[ital In] [ital situ] neutral pressure measurements in a compact high-field tokamak, Alcator C-Mod

Journal Article · Sun Jan 01 00:00:00 EST 1995 · Review of Scientific Instruments; (United States)

DOI:https://doi.org/10.1063/1.1146411· OSTI ID:6700450

Niemczewski, A; Lipschultz, B; LaBombard, B; McCracken, G M ^[1]

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1. Plasma Fusion Center, MIT, Cambridge, Massachusetts 02139 (United States)

The Alcator C-Mod advanced divertor program requires fast [ital in] [ital situ], absolutely calibrated neutral pressure measurements. The concept of a linear-geometry ionization gauge, first implemented at Princeton and Garching, was further developed at the MIT Plasma Fusion Center, to meet Alcator C-Mod requirements (high field, compact design). In order to correctly interpret experimental data, the gauge was subjected to a series of [ital in] [ital situ] calibration tests. It has been found that the gauge sensitivity increases with increasing parallel (to gauge axis) magnetic field. In the high-pressure, high-field limit the basic assumption of the operation of ionization gauges, [ital I][sub [ital i]]/[ital I][sub [ital e]][much lt]1, no longer holds. Consequently a modified expression for the gauge sensitivity, which is a strong function of the primary electron current, is necessary to linearize gauge response over a broad pressure range. Representative pressure measurements from the Alcator C-Mod divertor are included.

• DOE Contract Number: AC02-78ET51013
• OSTI ID: 6700450
• Journal Information: Review of Scientific Instruments; (United States), Vol. 66:1; ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALCATOR DEVICE
PRESSURE MEASUREMENT
IONIZATION GAGES
DESIGN
PLASMA DIAGNOSTICS
CALIBRATION
DIVERTORS
MAGNETIC FIELDS
SENSITIVITY
CLOSED PLASMA DEVICES
MEASURING INSTRUMENTS
PRESSURE GAGES
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
VACUUM GAGES
700320* - Plasma Diagnostic Techniques & Instrumentation- (1992-)