skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: From Soft to Hard X-ray with a Single Grating Monochromator

Abstract

Even if not well defined a border exists between the soft and the hard X-ray region. The optics adopted in one region is not suitable for the other region and vice versa. Nevertheless, recently more and more experimentalists wish to investigate their samples by using an energy range as wide as possible. Without adopting complicated and very expensive mechanical solutions, it is a major challenge, for the optical designer, to find a solution suitable for both spectral ranges. This was our task for the TwinMic beamline at Elettra, the Italian 3rd generation synchrotron radiation source. This beamline will house a twin x-ray microscope, which combines scanning and full-field imaging in a single multipurpose end station and is operated in the 0.2-3 keV photon energy range. This energy range will be covered by a blazed grating, which has a very shallow blaze angle of 0.4 deg. With this grating mechanically ruled in the grating laboratory of Carl Zeiss very high diffraction efficiency can be achieved, expected to be higher then 10% over the whole range. This grating was tested at the KMC 1 beamline in BESSY, which is particularly suitable for this kind of measurements since it has a crystal monochromatormore » that can go down to 1.7 keV and can be equipped with an high precision diffractometer. The obtained results demonstrate that it is possible to work with this grating up to 6 keV with still enough efficiency (5% at 6 keV and 15% at 1.8 keV). The efficiency in the lower part of the energy range was tested at Elettra, again with very good results (more then 20% at 950 eV and 15% at 600eV). A second grating, also produced by Carl Zeiss, with a blaze angle of 1.1 deg. will be mounted in the same monochromator, to cover the lower energy range. Both gratings have 600 grooves/mm, which is a good compromise for achieving the requested energy resolving power (of the order of 4000 in most of the range) and to have as much flux as possible, mandatory for the experiments proposed for this beamline. A multilayer mirror, mounted side by side with the two gratings, will permit a wide band selection of the incoming radiation. The beamline is expected to be operative in spring 2007.« less

Authors:
; ;  [1]; ; ;  [2]; ;  [3]
  1. Sincrotrone Trieste ScpA, S.S. 14-Km 163.5, 34012, Trieste (Italy)
  2. BESSY GmbH, Albert-Einstein-Str. 15, D-12489, Berlin (Germany)
  3. Carl Zeiss Optronics GmbH, 73446 Oberkochen (Germany)
Publication Date:
OSTI Identifier:
21052562
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: 10.1063/1.2436107; (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; ACCURACY; BEAM OPTICS; BESSY STORAGE RING; CRYSTALS; DIFFRACTION GRATINGS; EFFICIENCY; EV RANGE; HARD X RADIATION; KEV RANGE; LAYERS; MIRRORS; MONOCHROMATORS; PHOTON BEAMS; PHOTONS; SYNCHROTRON RADIATION SOURCES; X-RAY DIFFRACTION

Citation Formats

Cocco, D., Bianco, A., Kaulich, B., Schaefers, F., Mertin, M., Reichardt, G., Nelles, B., and Heidemann, K. F. From Soft to Hard X-ray with a Single Grating Monochromator. United States: N. p., 2007. Web. doi:10.1063/1.2436107.
Cocco, D., Bianco, A., Kaulich, B., Schaefers, F., Mertin, M., Reichardt, G., Nelles, B., & Heidemann, K. F. From Soft to Hard X-ray with a Single Grating Monochromator. United States. doi:10.1063/1.2436107.
Cocco, D., Bianco, A., Kaulich, B., Schaefers, F., Mertin, M., Reichardt, G., Nelles, B., and Heidemann, K. F. Fri . "From Soft to Hard X-ray with a Single Grating Monochromator". United States. doi:10.1063/1.2436107.
@article{osti_21052562,
title = {From Soft to Hard X-ray with a Single Grating Monochromator},
author = {Cocco, D. and Bianco, A. and Kaulich, B. and Schaefers, F. and Mertin, M. and Reichardt, G. and Nelles, B. and Heidemann, K. F.},
abstractNote = {Even if not well defined a border exists between the soft and the hard X-ray region. The optics adopted in one region is not suitable for the other region and vice versa. Nevertheless, recently more and more experimentalists wish to investigate their samples by using an energy range as wide as possible. Without adopting complicated and very expensive mechanical solutions, it is a major challenge, for the optical designer, to find a solution suitable for both spectral ranges. This was our task for the TwinMic beamline at Elettra, the Italian 3rd generation synchrotron radiation source. This beamline will house a twin x-ray microscope, which combines scanning and full-field imaging in a single multipurpose end station and is operated in the 0.2-3 keV photon energy range. This energy range will be covered by a blazed grating, which has a very shallow blaze angle of 0.4 deg. With this grating mechanically ruled in the grating laboratory of Carl Zeiss very high diffraction efficiency can be achieved, expected to be higher then 10% over the whole range. This grating was tested at the KMC 1 beamline in BESSY, which is particularly suitable for this kind of measurements since it has a crystal monochromator that can go down to 1.7 keV and can be equipped with an high precision diffractometer. The obtained results demonstrate that it is possible to work with this grating up to 6 keV with still enough efficiency (5% at 6 keV and 15% at 1.8 keV). The efficiency in the lower part of the energy range was tested at Elettra, again with very good results (more then 20% at 950 eV and 15% at 600eV). A second grating, also produced by Carl Zeiss, with a blaze angle of 1.1 deg. will be mounted in the same monochromator, to cover the lower energy range. Both gratings have 600 grooves/mm, which is a good compromise for achieving the requested energy resolving power (of the order of 4000 in most of the range) and to have as much flux as possible, mandatory for the experiments proposed for this beamline. A multilayer mirror, mounted side by side with the two gratings, will permit a wide band selection of the incoming radiation. The beamline is expected to be operative in spring 2007.},
doi = {10.1063/1.2436107},
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}
}
  • No abstract prepared.
  • A resolving power, [ital E]/[Delta][ital E], of [ge]13 000 has been achieved with the modified 6 m/160[degree] toroidal grating monochromator (TGM) installed on Beam Line 8-1 at the Stanford Synchrotron Radiation Laboratory. The resolving power of the TGM was increased by replacing the entrance and exit slits with high-precision slits, masking the horizontal part (short radius) of the grating, and improving the TGM scanning mechanisms. To determine the performance of the monochromator, we measured the dependences of resolution and photon flux on the entrance- and exit-slit widths, the exit-slit position, and the masking of the grating. The monochromator resolution inmore » the energy range of 25--65 eV was derived from photoionization measurements of extremely narrow core-excitation resonances in He and Ne. With 10-[mu]m vertical entrance- and exit-slit widths and 32% mask opening of the grating, the monochromator has a resolution (full-width at half maximum) of 5.0[plus minus]0.7 meV at a photon energy of 64.5 eV and a flux of 2[times]10[sup 7] photons/s/100 mA. The results suggest a simple procedure for converting a TGM with moderate resolution into a high-resolution monochromator with a moderate reduction in photon flux due to masking the grating, beyond the reduction attributable to the slit widths.« less
  • By using two aspherical variable-line-space active gratings and applying the energy compensation principle, we have designed a very efficient active grating monochromator -- active grating spectrometer (AGM-AGS) beamline system for the photon demanding inelastic soft-x-ray scattering experiments. During the energy scan, the defocus and coma aberrations of the AGM can be completely eliminated to make the focal point fixed at the sample position and to maintain high spectral resolution for the entire spectral range. The AGS, which has an optical system identical to that of the AGM, but positioned reversely along the optical path, collects the photons emitted from themore » sample with a nearly identical energy spread as the AGM and focus them onto a position sensitive detector located at the exit slit position. The ray tracing results show that the efficiency of the AGM-AGS is two orders of magnitudes higher than that of conventional design while maintaining a very high spectral resolution.« less
  • A plane-grating monochromator (PGM), the CAMD-PGM, designed for bending magnet radiation is described. In contrast with many other similar PGMs, the CAMD-PGM is equipped with an entrance slit. The wavelength range of 6--1500 A is covered with two gratings (1220 and 360 gr/mm). The expected performance is a resolving power, {lambda}/{Delta}{lambda}, of {similar to}2000 with the photon flux of {similar to} 10{sup 10} photons/s at the photon wavelength of 10.0 A. The beam spot size at the sample position is approximately 1{times}1 mm{sup 2}. The monochromator is being constructed and will be installed in the summer of 1992.
  • The performance of a toroidal grating monochromator can be significantly improved by compensating for the wavelength dependent defocusing aberration by means of a movable exit slit. Model calculations of a movable exit slit design show a resolving power that varies nearly linearly with wavelength over the scan range. The energy resolution follows the slope between two optimized resolution minima of a fixed slit TGM. The overall improvement in resolution due to the movable slit depends critically on the figure error of the toroid surface. The Al({ital L}{sub II,III}) core edges provide a means to calibrate gratings and determine the resolutionmore » at 72.8 eV. A method is described for using the shift in core edge with exit slit position to enable final alignment of the exit slit motion providing stability of energy calibration of 2 meV over the scan range. Comparison of calculations and measured resolution suggests that slope errors remain the limiting factor in performance.« less