Each target raster magnet is equipped with a pick-up coil at the center of magnet winding plane. The field pickup integrator converts the induced voltage signals into linear waveform and adjusts the amplitude of linear signals to the same amplitude of output of Pearson current probe.
This optional NIM module unit is designed for the use of G
experiment. Hall A has already preserved such capability for future's
application. The unit receives trigger signal from helicity reverse (MPS).
A phase-lock circuit generates two correlated raster frequency signals.
It enables the rastered beam starts at the exact same time of MPS.
Therefore, the instant beam positions are always the same for each MPS.
A Jorgger 4-channel VME ADC has been shared by Hall C and Hall A two raster systems. The trigger generator produces 60 Hz synchronization signals from one raster frequency as the trigger of ADC. The 2D and 3D raster pattern display software was written by Chris Slominski. By pushing control button on EPICS control screen, users could observe raster 2D and 3D pattern on-line.
It has the same function as of BRM/FSD system of old raster system. It takes analog magnet current signals to compare the calculated current amplitude value from beam energy and raster size. Fault warning signal will be given as soon as a discrepancy occurs.