Open AccessThe effect of non-uniform magnetic field on the energy spread of a low energy electron beam
Author(s) -
Nattawut Suksawat,
K. Wongrach,
Rattachai Pinchaipat
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1719/1/012048
Subject(s) - magnetic field , cathode ray , physics , optics , beam (structure) , electron , coherence length , coherence (philosophical gambling strategy) , electron gun , magnet , diffraction , beam diameter , laser beam quality , computational physics , m squared , ferrite (magnet) , condensed matter physics , laser beams , laser , quantum mechanics , superconductivity
This work aimed to enhance a resolution of the electron diffraction pattern by improving the longitudinal and lateral coherence of electron beam. Using a uniform magnetic field and slits is a cheap and straightforward method. However, such magnet requires a larger space. Smaller solenoids which create a non-uniform magnetic field are more applicable, especially when space was limited. bTherefore, the effect of a non-uniform magnetic field on the energy spread of the electron beam was investigated numerically and experimentally. The simulation results agreed well (within 10%) with the measurements. It has been found that the ferrite core solenoids together with a narrow slit can be used to improve the beam coherence. However, beam shape observed form the real measurement significantly deviates form the simulation result. In addition the non-uniform magnetic field, the beam trajectory was affected by the electric field form electron gun which causes the change of beam shape and spatial distribution.