TY - JOUR
T1 - Discharge cleaning and wall conditioning in a Novillo Tokamak
AU - Valencia, R.
AU - De La Rosa, J.
AU - Camps, E.
AU - Contreras, G.
AU - Muhl, S.
N1 - Funding Information:
Part of this work was supported by CONACyT under contract no. 29247U. The authors would like to thank the technicians S. Moran and M.T. Torres for their technical support in the experimental set-up.
PY - 2002/10
Y1 - 2002/10
N2 - Our Novillo Tokamak is a small toroidal device magnetically confined defined by the main design parameters: Ro=0.23 m, av=0.08 m, ap=0.06 m, BT=0.05-0.47 T, Ip=1-12 kA, ne=1-2×1013 cm-3, Te=150 eV, Ti=50 eV. For the initial discharge chamber cleaning we have often used vacuum baking up to 100 °C and then conditioning using Taylor discharge cleaning (TDC) in H2 and He. In this work we report that vacuum baking is effective for obtaining a final total pressure of the order of 1.6×10-7 Torr. We have found that a single parameter, the performance parameter (PP), can be used to optimize the TDC method. This parameter represents the quantity of electron and ion energy incident on the chamber wall during the Taylor discharge, it is equal to (Ipτ), where Ip is the peak-to-peak plasma current and τ is the plasma current duration. In graphs of PP versus the gas pressure for different oscillator powers, the maximum value of PP indicates the best cleaning conditions when using TDC. The results of the vacuum chamber wall conditioning using this criterion are reported.
AB - Our Novillo Tokamak is a small toroidal device magnetically confined defined by the main design parameters: Ro=0.23 m, av=0.08 m, ap=0.06 m, BT=0.05-0.47 T, Ip=1-12 kA, ne=1-2×1013 cm-3, Te=150 eV, Ti=50 eV. For the initial discharge chamber cleaning we have often used vacuum baking up to 100 °C and then conditioning using Taylor discharge cleaning (TDC) in H2 and He. In this work we report that vacuum baking is effective for obtaining a final total pressure of the order of 1.6×10-7 Torr. We have found that a single parameter, the performance parameter (PP), can be used to optimize the TDC method. This parameter represents the quantity of electron and ion energy incident on the chamber wall during the Taylor discharge, it is equal to (Ipτ), where Ip is the peak-to-peak plasma current and τ is the plasma current duration. In graphs of PP versus the gas pressure for different oscillator powers, the maximum value of PP indicates the best cleaning conditions when using TDC. The results of the vacuum chamber wall conditioning using this criterion are reported.
UR - http://www.scopus.com/inward/record.url?scp=0036793673&partnerID=8YFLogxK
U2 - 10.1016/S0022-3115(02)00900-5
DO - 10.1016/S0022-3115(02)00900-5
M3 - Artículo
SN - 0022-3115
VL - 305
SP - 232
EP - 235
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
IS - 2-3
ER -