Method for removing hydrogen detained on first wall in magnetic constraint device by ion involution oxygen plasma

Abstract

The invention discloses a method for removing hydrogen detained on a first wall in a magnetic constraint device by ion involution oxygen plasma. According to carbon and hydrogen codeposition characteristic in the magnetic constraint device, a plasma auxiliary chemical removing method is used, on a HT-7 superconducting tokmak and a EAST device having similar bit-type with ITER, under condition of keeping longitudinal magnetic fields of 1.5-2.0T and wall temperature of 400-470K, a ion involution plasma technology is employed, oxygen which is easy to react with carbon and hydrogen is employed to form ion involution oxygen plasma for removing carbon hydrogen re-deposition layer on the first wall, thereby effectively removing hydrogen detained on the first wall of a device. The technology is a unique and effective technology, creates excellent wall condition for re-deposition layer removal on the first wall, reduction of hydrogen detained in the device, particle recirculation lowering and nuclear fusion device high efficiency operation, and reduces safely and environment problems of future nuclear fusion device due to radioactive tritium detained on the first wall. Simultaneously, the treatment for the first wall can be carried out under condition that longitudinal field coil is not demagnetized, and is more suitable for future international thermonuclear fusion experiment reactor ITER and future fusion reactor.

Description

technical field

[0001] The invention relates to the fields of vacuum technology and magnetic confinement fusion, in particular to a method for removing hydrogen retention on the first wall of a magnetic confinement device by ion cyclotron oxygen plasma. Background technique

[0002] Impurity suppression is an important issue in tokamak operation. The current tokamak needs to limit the impurities in the plasma through the first wall tempering to obtain high-quality plasma. In the upcoming all-superconducting tokamak devices with quasi-steady-state high-parameter plasma operation, such as EAST and ITER, in addition to completing impurity confinement, it is also necessary to solve the retention of hydrogen isotopes in the vacuum chamber. The research on the removal technology and mechanism of a-C:H(D,T) deposition layer in the tokamak fusion experimental device can provide scientific understanding for the construction, operation and experiment of EAST and future fusion reactor...

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