학술논문

Pulse-shortening in recirculating planar magnetrons
Document Type
Conference
Source
2017 Eighteenth International Vacuum Electronics Conference (IVEC) Vacuum Electronics Conference (IVEC), 2017 Eighteenth International. :1-2 Apr, 2017
Subject
Components, Circuits, Devices and Systems
Fields, Waves and Electromagnetics
Magnetrons
Plasmas
Microwave imaging
Cathodes
Anodes
Cameras
Microwave oscillators
high power microwaves
magnetrons
electron beams
coherent radiation
pulse shortening
framing camera
Language
Abstract
Recent experiments on the UM Recirculating Planar Magnetron (RPM) [1], have utilized a 12-frame ultra-fast intensified CCD camera to analyze the effect of anode and cathode plasma formation on microwave pulse duration. The experiments were driven by MELBA-C, a Marx-Abramyan system, which delivers a −300 kV voltage pulse for 0.3-1.0 μs, with a 0.13-0.31 T axial magnetic field applied by a pair of electromagnets. The RPM was tested with both an S-band (2 GHz) and L-band (1 GHz) anode, as well as two different cathodes with substantially different thickness and end caps. A smaller anode-cathode gap, coupled with larger end-loss current, produced brighter plasma and allowed for improvements in temporal resolution of the imaging configuration. Many shots demonstrated a direct correlation between anode-plasma formation and a sharp reduction in RF power.