Conventional read-out electronics for the button-type BPM in the ATF damping ring

A conventional read-out electronics for button-type beam position monitor (BPM) has been developed for the KEK ATF (Accelerator Test Facility) damping ring. This electronics system is used in early stage of beam commissioning in the damping ring. The system can measure the beam orbit by single pass processing of bunch train, have the resolution of about 10 μm, and is reliable. It is also desirable that it is low cost because of a requirement of several hundreds of circuit channels. The system consists of charge-sensitive ADCs and clipping modules. The clipping module employs a clipping technique, which clips the bipolar signal from a BPM to integrate the signal charge. It is also useful for strip-line type BPM because of the enrichment of low frequency component. The design and test results with a beam operation are reported.