BEAM STOP High heat load beam stop
2014 | CHESS
This pneumatically operated photon shutter was designed and built by AVS US and is installed at an undulator beamline, receiving a peak heat flux of 155 W/mm2 totaling 2 kW.
The water-cooled copper block is tapered at 6º with respect to the beam axis to reduce heat flux density. The block features two independent cooling circuits, one for each (vertical) half of the block, which can be connected in series or attached independently to the facility cooling system.
The shutter provides 4” (110mm) of vertical beam acceptance, which can be adjusted within the 5” of actuator travel using the hard stop bolts. Two sets of position sensing switches are provided for redundancy. The vessel is shaped as a 6-way cross with 3 free arms, which can be used for viewports, additional instrumentation, pumping or simply capped.
Advantages of this design include extra-long bellows to extend its lifetime, and normally-closed pneumatic actuation which defaults to safe condition in the event of loss of power or air pressure. Its modularity allows in-situ maintenance.
Working pressure: UHV.