NEUTRON STORAGE BETWEEN PERFECT SILICON CRYSTAL PLATES

Backreflection at magnetically gated perfect crystal plates has been used to capture highly monochromatic neutrons (6.27 angstrom) in between two such plates on a 1 m long monolithic single crystal of silicon. Up to 78 back and forth reflections corresponding to storage periods up to 263 ms have been achieved. Several improvements are discussed which can further increase the efficiency of such a system by more than a factor of 10. From the measured loss rates we are able to deduce a lower limit for the mean reflectivity of the silicon crystal in the Darwin plateau region of 0.9978.