User name meekins
Log entry time 17:21:00 on October 15,1999
Entry number 28305
keyword=Bad Wien filter angle.
A problem was discovered with the Wien angle when a moller measurement was about to be started at 1500. The angle readback was ~0.3. The normal setting we have seen is arround -46.2. Several calls were placed and it was discovered that the readback for the Wien angle was correct. This means that instead of >60% polarization we were getting around 40%. It was decided amongst MCC, Hall B and Hall A that the Wien angle would be changed to its nominal value. Following this change a moller measurement will take place. This has some implications for our data. Runs 2298 and before will have a lower polarization than later runs and as such cannot be combined in the usual fashion. At 1640 the Wien angle was changed to -46.2. The lower polarization can be calculated using the sin of the Wien angle and the current moller measurement.