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Tests of scintillators. CsI, CsI(Na), BGO, NaI(Tl). CsI(Tl). CsI(Na). 15 x 15 mm. 9 x 9 mm. 170 mm. Full absorption. CsI(Na) scintillator with 2 PMT readout. Measurement without collimation 137 Cs, 661 keV. Energy of PMT 2 (big window). Energy of PMT 1 (small window). Ratio (position).
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Tests of scintillators CsI, CsI(Na), BGO, NaI(Tl) CsI(Tl)
CsI(Na) 15 x 15 mm 9 x 9 mm 170 mm
Full absorption CsI(Na) scintillator with 2 PMT readout Measurement without collimation 137Cs, 661 keV Energy of PMT 2 (big window) Energy of PMT 1 (small window)
Ratio (position) Sum (energy) CsI(Na) measured with a collimated source Energy of PMT 2 (big window) Energy of PMT 1 (small window)
Energy spectrum (sum of 2 PMT’s energies) Energy resolution 9.6% at 661 keV Constant for the position of the interaction Sum of 2 PMTs energies
Position resolution (ratio of the PMT’s energies) 5 cm 10 cm 15 cm Light division between 2 PMTs
Position resolution Position resolution 1.5 – 3 cm
Readout with one PMT 15 cm 10 cm 5 cm
Energy resolution Resolution 17 – 19 % Sum energy
Position resolution 5 cm 10 cm 15 cm Light division between 2 PMTs
Position resolution Position resolution 2 – 8 cm
BGO scintillator with 2 PMT readout Scintillator was illuminated by Cs137 source (661 keV) without a collimator Strong nonuniformity of light yield along the crystal distance Energy of PMT 2 (big window) Energy of PMT 1 (small window)
BGO collimated measurement Full absorption
BGO collimated measurement Full absorption
BGO results • Light yield is strongly non uniform along the crystal distance • Light separates always in the same proportion between left and right sides • Energy resolution • ≈18% (big window) ÷ 24% (small window)
CsI(Tl) 7% at 661 keV 2.5 cm 2.5 cm