STOPPING POWERS OF HAVAR FOR PROTONS FROM 0.45 TO 3.0 MEV

Stopping powers of havar (a cobalt based alloy) for protons from 0.45 to 3.0 MeV have been measured with an uncertainty of +/-0.35% using th e accelerator at Nara Women's University. The results agree fairly wel l with experimental data reported by Duder et al. [J.C. Duder, J.F. Gl are, H. Naylor, Nucl. Instr, and Meth. 123 (1975) 89] within the uncer tainties. The results also have been compared with the calculated stop ping power values obtained by Bragg's additivity rule using the stoppi ng power values for constituent elements calculated by Janni [J.F. Jan ni, At. Data Nucl. Data Tables 27 (1982) 147] and by Andersen and Zieg ler's formula [H.H. Andersen, J.F. Ziegler, Hydrogen Stopping Powers a nd Ranges in All Elements, Pergamon Press, New York, 1977]. Applying t he modified Bethe-Bloch formula for the stopping power of compounds as suming the validity of Bragg's additivity rule, we extracted an effect ive mean excitation energy, I value, for havar from the stopping power data. (C) 1998 Elsevier Science B.V.