A NUCLEAR-PHOTON ENERGY CONVERSION STUDY

Technical Report · Fri Feb 01 04:00:00 EST 1963

OSTI ID:4742969

Watts, H V; Oestreich, M D; Robinson, R J

A double energy conversion technique is studied for aerospace use as a radioisotope-powered, 10-watt electrical output power source. In this technique, beta particles from a radioisotope are absorbed by a luminescent material which emits a multiplicity of low energy photons. These photons are then converted to electrical energy by a photovoltaic device. The three components (radioisotope, phosphor, and photovoltaic cell) are discussed individually and then in combination in various geometries of sourcephosphor and phosphor-photovoltaic converter. Nuclear radiation effects on the phosphor and photovoltaic materials restrict the choice of the radioisotope to a low-energy beta emitter; and temperature effects limit the number of unit power cells'' that may be stacked in one bundle. These effects are more pronounced in silicon photovoltaic converters than in ZnCdS:Cu type phosphors. A ten-watt source (Pm-147, ZnCdS:Cu, and silicon photovoltaic cells) would have an overall energy conversion efficiency of about 0.2 percent and a power per weight ratio of 4 mw/lb. It is estimated that the power per weight could be increased by a factor of ten to forty if certain ideal'' materials were available. The rapid decrease in photovoltage and energy conversion efficiency of silicon cells at low illumination intensities causes an appreciable loss in the overall efficiency of such power source. (auth)

• Research Organization: Illinois Inst. of Tech., Chicago. Armour Research Foundation
• NSA Number: NSA-17-018215
• OSTI ID: 4742969
• Report Number(s): ASD-TDR-63-244
• Country of Publication: United States
• Language: English

Related Subjects

ENGINEERING AND EQUIPMENT