Direct measurement of refracted trajectory of transmitting electron cyclotron beam through plasma on the Large Helical Device

Takahashi, H.; Kubo, S.; Shimozuma, Τ.; Igami, H.; Yoshimura, Y.; Ito, Satoshi; Kobayasi, Sakuji; Mizuno, Yoshinori; Okada, K.; Kamio, S.; Mutoh, T.; Osakabe, M.; Nagasaki, K.; Marushchenko, N. B.; Turkin, Y.

doi:10.1051/epjconf/20158702019

Cited by 3 publications

(3 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here, we fill this gap by comparing experimental data with PARADE simulations, which account for diffraction, inhomogeneous dissipation, shear-driven mode conversion in the plasma periphery, and also dissipation-driven mode conversion near EC resonances. We show that these additional effects that were not addressed in reference [36] significantly modify the wave-beam propagation on LHD. This makes PARADE's signature features essential for modeling ECRH in practical fusion plasmas.…”

Section: Introductionmentioning

confidence: 84%

“…To facilitate progress in this area, a target-plate experiment was developed on the Large Helical Device (LHD) [34]. The development was described in reference [35], and a preliminary geometrical-optics analysis was done in reference [36]; however, the beam profile and mode conversion were not investigated, because they could not be modeled with the code available at that time. Here, we fill this gap by comparing experimental data with PARADE simulations, which account for diffraction, inhomogeneous dissipation, shear-driven mode conversion in the plasma periphery, and also dissipation-driven mode conversion near EC resonances.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Quasioptical propagation and absorption of electron cyclotron waves: simulations and experiment

et al. 2021

View full text Add to dashboard Cite

Electron-cyclotron resonance heating is an essential tool for manipulating fusion plasmas and has been diligently studied for decades through numerical simulations and experiments. Here, we report the first comparison of simulations using the quasioptical code PARADE (PAraxial RAy DEscription) with experiments using a target-plate system on the Large Helical Device. We find that the numerical and experimental results agree qualitatively, which makes PARADE a promising code for modeling of electron-cyclotron wave beams in future experiments. The signature advantage of PARADE is its ability to capture both mode conversion and inhomogeneity of the dissipation rate across the beam cross section. Accounting for these effects, which can noticeably affect the power deposition, significantly improves the agreement between numerical results and experimental data.

show abstract

Section: Introductionmentioning

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Quasioptical propagation and absorption of electron cyclotron waves: simulations and experiment

et al. 2021

View full text Add to dashboard Cite

show abstract

“…From the landing-point of the EC beam on the target plate the beam refraction due to electron density gradient was estimated. The displacement of the EC beam due to the refraction was found to agree well with ray trace calculations in the toroidal direction but not in the radial direction [77].…”

Section: Transport Of Rf Energymentioning

confidence: 56%

Plasma Physics Researches in Asia Pacific Region

Sen¹

2014

Proceedings of the 12th Asia Pacific Physics Conference (APPC12)

View full text Add to dashboard Cite

Development of the Molybdenum Millimeter Wave Target Tile for ECRH Antenna Alignment after the Evacuation in LHD

Igami

Yanai

Ito

et al. 2021

Plasma and Fusion Research

Self Cite

View full text Add to dashboard Cite

Alignment of the quasi-optical millimeter wave antenna for the electron cyclotron resonance heating (ECRH) can be required even after the evacuation of the vacuum vessel in fusion oriented plasma experimental devices. We developed a molybdenum millimeter wave target tile and installed it as one of the protection tiles of the vacuum vessel wall of the Large Helical Device (LHD) on the opposite side of the ECRH antennas. Inside the target tile, a sheathed thermocouple is mounted to measure the temperature increase during the millimeter wave injection toward this tile. In magnetic field configurations where neither the first nor the second electron cyclotron resonance (ECR) exists, the measured temperature increased sufficiently to be detected by the millimeter wave injection of approximately 100 kW for 0.1 s toward the target tile. Under the assumption that the distance between the target point that brings the largest temperature increase and the target point just above the thermocouple head gives the offset of the target point to be corrected, the offset of the antenna injection angle was confirmed with an accuracy of 0.4 • with changing the target point shot by shot.

show abstract

Direct measurement of refracted trajectory of transmitting electron cyclotron beam through plasma on the Large Helical Device

Cited by 3 publications

References 22 publications

Quasioptical propagation and absorption of electron cyclotron waves: simulations and experiment

Quasioptical propagation and absorption of electron cyclotron waves: simulations and experiment

Plasma Physics Researches in Asia Pacific Region

Development of the Molybdenum Millimeter Wave Target Tile for ECRH Antenna Alignment after the Evacuation in LHD

Contact Info

Product

Resources

About