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Abstract: Neutron refractive optics is a powerful tool for beam focusing due to its large effective aperture compared to reflective optics. Because neutron refraction angle decreases with shorter wavelengths, the application of refractive optics has been restricted to the cold neutron range. To expand the applicable wavelength range, we have developed a new refractive optics using an amorphous perfluoropolymer. This refractive optics is composed of several hundred thin sheets, each of which has a large number of grooves on the top surface. The refraction experiment was performed at the H-8 beam port of KENS, and it was confirmed that the thermal neutron beam can be refracted using this material prism. [Copyright &y& Elsevier]

We have constructed a focusing-geometry small-angle neutron scattering (FSANS) instrument, SANS-J-II, with two kinds of neutron focusing device: a series of compound refractive lenses made of MgF2 and a magnetic neutron lens based on an extended Halbach-type sextupole magnet. In this study, we investigated the performance of the FSANS instrument with the magnetic neutron lens. The intensity distribution of a direct neutron beam focused on the detector plane by the magnetic neutron lens had a ratio of the peak height to the background level of for a polarized neutron beam with a polarization degree of . It is found that a minimum value of the measurable range [where is the modulus of the scattering vector and is defined as , where is the scattering angle and is the neutron wavelength], , of Å−1 can be achieved by the FSANS instrument with the magnetic neutron lens using neutrons with Å and for the full width at half maximum. [ABSTRACT FROM AUTHOR]

Abstract: We have developed a magnetic neutron lens (MNL) based on an extended Halbach-type permanent sextupole magnet. The effective aperture size is 30mm in diameter and the length is 2400mm. The sextupole magnetic field distribution | B |=(G/2) r 2 with the gradient coefficient G=10,660±530T/m2 are generated inside the magnet, where r is the distance from the magnet center axis. The neutron-focusing property is investigated by using pulsed polarized neutrons. The obtained results are discussed in comparison with numerical simulation results. The application to the focusing-geometry small-angle neutron scattering experiments is discussed. [Copyright &y& Elsevier]

Abstract: A neutron scintillating detector and its data taking system have been developed for neutron scattering measurement. A 64-channel flatpanel photomultiplier is used for the Anger-camera method. The detection efficiency of γ-ray background is very low in the use of the ZnS/6LiF scintillator. The spatial resolution is less than 1mm. The effective area of this detector is around 25cm2, and it is easy to expand it to a larger area with small dead space using the multi-photomultiplier tubes system. The fast DAQ system has 10-bit 100MHz flash ADCs, FPGA chips and USB2.0 device. [Copyright &y& Elsevier]

Abstract: Precise measurement of neutron β decay allows determining the coupling constant of weak interaction independent of any nuclear structure. We have developed measurement system of neutron β decay at a thermal neutron beamline in JRR-3, JAEA. By using coincidence technique of two kinds of detectors, we have succeeded in detecting the signal of neutron β decay with S/N of 0.63 and count rate of 0.40cps. [Copyright &y& Elsevier]