Gas sheet view screen for intense ion and electron beams

Next-generation particle accelerators are pushing the intensities of their beams to never-before- seen levels. As such, it becomes ever more important to measure and control the beams to maximize their efficiency and minimize damage due to oversized or missteered beams. Traditional tools for measuring the transverse profile of a beam (scintillating screens and wire scanners) have no hope of surviving the impact of such beams. A less invasive means in necessary means of measuring beam widths is needed to monitor and tune tomorrow’s intense beams. RadiaBeam Technologies proposes to develop a transverse profile monitor that uses short bursts of gas injected into the beam pipe to measure the transverse beam profile. The injected gas forms a sheet for the beam to intercept. The interception ionizes the gas, and the freed electrons are accelerated and focused onto a multi-channel plate to create a two-dimensional image of the beam profile. The use of an injected gas allows for higher densities of gas and clearer images than techniques based on using residual gas but without increasing the load on the vacuum system. In Phase I of this project, physics analysis and simulations will be performed in order to guide design of all components of the system, including fluid dynamics simulations to optimize the gas sheet injection system and Monte Carlo simulations to predict the detection signal from the beam-gas interaction. The gas extraction system must also be engineered so that the injected gas does not spoil the vacuum in the rest of the beam transport system. Finally, the detection system and electronics will be designed to best match the expected signal from the other simulations of the interaction. The successful development of this device is of interest to a number of accelerator facilities, especially to high-intensity hadron beam laboratories like the Spallation Neutron Source at Oak Ridge, the European Spallation Source in Sweden, and many others in America and around the world. Other intense beam facilities such as nuclear waste transmutation facilities and high- intensity electron beam facilities will find this device useful where other beam monitors are inadequate for their beam intensities.