Nuclear fragmentation cross sections and cosmic-ray source abundances

1984 ◽  
Vol 4 (2-3) ◽  
pp. 93-96
Author(s):  
T.Gregory Guzik ◽  
John P. Wefel
Keyword(s):  
Cross Sections ◽  
Cosmic Ray ◽  
Nuclear Fragmentation

Light-fragment yield ratios from heavy-ion-induced fragmentation in atmospheric collisions of cosmic-ray primary nuclei

1991 ◽  
Vol 69 (12) ◽  
pp. 1481-1486
Author(s):  
M. J. Pantazopoulou ◽  
A. F. Barghouty ◽  
R. A. Witt
Keyword(s):  
Cross Sections ◽  
Cosmic Ray ◽  
Heavy Ion ◽  
Fragmentation Model ◽  
Light Fragment ◽  
Collision System ◽  
Nuclear Fragmentation ◽  
Good Correspondence ◽  
Total Cross Sections ◽  
Fragment Yield

A statistical nuclear-fragmentation model is used to calculate the total inclusive cross sections and yield ratios of light fragments (p, d, 3H, and 3He) from 800 MeV/nucleon mass-symmetric and mass-asymmetric collision systems. Comparison with available data reveal good correspondence between the observed total cross sections and fragment-yield ratios, and the calculated ones. The model is also used to calculate the 4He/3He ratio from CNO + CNO collisions at 1 GeV/nucleon. Averaging over the mass numberof the CNO collision system, we calculate a ratio of 5.76 ± 0.52 ± 12%. A mass-independent thermal-model formula gives a ratio of only ≈ 1.5. The appreciable calculated production of 4He relative to 3He, as fragmentation products in atmospheric CNO collisions with 1 GeV/nucleon cosmic-ray primary CNO nuclei, has important implications for studies of atmospheric secondaries as background sources for space-based and balloon-borne light-fragment observations.

scholarly journals Impact of cross sections uncertainties on the study of galactic cosmic-ray propagation with the DRAGON2 code

2021 ◽  
Author(s):  
Pedro De la Torre Luque ◽  
M. Nicola Mazziotta ◽  
Fabio Gargano ◽  
Francesco Loparco ◽  
Davide Serini
Keyword(s):  
Cross Sections ◽  
Cosmic Ray ◽  
Galactic Cosmic Ray

scholarly journals Are Further Cross Section Measurements Necessary for Space Radiation Protection or Ion Therapy Applications? Helium Projectiles

2020 ◽  
Vol 8 ◽  
Author(s):  
John W. Norbury ◽  
Giuseppe Battistoni ◽  
Judith Besuglow ◽  
Luca Bocchini ◽  
Daria Boscolo ◽  
...  
Keyword(s):  
Radiation Protection ◽  
Cross Section ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Production Cross ◽  
Cosmic Ray ◽  
Space Radiation ◽  
Radiation Shielding ◽  
Light Ions ◽  
Ion Therapy

The helium (4He) component of the primary particles in the galactic cosmic ray spectrum makes significant contributions to the total astronaut radiation exposure. 4He ions are also desirable for direct applications in ion therapy. They contribute smaller projectile fragmentation than carbon (12C) ions and smaller lateral beam spreading than protons. Space radiation protection and ion therapy applications need reliable nuclear reaction models and transport codes for energetic particles in matter. Neutrons and light ions (1H, 2H, 3H, 3He, and 4He) are the most important secondary particles produced in space radiation and ion therapy nuclear reactions; these particles penetrate deeply and make large contributions to dose equivalent. Since neutrons and light ions may scatter at large angles, double differential cross sections are required by transport codes that propagate radiation fields through radiation shielding and human tissue. This work will review the importance of 4He projectiles to space radiation and ion therapy, and outline the present status of neutron and light ion production cross section measurements and modeling, with recommendations for future needs.

GLUON SATURATION AND THE TOTAL PROTON-AIR CROSS SECTION

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1685-1689
Author(s):  
F. CARVALHO ◽  
F. O. DURÃES ◽  
S. SZPIGEL ◽  
F. S. NAVARRA
Keyword(s):  
Simple Model ◽  
Cross Section ◽  
Cross Sections ◽  
Cosmic Ray ◽  
Dipole Model ◽  
Perturbative Calculations ◽  
Experimental Cross ◽  
Energy Behavior ◽  
Gluon Saturation

In this work we propose a simple model for the total proton-air cross section, which is an improvement of the minijet model with the inclusion of a window in the pT-spectrum associated to the saturation physics. Our approach introduces a natural cutoff for the perturbative calculations which modifies the energy behavior of this component. The saturated component is calculated with a dipole model. The results are compared with experimental cross sections measured in cosmic ray experiments.

scholarly journals Showers produced by the penetrating cosmic radiation

1938 ◽  
Vol 166 (927) ◽  
pp. 529-543 ◽  
Keyword(s):  
Cross Sections ◽  
Cosmic Ray ◽  
Nuclear Forces ◽  
Qualitative Explanation ◽  
Rest Energy ◽  
Self Energy ◽  
Heavy Electron ◽  
Order Of Magnitude ◽  
Mathematical Difficulties ◽  
The One

In two recent papers by Fröhlich, Heitler and Kemmer (1938) and by Kemmer (1938) it has been shown that the properties of the nuclear particles proton and neutron can qualitatively be understood on the assumption that a proton (neutron) is capable of emitting a heavy positive ( negative ) electron (denoted by Y + , Y - ), transforming itself at the same time into a neutron (proton). The theory of the heavy electron—its wave equation and its interaction with the nuclear particles—was built up in close analogy to the theory of light and its interaction with an electron. We now apply this theory to the passage of a heavy electron through matter, and we shall find that it leads to a qualitative explanation of a number of cosmic-ray facts connected with the penetrating radiation. In applying the theory to collisions of fast heavy electrons with nuclei, there is, however, a serious difficulty from the start: From the discussion of the nuclear properties it has become evident that the theory in its present form can only claim validity for relative energies between the heavy electron and the nuclear particles not very much greater than the rest energy μc 2 of the heavy electron, i. e. up to at most a few times 10 8 e-volts. For higher energies the theory leads to serious mathematical difficulties (diverging self-energy, diverging nuclear forces of higher order, etc.). For cosmic rays the interesting region is just the one for energies greater than 10 8 e-volts. It may be justifiable, in spite of these facts, to apply the theory to cosmic-ray heavy electrons, for two reasons: In the first place it is to be expected that the processes derived from the theory for energies of the order μc 2 will exist also at higher energies and will preserve a number of their qualitative features. In the second place the theoretical cross-section obtained for these processes at energies of the order 10 8 e-volts will at least be right in the order of magnitude. On the other hand, we must not attach any significance to the way in which the cross-sections are found to depend on energy.

FORMATION CROSS SECTIONS OF VARIOUS RADIONUCLIDES FROM Ni, Fe, Si, Mg, O, AND C FOR PROTONS OF ENERGIES BETWEEN 130 AND 400 MEV

1964 ◽  
Vol 42 (5) ◽  
pp. 1149-1154 ◽  
Author(s):  
Garimella V. S. Rayudu
Keyword(s):  
Cross Sections ◽  
Cosmic Ray

Formation cross sections of Co56, Mn54, Mn52, Cr51, V48, P32, and Be7 from Fe and Ni; of Na24, Na22, and Be7 from Si and Mg; and of Be7 from C and O have been measured for incident protons of energies between 130 and 400 Mev to assist in the interpretation of data on cosmic-ray-produced nuclides in iron and stone meteorites. Formation cross sections of Mn54, Mn52, Cr51, V48, and P32 are found to be a factor of 2 to 3 lower from Ni than from Fe, whereas those of Co56 are 20- to 50-fold higher than from Fe. Be7 cross sections from C are found to be almost the same as from O, within experimental uncertainties. Cross sections of Na24 and Na22 from Mg and Si are found to be relatively energy independent, whereas those of P32 and Be7 from Ni and Fe are found to increase rapidly with increasing energy. Some qualitative conclusions are drawn about the production of cosmogenic activities in meteorites.

Nuclear fragmentation parameters needed for interpretation of observed fluxes of UH cosmic ray nuclei

1995 ◽  
Vol 15 (6) ◽  
pp. 39-48 ◽  
Author(s):  
C.J. Waddington ◽  
W.R. Binns ◽  
J.R. Cummings ◽  
T.L. Garrard ◽  
L.Y. Geer ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Nuclear Fragmentation

Optical potential for light nuclei and momentum-space eikonal phase function

2018 ◽  
Vol 96 (6) ◽  
pp. 642-649
Author(s):  
Charles M. Werneth ◽  
K.M. Maung ◽  
M.D. Vera ◽  
L.W. Townsend
Keyword(s):  
Cross Sections ◽  
Momentum Space ◽  
Phase Function ◽  
Optical Potential ◽  
Solution Method ◽  
Radiation Environment ◽  
Space Representation ◽  
Nuclear Fragmentation ◽  
Position Space ◽  
Space Radiation Environment

The space radiation environment comprises all of the nuclei in the periodic table with energies that extend from a fraction of an MeV/n to TeV/n. The vast range of projectile–target and energy combinations necessitates highly efficient and accurate cross section codes for use in radiation transport codes. As particles in the space radiation environment impinge on shielding materials, nuclear reactions, such as nuclear fragmentation, occur. One way of estimating nuclear fragmentation cross sections is to use an abrasion–ablation model, which describes how nucleons are dislodged from the nuclei as a result of nuclear collisions and the mechanism by which excited pre-fragments decay via particle emission to more stable states. The well-known partial wave solution method cannot be used directly for the computation of abrasion cross sections. Instead, abrasion cross sections may be computed by slightly altering the Eikonal solution method, which is a high energy (small scattering angle) approximation that depends on the nucleus–nucleus optical potential. The aim of the current work is to present two efficient methods for the computation of the Eikonal phase shift function. Analytic formulas of the optical potential are presented in the position-space representation for nuclei that are well-represented by harmonic-well nuclear matter densities (A < 20), which reduces the Eikonal phase factor to an integration over a single dimension. Next, the Eikonal phase function is presented in the momentum-space representation, which is particularly useful when the Fourier transform of the position-space optical potential is known. These new methods increase the computational efficiency by three orders of magnitude and allow for rapid prediction of elastic differential, total, elastic, and reaction cross sections in the Eikonal approximation.

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