Effects of high energy synchrotron radiation at copper surfaces

The European Synchrotron Radiation Facility (ESRF) at present under construction will produce intense X-radiation from straight section devices such as undulators and wigglers and also from the bending magnets of the storage ring. With the aim of optimizing the design of radiation absorbers in the ESRF, we have made measurements on the interactions of hard synchrotron radiation with copper blocks. We report the findings with beam doses up to several ampere hours and also present some preliminary observations on the compatibility of a crotch design with NEG pumping. The measurements in general stress the role of secondary photons as agents for desorbing gas in a direct desorption process. (author)