Optical alignment of X-ray microanalyzers

Apparatus for X-ray analysis of a sample, comprising:

• an X-ray excitation source, which is adapted to generate an X-ray beam;
• an optical radiation source, which is adapted to generate optical radiation;
• an X-ray optic, which is arranged to focus both the X-ray beam and the optical radiation onto a spot on the sample;
• one or more X-ray detectors, which are adapted to receive X-ray photons from the spot on the sample, and to generate a first signal in response to the photons that is indicative of a characteristic of the sample;
• an optical detector, which is arranged to receive the optical radiation that is reflected from the spot on the sample, and to generate a second signal that is indicative of an alignment of the spot with a target area of the sample;
• and
• a movable reflector, which is positionable to direct the optical radiation toward the X-ray optic during the alignment of the spot with the target area, and which is repositionable to permit the X-ray beam to impinge on the X-ray optic after the alignment is completed.

A method for X-ray analysis of a sample, comprising:

• aligning an optical radiation source with an X-ray excitation source, so that a spot on the sample that is irradiated by an X-ray beam generated by the X-ray excitation source along a beam axis is illuminated with optical radiation generated by the optical radiation source;
• receiving the optical radiation that is reflected from the sample, and responsively to the received optical radiation, generating a first signal that is indicative of an alignment of the spot on the sample;
• aligning the X-ray beam, responsively to the first signal, so that the spot coincides with a target area of the sample;
• and
• receiving X-ray photons from the spot on the sample after aligning the X-ray beam, and responsively to the received X-ray photons, generating a second signal that is indicative of a characteristic of the target area,
• wherein receiving the X-ray photons comprises arranging one or more X-ray detectors so as to define a ring around the spot, while leaving a gap in the ring at a location that is radially displaced from the beam axis, and
• wherein receiving the optical radiation comprises positioning an optical detector in the gap in the ring so as to receive the optical radiation that is reflected from the sample.

A method for X-ray analysis of a sample, comprising:

• aligning an optical radiation source with an X-ray excitation source, so that a spot on the sample that is irradiated by an X-ray beam generated by the X-ray excitation source is illuminated with optical radiation generated by the optical radiation source;
• receiving the optical radiation that is reflected from the sample, and responsively to the received optical radiation, generating a first signal that is indicative of an alignment of the spot on the sample;
• aligning the X-ray beam, responsively to the first signal, so that the spot coincides with a target area of the sample;
• and
• receiving X-ray photons from the spot on the sample after aligning the X-ray beam, and responsively to the received X-ray photons, generating a second signal that is indicative of a characteristic of the target area,
• wherein aligning the optical radiation source comprises irradiating an alignment target with the X-ray beam, so as to cause the target to emit light from a point on the target at which the X-ray beam is incident, and aligning the optical radiation source with the point on the target.