Abstract
A detailed study of the composition and energy spectra of heavy nuclei of charge Z⩾3 in the primary cosmic rays has been made during the period of low solar activity, using two stacks of nuclear emulsions exposed in balloon flights from Fort Churchill, Canada, in June 1963. Each of the stacks was composed of 120 nuclear emulsions of three different sensitivities and was exposed at about 3·5 g. cm.−2 of residual air for about 11.1 hr. Reliable resolution of charges of nuclei from lithium to oxygen was obtained; for heavier nuclei, charge groups were determined. From the analysis of 793 tracks of nuclei with Z⩾3, results on the following aspects were obtained:
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(1)
The differential energy spectra of L (Z=3–5), M (Z=6–9) and H (Z=10–28) nuclei were measured in the energy intervel 150–600 MeV/nucleon; integral fluxes were obtained for energy >600 MeV/nucleon;
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(2)
The energy dependence of the L/M ratio at the top of the atmosphere was determined; the ratios were obtained as 0·45 ± 0·06 and 0·29 ± 0·03 in the energy intervals of 200–575, and >575 MeV/nucleon respectively;
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(3)
Relative abundances of individual nuclei of Li, Be, B, C, N and O at the top of the atmosphere were determined as 36, 29, 55, 100, 60 and 106 respectively in the energy interval 150–600 MeV/nucleon; corresponding values were also obtained for energy >600 MeV/nucleon.
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(4)
The differential fluxes of multiply charged nuclei measured by us and by other investigators were used to determine the solar modulation between solar maximum to solar minimum. It was found that solar modulation of the fluxes of M and He nuclei were consistent with Rβ dependence and that the modulation parameter Δη between 1965 and 1957 was about 1·1.
The implications of these results are discussed.
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Aizu, H., Fujimoto, Y., Hasegawa, S., Koshiba, M., Mito, I., Nishimura, J. and Yokoi, K.Progr. of Theor. Phys. (Kyoto) Supl., 1960,16, 54.
Anand, K. C., Biswas, S., Lavakare, P. J., Ramadurai, S., Sreenivasan, N., Bhatia, V. S., Chohan, V. S. and Pabbi, S. D.J. Geophys. Res., 1966,71, 4687.
——, Daniel, R. R. and Stephens, S. A.Nature, 1968,217, 25.
Balasubrahmanyan, V. K., Hagge, D. E., Ludwig, G. H. and McDonald, F. M.J. Geophys. Res., 1966,71, 1771.
Barkas, W. H. ..UCRL Rept. No. 2426 (rev), 1965.
Bernas, R., Epherre, M., Gradsztajn, E., Klapisch, R. and Yiou, F.Phys. Letters, 1965,15, 147.
Bhatia, V. S. ..Ph.D. Thesis, Panjab University, 1967.
--, Biswas, S. and Ramadurai, S. 1969 (Space Research) (to be published).
Biswas, S. ..Colloquium on Cosmic Ray Studies in Relation to Recent Advances in Astronomy and Astrophysics, Bombay, Nov. 1968, Published by Tata Institute of Fundamental Research, p. 45.
—————..Astrophys. Space Sci, 1969,5, 59.
——, Ramadurai, S. and Sreenivasan, N.Phys. Rev., 1966,149, 1037.
——, Lavakare, P. J., Ramadurai, S. and Sreenivasan, N.Proc. Ind. Acad. Sci., 1967a,65, 104.
——, Ramadurai, S. and Sreenivasan, N...Phys. Rev., 1967b,159, 1063.
----- ..Can. J. Phys., 1968,46, S 593.
Burbidge, G. R., Fowler, W. A. and Hoyle, F.Nature, 1967,216, 22.
Comstock, G. M., Fan, C. Y. and Simpson, J. A.Astrophys. J., 1966,146, 51; 1969,155, 609.
Comstock, G. M. ..Can. J. Phys., 1968,46, S 553;Astrophys. J., 1969,155, 619.
Daniel, R. R. and Durgaprasad, N.Nuovo Cim. Suppl., 1962,23, 82.
Burgaprasad, N. ..Ph.D. Thesis, University of Bombay, 1964.
Engler, A., Kaplon, M. F. and Klarmann, J.Phys. Rev., 1958,112, 597.
Fichtel, C. E., Guss, D. E., Neelakantan, K. A. and Reames, D. V.Phys. Rev., 1966,138, 732.
—— and Reames, D. V... Ibid., 1968,175, 1564.
Foster, F. and Debenedetti, A...Nuovo Cim., 1963,28, 1190.
Freier, P. S., Ney, E. P. and Waddington, C. J.Phys. Rev., 1959,113, 921.
-- and Waddington, C. J.Can. J. Phys., 1968,46, S 578.
——, Rno, J. S. and Waddington, C. J.Proc. Int. Conf. Cosmic Rays, London, 1966,1, 38.
Friedlander, N. W., Neelakantan, K. A., Tokunaga, S., Stevenson, G. R. and Waddington, C. J.Phil. Mag., 1963,8, 1691.
Gloeckler, G. and Jokipii, J. R. ..Astrophys., J., 1967,148, L 41.
—————..Phys. Rev. Letters, 1966,17, 203.
Jokipii, J. R. ..Can. J. Phys., 1968,46, S 950.
Koshiba, M., Lohrman, E., Aizu, H. and Tamai, E...Phys. Rev., 1963,131, 2692.
Lim, Y. K. and Fukui, K...Nuovo Cim., 1965,40, 102.
Lockwood, J. A. and Webber, W. R.Can. J. Phys., 1968,46, S 903.
Malmquist, L...Arkiv. Fur. Phys., 1967,34, 33.
McDonald, F. B. and Webber, W. R...J. Geophys. Res., 1962,67, 2119.
O’Dell, F. W., Shapiro, M. M. and Stiller, B.J. Phys. Soc. Japan, 1962,17, Sup. A III, 23.
O’Gallagher, J. ..Can. J. Phys., 1968,46, S 946.
Parker, E. N...Interplanetary Dynamical Processes, Interscience, New York, 1963.
Powell, C. F., Fowler, P. H. and Perkins, D. H.Study of Elementary Particles by the Photographic Method, Pergamon Press, London, 1959, p. 74.
Ramaty, R. and Lingenfelter, R. E.Can. J. Phys., 1968,46, S 627.
Reames, D. V. and Fichtel, C. E. ..Ibid., 1968,46, S 544.
Sreenivasan, N. ..Ph.D. Thesis, Bombay University, 1967.
von Rosenvinge, T. F., Ormes, J. F. and Webber, W. R...Astrophys. Space Sci., 1969,3, 4;3, 80.
Webber, W. R., Ormes, J. F. and von Rosenvinge, T. F.Proc. Int. Conf. Cosmic Rays, London, 1966,1, 407.
—— and ——..J. Geophys. Res., 1967,72, 5957.
Webber, W. R...Aust. J. Phys., 1968,21, 845.
—————..Handbuch der Physik, 1967,46/2, p. 173.
Yiou, F. and Beck, F...Astrophys. Letters, 1968,1, 75.
--, Drefaure de Citres, J., Frehel, F., Gradsztajn, E. and Bernas, R.Can. J. Phys., 1968,46, S 557.
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Communicated by Prof. R. R. Daniel,f.a.sc.
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Anand, K.C., Biswas, S., Lavakare, P.J. et al. Cosmic ray nuclei of chargeZ⩾3 during the period of low solar activity. Proc. Indian Acad. Sci. 70, 201–220 (1969). https://doi.org/10.1007/BF03046678
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DOI: https://doi.org/10.1007/BF03046678