In this paper we introduce the concept of using a multileaf collimator (MLC) in conjunction with an emittance exchange beamline to allow for finely resolved, real-time control over a beam's current profile. Prior to this advancement, the beam's profile was defined using laser cut masks which were installed into the UHV beamline, requiring days to change masks. However, by using a MLC, real-time iteration is possible; this new approach is highly synergistic with machine learning and should enable very high transformer ratio wakefield acceleration. We have addressed two major considerations towards the implementation of such a system. First, simulations have shown that a practically realizable MLC with forty, two millimeter wide leaves has sufficient resolution to create beam profiles with the same fidelity as a static, laser cut mask. Further, we have introduced a conceptual design for the MLC that addresses the need for UHV compatibility by using magnetic coupling to external actuators.

The most direct application of this scheme will be the demonstration of higher transformer ratio wakefield acceleration which could reduce the footprint and cost of future accelerators, light sources, and colliders. It may also be useful for other applications which require very fine control over the beam's longitudinal profile, e.g. free electron lasers. This effort, a means of precision phase-space control, is aligned with CBB's Beam Dynamics and Control theme.

Reference:

N. Majernik, G. Andonian, R. Roussel, S. Doran, G. Ha, J. Power, E. Wisniewski, and J. Rosenzweig, “Multileaf Collimator for Real-Time Beam Shaping using Emittance Exchange,” arXiv:2107.00125 [physics], Jun. 2021, doi: 10.48550/arXiv.2107.00125. [Online]. Available: http://arxiv.org/abs/2107.00125