Micro-Bunched Beam Production at FAST for Narrow Band THz Generation Using a Slit-Mask

TL;DR

This paper presents simulations and experiments on producing micro-bunched electron beams at FAST for narrow band THz radiation, demonstrating the effectiveness of slit-mask micro-bunching techniques.

Contribution

It introduces a novel method of micro-bunch beam production using a slit-mask in the chicane at FAST, with experimental validation and simulation comparison.

Findings

Successful micro-bunching of 30 MeV electron beams demonstrated

Detection of micro-bunching signals using a skew quadrupole magnet

Good agreement between experimental results and simulations

Abstract

We discuss simulations and experiments on creating micro-bunch beams for generating narrow band THz radiation at the Fermilab Accelerator Science and Technology (FAST) facility. The low-energy electron beamline at FAST consists of a photoinjector-based RF gun, two L-band superconducting accelerating cavities, a chicane, and a beam dump. The electron bunches are lengthened with cavity phases set off-crest for better longitudinal separation and then micro-bunched with a slit-mask installed in the chicane. We carried out the experiments with 30 MeV electron beams and detected signals of the micro-bunching using a skew quadrupole magnet in the chicane. In this paper, the details of micro-bunch beam production, the detection of micro-bunching and comparison with simulations are described.