Cf252 NaI detector test. Apr 2012

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041212

  • NaI detector,
  • 300 mV threshold on gate channel
  • signal ADC4
  • -1030V at the beginning
  • -1055V at the end of run


Run # source shielding cnts rate Comments
2775 Co-60 away from NaI 2" Pb around, no front shielding 133,884
2776 bkgd 2" Pb around, no front shielding 7,289
2777 Co-60 infront of NaI 2" Pb around, no front shielding 313,427 1.2 and 1.4 MeV peaks, small peak around 4.3 MeV

Calibration 1.4 MeV/575 cnls = 0.00243 MeV/cnl

2778 bkgd 2" Pb around, no front 15,822 41.75 Hz
2779 bkgd all around 2" Pb around 8,566 15.74 Hz good area around 2000-3800 channels
2780 Cf252 all around 2" Pb around 12 kHz Cf252 just in front of NaI
2781 Cf252 all around 2" Pb around 5.4 kHz Cf252 about 15 cm away from NaI
2782 Cf252 all around 2" Pb around 607,790 1.1 kHz Cf252 17" away from NaI
2784 Cf252 all around 2" Pb around 1,372,745 1,142 Hz 20 min run. No shielding in front
2785 Cf252 all around 2" Pb around 153,508 129.5 Hz 20 min run. 2" Pb just after Cf252
2787 Cf252 all around 2" Pb around 1,231,537 1,024 Hz 20 min run. 2" Borated Poly just after Cf252
2788 Cf252 all around 2" Pb around 1,225,232 1,020 Hz 20 min run. 2" Unborated Poly just after Cf252
2790 Cf252 all around 2" Pb around 132,067 111.6 Hz 20 min run. 2" Pb, 2" Borated Poly just after Cf252
2791 Cf252 all around 2" Pb around 108,603 89.6 Hz 20 min run. 4" Pb just after Cf252
2792 bkgd all around 2" Pb around 45,904 25.04 Hz 20 min run. background checking


  • rise time of NaI 50 ns
  • decay time of NaI 3 us


  • run 2784: Cf252 no shielding infront. 1,372,745 events

Cf no shielding infront.png

  • run 2787: Cf252 2" Borated Poly infront. 1,231,537 events

Cf 2inchBoratedPoly infront.png

  • run 2788: Cf252 2" Unborated Poly infront. 1,225,232 events

Cf 2inchUnBoratedPoly infront.png

  • run 2792: background checking. 45,904 events

Background.png

  • run 2785: Cf252 2" Pb infront. 153,508 events

Cf 2inchPb shlng infront.png

  • run 2790: Cf252 2" Pb + 2" Borated Poly infront. 132,067 events

Cf 2inchBoratedPoly 2inchPb.png

  • run 2791: Cf252 4" Pb infront. 108,603 events

Cf 4inchPb shlng infront.png

041312

  • NaI detector,
  • 300 mV threshold on gate channel
  • signal ADC4
  • -1036V switched to modern power supply


Run # source cnts rate Comments
2793 bkg shielding: detector -> 2" Pb around -> 2" Poly around

V = -1014 V

2794 Cf252 1.24 Hz new power supply N471 CAEN, -1035V

Cf252 17 inch away from detector, DAQ crashed
shielding: Al around the NaI -> borated shielding (not infront)

2795 Cf252 55,458 88.23 Hz 4" Pb infront of Cf252 + Al around and inside the shilding

10 min

2796 Cf252 130,122 79.23 Hz 27 min, looking for (n,gamma) capture effect, 10B: 4.44 MeV (100%)

geometry: Cf252 -> 5" Pb -> bored Poly (small brick) -> 2" Al ----> NaI

2797 Cf252 80,763 81.79 Hz geometry: Cf252 -> 5" Pb -> bored Poly (whole) -> 2" Al ----> NaI
2798 Cf252 134,725 95.38 Hz geometry: no Boron but Al is still in

23 min

2799 bkg 21,6941 37.86 Hz background 108 min run

detector -> 2" Pb around (except on the top of detector was 2" Al) -> 2" Poly around

2800 bkg 71,080 12.5 Hz background 94 min run

detector -> 2" Pb around -> 2" Poly around, 4" Poly on top, no Al inside


Bkg.png Cf252 Al aroundandIn.png

Cf252 4inPb Al aroundandIn.png Cf252 5inPb Al aroundandIn smallBin.png

Cf252 5inPb Al aroundandIn wholeBin.png Cf252 5inPb Al aroundandIn noBin.png


  • run 2799, 2800

Background run.png Background run improved shldg.png