Relativistic corrections to η{sub c}-pair production in high energy proton–proton collisions

Energy Technology Data Exchange (ETDEWEB)

Martynenko, A.P., E-mail: a.p.martynenko@samsu.ru [Samara State University, Pavlov Street 1, 443011, Samara (Russian Federation); Samara State Aerospace University named after S.P. Korolyov, Moskovskoye Shosse 34, 443086, Samara (Russian Federation); Trunin, A.M., E-mail: amtrnn@gmail.com [Samara State Aerospace University named after S.P. Korolyov, Moskovskoye Shosse 34, 443086, Samara (Russian Federation)

2013-06-10

On the basis of perturbative QCD and the relativistic quark model we calculate relativistic corrections to the double η{sub c} meson production in proton–proton interactions at LHC energies. Relativistic terms in the production amplitude connected with the relative motion of heavy quarks and the transformation law of the bound state wave functions to the reference frame of moving charmonia are taken into account. For the gluon and quark propagators entering the amplitude we use a truncated expansion in relative quark momenta up to the second order. Relativistic corrections to the quark bound state wave functions are considered by means of the Breit-like potential. It turns out that the examined effects decrease total non-relativistic cross section more than two times and on 20 percents in the rapidity region of LHCb detector.

Probability model for worst case solar proton event fluences

International Nuclear Information System (INIS)

Xapsos, M.A.; Summers, G.P.; Barth, J.L.; Stassinopoulos, E.G.; Burke, E.A.

1999-01-01

The effects that solar proton events have on microelectronics and solar arrays are important considerations for spacecraft in geostationary orbits, polar orbits and on interplanetary missions. A predictive model of worst case solar proton event fluences is presented. It allows the expected worst case event fluence to be calculated for a given confidence level and for periods of time corresponding to space missions. The proton energy range is from >1 to >300 MeV, so that the model is useful for a variety of radiation effects applications. For each proton energy threshold, the maximum entropy principle is used to select the initial distribution of solar proton event fluences. This turns out to be a truncated power law, i.e., a power law for smaller event fluences that smoothly approaches zero at a maximum fluence. The strong agreement of the distribution with satellite data for the last three solar cycles indicates this description captures the essential features of a solar proton event fluence distribution. Extreme value theory is then applied to the initial distribution of events to obtain the model of worst case fluences

Biophysical characterization of a relativistic proton beam for image-guided radiosurgery.

Science.gov (United States)

Yu, Zhan; Vanstalle, Marie; La Tessa, Chiara; Jiang, Guo-Liang; Durante, Marco

2012-07-01

We measured the physical and radiobiological characteristics of 1 GeV protons for possible applications in stereotactic radiosurgery (image-guided plateau-proton radiosurgery). A proton beam was accelerated at 1 GeV at the Brookhaven National Laboratory (Upton, NY) and a target in polymethyl methacrylate (PMMA) was used. Clonogenic survival was measured after exposures to 1-10 Gy in three mammalian cell lines. Measurements and simulations demonstrate that the lateral scattering of the beam is very small. The lateral dose profile was measured with or without the 20-cm plastic target, showing no significant differences up to 2 cm from the axis A large number of secondary swift protons are produced in the target and this leads to an increase of approximately 40% in the measured dose on the beam axis at 20 cm depth. The relative biological effectiveness at 10% survival level ranged between 1.0 and 1.2 on the beam axis, and was slightly higher off-axis. The very low lateral scattering of relativistic protons and the possibility of using online proton radiography during the treatment make them attractive for image-guided plateau (non-Bragg peak) stereotactic radiosurgery.

Biophysical characterization of a relativistic proton beam for image-guided radiosurgery

International Nuclear Information System (INIS)

Yu, Z.; Vanstalle, M.; La Tessa, C.; Durante, M.; Jiang Guoliang

2012-01-01

We measured the physical and radiobiological characteristics of 1 GeV protons for possible applications in stereotactic radiosurgery (image-guided plateau-proton radiosurgery). A proton beam was accelerated at 1 GeV at the Brookhaven National Laboratory (Upton, NY) and a target in polymethyl methacrylate (PMMA) was used. Clonogenic survival was measured after exposures to 1-10 Gy in three mammalian cell lines. Measurements and simulations demonstrate that the lateral scattering of the beam is very small. The lateral dose profile was measured with or without the 20-cm plastic target, showing no significant differences up to 2 cm from the axis A large number of secondary swift protons are produced in the target and this leads to an increase of approximately 40% in the measured dose on the beam axis at 20 cm depth. The relative biological effectiveness at 10% survival level ranged between 1.0 and 1.2 on the beam axis, and was slightly higher off-axis. The very low lateral scattering of relativistic protons and the possibility of using online proton radiography during the treatment make them attractive for image-guided plateau (non-Bragg peak) stereotactic radiosurgery. (author)

Proton irradiation effects of amorphous silicon solar cell for solar power satellite

Energy Technology Data Exchange (ETDEWEB)

Morita, Yousuke; Oshima, Takeshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Sasaki, Susumu; Kuroda, Hideo; Ushirokawa, Akio

1997-03-01

Flexible amorphous silicon(fa-Si) solar cell module, a thin film type, is regarded as a realistic power generator for solar power satellite. The radiation resistance of fa-Si cells was investigated by the irradiations of 3,4 and 10 MeV protons. The hydrogen gas treatment of the irradiated fa-Si cells was also studied. The fa-Si cell shows high radiation resistance for proton irradiations, compared with a crystalline silicon solar cell. (author)

Statistical analysis of solar proton events

Directory of Open Access Journals (Sweden)

V. Kurt

2004-06-01

Full Text Available A new catalogue of 253 solar proton events (SPEs with energy >10MeV and peak intensity >10 protons/cm2.s.sr (pfu at the Earth's orbit for three complete 11-year solar cycles (1970-2002 is given. A statistical analysis of this data set of SPEs and their associated flares that occurred during this time period is presented. It is outlined that 231 of these proton events are flare related and only 22 of them are not associated with Ha flares. It is also noteworthy that 42 of these events are registered as Ground Level Enhancements (GLEs in neutron monitors. The longitudinal distribution of the associated flares shows that a great number of these events are connected with west flares. This analysis enables one to understand the long-term dependence of the SPEs and the related flare characteristics on the solar cycle which are useful for space weather prediction.

Analysis and verification of a prediction model of solar energetic proton events

Science.gov (United States)

Wang, J.; Zhong, Q.

2017-12-01

The solar energetic particle event can cause severe radiation damages near Earth. The alerts and summary products of the solar energetic proton events were provided by the Space Environment Prediction Center (SEPC) according to the flux of the greater than 10 MeV protons taken by GOES satellite in geosynchronous orbit. The start of a solar energetic proton event is defined as the time when the flux of the greater than 10 MeV protons equals or exceeds 10 proton flux units (pfu). In this study, a model was developed to predict the solar energetic proton events, provide the warning for the solar energetic proton events at least minutes in advance, based on both the soft X-ray flux and integral proton flux taken by GOES. The quality of the forecast model was measured against verifications of accuracy, reliability, discrimination capability, and forecast skills. The peak flux and rise time of the solar energetic proton events in the six channels, >1MeV, >5 MeV, >10 MeV, >30 MeV, >50 MeV, >100 MeV, were also simulated and analyzed.

Measurement of the North-South asymmetry in the solar proton albedo neutron flux

International Nuclear Information System (INIS)

Ifedili, S.O.

1979-01-01

The solar proton albedo neutron flux in the range 10 -2 --10 7 eV measured by a neutron detector on board the Ogo 6 satellite was examined for north-south asymmetry. For the solar proton event of December 19, 1969, the S/N ratio of the solar proton albedo neutron rate at geomagnetic latitude lambda>70 0 was 1.61 +- 0.27 during the event, while for the November 2, 1969, event at 40 0 0 and altitudes ranging from 700 km to 800 km the solar proton albedo neutron rate was 0.40 +- 0.10 count/s in the north and 0.00 +- 0.10 count/s in the south. During the solar proton event of December 18, 1969, the N/S ratio of the solar proton albedo neutron rate at lambda>70 0 was 1.00 +- 0.26. The results are consistent with the expected N-S asymmetry in the solar proton flux. An interplanetary proton anisotropy with the interplanetary magnetic field polarity away from the sun corresponded to larger fluxes of solar proton albedo neutrons at the north polar cap than at the south, while an interplanetary proton anisotropy with the interplanetary magnetic field polarity toward the sun corresponded to larger fluxes of solar proton albedo neutrons at the south polar cap than at the north. This evidence favors the direct access of solar protons to the earth's polar caps via the merged interplanetary and geomagnetic field lines

The virtual enhancements - solar proton event radiation (VESPER) model

Science.gov (United States)

Aminalragia-Giamini, Sigiava; Sandberg, Ingmar; Papadimitriou, Constantinos; Daglis, Ioannis A.; Jiggens, Piers

2018-02-01

A new probabilistic model introducing a novel paradigm for the modelling of the solar proton environment at 1 AU is presented. The virtual enhancements - solar proton event radiation model (VESPER) uses the European space agency's solar energetic particle environment modelling (SEPEM) Reference Dataset and produces virtual time-series of proton differential fluxes. In this regard it fundamentally diverges from the approach of existing SPE models that are based on probabilistic descriptions of SPE macroscopic characteristics such as peak flux and cumulative fluence. It is shown that VESPER reproduces well the dataset characteristics it uses, and further comparisons with existing models are made with respect to their results. The production of time-series as the main output of the model opens a straightforward way for the calculation of solar proton radiation effects in terms of time-series and the pairing with effects caused by trapped radiation and galactic cosmic rays.

Solar proton events and their effect on space systems

International Nuclear Information System (INIS)

Tranquille, C.

1994-01-01

Solar protons present a major problem to space systems because of the ionisation and displacement effects which arise from their interaction with matter. This is likely to become a greater problem in the future due to the use of more sensitive electronic components and the proposed expansion of manned activities in space. An outline is provided of the physical processes associated with individual solar events, the solar activity cycle and the transport of solar particles between the Sun and the Earth. The problems of predicting solar event fluences, both over short- and long-term periods, are discussed. The currently available solar proton event models used for long-term forecasting are briefly reviewed, and the advantages and deficiencies of each model are investigated. Predictions using the models are compared to measurements made by the GOES-7 satellite during the rising phase of the current solar cycle. These measurements are also used to illustrate the sensitivity of the models to the choice of confidence level and to the spectral form used for extrapolation over the solar proton energy range. (author)

Local Equation of State for Protons, and Implications for Proton Heating in the Solar Wind.

Science.gov (United States)

Zaslavsky, A.; Maksimovic, M.; Kasper, J. C.

2017-12-01

The solar wind protons temperature is observed to decrease with distance to the Sun at a slower rate than expected from an adiabatic expansion law: the protons are therefore said to be heated. This observation raises the question of the evaluation of the heating rate, and the question of the heat source.These questions have been investigated by previous authors by gathering proton data on various distances to the Sun, using spacecraft as Helios or Ulysses, and then computing the radial derivative of the proton temperature in order to obtain a heating rate from the internal energy equation. The problem of such an approach is the computation of the radial derivative of the temperature profile, for which uncertainties are very large, given the dispersion of the temperatures measured at a given distance.An alternative approach, that we develop in this paper, consists in looking for an equation of state that links locally the pressure (or temperature) to the mass density. If such a relation exists then one can evaluate the proton heating rate on a local basis, without having any space derivative to compute.Here we use several years of STEREO and WIND proton data to search for polytropic equation of state. We show that such relationships are indeed a good approximation in given solar wind's velocity intervals and deduce the associated protons heating rates as a function of solar wind's speed. The obtained heating rates are shown to scale from around 1 kW/kg in the slow wind to around 10 kW/kg in the fast wind, in remarkable agreement with the rate of energy observed by previous authors to cascade in solar wind's MHD turbulence at 1 AU. These results therefore support the idea of proton turbulent heating in the solar wind.

The turbulent cascade and proton heating in the solar wind during solar minimum

International Nuclear Information System (INIS)

Coburn, Jesse T.; Smith, Charles W.; Vasquez, Bernard J.; Stawarz, Joshua E.; Forman, Miriam A.

2013-01-01

Solar wind measurements at 1 AU during the recent solar minimum and previous studies of solar maximum provide an opportunity to study the effects of the changing solar cycle on in situ heating. Our interest is to compare the levels of activity associated with turbulence and proton heating. Large-scale shears in the flow caused by transient activity are a source that drives turbulence that heats the solar wind, but as the solar cycle progresses the dynamics that drive the turbulence and heat the medium are likely to change. The application of third-moment theory to Advanced Composition Explorer (ACE) data gives the turbulent energy cascade rate which is not seen to vary with the solar cycle. Likewise, an empirical heating rate shows no significan changes in proton heating over the cycle.

Timing Comparisons for GLEs and High-energy Proton Events using GPS Proton Measurements

Science.gov (United States)

Bernstein, V.; Winter, L. M.; Carver, M.; Morley, S.

2017-12-01

The newly released LANL GPS particle sensor data offers a unique snapshot of access of relativistic particles into the geomagnetic field. Currently, 23 of the 31 operational GPS satellites host energetic particle detectors which can detect the arrival of high-energy solar protons associated with Ground Level Enhancements (GLEs). We compare the timing profiles of solar energetic proton detections from GPS satellites as well as from ground-based Neutron Monitors and GOES spacecraft at geostationary orbit in order to understand how high-energy protons from the Sun enter the geomagnetic field and investigate potential differences in arrival time of energetic protons at GPS satellites as a function of location. Previous studies could only use one or two spacecraft at a similar altitude to track the arrival of energetic particles. With GPS data, we can now test whether the particles arrive isotropically, as assumed, or whether there exist differences in the timing and energetics viewed by each of the individual satellites. Extensions of this work could lead to improvements in space weather forecasting that predict more localized risk estimates for space-based technology.

Interplanetary Parameters Leading to Relativistic Electron Enhancement and Persistent Depletion Events at Geosynchronous Orbit and Potential for Prediction

Science.gov (United States)

Pinto, Victor A.; Kim, Hee-Jeong; Lyons, Larry R.; Bortnik, Jacob

2018-02-01

We have identified 61 relativistic electron enhancement events and 21 relativistic electron persistent depletion events during 1996 to 2006 from the Geostationary Operational Environmental Satellite (GOES) 8 and 10 using data from the Energetic Particle Sensor (EPS) >2 MeV fluxes. We then performed a superposed epoch time analysis of the events to find the characteristic solar wind parameters that determine the occurrence of such events, using the OMNI database. We found that there are clear differences between the enhancement events and the persistent depletion events, and we used these to establish a set of threshold values in solar wind speed, proton density and interplanetary magnetic field (IMF) Bz that can potentially be useful to predict sudden increases in flux. Persistent depletion events are characterized by a low solar wind speed, a sudden increase in proton density that remains elevated for a few days, and a northward turning of IMF Bz shortly after the depletion starts. We have also found that all relativistic electron enhancement or persistent depletion events occur when some geomagnetic disturbance is present, either a coronal mass ejection or a corotational interaction region; however, the storm index, SYM-H, does not show a strong connection with relativistic electron enhancement events or persistent depletion events. We have tested a simple threshold method for predictability of relativistic electron enhancement events using data from GOES 11 for the years 2007-2010 and found that around 90% of large increases in electron fluxes can be identified with this method.

Dynamical Changes Induced by the Solar Proton Events in October-November 2003

Science.gov (United States)

Jackman, C. H.; Roble, R. G.; Fleming, E. L.

2006-05-01

The very large solar storms in October-November 2003 caused solar proton events (SPEs) at the Earth and impacted the upper atmospheric polar cap regions. The Thermosphere Ionosphere Mesosphere Electrodynamic General Circulation Mode (TIME-GCM) was used to study the atmospheric dynamical influence of the solar protons that occurred in Oct-Nov 2003, the fourth largest period of SPEs measured in the past 40 years. The highly energetic solar protons caused ionization and changes in the electric field, which led to Joule heating of the mesosphere and lower thermosphere. This heating led to temperature increases up to 4K in the upper mesosphere. The solar proton-induced ionization, as well as dissociation processes, led to the production of odd hydrogen (HOx) and odd nitrogen (NOy). Substantial (>40%) short-lived ozone decreases followed these enhancements of HOx and NOy and led to a cooling of the mesosphere and upper stratosphere. This cooling led to temperature decreases up to 2.5K. The solar proton-caused temperature changes led to maximum meridional and zonal wind variations of +/- 2 m/s on background winds up to +/- 30 m/s. The solar proton-induced wind perturbations were computed to taper off over a period of several days past the SPEs. Solar cycle 23 was accompanied by ten very large SPEs between 1998 and 2005, along with numerous smaller events. These solar proton-driven atmospheric variations need to be carefully considered when examining other polar changes.

STATISTICAL STUDY ON THE DECAY PHASE OF SOLAR NEAR-RELATIVISTIC ELECTRON EVENTS

International Nuclear Information System (INIS)

Lario, D.

2010-01-01

We study the decay phase of solar near-relativistic (53-315 keV) electron events as observed by the Advanced Composition Explorer (ACE) and the Ulysses spacecraft during solar cycle 23. By fitting an exponential function (exp - t/τ) to the time-intensity profile in the late phase of selected solar near-relativistic electron events, we examine the dependence of τ on electron energy, electron intensity spectra, event peak intensity, event fluence, and solar wind velocity, as well as heliocentric radial distance, heliolatitude, and heliolongitude of the spacecraft with respect to the parent solar event. The decay rates are found to be either independent or slightly decrease with the electron energy. No clear dependence is found between τ and the heliolongitude of the parent solar event, with the exception of well-connected events for which low values of τ are more commonly observed than for poorly-connected events. For those events concurrently observed by ACE and Ulysses, decay rates increase at distances >3 AU. Events with similar decay rates at ACE and Ulysses were observed mainly when Ulysses was at high heliographic latitudes. We discuss the basic physical mechanisms that control the decay phase of the electron events and conclude that both solar wind convection and adiabatic deceleration effects influence the final shape of the decay phase of solar energetic particle events, but not as expressed by the models based on diffusive transport acting on an isotropic particle population.

Evolution of Proton and Alpha Particle Velocities through the Solar Cycle

Science.gov (United States)

Ďurovcová, T.; Šafránková, J.; Němeček, Z.; Richardson, J. D.

2017-12-01

Relative properties of solar wind protons and α particles are often used as indicators of a source region on the solar surface, and analysis of their evolution along the solar wind path tests our understanding of physics of multicomponent magnetized plasma. The paper deals with the comprehensive analysis of the difference between proton and α particle bulk velocities at 1 au with a special emphasis on interplanetary coronal mass ejections (ICMEs). A comparison of about 20 years of Wind observations at 1 au with Helios measurements closer to the Sun (0.3-0.7 au) generally confirms the present knowledge that (1) the differential speed between both species increases with the proton speed; (2) the differential speed is lower than the local Alfvén speed; (3) α particles are faster than protons near the Sun, and this difference decreases with the increasing distance. However, we found a much larger portion of observations with protons faster than α particles in Wind than in Helios data and attributed this effect to a preferential acceleration of the protons in the solar wind. A distinct population characterized by a very small differential velocity and nearly equal proton and α particle temperatures that is frequently observed around the maximum of solar activity was attributed to ICMEs. Since this population does not exhibit any evolution with increasing collisional age, we suggest that, by contrast to the solar wind from other sources, ICMEs are born in an equilibrium state and gradually lose this equilibrium due to interactions with the ambient solar wind.

Study of two-proton radioactivity within the relativistic mean-field plus BCS approach

International Nuclear Information System (INIS)

Singh, D.; Saxena, G.

2012-01-01

Inspired by recent experimental studies of two-proton radioactivity in the light-medium mass region, we have employed relativistic mean-field plus state-dependent BCS approach (RMF+BCS) to study the ground state properties of selected even-Z nuclei in the region 20 ≤ Z ≤ 40. It is found that the effective potential barrier provided by the Coulomb interaction and that due to centrifugal force may cause a long delay in the decay of some of the nuclei even with small negative proton separation energy. This may cause the existence of proton-rich nuclei beyond the proton drip-line. Nuclei 38 Ti, 42 Cr, 45 Fe, 48 Ni, 55 Zn, 60 Ge, 63, 64 Se, 68 Kr, 72 Sr and 76 Zr are found to be the potential candidates for exhibiting two-proton radioactivity in the region 20 ≤ Z ≤ 40. The reliability of these predictions is further strengthened by the agreement of the calculated results for the ground state properties such as binding energy, one- and two-proton separation energy, proton and neutron radii, and deformation with the available experimental data for the entire chain of the isotopes of the nuclei in the region 20 ≤ Z ≤ 40. (author)

Modeling the electron-proton telescope on Solar Orbiter

Energy Technology Data Exchange (ETDEWEB)

Boden, Sebastian; Steinhagen, Jan; Kulkarni, S.R.; Tammen, Jan; Elftmann, Robert; Martin, Cesar; Ravanbakhsh, Ali; Boettcher, Stephan; Seimetz, Lars; Wimmer-Schweingruber, Robert F. [Christian-Albrechts-Universitaet, Kiel (Germany)

2014-07-01

The Electron Proton Telescope (EPT) is one of four sensors in the Energetic Particle Detector suite for Solar Orbiter. It investigates low energy electrons and protons of solar events in an energy range from 20 - 400 keV for electrons and 20 keV - 7 MeV for protons. It distinguishes electrons from protons using a magnet/foil technique with silicon detectors. There will be two EPT units, each with double-barreled telescopes, one looking sunwards/antisunwards and the other north/south. We set up a Monte Carlo model of EPT using the GEANT4 framework, which we can use to simulate interactions of energetic particles in the sensor. Here we present simulation results of the energy coverage for different ion species, and we study how it is possible to distinguish between them.

Importance of energetic solar protons in ozone depletion

Energy Technology Data Exchange (ETDEWEB)

Stephenson, J A.E.; Scourfield, M W.J. [Natal Univ., Durban (South Africa). Space Physics Research Inst.

1991-07-11

CHLORINE-catalysed depletion of the stratospheric ozone layer has commanded considerable attention since 1985, when Farman et al. observed a decrease of 50% in the total column ozone over Antarctica in the austral spring. Here we examine the depletion of stratospheric ozone caused by the reaction of ozone with nitric oxide generated by energetic solar protons, associated with solar flares. During large solar flares in March 1989, satellite observations indicated that total column ozone was depleted by {approx} 9% over {approx} 20% of the total area between the South Pole and latitude 70{sup o}S. Chlorine-catalysed ozone depletion takes place over a much larger area, but our results indicate that the influence of solar protons on atmospheric ozone concentrations should not be ignored. (author).

Importance of energetic solar protons in ozone depletion

International Nuclear Information System (INIS)

Stephenson, J.A.E.; Scourfield, M.W.J.

1991-01-01

CHLORINE-catalysed depletion of the stratospheric ozone layer has commanded considerable attention since 1985, when Farman et al. observed a decrease of 50% in the total column ozone over Antarctica in the austral spring. Here we examine the depletion of stratospheric ozone caused by the reaction of ozone with nitric oxide generated by energetic solar protons, associated with solar flares. During large solar flares in March 1989, satellite observations indicated that total column ozone was depleted by ∼ 9% over ∼ 20% of the total area between the South Pole and latitude 70 o S. Chlorine-catalysed ozone depletion takes place over a much larger area, but our results indicate that the influence of solar protons on atmospheric ozone concentrations should not be ignored. (author)

Catalogue of {>} 55 MeV Wide-longitude Solar Proton Events Observed by SOHO, ACE, and the STEREOs at {≈} 1 AU During 2009 - 2016

Science.gov (United States)

Paassilta, Miikka; Papaioannou, Athanasios; Dresing, Nina; Vainio, Rami; Valtonen, Eino; Heber, Bernd

2018-04-01

Based on energetic particle observations made at {≈} 1 AU, we present a catalogue of 46 wide-longitude ({>} 45°) solar energetic particle (SEP) events detected at multiple locations during 2009 - 2016. The particle kinetic energies of interest were chosen as {>} 55 MeV for protons and 0.18 - 0.31 MeV for electrons. We make use of proton data from the Solar and Heliospheric Observatory/Energetic and Relativistic Nuclei and Electron Experiment (SOHO/ERNE) and the Solar Terrestrial Relations Observatory/High Energy Telescopes (STEREO/HET), together with electron data from the Advanced Composition Explorer/Electron, Proton, and Alpha Monitor (ACE/EPAM) and the STEREO/ Solar Electron and Proton Telescopes (SEPT). We consider soft X-ray data from the Geostationary Operational Environmental Satellites (GOES) and coronal mass ejection (CME) observations made with the SOHO/ Large Angle and Spectrometric Coronagraph (LASCO) and STEREO/ Coronagraphs 1 and 2 (COR1, COR2) to establish the probable associations between SEP events and the related solar phenomena. Event onset times and peak intensities are determined; velocity dispersion analysis (VDA) and time-shifting analysis (TSA) are performed for protons; TSA is performed for electrons. In our event sample, there is a tendency for the highest peak intensities to occur when the observer is magnetically connected to solar regions west of the flare. Our estimates for the mean event width, derived as the standard deviation of a Gaussian curve modelling the SEP intensities (protons {≈} 44°, electrons {≈} 50°), largely agree with previous results for lower-energy SEPs. SEP release times with respect to event flares, as well as the event rise times, show no simple dependence on the observer's connection angle, suggesting that the source region extent and dominant particle acceleration and transport mechanisms are important in defining these characteristics of an event. There is no marked difference between the speed

The Analysis of the Properties of Super Solar Proton Events and the Associated Phenomena

Science.gov (United States)

Cheng, L. B.; Le, G. M.; Lu, Y. P.; Chen, M. H.; Li, P.; Yin, Z. Q.

2014-05-01

The solar flare, the propagation speed of shock driven by coronal mass ejection (CME) from the sun to the Earth, the source longitudes and Carrington longitudes, and the geomagnetic storms associated with each super solar proton event with the peak flux equal to or exceeding 10000 pfu have been investigated. The analysis results show that the source longitudes of super solar proton events ranged from E30° to W75°. The Carrington longitudes of source regions of super solar proton events distributed in the two longitude bands, 130°˜220° and 260°˜320°, respectively. All super solar proton events were accompanied by major solar flares and fast CMEs. The averaged speeds of shocks propagated from the sun to the Earth were greater than 1200 km/s. Eight super solar proton events were followed by major geomagnetic storms (Dst≤-100 nT). One super solar proton event was followed by a geomagnetic storm with Dst=-96 nT.

Efficiencies for production of atomic nitrogen and oxygen by relativistic proton impact in air

Science.gov (United States)

Porter, H. S.; Jackman, C. H.; Green, A. E. S.

1976-01-01

Relativistic electron and proton impact cross sections are obtained and represented by analytic forms which span the energy range from threshold to 1 GeV. For ionization processes, the Massey-Mohr continuum generalized oscillator strength surface is parameterized. Parameters are determined by simultaneous fitting to (1) empirical data, (2) the Bethe sum rule, and (3) doubly differential cross sections for ionization. Branching ratios for dissociation and predissociation from important states of N2 and O2 are determined. The efficiency for the production of atomic nitrogen and oxygen by protons with kinetic energy less than 1 GeV is determined using these branching ratio and cross section assignments.

On proton events of different solar activity cycles

International Nuclear Information System (INIS)

Sattarov, I.; Sherdanov, Ch.; Sattarov, B.

1997-01-01

In solar activity cycle N21 and N22 the latitude distribution of the proton large flares and sunspot groups is being studied. It was found that higher proton activity of cycle N22 is connected with its higher latitude sunspot activity (author)

Predicting Atmospheric Ionization and Excitation by Precipitating SEP and Solar Wind Protons Measured By MAVEN

Science.gov (United States)

Jolitz, Rebecca; Dong, Chuanfei; Lee, Christina; Lillis, Rob; Brain, David; Curry, Shannon; Halekas, Jasper; Bougher, Stephen W.; Jakosky, Bruce

2017-10-01

Precipitating energetic particles ionize and excite planetary atmospheres, increasing electron content and producing aurora. At Mars, the solar wind and solar energetic particles (SEPs) can precipitate directly into the atmosphere because solar wind protons can charge exchange to become neutral and pass the magnetosheath, and SEPs are sufficiently energetic to cross the magnetosheath unchanged. We will compare ionization and Lyman alpha emission rates for solar wind and SEP protons during nominal solar activity and a CME shock front impact event on May 16 2016. We will use the Atmospheric Scattering of Protons and Energetic Neutrals (ASPEN) model to compare excitation and ionization rates by SEPs and solar wind protons currently measured by the SWIA (Solar Wind Ion Analyzer) and SEP instruments aboard the MAVEN spacecraft. Results will help quantify how SEP and solar wind protons influence atmospheric energy deposition during solar minimum.

Predicting Ionization Rates from SEP and Solar Wind Proton Precipitation into the Martian Atmosphere

Science.gov (United States)

Jolitz, R.; Dong, C.; Lee, C. O.; Curry, S.; Lillis, R. J.; Brain, D.; Halekas, J. S.; Larson, D. E.; Bougher, S. W.; Jakosky, B. M.

2017-12-01

Precipitating energetic particles ionize planetary atmospheres and increase total electron content. At Mars, the solar wind and solar energetic particles (SEPs) can precipitate directly into the atmosphere because solar wind protons can charge exchange to become neutrals and pass through the magnetosheath, while SEPs are sufficiently energetic to cross the magnetosheath unchanged. In this study we will present predicted ionization rates and resulting electron densities produced by solar wind and SEP proton ionization during nominal solar activity and a CME shock front impact event on May 16 2016. We will use the Atmospheric Scattering of Protons and Energetic Neutrals (ASPEN) model to compare ionization by SEP and solar wind protons currently measured by the SWIA (Solar Wind Ion Analyzer) and SEP instruments aboard the MAVEN spacecraft. Results will help to quantify how the ionosphere responds to extreme solar events during solar minimum.

LONG-TERM TRENDS IN THE SOLAR WIND PROTON MEASUREMENTS

Energy Technology Data Exchange (ETDEWEB)

Elliott, Heather A.; McComas, David J. [Southwest Research Institute, San Antonio, TX (United States); DeForest, Craig E. [Southwest Research Institute, Boulder, CO (United States)

2016-11-20

We examine the long-term time evolution (1965–2015) of the relationships between solar wind proton temperature ( T {sub p}) and speed ( V {sub p}) and between the proton density ( n {sub p}) and speed using OMNI solar wind observations taken near Earth. We find a long-term decrease in the proton temperature–speed ( T {sub p}– V {sub p}) slope that lasted from 1972 to 2010, but has been trending upward since 2010. Since the solar wind proton density–speed ( n {sub p}– V {sub p}) relationship is not linear like the T {sub p}– V {sub p} relationship, we perform power-law fits for n {sub p}– V {sub p}. The exponent (steepness in the n {sub p}– V {sub p} relationship) is correlated with the solar cycle. This exponent has a stronger correlation with current sheet tilt angle than with sunspot number because the sunspot number maxima vary considerably from cycle to cycle and the tilt angle maxima do not. To understand this finding, we examined the average n {sub p} for different speed ranges, and found that for the slow wind n {sub p} is highly correlated with the sunspot number, with a lag of approximately four years. The fast wind n {sub p} variation was less, but in phase with the cycle. This phase difference may contribute to the n {sub p}– V {sub p} exponent correlation with the solar cycle. These long-term trends are important since empirical formulas based on fits to T {sub p} and V {sub p} data are commonly used to identify interplanetary coronal mass ejections, but these formulas do not include any time dependence. Changes in the solar wind density over a solar cycle will create corresponding changes in the near-Earth space environment and the overall extent of the heliosphere.

Dynamical Changes Induced by the Very Large Solar Proton Events in October-November 2003

Science.gov (United States)

Jackman, Charles H.; Roble, Raymond G.

2006-01-01

The very large solar storms in October-November 2003 caused solar proton events (SPEs) at the Earth and impacted the upper atmospheric polar cap regions. The Thermosphere Ionosphere Mesosphere Electrodynamic General Circulation Mode (TIME-GCM) was used to study the atmospheric dynamical influence of the solar protons that occurred in Oct-Nov 2003, the fourth largest period of SPEs measured in the past 40 years. The highly energetic solar protons caused ionization and changes in the electric field, which led to Joule heating of the mesosphere and lower thermosphere. This heating led to temperature increases up to 4K in the upper mesosphere. The solar proton-induced ionization, as well as dissociation processes, led to the production of odd hydrogen (HO(x)) and odd nitrogen (NO(y)). Substantial (>40%) short-lived ozone decreases followed these enhancements of HO(x) and NO(y) and led to a cooling of the mesosphere and upper stratosphere. This cooling led to temperature decreases up to 2.5K. The solar proton-caused temperature changes led to maximum meridional and zonal wind variations of +/- 2 m/s on background winds up to +/- 30 m/s. The solar proton-induced wind perturbations were computed to taper off over a period of several days past the SPEs. Solar cycle 23 was accompanied by ten very large SPEs between 1998 and 2005, along with numerous smaller events. These solar proton-driven atmospheric variations need to be carefully considered when examining other polar changes.

SOLAR WIND PROTONS AT 1 AU: TRENDS AND BOUNDS, CONSTRAINTS AND CORRELATIONS

Energy Technology Data Exchange (ETDEWEB)

Hellinger, Petr; Trávníček, Pavel M., E-mail: petr.hellinger@asu.cas.cz [Astronomical Institute, AS CR, Bocni II/1401,CZ-14100 Prague (Czech Republic)

2014-03-20

The proton temperature anisotropy in the solar wind exhibits apparent bounds which are compatible with the theoretical constraints imposed by temperature-anisotropy-driven kinetic instabilities. Recent statistical analyses based on conditional averaging indicate that near these theoretical constraints the solar wind protons typically have enhanced temperatures and a weaker collisionality. Here we carefully analyze the solar wind data and show that these results are a consequence of superposition of multiple correlations in the solar wind, namely, they mostly result from the correlation between the proton temperature and the solar wind velocity and from the superimposed anti-correlation between the proton temperature anisotropy and the proton parallel beta in the fast solar wind. Colder and more collisional data are distributed around temperature isotropy whereas hotter and less collisional data have a wider range of the temperature anisotropy anti-correlated with the proton parallel beta with signatures of constraints owing to the temperature-anisotropy-driven instabilities. However, most of the hot and weakly collisional data, including the hottest and least collisional ones, lies far from the marginal stability regions. Consequently, we conclude that there is no clear relation between the enhanced temperatures and instability constraints and that the conditional averaging used for these analyses must be used carefully and need to be well tested.

Suprathermal protons in the interplanetary solar wind

Science.gov (United States)

Goodrich, C. C.; Lazarus, A. J.

1976-01-01

Using the Mariner 5 solar wind plasma and magnetic field data, we present observations of field-aligned suprathermal proton velocity distributions having pronounced high-energy shoulders. These observations, similar to the interpenetrating stream observations of Feldman et al. (1974), are clear evidence that such proton distributions are interplanetary rather than bow shock associated phenomena. Large Alfven speed is found to be a requirement for the occurrence of suprathermal proton distribution; further, we find the proportion of particles in the shoulder to be limited by the magnitude of the Alfven speed. It is suggested that this last result could indicate that the proton thermal anisotropy is limited at times by wave-particle interactions

Properties of solar proton events at large heliocentric distances near ecliptic

International Nuclear Information System (INIS)

Khiber, B.; Struminskij, A.B.

2005-01-01

The absolute intensities, fluences and propagation times of the solar protons with the energy of 38-125 MeV, obtained on the basis of the observation data of the Kilskij electron telescope (KET ULYSSES) onboard the ULYSSES cosmic apparatus and GOES proton detector, are compared. The observation data on the solar cosmic rays at the heliocentric distances above 5 a.e. are analyzed for the first time. Certain characteristics of the proton events under consideration and their possible parent flares are presented [ru

Short- and Medium-term Atmospheric Effects of Very Large Solar Proton Events

Science.gov (United States)

Jackman, Charles H.; Marsh, Daniel R.; Vitt, Francis M.; Garcia, Rolando R.; Fleming, Eric L.; Labow, Gordon J.; Randall, Cora E.; Lopez-Puertas, Manuel; Funke, Bernd

2007-01-01

Long-term variations in ozone have been caused by both natural and humankind related processes. In particular, the humankind or anthropogenic influence on ozone from chlorofluorocarbons and halons (chlorine and bromine) has led to international regulations greatly limiting the release of these substances. These anthropogenic effects on ozone are most important in polar regions and have been significant since the 1970s. Certain natural ozone influences are also important in polar regions and are caused by the impact of solar charged particles on the atmosphere. Such natural variations have been studied in order to better quantify the human influence on polar ozone. Large-scale explosions on the Sun near solar maximum lead to emissions of charged particles (mainly protons and electrons), some of which enter the Earth's magnetosphere and rain down on the polar regions. "Solar proton events" have been used to describe these phenomena since the protons associated with these solar events sometimes create a significant atmospheric disturbance. We have used the National Center for Atmospheric Research (NCAR) Whole Atmosphere Community Climate Model (WACCM) to study the short- and medium-term (days to a few months) influences of solar proton events between 1963 and 2005 on stratospheric ozone. The four largest events in the past 45 years (August 1972; October 1989; July 2000; and October-November 2003) caused very distinctive polar changes in layers of the Earth's atmosphere known as the stratosphere (12-50 km; -7-30 miles) and mesosphere (50-90 km; 30-55 miles). The solar protons connected with these events created hydrogen- and nitrogen- containing compounds, which led to the polar ozone destruction. The hydrogen-containing compounds have very short lifetimes and lasted for only a few days (typically the duration of the solar proton event). On the other hand, the nitrogen-containing compounds lasted much longer, especially in the Winter. The nitrogen oxides were predicted

First experiments on transmutation studies of iodine-129 and neptunium-237 using relativistic protons of 3.7 GeV

International Nuclear Information System (INIS)

Krivopustov, M.I.; Adam, J.; Bradnova, V.

1997-01-01

First experiments on the transmutation of long-lived 129 I and 237 Np using relativistic protons of 3.7 GeV are described. Relativistic protons generate in extended Pb-targets substantial neutron fluences. These neutrons get moderated in paraffin and are used for transmutation as follows: 129 (n, γ) 130 I(β - ) → 130 Xe(stable) and 237 Np(n, γ) 238 Np(β - ) →. The isotopes 130 I (T 1/2 =12.36 h) and 238 Np (T 1/2 =2.117 days) were identified radiochemically. One can estimate the transmutation cross section (n, γ) in the given neutron field as σ( 129 I(n, γ))=(10±2)b and σ( 237 Np(n, γ))=(140±30)b. The experiments were carried out in November 1996 at the Synchrophasotron, Laboratory of High Energies (LHE), Dubna, Russia

The Long-term Middle Atmospheric Influence of Very Large Solar Proton Events

Science.gov (United States)

Jackman, Charles H.; Marsh, Daniel R.; Vitt, Francis M.; Garcia, Rolando R.; Randall, Cora E.; Fleming, Eric L.; Frith, Stacey M.

2008-01-01

Long-term variations in ozone have been caused by both natural and humankind related processes. The humankind or anthropogenic influence on ozone originates from the chlorofluorocarbons and halons (chlorine and bromine) and has led to international regulations greatly limiting the release of these substances. Certain natural ozone influences are also important in polar regions and are caused by the impact of solar charged particles on the atmosphere. Such natural variations have been studied in order to better quantify the human influence on polar ozone. Large-scale explosions on the Sun near solar maximum lead to emissions of charged particles (mainly protons and electrons), some of which enter the Earth's magnetosphere and rain down on the polar regions. "Solar proton events" have been used to describe these phenomena since the protons associated with these solar events sometimes create a significant atmospheric disturbance. We have used the National Center for Atmospheric Research (NCAR) Whole Atmosphere Community Climate Model (WACCM) to study the long-term (> few months) influences of solar proton events from 1963 through 2004 on stratospheric ozone and temperature. There were extremely large solar proton events in 1972, 1989,2000,2001, and 2003. These events caused very distinctive polar changes in layers of the Earth's atmosphere known as the stratosphere (12-50 km; -7-30 miles) and mesosphere (50-90 km; 30-55 miles). The solar protons connected with these events created hydrogen- and nitrogen-containing compounds, which led to the polar ozone destruction. The nitrogen-containing compounds, called odd nitrogen, lasted much longer than the hydrogen-containing compounds and led to long-lived stratospheric impacts. An extremely active period for these events occurred in the five-year period, 2000- 2004, and caused increases in odd nitrogen which lasted for several months after individual events. Associated stratospheric ozone decreases of >lo% were calculated

Measurement of solar proton-proton fusion neutrinos with a Soviet-American gallium experiment: Technical progress report

International Nuclear Information System (INIS)

Cherry, M.L.

1989-06-01

A gallium solar neutrino detector is sensitive to low-energy proton-proton fusion neutrinos. A flux of 70 SNU is expected in a gallium detector from the p-p reaction independent of solar model calculations. If, however, neutrino oscillations in the solar interior are responsible for the suppressed 8 B flux measured by the Homestake 37 Cl experiment, then a comparison of the gallium and chlorine results may make possible a determination of the neutrino mass difference and mixing angle. A 60-ton gallium detector is currently being constructed in the Baksan Laboratory in the Soviet Union, and should be taking data by the end of 1989

Voyager observations of solar wind proton temperature - 1-10 AU

Science.gov (United States)

Gazis, P. R.; Lazarus, A. J.

1982-01-01

Simultaneous measurements are made of the solar wind proton temperatures by the Voyager 1 and 2 spacecraft, far from earth, and the IMP 8 spacecraft in earth orbit. This technique permits a separation of radial and temporal variations of solar wind parameters. The average value of the proton temperature between 1 and 9 AU is observed to decrease as r (the heliocentric radius) to the -(0.7 + or - 0.2). This is slower than would be expected for adiabatic expansion. A detailed examination of the solar wind stream structure shows that considerable heating occurs at the interface between high and low speed streams.

Source of proton anisotrophy in the high-speed solar wind

International Nuclear Information System (INIS)

Schwartz, S.J.; Feldman, W.C.; Gary, S.P.

1981-01-01

Two factors which can contribute to proton anisotropy in the high-speed solar wind are investigated. We present evidence that observed proton Tperpendicular< Tparallel anisotropies are maintained locally by plasma instabilities driven by proton and helium beams. The transfer of beam energy to T/sub perpendicular/ by means of these instabilities is shown to be sufficient to account for the aforementioned proton temperature anisotropy

Impact of solar proton events on noctilucent clouds

Energy Technology Data Exchange (ETDEWEB)

Rahpoe, Nabiz; Savigny, Christian von; Robert, Charles E.; Burrows, John P. [IEP, University of Bremen (Germany); DeLand, M. [Science Systems and Applications, Inc. (SSAI), Maryland (United States)

2010-07-01

The impact of SPEs (solar proton events) on NLCs (noctilucent clouds) is studied using the 23-year NLC data set based on measurements with SBUV instruments on NIMBUS 7 and the NOAA 9-17 satellites. We analyzed the GOES proton flux and NLC time series in order to find significant anti-correlations between proton fluxes and NLC occurrence rates and albedo. We focused on the analysis of the years when SPEs occurred during the core NLC season. For several cases anti-correlations of NLC and proton fluxes were found. For an increase of the proton flux of several orders of magnitude (with proton energies E>5 MeV) during the NLC season we find a NLC reduction in NLC occurence rate or albedo of up to 50 % (relative to maximum).

Relativistic Celestial Mechanics of the Solar System

Science.gov (United States)

Kopeikin, Sergei; Efroimsky, Michael; Kaplan, George

2011-09-01

The general theory of relativity was developed by Einstein a century ago. Since then, it has become the standard theory of gravity, especially important to the fields of fundamental astronomy, astrophysics, cosmology, and experimental gravitational physics. Today, the application of general relativity is also essential for many practical purposes involving astrometry, navigation, geodesy, and time synchronization. Numerous experiments have successfully tested general relativity to a remarkable level of precision. Exploring relativistic gravity in the solar system now involves a variety of high-accuracy techniques, for example, very long baseline radio interferometry, pulsar timing, spacecraft Doppler tracking, planetary radio ranging, lunar laser ranging, the global positioning system (GPS), torsion balances and atomic clocks. Over the last few decades, various groups within the International Astronomical Union have been active in exploring the application of the general theory of relativity to the modeling and interpretation of high-accuracy astronomical observations in the solar system and beyond. A Working Group on Relativity in Celestial Mechanics and Astrometry was formed in 1994 to define and implement a relativistic theory of reference frames and time scales. This task was successfully completed with the adoption of a series of resolutions on astronomical reference systems, time scales, and Earth rotation models by the 24th General Assembly of the IAU, held in Manchester, UK, in 2000. However, these resolutions only form a framework for the practical application of relativity theory, and there have been continuing questions on the details of the proper application of relativity theory to many common astronomical problems. To ensure that these questions are properly addressed, the 26th General Assembly of the IAU, held in Prague in August 2006, established the IAU Commission 52, "Relativity in Fundamental Astronomy". The general scientific goals of the new

Database of episode-integrated solar energetic proton fluences

Science.gov (United States)

Robinson, Zachary D.; Adams, James H.; Xapsos, Michael A.; Stauffer, Craig A.

2018-04-01

A new database of proton episode-integrated fluences is described. This database contains data from two different instruments on multiple satellites. The data are from instruments on the Interplanetary Monitoring Platform-8 (IMP8) and the Geostationary Operational Environmental Satellites (GOES) series. A method to normalize one set of data to one another is presented to create a seamless database spanning 1973 to 2016. A discussion of some of the characteristics that episodes exhibit is presented, including episode duration and number of peaks. As an example of what can be understood about episodes, the July 4, 2012 episode is examined in detail. The coronal mass ejections and solar flares that caused many of the fluctuations of the proton flux seen at Earth are associated with peaks in the proton flux during this episode. The reasoning for each choice is laid out to provide a reference for how CME and solar flares associations are made.

Database of episode-integrated solar energetic proton fluences

Directory of Open Access Journals (Sweden)

Robinson Zachary D.

2018-01-01

Full Text Available A new database of proton episode-integrated fluences is described. This database contains data from two different instruments on multiple satellites. The data are from instruments on the Interplanetary Monitoring Platform-8 (IMP8 and the Geostationary Operational Environmental Satellites (GOES series. A method to normalize one set of data to one another is presented to create a seamless database spanning 1973 to 2016. A discussion of some of the characteristics that episodes exhibit is presented, including episode duration and number of peaks. As an example of what can be understood about episodes, the July 4, 2012 episode is examined in detail. The coronal mass ejections and solar flares that caused many of the fluctuations of the proton flux seen at Earth are associated with peaks in the proton flux during this episode. The reasoning for each choice is laid out to provide a reference for how CME and solar flares associations are made.

Beam heating in solar flares - Electrons or protons?

International Nuclear Information System (INIS)

Brown, J.C.; Karlicky, M.; Mackinnon, A.L.; Van Den Oord, G.H.J.

1990-01-01

The current status of electron and proton beam models as candidates for the impulsive phase heating of solar flares is discussed in relation to observational constants and theoretical difficulties. It is concluded that, while the electron beam model for flare heating still faces theoretical and observational problems, the problems faced by low and high energy proton beam models are no less serious, and there are facets of proton models which have not yet been studied. At the present, the electron beam model remains the most viable and best developed of heating model candidates. 58 refs

Simulation results of the electron-proton telescope for Solar Orbiter

Energy Technology Data Exchange (ETDEWEB)

Boden, Sebastian; Steinhagen, Jan; Kulkarni, Shrinivasrao; Grunau, Jan; Paspirgilis, Rolf; Martin, Cesar; Boettcher, Stephan; Seimetz, Lars; Schuster, Bjoern; Kulemzin, Alexander; Wimmer-Schweingruber, Robert F. [Christian-Albrechts-Universitaet Kiel (Germany)

2013-07-01

The Electron Proton Telescope (EPT) is one of five instruments in the Energetic Particle Detector suite for Solar Orbiter. It investigates low energy electrons and protons of solar events. EPT covers an energy range from 20400 keV for electrons and 20 keV-7 MeV for protons and distinguishes electrons from protons using a magnet/foil technique with silicon detectors. There will be two EPT units, each with double-barreled telescopes, one looking sunwards/antisunwards and the other north/south. EPT is designed using the GEometry ANd Tracking (GEANT) simulation toolkit developed by CERN for Monte Carlo calculations. Here we present the details of our simulations and the simulation results with respect to energy coverage and the geometrical factor of the EPT instrument. We also look at the far-field of the EPT magnets, which is important for electromagnetic cleanliness considerations.

Electromagnetic Waves with Frequencies Near the Local Proton Gryofrequency: ISEF-3 1 AU Observations

Science.gov (United States)

Tsurutani, B.

1993-01-01

Low Frequency electromagnetic waves with periods near the local proton gyrofrequency have been detected near 1 AU by the magnetometer onboard ISEE-3. For these 1 AU waves two physical processes are possible: solar wind pickup of nuetral (interstellar?) particles and generation by relativistic electron beams propagating from the Sun.

Average profiles of the solar wind and outer radiation belt during the extreme flux enhancement of relativistic electrons at geosynchronous orbit

Directory of Open Access Journals (Sweden)

R. Kataoka

2008-06-01

Full Text Available We report average profiles of the solar wind and outer radiation belt during the extreme flux enhancement of relativistic electrons at geosynchronous orbit (GEO. It is found that seven of top ten extreme events at GEO during solar cycle 23 are associated with the magnetosphere inflation during the storm recovery phase as caused by the large-scale solar wind structure of very low dynamic pressure (<1.0 nPa during rapid speed decrease from very high (>650 km/s to typical (400–500 km/s in a few days. For the seven events, the solar wind parameters, geomagnetic activity indices, and relativistic electron flux and geomagnetic field at GEO are superposed at the local noon period of GOES satellites to investigate the physical cause. The average profiles support the "double inflation" mechanism that the rarefaction of the solar wind and subsequent magnetosphere inflation are one of the best conditions to produce the extreme flux enhancement at GEO because of the excellent magnetic confinement of relativistic electrons by reducing the drift loss of trapped electrons at dayside magnetopause.

Proton-proton bremsstrahlung in a relativistic covariant model

NARCIS (Netherlands)

Martinus, Gerard Henk

1998-01-01

Proton-proton bremsstrahlung is one of the simplest processes involving the half off-shell NN interaction. Since protons are equally-charged particles with the same mass, electric-dipole radiation is suppressed and higher-order effects play an important role. Thus it is possible to get information

Solar Wind Proton Temperature Anisotropy: Linear Theory and WIND/SWE Observations

Science.gov (United States)

Hellinger, P.; Travnicek, P.; Kasper, J. C.; Lazarus, A. J.

2006-01-01

We present a comparison between WIND/SWE observations (Kasper et al., 2006) of beta parallel to p and T perpendicular to p/T parallel to p (where beta parallel to p is the proton parallel beta and T perpendicular to p and T parallel to p are the perpendicular and parallel proton are the perpendicular and parallel proton temperatures, respectively; here parallel and perpendicular indicate directions with respect to the ambient magnetic field) and predictions of the Vlasov linear theory. In the slow solar wind, the observed proton temperature anisotropy seems to be constrained by oblique instabilities, by the mirror one and the oblique fire hose, contrary to the results of the linear theory which predicts a dominance of the proton cyclotron instability and the parallel fire hose. The fast solar wind core protons exhibit an anticorrelation between beta parallel to c and T perpendicular to c/T parallel to c (where beta parallel to c is the core proton parallel beta and T perpendicular to c and T parallel to c are the perpendicular and parallel core proton temperatures, respectively) similar to that observed in the HELIOS data (Marsch et al., 2004).

Slowly rotating general relativistic superfluid neutron stars with relativistic entrainment

International Nuclear Information System (INIS)

Comer, G.L.

2004-01-01

Neutron stars that are cold enough should have two or more superfluids or supercondutors in their inner crusts and cores. The implication of superfluidity or superconductivity for equilibrium and dynamical neutron star states is that each individual particle species that forms a condensate must have its own, independent number density current and equation of motion that determines that current. An important consequence of the quasiparticle nature of each condensate is the so-called entrainment effect; i.e., the momentum of a condensate is a linear combination of its own current and those of the other condensates. We present here the first fully relativistic modeling of slowly rotating superfluid neutron stars with entrainment that is accurate to the second-order in the rotation rates. The stars consist of superfluid neutrons, superconducting protons, and a highly degenerate, relativistic gas of electrons. We use a relativistic σ-ω mean field model for the equation of state of the matter and the entrainment. We determine the effect of a relative rotation between the neutrons and protons on a star's total mass, shape, and Kepler, mass-shedding limit

High and Low Energy Proton Radiation Damage in p/n InP MOCVD Solar Cells

Science.gov (United States)

Rybicki, George; Weinberg, Irv; Scheiman, Dave; Vargas-Aburto, Carlos; Uribe, Roberto

1995-01-01

InP p(+)/n/n(+) solar cells, fabricated by metal organic chemical vapor deposition, (MOCVD) were irradiated with 0.2 MeV and 10 MeV protons to a fluence of 10(exp 13)/sq cm. The power output degradation, IV behavior, carrier concentration and defect concentration were observed at intermediate points throughout the irradiations. The 0.2 MeV proton-irradiated solar cells suffered much greater and more rapid degradation in power output than those irradiated with 10 MeV protons. The efficiency losses were accompanied by larger increases in the recombination currents in the 0.2 MeV proton-irradiated solar cells. The low energy proton irradiations also had a larger impact on the series resistance of the solar cells. Despite the radiation induced damage, the carrier concentration in the base of the solar cells showed no reduction after 10 MeV or 0.2 MeV proton irradiations and even increased during irradiation with 0.2 MeV protons. In a deep level transient spectroscopy (DLTS) study of the irradiated samples, the minority carrier defects H4 and H5 at E(sub v) + 0.33 and E(sub v) + 0.52 eV and the majority carrier defects E7 and El0 at E(sub c) - 0.39 and E(sub c) - 0.74 eV, were observed. The defect introduction rates for the 0.2 MeV proton irradiations were about 20 times higher than for the 10 MeV proton irradiations. The defect El0, observed here after irradiation, has been shown to act as a donor in irradiated n-type InP and may be responsible for obscuring carrier removal. The results of this study are consistent with the much greater damage produced by low energy protons whose limited range causes them to stop in the active region of the solar cell.

MODULATION OF GALACTIC COSMIC RAY PROTONS AND ELECTRONS DURING AN UNUSUAL SOLAR MINIMUM

International Nuclear Information System (INIS)

Heber, B.; Kopp, A.; Gieseler, J.; Mueller-Mellin, R.; Fichtner, H.; Scherer, K.; Potgieter, M. S.; Ferreira, S. E. S.

2009-01-01

During the latest Ulysses out-of-ecliptic orbit the solar wind density, pressure, and magnetic field strength have been the lowest ever observed in the history of space exploration. Since cosmic ray particles respond to the heliospheric magnetic field in the expanding solar wind and its turbulence, the weak heliospheric magnetic field as well as the low plasma density and pressure are expected to cause the smallest modulation since the 1970s. In contrast to this expectation, the galactic cosmic ray (GCR) proton flux at 2.5 GV measured by Ulysses in 2008 does not exceed the one observed in the 1990s significantly, while the 2.5 GV GCR electron intensity exceeds the one measured during the 1990s by 30%-40%. At true solar minimum conditions, however, the intensities of both electrons and protons are expected to be the same. In contrast to the 1987 solar minimum, the tilt angle of the solar magnetic field has remained at about 30 deg. in 2008. In order to compare the Ulysses measurements during the 2000 solar magnetic epoch with those obtained 20 years ago, the former have been corrected for the spacecraft trajectory using latitudinal gradients of 0.25% deg. -1 and 0.19% deg. -1 for protons and electrons, respectively, and a radial gradient of 3% AU -1 . In 2008 and 1987, solar activity, as indicated by the sunspot number, was low. Thus, our observations confirm the prediction of modulation models that current sheet and gradient drifts prevent the GCR flux to rise to typical solar minimum values. In addition, measurements of electrons and protons allow us to predict that the 2.5 GV GCR proton intensity will increase by a factor of 1.3 if the tilt angle reaches values below 10 deg.

A quasilinear kinetic model for solar wind electrons and protons instabilities

Science.gov (United States)

Sarfraz, M.; Yoon, P. H.

2017-12-01

In situ measurements confirm the anisotropic behavior in temperatures of solar wind species. These anisotropies associated with charge particles are observed to be relaxed. In collionless limit, kinetic instabilities play a significant role to reshape particles distribution. The linear analysis results are encapsulated in inverse relationship between anisotropy and plasma beta based observations fittings techniques, simulations methods, or solution of linearized Vlasov equation. Here amacroscopic quasilinear technique is adopted to confirm inverse relationship through solutions of set of self-consistent kinetic equations. Firstly, for a homogeneous and non-collisional medium, quasilinear kinetic model is employed to display asymptotic variations of core and halo electrons temperatures and saturations of wave energy densities for electromagnetic electron cyclotron (EMEC) instability sourced by, T⊥}>T{∥ . It is shown that, in (β ∥ , T⊥}/T{∥ ) phase space, the saturations stages of anisotropies associated with core and halo electrons lined up on their respective marginal stability curves. Secondly, for case of electrons firehose instability ignited by excessive parallel temperature i.e T⊥}>T{∥ , both electrons and protons are allowed to dynamically evolve in time. It is also observed that, the trajectories of protons and electrons at saturation stages in phase space of anisotropy and plasma beta correspond to proton cyclotron and firehose marginal stability curves, respectively. Next, the outstanding issue that most of observed proton data resides in nearly isotropic state in phase space is interpreted. Here, in quasilinear frame-work of inhomogeneous solar wind system, a set of self-consistent quasilinear equations is formulated to show a dynamical variations of temperatures with spatial distributions. On choice of different initial parameters, it is shown that, interplay of electron and proton instabilities provides an counter-balancing force to slow

Recordings of solar protons during October 26-29, 1968

International Nuclear Information System (INIS)

Gjerde, A.; Amundsen, P.

1974-08-01

The composite events causing increased influx of solar particles during October 26-29, 1968 are studied using data from the polar orbiting ESRO IA satellite. Details on protons of 0.1-10 MeV are presented, and their interplanetary propagation characteristics discussed. Diffusion model fit to the prompt event commencing October 26, suggests an interplanetary diffusion coefficient for 200-350 keV protons of (2.8π+0.7).10 20 cm 2 s -1 . The most likely parent flare for this event is the 1N flare of 0119 UT October 26, occuring in McMath plage region 9740 at 32 deg E solar longitude. The slow decay of the event is then accounted for by co-rotation effects. The flares occurring in the same solar region on October 27 and leading to the delayed events of October 29, did not result in prompt events seen near the Earth, showing the great variability in energetic particle propagation conditions of interplanetary space. (auth)

The investigation of relativistic microscopic optical potential based on RBBG equation

International Nuclear Information System (INIS)

Chen Baoqiu; Ma Zhongyu

1992-01-01

The relativistic microscopic optical potential is derived from the RBBG equation. The nucleon complex effective mass is determined phenomenologically by a fit to 200 MeV proton-nucleus scattering data. Then the relativistic microscopic optical potentials of proton scattered from different targets: 16 O, 40 Ca, 90 Zr and 208 Pb in the energies range from 160 to 800 MeV have been got. The relativistic microscopic optical potentials have been used to study proton- 40 Ca scattering at 200 MeV. Theoretical predictions for cross section and spin observables are compared with experimental data and phenomenological Dirac optical potential

Ultra-relativistic heavy-ion physics with AFTER@LHC

DEFF Research Database (Denmark)

Rakotozafindrabe, A.; Arnaldi, R.; Brodsky, Stanley

2013-01-01

We outline the opportunities for ultra-relativistic heavy–ion physics which are offered by a next generation and multi-purpose fixed-target experiment exploiting the proton and ion LHC beams extracted by a bent crystal.......We outline the opportunities for ultra-relativistic heavy–ion physics which are offered by a next generation and multi-purpose fixed-target experiment exploiting the proton and ion LHC beams extracted by a bent crystal....

Complex active regions as the main source of extreme and large solar proton events

Science.gov (United States)

Ishkov, V. N.

2013-12-01

A study of solar proton sources indicated that solar flare events responsible for ≥2000 pfu proton fluxes mostly occur in complex active regions (CARs), i.e., in transition structures between active regions and activity complexes. Different classes of similar structures and their relation to solar proton events (SPEs) and evolution, depending on the origination conditions, are considered. Arguments in favor of the fact that sunspot groups with extreme dimensions are CARs are presented. An analysis of the flare activity in a CAR resulted in the detection of "physical" boundaries, which separate magnetic structures of the same polarity and are responsible for the independent development of each structure.

Effects of electrons on the solar wind proton temperature anisotropy

International Nuclear Information System (INIS)

Michno, M. J.; Lazar, M.; Schlickeiser, R.; Yoon, P. H.

2014-01-01

Among the kinetic microinstabilities, the firehose instability is one of the most efficient mechanisms to restrict the unlimited increase of temperature anisotropy in the direction of an ambient magnetic field as predicted by adiabatic expansion of collision-poor solar wind. Indeed, the solar wind proton temperature anisotropy detected near 1 AU shows that it is constrained by the marginal firehose condition. Of the two types of firehose instabilities, namely, parallel and oblique, the literature suggests that the solar wind data conform more closely to the marginal oblique firehose condition. In the present work, however, it is shown that the parallel firehose instability threshold is markedly influenced by the presence of anisotropic electrons, such that under some circumstances, the cumulative effects of both electron and proton anisotropies could describe the observation without considering the oblique firehose mode.

Consequences of Relativistic Neutron Outflow beyond the Accretion Disks of Active Galaxies

Science.gov (United States)

Ekejiuba, I. E.; Okeke, P. N.

1993-05-01

Three channels of relativistic electron injection in the jets of extragalactic radio sources (EGRSs) are discussed. With the assumption that an active galactic nucleus (AGN) is powered by a spinning supermassive black hole of mass ~ 10(8) M_⊙ which sits at the center of the nucleus and ingests matter and energy through an accretion disk, a model for extracting relativistic neutrons from the AGN is forged. In this model, the inelastic proton--proton and proton--photon interactions within the accretion disk, of relativistic protons with background thermal protons and photons, respectively, produce copious amounts of relativistic neutrons. These neutrons travel ballistically for ~ 10(3gamma_n ) seconds and escape from the disk before they decay. The secondary particles produced from the neutron decays then interact with the ambient magnetic field and/or other particles to produce the radio emissions observed in the jets of EGRSs. IEE acknowledges the support of the World Bank and the Federal University of Technology, Yola, Nigeria as well as the hospitality of Georgia State University.

Solar cycle distribution of strong solar proton events and the related solar-terrestrial phenomena

Science.gov (United States)

Le, Guiming; Yang, Xingxing; Ding, Liuguang; Liu, Yonghua; Lu, Yangping; Chen, Minhao

2014-08-01

We investigated the solar cycle distribution of strong solar proton events (SPEs, peak flux ≥1000 pfu) and the solar-terrestrial phenomena associated with the strong SPEs during solar cycles 21-23. The results show that 37 strong SPEs were registered over this period of time, where 20 strong SPEs were originated from the super active regions (SARs) and 28 strong SPEs were accompanied by the X-class flares. Most strong SPEs were not associated with the ground level enhancement (GLE) event. Most strong SPEs occurred in the descending phases of the solar cycles. The weaker the solar cycle, the higher the proportion of strong SPES occurred in the descending phase of the cycle. The number of the strong SPEs that occurred within a solar cycle is poorly associated with the solar cycle size. The intensity of the SPEs is highly dependent of the location of their source regions, with the super SPEs (≥20000 pfu) distributed around solar disk center. A super SPE was always accompanied by a fast shock driven by the associated coronal mass ejection and a great geomagnetic storm. The source location of strongest GLE event is distributed in the well-connected region. The SPEs associated with super GLE events (peak increase rate ≥100%) which have their peak flux much lower than 10000 pfu were not accompanied by an intense geomagnetic storm.

Forecast of solar proton flux profiles for well-connected events

Science.gov (United States)

Ji, Eun-Young; Moon, Yong-Jae; Park, Jinhye

2014-12-01

We have developed a forecast model of solar proton flux profiles (> 10 MeV channel) for well-connected events. Among 136 solar proton events (SPEs) from 1986 to 2006, we select 49 well-connected ones that are all associated with single X-ray flares stronger than M1 class and start to increase within 4 h after their X-ray peak times. These events show rapid increments in proton flux. By comparing several empirical functions, we select a modified Weibull curve function to approximate a SPE flux profile. The parameters (peak flux, rise time, and decay time) of this function are determined by the relationship between X-ray flare parameters (peak flux, impulsive time, and emission measure) and SPE parameters. For 49 well-connected SPEs, the linear correlation coefficient between the predicted and the observed proton peak fluxes is 0.65 with the RMS error of 0.55 log10(pfu). In addition, we determine another forecast model based on flare and coronal mass ejection (CME) parameters using 22 SPEs. The used CME parameters are linear speed and angular width. As a result, we find that the linear correlation coefficient between the predicted and the observed proton peak fluxes is 0.83 with the RMS error of 0.35 log10(pfu). From the relationship between error of model and CME acceleration, we find that CME acceleration is an important factor for predicting proton flux profiles.

Transmutation of.pub.239 Pu and other nuclides using spallation neutrons produced by relativistic protons reacting with massive U- and Pb-targets

Czech Academy of Sciences Publication Activity Database

Adam, Jindřich; Adloff, J. C.; Balabekyan, A.; Bamblevski, V. P.; Barabanov, M. Y.; Brandt, R.; Bradnova, V.; Chaloun, P.; Debeauvais, M.; Dwivedi, K. K.; Guo, S. L.; Hashemi-Nezhad, R. S.; Hella, K. M.; Kalinnikov, V. G.; Kievets, M. K.; Krivopustov, M. I.; Kulakov, B. A.; Langrock, E. J.; Li, Li.; Lomonosova, E. M.; Modolo, G.; Odoj, R.; Perelygin, V. P.; Pronskikh, V. S.; Solnyshkin, A. A.; Sosnin, A. N.; Stegailov, V. I.; Tsoupko-Sitnikov, V. M.; Vater, P.; Wan, J. S.; Westmeier, W.; Zamani-Valasiadou, M.; Zhuk, I. V.

2002-01-01

Roč. 90, - (2002), s. 441-442 ISSN 0033-8230 R&D Projects: GA AV ČR KSK1048102 Keywords : relativistic protons * transmutation * subcritical nuclear systems * long-lived radiactive waste Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.809, year: 2002

Relativistic positioning systems: perspectives and prospects

Science.gov (United States)

Coll Bartolomé

2013-11-01

Relativistic positioning systems are interesting technical objects for applications around the Earth and in the Solar system. But above all else, they are basic scientific objects allowing developing relativity from its own concepts. Some past and future features of relativistic positioning sys- tems, with special attention to the developments that they suggest for an epistemic relativity (relativistic experimental approach to physics), are analyzed. This includes relativistic stereometry, which, together with relativistic positioning systems, allows to introduce the general relativistic notion of (finite) laboratory (space-time region able to perform experiments of finite size).

Relativistic mean field model for entrainment in general relativistic superfluid neutron stars

International Nuclear Information System (INIS)

Comer, G.L.; Joynt, R.

2003-01-01

General relativistic superfluid neutron stars have a significantly more intricate dynamics than their ordinary fluid counterparts. Superfluidity allows different superfluid (and superconducting) species of particles to have independent fluid flows, a consequence of which is that the fluid equations of motion contain as many fluid element velocities as superfluid species. Whenever the particles of one superfluid interact with those of another, the momentum of each superfluid will be a linear combination of both superfluid velocities. This leads to the so-called entrainment effect whereby the motion of one superfluid will induce a momentum in the other superfluid. We have constructed a fully relativistic model for entrainment between superfluid neutrons and superconducting protons using a relativistic σ-ω mean field model for the nucleons and their interactions. In this context there are two notions of 'relativistic': relativistic motion of the individual nucleons with respect to a local region of the star (i.e. a fluid element containing, say, an Avogadro's number of particles), and the motion of fluid elements with respect to the rest of the star. While it is the case that the fluid elements will typically maintain average speeds at a fraction of that of light, the supranuclear densities in the core of a neutron star can make the nucleons themselves have quite high average speeds within each fluid element. The formalism is applied to the problem of slowly rotating superfluid neutron star configurations, a distinguishing characteristic being that the neutrons can rotate at a rate different from that of the protons

An investigation of relativistic microscopic optical potential in terms of relativistic Brueckner-Bethe-Goldstone equation

International Nuclear Information System (INIS)

Chen Baoqiu; Ma Zhongyu

1992-01-01

Relativistic microscopic optical potential of nucleon-nucleus is derived from the relativistic Brueckner-Bethe-Goldstone (RBBG) equation. The complex effective mass of a nucleon is determined by a fit to 200 MeV p- 40 Ca scattering data. The relativistic microscopic optical potentials with this effective mass are obtained from RBBG for p- 16O , 40 Ca, 90 Zr and 208 Pb scattering in energy range from 160 to 800 MeV. The microscopic optical potential is used to study the proton- 40 Ca scattering problem at 200 MeV. The results, such as differential cross section, analyzing power and spin rotation function are compared with those calculated from phenomenological relativistic optical potential

Neutron-decay Protons from Solar Flares as Seed Particles for CME-shock Acceleration in the Inner Heliosphere

Energy Technology Data Exchange (ETDEWEB)

Murphy, Ronald J. [Code 7650, Naval Research Laboratory, Washington, DC 20375 (United States); Ko, Yuan-Kuen, E-mail: ronald.murphy@nrl.navy.mil, E-mail: yuan-kuen.ko@nrl.navy.mil [Code 7680, Naval Research Laboratory, Washington, DC 20375 (United States)

2017-09-01

The protons in large solar energetic particle events are accelerated in the inner heliosphere by fast shocks produced by coronal mass ejections. Unless there are other sources, the protons these shocks act upon would be those of the solar wind (SW). The efficiency of the acceleration depends on the kinetic energy of the protons. For a 2000 km s{sup −1} shock, the most effective proton energies would be 30–100 keV; i.e., within the suprathermal tail component of the SW. We investigate one possible additional source of such protons: those resulting from the decay of solar-flare-produced neutrons that escape from the Sun into the low corona. The neutrons are produced by interactions of flare-accelerated ions with the solar atmosphere. We discuss the production of low-energy neutrons in flares and their decay on a interplanetary magnetic field line near the Sun. We find that even when the flaring conditions are optimal, the 30–100 keV neutron-decay proton density produced by even a very large solar flare would be only about 10% of that of the 30–100 keV SW suprathermal tail. We discuss the implication of a seed-particle source of more frequent, small flares.

Annealing enhancement effect by light illumination on proton irradiated Cu(In, Ga)Se2 thin-film solar cells

International Nuclear Information System (INIS)

Kawakita, Shirou; Imaizumi, Mitsuru; Matsuda, Sumio; Yamaguchi, Masafumi; Kushiya, Katsumi; Ohshima, Takeshi; Itoh, Hisayoshi

2002-01-01

In this paper, we investigated the high radiation tolerance of copper indium gallium di-selenide (CIGS) thin-film solar cells by conducting in situ measurements of short circuit current and open circuit voltage of CIGS thin-film solar cells during and after proton irradiation under short circuit condition. We found that the annealing rate of proton-induced defects in CIGS thin-film solar cells under light illumination with an AM0 solar simulator is higher than that under dark conditions. The activation energy of proton-induced defects in the CIGS thin-film solar cells with (without) light illumination is 0.80 eV (0.92 eV), which implies on enhanced defect annealing rate in CIGS thin-film solar cells due to minority-carrier injection. (author)

The effect of low energy protons on silicon solar cells with simulated coverglass cracks

Science.gov (United States)

Gasner, S.; Anspaugh, B.; Francis, R.; Marvin, D.

1991-01-01

Results of a series of low-energy proton (LEP) tests are presented. The purpose of the tests was to investigate the effect of low-energy protons on the electrical performance of solar cells with simulated cracked covers. The results of the tests were then related to the space environment. A matrix of LEP tests was set up using solar cells with simulated cracks to determine the effect on electrical performance as a function of fluence, energy, crack width, coverglass adhesive shielding, crack location, and solar cell size. The results of the test were, for the most part, logical, and consistent.

Net-baryon-, net-proton-, and net-charge kurtosis in heavy-ion collisions within a relativistic transport approach

International Nuclear Information System (INIS)

Nahrgang, Marlene; Schuster, Tim; Stock, Reinhard; Mitrovski, Michael; Bleicher, Marcus

2012-01-01

We explore the potential of net-baryon, net-proton and net-charge kurtosis measurements to investigate the properties of hot and dense matter created in relativistic heavy-ion collisions. Contrary to calculations in a grand-canonical ensemble we explicitly take into account exact electric and baryon charge conservation on an event-by-event basis. This drastically limits the width of baryon fluctuations. A simple model to account for this is to assume a grand-canonical distribution with a sharp cut-off at the tails. We present baseline predictions of the energy dependence of the net-baryon, net-proton and net-charge kurtosis for central (b≤2.75 fm) Pb+Pb/Au+Au collisions from E lab =2A GeV to √(s NN )=200 GeV from the UrQMD model. While the net-charge kurtosis is compatible with values around zero, the net-baryon number decreases to large negative values with decreasing beam energy. The net-proton kurtosis becomes only slightly negative for low √(s NN ). (orig.)

Relativistic protons in the Coma galaxy cluster: first gamma-ray constraints ever on turbulent reacceleration

Science.gov (United States)

Brunetti, G.; Zimmer, S.; Zandanel, F.

2017-12-01

The Fermi-LAT (Large Area Telescope) collaboration recently published deep upper limits to the gamma-ray emission of the Coma cluster, a cluster hosting the prototype of giant radio haloes. In this paper, we extend previous studies and use a formalism that combines particle reacceleration by turbulence and the generation of secondary particles in the intracluster medium to constrain relativistic protons and their role for the origin of the radio halo. We conclude that a pure hadronic origin of the halo is clearly disfavoured as it would require excessively large magnetic fields. However, secondary particles can still generate the observed radio emission if they are reaccelerated. For the first time the deep gamma-ray limits allow us to derive meaningful constraints if the halo is generated during phases of reacceleration of relativistic protons and their secondaries by cluster-scale turbulence. In this paper, we explore a relevant range of parameter space of reacceleration models of secondaries. Within this parameter space, a fraction of model configurations is already ruled out by current gamma-ray limits, including the cases that assume weak magnetic fields in the cluster core, B ≤ 2-3 μG. Interestingly, we also find that the flux predicted by a large fraction of model configurations assuming magnetic fields consistent with Faraday rotation measures (RMs) is not far from the limits. This suggests that a detection of gamma-rays from the cluster might be possible in the near future, provided that the electrons generating the radio halo are secondaries reaccelerated and the magnetic field in the cluster is consistent with that inferred from RM.

Relativistic ion acceleration by ultraintense laser interactions

International Nuclear Information System (INIS)

Nakajima, K.; Koga, J.K.; Nakagawa, K.

2001-01-01

There has been a great interest in relativistic particle generation by ultraintense laser interactions with matter. We propose the use of relativistically self-focused laser pulses for the acceleration of ions. Two dimensional PIC simulations are performed, which show the formation of a large positive electrostatic field near the front of a relativistically self-focused laser pulse. Several factors contribute to the acceleration including self-focusing distance, pulse depletion, and plasma density. Ultraintense laser-plasma interactions are capable of generating enormous electrostatic fields of ∼3 TV/m for acceleration of protons with relativistic energies exceeding 1 GeV

Proton thermal energetics in the solar wind: Helios reloaded

Czech Academy of Sciences Publication Activity Database

Hellinger, Petr; Trávníček, P.; Štverák, Štěpán; Matteini, L.; Velli, M.

2013-01-01

Roč. 118, č. 4 (2013), s. 1351-1365 ISSN 2169-9380 Institutional support: RVO:68378289 Keywords : solar wind * proton energetics * turbulent heating Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.440, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/jgra.50107/abstract

Pauli principle in the soft-photon approach to proton-proton bremsstrahlung

NARCIS (Netherlands)

Liou, MK; Timmermans, R; Gibson, BF

1996-01-01

A relativistic and manifestly gauge-invariant soft-photon amplitude, which is consistent with the soft-photon theorem and satisfies the Pauli principle, is derived for the proton-proton bremsstrahlung process. This soft-photon amplitude is the first two-u-two-t special amplitude to satisfy all

MIXING THE SOLAR WIND PROTON AND ELECTRON SCALES: EFFECTS OF ELECTRON TEMPERATURE ANISOTROPY ON THE OBLIQUE PROTON FIREHOSE INSTABILITY

Energy Technology Data Exchange (ETDEWEB)

Maneva, Y.; Lazar, M.; Poedts, S. [Centre for Mathematical Plasma Astrophysics, Celestijnenlaan 200B, 3001 Heverlee (Belgium); Viñas, A., E-mail: yana.maneva@wis.kuleuven.be [NASA Goddard Space Flight Center, Heliophysics Science Division, Greenbelt, MD 20771 (United States)

2016-11-20

The double adiabatic expansion of the nearly collisionless solar wind plasma creates conditions for the firehose instability to develop and efficiently prevent the further increase of the plasma temperature in the direction parallel to the interplanetary magnetic field. The conditions imposed by the firehose instability have been extensively studied using idealized approaches that ignore the mutual effects of electrons and protons. Recently, more realistic approaches have been proposed that take into account the interplay between electrons and protons, unveiling new regimes of the parallel oscillatory modes. However, for oblique wave propagation the instability develops distinct branches that grow much faster and may therefore be more efficient than the parallel firehose instability in constraining the temperature anisotropy of the plasma particles. This paper reports for the first time on the effects of electron plasma properties on the oblique proton firehose (PFH) instability and provides a comprehensive vision of the entire unstable wave-vector spectrum, unifying the proton and the smaller electron scales. The plasma β and temperature anisotropy regimes considered here are specific for the solar wind and magnetospheric conditions, and enable the electrons and protons to interact via the excited electromagnetic fluctuations. For the selected parameters, simultaneous electron and PFH instabilities can be observed with a dispersion spectrum of the electron firehose (EFH) extending toward the proton scales. Growth rates of the PFH instability are markedly boosted by the anisotropic electrons, especially in the oblique direction where the EFH growth rates are orders of magnitude higher.

Mixing the Solar Wind Proton and Electron Scales: Effects of Electron Temperature Anisotropy on the Oblique Proton Firehose Instability

Science.gov (United States)

Maneva, Y.; Lazar, M.; Vinas, A.; Poedts, S.

2016-01-01

The double adiabatic expansion of the nearly collisionless solar wind plasma creates conditions for the firehose instability to develop and efficiently prevent the further increase of the plasma temperature in the direction parallel to the interplanetary magnetic field. The conditions imposed by the firehose instability have been extensively studied using idealized approaches that ignore the mutual effects of electrons and protons. Recently, more realistic approaches have been proposed that take into account the interplay between electrons and protons,? unveiling new regimes of the parallel oscillatory modes. However, for oblique wave propagation the instability develops distinct branches that grow much faster and may therefore be more efficient than the parallel firehose instability in constraining the temperature anisotropy of the plasma particles. This paper reports for the first time on the effects of electron plasma properties on the oblique proton firehose (PFH) instability and provides a comprehensive vision of the entire unstable wave-vector spectrum, unifying the proton and the smaller electron scales. The plasma ß and temperature anisotropy regimes considered here are specific for the solar wind and magnetospheric conditions, and enable the electrons and protons to interact via the excited electromagnetic fluctuations. For the selected parameters, simultaneous electron and PFH instabilities can be observed with a dispersion spectrum of the electron firehose (EFH) extending toward the proton scales. Growth rates of the PFH instability are markedly boosted by the anisotropic electrons, especially in the oblique direction where the EFH growth rates are orders of magnitude higher.

The first SEPServer event catalogue ~68-MeV solar proton events observed at 1 AU in 1996–2010

Directory of Open Access Journals (Sweden)

Rodríguez-Gasén Rosa

2013-03-01

Full Text Available SEPServer is a three-year collaborative project funded by the seventh framework programme (FP7-SPACE of the European Union. The objective of the project is to provide access to state-of-the-art observations and analysis tools for the scientific community on solar energetic particle (SEP events and related electromagnetic (EM emissions. The project will eventually lead to better understanding of the particle acceleration and transport processes at the Sun and in the inner heliosphere. These processes lead to SEP events that form one of the key elements of space weather. In this paper we present the first results from the systematic analysis work performed on the following datasets: SOHO/ERNE, SOHO/EPHIN, ACE/EPAM, Wind/WAVES and GOES X-rays. A catalogue of SEP events at 1 AU, with complete coverage over solar cycle 23, based on high-energy (~68-MeV protons from SOHO/ERNE and electron recordings of the events by SOHO/EPHIN and ACE/EPAM are presented. A total of 115 energetic particle events have been identified and analysed using velocity dispersion analysis (VDA for protons and time-shifting analysis (TSA for electrons and protons in order to infer the SEP release times at the Sun. EM observations during the times of the SEP event onset have been gathered and compared to the release time estimates of particles. Data from those events that occurred during the European day-time, i.e., those that also have observations from ground-based observatories included in SEPServer, are listed and a preliminary analysis of their associations is presented. We find that VDA results for protons can be a useful tool for the analysis of proton release times, but if the derived proton path length is out of a range of 1 AU < s ≲ 3 AU, the result of the analysis may be compromised, as indicated by the anti-correlation of the derived path length and release time delay from the associated X-ray flare. The average path length derived from VDA is about 1.9 times

Forecasting solar proton event with artificial neural network

Science.gov (United States)

Gong, J.; Wang, J.; Xue, B.; Liu, S.; Zou, Z.

Solar proton event (SPE), relatively rare but popular in solar maximum, can bring hazard situation to spacecraft. As a special event, SPE always accompanies flare, which is also called proton flare. To produce such an eruptive event, large amount energy must be accumulated within the active region. So we can investigate the character of the active region and its evolving trend, together with other such as cm radio emission and soft X-ray background to evaluate the potential of SEP in chosen area. In order to summarize the omen of SPEs in the active regions behind the observed parameters, we employed AI technology. Full connecting neural network was chosen to fulfil this job. After constructing the network, we train it with 13 parameters that was able to exhibit the character of active regions and their evolution trend. More than 80 sets of event parameter were defined to teach the neural network to identify whether an active region was potential of SPE. Then we test this model with a data base consisting SPE and non-SPE cases that was not used to train the neural network. The result showed that 75% of the choice by the model was right.

Solar Particle Radiation Storms Forecasting and Analysis within the Framework of the `HESPERIA' HORIZON 2020 Project

Science.gov (United States)

Posner, A.; Malandraki, O.; Nunez, M.; Heber, B.; Labrenz, J.; Kühl, P.; Milas, N.; Tsiropoula, G.; Pavlos, E.

2017-12-01

Two prediction tools that have been developed in the framework of HESPERIA based upon the proven concepts UMASEP and REleASE. Near-relativistic (NR) electrons traveling faster than ions (30 MeV protons have 0.25c) are used to forecast the arrival of protons of Solar Energetic Particle (SEP) events with real-time measurements of NR electrons. The faster electrons arrive at L1 30 to 90 minutes before the slower protons. REleASE (Relativistic Electron Alert System for Exploration, Posner, 2007) uses this effect to predict the proton flux by utilizing actual electron fluxes and their most recent increases. Through HESPERIA, a clone of REleASE was built in open source programming language. The same forecasting principle was adapted to real-time data from ACE/EPAM. It is shown that HESPERIA REleASE forecasting works with any NR electron flux measurements. >500 MeV solar protons are so energetic that they usually have effects on the ground, producing Ground Level Enhancement (GLE) events. Within HESPERIA, a predictor of >500 SEP proton events near earth (geostationary orbit) has been developed. In order to predict these events, UMASEP (Núñez, 2011, 2015) has been used. UMASEP makes a lag-correlation of solar electromagnetic (EM) flux with the particle flux near earth. If the correlation is high, the model infers that there is a magnetic connection through which particles are arriving. If, additionally, the intensity of the flux of the associated solar event is also high, then UMASEP issues a SEP prediction. In the case of the prediction of >500 MeV SEP events, the implemented system, called HESPERIA UMASEP-500, correlates X-ray flux with differential proton fluxes by GOES, and with fluxes collected by neutron monitor stations around the world. When the correlation estimation and flare surpasses thresholds, a >500 MeV SEP forecast is issued. These findings suggest that a synthesis of the various approaches may improve over the status quo. Both forecasting tools are

Developing a forecast model of solar proton flux profiles for well-connected events

Science.gov (United States)

Ji, E. Y.; Moon, Y. J.; Park, J.

2014-12-01

We have developed a forecast model of solar proton flux profile (> 10 MeV channel) for well-connected events. Among 136 solar proton events (SPEs) from 1986 to 2006, we select 49 well-connected ones that are all associated with single X-ray flares stronger than M1 class and start to increase within four hours after their X-ray peak times. These events show rapid increments in proton flux. By comparing several empirical functions, we select a modified Weibull curve function to approximate a SPE flux profile, which is similar to the particle injection rate. The parameters (peak value, rise time and decay time) of this function are determined by the relationship between X-ray flare parameters (peak flux, impulsive time, and emission measure) and SPE parameters. For 49 well-connected SPEs, the linear correlation between the predicted proton peak flux and the observed proton peak fluxes is 0.65 with the RMS error of 0.55 pfu in the log10. In addition, we have developed another forecast model based on flare and CME parameters using 22 SPEs. The used CME parameters are linear speed and angular width. As a result, we find that the linear correlation between the predicted proton peak flux and the observed proton peak fluxes is 0.83 with the RMS error of 0.35 pfu in the log10. From the relationship between the model error and CME acceleration, we find that CME acceleration is also an important factor for predicting proton flux profiles.

Simultaneous electron-proton irradiation of crucible grown and float-zone silicon solar cells

International Nuclear Information System (INIS)

Bernard, J.

1974-01-01

The realisation of an irradiation chamber which permits simultaneous irradiations by electrons, protons, photons and in-situ measurements of solar cells main parameters (diffusion length, I.V. characteristics) is described. Results obtained on 20 solar cells n/p 10Ωcm made in silicon pulled crystals and 20 solar cells n/p 10Ωcm made in silicon float-zone simultaneously irradiated with electrons and photons are given [fr

Fast drift kilometric radio bursts and solar proton events

Science.gov (United States)

Cliver, E. W.; Kahler, S. W.; Cane, H. V.; Mcguire, R. E.; Vonrosenvinge, T. T.; Stone, R. G.

1985-01-01

Initial results of a comparative study of major fast drift kilometric bursts and solar proton events from Sep. 1978 to Feb. 1983 are presented. It was found that only about half of all intense, long duration ( 40 min above 500 sfu) 1 MHz bursts can be associated with F 20 MeV proton events. However, for the subset of such fast drift bursts accompanied by metric Type 2 and/or 4 activity (approximately 40% of the total), the degree of association with 20 MeV events is 80%. For the reverse association, it was found that proton events with J( 20 MeV) 0.01 1 pr cm(-2)s(-1)sr(-1)MeV(-1) were typically (approximately 80% of the time) preceded by intense 1 MHz bursts that exceeded the 500 sfu level for times 20 min (median duration approximately 35 min).

Fast drift kilometric radio bursts and solar proton events

International Nuclear Information System (INIS)

Cliver, E.W.; Kahler, S.W.; Cane, H.V.; Mcguire, R.E.; Vonrosenvinge, T.T.; Stone, R.G.

1985-01-01

Initial results of a comparative study of major fast drift kilometric bursts and solar proton events from Sep. 1978 to Feb. 1983 are presented. It was found that only about half of all intense, long duration ( 40 min above 500 sfu) 1 MHz bursts can be associated with F 20 MeV proton events. However, for the subset of such fast drift bursts accompanied by metric Type 2 and/or 4 activity (approximately 40% of the total), the degree of association with 20 MeV events is 80%. For the reverse association, it was found that proton events with J( 20 MeV) 0.01 1 pr cm(-2)s(-1)sr(-1)MeV(-1) were typically (approximately 80% of the time) preceded by intense 1 MHz bursts that exceeded the 500 sfu level for times of approx. 20 min (median duration approximately 35 min)

A possible interpretation of the zebra pattern in solar radiation

International Nuclear Information System (INIS)

Fomichev, V. V.; Fainshtein, S. M.; Chernov, G. P.

2009-01-01

The nature of the zebra pattern in continual type-IV solar radio bursts is discussed. It is shown that, when a weakly relativistic monoenergetic proton beam propagates in a highly nonisothermal plasma, the energy of the slow beam mode can be negative and explosive instability can develop due to the interaction of the slow and fast beam modes with ion sound. Due to weak spatial dispersion, ion sound generation is accompanied by cascade merging, which leads to stabilization of explosive instability. The zebra pattern forms due to the scattering of fast protons by ion sound harmonics. The efficiency of the new mechanism is compared with that of previously discussed mechanisms.

Non-thermal particle acceleration in collisionless relativistic electron-proton reconnection

Science.gov (United States)

Werner, G. R.; Uzdensky, D. A.; Begelman, M. C.; Cerutti, B.; Nalewajko, K.

2018-02-01

Magnetic reconnection in relativistic collisionless plasmas can accelerate particles and power high-energy emission in various astrophysical systems. Whereas most previous studies focused on relativistic reconnection in pair plasmas, less attention has been paid to electron-ion plasma reconnection, expected in black hole accretion flows and relativistic jets. We report a comprehensive particle-in-cell numerical investigation of reconnection in an electron-ion plasma, spanning a wide range of ambient ion magnetizations σi, from the semirelativistic regime (ultrarelativistic electrons but non-relativistic ions, 10-3 ≪ σi ≪ 1) to the fully relativistic regime (both species are ultrarelativistic, σi ≫ 1). We investigate how the reconnection rate, electron and ion plasma flows, electric and magnetic field structures, electron/ion energy partitioning, and non-thermal particle acceleration depend on σi. Our key findings are: (1) the reconnection rate is about 0.1 of the Alfvénic rate across all regimes; (2) electrons can form concentrated moderately relativistic outflows even in the semirelativistic, small-σi regime; (3) while the released magnetic energy is partitioned equally between electrons and ions in the ultrarelativistic limit, the electron energy fraction declines gradually with decreased σi and asymptotes to about 0.25 in the semirelativistic regime; and (4) reconnection leads to efficient non-thermal electron acceleration with a σi-dependent power-law index, p(σ _i)˜eq const+0.7σ _i^{-1/2}. These findings are important for understanding black hole systems and lend support to semirelativistic reconnection models for powering non-thermal emission in blazar jets, offering a natural explanation for the spectral indices observed in these systems.

Open heavy-flavor measurements in ultra-relativistic nuclear collisions

Energy Technology Data Exchange (ETDEWEB)

Averbeck, Ralf

2016-12-15

Recent results from open heavy-flavor measurements in proton-proton (pp), proton/deuteron-nucleus (p/d-A), and nucleus-nucleus collisions (A-A) at RHIC and at the LHC are presented. Predictions from theoretical models are compared with the data, and implications for the properties of the hot and dense medium produced in ultra-relativistic heavy-ion collisions are discussed.

The current status of development of the electron and proton telescope for Solar Orbiter

Energy Technology Data Exchange (ETDEWEB)

Steinhagen, Jan; Kulkarni, Shrinivasrao; Boden, Sebastian; Martin-Garcia, Cesar; Boettcher, Stephan; Schuster, Bjoern; Seimetz, Lars; Wimmer-Schweingruber, Robert F. [IEAP, Christian-Albrechts-Universitaet zu Kiel (Germany)

2013-07-01

ESA's Solar Orbiter mission, scheduled for launch in January 2017, will study how the sun creates the inner heliosphere. Therefore, the spacecraft will perform in situ and remote sensing measurements of the sun on a high inclination orbit with a perihelion of about 60 solar radii, making it possible to observe the poles of the sun from nearby. The Energetic Particle Detector suite on-board of Solar Orbiter will measure particles of a wide energy range and from multiple directions. One of the important sensors of the EPD suite is the Electron and Proton Telescope. It consists of two antiparallel telescopes with two silicon detectors respectively and is designed to detect electrons between 20 - 400 keV and protons from 20 keV to 7 MeV. EPT relies on a magnet/foil technique to discriminate between electrons and protons. Its design is driven by mass allocation, the thermal environment, power consumption and electronic noise; especially the magnet system must guarantee stray fields low enough to be compliant with the Solar Orbiter EMC requirements. Here, we present the current status of the Structural/Thermal Model and Engineering Model assembly as well as the integration and testing of the prototype.

Explaining the Diverse Response of the Ultra-relativistic Van Allen Radiation Belt to Solar Wind Forcing

Science.gov (United States)

Mann, I. R.; Ozeke, L.; Murphy, K. R.; Claudepierre, S. G.; Rae, J.; Milling, D. K.; Kale, A.; Baker, D. N.

2017-12-01

The NASA Van Allen Probes have opened a new window on the dynamics of ultra-relativistic electrons in the Van Allen radiation belts. Under different solar wind forcing the outer belt is seen to respond in a variety of apparently diverse and sometimes remarkable ways. For example, sometimes a third radiation belt is carved out (e.g., September 2012), or the belts can remain depleted for 10 days or more (September 2014). More usually there is a sequential response of a strong and sometimes rapid depletion followed by a re-energization, the latter increasing outer belt electron flux by orders of magnitude on hour timescales during some of the strongest storms of this solar cycle (e.g., March 2013, March 2015). Such dynamics also appear to be often bounded at low-L by an apparently impenetrable barrier at L 2.8 through which ultra-relativistic electrons do not penetrate. Many studies in the Van Allen Probes era have sought explanations for these apparently diverse features, often incorporating the effects from multiple plasma waves. In contrast, we show how this apparently diverse behaviour can instead be explained by one dominant process: ULF wave radial transport. Once ULF wave transport rates are accurately specified by observations, and coupled to the dynamical variation of the outer boundary condition at the edge of the outer belt, the observed diverse responses can all be explained. However, in order to get good agreement with observations, the modeling reveals the importance of still currently unexplained very fast loss in the main phase which results in an almost total extinction of the belts and decouples pre- and post-storm ultra-relativistic electron flux on hour timescales. Similarly, varying plasmasheet source populations are seen to be of critical importance such that near-tail dynamics play a crucial role in Van Allen belt dynamics. Nonetheless, simple models incorporating accurate transport rates derived directly from ULF wave measurements are shown to

Probability Estimates of Solar Proton Doses During Periods of Low Sunspot Number for Short Duration Missions

Science.gov (United States)

Atwell, William; Tylka, Allan J.; Dietrich, William F.; Rojdev, Kristina; Matzkind, Courtney

2016-01-01

In an earlier paper presented at ICES in 2015, we investigated solar particle event (SPE) radiation exposures (absorbed dose) to small, thinly-shielded spacecraft during a period when the monthly smoothed sunspot number (SSN) was less than 30. Although such months are generally considered "solar-quiet", SPEs observed during these months even include Ground Level Events, the most energetic type of SPE. In this paper, we add to previous study those SPEs that occurred in 1973-2015 when the SSN was greater than 30 but less than 50. Based on the observable energy range of the solar protons, we classify the event as GLEs, sub-GLEs, and sub-sub-GLEs, all of which are potential contributors to the radiation hazard. We use the spectra of these events to construct a probabilistic model of the absorbed dose due to solar protons when SSN < 50 at various confidence levels for various depths of shielding and for various mission durations. We provide plots and tables of solar proton-induced absorbed dose as functions of confidence level, shielding thickness, and mission-duration that will be useful to system designers.

Proton Fast Ignition

International Nuclear Information System (INIS)

Key, M H; Freeman, R R; Hatchett, S P; MacKinnon, A J; Patel, P K; Snavely, R A; Stephens, R B

2006-04-01

Fast ignition (FI) by a laser generated ballistically focused proton beam is a more recently proposed alternative to the original concept of FI by a laser generated beam of relativistic electrons. It has potential advantages in less complex energy transport into dense plasma. Recent successful target heating experiments motivate further investigation of the feasibility of proton fast ignition. The concept, the physics and characteristics of the proton beams, the recent experimental work on focusing of the beams and heating of solid targets and the overall prospects for proton FI are discussed

A Proton-Cyclotron Wave Storm Generated by Unstable Proton Distribution Functions in the Solar Wind

Science.gov (United States)

Wicks, R. T.; Alexander, R. L.; Stevens, M.; Wilson, L. B., III; Moya, P. S.; Vinas, A.; Jian, L. K.; Roberts, D. A.; O’Modhrain, S.; Gilbert, J. A.;

Relativistic finite-temperature Thomas-Fermi model

Science.gov (United States)

Faussurier, Gérald

2017-11-01

We investigate the relativistic finite-temperature Thomas-Fermi model, which has been proposed recently in an astrophysical context. Assuming a constant distribution of protons inside the nucleus of finite size avoids severe divergence of the electron density with respect to a point-like nucleus. A formula for the nuclear radius is chosen to treat any element. The relativistic finite-temperature Thomas-Fermi model matches the two asymptotic regimes, i.e., the non-relativistic and the ultra-relativistic finite-temperature Thomas-Fermi models. The equation of state is considered in detail. For each version of the finite-temperature Thomas-Fermi model, the pressure, the kinetic energy, and the entropy are calculated. The internal energy and free energy are also considered. The thermodynamic consistency of the three models is considered by working from the free energy. The virial question is also studied in the three cases as well as the relationship with the density functional theory. The relativistic finite-temperature Thomas-Fermi model is far more involved than the non-relativistic and ultra-relativistic finite-temperature Thomas-Fermi models that are very close to each other from a mathematical point of view.

High-energy and high-fluence proton irradiation effects in silicon solar cells

International Nuclear Information System (INIS)

Yamaguchi, M.; Taylor, S.J.; Yang, M.; Matsuda, S.; Kawasaki, O.; Hisamatsu, T.

1996-01-01

We have examined proton irradiation damage in high-energy (1 endash 10 MeV) and high-fluence (approx-gt 10 13 cm -2 ) Si n + -p-p + structure space solar cells. Radiation testing has revealed an anomalous increase in short-circuit current I sc followed by an abrupt decrease and cell failure, induced by high-fluence proton irradiation. We propose a model to explain these phenomena by expressing the change in carrier concentration p of the base region as a function of the proton fluence in addition to the well-known model where the short-circuit current is decreased by minority-carrier lifetime reduction after irradiation. The reduction in carrier concentration due to majority-carrier trapping by radiation-induced defects has two effects. First, broadening of the depletion layer increases both the generation endash recombination current and also the contribution of the photocurrent generated in this region to the total photocurrent. Second, the resistivity of the base layer is increased, resulting in the abrupt decrease in the short circuit current and failure of the solar cells. copyright 1996 American Institute of Physics

Proton Fluxes Measured by the PAMELA Experiment from the Minimum to the Maximum Solar Activity for Solar Cycle 24

Science.gov (United States)

Martucci, M.; Munini, R.; Boezio, M.; Di Felice, V.; Adriani, O.; Barbarino, G. C.; Bazilevskaya, G. A.; Bellotti, R.; Bongi, M.; Bonvicini, V.; Bottai, S.; Bruno, A.; Cafagna, F.; Campana, D.; Carlson, P.; Casolino, M.; Castellini, G.; De Santis, C.; Galper, A. M.; Karelin, A. V.; Koldashov, S. V.; Koldobskiy, S.; Krutkov, S. Y.; Kvashnin, A. N.; Leonov, A.; Malakhov, V.; Marcelli, L.; Marcelli, N.; Mayorov, A. G.; Menn, W.; Mergè, M.; Mikhailov, V. V.; Mocchiutti, E.; Monaco, A.; Mori, N.; Osteria, G.; Panico, B.; Papini, P.; Pearce, M.; Picozza, P.; Ricci, M.; Ricciarini, S. B.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stozhkov, Y. I.; Vacchi, A.; Vannuccini, E.; Vasilyev, G.; Voronov, S. A.; Yurkin, Y. T.; Zampa, G.; Zampa, N.; Potgieter, M. S.; Raath, J. L.

2018-02-01

Precise measurements of the time-dependent intensity of the low-energy (solar activity periods, i.e., from minimum to maximum, are needed to achieve comprehensive understanding of such physical phenomena. The minimum phase between solar cycles 23 and 24 was peculiarly long, extending up to the beginning of 2010 and followed by the maximum phase, reached during early 2014. In this Letter, we present proton differential spectra measured from 2010 January to 2014 February by the PAMELA experiment. For the first time the GCR proton intensity was studied over a wide energy range (0.08–50 GeV) by a single apparatus from a minimum to a maximum period of solar activity. The large statistics allowed the time variation to be investigated on a nearly monthly basis. Data were compared and interpreted in the context of a state-of-the-art three-dimensional model describing the GCRs propagation through the heliosphere.

Dependence of regular background noise of VLF radiation and thunder-storm activity on solar wind proton density

International Nuclear Information System (INIS)

Sobolev, A.V.; Kozlov, V.I.

1997-01-01

Correlation of the intensity of slowly changing regular background noise within 9.7 kHz frequency in Yakutsk (L = 3) and of the solar wind density protons was determined. This result explains the reverse dependence of the intensity of the regular background noise on the solar activity, 27-day frequency, increase before and following geomagnetic storms, absence of relation with K p index of geomagnetic activity. Conclusion is made that growth of density of the solar wind protons results in increase of the regular background noise and thunderstorm activity

Monitoring solar energetic particles with an armada of European spacecraft and the new automated SEPF (Solar Energetic Proton Fluxes) Tool

Science.gov (United States)

Sandberg, I.; Daglis, I. A.; Anastasiadis, A.; Balasis, G.; Georgoulis, M.; Nieminen, P.; Evans, H.; Daly, E.

2012-01-01

Solar energetic particles (SEPs) observed in interplanetary medium consist of electrons, protons, alpha particles and heavier ions (up to Fe), with energies from dozens of keVs to a few GeVs. SEP events, or SEPEs, are particle flux enhancements from background level ( 30 MeV. The main part of SEPEs results from the acceleration of particles either by solar flares and/or by interplanetary shocks driven by Coronal Mass Ejections (CMEs); these accelerated particles propagate through the heliosphere, traveling along the interplanetary magnetic field (IMF). SEPEs show significant variability from one event to another and are an important part of space weather, because they pose a serious health risk to humans in space and a serious radiation hazard for the spacecraft hardware which may lead to severe damages. As a consequence, engineering models, observations and theoretical investigations related to the high energy particle environment is a priority issue for both robotic and manned space missions. The European Space Agency operates the Standard Radiation Environment Monitor (SREM) on-board six spacecraft: Proba-1, INTEGRAL, Rosetta, Giove-B, Herschel and Planck, which measures high-energy protons and electrons with a fair angular and spectral resolution. The fact that several SREM units operate in different orbits provides a unique chance for comparative studies of the radiation environment based on multiple data gathered by identical detectors. Furthermore, the radiation environment monitoring by the SREM unit onboard Rosetta may reveal unknown characteristics of SEPEs properties given the fact that the majority of the available radiation data and models only refer to 1AU solar distances. The Institute for Space Applications and Remote Sensing of the National Observatory of Athens (ISARS/NOA) has developed and validated a novel method to obtain flux spectra from SREM count rates. Using this method and by conducting detailed scientific studies we have showed in

Diffusion length variation in 0.5- and 3-MeV-proton-irradiated, heteroepitaxial indium phosphide solar cells

Science.gov (United States)

Jain, Raj K.; Weinberg, Irving; Flood, Dennis J.

1993-01-01

Indium phosphide (InP) solar cells are more radiation resistant than gallium arsenide (GaAs) and silicon (Si) solar cells, and their growth by heteroepitaxy offers additional advantages leading to the development of light weight, mechanically strong, and cost-effective cells. Changes in heteroepitaxial InP cell efficiency under 0.5- and 3-MeV proton irradiations have been explained by the variation in the minority-carrier diffusion length. The base diffusion length versus proton fluence was calculated by simulating the cell performance. The diffusion length damage coefficient, K(sub L), was also plotted as a function of proton fluence.

Influence of non-bi-maxwellian distribution function of solar wind protons on the ion cyclotron instability

International Nuclear Information System (INIS)

Leubner, M.P.

1978-01-01

Satellite measurements of the thermal anisotropy of solar wind protons have shown that the particle velocity distributions at 1 AU are not adequately described by a bi-Maxwellian distribution function. On the other hand, the stability criteria derived from a bi-Maxwellian distribution require T/sub perpendicular/>T/sub parallel/, which is, however, hardly ever observed. A modified axisymmetric distribution function for solar wind protons is used here to calculate the stability and growth rate of the iom cyclotron instability in a warm slow speed solar plasma at 1 AU. Cyclotron wave growth is found also in the case t/sub parallel/>T/sub perpendicular/

Effect of front and rear incident proton irradiation on silicon solar cells

Science.gov (United States)

Anspaugh, Bruce; Kachare, Ram

1987-01-01

Four solar cell types of current manufacture were irradiated through the front and rear surfaces with protons in the energy range between 1 and 10 MeV. The solar cell parameters varied for this study were cell thickness and back surface field (BSF) vs. no BSF. Some cells were irradiated at normal incidence and an equal number were irradiated with simulated isotropic fluences. The solar cell electrical characteristics were measured under simulated AM0 illumination after each fluence. Using the normal incidence data, proton damage coefficients were computed for all four types of cells for both normal and omnidirectional radiation fields. These were found to compare well with the omnidirectional damage coefficients derived directly from the rear-incidence radiation data. Similarly, the rear-incidence omnidirectional radiation data were used to compute appropriate damage coefficients. A method for calculating the effect of a spectrum of energies is derived from these calculations. It is suitable for calculating the degradation of cells in space when they have minimal rear-surface shielding.

Stopping power of K electrons at extreme relativistic energies

International Nuclear Information System (INIS)

Leung, P.T.; Rustgi, M.L.

1983-01-01

The recent work of Anholt on K-vacancy production by relativistic projectiles has been applied to calculate the stopping power of the K electrons. The results show that for protons of energy approx.10 3 GeV and heavy target elements, the relativistic contributions to the stopping power amount to several times the resuls due to the longitudinal terms obtained from Walske's work

Adjusted NIEL calculations for estimating proton-induced degradation of GaInP/GaAs/Ge space solar cells

International Nuclear Information System (INIS)

Lu Ming; Wang Rong; Liu Yunhong; Hu Wentao; Feng Zhao; Han Zhaolei

2011-01-01

The non-ionizing energy loss (NIEL) values for protons in solar cells should be modified by taking into account the distribution of the Bragg damage peak in the active region to calculate the corresponding displacement damage dose. In this paper, based upon a thin target approximation, a new approach is presented to modify NIEL values for protons on a GaAs sub-cell. Adjusted NIEL values can be used to estimate the degradation induced by protons on GaInP/GaAs/Ge triple-junction space solar cells.

Proton-proton and deuteron-deuteron correlations in interactions of relativistic helium nuclei with protons

International Nuclear Information System (INIS)

Galazka-Friedman, J.; Sobczak, T.; Stepaniak, J.; Zielinski, I.P.; Bano, M.; Hlavacova, J.; Martinska, G.; Patocka, J.; Seman, M.; Sandor, L.; Urban, J.

1993-01-01

The reactions 4 Hep→pp+X, 3 Hep→pp+X and 4 Hep→ddp have been investigated and the correlation function has been measured for protons and deuterons with small relative momenta. Strong positive correlation has been observed for protons related mainly to the final state interactions in 1 S 0 state. The root mean square radius of the proton source calculated from the correlation function has been found to be equal to (1.7±0.3) fm and (2.1±0.3) fm for 4 He and 3 He respectively. It agrees with the known radii of these nuclei. (orig.)

Relativistic Celestial Mechanics of the Solar System

CERN Document Server

Kopeikin, Sergei; Kaplan, George

2011-01-01

This authoritative book presents the theoretical development of gravitational physics as it applies to the dynamics of celestial bodies and the analysis of precise astronomical observations. In so doing, it fills the need for a textbook that teaches modern dynamical astronomy with a strong emphasis on the relativistic aspects of the subject produced by the curved geometry of four-dimensional spacetime. The first three chapters review the fundamental principles of celestial mechanics and of special and general relativity. This background material forms the basis for understanding relativistic r

Sputtering of Lunar Regolith Simulant by Protons and Multicharged Heavy Ions at Solar Wind Energies

International Nuclear Information System (INIS)

Meyer, Fred W.; Harris, Peter R.; Taylor, C.N.; Meyer, Harry M. III; Barghouty, N.; Adams, J. Jr.

2011-01-01

We report preliminary results on sputtering of a lunar regolith simulant at room temperature by singly and multiply charged solar wind ions using quadrupole and time-of-flight (TOF) mass spectrometry approaches. Sputtering of the lunar regolith by solar-wind heavy ions may be an important particle source that contributes to the composition of the lunar exosphere, and is a possible mechanism for lunar surface ageing and compositional modification. The measurements were performed in order to assess the relative sputtering efficiency of protons, which are the dominant constituent of the solar wind, and less abundant heavier multicharged solar wind constituents, which have higher physical sputtering yields than same-velocity protons, and whose sputtering yields may be further enhanced due to potential sputtering. Two different target preparation approaches using JSC-1A AGGL lunar regolith simulant are described and compared using SEM and XPS surface analysis.

The current status of model development of the electron and proton telescope for Solar Orbiter

Energy Technology Data Exchange (ETDEWEB)

Steinhagen, Jan; Kulkarni, S.R.; Tammen, Jan; Boden, Sebastian; Elftmann, Robert; Martin, Cesar; Ravanbakhsh, Ali; Boettcher, Stephan I.; Seimetz, Lars; Schuster, Bjoern; Wimmer-Schweingruber, Robert [Institute for Experimental and Applied Physics, University of Kiel (Germany)

2014-07-01

ESA's Solar Orbiter mission, scheduled for launch in January 2017, will study how the sun creates the inner heliosphere. Therefore, the spacecraft will perform in situ and remote sensing measurements of the sun on a high inclination orbit with a perihelion of about 60 solar radii, making it possible to observe the poles of the sun from nearby. The Energetic Particle Detector suite on-board of Solar Orbiter will measure particles of a wide energy range and from multiple directions. One of the important sensors of the EPD suite is the Electron Proton Telescope. It consists of two antiparallel telescopes with two silicon detectors respectively and is designed to detect electrons between 20 - 400 keV and protons from 20 keV to 7 MeV. EPT relies on a magnet/foil technique to discriminate between electrons and protons. Here, we present the testing of the Structural and Thermal Model, which has already been delivered to ASTRIUM for spacecraft level tests as well as the integration and testing of the Engineering Model, which already provides full electrical functionality.

Superheavy nuclei in the relativistic mean-field theory

International Nuclear Information System (INIS)

Lalazissis, G.A.; Ring, P.; Gambhir, Y.K.

1996-01-01

We have carried out a study of superheavy nuclei in the framework of the relativistic mean-field theory. Relativistic Hartree-Bogoliubov (RHB) calculations have been performed for nuclei with large proton and neutron numbers. A finite-range pairing force of Gogny type has been used in the RHB calculations. The ground-state properties of very heavy nuclei with atomic numbers Z=100-114 and neutron numbers N=154-190 have been obtained. The results show that in addition to N=184 the neutron numbers N=160 and N=166 exhibit an extra stability as compared to their neighbors. For the case of protons the atomic number Z=106 is shown to demonstrate a closed-shell behavior in the region of well deformed nuclei about N=160. The proton number Z=114 also indicates a shell closure. Indications for a doubly magic character at Z=106 and N=160 are observed. Implications of shell closures on a possible synthesis of superheavy nuclei are discussed. (orig.)

Cosmic gamma-ray burst from intergalactic relativistic dust grains

International Nuclear Information System (INIS)

Dasgupta, A.K.

1979-01-01

Charged dust grains of radii a approximately 3 x 10 -6 approximately 3 x 10 -5 cm may acquire relativistic energy (>10 18 eV) in the intergalactic medium. In order to attain relativistic energy, dust grains have to move in and out ('scattering') of the magnetic field of the medium. A relativistic grain of radius a -5 cm with Lorentz factor γ approximately 10 3 approaching the Earth will break up either due to electrostatic charge or due to sputtering about 150 approximately 100 km, and may scatter solar photons via a fluorescence process. Dust grains may also melt into droplets in the solar vicinity and may contribute towards observed gamma-ray bursts. (Auth.)

Influence of ancient solar-proton events in the evolution of life

International Nuclear Information System (INIS)

Reid, G.C.; Isaksen, I.S.A.; Crutzen, P.J.; Holzer, T.E.

1976-01-01

It is stated that there is mounting evidence that past extinctions of faunal species have occurred in near coincidence with reversals in polarity of the geomagnetic field. Could the link lie in catastrophic depletions of stratospheric ozone caused by solar-proton irradiation over a reduced geomagnetic field. (author)

PROTON HEATING IN SOLAR WIND COMPRESSIBLE TURBULENCE WITH COLLISIONS BETWEEN COUNTER-PROPAGATING WAVES

Energy Technology Data Exchange (ETDEWEB)

He, Jiansen; Tu, Chuanyi; Wang, Linghua; Pei, Zhongtian [School of Earth and Space Sciences, Peking University, Beijing, 100871 (China); Marsch, Eckart [Institute for Experimental and Applied Physics, Christian-Albrechts-Universität zu Kiel, D-24118 Kiel (Germany); Chen, Christopher H. K. [Department of Physics, Imperial College London, London SW7 2AZ (United Kingdom); Zhang, Lei [Sate Key Laboratory of Space Weather, Chinese Academy of Sciences, Beijing 100190 (China); Salem, Chadi S.; Bale, Stuart D., E-mail: jshept@gmail.com [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States)

2015-11-10

Magnetohydronamic turbulence is believed to play a crucial role in heating laboratory, space, and astrophysical plasmas. However, the precise connection between the turbulent fluctuations and the particle kinetics has not yet been established. Here we present clear evidence of plasma turbulence heating based on diagnosed wave features and proton velocity distributions from solar wind measurements by the Wind spacecraft. For the first time, we can report the simultaneous observation of counter-propagating magnetohydrodynamic waves in the solar wind turbulence. As opposed to the traditional paradigm with counter-propagating Alfvén waves (AWs), anti-sunward AWs are encountered by sunward slow magnetosonic waves (SMWs) in this new type of solar wind compressible turbulence. The counter-propagating AWs and SWs correspond, respectively, to the dominant and sub-dominant populations of the imbalanced Elsässer variables. Nonlinear interactions between the AWs and SMWs are inferred from the non-orthogonality between the possible oscillation direction of one wave and the possible propagation direction of the other. The associated protons are revealed to exhibit bi-directional asymmetric beams in their velocity distributions: sunward beams appear in short, narrow patterns and anti-sunward in broad extended tails. It is suggested that multiple types of wave–particle interactions, i.e., cyclotron and Landau resonances with AWs and SMWs at kinetic scales, are taking place to jointly heat the protons perpendicular and in parallel.

Geosynchronous Relativistic Electron Events Associated with High-Speed Solar Wind Streams in 2006

Directory of Open Access Journals (Sweden)

Sungeun Lee

2009-12-01

Full Text Available Recurrent enhancements of relativistic electron events at geosynchronous orbit (GREEs were observed in 2006. These GREE enhancements were associated with high-speed solar wind streams coming from the same coronal hole. For the first six months of 2006, the occurrence of GREEs has 27 day periodicity and the GREEs were enhanced with various flux levels. Several factors have been studied to be related to GREEs: (1 High speed stream, (2 Pc5 ULF wave activity, (3 Southward IMF Bz, (4 substorm occurrence, (5 Whistler mode chorus wave, and (6 Dynamic pressure. In this paper, we have examined the effectiveness about those parameters in selected periods.

Study of the energetic proton production in relativistic heavy ions Ne + nuclei collisions, using Diogene detector. Hadronic matter temperature

International Nuclear Information System (INIS)

Rahmani, A.

1988-12-01

The study of the proton's production differential cross sections, in the collision of relativistic heavy ions, allows to obtain the nuclear-matter temperature and gives information about the nucleons large burst pulses in the nucleus. The chosen thermodynamic model is a generalized approach of the R. Hagedorn model, applied to heavy ions collisions: the nuclear matter is divided in volume elements δV assumed to be in thermal and chemical equilibrium and emitting particles and fragments isotropically, inside their own system. The applied nuclear-matter velocity distribution depended only on the impact parameter and on the relationship between the chemical potential and the temperature. The predictions of this thermodynamic model were compared to the Saturne experimental results, using Diogene detector. The obtained temperature values are similar to those given by D. Hahn and H. Stoker. The proton production cross sections were measured for backward emitting angles. A relationship between the cross sections and the burst pulse distribution in the nuclei was settled [fr

Scaling phenomenon in relativistic nucleus-nucleus collisions

International Nuclear Information System (INIS)

Wong, C.Y.; Blankenbecler, R.

1980-01-01

New scaling variables for proton and pion production in relativistic nucleus-nucleus collisions are introduced which are the generalizations of the Feynmann scaling variable. They allow a simple description of the cross sections at forward and backward angles. 2 figures

Recent progresses in relativistic beam-plasma instability theory

Directory of Open Access Journals (Sweden)

A. Bret

2010-11-01

Full Text Available Beam-plasma instabilities are a key physical process in many astrophysical phenomena. Within the fireball model of Gamma ray bursts, they first mediate a relativistic collisionless shock before they produce upstream the turbulence needed for the Fermi acceleration process. While non-relativistic systems are usually governed by flow-aligned unstable modes, relativistic ones are likely to be dominated by normally or even obliquely propagating waves. After reviewing the basis of the theory, results related to the relativistic kinetic regime of the poorly-known oblique unstable modes will be presented. Relevant systems besides the well-known electron beam-plasma interaction are presented, and it is shown how the concept of modes hierarchy yields a criterion to assess the proton to electron mass ratio in Particle in cell simulations.

Nitrate Deposition to Surface Snow at Summit, Greenland, Following the 9 November 2000 Solar Proton Event

Science.gov (United States)

Duderstadt, Katharine A.; Dibb, Jack E.; Schwadron, Nathan A.; Spence, Harlan E.; Jackman, Charles Herbert; Randall, Cora E.; Solomon, Stanley C.; Mills, Michael J.

2014-01-01

This study considers whether spurious peaks in nitrate ions in snow sampled at Summit, Greenland from August 2000 to August 2002 are related to solar proton events. After identifying tropospheric sources of nitrate on the basis of correlations with sulfate, ammonium, sodium, and calcium, we use the three-dimensional global Whole Atmosphere Community Climate Model (WACCM) to examine unaccounted for nitrate spikes. Model calculations confirm that solar proton events significantly impact HOx, NOx, and O3 levels in the mesosphere and stratosphere during the weeks and months following the major 9 November 2000 solar proton event. However, SPE-enhanced NOy calculated within the atmospheric column is too small to account for the observed nitrate ion peaks in surface snow. Instead, our WACCM results suggest that nitrate spikes not readily accounted for by measurement correlations are likely of anthropogenic origin. These results, consistent with other recent studies, imply that nitrate spikes in ice cores are not suitable proxies for individual SPEs and motivate the need to identify alternative proxies.

Is the relativistic approach really useful to nuclear reactions?

CERN Document Server

Miyazaki, K

2003-01-01

We have reconsidered the non-relativistic distorted-wave t-matrix approximation (NR-DWTA) for proton knockout (p,2p) reaction using modern high-quality phenomenological optical potentials and NN t-matrix. We have calculated 40Ca(p,2p) reactions at T_LAB=200MeV and compared the results with the relativistic distorted-wave impulse approximation (RDWIA) calculations. It is found that the NR-DWTA is superior to the RDWIA in consistent description of the cross section and the analyzing power. An immediate relativistic extension of the DWIA to the nuclear reaction has a problem.

Proton thermal energetics in the solar wind: Helios reloaded

Czech Academy of Sciences Publication Activity Database

Hellinger, Petr; Trávníček, Pavel M.; Štverák, Štěpán; Matteini, L.; Velli, M.

2013-01-01

Roč. 118, č. 4 (2013), s. 3151-3165 ISSN 2169-9380 R&D Projects: GA ČR GAP209/12/2041; GA ČR GAP209/12/2023 EU Projects: European Commission(XE) 263340 - SWIFF Grant - others:EU(XE) SHOCK Project No. 284515 Institutional support: RVO:67985815 ; RVO:68378289 Keywords : solar wind * proton energetics * turbulent heating Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics; BL - Plasma and Gas Discharge Physics (UFA-U) Impact factor: 3.440, year: 2013

The effects of electron and proton radiation on GaSb infrared solar cells

Science.gov (United States)

Gruenbaum, P. E.; Avery, J. E.; Fraas, L. M.

1991-01-01

Gallium antimonide (GaSb) infrared solar cells were exposed to 1 MeV electrons and protons up to fluences of 1 times 10(exp 15) cm (-2) and 1 times 10(exp 12) cm (-2) respectively. In between exposures, current voltage and spectral response curves were taken. The GaSb cells were found to degrade slightly less than typical GaAs cells under electron irradiation, and calculations from spectral response curves showed that the damage coefficient for the minority carrier diffusion length was 3.5 times 10(exp 8). The cells degraded faster than GaAs cells under proton irradiation. However, researchers expect the top cell and coverglass to protect the GaSb cell from most damaging protons. Some annealing of proton damage was observed at low temperatures (80 to 160 C).

Track structure model for damage to mammalian cell cultures during solar proton events

Science.gov (United States)

Cucinotta, F. A.; Wilson, J. W.; Townsend, L. W.; Shinn, J. L.; Katz, R.

1992-01-01

Solar proton events (SPEs) occur infrequently and unpredictably, thus representing a potential hazard to interplanetary space missions. Biological damage from SPEs will be produced principally through secondary electron production in tissue, including important contributions due to delta rays from nuclear reaction products. We review methods for estimating the biological effectiveness of SPEs using a high energy proton model and the parametric cellular track model. Results of the model are presented for several of the historically largest flares using typical levels and body shielding.

Proton fire hose instabilities in the expanding solar wind

Czech Academy of Sciences Publication Activity Database

Hellinger, Petr

2017-01-01

Roč. 83, č. 1 (2017), č. článku 705830105. ISSN 0022-3778 Institutional support: RVO:68378289 Keywords : astrophysicals plasmas * plasma expansion * plasma simulation Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.160, year: 2016 https://www.cambridge.org/ core /journals/journal-of-plasma-physics/article/proton-fire-hose-instabilities-in-the-expanding-solar-wind/6BA70378B25728533588A1A68073AC2F

ACCELERATION OF POLARIZED PROTONS AT RHIC

International Nuclear Information System (INIS)

HUANG, H.

2002-01-01

Relativistic Heavy Ion Collider (RHIC) ended its second year of operation in January 2002 with five weeks of polarized proton collisions. Polarized protons were successfully injected in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. This is the first time that polarized protons have been accelerated to 100 GeV. The machine performance and accomplishments during the polarized proton run will be reviewed. The plans for the next polarized proton run will be outlined

Diffusion length variation and proton damage coefficients for InP/In(x)Ga(1-x)As/GaAs solar cells

Science.gov (United States)

Jain, R. K.; Weinberg, I.; Flood, D. J.

1993-01-01

Indium phosphide solar cells are more radiation resistant than gallium arsenide and silicon solar cells, and their growth by heteroepitaxy offers additional advantages leading to the development of lighter, mechanically strong and cost-effective cells. Changes in heteroepitaxial InP cell efficiency under 0.5 and 3 MeV proton irradiations are explained by the variation in the minority-carrier diffusion length. The base diffusion length versus proton fluence is calculated by simulating the cell performance. The diffusion length damage coefficient K(L) is plotted as a function of proton fluence.

Relativistic shocks and particle acceleration

International Nuclear Information System (INIS)

Heavens, A.F.

1988-01-01

In this paper, we investigate the fluid dynamics of relativistic shock waves, and use the results to calculate the spectral index of particles accelerated by the Fermi process in such shocks. We have calculated the distributions of Fermi-accelerated particles at shocks propagating into cold proton-electron plasma and also cold electron-positron plasma. We have considered two different power spectra for the scattering waves, and find, in contrast to the non-relativistic case, that the spectral index of the accelerated particles depends on the wave power spectrum. On the assumption of thermal equilibrium both upstream and downstream, we present some useful fits for the compression ratio of shocks propagating at arbitrary speeds into gas of any temperature. (author)

A KINETIC ALFVEN WAVE AND THE PROTON DISTRIBUTION FUNCTION IN THE FAST SOLAR WIND

International Nuclear Information System (INIS)

Li Xing; Lu Quanming; Chen Yao; Li Bo; Xia Lidong

2010-01-01

Using one-dimensional test particle simulations, the effect of a kinetic Alfven wave on the velocity distribution function (VDF) of protons in the collisionless solar wind is investigated. We first use linear Vlasov theory to numerically obtain the property of a kinetic Alfven wave (the wave propagates in the direction almost perpendicular to the background magnetic field). We then numerically simulate how the wave will shape the proton VDF. It is found that Landau resonance may be able to generate two components in the initially Maxwellian proton VDF: a tenuous beam component along the direction of the background magnetic field and a core component. The streaming speed of the beam relative to the core proton component is about 1.2-1.3 Alfven speed.

Correlations for damage in diffused-junction InP solar cells induced by electron and proton irradiation

International Nuclear Information System (INIS)

Yamaguchi, M.; Takamoto, T.; Taylor, S.J.; Walters, R.J.; Summers, G.P.; Flood, D.J.; Ohmori, M.

1997-01-01

The damage to diffused-junction n + -p InP solar cells induced by electron and proton irradiations over a wide range of energy from 0.5 to 3 MeV and 0.015 to 20 MeV, respectively, has been examined. The experimental electron and proton damage coefficients have been analyzed in terms of displacement damage dose, which is the product of the particle fluence and the calculated nonionizing energy loss [G. P. Summers, E. A. Burke, R. Shapiro, S. R. Messenger, and R. J. Walters, IEEE Trans. Nucl. Sci. 40, 1300 (1993).] Degradation of InP cells due to irradiation with electrons and protons with energies of more than 0.5 MeV show a single curve as a function of displacement damage dose. Based on the deep-level transient spectroscopy analysis, damage equivalence between electron and proton irradiation is discussed. InP solar cells are confirmed to be substantially more radiation resistant than Si and GaAs-on-Ge cells. copyright 1997 American Institute of Physics

Elliptic flow based on a relativistic hydrodynamic model

Energy Technology Data Exchange (ETDEWEB)

Hirano, Tetsufumi [Department of Physics, Waseda Univ., Tokyo (Japan)

1999-08-01

Based on the (3+1)-dimensional hydrodynamic model, the space-time evolution of hot and dense nuclear matter produced in non-central relativistic heavy-ion collisions is discussed. The elliptic flow parameter v{sub 2} is obtained by Fourier analysis of the azimuthal distribution of pions and protons which are emitted from the freeze-out hypersurface. As a function of rapidity, the pion and proton elliptic flow parameters both have a peak at midrapidity. (author)

Test of Relativistic Gravity for Propulsion at the Large Hadron Collider

Science.gov (United States)

Felber, Franklin

2010-01-01

A design is presented of a laboratory experiment that could test the suitability of relativistic gravity for propulsion of spacecraft to relativistic speeds. An exact time-dependent solution of Einstein's gravitational field equation confirms that even the weak field of a mass moving at relativistic speeds could serve as a driver to accelerate a much lighter payload from rest to a good fraction of the speed of light. The time-dependent field of ultrarelativistic particles in a collider ring is calculated. An experiment is proposed as the first test of the predictions of general relativity in the ultrarelativistic limit by measuring the repulsive gravitational field of bunches of protons in the Large Hadron Collider (LHC). The estimated `antigravity beam' signal strength at a resonant detector of each proton bunch is 3 nm/s2 for 2 ns during each revolution of the LHC. This experiment can be performed off-line, without interfering with the normal operations of the LHC.

New approximation for Glauber theory on stripping of relativistic deuterons

International Nuclear Information System (INIS)

Nissen-Meyer, S.A.

1978-03-01

The momentum distribution of forward protons from relativistic collisions of deuterons with nuclei is computed from a Glauber theoretical Ansatz of Bertocchi and Tekou. The outgoing proton-neutron scattering state (disintegrated deuteron) with a plane wave minus the components of this plane wave along the deuteron bound state vector is approximated. With no fitted parameters good agreement is found with data from the reaction d + C 12 → p + X in the region corresponding to nonrelativistic Fermi momenta in the forward direction. At more relativistic Fermi momenta, the model deviates more from the data, which can be due to incorrect choice of the short distance part of the deuteron wave function as well as off-shell effects in the deuteron

Development of the relativistic impulse approximation

International Nuclear Information System (INIS)

Wallace, S.J.

1985-01-01

This talk contains three parts. Part I reviews the developments which led to the relativistic impulse approximation for proton-nucleus scattering. In Part II, problems with the impulse approximation in its original form - principally the low energy problem - are discussed and traced to pionic contributions. Use of pseudovector covariants in place of pseudoscalar ones in the NN amplitude provides more satisfactory low energy results, however, the difference between pseudovector and pseudoscalar results is ambiguous in the sense that it is not controlled by NN data. Only with further theoretical input can the ambiguity be removed. Part III of the talk presents a new development of the relativistic impulse approximation which is the result of work done in the past year and a half in collaboration with J.A. Tjon. A complete NN amplitude representation is developed and a complete set of Lorentz invariant amplitudes are calculated based on a one-meson exchange model and appropriate integral equations. A meson theoretical basis for the important pair contributions to proton-nucleus scattering is established by the new developments. 28 references

Causal relationships between solar proton events and single event upsets for communication satellites

Science.gov (United States)

Lohmeyer, W. Q.; Cahoy, K.; Liu, Shiyang

In this work, we analyze a historical archive of single event upsets (SEUs) maintained by Inmarsat, one of the world's leading providers of global mobile satellite communications services. Inmarsat has operated its geostationary communication satellites and collected extensive satellite anomaly and telemetry data since 1990. Over the course of the past twenty years, the satellites have experienced more than 226 single event upsets (SEUs), a catch-all term for anomalies that occur in a satellite's electronics such as bit-flips, trips in power supplies, and memory changes in attitude control systems. While SEUs are seemingly random and difficult to predict, we correlate their occurrences to space weather phenomena, and specifically show correlations between SEUs and solar proton events (SPEs). SPEs are highly energetic protons that originate from solar coronal mass ejections (CMEs). It is thought that when these particles impact geostationary (GEO) satellites they can cause SEUs as well as solar array degradation. We calculate the associated statistical correlations that each SEU occurs within one day, one week, two weeks, and one month of 10 MeV SPEs between 10 - 10,000 particle flux units (pfu). However, we find that SPEs are most prevalent at solar maximum and that the SEUs on Inmarsat's satellites occur out of phase with the solar maximum. Ultimately, this suggests that SPEs are not the primary cause of the Inmarsat SEUs. A better understanding of the causal relationship between SPEs and SEUs will help the satellite communications industry develop component and operational space weather mitigation techniques as well as help the space weather community to refine radiation models.

Solar wind proton temperature anisotropy: Linear theory and WIND/SWE observations

Czech Academy of Sciences Publication Activity Database

Hellinger, Petr; Trávníček, Pavel; Kasper, J. C.; Lazarus, A. J.

2006-01-01

Roč. 33, č. 9 (2006), L09101/1-L09101/4 ISSN 0094-8276 R&D Projects: GA AV ČR(CZ) IAA3042403 Grant - others:ESA(XE) PECS 98024; NASA (US) NAG-10915 Institutional research plan: CEZ:AV0Z30420517 Keywords : proton temperature anisotropy * solar wind * in situ observations Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.602, year: 2006

Protons and alpha particles in the expanding solar wind: Hybrid simulations

Czech Academy of Sciences Publication Activity Database

Hellinger, Petr; Trávníček, Pavel M.

2013-01-01

Roč. 118, č. 9 (2013), s. 5421-5429 ISSN 2169-9380 R&D Projects: GA ČR GAP209/12/2023 Grant - others:EU(XE) SHOCK Project No. 284515 Institutional support: RVO:67985815 ; RVO:68378289 Keywords : solar wind * proton energetics * turbulent heating Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics; BL - Plasma and Gas Discharge Physics (UFA-U) Impact factor: 3.440, year: 2013

Relativistic mean field calculations in neutron-rich nuclei

Energy Technology Data Exchange (ETDEWEB)

Gangopadhyay, G.; Bhattacharya, Madhubrata [Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700 009 (India); Roy, Subinit [Saha Institute of Nuclear Physics, Block AF, Sector 1, Kolkata- 700 064 (India)

2014-08-14

Relativistic mean field calculations have been employed to study neutron rich nuclei. The Lagrange's equations have been solved in the co-ordinate space. The effect of the continuum has been effectively taken into account through the method of resonant continuum. It is found that BCS approximation performs as well as a more involved Relativistic Continuum Hartree Bogoliubov approach. Calculations reveal the possibility of modification of magic numbers in neutron rich nuclei. Calculation for low energy proton scattering cross sections shows that the present approach reproduces the density in very light neutron rich nuclei.

Coherent production of {epsilon}{sup +} particles in crystal using proton beam from SSC

Energy Technology Data Exchange (ETDEWEB)

Okorokov, V.V.; Dubin, A.Yu. [ITER, Moscow, (Russian Federation)

1995-05-01

The unique possibilities of the SSC can be ideally used for a new generation of coherent generation experiments with relativistic protons which require 20 Tev energy of the incident beam. The availability of 20 Tev proton beam at SSC allows new experiments on coherent production of {var_epsilon}{sup +} particle by relativistic proton in crystal. Experiment carried out at low energies can now be extended with protons in very narrow energy region (resonance energy, which easy can be calculated) using the new accelerator facilities at SSC. We propose to study coherent production via the Coulomb field of the cristal atoms to excite the transition p + {gamma}{implies} {var_epsilon} {sup +} (1189).

Neutral escape at Mars induced by the precipitation of high-energy protons and hydrogen atoms of the solar wind origin

Science.gov (United States)

Shematovich, Valery I.

2017-04-01

One of the first surprises of the NASA MAVEN mission was the observation by the SWIA instrument of a tenuous population of protons with solar wind energies travelling anti-sunward near periapsis, at altitudes of 150-250 km (Halekas et al., 2015). While the penetration of solar wind protons to low altitude is not completely unexpected given previous Mars Express results, this population maintains exactly the same velocity as the solar wind observed. From previous studies it was known that some fraction of the solar wind can interact with the extended corona of Mars. By charge exchange with the neutral particles in this corona, some fraction of the incoming solar wind protons can gain an electron and become an energetic neutral hydrogen atom. Once neutral, these particles penetrate through the Martian induced magnetosphere with ease, with free access to the collisional atmosphere/ionosphere. The origin, kinetics and transport of the suprathermal O atoms in the transition region (from thermosphere to exosphere) of the Martian upper atmosphere due to the precipitation of the high-energy protons and hydrogen atoms are discussed. Kinetic energy distribution functions of suprathermal and superthermal (ENA) oxygen atoms formed in the Martian upper atmosphere were calculated using the kinetic Monte Carlo model (Shematovich et al., 2011, Shematovich, 2013) of the high-energy proton and hydrogen atom precipitation into the atmosphere. These functions allowed us: (a) to estimate the non-thermal escape rates of neutral oxygen from the Martian upper atmosphere, and (b) to compare with available MAVEN measurements of oxygen corona. Induced by precipitation the escape of hot oxygen atoms may become dominant under conditions of extreme solar events - solar flares and coronal mass ejections, - as it was shown by recent observations of the NASA MAVEN spacecraft (Jakosky et al., 2015). This work is supported by the RFBR project and by the Basic Research Program of the Praesidium of

Fast electrons in small solar flares

International Nuclear Information System (INIS)

Lin, R.P.

1975-01-01

Because approximately 5-100 keV electrons are frequently accelerated and emitted by the Sun in small flares, it is possible to define a detailed characteristic physical picture of these events. The review summarizes both the direct spacecraft observations of non-relativistic solar electrons, and observations of the X-ray and radio emission generated by these particles at the Sun and in the interplanetary medium. These observations bear on the basic astrophysical process of particle acceleration in tenuous plasmas. It is found that in many small solar flares the approximately 5-100 keV electrons accelerated during flash phase constitute the bulk of the total flare energy. Thus the basic flare mechanism in these flares essentially converts the available flare energy into fast electrons. These electrons may produce the other flare electromagnetic emissions through their interactions with the solar atmosphere. In large proton flares these electrons may provide the energy to eject material from the Sun and to create a shock wave which could then accelerate nuclei and electrons to much higher energies. (Auth.)

Anomalous effects in silicon solar cell irradiated by 1-MeV protons

Science.gov (United States)

Kachare, R.; Anspaugh, B. E.

1989-01-01

Several silicon solar cells having thicknesses of approximately 63 microns, with and without back-surface fields (BSF), were irradiated with 1-MeV protons having fluences between 10 to the 10th and 10 to the 12th sq cm. The irradiations were performed using both normal and isotropic incidence on the rear surfaces of the cells. It was observed that after irradiation with fluences greater than 10 to the 11th protons/sq cm, all BSF cells degraded at a faster rate than cells without BSF. The irradiation results are analyzed using a model in which irradiation-induced defects in the BSF region are taken into account. Tentatively, it is concluded that an increase in defect density due to the formation of aluminum and proton complexes in BSF cells is responsible for the higher-power loss in the BSF cells compared to the non-BSF cells.

A lower limit to the altitude of coronal particle storage regions deduced from solar proton energy spectra

Science.gov (United States)

Krimigis, S. M.

1973-01-01

The spectrum of low energy protons observed at 1 AU following solar flares shows little or no evidence of energy degradation down to approximately 0.3 MeV. Such observations may be used to set a lower limit on the altitude of hypothetical coronal particle storage regions, ranging from 2 to 7 R sub s. It is pointed out that closed coronal magnetic loop structures are observed to extend to 2R sub s, so that long-term storage of low energy protons does not take place in the immediate vicinity of the sun. It is further suggested that in the few cases where the proton spectrum appears to be degraded at low energies, the energy loss may be due to adiabatic deceleration in the expanding solar wind. The alternative of continual acceleration is suggested as a plausible substitute for the particle storage hypothesis.

Photocarrier Radiometry for Non-contact Evaluation of Monocrystalline Silicon Solar Cell Under Low-Energy (< 200 keV) Proton Irradiation

Science.gov (United States)

Oliullah, Md.; Liu, J. Y.; Song, P.; Wang, Y.

2018-06-01

A three-layer theoretical model is developed for the characterization of the electronic transport properties (lifetime τ, diffusion coefficient D, and surface recombination velocity s) with energetic particle irradiation on solar cells using non-contact photocarrier radiometry. Monte Carlo (MC) simulation is carried out to obtain the depth profiles of the proton irradiation layer at different low energies (solar cells are investigated under different low-energy proton irradiation, and the carrier transport parameters of the three layers are obtained by best-fitting of the experimental results. The results show that the low-energy protons have little influence on the transport parameters of the non-irradiated layer, but high influences on both of the p and n-region irradiation layers which are consisted of MC simulation.

Effects of solar proton events on dayglow observed by the TIMED/SABER satellite

Science.gov (United States)

Gao, Hong; Xu, Jiyao; Smith, Anne K.; Chen, Guang-Ming

2017-07-01

The effect of solar proton events on the daytime O2 and OH airglows and ozone and atomic oxygen concentrations in the mesosphere is studied using data from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER). Five events occurred in September 2005, December 2006, March 2012, May 2013, and June 2015 that satisfy two criteria: the maximum proton fluxes are larger than 1000 pfu, and daytime data in the high latitude region are available from SABER. The event in December 2006 is studied in detail, and the effects of all five events are compared in brief. The results indicate that all four parameters in the mesosphere decrease during the events. During the event in 2006, the maximum depletions of O2 and OH dayglow emission rates and ozone and atomic oxygen volume mixing ratios at 70 km are respectively 31.6%, 37.0%, 42.4%, and 38.9%. The effect of the solar proton event changes with latitude, longitude, and altitude. The depletions due to the stronger events are larger on average than those due to the weaker events. The depletions of both dayglow emission rates are weaker than those of ozone and atomic oxygen. The responses of O2 and OH nightglow emissions around their peak altitudes to the SPEs are not as strong and regular as those for dayglow in the mesosphere.

Rest frame properties of the proton

International Nuclear Information System (INIS)

Strobel, G.L.

1998-01-01

The proton is modeled as three quarks of small current quark mass. The three-body Dirac equation is solved with spin-independent central diagonal linear confining potentials with an attractive Coulombic term in a relativistic three-quark model. Hyperspherical coordinates are used, and the bound state is found analytically. After integrating over the hyperangles, the Hamiltonian is an 8 by 8 matrix of coupled first-order differential equations in one variable, the hyperradius. These are analytically solved in hypercentral approximation. For the (1/2 + ) 3 ground-state configuration in the nonrelativistic large-quark-mass limit, there are no nodes in the wave function. However, in the extreme relativistic limit of small current quark masses of a few MeV, the expectation value of the number of nodes is about 1.30 when the potential parameters are chosen to reproduce the proton rms charge radius. The quarks are assumed to possess a Pauli anomalous magnetic moment, like that of the electron and muon of (α/2π)(e/m). Assuming all three quarks have equal mass, one can fit the rest energy, magnetic moment, rms charge radius, and axial charge of the proton with this relativistic three-body Dirac equation model. The solution found shows the necessity of including all components of the composite three-quark wave function, as the upper component contributes only 0.585 to the norm

Galactic cosmic ray spectra during solar cycle 23 and 24. Measurement capabilities of the electron proton helium telescope on board SOHO

Energy Technology Data Exchange (ETDEWEB)

Kuehl, Patrick; Dresing, Nina; Gieseler, Jan; Heber, Bernd; Klassen, Andreas [Christian-Albrechts Universitaet zu Kiel (Germany)

2016-07-01

The solar modulation of galactic cosmic rays (GCR) can be studied in detail by long term variations of the GCR energy spectrum (e.g. on the scales of a solar cycle). With almost 20 years of data, the Electron Proton Helium INstrument (EPHIN) aboard SOHO is well suited for these kind of investigations. Although the design of the instrument is optimized to measure proton and helium isotope spectra up to 50 MeV/nucleon the capability exist that allow to determine energy spectra above 1.5 GeV/nucleon. Therefore we developed a sophisticated inversion method to calculate such proton spectra. The method relies on a GEANT4 Monte Carlo simulation of the instrument and a simplified spacecraft model that calculates the energy response function of EPHIN for electrons, protons and heavier ions. As a result we present galactic cosmic ray spectra from 1995 to 2015. For validation, the derived spectra are compared to AMS, BESS and PAMELA data. Furthermore we discuss the spectra with respect to the solar modulation.

Relativistic nuclear collisions: theory

International Nuclear Information System (INIS)

Gyulassy, M.

1980-07-01

Some of the recent theoretical developments in relativistic (0.5 to 2.0-GeV/nucleon) nuclear collisions are reviewed. The statistical model, hydrodynamic model, classical equation of motion calculations, billiard ball dynamics, and intranuclear cascade models are discussed in detail. Inclusive proton and pion spectra are analyzed for a variety of reactions. Particular attention is focused on how the complex interplay of the basic reaction mechanism hinders attempts to deduce the nuclear matter equation of state from data. 102 references, 19 figures

FLARE VERSUS SHOCK ACCELERATION OF HIGH-ENERGY PROTONS IN SOLAR ENERGETIC PARTICLE EVENTS

International Nuclear Information System (INIS)

Cliver, E. W.

2016-01-01

Recent studies have presented evidence for a significant to dominant role for a flare-resident acceleration process for high-energy protons in large (“gradual”) solar energetic particle (SEP) events, contrary to the more generally held view that such protons are primarily accelerated at shock waves driven by coronal mass ejections (CMEs). The new support for this flare-centric view is provided by correlations between the sizes of X-ray and/or microwave bursts and associated SEP events. For one such study that considered >100 MeV proton events, we present evidence based on CME speeds and widths, shock associations, and electron-to-proton ratios that indicates that events omitted from that investigation’s analysis should have been included. Inclusion of these outlying events reverses the study’s qualitative result and supports shock acceleration of >100 MeV protons. Examination of the ratios of 0.5 MeV electron intensities to >100 MeV proton intensities for the Grechnev et al. event sample provides additional support for shock acceleration of high-energy protons. Simply scaling up a classic “impulsive” SEP event to produce a large >100 MeV proton event implies the existence of prompt 0.5 MeV electron events that are approximately two orders of magnitude larger than are observed. While classic “impulsive” SEP events attributed to flares have high electron-to-proton ratios (≳5 × 10 5 ) due to a near absence of >100 MeV protons, large poorly connected (≥W120) gradual SEP events, attributed to widespread shock acceleration, have electron-to-proton ratios of ∼2 × 10 3 , similar to those of comparably sized well-connected (W20–W90) SEP events.

Features of energetic particle radial profiles inferred from geosynchronous responses to solar wind dynamic pressure enhancements

Directory of Open Access Journals (Sweden)

Y. Shi

2009-02-01

Full Text Available Determination of the radial profile of phase space density of relativistic electrons at constant adiabatic invariants is crucial for identifying the source for them within the outer radiation belt. The commonly used method is to convert flux observed at fixed energy to phase space density at constant first, second and third adiabatic invariants, which requires an empirical global magnetic field model and thus might produce some uncertainties in the final results. From a different perspective, in this paper we indirectly infer the shape of the radial profile of phase space density of relativistic electrons near the geosynchronous region by statistically examining the geosynchronous energetic flux response to 128 solar wind dynamic pressure enhancements during the years 2000 to 2003. We thus avoid the disadvantage of using empirical magnetic field models. Our results show that the flux response is species and energy dependent. For protons and low-energy electrons, the primary response to magnetospheric compression is an increase in flux at geosynchronous orbit. For relativistic electrons, the dominant response is a decrease in flux, which implies that the phase space density decreases toward increasing radial distance at geosynchronous orbit and leads to a local peak inside of geosynchronous orbit. The flux response of protons and non-relativistic electrons could result from a phase density that increases toward increasing radial distance, but this cannot be determined for sure due to the particle energization associated with pressure enhancements. Our results for relativistic electrons are consistent with previous results obtained using magnetic field models, thus providing additional confirmation that these results are correct and indicating that they are not the result of errors in their selected magnetic field model.

Relation between gamma-ray emission, radio bursts, and proton fluxes from solar flares

International Nuclear Information System (INIS)

Fomichev, V.V.; Chertok, I.M.

1985-01-01

Data on solar gamma-ray flares, including 24 flares with gamma-ray lines, recorded up to June 1982, are analyzed. It is shown that from the point of view of radio emission the differences between flares with and without gamma-ray lines has a purely quantitative character: the former are accompanied by the most intense microwave bursts. Meter type II bursts are not a distinctive feature of flares with gamma-ray lines. Pulsed flares, regardless of the presence or absence of gamma-ray lines, are not accompanied by significant proton fluxes at the earth. On the whole, contrary to the popular opinion in the literature, flares with gamma-ray lines do not display a deficit of proton flux in interplanetary space in comparison with similar flares without gamma-ray lines. The results of quantitative diagnostics of proton flares based on radio bursts are not at variance with the presence of flares without detectable gamma-ray emission in lines but with a pronounced increase in the proton flux at the earth. 23 references

Thermalization in high energy proton-nucleus collisions

International Nuclear Information System (INIS)

Wedemann, R.S.

1988-03-01

A relativistic proton-nucleus collision using the intranuclear cascade model is studied. The purpose is to verify the equilibration hypothesis at fragmentation time made by many nuclear fragmentation models. (author)

Correlation of near-Earth proton enhancements >100 MeV with parameters of solar microwave bursts

Science.gov (United States)

Grechnev, Victor; Kiselev, Valentin; Meshalkina, Nataliya; Chertok, Ilya

2017-09-01

We analyze the relations between various combinations of peak fluxes and fluences of solar microwave bursts at 35 GHz recorded with the Nobeyama Radio Polarimeters during 1990–2015, and corresponding parameters of proton enhancements with E>100 MeV exceeding 0.1 pfu registered by GOES monitors in near-Earth environment. The highest correlation has been found between the microwave and proton fluences. This fact reflects a dependence of the total number of protons on the total duration of the acceleration process. In the events with strong flares, the correlation coefficients of proton fluences with microwave and soft X-ray fluences are higher than those with speeds of coronal mass ejections. The results indicate a statistically larger contribution of flare processes to acceleration of high-energy protons. Acceleration by shock waves seems to be less important at high energies in events associated with strong flares, although its contribution probably prevails in weaker events. The probability of a detectable proton enhancement was found to directly depend on the peak flux and duration of a microwave burst. This can be used for diagnostics of proton enhancements based on microwave observations.

On the proton radius problem

OpenAIRE

Giannini, M. M.; Santopinto, E.

2013-01-01

The recent values of the proton charge radius obtained by means of muonic-hydrogen laser spectroscopy are about $4\\%$ different from the electron scattering data. It has been suggested that the proton radius is actually measured in different frames and that, starting from a non relativistic quark model calculation, the Lorentz transformation of the form factors accounts properly for the discepancy. We shall show that the relation between the charge radii measured in different frames can be de...

Proton-proton, anti-proton-anti-proton, proton-anti-proton correlations in Au+Au collisions measured by STAR at RHIC

International Nuclear Information System (INIS)

Gos, H.P.

2007-01-01

The analysis of two-particle correlations provides a powerful tool to study the properties of hot and dense matter created in heavy-ion collisions at ultra-relativistic energies. Applied to identical and non-identical hadron pairs, it makes the study of space-time evolution of the source in femtoscopic scale possible. Baryon femtoscopy allows extraction of the radii of produced sources which can be compared to those deduced from identical pion studies, providing complete information about the source characteristics. In this paper we present the correlation functions obtained for identical and non-identical baryon pairs of protons and anti-protons. The data were collected recently in Au+Au collisions at √(s NN )=62 GeV and √(s NN )=200 GeV by the STAR detector at the RHIC accelerator. We introduce corrections to the baryon-baryon correlations taking into account: residual correlations from weak decays, particle identification probability and the fraction of primary baryons. Finally we compare our results to theoretical predictions. (orig.)

Characterization of solar cell materials by Proton Back Scattering Spectroscopy

International Nuclear Information System (INIS)

Joynal Abedin, M.; Fazlul Hoque, A.K.M.; Firoz Hasan, S.M.

2001-01-01

The need for accurate chemical characterization of samples specially related to electronic and solar cell materials has assumed increasing importance in recent years. The importance of the study of the surfaces of materials of different origin also increased in recent years to a great extent. This need has created a worldwide spurt to develop rapid, accurate and sensitive tools for the characterization of materials. In recent years the proton backscattering spectrometry (PBS) method has been recognized as one of the useful analytical tool in several applications of material analysis and technology. The lack of information of the relevant scattering cross sections as a function of proton energy and the problems arising in conventional data analysis have so far rendered proton backscattering analysis of multielemental samples difficult at low energies. On the other hand advances in the computer evaluation of experimental data have, however, made it possible to utilize low-MeV protons as a sensitive probe for light elements in the μm range. The benefits of the method in comparison to alpha particle backscattering include the relatively higher non-Rutherford scattering cross sections of the light elements and to the lower proton stopping in the target material. These lead to higher sensitivity in detecting and profiling light elements in heavy targets and to significantly larger accessible depths and smaller straggling than with alpha particles. Research works on the development of methodologies of Proton Backscattering Spectrometry (PBS) for the analysis of thin films and surfaces has been in progress in the 3 MeV Van de Graaff Accelerator facilities of Atomic Energy Centre, Dhaka for some years. The PBS system comprises a target chamber with appropriate sample holders and a Surface Barrier Detector (SBD) with the associated electronics for data acquisition and reduction. For the evaluation of the PBS data RBS Universal Master Package, RUMP has been installed in the

TIME DEPENDENCE OF THE PROTON FLUX MEASURED BY PAMELA DURING THE 2006 JULY-2009 DECEMBER SOLAR MINIMUM

Energy Technology Data Exchange (ETDEWEB)

Adriani, O.; Bongi, M. [Department of Physics, University of Florence, I-50019 Sesto Fiorentino, Florence (Italy); Barbarino, G. C. [Department of Physics, University of Naples ' ' Federico II' ' , I-80126 Naples (Italy); Bazilevskaya, G. A. [Lebedev Physical Institute, RU-119991 Moscow (Russian Federation); Bellotti, R.; Bruno, A. [Department of Physics, University of Bari, I-70126 Bari (Italy); Boezio, M.; Bonvicini, V.; Carbone, R. [INFN, Sezione di Trieste, I-34149 Trieste (Italy); Bogomolov, E. A. [Ioffe Physical Technical Institute, RU-194021 St. Petersburg (Russian Federation); Borisov, S.; De Pascale, M. P.; De Santis, C.; De Simone, N. [INFN, Sezione di Rome ' ' Tor Vergata' ' , I-00133 Rome (Italy); Bottai, S. [INFN, Sezione di Florence, I-50019 Sesto Fiorentino, Florence (Italy); Cafagna, F. [INFN, Sezione di Bari, I-70126 Bari (Italy); Campana, D. [INFN, Sezione di Naples, I-80126 Naples (Italy); Carlson, P. [KTH, Department of Physics, and the Oskar Klein Centre for Cosmoparticle Physics, AlbaNova University Centre, SE-10691 Stockholm (Sweden); Casolino, M. [Department of Physics, University of Rome ' ' Tor Vergata' ' , I-00133 Rome (Italy); Castellini, G. [IFAC, I-50019 Sesto Fiorentino, Florence (Italy); and others

2013-03-10

The energy spectra of galactic cosmic rays carry fundamental information regarding their origin and propagation. These spectra, when measured near Earth, are significantly affected by the solar magnetic field. A comprehensive description of the cosmic radiation must therefore include the transport and modulation of cosmic rays inside the heliosphere. During the end of the last decade, the Sun underwent a peculiarly long quiet phase well suited to study modulation processes. In this paper we present proton spectra measured from 2006 July to 2009 December by PAMELA. The large collected statistics of protons allowed the time variation to be followed on a nearly monthly basis down to 400 MV. Data are compared with a state-of-the-art three-dimensional model of solar modulation.

Photon production in relativistic nuclear collisions at SPS and RHIC energies

CERN Document Server

Turbide, S; Rapp, R; 10.1142/S0217751X0402258X

2004-01-01

Chiral Lagrangians are used to compute the production rate of photons from the hadronic phase of relativistic nuclear collisions. Special attention is paid to the role of the a/sub 1/ pseudovector. Calculations that include strange meson reactions, form factors, the use of consistent vector spectral densities, the emission from a quark-gluon plasma, and primordial nucleon-nucleon collisions reproduce the photon spectra measured at the Super Proton Synchrotron (SPS). Some predictions for the Relativistic Heavy Ion Collider (RHIC) are made.

Relativistic QRPA Calculation of β-Decay Rates of r-process Nuclei

International Nuclear Information System (INIS)

Marketin, T.; Paar, N.; Niksic, T.; Vretenar, D.; Ring, P.

2009-01-01

A systematic, fully self-consistent calculation of β-decay rates is presented, based on a microscopic theoretical framework. Analysis is performed on a large number of nuclei from the valley of β stability towards the neutron drip-line. Nuclear ground state is determined using the Relativistic Hartree-Bogoliubov (RHB) model with density-dependent meson-nucleon coupling constants. Transition rates are calculated within the proton-neutron relativistic quasiparticle RPA (pn-RQRPA) using the same interaction that was used in the RHB equations.

Onsets of Solar Proton Events in Satellite and Ground Level Observations: A Comparison

Science.gov (United States)

He, Jing; Rodriguez, Juan V.

2018-03-01

The early detection of solar proton event onsets is essential for protecting humans and electronics in space, as well as passengers and crew at aviation altitudes. Two commonly compared methods for observing solar proton events that are sufficiently large and energetic to be detected on the ground through the creation of secondary radiation—known as ground level enhancements (GLEs)—are (1) a network of ground-based neutron monitors (NMs) and (2) satellite-based particle detectors. Until recently, owing to the different time resolution of the two data sets, it has not been feasible to compare these two types of observations using the same detection algorithm. This paper presents a comparison between the two observational platforms using newly processed >100 MeV 1 min count rates and fluxes from National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellite (GOES) 8-12 satellites, and 1 min count rates from the Neutron Monitor Database. We applied the same detection algorithm to each data set (tuned to the different background noise levels of the instrument types). Seventeen SPEs with GLEs were studied: GLEs 55-70 from Solar Cycle 23 and GLE 71 from Solar Cycle 24. The median difference in the event detection times by GOES and NM data is 0 min, indicating no innate benefit in time of either system. The 10th, 25th, 75th, and 90th percentiles of the onset time differences (GOES minus NMs) are -7.2 min, -1.5 min, 2.5 min, and 4.2 min, respectively. This is in contrast to previous studies in which NM detections led GOES by 8 to 52 min without accounting for different alert protocols.

Developments, characterization and proton irradiation damage tests of AlN detectors for VUV solar observations

Energy Technology Data Exchange (ETDEWEB)

BenMoussa, A., E-mail: ali.benmoussa@stce.be [Solar Terrestrial Center of Excellence (STCE), Royal Observatory of Belgium, Circular Avenue 3, B-1180 Brussels (Belgium); Soltani, A.; Gerbedoen, J.-C [Institut d’Electronique, de Microélectronique et de Nanotechnologie (IEMN), F-59652 Villeneuve d’Ascq (France); Saito, T. [Department of Environment and Energy, Tohoku Institute of Technology, 35-1, Yagiyama-Kasumi-cho, Taihaku-ku, Sendai, Miyagi 982-8577 (Japan); Averin, S. [Fryazino Branch of the Kotel’nikov Institute of Radioengineering and Electronics of Russian Academy of Sciences, 141190 Square Vvedenski 1, Fryazino, Moscow Region (Russian Federation); Gissot, S.; Giordanengo, B. [Solar Terrestrial Center of Excellence (STCE), Royal Observatory of Belgium, Circular Avenue 3, B-1180 Brussels (Belgium); Berger, G. [Catholic University of Louvain-la-Neuve, Chemin du Cyclotron 2, B-1348 Louvain la Neuve (Belgium); Kroth, U. [Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, D-10587 Berlin (Germany); De Jaeger, J.-C. [Institut d’Electronique, de Microélectronique et de Nanotechnologie (IEMN), F-59652 Villeneuve d’Ascq (France); Gottwald, A. [Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, D-10587 Berlin (Germany)

2013-10-01

For next generation spaceborne solar ultraviolet radiometers, innovative metal–semiconductor–metal detectors based on wurtzite aluminum nitride are being developed and characterized. A set of measurement campaigns and proton irradiation damage tests was carried out to obtain their ultraviolet-to-visible characterization and degradation mechanisms. First results on large area prototypes up to 4.3 mm diameter are presented here. In the wavelength range of interest, this detector is reasonably sensitive and stable under brief irradiation with a negligible low dark current (3–6 pA/cm{sup 2}). No significant degradation of the detector performance was observed after exposure to protons of 14.4 MeV energy, showing a good radiation tolerance up to fluences of 1 × 10{sup 11} protons/cm{sup 2}.

Proton Flares in Solar Activity Complexes: Possible Origins and Consequences

Science.gov (United States)

Isaeva, E. S.; Tomozov, V. M.; Yazev, S. A.

2018-03-01

Solar flares observed during the 24th solar-activity cycle and accompanied by fluxes of particles detected at the Earth's orbit with intensities exceeding 10 particles cm-2 s-1 and energies of more than 10 MeV per particle mainly occurred in activity complexes (82% of cases), with 80% of these occurring no more than 20 heliographic degrees from the nearest coronal holes. The correlation between the X-ray classes of flares and the proton fluxes detected at the Earth's orbit is weak. The work presented here supports the hypothesis that the leakage of particles into the heliosphere is due to the existence of long-lived magnetic channels, which facilitate the transport of flare-accelerated particles into the boundary regions of open magnetic structures of coronal holes. The possible contribution of exchange reconnection in the formation of such channels and the role of exchange reconnection in the generation of flares are discussed.

Energy Dependence of Near-relativistic Electron Spectrum at ...

Indian Academy of Sciences (India)

chronous altitudes during solar energetic proton events of 2005. ... discussed the radiation belt electron drop outs with respect to their local time, radial and ... number density (Nsw), solar wind speed (Vsw), solar wind pressure (Psw), average.

Hard X-ray bremsstrahlung production in solar flares by high-energy proton beams

Science.gov (United States)

Emslie, A. G.; Brown, J. C.

1985-01-01

The possibility that solar hard X-ray bremsstrahlung is produced by acceleration of stationary electrons by fast-moving protons, rather than vice versa, as commonly assumed, was investigated. It was found that a beam of protons which involves 1836 times fewer particles, each having an energy 1836 times greater than that of the electrons in the equivalent electron beam model, has exactly the same bremsstrahlung yield for a given target, i.e., the mechanism has an energetic efficiency equal to that of conventional bremsstrahlung models. Allowance for the different degrees of target ionization appropriate to the two models (for conventional flare geometries) makes the proton beam model more efficient than the electron beam model, by a factor of order three. The model places less stringent constraints than a conventional electron beam model on the flare energy release mechanism. It is also consistent with observed X-ray burst spectra, intensities, and directivities. The altitude distribution of hard X-rays predicted by the model agrees with observations only if nonvertical injection of the protons is assumed. The model is inconsistent with gamma-ray data in terms of conventional modeling.

Monte Carlo Simulations of Photospheric Emission in Relativistic Outflows

Science.gov (United States)

Bhattacharya, Mukul; Lu, Wenbin; Kumar, Pawan; Santana, Rodolfo

2018-01-01

We study the spectra of photospheric emission from highly relativistic gamma-ray burst outflows using a Monte Carlo code. We consider the Comptonization of photons with a fast-cooled synchrotron spectrum in a relativistic jet with a realistic photon-to-electron number ratio {N}γ /{N}{{e}}={10}5, using mono-energetic protons that interact with thermalized electrons through Coulomb interaction. The photons, electrons, and protons are cooled adiabatically as the jet expands outward. We find that the initial energy distributions of the protons and electrons do not have any appreciable effect on the photon peak energy {E}γ ,{peak} and the power-law spectrum above {E}γ ,{peak}. The Coulomb interaction between the electrons and the protons does not affect the output photon spectrum significantly as the energy of the electrons is elevated only marginally. {E}γ ,{peak} and the spectral indices for the low- and high-energy power-law tails of the photon spectrum remain practically unchanged even with electron-proton coupling. Increasing the initial optical depth {τ }{in} results in a slightly shallower photon spectrum below {E}γ ,{peak} and fewer photons at the high-energy tail, although {f}ν \\propto {ν }-0.5 above {E}γ ,{peak} and up to ∼1 MeV, independent of {τ }{in}. We find that {E}γ ,{peak} determines the peak energy and the shape of the output photon spectrum. Finally, we find that our simulation results are quite sensitive to {N}γ /{N}{{e}}, for {N}{{e}}=3× {10}3. For almost all our simulations, we obtain an output photon spectrum with a power-law tail above {E}γ ,{peak} extending up to ∼1 MeV.

D-region electron density and effective recombination coefficients during twilight – experimental data and modelling during solar proton events

Directory of Open Access Journals (Sweden)

A. Osepian

2009-10-01

Full Text Available Accurate measurements of electron density in the lower D-region (below 70 km altitude are rarely made. This applies both with regard to measurements by ground-based facilities and by sounding rockets, and during both quiet conditions and conditions of energetic electron precipitation. Deep penetration into the atmosphere of high-energy solar proton fluxes (during solar proton events, SPE produces extra ionisation in the whole D-region, including the lower altitudes, which gives favourable conditions for accurate measurements using ground-based facilities. In this study we show that electron densities measured with two ground-based facilities at almost the same latitude but slightly different longitudes, provide a valuable tool for validation of model computations. The two techniques used are incoherent scatter of radio waves (by the EISCAT 224 MHz radar in Tromsø, Norway, 69.6° N, 19.3° E, and partial reflection of radio-waves (by the 2.8 MHz radar near Murmansk, Russia, 69.0° N, 35.7° E. Both radars give accurate electron density values during SPE, from heights 57–60 km and upward with the EISCAT radar and between 55–70 km with the partial reflection technique. Near noon, there is little difference in the solar zenith angle between the two locations and both methods give approximately the same values of electron density at the overlapping heights. During twilight, when the difference in solar zenith angles increases, electron density values diverge. When both radars are in night conditions (solar zenith angle >99° electron densities at the overlapping altitudes again become equal. We use the joint measurements to validate model computations of the ionospheric parameters f+, λ, αeff and their variations during solar proton events. These parameters are important characteristics of the lower ionosphere structure which cannot be determined by other methods.

A study on the electric properties of single-junction GaAs solar cells under the combined radiation of low-energy protons and electrons

International Nuclear Information System (INIS)

Zhao Huijie; Wu Yiyong; Xiao Jingdong; He Shiyu; Yang Dezhuang; Sun Yanzheng; Sun Qiang; Lv Wei; Xiao Zhibin; Huang Caiyong

2008-01-01

Displacement damage induced by charged particle radiation is the main cause of degradation of orbital-service solar cells, while the radiation-induced ionization shows no permanent damage effect on their electrical properties. It is reported that in single crystal silicon solar cells, low-energy electron radiation does not exert permanent degradation of their properties, but the fluence of electron radiation exerts an influence on the damage magnitude under the combined radiation of protons and electrons. The electrical properties of the single-junction GaAs/Ge solar cells were investigated after irradiation by sequential and synchronous electron and proton beams. Low-energy electron radiation showed no effects on the change of the solar cell properties during sequential or synchronous irradiation, implying ionization during particle radiation could not exert influence on the displacement damage process to the solar cells under the experimental conditions

Latitudinal extent of the January 2005 solar proton event in the Northern Hemisphere from satellite observations of hydroxyl

Directory of Open Access Journals (Sweden)

P. T. Verronen

2007-11-01

Full Text Available We utilise hydroxyl observations from the MLS/Aura satellite instrument to study the latitudinal extent of particle forcing in the northern polar region during the January 2005 solar proton event. MLS is the first satellite instrument to observe HOx changes during such an event. We also predict the hydroxyl changes with respect to the magnetic latitude by the Sodankylä Ion and Neutral Chemistry model, estimating the variable magnetic cutoff energies for protons using a parameterisation based on magnetosphere modelling and the planetary magnetic index Kp. In the middle and lower mesosphere, HOx species are good indicators of the changes in the atmosphere during solar proton events, because they respond rapidly to both increases and decreases in proton forcing. Also, atmospheric transport has a negligible effect on HOx because of its short chemical lifetime. The observations indicate the boundary of the proton forcing and a transition region, from none to the "full" effect, which ranges from about 57 to 64 degrees of magnetic latitude. When saturating the rigidity cutoff Kp at 6 in the model, as suggested by earlier studies using observations of cosmic radio noise absorption, the equatorward boundary of the transition region is offset by ≈2 degrees polewards compared with the data, thus the latitudinal extent of the proton forcing in the atmosphere is underestimated. However, the model predictions are in reasonable agreement with the MLS measurements when the Kp index is allowed to vary within its nominal range, i.e., from 1 to 9 in the cutoff calculation.

β-decay rates of r-process nuclei in the relativistic quasiparticle random phase approximation

International Nuclear Information System (INIS)

Niksic, T.; Marketin, T.; Vretenar, D.; Paar, N.; Ring, P.

2005-01-01

The fully consistent relativistic proton-neutron quasiparticle random phase approximation (PN-RQRPA) is employed in the calculation of β-decay half-lives of neutron-rich nuclei in the N≅50 and N≅82 regions. A new density-dependent effective interaction, with an enhanced value of the nucleon effective mass, is used in relativistic Hartree-Bogoliubov calculation of nuclear ground states and in the particle-hole channel of the PN-RQRPA. The finite range Gogny D1S interaction is employed in the T=1 pairing channel, and the model also includes a proton-neutron particle-particle interaction. The theoretical half-lives reproduce the experimental data for the Fe, Zn, Cd, and Te isotopic chains but overestimate the lifetimes of Ni isotopes and predict a stable 132 Sn

On the energy dependence of the relative contributions ionospheric and solar sources of the ring current protons

International Nuclear Information System (INIS)

Kovtyukh, A.

2007-01-01

The energy dependence of a fraction of ring current protons of i onospheric origin is calculated using the AMPTE/CCE data for a typical magnetic storm (D st = -120 nT). It is shown that at L = 6-7 (L is the Mcllwain parameter) this fraction monotonically decreases from ∼83 to 25-30% with an increase in proton energy from 5 to 315 keV and is 30-40% at energy 40-50 keV corresponding to the maximum of proton energy density at L 6-7. It is evident that the core of the ring current (L = 3.7-4.7) is enriched by solar protons with E∼10-200 keV during storm main phase (the maximum effect is achieved at E∼20-50 keV). (author)

Radio Ranging Techniques to test Relativistic Gravitation

OpenAIRE

Cowsik, R.

1999-01-01

It is suggested that modern techniques of radio ranging when applied to study the motion of the Moon, can improve the accuracy of tests of relativistic gravitation obtained with currently operating laser ranging techniques. Other auxillary information relevant to the Solar system would also emerge from such a study.

Relativistic heavy ion experiments at BNL-AGS

International Nuclear Information System (INIS)

Miake, Yasuo

1992-01-01

Relativistic heavy ion program at BNL started in 1986. Already a few experiments have achieved their first goals. Several interesting features reported among which are: The black nuclear transparency, the enhanced K + /π + ratio and the larger t > for K + and proton in central Si+Au collisions. Comparisons of m t and dn/dy distributions between pp, pA and AA are discussed together with various model calculations. (orig.)

Measurement of the Neutron Component in a Shower Generated in a Lead Target by Relativistic Nuclear Beam

International Nuclear Information System (INIS)

Chultehm, D.; Damdinsurehn, Ts.; D'yachenko, V.M.; Ehnkhzhin, L.; Lomova, L.A.; Perelygin, V.P.; Tolstov, K.D.

1994-01-01

The present paper describes a method of determining the total number of neutrons generated in an extended lead target by relativistic nuclei and protons. It is shown that 101±20 neutrons per proton are produced in the target with the volume of 50x50x80 cm 3 at 3.65 GeV energy of protons. 11 refs., 14 figs., 1 tab

Measurement of J/{psi} production in proton-proton collisions by the PHENIX experiment

Energy Technology Data Exchange (ETDEWEB)

Bruner, Nichelle [University of New Mexico, Albuquerque, NM (United States)

2004-07-01

The PHENIX experiment at the Relativistic Heavy Ion Collider has measured J/{psi} production in proton-proton collisions at {radical}(s)= 200 GeV using data from the 2001-2002 collider run. Distributions of rapidity and transverse momentum are presented and compared with theoretical predictions. The total cross section and mean p{sub T} are calculated and compared to fixed-target results. The total J/{psi} cross section is 4.0{+-}0.6(stat){+-}0.6(sys){+-}0.4(abs){mu}b. The mean p{sub T} is 1.80{+-}0.23(stat){+-}0.16(sys) GeV/c. (orig.)

Measurement of J/ψ production in proton-proton collisions by the PHENIX experiment

International Nuclear Information System (INIS)

Bruner, Nichelle

2004-01-01

The PHENIX experiment at the Relativistic Heavy Ion Collider has measured J/ψ production in proton-proton collisions at √(s)= 200 GeV using data from the 2001-2002 collider run. Distributions of rapidity and transverse momentum are presented and compared with theoretical predictions. The total cross section and mean p T are calculated and compared to fixed-target results. The total J/ψ cross section is 4.0±0.6(stat)±0.6(sys)±0.4(abs)μb. The mean p T is 1.80±0.23(stat)±0.16(sys) GeV/c. (orig.)

Polarized Proton Collisions at RHIC

CERN Document Server

Bai, Mei; Alekseev, Igor G; Alessi, James; Beebe-Wang, Joanne; Blaskiewicz, Michael; Bravar, Alessandro; Brennan, Joseph M; Bruno, Donald; Bunce, Gerry; Butler, John J; Cameron, Peter; Connolly, Roger; De Long, Joseph; Drees, Angelika; Fischer, Wolfram; Ganetis, George; Gardner, Chris J; Glenn, Joseph; Hayes, Thomas; Hseuh Hsiao Chaun; Huang, Haixin; Ingrassia, Peter; Iriso, Ubaldo; Laster, Jonathan S; Lee, Roger C; Luccio, Alfredo U; Luo, Yun; MacKay, William W; Makdisi, Yousef; Marr, Gregory J; Marusic, Al; McIntyre, Gary; Michnoff, Robert; Montag, Christoph; Morris, John; Nicoletti, Tony; Oddo, Peter; Oerter, Brian; Osamu, Jinnouchi; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Roser, Thomas; Satogata, Todd; Smith, Kevin T; Svirida, Dima; Tepikian, Steven; Tomas, Rogelio; Trbojevic, Dejan; Tsoupas, Nicholaos; Tuozzolo, Joseph; Vetter, Kurt; Wilinski, Michelle; Zaltsman, Alex; Zelenski, Anatoli; Zeno, Keith; Zhang, S Y

2005-01-01

The Relativistic Heavy Ion Collider~(RHIC) provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC to avoid depolarizing resonances. In 2003, polarized proton beams were accelerated to 100~GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. RHIC polarized proton run experience demonstrates that optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limite...

Second relativistic mean field and virial equation of state for astrophysical simulations

International Nuclear Information System (INIS)

Shen, G.; Horowitz, C. J.; O'Connor, E.

2011-01-01

We generate a second equation of state (EOS) of nuclear matter for a wide range of temperatures, densities, and proton fractions for use in supernovae, neutron star mergers, and black hole formation simulations. We employ full relativistic mean field (RMF) calculations for matter at intermediate density and high density, and the virial expansion of a nonideal gas for matter at low density. For this EOS we use the RMF effective interaction FSUGold, whereas our earlier EOS was based on the RMF effective interaction NL3. The FSUGold interaction has a lower pressure at high densities compared to the NL3 interaction. We calculate the resulting EOS at over 100 000 grid points in the temperature range T=0 to 80 MeV, the density range n B =10 -8 to 1.6 fm -3 , and the proton fraction range Y p =0 to 0.56. We then interpolate these data points using a suitable scheme to generate a thermodynamically consistent equation of state table on a finer grid. We discuss differences between this EOS, our NL3-based EOS, and previous EOSs by Lattimer-Swesty and H. Shen et al. for the thermodynamic properties, composition, and neutron star structure. The original FSUGold interaction produces an EOS, which we call FSU1.7, that has a maximum neutron star mass of 1.7 solar masses. A modification in the high-density EOS is introduced to increase the maximum neutron star mass to 2.1 solar masses and results in a slightly different EOS that we call FSU2.1. The EOS tables for FSU1.7 and FSU2.1 are available for download.

Transmutation of 239Pu and other nuclides using spallation neutrons produced by relativistic protons reacting with massive U- and Pb- targets

International Nuclear Information System (INIS)

Adam, J.; Balabekyan, A.; Bamblevskij, V.P.

2001-01-01

Experimental studies on the transmutation of some long-lived radioactive waste nuclei, such as 129 I, 237 Np, and 239 Pu, as well as on natural uranium and lanthanum (all of them used as sensors) were carried out at the Synchrophasotron of the Laboratory of High Energies (JINR, Dubna). Spallation neutrons were produced by relativistic protons with energies in the range of 0.5 GeV ≤ E(p) ≤ 1.5 GeV interacting with 20 cm long uranium or lead target stacks. The targets were surrounded by 6 cm paraffin moderators. The radioactive sensors mentioned above were positioned on the outside surface of the moderator and contained typically approximately 0.5 up to 1 gram of long-lived isotopes. The highly radioactive targets were produced perfectly well-sealed in aluminium containers by the Institute of Physics and Power Engineering, Obninsk, Russia. From the experimentally observed transmutation rates one can easily extrapolate, that in a subcritical nuclear power assembly (or 'energy amplifier') using a 10 mA proton beam of 1 GeV onto a Pb-target as used here, one can transmute in one gram samples of the isotope within one month about 3 mg 129 I, 21 mg 237 Np, 3.3 mg 238 U, and 200 mg 239 Pu under the same geometrical conditions. Our observations show, that the transmutation ability of our system increases linearly with the proton energy within the energy interval studied

Photocarrier radiometry for predicting the degradation of electrical parameters of monocrystalline silicon (c-Si) solar cell irradiated by 100 KeV proton beams

International Nuclear Information System (INIS)

Song, P.; Liu, J.Y.; Yuan, H.M.; Oliullah, Md.; Wang, F.; Wang, Y.

2016-01-01

In this study, the monocrystalline silicon (c-Si) solar cell irradiated by 100 KeV proton beams at various fluences is investigated. A one-dimensional two-layer carrier density wave model has been developed to estimate the minority carrier lifetime of n-region and p-region of the non-irradiated c-Si solar cell by best fitting with the experimental photocarrier radiometry (PCR) signal (the amplitude and the phase). Furthermore, the lifetime is used to determine the initial defect density of the quasi-neutral region (QNR) of the solar cell to predict its I–V characteristics. The theoretically predicted short-circuit current density (J_s_c), and open-circuit voltage (V_o_c) of the non-irradiated samples are in good agreement with experiment. Then a three-region defect distribution model for the c-Si solar cell irradiated by proton beams is carried out to describe the defect density distribution according to Monte Carlo simulation results and the initial defect density of the non-irradiated sample. Finally, we find that the electrical measurements of J_s_c and V_o_c of the solar cells irradiated at different fluences using 100 KeV proton beams are consistent with the PCR predicting results.

Photocarrier radiometry for predicting the degradation of electrical parameters of monocrystalline silicon (c-Si) solar cell irradiated by 100 KeV proton beams

Energy Technology Data Exchange (ETDEWEB)

Song, P. [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China); Liu, J.Y., E-mail: ljywlj@hit.edu.cn [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China); State Key Laboratory of Robotics and System (HIT), Harbin 150001 (China); Yuan, H.M.; Oliullah, Md.; Wang, F. [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China); Wang, Y., E-mail: songpengkevin@126.com [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China); State Key Laboratory of Robotics and System (HIT), Harbin 150001 (China)

2016-09-15

In this study, the monocrystalline silicon (c-Si) solar cell irradiated by 100 KeV proton beams at various fluences is investigated. A one-dimensional two-layer carrier density wave model has been developed to estimate the minority carrier lifetime of n-region and p-region of the non-irradiated c-Si solar cell by best fitting with the experimental photocarrier radiometry (PCR) signal (the amplitude and the phase). Furthermore, the lifetime is used to determine the initial defect density of the quasi-neutral region (QNR) of the solar cell to predict its I–V characteristics. The theoretically predicted short-circuit current density (J{sub sc}), and open-circuit voltage (V{sub oc}) of the non-irradiated samples are in good agreement with experiment. Then a three-region defect distribution model for the c-Si solar cell irradiated by proton beams is carried out to describe the defect density distribution according to Monte Carlo simulation results and the initial defect density of the non-irradiated sample. Finally, we find that the electrical measurements of J{sub sc} and V{sub oc} of the solar cells irradiated at different fluences using 100 KeV proton beams are consistent with the PCR predicting results.

New General Relativistic Contribution to Mercury's Perihelion Advance

Science.gov (United States)

Will, Clifford M.

2018-05-01

We point out the existence of a new general relativistic contribution to the perihelion advance of Mercury that, while smaller than the contributions arising from the solar quadrupole moment and angular momentum, is 100 times larger than the second-post-Newtonian contribution. It arises in part from relativistic "crossterms" in the post-Newtonian equations of motion between Mercury's interaction with the Sun and with the other planets, and in part from an interaction between Mercury's motion and the gravitomagnetic field of the moving planets. At a few parts in 1 06 of the leading general relativistic precession of 42.98 arcseconds per century, these effects are likely to be detectable by the BepiColombo mission to place and track two orbiters around Mercury, scheduled for launch around 2018.

New General Relativistic Contribution to Mercury's Perihelion Advance.

Science.gov (United States)

Will, Clifford M

2018-05-11

We point out the existence of a new general relativistic contribution to the perihelion advance of Mercury that, while smaller than the contributions arising from the solar quadrupole moment and angular momentum, is 100 times larger than the second-post-Newtonian contribution. It arises in part from relativistic "crossterms" in the post-Newtonian equations of motion between Mercury's interaction with the Sun and with the other planets, and in part from an interaction between Mercury's motion and the gravitomagnetic field of the moving planets. At a few parts in 10^{6} of the leading general relativistic precession of 42.98 arcseconds per century, these effects are likely to be detectable by the BepiColombo mission to place and track two orbiters around Mercury, scheduled for launch around 2018.

1S0 proton superfluidity in neutron star matter: Impact of bulk properties

International Nuclear Information System (INIS)

Tanigawa, Tomonori; Matsuzaki, Masayuki; Chiba, Satoshi

2004-01-01

We study the 1 S 0 proton pairing gap in neutron star matter putting emphasis on influence of the Dirac effective mass and the proton fraction on the gap within the relativistic Hartree-Bogoliubov model. The gap equation is solved using the Bonn-B potential as a particle-particle channel interaction. It is found that the maximal pairing gap Δ max is 1-2 MeV, which has a strong correlation with the Dirac effective mass. Hence we suggest that it serves as a guide to narrow down parameter sets of the relativistic effective field theory. Furthermore, the more slowly protons increase with density in the core region of neutron stars, the wider the superfluid range and the slightly lower the peak of the gap become

Evolution of the solar wind proton temperature anisotropy from 0.3 to 2.5 AU

Czech Academy of Sciences Publication Activity Database

Matteini, L.; Landi, S.; Hellinger, Petr; Pantellini, F.; Maksimovic, M.; Velli, M.; Goldstein, B. E.; Marsch, E.

2007-01-01

Roč. 34, č. 20 (2007), L20105/1-L20105/5 ISSN 0094-8276 Grant - others:ASI(IT) I/015/07/0 Institutional research plan: CEZ:AV0Z30420517 Keywords : Proton temperature anisotropy * solar wind * radial evolution * observations Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.744, year: 2007

Role of cosmic ray protons in two types of extragalactic objects

International Nuclear Information System (INIS)

Vestrand, W.T.

1980-01-01

For many years the physics of galactic cosmic rays has been studied in detail. Very little work, however, has been done concerning cosmic ray protons in extragalactic objects. Here the role cosmic ray protons can play in two types of extragalactic sites are examined: (1) clusters of galaxies, and (2) the active nuclei of Quasars that produce superluminal radio components. Models of Coma-type radio halos must explain both their large extent and their rarity. A model is presented wherein secondary electrons produced by the interaction of cosmic ray protons with the observed intracluster gas are responsible for the diffuse radio emission. This model predicts a correlation between a cluster's evolutionary state and the presence of Coma-type halos. If a cluster's x-ray morphology is an indication of the cluster's evolutionary state, this prediction is supported by observations. This model also predicts that clusters with Coma-type halos will emit π 0 γ-rays. If the intracluster magnetic field in Coma has the strength favored by many authors, B/sub c/ = 0.2 microgauss, these γ-rays should be detectable with the proposed GRO satellite. Superluminal radio sources may originate in highly compact and relativistically hot plasmas. The production of mesons and their secondaries in an ultrarelativistic plasma is examined. Source functions from a relativistic Maxwellian distribution of protons are numerically calculated for conditions likely during the formation of superluminal radio components. Analytic expressions for the source functions from a power law distribution of relativistic protons are also presented

Relativistic solar sails

Science.gov (United States)

Güémez, J.; Fiolhais, M.

2018-05-01

We apply the four-vector formalism of special relativity to describe various interaction processes of photons with a solar sail, in two cases: when the sail’s surface is a perfect mirror, and when it is a body coated with a totally absorbing material. We stress the pedagogical value of implementing simultaneously both the linear momentum and the energy conservation in a covariant fashion, as our formalism inherently does. It also allows for a straightforward change of the description of a certain process in different inertial reference frames.

Forecasting E > 50-MeV Proton Events with the Proton Prediction System (PPS)

Science.gov (United States)

Kahler, S. W.; White, S. M.; Ling, A. G.

2017-12-01

Forecasting solar energetic (E > 10 MeV) particle (SEP) events is an important element of space weather. While several models have been developed for use in forecasting such events, satellite operations are particularly vulnerable to higher-energy (> 50 MeV) SEP events. Here we validate one model, the proton prediction system (PPS), which extends to that energy range. We first develop a data base of E > 50-MeV proton events > 1.0 proton flux units (pfu) events observed on the GOES satellite over the period 1986 to 2016. We modify the PPS to forecast proton events at the reduced level of 1 pfu and run PPS for four different solar input parameters: (1) all > M5 solar X-ray flares; (2) all > 200 sfu 8800-MHz bursts with associated > M5 flares; (3) all > 500 sfu 8800-MHz bursts; and (4) all > 5000 sfu 8800-MHz bursts. For X-ray flare inputs the forecasted event peak intensities and fluences are compared with observed values. The validation contingency tables and skill scores are calculated for all groups and used as a guide to use of the PPS. We plot the false alarms and missed events as functions of solar source longitude.

On the proton exchange contribution to electron-hydrogen atom elastic scattering

International Nuclear Information System (INIS)

Mignaco, J.A.; Tort, A.C.

1979-05-01

It is shown that the exchange contribution to the electron-proton potential Born term in elastic electron-hydrogen atom scattering arises as the non relativistic limit from the exchange of a proton between the two participant electrons - calculated from quantum electrodynamics including properly bound states (as solution of Bethe - Salpeter equation). (Author) [pt

SUNWARD PROPAGATING ALFVÉN WAVES IN ASSOCIATION WITH SUNWARD DRIFTING PROTON BEAMS IN THE SOLAR WIND

Energy Technology Data Exchange (ETDEWEB)

He, Jiansen; Pei, Zhongtian; Wang, Linghua; Tu, Chuanyi; Zhang, Lei [School of Earth and Space Sciences, Peking University, Beijing, 100871 (China); Marsch, Eckart [Institute for Experimental and Applied Physics, Christian-Albrechts-Universität zu Kiel, D-24118 Kiel (Germany); Salem, Chadi, E-mail: jshept@gmail.com [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States)

2015-06-01

Using measurements from the WIND spacecraft, here we report the observation of sunward propagating Alfvén waves (AWs) in solar wind that is magnetically disconnected from the Earth's bow shock. In the sunward magnetic field sector, we find a period lasting for more than three days in which there existed (during most time intervals) a negative correlation between the flow velocity and magnetic field fluctuations, thus indicating that the related AWs are mainly propagating sunward. Simultaneous observations of counter-streaming suprathermal electrons suggest that these sunward AWs may not simply be due to the deflection of an open magnetic field line. Moreover, no interplanetary coronal mass ejection appears to be associated with the counter-streaming suprathermal electrons. As the scale goes from the magnetohydrodynamic down to the ion kinetic regime, the wave vector of magnetic fluctuations usually becomes more orthogonal to the mean magnetic field direction, and the fluctuations become increasingly compressible, which are both features consistent with quasi-perpendicular kinetic AWs. However, in the case studied here, we find clear signatures of quasi-parallel sunward propagating ion-cyclotron waves. Concurrently, the solar wind proton velocity distribution reveals a sunward field-aligned beam that drifts at about the local Alfvén speed. This beam is found to run in the opposite direction of the normally observed (anti-sunward) proton beam, and is apparently associated with sunward propagating Alfvén/ion-cyclotron waves. The results and conclusions of this study enrich our knowledge of solar wind turbulence and foster our understanding of proton heating and acceleration within a complex magnetic field geometry.

β-decay rates of r-process nuclei in the relativistic quasiparticle random phase approximation

International Nuclear Information System (INIS)

Niksic, T.; Marketin, T.; Vretenar, D.; Paar, N.; Ring, P.

2004-01-01

The fully consistent relativistic proton-neutron quasiparticle random phase approximation (PN-RQRPA) is employed in the calculation of β-decay half-lives of neutron-rich nuclei in the N∼50 and N∼82 regions. A new density-dependent effective interaction, with an enhanced value of the nucleon effective mass, is used in relativistic Hartree-Bogolyubov calculation of nuclear ground states and in the particle-hole channel of the PN-RQRPA. The finite range Gogny D1S interaction is employed in the T=1 pairing channel, and the model also includes a proton-neutron particle-particle interaction. The theoretical half-lives reproduce the experimental data for the Fe, Zn, Cd, and Te isotopic chains, but overestimate the lifetimes of Ni isotopes and predict a stable 132 Sn. (orig.)

{beta}-decay rates of r-process nuclei in the relativistic quasiparticle random phase approximation

Energy Technology Data Exchange (ETDEWEB)

Niksic, T.; Marketin, T.; Vretenar, D. [Zagreb Univ. (Croatia). Faculty of Science, Physics Dept.; Paar, N. [Technische Univ. Darmstadt (Germany). Inst. fuer Kernphysik; Ring, P. [Technische Univ. Muenchen, Garching (Germany). Physik-Department

2004-12-08

The fully consistent relativistic proton-neutron quasiparticle random phase approximation (PN-RQRPA) is employed in the calculation of {beta}-decay half-lives of neutron-rich nuclei in the N{approx}50 and N{approx}82 regions. A new density-dependent effective interaction, with an enhanced value of the nucleon effective mass, is used in relativistic Hartree-Bogolyubov calculation of nuclear ground states and in the particle-hole channel of the PN-RQRPA. The finite range Gogny D1S interaction is employed in the T=1 pairing channel, and the model also includes a proton-neutron particle-particle interaction. The theoretical half-lives reproduce the experimental data for the Fe, Zn, Cd, and Te isotopic chains, but overestimate the lifetimes of Ni isotopes and predict a stable {sup 132}Sn. (orig.)

Relativistic impulse approximation and deuteron spin structure

International Nuclear Information System (INIS)

Tokarev, M.V.

1992-01-01

The fragmentation processes were considered of tensor- and vector-polarized deuterons to protons in the framework of the covariant approach in the light cone variables on the basis of the relativistic deuteron wave function with one nucleon on-mass shell. The experimental verification of predicted dependences of T 20 and K is of interest for the research of the momentum and spin distributions of high momentum deuteron constituents. 21 refs.; 6 figs

Cosmic ray variations of solar origin in relation to human physiological state during the December 2006 solar extreme events

Science.gov (United States)

Papailiou, M.; Mavromichalaki, H.; Vassilaki, A.; Kelesidis, K. M.; Mertzanos, G. A.; Petropoulos, B.

2009-02-01

There is an increasing amount of evidence linking biological effects to solar and geomagnetic disturbances. A series of studies is published referring to the changes in human physiological responses at different levels of geomagnetic activity. In this study, the possible relation between the daily variations of cosmic ray intensity, measured by the Neutron Monitor at the Cosmic Ray Station of the University of Athens (http://cosray.phys.uoa.gr) and the average daily and hourly heart rate variations of persons, with no symptoms or hospital admission, monitored by Holter electrocardiogram, is considered. This work refers to a group of persons admitted to the cardiological clinic of the KAT Hospital in Athens during the time period from 4th to 24th December 2006 that is characterized by extreme solar and geomagnetic activity. A series of Forbush decreases started on 6th December and lasted until the end of the month and a great solar proton event causing a Ground Level Enhancement (GLE) of the cosmic ray intensity on 13th December occurred. A sudden decrease of the cosmic ray intensity on 15th December, when a geomagnetic storm was registered, was also recorded in Athens Neutron Monitor station (cut-off rigidity 8.53 GV) with amplitude of 4%. It is noticed that during geomagnetically quiet days the heart rate and the cosmic ray intensity variations are positively correlated. When intense cosmic ray variations, like Forbush decreases and relativistic proton events produced by strong solar phenomena occur, cosmic ray intensity and heart rate get minimum values and their variations, also, coincide. During these events the correlation coefficient of these two parameters changes and follows the behavior of the cosmic ray intensity variations. This is only a small part of an extended investigation, which has begun using data from the year 2002 and is still in progress.

Proton-proton and neutron-proton bremsstrahlung in the potential model

International Nuclear Information System (INIS)

Herrmann, V.

1993-11-01

The nucleon-nucleon (NN) bremsstrahlung reaction is studied in the framework of a potential model. We investigate and explain the behavior of the most important corrections to the purely non-relativistic model considering only the external current; i.e. we include the relativistic spin correction, the one-body rescattering contribution and the Coulomb-effect, where it is needed. The important contribution of the two-body or meson-exchange current is treated in the soft-photon-approximation. In addition to the usual coplanar NNγ cross section we also study non-coplanar cross sections and spin observables like the analyzing power and spin correlation coefficients. It is shown that the behavior of the relativistic spin correction is governed by the 1 S 0 partial-wave state, is almost energy independent and reduces the NNγ cross section by roughly 20 - 30%. The one-body rescattering contribution enhances the ppγ cross section for the geometry of the last TRIUMF experiment by about 20% and thus almost compensates the effect of the relativistic spin corrections. The effects of each part of the NN interaction on the ppγ observables is studied in the coplanar geometry. We find that these effects depend on the proton scattering angles as well as on the considered observable. However, the tensor component of the NN interaction is important in all geometries. The comparison of different NN potential models yields that the NNγ reaction is not able to discriminate these potentials in their off-shell behavior, although the corresponding T-matrices deviate from each other off the energy shell. It is concluded that the occuring differences originate already from deviations on the energy shell or from the fact that the approximations made in the calculations for the two-body current are not of the same quality for all NN potential models. (orig.)

Isospin-dependent term in the relativistic microscopic optical potential

International Nuclear Information System (INIS)

Rong Jian; Ma Zhongyu; National Laboratory of Heavy Ion Accelerator of Lanzhou, Lanzhou; Chinese Academy of Sciences, Beijing

2005-01-01

The isospin-dependence of the relativistic microscopic optical potential is investigated in the Dirac Brueckner-Hartree-Fock approach. The isospin part of the microscopic optical potential is emphasized. A local density approximation is adopted for finite nuclei. Taking 208 Pb as example, the difference between proton and neutron optical potentials is studied and compared with the phenomenological Lane Model potential. (authors)

Color transparency and the structure of the proton in quantum chromodynamics

International Nuclear Information System (INIS)

Brodsky, S.J.

1989-06-01

Many anomalies suggest that the proton itself is a much more complex object than suggested by simple non-relativistic quark models. Recent analyses of the proton distribution amplitude using QCD sum rules points to highly-nontrivial proton structure. Solutions to QCD in one-space and one-time dimension suggest that the momentum distributions of non-valence quarks in the hadrons have a non-trivial oscillatory structure. The data seems also to be suggesting that the ''intrinsic'' bound state structure of the proton has a non-negligible strange and charm quark content, in addition to the ''extrinsic'' sources of heavy quarks created in the collision itself. As we shall see in this lecture, the apparent discrepancies with experiment are not so much a failure of QCD, but rather symptoms of the complexity and richness of the theory. An important tool for analyzing this complexity is the light-cone Fock state representation of hadron wavefunctions, which provides a consistent but convenient framework for encoding the features of relativistic many-body systems in quantum field theory. 121 refs., 44 figs., 1 tab

Prediction of SEP Peak Proton Intensity Based on CME Speed, Direction and Observations of Associated Solar Phenomena

Science.gov (United States)

Richardson, I. G.; Mays, M. L.; Thompson, B. J.; Kwon, R.; Frechette, B. P.

2017-12-01

We assess whether a formula obtained by Richardson et al. (Solar Phys., 289, 3059, 2014; DOI 10.1007/s11207-014-0524-8) relating the intensity of 14-24 MeV protons in a solar energetic particle event at 1 AU to the solar event location and the speed of the associated coronal mass ejection (CME), may be used to "predict" the intensity of a solar energetic particle event. Starting with a subset of several hundred CMEs in the CCMC/SWRC DONKI real-time database (http://kauai.ccmc.gsfc.nasa.gov/DONKI/) selected without consideration of whether they were associated with SEP events, we first use the CME speed and direction to predict the proton intensity at Earth or the STEREO spacecraft using this formula. Since most of these CMEs were not in fact associated with SEP events, many "false alarms" result. We then examine whether considering other phenomena which may accompany the CMEs, such as the X-ray flare intensity and the properties of type II and type III radio emissions, may help to reduce the false alarm rate. We also use CME parameters calculated from an ellipsoidal shell fit to multi-spacecraft CME shock observations for a smaller number of events to predict the SEP intensity. We calculate skill scores for each case and assess whether the Richardson et al. (2014) formula, using additional observations to reduce the false alarm rate, has any potential as a SEP prediction tool, assuming that the required observations could be acquired sufficiently rapidly following the onset of the related solar event/CME.

A Short-term ESPERTA-based Forecast Tool for Moderate-to-extreme Solar Proton Events

Science.gov (United States)

Laurenza, M.; Alberti, T.; Cliver, E. W.

2018-04-01

The ESPERTA (Empirical model for Solar Proton Event Real Time Alert) forecast tool has a Probability of Detection (POD) of 63% for all >10 MeV events with proton peak intensity ≥10 pfu (i.e., ≥S1 events, S1 referring to minor storms on the NOAA Solar Radiation Storms scale), from 1995 to 2014 with a false alarm rate (FAR) of 38% and a median (minimum) warning time (WT) of ∼4.8 (0.4) hr. The NOAA space weather scale includes four additional categories: moderate (S2), strong (S3), severe (S4), and extreme (S5). As S1 events have only minor impacts on HF radio propagation in the polar regions, the effective threshold for significant space radiation effects appears to be the S2 level (100 pfu), above which both biological and space operation impacts are observed along with increased effects on HF propagation in the polar regions. We modified the ESPERTA model to predict ≥S2 events and obtained a POD of 75% (41/55) and an FAR of 24% (13/54) for the 1995–2014 interval with a median (minimum) WT of ∼1.7 (0.2) hr based on predictions made at the time of the S1 threshold crossing. The improved performance of ESPERTA for ≥S2 events is a reflection of the big flare syndrome, which postulates that the measures of the various manifestations of eruptive solar flares increase as one considers increasingly larger events.

Studies of neutron emission from relativistic nuclear interactions

CERN Document Server

Guo, S L; Wang, Y L; Guo, H Y; Sá Ben-Hao; Zheng, Y M; Brandt, R; Vater, P; Wan, J S; Ochs, M; Kulakov, B A; Sosnin, A N; Krivopustov, M I; Butsev, V S; Bradnova, V

1999-01-01

Studies were carried out on the yields and spatial distributions of secondary neutrons produced in the relativistic nuclear interactions of 1.5 GeV to 14.4 GeV projectiles p, d and alpha-particles with targets Pb and U/Pb. CR-39 track detectors were used to measure the neutrons. It shows that: (1) Secondary neutrons are produced in the whole length of Pb or U targets having a thickness of 20 cm. The neutron intensities produced by proton bombardments are reduced along the proton beam direction in the targets. The higher the energy of protons, the lower the reduction rate of the neutrons. The reduction rate of neutrons in U target is higher than in Pb target for the same energy of protons. (2) The radial intensities of neutrons decrease as the distance increases from the target central line. (3) The neutron yield in U target by proton bombardments is approx 55% higher than in Pb target. (4) The ratio of neutron yield by 14.4 GeV alpha to 7.3 GeV d bombardment in Pb target is 1.74+-0.20.

Calculation of β-decay rates in a relativistic model with momentum-dependent self-energies

International Nuclear Information System (INIS)

Marketin, T.; Vretenar, D.; Ring, P.

2007-01-01

The relativistic proton-neutron quasiparticle random phase approximation (PN-RQRPA) is applied in the calculation of β-decay half-lives of neutron-rich nuclei in the Z≅28 and Z≅50 regions. The study is based on the relativistic Hartree-Bogoliubov calculation of nuclear ground states, using effective Lagrangians with density-dependent meson-nucleon couplings, and also extended by the inclusion of couplings between the isoscalar meson fields and the derivatives of the nucleon fields. This leads to a linear momentum dependence of the scalar and vector nucleon self-energies. The residual QRPA interaction in the particle-hole channel includes the π+ρ exchange plus a Landau-Migdal term. The finite-range Gogny interaction is employed in the T=1 pairing channel, and the model also includes a proton-neutron particle-particle interaction. The results are compared with available data, and it is shown that an extension of the standard relativistic mean-field framework to include momentum-dependent nucleon self-energies naturally leads to an enhancement of the effective (Landau) nucleon mass, and thus to an improved PN-QRPA description of β - -decay rates

Radiation damage and defect behavior in proton irradiated lithium-counterdoped n/sup +/p silicon solar cells

International Nuclear Information System (INIS)

Stupica, J.; Goradia, C.; Swartz, C.K.; Weinberg, I.

1987-01-01

Two lithium-counterdoped n/sup +/p silicon solar cells with different lithium concentrations were irradiated by 10 MeV protons. Cell performance was measured as a function of fluence, and it was found that the cell with the highest concentration of lithium had the higher radiation resistance. Deep level defects were studied using deep level transient spectroscopy which yielded two defects that were lithium related. Relating the defect energy levels obtained from this study under 10 MeV protons, with an earlier work using 1 MeV electron irradiations shows no correlation of the defect energy levels. There is one marked comparison though. The absence of the boron interstitial-oxygen interstitial defect. This consistency strengthens the belief that lithium interacts with oxygen to prevent the formation of the boron interstitial-oxygen interstitial defect. The present results indicate that, in general, addition of lithium in small amounts to the p-base of a boron doped silicon solar cell such that the base remains p-type, tends to increase the radiation resistance of the cell

Proton-nucleus dynamics at ultra-relativistic energies

International Nuclear Information System (INIS)

McCubbin, N.A.

1988-01-01

Some of the basic properties of proton-nucleus (pA) collisions at ultrarelativistic energies are reviewed. These include total and 'partonic' cross-sections, and the differential cross-sections as functions of rapidity, transverse energy, and particle p T , with particular emphasis in all cases on the A dependence. The aim is to introduce a nuclear physics audience to the main trends and ideas; experts in the field will find nothing very new here. (orig.)

Effects of a low-energy proton irradiation on n+/p-AlInGaP solar cells

International Nuclear Information System (INIS)

Lee, H.S.; Yamaguchi, M.; Ekins-Daukes, N.J.; Khan, A.; Takamoto, T.; Imaizumi, M.; Ohshima, T.; Itoh, H.

2006-01-01

For the first time, by deep-level transient spectroscopy, 30keV proton irradiation-induced defects in n + /p-AlInGaP solar cells have been observed. After the 30keV proton irradiation, new deep-level defects such as two majority-carrier (hole) traps HP1 (E V +0.98eV, N T =3.8x10 14 cm -3 ) and HP2, and two minority-carrier (electron) traps EP1 (E C -0.71eV, N T =2.0x10 15 cm -3 ) and EP2 have been observed in p-AlInGaP. The introduction rate of majority-carrier trap center (HP1) is 380cm -1 , which is lower than that (1500cm -1 ) in 100keV proton-irradiated p-InGaP. From the minority-carrier injection annealing for HP1 defect and carrier concentration in 30keV proton-irradiated p-AlInGaP, HP1 defect is likely to act as a recombination center as well as a compensator center

Examining Relativistic Electron Loss in the Outer Radiation Belt

Science.gov (United States)

Green, J. C.; Onsager, T. G.; O'Brien, P.

2003-12-01

Since the discovery of earth's radiation belts researchers have sought to identify the mechanisms that dictate the seemingly erratic relativistic electron flux levels in the outer belt. Contrary to intuition, relativistic electron flux levels do not always increase during geomagnetic storms even though these storms signify enhanced energy input from the solar wind to the magnetosphere [Reeves et al., 2003; O'Brien et al., 2001]. The fickle response of the radiation belt electrons to geomagnetic activity suggests that flux levels are determined by the outcome of a continuous competition between acceleration and loss. Some progress has been made developing and testing acceleration mechanisms but little is known about how relativistic electrons are lost. We examine relativistic electron losses in the outer belt focusing our attention on flux decrease events of the type first described by Onsager et al. [2002]. The study showed a sudden decrease of geosynchronous >2MeV electron flux occurring simultaneously with local stretching of the magnetic field. The decrease was first observed near 15:00 MLT and progressed to all local times after a period of ˜10 hours. Expanding on the work of Onsager et al. [2002], we have identified ˜ 51 such flux decrease events in the GOES and LANL data and present the results of a superposed epoch analysis of solar wind data, geomagnetic activity indicators, and locally measured magnetic field and plasma data. The analysis shows that flux decreases occur after 1-2 days of quiet condition. They begin when either the solar wind dynamic pressure increases or Bz turns southward pushing hot dense plasma earthward to form a partial ring current and stretched magnetic field at dusk. Adiabatic electron motion in response to the stretched magnetic field may explain the initial flux reduction; however, often the flux does not recover with the magnetic field recovery, indicating that true loss from the magnetosphere is occurring. Using Polar and

On interference of cumulative proton production mechanisms

International Nuclear Information System (INIS)

Braun, M.A.; Vechernin, V.V.

1993-01-01

The dynamical picture of the cumulative proton production in hA-collisions by means of diagram analysis with NN interaction described by a non-relativistic NN potential is considered. The contributions of the various mechanisms (spectator, direct and rescattering) for backward hemisphere proton production within the framework of this common approach is calculated. The emphasis is on the comparison of the relative contributions of these mechanisms for various angles, taking into account the interference of these contributions. Comparison with experimental data is also presented. (author)

Modern representation of databases on the example of the Catalog of Solar Proton Events in the 23rd Cycle of Solar Activity

Science.gov (United States)

Ishkov, V. N.; Zabarinskaya, L. P.; Sergeeva, N. A.

2017-11-01

The development of studies of solar sources and their effects on the state of the near-Earth space required systematization of the corresponding information in the form of databases and catalogs for the entire time of observation of any geoeffective phenomenon that includes, if possible at the time of creation, all of the characteristics of the phenomena themselves and the sources of these phenomena on the Sun. A uniform presentation of information in the form of a series of similar catalogs that cover long time intervals is of particular importance. The large amount of information collected in such catalogs makes it necessary to use modern methods of its organization and presentation that allow a transition between individual parts of the catalog and a quick search for necessary events and their characteristics, which is implemented in the presented Catalog of Solar Proton Events in the 23rd Cycle of Solar Activity of the sequence of catalogs (six separate issues) that cover the period from 1970 to 2009 (20th-23rd solar cycles).

On a method for high-energy electron beam production in proton synchrotrons

International Nuclear Information System (INIS)

Bessonov, E.G.; Vazdik, Ya.A.

1979-01-01

It is suggested to produce high-energy electron beams in such a way that the ultrarelativistic protons give an amount of their kinetic energy to the electrons of a thin target, placed inside the working volume of the proton synchrotron. The kinematics of the elastic scattering of relativistic protons on electrons at rest is treated. Evaluation of a number of elastically-scattered electrons by 1000 GeV and 3000 GeV proton beams is presented. The method under consideration is of certain practical interest and may appear to be preferable in a definite energy range of protons and electrons

N2 Dissociation In The Mesosphere Due To Secondary Electrons During A Solar Proton Event: The Effect On Atomic Nitrogen and Nitric Oxide

Science.gov (United States)

Verronen, P. T.; Shematovich, V. I.; Bisikalo, D. V.; Turunen, E.; Ulich, Th.

Solar proton events have an effect on the middle atmospheric odd nitrogen chem- istry. During a solar proton event high energy protons enter Earth's middle atmosphere where they ionize ambient gas. Ionization leads to production of atomic nitrogen, and further to production of nitric oxide, through ion chemistry. In addition, ionization processes produce secondary electrons that, if possessing 9.76 eV or more energy, dissociate N2 providing an additional source of atomic nitrogen. We have calculated mesospheric N2 dissociation rate due to secondary electrons dur- ing a solar proton event. Further, we have studied the effect on atomic nitrogen and nitric oxide at altitudes between 50 and 90 km. It was found that N2 is efficiently dis- sociated in the lower mesosphere by secondary electrons, with rates up to 103 cm-3 s-1 at 50 km. Thus, secondary electrons significantly add to odd nitrogen produc- tion. As a result of N2 dissociation, atomic nitrogen is greatly enhanced in both N(4S) and N(2D) states by 259% and 1220% maximum increases at 50 km, respectively. This further leads to a maximum increase of 16.5% in NO concentration at 61 km via chemical reactions. In our study a Monte Carlo model was used to calculate the total ionization rate and secondary electrons flux due to precipitating protons. These where then used as input to a detailed ion and neutral chemistry model and a steady-state solution was calcu- lated for two cases: With and without N2 dissociation due to secondary electrons.

Prediction Model for Relativistic Electrons at Geostationary Orbit

Science.gov (United States)

Khazanov, George V.; Lyatsky, Wladislaw

2008-01-01

We developed a new prediction model for forecasting relativistic (greater than 2MeV) electrons, which provides a VERY HIGH correlation between predicted and actually measured electron fluxes at geostationary orbit. This model implies the multi-step particle acceleration and is based on numerical integrating two linked continuity equations for primarily accelerated particles and relativistic electrons. The model includes a source and losses, and used solar wind data as only input parameters. We used the coupling function which is a best-fit combination of solar wind/interplanetary magnetic field parameters, responsible for the generation of geomagnetic activity, as a source. The loss function was derived from experimental data. We tested the model for four year period 2004-2007. The correlation coefficient between predicted and actual values of the electron fluxes for whole four year period as well as for each of these years is stable and incredibly high (about 0.9). The high and stable correlation between the computed and actual electron fluxes shows that the reliable forecasting these electrons at geostationary orbit is possible.

Forecasting E > 50-MeV proton events with the proton prediction system (PPS)

Science.gov (United States)

Kahler, Stephen W.; White, Stephen M.; Ling, Alan G.

2017-11-01

Forecasting solar energetic (E > 10-MeV) particle (SEP) events is an important element of space weather. While several models have been developed for use in forecasting such events, satellite operations are particularly vulnerable to higher-energy (≥50-MeV) SEP events. Here we validate one model, the proton prediction system (PPS), which extends to that energy range. We first develop a data base of E ≥ 50-MeV proton events >1.0 proton flux units (pfu) events observed on the GOES satellite over the period 1986-2016. We modify the PPS to forecast proton events at the reduced level of 1 pfu and run PPS for four different solar input parameters: (1) all ≥M5 solar X-ray flares; (2) all ≥200 sfu 8800-MHz bursts with associated ≥M5 flares; (3) all ≥500 sfu 8800-MHz bursts; and (4) all ≥5000 sfu 8800-MHz bursts. The validation contingency tables and skill scores are calculated for all groups and used as a guide to use of the PPS. We plot the false alarms and missed events as functions of solar source longitude, and argue that the longitude-dependence employed by PPS does not match modern observations. Use of the radio fluxes as the PPS driver tends to result in too many false alarms at the 500 sfu threshold, and misses more events than the soft X-ray predictor at the 5000 sfu threshold.

Solar flares, CMEs and solar energetic particle events during solar cycle 24

Science.gov (United States)

Pande, Bimal; Pande, Seema; Chandra, Ramesh; Chandra Mathpal, Mahesh

2018-01-01

We present here a study of Solar Energetic Particle Events (SEPs) associated with solar flares during 2010-2014 in solar cycle 24. We have selected the flare events (≥GOES M-class), which produced SEPs. The SEPs are classified into three categories i.e. weak (proton intensity ≤ 1 pfu), minor (1 pfu pfu) and major (proton intensity ≥ 10 pfu). We used the GOES data for the SEP events which have intensity greater than one pfu and SOHO/ERNE data for the SEP event less than one pfu intensity. In addition to the flare and SEP properties, we have also discussed different properties of associated CMEs.

RHIC spin: The first polarized proton collider

International Nuclear Information System (INIS)

Roser, T.

1994-01-01

The very successful program of QCD and electroweak tests at the high energy hadron colliders have shown that the perturbative QCD has progressed towards becoming a ''precision'' theory. At the same time, it has been shown that with the help of Siberian Snakes it is feasible to accelerate polarized protons to high enough energies where the proven methods of collider physics can be used to probe the spin content of the proton but also where fundamental tests of the spin effects in the standard model are possible. With Siberian Snakes the Relativistic Heavy Ion Collider (RHIC) will be the first collider to allow for 250 GeV on 250 GeV polarized proton collisions

Development of circular protons accelerator for ocular teletherapy

International Nuclear Information System (INIS)

Rabelo, L. A.; Campos, T.P.R.

2011-01-01

The proton therapy has been used for ocular tumors providing tumor control in most cases and vision preservations. The protons show high doses in depth depict lower scattering from beam than other particles, electrons and photons. The cyclotron is a type of accelerator that increases the kinetic energy of the charged particle, recirculating it on a magnetic field and crossing an accelerating electrical field. It can be used to produce radioisotopes to hospitals. The goal of this study is to investigate a unit of circular accelerator to be coupled in existing national cyclotrons to generate a proton beams suitable to ocular therapy. Herein, physical parameters are evaluable, including relativistic corrections. That result shows the viability of developing an accelerator unit to ocular proton therapy. (author)

Relativistic Electrons Produced by Foreshock Disturbances Observed Upstream of Earth's Bow Shock

Science.gov (United States)

Wilson, L. B., III; Sibeck, D. G.; Turner, D. L.; Osmane, A.; Caprioli, D.; Angelopoulos, V.

2016-01-01

Charged particles can be reflected and accelerated by strong (i.e., high Mach number) astrophysical collisionless shock waves, streaming away to form a foreshock region in communication with the shock. Foreshocks are primarily populated by suprathermal ions that can generate foreshock disturbances-largescale (i.e., tens to thousands of thermal ion Larmor radii), transient (approximately 5-10 per day) structures. They have recently been found to accelerate ions to energies of several keV. Although electrons in Saturn's high Mach number (M > 40) bow shock can be accelerated to relativistic energies (nearly 1000 keV), it has hitherto been thought impossible to accelerate electrons beyond a few tens of keV at Earth's low Mach number (1 =M foreshock disturbances to energies up to at least approximately 300 keV. Although such energetic electrons have been previously observed, their presence has been attributed to escaping magnetospheric particles or solar events. These relativistic electrons are not associated with any solar or magnetospheric activity. Further, due to their relatively small Larmor radii (compared to magnetic gradient scale lengths) and large thermal speeds (compared to shock speeds), no known shock acceleration mechanism can energize thermal electrons up to relativistic energies. The discovery of relativistic electrons associated with foreshock structures commonly generated in astrophysical shocks could provide a new paradigm for electron injections and acceleration in collisionless plasmas.

Relativistic electron dropout echoes induced by interplanetary shocks

Science.gov (United States)

Schiller, Q.; Kanekal, S. G.; Boyd, A. J.; Baker, D. N.; Blake, J. B.; Spence, H. E.

2017-12-01

Interplanetary shocks that impact Earth's magnetosphere can produce immediate and dramatic responses in the trapped relativistic electron population. One well-studied response is a prompt injection capable of transporting relativistic electrons deep into the magnetosphere and accelerating them to multi-MeV energies. The converse effect, electron dropout echoes, are observations of a sudden dropout of electron fluxes observed after the interplanetary shock arrival. Like the injection echo signatures, dropout echoes can also show clear energy dispersion signals. They are of particular interest because they have only recently been observed and their causal mechanism is not well understood. In the analysis presented here, we show observations of electron drift echo signatures from the Relativistic Electron-Proton Telescope (REPT) and Magnetic Electron and Ion Sensors (MagEIS) onboard NASA's Van Allen Probes mission, which show simultaneous prompt enhancements and dropouts within minutes of the associated with shock impact. We show that the observations associated with both enhancements and dropouts are explained by the inward motion caused by the electric field impulse induced by the interplanetary shock, and either energization to cause the enhancement, or lack of a seed population to cause the dropout.

Relativistic mean field theory for unstable nuclei

International Nuclear Information System (INIS)

Toki, Hiroshi

2000-01-01

We discuss the properties of unstable nuclei in the framework of the relativistic mean field (RMF) theory. We take the RMF theory as a phenomenological theory with several parameters, whose form is constrained by the successful microscopic theory (RBHF), and whose values are extracted from the experimental values of unstable nuclei. We find the outcome with the newly obtained parameter sets (TM1 and TMA) is promising in comparison with various experimental data. We calculate systematically the ground state properties of even-even nuclei up to the drip lines; about 2000 nuclei. We find that the neutron magic shells (N=82, 128) at the standard magic numbers stay at the same numbers even far from the stability line and hence provide the feature of the r-process nuclei. However, many proton magic numbers disappear at the neutron numbers far away from the magic numbers due to the deformations. We discuss how to describe giant resonances for the case of the non-linear coupling terms for the sigma and omega mesons in the relativistic RPA. We mention also the importance of the relativistic effect on the spin observables as the Gamow-Teller strength and the longitudinal and transverse spin responses. (author)

Cluster approach to intranuclear cascade for relativistic heavy ion colisions

International Nuclear Information System (INIS)

Kodama, T.; Duarte, S.B.; Chung, K.C.; Nazareth, R.A.M.S.

1982-01-01

A new approach to the intranuclear cascade model for relativistic heavy ion reaction is presented. The effect of nucleon conventration on the collision process is explicitly included. It is found that the contributions from the non-binary processes are far from being negligible. Such processes are shown to broaden the angular distribution of inclusive proton spectra for 20 Ne + 238 U head-on collisions. (Author) [pt

Highly relativistic magnetospheric electrons: A role in coupling to the middle atmosphere?

International Nuclear Information System (INIS)

Baker, D.N.; Blake, J.B.; Gorney, D.J.; Higbie, P.R.; Klebesadel, R.W.; King, J.H.

1987-01-01

Long-term (1979-present) observations of relativistic electrons (2--15 MeV) at geostationary orbit show a strong solar cycle dependence. Such electrons were largely absent near the last solar maximum (1979--80), while they were prominent during the approach to solar minimum (1983--85). This population now is dwindling as solar minimum has been reached. The strong magnetospheric presence of high-speed solar wind streams which results from solar coronal hole structures during the approach to solar activity (sunspot) minimum. We clearly observe 27-day periodic enhancements of the relativistic electrons in association with concurrently measured solar wind streams (V/sub S//sub W/approx. >600 km/s). We have used a numerical transport code to study the coupling of these high-energy electrons to earth's upper and middle atmosphere. We calculate using the observed energy spectra of the electrons that, when precipitated, these electrons show a large (maximum of ∼100 keV/cm 3 -s) energy deposition at 40--60 km altitude, which is 3--4 orders of magnitude greater than the galactic cosmic ray or solar EUV energy deposition at these altitudes. We also find that the global energy deposition in the mid-latitudes totals nearly 10 21 ergs for a typical 2--3 day event period. We conclude that this previously unrecognized electron population could play an important role in coupling solar wind and magnetospheric variability (on 27--day and 11--year cycles) to the middle atmosphere through a modulating effect on lower D-region ionization and, possibly, on upper level ozone chemistry. These electrons also may contribute to the recent Antarctic polar ozone depletion phenomenon. copyright American Geophysical Union 1987

Electrodisintegration of relativistic nuclei by a periodic crystal field in channeling

International Nuclear Information System (INIS)

Pivovarov, Yu.L.; Vorob'ev, S.A.

1981-01-01

Processes on channeled relativistic nuclei with transition into a continuous spectrum (electrodisintegration of nuclei with emission of neutron, proton, photon and etc.) are considered. A case of plane channeling is considered. The equivalent photon method is used for calculating the disintegration cross section. The beryllium disintegration cross section in the system of tungsten crystal (100) planes is calculated. At the γ=10 2 Lorentz factor the cross section value is 5.27 mb. The process considered is of interest from the viewpoint of production of monoenergy neutrons of high energies and γ quanta of excited nuclei. The channeling effect gives the possibility to study electromagnetic interactions of relativistic nuclei under suppre--ssion conditions of the nuclear interaction channel [ru

Half-lives of proton emitters using relativistic mean field theory

International Nuclear Information System (INIS)

Sahu, Bidhubhusan; Patra, S. K.; Agarwalla, S. K.

2011-01-01

The proton radioactivity lifetimes of proton emitters from the ground and the isomeric states are calculated using the microscopic M3Y + Ex and R3Y + Ex (proposed) nucleon-nucleus interaction potentials. These interaction potentials are obtained by single folding the densities of the daughter nuclei supplemented by a zero-range pseudopotential. The quantum-mechanical-tunneling probability is calculated within the WKB approximation. The calculated results are found to be in good agreement with the experimental data for both the M3Y and R3Y interactions.

CURRENT SHEET REGULATION OF SOLAR NEAR-RELATIVISTIC ELECTRON INJECTION HISTORIES

Energy Technology Data Exchange (ETDEWEB)

Agueda, N.; Sanahuja, B. [Departament d' Astronomia i Meteorologia, Institut de Ciencies del Cosmos, Universitat de Barcelona (Spain); Vainio, R. [Department of Physics, University of Helsinki (Finland); Dalla, S. [Jeremiah Horrocks Institute, University of Central Lancashire (United Kingdom); Lario, D. [Applied Physics Laboratory, Johns Hopkins University (United States)

2013-03-10

We present a sample of three large near-relativistic (>50 keV) electron events observed in 2001 by both the ACE and the Ulysses spacecraft, when Ulysses was at high-northern latitudes (>60 Degree-Sign ) and close to 2 AU. Despite the large latitudinal distance between the two spacecraft, electrons injected near the Sun reached both heliospheric locations. All three events were associated with large solar flares, strong decametric type II radio bursts and accompanied by wide (>212 Degree-Sign ) and fast (>1400 km s{sup -1}) coronal mass ejections (CMEs). We use advanced interplanetary transport simulations and make use of the directional intensities observed in situ by the spacecraft to infer the electron injection profile close to the Sun and the interplanetary transport conditions at both low and high latitudes. For the three selected events, we find similar interplanetary transport conditions at different heliolatitudes for a given event, with values of the mean free path ranging from 0.04 AU to 0.27 AU. We find differences in the injection profiles inferred for each spacecraft. We investigate the role that sector boundaries of the heliospheric current sheet (HCS) have on determining the characteristics of the electron injection profiles. Extended injection profiles, associated with coronal shocks, are found if the magnetic footpoints of the spacecraft lay in the same magnetic sector as the associated flare, while intermittent sparse injection episodes appear when the spacecraft footpoints are in the opposite sector or a wrap in the HCS bounded the CME structure.

High luminosity polarized proton collisions at RHIC

International Nuclear Information System (INIS)

Roser, T.

2001-01-01

The Brookhaven Relativistic Heavy Ion Collider (RHIC) provides the unique opportunity to collide polarized proton beams at a center-of-mass energy of up to 500 GeV and luminosities of up to 2 x 10 32 cm -2 s -1 . Such high luminosity and high energy polarized proton collisions will open up the possibility of studying spin effects in hard processes. However, the acceleration of polarized beams in circular accelerators is complicated by the numerous depolarizing spin resonances. Using a partial Siberian snake and a rf dipole that ensure stable adiabatic spin motion during acceleration has made it possible to accelerate polarized protons to 25 GeV at the Brookhaven AGS. After successful operation of RHIC with gold beams polarized protons from the AGS have been successfully injected into RHIC and accelerated using a full Siberian snakes built from four superconducting helical dipoles. A new high energy proton polarimeter was also successfully commissioned. Operation with two snakes per RHIC ring is planned for next year

Prompt double J/ψ production in proton-proton collisions at the LHC

International Nuclear Information System (INIS)

Baranov, S.P.; Rezaeian, Amir H.

2015-11-01

We provide a detailed study of prompt double J/ψ production within the non-relativistic QCD (NRQCD) framework in proton-proton collisions at the LHC.We confront the recent LHC data with the results obtained at leading-order (LO) in the NRQCD framework within two approaches of the collinear factorization and the k T -factorization. We show that the LHCb data can be fairly described within the k T -factorized LO NRQCD, while the collinearly factorized LO NRQCD significantly overshoots the LHCb data at low J/ψ-pair invariant mass. We show that the LO NRQCD formalism cannot describe the recent CMS data, with about one order of magnitude discrepancy. If the CMS data are confirmed, this indicates rather large higher-order corrections for prompt double J/ψ production. We provide various predictions which can further test the NRQCD-based approach at the LHC in a kinematic region that LO contributions dominate. We also investigate long-range in rapidity double J/ψ correlations. We found no evidence of a ridge-like structure for double J/ψ production in proton-proton collisions at the LHC up to subleading α 6 s accuracy.

Effects of low temperature periodic annealing on the deep-level defects in 200 keV proton irradiated AlGaAs-GaAs solar cells

Science.gov (United States)

Li, S. S.; Chiu, T. T.; Loo, R. Y.

1981-01-01

The GaAs solar cell has shown good potential for space applications. However, degradation in performance occurred when the cells were irradiated by high energy electrons and protons in the space environment. The considered investigation is concerned with the effect of periodic thermal annealing on the deep-level defects induced by the 200 keV protons in the AlGaAs-GaAs solar cells. Protons at a fluence of 10 to the 11th P/sq cm were used in the irradiation cycle, while annealing temperatures of 200 C (for 24 hours), 300 C (six hours), and 400 C (six hours) were employed. The most likely candidate for the E(c) -0.71 eV electron trap observed in the 200 keV proton irradiated samples may be due to GaAs antisite, while the observed E(v) +0.18 eV hole trap has been attributed to the gallium vacancy related defect. The obtained results show that periodic annealing in the considered case does not offer any advantages over the one time annealing process.

Higher order net-proton number cumulants dependence on the centrality definition and other spurious effects

Science.gov (United States)

Sombun, S.; Steinheimer, J.; Herold, C.; Limphirat, A.; Yan, Y.; Bleicher, M.

2018-02-01

We study the dependence of the normalized moments of the net-proton multiplicity distributions on the definition of centrality in relativistic nuclear collisions at a beam energy of \\sqrt{{s}{NN}}=7.7 {GeV}. Using the ultra relativistic quantum molecular dynamics model as event generator we find that the centrality definition has a large effect on the extracted cumulant ratios. Furthermore we find that the finite efficiency for the determination of the centrality introduces an additional systematic uncertainty. Finally, we quantitatively investigate the effects of event-pile up and other possible spurious effects which may change the measured proton number. We find that pile-up alone is not sufficient to describe the data and show that a random double counting of events, adding significantly to the measured proton number, affects mainly the higher order cumulants in most central collisions.

Beam-beam observations in the Relativistic Heavy Ion Collider

Energy Technology Data Exchange (ETDEWEB)

Luo, Y. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Laboratory (BNL), Upton, NY (United States); White, S. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

2015-06-24

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been operating since 2000. Over the past decade, thanks to the continuously increased bunch intensity and reduced β*s at the interaction points, the maximum peak luminosity in the polarized proton operation has been increased by more than two orders of magnitude. In this article, we first present the beam-beam observations in the previous RHIC polarized proton runs. Then we analyze the mechanisms for the beam loss and emittance growth in the presence of beam-beam interaction. The operational challenges and limitations imposed by beam-beam interaction and their remedies are also presented. In the end, we briefly introduce head-on beam-beam compensation with electron lenses in RHIC.

The effects of coronal holes on the propagation of solar energetic protons

International Nuclear Information System (INIS)

Kunches, Joseph M.; Zwickl, Ronald D.

1999-01-01

The accurate prediction of the start of a Solar Energetic Particle Event (SEP) is a high priority for space weather forecasters. The Space Environment Center (SEC) has recorded parameters related to SEPs since 1976, and that list includes a total of 134 events for the period 1976-1997. The onset times of individual events are variable, especially SEPs originating from the solar eastern hemisphere. An examination of the data shows the full set can be divided into two families -- those that begin at the geosynchronous satellite at a time consistent with what would be expected for activity from a given heliolongitude, and those whose onset is later than what accepted forecast techniques would predict. There are 21 'long onset' events in this historical record. Seeking to understand what factors distinguished the slow-to-arrive events, Helium I 1083.0 nm observations were examined for the presence of coronal holes at the times of the SEPs. It was found that all SEPs with long onset times had a coronal hole situated between the flare site and the footpoint of the interplanetary magnetic field line connecting to Earth ( Solar-Terrestrial Predictions-V, Hiraiso Solar-Terrestrial Research Center, Ibaraki, Japan). This coronal hole configuration is important for accurate predictions, although the hole may serve as merely a proxy for the plasma conditions that actually affect the propagation and acceleration of the protons. Since coronal holes are easily identifiable using Helium I and other wavelengths, operational forecasters can employ this technique to improve their predictions of SEPs

Relativistic Calculations and Measurements of Energies, Auger Rates, and Lifetimes.

Science.gov (United States)

1982-12-01

Research and Industry, Denton, Texas, 8-10 November 1982. 7. B. Crasemann: "Efectos Relativ’sticos y de QED Sobre las Transiciones Rayos - X y Auger Entre...INNER-SHELL IONIZATION BY PROTONS X -RAY EMISSION BREIT INTERACTION AUGER TRANSITIONS DIRAC-HARTREE-SLATER COMPUTATIONS SYNCHROTRON RADIATION RESONANT...computations, including relativistic and quantum- electrodynamic effects, of atomic energy levels and of x -ray and Auger transitions in atoms with one or

Strange particle correlations measured by the Star experiment in ultra-relativistic heavy ion collisions a RHIC; Etude des correlations de particules etranges mesurees par l'experience STAR dans les collisions d'ions lourds ultra-relativistes au RHIC

Energy Technology Data Exchange (ETDEWEB)

Renault, G

2004-09-01

Non-identical correlation functions allow to study the space-time evolution of the source of particles formed in ultra-relativistic heavy ion collisions. The STAR experiment is dedicated to probe the formation of a new state of nuclear matter called Quark Gluon Plasma. The proton - lambda correlation function is supposed to be more sensitive to bigger source sizes than the proton - proton because of the absence of the final state Coulomb interaction. In this thesis, proton - lambda, anti-proton - anti-lambda, anti-proton - lambda and proton - anti-lambda correlation functions are studied in Au+Au collisions at {radical}S{sub NN} = 200 GeV using an analytical model. The proton - lambda and anti-proton - anti-lambda correlation functions exhibit the same behavior as in previous measurements. The anti-proton - lambda and proton - anti-lambda correlation functions, measured for the first time, show a very strong signal corresponding to the baryon - anti-baryon annihilation channel. Parameterizing the correlation functions has allowed to characterize final state interactions. (author)

Radiative pion-proton scattering in the static Chew-Low model

International Nuclear Information System (INIS)

Ho-Kim, Q.; Lavine, J.P.

1976-01-01

The results of a non-relativistic calculation of π +- -proton bremsstrahlung cross-sections at the pion laboratory kinetic energy of 298 MeV for backward photon angles are presented. The πp interaction is described by the static Chew-Low model. (Auth.)

Recent results of the STAR high-energy polarized proton-proton program at RHIC at BNL

International Nuclear Information System (INIS)

Surrow, Bernd

2007-01-01

The STAR experiment at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is carrying out a spin physics program colliding transverse or longitudinal polarized proton beams at √(s) 200 - 500GeV to gain a deeper insight into the spin structure and dynamics of the proton. These studies provide fundamental tests of Quantum Chromodynamics (QCD).One of the main objectives of the STAR spin physics program is the determination of the polarized gluon distribution function through a measurement of the longitudinal double-spin asymmetry, ALL, for various processes. Recent results will be shown on the measurement of ALL for inclusive jet production, neutral pion production and charged pion production at √(s) = 200GeV. In addition to these measurements involving longitudinal polarized proton beams, the STAR collaboration has performed several important measurements employing transverse polarized proton beams. New results on the measurement of the transverse single-spin asymmetry, AN, for forward neutral pion production and the first measurement of AN for mid-rapidity di-jet production will be discussed

Calculations of the displacement damage and short-circuit current degradation in proton irradiated (AlGa)As-GaAs solar cells

Science.gov (United States)

Yeh, C. S.; Li, S. S.; Loo, R. Y.

1987-01-01

A theoretical model for computing the displacement damage defect density and the short-circuit current (I sub sc) degradation in proton-irradiated (AlGa)As-GaAs p-n junction solar cells is presented. Assumptions were made with justification that the radiation induced displacement defects form an effective recombination center which controls the electron and hole lifetimes in the junction space charge region and in the n-GaAs active layer of the irradiated GaAs p-n junction cells. The degradation of I sub sc in the (AlGa)As layer was found to be negligible compared to the total degradation. In order to determine the I sub sc degradation, the displacement defect density, path length, range, reduced energy after penetrating a distance x, and the average number of displacements formed by one proton scattering event were first calculated. The I sub sc degradation was calculated by using the electron capture cross section in the p-diffused layer and the hole capture cross section in the n-base layer as well as the wavelength dependent absorption coefficients. Excellent agreement was found between the researchers calculated values and the measured I sub sc in the proton irradiated GaAs solar cells for proton energies of 100 KeV to 10 MeV and fluences from 10 to the 10th power p/square cm to 10 to the 12th power p/square cm.

Relativistic and non-relativistic studies of nuclear matter

NARCIS (Netherlands)

Banerjee, MK; Tjon, JA

2002-01-01

We point out that the differences between the results of the non-relativistic lowest order Brueckner theory (LOBT) and the relativistic Dirac-Brueckner analysis predominantly arise from two sources. Besides effects from a nucleon mass modification M* in nuclear medium we have in a relativistic

Relativistic corrections to the elastic electron scattering from 208Pb

International Nuclear Information System (INIS)

Chandra, H.; Sauer, G.

1976-01-01

In the present work we have calculated the differential cross sections for the elastic electron scattering from 208 Pb using the charge distributions resulting from various corrections. The point proton and neutron mass distributions have been calculated from the spherical wave functions for 208 Pb obtained by Kolb et al. The relativistic correction to the nuclear charge distribution coming from the electromagnetic structure of the nucleon has been accomplished by assuming a linear superposition of Gaussian shapes for the proton and the neutron charge form factor. Results of this calculation are quite similar to an earlier calculation by Bertozzi et al., who have used a different wave function for 208 Pb and have assumed exponential smearing for the proton corresponding to the dipole fit for the form factor. Also in the present work, reason for the small spin orbit contribution to the effective charge distribution is discussed in some detail. It is also shown that the use of a single Gaussian shape for the proton smearing usually underestimates the actual theoretical cross section

Hard processes and fragmentation in a unified model for interactions at ultra-relativistic energies; Les processus durs et la fragmentation dans un modele unifie pour les interactions aux energies ultra-relativistes

Energy Technology Data Exchange (ETDEWEB)

Drescher, H.J

1999-06-11

In this work we have developed hard processes and string fragmentation in the framework of interactions at relativistic energies. The hypothesis of the universality of high energy interactions means that many elements of heavy ion collisions can be studied and simulated in simpler nuclear reactions. In particular this hypothesis implies that the fragmentation observed in the reaction e{sup +}e{sup -} follows the same rules as in the collision of 2 lead ions. This work deals with 2 nuclear processes: the e{sup +}e{sup -} annihilation reaction and the deep inelastic diffusion. For the first process the string model has been developed to simulate fragmentation by adding an artificial breaking of string due to relativistic effects. A monte-Carlo method has been used to determine the points in a Minkowski space where this breaking occurs. For the second reaction, the theory of semi-hard pomerons is introduced in order to define elementary hadron-hadron interactions. The model of fragmentation proposed in this work can be applied to more complicated reactions such as proton-proton or ion-ion collisions.

Studies of the relativistic electron source and related phenomena in Petawatt Laser matter interactions

International Nuclear Information System (INIS)

Key, M.H.; Campbell, E.M.; Cowan, T.E.; Hatchett, S.P.; Henry, E.A.; Koch, J.A.; Landgon, A.B.; Lasinski, B.F.; Lee, R.W.; MacKinnon, A.; Offenberger, A.; Pennington, D.M.; Perry, M.D.; Sangster, T.C.; Yasuike, K.; Snavely, R.; Roth, M.; Phillips, T.W.; Stoyer, M.A.; Wilks, S.C.; Singh, M.S.

1999-01-01

The interaction of laser radiation with solid targets at 1 petawatt power and intensity up to 3x10 20 Wcm -2 has been studied with emphasis on relativistic electrons and high energy ions. Secondary effects including Bremsstrahlung radiation, nuclear interactions and heating have been characterized. A collimated beam of protons with up to 55 MeV energy is emitted normal to the rear surface of thin targets and its characteristics and origin are discussed. The significance of the data for radiography, fast ignition and proton beam applications is summarized

Spatial characterization of relativistic electron enhancements in the Earth's outer radiation belt during the Van Allen Probes era

Science.gov (United States)

Pinto, V. A.; Bortnik, J.; Moya, P. S.; Lyons, L. R.; Sibeck, D. G.; Kanekal, S. G.

2017-12-01

Using Van Allen Probes Relativistic Electron-Proton Telescope (REPT) instrument we have identified 73 relativistic electron enhancement events in the outer radiation belt that occurred at different L values between L = 2.5 and L = 6.0. To determine an enhancement, we have used three different identification methods. We then determine the radial location, MLT location, timing and strength of those enhancements. We discuss the differences of each of the methods and test them to pinpoint the origin and spatial propagation of each enhancement. We have classified the events based on the radial propagation, speed of enhancement and intensity of fluxes and response for energy channels ranging from 1.8 MeV to 6.3 MeV. In addition, we have used OMNI data to study the statistical properties of the solar wind during each event and have classified similarities and differences that might be relevant for each group of enhancements and help us determine the physical process responsible for different types of enhancements. Additionally, we have used >2 MeV electron fluxes at geostationary orbit as measured by the GOES 13 and 15 Energetic Particle Sensor (EPS) instrument to compare our results with the geostationary orbit. Our results suggest that under certain conditions GOES data can be used to predict fluxes at the core of the radiation belt and vice-versa.

Chemical freeze-out study in proton-proton collisions at RHIC and LHC energies

International Nuclear Information System (INIS)

Das, Sabita; Mishra, Debadeepti; Mohanty, Bedangadas; Chatterjee, Sandeep

2016-01-01

Particle multiplicities measured at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) facilities can be used to understand the chemical freeze-out dynamics. At chemical freeze-out (CFO), inelastic collisions cease and the freeze-out parameters can be determined using measured particle multiplicities within the framework of a statistical model. The statistical model has proven to be quite successful in describing the particle production from elementary p-p and e"+e"- collisions up to heavy-ion collisions. It helps to do a systematic study of the centrality and energy dependence of freeze-out parameters in heavy-ion collisions from lower SPS to higher LHC energies. The new data at LHC along with the RHIC data can be used to do such a systematic study in proton-proton collisions

Nuclear response theory for spin-isospin excitations in a relativistic quasiparticle-phonon coupling framework

Energy Technology Data Exchange (ETDEWEB)

Robin, Caroline; Litvinova, Elena [Western Michigan University, Department of Physics, Kalamazoo, MI (United States)

2016-07-15

A new theoretical approach to spin-isospin excitations in open-shell nuclei is presented. The developed method is based on the relativistic meson-exchange nuclear Lagrangian of Quantum Hadrodynamics and extends the response theory for superfluid nuclear systems beyond relativistic quasiparticle random phase approximation in the proton-neutron channel (pn-RQRPA). The coupling between quasiparticle degrees of freedom and collective vibrations (phonons) introduces a time-dependent effective interaction, in addition to the exchange of pion and ρ-meson taken into account without retardation. The time-dependent contributions are treated in the resonant time-blocking approximation, in analogy to the previously developed relativistic quasiparticle time-blocking approximation (RQTBA) in the neutral (non-isospin-flip) channel. The new method is called proton-neutron RQTBA (pn-RQTBA) and is applied to the Gamow-Teller resonance in a chain of neutron-rich nickel isotopes {sup 68-78}Ni. A strong fragmentation of the resonance along with quenching of the strength, as compared to pn-RQRPA, is obtained. Based on the calculated strength distribution, beta-decay half-lives of the considered isotopes are computed and compared to pn-RQRPA half-lives and to experimental data. It is shown that a considerable improvement of the half-life description is obtained in pn-RQTBA because of the spreading effects, which bring the lifetimes to a very good quantitative agreement with data. (orig.)

RPA correlations and nuclear densities in relativistic mean field approach

International Nuclear Information System (INIS)

Van Giai, N.; Liang, H.Z.; Meng, J.

2007-02-01

The relativistic mean field approach (RMF) is well known for describing accurately binding energies and nucleon distributions in atomic nuclei throughout the nuclear chart. The random phase approximation (RPA) built on top of the RMF is also a good framework for the study of nuclear excitations. Here, we examine the consequences of long range correlations brought about by the RPA on the neutron and proton densities as given by the RMF approach. (authors)

Asymptotic matching of the solar-system gravitational yields

International Nuclear Information System (INIS)

Kopejkin, S.M.

1989-01-01

In the framework of the general relativity, the structure of the Solar-system gravitational fields is investigated and the relativistic formulae of transformation between nonrotating in the dynamical sense harmonic reference systems - barycentric, planetocentric and topocentric (satelite) ones - are derived by the method of the asymptotic mathing of components of the metric tensor. The derived formulae generalize the linear Poincare transformation in the case of curved space-time. With the help of the asymptotic matching formulae, the relationships between relativistic time scales inside the Solar system have been established, the equations of relativistic precession of the space axis of one reference system with respect to another one have been derived, the equations of translational motion of the center-of-mass of planets (the Sun) and their satellites have been obtained

Observational investigation of the solar oblateness

International Nuclear Information System (INIS)

Stebbins, R.T.

1975-01-01

The solar oblateness provides important information for solar physics and experimental relativity. After the solar neutrino flux, the sun's shape is the most revealing probe of the solar interior. Rapidly rotating interiors suggested to explain the solar neutrino paradox produce sizeable oblatenesses. Certain types of surface phenomena can also be investigated with precision diameter measurements. The relativistic advance of Mercury's perihelion has long been the principal experimental support for Einstein's theory of general relativity. Recent measurements of the solar oblateness have suggested that the relativistic advance is smaller than originally thought due to a contribution from a solar mass quadrupole moment. This interpretation of the perihelion advance would shift the experimental support to the scalar-tensor theory of gravitation. A debate over the interpretation of the oblateness measurements has resulted. In light of these circumstances, solar oblateness observations have been attempted. Improved experimental techniques have been devised, including a daytime astrometric telescope and an explicit definition of the sun's edge. Observations reveal a time varying excess equatorial brightness, that is, a variation in the limb darkening function between equator and pole, which would preclude accurate interpretation of previous solar oblateness measurements. This vindicates the alternate interpretations of other solar oblateness measurements. From these results, it can be concluded that the Mercury perihelion evidence firmly supports Einstein's General Theory of Relativity, the solar interiors cannot be rotating fast enough to account for the low solar neutrino flux, and a time varying excess equatorial brightness exists

Pickup Protons: Comparisons using the Three-Dimensional MHD HHMS-PI model and Ulysses SWICS Measurements

Science.gov (United States)

Intriligator, Devrie S.; Detman, Thomas; Gloecker, George; Gloeckler, Christine; Dryer, Murray; Sun, Wei; Intriligator, James; Deehr, Charles

2012-01-01

We report the first comparisons of pickup proton simulation results with in situ measurements of pickup protons obtained by the SWICS instrument on Ulysses. Simulations were run using the three dimensional (3D) time-dependent Hybrid Heliospheric Modeling System with Pickup Protons (HHMS-PI). HHMS-PI is an MHD solar wind model, expanded to include the basic physics of pickup protons from neutral hydrogen that drifts into the heliosphere from the local interstellar medium. We use the same model and input data developed by Detman et al. (2011) to now investigate the pickup protons. The simulated interval of 82 days in 2003 2004, includes both quiet solar wind (SW) and also the October November 2003 solar events (the Halloween 2003 solar storms). The HHMS-PI pickup proton simulations generally agree with the SWICS measurements and the HHMS-PI simulated solar wind generally agrees with SWOOPS (also on Ulysses) measurements. Many specific features in the observations are well represented by the model. We simulated twenty specific solar events associated with the Halloween 2003 storm. We give the specific values of the solar input parameters for the HHMS-PI simulations that provide the best combined agreement in the times of arrival of the solar-generated shocks at both ACE and Ulysses. We show graphical comparisons of simulated and observed parameters, and we give quantitative measures of the agreement of simulated with observed parameters. We suggest that some of the variations in the pickup proton density during the Halloween 2003 solar events may be attributed to depletion of the inflowing local interstellar medium (LISM) neutral hydrogen (H) caused by its increased conversion to pickup protons in the immediately preceding shock.

Parametric Model for Astrophysical Proton-Proton Interactions and Applications

Energy Technology Data Exchange (ETDEWEB)

Karlsson, Niklas [KTH Royal Institute of Technology, Stockholm (Sweden)

2007-01-01

Observations of gamma-rays have been made from celestial sources such as active galaxies, gamma-ray bursts and supernova remnants as well as the Galactic ridge. The study of gamma rays can provide information about production mechanisms and cosmic-ray acceleration. In the high-energy regime, one of the dominant mechanisms for gamma-ray production is the decay of neutral pions produced in interactions of ultra-relativistic cosmic-ray nuclei and interstellar matter. Presented here is a parametric model for calculations of inclusive cross sections and transverse momentum distributions for secondary particles--gamma rays, e^±, v_e, $\\bar{v}$_e, v_μ and $\\bar{μ}$_e--produced in proton-proton interactions. This parametric model is derived on the proton-proton interaction model proposed by Kamae et al.; it includes the diffraction dissociation process, Feynman-scaling violation and the logarithmically rising inelastic proton-proton cross section. To improve fidelity to experimental data for lower energies, two baryon resonance excitation processes were added; one representing the Δ(1232) and the other multiple resonances with masses around 1600 MeV/c². The model predicts the power-law spectral index for all secondary particle to be about 0.05 lower in absolute value than that of the incident proton and their inclusive cross sections to be larger than those predicted by previous models based on the Feynman-scaling hypothesis. The applications of the presented model in astrophysics are plentiful. It has been implemented into the Galprop code to calculate the contribution due to pion decays in the Galactic plane. The model has also been used to estimate the cosmic-ray flux in the Large Magellanic Cloud based on HI, CO and gamma-ray observations. The transverse momentum distributions enable calculations when the proton distribution is anisotropic. It is shown that the gamma-ray spectrum and flux due to a

Can high-energy proton events in solar wind be predicted via classification of precursory structures?

Energy Technology Data Exchange (ETDEWEB)

Hallerberg, Sarah [Chemnitz University of Technology (Germany); Ruzmaikin, Alexander; Feynman, Joan [Jet Propulsion Laboratory, California Institute of Technology (United States)

2011-07-01

Shock waves in the solar wind associated with solar coronal mass ejections produce fluxes of high-energy protons and ions with energies larger than 10 MeV. These fluxes present a danger to humans and electronic equipment in space, and also endanger passengers of over-pole air flights. The approaches that have been exploited for the prediction of high-energy particle events so far consist in training artificial neural networks on catalogues of events. Our approach towards this task is based on the identification of precursory structures in the fluxes of particles. In contrast to artificial neural networks that function as a ''black box'' transforming data into predictions, this classification approach can additionally provide information on relevant precursory events and thus might help to improve the understanding of underlying mechanisms of particle acceleration.

Investigation of the double exponential in the current-voltage characteristics of silicon solar cells. [proton irradiation effects on ATS 1 cells

Science.gov (United States)

Wolf, M.; Noel, G. T.; Stirn, R. J.

1977-01-01

Difficulties in relating observed current-voltage characteristics of individual silicon solar cells to their physical and material parameters were underscored by the unexpected large changes in the current-voltage characteristics telemetered back from solar cells on the ATS-1 spacecraft during their first year in synchronous orbit. Depletion region recombination was studied in cells exhibiting a clear double-exponential dark characteristic by subjecting the cells to proton irradiation. A significant change in the saturation current, an effect included in the Sah, Noyce, Shockley formulation of diode current resulting from recombination in the depletion region, was caused by the introduction of shallow levels in the depletion region by the proton irradiation. This saturation current is not attributable only to diffusion current from outside the depletion region and only its temperature dependence can clarify its origin. The current associated with the introduction of deep-lying levels did not change significantly in these experiments.

Acceleration and loss of relativistic electrons during small geomagnetic storms.

Science.gov (United States)

Anderson, B R; Millan, R M; Reeves, G D; Friedel, R H W

2015-12-16

Past studies of radiation belt relativistic electrons have favored active storm time periods, while the effects of small geomagnetic storms ( D s t  > -50 nT) have not been statistically characterized. In this timely study, given the current weak solar cycle, we identify 342 small storms from 1989 through 2000 and quantify the corresponding change in relativistic electron flux at geosynchronous orbit. Surprisingly, small storms can be equally as effective as large storms at enhancing and depleting fluxes. Slight differences exist, as small storms are 10% less likely to result in flux enhancement and 10% more likely to result in flux depletion than large storms. Nevertheless, it is clear that neither acceleration nor loss mechanisms scale with storm drivers as would be expected. Small geomagnetic storms play a significant role in radiation belt relativistic electron dynamics and provide opportunities to gain new insights into the complex balance of acceleration and loss processes.

Majority- and minority-carrier deep level traps in proton-irradiated n+/p-InGaP space solar cells

International Nuclear Information System (INIS)

Dharmarasu, Nethaji; Yamaguchi, Masafumi; Bourgoin, Jacques C.; Takamoto, Tatsuya; Ohshima, Takeshi; Itoh, Hisayoshi; Imaizumi, Mitsuru; Matsuda, Sumio

2002-01-01

We report the properties of observed defects in n + /p-InGaP solar cells created by irradiation of protons of different energies. Three majority (hole) and a minority-carrier traps, labeled respectively as HP1 (E v +0.90±0.05 eV), HP2 (E v +0.73±0.05 eV), H2 (E v +0.55 eV), and EP1 (E c -0.54 eV), were identified using deep level transient spectroscopy. All majority-carrier traps were found to act as recombination centers. While the H2 trap present in the proton-irradiated p-InGaP was found to anneal out by minority-carrier injection, the other traps were not

A SECOND-ORDER DIVERGENCE-CONSTRAINED MULTIDIMENSIONAL NUMERICAL SCHEME FOR RELATIVISTIC TWO-FLUID ELECTRODYNAMICS

Energy Technology Data Exchange (ETDEWEB)

Amano, Takanobu, E-mail: amano@eps.s.u-tokyo.ac.jp [Department of Earth and Planetary Science, University of Tokyo, 113-0033 (Japan)

2016-11-01

A new multidimensional simulation code for relativistic two-fluid electrodynamics (RTFED) is described. The basic equations consist of the full set of Maxwell’s equations coupled with relativistic hydrodynamic equations for separate two charged fluids, representing the dynamics of either an electron–positron or an electron–proton plasma. It can be recognized as an extension of conventional relativistic magnetohydrodynamics (RMHD). Finite resistivity may be introduced as a friction between the two species, which reduces to resistive RMHD in the long wavelength limit without suffering from a singularity at infinite conductivity. A numerical scheme based on HLL (Harten–Lax–Van Leer) Riemann solver is proposed that exactly preserves the two divergence constraints for Maxwell’s equations simultaneously. Several benchmark problems demonstrate that it is capable of describing RMHD shocks/discontinuities at long wavelength limit, as well as dispersive characteristics due to the two-fluid effect appearing at small scales. This shows that the RTFED model is a promising tool for high energy astrophysics application.

Particle acceleration in solar active regions being in the state of self-organized criticality.

Science.gov (United States)

Vlahos, Loukas

We review the recent observational results on flare initiation and particle acceleration in solar active regions. Elaborating a statistical approach to describe the spatiotemporally intermittent electric field structures formed inside a flaring solar active region, we investigate the efficiency of such structures in accelerating charged particles (electrons and protons). The large-scale magnetic configuration in the solar atmosphere responds to the strong turbulent flows that convey perturbations across the active region by initiating avalanche-type processes. The resulting unstable structures correspond to small-scale dissipation regions hosting strong electric fields. Previous research on particle acceleration in strongly turbulent plasmas provides a general framework for addressing such a problem. This framework combines various electromagnetic field configurations obtained by magnetohydrodynamical (MHD) or cellular automata (CA) simulations, or by employing a statistical description of the field’s strength and configuration with test particle simulations. We work on data-driven 3D magnetic field extrapolations, based on a self-organized criticality models (SOC). A relativistic test-particle simulation traces each particle’s guiding center within these configurations. Using the simulated particle-energy distributions we test our results against observations, in the framework of the collisional thick target model (CTTM) of solar hard X-ray (HXR) emission and compare our results with the current observations.

Recircular accelerator to proton ocular therapy

International Nuclear Information System (INIS)

Rabelo, Luisa A.; Campos, Tarcisio P.R.

2013-01-01

Proton therapy has been used for the treatment of Ocular Tumors, showing control in most cases as well as conservation of the eyeball, avoiding the enucleation. The protons provide higher energetic deposition in depth with reduced lateral spread, compared to the beam of photons and electrons, with characteristic dose deposition peak (Bragg peak). This technique requires large particle accelerators hampering the deployment a Proton Therapy Center in some countries due to the need for an investment of millions of dollars. This study is related to a new project of an electromagnetic unit of proton circular accelerator to be coupled to the national radiopharmaceutical production cyclotrons, to attend ocular therapy. This project evaluated physical parameters of proton beam circulating through classical and relativistic mechanical formulations and simulations based on an ion transport code in electromagnetic fields namely CST (Computer Simulation Technology). The structure is differentiated from other circular accelerations (patent CTIT/UFMG NRI research group/UFMG). The results show the feasibility of developing compact proton therapy equipment that works like pre-accelerator or post-accelerator to cyclotrons, satisfying the interval energy of 15 MeV to 64 MeV. Methods of reducing costs of manufacture, installation and operation of this equipment will facilitate the dissemination of the proton treatment in Brazil and consequently advances in fighting cancer. (author)

Recircular accelerator to proton ocular therapy

Energy Technology Data Exchange (ETDEWEB)

Rabelo, Luisa A.; Campos, Tarcisio P.R., E-mail: luisarabelo88@gmail.com, E-mail: tprcampos@pq.cnpq.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

2013-07-01

Proton therapy has been used for the treatment of Ocular Tumors, showing control in most cases as well as conservation of the eyeball, avoiding the enucleation. The protons provide higher energetic deposition in depth with reduced lateral spread, compared to the beam of photons and electrons, with characteristic dose deposition peak (Bragg peak). This technique requires large particle accelerators hampering the deployment a Proton Therapy Center in some countries due to the need for an investment of millions of dollars. This study is related to a new project of an electromagnetic unit of proton circular accelerator to be coupled to the national radiopharmaceutical production cyclotrons, to attend ocular therapy. This project evaluated physical parameters of proton beam circulating through classical and relativistic mechanical formulations and simulations based on an ion transport code in electromagnetic fields namely CST (Computer Simulation Technology). The structure is differentiated from other circular accelerations (patent CTIT/UFMG NRI research group/UFMG). The results show the feasibility of developing compact proton therapy equipment that works like pre-accelerator or post-accelerator to cyclotrons, satisfying the interval energy of 15 MeV to 64 MeV. Methods of reducing costs of manufacture, installation and operation of this equipment will facilitate the dissemination of the proton treatment in Brazil and consequently advances in fighting cancer. (author)

Pion Production from Proton Synchrotron Radiation under Strong Magnetic Field in Relativistic Quantum Approach

Directory of Open Access Journals (Sweden)

Maruyama Tomoyuki

2016-01-01

Full Text Available We study pion production from proton synchrotron radiation in the presence of strong magnetic fields by using the exact proton propagator in a strong magnetic field and explicitly including the anomalous magnetic moment. Results in this exact quantum-field approach do not agree with those obtained in the semi-classical approach. Furthermore, we also find that the anomalous magnetic moment of the proton greatly enhances the production rate about by two orders of magnitude, and that the polar angle of an emitted pion is the same as that of an initial proton.

A model for consecutive spallation and fragmentation reactions in inverse kinematics at relativistic energies

International Nuclear Information System (INIS)

Napolitani, P.; Tassan-Got, L.; Bernas, M.; Armbruster, P.

2003-04-01

Secondary reactions induced by relativistic beams in inverse kinematics in a thick target are relevant in several fields of experimental physics and technology, like secondary radioactive beams, production of exotic nuclei close to the proton drip line, and cross-section measurements for applications of spallation reactions for energy production and incineration of nuclear wastes. A general mathematical formulation is presented and successively applied as a tool to disentangle the primary reaction yields from the secondary production in the measurement of fission of a 238 U projectile impinging on a proton target at the energy of 1 A GeV. (orig.)

Relativistic equations

International Nuclear Information System (INIS)

Gross, F.

1986-01-01

Relativistic equations for two and three body scattering are discussed. Particular attention is paid to relativistic three body kinetics because of recent form factor measurements of the Helium 3 - Hydrogen 3 system recently completed at Saclay and Bates and the accompanying speculation that relativistic effects are important for understanding the three nucleon system. 16 refs., 4 figs

Solar nuclear energy

International Nuclear Information System (INIS)

Tlalka, R.

1977-01-01

Brief characteristics are given of solar radiation and of its spectral range. The relation is derived for the gas pressure in the centre of the Sun and the mechanism is described of particle interactions in the Sun. Using the Eddington model the basic nuclear reactions in the Sun are described, namely the proton-proton chain and the C-N cycle. The energy transfer is discussed from the Sun to the boundaries of the Earth atmosphere and inside the atmosphere. The measurement of solar energy is conducted with actinometers, i.e., pyrheliometers, pyranometers and combinations thereof. The results of solar radiation measurement in different weather conditions are graphically represented. (J.B.)

Transmutation of $^{239}$Pu and Other Nuclides Using Spallation Neutrons Produced by Relativistic Protons Reacting with Massive U- and Pb-Targets

CERN Document Server

Adam, J; Bamblevski, V P; Barabanov, M Yu; Bradnova, V; Chaloun, P; Hella, K M; Kalinnikov, V G; Krivopustov, M I; Kulakov, B A; Perelygin, V P; Pronskikh, V S; Pavliouk, A V; Solnyshkin, A A; Sosnin, A N; Stegailov, V I; Tsoupko-Sitnikov, V M; Zaverioukha, O S; Adloff, J C; Debeauvais, M; Brandt, R; Langrock, E J; Vater, P; Van, J S; Westmeier, W; Dwivedi, K K; Guo Shi Lun; Li Li Qiang; Hashemi-Nezhad, S R; Kievets, M K; Lomonosova, E M; Zhuk, I V; Modolo, G; Odoj, R; Zamani-Valassiadou, M

2001-01-01

Experimental studies on the transmutation of some long-lived radioactive waste nuclei, such as ^{129}I, ^{237}Np, and ^{239}Pu, as well as on natural uranium and lanthanum (all of them used as sensors) were carried out at the Synchrophasotron of the Laboratory for High Energies (JINR, Dubna). Spallation neutrons were produced by relativistic protons with energies in the range of 0.5 GeV\\le E(p)\\le 1.5 GeV interacting with 20 cm long uranium or lead target stacks. The targets were surrounded by 6 cm paraffin moderators. The radioactive sensors mentioned above were positioned on the outside surface of the moderator and contained typically approximately 0.5 up to 1 gram of long-lived isotopes. The highly radioactive targets were produced perfectly well-sealed in aluminum containers by the Institute of Physics and Power Engineering, Obninsk, Russia. From the experimentally observed transmutation rates one can easily extrapolate, that in a subcritical nuclear power assembly (or "energy amplifier") using a 10 mA pr...

Dynamic of non relativistic electrons and protons in the plasmasphere

International Nuclear Information System (INIS)

Mendes Junior, O.; Pinto Junior, O.; Gonzalez, W.D.

1985-01-01

A study of the dynamics of electrons and protons inside the plasmasphere is presented. These particles are subjected to the geomagnetic field and to plasmaspheric electric fields, given by simple static models, during magnetically quiet and disturbed periods. (author) [pt

Nearly constant ratio between the proton inertial scale and the spectrum break length scale in the plasma beta range from 0.2 to 1.4 in the solar wind turbulence

Science.gov (United States)

Wang, X.; Tu, C. Y.; He, J.; Wang, L.

2017-12-01

The spectrum break at the ion scale of the solar wind magnetic fluctuations are considered to give important clue on the turbulence dissipation mechanism. Among several possible mechanisms, the most notable ones are the two mechanisms that related respectively with proton thermal gyro-radius and proton inertial length. However, no definite conclusion has been given for which one is more reasonable because the two parameters have similar values in the normal plasma beta range. Here we do a statistical study for the first time to see if the two mechanism predictions have different dependence on the solar wind velocity and on the plasma beta in the normal plasma beta range in the solar wind at 1 AU. From magnetic measurements by Wind, Ulysses and Messenger, we select 60 data sets with duration longer than 8 hours. We found that the ratio between the proton inertial scale and the spectrum break scale do not change considerably with both varying the solar wind speed from 300km/s to 800km/s and varying the plasma beta from 0.2 to 1.4. The average value of the ratio times 2pi is 0.46 ± 0.08. However, the ratio between the proton gyro-radius and the break scale changes clearly. This new result shows that the proton inertial scale could be a single factor that determines the break length scale and hence gives a strong evidence to support the dissipation mechanism related to it in the normal plasma beta range. The value of the constant ratio may relate with the dissipation mechanism, but it needs further theoretical study to give detailed explanation.

Study of the strange baryons and mesons production (Λ and Ks0) in proton-proton collisions with the ALICE experiment at the LHC

International Nuclear Information System (INIS)

Ricaud, H.

2008-11-01

The ALICE experiment at LHC is dedicated to the investigation of the transition of matter from the hadron gas to the Quark and Gluons Plasma in which partons are deconfined. Ultra-relativistic heavy-ion collisions offer indeed the possibility to create extreme temperature and pressure conditions which are required to reach a deconfined phase. Elementary collisions such as proton-proton are of great importance since they are regarded as the hadronic reference. The aim of this thesis was to prepare the analysis of strange baryon and meson production mechanisms in proton-proton collisions at the LHC energies by the detection of Λ and K s 0 particles with ALICE. Strange particles are a major tool to probe the matter created. The behaviour of the Λ/K s 0 ratio at intermediate transverse momentum in high energy proton-proton collisions, that we have studied with several theoretical models, could also sign the presence of collective phenomena. Up to now, these phenomena have been observed only in heavy-ion collisions. (author)

Solar Particle Induced Upsets in the TDRS-1 Attitude Control System RAM During the October 1989 Solar Particle Events

Science.gov (United States)

Croley, D. R.; Garrett, H. B.; Murphy, G. B.; Garrard,T. L.

1995-01-01

The three large solar particle events, beginning on October 19, 1989 and lasting approximately six days, were characterized by high fluences of solar protons and heavy ions at 1 AU. During these events, an abnormally large number of upsets (243) were observed in the random access memory of the attitude control system (ACS) control processing electronics (CPE) on-board the geosynchronous TDRS-1 (Telemetry and Data Relay Satellite). The RAM unit affected was composed of eight Fairchild 93L422 memory chips. The Galileo spacecraft, launched on October 18, 1989 (one day prior to the solar particle events) observed the fluxes of heavy ions experienced by TDRS-1. Two solid-state detector telescopes on-board Galileo, designed to measure heavy ion species and energy, were turned on during time periods within each of the three separate events. The heavy ion data have been modeled and the time history of the events reconstructed to estimate heavy ion fluences. These fluences were converted to effective LET spectra after transport through the estimated shielding distribution around the TDRS-1 ACS system. The number of single event upsets (SEU) expected was calculated by integrating the measured cross section for the Fairchild 93L422 memory chip with average effective LET spectrum. The expected number of heavy ion induced SEU's calculated was 176. GOES-7 proton data, observed during the solar particle events, were used to estimate the number of proton-induced SEU's by integrating the proton fluence spectrum incident on the memory chips, with the two-parameter Bendel cross section for proton SEU'S. The proton fluence spectrum at the device level was gotten by transporting the protons through the estimated shielding distribution. The number of calculated proton-induced SEU's was 72, yielding a total of 248 predicted SEU'S, very dose to the 243 observed SEU'S. These calculations uniquely demonstrate the roles that solar heavy ions and protons played in the production of SEU

Nonlinear Evolution of Observed Fast Streams in the Solar Wind - Micro-instabilities and Energy Exchange between Protons and Alpha Particles

Science.gov (United States)

Maneva, Y. G.; Poedts, S.

2017-12-01

Non-thermal kinetic components such as deformed velocity distributions, temperature anisotropies and relative drifts between the multiple ion populations are frequently observed features in the collisionless fast solar wind streams near the Earth whose origin is still to be better understood. Some of the traditional models consider the formation of the temperature anisotropies through the effect of the solar wind expansion, while others assume in situ heating and particle acceleration by local fluctuations, such as plasma waves, or by spacial structures, such as advected or locally generated current sheets. In this study we consider the evolution of initial ion temperature anisotropies and relative drifts in the presence of plasma oscillations, such as ion-cyclotron and kinetic Alfven waves. We perform 2.5D hybrid simulations to study the evolution of observed fast solar wind plasma parcels, including the development of the plasma micro-instabilities, the field-particle correlations and the energy transfer between the multiple ion species. We consider two distinct cases of highly anisotropic and quickly drifting protons which excite ion-cyclotron waves and of moderately anisotropic slower protons, which co-exist with kinetic Alfven waves. The alpha particles for both cases are slightly anisotropic in the beginning and remain anisotropic throughout the simulation time. Both the imposed magnetic fluctuations and the initial differential streaming decrease in time for both cases, while the minor ions are getting heated. Finally we study the effects of the solar wind expansion and discuss its implications for the nonlinear evolution of the system.

Compression-amplified EMIC waves and their effects on relativistic electrons

Energy Technology Data Exchange (ETDEWEB)

Li, L. Y., E-mail: lyli-ssri@buaa.edu.cn; Yu, J.; Cao, J. B. [School of Space and Environment, Beihang University, Beijing (China); Yuan, Z. G. [School of Electronic Information, Wuhan University, Wuhan (China)

2016-06-15

During enhancement of solar wind dynamic pressure, we observe the periodic emissions of electromagnetic ion cyclotron (EMIC) waves near the nightside geosynchronous orbit (6.6R{sub E}). In the hydrogen and helium bands, the different polarized EMIC waves have different influences on relativistic electrons (>0.8 MeV). The flux of relativistic electrons is relatively stable if there are only the linearly polarized EMIC waves, but their flux decreases if the left-hand polarized (L-mode) EMIC waves are sufficiently amplified (power spectral density (PSD) ≥ 1 nT{sup 2}/Hz). The larger-amplitude L-mode waves can cause more electron losses. In contrast, the R-mode EMIC waves are very weak (PSD < 1 nT{sup 2}/Hz) during the electron flux dropouts; thus, their influence may be ignored here. During the electron flux dropouts, the relativistic electron precipitation is observed by POES satellite near the foot point (∼850 km) of the wave emission region. The quasi-linear simulation of wave-particle interactions indicates that the L-mode EMIC waves can cause the rapid precipitation loss of relativistic electrons, especially when the initial resonant electrons have a butterfly-like pitch angle distribution.

Compression-amplified EMIC waves and their effects on relativistic electrons

International Nuclear Information System (INIS)

Li, L. Y.; Yu, J.; Cao, J. B.; Yuan, Z. G.

2016-01-01

During enhancement of solar wind dynamic pressure, we observe the periodic emissions of electromagnetic ion cyclotron (EMIC) waves near the nightside geosynchronous orbit (6.6R E ). In the hydrogen and helium bands, the different polarized EMIC waves have different influences on relativistic electrons (>0.8 MeV). The flux of relativistic electrons is relatively stable if there are only the linearly polarized EMIC waves, but their flux decreases if the left-hand polarized (L-mode) EMIC waves are sufficiently amplified (power spectral density (PSD) ≥ 1 nT 2 /Hz). The larger-amplitude L-mode waves can cause more electron losses. In contrast, the R-mode EMIC waves are very weak (PSD < 1 nT 2 /Hz) during the electron flux dropouts; thus, their influence may be ignored here. During the electron flux dropouts, the relativistic electron precipitation is observed by POES satellite near the foot point (∼850 km) of the wave emission region. The quasi-linear simulation of wave-particle interactions indicates that the L-mode EMIC waves can cause the rapid precipitation loss of relativistic electrons, especially when the initial resonant electrons have a butterfly-like pitch angle distribution.

Self-consistent relativistic QRPA studies of soft modes and spin-isospin resonances in unstable nuclei

International Nuclear Information System (INIS)

Paar, N.; Niksic, T.; Marketin, T.; Vretenar, D.; Ring, P.

2005-01-01

The excitation phenomena in unstable nuclei are investigated in the framework of the relativistic quasiparticle random-phase approximation (RQRPA) in the relativistic Hartree-Bogolyubov model (RHB) which is extended to include effective interactions with explicit density-dependent meson-nucleon couplings. The properties of the pygmy dipole resonance (PDR) are examined in 132 Sn and within isotopic chains, showing that already at moderate proton-neutron asymmetry the PDR peak energy is located above the neutron emission threshold. A method is suggested for determining the size of the neutron skin within an isotopic chain, based on the measurement of the excitation energies of the Gamow-Teller resonance relative to the isobaric analog state. In addition, for the first time the relativistic RHB+RQRPA model, with tensor ω meson-nucleon couplings, is employed in calculations of β-decay half-lives of nuclei of the relevance for the r-process. (orig.)

Self-consistent relativistic QRPA studies of soft modes and spin-isospin resonances in unstable nuclei

Energy Technology Data Exchange (ETDEWEB)

Paar, N. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); University of Zagreb, Physics Department, Faculty of Science (Croatia); University of Washington, Institute for Nuclear Theory, Seattle (United States); Niksic, T. [University of Zagreb, Physics Department, Faculty of Science (Croatia); University of Washington, Institute for Nuclear Theory, Seattle (United States); Marketin, T.; Vretenar, D. [University of Zagreb, Physics Department, Faculty of Science (Croatia); Ring, P. [Physik-Department der Technischen Universitaet Muenchen, Garching (Germany)

2005-09-01

The excitation phenomena in unstable nuclei are investigated in the framework of the relativistic quasiparticle random-phase approximation (RQRPA) in the relativistic Hartree-Bogolyubov model (RHB) which is extended to include effective interactions with explicit density-dependent meson-nucleon couplings. The properties of the pygmy dipole resonance (PDR) are examined in {sup 132}Sn and within isotopic chains, showing that already at moderate proton-neutron asymmetry the PDR peak energy is located above the neutron emission threshold. A method is suggested for determining the size of the neutron skin within an isotopic chain, based on the measurement of the excitation energies of the Gamow-Teller resonance relative to the isobaric analog state. In addition, for the first time the relativistic RHB+RQRPA model, with tensor {omega} meson-nucleon couplings, is employed in calculations of {beta}-decay half-lives of nuclei of the relevance for the r-process. (orig.)

Initiation of non-tropical thunderstorms by solar activity

Energy Technology Data Exchange (ETDEWEB)

Herman, J R [Radio Sciences Co., Melbourne, Fla. (USA); Goldberg, R A

1978-02-01

Correlative evidence accumulating since 1926 suggests that there must be some physical coupling mechanism between solar activity and thunderstorm occurrence in middle to high latitudes. Such a link may be provided by alteration of atmospheric electric parameters through the influence of cosmic ray decreases and/or high-energy solar protons associated with active solar events. Galactic cosmic ray decreases tend to enhance the electric field at low heights. The protons produce excess ionization near and above 20 km, greatly increasing the atmospheric conductivity and possibly lowering the height of the electrosphere. Consequent effects near the solar proton cut-off latitude also lead to an enhancement of the atmospheric electric field near the surface. If appropriate meteorological conditions (warm moist air with updrafts) exist or develop during a solar event, the atmospheric electric field enhancement may be sufficient to trigger thunderstorm development. The suggested mechanism appears plausible enough to warrant a co-ordinated experimental effort involving satellite balloon and ground-based measurements of the possible forcing functions (solar protons and cosmic rays) and the responding atmospheric electrical and ionic species' characteristics.

Atomic physics using relativistic H- beams

International Nuclear Information System (INIS)

Bryant, H.C.

2005-01-01

Full text: An 8 GeV hydrogen atom can traverse a focused laser beam of width of 1 micron in a time of 353 attoseconds in its rest frame. A design is currently underway at Fermilab for a superconducting linear accelerator that will accelerate H - ions to 8 GeV. This 'Proton Driver' beam is intended to be injected, after stripping down to protons, into the 120 GeV Main Injector for the mass production of neutrinos aimed at a neutrino detector (MINOS) in a mine shaft in Soudan, Minnesota (USA) for the study of neutrino oscillations. It has not passed unnoticed that with some advance planning a few nanoamps from the up-to-250 mA beam could be diverted for atomic physics experiments. Relativistic kinematics enable the creation of extreme conditions for a beam atom. For example, the Doppler shift allows a very large tuning range in the atom's rest frame of a laser beam that is fixed- frequency in the lab. At 8 GeV the rest frame Doppler shift ranges from a factor of 19 in the forward direction to 0.05 backward. The laser intensity is enhanced by the square of the Doppler shift, so that the world's most intense laser beam would be amplified by a factor of 360 in the atom's rest frame. Furthermore, although there are extreme changes in the frequency and intensity in the atom's frame as one changes the intersection angle, the ponderomotive potential remains constant, as it is a relativistic invariant. One of the interesting problems that arises in the planning for this accelerator is the stripping of electrons from the negative ions by photodetachment from Doppler shifted thermal photons. We estimate that, if the transfer lines are kept at 300 K (room temperature), the mean free path at 8 GeV for stripping from collisions with cavity radiation is about 1300 km. The physics of the interactions of such a beam with very thin material foils, again in the attosecond regime, has been treated theoretically, but has not been studied experimentally at such high energies. We will

Northern Hemisphere Atmospheric Influence of the Solar Proton Events and Ground Level Enhancement in January 2005

Science.gov (United States)

Jackman, C. H.; Marsh, D. R.; Vitt, F. M.; Roble, R. G.; Randall, C. E.; Bernath, P. F.; Funke, B.; Lopez-Puertas, M.; Versick, S.; Stiller, G. P.;

Northern Hemisphere atmospheric influence of the solar proton events and ground level enhancement in January 2005

Directory of Open Access Journals (Sweden)

C. H. Jackman

2011-07-01

Full Text Available Solar eruptions in early 2005 led to a substantial barrage of charged particles on the Earth's atmosphere during the 16–21 January period. Proton fluxes were greatly increased during these several days and led to the production of HO_x (H, OH, HO₂ and NO_x (N, NO, NO₂, which then caused the destruction of ozone. We focus on the Northern polar region, where satellite measurements and simulations with the Whole Atmosphere Community Climate Model (WACCM3 showed large enhancements in mesospheric HO_x and NO_x constituents, and associated ozone reductions, due to these solar proton events (SPEs. The WACCM3 simulations show enhanced short-lived OH and HO₂ concentrations throughout the mesosphere in the 60–82.5° N latitude band due to the SPEs for most days in the 16–21 January 2005 period, somewhat higher in abundance than those observed by the Aura Microwave Limb Sounder (MLS. These HO_x enhancements led to huge predicted and MLS-measured ozone decreases of greater than 40 % throughout most of the northern polar mesosphere during the SPE period. Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS measurements of hydrogen peroxide (H₂O₂ show increases throughout the stratosphere with highest enhancements of about 60 pptv in the lowermost mesosphere over the 16–18 January 2005 period due to the solar protons. WACCM3 predictions indicate H₂O₂ enhancements over the same time period of about three times that amount. Measurements of nitric acid (HNO₃ by both MLS and MIPAS show an increase of about 1 ppbv above background levels in the upper stratosphere during 16–29 January 2005. WACCM3 simulations show only minuscule HNO₃ increases (<0.05 ppbv in the upper stratosphere during this time period. Polar mesospheric enhancements of NO_x are computed to be greater than 50

Type III-L Solar Radio Bursts and Solar Energetic Particle Events

Science.gov (United States)

Duffin, R. T.; White, S. M.; Ray, P. S.; Kaiser, M. L.

2015-09-01

A radio-selected sample of fast drift radio bursts with complex structure occurring after the impulsive phase of the associated flare (“Type III-L bursts”) is identified by inspection of radio dynamic spectra from 1 to 180 MHz for over 300 large flares in 2001. An operational definition that takes into account previous work on these radio bursts starting from samples of solar energetic particle (SEP) events is applied to the data, and 66 Type III-L bursts are found in the sample. In order to determine whether the presence of these radio bursts can be used to predict the occurrence of SEP events, we also develop a catalog of all SEP proton events in 2001 using data from the ERNE detector on the SOHO satellite. 68 SEP events are found, for 48 of which we can identify a solar source and hence look for associated Type III-L emission. We confirm previous work that found that most (76% in our sample) of the solar sources of SEP events exhibit radio emission of this type. However, the correlation in the opposite direction is not as strong: starting from a radio-selected sample of Type III-L events, around 64% of the bursts that occur at longitudes magnetically well-connected to the Earth, and hence favorable for detection of SEPs, are associated with SEP events. The degree of association increases when the events have durations over 10 minutes at 1 MHz, but in general Type III-L bursts do not perform any better than Type II bursts in our sample as predictors of SEP events. A comparison of Type III-L timing with the arrival of near-relativistic electrons at the ACE spacecraft is not inconsistent with a common source for the accelerated electrons in both phenomena.

Type III-L Solar Radio Bursts and Solar Energetic Particle Events

International Nuclear Information System (INIS)

Duffin, R T; White, S M; Ray, P S; Kaiser, M L

2015-01-01

A radio-selected sample of fast drift radio bursts with complex structure occurring after the impulsive phase of the associated flare (“Type III-L bursts”) is identified by inspection of radio dynamic spectra from 1 to 180 MHz for over 300 large flares in 2001. An operational definition that takes into account previous work on these radio bursts starting from samples of solar energetic particle (SEP) events is applied to the data, and 66 Type III-L bursts are found in the sample. In order to determine whether the presence of these radio bursts can be used to predict the occurrence of SEP events, we also develop a catalog of all SEP proton events in 2001 using data from the ERNE detector on the SOHO satellite. 68 SEP events are found, for 48 of which we can identify a solar source and hence look for associated Type III-L emission. We confirm previous work that found that most (76% in our sample) of the solar sources of SEP events exhibit radio emission of this type. However, the correlation in the opposite direction is not as strong: starting from a radio-selected sample of Type III-L events, around 64% of the bursts that occur at longitudes magnetically well-connected to the Earth, and hence favorable for detection of SEPs, are associated with SEP events. The degree of association increases when the events have durations over 10 minutes at 1 MHz, but in general Type III-L bursts do not perform any better than Type II bursts in our sample as predictors of SEP events. A comparison of Type III-L timing with the arrival of near-relativistic electrons at the ACE spacecraft is not inconsistent with a common source for the accelerated electrons in both phenomena. (paper)

Point form relativistic quantum mechanics and relativistic SU(6)

Science.gov (United States)

Klink, W. H.

1993-01-01

The point form is used as a framework for formulating a relativistic quantum mechanics, with the mass operator carrying the interactions of underlying constituents. A symplectic Lie algebra of mass operators is introduced from which a relativistic harmonic oscillator mass operator is formed. Mass splittings within the degenerate harmonic oscillator levels arise from relativistically invariant spin-spin, spin-orbit, and tensor mass operators. Internal flavor (and color) symmetries are introduced which make it possible to formulate a relativistic SU(6) model of baryons (and mesons). Careful attention is paid to the permutation symmetry properties of the hadronic wave functions, which are written as polynomials in Bargmann spaces.

Radiation damage and defect behavior in proton irradiated lithium-counterdoped n+p silicon solar cells

Science.gov (United States)

Stupica, John; Goradia, Chandra; Swartz, Clifford K.; Weinberg, Irving

1987-01-01

Two lithium-counterdoped n+p silicon solar cells with different lithium concentrations were irradiated by 10-MeV protons. Cell performance was measured as a function of fluence, and it was found that the cell with the highest concentration of lithium had the highest radiation resistance. Deep level transient spectroscopy which showed two deep level defects that were lithium related. Relating the defect energy levels obtained from this study with those from earlier work using 1-MeV electron irradiation shows no correlation of the defect energy levels. There is one marked similarity: the absence of the boron-interstitial-oxygen-interstitial defect. This consistency strengthens the belief that lithium interacts with oxygen to prevent the formation of the boron interstitial-oxygen interstitial defect. The results indicate that, in general, addition of lithium in small amounts to the p-base of a boron doped silicon solar cell such that the base remains p-type, tends to increase the radiation resistance of the cell.

Solar wind ion trends and signatures: STEREO PLASTIC observations approaching solar minimum

Directory of Open Access Journals (Sweden)

A. B. Galvin

2009-10-01

Full Text Available STEREO has now completed the first two years of its mission, moving from close proximity to Earth in 2006/2007 to more than 50 degrees longitudinal separation from Earth in 2009. During this time, several large-scale structures have been observed in situ. Given the prevailing solar minimum conditions, these structures have been predominantly coronal hole-associated solar wind, slow solar wind, their interfaces, and the occasional transient event. In this paper, we extend earlier solar wind composition studies into the current solar minimum using high-resolution (1-h sampling times for the charge state analysis. We examine 2-year trends for iron charge states and solar wind proton speeds, and present a case study of Carrington Rotation 2064 (December 2007 which includes minor ion (He, Fe, O kinetic and Fe composition parameters in comparison with proton and magnetic field signatures at large-scale structures observed during this interval.

Solar and interplanetary particles at 2 to 4 MEV during solar cycles 21, solar cycle variations of event sizes, and compositions

International Nuclear Information System (INIS)

Armstrong, T.P.; Shields, J.C.; Briggs, P.R.; Eckes, S.

1985-01-01

In this paper 2 to 4 MeV/nucleon protons, alpha particles, and medium (CNO) nuclei in the near-Earth interplanetary medium during the years 1974 to 1981 are studied. This period contains both the solar activity minimum in 1976 and the very active onset phase of Solar Cycle 21. Characteristic compositional differences between the solar minimum and solar maximum ion populations have been investigated. Previous studies of interplanetary composition at these energies have concentrated on well-defined samples of the heliospheric medium. During flare particle events, the ambient plasma is dominated by ions accelerated in specific regions of the solar atmosphere; observation of the proton/alpha and alpha/medium ratios for flare events shows that there is marked compositional variability both during an event and from event to event suggesting the complicated nature of flare particle production and transport

A unified treatment of the non-relativistic and relativistic hydrogen atom: Pt. 2

International Nuclear Information System (INIS)

Swainson, R.A.; Drake, G.W.F.

1991-01-01

This is the second in a series of three papers in which it is shown how the radial part of non-relativistic and relativistic hydrogenic bound-state calculations involving the Green functions can be presented in a unified manner. In this paper the non-relativistic Green function is examined in detail; new functional forms are presented and a clear mathematical progression is show to link these and most other known forms. A linear transformation of the four radial parts of the relativistic Green function is given which allows for the presentation of this function as a simple generalization of the non-relativistic Green function. Thus, many properties of the non-relativistic Green function are shown to have simple relativistic generalizations. In particular, new recursion relations of the radial parts of both the non-relativistic and relativistic Green functions are presented, along with new expressions for the double Laplace transforms and recursion relations between the radial matrix elements. (author)

Latitudinal and radial variation of >2 GeV/n protons and alpha-particles at solar maximum: ULYSSES COSPIN/KET and neutron monitor network observations

Directory of Open Access Journals (Sweden)

A. V. Belov

2003-06-01

Full Text Available Ulysses, launched in October 1990, began its second out-of-ecliptic orbit in September 1997. In 2000/2001 the spacecraft passed from the south to the north polar regions of the Sun in the inner heliosphere. In contrast to the first rapid pole to pole passage in 1994/1995 close to solar minimum, Ulysses experiences now solar maximum conditions. The Kiel Electron Telescope (KET measures also protons and alpha-particles in the energy range from 5 MeV/n to >2 GeV/n. To derive radial and latitudinal gradients for >2 GeV/n protons and alpha-particles, data from the Chicago instrument on board IMP-8 and the neutron monitor network have been used to determine the corresponding time profiles at Earth. We obtain a spatial distribution at solar maximum which differs greatly from the solar minimum distribution. A steady-state approximation, which was characterized by a small radial and significant latitudinal gradient at solar minimum, was interchanged with a highly variable one with a large radial and a small – consistent with zero – latitudinal gradient. A significant deviation from a spherically symmetric cosmic ray distribution following the reversal of the solar magnetic field in 2000/2001 has not been observed yet. A small deviation has only been observed at northern polar regions, showing an excess of particles instead of the expected depression. This indicates that the reconfiguration of the heliospheric magnetic field, caused by the reappearance of the northern polar coronal hole, starts dominating the modulation of galactic cosmic rays already at solar maximum.Key words. Interplanetary physics (cosmic rays; energetic particles – Space plasma physics (charged particle motion and acceleration

Predicted solar cell edge radiation effects

International Nuclear Information System (INIS)

Gates, M.T.

1993-01-01

The Advanced Solar Cell Orbital Test (ASCOT) will test six types of solar cells in a high energy proton environment. During the design of the experiment a question was raised about the effects of proton radiation incident on the edge of the solar cells and whether edge radiation shielding was required. Historical geosynchronous data indicated that edge radiation damage is not detectable over the normal end of life solar cell degradation; however because the ASCOT radiation environment has a much higher and more energetic fluence of protons, considerably more edge damage is expected. A computer analysis of the problem was made by modeling the expected radiation damage at the cell edge and using a network model of small interconnected solar cells to predict degradation in the cell's electrical output. The model indicated that the deepest penetration of edge radiation was at the top of the cell near the junction where the protons have access to the cell through the low density cell/cover adhesive layer. The network model indicated that the cells could tolerate high fluences at their edge as long as there was high electrical resistance between the edge radiated region and the contact system on top of the cell. The predicted edge radiation related loss was less than 2% of maximum power for GaAs/Ge solar cells. As a result, no edge radiation protection was used for ASCOT

Radiation dose of aircrews during a solar proton event without ground-level enhancement

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R. Kataoka

2015-01-01

Full Text Available A significant enhancement of radiation doses is expected for aircrews during ground-level enhancement (GLE events, while the possible radiation hazard remains an open question during non-GLE solar energetic particle (SEP events. Using a new air-shower simulation driven by the proton flux data obtained from GOES satellites, we show the possibility of significant enhancement of the effective dose rate of up to 4.5 μSv h−1 at a conventional flight altitude of 12 km during the largest SEP event that did not cause a GLE. As a result, a new GOES-driven model is proposed to give an estimate of the contribution from the isotropic component of the radiation dose in the stratosphere during non-GLE SEP events.

The role of charge-exchange cross-section for pickup protons and neutrals in the inner heliosheath

Science.gov (United States)

Chalov, S. V.

2018-06-01

The process of deceleration of the solar wind downstream of the termination shock is studied on the basis of a one-dimensional multi-component model. It is assumed that the solar wind consists of thermal protons, electrons and interstellar pickup protons. The protons interact with interstellar hydrogen atoms by charge-exchange. Two cases are considered. In the first one, the charge-exchange cross-section for thermal protons and hydrogen atoms is the same as for pickup protons and atoms. Under this condition, there is a strong dependence of the solar wind velocity on the downstream temperature of pickup protons. When the proton temperature is close to 10 keV, the change in the velocity with the distance from the termination shock is similar to that measured on the Voyager 1 spacecraft: linear velocity decrease is accompanied by an extended transition region with near-zero velocity. However, with a more careful approach to the choice of the charge-exchange cross-section, the situation changes dramatically. The strong dependence of the solar wind speed on the pickup proton temperature disappears and the transition region in the heliosheath disappears as well, at least at reasonable distances from the TS.

Relativistic GW calculations on CH3NH3PbI3 and CH3NH3SnI3 perovskites for solar cell applications.

Science.gov (United States)

Umari, Paolo; Mosconi, Edoardo; De Angelis, Filippo

2014-03-26

Hybrid AMX3 perovskites (A = Cs, CH3NH3; M = Sn, Pb; X = halide) have revolutionized the scenario of emerging photovoltaic technologies, with very recent results demonstrating 15% efficient solar cells. The CH3NH3PbI3/MAPb(I(1-x)Cl(x))3 perovskites have dominated the field, while the similar CH3NH3SnI3 has not been exploited for photovoltaic applications. Replacement of Pb by Sn would facilitate the large uptake of perovskite-based photovoltaics. Despite the extremely fast progress, the materials electronic properties which are key to the photovoltaic performance are relatively little understood. Density Functional Theory electronic structure methods have so far delivered an unbalanced description of Pb- and Sn-based perovskites. Here we develop an effective GW method incorporating spin-orbit coupling which allows us to accurately model the electronic, optical and transport properties of CH3NH3SnI3 and CH3NH3PbI3, opening the way to new materials design. The different CH3NH3SnI3 and CH3NH3PbI3 electronic properties are discussed in light of their exploitation for solar cells, and found to be dominantly due to relativistic effects. These effects stabilize the CH3NH3PbI3 material towards oxidation, by inducing a deeper valence band edge. Relativistic effects, however, also increase the material band-gap compared to CH3NH3SnI3, due to the valence band energy downshift (~0.7 eV) being only partly compensated by the conduction band downshift (~0.2 eV).

First Observation of the Seeded Proton Bunch Self-Modulation in Plasma

CERN Document Server

AUTHOR|(CDS)2093171; Vincke, Helmut

In this thesis I observe experimentally and study in simulations the seeded selfmodulation of a relativistic proton bunch in AWAKE, the Advanced Proton Driven Plasma Wakefield Acceleration Experiment. The 400 GeV/c proton bunch from the CERN SPS with a rms length of 12 cm propagates in a 10m long plasma with a density adjustable between 2-10x10^14 electrons/cm3. The seeded self-modulation process results in focusing and defocusing of the protons, thereby forming a bunch train that resonantly drives wakefields to large amplitudes. I use the two-screen measurement setup, to observe the result of the proton bunch self-modulation and to learn about its physics (i.e. growth of the process). The idea is to obtain images of protons that were defocused by the transverse wakefields, 2 and 10m downstream the end of the plasma. From these images I determine the maximum transverse momentum of the defocused protons as well as infer their point of origin along the plasma. I use simulations to guide the understanding of the...

Solar /flare/ cosmic ray proton fluxes in the recent past

International Nuclear Information System (INIS)

Venkatesan, T.R.; Nautiyal, C.M.; Padia, J.T.; Rao, M.N.

1980-01-01

A method for determining the average solar cosmic ray (SCR) proton fluxes which occurred in the last few million yr from He-3 samples from suitable lunar rocks is presented. Specimens removed from 0.3-1.5, 5-7, and 7-9 mm depths of the lunar surface were cleaned to reveal the feldspar grains of interest and heated for stepwise mass-spectrometric analyses. The 200 micron or greater grains were outgassed at 600, 1000, 1200, and 1600 C and noble gas data were recorded, along with isotopic ratio data. He-3 is assumed to have been degassed completely from rocks shocked by an impact event and diffusion losses are negligible due to the 90 C or less temperature exposures on the lunar surface. Thus the presence of He-3 is indicative of cosmic ray incidence, and known galactic cosmic ray production abundances for He-3 can be subtracted from the total He-3 observed, yielding the SCR flux results, which, when combined with exposure data, yield a history of SCR events

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

CIGS Solar Cells for Space Applications: Numerical Simulation of the Effect of Traps Created by High-Energy Electron and Proton Irradiation on the Performance of Solar Cells

Science.gov (United States)

Dabbabi, Samar; Ben Nasr, Tarek; Turki Kamoun, Najoua

2018-02-01

Numerical simulation is carried out using the Silvaco ATLAS software to predict the effect of 1-MeV electron and 4-MeV proton irradiation on the performance of a Cu(In, Ga)Se2 (CIGS) solar cell that operates under the air mass zero spectrum (AM0). As a consequence of irradiation, two types of traps are induced including the donor- and acceptor-type traps. Only one of them (the donor-type trap) is found responsible for the degradation of the open-circuit voltage (V OC), fill factor (FF) and efficiency (η), while the short circuit current (J SC) remains essentially unaffected. The modelling simulation validity is verified by comparison with the experimental data. This article shows that CIGS solar cells are suited for space applications.

Relativistic quasiparticle random-phase approximation calculation of total muon capture rates

International Nuclear Information System (INIS)

Marketin, T.; Paar, N.; Niksic, T.; Vretenar, D.

2009-01-01

The relativistic proton-neutron quasiparticle random phase approximation (pn-RQRPA) is applied in the calculation of total muon capture rates on a large set of nuclei from 12 C to 244 Pu, for which experimental values are available. The microscopic theoretical framework is based on the relativistic Hartree-Bogoliubov (RHB) model for the nuclear ground state, and transitions to excited states are calculated using the pn-RQRPA. The calculation is fully consistent, i.e., the same interactions are used both in the RHB equations that determine the quasiparticle basis, and in the matrix equations of the pn-RQRPA. The calculated capture rates are sensitive to the in-medium quenching of the axial-vector coupling constant. By reducing this constant from its free-nucleon value g A =1.262 by 10% for all multipole transitions, the calculation reproduces the experimental muon capture rates to better than 10% accuracy.

Energy loss distributions of 7 TeV protons channeled in a bent silicon crystals

Directory of Open Access Journals (Sweden)

Stojanov Nace

2013-01-01

Full Text Available The energy loss distributions of relativistic protons axially channeled through the bent Si crystals, with the constant curvature radius, R = 50 m, are studied here. The proton energy is 7 TeV and the thickness of the crystal is varied from 1 mm to 5 mm, which corresponds to the reduced crystal thickness, L, from 2.1 to 10.6, respectively. The proton energy was chosen in accordance with the large hadron collider project, at the European Organization for Nuclear Research, in Geneva, Switzerland. The energy loss distributions of the channeled protons were generated by the computer simulation method using the numerical solution of the proton equations of motion in the transverse plane. Dispersion of the proton scattering angle caused by its collisions with the crystal’s electrons was taken into account. [Projekat Ministarstva nauke Republike Srbije, br. III 45006

Spin rotation function in a microscopic non-relativistic optical model

International Nuclear Information System (INIS)

Bauhoff, W.

1984-01-01

A microscopic optical potential, which is calculated non-relativistically with a density-dependent effective force, is used to calculate cross-section, polarization and spin-rotation function for elastic proton scattering from 40 Ca at 160 MeV and 497 MeV. At 160 MeV, the agreement to the data is comparable to phenomenological fits, and the spin-rotation can be used to distinguish between microscopic and Woods-Saxon potentials. A good fit to the spin-rotation function results at 497 MeV, whereas the polarization data are not well reproduced

Relativistic electron acceleration during HILDCAA events: are precursor CIR magnetic storms important?

Czech Academy of Sciences Publication Activity Database

Hajra, R.; Tsurutani, B. T.; Echer, E.; Gonzalez, W. D.; Brum, Ch. G. M.; Antunes Vieira, L. E.; Santolík, Ondřej

2015-01-01

Roč. 67, Article Number 109 (2015), 109/1-109/11 ISSN 1880-5981 R&D Projects: GA MŠk LH12231 Institutional support: RVO:68378289 Keywords : HILDCAAs * high-speed streams * CIRs * chorus plasma waves * radiation belt * magnetospheric relativistic electrons * solar wind * geomagnetic storms Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.871, year: 2015

ρ - ω Mixing Effects in Relativistic Heavy-Ion Collisions

International Nuclear Information System (INIS)

Broniowski, W.; Florkowski, W.

1999-01-01

Full text: We have shown that even moderate excess of neutrons over protons in nuclear matter, such as in 208 Pb, can lead to large ρ - ω mixing at densities of the order of twice the nuclear saturation density and higher. The typical mixing angle is of the order of 10 o . The mixing may result in noticeable shifts of the positions and widths of resonances. We also analyze temperature effects and find that temperatures up to 50 MeV have practically no effect on the mixing. The results have relevance for the explanation of dilepton production in relativistic heavy-ion collisions. (author)

Relativistic quantum logic

International Nuclear Information System (INIS)

Mittelstaedt, P.

1983-01-01

on the basis of the well-known quantum logic and quantum probability a formal language of relativistic quantum physics is developed. This language incorporates quantum logical as well as relativistic restrictions. It is shown that relativity imposes serious restrictions on the validity regions of propositions in space-time. By an additional postulate this relativistic quantum logic can be made consistent. The results of this paper are derived exclusively within the formal quantum language; they are, however, in accordance with well-known facts of relativistic quantum physics in Hilbert space. (author)

Relativistic quantum mechanics; Mecanique quantique relativiste

Energy Technology Data Exchange (ETDEWEB)

Ollitrault, J.Y. [CEA Saclay, 91 - Gif-sur-Yvette (France). Service de Physique Theorique]|[Universite Pierre et Marie Curie, 75 - Paris (France)

1998-12-01

These notes form an introduction to relativistic quantum mechanics. The mathematical formalism has been reduced to the minimum in order to enable the reader to calculate elementary physical processes. The second quantification and the field theory are the logical followings of this course. The reader is expected to know analytical mechanics (Lagrangian and Hamiltonian), non-relativistic quantum mechanics and some basis of restricted relativity. The purpose of the first 3 chapters is to define the quantum mechanics framework for already known notions about rotation transformations, wave propagation and restricted theory of relativity. The next 3 chapters are devoted to the application of relativistic quantum mechanics to a particle with 0,1/5 and 1 spin value. The last chapter deals with the processes involving several particles, these processes require field theory framework to be thoroughly described. (A.C.) 2 refs.

Neutron production in interactions of relativistic protons and deuterons with lead targets

International Nuclear Information System (INIS)

Yurevich, V.I.; Amelin, N.S.; Yakovlev, R.M.; Nikolaev, V.A.; Lyapin, V.G.; Tsvetkov, I.O.

2005-01-01

Results on the neutron double-differential cross sections and yields obtained in the time-of-flight measurements with different lead targets and beams of protons and deuterons at an energy of about 2 GeV are discussed. The neutron spatial-energy distribution for an extended lead target was studied by the threshold detector method in the energy range of protons and deuterons 1-3.7 GeV. A dependence of the mean neutron multiplicity, energy of neutrons, and process of neutron multiplication in lead on the target dimension, and the type and energy of the beam particle is analyzed. (author)

Basic features of proton-proton interactions at ultra-relativistic energies and RFT-based quark-gluon string model

Directory of Open Access Journals (Sweden)

Zabrodin E.

2017-01-01

Full Text Available Proton-proton collisions at energies from √s = 200 GeV up to √s = 14 TeV are studied within the microscopic quark-gluon string model. The model is based on Gribov’s Reggeon Field Theory accomplished by string phenomenology. Comparison with experimental data shows that QGSM describes well particle yields, rapidity - and transverse momentum spectra, rise of mean 〈 pT 〉 and forward-backward multiplicity correlations. The latter arise in QGSM because of the addition of various processes with different mean multiplicities. The model also indicates fulfillment of extended longitudinal scaling and violation of Koba-Nielsen-Olesen scaling at LHC. The origin of both features is traced to short-range particle correlations in the strings. Predictions are made for √s = 14 TeV.

Solar storms; Tormentas solares

Energy Technology Data Exchange (ETDEWEB)

Collaboration: Pereira Cuesta, S.; Pereira Pagan, B.

2016-08-01

Solar storms begin with an explosion, or solar flare, on the surface of the sun. The X-rays and extreme ultraviolet radiation from the flare reach the Earths orbit minutes later-travelling at light speed. The ionization of upper layers of our atmosphere could cause radio blackouts and satellite navigation errors (GPS). Soon after, a wave of energetic particles, electrons and protons accelerated by the explosion crosses the orbit of the Earth, and can cause real and significant damage. (Author)

Dissipative relativistic hydrodynamics

International Nuclear Information System (INIS)

Imshennik, V.S.; Morozov, Yu.I.

1989-01-01

Using the comoving reference frame in the general non-inertial case, the relativistic hydrodynamics equations are derived with an account for dissipative effects in the matter. From the entropy production equation, the exact from for the dissipative tensor components is obtained. As a result, the closed system of equations of dissipative relativistic hydrodynamics is obtained in the comoving reference frame as a relativistic generalization of the known Navier-Stokes equations for Lagrange coordinates. Equations of relativistic hydrodynamics with account for dissipative effects in the matter are derived using the assocoated reference system in general non-inertial case. True form of the dissipative tensor components is obtained from entropy production equation. Closed system of equations for dissipative relativistic hydrodynamics is obtained as a result in the assocoated reference system (ARS) - relativistic generalization of well-known Navier-Stokes equations for Lagrange coordinates. Equation system, obtained in this paper for ARS, may be effectively used in numerical models of explosive processes with 10 51 erg energy releases which are characteristic for flashes of supernovae, if white dwarf type compact target suggested as presupernova

Self-modulation instability of a long proton bunch in plasmas

CERN Document Server

Kumar, Naveen; Lotov, Konstantin

2010-01-01

An analytical model for the self-modulation instability of a long relativistic proton bunch propagating in uniform plasmas is developed. The self-modulated proton bunch resonantly excites a large amplitude plasma wave (wake field), which can be used for acceleration of plasma electrons. Analytical expressions for the linear growth rate and the number of exponentiations are given. We use the full three-dimensional particle-in-cell (PIC) simulations to study the beam self-modulation and the transition to the nonlinear stage. It is shown that the self-modulation of the proton bunch competes with the hosing instability which tends to destroy the plasma wave. A method is proposed and studied through PIC simulations to circumvent this problem which relies on the seeding of the self-modulation instability in the bunch.

Short- and medium-term atmospheric constituent effects of very large solar proton events

Directory of Open Access Journals (Sweden)

C. H. Jackman

2008-02-01

Full Text Available Solar eruptions sometimes produce protons, which impact the Earth's atmosphere. These solar proton events (SPEs generally last a few days and produce high energy particles that precipitate into the Earth's atmosphere. The protons cause ionization and dissociation processes that ultimately lead to an enhancement of odd-hydrogen and odd-nitrogen in the polar cap regions (>60° geomagnetic latitude. We have used the Whole Atmosphere Community Climate Model (WACCM3 to study the atmospheric impact of SPEs over the period 1963–2005. The very largest SPEs were found to be the most important and caused atmospheric effects that lasted several months after the events. We present the short- and medium-term (days to a few months atmospheric influence of the four largest SPEs in the past 45 years (August 1972; October 1989; July 2000; and October–November 2003 as computed by WACCM3 and observed by satellite instruments. Polar mesospheric NO_x (NO+NO₂ increased by over 50 ppbv and mesospheric ozone decreased by over 30% during these very large SPEs. Changes in HNO₃, N₂O₅, ClONO₂, HOCl, and ClO were indirectly caused by the very large SPEs in October–November 2003, were simulated by WACCM3, and previously measured by Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS. WACCM3 output was also represented by sampling with the MIPAS averaging kernel for a more valid comparison. Although qualitatively similar, there are discrepancies between the model and measurement with WACCM3 predicted HNO₃ and ClONO₂ enhancements being smaller than measured and N₂O₅ enhancements being larger than measured. The HOCl enhancements were fairly similar in amounts and temporal variation in WACCM3 and MIPAS. WACCM3 simulated ClO decreases below 50 km, whereas MIPAS mainly observed increases, a very perplexing difference. Upper stratospheric

Beam-energy dependence of the directed flow of protons, antiprotons, and pions in Au+Au collisions.

Science.gov (United States)

Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Levine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

2014-04-25

Rapidity-odd directed flow (v1) measurements for charged pions, protons, and antiprotons near midrapidity (y=0) are reported in sNN=7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV Au+Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider. At intermediate impact parameters, the proton and net-proton slope parameter dv1/dy|y=0 shows a minimum between 11.5 and 19.6 GeV. In addition, the net-proton dv1/dy|y=0 changes sign twice between 7.7 and 39 GeV. The proton and net-proton results qualitatively resemble predictions of a hydrodynamic model with a first-order phase transition from hadronic matter to deconfined matter, and differ from hadronic transport calculations.

Beam-Energy Dependence of the Directed Flow of Protons, Antiprotons, and Pions in Au+Au Collisions

Science.gov (United States)

Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

2014-04-01

Rapidity-odd directed flow (v1) measurements for charged pions, protons, and antiprotons near midrapidity (y =0) are reported in √sNN =7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV Au+Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider. At intermediate impact parameters, the proton and net-proton slope parameter dv1/dy|y=0 shows a minimum between 11.5 and 19.6 GeV. In addition, the net-proton dv1/dy|y=0 changes sign twice between 7.7 and 39 GeV. The proton and net-proton results qualitatively resemble predictions of a hydrodynamic model with a first-order phase transition from hadronic matter to deconfined matter, and differ from hadronic transport calculations.

Prompt acceleration of ions by oblique turbulent shocks in solar flares

Science.gov (United States)

Decker, R. B.; Vlahos, L.

1985-01-01

Solar flares often accelerate ions and electrons to relativistic energies. The details of the acceleration process are not well understood, but until recently the main trend was to divide the acceleration process into two phases. During the first phase elctrons and ions are heated and accelerated up to several hundreds of keV simultaneously with the energy release. These mildly relativistic electrons interact with the ambient plasma and magnetic fields and generate hard X-ray and radio radiation. The second phase, usually delayed from the first by several minutes, is responsible for accelerating ions and electrons to relativistic energies. Relativistic electrons and ions interact with the solar atmosphere or escape from the Sun and generate gamma ray continuum, gamma ray line emission, neutron emission or are detected in space by spacecraft. In several flares the second phase is coincident with the start of a type 2 radio burst that is believed to be the signature of a shock wave. Observations from the Solar Maximum Mission spacecraft have shown, for the first time, that several flares accelerate particles to all energies nearly simultaneously. These results posed a new theoretical problem: How fast are shocks and magnetohydrodynamic turbulence formed and how quickly can they accelerate ions to 50 MeV in the lower corona? This problem is discussed.

Prompt acceleration of ions by oblique turbulent shocks in solar flares

International Nuclear Information System (INIS)

Decker, R.B.; Vlahos, L.

1985-01-01

Solar flares often accelerate ions and electrons to relativistic energies. The details of the acceleration process are not well understood, but until recently the main trend was to divide the acceleration process into two phases. During the first phase elctrons and ions are heated and accelerated up to several hundreds of keV simultaneously with the energy release. These mildly relativistic electrons interact with the ambient plasma and magnetic fields and generate hard x-ray and radio radiation. The second phase, usually delayed from the first by several minutes, is responsible for accelerating ions and electrons to relativistic energies. Relativistic electrons and ions interact with the solar atmosphere or escape from the Sun and generate gamma ray continuum, gamma ray line emission, neutron emission or are detected in space by spacecraft. In several flares the second phase is coincident with the start of a type 2 radio burst that is believed to be the signature of a shock wave. Observations from the Solar Maximum Mission spacecraft have shown, for the first time, that several flares accelerate particles to all energies nearly simultaneously. These results posed a new theoretical problem: How fast are shocks and magnetohydrodynamic turbulence formed and how quickly can they accelerate ions to 50 MeV in the lower corona. This problem is discussed

The effect of asymmetric solar wind on the Lyman α sky background

International Nuclear Information System (INIS)

Joselyn, J.A.; Holzer, T.E.

1975-01-01

The Lyman α (Ly α) sky background arises from the scattering of solar Ly α from a spatial distribution of neutral hydrogen in interplanetary space. This distribution is partially determined by the solar wind proton flux, which provides the principal mechanism of loss by charge exchange of the neutral hydrogen. By generating isophotal maps of scattered Ly α for several choices of interstellar wind direction and solar wind proton flux distributions, the results show that latitudinal variations of the solar wind proton flux can have a significant effect on the observed location and shape of the Ly α intensity maximum. This fact should aid in the interpretation of Ly α maps and also indicates a possible method for inferring values for the average solar wind proton flux out of the ecliptic plane

Relativistic Light Sails

Energy Technology Data Exchange (ETDEWEB)

Kipping, David, E-mail: dkipping@astro.columbia.edu [Department of Astronomy, Columbia University, 550 W. 120th St., New York, NY 10027 (United States)

2017-06-01

One proposed method for spacecraft to reach nearby stars is by accelerating sails using either solar radiation pressure or directed energy. This idea constitutes the thesis behind the Breakthrough Starshot project, which aims to accelerate a gram-mass spacecraft up to one-fifth the speed of light toward Proxima Centauri. For such a case, the combination of the sail’s low mass and relativistic velocity renders previous treatments incorrect at the 10% level, including that of Einstein himself in his seminal 1905 paper introducing special relativity. To address this, we present formulae for a sail’s acceleration, first in response to a single photon and then extended to an ensemble. We show how the sail’s motion in response to an ensemble of incident photons is equivalent to that of a single photon of energy equal to that of the ensemble. We use this principle of ensemble equivalence for both perfect and imperfect mirrors, enabling a simple analytic prediction of the sail’s velocity curve. Using our results and adopting putative parameters for Starshot , we estimate that previous relativistic treatments underestimate the spacecraft’s terminal velocity by ∼10% for the same incident energy. Additionally, we use a simple model to predict the sail’s temperature and diffraction beam losses during the laser firing period; this allows us to estimate that, for firing times of a few minutes and operating temperatures below 300°C (573 K), Starshot will require a sail that absorbs less than one in 260,000 photons.

Relativistic Light Sails

International Nuclear Information System (INIS)

Kipping, David

2017-01-01

One proposed method for spacecraft to reach nearby stars is by accelerating sails using either solar radiation pressure or directed energy. This idea constitutes the thesis behind the Breakthrough Starshot project, which aims to accelerate a gram-mass spacecraft up to one-fifth the speed of light toward Proxima Centauri. For such a case, the combination of the sail’s low mass and relativistic velocity renders previous treatments incorrect at the 10% level, including that of Einstein himself in his seminal 1905 paper introducing special relativity. To address this, we present formulae for a sail’s acceleration, first in response to a single photon and then extended to an ensemble. We show how the sail’s motion in response to an ensemble of incident photons is equivalent to that of a single photon of energy equal to that of the ensemble. We use this principle of ensemble equivalence for both perfect and imperfect mirrors, enabling a simple analytic prediction of the sail’s velocity curve. Using our results and adopting putative parameters for Starshot , we estimate that previous relativistic treatments underestimate the spacecraft’s terminal velocity by ∼10% for the same incident energy. Additionally, we use a simple model to predict the sail’s temperature and diffraction beam losses during the laser firing period; this allows us to estimate that, for firing times of a few minutes and operating temperatures below 300°C (573 K), Starshot will require a sail that absorbs less than one in 260,000 photons.

Nuclear matter in relativistic mean field theory with isovector scalar meson.

Energy Technology Data Exchange (ETDEWEB)

Kubis, S.; Kutschera, M. [Institute of Nuclear Physics, Cracow (Poland)

1996-12-01

Relativistic mean field (RMF) theory of nuclear matter with the isovector scalar mean field corresponding to the {delta}-meson [a{sub 0}(980)] is studied. While the {delta}-meson field vanishes in symmetric nuclear matter, it can influence properties of asymmetric nuclear matter in neutron stars. The RMF contribution due to {delta}-field to the nuclear symmetry energy is negative. To fit the empirical value, E{sub s}{approx}30 MeV, a stronger {rho}-meson coupling is required than in absence of the {delta}-field. The energy per particle of neutron star matter is than larger at high densities than the one with no {delta}-field included. Also, the proton fraction of {beta}-stable matter increases. Splitting of proton and neutron effective masses due to the {delta}-field can affect transport properties of neutron star matter. (author). 4 refs, 6 figs.

Nuclear matter in relativistic mean field theory with isovector scalar meson

International Nuclear Information System (INIS)

Kubis, S.; Kutschera, M.

1996-12-01

Relativistic mean field (RMF) theory of nuclear matter with the isovector scalar mean field corresponding to the δ-meson [a 0 (980)] is studied. While the δ-meson field vanishes in symmetric nuclear matter, it can influence properties of asymmetric nuclear matter in neutron stars. The RMF contribution due to δ-field to the nuclear symmetry energy is negative. To fit the empirical value, E s ∼30 MeV, a stronger ρ-meson coupling is required than in absence of the δ-field. The energy per particle of neutron star matter is than larger at high densities than the one with no δ-field included. Also, the proton fraction of β-stable matter increases. Splitting of proton and neutron effective masses due to the δ-field can affect transport properties of neutron star matter. (author). 4 refs, 6 figs

Experiments with stored relativistic exotic nuclei

International Nuclear Information System (INIS)

Klepper, O.; Attallah, F.; Beckert, K.; Bosch, F.; Dolinskiy, A.; Eickhoff, H.; Franczak, B.; Franzke, B.; Geissel, H.; Hausmann, M.; Hellstroem, M.; Herfurth, F.; Kluge, H.-J.; Kozhuharov, C.; Muenzenberg, G.; Nolden, F.; Quint, W.; Tradon, T.; Reich, H.; Scheidenberger, C.; Schlitt, B.; Steck, M.; Suemmerer, K.; Vermeeren, L.; Winkler, M.; Winkler, Th.; Falch, M.; Kerscher, Th.; Loebner, K.E.G.; Fujita, Y.; Novikov, Yu.; Patyk, Z.; Stadlmann, J.; Wollnik, H.

1999-01-01

Beams of relativistic exotic nuclei were produced, separated and investigated with the combination of the fragment separator FRS and the storage ring ESR. The following experiments are presented: 1) Direct mass measurements of relativistic nickel and bismuth projectile fragments were performed using Schottky spectrometry. Applying electron cooling, the relative velocity spread of the circulating secondary nuclear beams of low intensity was reduced to below 10 -6 . The achieved mass resolving power of m/Δm = 6.5·10 5 (FWHM) in recent measurements represents an improvement by a factor of two compared to authors' previous experiments. The previously unknown masses of more than 100 proton-rich isotopes have been measured in the range of 54≤Z≤84. The results are compared with mass models and estimated values based on extrapolations of experimental values. 2) Exotic nuclei with half-lives shorter than the time required for electron cooling can be investigated by time-of-flight measurements with the ESR being operated in the isochronous mode. This novel experimental technique has been successfully applied in a first measurement with nickel fragments. A mass resolving power of m/Δm = 1.5·10 5 (FWHM) was achieved in this mode of operation. 3) Nuclear half-lives of stored and cooled bare projectile fragments have been measured to study the influence of the ionic charge state on the beta-decay probability

Beta decay and muon capture rates in a self-consistent relativistic framework

Energy Technology Data Exchange (ETDEWEB)

Marketin, Tomislav; Paar, Nils; Niksic, Tamara; Vretenar, Dario [Physics Department, Faculty of Science, University of Zagreb (Croatia); Ring, Peter [Physik-Department, Technische Universitaet Muenchen, D-85748 Muenchen (Germany)

2009-07-01

A fully consistent calculation of muon capture and beta decay rates is presented, based on a microscopic theoretical framework describing the semileptonic weak interaction processes. Nuclear ground state is determined using the Relativistic Hartree-Bogolyubov (RHB) model with density dependent meson-nucleon coupling constants, and transition rates are calculated via proton-neutron relativistic quasiparticle RPA using the same interaction as in the RHB equations. Muon capture rates are calculated for a wide range of nuclei along the valley of stability, from {sup 12}C to {sup 244}Pu, with accuracy of approximately 30%, using the interaction DD-ME2. Previous studies of beta decay rates have only taken into account Gamow-Teller transitions. We extend this approach by including forbidden transitions and systematically study their contribution to decay rates of exotic nuclei along the r-process path, which are important for constraining the conditions in which nucleosynthesis takes place.

Radiative pion-proton scattering

International Nuclear Information System (INIS)

Ho-Kim, Q.; Lavine, J.P.

1977-01-01

The results are presented of a non-relativistic calculation of the π +- proton bremsstrahlung cross section at the pion kinetic energy of 298 MeV for backward photon angles. The pion-nucleon interaction is given by models that are based on the p-wave Chew-Low theory. An interaction current is included in an attempt to make the overall bremsstrahlung amplitude gauge-invariant. The predicted cross sections show little of the expected resonance, and are in fair agreement with the data. The authors have also calculated the cross sections at other kinetic energies, and have studied effects of the off-mass-shell electromagnetic vertex. (Auth.)

Alterations to the relativistic Love-Franey model and their application to inelastic scattering

International Nuclear Information System (INIS)

Zeile, J.R.

1989-01-01

The fictitious axial-vector and tensor mesons for the real part of the relativistic Love-Franey interaction are removed. In an attempt to make up for this loss, derivative couplings are used for the π and ρ mesons. Such derivative couplings require the introduction of axial-vector and tensor contact term corrections. Meson parameters are then fit to free nucleon-nucleon scattering data. The resulting fits are comparable to those of the relativistic Love-Franey model provided that the contact term corrections are included and the fits are weighted over the physically significant quantity of twice the tensor minus the axial-vector Lorentz invariants. Failure to include contact term corrections leads to poor fits at higher energies. The off-shell behavior of this model is then examined by looking at several applications from inelastic proton-nucleus scattering

Measurement of $\\Lambda_{\\rm c}$ Baryon production in the decay channel $\\Lambda_{\\rm c} \\rightarrow p \\rm K^{0}_{\\rm S}~$ in proton-proton and proton-lead collisions with ALICE detector at LHC

CERN Document Server

Meninno, Elisa

This thesis describes the study of the production of the charmed baryon $\\Lambda_{\\rm c}^{+}$ in proton-proton and proton-lead collisions with the ALICE experiment, operating at the Large Hadron Collider (LHC) at CERN. ALICE was built to study hadronic collisions (pp and A-A) and, in particular, aims to investigate the $Quark-Gluon Plasma$ (QGP), state of the matter during the first instants of life of the universe. When two ultra-relativistic heavy nuclei collide, the extreme conditions of temperature and pressure, necessary for the QGP formation, can be created. In particular, heavy quarks (charm and beauty) are produced in hard scattering processes during the first stages of the hadronic collision. The measurement of hadrons with heavy quarks in pp collisions at the LHC energies is a powerful test for perturbative quantum cromodynamics (pQCD) in this energy domain. Moreover, these studies are the necessary reference for studying the production of heavy quarks in nucleus-nucleus collisions. Results from pp ...

Modelling formation of new radiation belts and response to ULF oscillations following March 24, 1991 SSC

International Nuclear Information System (INIS)

Hudson, M.K.; Kotelnikov, A.D.; Li, X.; Lyon, J.G.; Roth, I.; Temerin, M.; Wygant, J.R.; Blake, J.B.; Gussenhoven, M.S.; Yumoto, K.; Shiokawa, K.

1996-01-01

The rapid formation of a new proton radiation belt at L≅2.5 following the March 24, 1991 Storm Sudden Commencement (SSC) observed at the CRRES satellite is modelled using a relativistic guiding center test particle code. The new radiation belt formed on a time scale shorter than the drift period of eg. 20 MeV protons. The SSC is modelled by a bipolar electric field and associated compression and relaxation in the magnetic field, superimposed on a background dipole magnetic field. The source population consists of solar protons that populated the outer magnetosphere during the solar proton event that preceeded the SSC and trapped inner zone protons. The simulations show that both populations contribute to drift echoes in the 20 endash 80 MeV range measured by the Aerospace instrument and in lower energy channels of the Protel instrument on CRRES, while primary contribution to the newly trapped population is from solar protons. Proton acceleration by the SSC differs from electron acceleration in two notable ways: different source populations contribute and nonrelativistic conservation of the first adiabatic invariant leads to greater energization of protons for a given decrease in L than for relativistic electrons. Model drift echoes, energy spectra and flux distribution in L at the time of injection compare well with CRRES observations. On the outbound pass, ∼2 hours after the SSC, the broad spectral peak of the new radiation belt extends to higher energies (20 endash 40 MeV) than immediately after formation. Electron flux oscillations observed at this later time are attributed to post-SSC impulses evident in ground magnetograms, while two minute period ULF oscillations also evident in CRRES field data appear to be cavity modes in the inner magnetosphere. copyright 1996 American Institute of Physics

Solar cosmic rays in the system of solar terrestrial relations

Science.gov (United States)

Miroshnichenko, Leonty I.

2008-02-01

In this brief review, we discuss a number of geophysical effects of solar energetic particles (SEPs) or solar cosmic rays (SCR). We concentrate mainly on the observational evidence and proposed mechanisms of some expected effects and/or poor-studied phenomena discovered within the last three decades, in particular, depletion of the ozone layer, perturbations in the global electric current, effects on the winter storm vorticity, change of the atmospheric transparency and production of nitrates. Some "archaeological" data on SCR fluxes in the past and upper limit of total energy induced by SEPs are also discussed. Due attention is paid to the periodicities in the solar particle fluxes. Actually, many solar, heliospheric and terrestrial parameters changing generally in phase with the solar activity are subjected to a temporary depression close to the solar maximum ("Gnevyshev Gap"). A similar gap has been found recently in the yearly numbers of the >10 MeV proton events. All the above-mentioned findings are evidently of great importance in the studies of general proton emissivity of the Sun and long-term trends in the behaviour of solar magnetic fields. In addition, these data can be very helpful for elaborating the methods for prediction of the radiation conditions in space and for estimation of the SEPs' contribution to solar effects on the geosphere, their relative role in the formation of terrestrial weather and climate and in the problem of solar-terrestrial relations (STR) on the whole.

Radiatively driven relativistic spherical winds under relativistic radiative transfer

Science.gov (United States)

Fukue, J.

2018-05-01

We numerically investigate radiatively driven relativistic spherical winds from the central luminous object with mass M and luminosity L* under Newtonian gravity, special relativity, and relativistic radiative transfer. We solve both the relativistic radiative transfer equation and the relativistic hydrodynamical equations for spherically symmetric flows under the double-iteration processes, to obtain the intensity and velocity fields simultaneously. We found that the momentum-driven winds with scattering are quickly accelerated near the central object to reach the terminal speed. The results of numerical solutions are roughly fitted by a relation of \\dot{m}=0.7(Γ _*-1)\\tau _* β _* β _out^{-2.6}, where \\dot{m} is the mass-loss rate normalized by the critical one, Γ* the central luminosity normalized by the critical one, τ* the typical optical depth, β* the initial flow speed at the central core of radius R*, and βout the terminal speed normalized by the speed of light. This relation is close to the non-relativistic analytical solution, \\dot{m} = 2(Γ _*-1)\\tau _* β _* β _out^{-2}, which can be re-expressed as β _out^2/2 = (Γ _*-1)GM/c^2 R_*. That is, the present solution with small optical depth is similar to that of the radiatively driven free outflow. Furthermore, we found that the normalized luminosity (Eddington parameter) must be larger than unity for the relativistic spherical wind to blow off with intermediate or small optical depth, i.e. Γ _* ≳ \\sqrt{(1+β _out)^3/(1-β _out)}. We briefly investigate and discuss an isothermal wind.

Solar wind classification from a machine learning perspective

Science.gov (United States)

Heidrich-Meisner, V.; Wimmer-Schweingruber, R. F.

2017-12-01

It is a very well known fact that the ubiquitous solar wind comes in at least two varieties, the slow solar wind and the coronal hole wind. The simplified view of two solar wind types has been frequently challenged. Existing solar wind categorization schemes rely mainly on different combinations of the solar wind proton speed, the O and C charge state ratios, the Alfvén speed, the expected proton temperature and the specific proton entropy. In available solar wind classification schemes, solar wind from stream interaction regimes is often considered either as coronal hole wind or slow solar wind, although their plasma properties are different compared to "pure" coronal hole or slow solar wind. As shown in Neugebauer et al. (2016), even if only two solar wind types are assumed, available solar wind categorization schemes differ considerably for intermediate solar wind speeds. Thus, the decision boundary between the coronal hole and the slow solar wind is so far not well defined.In this situation, a machine learning approach to solar wind classification can provide an additional perspective.We apply a well-known machine learning method, k-means, to the task of solar wind classification in order to answer the following questions: (1) How many solar wind types can reliably be identified in our data set comprised of ten years of solar wind observations from the Advanced Composition Explorer (ACE)? (2) Which combinations of solar wind parameters are particularly useful for solar wind classification?Potential subtypes of slow solar wind are of particular interest because they can provide hints of respective different source regions or release mechanisms of slow solar wind.

Handbook of relativistic quantum chemistry

International Nuclear Information System (INIS)

Liu, Wenjian

2017-01-01

This handbook focuses on the foundations of relativistic quantum mechanics and addresses a number of fundamental issues never covered before in a book. For instance: How can many-body theory be combined with quantum electrodynamics? How can quantum electrodynamics be interfaced with relativistic quantum chemistry? What is the most appropriate relativistic many-electron Hamiltonian? How can we achieve relativistic explicit correlation? How can we formulate relativistic properties? - just to name a few. Since relativistic quantum chemistry is an integral component of computational chemistry, this handbook also supplements the ''Handbook of Computational Chemistry''. Generally speaking, it aims to establish the 'big picture' of relativistic molecular quantum mechanics as the union of quantum electrodynamics and relativistic quantum chemistry. Accordingly, it provides an accessible introduction for readers new to the field, presents advanced methodologies for experts, and discusses possible future perspectives, helping readers understand when/how to apply/develop the methodologies.

Solar particle induced upsets in the TDRS-1 attitude control system RAM during the October 1989 solar particle events

International Nuclear Information System (INIS)

Croley, D.R.; Garrett, H.B.; Murphy, G.B.; Garrard, T.L.

1995-01-01

The three large solar particle events, beginning on October 19, 1989 and lasting approximately six days, were characterized by high fluences of solar protons and heavy ions at 1 AU. During these events, an abnormally large number of upsets (243) were observed in the random access memory of the attitude control system (ACS) control processing electronics (CPE) on-board the geosynchronous TDRS-1 (Telemetry and Data Relay Satellite). The RAM unit affected was composed of eight Fairchild 93L422 memory chips. The Galileo spacecraft, launched on October 18, 1989 (one day prior to the solar particle events) observed the fluxes of heavy ions experienced by TDRS-1. Two solid-state detector telescopes on-board Galileo, designed to measure heavy ion species and energy, were turned on during time periods within each of the three separate events. The heavy ion data have been modeled and the time history of the events reconstructed to estimate heavy ion fluences. These fluences were converted to effective LET spectra after transport through the estimated shielding distribution around the TDRS-1 ACS system. The number of single event upsets (SEU) expected was calculated by integrating the measured cross section for the Fairchild 93L422 memory chip with average effective LET spectrum. The expected number of heavy ion induced SEU's calculated was 176. GOES-7 proton data, observed during the solar particle events, were used to estimate the number of proton-induced SEU's by integrating the proton fluence spectrum incident on the memory chips, with the two-parameter Bendel cross section for proton SEU's. The proton fluence spectrum at the device level was gotten by transporting the protons through the estimated shielding distribution. The number of calculated proton-induced SEU's was 72, yielding a total of 248 predicted SEU's, very close to the 243 observed SEU's

Relativistic many-body theory of atomic transitions. The relativistic equation-of-motion approach

International Nuclear Information System (INIS)

Huang, K.

1982-01-01

An equation-of-motion approach is used to develop the relativistic many-body theory of atomic transitions. The relativistic equations of motion for transition matrices are formulated with the use of techniques of quantum-field theory. To reduce the equations of motion to a tractable form which is appropriate for numerical calculations, a graphical method to resolve the complication arising from the antisymmetrization and angular-momentum coupling is employed. The relativistic equation-of-motion method allows an ab initio treatment of correlation and relativistic effects in both closed- and open-shell many-body systems. A special case of the present formulation reduces to the relativistic random-phase approximation

Relativistic many-body theory of atomic transitions: the relativistic equation-of-motion approach

International Nuclear Information System (INIS)

Huang, K.N.

1981-01-01

An equation-of-motion approach is used to develop the relativistic many-body theory of atomic transitions. The relativistic equations of motion for transition matrices are formulated using techniques of quantum field theory. To reduce the equation of motion to a tractable form which is appropriate for numerical calculations, a graphical method is employed to resolve the complication arising from the antisymmetrization and angular momentum coupling. The relativistic equation-of-motion method allows an ab initio treatment of correlation and relativistic effects in both closed- and open-shell many-body systems. A special case of the present formulation reduces to the relativistic random-phase approximation

Beam dynamics simulation of a double pass proton linear accelerator

Directory of Open Access Journals (Sweden)

Kilean Hwang

2017-04-01

Full Text Available A recirculating superconducting linear accelerator with the advantage of both straight and circular accelerator has been demonstrated with relativistic electron beams. The acceleration concept of a recirculating proton beam was recently proposed [J. Qiang, Nucl. Instrum. Methods Phys. Res., Sect. A 795, 77 (2015NIMAER0168-900210.1016/j.nima.2015.05.056] and is currently under study. In order to further support the concept, the beam dynamics study on a recirculating proton linear accelerator has to be carried out. In this paper, we study the feasibility of a two-pass recirculating proton linear accelerator through the direct numerical beam dynamics design optimization and the start-to-end simulation. This study shows that the two-pass simultaneous focusing without particle losses is attainable including fully 3D space-charge effects through the entire accelerator system.

Pion Production from Proton Synchrotron Radiation under Strong Magnetic Field in a Relativistic Quantum Approach

Directory of Open Access Journals (Sweden)

Maruyama Tomoyuki

2016-01-01

Full Text Available We study pion production from proton synchrotron radiation in the presence of strong magnetic fields by using the exact proton propagator in a strong magnetic field and explicitly including the anomalous magnetic moment. Results in this exact quantum approach do not agree with those obtained in the semi-classical approach. Then, we find that the anomalous magnetic moment of the proton greatly enhances the production rate by about two orders magnitude, and that the decay width satisfies a robust scaling law.

Relativistic duality, and relativistic and radiative corrections for heavy-quark systems

International Nuclear Information System (INIS)

Durand, B.; Durand, L.

1982-01-01

We give a JWKB proof of a relativistic duality relation which relates an appropriate energy average of the physical cross section for e + e - →qq-bar bound states→hadrons to the same energy average of the perturbative cross section for e + e - →qq-bar. We show that the duality relation can be used effectively to estimate relativistic and radiative corrections for bound-quark systems to order α/sub s//sup ts2/. We also present a formula which relates the square of the ''large'' 3 S 1 Salpeter-Bethe-Schwinger wave function for zero space-time separation of the quarks to the square of the nonrelativistic Schroedinger wave function at the origin for an effective potential which reproduces the relativistic spectrum. This formula allows one to use the nonrelativistic wave functions obtained in potential models fitted to the psi and UPSILON spectra to calculate relativistic leptonic widths for qq-bar states via a relativistic version of the van Royen--Weisskopf formula

Handbook of relativistic quantum chemistry

Energy Technology Data Exchange (ETDEWEB)

Liu, Wenjian (ed.) [Peking Univ., Beijing (China). Center for Computational Science and Engineering

2017-03-01

This handbook focuses on the foundations of relativistic quantum mechanics and addresses a number of fundamental issues never covered before in a book. For instance: How can many-body theory be combined with quantum electrodynamics? How can quantum electrodynamics be interfaced with relativistic quantum chemistry? What is the most appropriate relativistic many-electron Hamiltonian? How can we achieve relativistic explicit correlation? How can we formulate relativistic properties? - just to name a few. Since relativistic quantum chemistry is an integral component of computational chemistry, this handbook also supplements the ''Handbook of Computational Chemistry''. Generally speaking, it aims to establish the 'big picture' of relativistic molecular quantum mechanics as the union of quantum electrodynamics and relativistic quantum chemistry. Accordingly, it provides an accessible introduction for readers new to the field, presents advanced methodologies for experts, and discusses possible future perspectives, helping readers understand when/how to apply/develop the methodologies.

Photosynthetic solar cell using nanostructured proton exchange membrane for microbial biofilm prevention.

Science.gov (United States)

Lee, Dong Hyun; Oh, Hwa Jin; Bai, Seoung Jae; Song, Young Seok

2014-06-24

Unwanted biofilm formation has a detrimental effect on bioelectrical energy harvesting in microbial cells. This issue still needs to be solved for higher power and longer durability and could be resolved with the help of nanoengineering in designing and manufacturing. Here, we demonstrate a photosynthetic solar cell (PSC) that contains a nanostructure to prevent the formation of biofilm by micro-organisms. Nanostructures were fabricated using nanoimprint lithography, where a film heater array system was introduced to precisely control the local wall temperature. To understand the heat and mass transfer phenomena behind the manufacturing and energy harvesting processes of PSC, we carried out a numerical simulation and experimental measurements. It revealed that the nanostructures developed on the proton exchange membrane enable PSC to produce enhanced output power due to the retarded microbial attachment on the Nafion membrane. We anticipate that this strategy can provide a pathway where PSC can ensure more renewable, sustainable, and efficient energy harvesting performance.

Relativistic non-Hamiltonian mechanics

International Nuclear Information System (INIS)

Tarasov, Vasily E.

2010-01-01

Relativistic particle subjected to a general four-force is considered as a nonholonomic system. The nonholonomic constraint in four-dimensional space-time represents the relativistic invariance by the equation for four-velocity u μ u μ + c 2 = 0, where c is the speed of light in vacuum. In the general case, four-forces are non-potential, and the relativistic particle is a non-Hamiltonian system in four-dimensional pseudo-Euclidean space-time. We consider non-Hamiltonian and dissipative systems in relativistic mechanics. Covariant forms of the principle of stationary action and the Hamilton's principle for relativistic mechanics of non-Hamiltonian systems are discussed. The equivalence of these principles is considered for relativistic particles subjected to potential and non-potential forces. We note that the equations of motion which follow from the Hamilton's principle are not equivalent to the equations which follow from the variational principle of stationary action. The Hamilton's principle and the principle of stationary action are not compatible in the case of systems with nonholonomic constraint and the potential forces. The principle of stationary action for relativistic particle subjected to non-potential forces can be used if the Helmholtz conditions are satisfied. The Hamilton's principle and the principle of stationary action are equivalent only for a special class of relativistic non-Hamiltonian systems.

Hydrogen effects on deep level defects in proton implanted Cu(In,Ga)Se{sub 2} based thin films

Energy Technology Data Exchange (ETDEWEB)

Lee, D.W.; Seol, M.S.; Kwak, D.W.; Oh, J.S. [Department of Physics, Dongguk University, Seoul 100-715 (Korea, Republic of); Jeong, J.H. [Photo-electronic Hybrids Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Cho, H.Y., E-mail: hycho@dongguk.edu [Department of Physics, Dongguk University, Seoul 100-715 (Korea, Republic of)

2012-08-01

Hydrogen effects on deep level defects and a defect generation in proton implanted Cu(In,Ga)Se{sub 2} (CIGS) based thin films for solar cell were investigated. CIGS films with a thickness of 3 {mu}m were grown on a soda-lime glass substrate by a co-evaporation method, and then were implanted with protons. To study deep level defects in the proton implanted CIGS films, deep level transient spectroscopy measurements on the CIGS-based solar cells were carried out, these measurements found 6 traps (including 3 hole traps and 3 electron traps). In the proton implanted CIGS films, the deep level defects, which are attributed to the recombination centers of the CIGS solar cell, were significantly reduced in intensity, while a deep level defect was generated around 0.28 eV above the valence band maximum. Therefore, we suggest that most deep level defects in CIGS films can be controlled by hydrogen effects. - Highlights: Black-Right-Pointing-Pointer Proton implanted Cu(In,Ga)Se{sub 2} thin film and solar cell are prepared. Black-Right-Pointing-Pointer Deep level defects of Cu(In,Ga)Se{sub 2} thin film and solar cell are investigated. Black-Right-Pointing-Pointer Hydrogenation using proton implantation and H{sub 2} annealing reduces deep level defects. Black-Right-Pointing-Pointer Hydrogenation could enhance electrical properties and efficiency of solar cells.

Solar energetic particles and radio burst emission

Directory of Open Access Journals (Sweden)

Miteva Rositsa

2017-01-01

Full Text Available We present a statistical study on the observed solar radio burst emission associated with the origin of in situ detected solar energetic particles. Several proton event catalogs in the period 1996–2016 are used. At the time of appearance of the particle origin (flare and coronal mass ejection we identified radio burst signatures of types II, III and IV by inspecting dynamic radio spectral plots. The information from observatory reports is also accounted for during the analysis. The occurrence of solar radio burst signatures is evaluated within selected wavelength ranges during the solar cycle 23 and the ongoing 24. Finally, we present the burst occurrence trends with respect to the intensity of the proton events and the location of their solar origin.

Characteristics of trapped proton anisotropy at Space Station Freedom altitudes

Science.gov (United States)

Armstrong, T. W.; Colborn, B. L.; Watts, J. W.

1990-01-01

The ionizing radiation dose for spacecraft in low-Earth orbit (LEO) is produced mainly by protons trapped in the Earth's magnetic field. Current data bases describing this trapped radiation environment assume the protons to have an isotropic angular distribution, although the fluxes are actually highly anisotropic in LEO. The general nature of this directionality is understood theoretically and has been observed by several satellites. The anisotropy of the trapped proton exposure has not been an important practical consideration for most previous LEO missions because the random spacecraft orientation during passage through the radiation belt 'averages out' the anisotropy. Thus, in spite of the actual exposure anisotropy, cumulative radiation effects over many orbits can be predicted as if the environment were isotropic when the spacecraft orientation is variable during exposure. However, Space Station Freedom will be gravity gradient stabilized to reduce drag, and, due to this fixed orientation, the cumulative incident proton flux will remain anisotropic. The anisotropy could potentially influence several aspects of Space Station design and operation, such as the appropriate location for radiation sensitive components and experiments, location of workstations and sleeping quarters, and the design and placement of radiation monitors. Also, on-board mass could possible be utilized to counteract the anisotropy effects and reduce the dose exposure. Until recently only omnidirectional data bases for the trapped proton environment were available. However, a method to predict orbit-average, angular dependent ('vector') trapped proton flux spectra has been developed from the standard omnidirectional trapped proton data bases. This method was used to characterize the trapped proton anisotropy for the Space Station orbit (28.5 degree inclination, circular) in terms of its dependence on altitude, solar cycle modulation (solar minimum vs. solar maximum), shielding thickness

Solar Energetic Particle Events at the Rise Phase of the 23rd Solar ...

Indian Academy of Sciences (India)

tribpo

Abstract. The experiment with 10K-80 aboard the INTER-BALL-2. (which detects protons with energies >7, 27-41, 41-58, 58-88, 88-180 and 180-300 MeV) registered six events of the solar energetic particle. (SEP) increase. These events are during the initial rise phase of the 23rd solar activity cycle. Solar flares with the ...

Radiative hazard of solar flares in the nearterrestrial cosmic space

International Nuclear Information System (INIS)

Kolomenskij, A.V.; Petrov, V.M.; Zil', M.V.; Eremkina, T.M.

1978-01-01

Simulation of radiation enviroment due to solar cosmic rays was carried out in the near-terrestrial space. Systematized are the data on cosmic ray flux and spectra detected during 19-th and 20-th cycles of solar activity. 127 flares are considered with proton fluxes of more than 10 proton/cm 2 at energies higher than 30 MeV. Obtained are distribution functions of intervals between flares, flux distribution of flares and characteristic rigidity, and also distribution of magnetic disturbances over Dsub(st)-variation amplitude. The totality of these distributions presents the statistic model of radiation enviroment caused by solar flare protons for the period of maximum solar .activity. This model is intended for estimation of radiation hazard at manned cosmic flights

Mercury's Surface Magnetic Field Determined from Proton-Reflection Magnetometry

Science.gov (United States)

Winslow, Reka M.; Johnson, Catherine L.; Anderson, Brian J.; Gershman, Daniel J.; Raines, Jim M.; Lillis, Robert J.; Korth, Haje; Slavin, James A.; Solomon, Sean C.; Zurbuchen, Thomas H.;

Final-state interactions and relativistic effects in the quasielastic (e,e') reaction

International Nuclear Information System (INIS)

Chinn, C.R.; Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545); Picklesimer, A.; Van Orden, J.W.

1989-01-01

The longitudinal and transverse response functions for the inclusive quasielastic (e,e') reaction are analyzed in detail. A microscopic theoretical framework for the many-body reaction provides a clear conceptual (nonrelativistic) basis for treating final-state interactions and goes far beyond simple plane-wave or Hermitean potential models. The many-body physics of inelastic final-state channels as described by optical and multiple scattering theories is properly included by incorporating a full complex optical potential. Explicit nonrelativistic and relativistic momentum-space calculations quantitatively demonstrate the importance of such a treatment of final-state interactions for both the transverse and longitudinal response. Nonrelativistic calculations are performed using final-state interactions based on phenomenology, local density models, and microscopic multiple scattering theory. Relativistic calculations span a similar range of models and employ Dirac bound-state wave functions. The theoretical extension to relativistic dynamics is of course not clear, but is done in obvious parallel to elastic proton scattering. Extensive calculations are performed for 40 Ca at momentum transfers of 410, 550, and 700 MeV/c. A number of interesting physical effects are observed, including significant relativistic suppressions (especially for R L ), large off-shell and virtual pair effects, enhancement of the tails of the response by the final-state interactions, and large qualitative and even shape distinctions between the predictions of the various models of the final-state interactions. None of the models is found to be able to simultaneously predict the data for both response functions. This strongly suggests that additional physical mechanisms are of qualitative importance in inclusive quasielastic electron scattering

Recent development of relativistic molecular theory

International Nuclear Information System (INIS)

Takahito, Nakajima; Kimihiko, Hirao

2005-01-01

Today it is common knowledge that relativistic effects are important in the heavy-element chemistry. The continuing development of the relativistic molecular theory is opening up rows of the periodic table that are impossible to treat with the non-relativistic approach. The most straightforward way to treat relativistic effects on heavy-element systems is to use the four-component Dirac-Hartree-Fock approach and its electron-correlation methods based on the Dirac-Coulomb(-Breit) Hamiltonian. The Dirac-Hartree-Fock (DHF) or Dirac-Kohn-Sham (DKS) equation with the four-component spinors composed of the large- and small-components demands severe computational efforts to solve, and its applications to molecules including heavy elements have been limited to small- to medium-size systems. Recently, we have developed a very efficient algorithm for the four-component DHF and DKS approaches. As an alternative approach, several quasi-relativistic approximations have also been proposed instead of explicitly solving the four-component relativistic equation. We have developed the relativistic elimination of small components (RESC) and higher-order Douglas-Kroll (DK) Hamiltonians within the framework of the two-component quasi-relativistic approach. The developing four-component relativistic and approximate quasi-relativistic methods have been implemented into a program suite named REL4D. In this article, we will introduce the efficient relativistic molecular theories to treat heavy-atomic molecular systems accurately via the four-component relativistic and the two-component quasi-relativistic approaches. We will also show several chemical applications including heavy-element systems with our relativistic molecular approaches. (author)

Relativistic ion collisions as the source of hypernuclei

Energy Technology Data Exchange (ETDEWEB)

Botvina, A.S. [J.W. Goethe University, Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); Russian Academy of Sciences, Institute for Nuclear Research, Moscow (Russian Federation); Bleicher, M.; Steinheimer, J. [J.W. Goethe University, Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); Pochodzalla, J. [J. Gutenberg-Universitaet, Helmholtz-Institut Mainz, Mainz (Germany); J. Gutenberg-Universitaet Mainz, Institut fuer Kernphysik and PRISMA Cluster of Excellence, Mainz (Germany)

2016-08-15

We shortly review the theory of hypernuclei production in relativistic ion collisions, that is adequate to future experiments at BM rate at N, NICA, and FAIR. Within a hybrid approach we use transport, coalescence and statistical models to describe the whole process. We demonstrate that the origin of hypernuclei can be explained by typical baryon interactions, that is similar to the production of conventional nuclei. In particular, heavy hypernuclei are coming mostly from projectile and target residues, whereas light hypernuclei can be produced at all rapidities. The yields of hypernuclei increase considerably above the energy threshold for Λ hyperon production, and there is a tendency to saturation of yields of hypernuclei with increasing the beam energy up to few TeV. There are unique opportunities in relativistic ion collisions which are difficult to realize in traditional hypernuclear experiments: The produced hypernuclei have a broad distribution in masses and isospin. They can even reach beyond the neutron and proton drip-lines and that opens a chance to investigate properties of exotic hypernuclei. One finds also the abundant production of multi-strange nuclei, of bound and unbound hypernuclear states with new decay modes. In addition, we can directly get an information on the hypermatter both at high and low temperatures. (orig.)

Re-hardening of hadron transverse mass spectra in relativistic heavy-ion collisions

International Nuclear Information System (INIS)

Ohnishi, A.; Otuka, N.; Sahu, P.K.; Isse, M.; Nara, Y.

2001-01-01

We analyze the spectra of pions and protons in heavy-ion collisions at relativistic energies from 2 A GeV to 65 + 65 A GeV by using a jet-implemented hadron-string cascade model. In this energy region, hadron transverse mass spectra first show softening until SPS energies, and re-hardening may emerge at RHIC energies. Since hadronic matter is expected to show only softening at higher energy densities, this re-hardening of spectra can be interpreted as a good signature of the quark-gluon plasma formation. (author)

Effects of proton irradiation and temperature on 1 ohm-cm and 10 ohm-cm silicon solar cells

Science.gov (United States)

Nicoletta, C. A.

1973-01-01

The 1 ohm-cm and 10 ohm-cm silicon solar cells were exposed to 1.0 MeV protons at a fixed flux of 10 to the 9th power P/sq cm-sec and fluences of 10 to the 10th power, 10 to the 11th power, 10 to the 12th power and 3 X 10 to the 12th power P/sq cm. I-V curves of the cells were made at room temperature, 65 C and 165 C after each irradiation. A value of 139.5 mw/sq cm was taken as AMO incident energy rate per unit area. Degradation occurred for both uncovered 1 ohm-cm and 10 ohm-cm cells. Efficiencies are generally higher than those of comparable U.S. cells tested earlier. Damage (loss in maximum power efficiency) with proton fluence is somewhat higher for 10 ohm-cm cells, measured at the three temperatures, for fluences above 2 X 10 to the 11th power P/sq cm. Cell efficiency, as expected, changes drastically with temperature.

Three-fluid, three-dimensional magnetohydrodynamic solar wind model with eddy viscosity and turbulent resistivity

Energy Technology Data Exchange (ETDEWEB)

Usmanov, Arcadi V.; Matthaeus, William H. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Goldstein, Melvyn L., E-mail: arcadi.usmanov@nasa.gov [Code 672, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2014-06-10

We have developed a three-fluid, three-dimensional magnetohydrodynamic solar wind model that incorporates turbulence transport, eddy viscosity, turbulent resistivity, and turbulent heating. The solar wind plasma is described as a system of co-moving solar wind protons, electrons, and interstellar pickup protons, with separate energy equations for each species. Numerical steady-state solutions of Reynolds-averaged solar wind equations coupled with turbulence transport equations for turbulence energy, cross helicity, and correlation length are obtained by the time relaxation method in the corotating with the Sun frame of reference in the region from 0.3 to 100 AU (but still inside the termination shock). The model equations include the effects of electron heat conduction, Coulomb collisions, photoionization of interstellar hydrogen atoms and their charge exchange with the solar wind protons, turbulence energy generation by pickup protons, and turbulent heating of solar wind protons and electrons. The turbulence transport model is based on the Reynolds decomposition and turbulence phenomenologies that describe the conversion of fluctuation energy into heat due to a turbulent cascade. In addition to using separate energy equations for the solar wind protons and electrons, a significant improvement over our previous work is that the turbulence model now uses an eddy viscosity approximation for the Reynolds stress tensor and the mean turbulent electric field. The approximation allows the turbulence model to account for driving of turbulence by large-scale velocity gradients. Using either a dipole approximation for the solar magnetic field or synoptic solar magnetograms from the Wilcox Solar Observatory for assigning boundary conditions at the coronal base, we apply the model to study the global structure of the solar wind and its three-dimensional properties, including embedded turbulence, heating, and acceleration throughout the heliosphere. The model results are

Second-order contributions to relativistic time delay in the parametrized post-Newtonian formalism

International Nuclear Information System (INIS)

Richter, G.W.; Matzner, R.A.

1983-01-01

Using a parametrized expansion of the solar metric to second order in the Newtonian potential, we calculate the relativistic delay in the round-trip travel time of a radar signal reflected from a nearby planet. We find that one second-order contribution to the delay is on the order of ten nanoseconds, which is comparable to the uncertainties in present-day experiments involving the Viking spacecraft

A potential diagnostic for low energy, nonthermal protons in solar flares

International Nuclear Information System (INIS)

MacKinnon, A.L.

1989-01-01

The current uncertainty in flare research regarding the role of low energy (<1 MeV) protons demands that we consider any possibilities for directly constraining their number and energy content. Here we point out that γ-ray lines, from radiative capture reactions of such protons, may in principle provide such constraints. Making allowance for the possibility that the protons slow down in a warm target, we show how observational upper limits to their strengths may be used to constrain the proton energy content and the temperature of the interaction region

Relativistic Kinetic Theory

Science.gov (United States)

Vereshchagin, Gregory V.; Aksenov, Alexey G.

2017-02-01

Preface; Acknowledgements; Acronyms and definitions; Introduction; Part I. Theoretical Foundations: 1. Basic concepts; 2. Kinetic equation; 3. Averaging; 4. Conservation laws and equilibrium; 5. Relativistic BBGKY hierarchy; 6. Basic parameters in gases and plasmas; Part II. Numerical Methods: 7. The basics of computational physics; 8. Direct integration of Boltzmann equations; 9. Multidimensional hydrodynamics; Part III. Applications: 10. Wave dispersion in relativistic plasma; 11. Thermalization in relativistic plasma; 12. Kinetics of particles in strong fields; 13. Compton scattering in astrophysics and cosmology; 14. Self-gravitating systems; 15. Neutrinos, gravitational collapse and supernovae; Appendices; Bibliography; Index.

Astronomical relativistic reference systems with multipolar expansion: the global one

International Nuclear Information System (INIS)

Xie Yi

2014-01-01

With the rapid development of techniques for astronomical observations, the precision of measurements has been significantly increasing. Theories describing astronomical relativistic reference systems, which are the foundation for processing and interpreting these data now and in the future, may require extensions to satisfy the needs of these trends. Besides building a framework compatible with alternative theories of gravity and the pursuit of higher order post-Newtonian approximation, it will also be necessary to make the first order post-Newtonian multipole moments of celestial bodies be explicitly expressed in the astronomical relativistic reference systems. This will bring some convenience into modeling the observations and experiments and make it easier to distinguish different contributions in measurements. As a first step, the global solar system reference system is expressed as a multipolar expansion and the post-Newtonian mass and spin moments are shown explicitly in the metric which describes the coordinates of the system. The full expression of the global metric is given. (research papers)

Relativistic Linear Restoring Force

Science.gov (United States)

Clark, D.; Franklin, J.; Mann, N.

2012-01-01

We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…

Relativistic decay widths of autoionization processes: The relativistic FanoADC-Stieltjes method

Energy Technology Data Exchange (ETDEWEB)

Fasshauer, Elke, E-mail: Elke.Fasshauer@uit.no [Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Tromsø–The Arctic University of Norway, N-9037 Tromsø (Norway); Theoretische Chemie, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany); Kolorenč, Přemysl [Institute of Theoretical Physics, Faculty of Mathematics and Physics, Charles University in Prague, V Holešovičkách 2, 180 00 Prague (Czech Republic); Pernpointner, Markus [Theoretische Chemie, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany)

2015-04-14

Electronic decay processes of ionized systems are, for example, the Auger decay or the Interatomic/ Intermolecular Coulombic Decay. In both processes, an energetically low lying vacancy is filled by an electron of an energetically higher lying orbital and a secondary electron is instantaneously emitted to the continuum. Whether or not such a process occurs depends both on the energetic accessibility and the corresponding lifetime compared to the lifetime of competing decay mechanisms. We present a realization of the non-relativistically established FanoADC-Stieltjes method for the description of autoionization decay widths including relativistic effects. This procedure, being based on the Algebraic Diagrammatic Construction (ADC), was adapted to the relativistic framework and implemented into the relativistic quantum chemistry program package Dirac. It is, in contrast to other existing relativistic atomic codes, not limited to the description of autoionization lifetimes in spherically symmetric systems, but is instead also applicable to molecules and clusters. We employ this method to the Auger processes following the Kr3d{sup −1}, Xe4d{sup −1}, and Rn5d{sup −1} ionization. Based on the results, we show a pronounced influence of mainly scalar-relativistic effects on the decay widths of autoionization processes.

Incident energy dependence of pt correlations at relativistic energies

CERN Document Server

Adams, J; Ahammed, Z; Amonett, J; Anderson, B D; Arkhipkin, D; Averichev, G S; Badyal, S K; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Berger, J; Bezverkhny, B I; Bharadwaj, S; Bhasin, A; Bhati, A K; Bhatia, V S; Bichsel, H; Bielcik, J; Bielcikova, J; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Bouchet, J; Brandin, A V; Bravar, A; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca-Sanchez, M; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Daugherity, M; De Moura, M M; Dedovich, T G; Derevshchikov, A A; Didenko, L; Dietel, T; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta, M R; Mazumdar; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faivre, J; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Yu; Fu, J; Gagliardi, C A; Gaillard, L; Gans, J; Ganti, M S; Geurts, F; Ghazikhanian, V; Ghosh, P; González, J E; Gos, H; Grachov, O; Grebenyuk, O; Grosnick, D P; Guertin, S M; Guo, Y; Sen-Gupta, A; Gutíerrez, T D; Hallman, T J; Hamed, A; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Jedynak, M; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Kislov, E M; Klay, J; Klein, S R; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kowalik, K L; Krämer, M; Kravtsov, P; Kravtsov, V I; Krüger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kutuev, R K; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lehocka, S; Le Vine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, L; Liu, Q J; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; López-Noriega, M; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahajan, S; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J N; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Meissner, F; Melnik, Yu M; Meschanin, A; Miller, M L; Minaev, N G; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnár, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Nurushev, S B; Odyniec, Grazyna Janina; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pal, S K; Panebratsev, Yu A; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevozchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M V; Potrebenikova, E V; Potukuchi, B V K S; Prindle, D; Pruneau, C A; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D M; Reid, J G; Reinnarth, J; Renault, G; Retière, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Sarsour, M; Savin, I; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schweda, K; Seger, J; Seyboth, P; Shahaliev, E; Shao, M; Shao, W; Sharma, M; Shen, W Q; Shestermanov, K E; Shimansky, S S; Sichtermann, E P; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sørensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M N; Stringfellow, B C; Suaide, A A P; Sugarbaker, E R; Suire, C; Sumbera, M; Surrow, B; Swanger, M; Symons, T J M; Szanto de Toledo, A; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T J; Thein, D; Thomas, J H; Timoshenko, S; Tokarev, M; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; Van Leeuwen, M; Van der Molen, A M; Varma, R; Vasilevski, I M; Vasilev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, X L; Wang, Y; Wang, Z M; Ward, H; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yamamoto, E; Yepes, P; Yurevich, V I; Zborovský, I; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N

2005-01-01

We present results for two-particle transverse momentum correlations, , as a function of event centrality for Au+Au collisions at sqrt(sNN) = 20, 62, 130, and 200 GeV at the Relativistic Heavy Ion Collider. We observe correlations decreasing with centrality that are similar at all four incident energies. The correlations multiplied by the multiplicity density increase with incident energy and the centrality dependence may show evidence of processes such as thermalization, minijet production, or the saturation of transverse flow. The square root of the correlations divided by the event-wise average transverse momentum per event shows little or no beam energy dependence and generally agrees with previous measurements at the Super Proton Synchrotron.

Momentum distributions in nuclei measured with relativistic heavy ions

International Nuclear Information System (INIS)

Hiller, B.; Huefner, J.; Heidelberg Univ.

1982-01-01

In a peripheral reaction between relativistic heavy ions, where one nucleon is knocked out of the projektile, the momentum distribution of the remaining fragment reflects the momentum distribution of the knocked out nucleon. This has been proven in a previous paper. Here we study how the final-state interaction between the knocked out nucleon and the observed fragment influences the result: The real part of the optical potential which describes the final-state interaction shifts the experimental momentum distribution by a value [ksub(||)] of a few tens of MeV/c and the imaginary part reduces the cross sections by a factor 2 roughly. We also derive the cross section for a proton as target. (orig.)

General Relativistic Theory of the VLBI Time Delay in the Gravitational Field of Moving Bodies

Science.gov (United States)

Kopeikin, Sergei

2003-01-01

The general relativistic theory of the gravitational VLBI experiment conducted on September 8, 2002 by Fomalont and Kopeikin is explained. Equations of radio waves (light) propagating from the quasar to the observer are integrated in the time-dependent gravitational field of the solar system by making use of either retarded or advanced solutions of the Einstein field equations. This mathematical technique separates explicitly the effects associated with the propagation of gravity from those associated with light in the integral expression for the relativistic VLBI time delay of light. We prove that the relativistic correction to the Shapiro time delay, discovered by Kopeikin (ApJ, 556, L1, 2001), changes sign if one retains direction of the light propagation but replaces the retarded for the advanced solution of the Einstein equations. Hence, this correction is associated with the propagation of gravity. The VLBI observation measured its speed, and that the retarded solution is the correct one.

Electronic structure of FeTiSb using relativistic and scalar-relativistic approaches

Energy Technology Data Exchange (ETDEWEB)

Sahariya, Jagrati [Department of Physics, Manipal University Jaipur, Jaipur-303007, Rajasthan (India); Mund, H. S., E-mail: hmoond@gmail.com [Department of Physics, M. L. Sukhadia University, Udaipur-313001, Rajasthan (India)

2016-05-06

Electronic and magnetic properties of FeTiSb have been reported. The calculations are performed using spin polarized relativistic Korringa-Kohn-Rostoker scheme based on Green’s function method. Within SPR-KKR a fully relativistic and scalar-relativistic approaches have been used to investigate electronic structure of FeTiSb. Energy bands, total and partial density of states, atom specific magnetic moment along with total moment of FeTiSb alloys are presented.

Mechanism of disintegration of sup 2 sup 3 sup 8 U nuclei by relativistic projectiles

CERN Document Server

Andronenko, L N; Kravtsov, A V; Solyakin, G E

2002-01-01

The sup 2 sup 3 sup 8 U nuclei disintegration through the 16 GeV energy protons and sup 3 He 2 GeV energy nuclei are considered. The pulse mechanism compensation is proposed to explain the formation of collinear mass fragments accompanied by a large amount of charged secondaries and neutrons flying on the m sub 1 relativistic particle heavy nuclei on the account of the particle emission with the mass m sub 2 > m sub 1

Probing the direct step of relativistic heavy ion fragmentation: (12C, 11B+p) at 2.1 GeV/nucleon with C and CH2 targets

International Nuclear Information System (INIS)

Webb, M.L.

1987-06-01

Relativistic heavy ion collisions may be classified as central (and near central), peripheral, and grazing with each collision type producing different proton and other charged projectile fragment scattering mechanisms and characteristics. This report focuses on peripheral and grazing collisions in the fragmentation of Carbon-12 into Boron-11 and a proton, testing models of the kinetics involved in this reaction. The data were measured at the Heavy Ion Superconducting Spectrometer (HISS) at Lawrence Berkeley Laboratory and include excitation energy for the p/Boron-11 pair, and rapidity versus transverse momentum for protons and Boron-11. 58 refs., 35 figs., 8 tabs

Dosimetric control on board the MIR space station during the solar proton events of September-October 1989

International Nuclear Information System (INIS)

Benghin, V.V.; Petrov, V.M.; Chernykh, I.V.; Teltsov, M.V.; Shumshurov, V.I.

1992-01-01

A set of dosimetric units for the control of radiation doses to cosmonauts on board the MIR space station contains an active dosimeter R-16 and a personal display dosimeter IPD-2. During the powerful solar proton events (SPE) in September-October 1989, the readings of these devices were used for the control of the crew's radiation damage. Results of the dose measurements and analysis of the dynamics caused by some heliogeophysical factors are given. It is shown that the total doses from SPE registered by the dosimeters R-16 and IPD-2 were 3.6 x 10 -2 and 0.9 x 10 -2 Gy, respectively. (author)

Relativistic entanglement from relativistic quantum mechanics in the rest-frame instant form of dynamics

International Nuclear Information System (INIS)

Lusanna, Luca

2011-01-01

After a review of the problems induced by the Lorentz signature of Minkowski space-time, like the need of a clock synchronization convention for the definition of 3-space and the complexity of the notion of relativistic center of mass, there is the introduction of a new formulation of relativistic quantum mechanics compatible with the theory of relativistic bound states. In it the zeroth postulate of non-relativistic quantum mechanics is not valid and the physics is described in the rest frame by a Hilbert space containing only relative variables. The non-locality of the Poincare' generators imply a kinematical non-locality and non-separability influencing the theory of relativistic entanglement and not connected with the standard quantum non-locality.

On the acceleration of alpha particles in the fast solar wind

International Nuclear Information System (INIS)

Gomberoff, L.; Hernandez, R.

1992-01-01

Recently, Gomberoff and Elgueta (1991) showed that in a plasma composed of anisotropic protons and alpha particles drifting along an external magnetic field with a small velocity relative to the protons, strong left-hand polarized electromagnetic ion cyclotron waves can be generated. These waves can accelerate the alpha particles to velocities well in excess of the proton bulk velocity. Here the authors assume a more realistic model of the solar wind by considering a double-humped proton distribution. It is shown that the secondary proton beam has no important effects on the ion cyclotron waves for beam densities of the order of those observed in fast solar wind conditions. The fact that the alpha proton drift velocity is modulated by the Alfven velocity remains unexplained

Relativistic Descriptions of Few-Body Systems

International Nuclear Information System (INIS)

Karmanov, V. A.

2011-01-01

A brief review of relativistic effects in few-body systems, of theoretical approaches, recent developments and applications is given. Manifestations of relativistic effects in the binding energies, in the electromagnetic form factors and in three-body observables are demonstrated. The three-body forces of relativistic origin are also discussed. We conclude that relativistic effects in nuclei can be important in spite of small binding energy. At high momenta they clearly manifest themselves and are necessary to describe the deuteron e.m. form factors. At the same time, there is still a discrepancy in three-body observables which might be a result of less clarity in understanding the corresponding relativistic effects, the relativistic NN kernel and the three-body forces. Relativistic few-body physics remains to be a field of very intensive and fruitful researches. (author)

Proton irradiation and endometriosis

International Nuclear Information System (INIS)

Wood, D.H.; Yochmowitz, M.G.; Salmon, Y.L.; Eason, R.L.; Boster, R.A.

1983-01-01

It was found that female rhesus monkeys given single total-body exposures of protons of varying energies developed endometriosis at a frequency significantly higher than that of nonirradiated animals of the same age. The minimum latency period was determined to be 7 years after the proton exposure. The doses and energies of the radiation received by the experimental animals were within the range that could be received by an aircrew member in near-earth orbit during a random solar flare event. It is concluded that endometriosis should be a consideration in assessing the risk of delayed radiation effects in female crew members. 15 references

Introduction into a two-dimensional model of the photochemistry of the stratosphere of precipitations of galactic and solar protons: case of the present terrestrial magnetic field and of field reversal

International Nuclear Information System (INIS)

Brard, D.

1982-11-01

In the aim of studying the climatic variations related to the reversal of the geomagnetic field, an analysis has been made of the effects of precipitations of galactic and solar protons, on oxide of nitrogen (NOsub(x) and NO) and ozone. Modifications are introduced into the one- and two-dimensional models which take into account the structure of the magnetic field. In situ measurements after the solar event of August 1972 enable changes due to the solar cycles to be introduced and the use of a 2D model to be justified [fr

Regional-Scale Surface Magnetic Fields and Proton Fluxes to Mercury's Surface from Proton-Reflection Magnetometry

Science.gov (United States)

Winslow, R. M.; Johnson, C. L.; Anderson, B. J.; Gershman, D. J.; Raines, J. M.; Lillis, R. J.; Korth, H.; Slavin, J. A.; Solomon, S. C.; Zurbuchen, T.

2014-12-01

The application of a recently developed proton-reflection magnetometry technique to MESSENGER spacecraft observations at Mercury has yielded two significant findings. First, loss-cone observations directly confirm particle precipitation to Mercury's surface and indicate that solar wind plasma persistently bombards the planet not only in the magnetic cusp regions but over a large fraction of the southern hemisphere. Second, the inferred surface field strengths independently confirm the north-south asymmetry in Mercury's global magnetic field structure first documented from observations of magnetic equator crossings. Here we extend this work with 1.5 additional years of observations (i.e., to 2.5 years in all) to further probe Mercury's surface magnetic field and better resolve proton flux precipitation to the planet's surface. We map regions where proton loss cones are observed; these maps indicate regions where protons precipitate directly onto the surface. The augmentation of our data set over that used in our original study allows us to examine the proton loss cones in cells of dimension 10° latitude by 20° longitude in Mercury body-fixed coordinates. We observe a transition from double-sided to single-sided loss cones in the pitch-angle distributions; this transition marks the boundary between open and closed field lines. At the surface this boundary lies between 60° and 70°N. Our observations allow the estimation of surface magnetic field strengths in the northern cusp region and the calculation of incident proton fluxes to both hemispheres. In the northern cusp, our regional-scale observations are consistent with an offset dipole field and a dipole moment of 190 nT RM3, where RM is Mercury's radius, implying that any regional-scale variations in surface magnetic field strengths are either weak relative to the dipole field or occur at length scales smaller than the resolution of our observations (~300 km). From the global proton flux map (north of 40° S

Simulation and quasilinear theory of proton firehose instability

Energy Technology Data Exchange (ETDEWEB)

Seough, Jungjoon [Korean Astronomy and Space Science Institute, Daejeon (Korea, Republic of); Faculty of Human Development, University of Toyama, 3190, Gofuku, Toyama City, Toyama, 930-8555 (Japan); Yoon, Peter H. [University of Maryland, College Park, Maryland 20742 (United States); School of Space Research, Kyung Hee University, Yongin, Gyeonggi 446-701 (Korea, Republic of); Hwang, Junga [Korean Astronomy and Space Science Institute, Daejeon (Korea, Republic of); Korea, University of Science and Technology, Daejeon (Korea, Republic of)

2015-01-15

The electromagnetic proton firehose instability is driven by excessive parallel temperature anisotropy, T{sub ∥} > T{sub ⊥} (or more precisely, parallel pressure anisotropy, P{sub ∥} > P{sub ⊥}) in high-beta plasmas. Together with kinetic instabilities driven by excessive perpendicular temperature anisotropy, namely, electromagnetic proton cyclotron and mirror instabilities, its role in providing the upper limit for the temperature anisotropy in the solar wind is well-known. A recent Letter [Seough et al., Phys. Rev. Lett. 110, 071103 (2013)] employed quasilinear kinetic theory for these instabilities to explain the observed temperature anisotropy upper bound in the solar wind. However, the validity of quasilinear approach has not been rigorously tested until recently. In a recent paper [Seough et al., Phys. Plasmas 21, 062118 (2014)], a comparative study is carried out for the first time in which quasilinear theory of proton cyclotron instability is tested against results obtained from the particle-in-cell simulation method, and it was demonstrated that the agreement was rather excellent. The present paper addresses the same issue involving the proton firehose instability. Unlike the proton cyclotron instability, however, it is found that the quasilinear approximation enjoys only a limited range of validity, especially for the wave dynamics and for the relatively high-beta regime. Possible causes and mechanisms responsible for the discrepancies are speculated and discussed.

Plasma Density Tapering for Laser Wakefield Acceleration of Electrons and Protons

International Nuclear Information System (INIS)

Ting, A.; Gordon, D.; Kaganovich, D.; Sprangle, P.; Helle, M.; Hafizi, B.

2010-01-01

Extended acceleration in a Laser Wakefield Accelerator can be achieved by tailoring the phase velocity of the accelerating plasma wave, either through profiling of the density of the plasma or direct manipulation of the phase velocity. Laser wakefield acceleration has also reached a maturity that proton acceleration by wakefield could be entertained provided we begin with protons that are substantially relativistic, ∼1 GeV. Several plasma density tapering schemes are discussed. The first scheme is called ''bucket jumping'' where the plasma density is abruptly returned to the original density after a conventional tapering to move the accelerating particles to a neighboring wakefield period (bucket). The second scheme is designed to specifically accelerate low energy protons by generating a nonlinear wakefield in a plasma region with close to critical density. The third scheme creates a periodic variation in the phase velocity by beating two intense laser beams with laser frequency difference equal to the plasma frequency. Discussions and case examples with simulations are presented where substantial acceleration of electrons or protons could be obtained.

Search for non-relativistic magnetic monopoles with IceCube

International Nuclear Information System (INIS)

Aartsen, M.G.; Hill, G.C.; Robertson, S.; Whelan, B.J.; Abbasi, R.; Ahlers, M.; Arguelles, C.; Baker, M.; BenZvi, S.; Chirkin, D.; Day, M.; Desiati, P.; Diaz-Velez, J.C.; Eisch, J.; Fadiran, O.; Feintzeig, J.; Gladstone, L.; Halzen, F.; Hoshina, K.; Jacobsen, J.; Jero, K.; Karle, A.; Kauer, M.; Kelley, J.L.; Kopper, C.; Krasberg, M.; Kurahashi, N.; Landsman, H.; Maruyama, R.; McNally, F.; Merck, M.; Morse, R.; Riedel, B.; Rodrigues, J.P.; Santander, M.; Tobin, M.N.; Toscano, S.; Van Santen, J.; Weaver, C.; Wellons, M.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Ackermann, M.; Benabderrahmane, M.L.; Berghaus, P.; Bernardini, E.; Bretz, H.P.; Cruz Silva, A.H.; Gluesenkamp, T.; Jacobi, E.; Kaminsky, B.; Karg, T.; Middell, E.; Mohrmann, L.; Nahnhauer, R.; Schoenwald, A.; Shanidze, R.; Spiering, C.; Stoessl, A.; Yanez, J.P.; Adams, J.; Brown, A.M.; Hickford, S.; Macias, O.; Aguilar, J.A.; Christov, A.; Montaruli, T.; Rameez, M.; Vallecorsa, S.; Altmann, D.; Classen, L.; Gora, D.; Kappes, A.; Tselengidou, M.; Arlen, T.C.; De Andre, J.P.A.M.; DeYoung, T.; Dunkman, M.; Eagan, R.; Groh, J.C.; Huang, F.; Quinnan, M.; Smith, M.W.E.; Stanisha, N.A.; Tesic, G.; Auffenberg, J.; Bissok, M.; Blumenthal, J.; Gretskov, P.; Haack, C.; Hallen, P.; Heinen, D.; Jagielski, K.; Kriesten, A.; Krings, K.; Leuermann, M.; Paul, L.; Raedel, L.; Reimann, R.; Schoenen, S.; Schukraft, A.; Vehring, M.; Wallraff, M.; Wiebusch, C.H.; Zierke, S.; Bai, X.; Evenson, P.A.; Gaisser, T.K.; Gonzalez, J.G.; Hussain, S.; Kuwabara, T.; Ruzybayev, B.; Seckel, D.; Stanev, T.; Tamburro, A.; Tilav, S.; Barwick, S.W.; Yodh, G.; Baum, V.; Eberhardt, B.; Koepke, L.; Kroll, G.; Luenemann, J.; Sander, H.G.; Schatto, K.; Wiebe, K.; Bay, R.; Filimonov, K.; Price, P.B.; Woschnagg, K.; Beatty, J.J.; Becker Tjus, J.; Eichmann, B.; Fedynitch, A.; Saba, S.M.; Schoeneberg, S.; Unger, E.; Becker, K.H.; Bindig, D.; Fischer-Wasels, T.; Helbing, K.; Hoffmann, R.; Klaes, J.; Kopper, S.; Naumann, U.; Obertacke, A.; Omairat, A.; Posselt, J.; Soldin, D.; Tepe, A.; Berley, D.; Blaufuss, E.; Christy, B.; Goodman, J.A.; Hellauer, R.; Hoffman, K.D.; Huelsnitz, W.; Meagher, K.; Olivas, A.; Redl, P.; Richman, M.; Schmidt, T.; Sullivan, G.W.; Wissing, H.; Bernhard, A.; Coenders, S.; Gross, A.; Leute, J.; Resconi, E.; Schulz, O.; Sestayo, Y.; Besson, D.Z.; Binder, G.; Gerhardt, L.; Ha, C.; Klein, S.R.; Miarecki, S.; Boersma, D.J.; Botner, O.; Euler, S.; Hallgren, A.; Perez de los Heros, C.; Stroem, R.; Taavola, H.; Bohm, C.; Danninger, M.; Finley, C.; Flis, S.; Hulth, P.O.; Hultqvist, K.; Walck, C.; Wolf, M.; Zoll, M.; Bose, D.; Rott, C.

2014-01-01

The IceCube Neutrino Observatory is a large Cherenkov detector instrumenting 1 km 3 of Antarctic ice. The detector can be used to search for signatures of particle physics beyond the Standard Model. Here, we describe the search for non-relativistic, magnetic monopoles as remnants of the Grand Unified Theory (GUT) era shortly after the Big Bang. Depending on the underlying gauge group these monopoles may catalyze the decay of nucleons via the Rubakov-Callan effect with a cross section suggested to be in the range of 10 -27 to 10 -21 cm 2 . In IceCube, the Cherenkov light from nucleon decays along the monopole trajectory would produce a characteristic hit pattern. This paper presents the results of an analysis of first data taken from May 2011 until May 2012 with a dedicated slow particle trigger for DeepCore, a subdetector of IceCube. A second analysis provides better sensitivity for the brightest non-relativistic monopoles using data taken from May 2009 until May 2010. In both analyses no monopole signal was observed. For catalysis cross sections of 10 -22 (10 -24 ) cm 2 the flux of non-relativistic GUT monopoles is constrained up to a level of Φ 90 ≤ 10 -18 (10 -17 ) cm -2 s -1 sr -1 at a 90 % confidence level, which is three orders of magnitude below the Parker bound. The limits assume a dominant decay of the proton into a positron and a neutral pion. These results improve the current best experimental limits by one to two orders of magnitude, for a wide range of assumed speeds and catalysis cross sections. (orig.)

Lunar radionuclide records of average solar-cosmic-ray fluxes over the last ten million years

International Nuclear Information System (INIS)

Reedy, R.C.

1980-01-01

Because changes in solar activity can modify the fluxes of cosmic-ray particles in the solar system, the nature of the galactic and solar cosmic rays and their interactions with matter are described and used to study the ancient sun. The use of cosmogenic nuclides in meteorites and lunar samples as detectors of past cosmic-ray variations are discussed. Meteorite records of the history of the galactic cosmic rays are reviewed. The fluxes of solar protons over various time periods as determined from lunar radionuclide data are presented and examined. The intensities of solar protons emitted during 1954 to 1964 (11-year solar cycle number 19) were much larger than those for 1965 to 1975 (solar cycle 20). Average solar-proton fluxes determined for the last one to ten million years from lunar 26 Al and 53 Mn data show little variation and are similar to the fluxes for recent solar cycles. Lunar activities of 14 C (and preliminary results for 81 Kr) indicate that the average fluxes of solar protons over the last 10 4 (and 10 5 ) years are several times larger than those for the last 10 6 to 10 7 years; however, cross-section measurements and other work are needed to confirm these flux variations

Properties of proton clusters in inelastic CC interactions accompanied by the production of Λ and K0 particles at p = 4.2 GeV/c per nucleon

International Nuclear Information System (INIS)

Bekmirzaev, R.N.; Shukurov, E.Kh.; Kuznetsov, A.A.; Yuldashev, B.S.

2004-01-01

Within a new relativistically invariant approach, the properties of proton clusters that are formed together with Λ and K 0 particles in inelastic CC interactions at p = 4.2 GeV/c per nucleon are investigated in the space of relative 4-velocities. The observed proton clusters are shown to be characterized by high values of the mean kinetic energy of the protons in the cluster rest frame: p > = 100 ± 2 MeV

Fourth workshop on experiments and detectors for a relativistic heavy ion collider

International Nuclear Information System (INIS)

Fatyga, M.; Moskowitz, B.

1990-01-01

This report contains papers on the following topics: physics at RHIC; flavor flow from quark-gluon plasma; space-time quark-gluon cascade; jets in relativistic heavy ion collisions; parton distributions in hard nuclear collisions; experimental working groups, two-arm electron/photon spectrometer collaboration; total and elastic pp cross sections; a 4π tracking TPC magnetic spectrometer; hadron spectroscopy; efficiency and background simulations for J/ψ detection in the RHIC dimuon experiment; the collision regions beam crossing geometries; Monte Carlo simulations of interactions and detectors; proton-nucleus interactions; the physics of strong electromagnetic fields in collisions of relativistic heavy ions; a real time expert system for experimental high energy/nuclear physics; the development of silicon multiplicity detectors; a pad readout detector for CRID/tracking; RHIC TPC R ampersand D progress and goals; development of analog memories for RHIC detector front-end electronic systems; calorimeter/absorber optimization for a RHIC dimuon experiment; construction of a highly segmented high resolution TOF system; progress report on a fast, particle-identifying trigger based on ring-imaging and highly integrated electronics for a TPC detector

Fourth workshop on experiments and detectors for a relativistic heavy ion collider

Energy Technology Data Exchange (ETDEWEB)

Fatyga, M.; Moskowitz, B. (eds.)

1990-01-01

This report contains papers on the following topics: physics at RHIC; flavor flow from quark-gluon plasma; space-time quark-gluon cascade; jets in relativistic heavy ion collisions; parton distributions in hard nuclear collisions; experimental working groups, two-arm electron/photon spectrometer collaboration; total and elastic pp cross sections; a 4{pi} tracking TPC magnetic spectrometer; hadron spectroscopy; efficiency and background simulations for J/{psi} detection in the RHIC dimuon experiment; the collision regions beam crossing geometries; Monte Carlo simulations of interactions and detectors; proton-nucleus interactions; the physics of strong electromagnetic fields in collisions of relativistic heavy ions; a real time expert system for experimental high energy/nuclear physics; the development of silicon multiplicity detectors; a pad readout detector for CRID/tracking; RHIC TPC R D progress and goals; development of analog memories for RHIC detector front-end electronic systems; calorimeter/absorber optimization for a RHIC dimuon experiment; construction of a highly segmented high resolution TOF system; progress report on a fast, particle-identifying trigger based on ring-imaging and highly integrated electronics for a TPC detector.

The relativistic virial theorem

International Nuclear Information System (INIS)

Lucha, W.; Schoeberl, F.F.

1989-11-01

The relativistic generalization of the quantum-mechanical virial theorem is derived and used to clarify the connection between the nonrelativistic and (semi-)relativistic treatment of bound states. 12 refs. (Authors)

Two Exceptions in the Large SEP Events of Solar Cycles 23 and 24

Science.gov (United States)

Thakur, N.; Gopalswamy, N.; Makela, P.; Akiyama, S.; Yashiro, S.; Xie, H.

2016-01-01

We discuss our findings from a survey of all large solar energetic particle (SEP) events of Solar Cycles 23 and 24, i.e. the SEP events where the intensity of greater than 10 megaelectronvolts protons observed by GOES (Geostationary Operational Environmental Satellite) was greater than 10 proton flux units. In our previous work (Gopalswamy et al. in Geophys.Res.Lett. 41, 2673, 2014) we suggested that ground level enhancements (GLEs) in Cycles 23 and 24 also produce an intensity increase in the GOES greater than 700 megaelectronvolts proton channel. Our survey, now extended to include all large SEP events of Cycle 23, confirms this to be true for all but two events: i) the GLE of 6 May 1998 (GLE57) for which GOES did not observe enhancement in greater than 700 megaelectronvolts protons intensities and ii) a high-energy SEP event of 8 November 2000, for which GOES observed greater than 700 megaelectronvolts protons but no GLE was recorded. Here we discuss these two exceptions. We compare GLE57 with other small GLEs, and the 8 November 2000 SEP event with those that showed similar intensity increases in the GOES greater than 700 megaelectronvolts protons but produced GLEs. We find that, because GOES greater than 700 megaelectronvolts proton intensity enhancements are typically small for small GLEs, they are difficult to discern near solar minima due to higher background. Our results also support that GLEs are generally observed when shocks of the associated coronal mass ejections (CMEs) form at heights 1.2-1.93 solar radii [R (sub solar)] and when the solar particle release occurs between 2-6 solar radii [R (sub solar)]. Our secondary findings support the view that the nose region of the CME-shock may be accelerating the first-arriving GLE particles and the observation of a GLE is also dependent on the latitudinal connectivity of the observer to the CME-shock nose. We conclude that the GOES greater than 700 megaelectronvolts proton channel can be used as an indicator

A consistent thermodynamics of the MHD wave-heated two-fluid solar wind

Directory of Open Access Journals (Sweden)

I. V. Chashei

Full Text Available We start our considerations from two more recent findings in heliospheric physics: One is the fact that the primary solar wind protons do not cool off adiabatically with distance, but appear to be heated. The other one is that secondary protons, embedded in the solar wind as pick-up ions, behave quasi-isothermal at their motion to the outer heliosphere. These two phenomena must be physically closely connected with each other. To demonstrate this we solve a coupled set of enthalpy flow conservation equations for the two-fluid solar wind system consisting of primary and secondary protons. The coupling of these equations comes by the heat sources that are relevant, namely the dissipation of MHD turbulence power to the respective protons at the relevant dissipation scales. Hereby we consider both the dissipation of convected turbulences and the dissipation of turbulences locally driven by the injection of new pick-up ions into an unstable mode of the ion distribution function. Conversion of free kinetic energy of freshly injected secondary ions into turbulence power is finally followed by partial reabsorption of this energy both by primary and secondary ions. We show solutions of simultaneous integrations of the coupled set of differential thermodynamic two-fluid equations and can draw interesting conclusions from the solutions obtained. We can show that the secondary proton temperature with increasing radial distance asymptotically attains a constant value with a magnitude essentially determined by the actual solar wind velocity. Furthermore, we study the primary proton temperature within this two-fluid context and find a polytropic behaviour with radially and latitudinally variable polytropic indices determined by the local heat sources due to dissipated turbulent wave energy. Considering latitudinally variable solar wind conditions, as published by McComas et al. (2000, we also predict latitudinal variations of primary proton temperatures at

A consistent thermodynamics of the MHD wave-heated two-fluid solar wind

Directory of Open Access Journals (Sweden)

I. V. Chashei

2003-07-01

Full Text Available We start our considerations from two more recent findings in heliospheric physics: One is the fact that the primary solar wind protons do not cool off adiabatically with distance, but appear to be heated. The other one is that secondary protons, embedded in the solar wind as pick-up ions, behave quasi-isothermal at their motion to the outer heliosphere. These two phenomena must be physically closely connected with each other. To demonstrate this we solve a coupled set of enthalpy flow conservation equations for the two-fluid solar wind system consisting of primary and secondary protons. The coupling of these equations comes by the heat sources that are relevant, namely the dissipation of MHD turbulence power to the respective protons at the relevant dissipation scales. Hereby we consider both the dissipation of convected turbulences and the dissipation of turbulences locally driven by the injection of new pick-up ions into an unstable mode of the ion distribution function. Conversion of free kinetic energy of freshly injected secondary ions into turbulence power is finally followed by partial reabsorption of this energy both by primary and secondary ions. We show solutions of simultaneous integrations of the coupled set of differential thermodynamic two-fluid equations and can draw interesting conclusions from the solutions obtained. We can show that the secondary proton temperature with increasing radial distance asymptotically attains a constant value with a magnitude essentially determined by the actual solar wind velocity. Furthermore, we study the primary proton temperature within this two-fluid context and find a polytropic behaviour with radially and latitudinally variable polytropic indices determined by the local heat sources due to dissipated turbulent wave energy. Considering latitudinally variable solar wind conditions, as published by McComas et al. (2000, we also predict latitudinal variations of primary proton temperatures at

Tailoring of silicon crystals for relativistic-particle channeling

International Nuclear Information System (INIS)

Guidi, V.; Antonini, A.; Baricordi, S.; Logallo, F.; Malagu, C.; Milan, E.; Ronzoni, A.; Stefancich, M.; Martinelli, G.; Vomiero, A.

2005-01-01

In the last years, the research on channeling of relativistic particles has progressed considerably. A significant contribution has been provided by the development of techniques for quality improvement of the crystals. In particular, a planar etching of the surfaces of the silicon crystals proved useful to remove the superficial layer, which is a region very rich in imperfections, in turn leading to greater channeling efficiency. Micro-fabrication techniques, borrowed from silicon technology, may also be useful: micro-indentation and deposition of tensile or compressive layers onto silicon samples allow one to impart an even curvature to the samples. In this way, different topologies may be envisaged, such as a bent crystal for deflection of protons and ions or an undulator to force coherent oscillations of positrons and electrons

Field theoretical approach to proton-nucleus reactions: II-Multiple-step excitation process

International Nuclear Information System (INIS)

Eiras, A.; Kodama, T.; Nemes, M.

1989-01-01

A field theoretical formulation to multiple step excitation process in proton-nucleus collision within the context of a relativistic eikonal approach is presented. A closed form expression for the double differential cross section can be obtained whose structure is very simple and makes the physics transparent. Glauber's formulation of the same process is obtained as a limit of ours and the necessary approximations are studied and discussed. (author) [pt

Covariant density functional theory for decay of deformed proton emitters: A self-consistent approach

Directory of Open Access Journals (Sweden)

L.S. Ferreira

2016-02-01

Full Text Available Proton radioactivity from deformed nuclei is described for the first time by a self-consistent calculation based on covariant relativistic density functionals derived from meson exchange and point coupling models. The calculation provides an important new test to these interactions at the limits of stability, since the mixing of different angular momenta in the single particle wave functions is probed.

June-July 1974 proton-flare region. III

International Nuclear Information System (INIS)

Bumba, V.

1982-01-01

In this third part of a series of papers describing the regularities in the magnetic field as well as solar activity development in a large portion of the solar atmosphere in which the processes related to the June-July 1974 proton-flare region formation take place, we study some characteristics of the solar wind which emanates from this portion of the solar atmosphere. It is shown that during the time when fast disintegration and disappearance of the large-scale characteristic magnetic field patterns occur and a sudden cease of sunspot, flare and coronal activity is observed, daily geomagnetic character figures C9 reach their maximum. This solar wind enhancement is taken as one of the last observable manifestations of the whole complex process. (author)

Contraint's theory and relativistic dynamics

International Nuclear Information System (INIS)

Longhi, G.; Lusanna, L.

1987-01-01

The purpose of this Workshop was to examine the current situation of relativistic dynamics. In particular, Dirac-Bergmann's theory of constraints, which lies at the heart of gauge theories, general relativity, relativistic mechanics and string theories, was chosen as the unifying theoretical framework best suited to investigate such a field. The papers discussed were on general relativity; relativistic mechanics; particle physics and mathematical physics. Also discussed were the problems of classical and quantum level, namely the identification of the classical observables of constrained systems, the equivalence of the nonequivalence of the various ways to quantize such systems; the problem of the anomalies; the best geometrical approach to the theory of constraints; the possibility of unifying all the treatments of relativistic mechanics. This book compiles the papers presented at proceedings of relativistic dynamics and constraints theory

Multiwavelength Observations of Relativistic Jets from General Relativistic Magnetohydrodynamic Simulations

Directory of Open Access Journals (Sweden)

Richard Anantua

2018-03-01

Full Text Available This work summarizes a program intended to unify three burgeoning branches of the high-energy astrophysics of relativistic jets: general relativistic magnetohydrodynamic (GRMHD simulations of ever-increasing dynamical range, the microphysical theory of particle acceleration under relativistic conditions, and multiwavelength observations resolving ever-decreasing spatiotemporal scales. The process, which involves converting simulation output into time series of images and polarization maps that can be directly compared to observations, is performed by (1 self-consistently prescribing models for emission, absorption, and particle acceleration and (2 performing time-dependent polarized radiative transfer. M87 serves as an exemplary prototype for this investigation due to its prominent and well-studied jet and the imminent prospect of learning much more from Event Horizon Telescope (EHT observations this year. Synthetic observations can be directly compared with real observations for observational signatures such as jet instabilities, collimation, relativistic beaming, and polarization. The simplest models described adopt the standard equipartition hypothesis; other models calculate emission by relating it to current density or shear. These models are intended for application to the radio jet instead of the higher frequency emission, the disk and the wind, which will be subjects of future investigations.

Three-hadron angular correlations in high-energy proton-proton and nucleus-nucleus collisions from perturbative QCD

International Nuclear Information System (INIS)

Ayala, Alejandro; Ortiz, Antonio; Paic, Guy; Jalilian-Marian, Jamal; Magnin, J.; Tejeda-Yeomans, Maria Elena

2011-01-01

We study three-hadron azimuthal angular correlations in high-energy proton-proton and central nucleus-nucleus collisions at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider at midrapidity. We use the leading-order parton matrix elements for 2→3 processes and include the effect of parton energy loss in the quark-gluon plasma using the modified fragmentation function approach. For the case when the produced hadrons have either the same or not too different momenta, we observe two away-side peaks at 2π/3 and 4π/3. We consider the dependence of the angular correlations on energy loss parameters that have been used in studies of single inclusive hadron production at RHIC. Our results on the angular dependence of the cross section agree well with preliminary data by the PHENIX Collaboration. We comment on the possible contribution of 2→3 processes to dihadron angular correlations and how a comparison of the two processes may help characterize the plasma further.

Phenomenological analysis of angular correlations in 7 TeV proton-proton collisions from the CMS experiment

International Nuclear Information System (INIS)

Ray, R. L.

2011-01-01

A phenomenological analysis is presented of recent two-particle angular correlation data on relative pseudorapidity (η) and azimuth reported by the Compact Muon Solenoid (CMS) Collaboration for √(s)=7 TeV proton-proton collisions. The data are described with an empirical jetlike model developed for similar angular correlation measurements obtained from heavy-ion collisions at the Relativistic Heavy-Ion Collider (RHIC). The sameside (small relative azimuth), η-extended correlation structure, referred to as the ridge, is compared with three phenomenological correlation structures suggested by theoretical analysis. These include additional angular correlations due to soft gluon radiation in 2→3 partonic processes, a one-dimensional sameside correlation ridge on azimuth motivated, for example, by color-glass condensate models, and an azimuth quadrupole similar to that required to describe heavy-ion angular correlations. The quadrupole model provides the best overall description of the CMS data, including the ridge, based on χ 2 minimization in agreement with previous studies. Implications of these results with respect to possible mechanisms for producing the CMS sameside correlation ridge are discussed.

An introduction to relativistic hydrodynamics

Energy Technology Data Exchange (ETDEWEB)

Font, Jose A [Departamento de AstronomIa y AstrofIsica, Universidad de Valencia, Dr. Moliner 50, 46100 Burjassot (Valencia) (Spain)

2007-11-15

We review formulations of the equations of (inviscid) general relativistic hydrodynamics and (ideal) magnetohydrodynamics, along with methods for their numerical solution. Both systems can be cast as first-order, hyperbolic systems of conservation laws, following the explicit choice of an Eulerian observer and suitable fluid and magnetic field variables. During the last fifteen years, the so-called (upwind) high-resolution shock-capturing schemes based on Riemann solvers have been successfully extended from classical to relativistic fluid dynamics, both special and general. Nowadays, general relativistic hydrodynamical simulations in relativistic astrophysics are routinely performed, particularly within the test-fluid approximation but also for dynamical spacetimes. While such advances also hold true in the case of the MHD equations, the astrophysical applications investigated so far are still limited, yet the field is bound to witness major developments in the near future. The article also presents a brief overview of numerical techniques, providing state-of-the-art examples of their applicability to general relativistic fluids and magneto-fluids in characteristic scenarios of relativistic astrophysics.

Plasma relativistic microwave electronics

International Nuclear Information System (INIS)

Kuzelev, M.V.; Loza, O.T.; Rukhadze, A.A.; Strelkov, P.S.; Shkvarunets, A.G.

2001-01-01

One formulated the principles of plasma relativistic microwave electronics based on the induced Cherenkov radiation of electromagnetic waves at interaction of a relativistic electron beam with plasma. One developed the theory of plasma relativistic generators and accelerators of microwave radiation, designed and studied the prototypes of such devices. One studied theoretically the mechanisms of radiation, calculated the efficiencies and the frequency spectra of plasma relativistic microwave generators and accelerators. The theory findings are proved by the experiment: intensity of the designed sources of microwave radiation is equal to 500 μW, the frequency of microwave radiation is increased by 7 times (from 4 up to 28 GHz), the width of radiation frequency band may vary from several up to 100%. The designed sources of microwave radiation are no else compared in the electronics [ru

Two-proton radioactivity with 2p halo in light mass nuclei A=18–34

Directory of Open Access Journals (Sweden)

G. Saxena

2017-12-01

Full Text Available Two-proton radioactivity with 2p halo is reported theoretically in light mass nuclei A=18–34. We predict 19Mg, 22Si, 26S, 30Ar and 34Ca as promising candidates of ground state 2p-radioactivity with S2p0. Observation of extended tail of spatial charge density distribution, larger charge radius and study of proton single particle states, Fermi energy and the wave functions indicate 2p halo like structure which supports direct 2p emission. The Coulomb and centrifugal barriers in experimentally identified 2p unbound 22Si show a quasi-bound state that ensures enough life time for such experimental probes. Our predictions are in good accord with experimental and other theoretical data available so far. Keywords: Relativistic mean-field theory, Nilson Strutinsky approach, Two-proton radioactivity, One- and two-proton separation energy, Halo nuclei, Proton drip-lines

A proton point source produced by laser interaction with cone-top-end target

International Nuclear Information System (INIS)

Yu, Jinqing; Jin, Xiaolin; Zhou, Weimin; Zhao, Zongqing; Yan, Yonghong; Li, Bin; Hong, Wei; Gu, Yuqiu

2012-01-01

In this paper, we propose a proton point source by the interaction of laser and cone-top-end target and investigate it by two-dimensional particle-in-cell (2D-PIC) simulations as the proton point sources are well known for higher spatial resolution of proton radiography. Our results show that the relativistic electrons are guided to the rear of the cone-top-end target by the electrostatic charge-separation field and self-generated magnetic field along the profile of the target. As a result, the peak magnitude of sheath field at the rear surface of cone-top-end target is higher compared to common cone target. We test this scheme by 2D-PIC simulation and find the result has a diameter of 0.79λ 0 , an average energy of 9.1 MeV and energy spread less than 35%.

Relativistic Quantum Mechanics

International Nuclear Information System (INIS)

Antoine, J-P

2004-01-01

The aim of relativistic quantum mechanics is to describe the finer details of the structure of atoms and molecules, where relativistic effects become nonnegligible. It is a sort of intermediate realm, between the familiar nonrelativistic quantum mechanics and fully relativistic quantum field theory, and thus it lacks the simplicity and elegance of both. Yet it is a necessary tool, mostly for quantum chemists. Pilkuhn's book offers to this audience an up-to-date survey of these methods, which is quite welcome since most previous textbooks are at least ten years old. The point of view of the author is to start immediately in the relativistic domain, following the lead of Maxwell's equations rather than classical mechanics, and thus to treat the nonrelativistic version as an approximation. Thus Chapter 1 takes off from Maxwell's equations (in the noncovariant Coulomb gauge) and gradually derives the basic aspects of Quantum Mechanics in a rather pedestrian way (states and observables, Hilbert space, operators, quantum measurement, scattering,. Chapter 2 starts with the Lorentz transformations, then continues with the Pauli spin equation and the Dirac equation and some of their applications (notably the hydrogen atom). Chapter 3 is entitled 'Quantum fields and particles', but falls short of treating quantum field theory properly: only creation/annihilation operators are considered, for a particle in a box. The emphasis is on two-electron states (the Pauli principle, the Foldy--Wouthuysen elimination of small components of Dirac spinors, Breit projection operators. Chapter 4 is devoted to scattering theory and the description of relativistic bound states. Chapter 5, finally, covers hyperfine interactions and radiative corrections. As we said above, relativistic quantum mechanics is by nature limited in scope and rather inelegant and Pilkuhn's book is no exception. The notation is often heavy (mostly noncovariant) and the mathematical level rather low. The central topic

Relativistic particle in a box

OpenAIRE

Alberto, P.; Fiolhais, Carlos; Gil, Victor

1996-01-01

The problem of a relativistic spin 1/2 particle confined to a one-dimensional box is solved in a way that resembles closely the solution of the well known quantum-mechanical textbook problem of a non-relativistic particle in a box. The energy levels and probability density are computed and compared with the non-relativistic case

Escape trajectories of solar sails and general relativity

Energy Technology Data Exchange (ETDEWEB)

Kezerashvili, Roman Ya. [Physics Department, New York City College of Technology, City University of New York, 300 Jay Street, Brooklyn, NY 11201 (United States); Graduate School and University Center, City University of New York, 365 Fifth Avenue, New York, NY 10016 (United States); Vazquez-Poritz, Justin F., E-mail: jvazquez-poritz@citytech.cuny.ed [Physics Department, New York City College of Technology, City University of New York, 300 Jay Street, Brooklyn, NY 11201 (United States); Graduate School and University Center, City University of New York, 365 Fifth Avenue, New York, NY 10016 (United States)

2009-11-16

General relativity can have a significant impact on the long-range escape trajectories of solar sails deployed near the sun. For example, spacetime curvature in the vicinity of the sun can cause a solar sail traveling from about 4 solar radii to 2550 AU to be deflected by on the order of a million kilometers, and should therefore be taken into account at the beginning of the mission. There are a number of smaller general relativistic effects, such as frame dragging due to the slow rotation of the sun which can cause a deflection of more than one thousand kilometers.

Escape trajectories of solar sails and general relativity

International Nuclear Information System (INIS)

Kezerashvili, Roman Ya.; Vazquez-Poritz, Justin F.

2009-01-01

General relativity can have a significant impact on the long-range escape trajectories of solar sails deployed near the sun. For example, spacetime curvature in the vicinity of the sun can cause a solar sail traveling from about 4 solar radii to 2550 AU to be deflected by on the order of a million kilometers, and should therefore be taken into account at the beginning of the mission. There are a number of smaller general relativistic effects, such as frame dragging due to the slow rotation of the sun which can cause a deflection of more than one thousand kilometers.

Relativistic hydrodynamics

CERN Document Server

Luciano, Rezzolla

2013-01-01

Relativistic hydrodynamics is a very successful theoretical framework to describe the dynamics of matter from scales as small as those of colliding elementary particles, up to the largest scales in the universe. This book provides an up-to-date, lively, and approachable introduction to the mathematical formalism, numerical techniques, and applications of relativistic hydrodynamics. The topic is typically covered either by very formal or by very phenomenological books, but is instead presented here in a form that will be appreciated both by students and researchers in the field. The topics covered in the book are the results of work carried out over the last 40 years, which can be found in rather technical research articles with dissimilar notations and styles. The book is not just a collection of scattered information, but a well-organized description of relativistic hydrodynamics, from the basic principles of statistical kinetic theory, down to the technical aspects of numerical methods devised for the solut...

Study of quantum spin correlations of relativistic electron pairs - Testing nonlocality of relativistic quantum mechanics

International Nuclear Information System (INIS)

Bodek, K.; Rozpędzik, D.; Zejma, J.; Caban, P.; Rembieliński, J.; Włodarczyk, M.; Ciborowski, J.; Enders, J.; Köhler, A.; Kozela, A.

2013-01-01

The Polish-German project QUEST aims at studying relativistic quantum spin correlations of the Einstein-Rosen-Podolsky-Bohm type, through measurement of the correlation function and the corresponding probabilities for relativistic electron pairs. The results will be compared to theoretical predictions obtained by us within the framework of relativistic quantum mechanics, based on assumptions regarding the form of the relativistic spin operator. Agreement or divergence will be interpreted in the context of non-uniqueness of the relativistic spin operator in quantum mechanics as well as dependence of the correlation function on the choice of observables representing the spin. Pairs of correlated electrons will originate from the Mo/ller scattering of polarized 15 MeV electrons provided by the superconducting Darmstadt electron linear accelerator S-DALINAC, TU Darmstadt, incident on a Be target. Spin projections will be determined using the Mott polarimetry technique. Measurements (starting 2013) are planned for longitudinal and transverse beam polarizations and different orientations of the beam polarization vector w.r.t. the Mo/ller scattering plane. This is the first project to study relativistic spin correlations for particles with mass

Relativistic viscoelastic fluid mechanics

International Nuclear Information System (INIS)

Fukuma, Masafumi; Sakatani, Yuho

2011-01-01

A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for the propagation of disturbance around a hydrostatic equilibrium in Minkowski space-time become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.

Relativistic viscoelastic fluid mechanics.

Science.gov (United States)

Fukuma, Masafumi; Sakatani, Yuho

2011-08-01

A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for the propagation of disturbance around a hydrostatic equilibrium in Minkowski space-time become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.

Relativistic Coulomb Fission

Science.gov (United States)

Norbury, John W.

1992-01-01

Nuclear fission reactions induced by the electromagnetic field of relativistic nuclei are studied for energies relevant to present and future relativistic heavy ion accelerators. Cross sections are calculated for U-238 and Pu-239 fission induced by C-12, Si-28, Au-197, and U-238 projectiles. It is found that some of the cross sections can exceed 10 b.

Relativistic Shock Acceleration

International Nuclear Information System (INIS)

Duffy, P.; Downes, T.P.; Gallant, Y.A.; Kirk, J.G.

1999-01-01

In this paper we briefly review the basic theory of shock waves in relativistic hydrodynamics and magneto-hydrodynamics, emphasising some astrophysically interesting cases. We then present an overview of the theory of particle acceleration at such shocks describing the methods used to calculate the spectral indices of energetic particles. Recent results on acceleration at ultra-relativistic shocks are discussed. (author)

Neutrino fluxes produced by high energy solar flare particles

International Nuclear Information System (INIS)

Kolomeets, E.V.; Shmonin, V.L.

1975-01-01

In this work the calculated differential energy spectra of neutrinos poduced by high energy protons accelerated during 'small' solar flares are presented. The muon flux produced by neutrino interactions with the matter at large depths under the ground is calculated. The obtained flux of muons for the total number of solar flare accelerated protons of 10 28 - 10 32 is within 10 9 - 10 13 particles/cm 2 X s x ster. (orig.) [de

Beam transfer functions for relativistic proton bunches with beam–beam interaction

Energy Technology Data Exchange (ETDEWEB)

Görgen, P., E-mail: goergen@temf.tu-darmstadt.de [Institut für Theorie Elektromagnetischer Felder (TEMF), Technische Universität Darmstadt, Schloßgartenstr. 8 64289 Darmstadt (Germany); Boine-Frankenheim, O. [Institut für Theorie Elektromagnetischer Felder (TEMF), Technische Universität Darmstadt, Schloßgartenstr. 8 64289 Darmstadt (Germany); Fischer, W. [Brookhaven National Laboratory, Upton, NY 11973 (United States)

2015-03-21

We present a method for the recovery of the transverse tune spread directly from the beam transfer function (BTF). The model is applicable for coasting beams and bunched beams at high energy with a tune spread from transverse nonlinearities induced by the beam–beam effect or by an electron lens. Other sources of tune spread can be added. A method for the recovery of the incoherent tune spread without prior knowledge of the nonlinearity is presented. The approach is based on the analytic model for BTFs of coasting beams, which agrees very well with simulations results for bunched beams at relativistic energies with typically low synchrotron tune. A priori the presented tune spread recovery method is usable only in the absence of coherent modes, but additional simulation data shows its applicability even in the presence of coherent beam–beam modes. Finally agreement of both the analytic and simulation models with measurement data obtained at RHIC is presented. The proposed method successfully recovers the tune spread from analytic, simulated and measured BTF.

Neutron fraction and neutrino mean free path predictions in relativistic mean field models

International Nuclear Information System (INIS)

Hutauruk, P.T.P.; Williams, C.K.; Sulaksono, A.; Mart, T.

2004-01-01

The equation of state (EOS) of dense matter and neutrino mean free path (NMFP) in a neutron star have been studied by using relativistic mean field models motivated by effective field theory. It is found that the models predict too large proton fractions, although one of the models (G2) predicts an acceptable EOS. This is caused by the isovector terms. Except G2, the other two models predict anomalous NMFP's. In order to minimize the anomaly, besides an acceptable EOS, a large M* is favorable. A model with large M* retains the regularity in the NMFP even for a small neutron fraction

Relativistic mean field theory with density dependent coupling constants for nuclear matter and finite nuclei with large charge asymmetry

Energy Technology Data Exchange (ETDEWEB)

Typel, S; Wolter, H H [Sektion Physik, Univ. Muenchen, Garching (Germany)

1998-06-01

Nuclear matter and ground state properties for (proton and neutron) semi-closed shell nuclei are described in relativistic mean field theory with coupling constants which depend on the vector density. The parametrization of the density dependence for {sigma}-, {omega}- and {rho}-mesons is obtained by fitting to properties of nuclear matter and some finite nuclei. The equation of state for symmetric and asymmetric nuclear matter is discussed. Finite nuclei are described in Hartree approximation, including a charge and an improved center-of-mass correction. Pairing is considered in the BCS approximation. Special attention is directed to the predictions for properties at the neutron and proton driplines, e.g. for separation energies, spin-orbit splittings and density distributions. (orig.)

Solar wind modulation of the Martian ionosphere observed by Mars Global Surveyor

Directory of Open Access Journals (Sweden)

J.-S. Wang

2004-06-01

Full Text Available Electron density profiles in the Martian ionosphere observed by the radio occultation experiment on board Mars Global Surveyor have been analyzed to determine if the densities are influenced by the solar wind. Evidence is presented that the altitude of the maximum ionospheric electron density shows a positive correlation to the energetic proton flux in the solar wind. The solar wind modulation of the Martian ionosphere can be attributed to heating of the neutral atmosphere by the solar wind energetic proton precipitation. The modulation is observed to be most prominent at high solar zenith angles. It is argued that this is consistent with the proposed modulation mechanism.

Proton spin tracking with symplectic integration of orbit motion

Energy Technology Data Exchange (ETDEWEB)

Luo, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Dutheil, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2015-05-03

Symplectic integration had been adopted for orbital motion tracking in code SimTrack. SimTrack has been extensively used for dynamic aperture calculation with beam-beam interaction for the Relativistic Heavy Ion Collider (RHIC). Recently proton spin tracking has been implemented on top of symplectic orbital motion in this code. In this article, we will explain the implementation of spin motion based on Thomas-BMT equation, and the benchmarking with other spin tracking codes currently used for RHIC. Examples to calculate spin closed orbit and spin tunes are presented too.

Search for non-relativistic magnetic monopoles with IceCube

Energy Technology Data Exchange (ETDEWEB)

Aartsen, M.G.; Hill, G.C.; Robertson, S.; Whelan, B.J. [University of Adelaide, School of Chemistry and Physics, Adelaide, SA (Australia); Abbasi, R.; Ahlers, M.; Arguelles, C.; Baker, M.; BenZvi, S.; Chirkin, D.; Day, M.; Desiati, P.; Diaz-Velez, J.C.; Eisch, J.; Fadiran, O.; Feintzeig, J.; Gladstone, L.; Halzen, F.; Hoshina, K.; Jacobsen, J.; Jero, K.; Karle, A.; Kauer, M.; Kelley, J.L.; Kopper, C.; Krasberg, M.; Kurahashi, N.; Landsman, H.; Maruyama, R.; McNally, F.; Merck, M.; Morse, R.; Riedel, B.; Rodrigues, J.P.; Santander, M.; Tobin, M.N.; Toscano, S.; Van Santen, J.; Weaver, C.; Wellons, M.; Wendt, C.; Westerhoff, S.; Whitehorn, N. [University of Wisconsin, Department of Physics and Wisconsin IceCube Particle Astrophysics Center, Madison, WI (United States); Ackermann, M.; Benabderrahmane, M.L.; Berghaus, P.; Bernardini, E.; Bretz, H.P.; Cruz Silva, A.H.; Gluesenkamp, T.; Jacobi, E.; Kaminsky, B.; Karg, T.; Middell, E.; Mohrmann, L.; Nahnhauer, R.; Schoenwald, A.; Shanidze, R.; Spiering, C.; Stoessl, A.; Yanez, J.P. [DESY, Zeuthen (Germany); Adams, J.; Brown, A.M.; Hickford, S.; Macias, O. [University of Canterbury, Department of Physics and Astronomy, Private Bag 4800, Christchurch (New Zealand); Aguilar, J.A.; Christov, A.; Montaruli, T.; Rameez, M.; Vallecorsa, S. [Universite de Geneve, Departement de physique nucleaire et corpusculaire, Geneva (Switzerland); Altmann, D.; Classen, L.; Gora, D.; Kappes, A.; Tselengidou, M. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erlangen (Germany); Arlen, T.C.; De Andre, J.P.A.M.; DeYoung, T.; Dunkman, M.; Eagan, R.; Groh, J.C.; Huang, F.; Quinnan, M.; Smith, M.W.E.; Stanisha, N.A.; Tesic, G. [Pennsylvania State University, Department of Physics, University Park, PA (United States); Auffenberg, J.; Bissok, M.; Blumenthal, J.; Gretskov, P.; Haack, C.; Hallen, P.; Heinen, D.; Jagielski, K.; Kriesten, A.; Krings, K.; Leuermann, M.; Paul, L.; Raedel, L.; Reimann, R.; Schoenen, S.; Schukraft, A.; Vehring, M.; Wallraff, M.; Wiebusch, C.H.; Zierke, S. [RWTH Aachen University, III. Physikalisches Institut, Aachen (Germany); Bai, X.; Evenson, P.A.; Gaisser, T.K.; Gonzalez, J.G.; Hussain, S.; Kuwabara, T.; Ruzybayev, B.; Seckel, D.; Stanev, T.; Tamburro, A.; Tilav, S. [University of Delaware, Bartol Research Institute and Department of Physics and Astronomy, Newark, DE (United States); Barwick, S.W.; Yodh, G. [University of California, Department of Physics and Astronomy, Irvine, CA (United States); Baum, V.; Eberhardt, B.; Koepke, L.; Kroll, G.; Luenemann, J.; Sander, H.G.; Schatto, K.; Wiebe, K. [University of Mainz, Institute of Physics, Mainz (Germany); Bay, R.; Filimonov, K.; Price, P.B.; Woschnagg, K. [University of California, Department of Physics, Berkeley, CA (United States); Beatty, J.J. [Ohio State University, Department of Physics and Center for Cosmology and Astro-Particle Physics, Columbus, OH (United States); Ohio State University, Department of Astronomy, Columbus, OH (United States); Becker Tjus, J.; Eichmann, B.; Fedynitch, A.; Saba, S.M.; Schoeneberg, S.; Unger, E. [Ruhr-Universitaet Bochum, Fakultaet fuer Physik and Astronomie, Bochum (Germany); Becker, K.H.; Bindig, D.; Fischer-Wasels, T.; Helbing, K.; Hoffmann, R.; Klaes, J.; Kopper, S.; Naumann, U.; Obertacke, A.; Omairat, A.; Posselt, J.; Soldin, D.; Tepe, A. [University of Wuppertal, Department of Physics, Wuppertal (Germany); Berley, D.; Blaufuss, E.; Christy, B.; Goodman, J.A.; Hellauer, R.; Hoffman, K.D.; Huelsnitz, W.; Meagher, K.; Olivas, A.; Redl, P.; Richman, M.; Schmidt, T.; Sullivan, G.W.; Wissing, H. [University of Maryland, Department of Physics, College Park, MD (United States); Bernhard, A.; Coenders, S.; Gross, A.; Leute, J.; Resconi, E.; Schulz, O.; Sestayo, Y. [T.U. Munich, Garching (Germany); Besson, D.Z. [University of Kansas, Department of Physics and Astronomy, Lawrence, KS (United States); Binder, G.; Gerhardt, L.; Ha, C.; Klein, S.R.; Miarecki, S. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Boersma, D.J.; Botner, O.; Euler, S.; Hallgren, A.; Perez de los Heros, C.; Stroem, R.; Taavola, H. [Uppsala University, Department of Physics and Astronomy, Box 516, Uppsala (Sweden); Bohm, C.; Danninger, M.; Finley, C.; Flis, S.; Hulth, P.O.; Hultqvist, K.; Walck, C.; Wolf, M.; Zoll, M. [Stockholm University, Oskar Klein Centre and Department of Physics, Stockholm (Sweden); Bose, D.; Rott, C. [Sungkyunkwan University, Department of Physics, Suwon (Korea, Republic of); Collaboration: IceCube Collaboration; and others

2014-07-15

The IceCube Neutrino Observatory is a large Cherenkov detector instrumenting 1 km{sup 3} of Antarctic ice. The detector can be used to search for signatures of particle physics beyond the Standard Model. Here, we describe the search for non-relativistic, magnetic monopoles as remnants of the Grand Unified Theory (GUT) era shortly after the Big Bang. Depending on the underlying gauge group these monopoles may catalyze the decay of nucleons via the Rubakov-Callan effect with a cross section suggested to be in the range of 10{sup -27} to 10{sup -21} cm{sup 2}. In IceCube, the Cherenkov light from nucleon decays along the monopole trajectory would produce a characteristic hit pattern. This paper presents the results of an analysis of first data taken from May 2011 until May 2012 with a dedicated slow particle trigger for DeepCore, a subdetector of IceCube. A second analysis provides better sensitivity for the brightest non-relativistic monopoles using data taken from May 2009 until May 2010. In both analyses no monopole signal was observed. For catalysis cross sections of 10{sup -22} (10{sup -24}) cm{sup 2} the flux of non-relativistic GUT monopoles is constrained up to a level of Φ{sub 90} ≤ 10{sup -18} (10{sup -17}) cm{sup -2} s{sup -1} sr{sup -1} at a 90 % confidence level, which is three orders of magnitude below the Parker bound. The limits assume a dominant decay of the proton into a positron and a neutral pion. These results improve the current best experimental limits by one to two orders of magnitude, for a wide range of assumed speeds and catalysis cross sections. (orig.)

Weakest solar wind of the space age and the current 'MINI' solar maximum

International Nuclear Information System (INIS)

McComas, D. J.; Angold, N.; Elliott, H. A.; Livadiotis, G.; Schwadron, N. A.; Smith, C. W.; Skoug, R. M.

2013-01-01

The last solar minimum, which extended into 2009, was especially deep and prolonged. Since then, sunspot activity has gone through a very small peak while the heliospheric current sheet achieved large tilt angles similar to prior solar maxima. The solar wind fluid properties and interplanetary magnetic field (IMF) have declined through the prolonged solar minimum and continued to be low through the current mini solar maximum. Compared to values typically observed from the mid-1970s through the mid-1990s, the following proton parameters are lower on average from 2009 through day 79 of 2013: solar wind speed and beta (∼11%), temperature (∼40%), thermal pressure (∼55%), mass flux (∼34%), momentum flux or dynamic pressure (∼41%), energy flux (∼48%), IMF magnitude (∼31%), and radial component of the IMF (∼38%). These results have important implications for the solar wind's interaction with planetary magnetospheres and the heliosphere's interaction with the local interstellar medium, with the proton dynamic pressure remaining near the lowest values observed in the space age: ∼1.4 nPa, compared to ∼2.4 nPa typically observed from the mid-1970s through the mid-1990s. The combination of lower magnetic flux emergence from the Sun (carried out in the solar wind as the IMF) and associated low power in the solar wind points to the causal relationship between them. Our results indicate that the low solar wind output is driven by an internal trend in the Sun that is longer than the ∼11 yr solar cycle, and they suggest that this current weak solar maximum is driven by the same trend.

Relativistic impulse dynamics.

Science.gov (United States)

Swanson, Stanley M

2011-08-01

Classical electrodynamics has some annoying rough edges. The self-energy of charges is infinite without a cutoff. The calculation of relativistic trajectories is difficult because of retardation and an average radiation reaction term. By reconceptuallizing electrodynamics in terms of exchanges of impulses rather than describing it by forces and potentials, we eliminate these problems. A fully relativistic theory using photonlike null impulses is developed. Numerical calculations for a two-body, one-impulse-in-transit model are discussed. A simple relationship between center-of-mass scattering angle and angular momentum was found. It reproduces the Rutherford cross section at low velocities and agrees with the leading term of relativistic distinguishable-particle quantum cross sections (Møller, Mott) when the distance of closest approach is larger than the Compton wavelength of the particle. Magnetism emerges as a consequence of viewing retarded and advanced interactions from the vantage point of an instantaneous radius vector. Radiation reaction becomes the local conservation of energy-momentum between the radiating particle and the emitted impulse. A net action is defined that could be used in developing quantum dynamics without potentials. A reinterpretation of Newton's laws extends them to relativistic motion.

Relativistic Few-Body Hadronic Physics Calculations

Energy Technology Data Exchange (ETDEWEB)

Polyzou, Wayne [Univ. of Iowa, Iowa City, IA (United States)

2016-06-20

The goal of this research proposal was to use ``few-body'' methods to understand the structure and reactions of systems of interacting hadrons (neutrons, protons, mesons, quarks) over a broad range of energy scales. Realistic mathematical models of few-hadron systems have the advantage that they are sufficiently simple that they can be solved with mathematically controlled errors. These systems are also simple enough that it is possible to perform complete accurate experimental measurements on these systems. Comparison between theory and experiment puts strong constraints on the structure of the models. Even though these systems are ``simple'', both the experiments and computations push the limits of technology. The important property of ``few-body'' systems is that the ``cluster property'' implies that the interactions that appear in few-body systems are identical to the interactions that appear in complicated many-body systems. Of particular interest are models that correctly describe physics at distance scales that are sensitive to the internal structure of the individual nucleons. The Heisenberg uncertainty principle implies that in order to be sensitive to physics on distance scales that are a fraction of the proton or neutron radius, a relativistic treatment of quantum mechanics is necessary. The research supported by this grant involved 30 years of effort devoted to studying all aspects of interacting two and three-body systems. Realistic interactions were used to compute bound states of two- and three-nucleon, and two- and three-quark systems. Scattering observables for these systems were computed for a broad range of energies - from zero energy scattering to few GeV scattering, where experimental evidence of sub-nucleon degrees of freedom is beginning to appear. Benchmark calculations were produced, which when compared with calculations of other groups provided an essential check on these complicated calculations. In

Centrality dependence of low-\\p_{T} and high-p_{T} particle production in proton--lead collisions with ATLAS.

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00287239; The ATLAS collaboration

2015-01-01

Measurements of the centrality dependence of low-p_{T} and high-p_{T} particle production in proton-lead collisions at the LHC can provide unique insight into the dynamics of soft and hard scattering processes and the initial state of ultra-relativistic nuclear collisions. Recent results have shown that both soft and hard processes may be significantly influenced by event-to-event fluctuations (variations) in the structure of the proton. In this proceedings, the latest measurements of the centrality dependence of charged particle, and Z boson production with the ATLAS detector at the LHC are used to explore these questions. In particular, the sensitivity of the charged particle pseudorapidity distribution in proton--lead collisions to the choice of centrality variable is discussed. Separately, to address recent measurements of the correlation between the initial-state hard scattering kinematics in dijet events and forward transverse energy in proton-proton collisions will be presented.

Helium abundance and speed difference between helium ions and protons in the solar wind from coronal holes, active regions, and quiet Sun

Science.gov (United States)

Fu, Hui; Madjarska, M. S.; Li, Bo; Xia, LiDong; Huang, ZhengHua

2018-05-01

Two main models have been developed to explain the mechanisms of release, heating and acceleration of the nascent solar wind, the wave-turbulence-driven (WTD) models and reconnection-loop-opening (RLO) models, in which the plasma release processes are fundamentally different. Given that the statistical observational properties of helium ions produced in magnetically diverse solar regions could provide valuable information for the solar wind modelling, we examine the statistical properties of the helium abundance (AHe) and the speed difference between helium ions and protons (vαp) for coronal holes (CHs), active regions (ARs) and the quiet Sun (QS). We find bimodal distributions in the space of AHeand vαp/vA(where vA is the local Alfvén speed) for the solar wind as a whole. The CH wind measurements are concentrated at higher AHeand vαp/vAvalues with a smaller AHedistribution range, while the AR and QS wind is associated with lower AHeand vαp/vA, and a larger AHedistribution range. The magnetic diversity of the source regions and the physical processes related to it are possibly responsible for the different properties of AHeand vαp/vA. The statistical results suggest that the two solar wind generation mechanisms, WTD and RLO, work in parallel in all solar wind source regions. In CH regions WTD plays a major role, whereas the RLO mechanism is more important in AR and QS.

The ionisation loss of relativistic charged particles in thin gas samples and its use for particle identification. I

International Nuclear Information System (INIS)

Cobb, J.H.; Allison, W.W.M.; Bunch, J.N.

1976-01-01

A brief review shows a significant discrepancy between available data and theoretical predictions on the ionisation loss of charged particles in thin gas-filled proportional counters. The discrepancy related both to the increase of the most probable loss at relativistic velocities (relativistic rise) and to the spectrum of such losses at a given velocity (the Landau distribution). The origin of this relativistic rise is discussed in simple terms and related to the phenomena of transition radiation and Cherenkov radiation. It is shown that the failure of the prediction is due to the small number of ionising collisions in a gas. This problem is overcome by using a Monte Carlo method rather than a continuous integral over the spectrum of single collision processes. A specific mode of the atomic form factors is used with a modified Born approximation to yield the differential cross sections needed for the calculation. The new predictions give improved agreement with experiment and are used to investigate the problem of identifying particles of known momenta in the relativistic region. It is shown that by measuring the ionisation loss of each particle several hundred times over 5m or more, kaon, pion and proton separation with good confidence level may be achieved. Many gases are considered and a comparison is made. The results are also compared with the velocity resolution achievable by measuring primary ionisation. (Auth.)

The two-proton shell gap in Sn isotopes

International Nuclear Information System (INIS)

Fleischer, P.; Kluepfel, P.; Reinhard, P.-G.; Cornelius, T.; Schramm, S.; Maruhn, J.A.; Buervenich, T.J.

2004-01-01

We present an analysis of two-proton shell gaps in Sn isotopes. As theoretical tool we use self-consistent mean-field models, namely the relativistic mean-field model and the Skyrme-Hartree-Fock approach, both with two different pairing forces, a delta interaction (DI) model and a density-dependent delta interaction (DDDI). We investigate the influence of nuclear deformation as well as collective correlations and find that both effects contribute significantly. Moreover, we find a further significant dependence on the pairing force used. The inclusion of deformation plus correlation effects and the use of DDDI pairing provides agreement with the data. (orig.)

Scattering in relativistic particle mechanics

International Nuclear Information System (INIS)

De Bievre, S.

1986-01-01

The problem of direct interaction in relativistic particle mechanics has been extensively studied and a variety of models has been proposed avoiding the conclusions of the so-called no-interaction theorems. In this thesis the authors studied scattering in the relativistic two-body problem. He uses the results to analyze gauge invariance in Hamiltonian constraint models and the uniqueness of the symplectic structure in manifestly covariant relativistic particle mechanics. A general geometric framework that underlies approaches to relativistic particle mechanics is presented and the kinematic properties of the scattering transformation, i.e., those properties that arise solely from the invariance of the theory under the Poincare group are studied. The second part of the analysis of the relativistic two-body scattering problem is devoted to the dynamical properties of the scattering process. Using general geometric arguments, gauge invariance of the scattering transformation in the Todorov-Komar Hamiltonian constraint model is proved. Finally, quantization of the models is discussed

Electron, proton, neutron as spheroidical particles

International Nuclear Information System (INIS)

Bagge, E.R.

1993-01-01

It is shown that it is possible to describe the electron and the proton at rest within the framework of Dirac's relativistic theory of particles as electro-magnetic stable, spheroidal particles like balloons with very thin envelopes. Their properties, especially their spins and their magnetic momenta, are exactly those, which have been measured at first and later on derived by Dirac. In this picture the neutron plays the role of a system of two concentric and synchronically rotating balloons with a small distance between them at a positive energetic minimum of balance at 1.26 MeV. The magnetic moment of this particle has a negative sign and is of the correct size. (orig.)

Structure of proton-rich nuclei of astrophysical interest

Energy Technology Data Exchange (ETDEWEB)

Roeckl, E [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany)

1998-06-01

Recent experimental data concerning proton-rich nuclei between A=20 and A=100 are presented and discussed with respect to their relevance to the astrophysical rp process and to the calibration of solar neutrino detectors. (orig.)

Solar wind heating by an embedded quasi-isothermal pick-up ion fluid

Directory of Open Access Journals (Sweden)

H. J. Fahr

Full Text Available It is well known that the solar wind plasma consists of primary ions of solar coronal origin and secondary ions of interstellar origin. Interstellar H-atoms penetrate into the inner heliosphere and when ionized there are converted into secondary ions. These are implanted into the magnetized solar wind flow and are essentially enforced to co-move with this flow. By nonlinear interactions with wind-entrained Alfvén waves the latter are processed in the co-moving velocity space. This pick-up process, however, also causes actions back upon the original solar wind flow, leading to a deceleration, as well as a heating of the solar wind plasma. The resulting deceleration is not only due to the loading effect, but also due to the action of the pressure gradient. To calculate the latter, it is important to take into account the stochastic acceleration that suffers at their convection out of the inner heliosphere by the quasi-linear interactions with MHD turbulences. Only then can the presently reported VOYAGER observations of solar wind decelerations and heatings in the outer heliosphere be understood in terms of the current, most likely values of interstellar gas parameters. In a consistent view of the thermodynamics of the solar wind plasma, which is composed of secondary ions and solar wind protons, we also derive that the latter are globally heated at their motion to larger solar distances. The arising heat transfer is due to the action of suprathermal ions which drive MHD waves that are partially absorbed by solar wind protons and thereby establish their observed quasi-polytropy. We obtain a quantitative expression for the solar wind proton pressure as a function of solar distance. This expression clearly shows the change from an adiabatic to a quasi-polytropic behaviour with a decreasing polytropic index at increasing distances, as has been observed by the VOYAGERS. This also allows one to calculate the average percentage of the intitial energy

Solar wind heating by an embedded quasi-isothermal pick-up ion fluid

Directory of Open Access Journals (Sweden)

H. J. Fahr

2002-10-01

Full Text Available It is well known that the solar wind plasma consists of primary ions of solar coronal origin and secondary ions of interstellar origin. Interstellar H-atoms penetrate into the inner heliosphere and when ionized there are converted into secondary ions. These are implanted into the magnetized solar wind flow and are essentially enforced to co-move with this flow. By nonlinear interactions with wind-entrained Alfvén waves the latter are processed in the co-moving velocity space. This pick-up process, however, also causes actions back upon the original solar wind flow, leading to a deceleration, as well as a heating of the solar wind plasma. The resulting deceleration is not only due to the loading effect, but also due to the action of the pressure gradient. To calculate the latter, it is important to take into account the stochastic acceleration that suffers at their convection out of the inner heliosphere by the quasi-linear interactions with MHD turbulences. Only then can the presently reported VOYAGER observations of solar wind decelerations and heatings in the outer heliosphere be understood in terms of the current, most likely values of interstellar gas parameters. In a consistent view of the thermodynamics of the solar wind plasma, which is composed of secondary ions and solar wind protons, we also derive that the latter are globally heated at their motion to larger solar distances. The arising heat transfer is due to the action of suprathermal ions which drive MHD waves that are partially absorbed by solar wind protons and thereby establish their observed quasi-polytropy. We obtain a quantitative expression for the solar wind proton pressure as a function of solar distance. This expression clearly shows the change from an adiabatic to a quasi-polytropic behaviour with a decreasing polytropic index at increasing distances, as has been observed by the VOYAGERS. This also allows one to calculate the average percentage of the intitial energy

Relativistic description of atomic nuclei

International Nuclear Information System (INIS)

Krutov, V.A.

1985-01-01

Papers on the relativistic description of nuclei are reviewed. The Brown and Rho ''small'' bag'' model is accepted for hardrons. Meson exchange potentials of the nucleon-nucleon interaction have been considered. Then the transition from a system of two interacting nucleons has been performed to the relativistic nucleus description as a multinucleon system on the basis of OBEP (one-boson exchange potential). The proboem of OPEP (one-pion-exchange potential) inclusion to a relativistic scheme is discussed. Simplicity of calculations and attractiveness of the Walecka model for specific computations and calculations was noted. The relativistic model of nucleons interacting through ''effective'' scalar and vector boson fields was used in the Walacka model for describing neutronaand nuclear mater matters

Effect of deformation on structure and reaction of Al isotopes using relativistic mean field densities in Glauber model

Science.gov (United States)

Panda, R. N.; Sharma, Mahesh K.; Panigrahi, M.; Patra, S. K.

2018-06-01

We have examined the ground state properties of Al isotopes towards the proton rich side from A = 22 to 28 using the well known relativistic mean field (RMF) formalism with NLSH parameter set. The calculated results are compared with the predictions of finite range droplet model and experimental data. The calculation is extended to estimate the reaction cross section for ^{22-28}Al as projectiles with ^{12}C as target. The incident energy of the projectiles are taken as 950 MeV/nucleon, for both spherical and deformed RMF densities as inputs in the Glauber model approximation. Further investigation of enhanced values of total reaction cross section for ^{23}Al and ^{24}Al in comparison to rest of the isotopes indicates the proton skin structure of these isotopes. Specifically, the large value of root mean square radius and total reaction cross section of ^{23}Al could not be ruled out the formation of proton halo.

Proton beam generation of whistler waves in the earth's foreshock

Science.gov (United States)

Wong, H. K.; Goldstein, M. L.

1987-01-01

It is shown that proton beams, often observed upstream of the earth's bow shock and associated with the generation of low-frequency hydromagnetic fluctuations, are also capable of generating whistler waves. The waves can be excited by an instability driven by two-temperature streaming Maxwellian proton distributions which have T (perpendicular)/T(parallel) much greater than 1. It can also be excited by gyrating proton beam distributions. These distributions generate whistler waves with frequencies ranging from 10 to 100 times the proton cyclotron frequency (in the solar wind reference frame) and provide another mechanism for generating the '1-Hz' waves often seen in the earth's foreshock.

Proton beam generation of whistler waves in the Earth's foreshock

International Nuclear Information System (INIS)

Wong, H.K.; Goldstein, M.L.

1987-01-01

We show that proton beams, often observed upstream of the Earth's bow shock and associated with the generation of low-frequency hydromagnetic fluctuations, are also capable of generating whistler waves. The waves can be excited by an instability driven by two-temperature streaming Maxwellian proton distributions which have T/sub perpendicular//T/sub parallel/>>1. It can also be excited by gyrating proton beam distributions. These distributions generate whistler waves with frequencies ranging from 10 to 100 times the proton cyclotron frequency (in the solar wind reference frame) and provide another mechanism for generating the ''1-Hz'' waves often seen in the Earth's foreshock

Relativistic mean field theory for deformed nuclei with pairing correlations

International Nuclear Information System (INIS)

Geng, Lisheng; Toki, Hiroshi; Sugimoto, Satoru; Meng, Jie

2003-01-01

We develop a relativistic mean field (RMF) description of deformed nuclei with pairing correlations in the BCS approximation. The treatment of the pairing correlations for nuclei whose Fermi surfaces are close to the threshold of unbound states needs special attention. With this in mind, we use a delta function interaction for the pairing interaction to pick up those states whose wave functions are concentrated in the nuclear region and employ the standard BCS approximation for the single-particle states obtained from the BMF theory with deformation. We apply the RMF + BCS method to the Zr isotopes and obtain a good description of the binding energies and the nuclear radii of nuclei from the proton drip line to the neutron drip line. (author)

Inclusive jet production in ultrarelativistic proton-nucleus collisions

CERN Document Server

Perepelitsa, Dennis

High-$p_\\mathrm{T}$ processes in proton- and deuteron-nucleus collisions at TeV energies are the best presently available way to study the partonic structure of the nucleus in a high-density regime. Jet production over a wide range of phase space can significantly constrain the current knowledge of nuclear parton distribution functions (nPDFs), which are substantially less well understood than the corresponding PDFs in protons and which have only recently begun to be treated in a spatially-dependent way. An accurate knowledge of nPDFs is crucial for a definitive control of perturbative processes in a cold nuclear environment, since high-$p_\\mathrm{T}$ probes are used to quantitatively investigate the hot QCD matter created in ultrarelativistic nucleus-nucleus collisions. Furthermore, jets from low Bjorken-$x$ partons can probe the transition from the dilute to saturated nuclear regimes. Jet production is investigated in $d$+Au collisions at $\\sqrt{s} = 200$ GeV with the PHENIX detector at the Relativistic Hea...

Baseline measures for net-proton distributions in high energy heavy-ion collisions

International Nuclear Information System (INIS)

Netrakanti, P.K.; Mishra, D.K.; Mohanty, A.K.; Mohanty, B.

2014-01-01

The STAR experiment at the Relativistic Heavy-Ion Collider facility has reported results for the cumulants and their ratios from the net-proton distributions upto the fourth order cumulants at various collision energies. These measurements were carried to look for the signatures of the possible critical point (CP) in the phase diagram for a system undertaking strong interactions. The results show an intriguing dependence of the cumulant ratios C 3 /C 2 and C 4 /C 2 as a function of beam energy. The beam energy dependence appears to be non-monotonic in nature. However the experiment also reports that the energy dependence is observed to be consistent with expectation from an approach based on the independent production of proton and anti-protons in the collisions. In this paper we emphasize the need to have a proper baseline for appropriate interpretation of the cumulant measurements and argue that the comparison to independent production approach needs to be done with extreme caution

Testing relativity with solar system dynamics

Science.gov (United States)

Hellings, R. W.

1984-01-01

A major breakthrough is described in the accuracy of Solar System dynamical tests of relativistic gravity. The breakthrough was achieved by factoring in ranging data from Viking Landers 1 and 2 from the surface of Mars. Other key data sources included optical transit circle observations, lunar laser ranging, planetary radar, and spacecraft (Mariner 9 to Mars and Mariner 10 to Mercury). The Solar System model which is used to fit the data and the process by which such fits are performed are explained and results are discussed. The results are fully consistent with the predictions of General Relativity.

Relativistic Jahn-Teller effect in tetrahedral systems

International Nuclear Information System (INIS)

Opalka, Daniel; Domcke, Wolfgang; Segado, Mireia; Poluyanov, Leonid V.

2010-01-01

It is shown that orbitally degenerate states in highly symmetric systems are split by Jahn-Teller forces which are of relativistic origin (that is, they arise from the spin-orbit coupling operator). For the example of tetrahedral systems, the relativistic Jahn-Teller Hamiltonians of orbitally degenerate electronic states with spin 1/2 are derived. While both electrostatic and relativistic forces contribute to the Jahn-Teller activity of vibrational modes of E and T 2 symmetry in 2 T 2 states of tetrahedral systems, the electrostatic and relativistic Jahn-Teller couplings are complementary for 2 E states: The E mode is Jahn-Teller active through electrostatic forces, while the T 2 mode is Jahn-Teller active through the relativistic forces. The relativistic Jahn-Teller parameters have been computed with ab initio relativistic electronic-structure methods. It is shown for the example of the tetrahedral cluster cations of the group V elements that the relativistic Jahn-Teller couplings can be of the same order of magnitude as the familiar electrostatic Jahn-Teller couplings for the heavier elements.

The relativistic rocket

Energy Technology Data Exchange (ETDEWEB)

Antippa, Adel F [Departement de Physique, Universite du Quebec a Trois-Rivieres, Trois-Rivieres, Quebec G9A 5H7 (Canada)

2009-05-15

We solve the problem of the relativistic rocket by making use of the relation between Lorentzian and Galilean velocities, as well as the laws of superposition of successive collinear Lorentz boosts in the limit of infinitesimal boosts. The solution is conceptually simple, and technically straightforward, and provides an example of a powerful method that can be applied to a wide range of special relativistic problems of linear acceleration.

Relativistic length agony continued

Directory of Open Access Journals (Sweden)

Redžić D.V.

2014-01-01

Full Text Available We made an attempt to remedy recent confusing treatments of some basic relativistic concepts and results. Following the argument presented in an earlier paper (Redžić 2008b, we discussed the misconceptions that are recurrent points in the literature devoted to teaching relativity such as: there is no change in the object in Special Relativity, illusory character of relativistic length contraction, stresses and strains induced by Lorentz contraction, and related issues. We gave several examples of the traps of everyday language that lurk in Special Relativity. To remove a possible conceptual and terminological muddle, we made a distinction between the relativistic length reduction and relativistic FitzGerald-Lorentz contraction, corresponding to a passive and an active aspect of length contraction, respectively; we pointed out that both aspects have fundamental dynamical contents. As an illustration of our considerations, we discussed briefly the Dewan-Beran-Bell spaceship paradox and the ‘pole in a barn’ paradox. [Projekat Ministarstva nauke Republike Srbije, br. 171028

Leading order relativistic chiral nucleon-nucleon interaction

Science.gov (United States)

Ren, Xiu-Lei; Li, Kai-Wen; Geng, Li-Sheng; Long, Bingwei; Ring, Peter; Meng, Jie

2018-01-01

Motivated by the successes of relativistic theories in studies of atomic/molecular and nuclear systems and the need for a relativistic chiral force in relativistic nuclear structure studies, we explore a new relativistic scheme to construct the nucleon-nucleon interaction in the framework of covariant chiral effective field theory. The chiral interaction is formulated up to leading order with covariant power counting and a Lorentz invariant chiral Lagrangian. We find that the relativistic scheme induces all six spin operators needed to describe the nuclear force. A detailed investigation of the partial wave potentials shows a better description of the {}1S0 and {}3P0 phase shifts than the leading order Weinberg approach, and similar to that of the next-to-leading order Weinberg approach. For the other partial waves with angular momenta J≥slant 1, the relativistic results are almost the same as their leading order non-relativistic counterparts. )

RANKINE-HUGONIOT RELATIONS IN RELATIVISTIC COMBUSTION WAVES

International Nuclear Information System (INIS)

Gao Yang; Law, Chung K.

2012-01-01

As a foundational element describing relativistic reacting waves of relevance to astrophysical phenomena, the Rankine-Hugoniot relations classifying the various propagation modes of detonation and deflagration are analyzed in the relativistic regime, with the results properly degenerating to the non-relativistic and highly relativistic limits. The existence of negative-pressure downstream flows is noted for relativistic shocks, which could be of interest in the understanding of the nature of dark energy. Entropy analysis for relativistic shock waves is also performed for relativistic fluids with different equations of state (EoS), denoting the existence of rarefaction shocks in fluids with adiabatic index Γ < 1 in their EoS. The analysis further shows that weak detonations and strong deflagrations, which are rare phenomena in terrestrial environments, are expected to exist more commonly in astrophysical systems because of the various endothermic reactions present therein. Additional topics of relevance to astrophysical phenomena are also discussed.

Solar Flares and the High Energy Solar Spectroscopic Imager (HESSI)

Science.gov (United States)

Holman, Gordon D.; Fisher, Richard R. (Technical Monitor)

2001-01-01

Solar flares are the biggest explosions in the solar system. They are important both for understanding explosive events in the Universe and for their impact on human technology and communications. The satellite-based HESSI is designed to study the explosive release of energy and the acceleration of electrons, protons, and other charged particles to high energies in solar flares. HESSI produces "color" movies of the Sun in high-energy X rays and gamma rays radiated by these energetic particles. HESSI's X-ray and gamma-ray images of flares are obtained using techniques similar to those used in radio interferometry. Ground-based radio observations of the Sun provide an important complement to the HESSI observations of solar flares. I will describe the HESSI Project and the high-energy aspects of solar flares, and how these relate to radio astronomy techniques and observations.

Relativistic quantum mechanics

International Nuclear Information System (INIS)

Ollitrault, J.Y.

1998-12-01

These notes form an introduction to relativistic quantum mechanics. The mathematical formalism has been reduced to the minimum in order to enable the reader to calculate elementary physical processes. The second quantification and the field theory are the logical followings of this course. The reader is expected to know analytical mechanics (Lagrangian and Hamiltonian), non-relativistic quantum mechanics and some basis of restricted relativity. The purpose of the first 3 chapters is to define the quantum mechanics framework for already known notions about rotation transformations, wave propagation and restricted theory of relativity. The next 3 chapters are devoted to the application of relativistic quantum mechanics to a particle with 0,1/5 and 1 spin value. The last chapter deals with the processes involving several particles, these processes require field theory framework to be thoroughly described. (A.C.)

Towards Extreme Field Physics: Relativistic Optics and Particle Acceleration in the Transparent-Overdense Regime

Science.gov (United States)

Hegelich, B. Manuel

2011-10-01

A steady increase of on-target laser intensity with also increasing pulse contrast is leading to light-matter interactions of extreme laser fields with matter in new physics regimes which in turn enable a host of applications. A first example is the realization of interactions in the transperent-overdense regime (TOR), which is reached by interacting a highly relativistic (a0 >10), ultra high contrast laser pulse [1] with a solid density target, turning it transparent to the laser by the relativistic mass increase of the electrons. Thus, the interactions becomes volumetric, increasing the energy coupling from laser to plasma, facilitating a range of effects, including relativistic optics and pulse shaping, mono-energetic electron acceleration [3], highly efficient ion acceleration in the break-out afterburner regime [4], and the generation of relativistic and forward directed surface harmonics. Experiments at the LANL 130TW Trident laser facility successfully reached the TOR, and show relativistic pulse shaping beyond the Fourier limit, the acceleration of mono-energetic ~40 MeV electron bunches from solid targets, forward directed coherent relativistic high harmonic generation >1 keV Break-Out Afterburner (BOA) ion acceleration of Carbon to >1 GeV and Protons to >100 MeV. Carbon ions were accelerated with a conversion efficiency of >10% for ions >20 MeV and monoenergetic carbon ions with an energy spread of ICF diagnostics over ion fast ignition to medical physics. Furthermore, TOR targets traverse a wide range of HEDP parameter space during the interaction ranging from WDM conditions (e.g. brown dwarfs) to energy densities of ~1011 J/cm3 at peak, then dropping back to the underdense but extremely hot parameter range of gamma-ray bursts. Whereas today this regime can only be accessed on very few dedicated facilities, employing special targets and pulse cleaning technology, the next generation of laser facilities will operate in this regime by default, turning its

A Distributed Lag Autoregressive Model of Geostationary Relativistic Electron Fluxes: Comparing the Influences of Waves, Seed and Source Electrons, and Solar Wind Inputs