The experimental end of the world’s brightest x-ray laser, generated by the linear accelerator at SLAC.

SXR will probe ultrafast chemistry with flash imaging of a quadrillionth of a second.

Inside this focusing optics chamber, two elliptically bent mirrors direct the FEL (free-electron laser) beam into the experimental chamber. Dynamically bent mirrors (silicon mirror bent with actuators) can be adjusted to focus the beam into an arbitrary position in the endstation to change the focal spot on the sample, depending upon the experimental requirements.

Mirrors with glancing angles are generally used for x-rays instead of lenses (although they are now starting to use beryllium concave lens arrays for the hard x-rays in the hutch next door).

The planar-elliptically bent mirrors are called Kirkpatrick Baez mirrors, named after the inventor - Joan Baez’s dad.