Cockcroft Institute, Warrington, Cheshire, United Kingdom
The University of Liverpool, Liverpool, United Kingdom
UMAN, Manchester, United Kingdom
UMD, College Park, Maryland, USA
High-resolution bunch length measurement is of the utmost importance for current and future generations of light sources and linacs. It is also key to the optimisation of the final beam quality in plasma-based acceleration. We present progress in the development of a novel RMS bunch length monitor based on imaging the coherent diffraction radiation (CDR) produced by a non-invasive circular aperture. Due to the bunch lengths involved, the radiation produced is in the THz range. This has led to the development of a novel THz imaging system, which can be applied to low energy electron beams. For high energy beams the imaging system can be used as a single shot technique. Simulation results show that the profile of a CDR image of a beam is sensitive to bunch length and can thus be used as a diagnostic. The associated benefits of this imaging distribution methodology over the typical angular distribution measurement are discussed. Plans for experiments conducted at the SwissFEL (PSI, Switzerland), along with plans for future high energy single shot measurements are also presented.
Cockcroft Institute, Warrington, Cheshire, United Kingdom
The University of Liverpool, Liverpool, United Kingdom
The exploitation of optical transition radiation (OTR) in imaging-based diagnostics for charged particle beams is a well-established technique. Simulations of the expected OTR transverse beam profiles are therefore important in both the design of such imaging systems and the analysis of the data. Simulating OTR images is relatively straightforward for low energy electron beams. However, in the near future electron machines will be using high-energy and low-emittance beams. Using such parameters can be challenging to simulate, and can be limiting in their account of practical factors, e.g. chromatic aberrations. In this work we show systematically that the use of low-energy parameters in high-energy OTR image simulations induces little deviation in the resulting transverse beam profiles. Simulations therefore become much easier to perform, and further analysis may be performed. This opens up exciting opportunities to perform simulations quicker and with reduced demands on the computation requirements. It will be shown in this contribution how this approach will enable enhanced ways to optimize OTR diagnostics.
The University of Liverpool, Liverpool, United Kingdom
