1. Tests of scintillators CsI, CsI(Na), BGO, NaI(Tl) CsI(Tl)

2. CsI(Na) 170 mm 15 x 15 mm 9 x 9 mm

3. Energy of PMT 1 (small window) Energy of PMT 2 (big window) CsI(Na) scintillator with 2 PMT readout Full absorption Measurement without collimation 137 Cs, 661 keV

4. Energy of PMT 1 (small window) Energy of PMT 2 (big window) CsI(Na) measured with a collimated source Sum (energy) Ratio (position)

5. Energy spectrum (sum of 2 PMT’s energies) Sum of 2 PMTs energies Energy resolution 9.6% at 661 keV Constant for the position of the interaction

6. Position resolution (ratio of the PMT’s energies) Light division between 2 PMTs 15 cm 10 cm 5 cm

7. Position resolution

8. Position resolution 1.5 – 3 cm

9. Mean absorption distance

10. Readout with one PMT 5 cm 10 cm 15 cm

11. CsI, pure

12. Energy resolution Resolution 17 – 19 % Sum energy

13. Position resolution Light division between 2 PMTs 15 cm 10 cm 5 cm

14. Position resolution

15. Position resolution 2 – 8 cm

16. BGO

17. Energy of PMT 1 (small window) Energy of PMT 2 (big window) 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

18. BGO collimated measurement Full absorption

19. BGO collimated measurement Full absorption

20. 1)Light yield is strongly non uniform along the crystal distance 2)Light separates always in the same proportion between left and right sides 3)Energy resolution ≈18% (big window) ÷ 24% (small window) BGO results

21. CsI(Tl) 7% at 661 keV 2.5 cm

22. to continue with..