TY - JOUR
T1 - Fundamental processes of fuel removal by cyclotron frequency range plasmas and integral scenario for fusion application studied with carbon co-deposits
AU - Möller, S.
AU - Wauters, T.
AU - Kreter, A.
AU - Petersson, P.
AU - Carrasco, A. G.
N1 - Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2015/7/22
Y1 - 2015/7/22
N2 - Abstract Plasma impact removal using radio frequency heated plasmas is a candidate method to control the co-deposit related tritium inventory in fusion devices. Plasma parameters evolve according to the balance of input power to losses (transport, radiation, collisions). Material is sputtered by the ion fluxes with impact energies defined by the plasma sheath. H2, D2 and 18O2 plasmas are produced in the carbon limiter tokamak TEXTOR. Pre-characterised a-C:D layers are exposed to study local removal rates. The D2 plasma exhibits the highest surface release rate of 5.7 ± 0.9 ∗ - 1019 D/m2s. Compared to this the rate of the O2 plasma is 3-fold smaller due to its 11-fold lower ion flux density. Re-deposition of removed carbon is observed, indicating that pumping and ionisation are limiting the removal in TEXTOR. Presented models can explain the observations and allow tailoring removal discharges. An integral application scenario using ICWC and thermo-chemical removal is presented, allowing to remove 700 g T from a-C:DT co-deposits in 20 h with fusion compatible wall conditions using technical specifications similar to ITER.
AB - Abstract Plasma impact removal using radio frequency heated plasmas is a candidate method to control the co-deposit related tritium inventory in fusion devices. Plasma parameters evolve according to the balance of input power to losses (transport, radiation, collisions). Material is sputtered by the ion fluxes with impact energies defined by the plasma sheath. H2, D2 and 18O2 plasmas are produced in the carbon limiter tokamak TEXTOR. Pre-characterised a-C:D layers are exposed to study local removal rates. The D2 plasma exhibits the highest surface release rate of 5.7 ± 0.9 ∗ - 1019 D/m2s. Compared to this the rate of the O2 plasma is 3-fold smaller due to its 11-fold lower ion flux density. Re-deposition of removed carbon is observed, indicating that pumping and ionisation are limiting the removal in TEXTOR. Presented models can explain the observations and allow tailoring removal discharges. An integral application scenario using ICWC and thermo-chemical removal is presented, allowing to remove 700 g T from a-C:DT co-deposits in 20 h with fusion compatible wall conditions using technical specifications similar to ITER.
UR - http://www.scopus.com/inward/record.url?scp=84937525421&partnerID=8YFLogxK
U2 - 10.1016/j.jnucmat.2015.01.022
DO - 10.1016/j.jnucmat.2015.01.022
M3 - Article
AN - SCOPUS:84937525421
SN - 0022-3115
VL - 463
SP - 1109
EP - 1112
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
M1 - 48880
ER -