Log entry time 23:27:56 on June16,2004

Entry number 126012

Followups:

• 126014 06/16/04 23:46 H. Benaoum strange oscillation ... see Bryan message
• 126129 06/17/04 23:46 Moffit Strange oscillations in BPM wires from the raster.

ADC12, 14 and scaler0 the devices that readout BPM 1, 4a, 4b (Beam Position Monitors closest to the target), are observing some sort of strange oscillation... that doesn't appear in the calculated positions (x = (X+ - X-)/(X+ + X-) )... looks like the amplitudes in the wires exactly cancel.

One period is approximately 700 events (700 ev / 30 Hz = 23.3seconds).

Frequency seems to vary a bit (period within 5 seconds or so).... and disappears when beam is gone (so... shouldn't effect the pedestals).

Maybe we shouldn't worry so much about this, because it's on a long timescale (compared to the helicity flip).