Chopper

The beam chopper functions by spinning a 2cm thick steel disk that has protrusions along the rim. The chopping can be done down to 6µs (the protrusions could, in principle, be made such that the chopping could be done on shorter time scales). Since the blocking entity is of 2 cm steel, the chopper can be used with X-Ray energies in excess of 80 keV. The spinning disk is cased in a substantial Al housing that both acts as a safety barrier and a vacuum vessel that allows the chopper to be operated in a HV environment.