Scintillators testing at Prague

1. V. Vorobel, SuperNEMO meeting, Bordeaux Scintillators testing at Prague Vít Vorobel, AivarasZukauskas, DimitriMathian PetrPridal, FadahatMamedov GuillaumeLutter, EmmanuelChauveau Oleg Kochetov (Financed by FMP ChU, IEAP CTU, JINR Dubna)

2. V. Vorobel, SuperNEMO meeting, Bordeaux Outline • Spectrometers - hysteresis, vacuum, calibration • Scintillator testing setup, stability • X-wall blocks (Envinet) scan

3. V. Vorobel, SuperNEMO meeting, Bordeaux “Spectrometers” • Dubna #1 Dubna #2 (in BlackBox) Praha • Best reached vacuum ~100 Pa in all three spectrometers

4. V. Vorobel, SuperNEMO meeting, Bordeaux Setup • NEMO3 PMT 5 inch + cookie inside steel tube (mag shielding) • Wrapped scintillator block • Aluminium frame supporting block with PMT • DeltaE detector - 100mm PVT + 2 PMT • Spectrometer • XY-table

5. V. Vorobel, SuperNEMO meeting, Bordeaux Setup • Black Box 100 x 130 x 130 cm • PMTs NEMO-3 5’. • Delta E - 100 mm PVT Eljen foil, 2 PMTs in coincidence • Signal readout – Digitizer CAEN V1720, 8 channel, alternatively Amplifier + ADC. • Monoenergetic electron source - “Spectrometer” • Power SuplyTTi, PC controlled. • magnet yoke - low hysteresis material. • 90Sr, 370MBq • Spectrometer calibration • Si detector, 1 mm thickness, 20 mm2. • 207Bi, 100 kBq. • XY-table Range 45 x 45 cm. Control with PC serial port

6. V. Vorobel, SuperNEMO meeting, Bordeaux Calibration • Bi207 used for calibration of Si detector (1 mm thickness) • FWHM ~20 keV at 976 keV

7. V. Vorobel, SuperNEMO meeting, Bordeaux Spectrometer calibration 260 keV 385 keV 510 keV 640 keV 770 keV 900 keV 1040 keV 1170 keV 1440 keV • FWHM ~30 keV at 1 MeV

8. V. Vorobel, SuperNEMO meeting, Bordeaux Hysteresis • – Set I = -2 A • – Increase gradually current • and measure Eup(I) • – Set I= +2 A • – Decrease gradually current • and measure Edown(I) • Electron energy measured with 1 mm Si detector Original yoke Low hyst. yoke

9. V. Vorobel, SuperNEMO meeting, Bordeaux Assembly procedure • Teflon tape 3 layers • Mylar 12 mm 2 layers • Optical grease BC630

10. V. Vorobel, SuperNEMO meeting, Bordeaux Stabilization • Electron energy from spectrometer set 1 MeV • Electrons measured with X-wall block • Peak position vs. time displayed • Stabilization reached in 15 hours Dubna spectrometer #2

11. V. Vorobel, SuperNEMO meeting, Bordeaux X-wall blocks – Envinet (exposition 20 min.)

12. V. Vorobel, SuperNEMO meeting, Bordeaux X-wall scintillator # 1 (FWHM at 1 MeV)

13. V. Vorobel, SuperNEMO meeting, Bordeaux X-wall scintillator # 2 (FWHM at 1 MeV)

14. V. Vorobel, SuperNEMO meeting, Bordeaux X-wall scintillator # 3 (FWHM at 1 MeV)

15. V. Vorobel, SuperNEMO meeting, Bordeaux Conclusion • We are ready to characterise the scintillator blocks • FWHM of 3 X-wall blocks measured 12.7-14.7 % (spectrometer resolution not subtracted), measurement will be repeated Plan • 69 X-wall blocks still in Prague • 4 of them should be measured in Prague, Bordeaux, UCL for cross-check

16. V. Vorobel, SuperNEMO meeting, Bordeaux Backup

17. V. Vorobel, SuperNEMO meeting, Bordeaux Stabilization Prague spectrometer

18. V. Vorobel, SuperNEMO meeting, Bordeaux Stabilization Dubna spectrometer #2 Dubna spectrometer #2

19. V. Vorobel, SuperNEMO meeting, Bordeaux Stabilization Dubna spectrometer #2

20. V. Vorobel, SuperNEMO meeting, Bordeaux

21. V. Vorobel, SuperNEMO meeting, Bordeaux

22. V. Vorobel, SuperNEMO meeting, Bordeaux