The design and initial commissioning of the first IR beamline at the ALS has been described previously. We report the final commissioning and first results of the mid-IR spectromicroscopy beamline 1.4.3. In addition, several improvements and two new branchlines are presented. Beamline 1.4.2 is connected to the front end under vacuum and consists of a Bruker Rapid- and Step-Scan vacuum FTIR bench. The modulated light is then coupled into a UHV surface science chamber for grazing incidence reflection studies. Several more external ports are available from the Bruker bench. Beamline 1.4.1 receives light from a separate port on the beamline 1.4 front end and connects to an optical table for photoluminescence and other experiments using photons with energies up to 6 eV.

A Fourier Transform X-ray Spectrometer has been designed and built for use at the Advanced light source at Lawrence Berkeley National Laboratory. The design requires a total rectilinear motion of 15 mm with a maximum pitch error of the stage below {+-}0.4 {mu}radians, to achieve this the authors chose to build the entire machine as a single monolithic flexure. A hydraulic driver with sliding O-ring seals was developed with the intention to provide motion with a stick-slip position error of less than 0.8 nm at a uniform velocity of 20 {mu}m/sec. The machine is comprised of two pairs of nested linear motion flexures, all explained by means of a theory published earlier by Hathaway. Certain manufacturing errors were successfully corrected by an extra weak-link feature in the monolith frame. The engineering details of all the subsystems of the linear motion machine are described and measured performance reported.

Bending magnet beamline 9.3.2 at the Advanced Light Source (ALS) was designed for high resolution spectroscopy with the capability for delivering circularly polarized light in the soft x-ray energy region using three gratings. The monochromator is a fixed included-angle spherical grating monochromator (SGM) and was originally used at SSRL as a prototype for later insertion-device-based monochromators for the ALS. For operation at the ALS, the toroidal pre-mirror used at SSRL was replaced by a horizontally focusing and a vertically focusing mirror in the Kirkpatrick-Baez configuration. Circularly polarized radiation is obtained by inserting a water-cooled movable aperture in front of the vertically focusing mirror to allow selecting the beam either above or below the horizontal plane. To maintain a stable beam intensity through the entrance slit, the photocurrent signals from the upper and lower jaws of the entrance slit are utilized to set a feedback loop with the vertically deflecting mirror piezoelectric drive. The beamline end station has a movable platform that accommodates two experimental chambers enabling the synchrotron radiation to be directed to either one of the two experimental chambers without breaking the vacuum. © 1996 American Institute of Physics.

A 55 meter spherical grating monochromator has been completed at the Stanford Synchrotron Radiation Laboratory (SSRL). The monochromator includes a unique capability for water cooled gratings, and is presently operating with a fused silica grating from 180 to 820 eV. A resolution of 60 meV has been achieved at 400 eV, inferred from the linewidths of the nitrogen 1s-π∗ resonance. A photon flux of 4 × 1010 photon/s has been observed at 440 eV and 40 mA ring current (and with 0.5 eV resolution). It is expected that this flux value will improve by a factor of approximately 10–30 when a full-performance condensing system is installed later this year.

The performance of a 55-meter Spherical Grating Monochromator (SGM) is described. A resolution of 60 meV has been achieved at 400eV, inferred from the linewidths of the nitrogen 1s-π* resonance. A photon flux of 4 × 1010 photons/s has been observed at 440eV (and with 0.5 eV resolution). An initial experiment has studied the core-shell resonances of gas-phase ethylene, C2H4. Vibrational fine structure was resolved both for the carbon 1s-π* and carbon 1s-Rydberg excitations. Comparison with the vibrational frequencies of ground state ethylene implies that the ν1 (C-H stretch) and ν2 (C-C stretch) or ν3 (H-C-H bend) are excited. It is suggested that the lower Rydberg orbitals, 3s and 3pσ, have molecular, anti-bonding character.