Energy Spectrum of the Heavy Nuclei in the Cosmic Radiation between 7- and 100-Bev/Nucleon

Abstract

The energy spectrum of the heavy nuclei of the cosmic radiation was determined between 7 Bev/nucleon and 100 Bev/nucleon. The distribution for the $M\left(6\mathrm{}\le Z\le 9\right)$ and $H(Z\ge 10)$ charge groups agree with one another within the limits of error. Combining both charge groups, the integral spectrum is of the form $N(>E)\mathrm{}\sim E^{-1.6\mathrm{}\pm 0.15}$ ($E=\mathrm{total}\mathrm{energy}/\mathrm{nucleon}$). Flux values for nuclei of the $M$, $H$, and $VH(Z\ge 20)$ charge groups at the geomagnetic equator are given. Comparing these results with flux values obtained at high latitudes, it is concluded that a power spectrum of the form $E^{-1.6\mathrm{}}$ fits all three charge groups within the limits of error between 2.5 Bev/nucleon and 7 Bev/nucleon. From the observation of $\alpha$-particle showers of very high energy we conclude that under certain assumptions the integral spectrum of $\alpha$ particles can be represented by $N(>E)\mathrm{}\sim E^n$ with $n=-{{1.58}_{-0.18\mathrm{}}}^{+0.21\mathrm{}}$ for energies ≤1500 Bev/nucleon.