Difference between revisions of "First beam into the hall"

Latest revision as of 12:28, 23 September 2022

https://hallcweb.jlab.org/doc-private/ShowDocument?docid=1186

Tasks for beam line checkout with no target

Prerequisites:

• Operational restrictions updated

• Target alignment done and target encoder positions propagated to MCC.

Empty target clearance: 1 inch ideal between reference cell and target foils; we will know the exact number after survey.

From Ellen: "The ideal "No target" clearance is 1 in. It should be something close to that, but may change by a bit depending on where the reference cell ends up when they install it. There is also a small amount of error on the motor positioning, which I will have a better number for after the next survey, but shouldn't be more than 100 microns or so."

This is from Hall C back in 2020 from Arun: https://hallcweb.jlab.org/DocDB/0011/001186/001/targ_clear.png

• Cu collimator diameter: 0.62 inch = 15.748 cm, https://hallcweb.jlab.org/DocDB/0011/001186/001/cucoll.png

Chris from the survey group will combine the recent survey results and the info from Robin's drawing into one document. MCC needs to have that document and put it into the CED before we send beam into the hall.

• IC calibration on empty target must be done right after first tune beam to the dump

• Raster off

Zero order determination of IPMH01,04 A,E offsets

Prerequisites:

The beam has been centered on the dump (according to Yves the accuracy of beam dump centering is ...)

Tasks for beam line checkout with target:

Beam centering on the 2 C-hole foils and raster calibration:

Calibration of BPMs against superharps:

• Bull's eye scan with "GEnII-NoGems" DAQ configuration and "remex sbsTS21 "rocSetTriggerSource(1)"" random trigger. The first constraint clearance-wise is from the Cu collimator: 0.31 inch = 7.874 mm from beam center. The "empty target" position clearance: 0.5 inch or 12.7 mm clearance from centered beam.

Calibration of BCMs against Unser:

• Upstream BCM calibration

Replays

• /adaqfs/home/a-onl/sbs/sbs_devel/SBS-replay/replay/replay_spot.C --> this is to replay BigBite data

• Replay processing

       data = evdata.GetData( Decoder::kPulseIntegral,d->crate,d->slot,chan,0 );

fRawPos(k)= data;