A View Screen beam profile monitor for the ARIEL e-linac at TRIUMF.

摘要

A megawatt class electron linear accelerator (e-linac) will be constructed at TRIUMF as part of the new ARIEL facility which will produce rare ion beams for the study of nuclear structure and astrophysics, and material science. The 50 MeV, 10mA, continuous wave e-linac will drive gamma ray induced fissioning of a Uranium target for the production of neutron rich beam species. View Screens located at a number of places along the e-linac beam-line will acquire two dimensional images of the transverse electron beam profiles, providing measurements of the size, position, and shape of the incident e-linac beam.;The design of the View Screens will be presented, based on design studies and simulations performed to evaluate the performance of the View Screens under various operating conditions. These studies include GEANT simulations of the energy loss and scattering of the electron beam as it passes through the scintillation and Optical Transition Radiation beam targets, the subsequent thermal response of the targets, and a ray tracing optics simulation to optimize the configuration of the imaging optics. Bench test have been performed on the resulting optics design to evaluate the imaging characteristics, verifying fulfillment of the design requirements.;Construction of a prototype View Screen device is currently underway, with beam tests scheduled for Fall 2011. A total of 14 View Screens will be constructed and installed along the e-linac beam-line.