| Autor: |
Moiseenko, V.E., Lozin, A.V., Chechkin, V.V., Chernyshenko, V.Ya., Grigor'eva, L.I., Kramskoi, Ye.D., Korovin, V.B., Kozulya, M.M., Lyssoivan, A.I., Schebetun, A.V., Shapoval, A.N., Shtan', A.F., Solodovchenko, S.I., Voitsenya, V.S., Garkusha, I.E. |
| Předmět: |
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| Zdroj: |
Nuclear Fusion; Mar2014, Vol. 54 Issue 3, p033009-033013, 5p |
| Abstrakt: |
The very high frequency (VHF) discharge for wall conditioning with hydrogen atoms is studied. It is driven by the RF power at frequencies ∼140 MHz, higher than usually used in ICRF. For wall conditioning a special small size antenna is designed. The antenna is aimed to excite the slow wave that is damped via electron collisions with neutral gas. The wave excitation is modelled using a 1D numerical code. In the experiment, the discharge parameters are studied as functions of confining magnetic field and gas pressure. The Langmuir probe measurements give the radial profiles of plasma density and electron temperature. The discharge is volumetric: plasma occupies whole confinement volume and even steps out at the edge. The characteristic value of plasma density is 1010 cm−3, electron temperature varies in the range 3–10 eV. The temperature values of probe measurements are compatible with the results of optical diagnostics. Such parameters of discharge are favourable for wall conditioning in hydrogen. The discharge parameters did not reveal any sensitive dependence on neutral gas pressure and the toroidal magnetic field. The mass spectrometry of the residual gas is used for monitoring the wall conditioning effect of the VHF discharge. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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