Improved high resolution grasshopper monochromator

The grasshopper monochromator [1] is a bakable ultrahigh vacuum instrument specifically designed for constant deviation with a synchrotron source. It can be used as low as 10 eV with a grating of small ruling density and above 1000 eV with a high density X-ray grating. Especially high flux is available at its exit slit when the monochromator is properly matched to the synchrotron source. Flux figures will be given as well as remarks on the performance of the first version of this instrument in operation at the Stanford Synchrotron Radiation Laboratory. Several improvements have been made in new versions of the monochromator now installed or under construction. These include adjustable slits, improved vacuum and relatively easy interchange of gratings.