Implementation of Rogowski coil and Taylor discharge for ionospheric plasma chamber experiments in the Versatile Toroidal Facility (VTF)

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:433867

Rowlands, M J; Riddolls, R J; Lee, M C; Dalrymple, N; Moriarty, D ^[1]

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1. Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center

The VTF is a large torus used to simulate ionospheric plasmas. Currently, plasmas can be generated by electron emission from four LaB{sub 6} cathodes, spaced around the bottom of the chamber, by electron cyclotron resonance heating (ECRH) with microwaves injected radially into the chamber from a 3 kilowatt magnetron, and by a Taylor discharge apparatus. Electron beams travel in a helical path till they reach a collector plate at the top of the chamber, and produce plasma currents from 500 to 1,500 amps. Recently, a Rogowski coil has been calibrated to quantitatively measure current in the plasma. A 4.2 meter coil of approximately 5,500 turns encircles the torus vertically. As a changing current goes through the coil, a changing magnetic field is produced perpendicular to each of the coil`s turns. Each turn produces a small voltage, and the sum of all the voltages from all the turns in the coil is proportional to the change in plasma current. The voltage signal is integrated and the result is the plasma current circulating toroidally inside the chamber. Good results measuring electron beam plasma current have been obtained and will be reported on. Continuing work will include measuring alternating current from the Taylor discharge plasma and is hoped to give insight as to how to increase plasma density using the Taylor discharge device.

• OSTI ID: 433867
• Report Number(s): CONF-960634--
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ECR HEATING
ELECTRIC CURRENTS
ELECTRIC DISCHARGES
IONOSPHERE
MAGNET COILS
PLASMA DIAGNOSTICS
PLASMA SIMULATION
SIMULATORS
TEST FACILITIES
TORI