oct 24 2011c. smith - pcal/ec commissioning 1 pcal/ec commissioning document
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Oct 24 2011 C. Smith - PCAL/EC Commissioning 1
PCAL/EC Commissioning Documenthttp://clasweb.jlab.org/wiki/index.php/PCAL_navigation
Oct 24 2011 C. Smith - PCAL/EC Commissioning 2
PCAL/EC Calibration and Commissioning
Final assembly and cosmic tests of six PCAL modules in EEL 125.
EC uncabling, refurbishment, recabling, integration into CLAS 12 trigger.
PCAL installation, checkout and joint commissioning/calibration with EC.
Oct 24 2011 C. Smith - PCAL/EC Commissioning 3
PCAL/EC Calibration and Commissioning
Final assembly and cosmic tests of six PCAL modules in EEL 125.Primary goals: PMT gains (HV settings), scint. fiber attenuation lengths, response uniformity, light yield.Evaluate CLAS12 DAQ environment: (FADC, trigger-based cluster finding, offline reconstruction).
FADCs still being bench tested, will use LeCroy 1881 ADCs and delay cables.
Manpower: PMT installation, light leak checking, cable routing and connections, DAQ.Software: HV slow controls, calibration database, legacy calibration code (C. Smith), reconstruction and calibration code in development (M. Wood, W. Brooks)
EC uncabling, refurbishment, recabling, integration into CLAS 12 trigger.
PCAL installation, checkout and joint commissioning/calibration with EC.
Oct 24 2011 C. Smith - PCAL/EC Commissioning 4
PCAL cosmic tests in EEL 125 - Status
First PCAL module waiting in
corner of room for fiber cutting
rig to be installed.
Stacking of second module has begun.
Oct 24 2011 C. Smith - PCAL/EC Commissioning 5
U fibersV,W fibers
PCAL cosmic tests in EEL 125 - Status
Goal: Fiber cutting and polishing complete by end of November
Oct 24 2011 C. Smith - PCAL/EC Commissioning 6
PCAL cosmic tests in EEL 125 - Status
• JMU delivered enough photomultiplier assemblies for at least 2 modules.
• Photomultiplier installation and light leak checks should take 1-2 weeks -> Dec 14
• Opaque RTV has already been applied to seams and mating surfaces of PCAL box.
• Cable installation and initial HV settings could take another week -> Dec 21
• Would be desirable to conduct cosmic runs over holidays if DAQ is ready.
PCAL PMT Assembly
Oct 24 2011 C. Smith - PCAL/EC Commissioning 7
Previous experience – slow start, fast finish1996 Test Lab checkout of EC modules
Oct 24 2011 C. Smith - PCAL/EC Commissioning 8
PCAL/EC Calibration and Commissioning
Final assembly and cosmic tests of six PCAL modules in EEL 125. Primary goals: PMT gains (HV settings), scint. fiber attenuation lengths, response uniformity, light yield. Evaluate CLAS12 DAQ environment: (FADC, trigger-based cluster finding, offline reconstruction).
FADCs still being bench tested, will use LeCroy 1881 ADCs and delay cables.
Manpower: PMT installation, light leak checking, cable routing and connections, DAQ. Software: HV slow controls, calibration database, legacy calibration code (C. Smith), reconstruction and calibration code in development (M. Wood, W. Brooks)
EC uncabling, refurbishment, recabling, integration into CLAS 12 trigger. Goals: Replacement of weak, broken, inaccessible PMTs/bases, repair light leaks. Still compiling list – possibly as many as 50 PMT/bases need to be accessed ~ 1 month work. Repair work difficult unless all cables and some railings removed. Schedule - CLAS 6 removal: 5/2012, DAQ /pre-cable installation: 10/2012, 1st PCAL installation: 1/2014.
More time for PCAL cosmic testing, less time for integration into CLAS 12 DAQ prior to commissioning runs. Earliest possible installation CLAS12 DAQ w/frontend/trigger electronics, cable up and test a single EC sector.
Possible to have ~1 year of EC / CLAS12 DAQ testing before arrival of PCAL.
PCAL installation, checkout and joint commissioning/calibration with EC.
Oct 24 2011 C. Smith - PCAL/EC Commissioning 9
EC Refurbishment – PMT replacement
EC uses a mixture of Phillips and EMI PMTs that run at different voltages and use non-interchangable socket/bases. PMTs running at or near their maximum HV ratings should be replaced.
Oct 24 2011 C. Smith - PCAL/EC Commissioning 10
EC Refurbishment – PMT replacement
Between 5-10 Phillips and EMI PMs are at or near max HV.SPARES - XP2262: ~6 JLAB, 113 available at UVA (D. Day)
No ET9954B spares, still available at $650 ea @ 50 minimum.
Oct 24 2011 C. Smith - PCAL/EC Commissioning 11
PCAL/EC Calibration and Commissioning
Final assembly and cosmic tests of six PCAL modules in EEL 125. Primary goals: PMT gains (HV settings), scint. fiber attenuation lengths, response uniformity, light yield. Evaluate CLAS12 DAQ environment: (FADC, trigger-based cluster finding, offline reconstruction).
FADCs still being bench tested, will use LeCroy 1881 ADCs and delay cables.
Manpower: PMT installation, light leak checking, cable routing and connections, DAQ. Software: HV slow controls, calibration database, legacy calibration code (C. Smith), reconstruction and calibration code in development (M. Wood, W. Brooks)
EC uncabling, refurbishment, recabling, integration into CLAS 12 trigger. Goals: Replacement of weak, broken, inaccessible PMTs/bases, repair light leaks. Still compiling list – possibly as many as 50 PMT/bases need to be accessed ~ 1 month work. Repair work difficult unless all cables and some railings removed. Schedule - CLAS 6 removal: 5/2012, DAQ /pre-cable installation: 10/2012, 1st PCAL installation: 1/2014.
More time for PCAL cosmic testing, less time for integration into CLAS 12 DAQ prior to commissioning runs. Earliest possible installation CLAS12 DAQ w/frontend/trigger electronics, cable up and test a single EC sector.
Possible to have ~1 year of EC / CLAS12 DAQ testing before arrival of PCAL.
PCAL installation, checkout and joint commissioning/calibration with EC. Cosmics: check EC calibration after PCAL installation, transverse alignment, recheck PCAL calibration (vertical vs. horizontal), spatial, energy uniformity and efficiency of (EC∙PCAL) trigger, debug cluster finding, evaluate trigger based software corrections (gain,attenuation,pedestal). Beam: Luminosity studies (vs. thresholds, beam energy, target, torus, solenoid, polarity, sector).
Oct 24 2011 C. Smith - PCAL/EC Commissioning 12
Flash ADC
JLAB FADC250 16 Channel 250 MHz
12-bit Wave Form Digitizer
Sector 3 inner
U21 - U25
3:1 UVA splitter
2/3
1/3
Current Test Setup on Forward Carriage
Sergey P. Sergey B.
Oct 24 2011 C. Smith - PCAL/EC Commissioning 13
FADC250 Tests
U21-U25
V22-V26
W22-W26
Time (1 ch=4 ns)
Ch
arg
e
Trigger studies: Capture windows (red) will be set to optimize S/N. Luminosity studies: Effect of multiple hits on energy and cluster reconstruction. Improved calorimetry: Event-by-event baseline subtraction possible.
Oct 24 2011 C. Smith - PCAL/EC Commissioning 14
FADC250 Tests
Current MIP based energy calibration fixes only a single point at 10 MeV (~ch. 100).
Extrapolating this calibration to 10 GeV e- may not be adequate.
More accurate calibration requires knowledge of conversion gain of each ADC channel and gain stability of PMTs at high rates or linearity over full dynamic range.
Oct 24 2011 C. Smith - PCAL/EC Commissioning 15
PCAL summed energy may require software corrections in trigger
EC: Dalitz u+v+w readout cancels scintillator attenuation x,y dependence to first order.
PCAL: u+v-w readout creates worst case scenario.
Oct 24 2011 C. Smith - PCAL/EC Commissioning 16
The End
Thank you
Oct 24 2011 C. Smith - PCAL/EC Commissioning 17
CLAS 12 Installation Timeline (old)
Oct 24 2011 C. Smith - PCAL/EC Commissioning 18
CLAS12 Forward Carriage Rack Layout
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