An electro-optical bunch profile monitor for FCC-ee
Abstract
The Future Circular Lepton Collider (FCC-ee) presents challenges for a longitudinal bunch profile monitor due to its wide range of bunch lengths and charge densities across its four distinct operational modes. For commissioning, monitoring the top-up injection, and energy calibration, the FCC-ee requires non-destructive, single-shot measurements of the bunch length and profile. This contribution proposes an in-vacuum electro-optical (EO) longitudinal bunch profile monitor for single-shot measurements at high repetition rates, building on the successful EO monitor at the Karlsruhe Research Accelerator (KARA) at the Karlsruhe Institute of Technology. A novel single-pass conceptual design for the in-vacuum holder of the electro-optical crystal is presented, utilizing prisms instead of a mirror to guide the laser through the crystal, which additionally allows measurements of the long bunches foreseen for FCC-ee operation mode at the Z-pole energy. A first prototype has been constructed and tested at the in-air test stand of the CERN Linear Electron Accelerator for Research (CLEAR). Results from the prototype tests are presented, demonstrating the proof of principle for the single-pass prism-based EO monitor design for FCC-ee.
Keywords
Cite
@article{arxiv.2510.02018,
title = {An electro-optical bunch profile monitor for FCC-ee},
author = {M. Reissig and E. Bründermann and S. Funkner and L. L. Grimm and B. Härer and G. Niehues and J. L. Steinmann and A. -S. Müller and R. Corsini and A. Gilardi and S. Mazzoni and C. Pakuza and A. Schloegelhofer and T. Lefevre and P. Korysko},
journal= {arXiv preprint arXiv:2510.02018},
year = {2025}
}
Comments
13 pages, 19 figures