Observing microscopic structures of a relativistic object using a time -stretch strategy

TL;DR

This paper introduces a novel method using time-stretch photonics to directly observe and analyze the microscopic structures within electron bunches in a storage ring, achieving subpicosecond resolution.

Contribution

It demonstrates the first direct observation of electron bunch microstructures with high temporal resolution using a time-stretch strategy in a synchrotron facility.

Findings

Successful visualization of electron microstructures

Subpicosecond temporal resolution achieved

Potential for improved control of synchrotron radiation sources

Abstract

Emission of light by a single electron moving on a curved trajectory (synchrotron radiation) is one of the most well-known fundamental radiation phenomena. However experimental situations are more complex as they involve many electrons, each being exposed to the radiation of its neighbors. This interaction has dramatic consequences, one of the most spectacular being the spontaneous formation of spatial structures inside electrons bunches. This fundamental effect is actively studied as it represents one of the most fundamental limitations in electron accelerators, and at the same time a source of intense terahertz radiation (Coherent Synchrotron Radiation, or CSR). Here we demonstrate the possibility to directly observe the electron bunch microstructures with subpicosecond resolution, in a storage ring accelerator. The principle is to monitor the terahertz pulses emitted by the structures, using a strategy from photonics, time-stretch, consisting in slowing-down the phenomena before recording. This opens the way to unpreceeded possibilities for analyzing and mastering new generation high power coherent synchrotron sources.