Qβ-measurements with a total absorption detector composed of through-hole HPGe detector and anti-Compton BGO detector

Abstract

A total absorption detector, which is composed of a through-hole type HPGe detector coupled with a surrounding annular anti-Compton BGO detector, has been developed for β −-decay energy (Q β) measurements of nuclei far off the β-stability line. This detector can measure radiations with an almost 4π solid angle by putting radioactive sources in the middle of the HPGe detector and also can suppress the scattered photons with the anti-Compton BGO scintillation detector. The systematic uncertainty was determined to be 30 keV by measuring 19 nuclei having Q β s between 3 and 8 MeV by means of conventional square root plot analysis. The Q β s of mass-separated fission products 147 La and 148 La were successfully determined to be 5366(40) and 7732(70) keV, respectively.