Research Report2022

Press ReleaseEurekAlert!LHD Research report May 19, 2022
Discovery of high-speed moving plasma turbulence for the first time in the world

In order to achieve a fusion power plant, it is necessary to stably confine a plasma of more than 100 million degrees Celsius in a magnetic field and maintain it for a long time. ...

Press ReleaseEurekAlert! April 28, 2022
Successful improvement of plasma thermal insulation layer with deuterium

In order to achieve nuclear fusion power generation, it is necessary to confine the plasma in a magnetic field and to make the center of the plasma hotter than 100 million degrees Celsius.・・・

LHD Research report April 1, 2022
Improvement of Plasma Thermal Insulation Layer with Deuterium ─High-speed beam of gold ions reveals plasma flow effects─

In Large Helical Device (LHD) experiments, it has been clarified that the plasma thermal insulation layer was reinforced in plasmas produced by heavier fuel gas. In order to explore the background physics, plasma flow was measured by the so-called heavy ion beam probe (HIBP). ...

Press ReleaseEurekAlert!LHD Research report March 31, 2022
Plasma turbulence spreading by magnetic fluctuation reduces heat load on a fusion device wall

A research group led by Associate Professor Masahiro Kobayashi of the National Institute for Fusion Science (NIFS) has discovered that in the Large Helical Device (LHD), ...

LHD Research report March 30, 2022
Cooling a plasma of 100 million degrees by ice pellet – Emergency plasma shutdown system in ITER

The Large Helical Device has performed a new experiment that injected ice pellets made of neon, which are planned to be used by the emergency shutdown system in ITER. ...

LHD Research report March 18, 2022
Improvement of ICRF Antenna Performance with Impedance Transformers

The Large Helical Device (LHD) is equipped with two types of antennas for Ion Cyclotron Range of Frequencies (ICRF) heating. One is the high-power-oriented antenna called the FAIT antenna, and the other is called the HAS antenna, where the wavenumber parallel to the magnetic field lines can be controlled. ...

LHD Research report March 4, 2022
Experimental and Theoretical Verification of Atomic Physics Effects Specific to Highly Charged Heavy Ions

We have investigated atomic number (Z) dependence of transition wavelengths of gallium-like lanthanide ions, based on spectroscopic measurements in the Large Helical Device (LHD) and an electron beam ion trap (EBIT). A peculiar Z dependence of the wavelength was found between Z=62 and 63. ...

LHD Research report March 2, 2022
Investigating plasma transport with a hollow temperature profile by heat pulse propagation

Heat transport in fusion plasmas is often modeled as a temperature gradient. In contrast, when a narrow region away from the plasma center is heated to create a plasma with a peculiar hollow temperature profile, and then a narrow region near the center is additionally heated, a transient phenomenon was observed in which the heat pulse propagates against the temperature gradient. ...

Press ReleaseEurekAlert!LHD Research report March 1, 2022
Self-sustained divertor oscillation mechanism identified in fusion plasma experiment

To harness the forces that power the Sun to produce substantial clean energy on Earth, researchers heat fuel to such a high temperature that atoms melt into electrons and nuclei to form a hot, ...

Press Release February 25, 2022
Deep Neural Network to Find Hidden Turbulent Motion on the Sun

A research group led by the National Astronomical Observatory of Japan (NAOJ), the National Institute for Fusion Science (NIFS), ...

LHD Research report February 21, 2022
Control of plasma particles by powerful vacuum pumping

In plasma experiments in the Large Helical Device (LHD), we discovered that the controllability of plasma particles can be improved by compressing fuel particles in a region called the divertor and by pumping them out strongly with a cryogenic vacuum pump. ...

Press Release January 28, 2022
Boron powder injection makes plasma temperature increase

In order to realize fusion power generation, it is necessary to maintain a high-temperature plasma...