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TEST SETUP FOR HF PMT AT IOWA LAB

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TEST SETUP FOR HF PMT AT IOWA LAB Powered By Docstoc
					WBS 2.5 HF PMT SYSTEM
            Y. Onel
       University of Iowa
   US CMS DOE/NSF Review
        May8-10, 2001
                                    Outline
•   HF PMT Specifications
•   Previous Experimental Data on Photodetectors by HF Group
•   Tasks of the Test System:
•   Procedures for measurements
•   Quality Assurance
•   HF PMT Test Station
•   Preliminary HF-PMT Candidate Tests/Specs
•   Experimental Data
•   Manpower and expert team to install the test system
•   Vendors
•   Milestones
•   Conclusions
        Previous Experimental Data on
         Photodetectors by HF Group
R6427
                            HF Radiation Environment
•   Recent radiation background simulations
    show improvement in the design of the
    shielding around the PMT region by a
    factor of ~two. There is no issue with the
    radiation dose or neutron flux where the
    PMTs are located.



•   All neturons                  2.54x1012
•   Neutrons (E>100KeV)           1.63x1012
•   Neutrons (E>20 MeV)           5.12x1011
•   Ch. Hadrons                   2.26x1010
•   Muons                         4.65x109
•   Photons                       1.53x1012
•   Dose                          7 krad
         HF PMT Quantum Eff.
• <QE>          >15 % 400-500 nm


                              QP Fiber
                            54 Mrad Dose
                     HF-PMT Specifications Summary
Window Material                Borosilicate glass
Effective photocathode dia     22 - 28 mm, head-on
<QE>                           >15 % 400-500 nm
Photocathode lifetime          > 200 mC
Anode current vs position      < +/- 20 % with 3 mm spot scan
Gain                           104 to 105, 105 at < 0.75 x VKA(max)
Single pe resolution           rms/mean of single pe peak 50 % or better
Pulse linearity                +/- 2 % for 1-3000 photoelectrons
Anode pulse rise-time          < 5 ns
Transit time                   < 25 ns preferred
Transit time spread            < 2 ns preferred
Pulse width                    < 15 ns FWHM
Gain (1/2)-lifetime            > 1500 C
Average current IK             < 1 nA ( g = 104 )
Average current IA             < 10 mA ( g = 104 )
Anode dark current             < 2 nA ( g = 104 )
Stability                      < +/- 3 % within any 48 hr. period
Envelope                       opaque and –HV conductive coating
           Tasks of the PMT Test System:

HF PMT Quality Control and Test System will address
 the following items:
•   label and catalogue each PMT at delivery and storage;
•   mechanical assembly with HV power supply and base;
•   installation in Test Boxes : individually or in groups;
                           Procedures for measurements
The following sequence of measurements will be performed for each PMT or each PMT batch:

    1 - PMT's installed in Test-Box are let to stabilize at standard HV; [each tube]
    2 - Check of normal operating conditions [each tube]
    3 - Noise and dark current measurements vs. HV; [each tube]
    4 - Gain vs. HV [laser]; [each tube]
    5 - Single photoelectron level; [each tube]
    6 - Linearity for 1- 3000 p.e.; [each tube]
    7 - Rate dependence for 0.1 - 40 MHz [LED]; [each tube]
    8 - Photocathode uniformity; [for each batch]
    9 - Quantum efficiency (300-600 nm) [dye laser]; [for each batch]
   10 - Pulse shape measurements at nominal HV. [for each batch]

According to specifications of the PMT (manufacturer's data sheet and preliminary measurements on
   a test sample) and requirements of HF application (Nphe/GeV, dynamic range, etc.) the test setup
   working conditions will be adjusted in a range of light yield and sensitivity appropriate for the
   standard test procedure. Three light sources will be used for the specific measurements:
   - laser
   - LED
   - Rad. sources + radiator
•   Measurements will be performed at stable (controlled) temperature using
    defined procedures for each PMT or each PMT batch.
•   Light sources will be installed (Tungsten Lamp, Laser, Dye Laser, Laser
    Diodes) for the specific measurements
•   The data for each PMT will be stored in appropriate archive files on disk
    and copied to permanent storage media. For each PMT an entry will be
    printed and logged to a general PMT directory and test logbooks.
•   The PMT's conforming to acceptance criteria, will be sorted in classes
    and stored. Those not conforming will be returned to the manufacturer.
•   All measurement procedures will be automated and computer-controlled,
    to minimize individual biases and interventions; daily test shifts will be
    supervised by an expert, who will also review the archived data of the day
    and certify their validity.
•   The fully automated PMT Test station will contain (x-y scanners, neutral
    density filter wheels [computer controlled], optical bench, DAQ
    [LabView] and interface systems.)
               Quality Assurance
• At the manufacturer
• testing/preselection as they arrive
• beam/calibration tests during the installation
  period
• PMT can be replaced
                            HF PMT Test Station
                                                                                   IEEE
                                                                                   488

                                Calib
                                Power
                                Meter

                                                       sync
                                                               Scope
                     VARIABLE                          trig
                        ND
                      FILTER            ND
                                        Filter
                                                               D8
             0-3mm                               PMT   CW                Nano-
LASER
                                                       base    A         ammeter
DIODE
             635 nm

                                                                                          PC

             sync                                  x-y stage
PULSAR                                  GATE                            CAMAC
             trig                                                gate    ADC
W/ double
4:1 option
                                                                                   scs
                                                                                   i
                   PMT Measurements
1.* Quantum Efficency
2.* Dark Current **
3.* Gain **
4.* pulse height resolution
5.   Gain vs. High Voltage **
6.   Linearity and pulse-rate dependance **
7.   Rise-time **
8.   Transit-time **
9.   Transit time spread **
10. Pulse width **
11. Current vs. Photocathode spot position
12. Anode sensitivity vs wave length
* Vendor measurements
** Iowa measurements on the candidate tubes
               Manpower and expert team to install the test
                               system


UI                                  ISU
U. Akgun (DAQ, Pulse Setup)         W. Anderson (DAQ, Specs)
A. Ayan (DAQ, Pulse Setup)
P. Bruecken (Dye Laser System,      Fairfield U
      Pulse Setup)
M. Miller (LED System, Optical      D. Winn (Gain Setup, Specs)
      Installation, Electronics)
Y. Onel (Project Manager,           International Team
      Procurement, Specs)           I. Dumanoglu Turkey (DAQ)
I. Schmidt (Mechanical              E. Gulmez Turkey (Electronics,
      Installations, Electronics,
      Gain Setup)                       Trigger)
Post-doc (TBN) (Test Facility
      Manager)
          Preliminary HF-PMT Candidate
                    Tests/Specs

Measurements
1. Anode Dark Current
2. Leading Edge Rise Time
3. Pulse Width
4. Transit Time
5. Transit Time – Spread
6. Current Gain
7. Linearity
Photodetector Linearity Measurements
Neutral Density Filter Setup
Scope View
                   Transit Time, Rise Time,
                         Pulse Width
     25



     20



     15
                                                  trans. Time
ns




                                                  rise time
     10                                           pulse width



     5



     0
      900   1000   1100   1200   1300   1400   1500
                           V
                     Gain & Dark Current
                                   1000000




                                    100000




              Gain


                            gain
                                     10000




                                      1000




                                       100
                                          100            1000      10000
                                                          V



       1
        100          1000                       10000




                                                        Dark Current
nA




      0.1




     0.01
                      V
       PMT Manufactures Contacted and
               Candidates

Hammamatsu      R7525
Electron Tube   D843WSB       D844WSB
Photonis        XP2960        XP3182
Burle           no response
ADIT            no response
Melz            no response
                     Procurement/Testing Strategy


•   Hamamatsu, for example, will deliver 200 PMTs/month. We need ~14.3
    months.
•   PMTs will be supplied with gain of 3x105 with gain measurements at
    1300, 1500 and 1650 V by Hamamatsu.
•   The cost estimate is 690 K$ based on 110 Yen/$.
•   Sole source or bidding? There are several PMTs that would do the job.
•   We should be able to test at the same rate as production, i.e. 10 PMTs/day,
    on average.
•   The PMT responsibilities are with Iowa, ISU and Fairfield.
                               Milestones
Draft RFP                                        March.15.01
Evaluate samples                                 May.15.01
PMT test station ready                           August.15.01
Final contract signed                            September.15.01
Delivery 1st batch 100 PMTS                      November.1.01
Delivery last batch                              January.1.03

*Assuming delivery of 200-300 PMT’s after 3 months of receiving
  order. Then delivery 200-300 PMT’s per month as last batch
  delivered by January 1, 2003.
*We budget total of 1 hour to unpack, test, label, repack, and enter,
  merge publish & archive data 2700 PMT. The selection database
  will be maintained for each PMT together with the base and front
  end electronics.
                         Tube Base

• Prototype completed end of January
   – Cockroft-Walton multiplier style base
   – Series resonant sine-wave converter invented by
     Claudio Rivetta and implemented by Sten Hansen
     (Fermilab)
      • Very low noise
      • Low power consumption
   – Last dynode voltage sags 0.5 V from 0 to 200
     microamps – factor of 20 headroom for the hottest
     tubes at eta = 5
   – Iowa State and Texas Tech Universities responsible for
     specifications and testing
Tube Base Prototype
                       Conclusions
• We had PRR at CERN in Feburary
• We have evaluated the performance of the candidate PMTs
• RFP is drafted and we expect to sign the final contract in
  early September
• We have designed the PMT test station and built a small
  prototype version to evaluate the candidate PMTs.
• Computer controlled x-y scanner and neutral density fibers
  are built and presently under test
• Major components of the final PMT station and related
  electronics are purchased and the system will be ready by
  mid-August
• Design of CW bases are in progress at FNAL
• The PMT readout project is on time and budget

				
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