CMS HF PMT SYSTEM
description
Transcript of CMS HF PMT SYSTEM
CMS HF PMT SYSTEM
By
Y. ONEL
U. of Iowa, Iowa City, IA
HF-RBX PRR
CERN
Apr 3-4, 2003
CMS-HF PMT Test and Quality Control System
U. Akgun1, A.S. Ayan1, F. Duru1, E. Gulmez2,
M. Miller1, J. Olson1
Y. Onel1, I. Schmidt1
with Quarknet Group – P. Bruecken, C. Like, R. Newland
1 University of Iowa, Iowa City, USA2 Bogazici University, Istanbul, Turkey
AbstractWe have measured the specifications proposed by the CMS-HCAL committee on the candidate phototubes from the three major manufacturers; Hamamatsu, EMI and Photonis. In this report, we present the results from those measurements and we outline the future measurements for the test and the quality control as well as the design of the new University of Iowa PMT test station facility.
Tasks of the Test System
For one tube in every batch:Double-pulse linearity,
Gain vs HV for each batchSingle photoelectron spectrumX-Y scan (spatial uniformity)
Lifetime
For each tube:Pulse width
Pulse rise timeTransit time
Transit time spreadAnode dark current
Relative gain coupled with cathode sensitivity, Pulse linearity
Quality control decision on each tube.
UNIVERSITY of IOWA PMT TEST STATION
LabVIEW software
PMT Timing Data (1900 PMT’s)
PMT Timing Data (1900 PMT’s)
PMT Data (1900 PMT’s)
CA0058 Double Pulse Linearity
Double Pulse Linearity Results on 10 PMTs
Note: Statistical error is %0.9
Single Photoelectron Spectrum at 1100V
Single Photoelectron Spectrum at 1500V
XY Uniformity
Definition of Relative Gain and Gain
Relative Gain (Normalized Output):Anode output of a PMT when exposed to the same
light intensity (±2%) as the Reference PMT and normalized with respect to the output of the Reference PMT
For each PMT, Reference PMT is also tested.
Gain:
Anode output current / Cathode output current
Relative Gain vs Gain
Relative Gain vs Gain at 1100V
1000
10000
100000
1000000
40 90 140 190
Relative Gain (%)
Ga
in
CONCLUSION: We can sort pmts w.r.t. their Relative Gain values
Gain vs HV for Relative Gain %50-%70
Gain vs HV for Relative Gain %50 - %70
1000
10000
100000
1000000
10000000
700 900 1100 1300 1500 1700
High Voltage
Gai
n
RG_52.4
RG_52.7
RG_57.8
RG_60
RG_65
RG_65.295
RG_68.7
RG_68.7
RG_70
Lifetime Measurement Setup
Timing characteristics after 1100 C
0472
Pulse Width Rise Time Av. Transit Time Transit Time Spread
Before 3.74ns 2.02ns 15.5ns 0.148ns
After 3.74ns 2.14ns 15.4ns 0.173ns
0252
Pulse Width Rise Time Av. Transit Time Transit Time Spread
Before 4.12ns 1.98ns 15.5ns 0.094ns
After 3.8ns 2.12ns 15.4ns 0.174ns
After more than 1100 C of charge accumulation: - No change in timing properties.- Gain dropped to %70 of initial value. - Experiment is still on.
PMT Web Database
Sort by column(Ascending or Descending)
Pagination reference for large data sets
Alternating colors to aid readability
More extensive search/sort options are being developed
PMT Web Database
Manufacturer spec Iowa Tests
Window Material Borosilicate glass PASS NA
Eff. Pho.cath. dia. 22-28mm, head-on PASS NA
Quantum efficiency >15% 400-500 nm PASS NA
Photocathode lifetime >200 mC PASS NA
Anode current vs position <+/-20% with 3 mm spot scan PASS PASS
Gain 10^4 to 10^5,10^5 at <0.75 x V ka(max)
PASS PASS
Single pe resolution rms/mean if single pe peak 50% or better
PASS PASS
Pulse linearity +/- 2% for 1-3000 photoelectrons (g=4X10^4)
PASS PASS
Anode pulse rise-time <5ns PASS PASS
Transit time <25 ns preferred PASS PASS
Transit time spread <2 ns preferred PASS PASS
Anode pulse width <15 ns FWHM PASS PASS
Gain (1/2)-lifetime >1500 C PASS NA
Gain recov. (2000pe pulse) within 10% of nominal (g=10^4) in 25 ns
PASS PASS
Average current Ik <1 nA (g=10^4) PASS PASS
Average current Ia <10 microA (g=10^4) PASS PASS
Anode dark current <2 nA (g=10^4) PASS PASS
Stability <+/- 3% within any 48 hr. period PASS NA
Envelope opaque and -HV conductive coating PASS NA