Photocurrent Generation from Basic Metals, Utilizing a Short Pulsed ArF Excimer Laser.
Abstract
An excimer laser used to produce cold photoelectrons from common metal surfaces offers an improvement over a standard heated (thermionic) cathode electron source. Photoelectrons accelerated across an anode cathode gap were observed under both space charge limited and emission limited conditions. Temporal characteristics of the resulting electron beam showed fast rise times of 3-5 nano seconds (ns) for space charge limited and 8-12ns (full width half maximum) for emission limited cases. Spatial characteristics of the output pulse shape revealed a classic clipped peak amplitude in the space charge pulse but identical characteristics in the emission limited pulse output. Both types of emission produced large current densities up to 91 amps/ sqcm. Varying the cathode metal used for the photocathode indicates Zinc (Zn) produced the largest current density, and therefore, the highest quantum efficiency in both space charge and emission limited cases.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1987
- Accession Number
- ADA184928
Entities
People
- Thomas J. Ringler
Organizations
- Naval Postgraduate School