AN EXPERIMENTAL TEST OF A DOUBLE-CRYSTAL MONOCHROMATOR FOR THERMAL-NEUTRONS BASED ON 2 BENT SILICON-CRYSTALS

Reflecting properties of a double-crystal (DC) monochromator consisting of two elastically bent perfect silicon crystals in the parallel non-dispersive (1, minus 1) setting were experimentally treated. Using an unconventional fully asymmetric geometry, the effective mosaicity may be significantly enhanced up to the value of about 10** minus **2 rad. Test experiments were performed on the 111 and 400 reflections for wavelengths of 0. 2 nm and 0. 157 nm, respectively. The experimental results obtained are found to be in good agreement with the theoretical predictions published in a previous paper.