Comment on “Ultrafast electron optics: Propagation dynamics of femtosecond electron packets” [J. Appl. Phys. 92, 1643 (2002)]
Year: 2003
Type: article
Abstract: In a recent article [J. Appl. Phys. 92, 1643 (2002)] Siwick et al. investigated the space-charge-limited electron pulse propagation in a photoelectron gun using an analytical approach, referred to as mean-field theory, and a numerical N-body simulation. The results were compared with a one-dimensional fluid model [J. Appl. Phys. 91, 462 (2002)], and a conclusion was made that the fluid model overestimates the pulse duration after a certain propagation time. Although the mean-field theory and N-body simulation give exactly the same results for all examples studied, we point out that the expression for the on-axis potential in their mean-field model is inapplicable to investigating the electron space-charge dynamics in an ultrafast electron packet. We correct that expression and derive a two-dimensional model that is in agreement with our previous one-dimensional fluid model. We also point out several areas where Siwick et al. have misinterpreted the one-dimensional fluid model.
Source: Journal of Applied Physics
DOI: 10.1063/1.1567816
Authors: Bao-Liang Qian, Hani E. Elsayed-Ali
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W1973156957