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Recent cavity monitor tests credit John Musson, Anna Boehle, Vince Sulkosky. Achieved goals but need repeat with constant gain scans. Detailed analysis methods provided for resolution and calibration. Cavity monitors working effectively with G0 version electronics.
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Recent Cavity Monitor Tests Credit: John Musson, Anna Boehle, Vince Sulkosky • Good position & current for 10 nA to 100 uA • At 10 nA : • Need absolute position to 0.2 mm • Need resolution of ~ 0.5 mm (1-shot at 200 nsec) • HRS rates ~ 200 kHz good for Q 2 Goals ~achieved, but need to repeat with a current & position scan withconstant gain.
Cavity BPM EPICS Interface (beam off)
High current tests (Jan 2008) Cavity BPMs correlated to Striplines Good Good Saturated gain (oops) Spectrometer DAQ
Low - Current ( 50 nA ) Tests Cavity X,Y,Q Steering Coils Target 8.8 kHz Bigbite deflected beam uA Stripline X,Y
50 nA: Calibration Changed ! (oops ! Gain adjusted)
At 9.5 uA (oops ! Gain adjusted)
Resolution Analysis Method 1: Use 1 BPM as a measure of beam motion on the other. Subtract it off, residual is the resolution (approx).
50 nA Resolution ~ 400 um 1-shot at 200 nsec. It will be better with averaging
Resolution Analysis Method 2: Using a line built from other monitors, look at residual to the line. Results comparable to method 1. Position is known much better than the beam pipe diameter !
Summary -- Cavity Monitors • Working well, we have the G0 version of electronics • Good signals at 10 nA Can measure Q • Plan to repeat scan ( Ibeam , X, Y ) • with constant gains 2 2