Stable silicon photodiodes for absolute intensity measurements in the VUV and soft X-ray regions

Gullikson, Eric M.; Korde, R.; Canfield, L. R.; Vest, Robert E.

doi:10.1016/0368-2048(96)02983-0

Cited by 121 publications

(49 citation statements)

References 9 publications

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“…The photon flux is measured by a movable silicon p-n junction photodiode (Model AXUV-100G, IRD Inc.) placed just above the substrate. This commercial photodiode was developed for absolute photon-intensity measurements (Gullikson et al 1996;Korde et al 1993). It has been widely used in the various fields of science because of its 100% collection efficiency of photogenerated carriers (e.g., Boivin et al 1999;Stutman et al 1999), while the uncertainty in quantum efficiency is less than 10%.…”

Section: Methodsmentioning

confidence: 99%

Laboratory Simulation of Competition between Hydrogenation and Photolysis in the Chemical Evolution of H₂O‐CO Ice Mixtures

Watanabe

Mouri

Nagaoka

et al. 2007

ApJ

115

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Hydrogenation and photolysis of H 2 O-CO binary ice mixtures at 10-50 K have been revisited in order to quantitatively evaluate their relative importance in the chemical evolution of interstellar dust icy mantles. The dominant product of photolysis was CO 2 , with lower yields of formaldehyde, methanol, and formic acid, while only formaldehyde and methanol were obtained by hydrogenation reactions. Hydrogenation has higher formation efficiencies and yields of formaldehyde and methanol than photolysis. However, the contribution of photolysis should not be negligible for the formation of these molecules in molecular clouds. The simultaneous irradiation of binary ice mixtures with hydrogen atoms and UV photons resulted in relative abundances of CO 2 , formaldehyde, methanol, and formic acid that are consistent with the observed abundances. Our results show that the composition and structure of ice are crucial in the chemical evolution of ice mantles, as much as the temperature and the type of irradiation.

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Section: Methodsmentioning

confidence: 99%

Laboratory Simulation of Competition between Hydrogenation and Photolysis in the Chemical Evolution of H₂O‐CO Ice Mixtures

Watanabe

Mouri

Nagaoka

et al. 2007

ApJ

115

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“…In order to obtain the absolute flux in number of photons per second, the measured photocurrent is multiplied by the photodiode quantum efficiency (Gullikson et al, 1996). Figs.…”

Section: Fluxmentioning

confidence: 99%

X-Treme beamline at SLS: X-ray magnetic circular and linear dichroism at high field and low temperature

et al. 2012

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Author(s) of this paper may load this reprint on their own web site or institutional repository provided that this cover page is retained. Republication of this article or its storage in electronic databases other than as specified above is not permitted without prior permission in writing from the IUCr.For further information see http://journals.iucr.org/services/authorrights.html Synchrotron radiation research is rapidly expanding with many new sources of radiation being created globally. Synchrotron radiation plays a leading role in pure science and in emerging technologies. The Journal of Synchrotron Radiation provides comprehensive coverage of the entire field of synchrotron radiation research including instrumentation, theory, computing and scientific applications in areas such as biology, nanoscience and materials science. Rapid publication ensures an up-to-date information resource for scientists and engineers in the field.Crystallography Journals Online is available from journals.iucr.org J. Synchrotron Rad. (2012 X-Treme is a soft X-ray beamline recently built in the Swiss Light Source at the Paul Scherrer Institut in collaboration with É cole Polytechnique Fé dé rale de Lausanne. The beamline is dedicated to polarization-dependent X-ray absorption spectroscopy at high magnetic fields and low temperature. The source is an elliptically polarizing undulator. The end-station has a superconducting 7 T-2 T vector magnet, with sample temperature down to 2 K and is equipped with an in situ sample preparation system for surface science. The beamline commissioning measurements, which show a resolving power of 8000 and a maximum flux at the sample of 4.7 Â 10 12 photons s À1, are presented. Scientific examples showing X-ray magnetic circular and X-ray magnetic linear dichroism measurements are also presented.

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“…Photons penetrate the diodes and create electron-hole pairs in the active region (n-on-p junction). The resulting photocurrent should, in principle, be proportional to the incident radiation power 11,12 . AXUV diodes offer a time resolution of less than 500 ns 13 .…”

Section: A Axuv Diode Diagnosticmentioning

confidence: 99%

Application of AXUV diode detectors at ASDEX Upgrade

Bernert

Eich

Burckhart

et al. 2014

Review of Scientific Instruments

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In the ASDEX Upgrade tokamak a radiation measurement for a wide spectral range, based on semiconductor detectors, with 256 lines of sight (LOS) and a time resolution of 5 µs was recently installed. In combination with the foil based bolometry, it is now possible to estimate the absolutely calibrated radiated power of the plasma on fast timescales. This work introduces this diagnostic based on AXUV (Absolute eXtended UltraViolet) n-on-p diodes made by International Radiation Detectors, Inc. (IRD). The measurement and the degradation of the diodes in a tokamak environment is shown. Even though the AXUV diodes are developed to have a constant sensitivity for all photon energies (1 eV to 8 keV), degradation leads to a photon energy dependence of the sensitivity. The foil bolometry, which is restricted to a time resolution of less than 1 kHz, offers a basis for a time dependent calibration of the diodes. The measurements of the quasi-calibrated diodes are compared with the foil bolometry and found to be accurate on the kHz time scale. Therefore, it is assumed, that the corrected values are also valid for the highest time resolution (200 kHz). With this improved diagnostic setup, the radiation induced by edge localized modes (ELMs) is analyzed on fast timescales.

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Stable silicon photodiodes for absolute intensity measurements in the VUV and soft X-ray regions

Cited by 121 publications

References 9 publications

Laboratory Simulation of Competition between Hydrogenation and Photolysis in the Chemical Evolution of H₂O‐CO Ice Mixtures

Laboratory Simulation of Competition between Hydrogenation and Photolysis in the Chemical Evolution of H₂O‐CO Ice Mixtures

X-Treme beamline at SLS: X-ray magnetic circular and linear dichroism at high field and low temperature

Application of AXUV diode detectors at ASDEX Upgrade

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Stable silicon photodiodes for absolute intensity measurements in the VUV and soft X-ray regions

Cited by 121 publications

References 9 publications

Laboratory Simulation of Competition between Hydrogenation and Photolysis in the Chemical Evolution of H2O‐CO Ice Mixtures

Laboratory Simulation of Competition between Hydrogenation and Photolysis in the Chemical Evolution of H2O‐CO Ice Mixtures

X-Treme beamline at SLS: X-ray magnetic circular and linear dichroism at high field and low temperature

Application of AXUV diode detectors at ASDEX Upgrade

Contact Info

Product

Resources

About

Laboratory Simulation of Competition between Hydrogenation and Photolysis in the Chemical Evolution of H₂O‐CO Ice Mixtures

Laboratory Simulation of Competition between Hydrogenation and Photolysis in the Chemical Evolution of H₂O‐CO Ice Mixtures