Fabrication and Comparison of Fuels for Advanced Gas Reactor Irradiation Tests (open access)

Fabrication and Comparison of Fuels for Advanced Gas Reactor Irradiation Tests

As part of the program to demonstrate TRISO-coated fuel for the Next Generation Nuclear Plant, a series of irradiation tests of Advanced Gas Reactor (AGR) fuel are being performed in the Advanced Test Reactor (ATR) at the Idaho National Laboratory. In the first test, called “AGR-1,” graphite compacts containing approximately 300,000 coated particles were irradiated from December 2006 until November 2009. Development of AGR-1 fuel sought to replicate the properties of German TRISO-coated particles. No particle failures were seen in the nearly 3-year irradiation to a burn up of 19%. The AGR-1 particles were coated in a two-inch diameter coater. Following fabrication of AGR-1 fuel, process improvements and changes were made in each of the fabrication processes. Changes in the kernel fabrication process included replacing the carbon black powder feed with a surface-modified carbon slurry and shortening the sintering schedule. AGR-2 TRISO particles were produced in a six-inch diameter coater using a change size about twenty-one times that of the two-inch diameter coater used to coat AGR-1 particles. Changes were also made in the compacting process, including increasing the temperature and pressure of pressing and using a different type of press. Irradiation of AGR-2 fuel began in late spring 2010. …
Date: October 1, 2010
Creator: Phillips, Jeffrey; Barnes, Charles & Hunn, John
Object Type: Article
System: The UNT Digital Library
Check Burner Air to Fuel Ratios (International Fact Sheet), Energy Tips-Process Heating, Process Heating Tip Sheet #2c (open access)

Check Burner Air to Fuel Ratios (International Fact Sheet), Energy Tips-Process Heating, Process Heating Tip Sheet #2c

This English/Chinese international tip sheet provides information for optimizing efficiency of industrial process heating systems and includes measurements in metric units.
Date: October 1, 2010
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Star Forming Dense Cloud Cores in the TeV -ray SNR RX J1713.7-3946 (open access)

Star Forming Dense Cloud Cores in the TeV -ray SNR RX J1713.7-3946

RX J1713.7-3946 is one of the TeV {gamma}-ray supernova remnants (SNRs) emitting synchrotron X rays. The SNR is associated with molecular gas located at {approx}1 kpc. We made new molecular observations toward the dense cloud cores, peaks A, C and D, in the SNR in the {sup 12}CO(J=2-1) and {sup 13}CO(J=2-1) transitions at angular resolution of 90 degrees. The most intense core in {sup 13}CO, peak C, was also mapped in the {sup 12}CO(J=4-3) transition at angular resolution of 38 degrees. Peak C shows strong signs of active star formation including bipolar outflow and a far-infrared protostellar source and has a steep gradient with a r{sup -2.2 {+-} 0.4} variation in the average density within radius r. Peak C and the other dense cloud cores are rim-brightened in synchrotron X rays, suggesting that the dense cloud cores are embedded within or on the outer boundary of the SNR shell. This confirms the earlier suggestion that the X rays are physically associated with the molecular gas (Fukui et al. 2003). We present a scenario where the densest molecular core, peak C, survived against the blast wave and is now embedded within the SNR. Numerical simulations of the shock-cloud interaction indicate that …
Date: October 27, 2010
Creator: Sano, H.; Sato, J.; Yamamoto, H.; Hayakawa, T.; Torii, K.; Moribe, N. et al.
Object Type: Article
System: The UNT Digital Library
Comparative Assessment of Direct Drive High Temperature Superconducting Generators in Multi-Megawatt Class Wind Turbines (open access)

Comparative Assessment of Direct Drive High Temperature Superconducting Generators in Multi-Megawatt Class Wind Turbines

This paper summarizes the work completed under the CRADA between NREL and American Superconductor (AMSC). The CRADA combined NREL and AMSC resources to benchmark high temperature superconducting direct drive (HTSDD) generator technology by integrating the technologies into a conceptual wind turbine design, and comparing the design to geared drive and permanent magnet direct drive (PMDD) wind turbine configurations. Analysis was accomplished by upgrading the NREL Wind Turbine Design Cost and Scaling Model to represent geared and PMDD turbines at machine ratings up to 10 MW and then comparing cost and mass figures of AMSC's HTSDD wind turbine designs to theoretical geared and PMDD turbine designs at 3.1, 6, and 10 MW sizes. Based on the cost and performance data supplied by AMSC, HTSDD technology has good potential to compete successfully as an alternative technology to PMDD and geared technology turbines in the multi megawatt classes. In addition, data suggests the economics of HTSDD turbines improve with increasing size, although several uncertainties remain for all machines in the 6 to 10 MW class.
Date: October 1, 2010
Creator: Maples, B.; Hand, M. & Musial, W.
Object Type: Report
System: The UNT Digital Library
Improving Natural Uranium Utilization By Using Thorium in Low Moderation PWRs - A Preliminary Neutronic Scoping Study (open access)

Improving Natural Uranium Utilization By Using Thorium in Low Moderation PWRs - A Preliminary Neutronic Scoping Study

The Th-U fuel cycle is not quite self-sustainable when used in water-cooled reactors and with fuel burnups higher than a few thousand of MWd/t characteristic of CANDU reactors operating with a continuous refueling. For the other industrially mature water-cooled reactors (i.e. PWRs and BWRs) it is economically necessary that the fuel has enough reactivity to reach fuel burnups of the order of a few tens of thousand of MWd/t. In this particular case, an additional input of fissile material is necessary to complement the bred fissile U-233. This additional fissile material could be included in the form of Highly Enriched Uranium (HEU) at the fabrication of the Th-U fuel. The objective of this preliminary neutronic scoping study is to determine (1) how much HEU and, consequently, how much natural uranium is necessary in such Th-U fuel cycle with U recycling and (2) how much TRansUranics (TRU=Pu, Np, Am and Cm) are produced. These numbers are then compared with those of a standard UO2 PWR. The thorium reactors considered have a homogeneous hexagonal lattice made up of the same (Th-U)O2 pins. Furthermore, at this point, we are not considering the use of blankets inside or outside the core. The lattice pitch …
Date: October 1, 2010
Creator: Youinou, Gilles & Somoza, Ignacio
Object Type: Report
System: The UNT Digital Library
A low-threshold analysis of CDMS shallow-site data (open access)

A low-threshold analysis of CDMS shallow-site data

Data taken during the final shallow-site run of the first tower of the Cryogenic Dark Matter Search (CDMS II) detectors have been reanalyzed with improved sensitivity to small energy depositions. Four {approx}224 g germanium and two {approx}105 g silicon detectors were operated at the Stanford Underground Facility (SUF) between December 2001 and June 2002, yielding 118 live days of raw exposure. Three of the germanium and both silicon detectors were analyzed with a new low-threshold technique, making it possible to lower the germanium and silicon analysis thresholds down to the actual trigger thresholds of {approx}1 keV and {approx}2 keV, respectively. Limits on the spin-independent cross section for weakly interacting massive particles (WIMPs) to elastically scatter from nuclei based on these data exclude interesting parameter space for WIMPs with masses below 9 GeV/c{sup 2}. Under standard halo assumptions, these data partially exclude parameter space favored by interpretations of the DAMA/LIBRA and CoGeNT experiments data as WIMP signals, and exclude new parameter space for WIMP masses between 3 GeV/c{sup 2} and 4 GeV/c{sup 2}.
Date: October 1, 2010
Creator: Akerib, D. S.; Attisha, M. J.; Baudis, L.; Bauer, D. A.; Bolozdynya, A. I.; Brink, P. L. et al.
Object Type: Article
System: The UNT Digital Library
Top quark physics: from Tevatron to LHC (open access)

Top quark physics: from Tevatron to LHC

None
Date: October 1, 2010
Creator: Shabalina, E.K. & /Gottingen U., II. Phys. Inst.
Object Type: Article
System: The UNT Digital Library
Chemical Hydrogen Storage Using Polyhedral Borane Anions and Aluminum-Ammonia-Borane Complexes (open access)

Chemical Hydrogen Storage Using Polyhedral Borane Anions and Aluminum-Ammonia-Borane Complexes

Phase 1. Hydrolysis of borohydride compounds offer the potential for significant hydrogen storage capacity, but most work to date has focused on one particular anion, BH4-, which requires high pH for stability. Other borohydride compounds, in particular polyhedral borane anions offer comparable hydrogen storage capacity without requiring high pH media and their long term thermal and hydrolytic stability coupled with non-toxic nature make them a very attractive alternative to NaBH4. The University of Missouri project provided the overall program focal point for the investigation of catalytic hydrolysis of polyhedral borane anions for hydrogen release. Due to their inherent stability, a transition metal catalyst was necessary for the hydrolysis of polyhedral borane anions. Transition metal ions such as cobalt, nickel, palladium and rhodium were investigated for their catalytic activity in the hydrolysis of nido-KB11H14, closo-K2B10H10, and closo-K2B12H12. The rate of hydrolysis follows first-order kinetics with respect to the concentration of the polyhedral borane anion and surface area of the rhodium catalyst. The rate of hydrolysis depends upon a) choice of polyhedral borane anion, c) concentration of polyhedral borane anion, d) surface area of the rhodium catalyst and e) temperature of the reaction. In all cases the yield of hydrogen was 100% …
Date: October 1, 2010
Creator: Hawthorne, M. Frederick; Jalisatgi, Satish S.; Safronov, Alexander V.; Lee, Han Beak & Wu, Jianguo
Object Type: Report
System: The UNT Digital Library
Observation of a Narrow Near-Threshold Structure in the $J/\psi\phi$ Mass Spectrum in $B^+\to J/\psi\phi K^+$ Decays (open access)

Observation of a Narrow Near-Threshold Structure in the $J/\psi\phi$ Mass Spectrum in $B^+\to J/\psi\phi K^+$ Decays

Observation is reported for a structure near the J/{psi}{phi} threshold in B{sup +} {yields} J/{psi}{phi}K{sup +} decays produced in {bar p}p collisions at {radical}s = 1.96 TeV with a statistical significance of beyond 5 standard deviations. There are 19 {+-} 6 events observed for this structure at a mass of 4143.4{sub -3.0}{sup +2.9}(stat) {+-} 0.6(syst) MeV/c{sup 2} and a width of 15.3{sub -6.1}{sup +10.4}(stat) {+-} 2.5(syst) MeV/c{sup 2}, which are consistent with the previous measurements reported as evidence of the Y(4140).
Date: October 1, 2010
Creator: collaboration, Kai Yi for the CDF
Object Type: Article
System: The UNT Digital Library
Current and Future Costs for Parabolic Trough and Power Tower Systems in the US Market: Preprint (open access)

Current and Future Costs for Parabolic Trough and Power Tower Systems in the US Market: Preprint

NREL's Solar Advisor Model (SAM) is employed to estimate the current and future costs for parabolic trough and molten salt power towers in the US market. Future troughs are assumed to achieve higher field temperatures via the successful deployment of low melting-point, molten-salt heat transfer fluids by 2015-2020. Similarly, it is assumed that molten salt power towers are successfully deployed at 100MW scale over the same time period, increasing to 200MW by 2025. The levelized cost of electricity for both technologies is predicted to drop below 11 cents/kWh (assuming a 10% investment tax credit and other financial inputs outlined in the paper), making the technologies competitive in the marketplace as benchmarked by the California MPR. Both technologies can be deployed with large amounts of thermal energy storage, yielding capacity factors as high as 65% while maintaining an optimum LCOE.
Date: October 1, 2010
Creator: Turchi, C.; Mehos, M.; Ho, C. K. & Kolb, G. J.
Object Type: Article
System: The UNT Digital Library
Assessing the Impact of Heat Rejection Technology on CSP Plant Revenue: Preprint (open access)

Assessing the Impact of Heat Rejection Technology on CSP Plant Revenue: Preprint

This paper explores the impact of cooling technology on revenue for hybrid-cooled plants with varying wet cooling penetration for four representative locations in the American Southwest. The impact of ACC design-point initial temperature difference (ITD - the difference between the condensing steam temperature and ambient dry-bulb) is also included in the analysis.
Date: October 1, 2010
Creator: Wagner, M. J. & Kutscher, C. F.
Object Type: Article
System: The UNT Digital Library
The Arctic Lower Troposphere Observed Structure (ALTOS) Campaign (open access)

The Arctic Lower Troposphere Observed Structure (ALTOS) Campaign

The ALTOS campaign focuses on operating a tethered observing system for routine in situ sampling of low-level (< 2 km) Arctic clouds. It has been a long-term hope to fly tethered systems at Barrow, Alaska, but it is clear that the Federal Aviation Administration (FAA) will not permit in-cloud tether systems at Barrow, even if unmanned aerial vehicle (UAV) operations are allowed in the future. We have provided the scientific rationale for long-term, routine in situ measurements of cloud and aerosol properties in the Arctic. The existing restricted air space at Oliktok offers an opportunity to do so.
Date: October 18, 2010
Creator: Verlinde, J.
Object Type: Report
System: The UNT Digital Library
Campbell Creek TVA 2010 First Year Performance Report July 1, 2009 August 31, 2010 (open access)

Campbell Creek TVA 2010 First Year Performance Report July 1, 2009 August 31, 2010

This research project was initiated by TVA in March 2008 and encompasses three houses that are of similar size, design and located within the same community - Campbell Creek, Farragut TN with simulated occupancy. This report covers the performance period from July 1, 2009 to August 31, 2010. It is the intent of TVA that this Valley Data will inform electric utilities future residential retrofit incentive program.
Date: October 1, 2010
Creator: Christian, Jeffrey E; Gehl, Anthony C; Boudreaux, Philip R & New, Joshua Ryan
Object Type: Report
System: The UNT Digital Library
New Air Cleaning Strategies for Reduced Commercial Building Ventilation Energy (open access)

New Air Cleaning Strategies for Reduced Commercial Building Ventilation Energy

Approximately ten percent of the energy consumed in U.S. commercial buildings is used by HVAC systems to condition outdoor ventilation air. Reducing ventilation rates would be a simple and broadly-applicable energy retrofit option, if practical counter measures were available that maintained acceptable concentrations of indoor-generated air pollutants. The two general categories of countermeasures are: 1) indoor pollutant source control, and 2) air cleaning. Although pollutant source control should be used to the degree possible, source control is complicated by the large number and changing nature of indoor pollutant sources. Particle air cleaning is already routinely applied in commercial buildings. Previous calculations indicate that particle filtration consumes only 10percent to 25percent of the energy that would otherwise be required to achieve an equivalent amount of particle removal with ventilation. If cost-effective air cleaning technologies for volatile organic compounds (VOCs) were also available, outdoor air ventilation rates could be reduced substantially and broadly in the commercial building stock to save energy. The research carried out in this project focuses on developing novel VOC air cleaning technologies needed to enable energy-saving reductions in ventilation rates. The minimum required VOC removal efficiency to counteract a 50percent reduction in ventilation rate for air cleaning systems …
Date: October 27, 2010
Creator: Sidheswaran, Meera; Destaillats, Hugo; Sullivan, Douglas P. & Fisk, William J.
Object Type: Report
System: The UNT Digital Library
Risk-Informed Safety Margin Characterization (RISMC): Integrated Treatment of Aleatory and Epistemic Uncertainty in Safety Analysis (open access)

Risk-Informed Safety Margin Characterization (RISMC): Integrated Treatment of Aleatory and Epistemic Uncertainty in Safety Analysis

The concept of “margin” has a long history in nuclear licensing and in the codification of good engineering practices. However, some traditional applications of “margin” have been carried out for surrogate scenarios (such as design basis scenarios), without regard to the actual frequencies of those scenarios, and have been carried out with in a systematically conservative fashion. This means that the effectiveness of the application of the margin concept is determined in part by the original choice of surrogates, and is limited in any case by the degree of conservatism imposed on the evaluation. In the RISMC project, which is part of the Department of Energy’s “Light Water Reactor Sustainability Program” (LWRSP), we are developing a risk-informed characterization of safety margin. Beginning with the traditional discussion of “margin” in terms of a “load” (a physical challenge to system or component function) and a “capacity” (the capability of that system or component to accommodate the challenge), we are developing the capability to characterize probabilistic load and capacity spectra, reflecting both aleatory and epistemic uncertainty in system response. For example, the probabilistic load spectrum will reflect the frequency of challenges of a particular severity. Such a characterization is required if decision-making is …
Date: October 1, 2010
Creator: Youngblood, R. W.
Object Type: Article
System: The UNT Digital Library
Commercial and Cost Effective Production of Two-Dimensional Read-Out Boards for Sub-Atomic Particle Detectors (open access)

Commercial and Cost Effective Production of Two-Dimensional Read-Out Boards for Sub-Atomic Particle Detectors

Tech-Etch has considerable experience in numerous related high precision etched Kapton® products including production of GEM foils. The required precision and production process for 2-D readout boards is similar to that developed for GEM foil production. Additionally, Tech-Etch has strong ties with several research institutions (namely Brookhaven National Laboratory, MIT and Yale University) that can help design and evaluate the performance of the readout boards produced at Tech-Etch. Since Tech-Etch is a small company, it also has the capability to produce a large variety of part configurations, optimized for a particular customer’s requirements. We report results from research aimed at developing and demonstrating production of 2-D readout structures for GEM (Gas Electron Multiplier) charged particle tracking chambers at Tech-Etch. Readout boards of two types, bi-planar and single plane, were fabricated and evaluated. The results show that Tech-Etch can produce suitable boards of either type however the single plane board has a number of advantages both in production and use that will likely make it the preferred choice for GEM tracking chambers.
Date: October 22, 2010
Creator: Crary, David & Majka, Richard
Object Type: Report
System: The UNT Digital Library
ARM Climate Research Facility Monthly Instrument Report September 2010 (open access)

ARM Climate Research Facility Monthly Instrument Report September 2010

The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.
Date: October 18, 2010
Creator: Voyles, J. W.
Object Type: Report
System: The UNT Digital Library
Benefit of Regional Energy Balancing Service on Wind Integration in the Western Interconnection of the United States: Preprint (open access)

Benefit of Regional Energy Balancing Service on Wind Integration in the Western Interconnection of the United States: Preprint

This analysis indicates the extent to which pooled regional dispatch for matching generation to load mitigates the costs and improves associated reliability, particularly in scenarios with high penetration of variable output resources, such as wind
Date: October 1, 2010
Creator: Milligan, M.; Kirby, B.; King, J. & Beuning, S.
Object Type: Article
System: The UNT Digital Library
Storage Viability and Optimization Web Service (open access)

Storage Viability and Optimization Web Service

Non-residential sectors offer many promising applications for electrical storage (batteries) and photovoltaics (PVs). However, choosing and operating storage under complex tariff structures poses a daunting technical and economic problem that may discourage potential customers and result in lost carbon and economic savings. Equipment vendors are unlikely to provide adequate environmental analysis or unbiased economic results to potential clients, and are even less likely to completely describe the robustness of choices in the face of changing fuel prices and tariffs. Given these considerations, researchers at Lawrence Berkeley National Laboratory (LBNL) have designed the Storage Viability and Optimization Web Service (SVOW): a tool that helps building owners, operators and managers to decide if storage technologies and PVs merit deeper analysis. SVOW is an open access, web-based energy storage and PV analysis calculator, accessible by secure remote login. Upon first login, the user sees an overview of the parameters: load profile, tariff, technologies, and solar radiation location. Each parameter has a pull-down list of possible predefined inputs and users may upload their own as necessary. Since the non-residential sectors encompass a broad range of facilities with fundamentally different characteristics, the tool starts by asking the users to select a load profile from a …
Date: October 11, 2010
Creator: Stadler, Michael; Marnay, Christ; Lai, Judy; Siddiqui, Afzal; Limpaitoon, Tanachai; Phan, Trucy et al.
Object Type: Report
System: The UNT Digital Library
Nanocrystal-enabled solid state bonding. (open access)

Nanocrystal-enabled solid state bonding.

In this project, we performed a preliminary set of sintering experiments to examine nanocrystal-enabled diffusion bonding (NEDB) in Ag-on-Ag and Cu-on-Cu using Ag nanoparticles. The experimental test matrix included the effects of material system, temperature, pressure, and particle size. The nanoparticle compacts were bonded between plates using a customized hot press, tested in shear, and examined post mortem using microscopy techniques. NEDB was found to be a feasible mechanism for low-temperature, low-pressure, solid-state bonding of like materials, creating bonded interfaces that were able to support substantial loads. The maximum supported shear strength varied substantially within sample cohorts due to variation in bonded area; however, systematic variation with fabrication conditions was also observed. Mesoscale sintering simulations were performed in order to understand whether sintering models can aid in understanding the NEDB process. A pressure-assisted sintering model was incorporated into the SPPARKS kinetic Monte Carlo sintering code. Results reproduce most of the qualitative behavior observed in experiments, indicating that simulation can augment experiments during the development of the NEDB process. Because NEDB offers a promising route to low-temperature, low-pressure, solid-state bonding, we recommend further research and development with a goal of devising new NEDB bonding processes to support Sandia's customers.
Date: October 1, 2010
Creator: San Diego State University, San Diego, CA; Puskar, Joseph David; Tikare, Veena; Garcia Cardona, Cristina (San Diego State University, San Diego, CA); Reece, Mark; Brewer, Luke N. (Naval Postgraduate School, Monterey, CA) et al.
Object Type: Report
System: The UNT Digital Library
Detailed Physical Trough Model for NREL's Solar Advisor Model: Preprint (open access)

Detailed Physical Trough Model for NREL's Solar Advisor Model: Preprint

Solar Advisor Model (SAM) is a free software package made available by the National Renewable Energy Laboratory (NREL), Sandia National Laboratory, and the US Department of Energy. SAM contains hourly system performance and economic models for concentrating solar power (CSP) systems, photovoltaic, solar hot-water, and generic fuel-use technologies. Versions of SAM prior to 2010 included only the parabolic trough model based on Excelergy. This model uses top-level empirical performance curves to characterize plant behavior, and thus is limited in predictive capability for new technologies or component configurations. To address this and other functionality challenges, a new trough model; derived from physical first principles was commissioned to supplement the Excelergy-based empirical model. This new 'physical model' approaches the task of characterizing the performance of the whole parabolic trough plant by replacing empirical curve-fit relationships with more detailed calculations where practical. The resulting model matches the annual performance of the SAM empirical model (which has been previously verified with plant data) while maintaining run-times compatible with parametric analysis, adding additional flexibility in modeled system configurations, and providing more detailed performance calculations in the solar field, power block, piping, and storage subsystems.
Date: October 1, 2010
Creator: Wagner, M. J.; Blair, N. & Dobos, A.
Object Type: Article
System: The UNT Digital Library
Real time intelligent process control system for thin film solar cell manufacturing (open access)

Real time intelligent process control system for thin film solar cell manufacturing

This project addresses the problem of lower solar conversion efficiency and waste in the typical solar cell manufacturing process. The work from the proposed development will lead toward developing a system which should be able to increase solar panel conversion efficiency by an additional 12-15% resulting in lower cost panels, increased solar technology adoption, reduced carbon emissions and reduced dependency on foreign oil. All solar cell manufacturing processes today suffer from manufacturing inefficiencies that currently lead to lower product quality and lower conversion efficiency, increased product cost and greater material and energy consumption. This results in slower solar energy adoption and extends the time solar cells will reach grid parity with traditional energy sources. The thin film solar panel manufacturers struggle on a daily basis with the problem of thin film thickness non-uniformity and other parameters variances over the deposited substrates, which significantly degrade their manufacturing yield and quality. Optical monitoring of the thin films during the process of the film deposition is widely perceived as a necessary step towards resolving the non-uniformity and non-homogeneity problem. In order to enable the development of an optical control system for solar cell manufacturing, a new type of low cost optical sensor is …
Date: October 29, 2010
Creator: Atanasoff, George
Object Type: Report
System: The UNT Digital Library
Performance Assessment Transport Modeling of Uranium at the Area 5 Radioactive Waste Management Site at the Nevada National Security Site (open access)

Performance Assessment Transport Modeling of Uranium at the Area 5 Radioactive Waste Management Site at the Nevada National Security Site

Following is a brief summary of the assumptions that are pertinent to the radioactive isotope transport in the GoldSim Performance Assessment model of the Area 5 Radioactive Waste Management Site, with special emphasis on the water-phase reactive transport of uranium, which includes depleted uranium products.
Date: October 12, 2010
Creator: Waste, NSTec Radioactive
Object Type: Report
System: The UNT Digital Library
New Method to Characterize Degradation of First Surface Aluminum Reflectors: Preprint (open access)

New Method to Characterize Degradation of First Surface Aluminum Reflectors: Preprint

This paper reports the development of a new optical instrument capable of characterizing the aging process of enhanced first surface aluminum reflectors for concentrating solar power (CSP) application. Samples were exposed outdoors at different sites and in accelerated exposure tests. All samples exposed outdoors showed localized corrosion spots. Degradation originated from points of damage in the protective coating, but propagated underneath the protective coating. The degraded samples were analyzed with a microscope and with a newly designed space-resolved specular reflectometer (SR)2 that is capable of optically detecting and characterizing the corrosion spots. The device measures the specular reflectance at three acceptance angles and the wavelengths with spatial resolution using a digital camera's CMOS sensor. It can be used to measure the corrosion growth rate during outdoor and accelerated exposure tests. These results will allow a correlation between the degraded mirror surface and its specular reflectance.
Date: October 1, 2010
Creator: Sutter, F.; Heller, P.; Meyen, S.; Pitz-Paal, R.; Kennedy, C.; Fernandez-Garcia, A. et al.
Object Type: Article
System: The UNT Digital Library