Areal-density measurement of C-12 and C-13 foils and layers using the (He-3,p) nuclear reaction

摘要

A method of accurately measuring the areal densities of isotopic stable carbon layers and foils is presented. The method utilizes the (3 He,p) nuclear reaction at incident energies near 3.5 MeV. A self-supporting foil whose areal density is accurately known from a Rutherford backscattering measurement is used as a standard. The particular advantage of the method presented here is that it can be used on C-12 or C-13 layers deposited on massive substrates. Accuracies of +/-5 are obtained. Preparation and characterisation of C-13 layers with areal densities near 20 mug/cm(2) is described. The application of this method to C-12 foils and layers is outlined. (C) 2001 Elsevier Science B.V. All rights reserved. References: 10