Electrostatic Potential Measurement by Using 6-MeV Heavy Ion Beam Probe on LHD

Ido, T.; Shimizu, A.; Nishiura, M.; Katō, Susumu; Nakano, H.; Nishizawa, A.; Hamada, Y.; Yokota, Mitsuhiro; Tsukada, K.; Ogawa, Hideki; Inoue, Taiki; Ida, K.; Yoshinuma, M.; Murakami, S.; Tanaka, K.; Narihara, K.; Yamada, I.; Kawahata, K.; Tamura, N.

doi:10.1585/pfr.3.031

Cited by 10 publications

(6 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In order to measure the electrostatic potential in LHD plasmas, an HIBP using a 6 MeV gold ion beam is installed [22]. The temporal resolution is about 250 kHz, and the spatial resolution is estimated to be a few cm [23].…”

Section: Apparatusmentioning

confidence: 99%

Identification of the energetic-particle driven GAM in the LHD

et al. 2015

View full text Add to dashboard Cite

n = 0 modes with frequency chirping have been observed by a heavy ion beam probe and Mirnov coils in the large helical device plasmas, where n is the toroidal mode number. The spatial structures of the electrostatic potential fluctuation and the density fluctuation correspond to those of the geodesic acoustic mode (GAM). The modes are observed only during the tangential neutral beam injection with the energy of 175 keV. The energy spectra of fast ions measured by a neutral particle analyzer implies that the modes are excited by the fast ions through the inverse Landau damping. The absolute values and the temperature dependence of the frequency of the mode can be interpreted by the dispersion relation taking into account the measured energy spectra of the fast ions. Therefore, the observed n = 0 modes are identified as the energetic-particle driven GAM.

show abstract

Section: Apparatusmentioning

confidence: 99%

Identification of the energetic-particle driven GAM in the LHD

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Thus, the HIBP is a powerful tool for investigating transport phenomena. In the large helical device (LHD ) [5], an HIBP has been installed in order to investigate the role of E r in high-temperature plasmas, and a transport study based on the measurement is in progress [6,7].…”

Section: Introductionmentioning

confidence: 99%

Experimental study of radial electric field and electrostatic potential fluctuation in the Large Helical Device

Ido

Shimizu

Nishiura

et al. 2010

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

A heavy ion beam probe was installed on the Large Helical Device (LHD) to investigate the roles of radial electric fields (E r ) in magnetically confined high-temperature plasmas. Two new observations are presented. One is the observation of electrostatic potential profiles during the formation of extremely hollow density profiles of impurities, called the impurity hole (Ida K et al 2009 Phys. Plasmas 16 056111), in the LHD plasmas. The measured E r is negative, and the E r determined by the ambipolarity condition of neoclassical particle fluxes is consistent with this observation. However, the transport analysis indicates that the formation of the extremely hollow profile is not attributable to the impurity fluxes driven by E r and the density and temperature gradients of the impurity. The other new observation is on the geodesic acoustic mode (GAM). The electrostatic potential fluctuation associated with the GAM, which is probably induced by energetic particles, in plasmas with the reversed or weak magnetic shear is identified. The GAM is localized in the core region of the plasma.

show abstract

“…purpose, a HIBP (heavy ion beam probe) [26] measurement for electric potential and then deducing E r profiles was performed, as shown in figure 4(a). Time averaging (0.3-0.4 s) was done to obtain a reasonable signal to noise ratio.…”

Section: Application Of Task3d-a To a Lhd Discharge (Examples Of Anal...mentioning

confidence: 99%

Extended capability of the integrated transport analysis suite, TASK3D-a, for LHD experiment

et al. 2017

View full text Add to dashboard Cite

The integrated transport analysis suite, TASK3D-a (Analysis), has been developed to be capable for routine whole-discharge analyses of plasmas confined in three-dimensional (3D) magnetic configuration such as the LHD. The routine dynamic energy balance analysis for NBI-heated plasmas was made possible in the first version released in September 2012. The suite has been further extended through implementing additional modules for neoclassical transport and ECH deposition for 3D configurations. The module has also been added for creating the systematic data for the International Stellarator-Heliotron Confinement and Profile Database (ISH-DB). Improvement of NBI modules for multiple-ion species plasmas and a loose-coupling with a largesimulation code are also highlights of recent development.

show abstract

Electrostatic Potential Measurement by Using 6-MeV Heavy Ion Beam Probe on LHD

Cited by 10 publications

References 33 publications

Identification of the energetic-particle driven GAM in the LHD

Identification of the energetic-particle driven GAM in the LHD

Experimental study of radial electric field and electrostatic potential fluctuation in the Large Helical Device

Extended capability of the integrated transport analysis suite, TASK3D-a, for LHD experiment

Contact Info

Product

Resources

About