POSITRON PRODUCTION TARGET

A positron production target design is required to convert 100 kW or more of electron beam average power to produce positrons with good beam quality and possibly high polarization- Conventional high power positron targets usually rely on mechanically rotating the target to distribute the heat load- Mechanical complications for a rotating target include limited cooling water flow, vibration, eddy currents, and wear of the vacuum rotary bearing- A novel approach is proposed to use beam dynamics manipulation based on a pair of rotating magnetic field to deflect the high-power electron beam along a line or around a circle on a fixed target window, and then to combine the produced positrons back into a beam- Proper beam optics design will distribute and dilute the heat load evenly, thus avoiding destructive focusing on a single spot, while achieving copious positron beam production- The fixed target assembly allows sufficiently high cooling water flow to circulate on the target perimeter to carry away deposited heat-