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. Akgun 1, A.S. Ayan 1, F. Duru 1, E. Gulmez 2, M. Miller 1, J. Olson 1 Y. Onel 1, I. Schmidt 1 with Quarknet Group – P. Bruecken, C. Like, R. Newland 1 University of Iowa, Iowa City, USA 2 Bogazici University, Istanbul, Turkey Abstract We 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 batch Single photoelectron spectrum X-Y scan (spatial uniformity) Lifetime For each tube: Pulse width Pulse rise time Transit time Transit time spread Anode 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 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 CONCLUSION: We can sort pmts w.r.t. their Relative Gain values

Gain vs HV for Relative Gain %50-%70

Lifetime Measurement Setup

Timing characteristics after 1100 C 0472 Pulse WidthRise TimeAv. Transit TimeTransit Time Spread Before 3.74ns2.02ns15.5ns0.148ns After 3.74ns2.14ns15.4ns0.173ns 0252 Pulse WidthRise TimeAv. Transit TimeTransit Time Spread Before 4.12ns1.98ns15.5ns0.094ns After 3.8ns2.12ns15.4ns0.174ns 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 specIowa Tests Window Material Borosilicate glass PASSNA Eff. Pho.cath. dia mm, head-on PASSNA Quantum efficiency >15% nm PASSNA Photocathode lifetime >200 mC PASSNA Anode current vs position <+/-20% with 3 mm spot scan PASS Gain 10^4 to 10^5,10^5 at <0.75 x V ka(max) PASS Single pe resolution rms/mean if single pe peak 50% or better PASS Pulse linearity +/- 2% for photoelectrons (g=4X10^4) PASS Anode pulse rise-time <5ns PASS Transit time <25 ns preferred PASS Transit time spread <2 ns preferred PASS Anode pulse width <15 ns FWHM PASS Gain (1/2)-lifetime >1500 C PASSNA Gain recov. (2000pe pulse) within 10% of nominal (g=10^4) in 25 ns PASS Average current Ik <1 nA (g=10^4) PASS Average current Ia <10 microA (g=10^4) PASS Anode dark current <2 nA (g=10^4) PASS Stability <+/- 3% within any 48 hr. period PASSNA Envelope opaque and -HV conductive coating PASSNA