High Energy Density Radiation Tolerant Capacitors for Cryogenic Temperature Applications

The Phase II proposal addresses the development of advance high energy density capacitors, for use in Power Processing Units (PPUs) of spacecraft, probes and landers, that are designed to operate in extreme temperature environments, with particular focus on cryogenic temperatures. Operating capacitors at cryogenic temperature presents unique challenges that need to be addressed to ensure a high level of reliability and performance. Space missions to planetary bodies that are distant from the sun, as well as lunar regions that are permanently shadowed, require electrical components with low temperature survivability and predictable and stable functionality at temperatures in the range of +125omicron;C to -240omicron;C. Furthermore, resistance to radiation exposure is a key requirement to reduce the added weight and volume of radiation shielding. The Phase I development demonstrated that NanoLamtrade; capacitor elementsnbsp;have excellent parametric stability from a cryogenic temperature of 5oK (liquid helium) to 160oC.nbsp; Comparison with state-of-the-art technologies shows that the NanoLamTM capacitors, have superior extreme temperature performance and multiple times higher energy density (J/cc) and specific energy (J/gr).nbsp;nbsp; The Phase II development is designed to produce and evaluate complete capacitors that comprise stacks of capacitor elements connected in parallel and packaged in a high temperature polymer box.nbsp; The packaged parts will be tested using a series of environmental, electrical and mechanical tests. These will include, accelerated life tests at different conditions of voltage, temperature, vacuum and gamma radiation, to simulate operating conditions at different environments, and to facilitate the development a life-law to predict long term performance. Components will be supplied to NASA personnel for further tests and integration into low voltage advance controller units of dynamic power conversion systems, and high voltage PPUs for Hull Ion Thruster propulsion systems.