THE CHARGE SPECTRUM AND INTERACTIONS OF RELATIVISTIC HEAVY NUCLEI IN THE PRIMARY COSMIC RADIATION

1966 ◽  
Vol 44 (5) ◽  
pp. 1121-1145 ◽  
Author(s):  
B. Judek ◽  
I. J. van Heerden
Keyword(s):  
Cosmic Radiation ◽  
Heavy Nuclei ◽  
Nuclear Emulsions ◽  
Charge Spectrum ◽  
Ceiling Height ◽  
Primary Cosmic Radiation ◽  
Relative Abundances

The charge spectrum of relativistic heavy nuclei in the primary cosmic radiation has been investigated in a stack of nuclear emulsions exposed over Texas at a ceiling height of 136 000 ft. Charges of 601 primary and of 203 fast secondary nuclei arising from fragmentations have been determined. Using a "range" criterion to count δ rays, charge resolutions up to Z = 15 have been obtained.All of the tracks have been followed through the stack and the interaction mean free paths in emulsion and the fragmentation probabilities evaluated for individual elements up to Z = 15. Using these probabilities, the relative abundances at the top of the atmosphere were 12.7 ± 1.3% L nuclei [Formula: see text], 63.5 ± 3.5% M nuclei [Formula: see text], 13.6 ± 1.6% H3 nuclei [Formula: see text], 1.7 ± 0.5% H2 nuclei [Formula: see text], and 8.5 ± 1.4% H1 nuclei [Formula: see text]. It was found that the interaction mean free paths in emulsion of the M and H nuclei were about 10% lower than previous experimental and calculated values. The fragmentation probabilities were generally in agreement with previous determinations, except for a significantly high value for the fragmentation of H1 to L nuclei.

The Heavy Nuclei of the Primary Cosmic Radiation

1950 ◽  
Vol 77 (1) ◽  
pp. 54-70 ◽  
Author(s):  
H. L. Bradt ◽  
B. Peters
Keyword(s):  
Cosmic Radiation ◽  
Heavy Nuclei ◽  
Primary Cosmic Radiation

The charge spectrum of ultra heavy nuclei, including actinides, in the cosmic radiation

1997 ◽  
Vol 19 (5) ◽  
pp. 739-742 ◽  
Author(s):  
A.J Keane ◽  
D.O Sullivan ◽  
A Thompson ◽  
L.O'C Drury ◽  
K.P Wenzel
Keyword(s):  
Cosmic Radiation ◽  
Heavy Nuclei ◽  
Charge Spectrum

Evidence for Heavy Nuclei as a Component of Primary Cosmic Radiation

1949 ◽  
Vol 21 (1) ◽  
pp. 101-103 ◽  
Author(s):  
H. L. Bradt ◽  
Phyllis Freier ◽  
E. J. Lofgren ◽  
E. P. Ney ◽  
F. Oppenheimer ◽  
...  
Keyword(s):  
Cosmic Radiation ◽  
Heavy Nuclei ◽  
Primary Cosmic Radiation

The energy spectrum of heavy nuclei above 10 GeV/nucleon

1968 ◽  
Vol 46 (10) ◽  
pp. S651-S652
Author(s):  
M. Koshiba ◽  
E. Suda ◽  
F. Takasaki
Keyword(s):  
Energy Spectrum ◽  
Total Energy ◽  
Experimental Observation ◽  
Preliminary Data ◽  
Cosmic Radiation ◽  
Heavy Nuclei ◽  
Nucleon Spectrum ◽  
Primary Cosmic Radiation

An experimental observation is made of the energy spectrum of heavy nuclei in the primary cosmic radiation using a large emulsion stack. The preliminary data so far accumulated indicate an exponent of 1.60 to 1.65 for the integral total-energy-per-nucleon spectrum.

Über die schweren Kerne in der primären kosmischen Strahlung

1955 ◽  
Vol 10 (7) ◽  
pp. 572-581 ◽  
Author(s):  
H. Fay
Keyword(s):  
Cross Sections ◽  
Heavy Nuclei ◽  
Secondary Products ◽  
Multiple Coulomb Scattering ◽  
Residual Material ◽  
Charge Spectrum ◽  
Primary Cosmic Radiation ◽  
Latitude Effect ◽  
Ray Density

The present paper describes the results of an investigation on heavy nuclei (Z > 2) of the primary cosmic radiation. The measurements were made in 40 stripped emulsions flown over Sardinia (λ~40°) in a height of about 27 km for 7 hours. The energy of the nuclei was deduced from their multiple Coulomb scattering, and, if they fragmentated, from the opening angles of their secondary products. For the determination of the charge number Ζ the measurement of the δ-ray density was sufficient, all particles having energies/nucleon ≥ 1,3 GeV. The result is thus independent of possible influences of spurious scattering.The charge spectrum under an average of 32 g/cm2 of residual material shows that the number of nuclei with 3 ≤ Z ≤ 5 is approximately equal to that of nuclei with 6 ≤ Z ≤ 9. This is in agreement with the charge spectrum found by Dainton, Fowler, and Kent, but at variance with the results of Bradt and Peters. The magnitude of the correction to be applied for the scanning loss of Li-nuclei is discussed. The correction factor used by Dainton et al. appears to be too high. With regard to the influence of the residual material it is shown that the calculated intensity of the Li-, Be-, and B-nuclei at the top of the atmosphere will be strongly affected by the uncertainty of the probabilities pki for fragmentation. The fragmentation probabilities found in this work are in good agreement with those obtained by Bradt and Peters and by Gottstein, they are, however, somewhat smaller than those measured by Noon, Kaplon, and Ritson. The values of the mean free paths in emulsion can be represented by a formula for the cross-sections given by Peters et al.The energy spectrum agrees with that deduced by Kaplon et al. from measurements of the latitude-effect. It was found that because of spurious scattering cell lengths of at least 4 mm are required in order to measure energies > 4 GeV/nucleon. A spectrum similar to that found by Dainton et al. is obtained, if one confines the scattering measurements on cells which are not long enough. The flux of nuclei Z ≥ 6 at the top of the atmosphere is somewhat smaller than measured by other authors at λ = 41°.

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