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User name N Toro
Log entry time 01:42:15 on July11,2010
Entry number 331389
keyword=right Q1 field after trips
variations in right Q1 over production running
The very short time-scale variation that shows up as thick stripes is almost certainly noisy hall probe readout, but we also see variations at few*10^-3 level before and after Q1 power supply trips/resets.
The larger dip July 10 around noon was due to replacement of controller board. After this we switched to manually setting the current to produce the right field readout in the hall probe. After midnight July 11 Heidi put the old board back in -- the hall probe reading has moved around more than it used to, but the excursion is only about a factor of 2 larger than what was typical in previous production running.
Similarly large excursions were seen in -10% optics running, so hopefully effects can be studied there.