TY - JOUR
T1 - Recent liquid lithium limiter experiments in CDX-U
AU - Majeski, R.
AU - Jardin, S.
AU - Kaita, R.
AU - Gray, T.
AU - Marfuta, P.
AU - Spaleta, J.
AU - Timberlake, J.
AU - Zakharov, L.
AU - Antar, G.
AU - Doerner, R.
AU - Luckhardt, S.
AU - Seraydarian, R.
AU - Soukhanovskii, V.
AU - Maingi, R.
AU - Finkenthal, M.
AU - Stutman, D.
AU - Rodgers, D.
AU - Angelini, S.
PY - 2005/6/1
Y1 - 2005/6/1
N2 - Recent experiments in the Current Drive Experiment-Upgrade (CDX-U) provide a first-ever test of large area liquid lithium surfaces as a tokamak first wall to gain engineering experience with a liquid metal first wall and to investigate whether very low recycling plasma regimes can be accessed with lithium walls. The CDX-U is a compact (R = 34 cm, a = 22 cm, Btoroidal = 2 kG, I P = 100 kA, Te(0)∼ 100 eV, ne(0) ∼ 5 × 1019 m-3) spherical torus at the Princeton Plasma Physics Laboratory. A toroidal liquid lithium pool limiter with an area of 2000 cm2 (half the total plasma limiting surface) has been installed in CDX-U. Tokamak discharges which used the liquid lithium pool limiter required a fourfold lower loop voltage to sustain the plasma current, and a factor of 5-8 increase in gas fuelling to achieve a comparable density, indicating that recycling is strongly reduced. Modelling of the discharges demonstrated that the lithium limited discharges are consistent with Zeffective < 1.2 (compared with 2.4 for the pre-lithium discharges), a broadened current channel and a 25% increase in the core electron temperature. Spectroscopic measurements indicate that edge oxygen and carbon radiation are strongly reduced.
AB - Recent experiments in the Current Drive Experiment-Upgrade (CDX-U) provide a first-ever test of large area liquid lithium surfaces as a tokamak first wall to gain engineering experience with a liquid metal first wall and to investigate whether very low recycling plasma regimes can be accessed with lithium walls. The CDX-U is a compact (R = 34 cm, a = 22 cm, Btoroidal = 2 kG, I P = 100 kA, Te(0)∼ 100 eV, ne(0) ∼ 5 × 1019 m-3) spherical torus at the Princeton Plasma Physics Laboratory. A toroidal liquid lithium pool limiter with an area of 2000 cm2 (half the total plasma limiting surface) has been installed in CDX-U. Tokamak discharges which used the liquid lithium pool limiter required a fourfold lower loop voltage to sustain the plasma current, and a factor of 5-8 increase in gas fuelling to achieve a comparable density, indicating that recycling is strongly reduced. Modelling of the discharges demonstrated that the lithium limited discharges are consistent with Zeffective < 1.2 (compared with 2.4 for the pre-lithium discharges), a broadened current channel and a 25% increase in the core electron temperature. Spectroscopic measurements indicate that edge oxygen and carbon radiation are strongly reduced.
UR - http://www.scopus.com/inward/record.url?scp=21144477643&partnerID=8YFLogxK
U2 - 10.1088/0029-5515/45/6/014
DO - 10.1088/0029-5515/45/6/014
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AN - SCOPUS:21144477643
SN - 0029-5515
VL - 45
SP - 519
EP - 523
JO - Nuclear Fusion
JF - Nuclear Fusion
IS - 6
ER -