The Experts below are selected from a list of 174 Experts worldwide ranked by ideXlab platform
Mark M. Somoza - One of the best experts on this subject based on the ideXlab platform.
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High-Power 365 nm UV LED Mercury Arc Lamp Replacement for Photochemistry and Chemical Photolithography
ACS Sustainable Chemistry and Engineering, 2017Co-Authors: Kathrin Hölz, Jory Lietard, Mark M. SomozaAbstract:Ultraviolet light emitting diodes (UV LEDs) have become widespread in chemical reseArch as highly efficient light sources for photochemistry and photopolymerization. However, in more complex experimental setups requiring highly concentrated light and highly spatially resolved patterning of the light, high-pressure mercury Arc Lamps are still widely used because they emit intense UV light from a compact Arc volume that can be efficienlty coupled into optical systems. Advances in the deposition and p-type doping of galium nitride have recently permitted the manufacture of UV LEDs capable of replacing mercury Arc Lamps also in these applications. These UV LEDs exceed the spectral radiance of mercury Lamps even at the intense I-line at 365 nm. Here we present the successful exchange of a high-pressure mercury Arc lamp for a new generation UV LED as a light source in photolithographic chemistry and its use in the fabrication of high-density DNA microarrays. We show that the improved light radiance and efficiency of these LEDs offers substantial practical, economic and ecological advantages, including faster synthesis, lower hardware costs, very long lifetime, a >85-fold reduction in electricity consumption and the elimination of mercury waste and contamination. KEYWORDS:
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High-Power 365 nm UV LED Mercury Arc Lamp Replacement for Photochemistry and Chemical Photolithography
ACS Sustainable Chemistry & Engineering, 2016Co-Authors: Kathrin Hölz, Jory Lietard, Mark M. SomozaAbstract:Ultraviolet light emitting diodes (UV LEDs) have become widespread in chemical reseArch as highly efficient light sources for photochemistry and photopolymerization. However, in more complex experimental setups requiring highly concentrated light and highly spatially resolved patterning of the light, high-pressure mercury Arc Lamps are still widely used because they emit intense UV light from a compact Arc volume that can be efficiently coupled into optical systems. Advances in the deposition and p-type doping of gallium nitride have recently permitted the manufacture of UV LEDs capable of replacing mercury Arc Lamps also in these applications. These UV LEDs exceed the spectral radiance of mercury Lamps even at the intense I-line at 365 nm. Here we present the successful exchange of a high-pressure mercury Arc lamp for a new generation UV LED as a light source in photolithographic chemistry and its use in the fabrication of high-density DNA microarrays. We show that the improved light radiance and efficie...
Kathrin Hölz - One of the best experts on this subject based on the ideXlab platform.
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High-Power 365 nm UV LED Mercury Arc Lamp Replacement for Photochemistry and Chemical Photolithography
ACS Sustainable Chemistry and Engineering, 2017Co-Authors: Kathrin Hölz, Jory Lietard, Mark M. SomozaAbstract:Ultraviolet light emitting diodes (UV LEDs) have become widespread in chemical reseArch as highly efficient light sources for photochemistry and photopolymerization. However, in more complex experimental setups requiring highly concentrated light and highly spatially resolved patterning of the light, high-pressure mercury Arc Lamps are still widely used because they emit intense UV light from a compact Arc volume that can be efficienlty coupled into optical systems. Advances in the deposition and p-type doping of galium nitride have recently permitted the manufacture of UV LEDs capable of replacing mercury Arc Lamps also in these applications. These UV LEDs exceed the spectral radiance of mercury Lamps even at the intense I-line at 365 nm. Here we present the successful exchange of a high-pressure mercury Arc lamp for a new generation UV LED as a light source in photolithographic chemistry and its use in the fabrication of high-density DNA microarrays. We show that the improved light radiance and efficiency of these LEDs offers substantial practical, economic and ecological advantages, including faster synthesis, lower hardware costs, very long lifetime, a >85-fold reduction in electricity consumption and the elimination of mercury waste and contamination. KEYWORDS:
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High-Power 365 nm UV LED Mercury Arc Lamp Replacement for Photochemistry and Chemical Photolithography
ACS Sustainable Chemistry & Engineering, 2016Co-Authors: Kathrin Hölz, Jory Lietard, Mark M. SomozaAbstract:Ultraviolet light emitting diodes (UV LEDs) have become widespread in chemical reseArch as highly efficient light sources for photochemistry and photopolymerization. However, in more complex experimental setups requiring highly concentrated light and highly spatially resolved patterning of the light, high-pressure mercury Arc Lamps are still widely used because they emit intense UV light from a compact Arc volume that can be efficiently coupled into optical systems. Advances in the deposition and p-type doping of gallium nitride have recently permitted the manufacture of UV LEDs capable of replacing mercury Arc Lamps also in these applications. These UV LEDs exceed the spectral radiance of mercury Lamps even at the intense I-line at 365 nm. Here we present the successful exchange of a high-pressure mercury Arc lamp for a new generation UV LED as a light source in photolithographic chemistry and its use in the fabrication of high-density DNA microarrays. We show that the improved light radiance and efficie...
Jory Lietard - One of the best experts on this subject based on the ideXlab platform.
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High-Power 365 nm UV LED Mercury Arc Lamp Replacement for Photochemistry and Chemical Photolithography
ACS Sustainable Chemistry and Engineering, 2017Co-Authors: Kathrin Hölz, Jory Lietard, Mark M. SomozaAbstract:Ultraviolet light emitting diodes (UV LEDs) have become widespread in chemical reseArch as highly efficient light sources for photochemistry and photopolymerization. However, in more complex experimental setups requiring highly concentrated light and highly spatially resolved patterning of the light, high-pressure mercury Arc Lamps are still widely used because they emit intense UV light from a compact Arc volume that can be efficienlty coupled into optical systems. Advances in the deposition and p-type doping of galium nitride have recently permitted the manufacture of UV LEDs capable of replacing mercury Arc Lamps also in these applications. These UV LEDs exceed the spectral radiance of mercury Lamps even at the intense I-line at 365 nm. Here we present the successful exchange of a high-pressure mercury Arc lamp for a new generation UV LED as a light source in photolithographic chemistry and its use in the fabrication of high-density DNA microarrays. We show that the improved light radiance and efficiency of these LEDs offers substantial practical, economic and ecological advantages, including faster synthesis, lower hardware costs, very long lifetime, a >85-fold reduction in electricity consumption and the elimination of mercury waste and contamination. KEYWORDS:
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High-Power 365 nm UV LED Mercury Arc Lamp Replacement for Photochemistry and Chemical Photolithography
ACS Sustainable Chemistry & Engineering, 2016Co-Authors: Kathrin Hölz, Jory Lietard, Mark M. SomozaAbstract:Ultraviolet light emitting diodes (UV LEDs) have become widespread in chemical reseArch as highly efficient light sources for photochemistry and photopolymerization. However, in more complex experimental setups requiring highly concentrated light and highly spatially resolved patterning of the light, high-pressure mercury Arc Lamps are still widely used because they emit intense UV light from a compact Arc volume that can be efficiently coupled into optical systems. Advances in the deposition and p-type doping of gallium nitride have recently permitted the manufacture of UV LEDs capable of replacing mercury Arc Lamps also in these applications. These UV LEDs exceed the spectral radiance of mercury Lamps even at the intense I-line at 365 nm. Here we present the successful exchange of a high-pressure mercury Arc lamp for a new generation UV LED as a light source in photolithographic chemistry and its use in the fabrication of high-density DNA microarrays. We show that the improved light radiance and efficie...
G. C. Wei - One of the best experts on this subject based on the ideXlab platform.
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Transparent ceramics for lighting
Journal of the European Ceramic Society, 2009Co-Authors: G. C. WeiAbstract:The development of ceramic Arc Lamps for optical applications requires consideration of materials other than sintered polycrystalline alumina (PCA). Regular PCA is translucent, not transparent. Except small-grained, regular PCA cannot be used for high luminance applications such as required by projection systems. Silica Lamps are currently operating close to their limit in highly loaded discharge Lamps. These may be replaced with ceramic Lamps so the Hg pressure may be elevated and/or higher powers achieved. Cubic materials can be polished to transparency for use as optical sources of short Arcs. The current paper surveys the composition, structure, and properties of transparent ceramic lamp tube materials including small-grained PCA, sapphire, aluminum oxynitride, yttrium aluminate garnet, and dysprosium oxide. The challenges beyond the optical transparency are to achieve (1) strong bonding between the transparent ceramic and electrode system to complete the discharge enclosure, (2) satisfactory characteristics including thermo-mechanical properties in order to withstand the rapid heating and cooling cycles encountered in both the discharge tube and seal, (3) durability to resist the attack from lamp chemicals at high temperatures, and (4) stability to maintain the optical quality throughout the life. Performance, energy efficiency, environmental sustainability, and economics are driving the development of ceramic envelopes in lighting products. Transparent ceramics offer opportunities to push the limits of envelope materials for improved Lamps. The paradigm used during the course of transparent ceramics reseArch exemplifies advancement of new and improved materials. © 2008 Elsevier Ltd. All rights reserved.
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Transparent ceramic lamp envelope materials
Journal of Physics D: Applied Physics, 2005Co-Authors: G. C. WeiAbstract:Transparent ceramic materials with optical qualities comparable to single crystals of similar compositions have been developed in recent years, as a result of the improved understanding of powder-processing-fabrication- sintering-property inter-relationships. These high-temperature materials with a range of thermal and mechanical properties are candidate envelopes for focused-beam, short-Arc Lamps containing various fills operating at temperatures higher than quartz. This paper reviews the composition, structure and properties of transparent ceramic lamp envelope materials including sapphire, small-grained polycrystalline alumina, aluminium oxynitride, yttrium aluminate garnet, magnesium aluminate spinel and yttria–lanthana. A satisfactory thermal shock resistance is required for the ceramic tube to withstand the rapid heating and cooling cycles encountered in Lamps. Thermophysical properties, along with the geometry, size and thickness of a transparent ceramic tube, are important parameters in the assessment of its resistance to fracture arising from thermal stresses in Lamps during service. The corrosive nature of lamp-fill liquid and vapour at high temperatures requires that all lamp components be carefully chosen to meet the target life. The wide range of new transparent ceramics represents flexibility in pushing the limit of envelope materials for improved beamer Lamps.
Adrian S Sabau - One of the best experts on this subject based on the ideXlab platform.
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a 6 mw m2 high heat flux testing facility of irradiated materials using infrared plasma Arc Lamps
Fusion Science and Technology, 2019Co-Authors: Adrian S Sabau, James O Kiggans, Charles R Schaich, Y Ueda, Ralph B Dinwiddie, Kazutoshi Tokunaga, Michael G Littleton, Daniel T Moore, Yutai KatohAbstract:AbstractAssessing the effect of neutron irradiation of plasma-facing materials has been challenging due to both the technical and radiological challenges involved. In an effort to address the radio...
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surface morphology of tungsten f82h after high heat flux testing using plasma Arc Lamps
Nuclear materials and energy, 2018Co-Authors: K Ibano, Adrian S Sabau, James O Kiggans, Charles R Schaich, Yutai Katoh, Kazutoshi Tokunaga, M Akiyoshi, Y UedaAbstract:Abstract F82H reduced activation steel coated with vacuum plasma sprayed (VPS) tungsten is a candidate as a plasma facing material for main chamber components in future fusion reactors. Due to different coefficients of thermal expansion (CTE), significant thermal stresses are expected in these bimetallic materials. Thus, a major uncertainty in the performance of W/F82H components during the operation under high-heat fluxes is the effect of CTE mismatch. In this study, a high intensity plasma-Arc lamp was used for high-heat flux cycling tests of W/F82H specimens. While no surface damage was observed for specimens tested for 100–200 cycles at a heat flux of 1.4 MW/m2 pulse when the backside surface temperature was maintained below 550 °C, significant cracking occurred at higher temperatures. A simple analytical model for bimetallic materials indicated that the stress in the VPS-W layer is likely to exceed its failure stress solely due to the bilayer thermal stress. A finite element analysis of the state of stress and deformation confirmed that a significant stress also would occur at the W surface due to the rigid-body like constraint imposed by the clamp, which can be the main cause of the cracking.
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evaluation of cooling conditions for a high heat flux testing facility based on plasma Arc Lamps
Fusion Science and Technology, 2015Co-Authors: Carlos H Charry, Adrian S Sabau, S I Abdelkhalik, Minami Yoda, L L SneadAbstract:The new Irradiated Material Target Station (IMTS) facility for fusion materials at Oak Ridge National Laboratory (ORNL) uses an infrared plasma-Arc lamp (PAL) to deliver incident heat fluxes as high as 27 MW/m2. The facility is being used to test irradiated plasma-facing component materials as part of the joint US-Japan PHENIX program. The irradiated samples are to be mounted on molybdenum sample holders attached to a water-cooled copper rod. Depending on the size and geometry of samples, several sample holders and copper rod configurations have been fabricated and tested. As a part of the effort to design sample holders compatible with the high heat flux (HHF) testing to be conducted at the IMTS facility, numerical simulations have been performed for two different water-cooled sample holder designs using the ANSYS FLUENT 14.0 commercial computational fluid dynamics (CFD) software package. The primary objective of this work is to evaluate the cooling capability of different sample holder designs, i.e. to estimate their maximum allowable incident heat flux values. 2D axisymmetric numerical simulations are performed using the realizable k-e turbulence model and the RPI nucleate boiling model within ANSYS FLUENT 14.0. The results of the numerical model were compared against the experimental data formore » two sample holder designs tested in the IMTS facility. The model has been used to parametrically evaluate the effect of various operational parameters on the predicted temperature distributions. The results were used to identify the limiting parameter for safe operation of the two sample holders and the associated peak heat flux limits. The results of this investigation will help guide the development of new sample holder designs.« less
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high heat flux testing of irradiated tungsten based materials for fusion applications using infrared plasma Arc Lamps
Fusion Science and Technology, 2014Co-Authors: Adrian S Sabau, Evan Keith Ohriner, James O Kiggans, David C Harper, Charles R Schaich, Y Ueda, Yutai Katoh, L L SneadAbstract:Testing of advanced materials and component mock-ups under prototypical fusion high-heat flux conditions, while historically a mainstay of fusion reseArch has proved challenging, especially for irradiated materials. A new high-heat flux testing facility based on water-wall Plasma Arc Lamps (PALs) is now being used for materials and small component testing. Two PAL systems, utilizing a 12,000 C plasma Arc contained in a quartz tube cooled by a spiral water flow over the inside tube surface, are currently in use. The first PAL system provides a maximum incident heat flux of 4.2 MW/m2 over an area of 9x12 cm2. The second PAL available at ORNL provides a maximum incident heat flux of 27 MW/m2 over an area of 1x10 cm2. The absorbed heat fluxes into a tungsten target for the two PALs are approximately 1.97 and 12.7 MW/m2, respectively. This paper will present the overall design of the new PAL facilities as well as the design and implementation of the Irradiated Material Target Station (IMTS). The IMTS is primarily designed for testing the effects of heat flux or thermal cycling on material coupons of interested, such as those for plasma facing components. Moreover, IMTS designs are underway to extend the testing more » of small mock-ups for assessing the combined heating and thermomechanical effects of cooled, irradiated components. For the testing of material coupons , the specimens are placed in a shallow recess within the molybdenum holder that is attached to a water-cooled copper alloy rod. As the measurement of the specimen temperature for PAL is historically challenging since traditional approaches of temperature measurement cannot be employed due to the infrared heating and proximity of the PAL reflector to the specimen that does not allow a direct line of site, experiments for temperature calibration are presented. Finally, results for the high-heat flux testing of tungsten-based materials using the PAL are presented. As a demonstration of the system, results will be shown of thermal fatigue and high-heat flux testing of tungsten coupon specimens that were neutron irradiated in the HFIR reactor to neutron dose consistent to ITER lifetime. « less
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facility for high heat flux testing of irradiated fusion materials and components using infrared plasma Arc Lamps
Physica Scripta, 2014Co-Authors: Adrian S Sabau, Evan Keith Ohriner, James O Kiggans, David C Harper, L L Snead, Charles R SchaichAbstract:A new high-heat flux testing (HHFT) facility using water-wall stabilized high-power high-pressure argon plasma Arc Lamps (PALs) has been developed for fusion applications. It can accommodate irradiated plasma facing component materials and sub-size mock-up divertor components. Two PALs currently available at Oak Ridge National Laboratory can provide maximum incident heat fluxes of 4.2 and 27 MW m−2, which are prototypic of fusion steady state heat flux conditions, over a heated area of 9 × 12 and 1 × 10 cm2, respectively. The use of PAL permits the heat source to be environmentally separated from the components of the test chamber, simplifying the design to accommodate safe testing of low-level irradiated articles and materials under high-heat flux. Issues related to the operation and temperature measurements during testing of tungsten samples are presented and discussed. The relative advantages and disadvantages of this photon-based HHFT facility are compared to existing e-beam and particle beam facilities used for similar purposes.