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

Journal Article · Sun Jan 01 04:00:00 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), Journal Name: Review of Scientific Instruments; (United States) Vol. 66:1; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

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