Fig. 1. Schematic representation of a short-pulse beamline.

Fig. 2. Comparison of the modelled spatial profile and expected transmission of the considered conversion crystal designs: (a) unconverted spatial profile, (b) original 325 mm circular, (c) 500 mm circular, (d) 320 mm square, (e) dual 325 mm circular, (f) dual 320 mm square.

Fig. 3. Frequency conversion chamber incorporating the twin crystal and ‘double-deck’ vertical dichroic mirrors.

Fig. 4. Measured hysteresis of an actuator driven mirror mount (a) before and (b) after software compensation.

Fig. 5. (a) Interference pattern created by temporally overlapping the two sub-aperture beamlets. (b) Composite image of the spatial profiles of the compressed beam and the two beamlets. The beam is measured on a diagnostic station after the second compressor grating. The profile was measured using an imaging camera positioned at the TCC.

Fig. 6. X-ray spot images. (a) At best focus, spot . (b) Defocus of , sub-apertures overlapped, spot .