X-ray source for X-ray diffraction apparatus, related apparatus and method

An X-ray diffraction apparatus, comprising:

• an X-ray source for irradiating a sample with an X-ray beam, the X-ray source comprising:
• an anode target and a cathode filament, the cathode filament having an elongated body, the anode target and the cathode filament being operable to generate the X-ray beam;
• a vacuum chamber enclosing the anode target and the cathode filament, the vacuum chamber having a window transparent to the X-ray beam;
• an outer housing mountable to the X-ray diffraction apparatus in a fixed position, the outer housing comprising outer housing openings;
• and
• an inner housing enclosing the vacuum chamber and rotatably mounted to the outer housing, the inner housing comprising inner housing openings positioned to be aligned with the window and the outer housing openings, the inner housing being rotatable with respect to the outer housing between a line focus configuration and a point focus configuration,
• wherein, upon rotation of the inner housing with respect to the outer housing, the cathode filament is engaged in rotation therewith and the outer housing remains in the fixed position, such that:
• in the line focus configuration, the elongated body of the cathode filament is substantially parallel to the window, thereby producing a line-shaped X-ray beam;
• and
• in the point focus configuration, the elongated body of the cathode filament is substantially perpendicular to the window, thereby producing a point-shaped X-ray beam;
• a sample holder for receiving the sample, the sample being positioned to receive the X-ray beam when held by the sample holder;
• and
• a detector for receiving X-rays scattered from the sample and outputting an X-ray diffraction pattern therefrom.

A method for producing an X-ray beam with an X-ray source of an X-ray diffraction apparatus, the X-ray source comprising an outer housing having outer housing openings and an inner housing having inner housing openings and rotatably mounted to the outer housing, the inner housing enclosing a vacuum chamber that encloses an anode target and a cathode filament operable to generate an X-ray beam, the method comprising:

• aligning the outer housing openings, the inner housing openings, and a window of the vacuum chamber while maintaining the outer housing in a fixed position;
• rotating the inner housing relative to the outer housing to select a line focus configuration or a point focus configuration;
• and
• operating the anode target and the cathode filament to generate the X-ray beam according to the selected line focus configuration or point focus configuration.