Runs 3282-3294 : 105 Mevts
Runs 22363-22374 : 84 Mevts
Total: 189 M
PT_Ave = 36.2 % (Max = 44%, Min= 32%)
Total Dose delivered was about 1.6 pe/cm2 during 5 hours of relatively steady 50nA beam. During this time, the polarization dropped from 44% to 32%. Extrapolating by eye, it appears the material will level out in mid to high 20's, after about 8-12 hours of good beam. With two cups, we can probably manage with a single anneal a day. Overall, the depolarization and asymptotic behavior looks better than the green book comparables.
Pushing the bpms down to 25nA would be desirable in order to run at higher average Pt, and reduce target overhead due to anneals. We'll be daq rate limited even at 50 nA for many of the planned 1.1, 1.7 and 2.2 GeV settings.
Figure 1
dose.pdf