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Fabian Zomer

Publications and source records attributed to Fabian Zomer.

8 recordsLinked to original sources
arXiv2026

Design of a thermal loading resilient optical enhancement cavity for operation at 515 nm for X-ray production through inverse Compton scattering in an energy recovery linac

A fast and simple method to optimize a high-power optical enhancement cavity is proposed. It is applied to a four-mirror bow-tie cavity operating at 515 nm, which is to be implemented within the PERLE ERL for the production of X-rays through inverse Compton scattering. The optimized figure of merit is the expected X-ray photon rate. Thermal loading is carefully evaluated, giving also a path towards very high average power operation in infrared. One shows that photon rates exceeding 10^11 per second at average energies above 280 keV in apertures of a few miliradians are within reach. For easier comparison with existing Compact X-ray sources providing high rates of photons, the performance of the proposed design is also evaluated for a system delivering infrared laser pulses. It is shown that a source delivering more than 10^13 photons per second is achievable with this design, an unprecedented performance for existing Compton X-ray sources. The design procedure employed here can be easily applied to other applications of high-power high-finesse optical cavities.

physics.optics↗
arXiv2026

Status report towards implementation of a Compton polarimeter at BEPCII

Precision beam polarization measurements based on Compton polarimeters are essential for the physics program of future high-energy colliders. In order to prepare for these and to extend the scope of physics measurements of the BESIII experiment at the BEPCII, a diagnostic of electron beam transverse polarization at BEPCII is of interest. The design and status report of the commissioning, until July 2025, of this device is reported in this paper. We report unambiguous observation of Compton interaction, discuss current limitations of the experimental setup and draw prospects for improvements and actual measurement of electron beam polarization in the near future.

physics.acc-ph↗
arXiv2025

Study of laser-beam arrival time synchronization towards sub-picosecond stability level

A precise synchronization between laser pulse and electron beam arrival time is essential for achieving sub-picosecond stability in modern accelerator facilities. In this work, a Low-Level RF system architecture combined with White Rabbit based timing system has been tested through a collaboration between KEK (Japan) and CNRS/IN2P3, IJClab (France). The setup combines a frequency standard generator, an IDROGEN carrier board with an embedded White Rabbit node, and SkyWorks synthesizers of different form factors to distribute phase-locked clock signals over telecommunication fiber. Phase noise power spectral density measurements were performed at several RF sub-harmonics to confirm synchronization performance. These results demonstrate the feasibility of implementing the White Rabbit-IDROGEN synchronization scheme for large-scale accelerators, including applications to laser-based diagnostics.

physics.acc-ph↗
arXiv2019

Low power commissioning of an innovative laser beam circulator for inverse Compton scattering Gamma-ray source

We report on the optical commissioning of the high power laser beam circulator (LBC) for the high brightness Compton γ-ray source Extreme Light Infrastructure for Nuclear Physics. Tests aiming at demonstrating the optical performances of the LBC have been realized with a low-power pulsed laser-beam system and without electron beam. We show that, with the developed alignment and synchronization methods coming from the LBC design study presented in the Dupraz et al. paper [1], the LBC enhances the laser-beam power available at the interaction point (IP) by a factor in excess of 25. This corresponds to a potential of bringing the average laser-beam power in excess of 1 kW when the LBC is injected with the interaction point laser-beam pulse energy of 400 mJ at 100 Hz.

physics.acc-ph↗
arXiv2005

Transmission matrix of a uniaxial optically active crystal platelet

Expressions corresponding to the transmission of a uniaxial optically active crystal platelet are provided for an optical axis parallel and perpendicular to the plane of interface. The optical activity is taken into account by a consistent multipolar expansion of the crystal medium response due to the path of an electromagnetic wave. Numerical examples of the effect of the optical activity are given for quartz platelets of chosen thicknesses. The optical activity's effects on the variations of the transmission of quartz platelets as a function of the angle of incidence is also investigated.

physics.optics↗
arXiv2003

Surfaces roughness effects on the transmission of Gaussian beams by anisotropic parallel plates

Influence of the plate surfaces roughness in precise ellipsometry experiments is studied. The realistic case of a Gaussian laser beam crossing a uniaxial platelet is considered. Expression for the transmittance is determined using the first order perturbation theory. In this frame, it is shown that interference takes place between the specular transmitted beam and the scattered field. This effect is due to the angular distribution of the Gaussian beam and is of first order in the roughness over wavelength ratio. As an application, a numerical simulation of the effects of quartz roughness surfaces at normal incidence is provided. The interference term is found to be strongly connected to the random nature of the surface roughness.

physics.acc-ph↗