Non-proportionality and energy resolution of CsI(T1)
2007 (English)In: IEEE Transactions on Nuclear Science, ISSN 0018-9499, E-ISSN 1558-1578, Vol. 54, no 5, 1836-1841 p.Article in journal (Refereed) Published
Experimental studies of CsI(Tl) crystals with different amounts of Tl activator are presented. Properties such as non-proportionality, energy resolution and the number of photoelectrons per 1 MeV-gamma were inspected at two different shaping time constants, i.e., 3 and 12 mu s. A CsI(Tl) crystal was coupled to the XP5212 PMT with a photocathode blue sensitivity of 12.2 mu A/lmF. Six CsI(Tl) crystals of different sizes were tested. Among them, three samples were of known Tl concentration, which amounted roughly 0.05, 0.1 and 0.25 mol%. The data analvsis showed a much more proportional character of the crystal response, higher number of photoelectrons/MeV-gamma, and consequently, a better overall energy resolution obtained for 12 mu s time constant for all tested samples. The calculated intrinsic resolution improved for longer shaping time constants as well, indicating that, for CsI(Tl) crystals, a more proportional response implies better intrinsic energy resolution of the host crystal. In contrast, the intrinsic resolution at the low energy region (below about 30 keV) deteriorated for the longer shaping time constant. An alpha/gamma ratio was also measured for each tested CsI(Tl) crystal in order to find any indication of an explanation of the intrinsic resolution deterioration for low energy photons at the 12 mu s integration time.
Place, publisher, year, edition, pages
2007. Vol. 54, no 5, 1836-1841 p.
CsI(T1), energy resolution, non-proportionality, area avalanche photodiodes, tl crystals, light yield, gamma-rays, csi, pure
IdentifiersURN: urn:nbn:se:kth:diva-17055DOI: 10.1109/tns.2007.906168ISI: 000250313700020ScopusID: 2-s2.0-35348975640OAI: oai:DiVA.org:kth-17055DiVA: diva2:335098
QC 201005252010-08-052010-08-05Bibliographically approved