Cam-driven monochromator for QEXAFS

Ito, So; Lenhard, A.; Siddons, D. P.

doi:10.1016/j.radphyschem.2005.07.047

Cited by 13 publications

(8 citation statements)

References 6 publications

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“…A channel-cut crystal is directly mounted on the axis of the drive, and first successful studies have just recently been reported [21]. At the NSLS, Caliebe and coworkers have installed another cam-driven monochromator that enables scans on timescales of 100 ms [22].…”

Section: Discussionmentioning

confidence: 99%

Advancing Time-resolved Methods in Monitoring and Characterization of Catalysts

Frahm

Stötzel

Lützenkirchen‐Hecht

2009

Synchrotron Radiation News

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Section: Discussionmentioning

confidence: 99%

Advancing Time-resolved Methods in Monitoring and Characterization of Catalysts

Frahm

Stötzel

Lützenkirchen‐Hecht

2009

Synchrotron Radiation News

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“…The artificial channel-cut monochromator delivers an exceptionally uniform beam that directly contributes to enhanced measurement stability and to improved X-ray beam brilliance preservation, both of which proportionally increase the signalto-noise ratio for XPCS measurements and, consequently, the range of sample dynamics that can be probed. Aside from its proven utility for XPCS measurements, the monochromator should also be very well suited for 'quick' XANES/EXAFS (Caliebe et al, 2006) and microdiffraction (Ice et al, 2000) type experiments provided that a downstream beam-defining vertical aperture selects a small portion of the beam relative to both the beam size and its vertical displacement with energy. Further, the sine-bar driven by the nanomotion stage can be operated at very high dynamic speeds with a very high repeatability and this has been tested to 0.5 keV s À1 with reproducibility within the energy resolution.…”

Section: Discussionmentioning

confidence: 99%

Design and performance of an ultra-high-vacuum-compatible artificial channel-cut monochromator

Narayanan

Sandy

Shu

et al. 2007

J Synchrotron Radiat

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The design and performance of a novel ultra-high-vacuum-compatible artificial channel-cut monochromator that has been commissioned at undulator beamline 8-ID-I at the Advanced Photon Source are presented. Details of the mechanical and optical design, control system implementation and performance of the new device are given. The monochromator was designed to meet the challenging stability and optical requirements of the X-ray photon correlation spectroscopy program hosted at this beamline. In particular, the device incorporates a novel in-vacuum sine-bar drive mechanism for the combined pitch motion of the two crystals and a flexure-based high-stiffness weak-link mechanism for fine-tuning the pitch and roll of the second crystal relative to the first crystal. The monochromator delivers an exceptionally uniform and stable beam and thereby improved brilliance preservation.

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“…Initial development of QEXAFS was with a relatively slow IK320 optical encoder as part of the VME crate and a 12 bit analog-to-digital ͑A/D͒ converter for data recording, 11 which recorded only 1000 data points/s. In this improved version, an IK220 optical encoder and a 16 bit National Instrument A/D converter, model NI 6036E, are used to record 2000 data points/s, and are capable of collecting up to 5000 data points/s.…”

Section: Methodsmentioning

confidence: 99%

“…QEXAFS was developed and applied in solving structure of materials over the past couple of decades by many groups. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] The latest piezodriven technology, developed by Frahm,8,19 is capable of oscillating the monochromator at high frequencies to collect x-ray absorption near edge structure ͑XANES͒ data in 5 ms.…”

Section: Introductionmentioning

confidence: 99%

Quick extended x-ray absorption fine structure instrument with millisecond time scale, optimized for in situ applications

Khalid

Siddons

Ito

et al. 2010

Review of Scientific Instruments

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In order to learn about in situ structural changes in materials at subseconds time scale, we have further refined the techniques of quick extended x-ray absorption fine structure (QEXAFS) and quick x-ray absorption near edge structure (XANES) spectroscopies at beamline X18B at the National Synchrotron Light Source. The channel cut Si (111) monochromator oscillation is driven through a tangential arm at 5 Hz, using a cam, dc motor, pulley, and belt system. The rubber belt between the motor and the cam damps the mechanical noise. EXAFS scan taken in 100 ms is comparable to standard data. The angle and the angular range of the monochromator can be changed to collect a full EXAFS or XANES spectrum in the energy range 4.7-40.0 KeV. The data are recorded in ascending and descending order of energy, on the fly, without any loss of beam time. The QEXAFS mechanical system is outside the vacuum system, and therefore changing the mode of operation from conventional to QEXAFS takes only a few minutes. This instrument allows the acquisition of time resolved data in a variety of systems relevant to electrochemical, photochemical, catalytic, materials, and environmental sciences.

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Cam-driven monochromator for QEXAFS

Cited by 13 publications

References 6 publications

Advancing Time-resolved Methods in Monitoring and Characterization of Catalysts

Advancing Time-resolved Methods in Monitoring and Characterization of Catalysts

Design and performance of an ultra-high-vacuum-compatible artificial channel-cut monochromator

Quick extended x-ray absorption fine structure instrument with millisecond time scale, optimized for in situ applications

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