A document discusses the creation of a high-voltage power supply (HVPS) that is able to contain voltages up to –20 kV, keep electrical field strengths to below 200 V/mil (≈7.87 kV/mm), and can provide a 200- nanosecond rise/fall time focus modulator swinging between cathode potential of 16.3 kV and –19.3 kV. This HVPS can protect the 95-GHz, pulsed extended interaction klystron (EIK) from arcs/discharges from all sources, including those from within the EIK's vacuum envelope.
This innovation has a multi-winding pulse transformer design, which uses new winding techniques to provide the same delays and rise/fall times (less than 10 nanoseconds) at different potential levels ranging from –20 kV to –16 kV. Another feature involves a high-voltage printed-wiring board that was corona-free at –20 kV DC with a 3-kV AC swing. The corona-free multilayer high-voltage board is used to simulate fields of less than 200 V/mil (≈7.87 kV/mm) at 20 kV DC. Drive techniques for the modulator FETs (field-effect transistors) (four to 10 in a series) were created to change states (3,000- V swing) without abrupt steps, while still maintaining required delays and transition times. The packing scheme includes a potting mold to house a ten-stage modulator in the space that, in the past, only housed a four-stage modulator.
Problems keeping heat down were solved using aluminum oxide substrate in the high-voltage section to limit temperature rise to less than 10° while withstanding –20 kV DC voltage and remaining corona-free.
This work was done by Johnny Duong, Scot Stride, Wayne Harvey, Inam Haque, Newton Packard, Quintin Ng, and Julie Y. Ispirian of Caltech; Christopher Waian of Robert M. Hadley Co.; and Drew Janes of Vallet Syncom Circuits for NASA's Jet Propulsion Laboratory.
In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to:
Innovative Technology Assets Management
Mail Stop 202-233
4800 Oak Grove Drive
Pasadena, CA 91109-8099
Refer to NPO-44241, volume and number of this NASA Tech Briefs issue, and the page number.