Development of a Supersonic Gas Jet Beam Profile Monitor

A supersonic gas jet beam profile monitor has been developed by the QUASAR Group at the Cockcroft Institute, UK. It creates a supersonic gas curtain which interacts with the primary beam, and then images the beam cross-section by collecting the generated ions. The gas curtain is inclined at 45 degrees to the beam and functions as a minimally intercepting screen, which allows it to be used in high energy and high power beams without worrying about material damage. An accurate profile measurement requires homogeneous gas density across the curtain, while high resolution measurement requires a very thin jet. In order to characterize the gas curtain density distribution and understand the jet better, a new movable gauge module has been installed in the gas jet test stand. In this contribution, we discuss the monitor design and the characterization of the gas curtain with the newly installed movable gauge module. In addition, we present a new method for the generation of a very narrow pencil jet using deBroglie wave focusing. Such a narrow jet could be used as a non-invasive counterpart to wire scanners in high-intensity beams where the latter cannot be used.