Measurement of end-loss ions originated from spontaneously excited high frequency waves by using an MCP detector on GAMMA 10/PDX

Koki Izumi, Ryuya Ikezoe, Makoto Ichimura, Mafumi Hirata, Mizuki Sakamoto, Shuhei Sumida, Seowon Jang, Atsuto Tanaka, Yushi Kubota, Ryo Sekine, Hiroki Kayano, Yousuke Nakashima

Research output: Contribution to journalArticle

Abstract

Effective ICRF heating creates a high ion-temperature plasma with strong ion-temperature anisotropy in the GAMMA 10/PDX central cell, where several Alfvén-ion-cyclotron (AIC) waves are spontaneously excited. It is clearly measured with a microwave reflectometer installed in the central cell that waves with the difference frequencies of the AIC waves are excited in a core region. In addition, it has been observed with an end-loss high-energy ion detector that high-energy ions of over 6 keV are axially transported along the magnetic field lines with the same frequencies as the difference frequencies of the AIC waves. In this study, in order to understand the related wave-particle interaction, another end-loss high-energy ion detector using a micro-channel plate has been developed. By changing the ion retarding grid voltage, which the new detector equips, it is found that an energy dependence exists in the loss mechanism; some frequencies that the axial transport includes disappear for high-energy ions of over 6 keV while they are significant for low-energy ions. In addition, by changing the radial position of the new detector, a radial localization of the axial transport to a core region, which is consistent with the profile of the difference frequencies waves, is indicated.

Original languageEnglish
Article number2402033
JournalPlasma and Fusion Research
Volume14
Issue numberSpecialissue1
DOIs
Publication statusPublished - Jan 1 2019

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detectors
ions
cyclotrons
ion temperature
energy
microwave reflectometers
wave-particle interactions
microchannel plates
cells
grids
retarding
anisotropy
heating
electric potential
profiles
magnetic fields

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics

Cite this

Measurement of end-loss ions originated from spontaneously excited high frequency waves by using an MCP detector on GAMMA 10/PDX. / Izumi, Koki; Ikezoe, Ryuya; Ichimura, Makoto; Hirata, Mafumi; Sakamoto, Mizuki; Sumida, Shuhei; Jang, Seowon; Tanaka, Atsuto; Kubota, Yushi; Sekine, Ryo; Kayano, Hiroki; Nakashima, Yousuke.

In: Plasma and Fusion Research, Vol. 14, No. Specialissue1, 2402033, 01.01.2019.

Research output: Contribution to journalArticle

Izumi, K, Ikezoe, R, Ichimura, M, Hirata, M, Sakamoto, M, Sumida, S, Jang, S, Tanaka, A, Kubota, Y, Sekine, R, Kayano, H & Nakashima, Y 2019, 'Measurement of end-loss ions originated from spontaneously excited high frequency waves by using an MCP detector on GAMMA 10/PDX', Plasma and Fusion Research, vol. 14, no. Specialissue1, 2402033. https://doi.org/10.1585/pfr.14.2402033
Izumi, Koki ; Ikezoe, Ryuya ; Ichimura, Makoto ; Hirata, Mafumi ; Sakamoto, Mizuki ; Sumida, Shuhei ; Jang, Seowon ; Tanaka, Atsuto ; Kubota, Yushi ; Sekine, Ryo ; Kayano, Hiroki ; Nakashima, Yousuke. / Measurement of end-loss ions originated from spontaneously excited high frequency waves by using an MCP detector on GAMMA 10/PDX. In: Plasma and Fusion Research. 2019 ; Vol. 14, No. Specialissue1.
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