Experimental study of β spectra using Si detectors

Several scientific users from different communities, such as nuclear medicine, ionizing radiation metrology, nuclear energy industries, and fundamental physics are seeking for a precise knowledge of beta spectra. Consequently, it is of great interest to investigate the spectral shape of beta decaying nuclei with best possible precision. In this work, we aim to investigate precisely beta decays. For this purpose, we have developed a quasi 4 pi beta spectrometer based on Silicon detectors (PIPS (R)). The measurement system is characterized by conversion electron peaks of Cd-109 and Bi-202 and has been compared with Monte Carlo simulations using nuclear decay data. The preliminary measurements of C-14 (allowed transition) and Cl-36 (second forbidden non-unique transition) decays have been performed and compared with simulations using the PENELOPE Monte Carlo code.