Operation of cold-cathode magnetron gauges in high magnetic fields
The Mirror Fusion Test Facility (MFTF-B), under construction at LLNL, requires measurement of the neutral gas density in high magnetic fields near the plasma at several axial regions. This background gas pressure (BGP) diagnostic will help us understand the role of background neutrals in particle and power balance, particularly in the maintenance of the cold halo plasma that shields the hot core plasma from the returning neutrals. The BGP consists of several cold-cathode, magnetron-type gauges stripped of their permanent magnets, and utilizes the MFTF-B ambient B-field in strengths of 5--25 kG. Similar gauges have operated in TMX-U in B-fields up to 3 kG. To determine how well the gauges will perform, we assembled a test stand which operated magnetron gauges in an external, uniform magnetic field of up to 30 kG, over a pressure range of 10/sup -8/--10/sup -5/ Torr, at several cathode voltages. This paper describes the test stand and presents the results of the tests.
- Research Organization:
- Lawrence Livermore National Laboratory, Livermore, California 94550
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 5521664
- Journal Information:
- J. Vac. Sci. Technol., A; (United States), Vol. 4:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
MFTF DEVICES
PLASMA DIAGNOSTICS
PRESSURE GAGES
OPERATION
PERFORMANCE
TESTING
DESIGN
HIGH VACUUM
MAGNETRONS
PRESSURE MEASUREMENT
ELECTRON TUBES
ELECTRONIC EQUIPMENT
EQUIPMENT
MAGNETIC MIRRORS
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
MICROWAVE TUBES
OPEN PLASMA DEVICES
THERMONUCLEAR DEVICES
700102* - Fusion Energy- Plasma Research- Diagnostics
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