Neutron focusing techniques with curved mirrors and supermirrors

Two kinds of curved supermirror deveices were proposed for focusing of thermal and cold neutrons. One is a focusing mirror with multiple-parabolic surface (mPRB) for thermal neutorns of wavelength of 1.8A, and the other is with paraboloidal surface (PRB) for cold neutrons of 8.8A. The mPRB was constructed by thirty-two pieces of 3Qc Ni/Ti supermirrors deposited on Borate float glass of 150mm×100mm×0.4mm. The supermirrors were lined with parabolic wedge-shaped acrylic-resin spacers so that they were formed into four pieces of 1200mm long mirror and constituted 3 channels with parabolic shapes. It converged 3.3 times as many neutrons of 1.8A on the area of lmm width one-dimensionally as would arrive without it at T1-3 beam port (HERMES) in JRR-3M, JAERI. The amount of detected neutrons had good agreement with that expected by the Monte Carlo simulation. The PRB consisted of four pieces of quartz glass substrates with a quarter of a paraboloidal surface. The surfaces of these pieces were coated by 3Qc Ni/Ti supermirror, 1.5Qc Ni/Ti supermirror, Ni layer, and no material. It converged 6.9 times as many neutrons of 9.5A on the area of lmm2 two-dimensionally as would arrived without it at NOP beam port in JRR-3M, JAERI. The amount of detected neutrons was about 14% in comparison with what is expected by the Monte Carlo simulation.