Femtosecond Thermionic Emission in the Space-Charge Limited Regime

Authors

D. Mark Riffe, Utah State UniversityFollow
X. Y. Wang
M. C. Downer
D. L. Fisher
T. Tajima
J. L. Erskine

Document Type

Article

Journal/Book Title/Conference

Journal of the Optical Society of America B

Volume

10

Issue

8

Publication Date

1993

First Page

1424

Last Page

1435

Abstract

We study femtosecond-laser-pulse-induced electron emission from W(100), Al(110), and Ag(lll) in the sub-damage regime (1–44 mJ/cm² fluence) by simultaneously measuring the incident-light reflectivity, total electron yield, and electron-energy distribution curves of the emitted electrons. The total-yield results are compared with a space-charge-limited extension of the Richardson-Dushman equation for short-time-scale thermionic emission and with particle-in-a-cell computer simulations of femtosecond-pulsed-induced thermionic emission. Quantitative agreement between the experimental results and two calculated temperature-dependent yields is obtained and shows that the yield varies linearly with temperature beginning at a threshold electron temperature of ~0.25 eV The particle-in-a-cell simulations also reproduce the experimental electron-energy distribution curves. Taken together, the experimental results, the theoretical calculations, and the results of the simulations indicate that thermionic emission from nonequilibrium electron heating provides the dominant source of the emitted electrons. Furthermore, the results demonstrate that a quantitative theory of space-charge-limited femtosecond-pulse-induced electron emission is possible.

Comments

Published in the Journal of the Optical Society of America B © 1993 Optical Society of America. Publisher PDF is available for download through link above.

Recommended Citation

"Femtosecond Thermionic Emission in the Space-Charge Limited Regime," D. M. Riffe, X. Y. Wang, M. C. Downer, D. L. Fisher, T. Tajima, and J. L. Erskine, J. Opt. Soc. Am. B 10, 1424 (1993).