User name R. Michaels
Log entry time 01:59:04 on July21,2005
Entry number 148842
keyword=sweeper on/off runs 2195, etcRaster is about 7x7 (reality).
Momentum P_Left = 2.736 GeV, P_Right = 2.732 GeV
Helium target.
Run 2195: Sweeper is OFF. 1M events
(it was on for all the other earlier runs tonight).
Run 2196: Sweeper is ON. 1M events
After this we follow the checklist and switch back to HAPPEX DAQ
mode. We have completed the steps through #9 of the run plan
in halog 148759.
Online analysis of these two runs reveals: a) The data was ok,
and 2) Between sweeper on & off there is an approx. 1 MeV change
in the average momentum -- see fig 1. I made the L-arm with
colors and the R-arm without, to try to be clear. Also, the
the L-arm and R-arm qsq distribution (which in absolute terms is
not yet meaningful but the relative change has some meaning)
changed by 1.0 & 1.6% for L-arm & R-arm respectively. The
conclusion is that it is important to do the "final alignment"
with the "final sweeper" setup, which is presumably 111A.
The main thing: the two are tied together.
FIGURE 1
