Apparatus and method for X-ray analysis with hybrid control of beam divergence

A method of X-ray analysis, using an apparatus comprising:

• an X-ray source (4) configured to generate X-rays;
• a sample stage (8) configured to support a sample (6), the X-ray source and the sample stage being arranged so that X-rays generated by the X-ray source define an incident beam that irradiates the sample;
• an adjustable slit (210) between the X-ray source and the sample;
• a further slit (220), between the X-ray source and the adjustable slit, or between the adjustable slit and the sample;
• and
• a controller (17) configured to control a width of the adjustable slit,
• the method comprising:
• setting (620), by the controller, the adjustable slit to a first width, at which the adjustable slit limits the divergence of the incident beam to a first divergence angle and thereby limits an area of the sample that is irradiated;
• setting (620), by the controller, the adjustable slit to a second width, at which the adjustable slit limits the divergence of the incident beam to a second divergence angle and thereby limits an area of the sample that is irradiated;
• and
• setting, by the controller, the adjustable slit to a third width, at which the adjustable slit does not limit the divergence of the incident beam, and the further slit limits the divergence of the incident beam to a third divergence angle and thereby limits an area of the sample that is irradiated,
• wherein the third width is greater than the second width, and the second width is greater than the first width, and
• wherein the third divergence angle is greater than the second divergence angle, and the second divergence angle is greater than the first divergence angle.

A method of X-ray analysis, using an apparatus comprising:

• an X-ray source (4) configured to generate X-rays;
• a sample stage (8) configured to support a sample (6), the X-ray source and the sample stage being arranged so that X-rays generated by the X-ray source define an incident beam that irradiates the sample;
• an adjustable slit (210) between the X-ray source and the sample;
• a goniometer, wherein the X-ray source is mounted to the goniometer so as to be rotatable about an axis of the goniometer, to irradiate the sample at a range of different incident angles;
• and
• a controller (17) configured to control the goniometer and a width of the adjustable slit,
• the method comprising:
• with the goniometer set (610) to a first incident angle, setting (620), by the controller, the adjustable slit to a first width, at which the adjustable slit limits the divergence of the incident beam to a first divergence angle and thereby limits an area of the sample that is irradiated;
• with the goniometer set (610) to a second incident angle, setting (620), by the controller, the adjustable slit to a second width, at which the adjustable slit limits the divergence of the incident beam to a second divergence angle and thereby limits an area of the sample that is irradiated;
• with the goniometer set (665) to a third incident angle, setting, by the controller, the adjustable slit to a third width, at which the adjustable slit limits the divergence of the incident beam to a third divergence angle and thereby limits an area of the sample that is irradiated;
• and
• with the goniometer set (665) to a fourth incident angle, setting, by the controller, the adjustable slit to the third width,
• wherein the third width is greater than the second width, and the second width is greater than the first width,
• wherein the third divergence angle is greater than the second divergence angle, and the second divergence angle is greater than the first divergence angle, and
• wherein the fourth incident angle is greater than the third incident angle, the third incident angle is greater than the second incident angle, and the second incident angle is greater than the first incident angle.