Alpha spectroscopy in CR-39 SSNTDs using energy simulation and matrix of energy equations for open field studies

Encouraged with the success of the matrix of energy equations in resolving alpha spectra for narrow energy band [O.A. Bondarenko, P.L. Salmon, D.L. Henshaw, A.P. Fews, Radiat. Meas. 26 (1996) 59; O.A. Bondarenko, P.L. Salmon, D.L. Henshaw, A.P. Fews, A.N. Ross, Nucl. Instrum. Methods A 369 (1996) 582] and wide energy band [E.M. Awad, A.A. Soliman, Y.S. Rammah, Phys. Lett. A 369 (5–6) (2007) 359] as well, the present work extends the applicability of this method to work out for open field studies. 241Am alpha source was used for irradiating CR-39 samples in air at normal temperature and pressure and at three different distances to obtain three different energies. Alpha particles were sorted to ten different bins according to their dip angle and the energy inside each bin was determined using alpha particle range–energy relation. Then, the energy matrix inside each bin was constructed using some selected calibration tracks. This matrix was composed of two track axes, the track minor axis (m)(m) and diameter of etched out track end (d)(d) of some selected elliptical tracks. The energy E   in (m,d)(m,d) coordinates was given by Ek=∑i,j=02aijdkimkj. The adjusting parameters aijaij were obtained by solving an over-determined system of energy equations using the SVD method. The three energies in each bin were well resolved.