全反射中性子線利用γ線分光装置の試作

抄録

Total reflection neutron induced γ spectroscopy (TN-γ) is a novel promising analytical method suitable for probing chemical composition in the layers and interfaces deeply buried under thick protection materials. The method measures prompt γ-ray spectra from specific elements in the sample, when neutrons impinge at grazing incidence and are reflected at specific surfaces/interfaces. The instrument has been developed at BL10, J-PARC Materials and Life Science Experimental Facility. Unlike ordinary prompt γ-ray Spectroscopy for solid samples, the experiment only uses very limited small size of neutron beam. Therefore, both reducing background significantly and designing optimum geometry for a γ detector are extremely important. The present paper describes the instrumentation and reports the first successful measurements of ¹¹⁵In γ-ray spectra from InP substrate under the neutron total reflection condition.