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New type of versatile neutron diffractometer with a double-crystal monochromator system

Published online by Cambridge University Press:  22 December 2014

P. Mikula  and
M. Vrána
P. Mikula*
Affiliation:
Nuclear Physics Institute ASCR, v.v.i., 25068 Řež, Czech Republic
M. Vrána
Affiliation:
Nuclear Physics Institute ASCR, v.v.i., 25068 Řež, Czech Republic
*
a)Author to whom correspondence should be addressed. Electronic mail: mikula@ujf.cas.cz
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Abstract

Properties of a special double-crystal (DC) monochromator employing bent-perfect crystals of Si in (1, −1) and (n, −m) settings are presented. The first monochromator was the bent Si(111) crystal (4 mm thickness) and the second one was in the form of a sandwich consisting of two bent Si(111) and Si(220) slabs (2 and 1.3 mm thickness, respectively). It has been found that by a simple exchange of diffraction conditions on the second monochromator one can use either Si(111) + Si(111) bent crystals in (1, −1) setting providing good luminosity and worse diffractometer resolution or Si(111) + Si(220) bent crystals in quasi-dispersive (n, −m) setting providing very good diffractometer resolution and correspondingly weaker luminosity. It has been found that besides an excellent focusing and reflectivity properties of the dispersive double-bent-crystal setting the obtained monochromatic neutron current is sufficiently high for diffraction experiments even at the medium-power research reactor.

Keywords

neutron diffractionquasi-dispersive monochromatorpowder diffraction
Type
Technical Articles
Information
Powder Diffraction , Volume 30 , Supplement S1 , June 2015 , pp. S41 - S46
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Copyright
Copyright © International Centre for Diffraction Data 2014 

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