Abstract of Publication No. 333
O. Guillot-Noel, J. C.
van't Spijker, J. T. M. de Haas, P. Dorenbos, C. W. E. van Eijk,
K. W. Krämer and H. U. Güdel
The scintillation properties of RbGd2Br7 crystals,
doped with Ce3+ concentrations of 0.02, 0.11, 0.88, 2.05, 4.1, and
9.8%, are studied under X-ray and g-quanta excitations.
For the RbGd2Br7 sample doped with 9.8% Ce, the authors
measured a light yield of 56000 ± 6000 photons per MeV of
absorbed g-ray energy with a main decay time of 43 ± 1 ns, using
a Hamamatsu R1791 photomultiplier (PMT), a 137Cs radioactive
source, and a shaping time of 10 ms. A time resolution of 790
± 10 ps was measured for the RbGd2Br7:9.8% Ce compound,
using Baf2 as second scintillator, two XP2020Q PMT's, a 22Na
source, and an energy threshold set at E 511 keV.
With the R1791 PMT, an energy resolution of 4.1% (FWHM
over peak position) for the 662-keV full absorption peak has been
observed for two crystals of 7 × 4 × 2 mm3 and
15 × 5 × 1 mm3
with 4.1 and 9.8% Ce content, respectively. Moreover, the
non-proportional response of three RbGd2Br7:Ce compounds with
different concentrations (0.11, 2.05, and 9.8%) were studied
revealing an almost-constant light output response from 17.4 keV
to 1 MeV.
These properties are compared to three other well-known
scintillators: NaI:Tl, CsI:Tl, and Lu2SiO5:Ce.