CDMS VETO Scintillator Material Evaluation
Under Construction
Purpose: 1. Evaluate candidate scintillator material for the CDMS2 VETO Panels
2. Test and evaluate the function of candidate scintillator panel light guides to determine what the final configuration will be.
3. Calibrate and charactorize 32 production panels and light pipes.
Method:
Make use of SUF Muon telescope components to test candidate scintillator material by comparing incident cosmic muon hits to those of the candidate material. The test will make use of three telescope test panels to determine when known indecent cosmic muons pass through the test panels and then determine weather or not the test panel PMT provided a response.
An alternate test method will employ a collimated radiation source (ie. high energy gama ray cobalt source) to excite areas of the test panel and evaluate scintillation quality by comparing resulting PMT amplitude spectra.
Experimental Setup Description:
The scintillator test system is outlined in the block diagram of figure 1. The three muon telescope panel pmt outputs will be applied to a bank of discriminators, the outputs of which are applied to a three input AND gate which feeds a CAMAC scaler N1. The discriminator output from the test panel PMT will be applied to a second scaler N2 after ANDing with the telescope ANDed signal. Amplitude and count data will be collected using existing LabVIEW programs which have been previously developed at SUF by Ray Bunker. The LabVIEW program will reside on a PC running the Windows NT operating system, communicating with the scalars and A/D converters through an HPIB/CAMAC link.
Schedule:
Week of 11 April:
Assemble NIM and CAMAC components in 5th floor CDMS lab. (in process)
Retrieve muon telescope components from SUF (done)
18 April:
Obtain radiation source from UCSB (in process, Jim Casto, available 1st week in May)
Integrate telescope data acquisition system in CDMS lab
Repair LeCroy HV Power supply for use in test
Acquire test PC, install software, make network connection
Integrate PC with CAMAC and carry out initial telescope tests.
Test PMT dark current
26 April:
Continue with system testing
Carry out dark-current and noise tests on PMT's
Integrate LeCroy HV supply in system
Gather wrapping material (May & Hale)
a. Al Mylar
b. Black paper
c. Tape
d. Optical grease (High Bay)
30 April:
CDMS Scintillator test panels ( 2" x 30" x 48") arrive
3 May:
Wrap scintillator panels
5 May:
Receive Hamamatsu PMT's, bases and shields.
7 May:
Test PMT's for gain, noise and operating voltage
Attach PMT to side, top and end of panels with optical grease (Figure 2) and carry out test sequence.
The radiation source will be placed on each of the 15 locations as shown on pnltestspots.ps. The source will be held at each positon for ___ seconds during which data will be collected. This pattern will be used on all prototype tests.
10 May:
Receive light guides
Attach light guides to scintillator panels (Figure 3) and carry out test sequence.
14 May:
Modify one scintillator panel by machining 22.5 degree angle on one end (Figure 4) and carry out test sequence.
17 May:
Modify light guide by changing length from 15"to 10". Configure components per Figure 3 and carry out test sequence.
1 June:
Review data and decide on final configuration
Move experimental setup to highbay clean room.
Figure 1. Veto test setup.
Equipment List / Cost
Radiation source on loan
Cosmic ray (muon) telescope on hand
HV Cables on hand
NIM Crate on hand
PMT Signal Amplifier LeCroy 612AM 6 ch. on hand
Quad descriminator, NIM, LeCroy 621 on hand
Dual 4 Input NIM logic unit LeCroy 365 on hand
CAMAC Crate on hand
Quad scaler, Jorway CAMAC Mod. 84 on hand
Four Channel CAMAC 12 bit A/D, LeCroy 2249 on hand
HPIB CAMAC crate controller, LeCroy 8901A on loan from FEL
HPIB Cable on hand
HPIB PCI-HPIB Board, NI 777073-01 on hand
12 ea 18" LEMO RG59 cables $432
PC Windows NT O/S $ 1360 total (detailed below)
PCI VXI Controller Interface kit ______________$4500 (future, could use BaBar unit)
PMT, Hamamatsu R329-02 $500 on order
PMT base, Hamamatsu E4512-501 $240 on order
NOTES:
1. Figures 2 - 4 not complete as yet, see Hale.
(Last update on 4/22/1999 by SB @ 11:00 AM)
Questions? Electronics: sburke@hep.ucsb.edu Mechanical dhale@hep.ucsb.edu