Design and Testing of a Prototype Beam Absorber for the PXIE MEBT.

摘要

One of the goals of the PXIE at Fermilab is to demonstrate the capability to form an arbitrary bunch pattern from an initially CW 162.5 MHz H- bunch train coming out of an RFQ. The bunch-by-bunch selection will take place in the 2.1 MeV Medium Energy Beam Transport (MEBT) by directing the undesired bunches onto an absorber that needs to withstand a beam power of up to 21 kW, focused onto a spot with a ~2 mm rms radius. A design was developed to respond to the driving requirements: high surface power density of 17W/mm (sup 2) and resistance to ion-induced surface blistering. A ? - size prototype of the absorber was manufactured, and its thermal properties were tested with an electron beam generating a peak power density similar to the one expected during normal operation of the PXIE beam line. The note describes the absorber concept, the prototype, the testing procedure with the electron beam, and the results of testing.