Ion energy and plasma measurements in the near field of an ICRF antenna

Conference · Sat Jul 01 04:00:00 EDT 1989 · AIP Conference Proceedings (American Institute of Physics); (USA)

OSTI ID:6508752

Ruzic, D N ^[1]; Hoffman, D J ^[2]

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1. University of Illinois, Urbana, IL (USA)
2. Oak Ridge National Laboratory, Oak Ridge, TN (USA)

Plasma properties and ion energies have been measured in the near field of an ICRF antenna to determine the effects of rf fields in a magnetized plasma sheath on the energy of ions incident on the surface of the Faraday shield. A resonant loop antenna with a two-tier Faraday shield was used on the RF Test Facility at Oak Ridge National Laboratory (ORNL). The magnetic field near the antenna is {similar to}2 kG, and the plasma density is {similar to}10{sup 11} cm{sup {minus}3} with an electron temperature of 6--10 eV. The time-varying floating potential was measured with a capacitively coupled probe, and the time-averaged electron temperature electron density, and floating potential were measured with a Langmuir probe. Both probes were canned poloidally in front of the antenna, parallel to the current strap. Diagnostic for measuring ion energies included a gridded energy analyzer located directly below the antenna. Measured ion energies are compared with predictions from a computational model for determining the energy and angular distibution of ions incident on a surface in a magnetized plasma sheath with a time-varying plasma potential.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6508752
• Report Number(s): CONF-8905120--
• Conference Information: Journal Name: AIP Conference Proceedings (American Institute of Physics); (USA) Journal Volume: 190:1
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
ANTENNAS
CLOSED PLASMA DEVICES
ELECTRIC PROBES
ELECTRICAL EQUIPMENT
ELECTRON TEMPERATURE
EQUIPMENT
HEATING
HIGH-FREQUENCY HEATING
ICR HEATING
LANGMUIR PROBE
PLASMA DENSITY
PLASMA DIAGNOSTICS
PLASMA HEATING
PROBES
THERMONUCLEAR DEVICES
TOKAMAK DEVICES