Diffractometer for charged-particle crystallography

A diffractometer for charged-particle crystallography of a crystalline sample, in particular for electron crystallography of a crystalline sample, the diffractometer comprising:

• a charged-particle source for generating a charged-particle beam along a charged-particle beam axis,
• a charged-particle-optical system for manipulating the charged-particle beam such as to irradiate the sample with the charged-particle beam;
• a sample holder for holding the sample,
• a manipulator operatively coupled to the sample holder for positioning the sample relative to the beam axis, wherein the manipulator comprises a rotation stage for tilting the sample holder with respect to the incident charged-particle beam around a tilt axis, and a multi-axes translation stage for moving the sample holder at least in a plane perpendicular to the tilt axis (44), wherein the multi-axes translation stage is operatively coupled between the sample holder and the rotation stage such that the multi-axes translation stage is in a rotational system of the rotation stage and the sample holder is in a moving system of the multi-axes translation stage (42), thereby enabling to position the center of mass of the sample substantially on-axis with regard to the tilt axis with a maximum lateral deviation from the tilt axis of at most 1 μm, in particular of at most 0.5 μm, preferably of at most 0.3 μm, even more preferably of at most 0.1 μm,
• a charged-particle detection system at least for collecting a diffraction pattern of the sample based on the beam of charged-particles transmitted through the sample,
• wherein the tilt axis is fixed in space and extends in a substantially vertical direction, that the diffractometer further comprises a measurement device including one or more capacitive position sensors or an interferometric measurement device, for measuring a position of the sample holder relative to the charged-particle beam, and that the diffractometer further comprises a feedback controller which is operatively coupled to the measurement device and the manipulator and configured to control the position of the sample relative to the charged-particle beam such that for each tilt angle position of the rotation stage the center of mass of the sample stays substantially on-axis with regard to the tilt axis with a maximum lateral deviation from the tilt axis of at most 1 μm, in particular of at most 0.5 μm, preferably of at most 0.3 μm, even more preferably of at most 0.1 μm and thus that for each tilt angle position of the rotation stage the volume of the sample substantially stays within the charged-particle beam.