Forward and backward photoemission yields from metals at various x-ray angles of incidence

Conference · Sat Dec 01 00:00:00 EST 1973 · IEEE (Inst. Elec. Electron. Eng.), Trans. Nucl. Sci., v. NS-20, no. 6, pp. 111-116

OSTI ID:4326919

Bernstein, M J; Paschen, K W

From annual conference on nuclear and space radiation effects; Logan, UT (23 Jul 1973). X-ray generated photoemission from thin metal foils backed by graphite was measured with radiation incident from the front and back sides at several angles. irradiation was provided by a 100-kV x-ray tube with three different filters to harden the spectrum. The 2 pi photoelectron emission current from a surface was measured; a biased grid retarded the low-energy secondary electrons, which added only 10-30% to the current at zero grid bias. Investigated metals were: Mg, Al, Ti, Fe, Cu, Ag, Ta, Au, and Pb; also the total emission from just the graphite support was measured. The front-to-back ratio of emission currents at normal incidence ranged from about 1.9 for Al and Mg down to about 1.1 for Ta. The photoelectron yield was found to be G/sub e/ mu /sub a/ S/ sub e/ electrons/p hoton where mu /sub a/ and S/sub e/ are the energy-dependent photon absorption cross section and computed electron mean path length in the emitter, and G/sub e/ is a constant assumed independent of photon energy in the range studied (but does depend on radiation angle of incidence). For the photon energy range of 20-70 keV, the measured emission current densities corresponded to the following average values for G/sub e/: 0.37 plus or minus 0.06 for C, 0.30 plus or minus 0.03 for Al, 0.21 plus or minus 0.02 for Cu and Ag, and 0.18 plus or minus 0.02 for Ta. (auth)

• Research Organization: Aerospace Corp., El Segundo, CA
• NSA Number: NSA-29-031056
• OSTI ID: 4326919
• Journal Information: IEEE (Inst. Elec. Electron. Eng.), Trans. Nucl. Sci., v. NS-20, no. 6, pp. 111-116, Conference: Annual conference on nuclear and space radiation effects, Logan, UT, 23 Jul 1973; Other Information: Orig. Receipt Date: 30-JUN-74
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

N72100* -Physics (Radiation & Shielding)-Radiation Physics
N60100 -Physics (Atomic & Molecular)-Atomic
Electron
Ion & Molecular Beams & Reactions
N50240 -Metals
Ceramics
& Other Materials-Metals & Alloys-Radiation Effects
*ALUMINIUM- PHOTOELECTRIC EFFECT
*COPPER- PHOTOELECTRIC EFFECT
*GOLD- PHOTOELECTRIC EFFECT
*GRAPHITE- PHOTOELECTRIC EFFECT
*IRON- PHOTOELECTRIC EFFECT
*LEAD- PHOTOELECTRIC EFFECT
*MAGNESIUM- PHOTOELECTRIC EFFECT
*SILVER- PHOTOELECTRIC EFFECT
*TANTALUM- PHOTOELECTRIC EFFECT
*TITANIUM- PHOTOELECTRIC EFFECT
*X RADIATION- COLLISIONS
ELECTRONS
PHOTOEMISSION