The total auxiliary heating
designed power on HL-2A was up to 4.5 MW（NBI/1.5MW,
The achieved ECRH and NBI power in the experimental campaign was over
1.6 MW and 1.0 MW respectively. In 2008, with the application of high
power NBI, ECRH and effective SMBI technique, the synergetic heating
used to fulfill the plasma heating and current drive. The physical task
was focused on plasma confinement and transport, edge plasma and
turbulence, energetic particle physics and impurity transport.
the HL-2A divertor discharges, by using high power ECRH and NBI heating,
the supershot discharges were achieved, which were characterized by peak
electron density profile. The corresponding plasma energy confinement
time made a marked improvement.
low frequency zonal flows（ZF）in
kHz, the associated geodesic acoustic
in 10 kHz, with the toroidal mode number approaching zero, were observed
in the float potential spectrum of Langmuir probe diagnostic system for
the first time. Analysis showed both the ZF and the GAM existed in the
edge region of HL-2A plasma. These results attracted worldwide
blob is a coherent structure extending in a fila- mentary way along a
magnetic field line, characterized by a density much higher than the
ambient density and leaving the plasma at a high radial velocity. By
using a fast scanning pneumatic-driven Langmuir probe system, the blobs
were observed. Some important parameters, such as its radial
distribution of poloidal wave number, radial velocity and poloidal
velocity were measured with half-overlapped time-window and two-point
spectrum analysis techniques.
fueling technique was improved in 2008. With microwave reflectormetry
and hydrogen atom radiation diagnostic system, the injection
penetration, particle deposition
distribution and fueling
efficiency were explored. It is prepared for the future pedestal fueling
neoclassical tearing mode with mode m/n＝2/1
was observed in the high power ECRH discharges in China for the first
time. It degrades plasma confinement by decreasing plasma beta by about
The analysis showed the non-linear growth evolution of magnetic island
was in consistent with the theoretical prediction. For the seed
magnetic island, control with ECRH for destabilizing large sawtooth
caused by neutral beam heating was achieved. It is one of the key issues
of NTMs controlling in the world.
fish-bone turbulence continued to be investigated during the ECRH and
NBI discharges. By using a newly installed CdTe spectrometer diagnostic
system, the relation between fish-bone turbulence and energetic electron
spectrum was studied. The chirping behavior in fish-bone frequency and
jumping of mode frequency were newly observed.
shear Alfven eigen mode, which was excited with sideband resonance by
neutral beam injection caused energetic ions, was studied. Observed
pitch-fork phenomena and BAE mode excited by large magnetic island
coupling to GAM curvature provided the experimental base for the
energetic ions dynamic research.