TY - JOUR
T1 - Conceptual design of a heavy ion beam probe for the QUEST spherical tokamak
AU - Ido, T.
AU - Hasegawa, M.
AU - Ikezoe, R.
AU - Onchi, T.
AU - Hanada, K.
AU - Idei, H.
AU - Kuroda, K.
AU - Nagashima, Y.
N1 - Funding Information:
This work was supported under the NIFS Bilateral Collaboration Research Program (Grant Nos. NIFS20KUTR147, NIFS19KUTR147, and NIFS19KUTR136) and partly supported by MEXT Japan under the Grant-in-Aid for Scientific Research (C) (Grant No. 18K03589). The authors appreciate Dr. A. Shimizu and Dr. M. Nishiura of NIFS for valuable discussion.
Publisher Copyright:
© 2022 Author(s).
PY - 2022/11/1
Y1 - 2022/11/1
N2 - A heavy ion beam probe (HIBP) has been designed for the QUEST spherical tokamak to measure plasma turbulence and the profiles of electric potential profiles. Using a cesium ion beam with an energy of several 10 keV, the observable region covers most of the upper half of the plasma. Although the probe beam is deflected by the poloidal magnetic field produced by plasma current and poloidal coil currents, it can be detected under plasma current up to 150 kA by modifying the trajectories with two electrostatic sweepers. According to the numerical estimation of the intensity of the detected beam, sufficient signal intensity for measuring plasma turbulence can be obtained over almost the measurable area when the electron density is up to 1 × 1019 m-3, which is larger than the cut-off density of electron cyclotron heating in QUEST. The performance of the designed HIBP is sufficient to explore the mechanisms of heat and particle transport in magnetically confined plasmas, including the influence of plasma wall interactions, which is a goal of the QUEST project.
AB - A heavy ion beam probe (HIBP) has been designed for the QUEST spherical tokamak to measure plasma turbulence and the profiles of electric potential profiles. Using a cesium ion beam with an energy of several 10 keV, the observable region covers most of the upper half of the plasma. Although the probe beam is deflected by the poloidal magnetic field produced by plasma current and poloidal coil currents, it can be detected under plasma current up to 150 kA by modifying the trajectories with two electrostatic sweepers. According to the numerical estimation of the intensity of the detected beam, sufficient signal intensity for measuring plasma turbulence can be obtained over almost the measurable area when the electron density is up to 1 × 1019 m-3, which is larger than the cut-off density of electron cyclotron heating in QUEST. The performance of the designed HIBP is sufficient to explore the mechanisms of heat and particle transport in magnetically confined plasmas, including the influence of plasma wall interactions, which is a goal of the QUEST project.
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U2 - 10.1063/5.0101770
DO - 10.1063/5.0101770
M3 - Article
C2 - 36461548
AN - SCOPUS:85143301459
SN - 0034-6748
VL - 93
JO - Review of Scientific Instruments
JF - Review of Scientific Instruments
IS - 11
M1 - 113516
ER -