process is rather challenging. Although it is not yet established whether waves or reconnection play the dominant role in heating the solar atmosphere, the present goal is to examine the tremendous increase of the temperature between the solar chromosphere and the corona in a very narrow transition region. Since we are dealing with very-high temperature plasma, the modeling of such heating process seems to require a two-fluid description consisting of ions and electrons. This treatment is an extension of the one-fluid model of resistive MHD that has been recently developed by [Hammoud et al., 2017] using the modern numerical openfoam toolbox. In this work, we outline the two-fluid approach using coronal conditions, show evidence of MGR in the two-fluid description, and investigate the temperature increase as a result of this MGR process.

A facility to test short superconducting accelerator magnets at Fermilab

International Nuclear Information System (INIS)

Lamm, M.J.; Hess, C.; Lewis, D.; Jaffery, T.; Kinney, W.; Ozelis, J.P.; Strait, J.; Butteris, J.; McInturff, A.D.; Coulter, K.J.

1992-10-01

During the past four years the Superconducting Magnet R ampersand D facility at Fermilab (Lab 2) has successfully tested superconducting dipole, quadrupole, and correction coil magnets less than 2 meters in length for the SSC project and the Tevatron D0/B0 Low-β Insertion. During this time several improvements have been made to the facility that have greatly enhanced its magnet testing capabilities. Among the upgrades have been a new rotating coil and data acquisition system for measuring magnetic fields, a controlled flow liquid helium transfer line using an electronically actuated cryo valve, and stand-alone systems for measuring AC loss and training low current Tevatron correction coil packages. A description of the Lab 2 facilities is presented

Superconducting dipole magnet for the UTSI MHD facility

International Nuclear Information System (INIS)

Wang, S.T.; Niemann, R.C.; Turner, L.R.

1978-01-01

The Argonne National Laboratory is designing and will build a large superconducting dipole magnet system for use in the Coal Fired Flow MHD Research Facility at the University of Tennessee Space Institute (UTSI). Presented in detail are the conceptual design of the magnet geometry, conductor design, cryostability evaluation, magnetic pressure computation, structural design, cryostat design, the cryogenics system design, and magnet instrumentations and control

Production of large volume, strongly magnetized laser-produced plasmas by use of pulsed external magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Albertazzi, B. [LULI, Ecole Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); INRS-EMT, Varennes, Quebec J3X 1S2 (Canada); Beard, J.; Billette, J.; Portugall, O. [LNCMI, UPR 3228, CNRS-UFJ-UPS-INSA, 31400 Toulouse (France); Ciardi, A. [LERMA, Observatoire de Paris, Ecole Normale Superieure, Universite Pierre et Marie Curie, CNRS UMR 8112, Paris (France); Vinci, T.; Albrecht, J.; Chen, S. N.; Da Silva, D.; Hirardin, B.; Nakatsutsumi, M.; Romagnagni, L.; Simond, S.; Veuillot, E.; Fuchs, J. [LULI, Ecole Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); Burris-Mog, T.; Dittrich, S.; Herrmannsdoerfer, T.; Kroll, F.; Nitsche, S. [Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); and others

2013-04-15

The production of strongly magnetized laser plasmas, of interest for laboratory astrophysics and inertial confinement fusion studies, is presented. This is achieved by coupling a 16 kV pulse-power system. This is achieved by coupling a 16 kV pulse-power system, which generates a magnetic field by means of a split coil, with the ELFIE laser facility at Ecole Polytechnique. In order to influence the plasma dynamics in a significant manner, the system can generate, repetitively and without debris, high amplitude magnetic fields (40 T) in a manner compatible with a high-energy laser environment. A description of the system and preliminary results demonstrating the possibility to magnetically collimate plasma jets are given.

Astronomy and astrophysics for the 1970's. Volume 2. Reports of the panels

International Nuclear Information System (INIS)

1973-01-01

Specific panel reports include: radio astronomy, optical astronomy, infrared astronomy, space astronomy, solar astronomy, theoretical astrophysics, dynamical astronomy, astrophysics and relativity, and statistics. These provide guidance as to the major trends anticipated in astronomical and astrophysical research. They also list instrumental facilities, auxiliary equipment, and programs of theoretical research and offer numerous recommendations

Experimental astrophysics with high power lasers and Z pinches

Energy Technology Data Exchange (ETDEWEB)

Remington, B A; Drake, R P; Ryutov, D D

2004-12-10

With the advent of high energy density (HED) experimental facilities, such as high-energy lasers and fast Z-pinch, pulsed-power facilities, mm-scale quantities of matter can be placed in extreme states of density, temperature, and/or velocity. This has enabled the emergence of a new class of experimental science, HED laboratory astrophysics, wherein the properties of matter and the processes that occur under extreme astrophysical conditions can be examined in the laboratory. Areas particularly suitable to this class of experimental astrophysics include the study of opacities relevant to stellar interiors; equations of state relevant to planetary interiors; strong shock driven nonlinear hydrodynamics and radiative dynamics, relevant to supernova explosions and subsequent evolution; protostellar jets and high Mach-number flows; radiatively driven molecular clouds and nonlinear photoevaporation front dynamics; and photoionized plasmas relevant to accretion disks around compact objects, such as black holes and neutron stars.

Plasma Astrophysics, part II Reconnection and Flares

CERN Document Server

Somov, Boris V

2007-01-01

This well-illustrated monograph is devoted to classic fundamentals, current practice, and perspectives of modern plasma astrophysics. The first part is unique in covering all the basic principles and practical tools required for understanding and working in plasma astrophysics. The second part presents the physics of magnetic reconnection and flares of electromagnetic origin in space plasmas within the solar system; single and double stars, relativistic objects, accretion disks, and their coronae are also covered. This book is designed mainly for professional researchers in astrophysics. However, it will also be interesting and useful to graduate students in space sciences, geophysics, as well as advanced students in applied physics and mathematics seeking a unified view of plasma physics and fluid mechanics.

Plasma Astrophysics, Part I Fundamentals and Practice

CERN Document Server

Somov, Boris V

2006-01-01

This well-illustrated monograph is devoted to classic fundamentals, current practice, and perspectives of modern plasma astrophysics. The first part is unique in covering all the basic principles and practical tools required for understanding and working in plasma astrophysics. The second part presents the physics of magnetic reconnection and flares of electromagnetic origin in space plasmas within the solar system; single and double stars, relativistic objects, accretion disks, and their coronae are also covered. This book is designed mainly for professional researchers in astrophysics. However, it will also be interesting and useful to graduate students in space sciences, geophysics, as well as advanced students in applied physics and mathematics seeking a unified view of plasma physics and fluid mechanics.

Doppler tomography in fusion plasmas and astrophysics

DEFF Research Database (Denmark)

Salewski, Mirko; Geiger, B.; Heidbrink, W. W.

2015-01-01

Doppler tomography is a well-known method in astrophysics to image the accretion flow, often in the shape of thin discs, in compact binary stars. As accretion discs rotate, all emitted line radiation is Doppler-shifted. In fast-ion Dα (FIDA) spectroscopy measurements in magnetically confined plasma......, the Dα-photons are likewise Doppler-shifted ultimately due to gyration of the fast ions. In either case, spectra of Doppler-shifted line emission are sensitive to the velocity distribution of the emitters. Astrophysical Doppler tomography has lead to images of accretion discs of binaries revealing bright...... and limits, analogies and differences in astrophysical and fusion plasma Doppler tomography and what can be learned by comparison of these applications....

The insertion device magnetic measurement facility: Prototype and operational procedures

International Nuclear Information System (INIS)

Burkel, L.; Dejus, R.; Maines, J.; O'Brien, J.; Vasserman, I.; Pfleuger, J.

1993-03-01

This report is a description of the current status of the magnetic measurement facility and is a basic instructional manual for the operation of the facility and its components. Please refer to the appendices for more detailed information about specific components and procedures. The purpose of the magnetic measurement facility is to take accurate measurements of the magnetic field in the gay of the IDs in order to determine the effect of the ID on the stored particle beam and the emitted radiation. The facility will also play an important role when evaluating new ideas, novel devices, and inhouse prototypes as part of the ongoing research and development program at the APS. The measurements will be performed with both moving search coils and moving Hall probes. The IDs will be evaluated by computer modeling of the emitted radiation for any given (measured) magnetic field map. The quality of the magnetic field will be described in terms of integrated multipoles for the effect on Storage Ring performance and in terms of the derived trajectories for the emitted radiation. Before being installed on the Storage Ring, every device will be measured and characterized to assure that it is compatible with Storage Ring requirements and radiation specifications. The accuracy that the APS needs to achieve for magnetic measurements will be based on these specifications

Nuclear astrophysics at DRAGON

International Nuclear Information System (INIS)

Hager, U.

2014-01-01

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

Cryogenics - Its influence on the selection of the ASTROMAG superconducting magnet coils

Science.gov (United States)

Green, M. A.

1990-01-01

ASTROMAG, a particle astrophysics experimental facility proposed for running alongside a Space Station, has a large superconducting magnet to analyze particles coming from deep space. Several types of magnets were investigated for use in the ASTROMAG central facility. The factors which influence the selection of the magnet coil design include: (1) the upper limit of particle momentum resolved (proportional to the integrated field) as a function of solid angle; (2)cryogenic design and its effect on cryogen lifetime for a given central facility mass; and (3) the overall cost of the magnet coils and cryostat. Four magnet types are analyzed in this paper. These include a simple two-coil solenoid (the baseline design),two disk coils at the ends of the helium tank, a two-coil toroid and a thin solenoid plus bucking coil. A balance must be struck between cryostat lifetime, total mass and the integrated field through the detectors. This balance tends to favor coils which are in the same vacuum vessel as the cryogen.

Astrophysics and particle physics in space with the Alpha Magnetic Spectrometer

CERN Document Server

Lamanna, G

2003-01-01

The Alpha Magnetic Spectrometer is a high energy particle physics experiment in space scheduled to be installed on the International Space Station (ISS) by 2006 for a three-year mission. After a precursor flight of a prototype detector on board of the NASA Space Shuttle in June 1998, the construction of the detector in its final configuration is started and it will be completed by 2004. The purpose of this experiment is to provide a high statistics measurement of charged particles and nuclei in rigidity range 0.5 GV to few TV and to explore the high-energy (>1 GeV) gamma-ray sky. In this paper we describe the detector layout and present an overview of the main scientific goals both in the domain of astrophysics: cosmic- ray origin, age and propagation and the exploration of the most energetic gamma-ray sources; and in the domain of astroparticle: the antimatter and the dark matter searches. (53 refs).

Cryogenic system for the HERA magnet measurement facility

International Nuclear Information System (INIS)

Barton, H.R. Jr.; Clausen, M.; Kebler, G.

1986-01-01

This paper describes the design for a helium, cryogenic distribution system that allows independent operation and testing of superconducting magnets of the HERA project before they are installed in the 6-km ring tunnel. The 820-GeV proton storage ring of HERA will contain approximately 650 magnets having superconducting coils which are clamped by aluminum/stainless-steel collars and surrounded by a yoke of magnetic iron at liquid helium temperature. When the magnets arive at DESY from the manufacture, each magnet will be individually tested at helium operating conditions in the magnet measurement facility to insure the quality of the magnetic characteristics and the cryogenic performance. The capabilities of the cryogenic system and the schedule for magnet testing are discussed

Nuclear astrophysics with radioactive beams: a TRIUMF perspective

International Nuclear Information System (INIS)

Shotter, A.C.

2003-01-01

Explosive nuclear burning in stellar environments involves reactions with a wide range of isotopes. For isotopes that are unstable, information on relevant reaction rates can only generally be obtained at radioactive beam facilities. The ISAC facility at TRIUMF is purpose built to provide a wide range of radioactive beams for nuclear astrophysics purposes as well as a range of other science

Superconducting magnet package for the TESLA test facility

International Nuclear Information System (INIS)

Koski, A.; Bandelmann, R.; Wolff, S.

1996-01-01

The magnetic lattice of the TeV electron superconducting linear accelerator (TESLA) will consist of superconducting quadrupoles for beam focusing and superconducting correction dipoles for beam steering, incorporated in the cryostats containing the superconducting cavities. This report describes the design of these magnets, presenting details of the magnetic as well as the mechanical design. The measured characteristics of the TESLA Test Facility (TTF) quadrupoles and dipoles are compared to the results obtained from numerical computations

Cosmological grand unification monopoles: astrophysical constraints

International Nuclear Information System (INIS)

Fry, J.N.

1982-01-01

I review the general arguments which suggest that relic GU magnetic monopoles should emerge from the early universe, and I discuss several astrophysical settings in which their effects could be, but are not, observed. This places limits on their possible flux, and their abundance bound to more ordinary material

Cosmic magnetic fields

CERN Document Server

Kronberg, Philipp P

2016-01-01

Magnetic fields are important in the Universe and their effects contain the key to many astrophysical phenomena that are otherwise impossible to understand. This book presents an up-to-date overview of this fast-growing topic and its interconnections to plasma processes, astroparticle physics, high energy astrophysics, and cosmic evolution. The phenomenology and impact of magnetic fields are described in diverse astrophysical contexts within the Universe, from galaxies to the filaments and voids of the intergalactic medium, and out to the largest redshifts. The presentation of mathematical formulae is accessible and is designed to add insight into the broad range of topics discussed. Written for graduate students and researchers in astrophysics and related disciplines, this volume will inspire readers to devise new ways of thinking about magnetic fields in space on galaxy scales and beyond.

Theoretical nuclear structure and astrophysics at FAIR

International Nuclear Information System (INIS)

Rodríguez, Tomás R

2014-01-01

Next generation of radioactive ion beam facilities like FAIR will open a bright future for nuclear structure and nuclear astrophysics research. In particular, very exotic nuclei (mainly neutron rich) isotopes will be produced and a lot of new exciting experimental data will help to test and improve the current nuclear models. In addition, these data (masses, reaction cross sections, beta decay half-lives, etc.) combined with the development of better theoretical approaches will be used as the nuclear physics input for astrophysical simulations. In this presentation I will review some of the state-of-the-art nuclear structure methods and their applications.

Simulations of Dynamo and Magnetorotational Instability in Madison Plasma Experiments and Astrophysical Disks

Energy Technology Data Exchange (ETDEWEB)

Ebrahimi, Fatima [Princeton Univ., NJ (United States). Dept. of Astrophysical Sciences

2018-02-22

Magnetic fields are observed to exist on all scales in many astrophysical sources such as stars, galaxies, and accretion discs. Understanding the origin of large scale magnetic fields, whereby the field emerges on spatial scales large compared to the fluctuations, has been a particularly long standing challenge. Our physics objective are: 1) what are the minimum ingredients for large-scale dynamo growth? 2) could a large-scale magnetic field grow out of turbulence and sustained despite the presence of dissipation? These questions are fundamental for understanding the large-scale dynamo in both laboratory and astrophysical plasmas. Here, we report major new findings in the area of Large-Scale Dynamo (magnetic field generation).

THE SZ EFFECT IN THE PLANCK ERA: ASTROPHYSICAL AND COSMOLOGICAL IMPACT

Directory of Open Access Journals (Sweden)

Sergio Colafrancesco

2013-12-01

Full Text Available The Sunyaev–Zel’dovich effect (SZE is a relevant probe for cosmology and particle astrophysics. The Planck Era marks a definite step forward in the use of this probe for astrophysics and cosmology. Astrophysical applications to galaxy clusters, galaxies, radiogalaxies and large-scale structures are discussed. Cosmological relevance for the Dark Energy equation of state, modified Gravity scenarios, Dark Matter search, cosmic magnetism and other cosmological applications is also reviewed. Future directions for the study of the SZE and its polarization are finally outlined.

Astrophysical fluid dynamics

Science.gov (United States)

Ogilvie, Gordon I.

2016-06-01

> These lecture notes and example problems are based on a course given at the University of Cambridge in Part III of the Mathematical Tripos. Fluid dynamics is involved in a very wide range of astrophysical phenomena, such as the formation and internal dynamics of stars and giant planets, the workings of jets and accretion discs around stars and black holes and the dynamics of the expanding Universe. Effects that can be important in astrophysical fluids include compressibility, self-gravitation and the dynamical influence of the magnetic field that is `frozen in' to a highly conducting plasma. The basic models introduced and applied in this course are Newtonian gas dynamics and magnetohydrodynamics (MHD) for an ideal compressible fluid. The mathematical structure of the governing equations and the associated conservation laws are explored in some detail because of their importance for both analytical and numerical methods of solution, as well as for physical interpretation. Linear and nonlinear waves, including shocks and other discontinuities, are discussed. The spherical blast wave resulting from a supernova, and involving a strong shock, is a classic problem that can be solved analytically. Steady solutions with spherical or axial symmetry reveal the physics of winds and jets from stars and discs. The linearized equations determine the oscillation modes of astrophysical bodies, as well as their stability and their response to tidal forcing.

Magnet Design Considerations for Fusion Nuclear Science Facility

Energy Technology Data Exchange (ETDEWEB)

Zhai, Y. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Kessel, C. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); El-Guebaly, L. [Univ. of Wisconsin, Madison, WI (United States) Fusion Technology Institute; Titus, P. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

2016-06-01

The Fusion Nuclear Science Facility (FNSF) is a nuclear confinement facility that provides a fusion environment with components of the reactor integrated together to bridge the technical gaps of burning plasma and nuclear science between the International Thermonuclear Experimental Reactor (ITER) and the demonstration power plant (DEMO). Compared with ITER, the FNSF is smaller in size but generates much higher magnetic field, i.e., 30 times higher neutron fluence with three orders of magnitude longer plasma operation at higher operating temperatures for structures surrounding the plasma. Input parameters to the magnet design from system code analysis include magnetic field of 7.5 T at the plasma center with a plasma major radius of 4.8 m and a minor radius of 1.2 m and a peak field of 15.5 T on the toroidal field (TF) coils for the FNSF. Both low-temperature superconductors (LTS) and high-temperature superconductors (HTS) are considered for the FNSF magnet design based on the state-of-the-art fusion magnet technology. The higher magnetic field can be achieved by using the high-performance ternary restacked-rod process Nb3Sn strands for TF magnets. The circular cable-in-conduit conductor (CICC) design similar to ITER magnets and a high-aspect-ratio rectangular CICC design are evaluated for FNSF magnets, but low-activation-jacket materials may need to be selected. The conductor design concept and TF coil winding pack composition and dimension based on the horizontal maintenance schemes are discussed. Neutron radiation limits for the LTS and HTS superconductors and electrical insulation materials are also reviewed based on the available materials previously tested. The material radiation limits for FNSF magnets are defined as part of the conceptual design studies for FNSF magnets.

Fermilab R and D test facility for SSC magnets

International Nuclear Information System (INIS)

Strait, J.; Bleadon, M.; Hanft, R.; Lamm, M.; McGuire, K.; Mantsch, P.; Mazur, P.O.; Orris, D.; Pachnik, J.

1989-01-01

The test facility used for R and D testing of full scale development dipole magnets for the SSC is described. The Fermilab Magnet Test Facility, originally built for production testing of Tevatron magnets, has been substantially modified to allow testing also of SSC magnets. Two of the original six test stands have been rebuilt to accommodate testing of SSC magnets at pressures between 1.3 Atm and 4 Atm and at temperatures between 1.8 K and 4.8 K and the power system has been modified to allow operation to at least 8 kA. Recent magnets have been heavily instrumented with voltage taps to allow detailed study of quench location and propagation and with strain gage based stress, force and motion transducers. A data acquisition system has been built with a capacity to read from each SSC test stand up to 220 electrical quench signals, 32 dynamic pressure, temperature and mechanical transducer signals during quench and up to 200 high precision, low time resolution, pressure, temperature and mechanical transducer signals. The quench detection and protection systems is also described. 23 refs., 4 figs. 2 tabs

VI European Summer School on Experimental Nuclear Astrophysics

Science.gov (United States)

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.

A Laboratory Astrophysical Jet to Study Canonical Flux Tubes

Energy Technology Data Exchange (ETDEWEB)

You, Setthivoine [Univ. of Washington, Seattle, WA (United States)

2017-12-20

Understanding the interaction between plasma flows and magnetic fields remains a fundamental problem in plasma physics, with important applications to astrophysics, fusion energy, and advanced space propulsion. For example, flows are of primary importance in astrophysical jets even if it is not fully understood how jets become so long without becoming unstable. Theories for the origin of magnetic fields in the cosmos rely on flowing charged fluids that should generate magnetic fields, yet this remains to be demonstrated experimentally. Fusion energy reactors can be made smaller with flows that improve stability and confinement. Advanced space propulsion could be more efficient with collimated and stable plasma flows through magnetic nozzles but must eventually detach from the nozzle. In all these cases, there appears to be a spontaneous emergence of flowing and/or magnetic structures, suggesting a form of self-organization in plasmas. Beyond satisfying simple intellectual curiosity, understanding plasma self-organization could enable the development of methods to control plasma structures for fusion energy, space propulsion, and other applications. The research project has therefore built a theory and an experiment to investigate the interaction between magnetic fields and plasma flows. The theory is called canonical field theory for short, and the experiment is called Mochi after a rice cake filled with surprising, yet delicious fillings.

BigData as a Driver for Capacity Building in Astrophysics

Science.gov (United States)

Shastri, Prajval

2015-08-01

Exciting public interest in astrophysics acquires new significance in the era of Big Data. Since Big Data involves advanced technologies of both software and hardware, astrophysics with Big Data has the potential to inspire young minds with diverse inclinations - i.e., not just those attracted to physics but also those pursuing engineering careers. Digital technologies have become steadily cheaper, which can enable expansion of the Big Data user pool considerably, especially to communities that may not yet be in the astrophysics mainstream, but have high potential because of access to thesetechnologies. For success, however, capacity building at the early stages becomes key. The development of on-line pedagogical resources in astrophysics, astrostatistics, data-mining and data visualisation that are designed around the big facilities of the future can be an important effort that drives such capacity building, especially if facilitated by the IAU.

Focusing Telescopes in Nuclear Astrophysics

CERN Document Server

Ballmoos, Peter von

2007-01-01

This volume is the first of its kind on focusing gamma-ray telescopes. Forty-eight refereed papers provide a comprehensive overview of the scientific potential and technical challenges of this nascent tool for nuclear astrophysics. The book features articles dealing with pivotal technologies such as grazing incident mirrors, multilayer coatings, Laue- and Fresnel-lenses - and even an optic using the curvature of space-time. The volume also presents an overview of detectors matching the ambitious objectives of gamma ray optics, and facilities for operating such systems on the ground and in space. The extraordinary scientific potential of focusing gamma-ray telescopes for the study of the most powerful sources and the most violent events in the Universe is emphasized in a series of introductory articles. Practicing professionals, and students interested in experimental high-energy astrophysics, will find this book a useful reference

Astrophysics a new approach

CERN Document Server

Kundt, Wolfgang

2005-01-01

For a quantitative understanding of the physics of the universe - from the solar system through the milky way to clusters of galaxies all the way to cosmology - these edited lecture notes are perhaps among the most concise and also among the most critical ones: Astrophysics has not yet stood the redundancy test of laboratory physics, hence should be wary of early interpretations. Special chapters are devoted to magnetic and radiation processes, supernovae, disks, black-hole candidacy, bipolar flows, cosmic rays, gamma-ray bursts, image distortions, and special sources. At the same time, planet earth is viewed as the arena for life, with plants and animals having evolved to homo sapiens during cosmic time. -- This text is unique in covering the basic qualitative and quantitative tools, formulae as well as numbers, needed for the precise interpretation of frontline phenomena in astrophysical research. The author compares mainstream interpretations with new and even controversial ones he wishes to emphasize. The...

Super Conducting and Conventional Magnets Test & Mapping Facilities

Data.gov (United States)

Federal Laboratory Consortium — Vertical Magnet Test Facility: Accommodate a device up to 3.85 m long, 0.61 m diameter, and 14,400 lbs. Configured for 5 psig sub-cooled liquid helium bath cooling...

Exploring the cosmic frontier. Astrophysical instruments for the 21st century

International Nuclear Information System (INIS)

Lobanov, A.P.; Zensus, J.A.; Cesarsky, C.; Diamond, P.

2007-01-01

In the coming decades, astrophysical science will benefit enormously from the construction and operation of several major international ground- and space based facilities, such as ALMA, Herschel/Planck, and SKA in the far infrared to radio band, Extremely Large Telescopes, JWST and GAIA in the optical to near infrared regime, XEUS and Constellation-X in the X-ray, and GLAST in the Gamma-ray regime. These and other new instruments will have a major impact in a wide range of scientific topics including the cosmological epoch of reionization, galactic dynamics and nuclear activity, stellar astronomy, extra-solar planets, gamma-ray bursts, X-ray binaries, and many others. On May 18-21, 2004, the Max-Planck-Society's Harnack-Haus in Dahlem, Berlin hosted the international symposium ''Exploring the Cosmic Frontier: Astrophysical Instruments for the 21st Century''. The symposium in Berlin was dedicated to exploring the complementarity and synergies between different branches of astrophysical research, by presenting and discussing the fundamental scientific problems that will be addressed by major future astrophysical facilities in the next few decades. This book contains 70 papers from the meeting and is intended to give a lasting account of a snapshot of an evolving scientific discourse and interaction throughout our field of research. (orig.)

Magnetically-coupled microcalorimeter arrays for x-ray astrophysics

Science.gov (United States)

Bandler, Simon

The "X-ray Surveyor" has been listed by NASA as one of the four major large mission concepts to be studied in the next Astrophysics Decadal Review in its preliminary list of large concepts. One of the key instruments on such a mission would be a very large format X-ray microcalorimeter array, with an array size of greater than 100 thousand pixels. Magnetically-coupled microcalorimeters (MCC) are one of the technologies with the greatest potential to meet the requirements of this mission, and this proposal is one to carry out research specifically to reach the goals of this vision. The "X-ray Surveyor" is a concept for a future mission that will make X-ray observations that are instrumental to understanding the quickly emerging population of galaxies and supermassive black holes at z ~10. The observations will trace the formation of galaxies and their assembly into large-scale structures starting from the earliest possible epochs. This mission would be observing baryons and large-scale physical processes outside of the very densest regions in the local Universe. This can be achieved with an X-ray observatory with similar angular resolution as Chandra but with significantly improved optic area and detector sensitivity. Chandra-scale angular resolution (1" or better) is essential in building more powerful, higher throughput observatories to avoid source confusion and remain photon-limited rather than background-limited. A prime consideration for the microcalorimeter camera on this type of mission is maintaining ~ 1 arcsec spatial resolution over the largest possible field of view, even if this means a slight trade-off against the spectral resolution. A uniform array of 1" pixels covering at least 5'x5' field of view is desired. To reduce the number of sensors read out, in geometries where extremely fine pitch (~50 microns) is desired, the most promising technologies are those in which a thermal sensor such an MCC can read out a sub-array of 20-25 individual 1'�

NEW METHODS AND FACILITIES OF MAGNETIC CONTROL OF THE MECHANICAL CHARACTERISTICS OF ARTICLES

Directory of Open Access Journals (Sweden)

V. F. Matjuk

2004-01-01

Full Text Available There are given the results of development in the State scientific university ''Institute of applied physics of the National Academy of Sciences of Belarus” of the facilities for magnetic control of the steels mechanical characteristics - coercimeter KIPF-1, impulse magnetic analyzers IMA- 4M, IMA-5B, impulse magnetic installations IMPOK-IB and facilities of their metrological support. The information about the scale of , using IS given.

NASA Ames’ COSmIC Laboratory Astrophysics Facility: Recent Results and Progress

Science.gov (United States)

Salama, Farid; Sciamma-O'Brien, Ella; Bejaoui, Salma

2018-06-01

The COSmIC facility was developed at NASA Ames to study interstellar, circumstellar and planetary analogs in the laboratory [1, 2]. COSmIC stands for “Cosmic Simulation Chamber” and is dedicated to the study of molecules, ions and nanoparticles under the low temperature and high vacuum conditions that are required to simulate space environments. COSmIC integrates a variety of instruments that allow generating; processing and monitoring simulated space conditions in the laboratory. It is composed of a Pulsed Discharge Nozzle expansion that generates a plasma in a free supersonic jet expansion coupled to high-sensitivity, complementary in situ diagnostic tools, used for the detection and characterization of the species present in the expansion: a Cavity Ring Down Spectroscopy (CRDS) and fluorescence spectroscopy systems for photonic detection, and a Reflectron Time-Of-Flight Mass Spectrometer (ReTOF-MS) for mass detection [3, 4].Recent advances achieved in laboratory astrophysics using COSmIC will be presented, in particular in the domain of the diffuse interstellar bands (DIBs) [5, 6] and the monitoring, in the laboratory, of the formation of dust grains and aerosols from their gas-phase molecular precursors in environments as varied as circumstellar outflows [7] and planetary atmospheres [8, 9, 10]. Plans for future laboratory experiments on cosmic molecules and grains in the growing field of laboratory astrophysics (NIR-MIR CRDS, Laser Induced Fluorescence spectra of cosmic molecule analogs and the laser induced incandescence spectra of cosmic grain analogs) will also be addressed as well as the implications for astronomy.References: [1] Salama F., Proceed. IAU S251, Kwok & Sandford eds. CUP, 4, 357 (2008).[2] Salama F., et al., Proceed. IAU S332, Y. Aikawa, M. Cunningham, T. Millar, eds., CUP (2018)[3] Biennier L., et al., J. Chem. Phys., 118, 7863 (2003)[4] Ricketts C. et al. IJMS, 300, 26 (2011)[5] Salama F., et al., ApJ., 728, 154 (2011)[6] EDIBLES

Superconducting magnet development capability of the LLNL [Lawrence Livermore National Laboratory] High Field Test Facility

International Nuclear Information System (INIS)

Miller, J.R.; Shen, S.; Summers, L.T.

1990-02-01

This paper discusses the following topics: High-Field Test Facility Equipment at LLNL; FENIX Magnet Facility; High-Field Test Facility (HFTF) 2-m Solenoid; Cryogenic Mechanical Test Facility; Electro-Mechanical Conductor Test Apparatus; Electro-Mechanical Wire Test Apparatus; FENIX/HFTF Data System and Network Topology; Helium Gas Management System (HGMS); Airco Helium Liquefier/Refrigerator; CTI 2800 Helium Liquefier; and MFTF-B/ITER Magnet Test Facility

Novel laboratory simulations of astrophysical jets

Science.gov (United States)

Brady, Parrish Clawson

This thesis was motivated by the promise that some physical aspects of astrophysical jets and collimation processes can be scaled to laboratory parameters through hydrodynamic scaling laws. The simulation of astrophysical jet phenomena with laser-produced plasmas was attractive because the laser- target interaction can inject energetic, repeatable plasma into an external environment. Novel laboratory simulations of astrophysical jets involved constructing and using the YOGA laser, giving a 1064 nm, 8 ns pulse laser with energies up to 3.7 + 0.2 J . Laser-produced plasmas were characterized using Schlieren, interferometry and ICCD photography for their use in simulating jet and magnetosphere physics. The evolution of the laser-produced plasma in various conditions was compared with self-similar solutions and HYADES computer simulations. Millimeter-scale magnetized collimated outflows were produced by a centimeter scale cylindrically symmetric electrode configuration triggered by a laser-produced plasma. A cavity with a flared nozzle surrounded the center electrode and the electrode ablation created supersonic uncollimated flows. This flow became collimated when the center electrode changed from an anodeto a cathode. The plasma jets were in axially directed permanent magnetic fields with strengths up to 5000 Gauss. The collimated magnetized jets were 0.1-0. 3 cm wide, up to 2.0 cm long, and had velocities of ~4.0 × 10 6 cm/s. The dynamics of the evolution of the jet were compared qualitatively and quantitatively with fluxtube simulations from Bellan's formulation [6] giving a calculated estimate of ~2.6 × 10 6 cm/s for jet evolution velocity and evidence for jet rotation. The density measured with interferometry was 1.9 ± 0.2 × 10 17 cm -3 compared with 2.1 × 10 16 cm -3 calculated with Bellan's pressure balance formulation. Kinks in the jet column were produced consistent with the Kruskal-Shafranov condition which allowed stable and symmetric jets to form with

The test facility for the short prototypes of the LHC superconducting magnets

International Nuclear Information System (INIS)

Delsolaro, W. Venturini; Arn, A.; Bottura, L.; Giloux, C.; Mompo, R.; Siemko, A.; Walckiers, L.

2002-01-01

The LHC development program relies on cryogenic tests of prototype and model magnets. This vigorous program is pursued in a dedicated test facility based on several vertical cryostats working at superfluid helium temperatures. The performance of the facility is detailed. Goals and test equipment for currently performed studies are reviewed: quench analysis and magnet protection studies, measurement of the field quality, test of ancillary electrical equipment like diodes and busbars. The paper covers the equipment available for tests of prototypes and some special series of LHC magnets to come

The test facility for the short prototypes of the LHC superconducting magnets

Science.gov (United States)

Delsolaro, W. Venturini; Arn, A.; Bottura, L.; Giloux, C.; Mompo, R.; Siemko, A.; Walckiers, L.

2002-05-01

The LHC development program relies on cryogenic tests of prototype and model magnets. This vigorous program is pursued in a dedicated test facility based on several vertical cryostats working at superfluid helium temperatures. The performance of the facility is detailed. Goals and test equipment for currently performed studies are reviewed: quench analysis and magnet protection studies, measurement of the field quality, test of ancillary electrical equipment like diodes and busbars. The paper covers the equipment available for tests of prototypes and some special series of LHC magnets to come.

Similarity and self-similarity in high energy density physics: application to laboratory astrophysics

International Nuclear Information System (INIS)

Falize, E.

2008-10-01

The spectacular recent development of powerful facilities allows the astrophysical community to explore, in laboratory, astrophysical phenomena where radiation and matter are strongly coupled. The titles of the nine chapters of the thesis are: from high energy density physics to laboratory astrophysics; Lie groups, invariance and self-similarity; scaling laws and similarity properties in High-Energy-Density physics; the Burgan-Feix-Munier transformation; dynamics of polytropic gases; stationary radiating shocks and the POLAR project; structure, dynamics and stability of optically thin fluids; from young star jets to laboratory jets; modelling and experiences for laboratory jets

Magnetic fields in diffuse media

CERN Document Server

Pino, Elisabete; Melioli, Claudio

2015-01-01

This volume presents the current knowledge of magnetic fields in diffuse astrophysical media. Starting with an overview of 21st century instrumentation to observe astrophysical magnetic fields, the chapters cover observational techniques, origin of magnetic fields, magnetic turbulence, basic processes in magnetized fluids, the role of magnetic fields for cosmic rays, in the interstellar medium and for star formation. Written by a group of leading experts the book represents an excellent overview of the field. Nonspecialists will find sufficient background to enter the field and be able to appreciate the state of the art.

Radiative properties of astrophysical matter: a quest to reproduce astrophysical conditions on earth

International Nuclear Information System (INIS)

Bailey, James E.

2010-01-01

Experiments in terrestrial laboratories can be used to evaluate the physical models that interpret astronomical observations. The properties of matter in astrophysical objects are essential components of these models, but terrestrial laboratories struggle to reproduce the extreme conditions that often exist. Megajoule-class DOE/NNSA facilities such as the National Ignition Facility and Z can create unprecedented amounts of matter at extreme conditions, providing new capabilities to test astrophysical models with high accuracy. Experiments at these large facilities are challenging, and access is very competitive. However, the cylindrically-symmetric Z source emits radiation in all directions, enabling multiple physics experiments to be driven with a single Z discharge. This helps ameliorate access limitations. This article describes research efforts under way at Sandia National Laboratories Z facility investigating radiation transport through stellar interior matter, population kinetics of atoms exposed to the intense radiation emitted by accretion powered objects, and spectral line formation in white dwarf (WD) photospheres. Opacity quantifies the absorption of radiation by matter and strongly influences stellar structure and evolution, since radiation dominates energy transport deep inside stars. Opacity models have become highly sophisticated, but laboratory tests at the conditions existing inside stars have not been possible - until now. Z research is presently focused on measuring iron absorption at conditions relevant to the base of the solar convection zone, where the electron temperature and density are 190 eV and 9 x 10 22 e/cc, respectively. Creating these conditions in a sample that is sufficiently large, long-lived, and uniform is extraordinarily challenging. A source of radiation that streams through the relatively-large samples can produce volumetric heating and thus, uniform conditions, but to achieve high temperatures a strong source is required. Z

A New Facility for Testing Superconducting Solenoid Magnets with Large Fringe Fields at Fermilab

Energy Technology Data Exchange (ETDEWEB)

Orris, D. [Fermilab; Carcagno, R. [Fermilab; Nogiec, J. [Fermilab; Rabehl, R. [Fermilab; Sylvester, C. [Fermilab; Tartaglia, M. [Fermilab

2013-09-01

Testing superconducting solenoid with no iron flux return can be problematic for a magnet test facility due to the large magnetic fringe fields generated. These large external fields can interfere with the operation of equipment while precautions must be taken for personnel supporting the test. The magnetic forces between the solenoid under test and the external infrastructure must also be taken under consideration. A new test facility has been designed and built at Fermilab specifically for testing superconducting magnets with large external fringe fields. This paper discusses the test stand design, capabilities, and details of the instrumentation and controls with data from the first solenoid tested in this facility: the Muon Ionization Cooling Experiment (MICE) coupling coil.

A 12 coil superconducting bumpy torus magnet facility for plasma research

Science.gov (United States)

Roth, J. R.; Holmes, A. D.; Keller, T. A.; Krawczonek, W. M.

1972-01-01

A summary is presented of the performance of the two-coil superconducting pilot rig which preceded the NASA Lewis bumpy torus. This pilot rig was operated for 550 experimental runs over a period of 7 years. The NASA Lewis bumpy torus facility consists of 12 superconducting coils, each with a 19 cm in diameter and capable of producing magnetic field strengths of 3.0 teslas on their axes. The magnets are equally spaced around a major circumference 1.52 m in diameter, and are mounted with the major axis of the torus vertical in a single vacuum tank 2.59 m in diameter. The design value of maximum magnetic field on the magnetic axis (3.0 teslas) was reached and exceeded. A maximum magnetic field of 3.23 teslas was held for a period of 60 minutes, and the coils did not go to normal. When the coils were charged to a maximum magnetic field of 3.35 teslas, the coil system was driven normal without damage to the facility.

Facile microwave synthesis of uniform magnetic nanoparticles with minimal sample processing

Energy Technology Data Exchange (ETDEWEB)

Schneider, Thomas, E-mail: tom.schneider@ubc.ca [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, V6T 1Z3 Canada (Canada); Löwa, Anna; Karagiozov, Stoyan [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, V6T 1Z3 Canada (Canada); Sprenger, Lisa [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, V6T 1Z3 Canada (Canada); TU Dresden, Chair of Magnetofluiddynamics, Measuring and Automation Technology, Dresden, 01062 Germany (Germany); Gutiérrez, Lucía [Instituto Universitario de Nanociencia de Aragón (INA), University of Zaragoza, Zaragoza, 50018 Spain (Spain); Esposito, Tullio; Marten, Gernot; Saatchi, Katayoun [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, V6T 1Z3 Canada (Canada); Häfeli, Urs O., E-mail: urs.hafeli@ubc.ca [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, V6T 1Z3 Canada (Canada)

2017-01-01

We present a simple and rapid method for the synthesis of small magnetic nanoparticles (diameters in the order of 5–20 nm) and narrow size distributions (CV's of 20–40%). The magnetite nanoparticles were synthesized in green solvents within minutes and the saturation magnetization of the particles was tunable by changes in the reaction conditions. We show that this particle synthesis method requires minimal processing steps and we present the successful coating of the particles with reactive bisphosphonates after synthesis without washing or centrifugation. We found minimal batch-to-batch variability and show the scalability of the particle synthesis method. We present a full characterization of the particle properties and believe that this synthesis method holds great promise for facile and rapid generation of magnetic nanoparticles with defined surface coatings for magnetic targeting applications. - Highlights: ●Rapid and facile synthesis of magnetic nanoparticles. ●Microwave synthesis in green solvent. ●Magnetite MNPs with small sizes and high saturation magnetization. ●Tunable particle properties depending on heating duration. ●Scalable MNP synthesis.

Laboratory Astrophysics Experiments to Study Star Formation

Science.gov (United States)

Young, Rachel

As a thesis project, I devised and implemented a scaled accretion shock experiment on the OMEGA laser (Laboratory for Laser Energetics). This effort marked the first foray into the growing field of laser-created magnetized flowing plasmas for the Center for Laser Experimental Astrophysical Research (CLEAR) here at the University of Michigan. Accretion shocks form when streams of accreting material fall to the surface of a young, growing star along magnetic field lines and, due to their supersonic flow, create shocks. As I was concerned with what was happening immediately on the surface of the star where the shock forms, I scaled the system by launching a plasma jet (the "accreting flow") and driving it into a solid surface (the "stellar surface") in the presence of an imposed magnetic field parallel to the jet flow (locally analogous to the dipole field of the star). Early work for this thesis project was dedicated to building a magnetized flowing plasma platform at CLEAR. I investigated a method for launching collimated plasma jets and studied them using Thomson scattering, a method which measures parameters such as temperature and density by scattering a probe beam off the experimental plasma. Although the data were corrupted with probe heating effects, I overcame this problem by finding the mass density of the jets and using it to determine they were isothermal rarefactions with a temperature of 6 eV. Scaling an astrophysical phenomenon to the laboratory requires tailoring the parameters of the experiment to preserve its physics, rather than creating an experiment that merely superficially resembles it. I ensured this by distilling the driving physical processes of the astrophysical system--accretion shocks--into a list of dimensionless number constraints and mapping these into plasma parameter space. Due to this project being the first magnetized flowing plasma effort at CLEAR, it suffered the growing pains typical of a young research program. Of my two primary

Nuclear astrophysics: Recent results on CNO-cycle reactions and AGB nucleosynthesis

International Nuclear Information System (INIS)

La Cognata, M.

2011-01-01

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, < 100 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 and new experimental facilities such as deep underground laboratories have been devised yielding new cutting-edge results.

Preface to special topic: High-energy density laboratory astrophysics

International Nuclear Information System (INIS)

Glenzer, Siegfried H

2017-01-01

Here, in the 1990s, when the large inertial confinement fusion facilities in the United States became accessible for discovery-class research, physicists soon realized that the combination of these energetic drivers with precision plasmas diagnostics would allow the unprecedented experimental study of astrophysical problems.

Design and development of a 3 axis magnetic field measurement facility using Hall probe

International Nuclear Information System (INIS)

Sahoo, Shantonu; Bhattacharyya, Sumantra; Chaddha, Niraj; Mishra, Santosh Kr.; Nandy, Partha P.; Nandi, Chinmay; Bhole, Rajendra B.; Pal, Sarbajit; Pal, Gautam

2015-01-01

A 3-axis drive system has been designed and developed in-house to measure the magnetic field with positional accuracy of 0.2 mm in a volume of 1.5 x 1.3 x 0.15 cubic-meter. Hall sensor based magnetometer is used to measure the magnetic field with a precision of 100 μT(1 Gauss). The drive of each axis has linear guide and zero backlash ball screw combination to achieve accurate movement of the hall probe with positional repeatability of +/- 0.2 micron per 50 mm. The hardware and software, also developed in-house, facilitate precise probe positioning and sophisticated visualization of field map. Dedicated microcontroller based motor controllers and encoder read-out cards for each axis have been developed. The facility is integrated with a rich touch-screen based intelligent GUI for automated scanning and data acquisition. This facility can be used for accurate magnetic field mapping of big dipole magnets, solenoids, etc. The facility has been tested successfully to characterize a Dipole Magnet designed for Radioactive Ion Beam (RIB) facility. (author)

Astrophysical Gyrokinetics: Kinetic and Fluid Turbulent Cascades In Magnetized Weakly Collisional Plasmas

International Nuclear Information System (INIS)

Schekochihin, A.A.; Cowley, S.C.; Dorland, W.; Hammett, G.W.; Howes, G.G.; Quataert, E.; Tatsuno, T.

2009-01-01

This paper presents a theoretical framework for understanding plasma turbulence in astrophysical plasmas. It is motivated by observations of electromagnetic and density fluctuations in the solar wind, interstellar medium and galaxy clusters, as well as by models of particle heating in accretion disks. All of these plasmas and many others have turbulent motions at weakly collisional and collisionless scales. The paper focuses on turbulence in a strong mean magnetic field. The key assumptions are that the turbulent fluctuations are small compared to the mean field, spatially anisotropic with respect to it and that their frequency is low compared to the ion cyclotron frequency. The turbulence is assumed to be forced at some system-specific outer scale. The energy injected at this scale has to be dissipated into heat, which ultimately cannot be accomplished without collisions. A kinetic cascade develops that brings the energy to collisional scales both in space and velocity. The nature of the kinetic cascade in various scale ranges depends on the physics of plasma fluctuations that exist there. There are four special scales that separate physically distinct regimes: the electron and ion gyroscales, the mean free path and the electron diffusion scale. In each of the scale ranges separated by these scales, the fully kinetic problem is systematically reduced to a more physically transparent and computationally tractable system of equations, which are derived in a rigorous way. In the 'inertial range' above the ion gyroscale, the kinetic cascade separates into two parts: a cascade of Alfvenic fluctuations and a passive cascade of density and magnetic-field strength fluctuations. The former are governed by the Reduced Magnetohydrodynamic (RMHD) equations at both the collisional and collisionless scales; the latter obey a linear kinetic equation along the (moving) field lines associated with the Alfvenic component (in the collisional limit, these compressive fluctuations

Astrophysical data analysis with information field theory

International Nuclear Information System (INIS)

Enßlin, Torsten

2014-01-01

Non-parametric imaging and data analysis in astrophysics and cosmology can be addressed by information field theory (IFT), a means of Bayesian, data based inference on spatially distributed signal fields. IFT is a statistical field theory, which permits the construction of optimal signal recovery algorithms. It exploits spatial correlations of the signal fields even for nonlinear and non-Gaussian signal inference problems. The alleviation of a perception threshold for recovering signals of unknown correlation structure by using IFT will be discussed in particular as well as a novel improvement on instrumental self-calibration schemes. IFT can be applied to many areas. Here, applications in in cosmology (cosmic microwave background, large-scale structure) and astrophysics (galactic magnetism, radio interferometry) are presented

Astrophysical data analysis with information field theory

Science.gov (United States)

Enßlin, Torsten

2014-12-01

Non-parametric imaging and data analysis in astrophysics and cosmology can be addressed by information field theory (IFT), a means of Bayesian, data based inference on spatially distributed signal fields. IFT is a statistical field theory, which permits the construction of optimal signal recovery algorithms. It exploits spatial correlations of the signal fields even for nonlinear and non-Gaussian signal inference problems. The alleviation of a perception threshold for recovering signals of unknown correlation structure by using IFT will be discussed in particular as well as a novel improvement on instrumental self-calibration schemes. IFT can be applied to many areas. Here, applications in in cosmology (cosmic microwave background, large-scale structure) and astrophysics (galactic magnetism, radio interferometry) are presented.

Astrophysical data analysis with information field theory

Energy Technology Data Exchange (ETDEWEB)

Enßlin, Torsten, E-mail: ensslin@mpa-garching.mpg.de [Max Planck Institut für Astrophysik, Karl-Schwarzschild-Straße 1, D-85748 Garching, Germany and Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, D-80539 München (Germany)

2014-12-05

Non-parametric imaging and data analysis in astrophysics and cosmology can be addressed by information field theory (IFT), a means of Bayesian, data based inference on spatially distributed signal fields. IFT is a statistical field theory, which permits the construction of optimal signal recovery algorithms. It exploits spatial correlations of the signal fields even for nonlinear and non-Gaussian signal inference problems. The alleviation of a perception threshold for recovering signals of unknown correlation structure by using IFT will be discussed in particular as well as a novel improvement on instrumental self-calibration schemes. IFT can be applied to many areas. Here, applications in in cosmology (cosmic microwave background, large-scale structure) and astrophysics (galactic magnetism, radio interferometry) are presented.

Solving the relativistic Rankine-Hugoniot condition in the presence of a magnetic field in the astrophysical scenario of a neutron star

International Nuclear Information System (INIS)

Mallick, Ritam

2011-01-01

The Rankine-Hugoniot condition has been solved to study phase transition in an astrophysical scenario mainly in the case of phase transition from a neutron star (NS) to a quark star (QS). The equations of state and temperature play a huge role in determining the nature of the front propagation, which brings about the phase transition in a NS. The shock jump conditions can be solved analytically, but the situation changes drastically by the inclusion of the magnetic field. High magnetic fields, which are always associated with a NS play a huge role in determining the structure and evolution of a NS. So, a magnetic field has been introduced in the shock jump condition in the de Hoffmann-Teller frame. The modified conservation condition for the perpendicular and oblique shocks is obtained in this frame. Numerical solution of the perpendicular shock has been obtained, which shows considerable deviation from the nonmagnetic case. The results show that the magnetic field helps in shock generation. It also indirectly hints at the instability of the matter and thereby the NS for very high magnetic field, implying that NSs can only support a magnetic field of some finite strength.

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Astrophysics and Astronomy; Volume 21; Issue 3-4. Tomography of the Solar Wind using Interplanetary Scintillation. Divya Oberoi A. Pramesh Rao. Session XI – Solar Wind & Interplanetary Magnetic Fields Volume 21 Issue 3-4 September-December 2000 pp 445-446 ...

PANDORA, a new facility for interdisciplinary in-plasma physics

Science.gov (United States)

Mascali, D.; Musumarra, A.; Leone, F.; Romano, F. P.; Galatà, A.; Gammino, S.; Massimi, C.

2017-07-01

PANDORA, Plasmas for Astrophysics, Nuclear Decays Observation and Radiation for Archaeometry, is planned as a new facility based on a state-of-the-art plasma trap confining energetic plasma for performing interdisciplinary research in the fields of Nuclear Astrophysics, Astrophysics, Plasma Physics and Applications in Material Science and Archaeometry: the plasmas become the environment for measuring, for the first time, nuclear decay rates in stellar-like condition (such as 7Be decay and beta-decay involved in s-process nucleosynthesis), especially as a function of the ionization state of the plasma ions. These studies will give important contributions for addressing several astrophysical issues in both stellar and primordial nucleosynthesis environment ( e.g., determination of solar neutrino flux and 7Li Cosmological Problem), moreover the confined energetic plasma will be a unique light source for high-performance stellar spectroscopy measurements in the visible, UV and X-ray domains, offering advancements in observational astronomy. As to magnetic fields, the experimental validation of theoretical first- and second-order Landé factors will drive the layout of next-generation polarimetric units for the high-resolution spectrograph of the future giant telescopes. In PANDORA new plasma heating methods will be explored, that will push forward the ion beam output, in terms of extracted intensity and charge states. More, advanced and optimized injection methods of ions in an ECR plasma will be experimented, with the aim to optimize its capture efficiency. This will be applied to the ECR-based Charge Breeding technique, that will improve the performances of the SPES ISOL-facility at Laboratori Nazionali di Legnaro-INFN. Finally, PANDORA will be suitable for energy conversion, making the plasma a source of high-intensity electromagnetic radiation, for applications in material science and archaeometry.

PANDORA, a new facility for interdisciplinary in-plasma physics

Energy Technology Data Exchange (ETDEWEB)

Mascali, D.; Gammino, S. [INFN-Laboratori Nazionali del Sud, Catania (Italy); Musumarra, A. [INFN-Laboratori Nazionali del Sud, Catania (Italy); University of Catania, Department of Physics and Astronomy, Catania (Italy); Leone, F. [INFN-Laboratori Nazionali del Sud, Catania (Italy); University of Catania, Department of Physics and Astronomy, Catania (Italy); INAF-OACT, Catania (Italy); Romano, F.P. [INFN-Laboratori Nazionali del Sud, Catania (Italy); CNR-IBAM, Catania (Italy); Galata, A. [INFN-Laboratori Nazionali di Legnaro, Legnaro (Italy); Massimi, C. [University of Bologna, Department of Physics and Astronomy, Bologna (Italy); INFN-Bologna, Bologna (Italy)

2017-07-15

PANDORA, Plasmas for Astrophysics, Nuclear Decays Observation and Radiation for Archaeometry, is planned as a new facility based on a state-of-the-art plasma trap confining energetic plasma for performing interdisciplinary research in the fields of Nuclear Astrophysics, Astrophysics, Plasma Physics and Applications in Material Science and Archaeometry: the plasmas become the environment for measuring, for the first time, nuclear decay rates in stellar-like condition (such as {sup 7}Be decay and beta-decay involved in s-process nucleosynthesis), especially as a function of the ionization state of the plasma ions. These studies will give important contributions for addressing several astrophysical issues in both stellar and primordial nucleosynthesis environment (e.g., determination of solar neutrino flux and {sup 7}Li Cosmological Problem), moreover the confined energetic plasma will be a unique light source for high-performance stellar spectroscopy measurements in the visible, UV and X-ray domains, offering advancements in observational astronomy. As to magnetic fields, the experimental validation of theoretical first- and second-order Lande factors will drive the layout of next-generation polarimetric units for the high-resolution spectrograph of the future giant telescopes. In PANDORA new plasma heating methods will be explored, that will push forward the ion beam output, in terms of extracted intensity and charge states. More, advanced and optimized injection methods of ions in an ECR plasma will be experimented, with the aim to optimize its capture efficiency. This will be applied to the ECR-based Charge Breeding technique, that will improve the performances of the SPES ISOL-facility at Laboratori Nazionali di Legnaro-INFN. Finally, PANDORA will be suitable for energy conversion, making the plasma a source of high-intensity electromagnetic radiation, for applications in material science and archaeometry. (orig.)

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... ... Journal of Astrophysics and Astronomy; Volume 21; Issue 3-4. Remote Sensing of the Heliospheric Solar Wind using Radio Astronomy Methods and Numerical Simulations. S. Ananthakrishnan. Session XI – Solar Wind & Interplanetary Magnetic Fields Volume 21 Issue 3-4 September-December 2000 pp ...

Challenges and opportunities in laboratory plasma astrophysics

Science.gov (United States)

Drake, R. Paul

2017-06-01

We are in a period of explosive success and opportunity in the laboratory study of plasma phenomena that are relevant to astrophysics. In this talk I will share with you several areas in which recent work, often foreshadowed 20 or 30 years ago, has produced dramatic initial success with prospects for much more. To begin, the talk will provide a brief look at the types of devices used and the regimes they access, showing how they span many orders of magnitude in parameters of interest. It will then illustrate the types of work one can do with laboratory plasmas that are relevant to astrophysics, which range from direct measurement of material properties to the production of scaled models of certain dynamics to the pursuit of complementary understanding. Examples will be drawn from the flow of energy and momentum in astrophysics, the formation and structure of astrophysical systems, and magnetization and its consequences. I hope to include some discussion of collisionless shocks, very dense plasmas, work relevant to the end of the Dark Ages, reconnection, and dynamos. The talk will conclude by highlighting some topics where it seems that we may be on the verge of exciting new progress.The originators of work discussed, and collaborators and funding sources when appropriate, will be included in the talk.

Pressurized helium II-cooled magnet test facility

International Nuclear Information System (INIS)

Warren, R.P.; Lambertson, G.R.; Gilbert, W.S.; Meuser, R.B.; Caspi, S.; Schafer, R.V.

1980-06-01

A facility for testing superconducting magnets in a pressurized bath of helium II has been constructed and operated. The cryostat accepts magnets up to 0.32 m diameter and 1.32 m length with current to 3000 A. In initial tests, the volume of helium II surrounding the superconducting magnet was 90 liters. Minimum temperature reached was 1.7 K at which point the pumping system was throttled to maintain steady temperature. Helium II reservoir temperatures were easily controlled as long as the temperature upstream of the JT valve remained above T lambda; at lower temperatures control became difficult. Positive control of the temperature difference between the liquid and cold sink by means of an internal heat source appears necessary to avoid this problem. The epoxy-sealed vessel closures, with which we have had considerable experience with normal helium vacuum, also worked well in the helium II/vacuum environment

Studies in nuclear structure relevant to Astrophysics: theoretical and experimental efforts

International Nuclear Information System (INIS)

Saha Sarkar, Maitreyee

2016-01-01

Experimental and theoretical investigations in the region around doubly magic neutron rich 132 Sn nucleus have recently revealed many intriguing issues concerning some newer aspects of nuclear structure in such exotic environments. These nuclei lie on or close to the path of the astrophysical r-process flow. A glimpse of the implication of these studies on the r-process nucleosynthesis will be discussed. Presently, the Nuclear Physics group in Saha Institute of Nuclear Physics is working for installation of a high-current, low energy Accelerator as the primary component of the Facility for Research in low Energy Nuclear Astrophysics (FRENA), a national facility, at Kolkata. Planning for future experiments has been undertaken for successful utilization of this facility. Implantation technique has been found to be one of the most effective methods to produce isotopically pure targets. We have prepared a few isotopically pure targets using this technique. Being the slowest process of the CNO cycle, study of the 14 N(p, γ) 15 O(Q = 7297 keV) capture reaction is of high astrophysical interest. From an experiment utilizing one of the newly prepared 14 N implanted targets, a preliminary estimate of the lifetime of 6792 keV state in 15 O has been obtained, using Doppler shift attenuation method (DSAM). The sensitivity of the results with respect to the uncertainties in various input quantities has been tested. This endeavour will be helpful to design a better experiment to extract more precise lifetime for this important state

Essential astrophysics

CERN Document Server

Lang, Kenneth R

2013-01-01

Essential Astrophysics is a book to learn or teach from, as well as a fundamental reference volume for anyone interested in astronomy and astrophysics. It presents astrophysics from basic principles without requiring any previous study of astronomy or astrophysics. It serves as a comprehensive introductory text, which takes the student through the field of astrophysics in lecture-sized chapters of basic physical principles applied to the cosmos. This one-semester overview will be enjoyed by undergraduate students with an interest in the physical sciences, such as astronomy, chemistry, engineering or physics, as well as by any curious student interested in learning about our celestial science. The mathematics required for understanding the text is on the level of simple algebra, for that is all that is needed to describe the fundamental principles. The text is of sufficient breadth and depth to prepare the interested student for more advanced specialized courses in the future. Astronomical examples are provide...

Origin of intense magnetic fields near black holes due to non-minimal gravitational-electromagnetic coupling

International Nuclear Information System (INIS)

Souza, Rafael S. de; Opher, Reuven

2011-01-01

The origin of magnetic fields in astrophysical objects is a challenging problem in astrophysics. Throughout the years, many scientists have suggested that non-minimal gravitational-electromagnetic coupling (NMGEC) could be the origin of the ubiquitous astrophysical magnetic fields. We investigate the possible origin of intense magnetic fields by NMGEC near rotating black holes, connected with quasars and gamma-ray bursts. Whereas these intense magnetic fields are difficult to explain astrophysically, we find that they are easily explained by NMGEC.

MHD turbulent dynamo in astrophysics: Theory and numerical simulation

Science.gov (United States)

Chou, Hongsong

2001-10-01

This thesis treats the physics of dynamo effects through theoretical modeling of magnetohydrodynamic (MHD) systems and direct numerical simulations of MHD turbulence. After a brief introduction to astrophysical dynamo research in Chapter 1, the following issues in developing dynamic models of dynamo theory are addressed: In Chapter 2, nonlinearity that arises from the back reaction of magnetic field on velocity field is considered in a new model for the dynamo α-effect. The dependence of α-coefficient on magnetic Reynolds number, kinetic Reynolds number, magnetic Prandtl number and statistical properties of MHD turbulence is studied. In Chapter 3, the time-dependence of magnetic helicity dynamics and its influence on dynamo effects are studied with a theoretical model and 3D direct numerical simulations. The applicability of and the connection between different dynamo models are also discussed. In Chapter 4, processes of magnetic field amplification by turbulence are numerically simulated with a 3D Fourier spectral method. The initial seed magnetic field can be a large-scale field, a small-scale magnetic impulse, and a combination of these two. Other issues, such as dynamo processes due to helical Alfvénic waves and the implication and validity of the Zeldovich relation, are also addressed in Appendix B and Chapters 4 & 5, respectively. Main conclusions and future work are presented in Chapter 5. Applications of these studies are intended for astrophysical magnetic field generation through turbulent dynamo processes, especially when nonlinearity plays central role. In studying the physics of MHD turbulent dynamo processes, the following tools are developed: (1)A double Fourier transform in both space and time for the linearized MHD equations (Chapter 2 and Appendices A & B). (2)A Fourier spectral numerical method for direct simulation of 3D incompressible MHD equations (Appendix C).

Technology of mirror machines: LLL facilities for magnetic mirror fusion experiments

International Nuclear Information System (INIS)

Batzer, T.H.

1977-01-01

Significant progress in plasma confinement and temperature has been achieved in the 2XIIB facility at Livermore. These encouraging results, and their theoretical corroboration, have provided a firm basis for the design of a new generation of magnetic mirror experiments, adding support to the mirror concept of a fusion reactor. Two new mirror experiments have been proposed to succeed the currently operating 2XIIB facility. The first of these called TMX (Tandem Mirror Experiment) has been approved and is currently under construction. TMX is designed to utilize the intrinsic positive plasma potential of two strong, and relatively small, minimum B mirror cells to enhance the confinement of a much larger, magnetically weaker, centrally-located mirror cell. The second facility, MFTF (Mirror Fusion Test Facility), is currently in preliminary design with line item approval anticipated for FY 78. MFTF is designed primarily to exploit the experimental and theoretical results derived from 2XIIB. Beyond that, MFTF will develop the technology for the transition from the present small mirror experiments to large steady-state devices such as the mirror FERF/FTR. The sheer magnitude of the plasma volume, magnetic field, neutral beam power, and vacuum pumping capacity, particularly in the case of MFTF, has placed new and exciting demands on engineering technology. An engineering overview of MFTF, TMX, and associated MFE activities at Livermore will be presented

Magnetic Flyer Facility Correlation and UGT Simulation

Science.gov (United States)

1978-05-01

assistance in this program from the following: Southern Research Institute - Material properties and C. Pears and G. Fornaro damage data Air Force ...techniques - flyer plate loading. The program was divided into two majur parts, the Facility Correlation Study and the UGT Simulation STudy. For the...current produces a magnetic field which then produces an accelerating force on the flyer plate, itself a current carry- ing part of the circuit. The flyer

Characteristics and performance of a superconducting bumpy-torus magnet facility for plasma research

Science.gov (United States)

Roth, J. R.; Holmes, A. D.; Keller, T. A.; Krawczonek, W. M.

1973-01-01

The NASA Lewis bumpy-torus facility consists of 12 superconducting coils, each 19 cm i.d. and capable of 3.0 T on its axis. The coils are equally spaced around a toroidal array with a major diameter of 1.52 m; they are mounted with the major axis of the torus vertical in a single vacuum tank 2.6 m in diameter. Tests of the facility mapped out its magnetic, cryogenic, vacuum, mechanical, and electrical performance. The design value of the maximum magnetic field on the magnetic axis, 3.0 T, was reached and exceeded. A maximum magnetic field of 3.23 T was held for a period of 60 minutes. When the coils were charged to a maximum magnetic field of 3.35 T, the coil system went normal without apparent damage or degradation of performance.

FOREWORD: Nuclear Physics in Astrophysics V

Science.gov (United States)

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

5th International conference on High Energy Density Laboratory Astrophysics

CERN Document Server

Kyrala, G.A

2005-01-01

During the past several years, research teams around the world have developed astrophysics-relevant utilizing high energy-density facilities such as intense lasers and z-pinches. Research is underway in many areas, such as compressible hydrodynamic mixing, strong shock phenomena, radiation flow, radiative shocks and jets, complex opacities, equations o fstat, and relativistic plasmas. Beyond this current research and the papers it is producing, plans are being made for the application, to astrophysics-relevant research, of the 2 MJ National Ignition Facility (NIF) laser at Lawrence Livermore National Laboratory; the 600 kj Ligne d'Intergration Laser (LIL) and the 2 MJ Laser Megajoule (LMJ) in Bordeaux, France; petawatt-range lasers now under construction around the world; and current and future Z pinches. The goal of this conference and these proceedings is to continue focusing and attention on this emerging research area. The conference brought together different scientists interested in this emerging new fi...

Possibilities at LAMPF for studying nuclei of astrophysical interest

International Nuclear Information System (INIS)

Talbert, W.L. Jr.; Bunker, M.E.

1985-01-01

Nuclear data needs in astrophysics range from neutron capture cross sections of a number of stable or near-stable nuclei to decay and neutron binding-energy data for highly neutron-rich nuclei. LAMPF has the potential to contribute significantly to these needs. The new Los Alamos Neutron Scattering Center (LANSCE, aka WNR/PSR) offers world-class capabilities for neutron capture studies up to an MeV or so. The study of nuclei far from stability could be extended into some regions of astrophysical interest using a proposed He-jet coupled mass separator system with a target/production chamber in the LAMPF beam stop area. Specific examples of possible studies at each facility are presented

Cosmic Magnetic Fields

Science.gov (United States)

Sánchez Almeida, J.; Martínez González, M. J.

2018-05-01

Magnetic fields play an important role in many astrophysical processes. They are difficult to detect and characterize since often their properties have to be inferred through interpreting the polarization of the light. Magnetic fields are also challenging to model and understand. Magnetized plasmas behave following highly non-linear differential equations having no general solution, so that every astrophysical problem represents a special case to be studied independently. Hence, magnetic fields are often an inconvenient subject which is overlooked or simply neglected (the elephant in the room, as they are dubbed in poster of the school). Such difficulty burdens the research on magnetic fields, which has evolved to become a very technical subject, with many small disconnected communities studying specific aspects and details. The school tried to amend the situation by providing a unifying view of the subject. The students had a chance to understand the behavior of magnetic fields in all astrophysical contexts, from cosmology to the Sun, and from starbursts to AGNs. The school was planed to present a balanced yet complete review of our knowledge, with excursions into the unknown to point out present and future lines of research. The subject of Cosmic Magnetic Fields was split into seven different topics: cosmic magnetic field essentials, solar magnetic fields, stellar magnetic fields, the role of magnetic fields on AGN feedback, magnetic fields in galaxies, magnetic fields in galaxy clusters and at larger scales, and primordial magnetic fields and magnetic fields in the early Universe. The corresponding lectures were delivered by seven well known and experienced scientists that have played key roles in the major advances of the field during the last years: F. Cattaneo, P. Judge, O. Kochukhov, R. Keppens, R. Beck, K. Dolag, and F. Finelli. Their lectures were recorded and are freely available at the IAC website: http://iactalks.iac.es/talks/serie/19.

Ten years of cryo-magnetic W7-X test facility construction and operation

International Nuclear Information System (INIS)

Renard, B.; Dispau, G.; Donati, A.; Genini, L.; Gournay, J.F.; Kuster, O.; Molinie, F.; Schild, T.; Touzery, R.; Vieillard, L.; Walter, C.

2011-01-01

The construction, commissioning, and operation phases of the W7-X cryo-magnetic test facility in CEA Saclay lasted ten years. The large diversity of equipments called, specialties involved and problems solved attest the expertise that was required to operate the test facility and test the coils. Nearly one hundred cryogenic tests were performed on the seventy W7-X coils, at a rate always increasing, using two cryostats each holding two coils. This paper presents the test facility and its operation first, the cryogenic difficulties that were confronted with their solutions, the electro-magnetic difficulties encountered along with corrective actions, and finally the instrumentation and data acquisition aspects. (authors)

Construction program for a large superconducting MHD magnet system at the coal-fired flow facility

International Nuclear Information System (INIS)

Wang, S.T.; Genens, L.; Gonczy, J.; Ludwig, H.; Lieberg, M.; Kraft, E.; Gacek, D.; Huang, Y.C.; Chen, C.J.

1980-01-01

The Argonne National Laboratory has designed and is constructing a 6 T large aperture superconducting MHD magnet for use in the Coal-Fired Flow Facility (CFFF) at the University of Tennessee Space Institute (UTSI) at Tullahoma, Tennessee. The magnet system consists of the superconducting magnet, a magnet power supply, an integrated instrumentation for operation, control and protection, and a complete cryogenic facility including a CTI Model 2800 helium refrigerator/liquefier with two compressors, helium gas handling system and a 7500 liter liquid helium dewar. The complete system will be tested at Argonne, IL in 1981. The magnet design is reviewed, and the coil fabrication programs are described in detail

HCP, grid and data infrastructures for astrophysics: an integrated view

International Nuclear Information System (INIS)

Pasian, F.

2009-01-01

Also in the case of astrophysics, the capability of performing Big Science requires the availability of large Hcp facilities. But computational resources alone are far from being enough for the community: as a matter of fact, the whole set of e-infrastructures (network, computing nodes, data repositories, applications) need to work in an inter operable way. This implies the development of common (or at least compatible) user interfaces to computing resources, transparent access to observations and numerical simulations through the Virtual Observatory, integrated data processing pipelines, data mining and semantic web applications. Achieving this inter operability goal is a must to build a real Knowledge Infrastructure in the astrophysical domain.

Fermilab R and D test facility for SSC [Superconducting Super Collider] magnets

International Nuclear Information System (INIS)

Strait, J.; Bleadon, M.; Hanft, R.; Lamm, M.; McGuire, K.; Mantsch, P.; Mazur, P.O.; Orris, D.; Pachnik, J.

1989-02-01

The test facility used for R and D testing of full scale development dipole magnets for the SSC is described. The Fermilab Magnet Test Facility, originally built for production testing of Tevatron magnets, has been substantially modified to allow testing also of SSC magnets. Two of the original six test stands have been rebuilt to accommodate testing of SSC magnets at pressures between 1.3 Atm and 4 Atm and at temperatures between 1.8 K and 4.8 K and the power system has been modified to allow operation to at least 8 kA. Recent magnets have been heavily instrumented with voltage taps to allow detailed study of quench location and propagation and with strain gage based stress, force and motion transducers. A data acquisition system has been built with a capacity to read from each SSC test stand up to 220 electrical quench signals, 32 dynamic pressure, temperature and mechanical transducer signals during quench and up to 200 high precision, low time resolution, pressure, temperature and mechanical transducer signals. The quench detection and protection systems is also described. 23 refs., 4 figs., 2 tabs

Black Hole Astrophysics The Engine Paradigm

CERN Document Server

Meier, David L

2012-01-01

As a result of significant research over the past 20 years, black holes are now linked to some of the most spectacular and exciting phenomena in the Universe, ranging in size from those that have the same mass as stars to the super-massive objects that lie at the heart of most galaxies, including our own Milky Way. This book first introduces the properties of simple isolated holes, then adds in complications like rotation, accretion, radiation, and magnetic fields, finally arriving at a basic understanding of how these immense engines work. Black Hole Astrophysics • reviews our current knowledge of cosmic black holes and how they generate the most powerful observed pheonomena in the Universe; • highlights the latest, most up-to-date theories and discoveries in this very active area of astrophysical research; • demonstrates why we believe that black holes are responsible for important phenomena such as quasars, microquasars and gammaray bursts; • explains to the reader the nature of the violent and spe...

Nuclear physics and astrophysics

International Nuclear Information System (INIS)

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

Nuclear astrophysics

International Nuclear Information System (INIS)

Lehoucq, Roland; Klotz, Gregory

2015-11-01

Astronomy deals with the position and observation of the objects in our Universe, from planets to galaxies. It is the oldest of the sciences. Astrophysics is the study of the physical properties of these objects. It dates from the start of the 20. century. Nuclear astrophysics is the marriage of nuclear physics, a laboratory science concerned with the infinitely small, and astrophysics, the science of what is far away and infinitely large. Its aim is to explain the origin, evolution and abundance of the elements in the Universe. It was born in 1938 with the work of Hans Bethe, an American physicist who won the Nobel Prize for physics in 1967, on the nuclear reactions that can occur at the center of stars. It explains where the incredible energy of the stars and the Sun comes from and enables us to understand how they are born, live and die. The matter all around us and from which we are made, is made up of ninety-two chemical elements that can be found in every corner of the Universe. Nuclear astrophysics explains the origin of these chemical elements by nucleosynthesis, which is the synthesis of atomic nuclei in different astrophysical environments such as stars. Nuclear astrophysics provides answers to fundamental questions: - Our Sun and the stars in general shine because nuclear reactions are taking place within them. - The stars follow a sequence of nuclear reaction cycles. Nucleosynthesis in the stars enables us to explain the origin and abundance of elements essential to life, such as carbon, oxygen, nitrogen and iron. - Star explosions, in the form of supernovae, disperse the nuclei formed by nucleosynthesis into space and explain the formation of the heaviest chemical elements such as gold, platinum and lead. Nuclear astrophysics is still a growing area of science. (authors)

Broadband Polarimetry with the Square Kilometre Array: A Unique Astrophysical Probe

NARCIS (Netherlands)

Gaensler, B.; Agudo, I.; Akahori, T.; Banfield, J.; Beck, R.; Carretti, E.; Farnes, J.; Haverkorn, M.; Heald, G.; Jones, D.; Landecker, T.; Mao, S. A.; Norris, R.; O'Sullivan, S.; Rudnick, L.; Schnitzeler, D.; Seymour, N.; Sun, X.

2015-01-01

Faraday rotation of polarised background sources is a unique probe of astrophysical magnetic fields in a diverse range of foreground objects. However, to understand the properties of the polarised sources themselves and of depolarising phenomena along the line of sight, we need to complement Faraday

Some astrophysical processes around magnetized black hole

Science.gov (United States)

Kološ, M.; Tursunov, A.; Stuchlík, Z.

2018-01-01

We study the dynamics of charged test particles in the vicinity of a black hole immersed into an asymptotically uniform external magnetic field. A real magnetic field around a black hole will be far away from to be completely regular and uniform, a uniform magnetic field is used as linear approximation. Ionized particle acceleration, charged particle oscillations and synchrotron radiation of moving charged particle have been studied.

Recent astrophysical applications of the Trojan Horse Method to nuclear astrophysics

International Nuclear Information System (INIS)

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.

2008-01-01

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 b (E) for some two-body processes are discussed

Relativistic Astrophysics

International Nuclear Information System (INIS)

Font, J. A.

2015-01-01

The relativistic astrophysics is the field of astrophysics employing the theory of relativity Einstein as physical-mathematical model is to study the universe. This discipline analyzes astronomical contexts in which the laws of classical mechanics of Newton's law of gravitation are not valid. (Author)

Facility Effects on a Helicon Plasma Source with a Magnetic Nozzle

Data.gov (United States)

National Aeronautics and Space Administration — Proposed here is an analysis of facility effects on a small helicon plasma source with a magnetic nozzle. Backpressure effects will first be recorded and analyzed....

HTS power lead testing at the Fermilab magnet test facility

Energy Technology Data Exchange (ETDEWEB)

Rabehl, R.; Carcagno, R.; Feher, S.; Huang, Y.; Orris, D.; Pischalnikov, Y.; Sylvester, C.; Tartaglia, M.; /Fermilab

2005-08-01

The Fermilab Magnet Test Facility has tested high-temperature superconductor (HTS) power leads for cryogenic feed boxes to be placed at the Large Hadron Collider (LHC) interaction regions and at the new BTeV C0 interaction region of the Fermilab Tevatron. A new test facility was designed and operated, successfully testing 20 pairs of HTS power leads for the LHC and 2 pairs of HTS power leads for the BTeV experiment. This paper describes the design and operation of the cryogenics, process controls, data acquisition, and quench management systems. Results from the facility commissioning are included, as is the performance of a new insulation method to prevent frost accumulation on the warm ends of the power leads.

HTS power lead testing at the Fermilab magnet test facility

International Nuclear Information System (INIS)

Rabehl, R.; Carcagno, R.; Feher, S.; Huang, Y.; Orris, D.; Pischalnikov, Y.; Sylvester, C.; Tartaglia, M.

2005-01-01

The Fermilab Magnet Test Facility has tested high-temperature superconductor (HTS) power leads for cryogenic feed boxes to be placed at the Large Hadron Collider (LHC) interaction regions and at the new BTeV CO interaction region of the Fermilab Tevatron. A new test facility was designed and operated, successfully testing 20 pairs of HTS power leads for the LHC and 2 pairs of HTS power leads for the BTeV experiment. This paper describes the design and operation of the cryogenics, process controls, data acquisition, and quench management systems. Results from the facility commissioning are included, as is the performance of a new insulation method to prevent frost accumulation on the warm ends of the power leads

Laboratory studies of photoionized plasma related to astrophysics

International Nuclear Information System (INIS)

Yang Peiqiang; Wang Feilu; Zhao Gang

2011-01-01

Photoionized plasma is universal in astronomy and has great importance on account of its close relation to compact astrophysical objects such as black holes. Recently, with the development of high energy density lasers and Z-pinch facilities, it has become possible to simulate astronomical photoionized plasma in the laboratory. These experiments help us to benchmark and modify the photoionization models, and to understand the photoionization processes to diagnose related astronomical plasma environments. (authors)

Development of the Facility for Transformation of Magnetic Characteristics of Weakly Magnetic Oxidized Iron Ores Related to Improvement of Technologies for Iron Ore Concentrate Production

Directory of Open Access Journals (Sweden)

Ponomarenko, O.M.

2016-01-01

Full Text Available New facility for continuous registration of iron ore magnetization depending on temperature by heating of iron ores upon reducing conditions was created. Facility allows to register the processes of transformation of weakly magnetic minerals into strongly magnetic ones under the influence of reducing agents and temperature, as well as to determine the Curie temperature of the minerals. Using created facility it was shown, that heating of goethite and hematite in the presence of 4 % of starch in the temperature range of 300—650 °С leads to significant increase of magnetization of the samples. X-Ray diffraction confirmed that under indicated conditions the structure of hematite and goethite is transformed into magnetite structure. Obtained results open up new possibilities for the development of effective technologies for oxidized iron ore beneficiation.

FIRST KODAI-TRIESTE WORKSHOP ON PLASMA ASTROPHYSICS

CERN Document Server

Hasan, S. S; Krishan, V; TURBULENCE, DYNAMOS, ACCRETION DISKS, PULSARS AND COLLECTIVE PLASMA PROCESSES

2008-01-01

It is well established and appreciated by now that more than 99% of the baryonic matter in the universe is in the plasma state. Most astrophysical systems could be approximated as conducting fluids in a gravitational field. It is the combined effect of these two that gives rise to the mind boggling variety of configurations in the form of filaments, loops , jets and arches. The plasma structures that cannot last for more than a second or less in a laboratory remain intact for astronomical time and spatial scales in an astrophysical setting. The case in point is the well known extragalactic jets whose collimation and stability has remained an enigma inspite of the efforts of many for many long years. The high energy radiation sources such as the active galactic nuclei again summon the coherent plasma radiation processes for their exceptionally large output from regions of relatively small physical sizes. The generation of magnetic field, anomalous transport of angular momentum with decisive bearing on star for...

Performance test of personal RF monitor for area monitoring at magnetic confinement fusion facility

International Nuclear Information System (INIS)

Tanaka, M.; Uda, T.; Wang, J.; Fujiwara, O.

2012-01-01

For safety management at a magnetic confinement fusion-test facility, protection from not only ionising radiation, but also non-ionising radiation such as the leakage of static magnetic and electromagnetic fields is an important issue. Accordingly, the use of a commercially available personal RF monitor for multipoint area monitoring is proposed. In this study, the performance of both fast- and slow-type personal RF monitors was investigated by using a transverse electromagnetic cell system. The range of target frequencies was between 10 and 300 MHz, corresponding to the ion cyclotron range of frequency in a fusion device. The personal RF monitor was found to have good linearity, frequency dependence and isotropic response. However, the time constant for the electric field sensor of the slow-type monitor was much longer than that for the fast-type monitor. Considering the time-varying field at the facility, it is found that the fast-type monitor is suitable for multipoint monitoring at magnetic confinement fusion test facilities. (authors)

Exploring the Cosmic Frontier Astrophysical Instruments for the 21st Century

CERN Document Server

Lobanov, Andrei P; Cesarsky, Catherine; Diamond, Phillip J

2007-01-01

In the coming decades, astrophysical science will benefit enormously from the construction and operation of several major international ground- and space based facilities, such as ALMA, Herschel/Planck, and SKA in the far infrared to radio band, Extremely Large Telescopes, JWST and GAIA in the optical to near infrared regime, XEUS and Constellation-X in the X-ray, and GLAST in the Gamma-ray regime. These and other new instruments will have a major impact in a wide range of scientific topics including the cosmological epoch of reionization, galactic dynamics and nuclear activity, stellar astronomy, extra-solar planets, gamma-ray bursts, X-ray binaries, and many others. On May 18-21, 2004, the Max-Planck-Society’s Harnack-Haus in Dahlem, Berlin hosted the international symposium "Exploring the Cosmic Frontier: Astrophysical Instruments for the 21st Century". The symposium in Berlin was dedicated to exploring the complementarity and synergies between different branches of astrophysical research, by presenting ...

Magnetic spectrograph for the Holifield heavy ion research facility

International Nuclear Information System (INIS)

Ford, J.L.C. Jr.; Enge, H.A.; Erskine, J.R.; Hendrie, D.L.; LeVine, M.J.

1977-01-01

The need for a new generation magnetic spectrograph for the Holifield Heavy Ion Research Facility is discussed. The advantages of a magnetic spectrograph for heavy ion research are discussed, as well as some of the types of experiments for which such an instrument is suited. The limitations which the quality of the incident beam, target and spectrograph itself impose on high resolution heavy ion measurements are discussed. Desired features of an ideal new spectrograph are: (1) intrinsic resolving power E/ΔE greater than or equal to 3000; (2) maximum solid angle greater than or equal to 20 msr; (3) dispersion approx. 4-8m; (4) maximum energy interval approx. 30%; and (5) mass-energy product greater than or equal to 200. Various existing and proposed spectrographs are compared with the specifications for a new heavy ion magnet design

Nuclear Data on Unstable Nuclei for Astrophysics

International Nuclear Information System (INIS)

Smith, Michael Scott; Meyer, Richard A; Lingerfelt, Eric; Scott, J.P.; Hix, William Raphael; Ma, Zhanwen; Bardayan, Daniel W.; Blackmon, Jeff C.; Guidry, Mike W.; KOZUB, RAYMOND L.; Chae, Kyung YuK.

2004-01-01

Recent measurements with radioactive beams at ORNL's Holifield Radioactive Ion Beam Facility (HRIBF) have prompted the evaluation of a number of reactions involving unstable nuclei needed for stellar explosion studies. We discuss these evaluations, as well as the development of a new computational infrastructure to enable the rapid incorporation of the latest nuclear physics results in astrophysics models. This infrastructure includes programs that simplify the generation of reaction rates, manage rate databases, and visualize reaction rates, all hosted at a new website http://www.nucastrodata.org

Construction and performance of the magnetic bunch compressor for the THz facility at Chiang Mai University

International Nuclear Information System (INIS)

Saisut, J.; Kusoljariyakul, K.; Rimjaem, S.; Kangrang, N.; Wichaisirimongkol, P.; Thamboon, P.; Rhodes, M.W.; Thongbai, C.

2011-01-01

The Plasma and Beam Physics Research Facility at Chiang Mai University has established a THz facility to focus on the study of ultra-short electron pulses. Short electron bunches can be generated from a system that consists of a radio-frequency (RF) gun with a thermionic cathode, an alpha magnet as a magnetic bunch compressor, and a linear accelerator as a post-acceleration section. The alpha magnet is a conventional and simple instrument for low-energy electron bunch compression. With the alpha magnet constructed in-house, several hundred femtosecond electron bunches for THz radiation production can be generated from the thermionic RF gun. The construction and performance of the alpha magnet, as well as some experimental results, are presented in this paper.

Construction and performance of the magnetic bunch compressor for the THz facility at Chiang Mai University

Science.gov (United States)

Saisut, J.; Kusoljariyakul, K.; Rimjaem, S.; Kangrang, N.; Wichaisirimongkol, P.; Thamboon, P.; Rhodes, M. W.; Thongbai, C.

2011-05-01

The Plasma and Beam Physics Research Facility at Chiang Mai University has established a THz facility to focus on the study of ultra-short electron pulses. Short electron bunches can be generated from a system that consists of a radio-frequency (RF) gun with a thermionic cathode, an alpha magnet as a magnetic bunch compressor, and a linear accelerator as a post-acceleration section. The alpha magnet is a conventional and simple instrument for low-energy electron bunch compression. With the alpha magnet constructed in-house, several hundred femtosecond electron bunches for THz radiation production can be generated from the thermionic RF gun. The construction and performance of the alpha magnet, as well as some experimental results, are presented in this paper.

The generation and amplification of intergalactic magnetic fields in analogue laboratory experiments with high power lasers

Science.gov (United States)

Gregori, G.; Reville, B.; Miniati, F.

2015-11-01

The advent of high-power laser facilities has, in the past two decades, opened a new field of research where astrophysical environments can be scaled down to laboratory dimensions, while preserving the essential physics. This is due to the invariance of the equations of magneto-hydrodynamics to a class of similarity transformations. Here we review the relevant scaling relations and their application in laboratory astrophysics experiments with a focus on the generation and amplification of magnetic fields in cosmic environment. The standard model for the origin of magnetic fields is a multi stage process whereby a vanishing magnetic seed is first generated by a rotational electric field and is then amplified by turbulent dynamo action to the characteristic values observed in astronomical bodies. We thus discuss the relevant seed generation mechanisms in cosmic environment including resistive mechanism, collision-less and fluid instabilities, as well as novel laboratory experiments using high power laser systems aimed at investigating the amplification of magnetic energy by magneto-hydrodynamic (MHD) turbulence. Future directions, including efforts to model in the laboratory the process of diffusive shock acceleration are also discussed, with an emphasis on the potential of laboratory experiments to further our understanding of plasma physics on cosmic scales.

The immediate environment of an astrophysical black hole

Science.gov (United States)

Contopoulos, I.

2018-01-01

In view of the upcoming observations with the Event Horizon Telescope (EHT), we present our thoughts on the immediate environment of an astrophysical black hole. We are concerned that two approximations used in general relativistic magnetohydrodynamic numerical simulations, namely numerical density floors implemented near the base of the black hole jet, and a magnetic field that comes from large distances, may mislead our interpretation of the observations. We predict that three physical processes will manifest themselves in EHT observations, namely dynamic pair formation just above the horizon, electromagnetic energy dissipation along the boundary of the black hole jet, and a region of weak magnetic field separating the black hole jet from the disc wind.

Construction and testing of the Mirror Fusion Test Facility magnets

International Nuclear Information System (INIS)

Kozman, T.; Shimer, D.; VanSant, J.; Zbasnik, J.

1986-08-01

This paper describes the construction and testing of the Mirror Fusion Test Facility superconducting magnet set. Construction of the first Yin Yang magnet was started in 1978. And although this particular magnet was later modified, the final construction of these magnets was not completed until 1985. When completed these 42 magnets weighed over 1200 tonnes and had a maximum stored energy of approximately 1200 MJ at full field. Together with power supplies, controls and liquid nitrogen radiation shields the cost of the fabrication of this system was over $100M. General Dynamics/Convair Division was responsible for the system design and the fabrication of 20 of the magnets. This contract was the largest single procurement action at the Lawrence Livermore National Laboratory. During the PACE acceptance tests, the 26 major magnets were operated at full field for more than 24 hours while other MFTF subsystems were tested. From all of the data, the magnets operated to the performance specifications. For physics operation in the future, additional helium and nitrogen leak checking and repair will be necessary. In this report we will discuss the operation and testing of the MFTF Magnet System, the world's largest superconducting magnet set built to date. The topics covered include a schedule of the major events, summary of the fabrication work, summary of the installation work, summary of testing and test results, and lessons learned

Vent rate of superconducting magnets during quench in the Mirror Fusion Test Facility

International Nuclear Information System (INIS)

Slack, D.S.

1979-01-01

When a superconducting magnet goes normal, resistive heating in the conductor evaporates surrounding LHe, which must be vented. The nature and speed at which the magnet goes normal and He is vented are not subject to rigorous analysis. This paper presents vent data from an existing magnet. An approximate mathematical model is derived and fitted to the data to permit scaling of vent requirements to larger size magnets. The worst case models of the vent employed in Mirror Fusion Test Facility (MFTF) cryogenic system design are also presented

Mechanical behavior of the mirror fusion test Facility superconducting magnet coils

International Nuclear Information System (INIS)

Horvath, J.A.

1980-01-01

The mechanical response to winding and electromagnetic loads of the Mirror Fusion Test Facility (MFTF) superconducting coil pack is presented. The 375-ton (3300 N) MFTF Yin-Yang magnet, presently the world's largest superconducting magnet, is scheduled for acceptance cold-testing in May of 1981. The assembly is made up of two identical coils which together contain over 15 miles (24 km) of superconductor wound in 58 consecutive layers of 24 turns each. Topics associated with mechanical behavior include physical properties of the coil pack and its components, winding pre-load effects, finite element analysis, magnetic load redistribution, and the design impact of predicted conductor motion

Stopping Power Measurements: Implications in Nuclear Astrophysics

International Nuclear Information System (INIS)

Carmen Angulo; Thierry Delbar; Jean-Sebastien Graulich; Pierre Leleux

1999-01-01

The stopping powers of C, CH 2 , Al, Ni, and polyvinylchloride (PVC) for several light ions ( 9 Be, 11 B, 12 C, 14 N, 16 O, 19 F, 20 Ne) with an incident energy of 1 MeV/amu have been measured at the Louvain-la-Neuve cyclotron facility. Stopping powers are given relative to the one for 5.5 MeV 4 He ions with an uncertainty of less than 1%. We compare our results with two widely used semiempirical models and we discuss some implications in nuclear astrophysics studies

Nuclear astrophysics

International Nuclear Information System (INIS)

Arnould, M.; Takahashi, K.

1999-01-01

Nuclear astrophysics is that branch of astrophysics which helps understanding of the Universe, or at least some of its many faces, through the knowledge of the microcosm of the atomic nucleus. It attempts to find as many nuclear physics imprints as possible in the macrocosm, and to decipher what those messages are telling us about the varied constituent objects in the Universe at present and in the past. In the last decades much advance has been made in nuclear astrophysics thanks to the sometimes spectacular progress made in the modelling of the structure and evolution of the stars, in the quality and diversity of the astronomical observations, as well as in the experimental and theoretical understanding of the atomic nucleus and of its spontaneous or induced transformations. Developments in other subfields of physics and chemistry have also contributed to that advance. Notwithstanding the accomplishment, many long-standing problems remain to be solved, and the theoretical understanding of a large variety of observational facts needs to be put on safer grounds. In addition, new questions are continuously emerging, and new facts endangering old ideas. This review shows that astrophysics has been, and still is, highly demanding to nuclear physics in both its experimental and theoretical components. On top of the fact that large varieties of nuclei have to be dealt with, these nuclei are immersed in highly unusual environments which may have a significant impact on their static properties, the diversity of their transmutation modes, and on the probabilities of these modes. In order to have a chance of solving some of the problems nuclear astrophysics is facing, the astrophysicists and nuclear physicists are obviously bound to put their competence in common, and have sometimes to benefit from the help of other fields of physics, like particle physics, plasma physics or solid-state physics. Given the highly varied and complex aspects, we pick here some specific nuclear

Exploring extreme plasma physics in the laboratory and in astrophysics

Science.gov (United States)

Silva, L. O.; Grismayer, T.; Fonseca, R. A.; Cruz, F.; Gaudio, F. D.; Martins, J. L.; Vieira, J.; Vranic, M.

2017-10-01

The interaction of ultra intense fields with plasmas is at the confluence of several sub-fields ranging from QED, and nuclear physics to high energy astrophysics, and fundamental plasma processes. It requires novel theoretical tools, highly optimised numerical codes and algorithms tailored to these complex scenarios, where physical mechanisms at very disparate temporal and spatial scales are self-consistently coupled in multidimensional geometries. The key developments implemented in Osiris will be presented along with some examples of problems, relevant for laboratory or astrophysical scenarios, that are being addressed resorting to the combination of massively parallel simulations with theoretical models. The relevance for near future experimental facilities such as ELI will also be presented. Work supported by the European Research Council (ERC-AdG-2015 InPairs Grant No. 695088).

Fundamental symmetries and astrophysics with radioactive beams

International Nuclear Information System (INIS)

Vogt, E.

1996-04-01

A major new initiative at TRIUMF pertains to the use of radioactive beams for astrophysics and for fundamental symmetry experiments. Some recent work is described in which the β-decay-followed by alpha particle emission of 16 N was used to find the resonance parameters dominating the alpha particle capture in 12 C and thus to find the astrophysical S-factor of this reaction which is of crucial importance for alpha-particle burning and the subsequent collapse of stars. In some work underway trapped neural atoms of radioactive potassium atoms will be used to study fundamental symmetries of the weak interactions. Trapping has been achieved and soon 38m K decay will be used to search for evidence of scalar interactions and 37 K decay to search for right-handed gauge-bosom interactions. Future experiments are planned to look for parity non-conservation in trapped francium atoms. This program is part of a revitalization for the TRIUMF laboratory accompanied by the construction of the radioactive beam facility (ISAC). (author)

Astrophysical Hydrodynamics An Introduction

CERN Document Server

Shore, Steven N

2007-01-01

This latest edition of the proven and comprehensive treatment on the topic -- from the bestselling author of ""Tapestry of Modern Astrophysics"" -- has been updated and revised to reflect the newest research results. Suitable for AS0000 and AS0200 courses, as well as advanced astrophysics and astronomy lectures, this is an indispensable theoretical backup for studies on celestial body formation and astrophysics. Includes exercises with solutions.

Silica aerogel and space astrophysics

International Nuclear Information System (INIS)

Koch-Miramond, L.

1985-09-01

Silica aerogels have been produced in large and transparent blocks for space astrophysics experiments since the beginning of the 1970's. They were used in cosmic ray experiments on board balloons by the Saclay group. A new space venture where aerogel Cerenkov radiators will play a decisive role is currently being prepared by a large collaboration of European and US Institutes. It will be part of the so-called International Solar Polar Mission (ISPM) which will explore the heliosphere over the full range of solar latitudes from the ecliptic (equatorial) plane to the magnetic poles of the sun. Comments on properties and long term behaviour of silica aerogel cerenkov radiators in space environment are given

Theory of magnetostatic equilibria and applications in astrophysics

International Nuclear Information System (INIS)

Amari, T.

1988-04-01

Magnetohydrostatic equations are used to study the properties of magnetic configurations of astrophysical interest, particularly in solar physics. Results on force-free solutions with singularities (with current sheets) and on solutions which take into account current sheets and gravitational fields are obtained. A general method to construct an infinite class of non-y-symmetric models of protuberances when the magnetic field of the support is assumed to be potential is outlined. The general integral properties of current sheets of arbitrary geometry plunged into a nonlinear force-free magnetic field are established. It is shown that for a given mass, the equilibrium height of the protuberance increases with the shear of the force-free field. The case where the current sheet is reduced to a filament is examined. It is also shown that there exists a critical pressure beyond which no equilibrium is possible [fr

Indirect techniques in nuclear astrophysics

International Nuclear Information System (INIS)

Mukhamedzhanov, A.M.; Tribble, R.E.; Blokhintsev, L.D.; Cherubini, S.; Spitaleri, C.; Kroha, V.; Nunes, F.M.

2005-01-01

It is very difficult or often impossible to measure in the lab conditions nuclear cross sections at astrophysically relevant energies. That is why different indirect techniques are used to extract astrophysical information. In this talk different experimental possibilities to get astrophysical information using radioactive and stable beams will be addressed. 1. The asymptotic normalization coefficient (ANC) method. 2. Radiative neutron captures are determined by the spectroscopic factors (SP). A new experimental technique to determine the neutron SPs will be addressed. 3. 'Trojan Horse' is another unique indirect method, which allows one to extract the astrophysical factors for direct and resonant nuclear reactions at astrophysically relevant energies. (author)

Scaling law in laboratory astrophysics

International Nuclear Information System (INIS)

Xia Jiangfan; Zhang Jie

2001-01-01

The use of state-of-the-art lasers makes it possible to produce, in the laboratory, the extreme conditions similar to those in astrophysical processes. The introduction of astrophysics-relevant ideas in laser-plasma interaction experiments is propitious to the understanding of astrophysical phenomena. However, the great difference between laser-produced plasma and astrophysical objects makes it awkward to model the latter by laser-plasma experiments. The author presents the physical reasons for modeling astrophysical plasmas by laser plasmas, connecting these two kinds of plasmas by scaling laws. This allows the creation of experimental test beds where observation and models can be quantitatively compared with laboratory data

Nuclear astrophysics

International Nuclear Information System (INIS)

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

MHD instabilities in astrophysical plasmas: very different from MHD instabilities in tokamaks!

Science.gov (United States)

Goedbloed, J. P.

2018-01-01

The extensive studies of MHD instabilities in thermonuclear magnetic confinement experiments, in particular of the tokamak as the most promising candidate for a future energy producing machine, have led to an ‘intuitive’ description based on the energy principle that is very misleading for most astrophysical plasmas. The ‘intuitive’ picture almost directly singles out the dominant stabilizing field line bending energy of the Alfvén waves and, consequently, concentrates on expansion schemes that minimize that contribution. This happens when the wave vector {{k}}0 of the perturbations, on average, is perpendicular to the magnetic field {B}. Hence, all macroscopic instabilities of tokamaks (kinks, interchanges, ballooning modes, ELMs, neoclassical tearing modes, etc) are characterized by satisfying the condition {{k}}0 \\perp {B}, or nearly so. In contrast, some of the major macroscopic instabilities of astrophysical plasmas (the Parker instability and the magneto-rotational instability) occur when precisely the opposite condition is satisfied: {{k}}0 \\parallel {B}. How do those instabilities escape from the dominance of the stabilizing Alfvén wave? The answer to that question involves, foremost, the recognition that MHD spectral theory of waves and instabilities of laboratory plasmas could be developed to such great depth since those plasmas are assumed to be in static equilibrium. This assumption is invalid for astrophysical plasmas where rotational and gravitational accelerations produce equilibria that are at best stationary, and the associated spectral theory is widely, and incorrectly, believed to be non-self adjoint. These complications are addressed, and cured, in the theory of the Spectral Web, recently developed by the author. Using this method, an extensive survey of instabilities of astrophysical plasmas demonstrates how the Alfvén wave is pushed into insignificance under these conditions to give rise to a host of instabilities that do not

Canonical Models of Geophysical and Astrophysical Flows: Turbulent Convection Experiments in Liquid Metals

Directory of Open Access Journals (Sweden)

Adolfo Ribeiro

2015-03-01

Full Text Available Planets and stars are often capable of generating their own magnetic fields. This occurs through dynamo processes occurring via turbulent convective stirring of their respective molten metal-rich cores and plasma-based convection zones. Present-day numerical models of planetary and stellar dynamo action are not carried out using fluids properties that mimic the essential properties of liquid metals and plasmas (e.g., using fluids with thermal Prandtl numbers Pr < 1 and magnetic Prandtl numbers Pm ≪ 1. Metal dynamo simulations should become possible, though, within the next decade. In order then to understand the turbulent convection phenomena occurring in geophysical or astrophysical fluids and next-generation numerical models thereof, we present here canonical, end-member examples of thermally-driven convection in liquid gallium, first with no magnetic field or rotation present, then with the inclusion of a background magnetic field and then in a rotating system (without an imposed magnetic field. In doing so, we demonstrate the essential behaviors of convecting liquid metals that are necessary for building, as well as benchmarking, accurate, robust models of magnetohydrodynamic processes in Pm ≪  Pr < 1 geophysical and astrophysical systems. Our study results also show strong agreement between laboratory and numerical experiments, demonstrating that high resolution numerical simulations can be made capable of modeling the liquid metal convective turbulence needed in accurate next-generation dynamo models.

ON THE ROLE OF REPETITIVE MAGNETIC RECONNECTIONS IN EVOLUTION OF MAGNETIC FLUX ROPES IN SOLAR CORONA

Energy Technology Data Exchange (ETDEWEB)

Kumar, Sanjay; Bhattacharyya, R.; Joshi, Bhuwan [Udaipur Solar Observatory, Physical Research Laboratory, Dewali, Bari Road, Udaipur-313001 (India); Smolarkiewicz, P. K. [European Centre for Medium-Range Weather Forecasts, Reading RG2 9AX (United Kingdom)

2016-10-20

Parker's magnetostatic theorem, extended to astrophysical magnetofluids with large magnetic Reynolds number, supports ceaseless regeneration of current sheets and, hence, spontaneous magnetic reconnections recurring in time. Consequently, a scenario is possible where the repeated reconnections provide an autonomous mechanism governing emergence of coherent structures in astrophysical magnetofluids. In this work, such a scenario is explored by performing numerical computations commensurate with the magnetostatic theorem. In particular, the computations explore the evolution of a flux rope governed by repeated reconnections in a magnetic geometry resembling bipolar loops of solar corona. The revealed morphology of the evolution process—including onset and ascent of the rope, reconnection locations, and the associated topology of the magnetic field lines—agrees with observations, and thus substantiates physical realizability of the advocated mechanism.

Radiation monitoring in a synchrotron light source facility using magnetically levitated electrode ionization chambers

International Nuclear Information System (INIS)

Ichiki, Hirofumi; Kawaguchi, Toshirou; Utsunomiya, Yoshitomo; Ishibashi, Kenji; Ikeda, Nobuo; Korenaga, Kazuhito

2009-01-01

We developed a highly accurate differential-type automatic radiation dosimeter to measure very low radiation doses. The dosimeter had two ionization chambers, each of which had a magnetically levitated electrode and it was operated in a repetitive-time integration mode. We first installed the differential-type automatic radiation dosimeter with MALICs at a high-energy electron accelerator facility (Kyushu Synchrotron Light Research Center Facility) and measured the background and ionizing radiations in the facility as well as the gaseous radiation in air. In the background dose measurements, the accuracy of the repetitive-time integration-type dosimeter was three times better than that of a commercial ionization chamber. When the radiation dose increased momentarily at the electron injection from the linac to the operating storage ring, the dosimeter with repetitive-time integral mode gave a successful response to the actual dose variation. The gaseous radiation dose in the facility was at the same level as that in Fukuoka City. We confirmed that the dosimeter with magnetically levitated electrode ionization chambers was usable in the accelerator facility, in spite of its limited response when operated in the repetitive-time integration mode. (author)

Relativistic astrophysics

CERN Document Server

Demianski, Marek

2013-01-01

Relativistic Astrophysics brings together important astronomical discoveries and the significant achievements, as well as the difficulties in the field of relativistic astrophysics. This book is divided into 10 chapters that tackle some aspects of the field, including the gravitational field, stellar equilibrium, black holes, and cosmology. The opening chapters introduce the theories to delineate gravitational field and the elements of relativistic thermodynamics and hydrodynamics. The succeeding chapters deal with the gravitational fields in matter; stellar equilibrium and general relativity

Relativistic astrophysics and theory of gravity

International Nuclear Information System (INIS)

Zel'dovich, Ya.B.

1982-01-01

A brief historical review of the development of astrophysical science in the State Astrophysical Institute named after Shternberg (SAISh) has been given in a popular form. The main directions of the SAISh astrophysical investigations have been presented: relativistic theory of gravity, relativistic astrophysics of interplanetary medium and cosmology

Particle and astrophysics aspects of ultrahigh energy cosmic rays

International Nuclear Information System (INIS)

Sigl, G.

2001-01-01

The origin of cosmic rays is one of the major unresolved astrophysical questions. In particular, the highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from conventional shock acceleration to particle physics beyond the Standard Model and processes taking place at the earliest moments of our Universe. Furthermore, many new experimental activities promise a strong increase of statistics at the highest energies and a combination with γ-ray and neutrino astrophysics will put strong constraints on these theoretical models. Detailed Monte Carlo simulations indicate that charged ultra-high energy cosmic rays can also be used as probes of large scale magnetic fields whose origin may open another window into the very early Universe. We give an overview over this quickly evolving research field. (author)

Particle and astrophysics aspects of ultrahigh energy cosmic rays

Energy Technology Data Exchange (ETDEWEB)

Sigl, G [Institut d' Astrophysique de Paris, Paris (France)

2001-11-15

The origin of cosmic rays is one of the major unresolved astrophysical questions. In particular, the highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from conventional shock acceleration to particle physics beyond the Standard Model and processes taking place at the earliest moments of our Universe. Furthermore, many new experimental activities promise a strong increase of statistics at the highest energies and a combination with {gamma}-ray and neutrino astrophysics will put strong constraints on these theoretical models. Detailed Monte Carlo simulations indicate that charged ultra-high energy cosmic rays can also be used as probes of large scale magnetic fields whose origin may open another window into the very early Universe. We give an overview over this quickly evolving research field. (author)

Introduction to stellar astrophysics. V. 1

International Nuclear Information System (INIS)

Boehm-Vitense, E.

1989-01-01

This textbook introduces basic elements of fundamental astronomy and astrophysics which serve as a foundation for understanding the structure, evolution, and observed properties of stars. The first half of the book explains how stellar motions, distances, luminosities, colours, radii, masses and temperatures are measured or derived. The author then shows how data of these sorts can be arranged to classify stars through their spectra. Stellar rotation and stellar magnetic fields are introduced. Stars with peculiar spectra and pulsating stars also merit special attention. The endpoints of stellar evolutions are briefly described. There is a separate chapter on the Sun and a final one on interstellar absorption. (author)

Astrophysics Decoding the cosmos

CERN Document Server

Irwin, Judith A

2007-01-01

Astrophysics: Decoding the Cosmos is an accessible introduction to the key principles and theories underlying astrophysics. This text takes a close look at the radiation and particles that we receive from astronomical objects, providing a thorough understanding of what this tells us, drawing the information together using examples to illustrate the process of astrophysics. Chapters dedicated to objects showing complex processes are written in an accessible manner and pull relevant background information together to put the subject firmly into context. The intention of the author is that the book will be a 'tool chest' for undergraduate astronomers wanting to know the how of astrophysics. Students will gain a thorough grasp of the key principles, ensuring that this often-difficult subject becomes more accessible.

Gravity, particles and astrophysics

International Nuclear Information System (INIS)

Wesson, P.S.

1980-01-01

The author deals with the relationship between gravitation and elementary particle physics, and the implications of these subjects for astrophysics. The text is split up into two parts. The first part represents a relatively non-technical overview of the subject, while the second part represents a technical examination of the most important aspects of non-Einsteinian gravitational theory and its relation to astrophysics. Relevant references from the fields of gravitation, elementary particle theory and astrophysics are included. (Auth.)

Temperature Measurements in the Magnetic Measurement Facility

Energy Technology Data Exchange (ETDEWEB)

Wolf, Zachary

2010-12-13

Several key LCLS undulator parameter values depend strongly on temperature primarily because of the permanent magnet material the undulators are constructed with. The undulators will be tuned to have specific parameter values in the Magnetic Measurement Facility (MMF). Consequently, it is necessary for the temperature of the MMF to remain fairly constant. Requirements on undulator temperature have been established. When in use, the undulator temperature will be in the range 20.0 {+-} 0.2 C. In the MMF, the undulator tuning will be done at 20.0 {+-} 0.1 C. For special studies, the MMF temperature set point can be changed to a value between 18 C and 23 C with stability of {+-}0.1 C. In order to ensure that the MMF temperature requirements are met, the MMF must have a system to measure temperatures. The accuracy of the MMF temperature measurement system must be better than the {+-}0.1 C undulator tuning temperature tolerance, and is taken to be {+-}0.01 C. The temperature measurement system for the MMF is under construction. It is similar to a prototype system we built two years ago in the Sector 10 alignment lab at SLAC. At that time, our goal was to measure the lab temperature to {+-}0.1 C. The system has worked well for two years and has maintained its accuracy. For the MMF system, we propose better sensors and a more extensive calibration program to achieve the factor of 10 increase in accuracy. In this note we describe the measurement system under construction. We motivate our choice of system components and give an overview of the system. Most of the software for the system has been written and will be discussed. We discuss error sources in temperature measurements and show how these errors have been dealt with. The calibration system is described in detail. All the LCLS undulators must be tuned in the Magnetic Measurement Facility at the same temperature to within {+-}0.1 C. In order to ensure this, we are building a system to measure the temperature of the

Detailed design of the large-bore 8 T superconducting magnet for the NAFASSY test facility

Science.gov (United States)

Corato, V.; Affinito, L.; Anemona, A.; Besi Vetrella, U.; Di Zenobio, A.; Fiamozzi Zignani, C.; Freda, R.; Messina, G.; Muzzi, L.; Perrella, M.; Reccia, L.; Tomassetti, G.; Turtù, S.; della Corte, A.

2015-03-01

The ‘NAFASSY’ (NAtional FAcility for Superconducting SYstems) facility is designed to test wound conductor samples under high-field conditions at variable temperatures. Due to its unique features, it is reasonable to assume that in the near future NAFASSY will have a preeminent role at the international level in the qualification of long coiled cables in operative conditions. The magnetic system consists of a large warm bore background solenoid, made up of three series-connected grading sections obtained by winding three different Nb3Sn Cable-in-Conduit Conductors. Thanks to the financial support of the Italian Ministry for University and Research the low-field coil is currently under production. The design has been properly modified to allow the system to operate also as a stand-alone facility, with an inner bore diameter of 1144 mm. This magnet is able to provide about 7 T on its axis and about 8 T close to the insert inner radius, giving the possibility of performing a test relevant for large-sized NbTi or medium-field Nb3Sn conductors. The detailed design of the 8 T magnet, including the electro-magnetic, structural and thermo-hydraulic analysis, is here reported, as well as the production status.

Nuclear astrophysics with DRAGON at ISAC: the 21Na(p, γ)22Mg reaction

International Nuclear Information System (INIS)

D'Auria, J.M.

2003-01-01

The DRAGON facility at the new intense radioactive beams facility, ISAC, is now operational. It was built to perform studies of radiative alpha and proton capture reactions involving radioactive reactants, and of interest to nuclear astrophysics. The rate of the 21 Na(p, γ) 22 Mg reaction has been measured using inverse kinematics. Resonance strengths have been measured for states of importance for novae explosions. This report will summarize aspects of this study and its impact. (orig.)

Constraining astrophysical reaction rates: using the storage rings at FAIR/GSI

Science.gov (United States)

Langer, Christoph; Glorius, Jan; Slavkovská, Zuzana; Litvinov, Sergey; Litvinov, Yuri A.; Reifarth, René

2018-01-01

Ion optical calculations for a storage ring at the present GSI facility for direct proton-induced reactions relevant for different astrophysical processes are presented. As an example case, the 59Cu(p,γ) and 59Cu(p,α) reactions are shown. The branching of these two reactions is important in X-ray burst scenarios, since it determines the breakout out of the major 56Ni waiting point.

Facile Synthesis of Magnetic Mesoporous Hollow Carbon Microspheres for Rapid Capture of Low-Concentration Peptides

OpenAIRE

Cheng, Gong; Zhou, Ming-Da; Zheng, Si-Yang

2014-01-01

Mesoporous and hollow carbon microspheres embedded with magnetic nanoparticles (denoted as MHM) were prepared via a facile self-sacrificial method for rapid capture of low-abundant peptides from complex biological samples. The morphology, structure, surface property, and magnetism were well-characterized. The hollow magnetic carbon microspheres have a saturation magnetization value of 130.2 emu g?1 at room temperature and a Brunauer?Emmett?Teller specific surface area of 48.8 m2 g?1 with an a...

Astrophysical Concepts

CERN Document Server

Harwit, Martin

2006-01-01

This classic text, aimed at senior undergraduates and beginning graduate students in physics and astronomy, presents a wide range of astrophysical concepts in sufficient depth to give the reader a quantitative understanding of the subject. Emphasizing physical concepts, the book outlines cosmic events but does not portray them in detail: it provides a series of astrophysical sketches. For this fourth edition, nearly every part of the text has been reconsidered and rewritten, new sections have been added to cover recent developments, and others have been extensively revised and brought up to date. The book begins with an outline of the scope of modern astrophysics and enumerates some of the outstanding problems faced in the field today. The basic physics needed to tackle these questions are developed in the next few chapters using specific astronomical processes as examples. The second half of the book enlarges on these topics and shows how we can obtain quantitative insight into the structure and evolution of...

Laboratory Astrophysics Using High Energy Density Photon and Electron Beams

CERN Document Server

Bingham, Robert

2005-01-01

The development of intense laser and particle beams has opened up new opportunities to study high energy density astrophysical processes in the Laboratory. With even higher laser intensities possible in the near future vacuum polarization processes such as photon - photon scattering with or without large magnetic fields may also be experimentally observed. In this talk I will review the status of laboratory experiments using intense beans to investigate extreme astrophysical phenomena such as supernovae explosions, gamma x-ray bursts, ultra-high energy cosmic accelerators etc. Just as intense photon or electron beams can excite relativistic electron plasma waves or wakefields used in plasma acceleration, intense neutrino beams from type II supernovae can also excite wakefields or plasma waves. Other instabilities driven by intense beams relevant to perhaps x-ray bursts is the Weibel instability. Simulation results of extreme processes will also be presented.

Encyclopedia of Astronomy and Astrophysics

CERN Document Server

2002-01-01

Interstellar medium, Light, Magnetisphere, Matter, Planet Earth, Public Impact, Solar Activity, Solar Heliosphere, Solar Interior, Solar Systems, Space, Stellar Astrophysics, Stellar Populations, Telescopes, Time The Encyclopedia of Astronomy and Astrophysics covers 30 major subject areas, such as Active galaxies, Astrometry, Astrophysical theory, Atmospheres, Binary stars, Biography, Clusters, Coordinates, Cosmology, Earth, Education, Galaxies,

Fabrication of Continuous Microfibers Containing Magnetic Nanoparticles by a Facile Magneto-Mechanical Drawing

Science.gov (United States)

Li, Jin-Tao; Jia, Xian-Sheng; Yu, Gui-Feng; Yan, Xu; He, Xiao-Xiao; Yu, Miao; Gong, Mao-Gang; Ning, Xin; Long, Yun-Ze

2016-09-01

A facile method termed magneto-mechanical drawing is used to produce polymer composite microfibers. Compared with electrospinning and other fiber spinning methods, magneto-mechanical drawing uses magnetic force generated by a permanent magnet to draw droplets of polymer/magnetic nanoparticle suspensions, leading to fabrication of composite microfibers. In addition, because of the rotating collector, it is easy to control the fiber assembly such as fibrous array in parallel or crossed fibrous structure. The general applicability of this method has also been proved by spinning different polymers and magnetic nanoparticles. The resultant fibers exhibit good superparamagnetic behavior at room temperature and ultrahigh stretchability (~443.8 %). The results indicate that magneto-mechanical drawing is a promising technique to fabricate magnetic and stretchable microfibers and devices.

The proceedings of the 1st international workshop on laboratory astrophysics experiments with large lasers

International Nuclear Information System (INIS)

Remington, B.A.; Goldstein, W.H.

1996-01-01

The world has stood witness to the development of a number of highly sophisticated and flexible, high power laser facilities (energies up to 50 kJ and powers up to 50 TW), driven largely by the world-wide effort in inertial confinement fusion (ICF). The charter of diagnosing implosions with detailed, quantitative measurements has driven the ICF laser facilities to be exceedingly versatile and well equipped with diagnostics. Interestingly, there is considerable overlap in the physics of ICF and astrophysics. Both typically involve compressible radiative hydrodynamics, radiation transport, complex opacities, and equations of state of dense matter. Surprisingly, however, there has been little communication between these two communities to date. With the recent declassification of ICF in the USA, and the approval to commence with construction of the next generation ''superlasers'', the 2 MJ National Ignition Facility in the US, and its equivalent, the LMJ laser in France, the situation is ripe for change. . Given the physics similarities that exist between ICF and astrophysics, one strongly suspects that there should exist regions of overlap where supporting research on the large lasers could be beneficial to the astrophysics community. As a catalyst for discussions to this end, Lawrence Livermore National Laboratory sponsored this workshop. Approximately 100 scientists attended from around the world, representing eight countries: the USA, Canada, UK, France, Germany, Russia, Japan, and Israel. A total of 30 technical papers were presented. The two day workshop was divided into four sessions, focusing on nonlinear hydrodynamics, radiative hydrodynamics, radiation transport, and atomic physics-opacities. Copies of the presentations are contained in these proceedings

The proceedings of the 1st international workshop on laboratory astrophysics experiments with large lasers

Energy Technology Data Exchange (ETDEWEB)

Remington, B.A.; Goldstein, W.H. [eds.

1996-08-09

The world has stood witness to the development of a number of highly sophisticated and flexible, high power laser facilities (energies up to 50 kJ and powers up to 50 TW), driven largely by the world-wide effort in inertial confinement fusion (ICF). The charter of diagnosing implosions with detailed, quantitative measurements has driven the ICF laser facilities to be exceedingly versatile and well equipped with diagnostics. Interestingly, there is considerable overlap in the physics of ICF and astrophysics. Both typically involve compressible radiative hydrodynamics, radiation transport, complex opacities, and equations of state of dense matter. Surprisingly, however, there has been little communication between these two communities to date. With the recent declassification of ICF in the USA, and the approval to commence with construction of the next generation ``superlasers``, the 2 MJ National Ignition Facility in the US, and its equivalent, the LMJ laser in France, the situation is ripe for change. . Given the physics similarities that exist between ICF and astrophysics, one strongly suspects that there should exist regions of overlap where supporting research on the large lasers could be beneficial to the astrophysics community. As a catalyst for discussions to this end, Lawrence Livermore National Laboratory sponsored this workshop. Approximately 100 scientists attended from around the world, representing eight countries: the USA, Canada, UK, France, Germany, Russia, Japan, and Israel. A total of 30 technical papers were presented. The two day workshop was divided into four sessions, focusing on nonlinear hydrodynamics, radiative hydrodynamics, radiation transport, and atomic physics-opacities. Copies of the presentations are contained in these proceedings.

Summary of sessions on nuclear astrophysics

Science.gov (United States)

Rolfs, C.

In the minds of some there exists the patronizing belief that nuclear physics is a mature science. The same is not believed about nuclear astrophysics, which has been an active branch of astrophysics for over fifty years, but is now in the midst of an exciting revival in experimental and theoretical research around the world. The ultimate goal is to understand how nuclear processes generate the energy of stars over their lifetimes and, in doing so, synthesize heavier elements from the primordial hydrogen and helium produced in the Big Bang, which led to the expanding universe. Impressive progress has been made in this goal and this was rewarded. However, there are major puzzles, such as the solar neutrino problem to name just one, which challenge the fundaments of the field. To solve these problems, new nuclear physics data are needed employing novel experimental techniques such as radioactive ion beams and underground accelerator facilities. Without such new data, much of the work done so far will - in an optimistic view - be incomplete and - in a pessimistic view - be possibly wrong. Thus, new data do not represent a fine structure information or a cleaning-up job, but they represent the major next step in this exciting field&

Underground Facilities, Technological Challenges

CERN Document Server

Spooner, N

2010-01-01

This report gives a summary overview of the status of international under- ground facilities, in particular as relevant to long-baseline neutrino physics and neutrino astrophysics. The emphasis is on the technical feasibility aspects of creating the large underground infrastructures that will be needed in the fu- ture to house the necessary detectors of 100 kton to 1000 kton scale. There is great potential in Europe to build such a facility, both from the technical point of view and because Europe has a large concentration of the necessary engi- neering and geophysics expertise. The new LAGUNA collaboration has made rapid progress in determining the feasibility for a European site for such a large detector. It is becoming clear in fact that several locations are technically fea- sible in Europe. Combining this with the possibility of a new neutrino beam from CERN suggests a great opportunity for Europe to become the leading centre of neutrino studies, combining both neutrino astrophysics and neutrino beam stu...

Astrophysics in a nutshell

CERN Document Server

Maoz, Dan

2007-01-01

A concise but thorough introduction to the observational data and theoretical concepts underlying modern astronomy, Astrophysics in a Nutshell is designed for advanced undergraduate science majors taking a one-semester course. This well-balanced and up-to-date textbook covers the essentials of modern astrophysics--from stars to cosmology--emphasizing the common, familiar physical principles that govern astronomical phenomena, and the interplay between theory and observation. In addition to traditional topics such as stellar remnants, galaxies, and the interstellar medium, Astrophysics in a N

Probing Black Hole Magnetic Fields with QED

Directory of Open Access Journals (Sweden)

Ilaria Caiazzo

2018-05-01

Full Text Available The effect of vacuum birefringence is one of the first predictions of quantum electrodynamics (QED: the presence of a charged Dirac field makes the vacuum birefringent when threaded by magnetic fields. This effect, extremely weak for terrestrial magnetic fields, becomes important for highly magnetized astrophysical objects, such as accreting black holes. In the X-ray regime, the polarization of photons traveling in the magnetosphere of a black hole is not frozen at emission but is changed by the local magnetic field. We show that, for photons traveling along the plane of the disk, where the field is expected to be partially organized, this results in a depolarization of the X-ray radiation. Because the amount of depolarization depends on the strength of the magnetic field, this effect can provide a way to probe the magnetic field in black-hole accretion disks and to study the role of magnetic fields in astrophysical accretion in general.

ZAPP: The Z Astrophysical Plasma Properties collaboration

International Nuclear Information System (INIS)

Rochau, G. A.; Bailey, J. E.; Falcon, R. E.; Loisel, G. P.; Nagayama, T.; Mancini, R. C.; Hall, I.; Winget, D. E.; Montgomery, M. H.; Liedahl, D. A.

2014-01-01

The Z Facility at Sandia National Laboratories [Matzen et al., Phys. Plasmas 12, 055503 (2005)] provides MJ-class x-ray sources that can emit powers >0.3 PW. This capability enables benchmark experiments of fundamental material properties in radiation-heated matter at conditions previously unattainable in the laboratory. Experiments on Z can produce uniform, long-lived, and large plasmas with volumes up to 20 cc, temperatures from 1–200 eV, and electron densities from 10 17–23  cc −1 . These unique characteristics and the ability to radiatively heat multiple experiments in a single shot have led to a new effort called the Z Astrophysical Plasma Properties (ZAPP) collaboration. The focus of the ZAPP collaboration is to reproduce the radiation and material characteristics of astrophysical plasmas as closely as possible in the laboratory and use detailed spectral measurements to strengthen models for atoms in plasmas. Specific issues under investigation include the LTE opacity of iron at stellar-interior conditions, photoionization around active galactic nuclei, the efficiency of resonant Auger destruction in black-hole accretion disks, and H-Balmer line shapes in white dwarf photospheres

Final Report. Hydrodynamics by high-energy-density plasma flow and hydrodynamics and radiative hydrodynamics with astrophysical application

International Nuclear Information System (INIS)

R Paul Drake

2004-01-01

OAK-B135 This is the final report from the project Hydrodynamics by High-Energy-Density Plasma Flow and Hydrodynamics and Radiation Hydrodynamics with Astrophysical Applications. This project supported a group at the University of Michigan in the invention, design, performance, and analysis of experiments using high-energy-density research facilities. The experiments explored compressible nonlinear hydrodynamics, in particular at decelerating interfaces, and the radiation hydrodynamics of strong shock waves. It has application to supernovae, astrophysical jets, shock-cloud interactions, and radiative shock waves

Astrophysical Institute, Potsdam

Science.gov (United States)

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...

Black hole astrophysics

International Nuclear Information System (INIS)

Blandford, R.D.; Thorne, K.S.

1979-01-01

Following an introductory section, the subject is discussed under the headings: on the character of research in black hole astrophysics; isolated holes produced by collapse of normal stars; black holes in binary systems; black holes in globular clusters; black holes in quasars and active galactic nuclei; primordial black holes; concluding remarks on the present state of research in black hole astrophysics. (U.K.)

Cold test facility for 1.8 m superconducting model magnets at the SSC

International Nuclear Information System (INIS)

LaBarge, A.

1993-07-01

A new facility has been constructed to measure the characteristic features of superconducting model magnets and cable at cryogenic temperatures -- a function which supports the design and development process for building full-scale accelerator magnets. There are multiple systems operating in concert to test the model magnets, namely: cryogenic, magnet power, data acquisition and system control. A typical model magnet test includes the following items: (1) warm measurements of magnet coils, strain gauges and voltage taps; (2) hipot testing of insulation integrity; (3) cooling with liquid nitrogen and then liquid helium; (4) measuring quench current and magnetic field; (5) magnet warm-up. While the magnet is being cooled to 4.22 K, the mechanical stress is monitored through strain gauges. Current is then ramped into the magnet until it reaches some maximum value and the magnet transitions from the superconducting state to the normal state. Normal-zone propagation is monitored using voltage taps on the magnet coils during this process, thus indicating where the transition began. The current ramp is usually repeated until a plateau current is reached, where the magnet has mechanically settled

The RIB facility EXOTIC and its experimental program at INFN-LNL

Science.gov (United States)

Parascandolo, Concetta

2018-05-01

In this contribution, I will present a review about the EXOTIC facility and the research field accessible by using its Radioactive Ion Beams. The EXOTIC facility, installed at the INFN-Laboratori Nazionali di Legnaro, is devoted to the in-flight production of light Radioactive Ion Beams in the energy range between 3-5 MeV/nucleon. The scientific activity performed at EXOTIC concerns different aspects of nuclear physics and nuclear astrophysics, such as, the investigation of reaction mechanisms and nuclear structure, resonant scattering experiments and measurements of nuclear reaction cross sections of astrophysical interest.

An invitation to astrophysics

CERN Document Server

Padmanabhan, Thanu

2006-01-01

This unique book provides a clear and lucid description of several aspects of astrophysics and cosmology in a language understandable to a physicist or beginner in astrophysics. It presents the key topics in all branches of astrophysics and cosmology in a simple and concise language. The emphasis is on currently active research areas and exciting new frontiers rather than on more pedantic topics. Many complicated results are introduced with simple, novel derivations which strengthen the conceptual understanding of the subject. The book also contains over one hundred exercises which will help s

Spanish Minister of Science and Technology visits the LHC magnet test facility

CERN Multimedia

Patrice Loïez

2002-01-01

H.E. Mr Josep Piqué i Camps, Minister for Science and Technology, Spain, toured the test facility for LHC magnets in building SM18 during his visit to CERN in November. Photo 01: The Minister (left) with M. Cerrada and G. Babé.

The B00 model coil in the ATLAS Magnet Test Facility

CERN Document Server

Dudarev, A; ten Kate, H H J; Anashkin, O P; Keilin, V E; Lysenko, V V

2001-01-01

A 1-m size model coil has been developed to investigate the transport properties of the three aluminum-stabilized superconductors used in the ATLAS magnets. The coil, named B00, is also used for debugging the cryogenic, power and control systems of the ATLAS Magnet Test Facility. The coil comprises two double pancakes made of the barrel toroid and end-cap toroid conductors and a single pancake made of the central solenoid conductor. The pancakes are placed inside an aluminum coil casing. The coil construction and cooling conditions are quite similar to the final design of the ATLAS magnets. The B00 coil is well equipped with various sensors to measure thermal and electrodynamic properties of the conductor inside the coils. Special attention has been paid to the study of the current diffusion process and the normal zone propagation in the ATLAS conductors and windings. Special pick-up coils have been made to measure the diffusion at different currents and magnetic field values. (6 refs).

Contributions to the study of astrophysical plasmas. From accretion-ejection flows to particle acceleration in shocks

International Nuclear Information System (INIS)

Casse, Fabien

2013-01-01

After having outlined that the study of turbulence is a point of convergence between mathematics and physics, and that magnetic turbulence is omnipresent in astrophysical plasmas and also present in the interstellar medium, in stars and in their environment, in accretion disks, at the vicinity of shocks, and so on, the author proposes an overview of his research works which started with a research thesis on magnetised accretion disks and transport of relativistic particles in a magnetic turbulence. So, in this report for an accreditation to supervise research (HDR), he first focuses on physics of systems in accretion, and particularly on magnetised accretion-ejection structures. He evokes his work on a stationary modelling of these structures, on magnetohydrodynamics digital simulation of these systems, and on some instabilities in accretion disks and their interest in astrophysics. In a second part, the author reports his works on numerical assessment of coefficients of spatial diffusion of cosmic rays in a magnetic turbulence, and the description of multi-scale environments such as supernovae debris or different regions of extra-galactic jets.

From the Telescope to the Laboratory and Back Again: The Center for Astrophysical Plasma Properties

Science.gov (United States)

Houston Montgomery, Michael; Winget, Don; Schaeuble, Marc; Hawkins, Keith; Wheeler, Craig

2018-01-01

The Center for Astrophysical Plasma Properties (CAPP) is a new center focusing on the spectroscopic properties of stars and accretion disks using “at-parameter” experiments. Currently, these experiments use the X-ray output of the Z machine at Sandia National Laboratories—the largest X-ray source in the world—to heat plasmas to the same conditions (temperature, density, and radiation environment) as those observed in astronomical objects. Current experiments include measuring (1) density-dependent opacities of iron-peak elements at solar interior conditions, (2) spectral lines of low-Z elements at white dwarf photospheric conditions, (3) atomic population kinetics of neon in a radiation-dominated environment, and (4) resonant Auger destruction (RAD) of silicon at accretion disk conditions around supermassive black holes. We will be moving to new astrophysical environments and additional experimental facilities, such as the National Ignition Facility (NIF) and the OMEGA facility at the Laboratory for Laser Energetics (LLE). We seek students and collaborators to work on these experiments as well as the calculations that complement them. CAPP has funding for 5 years and can support up to six graduate students and three post-docs.

Astrophysics education at Universidad de Guadalajara, Mexico: From children popularization to posgraduate courses

Science.gov (United States)

de Alba-Martinez, D. J.

1999-05-01

Astrophysics growing group of the Universidad de Guadalajara situation is shown. Programs and activities developed at different levels are described, as popularization for children and adults (some in colaboration with Tourism Bureau and Jalisco State Education Secretary), licenciatura \\" (\\ BSc) courses actually taugth and posgraduate courses to be taugth in near future. Facilities and some exercises are shown.

Cryogenic Design of the New High Field Magnet Test Facility at CERN

Science.gov (United States)

Benda, V.; Pirotte, O.; De Rijk, G.; Bajko, M.; Craen, A. Vande; Perret, Ph.; Hanzelka, P.

In the framework of the R&D program related to the Large Hadron Collider (LHC) upgrades, a new High Field Magnet (HFM) vertical test bench is required. This facility located in the SM18 cryogenic test hall shall allow testing of up to 15 tons superconducting magnets with energy up to 10 MJ in a temperature range between 1.9 K and 4.5 K. The article describes the cryogenic architecture to be inserted in the general infrastructure of SM18 including the process and instrumentation diagram, the different operating phases including strategy for magnet cool down and warm up at controlled speed and quench management as well as the design of the main components.

Artium mater in relativistic astrophysics : New perspectives for a European-Latin American PhD program

Energy Technology Data Exchange (ETDEWEB)

Chardonnet, Pascal [Coordinator IRAP PhD EMJD, Université de Nice 28, avenue Valrose 06103 Nice (France); LAPTh, Université de Savoie, CNRS, B.P. 110, Annecy-le-Vieux F-74941 (France); ICRANet, Piazza della Repubblica 10, 65122 Pescara (Italy); Department for Theoretical Nuclear Physics, National Research Nuclear University Moscow Engineering Physics Institute, MEPhI, Moscow (Russian Federation)

2015-12-17

Following the successful scientific space missions by the European Space Agency (ESA) and the European Southern Observatory (ESO) in Chile, as well as the high-energy particle activities at CERN in Genve, we have created a Ph.D. program dedicated to the formation of scientists in the field of relativistic astrophysics. The students of such a program will lead the theoretical developments of one of the most active fields of research, based on the above observational and experimental facilities. This program needs expertise in the most advanced topics of mathematical and theoretical physics, and in relativistic field theories. It requires the ability to model the observational data received from the above facilities, as well as all the basic knowledge in astronomy, astrophysics and cosmology. This activity is necessarily international, no single university can cover the broad expertises. From this, the proposed program of the IRAP Ph.D., in one of the youngest and most dynamical French universities, pole of research and teaching in the Euro-Mediterranean region (PRES): the University of Nice. It benefits from the presence of the astrophysics research institute of Observatoire de la Cte d’Azur involved in relativistic and non-photonic astrophysics. The participation of the Freie Universitaet Berlin, Oldenburg and Bremen Universities and of the Einstein Institute in Potsdam offers the possibility of teaching in relativistic field theories at the highest level. The University of Savoy offers the link to the particle physics at CERN. The activities at the University of Rome, at Stockholm University and at ICRANet offer teaching programs in all the fields of relativistic astrophysics, including cosmology, the physics of gravitational collapse, gamma-ray bursts, and black hole physics. Finally, the University of Ferrara will be present with lectures and researches in the topics they have pioneered such as x-ray astrophysics and observational cosmology. Through ICRANet

Artium mater in relativistic astrophysics : New perspectives for a European-Latin American PhD program

International Nuclear Information System (INIS)

Chardonnet, Pascal

2015-01-01

Following the successful scientific space missions by the European Space Agency (ESA) and the European Southern Observatory (ESO) in Chile, as well as the high-energy particle activities at CERN in Genve, we have created a Ph.D. program dedicated to the formation of scientists in the field of relativistic astrophysics. The students of such a program will lead the theoretical developments of one of the most active fields of research, based on the above observational and experimental facilities. This program needs expertise in the most advanced topics of mathematical and theoretical physics, and in relativistic field theories. It requires the ability to model the observational data received from the above facilities, as well as all the basic knowledge in astronomy, astrophysics and cosmology. This activity is necessarily international, no single university can cover the broad expertises. From this, the proposed program of the IRAP Ph.D., in one of the youngest and most dynamical French universities, pole of research and teaching in the Euro-Mediterranean region (PRES): the University of Nice. It benefits from the presence of the astrophysics research institute of Observatoire de la Cte d’Azur involved in relativistic and non-photonic astrophysics. The participation of the Freie Universitaet Berlin, Oldenburg and Bremen Universities and of the Einstein Institute in Potsdam offers the possibility of teaching in relativistic field theories at the highest level. The University of Savoy offers the link to the particle physics at CERN. The activities at the University of Rome, at Stockholm University and at ICRANet offer teaching programs in all the fields of relativistic astrophysics, including cosmology, the physics of gravitational collapse, gamma-ray bursts, and black hole physics. Finally, the University of Ferrara will be present with lectures and researches in the topics they have pioneered such as x-ray astrophysics and observational cosmology. Through ICRANet

Artium mater in relativistic astrophysics : New perspectives for a European-Latin American PhD program

Science.gov (United States)

Chardonnet, Pascal

2015-12-01

Following the successful scientific space missions by the European Space Agency (ESA) and the European Southern Observatory (ESO) in Chile, as well as the high-energy particle activities at CERN in Genve, we have created a Ph.D. program dedicated to the formation of scientists in the field of relativistic astrophysics. The students of such a program will lead the theoretical developments of one of the most active fields of research, based on the above observational and experimental facilities. This program needs expertise in the most advanced topics of mathematical and theoretical physics, and in relativistic field theories. It requires the ability to model the observational data received from the above facilities, as well as all the basic knowledge in astronomy, astrophysics and cosmology. This activity is necessarily international, no single university can cover the broad expertises. From this, the proposed program of the IRAP Ph.D., in one of the youngest and most dynamical French universities, pole of research and teaching in the Euro-Mediterranean region (PRES): the University of Nice. It benefits from the presence of the astrophysics research institute of Observatoire de la Cte d'Azur involved in relativistic and non-photonic astrophysics. The participation of the Freie Universitaet Berlin, Oldenburg and Bremen Universities and of the Einstein Institute in Potsdam offers the possibility of teaching in relativistic field theories at the highest level. The University of Savoy offers the link to the particle physics at CERN. The activities at the University of Rome, at Stockholm University and at ICRANet offer teaching programs in all the fields of relativistic astrophysics, including cosmology, the physics of gravitational collapse, gamma-ray bursts, and black hole physics. Finally, the University of Ferrara will be present with lectures and researches in the topics they have pioneered such as x-ray astrophysics and observational cosmology. Through ICRANet the

FENIX [Fusion ENgineering International eXperimental]: A test facility for ITER [International Thermonuclear Experimental Reactor] and other new superconducting magnets

International Nuclear Information System (INIS)

Slack, D.S.; Patrick, R.E.; Miller, J.R.

1990-01-01

The Fusion ENgineering International eXperimental (FENIX) Test Facility which is nearing completion at Lawrence Livermore National Laboratory, is a 76-t set of superconducting magnets housed in a 4-m-diameter cryostat. It represents a significant step toward meeting the testing needs for the development of superconductors appropriate for large-scale magnet applications such as the International Thermonuclear Experimental Reactor (ITER). The magnet set is configured to allow radial access to the 0.4-m-diameter high-field region where maximum fields up to 14 T will be provided. The facility is fitted with a thermally isolated test well with a port to the high-field region that allows insertion and removal of test conductors without disturbing the cryogenic environment of the magnets. It is expected that the facility will be made available to magnet developers internationally, and this paper discusses its general design features, its construction, and its capabilities

Nuclear astrophysics: An application of nuclear physics

International Nuclear Information System (INIS)

Fueloep, Z.

2005-01-01

Nuclear astrophysics, a fruitful combination of nuclear physics and astrophysics can be viewed as a special application of nuclear physics where the study of nuclei and their reactions are motivated by astrophysical problems. Nuclear astrophysics is also a good example for the state of the art interdisciplinary research. The origin of elements studied by geologists is explored by astrophysicists using nuclear reaction rates provided by the nuclear physics community. Due to the high interest in the field two recent Nuclear Physics Divisional Conferences of the European Physical Society were devoted to nuclear astrophysics and a new conference series entitled 'Nuclear Physics in Astrophysics' has been established. Selected problems of nuclear astrophysics will be presented emphasizing the interplay between nuclear physics and astrophysics. As an example the role of 14 N(p,r) 15 O reaction rate in the determination of the age of globular clusters will be discussed in details

Indian participation in FAIR accelerator facility

International Nuclear Information System (INIS)

Sur, Amitava

2015-01-01

India is a founder member of the FAIR-GmbH, the upcoming International Accelerator Facility at Darmstadt, Germany. Indian participation at FAIR is being funded jointly by the Department of Science and Technology (DST) and the Department of Atomic Energy (DAE). Indo- FAIR Coordination Centre at Bose Institute (BI-IFCC) is coordinating the Indian efforts of both in-kind contribution as well as experimental programmes at FAIR. FAIR aims for beams of stable and unstable nuclei as well as antiprotons in a wide range of intensities and energies. A superconducting double-synchrotron SIS100/300 with a circumference of 1,100 meters and with magnetic rigidities of 100 and 300 Tm, respectively, is at the heart of the FAIR accelerator facility. The existing GSI accelerators UNILAC and SIS18 will serve as an injector. Adjacent to the large double- synchrotron is a complex system of storage- cooler rings and experiment stations, including a superconducting nuclear fragment separator (Super-FRS) and an antiproton production target. FAIR will supply rare isotope beams (RIBs) and antiproton beams. In FAIR accelerator facility up to four research programs can be run in a parallel mode. The multidisciplinary research program covers the fields of QCD studies with cooled beams of antiprotons, nucleus nucleus collisions at highest baryon density, nuclear structure and nuclear astrophysics investigations with nuclei far off stability, high density plasma physics, atomic and material science studies, radio-biological and other application-oriented studies will contribute in providing in-kind items both for the accelerator and the experiments. As per current plans Indian in kind contributions include: Power Converters, Superconducting Magnets, Beam Stopper, Vacuum Chamber. A short sample from an Indian Industry has been tested successfully at FAIR. Indian participation in building the accelerator components for FAIR is presented

JSME construction standard for superconducting magnets of fusion facilities. Toward the construction of ITER

International Nuclear Information System (INIS)

Nakasone, Yuji; Takahashi, Yukio; Sato, Kazuyoshi; Nishimura, Arata; Suzuki, Tetsuya; Irie, Hirosada; Nakahira, Masataka

2009-01-01

The present paper describes the general view of the construction standard, which the Japan Society of Mechanical Engineers (JSME) has recently set up and published, for superconducting magnet structures to be used in nuclear fusion facilities. The present target of the standard is tokamak-type fusion energy facilities, especially the International Thermonuclear Experimental Reactor called ITER for short. The standard contains rules for structural materials including cryogenic materials, structural design considering magnetic forces, manufacture including welding and installation, nondestructive testing, pressure proof tests and leak tests of toroidal field magnet structures. The standard covers requirements for structural integrity, deformation control, and leak tightness of all the components of the superconducting magnets and their supports except for superconducting strands and electrical insulators. The standard does not cover deterioration, which may occur in service as a result of corrosion, radiation effects, or instability of material. The standard consists of seven articles and twelve mandatory and non-mandatory appendices to the articles; i.e., (1) Scope, roles and responsibilities, (2) Materials, (3) Structural design, (4) Fabrication and installation, (5) Non-destructive examination, (6) Pressure and leak testing, and (7) Terms used in general requirements. (author)

Magnets for the Mirror Fusion Test Facility: testing of the first Yin-Yang and the design and development of other magnets

International Nuclear Information System (INIS)

Kozman, T.A.; Wang, S.T.; Chang, Y.

1983-01-01

Completed in May 1981, the first Yin-Yang magnet for the tandem Mirror Fusion Test Facility (MFTF-B) at Lawrence Livermore National Laboratory (LLNL) was successfully tested in February 1982 to its full design field (7.68 T) and current (5775 A). Since that time, the entire magnet array has been reconfigured - from the original A-cell to an axicell design. The MFTF-B magnet array now contains a total of 26 large superconducting coils: 2 sets of yin-yang pairs, 2 sets of transition magnets (each containing two coils), 2 sets of axicell magnets (each containing three coils), and 12 central-cell solenoids. This paper chronicles recent magnet history - from te testing of the initial yin-yang set, through the design of the axicell configuration, to the planned development of the system

Lunar Magnetism: IRMs Normalization and Impact Related Magnetization

Czech Academy of Sciences Publication Activity Database

Fuller, M.; Halekas, J.; Adachi, T.; Kletetschka, Günther; Kohout, Tomáš

2007-01-01

Roč. 88, č. 23 (2007), P23A-06 ISSN 0096-3941. [American Geophysical Union ; Joint Assembly. 22.05.2007-25.05.2007, Acapulco] Institutional research plan: CEZ:AV0Z30130516 Keywords : Moon * magnetization * impact Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

Minicourses in Astrophysics, Modular Approach, Vol. I.

Science.gov (United States)

Illinois Univ., Chicago.

This is the first volume of a two-volume minicourse in astrophysics. It contains chapters on the following topics: planetary atmospheres; X-ray astronomy; radio astrophysics; molecular astrophysics; and gamma-ray astrophysics. Each chapter gives much technical discussion, mathematical treatment, diagrams, and examples. References are included with…

Neutrino astrophysics

International Nuclear Information System (INIS)

Roulet, E.

2001-01-01

A general overview of neutrino physics and astrophysics is given, starting with a historical account of the development of our understanding of neutrinos and how they helped to unravel the structure of the Standard Model. We discuss why it is so important to establish if neutrinos are massive and introduce the main scenarios to provide them a mass. The present bounds and the positive indications in favor of non-zero neutrino masses are discussed, including the recent results on atmospheric and solar neutrinos. The major role that neutrinos play in astrophysics and cosmology is illustrated. (author)

Spanish Minister of Science and Technology visits the LHC magnet test facility

CERN Multimedia

Patrice Loïez

2002-01-01

H.E. Mr Josep Piqué i Camps, Minister for Science and Technology, Spain, toured the test facility for LHC magnets in building SM18 during his visit to CERN in November. Photos 01, 02: Felix Rodriguez Mateos (right) explains some of a cryomagnet's myriad connections to the Minister.

Magnetic Measurement System for the NSLS Superconducting Undulator Vertical Test Facility

CERN Document Server

Harder, David; Skaritka, John

2005-01-01

One of the challenges of small-gap superconducting undulators is measurement of magnetic fields within the cold bore to characterize the device performance and to determine magnetic field errors for correction or shimming, as is done for room-temperature undulators. Both detailed field maps and integrated field measurements are required. This paper describes a 6-element, cryogenic Hall probe field mapper for the NSLS Superconducting Undulator Vertical Test Facility (VTF). The probe is designed to work in an aperture only 3 mm high. A pulsed-wire insert is also being developed, for visualization of the trajectory, for locating steering errors and for determining integrated multi-pole errors. The pulsed-wire insert will be interchangeable with the Hall probe mapper. The VTF and the magnetic measurement systems can accommodate undulators up to 0.4 m in length.

The fundamentals of modern astrophysics a survey of the cosmos from the home planet to space frontiers

CERN Document Server

Marov, Mikhail Ya

2015-01-01

The Fundamentals of Modern Astrophysics provides an overview of the modern science of astrophysics. It covers the Sun, Solar System bodies, exoplanets, stars, and star life cycle, planetary systems origin and evolution, basics of astrobiology, our galaxy the Milky Way, other galaxies and galactic clusters, a general view of the Universe, its structure, evolution and fate, modern views and advanced models of cosmology as well as the synergy of micro- and macro physics, standard model, superstring theory, multiversity and worm holes. The main concepts of modern astrophysics and prospects for future studies are accompanied by numerous illustrations and a summary of the advanced projects at various astronomical facilities and space missions. Dr. Marov guides readers through a maze of complicated topics to demystify the field and open its wonders to all.

Preface: Eighth European Summer School on Experimental Nuclear Astrophysics

International Nuclear Information System (INIS)

Claudio, Spitaleri; Livio, Lamia; Gianluca, Pizzone Rosario

2016-01-01

In this book a collection of the lecture notes given during the Eighth European Summer School on Experimental Nuclear Astrophysics is given. The school, whose first edition was first held in 2003, took place from 13 to 20 of September 2015 in Santa Tecla, a small village about 15 km north of Catania, characterized by its position on the volcanic shores of the Ionian Sea, surrounded by the spectacular “Timpa” area, a green protected park specific for its mediterranean vegetation. 80 young students and researchers from more than 20 countries attended the lectures and were also encouraged to present their work and results. The school, has tried once more to present to the young students the global picture of nuclear astrophysics research in the last years. Thus the scientific program of the school covered a wide range of topics dealing with various aspects of nuclear astrophysics, such as stellar evolution and nucleosynthesis, neutrino physics, the Big Bang, direct and indirect methods and radioactive ion beams. Nuclear astrophysics plays a key role in understanding energy production in stars, stellar evolution and the concurrent synthesis of the chemical elements and their isotopes. It is also a fundamental tool to explain the ashes of the early universe, to determine the age of the universe through the study of pristine stellar objects and to predict the evolution of the Sun or Stars. The “bone structure” for the above aspects is based on nuclear reactions, whose rates need to be determined in laboratories. Although impressive progress has been made over the past decades, which was rewarded by Nobel prizes, several open questions are still unsolved, which challenge the basis of the present understanding. A list of the lecture topics is given below: —Big Bang Nucleosynthesis —Stellar evolution and Nucleosynthesis —radioactive ion beams —detector and facilities for nuclear astrophysics —indirect methods in nuclear astrophysics —plasma physics An

Hydrodynamic Instability, Integrated Code, Laboratory Astrophysics, and Astrophysics

Science.gov (United States)

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.

The new astrophysics

International Nuclear Information System (INIS)

Longair, M.

1989-01-01

The author offers a review of advances in astrophysics since 1945 when astronomers started to explore the universe beyond the bounds of the optical wavelength of the electromagnetic spectrum, especially in the fields of radio, x ray and gamma ray, cosmic ray, ultraviolet and infrared astronomies, as well as neutral hydrogen and molecular line studies. Theoretical and technological advances have also kept pace. An overview of the new astrophysics is offered focusing on the large-scale distribution of matter and the background microwave radiation, galaxies, stellar evolution and the interstellar media (dust, gas and high energy particles). Nucleosynthesis in stars is mentioned in a broader discussion of stellar evolution, and dead stars including supernovae. Active galaxies and quasars are discussed. After considering what should be included in astrophysical cosmology, the author looks to the future of the science. (U.K.)

Astrophysics related programs at center for underground physics (CUP)

Science.gov (United States)

Kim, Yeongduk

2018-04-01

We are developing experimental programs related to particle astrophysics at the Center for Underground Physics (CUP); searching for neutrino-less double beta decay (0νββ) of 100Mo nuclei and sterile neutrinos in the mass range of eV using reactor neutrinos. Expected sensitivities of AMoRE double beta decay experiment and the results from recent NEOS experiment are described. Utilizing the facilities for ultra-low radioactivity measurement at the center, we are planning to measure the decay of 180mTa which is important to the nucleosynthesis of heavy nuclei.

Magnetic Fields on the National Ignition Facility (MagNIF)

International Nuclear Information System (INIS)

Mason, D.; Folta, J.

2016-01-01

A magnetized target capability on the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) has been investigated. Stakeholders' needs and project feasibility analysis were considered in order to down-select from a wide variety of different potential magnetic field magnitudes and volumes. From the large range of different target platforms, laser configurations, and diagnostics configurations of interest to the stakeholders, the gas-pipe platform has been selected for the first round of magnetized target experiments. Gas pipe targets are routinely shot on the NIF and provide unique value for external collaborators. High-level project goals have been established including an experimentally relevant 20Tesla magnetic field magnitude. The field will be achieved using pulsed power-driven coils. A system architecture has been proposed. The pulsed power drive system will be located in the NIF target bay. This decision provides improved maintainability and mitigates equipment safety risks associated with explosive failure of the drive capacitor. High-level and first-level subsystem requirements have been established. Requirements have been included for two distinct coil designs - full solenoid and quasi-Helmholtz. A Failure Modes and Effects Analysis (FMEA) has been performed and documented. Additional requirements have been derived from the mitigations included in the FMEA document. A project plan is proposed. The plan includes a first phase of electromagnetic simulations to assess whether the design will meet performance requirements, then a second phase of risk mitigation projects to address the areas of highest technical risk. The duration from project kickoff to the first magnetized target shot is approximately 29 months.

Magnetic Fields on the National Ignition Facility (MagNIF)

Energy Technology Data Exchange (ETDEWEB)

Mason, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Folta, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-08-12

A magnetized target capability on the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) has been investigated. Stakeholders’ needs and project feasibility analysis were considered in order to down-select from a wide variety of different potential magnetic field magnitudes and volumes. From the large range of different target platforms, laser configurations, and diagnostics configurations of interest to the stakeholders, the gas-pipe platform has been selected for the first round of magnetized target experiments. Gas pipe targets are routinely shot on the NIF and provide unique value for external collaborators. High-level project goals have been established including an experimentally relevant 20Tesla magnetic field magnitude. The field will be achieved using pulsed power-driven coils. A system architecture has been proposed. The pulsed power drive system will be located in the NIF target bay. This decision provides improved maintainability and mitigates equipment safety risks associated with explosive failure of the drive capacitor. High-level and first-level subsystem requirements have been established. Requirements have been included for two distinct coil designs – full solenoid and quasi-Helmholtz. A Failure Modes and Effects Analysis (FMEA) has been performed and documented. Additional requirements have been derived from the mitigations included in the FMEA document. A project plan is proposed. The plan includes a first phase of electromagnetic simulations to assess whether the design will meet performance requirements, then a second phase of risk mitigation projects to address the areas of highest technical risk. The duration from project kickoff to the first magnetized target shot is approximately 29 months.

DIFFUSION OF MAGNETIC FIELD AND REMOVAL OF MAGNETIC FLUX FROM CLOUDS VIA TURBULENT RECONNECTION

International Nuclear Information System (INIS)

Santos-Lima, R.; De Gouveia Dal Pino, E. M.; Lazarian, A.; Cho, J.

2010-01-01

The diffusion of astrophysical magnetic fields in conducting fluids in the presence of turbulence depends on whether magnetic fields can change their topology via reconnection in highly conducting media. Recent progress in understanding fast magnetic reconnection in the presence of turbulence reassures that the magnetic field behavior in computer simulations and turbulent astrophysical environments is similar, as far as magnetic reconnection is concerned. This makes it meaningful to perform MHD simulations of turbulent flows in order to understand the diffusion of magnetic field in astrophysical environments. Our studies of magnetic field diffusion in turbulent medium reveal interesting new phenomena. First of all, our three-dimensional MHD simulations initiated with anti-correlating magnetic field and gaseous density exhibit at later times a de-correlation of the magnetic field and density, which corresponds well to the observations of the interstellar media. While earlier studies stressed the role of either ambipolar diffusion or time-dependent turbulent fluctuations for de-correlating magnetic field and density, we get the effect of permanent de-correlation with one fluid code, i.e., without invoking ambipolar diffusion. In addition, in the presence of gravity and turbulence, our three-dimensional simulations show the decrease of the magnetic flux-to-mass ratio as the gaseous density at the center of the gravitational potential increases. We observe this effect both in the situations when we start with equilibrium distributions of gas and magnetic field and when we follow the evolution of collapsing dynamically unstable configurations. Thus, the process of turbulent magnetic field removal should be applicable both to quasi-static subcritical molecular clouds and cores and violently collapsing supercritical entities. The increase of the gravitational potential as well as the magnetization of the gas increases the segregation of the mass and magnetic flux in the

Measurements of radiative material properties for astrophysical plasmas

International Nuclear Information System (INIS)

Bailey, James E.

2010-01-01

The new generation of z-pinch, laser, and XFEL facilities opens the possibility to produce astrophysically-relevant laboratory plasmas with energy densities beyond what was previously possible. Furthermore, macroscopic plasmas with uniform conditions can now be created, enabling more accurate determination of the material properties. This presentation will provide an overview of our research at the Z facility investigating stellar interior opacities, AGN warm-absorber photoionized plasmas, and white dwarf photospheres. Atomic physics in plasmas heavily influence these topics. Stellar opacities are an essential ingredient of stellar models and they affect what we know about the structure and evolution of stars. Opacity models have become highly sophisticated, but laboratory tests have not been done at the conditions existing inside stars. Our research is presently focused on measuring Fe at conditions relevant to the base of the solar convection zone, where the electron temperature and density are believed to be 190 eV and 9 x 10 22 e/cc, respectively. The second project is aimed at testing atomic kinetics models for photoionized plasmas. Photoionization is an important process in many astrophysical plasmas and the spectral signatures are routinely used to infer astrophysical object's characteristics. However, the spectral synthesis models at the heart of these interpretations have been the subject of very limited experimental tests. Our current research examines photoionization of neon plasma subjected to radiation flux similar to the warm absorber that surrounds active galactic nuclei. The third project is a recent initiative aimed at producing a white dwarf photosphere in the laboratory. Emergent spectra from the photosphere are used to infer the star's effective temperature and surface gravity. The results depend on knowledge of H, He, and C spectral line profiles under conditions where complex physics such as quasi-molecule formation may be important. These

astrophysical significance

Directory of Open Access Journals (Sweden)

Dartois E.

2014-02-01

Full Text Available Clathrate hydrates, ice inclusion compounds, are of major importance for the Earth’s permafrost regions and may control the stability of gases in many astrophysical bodies such as the planets, comets and possibly interstellar grains. Their physical behavior may provide a trapping mechanism to modify the absolute and relative composition of icy bodies that could be the source of late-time injection of gaseous species in planetary atmospheres or hot cores. In this study, we provide and discuss laboratory-recorded infrared signatures of clathrate hydrates in the near to mid-infrared and the implications for space-based astrophysical tele-detection in order to constrain their possible presence.

Space astronomy and astrophysics program by NASA

Science.gov (United States)

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.

Nuclear physics and astrophysics

International Nuclear Information System (INIS)

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

Astrophysics days and MHD

International Nuclear Information System (INIS)

Falgarone, Edith; Rieutord, Michel; Richard, Denis; Zahn, Jean-Paul; Dauchot, Olivier; Daviaud, Francois; Dubrulle, Berengere; Laval, Jean-Philippe; Noullez, Alain; Bourgoin, Mickael; Odier, Philippe; Pinton, Jean-Francois; Leveque, Emmanuel; Chainais, Pierre; Abry, Patrice; Mordant, Nicolas; Michel, Olivier; Marie, Louis; Chiffaudel, Arnaud; Daviaud, Francois; Petrelis, Francois; Fauve, Stephan; Nore, C.; Brachet, M.-E.; Politano, H.; Pouquet, A.; Leorat, Jacques; Grapin, Roland; Brun, Sacha; Delour, Jean; Arneodo, Alain; Muzy, Jean-Francois; Magnaudet, Jacques; Braza, Marianna; Boree, Jacques; Maurel, S.; Ben, L.; Moreau, J.; Bazile, R.; Charnay, G.; Lewandowski, Roger; Laveder, Dimitri; Bouchet, Freddy; Sommeria, Joel; Le Gal, P.; Eloy, C.; Le Dizes, S.; Schneider, Kai; Farge, Marie; Bottausci, Frederic; Petitjeans, Philippe; Maurel, Agnes; Carlier, Johan; Anselmet, Fabien

2001-05-01

This publication gathers extended summaries of presentations proposed during two days on astrophysics and magnetohydrodynamics (MHD). The first session addressed astrophysics and MHD: The cold interstellar medium, a low ionized turbulent plasma; Turbulent convection in stars; Turbulence in differential rotation; Protoplanetary disks and washing machines; gravitational instability and large structures; MHD turbulence in the sodium von Karman flow; Numerical study of the dynamo effect in the Taylor-Green eddy geometry; Solar turbulent convection under the influence of rotation and of the magnetic field. The second session addressed the description of turbulence: Should we give up cascade models to describe the spatial complexity of the velocity field in a developed turbulence?; What do we learn with RDT about the turbulence at the vicinity of a plane surface?; Qualitative explanation of intermittency; Reduced model of Navier-Stokes equations: quickly extinguished energy cascade; Some mathematical properties of turbulent closure models. The third session addressed turbulence and coherent structures: Alfven wave filamentation and formation of coherent structures in dispersive MHD; Statistical mechanics for quasi-geo-strophic turbulence: applications to Jupiter's coherent structures; Elliptic instabilities; Physics and modelling of turbulent detached unsteady flows in aerodynamics and fluid-structure interaction; Intermittency and coherent structures in a washing machine: a wavelet analysis of joint pressure/velocity measurements; CVS filtering of 3D turbulent mixing layer using orthogonal wavelets. The last session addressed experimental methods: Lagrangian velocity measurements; Energy dissipation and instabilities within a locally stretched vortex; Study by laser imagery of the generation and breakage of a compressed eddy flow; Study of coherent structures of turbulent boundary layer at high Reynolds number

Nuclear physics and astrophysics

Energy Technology Data Exchange (ETDEWEB)

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.

New Prospects in High Energy Astrophysics

Energy Technology Data Exchange (ETDEWEB)

Blandford, Roger; /KIPAC, Menlo Park

2011-11-15

Recent discoveries using TeV, X-ray and radio telescopes as well as Ultra High Energy Cosmic Ray arrays are leading to new insights into longstanding puzzles in high energy astrophysics. Many of these insights come from combining observations throughout the electromagnetic and other spectra as well as evidence assembled from different types of source to propose general principles. Issues discussed in this general overview include methods of accelerating relativistic particles, and amplifying magnetic field, the dynamics of relativistic outflows and the nature of the prime movers that power them. Observational approaches to distinguishing hadronic, leptonic and electromagnetic outflows and emission mechanisms are discussed along with probes of the velocity field and the confinement mechanisms. Observations with GLAST promise to be very prescriptive for addressing these problems.

A magnetodynamic mechanism for the formation of astrophysical jets, 2

International Nuclear Information System (INIS)

Shibata, Kazunari; Uchida, Yutaka.

1986-01-01

We present a nonsteady magnetodynamic mechanism for the formation of astrophysical jets in a magnetized accretion disk system. The dynamical processes in the contraction of a rotating disk, which is penetrated by a magnetic field parallel to the rotation axis, are investigated by using axially symmetric 2.5-dimensional MHD numerical simulations. As the rotating disk contracts, it pulls the magnetic field towards the center as well as to the azimuthal direction, producing a helically twisted magnetic field, and as the magnetic twist is accumulated and begins to relax along the poloidal field, the gas in the surface layers of the disk is pushed out to the polar directions by the J x B force with the relaxing magnetic twist. It is shown that the accelerated gas is collimated by the magnetic field and forms a supersonic bipolar jet which has a hollow cylindrical shell structure with helical motion in it. A considerable fraction of the gravitational potential energy released in the contraction of the disk is transformed to the kinetic energy of the jet through the action of the magnetic field. Also, angular momentum is carried away from the disk by the magnetic torque especially in the phase of the jet formation, and this allows the disk to keep contracting towards the gravitating center and can continue the ejection of the jet. (author)

Neutron-irradiation facilities at the Intense Pulsed Neutron Source-I for fusion magnet materials studies

International Nuclear Information System (INIS)

Brown, B.S.; Blewitt, T.H.

1982-01-01

The decommissioning of reactor-based neutron sources in the USA has led to the development of a new generation of neutron sources that employ high-energy accelerators. Among the accelerator-based neutron sources presently in operation, the highest-flux source is the Intense Pulsed Neutron Source (IPNS), a user facility at Argonne National Laboratory. Neutrons in this source are produced by the interaction of 400 to 500 MeV protons with either of two 238 U target systems. In the Radiation Effects Facility (REF), the 238 U target is surrounded by Pb for neutron generatjion and reflection. The REF has three separate irradiation thimbles. Two thimbles provide irradiation temperatures between that of liquid He and several hundred degrees centigrade. The third thimble operates at ambient temperature. The large irradiation volume, the neutron spectrum and flux, the ability to transfer samples without warm up, and the dedication of the facilities during the irradiation make this ideally suited for radiation damage studies on components for superconducting fusion magnets. Possible experiments for fusion magnet materials are discussed on cyclic irradiation and annealing of stabilizers in a high magnetic field, mechanical tests on organic insulation irradiated at 4 K, and superconductors measured in high fields after irradiation

High energy astrophysics. An introduction

Energy Technology Data Exchange (ETDEWEB)

Courvoisier, Thierry J.L. [Geneva Univ., Versoix (Switzerland). ISDC, Data Centre for Astrophysics

2013-07-01

Based on observational examples this book reveals and explains high-energy astrophysical processes. Presents the theory of astrophysical processes in a didactic approach by deriving equations step by step. With several attractive astronomical pictures. High-energy astrophysics has unveiled a Universe very different from that only known from optical observations. It has revealed many types of objects in which typical variability timescales are as short as years, months, days, and hours (in quasars, X-ray binaries, and other objects), and even down to milli-seconds in gamma ray bursts. The sources of energy that are encountered are only very seldom nuclear fusion, and most of the time gravitation, a paradox when one thinks that gravitation is, by many orders of magnitude, the weakest of the fundamental interactions. The understanding of these objects' physical conditions and the processes revealed by high-energy astrophysics in the last decades is nowadays part of astrophysicists' culture, even of those active in other domains of astronomy. This book evolved from lectures given to master and PhD students at the University of Geneva since the early 1990s. It aims at providing astronomers and physicists intending to be active in high-energy astrophysics a broad basis on which they should be able to build the more specific knowledge they will need. While in the first part of the book the physical processes are described and derived in detail, the second part studies astrophysical objects in which high-energy astrophysics plays a crucial role. This two-pronged approach will help students recognise physical processes by their observational signatures in contexts that may differ widely from those presented here.

Superconducting ring magnets of the PIOTRON Pi-meson therapy facility at SIN

Energy Technology Data Exchange (ETDEWEB)

Maix, R K; Meyer, G; Roman, T; Horvath, I; Vecsey, G; Zellweger, J

1982-01-01

Negative Pi-mesons seem to be very promising for cancer therapy, because of their well defined penetration depth and their enhanced energy deposition in the absorption region. A prototype Pi-meson therapy facility, called PIOTRON, has been constructed at SIN, where also pion beams of sufficient intensity are available. The central part of this system are two ring magnets, consisting each of 60 superconducting flat coils, with the aid of which 60 pion beams can be guided around a heavy iron shield and focused on the patient. In this paper the fabrication and the initial operation of these magnets is discussed.

Nuclear magnetic resonance facility for investigation of a disk of the body

International Nuclear Information System (INIS)

Clow, H.; Walters, P.E.

1979-01-01

By means of the facility there can be determined the distribution of the water content or of the relaxation-time constants in cross-sectional deils or volumes of the patient. The magnetic field applied is described in form of pulses. In order to achieve the required equal field integrals there is performed an inquiry on the magnetic field at times predetermined for the gradient-pulse shape. The gradient-pulse shape itself is sinusoidal or deformed-sinusoidal. In the circuit for field measurement and error signal there are used Yttrium-Iron-Garnet (YIG) oscillator probes. (RW) [de

Aespoe Hard Rock Laboratory. Ground magnetic survey at site for planned facility for calibration of borehole orientation equipment at Aespoe

Energy Technology Data Exchange (ETDEWEB)

Mattsson, Haakan (GeoVista AB (Sweden))

2012-01-15

This report presents survey description and results of ground magnetic measurements carried out by GeoVista AB at Aespoe in December, 2011. The purpose of the ground magnetic measurement was to measure variations in the earth magnetic field and to gain knowledge of the magnetization of the bedrock in an area where SKB plan to build a facility for calibration of equipment for measurements of borehole orientation. A total of 312 data points were collected along three survey lines, 104 points/profile. The data show nice and smooth variations that appear to be natural. There is a clear consistency of the magnetic field variations between the three survey lines, which indicates that the variations in the magnetic field reflect geological variations related to lithology and content of magnetic minerals. There are no indications of artifacts or erroneous data. The anomaly field averages at -32 nT with peak values of Min = -1,016 nT and Max = +572 nT. The strongest anomalies occur at profile length c. 130-140 m. Adding the background field of 50,823 nT, measured at a base station located close to the survey area, the total magnetic field averages at 50,791+-226 nT. The ground magnetic measurement gives background information before the construction of the calibration facility. The magnetic anomaly at c. 130-140 m give possibilities to control disturbances of magnetic-accelerometer based instruments. The magnetic measurements show that it is possible to construct the facility at the site

Aespoe Hard Rock Laboratory. Ground magnetic survey at site for planned facility for calibration of borehole orientation equipment at Aespoe

International Nuclear Information System (INIS)

Mattsson, Haakan

2012-01-01

This report presents survey description and results of ground magnetic measurements carried out by GeoVista AB at Aespoe in December, 2011. The purpose of the ground magnetic measurement was to measure variations in the earth magnetic field and to gain knowledge of the magnetization of the bedrock in an area where SKB plan to build a facility for calibration of equipment for measurements of borehole orientation. A total of 312 data points were collected along three survey lines, 104 points/profile. The data show nice and smooth variations that appear to be natural. There is a clear consistency of the magnetic field variations between the three survey lines, which indicates that the variations in the magnetic field reflect geological variations related to lithology and content of magnetic minerals. There are no indications of artifacts or erroneous data. The anomaly field averages at -32 nT with peak values of Min = -1,016 nT and Max = +572 nT. The strongest anomalies occur at profile length c. 130-140 m. Adding the background field of 50,823 nT, measured at a base station located close to the survey area, the total magnetic field averages at 50,791±226 nT. The ground magnetic measurement gives background information before the construction of the calibration facility. The magnetic anomaly at c. 130-140 m give possibilities to control disturbances of magnetic-accelerometer based instruments. The magnetic measurements show that it is possible to construct the facility at the site

Magnetic reconnection in nontoroidal plasmas

International Nuclear Information System (INIS)

Boozer, Allen H.

2005-01-01

Magnetic reconnection is a major issue in solar and astrophysical plasmas. The mathematical result that the evolution of a magnetic field with only point nulls is always locally ideal limits the nature of reconnection in nontoroidal plasmas. Here it is shown that the exponentially increasing separation of neighboring magnetic field lines, which is generic, tends to produce rapid magnetic reconnection if the length of the field lines is greater than about 20 times the exponentiation, or Lyapunov, length

Magnetic field strength distribution of magnetic bright points inferred from filtergrams and spectro-polarimetric data

Czech Academy of Sciences Publication Activity Database

Utz, D.; Jurčák, Jan; Hanslmeier, A.; Muller, R.; Veronig, A.; Kühner, O.

2013-01-01

Roč. 554, June (2013), A65/1-A65/12 ISSN 0004-6361 R&D Projects: GA ČR GAP209/12/0287; GA MŠk(CZ) MEB061109 Institutional support: RVO:67985815 Keywords : Sun * magnetic topology * surface magnetism Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.479, year: 2013

The Airborne Astronomy Ambassadors (AAA) Program and NASA Astrophysics Connections

Science.gov (United States)

Backman, Dana Edward; Clark, Coral; Harman, Pamela

2018-01-01

The NASA Airborne Astronomy Ambassadors (AAA) program is a three-part professional development (PD) experience for high school physics, astronomy, and earth science teachers. AAA PD consists of: (1) blended learning via webinars, asynchronous content delivery, and in-person workshops, (2) a STEM immersion experience at NASA Armstrong’s B703 science research aircraft facility in Palmdale, California, including interactions with NASA astrophysics & planetary science Subject Matter Experts (SMEs) during science flights on SOFIA, and (3) continuing post-flight opportunities for teacher & student connections with SMEs.

Bloch–Siegert shift in application to the astrophysical determination of the fundamental constants variation

International Nuclear Information System (INIS)

Solovyev, Dmitry

2013-01-01

We have evaluated the Bloch–Siegert shift for the different values of magnetic field's strengths defined at astrophysical conditions, i.e. when the stars with the strong surface magnetic fields are taken as a powerful pumping source of radiation. It is found that the additional shift of resonant frequency should be taken into account in the search for the time variation of the fundamental constants. The main conclusion is that the influence of the electromagnetic field should be considered carefully in each special case of the corresponding frequency determination

Lasers plasmas and magnetic field

International Nuclear Information System (INIS)

Albertazzi, Bruno

2014-01-01

We studied the coupling between a laser produced plasmas and a magnetic field in two cases: 1) in the context of Inertial Fusion Confinement (ICF), we first studied how magnetic fields are self generated during the interaction between a target and a laser, then 2) to progress in the understanding of the large-scale shaping of astrophysical jets, we studied the influence of an externally applied magnetic field on the dynamics of a laser-produced plasma expanding into vacuum. The first part of this thesis is thus dedicated to a numerical and experimental study of the self generated magnetic fields that are produced following the irradiation of a solid target by a high power laser (having pulse duration in the nanosecond and picosecond regimes). These fields play an important role in the frame of ICF since they influence the dynamics of the electrons produced during the laser-matter interaction, and thus condition the success of ICF experiments. The second part of this thesis is a numerical and experimental study of the influence of an externally applied magnetic field on the morphology of a laser produced plasma freely otherwise expanding into vacuum. This work aims at better understanding the observed large-scale collimation of astrophysical jets which cannot be understood in the frame of existing models. We notably show that a purely axial magnetic field can force an initially isotropic laboratory flow, scaled to be representative of a flow emerging from a Young Star Object, in a re-collimation shock, from which emerges a narrow, well collimated jet. We also show that the plasma heating induced at the re-collimation point could explain the 'puzzling' observations of stationary X ray emission zones embedded within astrophysical jets. (author) [fr

Complex astrophysical experiments relating to jets, solar loops, and water ice dusty plasma

Science.gov (United States)

Bellan, P. M.; Zhai, X.; Chai, K. B.; Ha, B. N.

2015-10-01

> Recent results of three astrophysically relevant experiments at Caltech are summarized. In the first experiment magnetohydrodynamically driven plasma jets simulate astrophysical jets that undergo a kink instability. Lateral acceleration of the kinking jet spawns a Rayleigh-Taylor instability, which in turn spawns a magnetic reconnection. Particle heating and a burst of waves are observed in association with the reconnection. The second experiment uses a slightly different setup to produce an expanding arched plasma loop which is similar to a solar corona loop. It is shown that the plasma in this loop results from jets originating from the electrodes. The possibility of a transition from slow to fast expansion as a result of the expanding loop breaking free of an externally imposed strapping magnetic field is investigated. The third and completely different experiment creates a weakly ionized plasma with liquid nitrogen cooled electrodes. Water vapour injected into this plasma forms water ice grains that in general are ellipsoidal and not spheroidal. The water ice grains can become quite long (up to several hundred microns) and self-organize so that they are evenly spaced and vertically aligned.

A facile way to realize exchange coupling interaction in hard/soft magnetic composites

Energy Technology Data Exchange (ETDEWEB)

Li, Dongyun, E-mail: lidongyun@cjlu.edu.cn [College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 (China); Wang, Fan [College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 (China); Xia, Ailin, E-mail: alxia@126.com [Anhui Key Laboratory of Metal Materials and Processing, School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243032 (China); Zhang, Lijiao [School of Science, Hebei University of Science and Technology, Shijiazhuang 050018 (China); Li, Tingting; Jin, Chuangui; Liu, Xianguo [Anhui Key Laboratory of Metal Materials and Processing, School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243032 (China)

2016-11-01

SrFe{sub 12}O{sub 19}/CoFe{sub 2}O{sub 4} and SrFe{sub 12}O{sub 19}/Fe–B hard/soft magnetic composites were obtained by using powders synthesized via a hydrothermal and a molten salt method, respectively. The exchange coupling interaction was found to exist in the composites after a facile grinding according to the results of magnetic hysteresis loops and irreversible sloping recoil loops. It can be found that different grinding time affects their magnetic properties slightly. Our study proves that the conditions of realizing exchange coupling interaction may not be so stringent. - Highlights: • SrM/CFO and SrM/Fe–B with exchange coupling were obtained via a grinding way. • Different grinding time affects their magnetic properties slightly. • The conditions of realizing exchange coupling may not be so stringent.

Astrophysical Nuclear Reaction Rates in the Dense Metallic Environments

Science.gov (United States)

Kilic, Ali Ihsan

2017-09-01

Nuclear reaction rates can be enhanced by many orders of magnitude in dense and relatively cold astrophysical plasmas such as in white dwarfs, brown dwarfs, and giant planets. Similar conditions are also present in supernova explosions where the ignition conditions are vital for cosmological models. White dwarfs are compact objects that have both extremely high interior densities and very strong local magnetic fields. For the first time, a new formula has been developed to explain cross section and reaction rate quantities for light elements that includes not only the nuclear component but also the material dependence, magnetic field, and crystal structure dependency in dense metallic environments. I will present the impact of the developed formula on the cross section and reaction rates for light elements. This could have possible technological applications in energy production using nuclear fusion reactions.

Large-Scale Astrophysical Visualization on Smartphones

Science.gov (United States)

Becciani, U.; Massimino, P.; Costa, A.; Gheller, C.; Grillo, A.; Krokos, M.; Petta, C.

2011-07-01

Nowadays digital sky surveys and long-duration, high-resolution numerical simulations using high performance computing and grid systems produce multidimensional astrophysical datasets in the order of several Petabytes. Sharing visualizations of such datasets within communities and collaborating research groups is of paramount importance for disseminating results and advancing astrophysical research. Moreover educational and public outreach programs can benefit greatly from novel ways of presenting these datasets by promoting understanding of complex astrophysical processes, e.g., formation of stars and galaxies. We have previously developed VisIVO Server, a grid-enabled platform for high-performance large-scale astrophysical visualization. This article reviews the latest developments on VisIVO Web, a custom designed web portal wrapped around VisIVO Server, then introduces VisIVO Smartphone, a gateway connecting VisIVO Web and data repositories for mobile astrophysical visualization. We discuss current work and summarize future developments.

The Magnetic Reconnection Code: Center for Magnetic Reconnection Studies

Energy Technology Data Exchange (ETDEWEB)

Amitava Bhattacharjee

2007-04-20

Understanding magnetic reconnection is one of the principal challenges in plasma physics. Reconnection is a process by which magnetic fields reconfigure themselves, releasing energy that can be converted to particle energies and bulk flows. Thanks to the availability of sophisticated diagnostics in fusion and laboratory experiments, in situ probing of magnetospheric and solar wind plasmas, and X-ray emission measurements from solar and stellar plasmas, theoretical models of magnetic reconnection can now be constrained by stringent observational tests. The members of the CMRS comprise an interdisciplinary group drawn from applied mathematics, astrophysics, computer science, fluid dynamics, plasma physics, and space science communities.

Recent Progress in Planetary Laboratory Astrophysics achieved with NASA Ames' COSmIC Facility

Science.gov (United States)

Salama, Farid; Sciamma-O'Brien, Ella; Bejaoui, Salma

2016-10-01

We describe 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 nanoparticles under the low temperature and high vacuum conditions that are required to simulate various space environments such as planetary atmospheres. 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. The COSmIC experimental setup is composed of a Pulsed Discharge Nozzle (PDN) expansion, that generates a plasma in the stream of a 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 [2, 3], and a Reflectron Time-Of-Flight Mass Spectrometer (ReTOF-MS) for mass detection [4].Recent results obtained using COSmIC will be highlighted. In particular, the progress that has been achieved in an on-going study investigating the formation and the characterization of laboratory analogs of Titan's aerosols generated from gas-phase molecular precursors [5] will be presented. Plans for future laboratory experiments on planetary molecules and aerosols in the growing field of planetary laboratory astrophysics will also be addressed, as well as the implications of studies underway for astronomical observations.References: [1] Salama F., in Organic Matter in Space, IAU S251, Kwok & Sandford eds, CUP, S251, 4, 357 (2008).[2] Biennier L., Salama, F., Allamandola L., & Scherer J., J. Chem. Phys., 118, 7863 (2003)[3] Tan X, & Salama F., J. Chem. Phys. 122, 84318 (2005)[4] Ricketts C., Contreras C., Walker, R., Salama F., Int. J. Mass Spec, 300

Magnetized environs of a repeating radio burst

Science.gov (United States)

Metzger, Brian D.

2018-03-01

One of the astrophysical sources that gives rise to the mysterious transients known as fast radio bursts is embedded in a highly magnetized environment, such as the vicinity of an accreting massive black hole or the birth nebula of a highly magnetized neutron star.

Can a marginally open universe amplify magnetic fields?

International Nuclear Information System (INIS)

Shtanov, Yuri; Sahni, Varun

2013-01-01

In a series of recent papers, including arXiv:1210.1183, it was claimed that large-scale magnetic fields generated during inflation in a spatially open universe could remain astrophysically significant at the present time since they experienced superadiabatic amplification specific to an open universe. We reexamine this assertion and show that, on the contrary, large-scale magnetic fields in a realistic open universe decay in much the same manner as they would in a spatially flat universe. Consequently, their amplitude today is extremely small (B 0 ∼ −59 G) and is unlikely to be of astrophysical significance

New insight into the origin of anomalous magnetism of titanohematite lamellae in rhombohedral oxide assemblages -consequence for Mars magnetism

Czech Academy of Sciences Publication Activity Database

Kletetschka, Günther; Zbořil, R.; Adachi, T.; Mikula, V.; Heřmánek, M.; Wasilewski, P. J.

2007-01-01

Roč. 88, č. 23 (2007), GP33A-07 ISSN 0096-3941. [American Geophysical Union ; Joint Assembly. 22.05.2007-25.05.2007, Acapulco] Institutional research plan: CEZ:AV0Z30130516 Keywords : titanohematite * magnetization * magnetic anomalies Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

An introduction to observational astrophysics

CERN Document Server

Gallaway, Mark

2016-01-01

Observational Astrophysics follows the general outline of an astrophysics undergraduate curriculum targeting practical observing information to what will be covered at the university level. This includes the basics of optics and coordinate systems to the technical details of CCD imaging, photometry, spectography and radio astronomy.  General enough to be used by students at a variety of institutions and advanced enough to be far more useful than observing guides targeted at amateurs, the author provides a comprehensive and up-to-date treatment of observational astrophysics at undergraduate level to be used with a university’s teaching telescope.  The practical approach takes the reader from basic first year techniques to those required for a final year project. Using this textbook as a resource, students can easily become conversant in the practical aspects of astrophysics in the field as opposed to the classroom.

Nonlinear dynamics and astrophysics

International Nuclear Information System (INIS)

Vallejo, J. C.; Sanjuan, M. A. F.

2000-01-01

Concepts and techniques from Nonlinear Dynamics, also known as Chaos Theory, have been applied successfully to several astrophysical fields such as orbital motion, time series analysis or galactic dynamics, providing answers to old questions but also opening a few new ones. Some of these topics are described in this review article, showing the basis of Nonlinear Dynamics, and how it is applied in Astrophysics. (Author)

Nuclear astrophysics with radioactive beams

International Nuclear Information System (INIS)

Bertulani, C.A.; Gade, A.

2010-01-01

The quest to comprehend how nuclear processes influence astrophysical phenomena is driving experimental and theoretical research programs worldwide. One of the main goals in nuclear astrophysics is to understand how energy is generated in stars, how elements are synthesized in stellar events and what the nature of neutron stars is. New experimental capabilities, the availability of radioactive beams and increased computational power paired with new astronomical observations have advanced the present knowledge. This review summarizes the progress in the field of nuclear astrophysics with a focus on the role of indirect methods and reactions involving beams of rare isotopes.

Nuclear reactions in astrophysics

International Nuclear Information System (INIS)

Arnould, M.; Rayet, M.

1990-01-01

At all times and at all astrophysical scales, nuclear reactions have played and continue to play a key role. This concerns the energetics as well as the production of nuclides (nucleosynthesis). After a brief review of the observed composition of various objects in the universe, and especially of the solar system, the basic ingredients that are required in order to build up models for the chemical evolution of galaxies are sketched. Special attention is paid to the evaluation of the stellar yields through an overview of the important burning episodes and nucleosynthetic processes that can develop in non-exploding or exploding stars. Emphasis is put on the remaining astrophysical and nuclear physics uncertainties that hamper a clear understanding of the observed characteristics, and especially compositions, of a large variety of astrophysical objects

Laboratory astrophysics with high energy and high power lasers: from radiative shocks to young star jets

International Nuclear Information System (INIS)

Diziere, A.

2012-01-01

Laboratory astrophysics are a rapidly developing domain of the High Energy Density Physics. It aims to recreate at smaller scales physical processes that astronomical telescopes have difficulties observing. We shall approach, in this thesis, three major subjects: 1) Jets ejected from young stars, characterized by an important collimation degree and ending with a bow shock; 2) Radiative shocks in which radiation emitted by the shock front itself plays a dominant role in its structure and 3) Accretion shocks in magnetic cataclysmic variables whose important cooling factor allows them to reach stationarity. From the conception to experimental realization, we shall attempt to reproduce in laboratory each of these processes by respecting the scaling laws linking both situations (experimental and astrophysical) established beforehand. The implementation of a large array of visible and X-ray diagnostics will finally allow to completely characterize them and calculate the dimensionless numbers that validate the astrophysical relevance. (author) [fr

Cyberinfrastructure for Computational Relativistic Astrophysics

OpenAIRE

Ott, Christian

2012-01-01

Poster presented at the NSF Office of Cyberinfrastructure CyberBridges CAREER PI workshop. This poster discusses the computational challenges involved in the modeling of complex relativistic astrophysical systems. The Einstein Toolkit is introduced. It is an open-source community infrastructure for numerical relativity and computational astrophysics.

Laboratory astrophysics. Model experiments of astrophysics with large-scale lasers

International Nuclear Information System (INIS)

Takabe, Hideaki

2012-01-01

I would like to review the model experiment of astrophysics with high-power, large-scale lasers constructed mainly for laser nuclear fusion research. The four research directions of this new field named 'Laser Astrophysics' are described with four examples mainly promoted in our institute. The description is of magazine style so as to be easily understood by non-specialists. A new theory and its model experiment on the collisionless shock and particle acceleration observed in supernova remnants (SNRs) are explained in detail and its result and coming research direction are clarified. In addition, the vacuum breakdown experiment to be realized with the near future ultra-intense laser is also introduced. (author)

The importance of CNO isotopes in astrophysics

International Nuclear Information System (INIS)

Audoze, J.

1977-01-01

The research into CNO isotopes in astrophysics includes many different subfields of astrophysics such as meteoretical studies, experimental and theoretical nuclear astrophysics, optical astronomy, radio astronomy, etc. The purpose of this paper is to give some overview of the topic and guideline among these different subfields. (G.T.H.)

Electromagnetic design, engineering development and magnetic qualification of a horizontal layered scaled magnet for physics experiments

Energy Technology Data Exchange (ETDEWEB)

Trivedi, Praveen; Teotia, Vikas; Malhotra, Sanjay; Taly, Y.K., E-mail: praveent@barc.gov.in [Control Instrumentation Division, Bhabha Atomic Research Centre, Mumbai (India)

2014-07-01

Neutrino detectors around the world have shown evidence that these weakly interacting, little-understood particles are not really mass less, as was thought so far. Not only do they have non-zero masses, different species (or flavors) of neutrinos seem to mix and oscillate into one another as they traverse through the cosmos. If this is true, this is not only one of the first pieces of evidence for physics beyond the so-called Standard Model of Particle Physics, but would also have great impact on diverse fields such as nuclear and particle physics, astrophysics and cosmology. It is thus imperative to study the details of the interactions of these particles. These will be detected by means of an iron calorimeter (ICAL), comprising detectors sandwiched in alternate layers of soft magnetic iron. The iron core is magnetized to allow bending of the charged particles. The direction and the energy of the original incoming neutrino, that caused the interaction, can then be accurately determined. Racetrack coils through slots cut in the iron core create a uniform magnetic field in the iron core. A highly uniform magnetic field in the soft iron core is required to accurately determine the mass and energy of incident particle. The charged particles bend in this magnetic field; oppositely charged particles bending in opposite directions. The charge, energy and momentum of the emitted particle is thus determined. An electromagnet was designed as a laboratory facility for conducting experimental studies in particle physics. This paper discusses the electromagnetic design, development, fabrication, magnetic qualification and magnetic measurement issues of an electromagnet developed for physics studies. (author)

Magnetic cloud fit by uniform-twist toroidal flux ropes

Czech Academy of Sciences Publication Activity Database

Vandas, Marek; Romashets, E.

2017-01-01

Roč. 608, December (2017), A118/1-A118/12 E-ISSN 1432-0746 R&D Projects: GA ČR(CZ) GA17-06065S Institutional support: RVO:67985815 Keywords : magnetic fields * coronal mass ejections * solar wind Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 5.014, year: 2016

General relativistic razor-thin disks with magnetically polarized matter

Science.gov (United States)

Navarro-Noguera, Anamaría; Lora-Clavijo, F. D.; González, Guillermo A.

2018-06-01

The origin of magnetic fields in the universe still remains unknown and constitutes one of the most intriguing questions in astronomy and astrophysics. Their significance is enormous since they have a strong influence on many astrophysical phenomena. In regards of this motivation, theoretical models of galactic disks with sources of magnetic field may contribute to understand the physics behind them. Inspired by this, we present a new family of analytical models for thin disks composed by magnetized material. The solutions are axially symmetric, conformastatic and are obtained by solving the Einstein-Maxwell Field Equations for continuum media without the test field approximation, and assuming that the sources are razor-thin disk of magnetically polarized matter. We find analytical expressions for the surface energy density, the pressure, the polarization vector, the electromagnetic fields, the mass and the rotational velocity for circular orbits, for two particular solutions. In each case, the energy-momentum tensor agrees with the energy conditions and also the convergence of the mass for all the solutions is proved. Since the solutions are well-behaved, they may be used to model astrophysical thin disks, and also may contribute as initial data in numerical simulations. In addition, the process to obtain the solutions is described in detail, which may be used as a guide to find solutions with magnetized material in General Relativity.

Magnetohydrodynamic Kelvin-Helmholtz instabilities in astrophysics. 4. Single shear layer in MHD flows

Energy Technology Data Exchange (ETDEWEB)

Ferrari, A [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Turin Univ. (Italy). Ist. di Fisica Generale); Trussoni, E [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Max-Planck-Institut fuer Physik und Astrophysik, Garching (Germany, F.R.). Inst. fuer Extraterrestrische Physik)

1983-11-01

In this further paper on the physics of Kelvin-Helmholtz instabilities the case in which the fluids in relative motion are magnetized and separated by a shear layer is investigated. The present study points out, with respect to previous treatments, that different velocity profiles affect perturbations of short wavelength (as compared to the scale of the shear). Another new result is in the destabilizing effect, even in the subsonic regime, of the magnetic field on modes neutrally stable in the vortex sheet approximation. Such a behaviour is analogous to that found in the fluid case for Mach numbers >approx. = to 2. Possible astrophysical implications are also discussed.

Astrophysical opacity library

International Nuclear Information System (INIS)

Huebner, W.F.; Merts, A.L.; Magee, N.H. Jr.; Argo, M.F.

1977-08-01

The astrophysical elements opacity library includes equation of state data, various mean opacities, and 2000 values of the frequency-dependent extinction coefficients in equally spaced intervals u identical with hν/kT from 0 to 20 for 41 degeneracy parameters eta from -28 (nondegenerate) to 500 and 46 temperatures kT from 1 eV to 100 keV. Among available auxiliary quantities are the free electron density, mass density, and plasma cutoff frequency. A library-associated program can produce opacities for mixtures with up to 20 astrophysically abundant constituent elements at 4 levels of utility for the user

Astrophysics Update 2

CERN Document Server

Mason, John W

2006-01-01

"Astrophysics Updates" is intended to serve the information needs of professional astronomers and postgraduate students about areas of astronomy, astrophysics and cosmology that are rich and active research spheres. Observational methods and the latest results of astronomical research are presented as well as their theoretical foundations and interrelations. The contributed commissioned articles are written by leading exponents in a format that will appeal to professional astronomers and astrophysicists who are interested in topics outside their own specific areas of research. This collection of timely reviews may also attract the interest of advanced amateur astronomers seeking scientifically rigorous coverage.

Coil winder for the magnet of the mirror fusion test facility

International Nuclear Information System (INIS)

Ling, R.C.

1977-01-01

A coil winder was designed for the purpose of fabricating the superconducting magnets of the Mirror Fusion Test Facility. The superconducting magnets are a displaced ying-yang pair, each having major and minor radii of 2.5 and 0.75 m, respectively, and cross section of 0.42 m by about 1.03 m. The superconductor cross section is a square, 13 mm on a side, and consists of a core of niobium-titanium embedded copper and a solid copper stabilizer. Conceptual studies made at Lawrence Livermore Laboratory of the coil winder resulted in concept drawings and a procurement specification. Final design was made by the contractor, and the coil winder is now in fabrication. This paper describes the performance requirements of the winder, and the evolution of its design from conceptual stage to completion

Prospects of High Energy Laboratory Astrophysics

International Nuclear Information System (INIS)

Ng, Johnny S.T.; SLAC

2006-01-01

Ultra high energy cosmic rays (UHECR) have been observed but their sources and production mechanisms are yet to be understood. We envision a laboratory astrophysics program that will contribute to the understanding of cosmic accelerators with efforts to: (1) test and calibrate UHECR observational techniques, and (2) elucidate the underlying physics of cosmic acceleration through laboratory experiments and computer simulations. Innovative experiments belonging to the first category have already been done at the SLAC FFTB. Results on air fluorescence yields from the FLASH experiment are reviewed. Proposed future accelerator facilities can provided unprecedented high-energy-densities in a regime relevant to cosmic acceleration studies and accessible in a terrestrial environment for the first time. We review recent simulation studies of nonlinear plasma dynamics that could give rise to cosmic acceleration, and discuss prospects for experimental investigation of the underlying mechanisms

Regulations Pertaining to Section 8 of Chapter 636 of the Acts of 1974, Regarding Magnet School Facilities (Subsection 37I), and Magnet Educational Programs (Subsection 37J).

Science.gov (United States)

Massachusetts State Dept. of Education, Boston.

Racial balance is the primary goal of the regulations presented in this document. For the purpose of expending funds under these regulations, the terms "magnet school facilities" and "magnet educational program" are defined and school eligibility requirements are listed. Program requirements are also listed along with proposals…

Recent results in nuclear astrophysics

Energy Technology Data Exchange (ETDEWEB)

Coc, Alain; Kiener, Juergen [CNRS/IN2P3 et Universite Paris Sud 11, UMR 8609, Centre de Sciences Nucleaires et de Sciences de la Matiere (CSNSM), Orsay Campus (France); Hammache, Fairouz [CNRS/IN2P3 et Universite Paris Sud 11, UMR 8608, Institut de Physique Nucleaire d' Orsay (IPNO), Orsay Campus (France)

2015-03-01

In this review, we emphasize the interplay between astrophysical observations, modeling, and nuclear physics laboratory experiments. Several important nuclear cross sections for astrophysics have long been identified, e.g., {sup 12}C(α, γ){sup 16}O for stellar evolution, or {sup 13}C(α, n){sup 16}O and {sup 22}Ne(α, n){sup 25}Mg as neutron sources for the s-process. More recently, observations of lithium abundances in the oldest stars, or of nuclear gamma-ray lines from space, have required new laboratory experiments. New evaluation of thermonuclear reaction rates now includes the associated rate uncertainties that are used in astrophysical models to i) estimate final uncertainties on nucleosynthesis yields and ii) identify those reactions that require further experimental investigation. Sometimes direct cross section measurements are possible, but more generally the use of indirect methods is compulsory in view of the very low cross sections. Non-thermal processes are often overlooked but are also important for nuclear astrophysics, e.g., in gamma-ray emission from solar flares or in the interaction of cosmic rays with matter, and also motivate laboratory experiments. Finally, we show that beyond the historical motivations of nuclear astrophysics, understanding i) the energy sources that drive stellar evolution and ii) the origin of the elements can also be used to give new insights into physics beyond the standard model. (orig.)

Recent results in nuclear astrophysics

International Nuclear Information System (INIS)

Coc, Alain; Kiener, Juergen; Hammache, Fairouz

2015-01-01

In this review, we emphasize the interplay between astrophysical observations, modeling, and nuclear physics laboratory experiments. Several important nuclear cross sections for astrophysics have long been identified, e.g., 12 C(α, γ) 16 O for stellar evolution, or 13 C(α, n) 16 O and 22 Ne(α, n) 25 Mg as neutron sources for the s-process. More recently, observations of lithium abundances in the oldest stars, or of nuclear gamma-ray lines from space, have required new laboratory experiments. New evaluation of thermonuclear reaction rates now includes the associated rate uncertainties that are used in astrophysical models to i) estimate final uncertainties on nucleosynthesis yields and ii) identify those reactions that require further experimental investigation. Sometimes direct cross section measurements are possible, but more generally the use of indirect methods is compulsory in view of the very low cross sections. Non-thermal processes are often overlooked but are also important for nuclear astrophysics, e.g., in gamma-ray emission from solar flares or in the interaction of cosmic rays with matter, and also motivate laboratory experiments. Finally, we show that beyond the historical motivations of nuclear astrophysics, understanding i) the energy sources that drive stellar evolution and ii) the origin of the elements can also be used to give new insights into physics beyond the standard model. (orig.)

Toward laboratory torsional spine magnetic reconnection

Science.gov (United States)

Chesny, David L.; Orange, N. Brice; Oluseyi, Hakeem M.; Valletta, David R.

2017-12-01

Magnetic reconnection is a fundamental energy conversion mechanism in nature. Major attempts to study this process in controlled settings on Earth have largely been limited to reproducing approximately two-dimensional (2-D) reconnection dynamics. Other experiments describing reconnection near three-dimensional null points are non-driven, and do not induce any of the 3-D modes of spine fan, torsional fan or torsional spine reconnection. In order to study these important 3-D modes observed in astrophysical plasmas (e.g. the solar atmosphere), laboratory set-ups must be designed to induce driven reconnection about an isolated magnetic null point. As such, we consider the limited range of fundamental resistive magnetohydrodynamic (MHD) and kinetic parameters of dynamic laboratory plasmas that are necessary to induce the torsional spine reconnection (TSR) mode characterized by a driven rotational slippage of field lines - a feature that has yet to be achieved in operational laboratory magnetic reconnection experiments. Leveraging existing reconnection models, we show that within a 3$ apparatus, TSR can be achieved in dense plasma regimes ( 24~\\text{m}-3$ ) in magnetic fields of -1~\\text{T}$ . We find that MHD and kinetic parameters predict reconnection in thin current sheets on time scales of . While these plasma regimes may not explicitly replicate the plasma parameters of observed astrophysical phenomena, studying the dynamics of the TSR mode within achievable set-ups signifies an important step in understanding the fundamentals of driven 3-D magnetic reconnection and the self-organization of current sheets. Explicit control of this reconnection mode may have implications for understanding particle acceleration in astrophysical environments, and may even have practical applications to fields such as spacecraft propulsion.

Neutron Capture Reactions on Fe and Ni Isotopes for the Astrophysical s-process

Energy Technology Data Exchange (ETDEWEB)

Lederer, C., E-mail: claudia.lederer@ed.ac.uk [University of Vienna, Faculty of Physics, 1090 Vienna (Austria); Johann-Wolfgang-Goethe Universität, 60438 Frankfurt (Germany); Giubrone, G. [Instituto de Física Corpuscular, CSIC-Universidad de Valencia, 46071 Valencia (Spain); Massimi, C. [Dipartimento di Fisica, Università di Bologna, and Sezione INFN di Bologna, 40100 Bologna (Italy); Žugec, P. [Department of Physics, Faculty of Science, University of Zagreb, 10002 Zagreb (Croatia); Barbagallo, M.; Colonna, N. [Istituto Nazionale di Fisica Nucleare, 70125 Bari (Italy); Domingo-Pardo, C. [Instituto de Física Corpuscular, CSIC-Universidad de Valencia, 46071 Valencia (Spain); Guerrero, C. [European Organization for Nuclear Research (CERN), CH-1211 Geneva (Switzerland); Gunsing, F. [Commissariat à l' Énergie Atomique (CEA) Saclay – Irfu, 91191 Gif-sur-Yvette (France); Käppeler, F. [Karlsruhe Institute of Technology, Campus Nord, Institut für Kernphysik, 76021 Karlsruhe (Germany); Tain, J.L. [Instituto de Física Corpuscular, CSIC-Universidad de Valencia, 46071 Valencia (Spain); Altstadt, S. [Johann-Wolfgang-Goethe Universität, 60438 Frankfurt (Germany); Andrzejewski, J. [Uniwersytet Łódzki, 90131 Lodz (Poland); Audouin, L. [Centre National de la Recherche Scientifique/IN2P3 – IPN, 91406 Orsay (France); Bécares, V. [Centro de Investigaciones Energeticas Medioambientales y Tecnológicas (CIEMAT), 28040 Madrid (Spain); Bečvář, F. [Faculty of Mathematics and Physics, Charles University, CZ-180 00 Prague (Czech Republic); 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.

International Olympiad on Astronomy and Astrophysics

Science.gov (United States)

Soonthornthum, B.; Kunjaya, C.

2011-01-01

The International Olympiad on Astronomy and Astrophysics, an annual astronomy and astrophysics competition for high school students, is described. Examples of problems and solutions from the competition are also given. (Contains 3 figures.)

Computational Infrastructure for Nuclear Astrophysics

International Nuclear Information System (INIS)

Smith, Michael S.; Hix, W. Raphael; Bardayan, Daniel W.; Blackmon, Jeffery C.; Lingerfelt, Eric J.; Scott, Jason P.; Nesaraja, Caroline D.; Chae, Kyungyuk; Guidry, Michael W.; Koura, Hiroyuki; Meyer, Richard A.

2006-01-01

A Computational Infrastructure for Nuclear Astrophysics has been developed to streamline the inclusion of the latest nuclear physics data in astrophysics simulations. The infrastructure consists of a platform-independent suite of computer codes that is freely available online at nucastrodata.org. Features of, and future plans for, this software suite are given

Reflectometer end station for synchrotron calibrations of Advanced X-ray Astrophysics Facility flight optics and for spectrometric research applications

International Nuclear Information System (INIS)

Graessle, D.E.; Fitch, J.J.; Ingram, R.; Zhang Juda, J.; Blake, R.L.

1995-01-01

Preparations have been underway to construct and test a facility for grazing incidence reflectance calibrations of flat mirrors at the National Synchrotron Light Source. The purpose is to conduct calibrations on witness flats to the coating process of the flight mirrors for NASA's Advanced X-ray Astrophysics Facility (AXAF). The x-ray energy range required is 50 eV--12 keV. Three monochromatic beamlines (X8C, X8A, U3A) will provide energy tunability over this entire range. The goal is to calibrate the AXAF flight mirrors with uncertainties approaching 1%. A portable end station with a precision-positioning reflectometer has been developed for this work. We have resolved the vacuum cleanliness requirements to preserve the coating integrity of the flats with the strict grazing-angle certainty requirements placed on the rotational control system of the reflectometer. A precision positioning table permits alignment of the system to the synchrotron beam to within 10 arcsec; the reflectometer's rotational control system can then produce grazing angle accuracy to within less than 2 arcsec, provided that the electron orbit is stable. At 10--12 keV, this degree of angular accuracy is necessary to achieve the calibration accuracy required for AXAF. However the most important energy regions for the synchrotron calibration are in the 2000--3200 eV range, where the M-edge absorption features of the coating element, iridium, appear, and the 300--700 eV range of the Ir N edges. The detail versus energy exhibited in these features cannot be traced adequately without a tunable energy source, which necessitates a synchrotron for this work. We present the mechanical designs, motion control systems, detection and measurement capabilities, and selected procedures for our measurements, as well as reflectance data

The Explorer program for astronomy and astrophysics

International Nuclear Information System (INIS)

Savage, B.D.; Becklin, E.E.; Cassinelli, J.P.; Dupree, A.K.; Elliot, J.L.; Hoffmann, W.F.; Hudson, H.S.; Jura, M.; Kurfess, J.; Murray, S.S.

1986-01-01

This report was prepared to provide NASA with a strategy for proceeding with Explorer-class programs for research in space astronomy and astrophysics. The role of Explorers in astronomy and astrophysics and their past accomplishments are discussed, as are current and future astronomy and astrophysics Explorers. Specific cost needs for an effective Explorer program are considered

PARTICLE-IN-CELL SIMULATIONS OF CONTINUOUSLY DRIVEN MIRROR AND ION CYCLOTRON INSTABILITIES IN HIGH BETA ASTROPHYSICAL AND HELIOSPHERIC PLASMAS

International Nuclear Information System (INIS)

Riquelme, Mario A.; Quataert, Eliot; Verscharen, Daniel

2015-01-01

We use particle-in-cell simulations to study the nonlinear evolution of ion velocity space instabilities in an idealized problem in which a background velocity shear continuously amplifies the magnetic field. We simulate the astrophysically relevant regime where the shear timescale is long compared to the ion cyclotron period, and the plasma beta is β ∼ 1-100. The background field amplification in our calculation is meant to mimic processes such as turbulent fluctuations or MHD-scale instabilities. The field amplification continuously drives a pressure anisotropy with p > p ∥ and the plasma becomes unstable to the mirror and ion cyclotron instabilities. In all cases, the nonlinear state is dominated by the mirror instability, not the ion cyclotron instability, and the plasma pressure anisotropy saturates near the threshold for the linear mirror instability. The magnetic field fluctuations initially undergo exponential growth but saturate in a secular phase in which the fluctuations grow on the same timescale as the background magnetic field (with δB ∼ 0.3 (B) in the secular phase). At early times, the ion magnetic moment is well-conserved but once the fluctuation amplitudes exceed δB ∼ 0.1 (B), the magnetic moment is no longer conserved but instead changes on a timescale comparable to that of the mean magnetic field. We discuss the implications of our results for low-collisionality astrophysical plasmas, including the near-Earth solar wind and low-luminosity accretion disks around black holes

On the generalized gravi-magnetic hypothesis

International Nuclear Information System (INIS)

Massa, C.

1989-01-01

According to a generalization of the gravi-magnetic hypothesis (GMH) any neutral mass moving in a curvilinear path with respect to an inertial frame creates a magnetic field, dependent on the curvature radius of the path. A simple astrophysical consequence of the generalized GMH is suggested considering the special cases of binary pulsars and binary neutron stars

Split-Field Magnet facility upgraded

CERN Multimedia

CERN PhotoLab

1977-01-01

The Split Field Magnet (SFM) was the largest spectrometer for particles from beam-beam collisions in the ISR. It could determine particle momenta in a large solid angle, but was designed mainly for the analysis of forward travelling particles.As the magnet was working on the ISR circulating beams, its magnetic field had to be such as to restore the correct proton orbit.The SFM, therefore, produced zero field at the crossing point and fields of opposite signs upstream and downstream of it and was completed by 2 large and 2 small compensator magnets. The gradient effects were corrected by magnetic channels equipped with movable flaps. The useful magnetic field volume was 28 m3, the induction in the median plane 1.14 T, the gap heigth 1.1 m, the length 10.5 m, the weight about 1000 ton. Concerning the detectors, the SFM was the first massive application of multiwire proportional chambers (about 70000 wires) which filled the main and the large compensator magnets. In 1976 an improved programme was started with tw...

The Holifield Radioactive Ion Beam Facility at the Oak Ridge National Laboratory: Present status and future plans

International Nuclear Information System (INIS)

Alton, G.D.; Beene, J.R.

1998-01-01

The Holifield Radioactive Ion Beam Facility (HRIBF) is a first generation national user facility for nuclear physics and nuclear astrophysics research with radioactive ion beams (RIBs). The reconfiguration, construction, and equipment commissioning phases have been completed and the beam development program is in progress. In this article, descriptions of the facility and newly implemented experimental equipment for use in the nuclear and astrophysics programs will be given and an outline of the initial experimental program will be presented. Special target ion source related problems, endemic to the production of specific short lived RIBs will be discussed. In addition, plans, which involve either a 200 MeV or a 1 GeV proton linac driver for a second generation ISOL facility, will be presented

Collisionless plasmas in astrophysics

CERN Document Server

Belmont, Gerard; Mottez, Fabrice; Pantellini, Filippo; Pelletier, Guy

2013-01-01

Collisionless Plasmas in Astrophysics examines the unique properties of media without collisions in plasma physics. Experts in this field, the authors present the first book to concentrate on collisionless conditions in plasmas, whether close or not to thermal equilibrium. Filling a void in scientific literature, Collisionless Plasmas in Astrophysics explains the possibilities of modeling such plasmas, using a fluid or a kinetic framework. It also addresses common misconceptions that even professionals may possess, on phenomena such as "collisionless (Landau) damping". Abundant illustrations

Facile synthesis of polymer-enveloped ultrasmall superparamagnetic iron oxide for magnetic resonance imaging

International Nuclear Information System (INIS)

Hong Jun; Xu Dongmei; Yu Jiahui; Gong Peijun; Ma Hongjuan; Yao Side

2007-01-01

Ultrasmall superparamagnetic iron oxide (USPIO) with synthetic polymer, based on magnetite core, was synthesized via facile photochemical in situ polymerization. A possible mechanism of photochemical in situ polymerization was proposed. The obtained polymer-enveloped UPSIO was characterized by transmission electron microscopy (TEM), photo-correlation spectroscopy (PCS), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric (TG) analysis and vibrating sampling magnetometer (VSM) measurement. Properties such as ultrasmall particle size, hydrophilicity, strong magnetization and surface characteristics, which are desirable for magnetic resonance imaging (MRI) contrast agents, were evaluated in detail. The resultant USPIO-based MRI contrast agent holds considerable promise in molecular MR tracking, MR immune imaging, cell tracking and targeted intracellular hyperthermia, etc

Photonuclear reactions in astrophysical p-process: Theoretical calculations and experiment simulation based on ELI-NP

Science.gov (United States)

Xu, Yi; Luo, Wen; Balabanski, Dimiter; Goriely, Stephane; Matei, Catalin; Tesileanu, Ovidiu

2017-09-01

The astrophysical p-process is an important way of nucleosynthesis to produce the stable and proton-rich nuclei beyond Fe which can not be reached by the s- and r-processes. In the present study, the astrophysical reaction rates of (γ,n), (γ,p), and (γ,α) reactions are computed within the modern reaction code TALYS for about 3000 stable and proton-rich nuclei with 12 Infrastructure-Nuclear Physics (ELI-NP) facility is being developed, which will provide the great opportunity to experimentally study the photonuclear reactions in p-process. Simulations of the experimental setup for the measurements of the photonuclear reactions 96Ru(γ,p) and 96Ru(γ,α) are performed. It is shown that the experiments of photonuclear reactions in p-process based on ELI-NP are quite promising.

Nuclear astrophysics at ISAC with DRAGON: Initial studies

International Nuclear Information System (INIS)

Olin, Art; Bishop, Shawn; D'Auria, John M.; Lamey, Michael; Liu, Wenjie; Wrede, Chris; Buchmann, Lothar; Chen, Alan; Hunter, Don; Laird, Alison M.; Ottewell, Dave; Rogers, Joel; Chatterjee, Mohan L.; Engel, Sabine; Strieder, Frank; Gigliotti, Dario; Hussein, Ahmed; Greife, Uwe; Jewett, Cybele; Hutcheon, Dave

2002-01-01

The new DRAGON recoil separator facility, designed and built to measure directly the rates of radiative proton and alpha capture reactions important for nuclear astrophysics, is now in operation at the TRIUMF-ISAC radioactive beams facility in Vancouver, Canada. Experiments have been conducted for the first time on the 21Na(p,γ)22Mg reaction. The evolution of nova explosions, and particularly their 22Na abundance, depends sensitively on this reaction rate. The radioactive 21Na beam with an intensity of up to 5 x 108 /s was directed onto a windowless hydrogen gas target (3.8 x 1018 H atoms/cm2). Prompt reaction gamma rays were detected using a BGO array and separated reaction products detected using a silicon strip detector at the end of the 20.8 m recoil mass separator. Yield measurements recording simultaneously singles and coincident signals were performed by scanning in energy over the known resonance reported previously in 22Mg at Ecm = 212 keV, and in addition, over a strong resonance observed at Ecm ≅822 keV. Known resonances in the 21Ne(p,γ)22Na, 20Ne(p,γ)21Na, and 24Mg(p,γ)25Al reactions have been used to calibrate the DRAGON. Studies are in progress to further define the performance of the DRAGON facility. Status of the data analysis and results from system performance studies will be presented along with a brief description of the new ISAC and DRAGON facilities

Toward observational neutrino astrophysics

International Nuclear Information System (INIS)

Koshiba, M.

1988-01-01

It is true that: (1) The first observation of the neutrino burst from the supernova SN1987a by Kamiokande-II which was immediately confirmed by IBM; and (2) the first real-time, directional, and spectral observation of solar 8 B neutrinos also by Kamiokande-II could perhaps be considered as signalling the birth of observational astrophysics. The field, however, is still in its infancy and is crying out for tender loving care. Namely, while the construction of astronomy requires the time and the direction of the signal and that of astrophysics requires, in addition to the spectral information, the observations of (1) could not give the directional information and the results of both (1) and (2) are still suffering from the meager statistics. How do we remedy this situation to let this new born science of observational neutrino astrophysics grow healthy. This is what the author addresses in this talk. 15 refs., 8 figs

Long-term Regularities in Distribution of Global Solar and Interplanetary Magnetic Fields

Czech Academy of Sciences Publication Activity Database

Ambrož, Pavel

2013-01-01

Roč. 37, č. 2 (2013), s. 637-642 ISSN 1845-8319. [Hvar Astrophysical Colloquium /12./. Hvar, 03.09.2012-07.09.2012] R&D Projects: GA AV ČR IAA300030808 Institutional support: RVO:67985815 Keywords : interplanetary magnetic field * solar wind Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

Conditions for double layers in the earth's magnetosphere and perhaps in other astrophysical objects

Science.gov (United States)

Lyons, L. R.

1987-01-01

It is suggested that the features which govern the formation of the double layers are: (1) the divergence of the magnetospheric electric field, (2) the ionospheric conductivity, and (3) the current-voltage characteristics of auroral magnetic field lines. Also considered are conditions in other astrophysical objects that could lead to the formation of DLs in a manner analogous to what occurs in the earth's auroral zones. It is noted that two processes can drive divergent Pedersen currents within a collisional conducting layer: (1) sheared plasma flow applied anywhere along the magnetic field lines connected to the conducting layer and (2) a neutral flow with shear within the conducting layer.

Theoretical astrophysics an introduction

CERN Document Server

Bartelmann, Matthias

2013-01-01

A concise yet comprehensive introduction to the central theoretical concepts of modern astrophysics, presenting hydrodynamics, radiation, and stellar dynamics all in one textbook. Adopting a modular structure, the author illustrates a small number of fundamental physical methods and principles, which are sufficient to describe and understand a wide range of seemingly very diverse astrophysical phenomena and processes. For example, the formulae that define the macroscopic behavior of stellar systems are all derived in the same way from the microscopic distribution function. This function it

Observational astrophysics

CERN Document Server

Léna, Pierre; Lebrun, François; Mignard, François; Pelat, Didier

2012-01-01

This is the updated, widely revised, restructured and expanded third edition of Léna et al.'s successful work Observational Astrophysics. It presents a synthesis on tools and methods of observational astrophysics of the early 21st century. Written specifically for astrophysicists and graduate students, this textbook focuses on fundamental and sometimes practical limitations on the ultimate performance that an astronomical system may reach, rather than presenting particular systems in detail. In little more than a decade there has been extraordinary progress in imaging and detection technologies, in the fields of adaptive optics, optical interferometry, in the sub-millimetre waveband, observation of neutrinos, discovery of exoplanets, to name but a few examples. The work deals with ground-based and space-based astronomy and their respective fields. And it also presents the ambitious concepts behind space missions aimed for the next decades. Avoiding particulars, it covers the whole of the electromagnetic spec...

Observational astrophysics

CERN Document Server

Smith, Robert C

1995-01-01

Combining a critical account of observational methods (telescopes and instrumentation) with a lucid description of the Universe, including stars, galaxies and cosmology, Smith provides a comprehensive introduction to the whole of modern astrophysics beyond the solar system. The first half describes the techniques used by astronomers to observe the Universe: optical telescopes and instruments are discussed in detail, but observations at all wavelengths are covered, from radio to gamma-rays. After a short interlude describing the appearance of the sky at all wavelengths, the role of positional astronomy is highlighted. In the second half, a clear description is given of the contents of the Universe, including accounts of stellar evolution and cosmological models. Fully illustrated throughout, with exercises given in each chapter, this textbook provides a thorough introduction to astrophysics for all physics undergraduates, and a valuable background for physics graduates turning to research in astronomy.

The non-linear growth of the magnetic Rayleigh-Taylor instability

Science.gov (United States)

Carlyle, Jack; Hillier, Andrew

2017-09-01

This work examines the effect of the embedded magnetic field strength on the non-linear development of the magnetic Rayleigh-Taylor instability (RTI) (with a field-aligned interface) in an ideal gas close to the incompressible limit in three dimensions. Numerical experiments are conducted in a domain sufficiently large so as to allow the predicted critical modes to develop in a physically realistic manner. The ratio between gravity, which drives the instability in this case (as well as in several of the corresponding observations), and magnetic field strength is taken up to a ratio which accurately reflects that of observed astrophysical plasma, in order to allow comparison between the results of the simulations and the observational data which served as inspiration for this work. This study finds reduced non-linear growth of the rising bubbles of the RTI for stronger magnetic fields, and that this is directly due to the change in magnetic field strength, rather than the indirect effect of altering characteristic length scales with respect to domain size. By examining the growth of the falling spikes, the growth rate appears to be enhanced for the strongest magnetic field strengths, suggesting that rather than affecting the development of the system as a whole, increased magnetic field strengths in fact introduce an asymmetry to the system. Further investigation of this effect also revealed that the greater this asymmetry, the less efficiently the gravitational energy is released. By better understanding the under-studied regime of such a major phenomenon in astrophysics, deeper explanations for observations may be sought, and this work illustrates that the strength of magnetic fields in astrophysical plasmas influences observed RTI in subtle and complex ways.

Fundamental relations of mineral specific magnetic carriers for paleointensity determination

Czech Academy of Sciences Publication Activity Database

Kletetschka, Günther; Wieczorek, M. A.

2017-01-01

Roč. 272, November 2017 (2017), s. 44-49 ISSN 0031-9201 Institutional support: RVO:67985831 Keywords : Paleofield determination * TRM * Planetary magnetic anomalies * Néel’s theory of magnetism * Magnetic acquisition * Moon * Mars Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Particles and field physics Impact factor: 2.075, year: 2016

Novel electro-magnetic test facility for the calibration of a propulsor fluctuating force module

International Nuclear Information System (INIS)

Schofield, N.; Lonsdale, A.; Hodges, A.Y.

2004-01-01

The testing of scale model propulsors is an essential part of any marine propulsion design process. The fluctuating force module (FFM) is a self-contained, instrumented propulsor drive system designed to be an integral part of a scaled propulsor test facility. This paper describes a novel electro-magnetic test facility which provides a static axial thrust of 0-1 kN and triaxial dynamic forces of 0.3-3 Nrms, at frequencies of 80-800 Hz, to an equivalent propulsor mass rotating at speeds of 0-900 rpm, in order to calibrate the FFM force measurement systems

Recent Astrophysical Studies with Exotic Beams at ORNL

Energy Technology Data Exchange (ETDEWEB)

Bardayan, Daniel W [ORNL

2006-02-01

The availability of exotic beams has produced great opportunities for advances in our understanding of the nucleosynthesis occurring in stellar burning and stellar explosions such as novae, X-ray bursts, and supernovae. In these extreme environments, synthesized radioactive nuclei can undergo subsequent nuclear processing before they decay, and thus to understand these events, we must understand reaction rates involving radioactive nuclei. At the ORNL Holi led Radioactive Ion Beam Facility (HRIBF), we have made several recent measurements using proton-rich beams such as 18F and 7Be and neutron-rich beams such as 82Ge and 84Se that help clarify the structure of astrophysically-important nuclei. We are also poised to begin studies with doubly-magic 132Sn. The experimental methods and results are discussed.

Recent Astrophysical Studies with Exotic Beams at ORNL

International Nuclear Information System (INIS)

Bardayan, Daniel W.

2006-01-01

The availability of exotic beams has produced great opportunities for advances in our understanding of the nucleosynthesis occurring in stellar burning and stellar explosions such as novae, X-ray bursts, and supernovae. In these extreme environments, synthesized radioactive nuclei can undergo subsequent nuclear processing before they decay, and thus to understand these events, we must understand reaction rates involving radioactive nuclei. At the ORNL Holi led Radioactive Ion Beam Facility (HRIBF), we have made several recent measurements using proton-rich beams such as 18F and 7Be and neutron-rich beams such as 82Ge and 84Se that help clarify the structure of astrophysically-important nuclei. We are also poised to begin studies with doubly-magic 132Sn. The experimental methods and results are discussed.

Magnetohydrodynamic models of astrophysical jets

International Nuclear Information System (INIS)

Beskin, Vasily S

2010-01-01

In this review, analytical results obtained for a wide class of stationary axisymmetric flows in the vicinity of compact astrophysical objects are analyzed, with an emphasis on quantitative predictions for specific sources. Recent years have witnessed a great increase in understanding the formation and properties of astrophysical jets. This is due not only to new observations but also to advances in analytical theory which has produced fairly simple relations, and to what can undoubtedly be called a breakthrough in numerical simulation which has enabled confirmation of theoretical predictions. Of course, we are still very far from fully understanding the physical processes occurring in compact sources. Nevertheless, the progress made raises hopes for near-future test observations that can give insight into the physical processes occurring in active astrophysical objects. (reviews of topical problems)

Self-Generated Magnetic Fields in the Stagnation Phase of Indirect-Drive Implosions on the National Ignition Facility

Science.gov (United States)

Walsh, C. A.; Chittenden, J. P.; McGlinchey, K.; Niasse, N. P. L.; Appelbe, B. D.

2017-04-01

Three-dimensional extended-magnetohydrodynamic simulations of the stagnation phase of inertial confinement fusion implosion experiments at the National Ignition Facility are presented, showing self-generated magnetic fields over 104 T . Angular high mode-number perturbations develop large magnetic fields, but are localized to the cold, dense hot-spot surface, which is hard to magnetize. When low-mode perturbations are also present, the magnetic fields are injected into the hot core, reaching significant magnetizations, with peak local thermal conductivity reductions greater than 90%. However, Righi-Leduc heat transport effectively cools the hot spot and lowers the neutron spectra-inferred ion temperatures compared to the unmagnetized case. The Nernst effect qualitatively changes the results by demagnetizing the hot-spot core, while increasing magnetizations at the edge and near regions of large heat loss.

The 3D MHD code GOEMHD3 for astrophysical plasmas with large Reynolds numbers Code description, verification, and computational performance

Czech Academy of Sciences Publication Activity Database

Skála, Jan; Baruffa, F.; Rampp, M.

2015-01-01

Roč. 580, August (2015), A48-A48 ISSN 0004-6361 R&D Projects: GA ČR GA13-24782S Institutional support: RVO:67985815 Keywords : magnetohydrodynamics * corona * magnetic fields Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.378, year: 2014

Concepts for the magnetic design of the MITICA neutral beam test facility ion accelerator.

Science.gov (United States)

Chitarin, G; Agostinetti, P; Marconato, N; Marcuzzi, D; Sartori, E; Serianni, G; Sonato, P

2012-02-01

The megavolt ITER injector concept advancement neutral injector test facility will be constituted by a RF-driven negative ion source and by an electrostatic Accelerator, designed to produce a negative Ion with a specific energy up to 1 MeV. The beam is then neutralized in order to obtain a focused 17 MW neutral beam. The magnetic configuration inside the accelerator is of crucial importance for the achievement of a good beam efficiency, with the early deflection of the co-extracted and stripped electrons, and also of the required beam optic quality, with the correction of undesired ion beamlet deflections. Several alternative magnetic design concepts have been considered, comparing in detail the magnetic and beam optics simulation results, evidencing the advantages and drawbacks of each solution both from the physics and engineering point of view.

A remote monitoring system of environmental electromagnetic field in magnetic confinement fusion test facilities

International Nuclear Information System (INIS)

Tanaka, Masahiro; Uda, Tatsuhiko; Takami, Shigeyuki; Wang, Jianqing; Fujiwara, Osamu

2010-01-01

A remote, continuous environmental electromagnetic field monitoring system for use in magnetic confinement fusion test facilities is developed. Using this system, both the static magnetic field and the high frequency electromagnetic field could be measured. The required frequency range of the measurement system is from 25 to 100 MHz for the ICRF (Ion Cyclotron Range of Frequencies) heating system. The outputs from the measurement instruments are measured simultaneously by custom-built software using a laptop-type personal computer connected to a local area network. In this way, the electromagnetic field strength could be monitored from a control room located about 200 m from the fusion device building. Examples of measurement data from the vicinity of a high-frequency generator and amplifier and the leakage static magnetic field from a fusion test device are presented. (author)

Cryogenic magnet tests for the LHC process operation using web-based tools and facilities

CERN Document Server

Hemelsoet, G H; Chohan, V; Veyrunes, E

2005-01-01

For the Large Hadron Collider under construction at CERN, an essential requirement is the acceptance test of its 1706 Cryo-magnets in cryogenic conditions in a purpose-built facility at CERN. Several teams ensure the proper operation of the infrastructure on a round the clock basis. The cold test part is one of the key elements amongst many other essential activities requiring magnet transport and connections/disconnections, cryogenic preparation and pumping, cooling down to 1.9 K as well warm up before disconnection & removal. All these operations involve multi-tasking and usage of 12 test benches with nominal turn-round time per dipole magnet of 120 hours. It also involves multiple teams of industrial contractors, a support contract for cryogenics operation, CERN staff in magnet testing Operation, aided by a large external collaboration of visiting staff for round the clock operation. This paper gives a flavour of the operation and exposes the software tools that were necessary, designed and developed t...

Progress at LAMPF (Los Alamos Meson Physics Facility), January--December 1989

Energy Technology Data Exchange (ETDEWEB)

Poelakker, K. (ed.)

1990-12-01

This report contains brief papers on research conducted at the lampf facility in the following areas: nuclear and particle physics; astrophysics; atomic and molecular physics; materials science; nuclear chemistry; radiation effects and radioisotope production.

Progress at LAMPF [Los Alamos Meson Physics Facility], January--December 1989

International Nuclear Information System (INIS)

Poelakker, K.

1990-12-01

This report contains brief papers on research conducted at the lampf facility in the following areas: nuclear and particle physics; astrophysics; atomic and molecular physics; materials science; nuclear chemistry; radiation effects and radioisotope production

Scientific and technical progress in high-energy astrophysics at INPE

International Nuclear Information System (INIS)

Bui-Van, N.A.; Jayanthi, U.B.; Jardim, J.O.D.; Braga, J.; Santo, C.M.E.

1984-01-01

The recent advances in high-energy Astrophysics pertains to the study of compact objects in galactic nuclei, binary systems and pulsars. These aspects are best understood by the study of the emissions in X- and gamma rays of these objects through the temporal variation in flux and spectrum. The Southern Hemisphere offers some of the unique objects for investigations such as galactic center, the Vela pulsar etc. For high temporal and spectra resolution studies two telescopes 'GeLi' and 'Pulsar' were designed and constructed. To support these scientific activities, a program in balloon launching and data acquisition facilities has been developed since 1971. The 'Balloon Launching Center' of INPE has capacity to launch balloons of -850,000 m 3 with payloads weighting about 1,000 Kg. Taking advantage of these facilities, project 'Bantar', with the goal to measure the atmospheric gamma-ray radiation in the Antartic Region, is under progress. (Author) [pt

Relativistic astrophysics

CERN Document Server

Price, R H

1993-01-01

Work reported in the workshop on relativistic astrophysics spanned a wide varicy of topics. Two specific areas seemed of particular interest. Much attention was focussed on gravitational wave sources, especially on the waveforms they produce, and progress was reported in theoretical and observational aspects of accretion disks.

Astrophysics at very high energies

International Nuclear Information System (INIS)

Aharonian, Felix; Bergstroem, Lars; Dermer, Charles

2013-01-01

Presents three complementary lectures on very-high-energy astrophysics given by worldwide leaders in the field. Reviews the recent advances in and prospects of gamma-ray astrophysics and of multi-messenger astronomy. Prepares readers for using space and ground-based gamma-ray observatories, as well as neutrino and other multi-messenger detectors. With the success of Cherenkov Astronomy and more recently with the launch of NASA's Fermi mission, very-high-energy astrophysics has undergone a revolution in the last years. This book provides three comprehensive and up-to-date reviews of the recent advances in gamma-ray astrophysics and of multi-messenger astronomy. Felix Aharonian and Charles Dermer address our current knowledge on the sources of GeV and TeV photons, gleaned from the precise measurements made by the new instrumentation. Lars Bergstroem presents the challenges and prospects of astro-particle physics with a particular emphasis on the detection of dark matter candidates. The topics covered by the 40th Saas-Fee Course present the capabilities of current instrumentation and the physics at play in sources of very-high-energy radiation to students and researchers alike. This book will encourage and prepare readers for using space and ground-based gamma-ray observatories, as well as neutrino and other multi-messenger detectors.

Astrophysical implications of periodicity

International Nuclear Information System (INIS)

Muller, R.A.

1988-01-01

Two remarkable discoveries of the last decade have profound implications for astrophysics and for geophysics. These are the discovery by Alvarez et al., that certain mass extinctions are caused by the impact on the earth of a large asteroid or comet, and the discovery by Raup and Sepkoski that such extinctions are periodic, with a cycle time of 26 to 30 million years. The validity of both of these discoveries is assumed and the implications are examined. Most of the phenomena described depend not on periodicity, but just on the weaker assumption that the impacts on the earth take place primarily in showers. Proposed explanations for the periodicity include galactic oscillations, the Planet X model, and the possibility of Nemesis, a solar companion star. These hypotheses are critically examined. Results of the search for the solar companion are reported. The Deccan flood basalts of India have been proposed as the impact site for the Cretaceous impact, but this hypotheisis is in contradiction with the conclusion of Courtillot et al., that the magma flow began during a period of normal magnetic field. A possible resolution of this contradiction is proposed

Analogue Hawking radiation from astrophysical black-hole accretion

International Nuclear Information System (INIS)

Das, Tapas K

2004-01-01

We show that spherical accretion onto astrophysical black holes can be considered as a natural example of an analogue system. We provide, for the first time, an exact analytical scheme for calculating the analogue Hawking temperature and surface gravity for general relativistic accretion onto astrophysical black holes. Our calculation may bridge the gap between the theory of transonic astrophysical accretion and the theory of analogue Hawking radiation. We show that the domination of the analogue Hawking temperature over the actual Hawking temperature may be a real astrophysical phenomenon, though observational tests of this fact will at best be difficult and at worst might prove to be impossible. We also discuss the possibilities of the emergence of analogue white holes around astrophysical black holes. Our calculation is general enough to accommodate accreting black holes with any mass

The Temperature - Magnetic Field Relation in Observed and Simulated Sunspots

Czech Academy of Sciences Publication Activity Database

Sobotka, Michal; Rezaei, R.

2017-01-01

Roč. 292, č. 12 (2017), 188/1-188/12 ISSN 0038-0938 R&D Projects: GA ČR(CZ) GA14-04338S; GA MŠk(CZ) 7E13003 EU Projects: European Commission(XE) 312495 - SOLARNET Institutional support: RVO:67985815 Keywords : sunspots * magnetic fields * comparison Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 2.682, year: 2016

Recent progress on astrophysical opacity

International Nuclear Information System (INIS)

Rogers, F.J.; Iglesias, C.A.

1992-08-01

Improvements in the calculation of the opacity of astrophysical plasmas has helped to resolve several long-standing puzzles in the modeling of variable stars. The most significant opacity enhancements over the Los Alamos Astrophysical Library (LAOL) are due to improvements in the equation of state and atomic physics. Comparison with experiment has corroborated the predicted large opacity increases due to transitions in M-shell iron. We give a summary of recent developments

Introduction to Nuclear Astrophysics

International Nuclear Information System (INIS)

Iliadis, Christian

2010-01-01

In the first lecture of this volume, we will present the basic fundamental ideas regarding nuclear processes occurring in stars. We start from stellar observations, will then elaborate on some important quantum-mechanical phenomena governing nuclear reactions, continue with how nuclear reactions proceed in a hot stellar plasma and, finally, we will provide an overview of stellar burning stages. At the end, the current knowledge regarding the origin of the elements is briefly summarized. This lecture is directed towards the student of nuclear astrophysics. Our intention is to present seemingly unrelated phenomena of nuclear physics and astrophysics in a coherent framework.

Current trends in non-accelerator particle physics: 1, Neutrino mass and oscillation. 2, High energy neutrino astrophysics. 3, Detection of dark matter. 4, Search for strange quark matter. 5, Magnetic monopole searches

International Nuclear Information System (INIS)

He, Yudong

1995-07-01

This report is a compilation of papers reflecting current trends in non-accelerator particle physics, corresponding to talks that its author was invited to present at the Workshop on Tibet Cosmic Ray Experiment and Related Physics Topics held in Beijing, China, April 4--13, 1995. The papers are entitled 'Neutrino Mass and Oscillation', 'High Energy Neutrino Astrophysics', 'Detection of Dark Matter', 'Search for Strange Quark Matter', and 'Magnetic Monopole Searches'. The report is introduced by a survey of the field and a brief description of each of the author's papers

Nuclear Astrophysics Data from Radioactive Beam Facilities. Final report

International Nuclear Information System (INIS)

Chen, Alan A.

2008-01-01

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): 21 Na(p,γ) 22 Mg and 18 Ne(α,p) 21 Na - The importance of the 21 Na(p,γ) 22 Mg and the 18 Ne(α,p) 21 Na reactions in models of exploding stars has been well documented: the first is connected to the production of the radioisotope 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: 21 Na(p,γ) 22 Mg at the TRIUMF-ISAC laboratory (DRAGON collaboration), and 18Ne(α,p) 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,γ) 26 Si and 13 N(p,γ)14O reactions - For Year 2, we worked on evaluations of the 25 Al(p,γ) 26 Si and 13 N(p,γ) 14 O reactions, in accordance with our proposed deliverables and following similar standard procedures to those used in Year 1. The 25 Al(p,γ) 26 Si reaction is a key uncertainty in the understanding the origin of galactic 26 Al, a target radioisotope for gamma ray astronomy; the 13 N(p,γ) 14 O reaction in turn is the trigger

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Indian Institute of Astrophysics, Koramangala, Bangalore 560 034, India. Kavli Institute for Astronomy & Astrophysics, Peking University, Beijing 100871, China. National Research Council of Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, British Columbia, Canada. Thirty Meter Project Office, ...

Effects of magnetic geometry, fluctuations, and electric fields on confinement in the Advanced Toroidal Facility

International Nuclear Information System (INIS)

Isler, R.C.; Aceto, S.; Baylor, L.R.; Bigelow, T.S.; Bell, G.L.; Bell, J.D.; Carreras, B.A.; Colchin, R.J.; Crume, E.C.; Dominguez, N.; Dory, R.A.; Dunlap, J.L.; Dyer, G.R.; England, A.C.; Gandy, R.F.; Glowienka, J.C.; Hanson, G.R.; Harris, J.H.; Hiroe, S.; Horton, L.D.; Jernigan, T.C.; Ji, H.; Langley, R.A.; Lee, D.K.; Likin, K.M.; Lyon, J.F.; Ma, C.H.; Morimoto, S.; Murakami, M.; Okada, H.; Qualls, A.L.; Rasmussen, D.A.; Rome, J.A.; Sato, M.; Schwelberger, J.G.; Shats, M.G.; Simpkins, J.E.; Thomas, C.E.; Uckan, T.; Wade, M.R.; Wilgen, J.B.; Wing, W.R.; Yamada, H.; Zielinski, J.J.

1992-01-01

Recent experiments in the Advanced Toroidal Facility (ATF) [Fusion Technol. 10, 179 (1986)] have been directed toward investigations of the basic physics mechanisms that control confinement in this device. Measurements of the density fluctuations throughout the plasma volume have provided indications for the existence of theoretically predicted dissipative trapped electron and resistive interchange instabilities. These identifications are supported by results of dynamic configuration scans of the magnetic fields during which the magnetic well volume, shear, and fraction of confined trapped particles are changed continuously. The influence of magnetic islands on the global confinement has been studied by deliberately applying error fields which strongly perturb the nested flux-surface geometry, and the effects of electric fields have been investigated by means of biased limiter experiments

Astrophysics with small satellites in Scandinavia

DEFF Research Database (Denmark)

Lund, Niels

2003-01-01

The small-satellites activities in the Scandinavian countries are briefly surveyed with emphasis on astrophysics research. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.......The small-satellites activities in the Scandinavian countries are briefly surveyed with emphasis on astrophysics research. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved....

Computational Laboratory Astrophysics to Enable Transport Modeling of Protons and Hydrogen in Stellar Winds, the ISM, and other Astrophysical Environments

Science.gov (United States)

Schultz, David

As recognized prominently by the APRA program, interpretation of NASA astrophysical mission observations requires significant products of laboratory astrophysics, for example, spectral lines and transition probabilities, electron-, proton-, or heavy-particle collision data. Availability of these data underpin robust and validated models of astrophysical emissions and absorptions, energy, momentum, and particle transport, dynamics, and reactions. Therefore, measured or computationally derived, analyzed, and readily available laboratory astrophysics data significantly enhances the scientific return on NASA missions such as HST, Spitzer, and JWST. In the present work a comprehensive set of data will be developed for the ubiquitous proton-hydrogen and hydrogen-hydrogen collisions in astrophysical environments including ISM shocks, supernova remnants and bubbles, HI clouds, young stellar objects, and winds within stellar spheres, covering the necessary wide range of energy- and charge-changing channels, collision energies, and most relevant scattering parameters. In addition, building on preliminary work, a transport and reaction simulation will be developed incorporating the elastic and inelastic collision data collected and produced. The work will build upon significant previous efforts of the principal investigators and collaborators, will result in a comprehensive data set required for modeling these environments and interpreting NASA astrophysical mission observations, and will benefit from feedback from collaborators who are active users of the work proposed.

Design and fabrication of the superconducting-magnet system for the Mirror Fusion Test Facility (MFTF-B)

International Nuclear Information System (INIS)

Tatro, R.E.; Wohlwend, J.W.; Kozman, T.A.

1982-01-01

The superconducting magnet system for the Mirror Fusion Test Facility (MFTF-B) consists of 24 magnets; i.e. two pairs of C-shaped Yin-Yang coils, four C-shaped transition coils, four solenoidal axicell coils, and a 12-solenoid central cell. General Dynamics Convair Division has designed all the coils and is responsible for fabricating 20 coils. The two Yin-Yang pairs (four coils) are being fabricated by the Lawrence Livermore National Laboratory. Since MFTF-B is not a magnet development program, but rather a major physics experiment critical to the mirror fusion program, the basic philosophy has been to use proven materials and analytical techniques wherever possible. The transition and axicell coils are currently being analyzed and designed, while fabrication is under way on the solenoid magnets

An introduction to astrophysical hydrodynamics

CERN Document Server

Shore, Steven N

1992-01-01

This book is an introduction to astrophysical hydrodynamics for both astronomy and physics students. It provides a comprehensive and unified view of the general problems associated with fluids in a cosmic context, with a discussion of fluid dynamics and plasma physics. It is the only book on hydrodynamics that addresses the astrophysical context. Researchers and students will find this work to be an exceptional reference. Contents include chapters on irrotational and rotational flows, turbulence, magnetohydrodynamics, and instabilities.

High energy astrophysics

International Nuclear Information System (INIS)

Engel, A.R.

1979-01-01

High energy astrophysical research carried out at the Blackett Laboratory, Imperial College, London is reviewed. Work considered includes cosmic ray particle detection, x-ray astronomy, gamma-ray astronomy, gamma and x-ray bursts. (U.K.)

Synchrotron Intensity Gradients as Tracers of Interstellar Magnetic Fields

Energy Technology Data Exchange (ETDEWEB)

Lazarian, A.; Yuen, Ka Ho; Lee, Hyeseung; Cho, J. [Department of Astronomy, University of Wisconsin-Madison, 2535 Sterling Hall, 475 North Charter Street, Madison, WI 53706-1507 (United States)

2017-06-10

On the basis of the modern understanding of MHD turbulence, we propose a new way of using synchrotron radiation: using synchrotron intensity gradients (SIGs) for tracing astrophysical magnetic fields. We successfully test the new technique using synthetic data obtained with 3D MHD simulations and provide the demonstration of the practical utility of the technique by comparing the directions of magnetic fields that are obtained with PLANCK synchrotron intensity data to the directions obtained with PLANCK synchrotron polarization data. We demonstrate that the SIGs can reliably trace magnetic fields in the presence of noise and can provide detailed maps of magnetic field directions. We also show that the SIGs are relatively robust for tracing magnetic fields while the low spatial frequencies of the synchrotron image are removed. This makes the SIGs applicable to the tracing of magnetic fields using interferometric data with single-dish measurement absent. We discuss the synergy of using the SIGs together with synchrotron polarization in order to find the actual direction of the magnetic fields and quantify the effects of Faraday rotation as well as with other ways of studying astrophysical magnetic fields. We test our method in the presence of noise and the resolution effects. We stress the complementary nature of the studies using the SIG technique and those employing the recently introduced velocity gradient techniques that trace magnetic fields using spectroscopic data.

Synchrotron Intensity Gradients as Tracers of Interstellar Magnetic Fields

International Nuclear Information System (INIS)

Lazarian, A.; Yuen, Ka Ho; Lee, Hyeseung; Cho, J.

2017-01-01

On the basis of the modern understanding of MHD turbulence, we propose a new way of using synchrotron radiation: using synchrotron intensity gradients (SIGs) for tracing astrophysical magnetic fields. We successfully test the new technique using synthetic data obtained with 3D MHD simulations and provide the demonstration of the practical utility of the technique by comparing the directions of magnetic fields that are obtained with PLANCK synchrotron intensity data to the directions obtained with PLANCK synchrotron polarization data. We demonstrate that the SIGs can reliably trace magnetic fields in the presence of noise and can provide detailed maps of magnetic field directions. We also show that the SIGs are relatively robust for tracing magnetic fields while the low spatial frequencies of the synchrotron image are removed. This makes the SIGs applicable to the tracing of magnetic fields using interferometric data with single-dish measurement absent. We discuss the synergy of using the SIGs together with synchrotron polarization in order to find the actual direction of the magnetic fields and quantify the effects of Faraday rotation as well as with other ways of studying astrophysical magnetic fields. We test our method in the presence of noise and the resolution effects. We stress the complementary nature of the studies using the SIG technique and those employing the recently introduced velocity gradient techniques that trace magnetic fields using spectroscopic data.

Carbon nanotubes/magnetite hybrids prepared by a facile synthesis process and their magnetic properties

International Nuclear Information System (INIS)

Zhang Li; Ni, Qing-Qing; Natsuki, Toshiaki; Fu Yaqin

2009-01-01

In this paper, a facile synthesis process is proposed to prepare multiwalled carbon nanotubes/magnetite (MWCNTs/Fe 3 O 4 ) hybrids. The process involves two steps: (1) water-soluble CNTs are synthesized by one-pot modification using potassium persulfate (KPS) as oxidant. (2) Fe 3 O 4 is assembled along the treated CNTs by employing a facile hydrothermal process with the presence of hydrazine hydrate as the mineralizer. The treated CNTs can be easily dispersed in aqueous solvent. Moreover, X-ray photoelectron spectroscopy (XPS) analysis reveals that several functional groups such as potassium carboxylate (-COOK), carbonyl (-C=O) and hydroxyl (-C-OH) groups are formed on the nanotube surfaces. The MWCNTs/Fe 3 O 4 hybrids are characterized with respect to crystal structure, morphology, element composition and magnetic property by X-ray diffraction (XRD), transmission electron microscopy (TEM), XPS and superconducting quantum interference device (SQUID) magnetometer. XRD and TEM results show that the Fe 3 O 4 nanoparticles with diameter in the range of 20-60 nm were firmly assembled on the nanotube surface. The magnetic property investigation indicated that the CNTs/Fe 3 O 4 hybrids exhibit a ferromagnetic behavior and possess a saturation magnetization of 32.2 emu/g. Further investigation indicates that the size of assembled Fe 3 O 4 nanoparticles can be turned by varying experiment factors. Moreover, a probable growth mechanism for the preparation of CNTs/Fe 3 O 4 hybrids was discussed.

Approximate fitting of expanding magnetic clouds: a statistical study

Czech Academy of Sciences Publication Activity Database

Lynnyk, A.; Vandas, Marek

2009-01-01

Roč. 57, č. 12 (2009), s. 1375-1380 ISSN 0032-0633 R&D Projects: GA AV ČR(CZ) 1QS300120506 Institutional research plan: CEZ:AV0Z10030501 Keywords : magnetic cloud s * interplanetary magnetic field * solar wind Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.067, year: 2009

2004 ASTRONOMY & ASTROPHYSICS

Indian Academy of Sciences (India)

user

This publication of the Academy on Astronomy and Astrophysics is unique in ... bring out position papers on societal issues where science plays a major ..... funding agencies, the Astronomical Society of ..... orbit very close to the parent star.

78 FR 2293 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

Science.gov (United States)

2013-01-10

... Committee; Astrophysics Subcommittee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... amended, the National Aeronautics and Space Administration (NASA) announces a meeting of the Astrophysics... meeting includes the following topics: --Astrophysics Division Update --NASA Astrophysics Roadmapping It...

78 FR 66384 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

Science.gov (United States)

2013-11-05

... Committee; Astrophysics Subcommittee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... amended, the National Aeronautics and Space Administration (NASA) announces a meeting of the Astrophysics...: --Astrophysics Division Update --Presentation of Astrophysics Roadmap --Reports from Program Analysis Groups...

75 FR 51116 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

Science.gov (United States)

2010-08-18

... Committee; Astrophysics Subcommittee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... amended, the National Aeronautics and Space Administration (NASA) announces a meeting of the Astrophysics... topics: --Astrophysics Division Update --2010 Astronomy and Astrophysics Decadal Survey --Update on...

Workshop on CEBAF [Continuous Electron Beam Accelerator Facility] spectrometer magnet design and technology: Proceedings

International Nuclear Information System (INIS)

1986-09-01

The planned experimental program at CEBAF includes high-resolution, large acceptance spectrometers and a large toroidal magnetic, detector. In order to take full advantage of the high quality beam characteristics, the performances required will make these devices quite unique instruments compared to existing facilities in the same energy range. Preliminary designs have shown that such performances can be reached, but key questions concerning design concepts and most appropriate and cost-effective technologies had to be answered before going further with the designs. It was the purpose of the Workshop on CEBAF Spectrometer Magnet Design and Technology, organized by the CEBAF Research and Engineering Divisions, to provide the most complete information about the state-of-the-art tools and techniques in magnet design and construction and to discuss the ones most appropriate to the CEBAF spectrometers. In addition, it is expected that this Workshop will be the staring point for further interactions and collaborations between international magnet experts and the CEBAF staff, during the whole process of designing and building the spectrometers

White Paper on Nuclear Astrophysics

OpenAIRE

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

2016-01-01

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 mee...

Cryogenic techniques for large superconducting magnets in space

Science.gov (United States)

Green, M. A.

1989-01-01

A large superconducting magnet is proposed for use in a particle astrophysics experiment, ASTROMAG, which is to be mounted on the United States Space Station. This experiment will have a two-coil superconducting magnet with coils which are 1.3 to 1.7 meters in diameter. The two-coil magnet will have zero net magnetic dipole moment. The field 15 meters from the magnet will approach earth's field in low earth orbit. The issue of high Tc superconductor will be discussed in the paper. The reasons for using conventional niobium-titanium superconductor cooled with superfluid helium will be presented. Since the purpose of the magnet is to do particle astrophysics, the superconducting coils must be located close to the charged particle detectors. The trade off between the particle physics possible and the cryogenic insulation around the coils is discussed. As a result, the ASTROMAG magnet coils will be operated outside of the superfluid helium storage tank. The fountain effect pumping system which will be used to cool the coil is described in the report. Two methods for extending the operating life of the superfluid helium dewar are discussed. These include: operation with a third shield cooled to 90 K with a sterling cycle cryocooler, and a hybrid cryogenic system where there are three hydrogen-cooled shields and cryostat support heat intercept points.

75 FR 2893 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

Science.gov (United States)

2010-01-19

... Committee; Astrophysics Subcommittee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... of the Astrophysics Subcommittee of the NASA Advisory Council (NAC). This Subcommittee reports to the... following topics: --Astrophysics Division Update --Updates on Select Astrophysics Missions --Discussion of...

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Astrophysics and Astronomy. Anjan A. Sen. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 33 Review. Cosmology and Astrophysics using the Post-Reionization HI · Tapomoy Guha Sarkar Anjan A. Sen · More Details Abstract Fulltext PDF.

The path to improved reaction rates for astrophysics

International Nuclear Information System (INIS)

Rauscher, T.

2011-01-01

This review focuses on nuclear reactions in astrophysics and, more specifically, on reactions with light ions (nucleons and α particles) proceeding via the strong interaction. It is intended to present the basic definitions essential for studies in nuclear astrophysics, to point out the differences between nuclear reactions taking place in stars and in a terrestrial laboratory, and to illustrate some of the challenges to be faced in theoretical and experimental studies of those reactions. The discussion revolves around the relevant quantities for astrophysics, which are the astrophysical reaction rates. The sensitivity of the reaction rates to the uncertainties in the prediction of various nuclear properties is explored and some guidelines for experimentalists are also provided. (author)

Astrophysics a very short introduction

CERN Document Server

Binney, James

2016-01-01

Astrophysics is the physics of the stars, and more widely the physics of the Universe. It enables us to understand the structure and evolution of planetary systems, stars, galaxies, interstellar gas, and the cosmos as a whole. In this Very Short Introduction, the leading astrophysicist James Binney shows how the field of astrophysics has expanded rapidly in the past century, with vast quantities of data gathered by telescopes exploiting all parts of the electromagnetic spectrum, combined with the rapid advance of computing power, which has allowed increasingly effective mathematical modelling. He illustrates how the application of fundamental principles of physics - the consideration of energy and mass, and momentum - and the two pillars of relativity and quantum mechanics, has provided insights into phenomena ranging from rapidly spinning millisecond pulsars to the collision of giant spiral galaxies. This is a clear, rigorous introduction to astrophysics for those keen to cut their teeth on a conceptual trea...

High energy astrophysics an introduction

CERN Document Server

Courvoisier, Thierry J -L

2013-01-01

High-energy astrophysics has unveiled a Universe very different from that only known from optical observations. It has revealed many types of objects in which typical variability timescales are as short as years, months, days, and hours (in quasars, X-ray binaries, and other objects), and even down to milli-seconds in gamma ray bursts. The sources of energy that are encountered are only very seldom nuclear fusion, and most of the time gravitation, a paradox when one thinks that gravitation is, by many orders of magnitude, the weakest of the fundamental interactions. The understanding of these objects' physical conditions and the processes revealed by high-energy astrophysics in the last decades is nowadays part of astrophysicists' culture, even of those active in other domains of astronomy. This book evolved from lectures given to master and PhD students at the University of Geneva since the early 1990s. It aims at providing astronomers and physicists intending to be active in high-energy astrophysics a broad...

Development of low temperature and high magnetic field X-ray diffraction facility

Energy Technology Data Exchange (ETDEWEB)

Shahee, Aga; Sharma, Shivani; Singh, K.; Lalla, N. P., E-mail: nplallaiuc82@gmail.com; Chaddah, P. [UGC-DAE Consortium for Scientific Research, University campus, Khandwa Road, Indore-452001 (India)

2015-06-24

The current progress of materials science regarding multifunctional materials (MFM) has put forward the challenges to understand the microscopic origin of their properties. Most of such MFMs have magneto-elastic correlations. To investigate the underlying mechanism it is therefore essential to investigate the structural properties in the presence of magnetic field. Keeping this in view low temperature and high magnetic field (LTHM) powder x-ray diffraction (XRD), a unique state-of-art facility in the country has been developed at CSR Indore. This setup works on symmetric Bragg Brentano geometry using a parallel incident x-ray beam from a rotating anode source working at 17 kW. Using this one can do structural studies at non-ambient conditions i.e. at low- temperatures (2-300 K) and high magnetic field (+8 to −8 T). The available scattering angle ranges from 5° to 115° 2θ with a resolution better than 0.1°. The proper functioning of the setup has been checked using Si sample. The effect of magnetic field on the structural properties has been demonstrated on Pr{sub 0.5}Sr{sub 0.5}MnO{sub 3} sample. Clear effect of field induced phase transition has been observed. Moreover, the effect of zero field cooled and field cooled conditions is also observed.

Allen's astrophysical quantities

CERN Document Server

2000-01-01

This new, fourth, edition of Allen's classic Astrophysical Quantities belongs on every astronomer's bookshelf. It has been thoroughly revised and brought up to date by a team of more than ninety internationally renowned astronomers and astrophysicists. While it follows the basic format of the original, this indispensable reference has grown to more than twice the size of the earlier editions to accommodate the great strides made in astronomy and astrophysics. It includes detailed tables of the most recent data on: - General constants and units - Atoms, molecules, and spectra - Observational astronomy at all wavelengths from radio to gamma-rays, and neutrinos - Planetary astronomy: Earth, planets and satellites, and solar system small bodies - The Sun, normal stars, and stars with special characteristics - Stellar populations - Cataclysmic and symbiotic variables, supernovae - Theoretical stellar evolution - Circumstellar and interstellar material - Star clusters, galaxies, quasars, and active galactic nuclei ...

Propagation of Ion Solitary Pulses in Dense Astrophysical Electron-Positron-Ion Magnetoplasmas

Science.gov (United States)

Ata-Ur-Rahman; A. Khan, S.; Qamar, A.

2015-12-01

In this paper, we theoretically investigate the existence and propagation of low amplitude nonlinear ion waves in a dense plasma under the influence of a strong magnetic field. The plasma consists of ultra-relativistic and degenerate electrons and positrons and non-degenerate cold ions. Firstly, the appearance of two distinct linear modes and their evolution is studied by deriving a dispersion equation with the aid of Fourier analysis. Secondly, the dynamics of low amplitude ion solitary structures is investigated via a Korteweg-de Vries equation derived by employing a reductive perturbation method. The effects of various plasma parameters like positron concentration, strength of magnetic field, obliqueness of field, etc., are discussed in detail. At the end, analytical results are supplemented through numerical analysis by using typical representative parameters consistent with degenerate and ultra-relativistic magnetoplasmas of astrophysical regimes.

"SOLAR MAGNETIZED ""TORNADOES:"" RELATION TO FILAMENTS"

OpenAIRE

Su, Yang; Wang, Tongjiang; Veronig, Astrid; Temmer, Manuela; Gan, Weiqun

2012-01-01

Solar magnetized "tornadoes", a phenomenon discovered in the solar atmosphere, appear as tornado-like structures in the corona but root in the photosphere. Like other solar phenomena, solar tornadoes are a feature of magnetized plasma and therefore differ distinctly from terrestrial tornadoes. Here we report the first analysis of solar "tornadoes" {Two papers which focused on different aspect of solar tornadoes were published in the Astrophysical Journal Letters (Li et al. 2012) and Nature (W...

High-Mach number, laser-driven magnetized collisionless shocks

International Nuclear Information System (INIS)

Schaeffer, Derek B.; Fox, W.; Haberberger, D.; Fiksel, G.; Bhattacharjee, A.

2017-01-01

Collisionless shocks are ubiquitous in space and astrophysical systems, and the class of supercritical shocks is of particular importance due to their role in accelerating particles to high energies. While these shocks have been traditionally studied by spacecraft and remote sensing observations, laboratory experiments can provide reproducible and multi-dimensional datasets that provide complementary understanding of the underlying microphysics. We present experiments undertaken on the OMEGA and OMEGA EP laser facilities that show the formation and evolution of high-Mach number collisionless shocks created through the interaction of a laser-driven magnetic piston and magnetized ambient plasma. Through time-resolved, 2-D imaging we observe large density and magnetic compressions that propagate at super-Alfvenic speeds and that occur over ion kinetic length scales. Electron density and temperature of the initial ambient plasma are characterized using optical Thomson scattering. Measurements of the piston laser-plasma are modeled with 2-D radiation-hydrodynamic simulations, which are used to initialize 2-D particle-in-cell simulations of the interaction between the piston and ambient plasmas. The numerical results show the formation of collisionless shocks, including the separate dynamics of the carbon and hydrogen ions that constitute the ambient plasma and their effect on the shock structure. Furthermore, the simulations also show the shock separating from the piston, which we observe in the data at late experimental times.

NASA Astrophysics Funds Strategic Technology Development

Science.gov (United States)

Seery, Bernard D.; Ganel, Opher; Pham, Bruce

2016-01-01

The COR and PCOS Program Offices (POs) reside at the NASA Goddard Space Flight Center (GSFC), serving as the NASA Astrophysics Division's implementation arm for matters relating to the two programs. One aspect of the PO's activities is managing the COR and PCOS Strategic Astrophysics Technology (SAT) program, helping mature technologies to enable and enhance future astrophysics missions. For example, the SAT program is expected to fund key technology developments needed to close gaps identified by Science and Technology Definition Teams (STDTs) planned to study several large mission concept studies in preparation for the 2020 Decadal Survey.The POs are guided by the National Research Council's "New Worlds, New Horizons in Astronomy and Astrophysics" Decadal Survey report, NASA's Astrophysics Implementation Plan, and the visionary Astrophysics Roadmap, "Enduring Quests, Daring Visions." Strategic goals include dark energy, gravitational waves, and X-ray observatories. Future missions pursuing these goals include, e.g., US participation in ESA's Euclid, Athena, and L3 missions; Inflation probe; and a large UV/Optical/IR (LUVOIR) telescope.To date, 65 COR and 71 PCOS SAT proposals have been received, of which 15 COR and 22 PCOS projects were funded. Notable successes include maturation of a new far-IR detector, later adopted by the SOFIA HAWC instrument; maturation of the H4RG near-IR detector, adopted by WFIRST; development of an antenna-coupled transition-edge superconducting bolometer, a technology deployed by BICEP2/BICEP3/Keck to measure polarization in the CMB signal; advanced UV reflective coatings implemented on the optics of GOLD and ICON, two heliophysics Explorers; and finally, the REXIS instrument on OSIRIS-REx is incorporating CCDs with directly deposited optical blocking filters developed by another SAT-funded project.We discuss our technology development process, with community input and strategic prioritization informing calls for SAT proposals and

Transport processes in space physics and astrophysics

CERN Document Server

Zank, Gary P

2014-01-01

Transport Processes in Space Physics and Astrophysics' is aimed at graduate level students to provide the necessary mathematical and physics background to understand the transport of gases, charged particle gases, energetic charged particles, turbulence, and radiation in an astrophysical and space physics context. Subjects emphasized in the work include collisional and collisionless processes in gases (neutral or plasma), analogous processes in turbulence fields and radiation fields, and allows for a simplified treatment of the statistical description of the system. A systematic study that addresses the common tools at a graduate level allows students to progress to a point where they can begin their research in a variety of fields within space physics and astrophysics. This book is for graduate students who expect to complete their research in an area of plasma space physics or plasma astrophysics. By providing a broad synthesis in several areas of transport theory and modeling, the work also benefits resear...

Astrophysically relevant radiatively cooled hypersonic bow shocks in nested wire arrays

Science.gov (United States)

Ampleford, David

2009-11-01

We have performed laboratory experiments which introduce obstructions into hypersonic plasma flows to study the formation of shocks. Astrophysical observations have demonstrated many examples of equivalent radiatively cooled bow shocks, for example the head of protostellar jets or supernova remnants passing through the interstellar medium or between discrete clumps in jets. Wire array z-pinches allow us to study quasi-planar radiatively cooled flows in the laboratory. The early stage of a wire array z-pinch implosion consists of a steady flow of the wire material towards the axis. Given a high rate of radiative cooling, these flows reach high sonic- Mach numbers, typically up to 5. The 2D nature of this configuration allows the insertion of obstacles into the flow, such as a concentric ``inner'' wire array, as has previously been studied for ICF research. Here we study the application of such a nested array to laboratory astrophysics where the inner wires act as obstructions perpendicular to the flow, and induce bow shocks. By varying the wire array material (W/Al), the significance of radiative cooling on these shocks can be controlled, and is shown to change the shock opening angle. As multiple obstructions are present, the experiments show the interaction of multiple bow shocks. It is also possible to introduce a magnetic field around the static object, increasing the opening angle of the shocks. Further experiments can be designed to control the flow density, magnetic field structure and obstruction locations. In collaboration with: S.V. Lebedev, M.E. Cuneo, C.A. Jennings, S.N. Bland, J.P. Chittenden, A. Ciardi, G.N. Hall, S.C. Bott, M. Sherlock, A. Frank, E. Blackman

Magnetic Reconnection as a Driver for a Sub-ion-scale Cascade in Plasma Turbulence

Czech Academy of Sciences Publication Activity Database

Franci, L.; Cerri, S.S.; Califano, F.; Landi, S.; Papini, E.; Verdini, A.; Matteini, L.; Jenko, F.; Hellinger, Petr

2017-01-01

Roč. 850, č. 1 (2017), L16/1-L16/6 ISSN 2041-8205 R&D Projects: GA ČR GA15-10057S Institutional support: RVO:67985815 Keywords : magnetic reconnection * solar wind * turbulence Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 5.522, year: 2016

Astrophysics in a nutshell

CERN Document Server

Maoz, Dan

2016-01-01

Winner of the American Astronomical Society's Chambliss Award, Astrophysics in a Nutshell has become the text of choice in astrophysics courses for science majors at top universities in North America and beyond. In this expanded and fully updated second edition, the book gets even better, with a new chapter on extrasolar planets; a greatly expanded chapter on the interstellar medium; fully updated facts and figures on all subjects, from the observed properties of white dwarfs to the latest results from precision cosmology; and additional instructive problem sets. Throughout, the text features the same focused, concise style and emphasis on physics intuition that have made the book a favorite of students and teachers.

High Time Resolution Astrophysics

CERN Document Server

Phelan, Don; Shearer, Andrew

2008-01-01

High Time Resolution Astrophysics (HTRA) is an important new window to the universe and a vital tool in understanding a range of phenomena from diverse objects and radiative processes. This importance is demonstrated in this volume with the description of a number of topics in astrophysics, including quantum optics, cataclysmic variables, pulsars, X-ray binaries and stellar pulsations to name a few. Underlining this science foundation, technological developments in both instrumentation and detectors are described. These instruments and detectors combined cover a wide range of timescales and can measure fluxes, spectra and polarisation. These advances make it possible for HTRA to make a big contribution to our understanding of the Universe in the next decade.

Tri-axial square Helmholtz coil system at the Alibag Magnetic Observatory: upgraded to a magnetic sensor calibration facility

Science.gov (United States)

Mahavarkar, Prasanna; John, Jacob; Dhapre, Vijay; Dongre, Varun; Labde, Sachin

2018-04-01

A tri-axial square Helmholtz coil system for the study of palaeomagnetic studies, manufactured by GEOFYZIKA (former Czechoslovakia), was successfully commissioned at the Alibag Magnetic Observatory (IAGA code: ABG) in the year 1985. This system was used for a few years, after which the system encountered technical problems with the control unit. Rectification of the unit could not be undertaken, as the information document related to this system was not available, and as a result the system had been lying in an unused state for a long time, until 2015, when the system was recommissioned and upgraded to a test facility for calibrating the magnetometer sensors. We have upgraded the system with a constant current source and a data-logging unit. Both of these units have been designed and developed in the institute laboratory. Also, re-measurements of the existing system have been made thoroughly. The upgraded system is semi-automatic, enabling non-specialists to operate it after a brief period of instruction. This facility is now widely used at the parent institute and external institutions to calibrate magnetometers and it also serves as a national facility. Here the design of this system with the calibration results for the space-borne fluxgate magnetometers is presented.

Tri-axial square Helmholtz coil system at the Alibag Magnetic Observatory: upgraded to a magnetic sensor calibration facility

Directory of Open Access Journals (Sweden)

P. Mahavarkar

2018-04-01

Full Text Available A tri-axial square Helmholtz coil system for the study of palaeomagnetic studies, manufactured by GEOFYZIKA (former Czechoslovakia, was successfully commissioned at the Alibag Magnetic Observatory (IAGA code: ABG in the year 1985. This system was used for a few years, after which the system encountered technical problems with the control unit. Rectification of the unit could not be undertaken, as the information document related to this system was not available, and as a result the system had been lying in an unused state for a long time, until 2015, when the system was recommissioned and upgraded to a test facility for calibrating the magnetometer sensors. We have upgraded the system with a constant current source and a data-logging unit. Both of these units have been designed and developed in the institute laboratory. Also, re-measurements of the existing system have been made thoroughly. The upgraded system is semi-automatic, enabling non-specialists to operate it after a brief period of instruction. This facility is now widely used at the parent institute and external institutions to calibrate magnetometers and it also serves as a national facility. Here the design of this system with the calibration results for the space-borne fluxgate magnetometers is presented.

Advances in astronomy and astrophysics

CERN Document Server

Kopal, Zdenek

1962-01-01

Advances in Astronomy and Astrophysics, Volume 1 brings together numerous research works on different aspects of astronomy and astrophysics. This book is divided into five chapters and begins with an observational summary of the shock-wave theory of novae. The subsequent chapter provides the properties and problems of T tauri stars and related objects. These topics are followed by discussions on the structure and origin of meteorites and cosmic dust, as well as the models for evaluation of mass distribution in oblate stellar systems. The final chapter describes the methods of polarization mea

Advances in astronomy and astrophysics

CERN Document Server

Kopal, Zdenek

1963-01-01

Advances in Astronomy and Astrophysics, Volume 2 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of six chapters and begins with a summary of observational record on twilight extensions of the Venus cusps. The next chapter deals with the common and related properties of binary stars, with emphasis on the evaluation of their cataclysmic variables. Cataclysmic variables refer to an object in one of three classes: dwarf nova, nova, or supernova. These topics are followed by discussions on the eclipse phenomena and the eclipses i

Advances in astronomy and astrophysics

CERN Document Server

Kopal, Zdenek

1966-01-01

Advances in Astronomy and Astrophysics, Volume 4 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of five chapters, and starts with a description of objective prism and its application in space observations. The next chapter deals with the possibilities of deriving reliable models of the figure, density distribution, and gravity field of the Moon based on data obtained through Earth-bound telescopes. These topics are followed by a discussion on the ideal partially relativistic, partially degenerate gas in an exact manner. A ch

Advances in astronomy and astrophysics

CERN Document Server

Kopal, Zdenek

1968-01-01

Advances in Astronomy and Astrophysics, Volume 6 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of five chapters, and starts with the description of improved methods for analyzing and classifying families of periodic orbits in a conservative dynamical system with two degrees of freedom. The next chapter describes the variation of fractional luminosity of distorted components of close binary systems in the course of their revolution, or the accompanying changes in radial velocity. This topic is followed by discussions on vari

Nuclear astrophysics data at ORNL

International Nuclear Information System (INIS)

Smith, M.S.; Blackmon, J.C.

1998-01-01

There is a new program of evaluation and dissemination of nuclear data of critical importance for nuclear astrophysics within the Physics Division of Oak Ridge National Laboratory. Recent activities include determining the rates of the important 14 O(α,p) 17 F and 17 F(p,γ) 18 Ne reactions, disseminating the Caughlan and Fowler reaction rate compilation on the World Wide Web, and evaluating the 17 O(p,α) 14 N reaction rate. These projects, which are closely coupled to current ORNL nuclear astrophysics research, are briefly discussed along with future plans

Direct measurement of nuclear cross-section of astrophysical interest: Results and perspectives

Science.gov (United States)

Cavanna, Francesca; Prati, Paolo

2018-03-01

Stellar evolution and nucleosynthesis are interconnected by a wide network of nuclear reactions: the study of such connection is usually known as nuclear astrophysics. The main task of this discipline is the determination of nuclear cross-section and hence of the reaction rate in different scenarios, i.e. from the synthesis of a few very light isotopes just after the Big Bang to the heavy element production in the violent explosive end of massive stars. The experimental determination of reaction cross-section at the astrophysical relevant energies is extremely difficult, sometime impossible, due to the Coulomb repulsion between the interacting nuclei which turns out in cross-section values down to the fbar level. To overcome these obstacles, several experimental approaches have been developed and the adopted techniques can be roughly divided into two categories, i.e. direct and indirect methods. In this review paper, the general problem of nuclear astrophysics is introduced and discussed from the point of view of experimental approach. We focus on direct methods and in particular on the features of low-background experiments performed at underground laboratory facilities. The present knowledge of reactions involved in the Big Bang and stellar hydrogen-burning scenarios is discussed as well as the ongoing projects aiming to investigate mainly the helium- and carbon-burning phases. Worldwide, a new generation of experiment in the MeV range is in the design phase or at the very first steps and decisive progresses are expected to come in the next years.

Nuclear Data for Astrophysics Research: A New Online Paradigm

International Nuclear Information System (INIS)

Smith, Michael Scott

2011-01-01

Our knowledge of a wide range of astrophysical processes depends crucially on nuclear physics data. While new nuclear information is being generated at an ever-increasing rate, the methods to process this information into astrophysical simulations have changed little over the decades and cannot keep pace. Working online, 'cloud computing', may be the methodology breakthrough needed to ensure that the latest nuclear data quickly gets into astrophysics codes. The successes of the first utilization of cloud computing for nuclear astrophysics will be described. The advantages of cloud computing for the broader nuclear data community are also discussed.

Astrophysical black holes

CERN Document Server

Gorini, Vittorio; Moschella, Ugo; Treves, Aldo; Colpi, Monica

2016-01-01

Based on graduate school lectures in contemporary relativity and gravitational physics, this book gives a complete and unified picture of the present status of theoretical and observational properties of astrophysical black holes. The chapters are written by internationally recognized specialists. They cover general theoretical aspects of black hole astrophysics, the theory of accretion and ejection of gas and jets, stellar-sized black holes observed in the Milky Way, the formation and evolution of supermassive black holes in galactic centers and quasars as well as their influence on the dynamics in galactic nuclei. The final chapter addresses analytical relativity of black holes supporting theoretical understanding of the coalescence of black holes as well as being of great relevance in identifying gravitational wave signals. With its introductory chapters the book is aimed at advanced graduate and post-graduate students, but it will also be useful for specialists.

Simulating Magnetized Laboratory Plasmas with Smoothed Particle Hydrodynamics

Energy Technology Data Exchange (ETDEWEB)

Johnson, Jeffrey N. [Univ. of California, Davis, CA (United States)

2009-01-01

The creation of plasmas in the laboratory continues to generate excitement in the physics community. Despite the best efforts of the intrepid plasma diagnostics community, the dynamics of these plasmas remains a difficult challenge to both the theorist and the experimentalist. This dissertation describes the simulation of strongly magnetized laboratory plasmas with Smoothed Particle Hydrodynamics (SPH), a method born of astrophysics but gaining broad support in the engineering community. We describe the mathematical formulation that best characterizes a strongly magnetized plasma under our circumstances of interest, and we review the SPH method and its application to astrophysical plasmas based on research by Phillips [1], Buerve [2], and Price and Monaghan [3]. Some modifications and extensions to this method are necessary to simulate terrestrial plasmas, such as a treatment of magnetic diffusion based on work by Brookshaw [4] and by Atluri [5]; we describe these changes as we turn our attention toward laboratory experiments. Test problems that verify the method are provided throughout the discussion. Finally, we apply our method to the compression of a magnetized plasma performed by the Compact Toroid Injection eXperiment (CTIX) [6] and show that the experimental results support our computed predictions.

Slow decay of magnetic fields in open Friedmann universes

International Nuclear Information System (INIS)

Barrow, John D.; Tsagas, Christos G.

2008-01-01

Magnetic fields in Friedmann universes can experience superadiabatic growth without departing from conventional electromagnetism. The reason is the relativistic coupling between vector fields and spacetime geometry, which slows down the decay of large-scale magnetic fields in open universes, compared to that seen in perfectly flat models. The result is a large relative gain in magnetic strength that can lead to astrophysically interesting B fields, even if our Universe is only marginally open today

Searches for astrophysical neutrinos with IceCube

International Nuclear Information System (INIS)

Williams, D.

2014-01-01

Powerful astrophysical objects such as active galactic nuclei (AGN), core collapse supernovae and gamma ray bursts (GRBs) are potential sources of the highest energy cosmic rays. Many models of cosmic ray proton acceleration predict a corresponding flux of neutrinos in the TeV-PeV energy range. The detection of astrophysical neutrinos requires the largest neutrino detector ever built: IceCube, a cubic-kilometer array located near the geographic South Pole. IceCube has been collecting data throughout its construction, which was complete in December 2010. Data from the partial IceCube detector have already set interesting limits on astrophysical neutrino fluxes, including stringent limits on neutrino production in GRBs. (authors)

Irradiated radiation dose measurements of multilayer mirrors and permanent magnets used at FELI facilities

International Nuclear Information System (INIS)

Wakisaka, K.; Tongu, H.; Okuma, S.; Oshita, E.; Wakita, K.; Takii, T.; Tomimasu, Takio

1997-01-01

Recently the operation time of the free electron laser (FEL) user's facilities is close on three thousand hours per year. Cavity mirrors of their optical resonators and permanent magnets of their undulators are used under high intensity radiation field along their high current electron beam lines. Among these mirrors and permanent magnets, multilayer mirrors and Nd-Fe-B permanent magnets are not so strong against radiation damage compared with Au-coated copper mirrors and Sm-Co permanent magnets. A radiation damage on Ta 2 O 5 /SiO 2 mirrors was found for the first time after about fifty hours visible FEL operation at the FELI. The damage is due to irradiated bremsstrahlung and intracavity FEL. However, radiation damages on Nd-Fe-B permanent magnets were already reported compared with Sm-Co ones using high energy neutrons, protons, deuterons and 60 Coγ-rays. Mixed irradiation effects of 85-MeV electrons, bremsstrahlung and 60 Coγ-rays and of 17-MeV electrons and 60 Coγ-rays were also studied. The latest results show that the magnetic flux loss of Nd-Fe-B is 2% at an absorbed dose of 10 MGy. The present work was carried out to study the irradiated dose distributions near the multilayer mirrors and Nd-Fe-B permanent magnets with thermoluminescence dosimeters (TLDs). The irradiated dose to the cavity mirrors used in Linac-based FEL experiment is estimated to be 0.3 MGray for fifty hours irradiation. The irradiated dose to the Nd-Fe-B magnets is estimated to be 16 MGray for 2 thousand hours operation. The decrease of their magnetic flux due to 16 MGray is estimated to be about 3%. These dose monitorings are useful to reduce irradiated dosages to the mirrors and the permanent magnets as low as possible and to estimate their safety lifetimes. (author)

Particle Physics & Astrophysics (PPA)

Data.gov (United States)

Federal Laboratory Consortium — Scientists at SLAC's Particle Physics and Astrophysics develop and utilize unique instruments from underground to outer space to explore the ultimate laws of nature...

Astrophysical Sources of Cosmic Rays and Related Measurements with the Pierre Auger Observatory

Energy Technology Data Exchange (ETDEWEB)

Abraham, : J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.

2009-06-01

These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Correlation of the highest energy cosmic rays with nearby extragalactic objects in Pierre Auger Observatory data; (2) Discriminating potential astrophysical sources of the highest energy cosmic rays with the Pierre Auger Observatory; (3) Intrinsic anisotropy of the UHECR from the Pierre Auger Observatory; (4) Ultra-high energy photon studies with the Pierre Auger Observatory; (5) Limits on the flux of diffuse ultra high energy neutrinos set using the Pierre Auger Observatory; (6) Search for sidereal modulation of the arrival directions of events recorded at the Pierre Auger Observatory; (7) Cosmic Ray Solar Modulation Studies in the Pierre Auger Observatory; (8) Investigation of the Displacement Angle of the Highest Energy Cosmic Rays Caused by the Galactic Magnetic Field; (9) Search for coincidences with astrophysical transients in Pierre Auger Observatory data; and (10) An alternative method for determining the energy of hybrid events at the Pierre Auger Observatory.

Supervision software for string 2 magnet test facility of large hadron collider project

International Nuclear Information System (INIS)

Mayya, Y.S.; Sanadhya, Vivek; Lal, Pradeep; Goel, Vijay; Mukhopadhyay, S.; Saha, Shilpi

2001-01-01

The Supervisory Control and Data Acquisition (SCADA) software for the String 2 test facility at CERN, Geneva is developed by BARC under the framework of CERN-DAE collaboration for LHC. The supervision application is developed using PCVue32 SCADA/MMI software. The String 2 test facility prototypes one full cell of LHC and is aimed at studying and validating the individual and collective behaviour of the superconducting magnets, before installing in the tunnel. The software integrates monitoring and supervisory control of all the main subsystems of String 2 such as Cryogenics, Vacuum, Power converters, Magnet protection, Energy extraction and interlock systems. It incorporates animated process synoptics, loop and equipment control panels, configurable trend windows for real-time and historical trending of process parameters, user settability for interlock and alarm thresholds, logging of process events, equipment faults and operator activity. The plant equipment are controlled by a variety of field located Programmable Logic Controllers and VME crates which communicate process IO to the central IO server using both vendor specific and custom protocols. The system leverages OPC (OLE for Process Controls) technology for realising a generic IO server. A large number of geographically distributed client stations are arranged to provide the process specific operator interface and these are connected to the Main IO server over CERN wide intranet and internet. (author)

Plunging neutron stars as origin of organised magnetic field in galactic nuclei

Czech Academy of Sciences Publication Activity Database

Karas, Vladimír; Kopáček, Ondřej; Kunneriath, D.; Zajaček, M.; Araudo, Anabella; Eckart, A.; Kovář, J.

2017-01-01

Roč. 47, č. 2 (2017), s. 124-132 ISSN 1335-1842 R&D Projects: GA ČR GA17-16287S; GA MŠk LD15061 Grant - others:COST(XE) MP1304 Institutional support: RVO:67985815 Keywords : magnetic fields * neutron stars * galactic centre Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 0.336, year: 2016

Magnetic Field Effects on Plasma Plumes

Science.gov (United States)

Ebersohn, F.; Shebalin, J.; Girimaji, S.; Staack, D.

2012-01-01

Here, we will discuss our numerical studies of plasma jets and loops, of basic interest for plasma propulsion and plasma astrophysics. Space plasma propulsion systems require strong guiding magnetic fields known as magnetic nozzles to control plasma flow and produce thrust. Propulsion methods currently being developed that require magnetic nozzles include the VAriable Specific Impulse Magnetoplasma Rocket (VASIMR) [1] and magnetoplasmadynamic thrusters. Magnetic nozzles are functionally similar to de Laval nozzles, but are inherently more complex due to electromagnetic field interactions. The two crucial physical phenomenon are thrust production and plasma detachment. Thrust production encompasses the energy conversion within the nozzle and momentum transfer to a spacecraft. Plasma detachment through magnetic reconnection addresses the problem of the fluid separating efficiently from the magnetic field lines to produce maximum thrust. Plasma jets similar to those of VASIMR will be studied with particular interest in dual jet configurations, which begin as a plasma loops between two nozzles. This research strives to fulfill a need for computational study of these systems and should culminate with a greater understanding of the crucial physics of magnetic nozzles with dual jet plasma thrusters, as well as astrophysics problems such as magnetic reconnection and dynamics of coronal loops.[2] To study this problem a novel, hybrid kinetic theory and single fluid magnetohydrodynamic (MHD) solver known as the Magneto-Gas Kinetic Method is used.[3] The solver is comprised of a "hydrodynamic" portion based on the Gas Kinetic Method and a "magnetic" portion that accounts for the electromagnetic behaviour of the fluid through source terms based on the resistive MHD equations. This method is being further developed to include additional physics such as the Hall effect. Here, we will discuss the current level of code development, as well as numerical simulation results

Turbulent Magnetic Relaxation in Pulsar Wind Nebulae

Science.gov (United States)

Zrake, Jonathan; Arons, Jonathan

2017-09-01

We present a model for magnetic energy dissipation in a pulsar wind nebula. A better understanding of this process is required to assess the likelihood that certain astrophysical transients may be powered by the spin-down of a “millisecond magnetar.” Examples include superluminous supernovae, gamma-ray bursts, and anticipated electromagnetic counterparts to gravitational wave detections of binary neutron star coalescence. Our model leverages recent progress in the theory of turbulent magnetic relaxation to specify a dissipative closure of the stationary magnetohydrodynamic (MHD) wind equations, yielding predictions of the magnetic energy dissipation rate throughout the nebula. Synchrotron losses are self-consistently treated. To demonstrate the model’s efficacy, we show that it can reproduce many features of the Crab Nebula, including its expansion speed, radiative efficiency, peak photon energy, and mean magnetic field strength. Unlike ideal MHD models of the Crab (which lead to the so-called σ-problem), our model accounts for the transition from ultra to weakly magnetized plasma flow and for the associated heating of relativistic electrons. We discuss how the predicted heating rates may be utilized to improve upon models of particle transport and acceleration in pulsar wind nebulae. We also discuss implications for the Crab Nebula’s γ-ray flares, and point out potential modifications to models of astrophysical transients invoking the spin-down of a millisecond magnetar.

Turbulent Magnetic Relaxation in Pulsar Wind Nebulae

Energy Technology Data Exchange (ETDEWEB)

Zrake, Jonathan [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Arons, Jonathan [Astronomy Department and Theoretical Astrophysics Center, University of California, Berkeley, 601 Campbell Hall, Berkeley, CA 94720 (United States)

2017-09-20

We present a model for magnetic energy dissipation in a pulsar wind nebula. A better understanding of this process is required to assess the likelihood that certain astrophysical transients may be powered by the spin-down of a “millisecond magnetar.” Examples include superluminous supernovae, gamma-ray bursts, and anticipated electromagnetic counterparts to gravitational wave detections of binary neutron star coalescence. Our model leverages recent progress in the theory of turbulent magnetic relaxation to specify a dissipative closure of the stationary magnetohydrodynamic (MHD) wind equations, yielding predictions of the magnetic energy dissipation rate throughout the nebula. Synchrotron losses are self-consistently treated. To demonstrate the model’s efficacy, we show that it can reproduce many features of the Crab Nebula, including its expansion speed, radiative efficiency, peak photon energy, and mean magnetic field strength. Unlike ideal MHD models of the Crab (which lead to the so-called σ -problem), our model accounts for the transition from ultra to weakly magnetized plasma flow and for the associated heating of relativistic electrons. We discuss how the predicted heating rates may be utilized to improve upon models of particle transport and acceleration in pulsar wind nebulae. We also discuss implications for the Crab Nebula’s γ -ray flares, and point out potential modifications to models of astrophysical transients invoking the spin-down of a millisecond magnetar.

Magnetically-coupled microcalorimeter arrays for x-ray astrophysics with sub-eV spectral resolution and large format capability Project

Data.gov (United States)

National Aeronautics and Space Administration — "We propose to develop a revolutionary x-ray camera for astrophysical imaging spectroscopy. High-resolution x-ray spectroscopy is a powerful tool for studying the...

Los Alamos Meson Physics Facility high-resolution-spectrometer dipole magnets: a summary report

International Nuclear Information System (INIS)

Kozlowski, T.; Madland, D.G.; Rolfe, R.; Smith, W.E.; Spencer, J.E.; Tanaka, N.; Thiessen, H.A.; Varghese, P.; Wilkerson, L.C.

1982-12-01

This report explains the design, fabrication, measurement, optimization, and installation of two 122 metric ton electromagnets for the High Resolution Proton Spectrometer at the Los Alamos Meson Physics Facility. These two magnets are the principal components of the proton spectrometer, which has an energy resolution of less than or equal to 10 - 4 FWHM. Many technical problems occurred during fabrication, measurement, and optimization, and the majority have been successfully solved. We hope that this report will help others planning similar projects

Trojin horse method for indirect measurement of astrophysic S factor

International Nuclear Information System (INIS)

Fu Yuanyong; Zhou Shuhua; Li Chengbo; Wen Qungang

2014-01-01

The nuclear reaction rates in the astrophysical environment are indispensable input parameters in different astrophysics theories, and play important roles in understanding the astrophysical nuclear synthesis and the evolution of the universe. However, at the astrophysical temperature, the nuclear reactions proceed at very low energies. Due to the Coulomb barrier the reaction cross sections are very small, so that the direct measurement is almost impossible. The Trojin horse theory provides a useful method to measure indirectly the low energy two body cross sections by measuring the suitable three body reactions. Some approximations are applied in the theory to get convenient formula. This paper introduces the Trojin horse theory and its application in astrophysics nuclear reactions. (authors)

Astrophysics today

International Nuclear Information System (INIS)

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

Three-Dimensional View of Transient Horizontal Magnetic Fields in the Photosphere

Czech Academy of Sciences Publication Activity Database

Ishikawa, R.; Tsuneta, S.; Jurčák, Jan

2010-01-01

Roč. 713, č. 2 (2010), s. 1310-1321 ISSN 0004-637X R&D Projects: GA AV ČR IAA300030808 Institutional research plan: CEZ:AV0Z10030501 Keywords : magnetic fields * Sun * photosphere * granulation * surface magnetism Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 7.436, year: 2010

Galactic and intergalactic magnetic fields

CERN Document Server

Klein, Ulrich

2014-01-01

This course-tested textbook conveys the fundamentals of magnetic fields and relativistic plasma in diffuse cosmic media, with a primary focus on phenomena that have been observed at different wavelengths. Theoretical concepts are addressed wherever necessary, with derivations presented in sufficient detail to be generally accessible.In the first few chapters the authors present an introduction to various astrophysical phenomena related to cosmic magnetism, with scales ranging from molecular clouds in star-forming regions and supernova remnants in the Milky Way, to clusters of galaxies. Later c

Cryogenic techniques for large superconducting magnets in space

International Nuclear Information System (INIS)

Green, M.A.

1988-12-01

A large superconducting magnet is proposed for use in a particle astrophysics experiment, ASTROMAG, which is to be mounted on the United States Space Station. This experiment will have a two-coil superconducting magnet with coils which are 1.3 to 1.7 meters in diameter. The two-coil magnet will have zero net magnetic dipole moment. The field 15 meters from the magnet will approach earth's field in low earth orbit. The issue of high Tc superconductor will be discussed in the paper. The reasons for using conventional niobium-titanium superconductor cooled with superfluid helium will be presented. Since the purpose of the magnet is to do particle astrophysics, the superconducting coils must be located close to the charged particle detectors. The trade off between the particle physics possible and the cryogenic insulation around the coils is discussed. As a result, the ASTROMAG magnet coils will be operated outside of the superfluid helium storage tank. The fountain effect pumping system which will be used to cool the coil is described in the report. Two methods for extending the operating life of the superfluid helium dewar are discussed. These include: operation with a third shield cooled to 90 K with a sterling cycle cryocooler, and a hybrid cryogenic system where there are three hydrogen-cooled shields and cryostat support heat intercept points. Both of these methods will extend the ASTROMAG cryogenic operating life from 2 years to almost 4 years. 14 refs., 8 figs., 4 tabs

Astrophysics of Red Supergiants

Science.gov (United States)

Levesque, Emily M.

2017-12-01

'Astrophysics of Red Supergiants' is the first book of its kind devoted to our current knowledge of red supergiant stars, a key evolutionary phase that is critical to our larger understanding of massive stars. It provides a comprehensive overview of the fundamental physical properties of red supergiants, their evolution, and their extragalactic and cosmological applications. It serves as a reference for researchers from a broad range of fields (including stellar astrophysics, supernovae, and high-redshift galaxies) who are interested in red supergiants as extreme stages of stellar evolution, dust producers, supernova progenitors, extragalactic metallicity indicators, members of massive binaries and mergers, or simply as compelling objects in their own right. The book is accessible to a range of experience levels, from graduate students up to senior researchers.

Nuclear reactions in astrophysics

International Nuclear Information System (INIS)

Cardenas, M.

1976-01-01

It is revised the nuclear reactions which present an interest in astrophysics regarding the explanation of some problems such as the relative quantity of the elements, the structure and evolution of the stars. The principal object of the study is the determination of the experimental possibilities in the field of astrophysics, of an accelerator Van de Graaff's 700 KeV type. Two hundred nuclear reactions approximately, were found, and nothing or very little has been done in the intervals of energy which are of interest. Since the bombardment energies and the involved sections are low in some cases, there are real possibilities, for the largest number of stars to obtain important statistical data with the above mentioned accelerator, taking some necessary precautions. (author)

High energy astrophysics

International Nuclear Information System (INIS)

Shklorsky, I.S.

1979-01-01

A selected list of articles of accessible recent review articles and conference reports, wherein up-to-date summaries of various topics in the field of high energy astrophysics can be found, is presented. A special report outlines work done in the Soviet Union in this area. (Auth.)

Laboratory Astrophysics Division of The AAS (LAD)

Science.gov (United States)

Salama, Farid; Drake, R. P.; Federman, S. R.; Haxton, W. C.; Savin, D. W.

2012-10-01

The purpose of the Laboratory Astrophysics Division (LAD) is to advance our understanding of the Universe through the promotion of fundamental theoretical and experimental research into the underlying processes that drive the Cosmos. LAD represents all areas of astrophysics and planetary sciences. The first new AAS Division in more than 30 years, the LAD traces its history back to the recommendation from the scientific community via the White Paper from the 2006 NASA-sponsored Laboratory Astrophysics Workshop. This recommendation was endorsed by the Astronomy and Astrophysics Advisory Committee (AAAC), which advises the National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA), and the U.S. Department of Energy (DOE) on selected issues within the fields of astronomy and astrophysics that are of mutual interest and concern to the agencies. In January 2007, at the 209th AAS meeting, the AAS Council set up a Steering Committee to formulate Bylaws for a Working Group on Laboratory Astrophysics (WGLA). The AAS Council formally established the WGLA with a five-year mandate in May 2007, at the 210th AAS meeting. From 2008 through 2012, the WGLA annually sponsored Meetings in-a-Meeting at the AAS Summer Meetings. In May 2011, at the 218th AAS meeting, the AAS Council voted to convert the WGLA, at the end of its mandate, into a Division of the AAS and requested draft Bylaws from the Steering Committee. In January 2012, at the 219th AAS Meeting, the AAS Council formally approved the Bylaws and the creation of the LAD. The inaugural gathering and the first business meeting of the LAD were held at the 220th AAS meeting in Anchorage in June 2012. You can learn more about LAD by visiting its website at http://lad.aas.org/ and by subscribing to its mailing list.

Laboratory Astrophysics Division of the AAS (LAD)

Science.gov (United States)

Salama, Farid; Drake, R. P.; Federman, S. R.; Haxton, W. C.; Savin, D. W.

2012-01-01

The purpose of the Laboratory Astrophysics Division (LAD) is to advance our understanding of the Universe through the promotion of fundamental theoretical and experimental research into the underlying processes that drive the Cosmos. LAD represents all areas of astrophysics and planetary sciences. The first new AAS Division in more than 30 years, the LAD traces its history back to the recommendation from the scientific community via the White Paper from the 2006 NASA-sponsored Laboratory Astrophysics Workshop. This recommendation was endorsed by the Astronomy and Astrophysics Advisory Committee (AAAC), which advises the National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA), and the U.S. Department of Energy (DOE) on selected issues within the fields of astronomy and astrophysics that are of mutual interest and concern to the agencies. In January 2007, at the 209th AAS meeting, the AAS Council set up a Steering Committee to formulate Bylaws for a Working Group on Laboratory Astrophysics (WGLA). The AAS Council formally established the WGLA with a five-year mandate in May 2007, at the 210th AAS meeting. From 2008 through 2012, the WGLA annually sponsored Meetings in-a-Meeting at the AAS Summer Meetings. In May 2011, at the 218th AAS meeting, the AAS Council voted to convert the WGLA, at the end of its mandate, into a Division of the AAS and requested draft Bylaws from the Steering Committee. In January 2012, at the 219th AAS Meeting, the AAS Council formally approved the Bylaws and the creation of the LAD. The inaugural gathering and the first business meeting of the LAD were held at the 220th AAS meeting in Anchorage in June 2012. You can learn more about LAD by visiting its website at http://lad.aas.org/ and by subscribing to its mailing list.

The magnetic universe through vector potential SPMHD simulations

Science.gov (United States)

Stasyszyn, F. A.

2017-10-01

The use of Smoothed Particle Magneto Hydrodynamics (SPMHD) is getting nowadays more and more common in Astrophysics. From galaxy clusters to neutron starts, there are multiple applications already existing in the literature. I will review some of the common methods used and highlight the successful approach of using vector potentials to describe the evolution of the magnetic fields. The latter have some interesting advantages, and their results challenge previous findings, being the magnetic divergence problem naturally vanished. We select a few examples to discuss some areas of interest. First, we show some Galaxy Clusters from the MUSIC project. These cosmological simulations are done with the usual sub-grid recipes, as radiative cooling and star formation, being the first ones obtained with an SPH code in a self consistent way. This demonstrates the robustness of the new method in a variety of astrophysical scenarios.

MPI-AMRVAC 2.0 for Solar and Astrophysical Applications

Science.gov (United States)

Xia, C.; Teunissen, J.; El Mellah, I.; Chané, E.; Keppens, R.

2018-02-01

We report on the development of MPI-AMRVAC version 2.0, which is an open-source framework for parallel, grid-adaptive simulations of hydrodynamic and magnetohydrodynamic (MHD) astrophysical applications. The framework now supports radial grid stretching in combination with adaptive mesh refinement (AMR). The advantages of this combined approach are demonstrated with one-dimensional, two-dimensional, and three-dimensional examples of spherically symmetric Bondi accretion, steady planar Bondi–Hoyle–Lyttleton flows, and wind accretion in supergiant X-ray binaries. Another improvement is support for the generic splitting of any background magnetic field. We present several tests relevant for solar physics applications to demonstrate the advantages of field splitting on accuracy and robustness in extremely low-plasma β environments: a static magnetic flux rope, a magnetic null-point, and magnetic reconnection in a current sheet with either uniform or anomalous resistivity. Our implementation for treating anisotropic thermal conduction in multi-dimensional MHD applications is also described, which generalizes the original slope-limited symmetric scheme from two to three dimensions. We perform ring diffusion tests that demonstrate its accuracy and robustness, and show that it prevents the unphysical thermal flux present in traditional schemes. The improved parallel scaling of the code is demonstrated with three-dimensional AMR simulations of solar coronal rain, which show satisfactory strong scaling up to 2000 cores. Other framework improvements are also reported: the modernization and reorganization into a library, the handling of automatic regression tests, the use of inline/online Doxygen documentation, and a new future-proof data format for input/output.

Terrestrial aurora: astrophysical laboratory for anomalous abundances in stellar systems

Directory of Open Access Journals (Sweden)

I. Roth

2014-02-01

Full Text Available The unique magnetic structure of the terrestrial aurora as a conduit of information between the ionosphere and magnetosphere can be utilized as a laboratory for physical processes at similar magnetic configurations and applied to various evolutionary phases of the solar (stellar system. The most spectacular heliospheric abundance enhancement involves the 3He isotope and selective heavy elements in impulsive solar flares. In situ observations of electromagnetic waves on active aurora are extrapolated to flaring corona in an analysis of solar acceleration processes of 3He, the only element that may resonate strongly with the waves, as well as heavy ions with specific charge-to-mass ratios, which may resonate weaker via their higher gyroharmonics. These results are applied to two observed anomalous astrophysical abundances: (1 enhanced abundance of 3He and possibly 13C in the late stellar evolutionary stages of planetary nebulae; and (2 enhanced abundance of the observed fossil element 26Mg in meteorites as a decay product of radioactive 26Al isotope due to interaction with the flare-energized 3He in the early solar system.

Astrophysical observations: lensing and eclipsing Einstein's theories.

Science.gov (United States)

Bennett, Charles L

2005-02-11

Albert Einstein postulated the equivalence of energy and mass, developed the theory of special relativity, explained the photoelectric effect, and described Brownian motion in five papers, all published in 1905, 100 years ago. With these papers, Einstein provided the framework for understanding modern astrophysical phenomena. Conversely, astrophysical observations provide one of the most effective means for testing Einstein's theories. Here, I review astrophysical advances precipitated by Einstein's insights, including gravitational redshifts, gravitational lensing, gravitational waves, the Lense-Thirring effect, and modern cosmology. A complete understanding of cosmology, from the earliest moments to the ultimate fate of the universe, will require developments in physics beyond Einstein, to a unified theory of gravity and quantum physics.

Nuclear astrophysics away from stability

International Nuclear Information System (INIS)

Mathews, G.J.; Howard, W.M.; Takahashi, K.; Ward, R.A.

1985-08-01

Explosive astrophysical environments invariably lead to the production of nuclei away from stability. An understanding of the dynamics and nucleosynthesis in such environments is inextricably coupled to an understanding of the properties of the synthesized nuclei. In this talk a review is presented of the basic explosive nucleosynthesis mechanisms (s-process, r-process, n-process, p-process, and rp-process). Specific stellar model calculations are discussed and a summary of the pertinent nuclear data is presented. Possible experiments and nuclear-model calculations are suggested that could facilitate a better understanding of the astrophysical scenarios. 39 refs., 4 figs

12th Italian-Korean Symposium on Relativistic Astrophysics

International Nuclear Information System (INIS)

Won Lee, Hyung; Remo Riffini; Vereshchagin

2013-01-01

This series of biannual symposia, since 1987, has been boosting exchange of information and collaborations between Italian and Korean astrophysicists on new and hot issues in the field of Relativistic Astrophysics. These symposia cover relativistic field theories, astrophysics and cosmology, topics such as gamma-ray bursts and compact stars, high energy cosmic rays, dark energy and dark matter, general relativity, black holes, and new physics related to cosmology. The organizers are confident that this symposium could deepen the understanding of not only astrophysics and cosmology but also Eastern and Western cultures.

Modeling of magnetic cloud expansion

Czech Academy of Sciences Publication Activity Database

Vandas, Marek; Romashets, E.; Geranios, A.

2015-01-01

Roč. 583, November (2015), A78/1-A78/10 ISSN 0004-6361 R&D Projects: GA ČR GA205/09/0170; GA ČR(CZ) GA14-19376S Institutional support: RVO:67985815 Keywords : solar wind * magnetic fields * magnetohydrodynamics Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.378, year: 2014

Development of the Holifield Radioactive Ion Beam Facility

International Nuclear Information System (INIS)

Tatum, B.A.

1997-01-01

The Holifield Radioactive Ion Beam Facility (HRIBF) construction project has been completed and the first radioactive ion beam has been successfully accelerated. The project, which began in 1992, has involved numerous facility modifications. The Oak Ridge Isochronous Cyclotron has been converted from an energy booster for heavy ion beams to a light ion accelerator with internal ion source. A target-ion source and mass analysis system have been commissioned as key components of the facility's radioactive ion beam injector to the 25MV tandem electrostatic accelerator. Beam transport lines have been completed, and new diagnostics for very low intensity beams have been developed. Work continues on a unified control system. Development of research quality radioactive beams for the nuclear structure and nuclear astrophysics communities continues. This paper details facility development to date

Topics in Nuclear Astrophysics

International Nuclear Information System (INIS)

Chung, K.C.

1982-01-01

Some topics in nuclear astrophysics are discussed, e.g.: highly evolved stellar cores, stellar evolution (through the temperature analysis of stellar surface), nucleosynthesis and finally the solar neutrino problem. (L.C.) [pt

Highlights of modern astrophysics: Concepts and controversies

International Nuclear Information System (INIS)

Shapiro, S.L.; Teukolsky, V.

1986-01-01

In this book, physicists and astronomers review issues in astrophysics. The book stresses accomplishments of observational and theoretical work, and demonstrates how to reveal information about stars and galaxies by applying the basic principles of physics. It pinpoints conflicting views and findings on important topics and indicates possibilities for future research in the field of modern astrophysics

Creation and transmutation of magnetized nuclei at explosively dense matter

Directory of Open Access Journals (Sweden)

Kondratyev V. N.

2012-12-01

Full Text Available Synthesis of iron group chemical elements is considered for the ultra-magnetized astrophysical plasma in supernovae. Maximum of nucleosynthesis products is shown to shift towards smaller mass numbers approaching titanium due to magnetic modification of nuclear structure. The results are corroborated with an excess of 44Ti revealed from the INTEGRAL mission data.

Dusty plasmas in application to astrophysics

International Nuclear Information System (INIS)

Verheest, F.

1999-01-01

Highly charged and massive dust grains have much smaller characteristic frequencies than electrons and ions and lead to interesting modifications of existing modes and to exciting new possibilities for modes and instabilities at the lower frequency end of the spectrum. Space observations of planets and comets have shown wave-like behaviour which can only be explained by the presence of charged dust grains. Two typical solar system applications are spokes and braids in the rings of Saturn and the influence of charged dust on the pickup process of ions of cometary origin by the solar wind. As dust is ubiquitous in the universe, the Jeans instability in astrophysics is modified by incorporating plasma and charged dust and treating electromagnetic and self-gravitational aspects together. Besides the usual mechanism based upon thermal agitation, other ways of countering gravitational contraction are via excitation of electrostatic dust-acoustic modes or via Alfven-Jeans instabilities for perpendicular magnetosonic waves. The unstable wavelengths tend to be much larger, due to the dominance of plasma and magnetic pressures in inhibiting gravitational collapse. (author)

Cosmological and astrophysical neutrino mass measurements

DEFF Research Database (Denmark)

Abazajian, K.N.; Calabrese, E.; Cooray, A.

2011-01-01

Cosmological and astrophysical measurements provide powerful constraints on neutrino masses complementary to those from accelerators and reactors. Here we provide a guide to these different probes, for each explaining its physical basis, underlying assumptions, current and future reach.......Cosmological and astrophysical measurements provide powerful constraints on neutrino masses complementary to those from accelerators and reactors. Here we provide a guide to these different probes, for each explaining its physical basis, underlying assumptions, current and future reach....

Astrophysical hints of axion-like particles

Science.gov (United States)

Roncadelli, M.; Galanti, G.; Tavecchio, F.; Bonnoli, G.

2015-01-01

After reviewing three astrophysical hints of the existence of axion-like particles (ALPs), we describe in more detail a new similar hint involving flat spectrum radio quasars (FSRQs). Detection of FSRQs above about 20GeV pose a challenge to very-high-energy (VHE) astrophysics, because at those energies the ultraviolet emission from their broad line region should prevent photons produced by the central engine to leave the source. Although a few astrophysical explanations have been put forward, they are totally ad hoc. We show that a natural explanation instead arises within the conventional models of FSRQs provided that photon-ALP oscillations occur inside the source. Our analysis takes the FSRQ PKR 1222+206 as an example, and it looks tantalizing that basically the same choice of the free model parameters adopted in this case is consistent with those that provide the other three hints of the existence of ALPs.

The Astrophysical Multimessenger Observatory Network (AMON)

Science.gov (United States)

Smith. M. W. E.; Fox, D. B.; Cowen, D. F.; Meszaros, P.; Tesic, G.; Fixelle, J.; Bartos, I.; Sommers, P.; Ashtekar, Abhay; Babu, G. Jogesh;

Astrophysical disks Collective and Stochastic Phenomena

CERN Document Server

Fridman, Alexei M; Kovalenko, Ilya G

2006-01-01

The book deals with collective and stochastic processes in astrophysical discs involving theory, observations, and the results of modelling. Among others, it examines the spiral-vortex structure in galactic and accretion disks , stochastic and ordered structures in the developed turbulence. It also describes sources of turbulence in the accretion disks, internal structure of disk in the vicinity of a black hole, numerical modelling of Be envelopes in binaries, gaseous disks in spiral galaxies with shock waves formation, observation of accretion disks in a binary system and mass distribution of luminous matter in disk galaxies. The editors adaptly brought together collective and stochastic phenomena in the modern field of astrophysical discs, their formation, structure, and evolution involving the methodology to deal with, the results of observation and modelling, thereby advancing the study in this important branch of astrophysics and benefiting Professional Researchers, Lecturers, and Graduate Students.

Stellar astrophysics

International Nuclear Information System (INIS)

1987-01-01

A number of studies in the field of steller astrophysics were undertaken by the South African Astronomical Observatory in 1986. These studies included; evolutionary effects on the surface abundances of an early-type supergiant; hydrogen deficient stars; t tauri stars; rotational modulation and flares on RS CVn and BY Dra stars; carbon and heavy element stars, and slow variability and circumstellar shells of red variable stars. 4 figs

GROWTH OF A LOCALIZED SEED MAGNETIC FIELD IN A TURBULENT MEDIUM

International Nuclear Information System (INIS)

Cho, Jungyeon; Yoo, Hyunju

2012-01-01

Turbulence dynamo deals with the amplification of a seed magnetic field in a turbulent medium and has been studied mostly for uniform or spatially homogeneous seed magnetic fields. However, some astrophysical processes (e.g., jets from active galaxies, galactic winds, or ram-pressure stripping in galaxy clusters) can provide localized seed magnetic fields. In this paper, we numerically study amplification of localized seed magnetic fields in a turbulent medium. Throughout the paper, we assume that the driving scale of turbulence is comparable to the size of the system. Our findings are as follows. First, turbulence can amplify a localized seed magnetic field very efficiently. The growth rate of magnetic energy density is as high as that for a uniform seed magnetic field. This result implies that magnetic field ejected from an astrophysical object can be a viable source of a magnetic field in a cluster. Second, the localized seed magnetic field disperses and fills the whole system very fast. If turbulence in a system (e.g., a galaxy cluster or a filament) is driven at large scales, we expect that it takes a few large-eddy turnover times for the magnetic field to fill the whole system. Third, growth and turbulence diffusion of a localized seed magnetic field are also fast in high magnetic Prandtl number turbulence. Fourth, even in decaying turbulence, a localized seed magnetic field can ultimately fill the whole system. Although the dispersal rate of the magnetic field is not fast in purely decaying turbulence, it can be enhanced by an additional forcing.

Inference of magnetic fields in the very quiet Sun

Czech Academy of Sciences Publication Activity Database

Martinez Gonzalez, M. J.; Pastor Yabar, A.; Lagg, A.; Asensio Ramos, A.; Collados Vera, M.; Solanki, S.K.; Balthasar, H.; Berkefeld, T.; Denker, C.; Dörr, H.P.; Feller, A.; Franz, M.; Gonzalez Manrique, S. J.; Hofmann, A.; Kneer, F.; Kuckein, C.; Louis, R.E.; von der Lühe, O.; Nicklas, H.; Orozco Suárez, D.; Rezaei, R.; Schlichenmaier, R.; Schmidt, D.; Schmidt, W.; Sigwarth, M.; Sobotka, Michal; Soltau, D.; Staude, J.; Strassmeier, K.G.; Verma, M.; Waldmann, T.A.; Volkmer, R.

2016-01-01

Roč. 596, December (2016), A5/1-A5/11 ISSN 0004-6361 Institutional support: RVO:67985815 Keywords : Sun * atmosphere * magnetic fields Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.378, year: 2014

Extrasolar Planets Swiss Society for Astrophysics and Astronomy

CERN Document Server

Cassen, Patrick; Quirrenbach, Andreas

2006-01-01

Research on extrasolar planets is one of the most exciting fields of activity in astrophysics. In a decade only, a huge step forward has been made from the early speculations on the existence of planets orbiting "other stars" to the first discoveries and to the characterization of extrasolar planets. This breakthrough is the result of a growing interest of a large community of researchers as well as the development of a wide range of new observational techniques and facilities. Based on their lectures given at the 31st Saas-Fee Advanced Course, Andreas Quirrenbach, Tristan Guillot and Pat Cassen have written up up-to-date comprehensive lecture notes on the "Detection and Characterization of Extrasolar Planets", "Physics of Substellar Objects Interiors, Atmospheres, Evolution" and "Protostellar Disks and Planet Formation". This book will serve graduate students, lecturers and scientists entering the field of extrasolar planets as detailed and comprehensive introduction.

Solar, Stellar and Galactic Connections between Particle Physics and Astrophysics

CERN Document Server

Carraminana, Alberto

2007-01-01

This book collects extended and specialized reviews on topics linking astrophysics and particle physics at a level intermediate between a graduate student and a young researcher. The book includes also three reviews on observational techniques used in forefront astrophysics and short articles on research performed in Latin America. The reviews, updated and written by specialized researchers, describe the state of the art in the related research topics. This book is a valuable complement not only for research but also for lecturers in specialized course of high energy astrophysics, cosmic ray astrophysics and particle physics.

Particle Acceleration, Magnetic Field Generation and Emission from Relativistic Jets

Science.gov (United States)

Nishikawa, K.-I.; Hardee, P.; Hededal, C.; Mizuno, Yosuke; Fishman, G. Jerry; Hartmann, D. H.

2006-01-01

Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., active galactic nuclei (AGNs), gamma-ray bursts (GRBs), supernova remnants, and Galactic microquasar systems usually have power-law emission spectra. Fermi acceleration is the mechanism usually assumed for the acceleration of particles in astrophysical environments. Recent PIC simulations using injected relativistic electron-ion (electro-positron) jets show that particle acceleration occurs within the downstream jet, rather than by the scattering of particles back and forth across the shock as in Fermi acceleration. Shock acceleration' is a ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, other two-streaming instability, and the Weibel instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection behind the jet head. The "jitter" radiation from deflected electrons has different spectral properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants. We will review recent PIC simulations of relativistic jets and try to make a connection with observations.

The High-Energy Astrophysics Learning Center, Version 1. [CD-ROM].

Science.gov (United States)

Whitlock, Laura A.; Allen, Jesse S.; Lochner, James C.

The High-Energy Astrophysics (HEA) Learning Center gives students, teachers, and the general public a window into the world of high-energy astrophysics. The universe is revealed through x-rays and gamma rays where matter exists under extreme conditions. Information is available on astrophysics at a variety of reading levels, and is illustrated…

Statistics and Informatics in Space Astrophysics

Science.gov (United States)

Feigelson, E.

2017-12-01

The interest in statistical and computational methodology has seen rapid growth in space-based astrophysics, parallel to the growth seen in Earth remote sensing. There is widespread agreement that scientific interpretation of the cosmic microwave background, discovery of exoplanets, and classifying multiwavelength surveys is too complex to be accomplished with traditional techniques. NASA operates several well-functioning Science Archive Research Centers providing 0.5 PBy datasets to the research community. These databases are integrated with full-text journal articles in the NASA Astrophysics Data System (200K pageviews/day). Data products use interoperable formats and protocols established by the International Virtual Observatory Alliance. NASA supercomputers also support complex astrophysical models of systems such as accretion disks and planet formation. Academic researcher interest in methodology has significantly grown in areas such as Bayesian inference and machine learning, and statistical research is underway to treat problems such as irregularly spaced time series and astrophysical model uncertainties. Several scholarly societies have created interest groups in astrostatistics and astroinformatics. Improvements are needed on several fronts. Community education in advanced methodology is not sufficiently rapid to meet the research needs. Statistical procedures within NASA science analysis software are sometimes not optimal, and pipeline development may not use modern software engineering techniques. NASA offers few grant opportunities supporting research in astroinformatics and astrostatistics.

Balance in the NASA Astrophysics Program

Science.gov (United States)

Elvis, Martin

2017-08-01

The Decadal studies are usually instructed to come up with a “balanced program” for the coming decade of astrophysics initiatives, both on the ground and in space. The meaning of “balance” is left up to the Decadal panels. One meaning is that there should be a diversity of mission costs in the portfolio. Another that there should be a diversity of science questions addressed. A third is that there should be a diversity of signals (across electromagnetic wavebands, and of non-em carriers). It is timely for the astronomy community to debate the meaning of balance in the NASA astrophysics program as the “Statement of Task” (SoT) that defines the goals and process of the 2020 Astrophysics Decadal review are now being formulated.Here I propose some ways in which the Astro2020 SoT could be made more specific in order to make balance more evident and so avoid the tendency for a single science question, and a single mission to answer that question, to dominate the program. As an example of an alternative ambitious approach, I present a proof-of-principle program of 6, mostly “probe-class” missions, that would fit the nominal funding profile for the 2025-2035 NASA Astrophysics Program, while being more diverse in ambitious science goals and in wavelength coverage.

Spectroscopics database for warm Xenon and Iron in Astrophysics and Laboratory Astrophysics conditions

Science.gov (United States)

Busquet, Michel; Klapisch, Marcel; Bar-Shalom, Avi; Oreg, Josse

2010-11-01

The main contribution to spectral properties of astrophysics mixtures come often from Iron. On the other hand, in the so-called domain of ``Laboratory Astrophysics,'' where astrophysics phenomena are scaled down to the laboratory, Xenon (and Argon) are commonly used gases. At so called ``warm'' temperatures (T=5-50eV), L-shell Iron and M-shell Xenon present a very large number of spectral lines, originating from billions of levels. More often than not, Local Thermodynamical Equilibrium is assumed, leading to noticeable simplification of the computation. Nevertheless, complex and powerful atomic structure codes are required. We take benefit of powerful statistics and numerics, included in our atomic structure codes, STA[1] and HULLAC[2], to generate the required spectra. Recent improvements in both fields (statistics, numerics and convergence control) allow obtaining large databases (ro x T grid of > 200x200 points, and > 10000 frequencies) for temperature down to a few eV. We plan to port these improvements in the NLTE code SCROLL[3]. [1] A.Bar-Shalom, et al, Phys. Rev. A 40, 3183 (1989) [2] M.Busquet,et al, J.Phys. IV France 133, 973-975 (2006); A.Bar-Shalom, M.Klapisch, J.Oreg, J.Oreg, JQSRT 71, 169, (2001) [3] A.Bar-Shalom, et al, Phys. Rev. E 56, R70 (1997)

Physical-chemical processes of astrophysical interest: nitrogen chemistry

International Nuclear Information System (INIS)

Loison, Jean-Christophe; Hickson, Kevin; Hily-Blant, Pierre; Faure, Alexandre; Vuitton, Veronique; Bacmann, A.; Maret, Sebastien; Legal, Romane; Rist, Claire; Roncero, Octavio; Larregaray, Pascal; Hochlaf, Majdi; Senent, M. L.; Capron, Michael; Biennier, Ludovic; Carles, Sophie; Bourgalais, Jeremy; Le Picard, Sebastien; Cordier, Daniel; Guillemin, Jean-Claude; Trolez, Yann; Bertin, M.; Poderoso, H.A.M.; Michaut, X.; Jeseck, P.; Philippe, L.; Fillion, J.H.; Fayolle, E.C.; Linnartz, H.; Romanzin, C.; Oeberg, K.I.; Roueff, Evelyne; Pagani, Laurent; Padovani, Marco; Wakelam, Veronique; Honvault, Beatrice; Zvereva-Loete, Natalia; Ouk, Chanda-Malis; Scribano, Yohann; Hartmann, J.M.; Pineau des Forets, Guillaume; Hernandez, Mario; Lique, Francois; Kalugina, Yulia N.; Stoecklin, T.; Hochlaf, M.; Crespos, C.; Larregaray, P.; Martin-Gondre, L.; Petuya, R.; Quintas Sanchez, E.L.; Zanchet, Alexandre; Rodriguez-Lazcano, Yamilet; Mate, Belen

2013-06-01

This document contains the programme and abstracts of contributions to a workshop on nitrogen chemistry within an astrophysical perspective. These contributions have been presented in sessions: Introduction (opening lecture, experimental approaches to molecular astrophysics, theoretical approaches to astrophysics, observations in molecular astrophysics), Physical-chemical theory of the gas phase (time-dependent approach in elementary activity, statistic approach in elementary activity in the case of the N+H_2 reaction, potential energy surfaces for inelastic and reactive collisions, collision rate for N_2H"+, ortho/para selection rules in the chemistry of nitrogen hydrides, cyanides/iso-cyanides excitation in the ISM, CN excitation, radiative association with N_2H as new interstellar anion, ro-vibratory excitation of HCN) Laboratory astrophysics (measurement of reaction products in the CRESUSOL project, reactivity of the CN- anion, N_2 photo-desorption in ices, CRESU study of nitrogen chemistry, chemistry of nitrogen complex molecules), Observations and chemistry of astrophysical media (the problem of interstellar nitrogen fractioning, abundance of N_2 in proto-stellar cores, HNC in Titan atmosphere and nitrogen-related mechanisms in hot Jupiters, HCN and HNC in dark clouds or how theoretical modelling helps in interpreting observations, nitrogen chemistry in cold clouds, deuteration of nitrogen hydrides, nitrogen in interstellar ices, biochemical molecules on Titan, coupling between excitation and chemistry, radiative transfer of nitrogen hydrides, ortho/para chemistry of nitrogen hydrides), Physical-chemical theory of gas-grain interactions (nitrogen reactivity on surfaces, IR spectra of ices of NH_3 and NH_3/N_2 mixtures)

Turbulence, Magnetic Reconnection in Turbulent Fluids and Energetic Particle Acceleration

Science.gov (United States)

Lazarian, A.; Vlahos, L.; Kowal, G.; Yan, H.; Beresnyak, A.; de Gouveia Dal Pino, E. M.

2012-11-01

Turbulence is ubiquitous in astrophysics. It radically changes many astrophysical phenomena, in particular, the propagation and acceleration of cosmic rays. We present the modern understanding of compressible magnetohydrodynamic (MHD) turbulence, in particular its decomposition into Alfvén, slow and fast modes, discuss the density structure of turbulent subsonic and supersonic media, as well as other relevant regimes of astrophysical turbulence. All this information is essential for understanding the energetic particle acceleration that we discuss further in the review. For instance, we show how fast and slow modes accelerate energetic particles through the second order Fermi acceleration, while density fluctuations generate magnetic fields in pre-shock regions enabling the first order Fermi acceleration of high energy cosmic rays. Very importantly, however, the first order Fermi cosmic ray acceleration is also possible in sites of magnetic reconnection. In the presence of turbulence this reconnection gets fast and we present numerical evidence supporting the predictions of the Lazarian and Vishniac (Astrophys. J. 517:700-718, 1999) model of fast reconnection. The efficiency of this process suggests that magnetic reconnection can release substantial amounts of energy in short periods of time. As the particle tracing numerical simulations show that the particles can be efficiently accelerated during the reconnection, we argue that the process of magnetic reconnection may be much more important for particle acceleration than it is currently accepted. In particular, we discuss the acceleration arising from reconnection as a possible origin of the anomalous cosmic rays measured by Voyagers as well as the origin cosmic ray excess in the direction of Heliotail.

ISOL science at the Holifield Radioactive Ion Beam Facility

Energy Technology Data Exchange (ETDEWEB)

Beene, James R [ORNL; Bardayan, Daniel W [ORNL; Galindo-Uribarri, Alfredo {nmn} [ORNL; Gross, Carl J [ORNL; Jones, K. L. [University of Tennessee, Knoxville (UTK); Liang, J Felix [ORNL; Nazarewicz, Witold [ORNL; Stracener, Daniel W [ORNL; Tatum, B Alan [ORNL; Varner Jr, Robert L [ORNL

2011-01-01

The Holi eld Radioactive Ion Beam Facility, located in Oak Ridge, Tennessee, is operated as a National User Facility for the U.S. Department of Energy, producing high quality ISOL beams of short-lived, radioactive nuclei for studies of exotic nuclei, astrophysics research, and various societal applications. The primary driver, the Oak Ridge Isochronous Cyclotron, produces rare isotopes by bombarding highly refractory targets with light ions. The radioactive isotopes are ionized, formed into a beam, mass selected, injected into the 25-MV Tandem, accelerated, and used in experiments. This article reviews HRIBF and its science.

Holifield Radioactive Ion Beam Facility Development and Status

CERN Document Server

Tatum, Alan

2005-01-01

The Holifield Radioactive Ion Beam Facility (HRIBF) is a national user facility dedicated to nuclear structure, reactions, and nuclear astrophysics research with radioactive ion beams (RIBs) using the isotope separator on-line (ISOL) technique. An integrated strategic plan for physics, experimental systems, and RIB production facilities have been developed and implementation of the plan is under way. Specific research objectives are defined for studying the nature of nucleonic matter, the origin of elements, solar physics, and synthesis of heavy elements. Experimental systems upgrade plans include new detector arrays and beam lines, and expansion and upgrade of existing devices. A multifaceted facility expansion plan includes a $4.75M High Power Target Laboratory (HPTL), presently under construction, to provide a facility for testing new target materials, target geometries, ion sources, and beam preparation techniques. Additional planned upgrades include a second RIB production system (IRIS2), an external axi...

Rounding Up the Astrophysical Weeds

Science.gov (United States)

McMillan, James P.

2016-09-01

New instruments used for astronomy such as ALMA, Herschel, and SOFIA have greatly increased the quality of available astrophysical data. These improved data contain spectral lines and features which are not accounted for in the quantum mechanical (QM) catalogs. A class of molecules has been identified as being particularly problematic, the so-called "weeds". These molecules have numerous transitions, of non-trivial intensity, which are difficult to model due to highly perturbed low lying vibrational states. The inability to properly describe the complete contribution of these weeds to the astrophysical data has led directly to the misidentification of other target molecules. Ohio State's Microwave Laboratory has developed an alternative approach to this problem. Rather than relying on complex QM calculations, we have developed a temperature dependent approach to laboratory based terahertz spectroscopy. We have developed a set of simple packages, in addition to traditional line list catalogs, that enable astronomers to successfully remove the weed signals from their data. This dissertation will detail my laboratory work and analysis of three keys weeds: methanol, methyl formate and methyl cyanide. Also, discussed will be the analytical technique I used to apply these laboratory results to astrophysical data.

Facile and rapid synthesis of nickel nanowires and their magnetic properties

International Nuclear Information System (INIS)

Tang Shaochun; Zheng Zhou; Vongehr, Sascha; Meng Xiangkang

2011-01-01

The present work reports a facile and rapid microwave-assisted route to synthesize nickel nanowires with a necklace-like morphology and lengths up to several hundreds of microns. The wires consist of many crystallites with an average size of 25 ± 2 nm. The synthesis does not use templates or magnetic fields and needs only 6 min, which is more than 480 times faster than that needed for Ni wires prepared at 180 °C using conventional heating. Nickel nanostructures with various morphologies including spheres, chains and irregular particles with porous surfaces can also be obtained by adjusting reaction parameters. Polyvinylpyrrolidone (PVP) is found to be vital for the formation of the one-dimensional chains and a high concentration of PVP smoothes their surfaces to result in the appearance of wires. This rapid one-pot procedure combines the formation of nanoparticles, their oriented assembly into chains, and the subsequent shaping of wires. The Ni nanostructures show variable magnetic properties. The prepared nickel wires have a high mechanical stability and exhibit much higher coercivity than bulk nickel, Ni nanoparticles and their aggregations, which promise potential applications in micromechanical sensors, memory devices and other fields.

Advanced LIGO: sources and astrophysics

International Nuclear Information System (INIS)

Creighton, Teviet

2003-01-01

Second-generation detectors in LIGO will take us from the discovery phase of gravitational-wave observations to the phase of true gravitational-wave astrophysics, with hundreds or thousands of potential sources. This paper surveys the most likely and interesting potential sources for Advanced LIGO, and the astrophysical processes that each one will probe. I conclude that binary inspiral signals are expected, while continuous signals from pulsars are plausible but not guaranteed. Other sources, such as core-collapse bursts, cosmic strings and primordial stochastic backgrounds, are speculative sources for Advanced LIGO, but also potentially the most interesting, since they push the limits of our theoretical knowledge

Nuclear astrophysics lessons from INTEGRAL.

Science.gov (United States)

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.

Astrophysical Russian Dolls

OpenAIRE

Loeb, Abraham; Imara, Nia

2017-01-01

Are there examples of "astrophysical Russian dolls," and what could we learn from their similarities? In this article, we list a few such examples, including disks, filaments, and clusters. We suggest that forging connections across disciplinary borders enhances our perception of beauty, while simultaneously leading to a more comprehensive understanding of the Universe.

Nuclear Data and Reaction Rate Databases in Nuclear Astrophysics

Science.gov (United States)

Lippuner, Jonas

2018-06-01

Astrophysical simulations and models require a large variety of micro-physics data, such as equation of state tables, atomic opacities, properties of nuclei, and nuclear reaction rates. Some of the required data is experimentally accessible, but the extreme conditions present in many astrophysical scenarios cannot be reproduced in the laboratory and thus theoretical models are needed to supplement the empirical data. Collecting data from various sources and making them available as a database in a unified format is a formidable task. I will provide an overview of the data requirements in astrophysics with an emphasis on nuclear astrophysics. I will then discuss some of the existing databases, the science they enable, and their limitations. Finally, I will offer some thoughts on how to design a useful database.

Experiments and models of MHD jets and their relevance to astrophysics and solar physics

Science.gov (United States)

Bellan, Paul

2017-10-01

MHD-driven flows exist in both space and lab plasmas because the MHD force-balance equation J × B - ∇ P = 0 can only be satisfied in situations having an unusual degree of symmetry. In the normal situation where such symmetry does not exist, an arbitrary magnetic field B and its associated current J =μ0- 1 ∇ × B provide a magnetic force F = J × B having the character of a torque, i.e., ∇ × F ≠ 0 . Because ∇ × ∇ P = 0 is a mathematical identity, no pressure gradient can balance this torque so a flow is driven. Additionally, since ideal MHD has magnetic flux frozen into the frame of the moving plasma, the flow convects frozen-in magnetic flux. If the flow slows and piles up, both the plasma and the frozen-in magnetic flux will be compressed. This magnetic flux compression amplifies both the frozen-in B and its associated J . Slowing down thus increases certain components of F , in particular the pinch force associated with the electric current in the flow direction. This increased pinching causes the flow to self-collimate if the leading edge of the flow moves slower than the trailing part so there is compression in the flow frame. The result is that the flow self-collimates and forms a narrow jet. Self-collimating jets with embedded electric current and helical magnetic field are analogous to the straight cylindrical approximation of a tokamak, but now with the length of the cylinder continuously increasing and the radius depending on axial position. The flows are directed from axial regions having small radius to axial regions having large radius. The flow velocity is proportional to the axial electric current and is a significant fraction of the Alfvén velocity. Examples of these MHD-driven flows are astrophysical jets, certain solar coronal situations, and the initial plasma produced by the coaxial magnetized plasma guns used for making spheromaks. The above picture has been developed from laboratory measurements, analytic models, and numerical

75 FR 13597 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

Science.gov (United States)

2010-03-22

... Committee; Astrophysics Subcommittee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... of the Astrophysics Subcommittee of the NASA Advisory Council (NAC). This Subcommittee reports to the...: The agenda for the meeting includes the following topics: --Astrophysics Division Update. --Kepler...

76 FR 5405 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

Science.gov (United States)

2011-01-31

... Committee; Astrophysics Subcommittee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... amended, the National Aeronautics and Space Administration (NASA) announces a meeting of the Astrophysics... contacting Marian Norris. The agenda for the meeting includes the following topics: --Astrophysics Division...

77 FR 4370 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

Science.gov (United States)

2012-01-27

... Committee; Astrophysics Subcommittee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... amended, the National Aeronautics and Space Administration (NASA) announces a meeting of the Astrophysics... topics: --Astrophysics Division Update --Update on Balloons Return to Flight Changes --James Webb Space...

77 FR 38090 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

Science.gov (United States)

2012-06-26

... Committee; Astrophysics Subcommittee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... amended, the National Aeronautics and Space Administration (NASA) announces a meeting of the Astrophysics...: --Astrophysics Division Update --James Webb Space Telescope Update --Wide-Field Infrared Survey Telescope Report...

Building better optical model potentials for nuclear astrophysics applications

International Nuclear Information System (INIS)

Bauge, Eric; Dupuis, Marc

2004-01-01

In nuclear astrophysics, optical model potentials play an important role, both in the nucleosynthesis models, and in the interpretation of astrophysics related nuclear physics measurements. The challenge of nuclear astrophysics resides in the fact that it involves many nuclei far from the stability line, implying than very few (if any) experimental results are available for these nuclei. The answer to this challenge is a heavy reliance on microscopic optical models with solid microscopic physics foundations that can predict the relevant physical quantities with good accuracy. This use of microscopic information limits the likelihood of the model failing spectacularly (except if some essential physics was omitted in the modeling) when extrapolating away from the stability line, in opposition to phenomenological models which are only suited for interpolation between measured data points and not for extrapolating towards unexplored areas of the chart of the nuclides.We will show how these microscopic optical models are built, how they link to our present knowledge of nuclear structure, and how they affect predictions of nuclear astrophysics models and the interpretation of some key nuclear physics measurements for astrophysics

76 FR 7882 - Astronomy and Astrophysics Advisory Committee; Notice of Meeting

Science.gov (United States)

2011-02-11

... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee; Notice of Meeting In... Foundation announces the following meeting: Name: Astronomy and Astrophysics Advisory Committee ( 13883... of astronomy and astrophysics that are of mutual interest and concern to the agencies. Agenda: To...

78 FR 2450 - Astronomy and Astrophysics Advisory Committee; Notice of Meeting

Science.gov (United States)

2013-01-11

... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee; Notice of Meeting In... Foundation announces the following meeting: Name: Astronomy and Astrophysics Advisory Committee ( 13883...) on issues within the field of astronomy and astrophysics that are of mutual interest and concern to...

77 FR 8288 - Astronomy and Astrophysics Advisory Committee; Notice of Meeting

Science.gov (United States)

2012-02-14

... NATIONAL SCIENCE FOUNDATION Astronomy and Astrophysics Advisory Committee; Notice of Meeting In... Foundation announces the following meeting: Name: Astronomy and Astrophysics Advisory Committee ( 13883... of astronomy and astrophysics that are of mutual interest and concern to the agencies. Agenda: To...

78 FR 20356 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

Science.gov (United States)

2013-04-04

... Committee; Astrophysics Subcommittee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... amended, the National Aeronautics and Space Administration (NASA) announces a meeting of the Astrophysics... password [email protected] The agenda for the meeting includes the following topics: --Astrophysics Division...

Dynamics of a toroidal magnetic cloud in the solar wind

Czech Academy of Sciences Publication Activity Database

Romashets, E. P.; Vandas, Marek

2001-01-01

Roč. 106, A6 (2001), s. 10 615 - 10 624 ISSN 0148-0227 R&D Projects: GA AV ČR IAA3003003; GA AV ČR IBS1003006 Institutional research plan: CEZ:AV0Z1003909 Keywords : magnetic cloud s * coronal masss ejections * interplanetry magnetic field Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.609, year: 2001

Performance and Facility Background Pressure Characterization Tests of NASAs 12.5-kW Hall Effect Rocket with Magnetic Shielding Thruster

Science.gov (United States)

Kamhawi, Hani; Huang, Wensheng; Haag, Thomas; Shastry, Rohit; Thomas, Robert; Yim, John; Herman, Daniel; Williams, George; Myers, James; Hofer, Richard;

Astrophysical relevance of γ transition energies

International Nuclear Information System (INIS)

Rauscher, Thomas

2008-01-01

The relevant γ energy range is explicitly identified where additional γ strength must be located to have an impact on astrophysically relevant reactions. It is shown that folding the energy dependences of the transmission coefficients and the level density leads to maximal contributions for γ energies of 2≤E γ ≤4 unless quantum selection rules allow isolated states to contribute. Under this condition, electric dipole transitions dominate. These findings allow us to more accurately judge the relevance of modifications of the γ strength for astrophysics

Astronomy and astrophysics in the new millennium: Panel reports

National Research Council Canada - National Science Library

Astronomy and Astrophysics Survey Committee, Board on Physics and Astronomy, Space Studies Board, National Research Council

2001-01-01

In preparing the report, Astronomy and Astrophysics in the New Millenium , the AASC made use of a series of panel reports that address various aspects of ground- and space-based astronomy and astrophysic...

An infrared diagnostic for magnetism in hot stars

Science.gov (United States)

Oksala, M. E.; Grunhut, J. H.; Kraus, M.; Borges Fernandes, M.; Neiner, C.; Condori, C. A. H.; Campagnolo, J. C. N.; Souza, T. B.

2015-06-01

Magnetospheric observational proxies are used for indirect detection of magnetic fields in hot stars in the X-ray, UV, optical, and radio wavelength ranges. To determine the viability of infrared (IR) hydrogen recombination lines as a magnetic diagnostic for these stars, we have obtained low-resolution (R~ 1200), near-IR spectra of the known magnetic B2V stars HR 5907 and HR 7355, taken with the Ohio State Infrared Imager/Spectrometer (OSIRIS) attached to the 4.1 m Southern Astrophysical Research (SOAR) Telescope. Both stars show definite variable emission features in IR hydrogen lines of the Brackett series, with similar properties as those found in optical spectra, including the derived location of the detected magnetospheric plasma. These features also have the added advantage of a lowered contribution of stellar flux at these wavelengths, making circumstellar material more easily detectable. IR diagnostics will be useful for the future study of magnetic hot stars, to detect and analyze lower-density environments, and to detect magnetic candidates in areas obscured from UV and optical observations, increasing the number of known magnetic stars to determine basic formation properties and investigate the origin of their magnetic fields. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the US National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

Intermittent Astrophysical Radiation Sources and Terrestrial Life

Science.gov (United States)

Melott, Adrian

2013-04-01

Terrestrial life is exposed to a variety of radiation sources. Astrophysical observations suggest that strong excursions in cosmic ray flux and spectral hardness are expected. Gamma-ray bursts and supernovae are expected to irradiate the atmosphere with keV to GeV photons at irregular intervals. Supernovae will produce large cosmic ray excursions, with time development varying with distance from the event. Large fluxes of keV to MeV protons from the Sun pose a strong threat to electromagnetic technology. The terrestrial record shows cosmogenic isotope excursions which are consistent with major solar proton events, and there are observations of G-stars suggesting that the rate of such events may be much higher than previously assumed. In addition there are unknown and unexplained astronomical transients which may indicate new classes of events. The Sun, supernovae, and gamma-ray bursts are all capable of producing lethal fluences, and some are expected on intervals of 10^8 years or so. The history of life on Earth is filled with mass extinctions at a variety of levels of intensity. Most are not understood. Astrophysical radiation may play a role, particularly from large increases in muon irradiation on the ground, and changes in atmospheric chemistry which deplete ozone, admitting increased solar UVB. UVB is strongly absorbed by DNA and proteins, and breaks the chemical bonds---it is a known carcinogen. High muon fluxes will also be damaging to such molecules, but experiments are needed to pin down the rate. Solar proton events which are not directly dangerous for the biota may nevertheless pose a major threat to modern electromagnetic technology through direct impact on satellites and magnetic induction of large currents in power grids, disabling transformers. We will look at the kind of events that are expected on timescales from human to geological, and their likely consequences.

76 FR 14106 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

Science.gov (United States)

2011-03-15

... Committee; Astrophysics Subcommittee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... amended, the National Aeronautics and Space Administration (NASA) announces a meeting of the Astrophysics...: --Astrophysics Division Update. It is imperative that the meeting be held on these dates to accommodate the...

Excitation of compound states in the subsystems as indirect tool in nuclear astrophysics

Directory of Open Access Journals (Sweden)

Tribble R.E.

2010-03-01

Full Text Available 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 astrophysically relevant energies. Here the theory and application of the THM for the resonant reactions is addressed.

3rd Session of the Sant Cugat Forum on Astrophysics

CERN Document Server

Gravitational wave astrophysics

2015-01-01

This book offers review chapters written by invited speakers of the 3rd Session of the Sant Cugat Forum on Astrophysics — Gravitational Waves Astrophysics. All chapters have been peer reviewed. The book goes beyond normal conference proceedings in that it provides a wide panorama of the astrophysics of gravitational waves and serves as a reference work for researchers in the field.

Spanish Minister of Science and Technology visits the LHC magnet test facility

CERN Multimedia

Patrice Loïez

2002-01-01

H.E. Mr Josep Piqué i Camps, Minister for Science and Technology, Spain, toured the test facility for LHC magnets in building SM18 during his visit to CERN in November. Photos 01, 02: (left to right) M. Cerrada, CERN; Francisco Giménez-Reyna, Spanish delegate to the CERN Finance Committee; G. Léon; Juan Antonio Rubio, leader of the Education and Technology Transfer division at CERN; M. Aguilar-Benitez, Spanish delegate to CERN Council; (behind) H.E. Mr Joaquin Pérez-Villanueva y Tovar, Ambassador and Permanent Representative of Spain to the United Nations in Geneva; the Minister; Manuel Delfino, leader of the Information Technology division at CERN; bodyguard; Matteo Cavalli-Sforza, ATLAS national contact physicist for Spain; Felix Rodriguez Mateos, CERN; G. Babé. Visible in the left background is one of the test benches where magnets are prepared for installation in String 2: the full-scale model of an LHC cell of the regular part of the arc. The extremity of String 2, which measures 120 m and runs the ...

Astronomical optical interferometry, II: Astrophysical results

Directory of Open Access Journals (Sweden)

Jankov S.

2011-01-01

Full Text Available Optical interferometry is entering a new age with several ground- based long-baseline observatories now making observations of unprecedented spatial resolution. Based on a great leap forward in the quality and quantity of interferometric data, the astrophysical applications are not limited anymore to classical subjects, such as determination of fundamental properties of stars; namely, their effective temperatures, radii, luminosities and masses, but the present rapid development in this field allowed to move to a situation where optical interferometry is a general tool in studies of many astrophysical phenomena. Particularly, the advent of long-baseline interferometers making use of very large pupils has opened the way to faint objects science and first results on extragalactic objects have made it a reality. The first decade of XXI century is also remarkable for aperture synthesis in the visual and near-infrared wavelength regimes, which provided image reconstructions from stellar surfaces to Active Galactic Nuclei. Here I review the numerous astrophysical results obtained up to date, except for binary and multiple stars milliarcsecond astrometry, which should be a subject of an independent detailed review, taking into account its importance and expected results at microarcsecond precision level. To the results obtained with currently available interferometers, I associate the adopted instrumental settings in order to provide a guide for potential users concerning the appropriate instruments which can be used to obtain the desired astrophysical information.

Shape: A 3D Modeling Tool for Astrophysics.

Science.gov (United States)

Steffen, Wolfgang; Koning, Nicholas; Wenger, Stephan; Morisset, Christophe; Magnor, Marcus

2011-04-01

We present a flexible interactive 3D morpho-kinematical modeling application for astrophysics. Compared to other systems, our application reduces the restrictions on the physical assumptions, data type, and amount that is required for a reconstruction of an object's morphology. It is one of the first publicly available tools to apply interactive graphics to astrophysical modeling. The tool allows astrophysicists to provide a priori knowledge about the object by interactively defining 3D structural elements. By direct comparison of model prediction with observational data, model parameters can then be automatically optimized to fit the observation. The tool has already been successfully used in a number of astrophysical research projects.

Experiments and models of MHD jets and their relevance to astrophysics and solar physics

Science.gov (United States)

Bellan, Paul M.

2018-05-01

Magnetohydrodynamic (MHD)-driven jets involve poloidal and toroidal magnetic fields, finite pressure gradients, and unbalanced forces. The mechanism driving these jets is first discussed qualitatively by decomposing the magnetic force into a curvature and a gradient component. The mechanism is then considered quantitatively by consideration of all terms in the three components of the MHD equation of motion and in addition, the implications of Ampere's law, Faraday's law, the ideal Ohm's law, and the equation of continuity. The analysis shows that jets are self-collimating with the tip of the jet moving more slowly than the main column of the jet so there is a continuous stagnation near the tip in the jet frame. Experiments supporting these conclusions are discussed and it is shown how this mechanism relates to jets in astrophysical and solar corona contexts.

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Since 1977, papers in Astrophysics and Astronomy appeared as a special section in Pramana. ... The journal publishes original research papers on all aspects of astrophysics and ... Articles are also visible in Web of Science immediately.

Nuclear astrophysics: a new era

Energy Technology Data Exchange (ETDEWEB)

Wiescher, Michael; Aprahamian, Ani [Department of Physics, University of Notre Dame (United States); Regan, Paddy [Department of Physics, University of Surrey (United Kingdom)

2002-02-01

The latest generation of radioactive-ion-beam facilities promises to shed light on the complex nuclear processes that control the evolution of stars and stellar explosions. The most fundamental question in nature is where do we come from, or, put another way, what are we made of? The late Carl Sagan poetically said that we are all made of stardust, but the origin of the elements has fascinated scientists for thousands of years. Many of the greatest medieval and renaissance scientists dabbled in alchemy, trying to create the elements that make up the cosmos, but we had to wait until the early 20th century to recognize that elements are really defined by the number of protons in the nucleus. According to our current understanding, after the big bang most of the normal or baryonic material in the universe consisted of the lightest two elements, hydrogen and helium, with only trace amounts of lithium and beryllium. All the heavier elements that occur naturally on Earth were created from this original material via a series of nuclear reactions in the cores of stars or in stellar explosions. Over the last decade, ground-based telescopes and satellite-based Observatories have opened new windows on the stars across the electromagnetic spectrum, from infrared to gamma radiation. New technology now makes it possible to observe and analyse short-lived stellar explosions. Indeed, the distribution of elements in 'planetary nebula' and in the ejecta of supernovae and novae give a direct glimpse of individual nucleosynthesis processes. In the February issue of Physics World, Michael Wiescher, Paddy Regan and Ani Aprahamian describe how sate-of-the-art facilities are set to plug many of the gaps in our understanding of nuclear astrophysics. (U.K.)

Nuclear astrophysics and nuclei far from stability

International Nuclear Information System (INIS)

Schatz, H.

2003-01-01

Unstable nuclei play a critical role in a number of astrophysical scenarios and are important for our understanding of the origin of the elements. Among the most important scenarios are the r-process (Supernovae), Novae, X-ray bursters, and Superbursters. For these astrophysical events I review the open questions, recent developments in astronomy, and how nuclear physics, in particular experiments with radioactive beams, needs to contribute to find the answers. (orig.)

Technology Development for a Neutrino Astrophysical Observatory

International Nuclear Information System (INIS)

Chaloupka, V.; Cole, T.; Crawford, H.J.; He, Y.D.; Jackson, S.; Kleinfelder, S.; Lai, K.W.; Learned, J.; Ling, J.; Liu, D.; Lowder, D.; Moorhead, M.; Morookian, J.M.; Nygren, D.R.; Price, P.B.; Richards, A.; Shapiro, G.; Shen, B.; Smoot, George F.; Stokstad, R.G.; VanDalen, G.; Wilkes, J.; Wright, F.; Young, K.

1996-01-01

We propose a set of technology developments relevant to the design of an optimized Cerenkov detector for the study of neutrino interactions of astrophysical interest. Emphasis is placed on signal processing innovations that enhance significantly the quality of primary data. These technical advances, combined with field experience from a follow-on test deployment, are intended to provide a basis for the engineering design for a kilometer-scale Neutrino Astrophysical Observatory

Advances in astronomy and astrophysics 9

CERN Document Server

Kopal, Zdenek

1972-01-01

Advances in Astronomy and Astrophysics, Volume 9 covers reviews on the advances in astronomy and astrophysics. The book presents reviews on the Roche model and its applications to close binary systems. The text then describes the part played by lunar eclipses in the evolution of astronomy; the classical theory of lunar eclipses; deviations from geometrical theory; and the methods of photometric observations of eclipses. The problems of other phenomena related in one way or another to lunar eclipses are also considered. The book further tackles the infrared observation on the eclipsed moon, as

Spherical Panoramas for Astrophysical Data Visualization

Science.gov (United States)

Kent, Brian R.

2017-05-01

Data immersion has advantages in astrophysical visualization. Complex multi-dimensional data and phase spaces can be explored in a seamless and interactive viewing environment. Putting the user in the data is a first step toward immersive data analysis. We present a technique for creating 360° spherical panoramas with astrophysical data. The three-dimensional software package Blender and the Google Spatial Media module are used together to immerse users in data exploration. Several examples employing these methods exhibit how the technique works using different types of astronomical data.

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

Energy Technology Data Exchange (ETDEWEB)

Belyaev, V. S., E-mail: belyaev@tsniimash.ru; Zagreev, B. V.; Kedrov, A. Yu.; Lobanov, A. V.; Matafonov, A. P. [Russian Space Agency, Pionerskaya, Central Research Institute for Machine Building (TsNIIMash) (Russian Federation); Bolshakov, V. V.; Savel’ev, A. B.; Mordvintsev, I. M.; Tsymbalov, I. N.; Shulyapov, S. A. [Moscow State University, International Laser Center (Russian Federation); Pikuz, S. A.; Skobelev, I. Yu.; Filippov, E. D.; Faenov, A. Ya. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation); Krainov, V. P. [Moscow Institute of Physics and Technology (State University) (Russian Federation)

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.

Annual Report 2006 for Hydrodynamics and Radiation Hydrodynamics with Astrophysical Applications

Energy Technology Data Exchange (ETDEWEB)

R. Paul Drake

2007-04-05

We report the ongoing work of our group in hydrodynamics and radiation hydrodynamics with astrophysical applications. During the period of the existing grant, we have carried out two types of experiments at the Omega laser. One set of experiments has studied radiatively collapsing shocks, obtaining data using a backlit pinhole with a 100 ps backlighter and beginning to develop the ability to look into the shock tube with optical or x-ray diagnostics. Other experiments have studied the deeply nonlinear development of the Rayleigh-Taylor (RT) instability from complex initial conditions, using dual-axis radiographic data with backlit pinholes and ungated detectors to complete the data set for a Ph.D. student. We lead a team that is developing a proposal for experiments at the National Ignition Facility and are involved in experiments at NIKE and LIL. All these experiments have applications to astrophysics, discussed in the corresponding papers. We assemble the targets for the experiments at Michigan, where we also prepare many of the simple components. We also have several projects underway in our laboratory involving our x-ray source. The above activities, in addition to a variety of data analysis and design projects, provide good experience for graduate and undergraduates students. In the process of doing this research we have built a research group that uses such work to train junior scientists.

Electron-Scale Measurements of Magnetic Reconnection in Space

Science.gov (United States)

Burch, J. L.; Torbert, R. B.; Phan, T. D.; Chen, L.-J.; Moore, T. E.; Ergun, R. E.; Eastwood, J. P.; Gershman, D. J.; Cassak, P. A.; Argall, M. R.;

Toroid magnet test facility

CERN Multimedia

2002-01-01

Because of its exceptional size, it was not feasible to assemble and test the Barrel Toroid - made of eight coils - as an integrated toroid on the surface, prior to its final installation underground in LHC interaction point 1. It was therefore decided to test these eight coils individually in a dedicated test facility.

The Astrophysics Science Division Annual Report 2008

Science.gov (United States)

Oegerle, William; Reddy, Francis; Tyler, Pat

2009-01-01

The Astrophysics Science Division (ASD) at Goddard Space Flight Center (GSFC) is one of the largest and most diverse astrophysical organizations in the world, with activities spanning a broad range of topics in theory, observation, and mission and technology development. Scientific research is carried out over the entire electromagnetic spectrum from gamma rays to radio wavelengths as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for three orbiting astrophysics missions WMAP, RXTE, and Swift, as well as the Science Support Center for the Fermi Gamma-ray Space Telescope. A number of key technologies for future missions are also under development in the Division, including X-ray mirrors, and new detectors operating at gamma-ray, X-ray, ultraviolet, infrared, and radio wavelengths. This report includes the Division's activities during 2008.

Internal Magnetic Field, Temperature and Density Measurements on Magnetized HED plasmas using Pulsed Polarimetry

International Nuclear Information System (INIS)

Smith, Roger J.

2016-01-01

The goals were to collaborate with the MSX project and make the MSX platform reliable with a performance where pulsed polarimetry would be capable of adding a useful measurement and then to achieve a first measurement using pulsed polarimetry. The MSX platform (outside of laser blow off plasmas adjacent to magnetic fields which are low beta) is the only device that can generate high-beta magnetized collisionless supercritical shocks, and with a large spatial size of ~10 cm. Creating shocks at high Mach numbers and investigating the dynamics of the shocks was the main goal of the project. The MSX shocks scale to astrophysical magnetized shocks and potentially throw light on the generation of highly energetic particles via a mechanism like the Fermi process.

Internal Magnetic Field, Temperature and Density Measurements on Magnetized HED plasmas using Pulsed Polarimetry

Energy Technology Data Exchange (ETDEWEB)

Smith, Roger J. [Univ. of Washington, Seattle, WA (United States)

2016-10-20

The goals were to collaborate with the MSX project and make the MSX platform reliable with a performance where pulsed polarimetry would be capable of adding a useful measurement and then to achieve a first measurement using pulsed polarimetry. The MSX platform (outside of laser blow off plasmas adjacent to magnetic fields which are low beta) is the only device that can generate high-beta magnetized collisionless supercritical shocks, and with a large spatial size of ~10 cm. Creating shocks at high Mach numbers and investigating the dynamics of the shocks was the main goal of the project. The MSX shocks scale to astrophysical magnetized shocks and potentially throw light on the generation of highly energetic particles via a mechanism like the Fermi process.

Elliptical magnetic clouds and geomagnetic storms

Czech Academy of Sciences Publication Activity Database

Antoniadou, I.; Geranios, A.; Vandas, Marek; Panagopoulou, M.; Zacharopoulou, O.; Malandraki, O.

2008-01-01