VPT information

VPT ECAL Endcap web page

VPT Point5 analysis

VPT irradiation studies

VPT conditioning, consolidated rig data

John Wood UVa VPT conditioning data

VPT conditioning estimates

UVA and Brunel conditioning data

EE HV scans

RCA photomultiplier handbook - high rate operation

Single VPT test rig

VPT DC gain and pulsed gain

For the DC gain measured at RIE (at B = 0 T), g:
i_anode = g * i_pc
This can be re-phrased assuming a dynode-anode net gain, g^'
i_anode = 0.5 * i_pc + 0.5 * i_pc * g^'
where the 0.5 is the fraction of i_pc going direct to the anode, and also the fraction of i_pc going to the dynode
since the anode transparency factor is 0.5.

Therefore:
g = i_anode / i_pc = ( 0.5 * i_pc + 0.5 * i_pc * g^' ) / i_pc
Thus:
g^' = (g / 0.5) - 1 = 2g -1

For pulsed gain, the direct photo-cathode to anode current does not contribute since the RC time is so large wrt timescales of 40 ns.
Only the photo-current to the dynode counts, thus:
i_anodepulsed = 0.5 * i_pc * g^'

Thus:
Pulsed gain = i_anodepulsed / i_pc = 0.5 * g^'
so:
Pulsed gain = 0.5 * (2g - 1) = g - 0.5
where g is the DC gain measured by RIE

Conditioning data

• John Wood - all tube conditioning data and fits

John Wood's plotting and analysis code:

git clone "https://github.com/jgwood3141/cms_vpt_studies.git" 

Macro: vpt_plots.C

VPT papers

• VPT_Paper_V3.pdf, 9 Feb 2012
• UVa, preliminary, 28 July 2011
• The_Imrie_papers.pdf

RIE VPT Specifications:

• RIE, 0T, gain > 7 at 1.0/0.8kV
• RIE, 0T, q.e > 15% at 420nm
• RIE, 0T, gain*q.e. > 1.4
• RIE, 0T, gain*q.e. < 3.8
• RAL, visual cathode lost < 20%
• RAL, I leakage at 1.0/0.8 kV < 2nA
• RAL, yield at 1.8T, Y>10, Y<70 e/MeV
• Brunel, yield 4T (where measured) 4T/0T > 0.75

• Temperature Ranges:
• Operational temperature range 10 degC < T < 35 degC
• Non-operational temperature range -5 degC < T < 50 degC

• Training: Photocurrent 100 nA for 2h
• Burn-in: Photocurrent 100 nA for 4h = 1.44 mC
• Burn-in If/Io > 0.9 for acceptance

• VPT acceptance cuts

• VPT Point 5 info, ELMB channel information, ELMB-correspondences.txt

• VPT temperature dependance, P Hobson, 22 March 2010, p8-9

VPT Data

Files at RIE data files. They contain:

vpt-barcode  vpt-prod-number  Glass-batch  Burn-in-I0  Burn-in If  Ratio-If/I0  Idark  QE  G   Ia(G)  P*G

Best Crystal + VPT data

File from from F Cavallari, 18 May 2011 (email complete_file.txt)

File final_endcap_ly_plustb.xls, which contains:

z    x   y   barcode   batch   producer      gain   qe   pg   sig0cal   sigcal   grid0offC   pkmissFrac   status   sc-pos-in-Dee   vpt-pos
t360   t420   t620   ly8x0 fnuf   rnuf    wavw_disp  ttgrad   dee-number   SC-number   crystal-barcode-short   vpt-barcode-short   producer   
lycoef75     YY   MM   DD   hh   mm   ss   mach   lyref     CRYSTALBarcode    z   x   y   cali   caliBcor   Bcor    lyb*gbest    tbcali   lybest   gainbest   xtal-barcode

RIE burn in data, endcaps-burn-in.root

VPT test reports

2013

14.11.2013 UVa VPT test stand project update to DPG, John Wood, DPG slides

14.5.2013 VPT Conditioning, D Cockerill to ECAL Ugrade meeting

1.2.2013 New Brunel VPT 947, new UVa VPT set EE op mtg 1 Feb 2013

2012

27.11.2012 John Wood, UVa, update, EE Performance and Stability, EE op mtg 27 Nov 2012

14.6.2012 VPT burn-in measurements, D Cockerill to ECAL MoCa meeting

9.2.2012 VPT paper, V3 draft, faceplate irradiation results. NO FURTHER BRUNEL data in 2012 ?? EE op mtg 9.2.2012

2011

1.12.2011 UVa paper draft at EE op mtg 1.12.2011

11.8.2011 New Brunel paper draft with UVa text/figs incorporated EE op mtg 11.8.2011

28.7.2011John Wood, UVa paper draft. Peter agreed to merge UVA/Brunel texts EE op mtg 28.7.2011

19.5.2011 Sasha: Blue/Orange precision, summary result for Brunel VPT 16203 EE op mtg 19.5.2011

21.4.2011 DC gains, UVa first VPT set EE op mtg 21.4.2011

24.3.2011 New VPT paper draft v1, new Brunel VPT, 2696 EE op mtg 24.3.2011

10.3.2011 Report on 75C heating of VPT, new VPT set at UVa EE op mtg 10.3.2011

10.2.2011 Faceplate irradiations EE op mtg 10.2.2011

13.1.2011 Dawn, VPT annealing and subsequent load results, EE op mtg 13.1.2011

2010

25.11.2010 Brunel - Proton faceplate irradiation results, UVa/Brunel - DC gain measurements EE op mtg 25.11.2010

28.10.2010 Discuss move to new VPTs in test rigs at UVa and Brunel

14.10.2010 UVa - initial fits, Sasha - Blue/Orange results EE op mtg 14.10.2010

2.9.2010 EE op mtg 2.9.2010
John Wood joins Michael Balazs at UVa
Dawn - VPT annealing
Dave C - EE long term performance draft
Vince - EE HV interventions

5.8.2010 Dawn Leslie, VPT recovery/annealing EE op mtg 5.8.2010
5.8.2010 Sasha Ledovskoy, comments on load on/off jumps EE op mtg 5.8.2010

8.7.2010 Dave Cockerill, HV scan results EE op mtg 8.7.2010

24.6.2010 Sasha Ledovskoy, stabilizing effects of stability pulser EE op mtg 24.6.2013

29.4.2010 Dawn - Proposed title "The stability of vacuum phototriodes to varying light loads and long term changes in response" List of contents discussed. First draft mid June. See docs at EE op mtg 29.4.2010

4.3.2010 From Dawn Leslie, first draft outline and first 'to do list' for the VPT paper, see docs at EE op mtg 4.3.2010

18.2.2010 VPT paper - discussion. Agreed - will make a start on a VPT paper. Sasha, Dave and Dawn to meet to draw up list of topics, see minutes at EE op mtg 18.2.2010

EE Upgrade considerations

• Upgrade talks

Theories concerning VPT conditioning

• FNAL, 20 Nov 2008, Pictures/Slides from Bob Brown's upgrade talk

Right click to view image full scale

* VPT-Picture1.png:

* VPT-Picture2.png:

• VPT-Picture3.png:
  

* VPT-Picture4.png:

• VPT-Picture1.png:
  

• VPT-Picture2.png:
  

• VPT-Picture3.png:
  

• VPT-Picture4.png:
  

• PM-tube-Nuggets.pdf: PM-tube-Nuggets.pdf

• ELMB-correspondences.txt: ELMB-correspondences.txt

• complete_file.txt: complete_file.txt

• endcaps-burn-in.root: endcaps-burn-in.root

• The_Imrie_papers.pdf: The_Imrie_papers.pdf

• The_Imrie_papers.pdf: The_Imrie_papers.pdf

• The_Imrie_papers.pdf: The_Imrie_papers.pdf

• CMS__ECAL_DPG__VPT_Conditioning_Studies__Update_of_UVa_TestStand_20131114.pdf: CMS__ECAL_DPG__VPT_Conditioning_Studies__Update_of_UVa_TestStand_20131114.pdf