Abstract
In this paper we present our most recent results on the sub-iron (Sc to Cr) to Fe nuclei abundance ratios in the low-energy cosmic rays of 50 to 250 MeV nucl.−1 and their implications as observed in theSkylab experiment. In view of the importance of this ratio in determining the cosmic-ray pathlength in interstellar medium, we have obtained additional data in the same detector module and the results of final analysis are reported. Charge determinations in the Lexan detector were made from an average of about four independent measurements ofZ for each of the cosmic-ray events and the mean charge resolution is obtained asΔZ/Z≈0.2. From about 100 events of calcium to nickel in low-energy cosmic rays, sub-iron (Sc to Cr) to Fe−Co ratio is determined as 1.43±0.40 in 50–250 MeV nucl.−1. This shows a large energy dependence of the ratio as compared to the value of 0.4–0.8 in 200–1000 MeV nucl.−1 as measured by many investigators. The origin of this large enhancement of the ratios in low-energy cosmic rays is not known at present. Some possible suggestions are briefly mentioned.
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Bhatia, V. S. and Singh, G.: 1980,Astrophys. Space Sci. 69, 461.
Biswas, S. and Durgaprasad, N.: 1980,Space Sci. Rev. 25, 285.
Biswas, S., Durgaprasad, N., Ramadurai, S., and Yadav, J. S.: 1983,Proc. 18th Int. Cosmic Ray Conf., Bangalore 2, 85.
Biswas, S., Durgaprasad, N., Dutta, A., Goswami J. N., Kajarekar, P. J., Singh, R. K., Vahia, M. N., and Yadav, J. S.: 1987,Proc. 20th Int. Cosmic Ray Conf., Moscow 3, 458.
Biswas, S., Nevatia, J., Durgaprasad, N., and Venkatavaradan, V. S.: 1975,Nature (London) 258, 409.
Cowsik, R. and Gaisser, T. K.: 1981,Proc. 17th Int. Cosmic Ray Conf., Paris 2, 218.
Durgaprasad, N., Venkatavaradan, V. S., and Biswas, S.: 1979,Proc. 16th Int. Cosmic Ray Conf., Kyoto 1, 296.
Durgaprasad, N., Yadav, J. S., and Biswas, S.: 1985,Proc. 19th Int. Cosmic Ray Conf., La Jolla 2, 12.
Englemann, J. J., Goret, P., Juliusson, E., Koch-Miramond, L., Masse, P., Soutoul, A., Byrnak, B., Lund, N., Peters, B., Rasmussen, I. L., Rotenberg, M. and Westergaard, N. J.: 1983,Proc. 18th Int. Cosmic Ray Conf., Bangalore 2, 17.
Fleischer, R. L., Hart, H. R. Jr., and Renshaw, A.: 1974,General Electric Tech. Report, No. CRD-138, Schenectady, New York.
Fleischer, R. L., Price, P. B. and Walker, R. M.: 1975,Nuclear Tracks in Solids: Principles and Applications, Univ. of California Press, California.
Gaisser, T. K., and Maurer, R. H.: 1973),Phys. Rev. Letters,30, 1264.
Garcia-Munoz, M., Guzik, T. G., Simpson, J. A., and Wefel, J. P.: 1984,Astrophys. J. 280, L13.
Garcia-Munoz, M., Simpson, J. A., Guzik, T. G., Wefel, J. P., and Margolis, S. H.: 1987,Astrophys. J. Suppl. 64, 269.
Ginzburg, V. L. and Ptuskin, V. S.: 1981,Soviet Astron. Letters 7, 325.
Henke, R. P. and Benton, E. V.: 1971,Nucl. Instr. Methods 97, 483.
Lezniak, J. A. and Webber, W. R.: 1978,Astrophys. J. 223, 676.
Lezniak, J. A. and Webber, W. R.: 1979,Astrophys. Space Sci. 63, 35.
Maehl, R. C., Ormes, J. F., Fisher, A. J., and Hagen, F. A.: 1977,Astrophys. Space Sci. 47, 163.
O'Sullivan, D., Thompson, A., and Price, P. B.: 1973,Nature (London), Phys. Sci. 243, 8.
Ramadurai, S., Vahia, M. N., Yadav, J. S., Biswas, S., and Durgaprasad, N.: 1984,Adv. Space Res. 4, 97.
Soutoul, A., Englemann, J. J., Ferrando, P. H., Koch-Miramond, L., Masse, P., and Webber, W. R.: 1985,Proc. 19th Int. Cosmic Ray Conf., Ja Jolla 2, 8.
Stephens, S. A.: 1983,Proc. 18th Int. Cosmic Ray Conf., Bangalore 9, 167.
Young, J. S., Freier, S. P., Waddington, C. J., Brewster, N. C., and Fickle, R. K.: 1981,Astrophys. J. 246, 1014.
Webber, W. R.: 1982,Astrophys. J.,252, 386.
Webber, W. R.: 1985, in W. V. Jones and J. P. Wefel (eds.),Workshop on Cosmic Ray and High Energy Gamma Ray Experiments for the Space Station Era, Baton Rouge, p 283.
Webber, W. R., Brautigam, D. A., Kish, J. C., and Schrier, D.: 1983,Proc. 18th Int. Cosmic Ray Conf., Bangalore 2, 198.
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Durgaprasad, N., Biswas, S. Sub-iron to iron nuclei in low-energy (50–200 MeV nucl−1) cosmic rays as observed in the Skylab experiment. Astrophys Space Sci 149, 163–170 (1988). https://doi.org/10.1007/BF00640476
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DOI: https://doi.org/10.1007/BF00640476