Analog processor for emittance monitor in SPring-8 linac

The analog processor for the emittance monitor in the SPring-8 linac is composed of a charge sensitive amplifier with gain control, a sample/hold circuit and an isolation circuit. The charge sensitive amplifier detects pulsed charge from the wire scanner. The sample/hold circuit maintains the signal to which can be accepted by an A/D converter on VME computer. It is designed as 1 V/pC, 0.1 V/pC or 1 V/nC. The linear region was measured as -5V∼5V of output. Fluctuation of output for 200 seconds was ∼1.5 mV of 1 σ. However voltage drift was observed for 150 hours. But this is acceptable for emittance measurement. (author)