Summary of Experimental Results in LHD
Since the successful production of the first plasma in 1998, outstanding plasma parameters have been achieved, such as a plasma stored energy of 1MJ, electron temperatures of 10 keV, and ion temperatures of 7 keV. These results show that LHD has plasma confinement properties comparable to those of the world's largest fusion machines.
Attained Plasma Parameters
Plasma parameters have been improved by higher heating power. Attained plasma parameters are summarized below.
|Experiment with maximum electron temperature||10keV||2.0keV||0.06s||1.2MW||5.0x1018m-3|
|Experiment with maximum ion temperature||4.2keV||7.0keV||0.06s||3.1MW||2.9x1018m-3|
|Experiment with maximum confinement time||1.3keV||1.3keV||0.36s||1.5MW||4.8x1019m-3|
|Fusion triple product||(nτTi=2.2x1019keVm-3s)|
|Maximum stored energy||1.16MJ|
|Maximum beta||<beta>=3.2% at Bt=0.5T|
Values in bold are maximum attained values.
Extension of operating Region and Elucidation of Physics behind the Phenomena
Many experiments have been performed to extend the operating region, to obtain better confinement, and to elucidate physics behind the phenomena. Much useful information has been obtained, such as the dependence of plasma confinement on magnetic configuration and the mechanism of high energy ion production.
|Soft X-ray Image of an LHD plasma viewed from a tangential port
White colored portion corresponds to a high temperature region in the plasma. Movement of the plasma center can be measured during a plasma discharge.