Dice Question Streamline Icon: https://streamlinehq.com

Link CTR image features to absolute bunch length via TDC benchmarking

Establish a quantitative mapping between broadband coherent transition radiation (CTR) images and the absolute longitudinal bunch length of electron bunches by benchmarking the CTR-based imaging against transverse deflecting cavity (TDC) measurements, enabling conversion from relative compression monitoring to direct bunch-length estimation.

Information Square Streamline Icon: https://streamlinehq.com

Background

The paper demonstrates proof-of-concept bunch-by-bunch compression monitoring using broadband imaging of coherent transition radiation (CTR) and non-invasive coherent synchrotron radiation (CSR) at the MAX IV Short Pulse Facility. The method reliably tracks changes in compression via image intensity and width but currently provides only relative information.

To move from relative compression monitoring to absolute bunch-length determination, the authors note that CTR image data must be calibrated against a ground-truth longitudinal diagnostic. They identify benchmarking with a transverse deflecting cavity (TDC) as the necessary step, without which any direct comparison to bunch length would be speculative.

References

The other improvement would be to link the CTR images to the bunch length. This could be achieved via simulation studies, but would require a TDC to benchmark against. A comparison at this stage would be pure conjecture.

— First demonstration of coherent radiation imaging for bunch-by-bunch longitudinal compression monitoring (2509.04689 - Wolfenden et al., 4 Sep 2025) in Section 6 (Conclusions)