A_T scan summary

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User name jwexler

Log entry time 09:26:32 on April 4,2010

Entry number 316130

keyword=A_T scan summary

The A_T scan ran from 4AM to 9AM. Of note, I changed the nomenclature of the motor positions for the sake of clarity. In the summary, all distances will be in terms of positive distance from the motor (so 0 represents the detector closest to the motor). Therefore, +y is moving away from the beamline, and +x is moving away from the target/radiative tail.

First did a sweep across y then x at -1500V to find any large spikes in the number of channels. These were runs 2554-2556. They showed the number of channels increased with y and x, peaking at ~(+6cm, +6cm), though decide to keep A_T hole PMT voltage at -1500V.

Second did multiple scans of 5mm increments in x,y in order to test reproducability and use the scandata function in greemonster to help analysis later. For the scans using scandata, the values of scandata correlate to the sweep as follows (scandata,position from motor):
(1, 0mm), (2, 5mm), (3, 10mm), ..., (13, 60mm)

Scan 1: Middle (3cm) of mover in x, scanning in y. The run numbers for each scan are:
1st: 2558, 2559
2nd: 2560, 2561
3rd: 2562, 2563

Scan 2: -ve edge (0cm) in x, scanning in y. The run numbers are:
1st: 2568, 2569, 2570
2nd: 2571, 2572

Scan 3: +ve edge (left arm at 5.8, right arm at 6cm) in x, scanning in y. The run numbers are:
1st: 2573, 2574
2nd: 2575, 2576

Scan 4: Far edge in y (determined to have highest # of channels), scanning in x. The run numbers are:
1st: 2577, 2578
2nd: 2579, 2580