HEAVY FRAGMENT PRODUCTION CROSS-SECTIONS FROM 1.05 GEV NUCLEON FE-56 IN C, AL, CU, PB, AND CH2 TARGETS/

We have obtained charge-changing cross sections and partial cross sect ions for fragmentation of 1.05 GeV/nucleon Fe projectiles incident on H, C, Al, Cu, and Pb nuclei. The energy region covered by this experim ent is critical for an understanding of galactic cosmic ray propagatio n and space radiation biophysics. Surviving primary beam particles and fragments with charges from 12 to 25 produced within a forward cone o f half-angle 61 mrad were detected using a silicon detector telescope to identify their charge and the cross sections were calculated after correction of the measured yields for finite target thickness effects. The cross sections are compared to model calculations and to previous measurements. Cross sections for the production of fragments with eve n-numbered nuclear charges are seen to be enhanced in almost all cases .