Publication Date:
2014-06-20
Description:
Using a handshake shape (HAS) antenna phasing dipole for ion cyclotron heating (ICH), the heating efficiency was higher than that using a previous poloidal array antenna in the Large Helical Device. In order to sustain the dipole operation, real-time feedback for impedance matching and maintaining the same phase and power was adopted during long-pulse discharge. The HAS antenna was designed to reduce parasitic losses associated with energetic particle and radio-frequency (RF) sheath effects by field-aligned current concentration on the midplane. Local hot spots and the inhomogeneity of the diverter heat profile in the toroidal direction were reduced. The long-pulse discharge with an electron density ( n e0 ) of 1 × 10 19 m −3 , center electron temperature ( T e0 ) of 2.5 keV, a plasma duration time ( t d ) of 19 min, and RF heating power ( P RF ) of 1 MW was achieved by ICH and electron cyclotron heating.
Print ISSN:
1070-664X
Electronic ISSN:
1089-7674
Topics:
Physics
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