Mott Run 2 Journal

Friday, October 23 DAY (Matt, Joe)

Started DAY shift with PSS down until ~1pm due to PSS BCM fault. Hall B beam at 31MHz recovered to FC1 and Vertical Wien filter set to +90 deg. Later INJ/NL locked-up and beam restored to FC2 fine. A "momentum measurement" setup was created, one with quads between IPM0L02-IPM0L03 nulled and minimal correctors; IPM GOF's are here. Central momentum of 5.487MeV/c was set using DL magnet. Crested gradients of 5.27MV/m(146.5deg) and 4.120MV/m(94.2deg) were found to be the best average of 2D line (no survey elements) and 5D line (incomplete survey information), expect both will be consistent at the <1%.

Friday, October 23 SWING (Tim, Marcy)

Started shift with white board tool-box meeting (Tim, Daniel, Matt, Marcy, Riad, Joe). The look up table of R028GSET values has an error - DO NOT use this table. We stepped through energy settings while keeping 0L launch fixed measuring a) 5D BPM's with fixed DL and then b) DL settings with fixed 5D BPM's. We later found the actual range of R028GSET was +/- 40keV, not +/- 400keV. Still the measurement is here.

Saturday, October 24 OWL (Daniel, Riad)

Beam was restored after bypass SL klystron. BCM0L02 cal factors had to be reset (ioc reboot?). Clean launch set to Mott, detector timing adjusted (DAQ or RF trigger drift?), PITA settings to null charge asymmetry corrected (orbit/transmission change since last calibration?), vertical polarization set and total rate vs. thickness measured. Detailed shift summary here.

Saturday, October 24 DAY (Marty, Joe)

We are commencing with Mott asymmetry vs. beam energy, using the 0.35um and 1.0um gold foils. After the R028GSET=4.120 (KE=5.0MeV) measurement realized there was a typo in the energy look-up table, we were changing beam energy by +/-40keV instead of +/-400keV. A new table is attached ....

More Mott.

here is a good link