Speaker
Mr
Nikolay Stupishin
(Budker Institute of Nuclear Physics)
Description
Diagnostic neutral beam injector on the based arc-discharge plasma generator with cold cathode has been produced and successfully tested at BINP for upgraded T-15 tokamak (Kurchatov Institute, Moscow).
One of the main advantages of cold cathode type of arc plasma source is a high proton fraction 80%–90%. However, the lifetime of the plasma source is limited due to intensive electrode’s erosion, especially at the cathode region. An optimized design of the cathode and the nearest electrodes is found which reduces the erosion and allows us to increase the pulse length. Compared with the prototype designed for TCV machine [1] significantly improved characteristics of the generator. The plasma source produces the extracted ion current up to 7 A at a low angular divergence. Arc plasma generator has been tested with a pulse duration up to 4 second.
The beam is extracted and accelerated by a four-grids ion-optics system. The diameter of plasma emitter at first grid is about 160 mm. Ion-optical systems, vacuum tank and beam duct are similar to those used in the diagnostic injector for Alcator C-mod devise (Boston). [2].
The main parameters of the NBI:
— particle energy up to 60 keV
— beam current (in ions) – 6.1 A
— intensive arc discharge current up to 600 A
— focal length - 4 m
— beam divergence – less than10 mrad
— duty ratio – from 1:1 to 1:10
— active pulse duration – 1 second
— full pulse duration – up to 11 seconds
— working species of ion – hydrogen (deuterium and another species also are possible).
[1] P. P. Deichuli, A. A. Ivanov, and N. V. Stupishin. Long-pulse arc-discharge plasma source with cold cathode for diagnostic neutral beam injector. Review of Scientific Instruments 79, 02C106 2008
[2] P. P. Deichuli, G. F. Abdrashitov, A. A. Ivanov, V. V. Kolmogorov, V. V. Mishagin, G. I. Shul’zhenko, N. V. Stupishin, D. Beals, and R. Granetz. Ion source with LaB6 hollow cathode for a diagnostic neutral beam injector. Review of Scientific Instruments 77, 03B514 (2006)
Primary author
Mr
Nikolay Stupishin
(Budker Institute of Nuclear Physics)
Co-authors
Mr
Aleksander Gorbovsky
(Budker Institute of Nuclear Physics)
Dr
Alexander Ivanov
(Budker Institute of Nuclear Physics)
Mr
Andrey Abdrashitov
(Budker Institute of Nuclear Physics)
Mr
Grigoriy Abdrashitov
(Budker Institute of Nuclear Physics)
Dr
Petr Deichuli
(Budker Institute of Nuclear Physics)
Mr
Valeriy Kapitonov
(Budker Institute of Nuclear Physics)
Mr
Valeriy Mishagin
(Budker Institute of Nuclear Physics)
Mr
Vladimir Rashenko
(Budker Institute of Nuclear Physics)
