Soft x-rays at XOR
SXSI: the ASRP’s New Soft X-Ray End-Station
The end-station is a multi-user XANES and XPS facility with the following main features:
One forte of the end-station is the ability to handle volatile samples throughout the entire system by cooling to liquid Nitrogen temperatures: This feature is particularly useful in the study of volatile mineral samples, and was a major design goal for the system.
The Opening Ceremony
At the end of April the ASRP celebrated the successful commissioning of the endstation with an opening ceremony and mini-symposium at the NSRRC. The event also served to thank the NSRRC and its staff for making ASRP operations such a success in Taiwan.
The ASRP has successfully designed, constructed and now operates a soft x-ray end-station at the National Synchrotron Radiation Research Centre (NSRRC) of Taiwan to support Australian soft x-ray research. This instrument, dubbed SXSI (Soft Xray Synchrotron Instrument) and costing approximately $1 million, is the largest single piece of infrastructure funded under the current Major National Research Facilities grant to the ASRP. The end-station represents a major investment by the Federal Government to assist Australian soft x-ray synchrotron research. It is expected that the system will be transferred to Melbourne in late 2007 where it will be stationed on the soft x-ray beam-line at the Australian synchrotron.
The end-station is a multi-user XANES and XPS facility with the following main features:
- High through-put photoemission energy analyser (SPECS-150MCD), <5 meV resolution
- NEXAFS detector (partial electron yield and total fluorescence yield)
- Sample cooling to 120K (using LN2) or ~40K (using LHe)
- Flood gun and dual-anode x-ray source
- Ability to transfer samples at 120K
- Rotary distribution chamber allows sample transfer to 8 chambers.
- Fast sample entry load-lock with glove-box
- Sample fracture chamber and sample parking chamber
- Preparation chamber for sputtering, evaporation etc.
- Ability to be upgraded via add-on chambers using spare-ports.
- Motorised sample manipulators and user friendly control system
- Support frame with a large range of adjustment, to allow SXSI to be mounted on the complete range of NSRRC soft X-ray beamlines, and on the Australian Synchrotron.
One forte of the end-station is the ability to handle volatile samples throughout the entire system by cooling to liquid Nitrogen temperatures: This feature is particularly useful in the study of volatile mineral samples, and was a major design goal for the system.
The SXSI commissioning team: it included Australian users and personnel from the manufacturer Prevac/Omnivac, the NSRRC and the ASRP.
The Opening Ceremony
At the end of April the ASRP celebrated the successful commissioning of the endstation with an opening ceremony and mini-symposium at the NSRRC. The event also served to thank the NSRRC and its staff for making ASRP operations such a success in Taiwan.
The opening ceremony. Left: SXSI is dressed up for the ribbon cutting by Alice Wu and Evonne Chien of the NSRRC. Right: Rob Lamb, Anton Stampfl
and Richard Garrett (left to right) with Yaw-Wen Yang (second from left, NSRRC Deputy Director) and Keng Liang (right, NSRRC Director) at the opening.
and Richard Garrett (left to right) with Yaw-Wen Yang (second from left, NSRRC Deputy Director) and Keng Liang (right, NSRRC Director) at the opening.
The photos above show SXSI set up in the ASRP laboratory at the NSRRC, where it lives between experiments on beamlines. This large laboratory was made available by the NSRRC and includes space for UHV parts assembly and chemical facilities for sample preparation. The laboratory is yet another example of the extraordinary assistance that he NSRRC has given the ASRP’s soft X-ray program.
Some Science
Once the basic commissioning tasks were complete, the commissioning team began to use the system for actual experiments. Below are some photoemission spectra taken during the commissioning beamtime, which indicate some of the capability of the system. (spectra courtesy W. Skinner, Ian Wark Institute).
Some Science
Once the basic commissioning tasks were complete, the commissioning team began to use the system for actual experiments. Below are some photoemission spectra taken during the commissioning beamtime, which indicate some of the capability of the system. (spectra courtesy W. Skinner, Ian Wark Institute).
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Valance band spectrum from a fracture surface of the mineral Troilite (FeS) taken with SXSI at a photon energy of 250 eV. The large peak at the Fermi level indicates that the fracture surface is metallic, via a fracture induced reconstruction. |
Sulphur 2p XPS spectrum of Pyrite (FeS2) with Cu adsorbed on the surface. This shows the power of synchrotron XPS, where the photon energy can be selected to enhance contributions from the surface or bulk. |