Energy-loss fluctuation of heavy charged particles in silicon absorbers

Abstract

The energy straggling of 4He, 12C, 14N, 31P and 40Ar ions passing through thin uniform silicon absorbers has been studied in the range of relatively low velocity of the incident ions [(νZe2 ℏ−1) ≲ 1]. The experimental results are compared with the theoretical predictions of the energy-loss fluctuation: it is suggested that the fluctuation of the effective charge of ions is primarily responsible for the existing discrepancy between measured and theoretical energy-loss distributions for heavy ions, but there is rather good agreement for α-particles.