title: An alpha particle measurement system using an energetic neutral helium beam in ITER (invited).
abstract: An energetic helium neutral beam is involved in the beam neutralization measurement system of alpha particles confined in a DT fusion plasma. A full size strong-focusing He(+) ion source (2 A, the beam radius of 11.3 mm, the beam energy less than 20 keV). Present strong-focusing He(+) ion source shows an emittance diagram separated for each beamlet of multiple apertures without phase space mixing, despite the space charge of a beamlet is asymmetric and the beam flow is non-laminar. The emittance of beamlets in the peripheral region was larger than that of center. The heat load to the plasma electrode was studied to estimate the duty factor for the ITER application.
authors.affiliation: Graduate school of Engineering, Tohoku University, Sendai 980-8579, Japan. mnsasao@yahoo.co.jp
authors.forename: M
authors.initials: M
authors.lastname: Sasao
authors.forename: M
authors.initials: M
authors.lastname: Kisaki
authors.forename: T
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authors.lastname: Kobuchi
authors.forename: K
authors.initials: K
authors.lastname: Tsumori
authors.forename: N
authors.initials: N
authors.lastname: Tanaka
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authors.lastname: Terai
authors.forename: A
authors.initials: A
authors.lastname: Okamoto
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authors.initials: S
authors.lastname: Kitajima
authors.forename: O
authors.initials: O
authors.lastname: Kaneko
authors.forename: K
authors.initials: K
authors.lastname: Shinto
authors.forename: M
authors.initials: M
authors.lastname: Wada