R. Bottger et al., SPECIFICATION OF BERYLLIUM TARGETS FOR NEUTRON-PRODUCTION, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 334(1), 1993, pp. 160-164
The absolute mass of a thin Be layer deposited onto a tantalum backing
was determined by differential weighing of four targets to obtain the
average areal density before their utilization in a Be(alpha, n)C cro
ss section measurement. In a number of preliminary investigations, the
homogeneity of the sample area was checked non-destructively by measu
ring the spectral neutron yield when the target was bombarded with an
alpha beam in various geometrical arrangements. The inhomogeneities fo
und contributed significantly to the 2.5% total uncertainty on the are
al density of the deposit.