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Setup

The preliminary tests to determine the attenuation length and timing resolution of the fibers were done using cosmic rays at the Regina Hall D test lab. Although statistics were limited, the tests were useful in providing general ideas for appropriate electronics, software, and physical setup, as well as for trends of the fiber performance, to the benefit of the subsequent TRIUMF measurements.

The event trigger was set to be a coincidence between the two paddle counters, and leading edge discriminators were used to produce the logic timing signal. These signals were then fed into CAMAC ADC (LeCroy 2249A) and TDC (LeCroy 2228) units. The TRIUMF Midas DAQ system [11] was used to analyze the data collected. The high voltage (HV) of each counter was selected to be in its plateau region. The final high voltage values and thresholds used for the cosmics ray measurements are displayed in Table 1.


Table 1: High voltages and discriminator thresholds used during the cosmic ray tests.
PMT No. HV (Volts) Threshold (mV)
1 2500 15
2 2500 15
3 2100 50
4 2200 50
5 2400 20



next up previous
Next: Measurements and Results Up: Tests with Cosmic Rays Previous: Tests with Cosmic Rays
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2001-10-29