X-ray diffraction instrument, for in-situ analysis e.g. of catalyst substrates or adsorbents used in petroleum industry, mimics atmosphere, temperature and agitation conditions

摘要

A positioner (1) locates the capillary in the incident X-ray beam. Circulation (22, 25) and heating systems are provided for fluid (gas especially) in the capillary. The capillary is also oscillated (1) along its longitudinal axis. The oscillator includes a geared-down motor (4) and sensors for the end of travel, enabling control of the capillary oscillation amplitude. The heater is a metallic cylinder with openings dimensioned to pass incident X-rays and diffracted X-rays. An insulating collar placed around the cylinder has openings corresponding with those in the cylinder. Circulation is provided through connections to the capillary mounted on a slider fixed to the positioner. The capillary is removed by taking off the connections and moving the slider. The positioner displaces the capillary axially, on a goniometric head. The connector fittings are unions. They withstand pressures up to 5 bar and have sufficient flexibility to resist the oscillations. The external surface of the cylinder carries a shielded resistance for heating up to 250[deg]C, and a thermocouple for temperature control.