Sharov, V. A., Xiao, Q. F., Ponomarev, I. Y., Mildner, D. F. R., Chen-Mayer, H. H.
Cold Neutron Microprobe for Materials Analysis Using Tapered Capillary Optics
Review of Scientific Instruments. 2000 Sep 01; 71(9): 3247-3253.
A prototype monolithic capillary lens for focusing neutrons produced by thermally drawing straight multicapillary bundles has been characterized with cold neutrons, and gives an intensity gain of a factor of 25 at a focal distance of 8 mm, over the focal spot area of width 87 mu m. This is over an order of magnitude smaller in area than for the multifiber capillary lens. The spatial resolution available with the lens has been tested with prompt gamma measurements on slivers of dysprosium. Background problems that can affect the spatial resolution of measurements taken at the focal position of the lens are addressed. The boron glass of the tapered monolithic lens provides good shielding from unfocused neutrons in the vicinity of the lens focus. (C) 2000 American Institute of Physics. [S0034-6748(00)05109-1].