Ring Imaging Cerenkov Detectors @ ICFA 2010, Bariloche, Argentina

Tutors

• Samo Korpar ( University of Maribor and Jozef Stefan Institute, Ljubljana, Slovenia )
• Rok Pestotnik ( Jozef Stefan Institute, Ljubljana, Slovenia )

Course Description

The laboratory for Ring Imaging Cerenkov Detectors introduced the students to the Ring Imaging Cerenkov technique. After the introductory presentation, the students worked with multi-anode photo-multipliers Hamamatsu R5900-M16 and R5900-L16 PMT, with which three measurements requiring position sensitive detection of single photons were performed. The first exercise was to determine the optimal high voltage and to investigate the position dependence of the M16 count rate by using a pencil beam. From the results of this measurement the position resolution, the cross talk between adjacent pads and the response variation across a given pad were studied. The second exercise was a measurement of a diffraction pattern by counting individual photons passing through a slit. With sufficiently low counting rate one may in principle simultaneously observe the count increment of individual channels and the appearance of the diffraction histogram. Finally Cerenkov rings produced by high energy cosmic muons in an aerogel radiator were measured. The Cerenkov photons were detected by an array of 4x4 M16 photo-multipliers lying 16 cm below the aerogel radiator entrance surface. The photomultiplier signals were measured by using standard NIM, CAMAC and VME electronic modules, enabling students to connect and follow signals through different stages from the sensor to the DAQ system.

Figure 1: The position sensitivity of the multianode PMT	Figure 2: The proximity focusing RICH with aerogel radiator	Figure 3: The diffraction pattern setup

Course Material

• Lab course notes
• Source code:Experiment 2

Equipment

Experiment 1 - Position sensitivity of single photons:

• Experimental box with R5900-M16 PMT, PMT base and blue LED light source, manual stage
• NIM crate - Ortec BlackMax 4002E 300W
• NIM Power supply for the LED light source
• NIM High Voltage Power supply for the PMT - CAEN Mod. N470
• NIM Fast Timing Amplifier - Ortec FTA 820 neg./neg.
• NIM Discriminator unit - Ortec CF8000 (leading edge)
• NIM Quad Scaler and Preset Counter- Timer - CAEN Mod. N145
• Osciloscope min. 200MHz + Multimeter probes
• 2x LEMO T splitter
• 2x LEMO 50 Ohm termination
• Cables:
  • 6x LEMO 8ns
  • 8x LEMO 1ns
  • 2x LEMO 2ns
  • 1x LEMO 5ns
  • 2x LEMO 0.5ns
  • HV cable 2m
• 1 small screwdriver for the discriminator threshold adjustments
• PC for data analysis

Figure 4: Front panel connections	Figure 5: The NIM crate with the electronics

Experiment 2 - Diffraction pattern with single photons:

• Experimental box with R5900-L16 PMT, PMT base and blue LED light source, manual stage
• CAMAC crate - Wiener Minicrate
• Power supply for the LED light source
• NIM High Voltage Power supply for the PMT - CAEN Mod. N126
• 2x NIM Fast Timing Amplifier - Ortec FTA 820 neg./neg.
• CAMAC Discriminator unit - Philips Scientific PS706
• CAMAC Scaler - CAEN Mod. C257

• CAMAC Controller - LeCroy 8901 GPIB interface
• National Instruments GPIB-USB-HS
• PC for Data Acquisition with National Instruments LabWindows CVI
• Osciloscope min. 200MHz + Multimeter probes - shared with Exercise 1
• 2x LEMO T splitter
• 2x LEMO 50 Ohm termination
• Cables:
  • 17x LEMO 8ns
  • 8x LEMO 2ns
  • 9x LEMO 1ns
  • 1x twisted pair cable 1x34wire->2x16wire
  • HV cable 2m
  • Laser Pointer

Figure 6: Front panel connections	Figure 7: The CAMAC crate with the NIM (backplane adapter) and CAMAC modules and the controller

Experiment 3 - Proximity focusing RICH with silica aerogel and an array of multianode PMTs:

• Experimental box with 16 R5900-M16 PMTs (@-950V), 2 tiles of aerogel (n=1.05 d=2cm + n=1.06 d=2cm) and plastic scintillation counter (@HV=-600V)
• black foil
• NIM crate - Ortec BlackMax 4002E 300W - shared with Experiment 1
• NIM High Voltage Power supply for the PMT - CAEN Mod. N470 - shared with Experiment 1
• NIM 2x AMPDISH - Amplifier, Discriminator, Shaper
• NIM Low Voltage for AMPDISSH Threshold (+6.5V)
• VME crate - Wiener Minicrate
• VME crate controller - Wiener VMUSB
• VME multihit TDC - CAEN Mod. V673A
• PC for Data Acquisition
• Cables
  • 2x HV cable 3m
  • 8x twisted pair 34 wire cables 2m
  • 6x LEMO 64ns
  • 8x LEMO 1ns
  • 2x LEMO 0.5ns
  • twisted pair cable 2wire 2m
  • standard USB cable

Figure 8: Front panel connections	Figure 9: Amplification, discrimination, shaper stage in the NIM crate	Figure 10: The VME crate with the USB controller and with the multihit TDC