Detector 7 anneal 2012

There was an arc that led to a long period of extended noise in D7. See Tohban_Report_2013-07-24 for details.

 D7 HV was stepped down by 10 steps because of this.  (HV adjustment was on July 24, 2013 (day 205) at 19:29:15 UTC).  HV after the stepdown was ~3800 V.  This made no change in the noise level.
 Update as of Aug. 7 2013: David has determined that the noise is not affecting D7 spectroscopy (although the calibration may have changed slightly), and livetime is not being significantly affected, so no further steps will be taken for now.