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