4 research outputs found
Characterization of Large Volume 3.5 x 8 inches LaBr3:Ce Detectors
The properties of large volume cylindrical 3.5 x 8 inches (89 mm x 203 mm)
LaBr3:Ce scintillation detectors coupled to the Hamamatsu R10233-100SEL
photo-multiplier tube were investigated. These crystals are among the largest
ones ever produced and still need to be fully characterized to determine how
these detectors can be utilized and in which applications. We tested the
detectors using monochromatic gamma-ray sources and in-beam reactions producing
gamma rays up to 22.6 MeV; we acquired PMT signal pulses and calculated
detector energy resolution and response linearity as a function of gamma-ray
energy. Two different voltage dividers were coupled to the Hamamatsu
R10233-100SEL PMT: the Hamamatsu E1198-26, based on straightforward resistive
network design, and the LABRVD, specifically designed for our large volume
LaBr3:Ce scintillation detectors, which also includes active semiconductor
devices. Because of the extremely high light yield of LaBr3:Ce crystals we
observed that, depending on the choice of PMT, voltage divider and applied
voltage, some significant deviation from the ideally proportional response of
the detector and some pulse shape deformation appear. In addition, crystal
non-homogeneities and PMT gain drifts affect the (measured) energy resolution
especially in case of high-energy gamma rays. We also measured the time
resolution of detectors with different sizes (from 1x1 inches up to 3.5x8
inches), correlating the results with both the intrinsic properties of PMTs and
GEANT simulations of the scintillation light collection process. The detector
absolute full energy efficiency was measured and simulated up to gamma-rays of
30 Me
Characterization of Large Volume 3.5″ x 8″ LaBr3:Ce Detectors for the HECTOR+ array
A selection of the properties of large volume, cylindrical 3.5" x 8" LaBr 3 :Ce scintillation detectors coupled to a 3.5" PMT (model R10233-1000SEL from HAMAMATSU) and a special designed Voltage Divider (LABRVD) will be discussed. A number of 10 of such detectors constitute the HECTOR + array which, in fall 2012, measured at GSI coupled to the AGATA DEMOSTRATOR at the PRESPEC experimental setup. These crystals are among the largest ever produced and needed to be characterized. We have performed several tests and here we discuss, in particular, the energy resolution measured using monochromatic γ −ray sources and in-beam reactions producing γ −rays up to 22.6 MeV. As already measured in two previous works a saturation in the energy resolution was observed in case of high energy gamma rays. Crystal non-homogeneities and PMT gain drifts can affect the resolution of measurements especially in case of high energy γ −rays
Measurement of high energy gamma rays with large volume LaBr3(Ce) scintillators
none20nonePellegri, L.; Brambilld, S.; Riboldi, S.; Camera, F.; Giaz, A.; Krasznahorkay, A.; Stuhl, L.; Csatlds, M.; Gulyàs, J.; Benzoni, G.; Blasi, N.; Bottoni, S.; Bracco, A.; Boiano, C.; Crespi, F.C.L.; Leoni, S.; Million, B.; Nicolini, R.; Vandone, V.; Wieland, O.Pellegri, L.; Brambilld, S.; Riboldi, S.; Camera, F.; Giaz, Agnese; Krasznahorkay, A.; Stuhl, L.; Csatlds, M.; Gulyàs, J.; Benzoni, G.; Blasi, N.; Bottoni, S.; Bracco, A.; Boiano, C.; Crespi, F. C. L.; Leoni, S.; Million, B.; Nicolini, R.; Vandone, V.; Wieland, O