Time Dependence of the Intensity of Diffracted Radiation Produced by a Relativistic Particle Passing through a Natural or Photonic Crystal

TL;DR

This paper derives formulas describing how radiation from a relativistic particle in a crystal evolves over time, showing that various types of diffracted radiation can last longer than the particle’s transit time, with experimental evidence of delayed radiation peaks.

Contribution

It provides a theoretical framework for the time dependence of diffracted radiation from relativistic particles in crystals, including experimental validation of delayed radiation peaks.

Findings

Radiation persists longer than particle transit time

Experimental detection of delayed radiation peaks

Formulas describing time evolution of diffracted radiation

Abstract

The formulas which describe the time evolution of radiation produced by a relativistic particle moving in a crystal are derived. It is shown that the conditions are realizable under which parametric (quasi-Cherenkov) radiation, transition radiation, diffracted radiation of the oscillator, surface quasi-Cherenkov and Smith-Purcell radiation last considerably longer than the time of the particle flight through the crystal. The results of carried out experiments demonstrate the presence of additional radiation peak appearing after the electron beam has left the photonic crystal.