Boron-GEM3 – Further measurements

1. Boron-GEM3 – Further measurements Dorothea Pfeiffer 19.03.2014

2. Content • X-ray spectrum of 241 AmBe source • Neutron spectrum measured with Boron-GEM3 with 8 mm drift • Mesaurements with SRS • What’s next? Dorothea Pfeiffer

3. Measurements with AMPTEK XR-100CRSi-PIN X-Ray detector 5.9 keV 6.49 keV

4. Efficiency of AMPTEK XR-100CRSi-PIN X-Ray detector (500 um Si, 1 mm Be) Dorothea Pfeiffer

5. 241 Am example spectrum AMPTEK XR-100CRSi-PIN X-Ray detector

6. Measurements with AMPTEK XR-100CRSi-PIN X-Ray detector (efficiency corrected) 13.95 keV 17.74 keV 59.54 keV

7. Triple GEM with Boron-10 converter (variant 2) Drift cathode: 18 um Al foil coated with 1.3 um10B4C one side 8mm 2 mm 2 mm 2 mm Dorothea Pfeiffer

8. Boron GEM3: 18 um Al foilwith 1.3 um 10B4C y coordinate (APV chips not connected) x coordinate (APV chips not connected) Dorothea Pfeiffer

9. 55 Fespectrum ADC channel 50 at preamp gain 10 = about channel 25 at preamp gain 5 ?

10. 241 AmBespectrum, driftgap 8 mm ADC channel 2800(~ 672 keV)Li peak 840 keV) ADC channel 5000 (~ 1.2 MeV)alpha peak 1.47 MeV

11. SpectrumfromBoron Blade DetectoratILL Looks similar to our spectrum, also only one peak (not two peaks for alpha and Li ion) Dorothea Pfeiffer

12. Boron GEM3: twosectors:withandwithout 18 um Al foilwith 1.3 um 10B4C 1 cm of lead covering whole detector Normal cathode on top 1 2 y Sector 1: 1 cm lead Sector 2: 10B4C converter and 1 cm lead x Dorothea Pfeiffer

13. Boron GEM3: twosectors – 55 Fesource Looks similar to our spectrum, also only one peak (not two peaks for alpha and Li ion) 1 2

14. Boron GEM3: twosectors – 55 Fesource Looks similar to our spectrum, also only one peak (not two peaks for alpha and Li ion) 1 2

15. Boron GEM3: twosectors – 55 Fesource 1: x 1: y Spectra in sector 2 have 50% of the hits 2: x 2: y

16. Boron GEM3: twosectors – 55 Fesource 1: x 1: y Cut in sector 2, x=4: Kapton tape? But in y? 2: x 2: y

17. Boron GEM3: twosectors – 241AmBe source • Due to limited dynamic range of the APV, measurement had to be carried out with very low gain of about 15 (I=565 uA, U=3250 V) • Even then saturation visible saturation Dorothea Pfeiffer

18. Boron GEM3: twosectors – 241AmBe source Looks similar to our spectrum, also only one peak (not two peaks for alpha and Li ion) 1 2

19. Boron GEM3: twosectors – 241AmBe source Looks similar to our spectrum, also only one peak (not two peaks for alpha and Li ion) 1 2

20. Boron GEM3: twosectors – 241AmBe source Sector1 + 2 Looks similar to our spectrum, also only one peak (not two peaks for alpha and Li ion)

21. Boron GEM3: twosectors – 241AmBe source sector1 Looks similar to our spectrum, also only one peak (not two peaks for alpha and Li ion)

22. Boron GEM3: twosectors – 241AmBe source sector2 Looks similar to our spectrum, also only one peak (not two peaks for alpha and Li ion)

23. Boron GEM3: twosectors – 241 AmBesource 1: x 1: y 2: x 2: y

24. Boron GEM3: twosectors – 241 AmBesource 1: x 1: y Spectra in sector 2 have 2% of the hits compared to sector 1 2: x 2: y

25. Boron GEM3: twosectors – 241 AmBesource Calculation of “neutron spectra”: sector 2 – sector 1 6Li peak and alpha peak? Energy calibration with APVs and SRS? Dorothea Pfeiffer

26. Boron GEM3: twosectors – 241 AmBesource 1: x 1: y Source not perfectly centered on detector 2: x 2: y

27. Boron GEM3: Foursectors Sector 1: free (normal GEM) Sector 2: 1 cm lead Sector 3: 10B4C converter 1 cm of lead 1 3 Sector 4: 10B4C converter and 1 cm lead y 2 4 x Dorothea Pfeiffer

28. Boron GEM3: Foursectors 2 sector measurements 4 sector measurements Problem with one of the APVs apparent at the end of the measurement, but also variability very large in first part of dataset (event number < 150000) => repeat measurements Dorothea Pfeiffer

29. TO DO • Measure X-ray spectrum of 241 AmBe source with lead in front • Measure gamma spectrum of 241 AmBe with Sodium Iodide chrystal • Repeat 4 sector measurement with SRS • Organize Gadolinium samples Dorothea Pfeiffer