Response or Comment
Journal of Applied Physics
In a recent article 关J. Appl. Phys. 92, 1643 共2002兲兴 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 关J. Appl. Phys. 91, 462 共2002兲兴, 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. © 2003 American Institute of Physics.
Original Publication Citation
Qian, B. L., & Elsayed-Ali, H. E. (2003). Comment on "Ultrafast electron optics: Propagation dynamics of femtosecond electron packets" j. Appl. Phys. 92, 1643 (2002). Journal of Applied Physics, 94(1), 803-806. doi:10.1063/1.1567816
Qian, Bao-Liang and Elsayed-Ali, Hani E., "Comment on "Ultrafast Electron Optics: Propagation Dynamics of Femtosecond Electron Packets" J. Appl. Phys. 92, 1643 (2002)" (2002). Electrical & Computer Engineering Faculty Publications. 183.