How x-ray diffraction with synchrotron radiation got started

The need to record low angle scattering x-ray fibre diagrams from muscle with milli-second time resolution drove the use of synchrotron radiation as an x-ray light source. The first smudgy diffraction patterns were obtained from a slice of insect flight muscle. Out of this grew the EMBL Outstation at DESY.

First diffraction experiments are carried out at DESY

In 1969 Rosenbaum started his doctorate in Heidelberg on developing x-ray sources for diffraction studies of muscle Together with H.E. Huxley in Cambridge a rotating anode x-ray tube of high brilliance was developed (which became the GX18 of Elliott Bros). However, one quickly runs into a performance barrier set by the strength of materials (Rosenbaum, 1979). Frustration with rotating anode tubes drove us to re-evaluate the performance of synchrotrons as x-ray sources. Initial estimates of the strength of synchrotron radiation K.C. Holmes had made in the '60s indicated that synchrotrons at 6.0 GeV would not be much better than existing rotating anode tubes. In the mean time the energy of the machine had risen from 6.0GeV to 7.2GeV and the beam current was often in excess of 10mA. Now things looked more promising. Moreover, G. Rosenbaum had done his diploma work at DESY in the F41 VUV group so that he could provide important know-how about the physical set up at DESY. Therefore, with the ecouragement of Dr Heansel and the F41 group we set about conducting trials in the VUV bunker at DESY.

Working together with Jean Witz, who was an authority on x-ray optical systems, we introduced a focusing x-ray quartz monochromator into the synchrotron beam. A vacuum chamber was constructed to house a bent quartz monochromator and slit assemblies with a berillium exit window (Fig. 3). The quartz monochromator could be moved across the beam by remote control. For all other adjustments the main beam shutter had to be closed: reopening the beam shutter required retreating behind a massive sheilding wall, setting up the interlocks, and a telephone call to the main control room. This process made adjustment rather tedious. However, estimates of the monochromatic beam intensity were very encouraging. Therefore we set up a primitive x-ray diffraction camera on the monochromatic beam and the first rather smudged x-ray diffraction photograph using synchrotron radiation (from a strip of insect flight muscle kindly supplied by Dr. H-G. Mannherz) was obtained in August 1970 (Rosenbaum et al ., 1971).

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