DEVELOPMENT OF AN X-RAY BEAM SIZE MONITOR WITH SINGLE PASS MEASUREMENT CAPABILITY FOR CESRTA*

The CESR Test Accelerator (CesrTA) program targets the study of beam physics issues relevant to linear collider damping rings. This endeavour requires new instrumentation to study the beam dynamics along trains of ultra low emittance bunches. A key element of the program has been the development of an x-ray beam size monitor (xBSM) capable of collecting single pass measurements of individual bunches in a train over thousands of turns. This instrument utilizes custom, high bandwidth amplifiers and digitization hardware to collect signals from a linear InGaAs diode array. The digitizer is synchronized with the CESR timing system and is capable of recording beam size measurements for bunches spaced by as little as 4ns. The x-ray source is a bending magnet with Ec=0.6keV during 2GeV CesrTA operations. For these conditions the amplifier dynamic range was optimized to allow measurements with 3e9 to 1e11 particles per bunch. Initial testing is complete. Data analysis and examples of key measurements which illustrate the instrument’s performance are presented. This device offers unique measurement capabilities applicable to future high energy physics accelerators and light sources.