Lithium pellet deposition and penetration in TFTR

Journal Article · Thu Oct 01 04:00:00 EDT 1992 · Review of Scientific Instruments; (United States)

DOI:https://doi.org/10.1063/1.1143521· OSTI ID:7250790

Sergeev, V Y ^[1]; Marmar, E S; Snipes, J A; Terry, J L ^[2]; Park, H; Mansfield, D K; Bell, M; McCune, D ^[3]

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1. Technical University, Plasma Physics Department, St. Petersburg 195251 (Russia)
2. MIT Plasma Fusion Center, Cambridge, Massachusetts 02139 (United States)
3. Princeton University, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

The electron deposition resulting from the injection of Li pellets into Tokamak Fusion Test Reactor, measured by a multichannel (10) infrared interferometer, is compared with that deduced from the pellet ablation cloud emission, measured by a filtered diode array which views the pellet from behind. By assuming that the ablation rate {ital {dot N}}({ital r}) is proportional to the pellet cloud emissivity, which is dominated by Li{sup +} line emission in the 548.5{plus minus}5 nm bandpass of the interference filter, the post-pellet, line averaged density perturbations along the interferometer chords were calculated and compared with those measured. Good agreement is observed. The experimental ablation rate profiles obtained using the emissivity have also been compared with predictions of the theoretical models. There is an agreement between the time history of the emissivity and the predicted ablation rate at the plasma edge where the electron temperature values are less than 1--1.5 keV. When the pellet penetrates more deeply, the experimental {ital {dot N}}({ital r}) values are systematically smaller than those predicted. This points out the necessity of taking into account plasma shielding and/or precooling of the target plasma during pellet injection in the ablation model.

• DOE Contract Number: FG02-90ER54084
• OSTI ID: 7250790
• Journal Information: Review of Scientific Instruments; (United States), Journal Name: Review of Scientific Instruments; (United States) Vol. 63:10; ISSN RSINA; ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700320* -- Plasma Diagnostic Techniques & Instrumentation-- (1992-)
ABLATION
ALKALI METALS
CLOSED PLASMA DEVICES
ELECTRON TEMPERATURE
ELEMENTS
EMISSION SPECTRA
INTERFEROMETRY
LITHIUM
METALS
PELLET INJECTION
PLASMA DIAGNOSTICS
SPECTRA
TFTR TOKAMAK
THERMONUCLEAR DEVICES
TOKAMAK DEVICES