An ultrafast mechanical shuttering system for separating single x-ray pulses from a synchrotron (abstract)

Abstract

A mechanical shutter system for conducting time resolved experiments at the APS and ESRF storage rings which is suitable for use with white and monochromatic x-ray beams has been developed. The system is able to isolate single x-ray pulses from synchrotron sources with large orbit times, such as the APS, ESRF, and CHESS when they are operated in single bunch mode. It consists of three components: a slotted rotating disk which opens for 3.28 μs every 2 ms, a fast magnetic shutter which can open and close in less than 1.5 ms, and dedicated electronics which can predict when the arrival of the x-rays from the storage ring and the opening of the rotating disk will coincide. When this occurs, the electronics open the magnetic shutter, allowing the x-ray pulse through, and generates a trigger signal with an adjustable delay of up to 2 ms with an accuracy of 10 ns or better before the arrival of the x-ray pulse. This system has been tested at both the CESR and the ESRF storage rings where it has been used to collect Laue data from three crystals: a small organic molecule and two forms of the protein lysozyme. We present results from these tests and discuss their implications for future experiments.