Temperature effects on an InGaP (GaInP) (55)Fe X-ray photovoltaic cell.

This paper investigates the effects of temperature on an InGaP (GaInP) (55)Fe X-ray photovoltaic cell prototype for a radioisotope microbattery (also called a nuclear microbattery). An In0.5Ga0.5P p-i-n (5 μm i-layer) mesa photodiode was illuminated by a standard 206 MBq (55)Fe radioisotope X-ray source and characterised over the temperature range -20 °C to 100 °C. The electrical power output of the device reached its maximum value of 1.5 pW at a temperature of -20 °C. An open circuit voltage and a short circuit current of 0.82 V and 2.5 pA, respectively, were obtained at -20 °C. While the electrical power output and the open circuit voltage decreased with increasing temperature, an almost flat trend was found for the short circuit current. The cell conversion efficiency decreased from 2.1% at -20 °C to 0.7% at 100 °C

Nuclear pumping of a neutral carbon laser

Nuclear pumped lasing on the neutral carbon line at 1.45 micron was achieved in mixtures of He-CO, He-N2-CO, He-CO2, and Ne-CO and Ne-CO2. A minimum thermal neutron flux of 2 x 10 to the 14th power sq cm-sec was sufficient for oscillation in the helium mixtures. The peak of the laser output was delayed up to 5.5 ms relative to the neutron pulse in He-CO2, He-N2-CO, Ne-CO, and Ne-CO2 mixtures while no delay was observed in He-CO mixtures. Lasing was obtained with helium pressures from 20 to 800 T, Ne pressures from 100 to 200 T, CO from 0.25 to 20 mT, N2 from 0.5 mT, and CO2 from 0.1 to 25 mT in the respective mixtures

Remote pumping of solid state lasers with nuclear driven fluorescers. Final report, October 1, 1990--March 31, 1993

Development of an electron density model, microwave propagation model and power density model was completed for various visible excimer gas media including the xenon oxide excimer (XeO*). In addition, a heat transfer model has been developed. Optimization of a microwave pumped excimer lamp has begun and the results indicate that high frequency modes can be excited efficiently. A model for power density in the cavity has been developed and indicates that 111 modes appear to be the most uniform. A He{sup 3} excited nuclear ``pumped`` lamp was built to take spectra of gas mixtures in a reactor environment. The effects of nuclear radiation on optical materials was examined from 350 nm to 950 nm. The results demonstrated that radiation effects are nonlinear with power. Additionally, radiation damage was strongest in the UV bandwidth. Studies were also made of radiation induced fluorescence. A method was developed to subtract radiation induced fluorescence from the fluorescence signal in the lamp. Using the results of radiation induced absorption and radiation induced fluorescence, a technique for determining absolutely calibrated spectra from the lamp was developed. Absolutely calibrated spectra from He, He-Ar, He-Xe, and He-Kr were taken. The results from this study were compared to electrically driven flashlamps. A heat pipe for a reactor experimentation with alkali metals was developed. Several experiments were run using the heat pipe filled with 5 grams of sodium. Radiation from the violet bands of sodium at around 436 nm was expected. Indeed observations of emission at 436 nm were made. The overall results of this work were: (1) development of a microwave excitation system which approximated nuclear ``pumping.`` (2) Development of methods to compensate for radiation induced absorption and radiation induced fluorescence in optical systems in high radiation environments. (3) Development of methods to obtain absolutely calibrated spectra from light

Solid state laser media driven by remote nuclear powered fluorescence

An apparatus is provided for driving a solid state laser by a nuclear powered fluorescence source which is located remote from the fluorescence source. A nuclear reaction produced in a reaction chamber generates fluorescence or photons. The photons are collected from the chamber into a waveguide, such as a fiber optic waveguide. The waveguide transports the photons to the remote laser for exciting the laser