High-intensity positron microprobe at the Thomas Jefferson National Accelerator Facility

Abstract: We present a conceptual design for a novel continuous wave electron-linac based high-intensity high-brightness slow-positron production source with a projected intensity on the order of 10$^{10}$ e$^+$/s. Reaching this intensity in our design relies on the transport of positrons (T$_+$ below 600 keV) from the electron-positron pair production converter target to a low-radiation and low-temperature area for moderation in a high-efficiency cryogenic rare gas moderator, solid Ne. This design progressed through Monte Carlo optimizations of: electron/positron beam energies and converter target thickness, transport of the e$^+$ beam from the converter to the moderator, extraction of the e$^+$ beam from the magnetic channel, a synchronized raster system, and moderator efficiency calculations. For the extraction of e$^+$ from the magnetic channel, a magnetic field terminator plug prototype has been built and experimental results on the effectiveness of the prototype are presented. The dissipation of the heat away from the converter target and radiation protection measures are also discussed.