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Title: Fabrication of Compound Refractive X-ray Lenses Using LIGA Process and Performance Tests

Abstract

Recent advances of X-ray microscopy technology enable the visualization of some micro/nano-scale objects which optical microscopy and electron microscopy cannot be used to observe. The X-ray microscopy can be applied to observe the internal structure of a thicker sample than the electron microscopy can, and its spatial resolution is higher than that of the optical microscopy. Moreover, it has a powerful element specific imaging ability. For further improving the X-ray microscope, it is indispensable to make X-ray optics for focusing X-rays more effectively. Recently, various X-ray lenses such as diffraction lenses of FZP(Fresnel zone plate) and spatter-sliced FZT, total reflection lenses of K-B(Kirkpatrick-Baez) mirror and Wolter mirror, and refractive lens of CRL(compound refractive lens) were introduced. Compared with the other types of lenses, CRL is easy to fabricate and handle. In this study, we designed and fabricated various types of CRLs using LIGA(LIthographie, Galvanoformung, Abformtechnik) process, and used PMMA(Poly(methyl methacrylate)) material as the material of CRL. Their performances are tested with varying parameters such as parabolic/kinoform shape, radius of curvature, wall thickness between adjacent lenses, and width of lenses. The performance tests were carried out by using a simple synchrotron X-ray imaging method. The tests results revealed that hard x-raysmore » could be condensed well by the CRL of PMMA material at the focal point we expect We captured sample images one-dimensionally magnified by CRLs. Furthermore, we found which parameter is more effective for enhancing focus efficiency and which parameter should be considered more carefully in the fabrication process of LIGA.« less

Authors:
 [1];  [2]; ;  [3];  [2];  [4]
  1. School of Environmental Science and Engineering, POSTECH, Pohang, 790-784 (Korea, Republic of)
  2. Dept. of Mechanical Engineering, POSTECH, Pohang, 790-784 (Korea, Republic of)
  3. Pohang Accelerator Laboratory, POSTECH, Pohang, 790-784 (Korea, Republic of)
  4. (Korea, Republic of)
Publication Date:
OSTI Identifier:
21052686
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 879; Journal Issue: 1; Conference: 9. international conference on synchrotron radiation instrumentation, Daegu (Korea, Republic of), 28 May - 2 Jun 2006; Other Information: DOI: 10.1063/1.2436226; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; BEAM PRODUCTION; ELECTRON MICROSCOPY; FABRICATION; FOCUSING; HARD X RADIATION; IMAGES; LENSES; METHACRYLIC ACID ESTERS; MIRRORS; OPTICAL MICROSCOPY; PERFORMANCE; PHOTON BEAMS; PMMA; REFLECTION; SPATIAL RESOLUTION; SYNCHROTRON RADIATION

Citation Formats

Lee, Jin Pyoung, Kim, Guk Bae, Kim, Jong Hyun, Chang, Suk Sang, Lee, Sang Joon, and School of Environmental Science and Engineering, POSTECH, Pohang, 790-784. Fabrication of Compound Refractive X-ray Lenses Using LIGA Process and Performance Tests. United States: N. p., 2007. Web. doi:10.1063/1.2436226.
Lee, Jin Pyoung, Kim, Guk Bae, Kim, Jong Hyun, Chang, Suk Sang, Lee, Sang Joon, & School of Environmental Science and Engineering, POSTECH, Pohang, 790-784. Fabrication of Compound Refractive X-ray Lenses Using LIGA Process and Performance Tests. United States. doi:10.1063/1.2436226.
Lee, Jin Pyoung, Kim, Guk Bae, Kim, Jong Hyun, Chang, Suk Sang, Lee, Sang Joon, and School of Environmental Science and Engineering, POSTECH, Pohang, 790-784. Fri . "Fabrication of Compound Refractive X-ray Lenses Using LIGA Process and Performance Tests". United States. doi:10.1063/1.2436226.
@article{osti_21052686,
title = {Fabrication of Compound Refractive X-ray Lenses Using LIGA Process and Performance Tests},
author = {Lee, Jin Pyoung and Kim, Guk Bae and Kim, Jong Hyun and Chang, Suk Sang and Lee, Sang Joon and School of Environmental Science and Engineering, POSTECH, Pohang, 790-784},
abstractNote = {Recent advances of X-ray microscopy technology enable the visualization of some micro/nano-scale objects which optical microscopy and electron microscopy cannot be used to observe. The X-ray microscopy can be applied to observe the internal structure of a thicker sample than the electron microscopy can, and its spatial resolution is higher than that of the optical microscopy. Moreover, it has a powerful element specific imaging ability. For further improving the X-ray microscope, it is indispensable to make X-ray optics for focusing X-rays more effectively. Recently, various X-ray lenses such as diffraction lenses of FZP(Fresnel zone plate) and spatter-sliced FZT, total reflection lenses of K-B(Kirkpatrick-Baez) mirror and Wolter mirror, and refractive lens of CRL(compound refractive lens) were introduced. Compared with the other types of lenses, CRL is easy to fabricate and handle. In this study, we designed and fabricated various types of CRLs using LIGA(LIthographie, Galvanoformung, Abformtechnik) process, and used PMMA(Poly(methyl methacrylate)) material as the material of CRL. Their performances are tested with varying parameters such as parabolic/kinoform shape, radius of curvature, wall thickness between adjacent lenses, and width of lenses. The performance tests were carried out by using a simple synchrotron X-ray imaging method. The tests results revealed that hard x-rays could be condensed well by the CRL of PMMA material at the focal point we expect We captured sample images one-dimensionally magnified by CRLs. Furthermore, we found which parameter is more effective for enhancing focus efficiency and which parameter should be considered more carefully in the fabrication process of LIGA.},
doi = {10.1063/1.2436226},
journal = {AIP Conference Proceedings},
number = 1,
volume = 879,
place = {United States},
year = {Fri Jan 19 00:00:00 EST 2007},
month = {Fri Jan 19 00:00:00 EST 2007}
}
  • SU-8 polymer and Nickel were used to manufacture planar high aspect ratio X-ray refractive lenses by the LIGA process (Deep X-ray lithography, electroforming). The exposure of PMMA and highly sensitive SU-8 resist layers were carried out at the ANKA storage ring, Karlsruhe. Lenses of either round, segment or quasi-parabolic (kinoform) profiles have been designed, fabricated and tested at the ESRF and at the ANKA synchrotron sources with X-ray energies ranging from 12 to 55 keV. The SU-8 polymer lenses tested at ESRF showed an uniform focal line spot with FWHM of appr. 0.32 {mu}m and gains in the range ofmore » 320. The characteristics did not alter after an absorbed dose of 2 MJ/cm3. Lenses fabricated from electroplated Ni, 320 {mu}m thick, were tested at a photon energy of 212 keV. In this case the uniform focal line spot was about 5 {mu}m.« less
  • We have measured the intensity profile of x rays focused by compound refractive lenses (CRLs) fabricated using acrylic (Lucite) and polyethylene plastics. A linear array of closely spaced holes acts as multiple cylindrical lenses. The important parameters for this type of focusing are the focal length and absorption, and, for wavelengths shorter than 3 [Angstrom], low atomic number plastics are suitable. We have experimentally demonstrated that we can achieve one-dimensional focusing for photon energies between 9 and 19.5 keV with focal lengths between 20 and 100 cm. For example, using 12 keV x rays we have achieved focal full widthmore » at half maximum linewidths down to 21 [mu]m at a distance of only 20 cm from the CRL. The x-ray source was a synchrotron emitter whose source size in the vertical dimension was 445 [mu]m. [copyright] [ital 1999 American Institute of Physics.]« less
  • No abstract prepared.
  • We have fabricated and tested short focal-length compound refractive lenses (CRLs) composed of microbubbles embedded in epoxy encased in glass capillaries. The interface between the bubbles formed 90 to 350 spherical biconcave microlenses reducing the overall focal length inversely by the number of lenses or bubbles. When compared with CRLs manufactured using other methods, the microbubble lenses have shorter focal lengths with higher transmissions and larger gains for moderate energy x rays (e.g., 7-20 keV). We used beamline 2-3 at the Stanford Synchrotron Radiation Laboratory and beamline 5BM-D-DND at the Advanced Photon Source to measure focal lengths between 100-250 mmmore » with lens apertures varying between 97 and 321 {mu}m. Transmission profiles were measured giving, for example, a peak transmission of 46% for a 240 mm focal length CRL at 20 keV. The focal-spot sizes were also measured yielding, for example, a vertical spot size of 1.2 {mu}m resulting from an approximate 20-fold demagnification of the APS 23 {mu}m source size. The measured gains in intensity over that of unfocused beam were between 9 and 26.« less
  • We suggest a novel X-ray energy filter based on LIGA fabricated compound refractive lenses, and describe the results that we have been carrying out a feasibility study on our proposal. The filter consists of both of lenses array and slits, which are exactly aligned to optical axis by a lens-guide built on the same plan with slit. Its fine resist microstructure is obtained through an exposure/develops process to be characterized, optimized, and stabilized. In addition, the resist structure of slits is filled as Cu by using electroforming with accurate replication after the developing process. We describe a manufacturing process ofmore » the filter and describe some quantitative results to prove that our proposal is feasible.« less