Detection of soft x rays with NEA III-V photocathodes.
We describe the experimental energy response of a negative electron affinity (NEA) III-V photocathode to x rays with energies from approximately 0.8 to approximately 3 keV. Energy resolutions, E/DeltaE, from approximately 1 to approximately 3 are obtained, together with approximately 100% quantum efficiency. Theoretical calculations based on an electron diffusion model are shown to be in good agreement with the experimental results. The use of NEA III-V photocathodes as efficient soft x-ray detectors with good energy and spatial resolution is discussed for imaging applications in x-ray astronomy.
Bardas
D
D
Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, Massachusetts 02138Light Sensing and Emitting Division, Varian Associates, Inc. 601 California Ave., Palo Alto, California 94303.
Kellogg
E
E
Murray
S
S
Enck
R
R