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.

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.

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.

Inelastic cross sections of nucleons and π mesons in carbon and lead near 100 GeV

1968 ◽  
Vol 46 (10) ◽  
pp. S694-S696 ◽  
Author(s):  
A. V. Alakoz ◽  
V. N. Bolotov ◽  
M. I. Devishev ◽  
L. F. Klimanova ◽  
A. P. Shmeleva
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Cosmic Ray ◽  
High Energy ◽  
Active Particle ◽  
Particle Interactions ◽  
Active Particles ◽  
The Cross

An experiment to measure the cross section for high-energy cosmic-ray neutrons and charged nuclear-active particle interactions with Pb and C nuclei has been carried out at an altitude of 2 000 m. Large spark chambers were used in a detector which selected neutrons and charged nuclear-active particles in the region of 100 GeV. The results are σπ(nPb) = (1.65 ± 0.17) barn, σπ(nC) = (0.204 ± 0.02) barn, σπ(πPb) = (1.53 ± 0.17) barn, σπ(πC) = (0.168 ± 0.017) barn.

Cosmic-ray nuclei up to 10 10 eV/u in the galaxy

1975 ◽  
Vol 277 (1270) ◽  
pp. 319-348 ◽  
Keyword(s):  
Cosmic Rays ◽  
Solar System ◽  
Cross Sections ◽  
Cosmic Ray ◽  
Interstellar Space ◽  
Heavy Nuclei ◽  
Hydrogen Atoms ◽  
Interstellar Gas ◽  
The Galaxy ◽  
Ionization Cross Sections

O f the nuclear cosmic rays arriving in the vicinity of Earth from interstellar space, more than 90% have energies less than 1010 eV /u.f Some effects of their modulation (including deceleration) in the Solar System are briefly discussed. The origin of particles at energies < 107 eV/u is still obscure. They could be due to stellar explosions or to solar emissions, or perhaps to interaction of interstellar gas with the solar wind. Between 108 and 1010 eV/u, the composition appears constant to ca. 30% within the statistics of available data. Cosmic rays traverse a mean path length of 6 g/cm 2 in a medium assumed to contain nine hydrogen atoms for each helium atom. Spallation reactions occurring in this medium result in enhancement of many cosmic-ray elements that are more scarce in the general abundances by several orders of magnitude. Cosmic-ray dwell time in the Galaxy seems to be < 107 years. The source composition of cosmic rays has been derived for elements with atomic numbers 1 ≤ Z ≤ 26. A comparison with abundances in the Solar System implies that the latter is richer in hydrogen and helium by a factor of ca. 20, in N and O by ca. 5, and in C by a factor of ca.2. Possible interpretations invoke (a) nucleosynthesis of cosmic rays in certain sources, e.g. supernovae, or (b) models of selective injection that depend, e.g. on ionization potentials or ionization cross sections. Calculated isotopic abundances of arriving cosmic rays are compared with the observed values now becoming available, and found to be in general agreement. Recent progress in probing the composition and spectrum of ultra-heavy nuclei is outlined.

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