Dr. Barry Y. Welsh Profile

Dr. Barry Y. Welsh

at Univ of California Berkeley

SPIE Involvement:

Author

Publications (20)

Proceedings Article | 21 July 2010 Paper

Time resolved astronomy with the SALT

D. A. Buckley, S. Crawford, A. A. Gulbis, J. McPhate, K. Nordsieck, S. Potter, D. O'Donoghue, O. H. Siegmund, P. Schellart, M. Spark, B. Welsh, E. Zietsman

Proceedings Volume 7735, 773559 (2010) https://doi.org/10.1117/12.858039

KEYWORDS: Stars, Telescopes, Astronomy, Charge-coupled devices, Sensors, X-rays, Cameras, Magnetism, Photometry, Photon counting

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Proceedings Article | 15 July 2008 Paper

Project Lyman

Stephan McCandliss, Jeffrey Kruk, William Blair, Mary Elizabeth Kaiser, Paul Feldman, Gerhardt Meurer, William Dixon, David Sahnow, David Neufeld, Roxana Lupu, Brian Fleming, Stephen Smee, B. Andersson, Samuel Moseley, Alexander Kutyrev, Mary Li, George Sonneborn, Oswald Siegmund, John Vallerga, Barry Welsh, Massimo Stiavelli, Rogier Windhorst, Alice Shapley

Proceedings Volume 7011, 701120 (2008) https://doi.org/10.1117/12.789574

KEYWORDS: Galactic astronomy, Camera shutters, Stars, Sensors, Photons, Telescopes, Near ultraviolet, Ionization, Spectroscopy, James Webb Space Telescope

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We explore the design of a space mission called Project Lyman that has the goal of quantifying the ionization history of the universe from the present epoch to a redshift of z ~ 3. Observations from WMAP and SDSS show that before a redshift of z (Symbol not available. See manuscript.) 6 the first collapsed objects, possibly dwarf galaxies, emitted Lyman continuum (LyC) radiation shortward of 912 Å that reionized most of the universe. Theoretical estimates of the LyC escape fraction ( f_esc ) required from these objects to complete reionization is f_esc~10%. How LyC escapes from galactic environments, whether it induces positive or negative feedback on the local and global collapse of structures, and the role played by clumping, molecules, metallicity and dust are major unanswered theoretical questions, requiring observational constraint. Numerous intervening Lyman limit systems frustrate the detection of LyC from high z objects. They thin below z ~ 3 where there are reportedly a few cases of apparently very high fesc. At low z there are only controversial detections and a handful of upper limits. A wide-field multi-object spectroscopic survey with moderate spectral and spatial resolution can quantify f_esc within diverse spatially resolved galactic environments over redshifts with significant evolution in galaxy assemblage and quasar activity. It can also calibrate LyC escape against Lyα escape, providing an essential tool to JWST for probing the beginnings of reionization. We present calculations showing the evolution of the characteristic apparent magnitude of star-forming galaxy luminosity functions at 900 Å, as a function of redshift and assumed escape fraction. These calculations allow us to determine the required aperture for detecting LyC and conduct trade studies to guide technology choices and balance science return against mission cost. Finally we review our efforts to build a pathfinding dual order multi-object spectro/telescope with a (0.5°)² field-of-view, using a GSFC microshutter array, and crossed delay-line micro-channel plate detector.

Proceedings Article | 30 May 2006 Paper

High-performance microchannel plate imaging photon counters for spaceborne sensing

Oswald Siegmund, Barry Welsh, John Vallerga, Anton Tremsin, Jason McPhate

Proceedings Volume 6220, 622004 (2006) https://doi.org/10.1117/12.666258

KEYWORDS: Sensors, Microchannel plates, Electronics, Ultraviolet radiation, Satellites, Stars, Satellite imaging, Telescopes, Photon counting, Synchrotrons

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Proceedings Article | 30 August 2005 Paper

The effect of out-gassing from commonly used spacecraft/space instrument materials on the UV-visible-IR reflectivity of optical surfaces

Barry Welsh, Sharon Jelinsky

Proceedings Volume 5897, 58970B (2005) https://doi.org/10.1117/12.614178

KEYWORDS: Reflectivity, Ultraviolet radiation, Mirrors, Absorption, Contamination, Thin films, UV optics, Visible radiation, Aerospace engineering, Space operations

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Proceedings Article | 11 October 2004 Paper

The GALEX mission and detectors

Oswald Siegmund, Barry Welsh, Christopher Martin, Thomas Barlow, Luciana Bianchi, Yong-Ik Byun, Karl Forster, Peter Friedman, Patrick Jelinsky, Barry Madore, Roger Malina, Bruno Milliard, Patrick Morrissey, Susan Neff, Michael Rich, David Schiminovich, Todd Small, Alexander Szalay, Ted Wyder

Proceedings Volume 5488, (2004) https://doi.org/10.1117/12.561488

KEYWORDS: Sensors, Ultraviolet radiation, Stars, Galactic astronomy, Microchannel plates, Imaging spectroscopy, Quantum efficiency, Electronics, Spectroscopy, Telescopes

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Proceedings Article | 8 December 2003 Paper

Proposed mission concept for the Astrophysical Plasmadynamic Explorer (APEX): an EUV high-resolution spectroscopic SMEX

Michael Kowalski, Raymond Cruddace, Kent Wood, Daryl Yentis, Michael Wolff, J. Laming, Herbert Gursky, George Carruthers, Troy Barbee, Joseph Kordas, Chris Mauche, Gilbert Fritz, Steve Varlese, Martin Barstow, George Fraser, Oswald Siegmund, Barry Welsh, Nancy Brickhouse, Andrea Dupree, Alex Brown, Frederick Bruhweiler, Andrew Cameron, Jay Holberg, Steven Howell, Carole Jordan, Jeffrey Linsky, Sarah Matthews, Edward Sion, Klaus Werner

Proceedings Volume 5164, (2003) https://doi.org/10.1117/12.508548

KEYWORDS: Stars, Sensors, Extreme ultraviolet, Spectrometers, Plasmas, Microchannel plates, Iron, Space operations, Magnetism, Ionization

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Proceedings Article | 7 March 2003 Paper

The future of imaging photon counting detectors for ground-based astronomy

John Vallerga, Barry Welsh, Oswald Siegmund

Proceedings Volume 4841, (2003) https://doi.org/10.1117/12.461098

KEYWORDS: Sensors, Microchannel plates, Photon counting, Charge-coupled devices, Quantum efficiency, Image sensors, CCD image sensors, Astronomy, Silicon, Electrons

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Proceedings Article | 24 February 2003 Paper

The Galaxy Evolution Explorer

Christopher Martin, Thomas Barlow, William Barnhart, Luciana Bianchi, Brian Blakkolb, Dominique Bruno, Joseph Bushman, Yong-Ik Byun, Michael Chiville, Timothy Conrow, Brian Cooke, Jose Donas, James Fanson, Karl Forster, Peter Friedman, Robert Grange, David Griffiths, Timothy Heckman, James Lee, Patrick Jelinsky, Sug-Whan Kim, Siu-Chun Lee, Young-Wook Lee, Dankai Liu, Barry Madore, Roger Malina, Alan Mazer, Ryan McLean, Bruno Milliard, William Mitchell, Marco Morais, Patrick Morrissey, Susan Neff, Frederic Raison, David Randall, Michael Rich, David Schiminovich, Wes Schmitigal, Amit Sen, Oswald Siegmund, Todd Small, Joseph Stock, Frank Surber, Alexander Szalay, Arthur Vaughan, Timothy Weigand, Barry Welsh, Patrick Wu, Ted Wyder, C. Kevin Xu, Jennifer Zsoldas

Proceedings Volume 4854, (2003) https://doi.org/10.1117/12.460034

KEYWORDS: Sensors, Galactic astronomy, Space operations, Ultraviolet radiation, Imaging spectroscopy, Space telescopes, Telescopes, Spectroscopy, Satellites, Electronics

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Proceedings Article | 24 February 2003 Paper

The Spectroscopy of Plasma Evolution from Astrophysical Radiation (SPEAR) mission

Jerry Edelstein, Eric Korpela, Wonyong Han, Kyung-wook Min, Uk-won Nam, Barry Welsh

Proceedings Volume 4854, (2003) https://doi.org/10.1117/12.460010

KEYWORDS: Plasma, Plasma spectroscopy, Stars, Spectroscopy, Galactic astronomy, Physics, Clouds, Ultraviolet radiation, Aerospace engineering, Signal to noise ratio

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Proceedings Article | 24 February 2003 Paper

The SPEAR science payload

Eric Korpela, Jerry Edelstein, Peter Berg, Mark Bowen, Raymond Chung, Michael Feuerstein, Wonyong Han, Jeffrey Hull, Ho Jin, Dae-hee Lee, Kyung-wook Min, Uk-won Nam, Kaori Nishikida, Jin-geun Rhee, Kwangsun Ryu, Kwangil Seon, Barry Welsh, Insoo Yuk

Proceedings Volume 4854, (2003) https://doi.org/10.1117/12.459970

KEYWORDS: Sensors, Digital signal processing, Control systems, Camera shutters, Electronics, Sun, Spectral resolution, Microchannel plates, Mirrors, Spectrographs

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Proceedings Article | 12 October 1996 Paper

Lyman Imaging Telescope Experiment

Barry Welsh, Oswald Siegmund, Patrick Jelinsky

Proceedings Volume 2807, (1996) https://doi.org/10.1117/12.255100

KEYWORDS: Sensors, Telescopes, Microchannel plates, Bandpass filters, Space operations, Space telescopes, Spatial resolution, Mirrors, Electronics, Optical filters

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Proceedings Article | 1 September 1995 Paper

Microchannel plates for the UVCS and SUMER instruments on the SOHO satellite

Oswald Siegmund, Mark Gummin, Timothy Sasseen, Patrick Jelinsky, Geoffrey Gaines, Jeffrey Hull, Joseph Stock, Michael Edgar, Barry Welsh, Sharon Jelinsky, John Vallerga

Proceedings Volume 2518, (1995) https://doi.org/10.1117/12.218388

KEYWORDS: Microchannel plates, Sensors, Modulation, Quantum efficiency, Lamps, Information operations, Ultraviolet radiation, Calibration, Spectrographs, Solar processes

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Proceedings Article | 2 June 1995 Paper

SEQUOIA mission

Barry Welsh, Timothy Carone, Oswald Siegmund, Patrick Jelinsky, Ronald Polidan

Proceedings Volume 2478, (1995) https://doi.org/10.1117/12.210922

KEYWORDS: Sensors, Space operations, Sun, Spatial resolution, Mirrors, Receivers, Astronomy, Microchannel plates, Telescopes, Indium

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Proceedings Article | 2 June 1995 Paper

BDSR: instrument design and initial calibration results

Erik Wilkinson, James Green, Barry Welsh, Ryan McLean

Proceedings Volume 2478, (1995) https://doi.org/10.1117/12.210920

KEYWORDS: Telescopes, Spectrographs, Extreme ultraviolet, Calibration, Sensors, Stars, Absorption, Rockets, Mirrors, Radon

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Proceedings Article | 16 September 1994 Paper

Delay-line detectors for the UVCS and SUMER instruments on the SOHO Satellite

Oswald Siegmund, Joseph Stock, Daniel Marsh, Mark Gummin, Richard Raffanti, Jeffrey Hull, Geoffrey Gaines, Barry Welsh, B. Donakowski, Patrick Jelinsky, Timothy Sasseen, James Tom, B. Higgins, Tony Magoncelli, Jon Hamilton, Steven Battel, Arthur Poland, Murzy Jhabvala, K. Sizemore, James Shannon

Proceedings Volume 2280, (1994) https://doi.org/10.1117/12.186839

KEYWORDS: Sensors, Microchannel plates, Electronics, Modulation, Amplifiers, Power supplies, Computer programming, Control systems, Resistance, Solar processes

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Proceedings Article | 8 October 1992 Paper

NASA's Ultraviolet Astrophysics Branch: the next decade

Barry Welsh, Michael Kaplan

Proceedings Volume 1743, (1992) https://doi.org/10.1117/12.130704

KEYWORDS: Ultraviolet radiation, Astrophysics, Space telescopes, X-ray astronomy, Extreme ultraviolet, Sensors, X-rays, Interferometry, Visible radiation, X-ray optics

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Proceedings Article | 1 January 1992 Paper

Prospect of space-based interferometry at EUV and soft x-ray wavelengths

Barry Welsh, Supriya Chakrabarti

Proceedings Volume 1546, (1992) https://doi.org/10.1117/12.51227

KEYWORDS: Extreme ultraviolet, X-rays, Spectral resolution, Spectroscopy, Interferometers, Sensors, Mirrors, Crystals, Reflectivity, Diffraction gratings

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Proceedings Article | 1 February 1991 Paper

Results from the calibration of the Extreme Ultraviolet Explorer instruments

Barry Welsh, Patrick Jelinsky, Peter Vedder, John Vallerga, David Finley, Roger Malina

Proceedings Volume 1343, (1991) https://doi.org/10.1117/12.23190

KEYWORDS: Extreme ultraviolet, Scanners, Telescopes, Calibration, Sensors, Spectroscopy, Mirrors, Optical filters, Stars, Extreme ultraviolet lithography

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Proceedings Article | 1 November 1990 Paper

Contamination control program results from three years of ground operations on the Extreme Ultraviolet Explorer instruments

David Ray, Sharon Jelinsky, Barry Welsh, Roger Malina

Proceedings Volume 1329, (1990) https://doi.org/10.1117/12.22589

KEYWORDS: Contamination, Mirrors, Calibration, Extreme ultraviolet, Contamination control, Optical fabrication, Telescopes, Space telescopes, Aerospace engineering, Assembly equipment

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