Neutron Activation Measurement

[Objectives]
Shot-integrated measurement of the total and 14 MeV neutron yield for;
Fusion performance study
・ Triton burnup study
・ Cross-calibration of the neutron monitor
・ Calibration of 14 MeV neutron detectors

[Detectors, Diagnostics Method]
Metal foil is tranfered to the irradiation point in side the vacuum vessel by a pneumatic tube. After the shot, the foil retured to the measurement station located on the basement. Then the activation gamma from the foil is measured by the High Purity Ge detector.

Reactions Threshold energy (MeV)
115In(n,n')115In 0.3
64Zn(n,p)64Cu 1
27Al(n,alpha)24Na 2.5
28Si(n,p)28Al 4
63Cu(n,2n)62Cu 11.5

[Specifications]
・ Irradiation Position: Re-entrant port of the horizontal port of P-15 sections
・ Measurement station: Basement
・ Gamma-ray detector : 2 inch diam. x 2 inch hight high-purity Ge detector

[Reference]
(1) M. Hoek, T. Nishitani, Y. Ikeda, A. Morioka, "Initial Results from Neutron Yield Measurements by Activation Technique at JT-60U", JAERI-M 94-002, (1993).
(2) M. Hoek, T. Nishitani, M. Carlson, T. Carlson, "Triton Burnup Measurements by Neutron Activation at JT-60U", Nucl. Instrum Methods A368 (1996) 804.