TY - JOUR
T1 - Thomson scattering diagnostics of SF6 gas-blasted arcs confined by a nozzle under free-recovery conditions
AU - Tomita, Kentaro
AU - Gojima, Daisuke
AU - Shimizu, Takahiro
AU - Uchino, Kiichiro
AU - Nakano, Tomoyuki
AU - Tanaka, Yasunori
AU - Suzuki, Katsumi
AU - Iijima, Takanori
AU - Shinkai, Takeshi
PY - 2015/7/8
Y1 - 2015/7/8
N2 - Collective Thomson scattering has been applied to gas-blasted arcs confined by a nozzle to measure their decay processes with respect to electron density (ne). Pure SF6 gas, an Ar/SF6 gas mixture (SF6 was 20, 40, 60, and 80% of the mixture), and pure Ar gas were used as arc-quenching media at atmospheric pressure. Copper-tungsten (40% copper) electrodes were installed inside a polytetrafluoroethylene (PTFE) nozzle and 50 mm-long gap arcs were generated between the electrodes. First, steady-state arcs were generated with 50 A current. Then, a semiconductor switch removed the arc current. It was found that after the current decreased to zero, ne exponentially decreased and the decay time constant of ne systematically decreased with an increasing SF6 gas ratio. Thomson scattering measured ne in the range 1021-1023 m-3. Self-emission measurements, which were performed with a high-speed camera at 200 000 frames per second, exhibited good agreement with the results of the Thomson scattering.
AB - Collective Thomson scattering has been applied to gas-blasted arcs confined by a nozzle to measure their decay processes with respect to electron density (ne). Pure SF6 gas, an Ar/SF6 gas mixture (SF6 was 20, 40, 60, and 80% of the mixture), and pure Ar gas were used as arc-quenching media at atmospheric pressure. Copper-tungsten (40% copper) electrodes were installed inside a polytetrafluoroethylene (PTFE) nozzle and 50 mm-long gap arcs were generated between the electrodes. First, steady-state arcs were generated with 50 A current. Then, a semiconductor switch removed the arc current. It was found that after the current decreased to zero, ne exponentially decreased and the decay time constant of ne systematically decreased with an increasing SF6 gas ratio. Thomson scattering measured ne in the range 1021-1023 m-3. Self-emission measurements, which were performed with a high-speed camera at 200 000 frames per second, exhibited good agreement with the results of the Thomson scattering.
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U2 - 10.1088/0022-3727/48/26/265201
DO - 10.1088/0022-3727/48/26/265201
M3 - Article
AN - SCOPUS:84930944018
VL - 48
JO - Journal Physics D: Applied Physics
JF - Journal Physics D: Applied Physics
SN - 0022-3727
IS - 26
M1 - 265201
ER -