X-10: Transformer Ratio Optimisation

Principle Investigator:
Carl Andreas Lindstroem

Contact in absentia:
Stephan Wesch

Description and goals:
The transformer ratio - theoretically defined as the ratio between the accelerating field seen by the witness beam and the maximum decelerating field observed by the drive beam, but experimentally registered as the ratio of the witness energy gain to the maximum driver energy loss - is a key characteristic of a beam-driven plasma-wakefield accelerator, partly defining how much energy is gained by the witness bunch within a fixed acceleration length. Wakefield theory states that, for symmetric Gaussian drive beams, transformer ratios are limited to a value of 2. However, for asymmetric beams with bespoke profiles, e.g. triangular shaped current profiles, higher values are possible.

The key goal of the X-10 experiment is, therefore, to study the dependence of the transformer ratio on the drive beam parameters, especially its current profile, and to maximise this important parameter.