The "Sphere Dump" - A New Low-Cost High-Power Beam Dump Concept and a Catalytic Hydrogen-Oxygen Recombiner for Radioactive Water Systems

This paper reveals a new high-power beam dump concept developed at SLAC. Its principal features are relatively low production costs, simple assembly procedures, compactness, and rather high power absorption capacity. The main power absorption medium is a water-cooled bed of 1 cm diameter aluminum spheres contained in a tube. This "Sphere Beam Dump" is rated at 500 kW and its production costs are compatible with other designs at powers as low as 50 kW. The main features of the dump are discussed with emphasis on heat transfer in the bed of spheres, detection of burnout, and flow and mixing of the coolant. A prototype of such a dump was successfully tested in the electron beam at powers up to 495 kW and at an energy of 18 GeV. The experimental results are discussed and potential applications for other high-power absorbers are indicated. A catalytic hydrogen-oxygen recombiner for removal of radiolytically produced hydrogen from such a dump and other water-cooled power absorbers is described in the second part of the paper. Such topics as operational parameters, instrumentation, safety, and performance are stressed.