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Title: Precise rotational alignment of x-ray transmission diffraction gratings

Abstract

Gold transmission diffraction gratings used for x-ray spectroscopy must sometimes be rotationally aligned to the axis of a diagnostic instrument to within sub-milliradian accuracy. We have fabricated transmission diffraction gratings with high line-densities (grating period of 200 and 300 nm) using uv holographic and x-ray lithography. Since the submicron features of the gratings are not optically visible, precision alignment is time consuming and difficult to verify in situ. We have developed a technique to write an optically visible alignment pattern onto these gratings using a scanning electron microscope (SEM). At high magnification (15000 X) several submicron lines of the grating are observable in the SEM, making it possible to write an alignment pattern parallel to the grating lines in an electron-beam-sensitive coating that overlays the grating. We create an alignment pattern by following a 1-cm-long grating line using the SEM's joystick-controlled translation stage. By following the same grating line we are assured the traveled direction of the SEM electron beam is parallel to the grating to better than 10 ..mu..radian. The electron-beam-exposed line-width can be large (5 to 15 ..mu..m wide) depending on the SEM magnification, and is therefore optically visible. The exposed pattern is eventually made a permanent featuremore » of the grating by ion beam etching or gold electroplating. The pattern can be used to accurately align the grating to the axis of a diagnostic instrument. More importantly, the alignment of the grating can be quickly verified in situ.« less

Authors:
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
OSTI Identifier:
6995086
Report Number(s):
UCID-21386
ON: DE88010599
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; GRATINGS; FABRICATION; GOLD; X-RAY DIFFRACTION; X-RAY SPECTROSCOPY; COHERENT SCATTERING; DIFFRACTION; ELEMENTS; METALS; SCATTERING; SPECTROSCOPY; TRANSITION ELEMENTS; 640300* - Atomic, Molecular & Chemical Physics

Citation Formats

Hill, S L. Precise rotational alignment of x-ray transmission diffraction gratings. United States: N. p., 1988. Web. doi:10.2172/6995086.
Hill, S L. Precise rotational alignment of x-ray transmission diffraction gratings. United States. https://doi.org/10.2172/6995086
Hill, S L. 1988. "Precise rotational alignment of x-ray transmission diffraction gratings". United States. https://doi.org/10.2172/6995086. https://www.osti.gov/servlets/purl/6995086.
@article{osti_6995086,
title = {Precise rotational alignment of x-ray transmission diffraction gratings},
author = {Hill, S L},
abstractNote = {Gold transmission diffraction gratings used for x-ray spectroscopy must sometimes be rotationally aligned to the axis of a diagnostic instrument to within sub-milliradian accuracy. We have fabricated transmission diffraction gratings with high line-densities (grating period of 200 and 300 nm) using uv holographic and x-ray lithography. Since the submicron features of the gratings are not optically visible, precision alignment is time consuming and difficult to verify in situ. We have developed a technique to write an optically visible alignment pattern onto these gratings using a scanning electron microscope (SEM). At high magnification (15000 X) several submicron lines of the grating are observable in the SEM, making it possible to write an alignment pattern parallel to the grating lines in an electron-beam-sensitive coating that overlays the grating. We create an alignment pattern by following a 1-cm-long grating line using the SEM's joystick-controlled translation stage. By following the same grating line we are assured the traveled direction of the SEM electron beam is parallel to the grating to better than 10 ..mu..radian. The electron-beam-exposed line-width can be large (5 to 15 ..mu..m wide) depending on the SEM magnification, and is therefore optically visible. The exposed pattern is eventually made a permanent feature of the grating by ion beam etching or gold electroplating. The pattern can be used to accurately align the grating to the axis of a diagnostic instrument. More importantly, the alignment of the grating can be quickly verified in situ.},
doi = {10.2172/6995086},
url = {https://www.osti.gov/biblio/6995086}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Mar 28 00:00:00 EST 1988},
month = {Mon Mar 28 00:00:00 EST 1988}
}