Run Plan for 4-pass Setup
From SBS wiki
- OPS tunes the beam on the dump with nominal beam positions x=-0.7 y=0.6 on 1H04A/E. BigBite is at 750A. SBS is off. GEMs are off. All other detectors on.
- Harp scans to check beam spot size. Ask MCC to take harp scans on Harps A and B (IHA1H04A and IHA1H04B) and ask them to post the results to our logbook Halog. When the results arrive fill in the green blanks in "Beam spot size at target" section of this spreadsheet and report/halog the values of the spot size calculated which show up in the red blanks. If the average of the Xsigma and Ysigma spot radii (1 sigma) is significantly less than 100 microns. Call the RC and ask what to do.
- Ion chamber calibration on the dump
- Move Target to home position. Set BBcal threshold to -100 mV. Request 1 uA. Monitor ion chamber rates in strip chart. Record trigger rate (TS1-BB)
- Ion chamber calibraiton on the 5-foil optics (this covers all optics targets)
- Repeat step #4 on 5mm carbon hole. Are the rates the same? If not contact RC. HALOG strip chart and beam current from both steps.
- Request MCC to perform the "Hall A SBS Dipole Setup Procedure" for the SBS magnet at 1,575 A @ 24.7 degrees. Ask MCC to post results to HALOG.
- With SBS at +75% settiing, do target centering/raster calibration on the 2mm hole. Start with raster setting of H=4.5, W=1.5 as the best estimate of a 3mm*3mm raster. Use 1 uA. Step by step info here.. End with a raster setting that gives us a 2mm by 2mm spot as compared to the hole. Tolerances:+/- 0.2 mm on raster size and on hole position.
- Move to LH2
- Ion chamber calibration on LH2
- This step will be performed by a GEM expert. Turn on GEMS. Start with 2 uA and monitor current draw. Move to 4 uA. Expert will decide if we can move to 6 uA and what current we will run on LH2 target
- Using current from last step, determine BBcal threshold, and take data on LH2 (10 M events) (~3.3 GeV, check Provakar's table)
- Change to single-foil carbon. Take 1hr at 6uA. Have HCal expert look at LH2 data to verify we are happy with +75% setting.
- Make a HALOG titled "Pass 4 Beam Checkout". Include links to the following log entries: final carbon hole image, ion chamber calibrations, SBS setup procedure result, 5mm hole log entry.
- Move to production running