Charge-exchange neutral particle analyzer up to MeV range

Measure energy spectrum of charge-exchange neutral particles of energetic alpha particle and hydrogen isotopes (H, D, T) emitted from the plasma.

[Detectors, Diagnostic Method]
Energetic neutral particles entering the analyzer are ionized by stripping in a thin carbon foil. The energy and mass of secondary ions are resolved by a combination of magnetic and electrostatic fields (E//B type). Secondary ions are measured with detectors consisting of CsI(Tl) scintillators each connected to a photomultiplier tube (PMT).

Two analyzers have been installed in a vertical and tangential direction.

Vertical analyzer Tangential analyzer
-Maximum energy : 4 MeV for
2 MeV for H
4 MeV for
4 MeV for H
-Energy ratio : 4 3.85
-Number of detectors : 8 8ch 2 arrays
-Scintillator thickness : 10 mm 2-23 mm
-Energy resolution : 6-11% 6-11%
-Position : P-12 section P-8 section

Tangential analyzer
Vertical analyzer

Development, installation and commissioning under the collaboration between JAERI and the Ioffe Institute, Russia.

(1) Y. Kusama et al., "Charge-exchange neutral particle measurement in MeV energy range on JT-60U", Rev. Sci. Instrum. 66(1) 339(1995).