SBIR-STTR Award

Advancing the instrumentation to detect elementary particles is critical for future space weather missions. To progress the study of the flow of energy that heats and accelerates solar corona and wind, a next generation Faraday Cup is needed. Extending the range of solar wind speed measurements to 2,500 km/sec or more requires a new, innovative power supply with significant high-voltage DC and AC modulation capabilities. We propose a variable sine wave power supply capable of delivering up to 40kV DC with a 2kHz AC modulation up to 4kV peak to peak. This venture will leverage Busek’s previous experience with delivering radiation hardened PPUs and developing a suite of Plasma Probes with custom electronics to deliver a prototype with a path to a radiation hardened flight system. The proposed architecture is based on a Cockroft Walton Voltage Multiplier to generate a high voltage DC offset and a Resonant Royer Oscillator to produce an AC waveform superimposed on the high voltage DC bias. The proposed architecture offers many advantages that will simplify the path to flight design process. The multiplier circuit contains simple passives and imposes equal voltage stress on each stage. This eases component selection, reduces BOM costs, and improves compactness. The Resonant Royer Oscillator is a self-resonating circuit used in many high voltage applications that offers user flexibility, simplicity, efficiency and low component count. By implementing high voltage design techniques and testing considerations, this Phase I effort will validate the feasibility of the proposed power supply in a laboratory environment to meet the needs of next generation Faraday Cup. Potential NASA Applications (Limit 1500 characters, approximately 150 words): NASA applications include continued and extended research of space weather missions such as characterizing the dynamics of the plasma at the sources of solar wind. This innovation will support the development and use of new particle sensors and instrumentation. In addition, the industry has a large gap in available radiation hardened high voltage supplies. Other NASA missions require advancements in this area. The proposed technology offers to extend that range and introduce a supply that can support various DC offset voltages and applications. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): Non-NASA applications which utilize high voltage power supplies and probe diagnostic tools for ground based or flight ventures in both academic and commercial fields. There is a critical gap in compact, radiation hardened power supplies that can be applied to other applications such as Electrospray work, Retarding Potential Analyzers, and other missions that require high voltage supplies. Duration: 6

Advancing the instrumentation to detect elementary particles is critical for future space weather missions. To progress the study of the flow of energy that heats and accelerates solar corona and wind, a next generation Faraday Cup is needed. Extending the range of solar wind speed measurements to 2,500 km/sec or more requires a new, innovative power supply with significant high-voltage DC and AC modulation capabilities. The desired voltage output range for a next generation Faraday Cup is 150V to 40kV. The power supply developed in this effort handles the upper range of 8kV to 40kV. The Upper Range Power Supply (URPS) is broken up into two main subsystems for the DC voltage generation and the variable AC sine wave generation, which will be AC Coupled to the DC bias. The URPS includes AC and DC voltage generating sub-systems that are superimposed on each other via a coupling network. The AC sub-system is a novel resonant push-pull (RPP) converter that generates a 2kHz sine wave with variable peak to peak voltage from 1kV to 4kV. The RPP converter achieves zero voltage switching (ZVS) with a self-tracking gate drive circuitry implemented with GaN technology. The output of the 2kHz circuit is capacitively coupled to the DC bias to produce a high voltage sine wave with an ultra-high voltage offset for the Faraday Cup. The DC subsystem includes a five stage Cockroft Walton Voltage Multiplier (CWVM) driven by another RPP converter oscillating at 200kHz. The two sub-circuits are controlled independently to allow for maximum flexibility in setting DC offset and AC amplitude. Both outputs are coupled together and connected to a load that is a representative model of an actual Faraday Cup. Potential NASA Applications (Limit 1500 characters, approximately 150 words): This technology will advance Heliophysics missions such as the next generation Faraday Cup. The developed power supply has user controllable DC and AC subsystems that can offer a compact solution for an adjustable high voltage supply that ranges from 10kV-40kV or a fixed output. The proposed modular power supplies would include radiation tolerant components greater than 100kRad that can be integrated with other subsystems to supply critical high voltage needs for flight missions including Electrospray and RF Ion Thruster applications. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): The commercial sector is rapidly adopting Electric Propulsion. Electrospray applications, Hall-Effect and Gridded Ion Thrusters require high voltages to accelerate ions and produce thrust. Companies which utilize high voltage power supplies and probe diagnostic tools for ground based or flight ventures in both academic and commercial fields can utilize the proposed high voltage power supply. Duration: 24