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Title: Stacked Fresnel Zone Plates for High Energy X-rays

Abstract

A stacking technique was developed in order to increase focusing efficiency of Fresnel zone plates (FZP) at high energies. Two identical Si chips each of which containing 9 FZPs were used for stacking. Alignment of the chips was achieved by on-line observation of the moire pattern. The formation of moire patterns was studied theoretically and experimentally at different experimental conditions. To provide the desired stability Si-chips were bonded together with slow solidification speed epoxy glue. A technique of angular alignment in order to compensate a linear displacement in the process of gluing was proposed. Two sets of stacked FZPs were experimentally tested to focus 15 and 50 keV x rays. The gain in the efficiency by factor 2.5 was demonstrated at 15 keV. The focal spot of 1.8 {mu}m vertically and 14 {mu}m horizontally with 35% efficiency was measured at 50 keV. Forecast for the stacking of nanofocusing FZPs was discussed.

Authors:
; ; ;  [1];  [2]; ;  [3]
  1. ESRF, B.P. 220, 6 rue Jules Horowitz, 38043 Grenoble (France)
  2. Russian Research Centre Kurchatov Institute, 123182 Moscow (Russian Federation)
  3. Institute of Microelectronics Technology RAS, 142432 Chernogolovka, Moscow region (Russian Federation)
Publication Date:
OSTI Identifier:
21052690
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: 10.1063/1.2436230; (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 OPTICS; BEAM PRODUCTION; EFFICIENCY; FOCUSING; GAIN; KEV RANGE; PHOTON BEAMS; SILICON; STABILITY; X RADIATION

Citation Formats

Snigireva, Irina, Snigirev, Anatoly, Vaughan, Gavin, Di Michiel, Marco, Kohn, Viktor, Yunkin, Vyacheslav, and Grigoriev, Maxim. Stacked Fresnel Zone Plates for High Energy X-rays. United States: N. p., 2007. Web. doi:10.1063/1.2436230.
Snigireva, Irina, Snigirev, Anatoly, Vaughan, Gavin, Di Michiel, Marco, Kohn, Viktor, Yunkin, Vyacheslav, & Grigoriev, Maxim. Stacked Fresnel Zone Plates for High Energy X-rays. United States. doi:10.1063/1.2436230.
Snigireva, Irina, Snigirev, Anatoly, Vaughan, Gavin, Di Michiel, Marco, Kohn, Viktor, Yunkin, Vyacheslav, and Grigoriev, Maxim. Fri . "Stacked Fresnel Zone Plates for High Energy X-rays". United States. doi:10.1063/1.2436230.
@article{osti_21052690,
title = {Stacked Fresnel Zone Plates for High Energy X-rays},
author = {Snigireva, Irina and Snigirev, Anatoly and Vaughan, Gavin and Di Michiel, Marco and Kohn, Viktor and Yunkin, Vyacheslav and Grigoriev, Maxim},
abstractNote = {A stacking technique was developed in order to increase focusing efficiency of Fresnel zone plates (FZP) at high energies. Two identical Si chips each of which containing 9 FZPs were used for stacking. Alignment of the chips was achieved by on-line observation of the moire pattern. The formation of moire patterns was studied theoretically and experimentally at different experimental conditions. To provide the desired stability Si-chips were bonded together with slow solidification speed epoxy glue. A technique of angular alignment in order to compensate a linear displacement in the process of gluing was proposed. Two sets of stacked FZPs were experimentally tested to focus 15 and 50 keV x rays. The gain in the efficiency by factor 2.5 was demonstrated at 15 keV. The focal spot of 1.8 {mu}m vertically and 14 {mu}m horizontally with 35% efficiency was measured at 50 keV. Forecast for the stacking of nanofocusing FZPs was discussed.},
doi = {10.1063/1.2436230},
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}
}
  • Fresnel zone plates are widely used as x-ray nanofocusing optics. To achieve high spatial resolution combined with good focusing efficiency, high aspect ratio nanolithography is required, and one way to achieve that is through multiple e-beam lithography writing steps to achieve on-chip stacking. A two-step writing process producing 50 nm finest zone width at a zone thickness of 1.14 ┬Ám for possible hard x-ray applications is shown here. The authors also consider in simulations the case of soft x-ray focusing where the zone thickness might exceed the depth of focus. In this case, the authors compare on-chip stacking with, andmore » without, adjustment of zone positions and show that the offset zones lead to improved focusing efficiency. The simulations were carried out using a multislice propagation method employing Hankel transforms.« less
  • Fresnel zone plates with minimum zone widths down to 50 nm were fabricated by electron-beam lithography, tested, and used in the scanning x-ray microscope at the Brookhaven National Synchrotron Light Source. The zone plates consist of gold rings on a silicon nitride window. Characterization of the zone plates included efficiency and resolution measurements in the first order focus. Spatial resolution down to 75 nm was measured. The best zone plates showed negligible astigmatism, and a first order efficiency in excess of 5% has been achieved. A new method for development monitoring during the fabrication procedure using an optical microscope withmore » polarized light and crossed analyzer was introduced. For the inspection of the fabrication accuracy and, in particular, for ellipticity, a moire pattern technique was employed. Using these zone plates as objective lenses, x-ray images of biological specimens were obtained with 70 nm resolution.« less
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