Inverted relativistic magnetron with a single axial output

Technical Report · Wed Jan 01 00:00:00 EST 1986

OSTI ID:6044191

Ballard, W P; Earley, L M; Wharton, C B

A twelve vane, 1 MV, S-band magnetron has been designed and tested. An inverted design was selected to minimize the parasitic axial electron losses. The stainless steel anode is approximately one wavelength long. One end is partially short-circuited to rf, while the other end has a mode transformer to couple the 3.16 GHz ..pi..-mode out into a TM/sub 01/ circular waveguide. The magnetron has a loaded output Q of about 100. Operation at 1 MV, 0.31 T, 5 kA routinely produces approx.150 MW peak rms and 100 MW average rms with pulse lengths adjustable from 5 to 70 ns. The microwave power pulse has a rise time of approx.2 ns. The output power is diagnosed using four methods: calorimetry, two circular-waveguide directional couplers installed on the magnetron, two transmitting-receiving systems, and gaseous breakdown. Operation at other voltages and magnetic fields shows that the oscillation frequency is somewhat dependent on the magnetron current. Frequency changes of approx.20 MHz/kA occur as the operating conditions are varied. A series of experiments varying the anode conductivity, the electron emission profile, and the output coupling transformer design showed that none of these significantly increased the output power. Therefore, we have concluded that this magnetron operates in saturation. Because of the anode lifetime and repeatability, this magnetron has the potential to be repetitively pulsed. 36 refs., 16 figs.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA); Cornell Univ., Ithaca, NY (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6044191
• Report Number(s): SAND-85-1952; ON: DE86005853
• Resource Relation: Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
MAGNETRONS
DESIGN
PERFORMANCE TESTING
CALORIMETERS
ELECTRIC CONDUCTIVITY
FLUCTUATIONS
POWER SUPPLIES
WAVEGUIDES
ELECTRICAL PROPERTIES
ELECTRON TUBES
ELECTRONIC EQUIPMENT
EQUIPMENT
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
MICROWAVE TUBES
PHYSICAL PROPERTIES
TESTING
VARIATIONS
430301* - Particle Accelerators- Ion Sources