General Introduction
Time-Calibrations
Photos
Dimensions
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The Cerenkov Counters for BLAST are under development by the group from Arizona State University. Prof. R. Alarcon is the principal. These Cerenkov detectors cover the entire solid angle of the two BLAST sectors that are initially being instrumented. We have chosen diffusely reflective detectorss that use clear aerogel from Matsushita Electric Works Ltd. as a radiator. There are four Cerenkov units in each sector of BLAST. In each unit Cerenkov light is detected by an ar ray of at most twelve 5" photomultipliers. The units are not identical as their sizes decrease at forward angles.
Ed Six, who tests the Cerenkov counters, in the high bay.
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Cerenkov counters with other detectors
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Cerenkov counters are tested using cosmic rays. Two of the BLAST timing scintillators were used to trigger cosmic rays. This permitted the study of the response of the Cerenkov along its length. Around 90% of trigger events produced Cerenkov light; no attempt was made to ensure that all cosmic rays, which triggered the scintillators, correspond to relativistic particles. data have been fitted toa Poisson distribution following the method of Alexa et al. A uniform efficiency along the length of the detector was observed. This was accomplished usingthe BLAST timing scintillators to select events along the length of the detector. Final testing will be done with the BLAST field during the installation phase. For more information, see D.W Higinbotham's "Diffusely reflective aerogel Cherenkov detector simulation techniques" in Nuclear Instruments and Methods in Physics Research A.
Click here for ADC results
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Frame of the counter
Third side on the Cerenkov Counter
Attachments on the Counter
Frame nearly complete
Photomultipliers on the Cerenkov Counters
Aerogel in the Counter
The Completed Cerenkov Counter
Holes of the Cerenkov Counter
Part of the Side
ASU Tech John Prince with Cerenkov Skeleton
Completed Cerenkov Box prior to testing
Cerenkov Box open prior to testing
Assembly station for Cerenkov PMT's
Iron Shielding tubes
Included below are technical figures.
Three dimensional Cerenkob
Cerenkov Close up
The photomultiplier
Ed Six
Dan Scolnic
