Title

A Nuclear-Photon Energy Conversion Study

Creator

Watts, H. V.

Oestreich, M. D.

Robinson, R. J.

Date

1963

Identifier

AD0402695

AD0402695

Abstract

A double energy conversion technique was 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 source-phosphor 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 which may be stacked in one bundle. These effects are more pronounced in silicon photovoltaic converters than in ZnCdS: Cu type phosphors. A ten watt output power source fabricated with currently available materials (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 in creased by a factor of ten to forty if certain ideal materials were available. The rapid decrease in photo voltage and energy conversion efficiency of silicon cells at low illumination intensities causes an appreciable loss in the over all efficiency of such power source.

Date Issued

1963-03

Extent

61

Corporate Author

Armour Research Foundation

Report Number

ASD TSR 63-244

AD Number

AD-402 695

Contract

AF 33(657)8527

DoD Project

8173

DoD Task

817301

Distribution Conflict

No

Index In

U.S. Government Research Reports, Vol. 38, No. 15, p. 57 and p. S-18

Index Price

$6.60 and $1.75

Distribution Classification

1

DTIC Record Exists

Yes

Report Availability

Not available via Contrails

Type

report