Fast Mapping of Terahertz Bursting Thresholds and Characteristics at Synchrotron Light Sources

TL;DR

This paper introduces a rapid measurement method for analyzing terahertz bursting thresholds in synchrotron light sources, enabling quick, comprehensive studies of electron bunch dynamics and comparison with theoretical models.

Contribution

The paper presents a novel quasi-instantaneous measurement technique that significantly reduces the time needed to analyze bursting characteristics in synchrotron light sources.

Findings

Measurement time reduced from hours to seconds

First results demonstrate method effectiveness at ANKA facility

Systematic comparison with bunched-beam theory enabled

Abstract

Dedicated optics with extremely short electron bunches enable synchrotron light sources to generate intense coherent THz radiation. The high degree of spatial compression in this so-called low-alpha optics entails a complex longitudinal dynamics of the electron bunches, which can be probed studying the fluctuations in the emitted terahertz radiation caused by the micro-bunching instability ("bursting"). This article presents a "quasi-instantaneous" method for measuring the bursting characteristics by simultaneously collecting and evaluating the information from all bunches in a multi-bunch fill, reducing the measurement time from hours to seconds. This speed-up allows systematic studies of the bursting characteristics for various accelerator settings within a single fill of the machine, enabling a comprehensive comparison of the measured bursting thresholds with theoretical predictions by the bunched-beam theory. This paper introduces the method and presents first results obtained at the ANKA synchrotron radiation facility.