%0 Journal Article
%T A Multi-Component Measurement of the Cosmic Ray Composition Between 10^{17} eV and 10^{18} eV
%A T. Abu-Zayyad
%A K. Belov
%A D. J. Bird
%A J. Boyer
%A Z. Cao
%A M. Catanese
%A G. F. Chen
%A R. W. Clay
%A C. E. Covault
%A J. W. Cronin
%A H. Y. Dai
%A B. R. Dawson
%A J. W. Elbert
%A B. E. Fick
%A L. F. Fortson
%A J. W. Fowler
%A K. G. Gibbs
%A M. A. K. Glasmacher
%A K. D. Green
%A Y. Ho
%A A. Huang
%A C. C. Jui
%A M. J. Kidd
%A D. B. Kieda
%A B. C. Knapp
%A S. Ko
%A C. G. Larsen
%A W. Lee
%A E. C. Loh
%A E. J. Mannel
%A J. Matthews
%A J. N. Matthews
%A B. J. Newport
%A D. F. Nitz
%A R. A. Ong
%A K. M. Simpson
%A J. D. Smith
%A D. Sinclair
%A P. Sokolsky
%A P. Sommers
%A C. Song
%A J. K. K. Tang
%A S. B. Thomas
%A J. C. van der Velde
%A L. R. Wiencke
%A C. R. Wilkinson
%A S. Yoshida
%A X. Z. Zhang
%J Physics
%D 1999
%I arXiv
%R 10.1103/PhysRevLett.84.4276
%X The average mass composition of cosmic rays with primary energies between $10^{17}$eV and $10^{18}$eV has been studied using a hybrid detector consisting of the High Resolution Fly's Eye (HiRes) prototype and the MIA muon array. Measurements have been made of the change in the depth of shower maximum, $X_{max}$, and in the change in the muon density at a fixed core location, $\rho_\mu(600m)$, as a function of energy. The composition has also been evaluated in terms of the combination of $X_{max}$ and $\rho_\mu(600m)$. The results show that the composition is changing from a heavy to lighter mix as the energy increases.
%U http://arxiv.org/abs/astro-ph/9911144v1