A VME-based photodiode array system for energy dispersive extended x-ray absorption fine structure

Abstract

A VME-based control and data acquisition system has been constructed for time resolved energy dispersive extended x-ray absorption fine structure. The system is discussed from initial concept to installation on the Daresbury SRS. The system performance is presented in detail together with examples of test data. Current operational characteristics are a 2-ms readout time for one scan of 512 pixels, at 16 bits resolution. Accumulation of 65 000 scans in a single frame and a total of 64 frames stored in memory. The system has been designed to run at rates of 0.2 ms per scan and a burst mode allowing 128 single scan frames to be accumulated.

Detectors for energy-dispersive EXAFS (EDE) experiments

“…These sensors, when used as X-ray detectors and combined with custom-designed electronics gave effective but somewhat limited performance systems [4][5][6][7]. These arrays were limited in their readout speed to, at best, one frame every 512 ms and displayed significant problems with efficiency, radiation hardness and image reset.…”

“…This system was originally established in the late 1980s, underwent significant evolution through the 1990s and culminated in an improved and reliable instrument for catalysis studies on the dedicated wiggler station 9.3 on the synchrotron radiation source (SRS) [6,9,10,21].…”

A tribute to the scientific career of Neville Greaves: the Daresbury years

“…The EDE experiments, described earlier, are a good example of the new demands on detectors. A VME-based control and data acquisition system was constructed [23] with performance characteristics of a 2 ms readout time for one scan of 512 pixels, at 16 bits resolution. Accumulation of 65 000 scans in a single frame and a total of 64 frames stored in memory.…”