September 7, 2011

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Wednesday Run Plan

• Tune up beam
• During this time, as much as possible tune up daq timing
• Kicker magnet calibration with viewscreen
• Pair spectrometer checkout/debugging

    This should include setting thresholds, studying rates with air converter, looking at rates with photon hole open
     versus blocked, ...

• Check detector rates with D2O. See if we can get a good time of flight spectrum.

Pair-spectrometer threshold calibration with beam

By using analog counter. Beam On. Dump out. Collimator Open. Radiator in (10 um Al).

By using analog counter. Beam On. Dump out. Collimator Open. Radiator in (10 um Al).

was not done

By using TDC to count PS pulses (10,000 beam pulses). Beam On. Dump in. Collimator Open. Radiator in (10 um Al).

• upstream PS: 150 mV threshold, 545 cnts/10,000 beam pulses
• downstream PS: 150 mV threshold, 476 cnts/10,000 beam pulses

By using TDC to count PS pulses (10,000 beam pulses). Beam On. Dump in. Collimator Open. Radiator out (10 um Al).

• upstream PS: 150 mV threshold, 74 cnts/10,000 beam pulses.
• downstream PS: 150 mV threshold, 101 cnts/10,000 beam pulses

There are effect from radiator in/out, but not so much as wanted.

By using TDC to count PS pulses (10,000 beam pulses). Beam On. Dump in. Collimator blocked (see lab log books). Radiator in (10 um Al).

• upstream PS: 150 mV threshold, 19 cnts/10,000 beam pulses
• downstream PS: 150 mV threshold, 18 cnts/10,000 beam pulses

(19/545 -> about 96.5% of beam is coming trough collimator!)

By using TDC to count PS pulses (10,000 beam pulses). Beam On. Dump in. Collimator blocked (see lab log books). Radiator out (10 um Al).

• downstream PS: 150 mV threshold, 20 cnts/10,000 beam pulses.

 About the same as previous, good

By using TDC to count PS pulses (10,000 beam pulses). Beam Blocked. Dump in. Collimator blocked (see lab log books). Radiator out (10 um Al).

• downstream PS: 150 mV threshold, 0 cnts/10,000 beam pulses.

Summary of counting with TDC (10k beam pulses) for different beam line configuration. -150 mV threshold

	Beam	Dump magnet	Collimator	Radiator	Threshold	Counts
upstream/downstream	On	In	Open	In	-150 mV	545/476
upstream/downstream	On	In	Open	Out	-150 mV	74/101
upstream/downstream	On	In	Upstream blocked w/ 2" Al	Out	-150 mV	43/*
upstream/downstream	On	In	Upstream blocked w/ 4" Al	Out	-150 mV	41/*
upstream/downstream	On	In	Upstream blocked w/ 4" Al	Completely Out	-150 mV	30/*
upstream/downstream	On	In	Blocked	In	-150 mV	19/18
upstream/downstream	On	In	Blocked	Out	-150 mV	*/20
upstream/downstream	Blocked	In	Blocked	Out	-150 mV	*/0

about meaning of the different adjectives (like completely) see the log books