Preliminary experiments on apparatus for in situ studies of microwave-driven reactions by small angle neutron scattering

In this article we describe apparatus for the study of the microwave-driven growth of particles in solution by in situ small angle neutron scattering (SANS). This apparatus has enabled the first preliminary experiments using microwave-activated in situ diffraction. We take iron oxide as the prototyp e system, but the technique may be extended to a wide variety of chemical r eactions that deposit solids from solution. The key features of the apparat us are a microwave cavity with a modular construction that may be adapted t o the geometric constraints of the diffractometer, and a computer-controlle d microwave generator that may be set to maintain either constant pressure or temperature in the reaction vessel. In this particular piece of equipmen t the reaction vessel is adapted so that part of the sample fills a cell of identical construction to those commonly used in SANS measurements for opt imal transmission of the neutron beam. (C) 2001 American Institute of Physi cs.