The influence of the structure imperfectness of a crystalline undulator on the emission spectrum

TL;DR

This paper investigates how structural imperfections in crystalline undulators, caused by surface deformations, affect their radiation spectrum, revealing that amplitude variations and subharmonics alter the emitted radiation's monochromaticity.

Contribution

It introduces a detailed analysis of how surface-induced imperfections impact the emission spectrum of crystalline undulators, highlighting the effects of amplitude variation and subharmonics.

Findings

Amplitude variation over crystal thickness affects radiation spectrum

Presence of subharmonics influences monochromatic pattern

Imperfections significantly alter undulator radiation characteristics

Abstract

We study the influence of an imperfect structure of a crystalline undulator on the spectrum of the undulator radiation. The main attention is paid to the undulators in which the periodic bending in the bulk appears as a result of a regular (periodic) surface deformations. We demonstrate that this method of preparation of a crystalline undulator inevitably leads to a variation of the bending amplitude over the crystal thickness and to the presence of the subharmonics with smaller bending period. Both of these features noticeably influence the monochromatic pattern of the undulator radiation.