Abstract
Capillary concentrators condense x-rays by multiple reflections down a gradually tapering capillary. They can provide sub-micron beam spots, and are promising candidates for use in the next generation x-ray microprobe beamlines. The weak energy dependence of their properties make them especially useful for energy scanning applications such as micro-XAFS. This paper examines the potential performance of capillary optics for an x-ray microprobe, as well as some practical issues such as fabrication and alignment. Best performance at third generation sources requires long capillaries, and we have been using fiber optics techniques to fabricate capillaries up to one meter in length. The performance of shorter (less than about 0.5 m) capillaries has often been found to agree well with theoretical calculations, indicating the inner surface is a high quality x-ray reflector. These capillaries have been tested at the NSLS for imaging and micro-XAFS down to 2.6 μm resolution with excellent results. On an unfocused bend magnet line flux density approaching 106 ph/sec/μm2 has been achieved. While nearly optimum profiles have been achieved for longer capillaries, the results have been disappointing, and alignment problems are suspected. The dramatic improvement in performance possible at third generation synchrotrons such as the APS is discussed along with improvements possible by using the capillaries in conjunction with coupling optics.
| Original language | English |
|---|---|
| Pages (from-to) | 36-47 |
| Number of pages | 12 |
| Journal | Proceedings of SPIE - The International Society for Optical Engineering |
| Volume | 2856 |
| DOIs | |
| State | Published - 22 Nov 1996 |
| Externally published | Yes |
| Event | Optics for High-Brightness Synchrotron Radiation Beamlines II 1996 - Denver, United States Duration: 4 Aug 1996 → 9 Aug 1996 |
Bibliographical note
Funding Information:We gratefully acknowledge M. Bliss and R. A. Craig at PNNL for use ofthe glass fabrication facility, and helpful discussions and suggestions, Dr. C. Saw for the use of the CCD detector, and Dr. Y. Nishihata for help in taking the data. We are also grateful to J. Fulton at PNNL for the use ofthe LabVIEW® system, and valuable suggestions during the development of the imaging system. The PNC-CAT is supported by funding from the University of Washington, the U.S. Department of Energy Basic Energy Sciences, and the NSERC in Canada. The Pacific Northwest National Laboratory is a multiprogram National Laboratory, operated by Battelle Memorial Institute for the U.S. Department ofEnergy. Beamline Xll at the National Synchrotron Light Source is supported by the U.S. Department ofEnergy under contract # DE-FGO5-89ER45384.
Funding Information:
We gratefully acknowledge M. Bliss and R. A. Craig at PNNL for use of the glass fabrication facility, and helpful discussions and suggestions, Dr. C. Saw for the use of the CCD detector, and Dr. Y. Nishihata for help in taking the data. We are also grateful to J. Fulton at PNNL for the use of the Lab VIEW? system, and valuable suggestions during the development of the imaging system. The PNC-CAT is supported by funding from the University of Washington, the U.S. Department of Energy Basic Energy Sciences, and the NSERC in Canada. The Pacific Northwest National Laboratory is a multiprogram National Laboratory, operated by Battelle Memorial Institute for the U.S. Department of Energy. Beamline XI1 at the National Synchrotron Light Source is supported by the U.S. Department of Energy under contract # DE-FG05-89ER45384.
Publisher Copyright:
© 1996 SPIE. All rights reserved.
Keywords
- Micro-XAFS
- Synchrotron radiation
- Tapered capillary
- X-ray imaging
- X-ray microprobe
- X-ray optics