### Abstract

Coherent transition radiation (CTR), produced by short electron bunches, is a well-known radiation mechanism which is applied for bunch length monitoring. By analyzing the CTR spectrum it is possible to reconstruct the longitudinal bunch shape. Such a technique is widely used for accelerators with electron beams possessing bunch lengths σ_{z} much larger than their transverse beam sizes σ_{x,y} (with σ_{x,y,z} the rms transverse and longitudinal beam sizes). New developments in the field of accelerator technology allow to produce and accelerate bunches with a duration of less than 1 fs with a "pancake-like" bunch shape, i.e. with σ_{z} ll σ_{x,y}. Diagnostic schemes of this kind of bunches give rise to interesting effects, for example connected with a transverse asymmetry (σ_{x} σ_{y}), with a tilting of the bunches (i.e. the bunch axis does not coincide with the velocity direction), and even more. Spectral-angular distributions of coherent backward transition radiation (BTR) were simulated taking into account a possible bunch tilt. It is shown that spectral intensity measurements of coherent BTR emitted in backward direction allow to obtain information about the bunch length.

Original language | English |
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Article number | C02055 |

Journal | Journal of Instrumentation |

Volume | 13 |

Issue number | 2 |

DOIs | |

Publication status | Published - 27 Feb 2018 |

### Keywords

- beam-intensity monitors
- Beam-line instrumentation (beam position and profile monitors
- bunch length monitors)
- Instrumentation for FEL

### ASJC Scopus subject areas

- Instrumentation
- Mathematical Physics