1 / 9

Study of scintillator/PMT properties for PoGO experiment

Study of scintillator/PMT properties for PoGO experiment. August 25, 2003@ PoGO Teleconference Tsunefumi Mizuno mizuno@SLAC.Stanford.EDU. BGO Transmission efficiency: pp.2-3 Comparison between two PMTs (normal cathode vs. prism one): pp.4-8 Summary: p.9. BGO transmission efficiency (1).

zena-washington
Download Presentation

Study of scintillator/PMT properties for PoGO experiment

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Study of scintillator/PMT properties for PoGO experiment August 25, 2003@ PoGO Teleconference Tsunefumi Mizuno mizuno@SLAC.Stanford.EDU • BGO Transmission efficiency: pp.2-3 • Comparison between two PMTs (normal cathode vs. prism one): pp.4-8 • Summary: p.9

  2. BGO transmission efficiency (1) 241Am(59.5keV) Hexagonal plastic scintillator BC404 (fast scintillator) wrapped with VM2000. 20cm long Lead block • two types of BGO scintillators wrapped with teflon tape. • manufacture way of polishing; rough surface in sides. Top/bottom surfaces are polished. • Tune’s proposed way polishing; rough surface in bottom. Other planes are polished. Princeton PMT(H3178) We compared transmission efficiency between two types of BGO scintillators; one is in the original way of polishing and the other is re-polished in the way proposed by Tune.

  3. BGO transmission efficiency (2) Peak~3.15 Through re-polished BGO Peak~2.36 Spectrum obtained without BGO fitted with gaussian+BG function. Through BGO in original way of polishing. Peak~2.30 Transmission efficiency: ~75%(re-polished BGO) ~73%(original way of polishing)

  4. Comparison between normal cathode and prism one (1) 55Fe(5.9keV) Hexagonal plastic scintillator BC404 (fast scintillator) wrapped with VM2000. 20cm long Re-polished BGO wrapped with teflon tape Two types of PMTs borrowed from TIT; a) R7899-mod1(normal cathode; S/N AA2190) b) R7899-mod2(prism cathode; S/N ZL1692) We compared the scintillator light yield between normal cathode PMT and prism cathode one in the condition close to PoGO mission(pp.5-6). We also investigated the HV dependence of the light yield(pp.7-8).

  5. Comparison between normal cathode and prism one (2) R7899-mod1 (normal cathode), -1000V Single photo-electron events 55Fe background ??? Background is unstable? BG subtracted spectrum fitted with poisson function. Npe~3.1. Spikes in spectrum are due to the mismatch between histogram binning and ADC resolution. Funny structure seen in ~3.5V needs to be investigated. Normalized BG and 55Fe spectra. (Live time is taken into account)

  6. Comparison between normal cathode and prism one (3) R7899-mod2 (prism cathode), -1000V Single photo-electron events 55Fe background ??? BG subtracted spectrum fitted with poisson function. Npe~3.5. Spikes in spectrum is due to the mismatch between histogram binning and ADC resolution. Funny structure seen in ~3.5V need to be investigated. Normalized BG and 55Fe spectra.

  7. Comparison between normal cathode and prism one (4) R7899-mod2 (prism cathode), -1500V Single photo-electron events 55Fe background ??? Background is unstable? BG subtracted spectrum fitted with poisson function. Npe~3.6. Spikes in spectrum is due to the mismatch between histogram binning and ADC resolution. Funny structure seen in ~3.5V need to be investigated. Normalized BG and 55Fe spectra

  8. Comparison between normal cathode and prism one (5) R7899-mod2 (prism cathode), -800V Single photo-electron events Background 55Fe Background is unstable? BG subtracted spectrum fitted with poisson function. Npe~3.45. Spikes in spectrum is due to the mismatch between histogram binning and ADC resolution. Normalized BG and 55Fe spectra

  9. Summary • BGO transmission efficiency is ~75%. Although it does not depend on the way of polishing very much, Tune’s proposed way of polishing showed slightly better efficiency. • Prism cathode PMT gives a little bit higher light yield (by ~10%) than normal cathode one. • Absolute light yield is >=0.5 p.e./keV for 20cm fast scintillator (wrapped with VM2000) with BGO (wrapped with teflon tape). This does not depend on the applied voltage very much.

More Related