Diffractometer

A diffractometer microscope selectively convertible for use as a diffractometer and as a microscope and comprising:

• a condenser arranged to receive at least one light beam substantially normal to a specimen plane and transmit the or each light beam across the specimen plane at an acute angle thereto;
• a diaphragm upstream of the condenser, the diaphragm being formed with a respective aperture offset from the principal axis of the condenser for transmitting to the condenser a respective said light beam which, after exit from the condenser, crosses the specimen plane at said angle thereto;
• a respective lens for converging a respective said, light beam to a focus at a respective said aperture;
• a positive lens having its principal axis substantially normal to the specimen plane, for converging rays diffracted substantially normally from the specimen plane;
• a field stop, adjacent the specimen plane, for restricting the light which is converged by said positive lens;
• an aperture stop downstream of said positive lens, for limiting the light-rays converged by said positive lens to those diffracted substantially normally to the specimen plane;
• a photo-electric detection means for detecting light from said positive lens;
• means for providing relative rotation between said specimen plane and said light beams about the principal axis of said positive lens;
• and
• a rotatable microscope nosepiece in which said positive lens, field and aperture stops, and photoelectric detection means are engaged as a removable modular assembly.