Modelling of Flux Concentrator for Linear Accelerator Positron Source

Tuesday 21 Jan 2020, 14:00 → 15:00 Europe/Zurich

30/7-010 (CERN)

Hugo Bajas (CERN)

Abstract: The positron sources for the SuperKEK at the High Energy Accelerator Research Organization in Japan, the Circular Electron-Positron Collider at the Institute of High Energy Physics in China, at the Stanford Linear Accelerator center in the US and the Compact Linear Collider at CERN require the use of Flux Concentrators in order to focus the positrons and match the acceptance of the accelerator aperture. A Flux Concentrator (FC) is a solenoid that features a tapered cross-section. When powered with a pulsed current, it is able to produce a localized pulsed axial magnetic field. The field within such conical aperture creates a strong yielding of emerging positrons coming from the collision of the electron beam on a fixed target. Recent FCs are affected by dielectric breakdowns between the first turns when operating at nominal current, thus severely limiting the FC performance. In order to address this issue and to understand how to improve the design of this device, a transient electromagnetic numerical model of FC has been conceived using Opera software. The model successfully reproduces experimental measurements and now allows identifying the relevant parameters to be optimized for future FCs.

Flux Concentrator Model 231019 H Bajas v10.pptx