TY - JOUR
T1 - The occurrence and damage of unipolar arcing on fuzzy tungsten
JF - Journal of Nuclear Materials
Y1 - 2015
A1 - Aussems, D. U. B.
A1 - Nishijima, D.
A1 - Brandt, C.
A1 - van der Meiden, H. J.
A1 - M. Vilémová
A1 - J. Matějíček
A1 - De Temmerman, G.
A1 - Doerner, R. P.
A1 - N.J. Lopes Cardozo
AB - Abstract This research investigated whether unipolar arcing in the divertor of fusion reactors is a potential cause for enhanced wear of the divertor. It was found that 1 μm of nano-fuzz growth is sufficient to initiate arcing, mainly depending on the sheath potential drop and electron density. The average mass loss rate induced by the arc was determined from mass loss measurements and found to be consistent with the value estimated from the arc current. The average arc track erosion depth was estimated by using the measured mass loss and damaged surface area and was found to be one tenth of the fuzzy layer thickness. Due to melting of the fuzzy structures the actual depth is larger and some arc tracks occasionally appeared to even reach the bulk beyond the fuzzy layer. The conclusion of this study is therefore that arcing in the divertor of future tokamaks (e.g. ITER) potentially is an important cause for surface damage and plasma pollution.
VL - 463
IS - Aug
N1 - PLASMA-SURFACE İNTERACTIONS\} 21 Proceedings of the 21st International Conference on Plasma-Surface Interactions in Controlled Fusion Devices Kanazawa, Japan May 26-30, 2014
U1 - PSI
U2 - PSI-E
U5 - c3b2d2fa98a1df5755e7feedf7ed818c
ER -
TY - JOUR
T1 - Plasma temperature rise toward the plasma-facing surface
JF - Journal of Nuclear Materials
Y1 - 2015
A1 - Nishijima, D.
A1 - Doerner, R. P.
A1 - Seraydarian, R. P.
A1 - De Temmerman, G.
A1 - van der Meiden, H. J.
AB - Detailed measurements of axial electron temperature, Te, profiles in the presheath region were carried out using a Langmuir probe and the line intensity ratio technique for both He I (728.1 nm/706.5 nm) and Be II (467.3 nm/313.1 nm). The results show that Te increases toward the material surface, which contradicts the standard picture that Te is constant along the magnetic field in the sheath-limited regime. While no target bias voltage, Vb, dependence is seen, the Te rise becomes more prominent with decreasing neutral pressure. Similarly, the ion temperature, Ti, evaluated from Doppler broadening of a He II line emission at 468.6 nm is found to increase toward the surface, but also does not depend on Vb. Possible mechanisms of the Te and Ti rise as well as validity of the line intensity ratio technique near the material surface are discussed.
VL - 463
IS - Aug
N1 - PLASMA-SURFACE INTERACTIONS 21 Proceedings of the 21st International Conference on Plasma-Surface Interactions in Controlled Fusion Devices Kanazawa, Japan May 26-30, 2014
U1 - PSI
U2 - PSI-E
U5 - 4a740a3caccb4311b0a5a70db1dd5342
ER -
TY - JOUR
T1 - Spectroscopic characterization and imaging of laser- and unipolar arc-induced plasmas
JF - Journal of Applied Physics
Y1 - 2014
A1 - Aussems, D. U. B.
A1 - Nishijima, D.
A1 - Brandt, C.
A1 - Doerner, R. P.
A1 - N.J. Lopes Cardozo
AB - Tungsten plasmas induced by unipolar arcs were investigated using optical emission spectroscopy and imaging, and compared with laser-induced tungsten plasmas. The unipolar arcs were initiated in the linear-plasma simulator PISCES-A at UCSD under fusion relevant conditions. The electron temperature and density of the unipolar arc plasmas were in the range 0.5-0.7 eV and 0.7-2.0 x 10(20) m(-3), respectively, and increased with increasing negative bias voltage, but did not correlate with the surface temperature. In comparison, the electron temperature and density of the laser-induced plasmas were in the range 0.6-1.4 eV and 7 x 10(19)-1 x 10(22) m(-3), respectively.

VL - 116
IS - 6
U1 - MaSF

U2 - MaSF-E

U5 - 00bc5c41bfa979b0bd2bb5ed0cc1d9a1
ER -
TY - JOUR
T1 - Modelling of Impurity Transport in the Linear Plasma Devices PISCES-B and Pilot-PSI Using the Monte-Carlo Code ERO
JF - Contributions to Plasma Physics
Y1 - 2010
A1 - Borodin, D.
A1 - Kirschner, A.
A1 - Nishijima, D.
A1 - Doerner, R.
A1 - Westerhout, J.
A1 - van Rooij, G. J.
A1 - Rapp, J.
A1 - Kreter, A.
A1 - Ding, R.
A1 - Galonska, A.
A1 - Philipps, V.
KW - beryllium
KW - CHEMICAL EROSION
KW - hydrocarbons
KW - plasma impurities
KW - plasma-surface interaction
KW - SPECTROSCOPY
AB - The simulations for linear devices using the 3D Monte-Carlo code ERO have a number of particularities of both physical and technical nature. Many physical effects introduced and tested for these simulations (elastic collisions, population of metastable states, etc.) can be relevant for tokamaks as well. The current status of these activities is summarized. As an example some simulations reproducing the experimental observations at PISCES-B and Pilot-PSI are presented. Main deviations and ideas for their origins are discussed. (c) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
VL - 50
SN - 0863-1042
UR - ://000278438900033
N1 - ISI Document Delivery No.: 606PITimes Cited: 0Cited Reference Count: 17Sp. Iss. SI
U1 - Fusion Physics
U5 - 414f2eb374515792a6a185d1b6b13467
ER -
TY - JOUR
T1 - Overview of ASDEX upgrade results
JF - Nuclear Fusion
Y1 - 2003
A1 - Zohm, H.
A1 - Angioni, C.
A1 - Arslanbekov, R.
A1 - Atanasiu, C.
A1 - Becker, G.
A1 - Becker, W.
A1 - Behler, K.
A1 - Behringer, K.
A1 - Bergmann, A.
A1 - Bilato, R.
A1 - Bobkov, V.
A1 - Bolshukhin, D.
A1 - Bolzonella, T.
A1 - Borrass, K.
A1 - Brambilla, M.
A1 - Braun, F.
A1 - Buhler, A.
A1 - Carlson, A.
A1 - Conway, G. D.
A1 - Coster, D. P.
A1 - Drube, R.
A1 - Dux, R.
A1 - Egorov, S.
A1 - Eich, T.
A1 - Engelhardt, K.
A1 - Fahrbach, H. U.
A1 - Fantz, U.
A1 - Faugel, H.
A1 - Finken, K.H.
A1 - Foley, M.
A1 - Franzen, P.
A1 - Fuchs, J. C.
A1 - Gafert, J.
A1 - Fournier, K. B.
A1 - Gantenbein, G.
A1 - Gehre, O.
A1 - Geier, A.
A1 - Gernhardt, J.
A1 - Goodman, T.
A1 - Gruber, O.
A1 - Gude, A.
A1 - Gunter, S.
A1 - Haas, G.
A1 - Hartmann, D.
A1 - Heger, B.
A1 - Heinemann, B.
A1 - Herrmann, A.
A1 - Hobirk, J.
A1 - Hofmeister, F.
A1 - Hohenocker, H.
A1 - Horton, L. D.
A1 - Igochine, V.
A1 - Jacchia, A.
A1 - Jakobi, M.
A1 - Jenko, F.
A1 - Kallenbach, A.
A1 - Kardaun, O.
A1 - Kaufmann, M.
A1 - Keller, A.
A1 - Kendl, A.
A1 - Kim, J. W.
A1 - Kirov, K.
A1 - Kochergov, R.
A1 - Kollotzek, H.
A1 - Kraus, W.
A1 - Krieger, K.
A1 - Kurki-Suonio, T.
A1 - Kurzan, B.
A1 - Lang, P. T.
A1 - Lasnier, C.
A1 - Lauber, P.
A1 - Laux, M.
A1 - Leonard, A. W.
A1 - Leuterer, F.
A1 - Lohs, A.
A1 - Lorenz, A.
A1 - Lorenzini, R.
A1 - Maggi, C.
A1 - Maier, H.
A1 - Mank, K.
A1 - Manso, M. E.
A1 - Mantica, P.
A1 - Maraschek, M.
A1 - Martines, E.
A1 - Mast, K. F.
A1 - McCarthy, P.
A1 - Meisel, D.
A1 - Meister, H.
A1 - Meo, F.
A1 - Merkel, P.
A1 - Merkel, R.
A1 - Merkl, D.
A1 - Mertens, V.
A1 - Monaco, F.
A1 - Muck, A.
A1 - Muller, H. W.
A1 - Munich, M.
A1 - Murmann, H.
A1 - Na, Y. S.
A1 - Neu, G.
A1 - Neu, R.
A1 - Neuhauser, J.
A1 - Nguyen, F.
A1 - Nishijima, D.
A1 - Nishimura, Y.
A1 - Noterdaeme, J. M.
A1 - Nunes, I.
A1 - Pautasso, G.
A1 - Peeters, A.G.
A1 - Pereverzev, G.
A1 - Pinches, S. D.
A1 - Poli, E.
A1 - Proschek, M.
A1 - Pugno, R.
A1 - Quigley, E.
A1 - Raupp, G.
A1 - Reich, M.
A1 - Ribeiro, T.
A1 - Riedl, R.
A1 - Rohde, V.
A1 - Roth, J.
A1 - Ryter, F.
A1 - Saarelma, S.
A1 - Sandmann, W.
A1 - Savtchkov, A.
A1 - Sauter, O.
A1 - Schade, S.
A1 - Schilling, H. B.
A1 - Schneider, W.
A1 - Schramm, G.
A1 - Schwarz, E.
A1 - Schweinzer, J.
A1 - Schweizer, S.
A1 - Scott, B. D.
A1 - Seidel, U.
A1 - Serra, F.
A1 - Sesnic, S.
A1 - Sihler, C.
A1 - Silva, A.
A1 - Sips, A.C.C.
A1 - Speth, E.
A1 - Stabler, A.
A1 - Steuer, K. H.
A1 - Stober, J.
A1 - Streibl, B.
A1 - Strumberger, E.
A1 - Suttrop, W.
A1 - Tabasso, A.
A1 - Tanga, A.
A1 - Tardini, G.
A1 - Tichmann, C.
A1 - Treutterer, W.
A1 - Troppmann, M.
A1 - Urano, H.
A1 - Varela, P.
A1 - Vollmer, O.
A1 - Wagner, D.
A1 - Wenzel, U.
A1 - Wesner, F.
A1 - Westerhof, E.
A1 - Wolf, R.
A1 - Wolfrum, E.
A1 - Wursching, E.
A1 - Yoon, S. W.
A1 - Yu, Q.
A1 - Zasche, D.
A1 - Zehetbauer, T.
A1 - Zehrfeld, H. P.
VL - 43
SN - 0029-5515
UR - ://000187838300005
U1 - Fusion Physics
U2 - Tokamak physics
U5 - 988d14e5a44c19882b112fcb8692c1fb
ER -