Large Helical Device

The Large Helical Device (大型ヘリカル装置, Ōgata Herikaru Sōchi) (LHD) is a fusion research device in Toki, Gifu, Japan, belonging to the National Institute for Fusion Science. It is the second largest superconducting stellarator in the world, after the Wendelstein 7-X. The LHD employs a heliotron magnetic field originally developed in Japan.

The objective of the project is to conduct fusion plasma confinement research in a steady state in order to elucidate possible solutions to physics and engineering problems in helical plasma reactors. The LHD uses neutral beam injection, ion cyclotron radio frequency (ICRF), and electron cyclotron resonance heating (ECRH) to heat the plasma, much like conventional tokamaks.

History

Design finalized 1987
Start of construction 1990
Plasma operations from 1998
Neutral Beam Injection of 3 MW was used in 1999.[1]
In 2005 it maintained a plasma for 3,900 seconds.[2]
In 2006 a new helium cooler was added. Using the new cooler, by 2018 a total of 10 long term operations have been achieved, reaching a maximum power level of 11.833 kA.[3]
To aid public acceptance, an exhaust system was designed to catch and filter the radioactive Tritium the fusion process produces.[4][icon]
This section needs expansion. You can help by adding to it. (March 2018)

See also

Fusion reactor
National Institutes of Natural Sciences, Japan

References

Fujiwara, M.; Yamada, H.; Ejiri, A.; Emoto, M.; Funaba, H.; Goto, M.; Ida, K.; Idei, H.; Inagaki, S.; Kado, S.; Kaneko, O.; Kawahata, K.; Kobuchi, T.; Komori, A.; Kubo, S.; Kumazawa, R.; Masuzaki, S.; Minami, T.; Miyazawa, J.; Morisaki, T.; Morita, S.; Murakami, S.; Muto, S.; Mutoh, T.; Nagayama, Y.; Nakamura, Y.; Nakanishi, H.; Narihara, K.; Nishimura, K.; et al. (1999). "Plasma confinement studies in LHD". Nuclear Fusion. 39 (11Y): 1659–1666. doi:10.1088/0029-5515/39/11Y/305. "Heating by NBI of 3 MW produced plasmas with a fusion triple product of 8 × 10¹⁸m⁻³ keV s at a magnetic field strength of 1.5 T. An electron temperature of 1.5 keV and an ion temperature of 1.1 keV were achieved simultaneously at a line averaged electron density of 1.5 × 10¹⁹m⁻³"
Achievement of One Hour Discharge with ECH on LHD 2005
Hamaguchi, Imagawa, Obana, Yanagi and Mito (2018). "Operations of the Helium Subcooling System for the LHD HelicalCoils during Ten Plasma Experimental Campaigns". Plasma and Fusion Research. 13: 4. doi:10.1585/pfr.13.3405057.
"Design and commissioning of the exhaust detritiation system for the Large Helical Device". ResearchGate. Retrieved 2019-03-04.

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Fusion power, processes and devices
Core topics

Nuclear fusion
Timeline List of experiments Nuclear power Nuclear reactor Atomic nucleus Fusion energy gain factor Lawson criterion Magnetohydrodynamics Neutron Plasma

Processes,
methods
Confinement
type
Gravitational

Alpha process Triple-alpha process CNO cycle Fusor Helium flash Nova
remnants Proton-proton chain Carbon-burning Lithium burning Neon-burning Oxygen-burning Silicon-burning R-process S-process

Magnetic

Dense plasma focus Field-reversed configuration Levitated dipole Magnetic mirror
Bumpy torus Reversed field pinch Spheromak Stellarator Tokamak
Spherical Z-pinch

Inertial

Bubble (acoustic) Laser-driven Magnetized Liner Inertial Fusion

Electrostatic

Fusor Polywell

Other forms

Colliding beam Magnetized target Migma Muon-catalyzed Pyroelectric

Devices, experiments
Magnetic confinement
Tokamak

International

ITER DEMO PROTO

Americas

Canada STOR-M United States Alcator C-Mod ARC
SPARC DIII-D Electric Tokamak LTX NSTX
PLT TFTR Pegasus Brazil ETE Mexico Novillo [es]

Asia,
Oceania

China CFETR EAST
HT-7 SUNIST India ADITYA SST-1 Japan JT-60 QUEST [ja] Pakistan GLAST South Korea KSTAR

Europe

European Union JET Czech Republic COMPASS GOLEM [cs] France TFR WEST Germany ASDEX Upgrade TEXTOR Italy FTU IGNITOR Portugal ISTTOK Russia T-15 Switzerland TCV United Kingdom MAST-U START STEP