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Sample records for measuring energy deposition

  1. Measurement of energy deposition near high energy, heavy ion tracks. Progress report, December 1982-April 1985

    SciTech Connect

    Metting, N.F.; Braby, L.A.; Rossi, H.H.; Kliauga, P.J.; Howard, J.; Schimmerling, W.; Wong, M.; Rapkin, M.

    1986-08-01

    The microscopic spatial distribution of energy deposition in irradiated tissue plays a significant role in the final biological effect produced. Therefore, it is important to have accurate microdosimetric spectra of radiation fields used for radiobiology and radiotherapy. The experiments desribed here were designed to measure the distributions of energy deposition around high energy heavy ion tracks generated at Lawrence Berkeley Laboratory's Bevalac Biomedical Facility. A small proportional counter mounted in a large (0.6 by 2.5 m) vacuum chamber was used to measure energy deposition distributions as a function of the distance between detector and primary ion track. The microdosimetric distributions for a homogeneous radiation field were then calculated by integrating over radial distance. This thesis discusses the rationale of the experimental design and the analysis of measurements on 600 MeV/amu iron tracks. 53 refs., 19 figs.

  2. Local Measurement of Fuel Energy Deposition and Heat Transfer Environment During Fuel Lifetime Using Controlled Calorimetry

    SciTech Connect

    Don W. Miller; Andrew Kauffmann; Eric Kreidler; Dongxu Li; Hanying Liu; Daniel Mills; Thomas D. Radcliff; Joseph Talnagi

    2001-12-31

    A comprehensive description of the accomplishments of the DOE grant titled, ''Local Measurement of Fuel Energy Deposition and Heat Transfer Environment During Fuel Lifetime using Controlled Calorimetry''.

  3. Theoretical study of energy deposition in ionization chambers for tritium measurements

    NASA Astrophysics Data System (ADS)

    Chen, Zhilin; Peng, Shuming; Meng, Dan; He, Yuehong; Wang, Heyi

    2013-10-01

    Energy deposition in ionization chambers has been theoretically studied for tritium measurements in gaseous form. A one-dimension model is introduced to establish the quantitative relationship between energy deposition rate and many factors, including carrier gas, gas pressure, wall material, chamber size, and gas temperature. Energy deposition rate has been calculated at pressure varying from 5 kPa to 500 kPa based on some approximations. It is found that energy deposition rate varies greatly for different parameters, especially at low gas pressure. For the same chamber, energy deposition rate in argon is much higher than in deuterium, as much as 70.7% higher at 5 kPa. Gold plated chamber gives highest energy deposition rate in the calculations while aluminum chamber results in the lowest. As chamber size gets smaller, β ray emitted by tritium will deposit less energy in the sensitive region of the chamber. For chambers flowing through with the same gas, energy deposition rate in a 10 L chamber is 23.9% higher than in a 0.05 L chamber at 5 kPa. Gas temperature also places slight influence on energy deposition rate, and 373 K will lead to 6.7% lower deposition rate than 233 K at 5 kPa. In addition, experiments have been performed to obtain energy deposition rate in a gold plated chamber, which show good accordance with theoretical calculations.

  4. Theoretical study of energy deposition in ionization chambers for tritium measurements

    SciTech Connect

    Chen, Zhilin; Peng, Shuming; Meng, Dan; He, Yuehong; Wang, Heyi

    2013-10-15

    Energy deposition in ionization chambers has been theoretically studied for tritium measurements in gaseous form. A one-dimension model is introduced to establish the quantitative relationship between energy deposition rate and many factors, including carrier gas, gas pressure, wall material, chamber size, and gas temperature. Energy deposition rate has been calculated at pressure varying from 5 kPa to 500 kPa based on some approximations. It is found that energy deposition rate varies greatly for different parameters, especially at low gas pressure. For the same chamber, energy deposition rate in argon is much higher than in deuterium, as much as 70.7% higher at 5 kPa. Gold plated chamber gives highest energy deposition rate in the calculations while aluminum chamber results in the lowest. As chamber size gets smaller, β ray emitted by tritium will deposit less energy in the sensitive region of the chamber. For chambers flowing through with the same gas, energy deposition rate in a 10 L chamber is 23.9% higher than in a 0.05 L chamber at 5 kPa. Gas temperature also places slight influence on energy deposition rate, and 373 K will lead to 6.7% lower deposition rate than 233 K at 5 kPa. In addition, experiments have been performed to obtain energy deposition rate in a gold plated chamber, which show good accordance with theoretical calculations.

  5. Efficiency of energy and protein deposition in swine measured by dual energy X-ray absorptiometry (DXA)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of studies were conducted using dual energy X-ray absorptiometry (DXA) to measure energy and protein deposition in pigs. In an initial validation study DXA was compared directly with slaughter analysis as a method for measuring body composition and energy deposition in pigs. Mean values fo...

  6. Estimating the energy deposition based on anisotropic fluxes measured by POES MEPED

    NASA Astrophysics Data System (ADS)

    Sandanger, Marit Irene; Stadsnes, Johan; Nesse Tyssøy, Hilde; Glesnes Ødegaard, Linn-Kristine; Åsnes, Arne

    2015-04-01

    The Medium Energy Proton and Electron Detector (MEPED) onboard the Polar Orbiting Operational Environmental Satellites (POES) consists of two electron telescopes, one viewing nearly radially outward from Earth (the 0o detector) and the other viewing antiparallel to the satellite's velocity (the 90o detector). Energetic particle measurements from POES are often used to estimate the energy deposition in the mesosphere. The electron fluxes usually show strong pitch angle anisotropy. Until now, it has been customary to derive a lower estimate of the energy deposition in the mesosphere from the 0o detector, while an upper estimate is derived from the 90odetector. We have developed a method using measurements from both the 0o and 90o telescopes in a combination with theoretically determined pitch angle distributions, in order to give a more precise estimate of the energy deposition in the upper atmosphere. The derived anisotropic flux distributions are used to calculate the energy deposition during Relativistic Electron Precipitation (REP) events.

  7. Monte Carlo calculation of energy deposition in ionization chambers for tritium measurements

    NASA Astrophysics Data System (ADS)

    Zhilin, Chen; Shuming, Peng; Dan, Meng; Yuehong, He; Heyi, Wang

    2014-10-01

    Energy deposition in ionization chambers for tritium measurements has been theoretically studied using Monte Carlo code MCNP 5. The influence of many factors, including carrier gas, chamber size, wall materials and gas pressure, has been evaluated in the simulations. It is found that β rays emitted by tritium deposit much more energy into chambers flowing through with argon than with deuterium in them, as much as 2.7 times higher at pressure 100 Pa. As chamber size gets smaller, energy deposition decreases sharply. For an ionization chamber of 1 mL, β rays deposit less than 1% of their energy at pressure 100 Pa and only 84% even if gas pressure is as high as 100 kPa. It also indicates that gold plated ionization chamber results in the highest deposition ratio while aluminum one leads to the lowest. In addition, simulations were validated by comparison with experimental data. Results show that simulations agree well with experimental data.

  8. Quantitation of absorbed or deposited materials on a substrate that measures energy deposition

    DOEpatents

    Grant, Patrick G.; Bakajin, Olgica; Vogel, John S.; Bench, Graham

    2005-01-18

    This invention provides a system and method for measuring an energy differential that correlates to quantitative measurement of an amount mass of an applied localized material. Such a system and method remains compatible with other methods of analysis, such as, for example, quantitating the elemental or isotopic content, identifying the material, or using the material in biochemical analysis.

  9. Measurements of the energy deposit of inclined muon bundles in the CWD NEVOD

    NASA Astrophysics Data System (ADS)

    Kokoulin, R. P.; Bogdanov, A. G.; Dushkin, L. I.; Khokhlov, S. S.; Khomyakov, V. A.; Kindin, V. V.; Kovylyaeva, E. A.; Mannocchi, G.; Petrukhin, A. A.; Saavedra, O.; Shutenko, V. V.; Trinchero, G.; Yashin, I. I.

    2015-08-01

    First results of investigations of the energy deposits of inclined muon bundles in the ground-based Cherenkov water detector NEVOD are presented. As a measure of the muon bundle energy deposit, the total number of photoelectrons detected by PMTs of the Cherenkov calorimeter is used. For each event, the local muon density at the observation point and the muon bundle arrival direction are estimated from the data of the coordinate-tracking detector DECOR. Registration of the bundles in a wide range of zenith angles allows to explore the interval of primary particle energies from ∼ 1016 to ∼ 1018 eV. Measurement results are compared with CORSIKA based simulations of EAS muon component. It is found that the mean energy of muons detected in the bundles rapidly increases with the zenith angle and reaches about 500 GeV near the horizon.

  10. Measuring the energy flux at the substrate position during magnetron sputter deposition processes

    SciTech Connect

    Cormier, P.-A.; Thomann, A.-L.; Dussart, R.; Semmar, N.; Mathias, J.; Balhamri, A.; Snyders, R.; Konstantinidis, S.

    2013-01-07

    In this work, the energetic conditions at the substrate were investigated in dc magnetron sputtering (DCMS), pulsed dc magnetron sputtering (pDCMS), and high power impulse magnetron sputtering (HiPIMS) discharges by means of an energy flux diagnostic based on a thermopile sensor, the probe being set at the substrate position. Measurements were performed in front of a titanium target for a highly unbalanced magnetic field configuration. The average power was always kept to 400 W and the probe was at the floating potential. Variation of the energy flux against the pulse peak power in HiPIMS was first investigated. It was demonstrated that the energy per deposited titanium atom is the highest for short pulses (5 {mu}s) high pulse peak power (39 kW), as in this case, the ion production is efficient and the deposition rate is reduced by self-sputtering. As the argon pressure is increased, the energy deposition is reduced as the probability of scattering in the gas phase is increased. In the case of the HiPIMS discharge run at moderate peak power density (10 kW), the energy per deposited atom was found to be lower than the one measured for DCMS and pDCMS discharges. In these conditions, the HiPIMS discharge could be characterized as soft and close to a pulsed DCMS discharge run at very low duty cycle. For the sake of comparison, measurements were also carried out in DCMS mode with a balanced magnetron cathode, in the same working conditions of pressure and power. The energy flux at the substrate is significantly increased as the discharge is generated in an unbalanced field.

  11. Comparison between calculation and measurement of energy deposited by 800 MeV protons

    SciTech Connect

    Loewe, W.E.

    1980-04-03

    The High Energy Transport Code, HETC, was obtained from the Radiation Shielding Information Center (RSIC) at Oak Ridge National Laboratory and altered as necessary to run on a CDC 7600 using the LTSS software in use at LLNL. HETC was then used to obtain calculated estimates of energy deposited, for comparison with a series of benchmark experiments done by LLNL. These experiments used proton beams of various energies incident on well-defined composite targets in good geometry. In this report, two aspects of the comparison between calculated and experimental energy depositions from an 800 MeV proton beam are discussed. Both aspects involve the fact that workers at SAI had previously used their version of HETC to calculate this experiment and reported their comparison with the measured data. The first aspect addressed is that their calculated data and LLNL calculations do not agree, suggesting an error in the conversion process from the RSIC code. The second aspect is not independent of the first, but is of sufficient importance to merit separate emphasis. It is that the SAI calculations agree well with experiments at the detector plate located some distance from the shower plate, whereas the LLNL calculations show a clearcut discrepancy there in comparison with the experiment. A contract was let in January 1980 by LLNL with SAI in order to obtain full details on the two cited aspects of the comparison between calculated and experimental energy depositions from an 800 MeV proton beam. The ensuing discussion is based on the final report of that contracted work.

  12. Calorimetric measurement of electron energy deposition in extended media. Theory vs experiment

    SciTech Connect

    Lockwood, G.J.; Ruggles, L.E.; Miller, G.H.; Halbleib, J.A.

    1980-01-01

    A new calorimetric technique has been developed for measuring electron energy deposition profiles in one dimension. The experimental procedures and theoretical analyses required in the application of the new method are reviewed. Extensive results are presented for electron energy deposition profiles in semi-infinite homogeneous and multilayer configurations. These data cover a range of elements from beryllium through uranium at source energies from 0.3 to 1.0 MeV (selected data at 0.5 and 0.1 MeV) and at incident angles from 0/sup 0/ to 60/sup 0/. In every case, the experimental profiles are compared with the predictions of a coupled electron/photon Monte Carlo transport code. Overall agreement between theory and experiment is very good. However, there appears to be a tendency for the theoretical profiles to be higher near the peaks and lower near the tails, especially in high-Z materials. There is also a discrepancy between theory and experiment in low-Z materials near high-Z/low-Z interfaces.

  13. Estimating regional auroral electron energy deposition using ground-based optical measurements

    NASA Astrophysics Data System (ADS)

    Hampton, D. L.; Conde, M.; Ahrns, M. J.; Bristow, W.; Lynch, K. A.; Zettergren, M. D.

    2014-12-01

    Two key parameters for understanding the coupling between the magnetosphere and the thermosphere/ionosphere in polar regions are the characteristic energy and the total energy flux of precipitating auroral electrons. Ionization due to precipitating electrons modifies the ionospheric electron density profile and thereby the height-dependent conductivity in a complex manner in both time and space. Global or regional thermospheric dynamics models typically rely on empirical models (Ovation) or low-resolution global EUV imagery (POLAR) for electron precipitation input which smear out the mesoscale detail of the location and timing of auroral arcs. We have developed a method for measuring the time-dependent auroral electron energy deposition over a several-hundred km range with 25 km resolution using a combination of two ground-based optical instruments - a scanning-doppler imager observing green-line temperatures and a filtered all-sky imager measuring the N2+ first negative emission at 427.8 nm. We will discuss the details of the method, and show several examples including those from the MICA sounding rocket experiment as well as several events from the AMISR PINOT campaign. We will also show comparisons with alternate optical and radar techniques, compare our estimated energy flux to those from Ovation, and discuss limitations and advantages of the technique when examining mesoscale dynamics in the auroral zone.

  14. Dispersion of heavy ion deposited energy in nanometric electronic devices: Experimental measurements and simulation possibilities

    NASA Astrophysics Data System (ADS)

    Raine, M.; Gaillardin, M.; Paillet, P.; Duhamel, O.; Martinez, M.; Bernard, H.

    2015-12-01

    The dispersion of heavy ion deposited energy is explored in nanometric electronic devices. Experimental data are reported, in a large thin SOI diode and in a SOI FinFET device, showing larger distributions of collected charge in the nanometric volume device. Geant4 simulations are then presented, using two different modeling approaches. Both of them seem suitable to evaluate the dispersion of deposited energy induced by heavy ion beams in advanced electronic devices with nanometric dimensions.

  15. Measurement of energy deposited by charged-particle beams in composite targets

    SciTech Connect

    Farley, E.; Becker, J.; Crase, K.; Howe, R.; Selway, D.

    1980-07-02

    We have measured the energy deposited in two types of composite targets by a number of charged-particle beams: targets made of /sup 238/U, Lucite, and polyethylene were exposed to 0.26-GeV protons and 0.33-GeV deuterons, and aluminum-Lucite composites were exposed to 0.5-GeV electrons. In addition, we measured neutrons and gamma rays emitted from solid targets of various materials (including /sup 238/U and iron) exposed to 0.26-GeV protons and 0.33-GeV deuterons. We used passive detectors (thermoluminescence dosimeters, Lexan fission track recorders, and photographic emulsions) to measure the nonfission dose and the fission-fragment dose from the primary beam and its shower of products. Measurements were made at various depths and radial positions in the targets. Plots and numerical values of the measured doses are presented. The emission of neutrons and gamma rays was measured with a liquid-deuterated-benzene detector. In general, the dose profile with depth is similar for 0.26-GeV protons and 0.33-GeV deuterons. The ratio of return neutrons to gamma rays increases with increasing target mass number. Deuterons, however, produce from 1.7 to 5.8 times as many neutrons and gamma rays per particle as do protons.

  16. Solar Energy Deposition Rates in the Mesosphere Derived from Airglow Measurements: Implications for the Ozone Model Deficit Problem

    NASA Technical Reports Server (NTRS)

    Mlynczak, Martin G.; Garcia, Rolando R.; Roble, Raymond G.; Hagan, Maura

    2000-01-01

    We derive rates of energy deposition in the mesosphere due to the absorption of solar ultraviolet radiation by ozone. The rates are derived directly from measurements of the 1.27-microns oxygen dayglow emission, independent of knowledge of the ozone abundance, the ozone absorption cross sections, and the ultraviolet solar irradiance in the ozone Hartley band. Fifty-six months of airglow data taken between 1982 and 1986 by the near-infrared spectrometer on the Solar-Mesosphere Explorer satellite are analyzed. The energy deposition rates exhibit altitude-dependent annual and semi-annual variations. We also find a positive correlation between temperatures and energy deposition rates near 90 km at low latitudes. This correlation is largely due to the semiannual oscillation in temperature and ozone and is consistent with model calculations. There is also a suggestion of possible tidal enhancement of this correlation based on recent theoretical and observational analyses. The airglow-derived rates of energy deposition are then compared with those computed by multidimensional numerical models. The observed and modeled deposition rates typically agree to within 20%. This agreement in energy deposition rates implies the same agreement exists between measured and modeled ozone volume mixing ratios in the mesosphere. Only in the upper mesosphere at midlatitudes during winter do we derive energy deposition rates (and hence ozone mixing ratios) consistently and significantly larger than the model calculations. This result is contrary to previous studies that have shown a large model deficit in the ozone abundance throughout the mesosphere. The climatology of solar energy deposition and heating presented in this paper is available to the community at the Middle Atmosphere Energy Budget Project web site at http://heat-budget.gats-inc.com.

  17. Solar energy deposition rates in the mesosphere derived from airglow measurements: Implications for the ozone model deficit problem

    NASA Astrophysics Data System (ADS)

    Mlynczak, Martin G.; Garcia, Rolando R.; Roble, Raymond G.; Hagan, Maura

    2000-07-01

    We derive rates of energy deposition in the mesosphere due to the absorption of solar ultraviolet radiation by ozone. The rates are derived directly from measurements of the 1.27-μm oxygen dayglow emission, independent of knowledge of the ozone abundance, the ozone absorption cross sections, and the ultraviolet solar irradiance in the ozone Hartley band. Fifty-six months of airglow data taken between 1982 and 1986 by the near-infrared spectrometer on the Solar-Mesosphere Explorer satellite are analyzed. The energy deposition rates exhibit altitude-dependent annual and semi-annual variations. We also find a positive correlation between temperatures and energy deposition rates near 90 km at low latitudes. This correlation is largely due to the semiannual oscillation in temperature and ozone and is consistent with model calculations. There is also a suggestion of possible tidal enhancement of this correlation based on recent theoretical and observational analyses. The airglow-derived rates of energy deposition are then compared with those computed by multidimensional numerical models. The observed and modeled deposition rates typically agree to within 20%. This agreement in energy deposition rates implies the same agreement exists between measured and modeled ozone volume mixing ratios in the mesosphere. Only in the upper mesosphere at midlatitudes during winter do we derive energy deposition rates (and hence ozone mixing ratios) consistently and significantly larger than the model calculations. This result is contrary to previous studies that have shown a large model deficit in the ozone abundance throughout the mesosphere. The climatology of solar energy deposition and heating presented in this paper is available to the community at the Middle Atmosphere Energy Budget Project web site at http://heat.budget.gats.inc.com.

  18. Time-specific measurements of energy deposition from radiation fields in simulated sub-micron tissue volumes

    SciTech Connect

    Famiano, M.A.

    1997-07-07

    A tissue-equivalent spherical proportional counter is used with a modified amplifier system to measure specific energy deposited from a uniform radiation field for short periods of time ({approximately}1 {micro}s to seconds) in order to extrapolate to dose in sub-micron tissue volumes. The energy deposited during these time intervals is compared to biological repair processes occurring within the same intervals after the initial energy deposition. The signal is integrated over a variable collection time which is adjusted with a square-wave pulse. Charge from particle passages is collected on the anode during the period in which the integrator is triggered, and the signal decays quickly to zero after the integrator feedback switch resets; the process repeats for every triggering pulse. Measurements of energy deposited from x rays, {sup 137}Cs gamma rays, and electrons from a {sup 90}Sr/{sup 90}Y source for various time intervals are taken. Spectral characteristics as a function of charge collection time are observed and frequency plots of specific energy and collection time-interval are presented. In addition, a threshold energy flux is selected for each radiation type at which the formation of radicals (based on current measurements) in mammalian cells equals the rate at which radicals are repaired.

  19. Track based software package for measurement of the energy deposited by muons in the calorimeters of the ATLAS detector

    NASA Astrophysics Data System (ADS)

    Bachas, K.; Hassani, S.

    2008-07-01

    The measurement of the muon energy deposition in the calorimeters is an integral part of muon identification, track isolation and correction for catastrophic muon energy losses, which are the prerequisites to the ultimate goal of refitting the muon track using calorimeter information as well. To this end, an accurate energy loss measurement method in the calorimeters is developed which uses only Event Data Model tools and is used by the muon isolation tool in the official ATLAS software, in order to provide isolation related variables at the Event Summary Data level. The strategy of the energy deposition measurement by the track in the calorimeters is described. Inner Detector, or Muon Spectrometer tracks are extrapolated to each calorimeter compartment using existing tools, which take into account multiple scattering and bending due to the magnetic field. The energy deposited in each compartment is measured by summing-up cells, corrected for noise, inside a cone of desired size around the track. The results of the measured energy loss in the calorimeters with this method are validated with Monte Carlo single muon samples.

  20. Efficiency of energy and protein deposition in swine during compensatory growth measured by dual energy X-ray absorptiometry (DXA)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to examine the effects of controlled intake, dietary protein (CP) level, and ractopamine supplementation on growth, body composition, and the efficiency of energy and protein deposition in pigs during uninterrupted or compensatory growth from 60 to 100 kg. Seven groups of pigs ...

  1. Intercomparison measurements with energy deposition spectrometer Liulin and TEPC Hawk at HIMAC, and related calculations with PHITS

    NASA Astrophysics Data System (ADS)

    Ploc, Ondrej; Uchihori, Yukio; Kitamura, H.; Kodaira, S.; Dachev, Tsvetan; Spurny, Frantisek; Jadrnickova, Iva; Mrazova, Zlata; Kubancak, Jan

    Liulin type detectors are recently used in a wide range of cosmic radiation measurements, e.g. at alpine observatories, onboard aircrafts and spacecrafts. They provide energy deposition spectra up to 21 MeV, higher energy deposition events are stored in the last (overflow) channel. Their main advantages are portability (about the same size as a pack of cigarettes) and ability to record spectra as a function of time, so they can be used as personal dosimeters. Their well-known limitations are: (i) the fact that they are not tissue equivalent, (ii) they can be used as LET spectrometer only under specific conditions (e.g. broad parallel beam), and (iii) that the energy deposition event from particles of LETH20¿35 keV/µm is stored in the overflow bin only so the spectral information is missing. Tissue equivalent proportional counter (TEPC) Hawk has no of these limitations but on the other hand, it cannot be used as personal dosimeter because of its big size (cylinder of 16 cm diameter and 34 cm long). An important fraction of dose equivalent onboard spacecrafts is caused by heavy ions. This contribution presents results from intercomparison measurements with Liulin and Hawk at Heavy Ion Medical Accelerator in Chiba (HIMAC) and cyclotron beams, and related calculations with PHITS (Particle and Heavy-ion Transport code System). Following particles/ions and energies were used: protons 70 MeV, He 150 MeV, Ne 400 MeV, C 135 MeV, C 290 MeV, and Fe 500 MeV. Calculations of LET spectra by PHITS were performed for both, Liulin and Hawk. In case of Liulin, the dose equivalent was calculated using simulations in which several tissue equivalent materials were used as active volume instead of the silicon diode. Dose equivalents calculated in such way was compared with that measured with Hawk. LET spectra measured with Liulin and Hawk were compared for each ion at several points behind binary filters along the Brag curve. Good agreement was observed for some configurations; for

  2. Preliminary measurements of auroral energy deposition and middle atmosphere electrodynamic response during MAC/Epsilon

    NASA Technical Reports Server (NTRS)

    Goldberg, R. A.

    1989-01-01

    On the nights of October 21 and 28, 1987 (UT), two Nike Orion payloads (NASA 31.066 and 31.067) were launched from Andoya, Norway, as part of the MAC/Epsilon campaign, to study auroral energetics and their effect on the middle atmosphere. Each payload carried instrumentation to measure relativistic electrons from 0.1 to 1.0 MeV in 12 differential channels, and Bremsstrahlung X-rays from greater than 5 to greater than 80 KeV in 5 integral channels. In addition, instrumentation to measure ion densities and electric fields were also included on these and, in the case of 31.066, on other near simultaneous payloads. The first flight, 31.066, was launched under pre-magnetic midnight conditions during relatively stable auroral conditions. Flight 31.067 was launched during post-breakup conditions at which time pulsations of approx. 100 seconds duration were evident. The measured radiations including their spectral characteristics are compared for these two events, to appraise their effect on the electrodynamic properties of the middle atmosphere as determined by other rocket-borne measurements.

  3. Measurement and Simulation of the Variation in Proton-Induced Energy Deposition in Large Silicon Diode Arrays

    NASA Technical Reports Server (NTRS)

    Howe, Christina L.; Weller, Robert A.; Reed, Robert A.; Sierawski, Brian D.; Marshall, Paul W.; Marshall, Cheryl J.; Mendenhall, Marcus H.; Schrimpf, Ronald D.

    2007-01-01

    The proton induced charge deposition in a well characterized silicon P-i-N focal plane array is analyzed with Monte Carlo based simulations. These simulations include all physical processes, together with pile up, to accurately describe the experimental data. Simulation results reveal important high energy events not easily detected through experiment due to low statistics. The effects of each physical mechanism on the device response is shown for a single proton energy as well as a full proton space flux.

  4. Parametric study of the energy deposition inside the calorimeter measuring the nuclear heating in Material Testing Reactors

    NASA Astrophysics Data System (ADS)

    Amharrak, H.; Reynard-Carette, C.; Lyoussi, A.; Carette, M.; Brun, J.; De Vita, C.; Fourmentel, D.; Villard, J.-F.

    2015-11-01

    The nuclear heating measurements in Material Testing Reactors (MTRs) are crucial for the study of nuclear materials and fuels under irradiation. The reference measurements of this nuclear heating are especially performed by a differential calorimeter including a graphite sample material and two calorimetric cells. Then these measurements are used for other experimental conditions in order to predict the nuclear heating and thermal conditions induced in the irradiation devices. This paper will present simulations with MCNP5 Monte-Carlo transport code (using ENDF/B-VI nuclear data library) to evaluate the nuclear heating inside the calorimeter during irradiation campaigns of the CARMEN-1P mock-up inside OSIRIS reactor periphery (MTR based on Saclay, France). The whole complete geometry of the sensor has been considered. The calculation method corresponds to a calculation in two steps. Consequently, we used as an input source in the model, the neutron and photon spectra calculated in various experimental locations tested during the irradiation campaign (H9, H10, H11, D9). After a description of the differential calorimeter sensor, the MCNP5 model used for the calculations of nuclear heating inside the calorimeter elements is introduced by two quantities: KERMA and energy deposition rate per mass unit. The Charged Particle Equilibrium (CPE) inside the calorimeter elements is studied. The contribution of prompt gamma and neutron is determined. A comparison between this total nuclear heating calculation and the experimental results in a graphite sample will be made. Then parametric studies performed on the influence of the various calorimeter components on the nuclear heating are presented and discussed. The studies of the influence of the nature of materials, the sensor jacket, the source type and the comparison of the results obtained for the two calorimetric cells leads to some proposals for the sensor improvement.

  5. Measuring coal deposits by radar

    NASA Technical Reports Server (NTRS)

    Barr, T. A.

    1980-01-01

    Front-surface, local-oscillator radar directly compares frequency of signals reflected from front and back surfaces of coal deposits. Thickness is measured directly as frequency difference. Transmitter is frequency modulated, so thickness is computed directly from frequency difference. Because front and back reflections are detected in combination rather than separately, masking of comparatively weak back signal is less problem. Also system is not sensitive to extraneous reflections from targets between transmitting antenna and coal surface.

  6. Application of diamond films to electric propulsion: Low energy sputter yield measurement and MPD plasma assisted chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Blandino, John Joseph

    One application of chemically vapor deposited (CVD) diamond films under evaluation at the Jet Propulsion Laboratory is the coating of ion thruster electrodes subject to sputter erosion from xenon ions. Sputter yields were measured for polycrystalline diamond, single crystal diamond, a carbon-carbon composite, and molybdenum subject to xenon ion bombardment. The tests were performed using a 3 cm Kaufman ion source to produce incident ions with energy in the range of 150--750 eV and a profilometry-based technique to measure the amount of sputtered material. The yields increased monotonically with energy with values ranging from 0.16 atoms/ion at 150 eV to 0.80 at 750 eV for the molybdenum and 0.06 to 0.14 for the carbon-carbon. At 150 eV the yield for both diamond samples was 0.07 and at 7 50 eV, 0.19 and 0.17 for the CVD and single crystal diamond respectively. In terms of erosion rate, this translates into a factor of 7--12 lower erosion rate for diamond compared to molybdenum and at least a factor of 1.5 compared to carbon-carbon. In addition, an experimental investigation of an electromagnetic (magnetoplasmadynamic or MPD) plasma source for diamond CVD was undertaken using gas mixtures of methane, hydrogen and argon. Numerous trials were conducted using methane to hydrogen mixture ratios of 1.5--3.5 percent by volume, four different methane injector configurations, and substrate biasing at potentials of 25--75 V positive with respect to facility ground. These tests were performed at discharge currents of 700--950 A at approximately 18 V (12--17 kW). Crystalline films were produced with growth rates of 0.8 to 6.3 microns/hr. X-ray diffraction spectroscopy was used to identify at least one unambiguous diamond peak in each sample. The films all exhibited poor Raman spectra with no well defined peak at 1332 cm-1 and a broad background possibly due to high background levels of nitrogen, defects, and metal vapor contamination. Finally, the potential benefits of the MPD

  7. Measurement of deposition rate and ion energy distribution in a pulsed dc magnetron sputtering system using a retarding field analyzer with embedded quartz crystal microbalance

    NASA Astrophysics Data System (ADS)

    Sharma, Shailesh; Gahan, David; Scullin, Paul; Doyle, James; Lennon, Jj; Vijayaraghavan, Rajani K.; Daniels, Stephen; Hopkins, M. B.

    2016-04-01

    A compact retarding field analyzer with embedded quartz crystal microbalance has been developed to measure deposition rate, ionized flux fraction, and ion energy distribution arriving at the substrate location. The sensor can be placed on grounded, electrically floating, or radio frequency (rf) biased electrodes. A calibration method is presented to compensate for temperature effects in the quartz crystal. The metal deposition rate, metal ionization fraction, and energy distribution of the ions arriving at the substrate location are investigated in an asymmetric bipolar pulsed dc magnetron sputtering reactor under grounded, floating, and rf biased conditions. The diagnostic presented in this research work does not suffer from complications caused by water cooling arrangements to maintain constant temperature and is an attractive technique for characterizing a thin film deposition system.

  8. Measurement of deposition rate and ion energy distribution in a pulsed dc magnetron sputtering system using a retarding field analyzer with embedded quartz crystal microbalance.

    PubMed

    Sharma, Shailesh; Gahan, David; Scullin, Paul; Doyle, James; Lennon, Jj; Vijayaraghavan, Rajani K; Daniels, Stephen; Hopkins, M B

    2016-04-01

    A compact retarding field analyzer with embedded quartz crystal microbalance has been developed to measure deposition rate, ionized flux fraction, and ion energy distribution arriving at the substrate location. The sensor can be placed on grounded, electrically floating, or radio frequency (rf) biased electrodes. A calibration method is presented to compensate for temperature effects in the quartz crystal. The metal deposition rate, metal ionization fraction, and energy distribution of the ions arriving at the substrate location are investigated in an asymmetric bipolar pulsed dc magnetron sputtering reactor under grounded, floating, and rf biased conditions. The diagnostic presented in this research work does not suffer from complications caused by water cooling arrangements to maintain constant temperature and is an attractive technique for characterizing a thin film deposition system. PMID:27131678

  9. Niobium Thin Film Properties Affected by Deposition Energy during Vacuum Deposition

    SciTech Connect

    Genfa Wu; H. Phillips; Ronald Sundelin; Anne-Marie Valente

    2003-05-01

    In order to understand and improve the super-conducting performance of niobium thin films at cryogenic temperatures, an energetic vacuum deposition system has been developed to study deposition energy effects on the properties of niobium thin films on various substrates. Ultra high vacuum avoids the gaseous inclusions in thin films commonly seen in sputtering deposition. A retarding field energy analyzer is used to measure the kinetic energy of niobium ions at the substrate location. A biased substrate holder controls the deposition energy. Transition temperature and residual resistivity ratio (RRR) of the niobium thin films at several deposition energies are obtained together with crystal orientation measurements and atomic force microscope (AFM) inspection, and the results show that there exists a preferred deposition energy around 115eV (the average deposition energy 64 eV plus the 51 V bias voltage).

  10. Localized flow control with energy deposition

    NASA Astrophysics Data System (ADS)

    Adelgren, Russell Gene

    A series of experiments with energy deposition via laser-induced optical breakdown of air, i.e., a laser spark, have been performed. These experiments have demonstrated the possibility of using a laser spark for supersonic flow control. In the first of these experiments, Rayleigh scattering flow visualization was taken for energy deposition into quiescent air. A time sequence of images showed the post breakdown fluid motion created by the laser spark for different laser energy levels. Blast wave radius and wave speed measurements were made and correlated to five different laser energy deposition levels. Laser energy was deposited upstream of a sphere in Mach 3.45 flow. The energy was deposited one sphere diameter and 0.6 diameters upstream of the front of the sphere. The frontal surface pressure on the sphere was recorded as the laser spark perturbed region interacted with the flow about the sphere. Tests for three different energy levels and two different incident laser beam diameters were completed. It has been demonstrated that the peak surface pressure associated with the Edney IV interaction can be momentarily reduced by 30% by the interaction with the thermal spot created by the laser spark. The effects of laser energy deposition on another shock interaction phenomena were studied. Laser energy deposition was used to modify the shock structure formed by symmetric wedges at Mach 3.45 within the dual solution domain. It was demonstrated experimentally that the Mach reflection could be reduced by 80% momentarily. The numerical simulations show a transition from the stable Mach reflection to a stable regular reflection. Two energy deposition methods (electric arcing and laser energy deposition) were used to force and control compressible mixing layers of axisymmetric jets. The energy deposition forcing methods have been experimentally investigated with the schlieren technique, particle image velocimetry, Mie scattering, and static pressure probe diagnostic

  11. Energy deposition and dynamic response of materials

    NASA Astrophysics Data System (ADS)

    Perry, Frank C.

    1993-07-01

    We are exploring new applications of the technology of energy deposition and dynamic response. Early studies involved analytical solutions of the coupled thermal and elastic response of materials to pulsed energy deposition. Experiments designed to test the theory led to determinations of thermal pressure coefficients for a variety of materials and an understanding of the effects of the time dependence of the energy source on dynamic response. Subsequent experiments at higher deposited energies required analysis by an energy deposition-wave propagation code to explain the observed elastic-plastic behavior. Instrumentation included laser interferometry and holographic interferometry for multi- dimensional response. A possible application of this technology to Biomedical Science is a technique to measure ion transport in biological material. It requires a combination of holographic interferometry and spectroscopy, namely, Resonant Holographic Interferometry Spectroscopy (RHIS). The technique involves the absorption and refraction of light near absorption lines. Stress waves arising from the absorbed light can be assessed with the energy deposition-wave propagation code. Such calculations will require the inclusion of appropriate biomaterial properties.

  12. Measuring the scintillation decay time for different energy depositions in NaI:Tl, LSO:Ce and CeBr3 scintillators

    NASA Astrophysics Data System (ADS)

    Swiderski, Lukasz; Moszynski, Marek; Syntfeld-Kazuch, Agnieszka; Szawlowski, Marek; Szczesniak, Tomasz

    2014-06-01

    This study presents a simple experimental setup for precise inspection of scintillation decay characteristics as a function of the energy deposited in scintillators. The results are discussed for NaI:Tl, LSO:Ce and CeBr3 crystals. The tested samples were coupled to a fast response R5320 photomultiplier from Hamamatsu. The decay time constants were measured by fitting the anode pulses of the PMT registered directly with a TDS5054B digital oscilloscope from Tektronix. Simple analog electronics composed of timing single channel analyzers, gate generators and coincidence/logic unit was used for selection of the deposited energy converted into light within the scintillator, and for triggering the scope to register relevant scintillation pulses. High precision of the experimental setup allowed for registration of non-proportionality curves for all samples. Moreover, non-proportionality was measured for fast and slow decay mode of NaI:Tl separately. The measurement was also used for inspection of possible differences in the pulse shapes originating from Compton scattering events and photoabsorption.

  13. Time Resolved Deposition Measurements in NSTX

    SciTech Connect

    C.H. Skinner; H. Kugel; A.L. Roquemore; J. Hogan; W.R. Wampler; the NSTX team

    2004-08-03

    Time-resolved measurements of deposition in current tokamaks are crucial to gain a predictive understanding of deposition with a view to mitigating tritium retention and deposition on diagnostic mirrors expected in next-step devices. Two quartz crystal microbalances have been installed on NSTX at a location 0.77m outside the last closed flux surface. This configuration mimics a typical diagnostic window or mirror. The deposits were analyzed ex-situ and found to be dominantly carbon, oxygen, and deuterium. A rear facing quartz crystal recorded deposition of lower sticking probability molecules at 10% of the rate of the front facing one. Time resolved measurements over a 4-week period with 497 discharges, recorded 29.2 {micro}g/cm{sup 2} of deposition, however surprisingly, 15.9 {micro}g/cm{sup 2} of material loss occurred at 7 discharges. The net deposited mass of 13.3 {micro}g/cm{sup 2} matched the mass of 13.5 {micro}g/cm{sup 2} measured independently by ion beam analysis. Monte Carlo modeling suggests that transient processes are likely to dominate the deposition.

  14. Global Auroral Energy Deposition Derived from Polar UVI Images

    NASA Technical Reports Server (NTRS)

    Fillingim, M. O.; Brittnacher, M. J.; Elsen, R.; Parks, G. K.; Spann, J. F., Jr.; Germany, G. A.

    1997-01-01

    Quantitative measurement of the transfer of energy and momentum to the ionosphere from the solar wind is one of the main objectives of the ISTP program. Global measurement of auroral energy deposition derived from observations of the longer wavelength LBH band emissions made by the Ultraviolet Imager on the Polar spacecraft is one of the key elements in this satellite and ground-based instrument campaign. These "measurements" are inferred by combining information from consecutive images using different filters and have a time resolution on the average of three minutes and are made continuously over a 5 to 8 hour period during each 18 hour orbit of the Polar spacecraft. The energy deposition in the ionosphere from auroral electron precipitation augments are due to Joule heating associated with field aligned currents. Assuming conjugacy of energy deposition between the two hemispheres the total energy input to the ionosphere through electron precipitation can be determined at high time resolution. Previously, precipitating particle measurements along the tracks of low altitude satellites provided only local measurements and the global energy precipitation could be inferred through models but not directly measured. We use the UVI images for the entire month of January 1997 to estimate the global energy deposition at high time resolution. We also sort the energy deposition into sectors to find possible trends, for example, on the dayside and nightside, or the dawn and dusk sides.

  15. LABORATORY MEASUREMENT OF SULFUR DIOXIDE DEPOSITION VELOCITIES

    EPA Science Inventory

    Measurements of sulfur dioxide deposition velocities have been carried out in the laboratory with the use of a cylindrical flow reaction. Analysis of data from these experiments was performed with models that specifically account for diffusive transport in the system. Consequentl...

  16. Global Auroral Energy Deposition Compared with Magnetic Indices

    NASA Technical Reports Server (NTRS)

    Brittnacher, M. J.; Fillingim, M. O.; Elsen, R.; Parks, G. K.; Germany, G. A.; Spann, J. F., Jr.

    1997-01-01

    Measurement of the global rate of energy deposition in the ionosphere via auroral particle precipitation is one of the primary goals of the Polar UVI program and is an important component of the ISTP program. The instantaneous rate of energy deposition for the entire month of January 1997 has been calculated by applying models to the UVI images and is presented by Fillingim et al. in this session. Magnetic indices, such as Kp, AE, and Dst, which are sensitive to variations in magnetospheric current systems have been constructed from ground magnetometer measurements and employed as measures of activity. The systematic study of global energy deposition raises the possibility of constructing a global magnetospheric activity index explicitly based on particle precipitation to supplement magnetic indices derived from ground magnetometer measurements. The relationship between global magnetic activity as measured by these indices and the rate of total global energy loss due to precipitation is not known at present. We study the correlation of the traditional magnetic index of Kp for the month of January 1997 with the energy deposition derived from the UVI images. We address the question of whether the energy deposition through particle precipitation generally matches the Kp and AE indices, or the more exciting, but distinct, possibility that this particle-derived index may provide an somewhat independent measure of global magnetospheric activity that could supplement traditional magnetically-based activity indices.

  17. Simple Approaches for Measuring Dry Atmospheric Nitrogen Deposition to Watersheds

    EPA Science Inventory

    Assessing the effects of atmospheric nitrogen (N) deposition on surface water quality requires accurate accounts of total N deposition (wet, dry, and cloud vapor); however, dry deposition is difficult to measure and is often spatially variable. Affordable passive sampling methods...

  18. Energy deposition in STARFIRE reactor components

    SciTech Connect

    Gohar, Y.; Brooks, J.N.

    1985-04-01

    The energy deposition in the STARFIRE commercial tokamak reactor was calculated based on detailed models for the different reactor components. The heat deposition and the 14 MeV neutron flux poloidal distributions in the first wall were obtained. The poloidal surface heat load distribution in the first wall was calculated from the plasma radiation. The Monte Carlo method was used for the calculation to allow an accurate modeling for the reactor geometry.

  19. Calculation of energy deposition distributions for simple geometries

    NASA Technical Reports Server (NTRS)

    Watts, J. W., Jr.

    1973-01-01

    When high-energy charged particles pass through a thin detector, the ionization energy loss in that detector is subject to fluctuations or straggling which must be considered in interpreting the data. Under many conditions, which depend upon the charge and energy of the incident particle and the detector geometry, the ionization energy lost by the particle is significantly different from the energy deposited in the detector. This problem divides naturally into a calculation of the energy loss that results in excitation and low-energy secondary electrons which do not travel far from their production points, and a calculation of energy loss that results in high-energy secondary electrons which can escape from the detector. The first calculation is performed using a modification of the Vavilov energy loss distribution. A cutoff energy is introduced above which all electrons are ignored and energy transferred to low energy particles is assumed to be equivalent to the energy deposited by them. For the second calculation, the trajectory of the primary particle is considered as a source of secondary high-energy electrons. The electrons from this source are transported using Monte Carlo techniques and multiple scattering theory, and the energy deposited by them in the detector is calculated. The results of the two calculations are then combined to predict the energy deposition distribution. The results of these calculations are used to predict the charge resolution of parallel-plate pulse ionization chambers that are being designed to measure the charge spectrum of heavy nuclei in the galactic cosmic-ray flux.

  20. Verifying eddy-correlation measurements of dry deposition: A study of the energy-balance components of the Pawnee grasslands. Forest Service research paper

    SciTech Connect

    Massman, W.J.; Fox, D.G.; Zeller, K.F.; Lukens, D.

    1990-02-01

    At the Central Plains Experimental Range/Long-Term Ecological Research (CPER/LTER) site at the Pawnee National Grasslands, scientists from both the Rocky Mountain Station and the Natural Resources Ecology Laboratory of Colorado State University are independently attempting to measure several major components of the surface energy balance. The report describes how well independent measurements of radiation and the transport of heat and water vapor achieve closure of the surface energy balance and, thereby, account for the gross energy available to and processed by an ecosystem. The motivation behind the study is to evaluate the eddy correlation technology which the authors have been using to measure the exchange of gaseous pollutants (NO{sub 2}, NOx, and O{sub 3}) between the atmosphere and the grassland ecosystem.

  1. DepositScan, a Scanning Program to Measure Spray Deposition Distributions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    DepositScan, a scanning program was developed to quickly measure spray deposit distributions on water sensitive papers or Kromekote cards which are widely used for determinations of pesticide spray deposition quality on target areas. The program is installed in a portable computer and works with a ...

  2. Measuring Thicknesses Of Vacuum-Deposited Organic Thin Films

    NASA Technical Reports Server (NTRS)

    David, Carey E.

    1996-01-01

    Method of measuring thickness of thin organic liquid film deposited in vacuum involves use of quartz-crystal monitor (QCM) calibrated by use of witness plate that has, in turn, calibrated by measurement of absorption of infrared light in deposited material. Present procedure somewhat tedious, but once calibration accomplished, thicknesses of organic liquid deposits monitored in real time and in situ by use of QCM.

  3. Physical deposit measures and commercial potential: The case of titanium-bearing heavy-mineral deposits

    USGS Publications Warehouse

    Attanasi, E.D.; DeYoung, J.H., Jr.

    1988-01-01

    Physical measures of mineral deposit characteristics, such as grade and tonnage, long have been used in both subjective and analytic models to predict favorability of areas for the occurrence of mineral deposits of particular types. After a deposit has been identified, however, the explorationist must decide whether to continue data collection, begin an economic feasibility study, or abandon the prospect. The decision maker can estimate the probability that a deposit will be commercial by examining physical measures. The amount of sampling data required before such a probability estimate can be considered reliable can be determined. A logit probability model estimated from onshore titanium-bearing heavy-mineral deposit data identifies and quantifies the relative influence of a deposit's physical measures on the chances of the deposit becoming commercial. A principal conclusion that can be drawn from the analysis is that, along with a measure of deposit size, the characteristics most important in predicting commercial potential are grades of the constituent minerals. Total heavy-mineral-bearing sand grade or even total titanium grade (without data on constituent mineral grades) are poor predictors of the deposit's commercial potential. ?? 1988 International Association for Mathematical Geology.

  4. Measuring Energy Sustainability

    SciTech Connect

    Greene, David L

    2009-01-01

    For the purpose of measurement, energy sustainability is defined as ensuring that future generations have energy resources that enable them to achieve a level of well-being at least as good as that of the current generation. It is recognized that there are valid, more comprehensive understandings of sustainability and that energy sustainability as defined here is only meaningful when placed in a broader context. Still, measuring energy sustainability is important to society because the rates of consumption of some fossil resources are now substantial in relation to measures of ultimate resources, and because conflicts between fossil energy use and environmental sustainability are intensifying. Starting from the definition, an equation for energy sustainability is derived that reconciles renewable fl ows and nonrenewable stocks, includes the transformation of energy into energy services, incorporates technological change and, at least notionally, allows for changes in the relationship between energy services and societal well-being. Energy sustainability must be measured retrospectively as well as prospectively, and methods for doing each are discussed. Connections to the sustainability of other resources are also critical. The framework presented is merely a starting point; much remains to be done to make it operational.

  5. Modeling Atmospheric Energy Deposition (by energetic ions)

    NASA Astrophysics Data System (ADS)

    Parkinson, C. D.; Brain, D. A.; Lillis, R. J.; Liemohn, M. W.; Bougher, S. W.

    2011-12-01

    deposition is conducted including a comparison of the influence relative to other energy sources (namely EUV photons) and previous efforts using the guiding center approximation.

  6. Substrate heating measurements in pulsed ion beam film deposition

    SciTech Connect

    Olson, J.C.; Davis, H.A.; Rej, D.J.; Waganaar, W.J.; Tallant, D.R.; Thompson, M.O.

    1995-05-01

    Diamond-like Carbon (DLC) films have been deposited at Los Alamos National Laboratory by pulsed ion beam ablation of graphite targets. The targets were illuminated by an intense beam of hydrogen, carbon, and oxygen ions at a fluence of 15-45 J/cm{sup 2}. Ion energies were on the order of 350 keV, with beam current rising to 35 kA over a 400 ns ion current pulse. Raman spectra of the deposited films indicate an increasing ratio of sp{sup 3} to sp{sup 2} bonding as the substrate is moved further away from the target and further off the target normal. Using a thin film platinum resistor at varying positions, we have measured the heating of the substrate surface due to the kinetic energy and heat of condensation of the ablated material. This information is used to determine if substrate heating is responsible for the lack of DLC in positions close to the target and near the target normal. Latest data and analysis will be presented.

  7. A nuclear fragmentation energy deposition model

    NASA Technical Reports Server (NTRS)

    Ngo, D. M.; Wilson, J. W.; Fogarty, T. N.; Buck, W. W.; Townsend, L. W. (Principal Investigator)

    1991-01-01

    A formalism for target fragment transport is presented with application to energy loss spectra in thin silicon devices. A nuclear data base is recommended that agrees well with the measurements of McNulty et al. using surface barrier detectors. High-energy events observed by McNulty et al., which are not predicted by intranuclear cascade models, are well represented by the present work.

  8. Motor Energy Conservation Measures

    Energy Science and Technology Software Center (ESTSC)

    2010-12-31

    This software requires inputs of simple motor inventory information and calculates the energy and cost benefits of various retrofit opportunities. This tool includes energy conservation measures for: High Efficiency Motor retrofit and Cogged V-belts retrofit. This tool calculates energy savings, demand reduction, cost savings, and building life cycle costs including: simple payback, discounted payback, net-present value, and savings to investment ratio. In addition this tool also displays the environmental benefits of a project.

  9. Overall elemental dry deposition velocities measured around Lake Michigan

    NASA Astrophysics Data System (ADS)

    Yi, Seung-Muk; Shahin, Usama; Sivadechathep, Jakkris; Sofuoglu, Sait C.; Holsen, Thomas M.

    Overall dry deposition velocities of several elements were determined by dividing measured fluxes by measured airborne concentrations in different particle size ranges. The dry deposition measurements were made with a smooth surrogate surface on an automated dry deposition sampler (Eagle II) and the ambient particle concentrations were measured with a dichotomous sampler. These long-term measurements were made in Chicago, IL, South Haven, MI, and Sleeping Bear Dunes, MI, from December 1993 through October 1995 as part of the Lake Michigan Mass Balance Study. In general, the dry deposition fluxes of elements were highly correlated with coarse particle concentrations, slightly less well correlated with total particle concentrations, and least well correlated with fine particle concentrations. The calculated overall dry deposition velocities obtained using coarse particle concentrations varied from approximately 12 cm s -1 for Mg in Chicago to 0.2 cm s -1 for some primarily anthropogenic metals at the more remote sites. The velocities calculated using total particle concentrations were slightly lower. The crustal elements (Mg, Al, and Mn) had higher deposition velocities than anthropogenic elements (V, Cr, Cu, Zn, Mo, Ba and Pb). For crustal elements, overall dry deposition velocities were higher in Chicago than at the other sites.

  10. Energy Deposition Processes in Titan's Upper Atmosphere

    NASA Technical Reports Server (NTRS)

    Sittler, Edward C., Jr.; Bertucci, Cesar; Coates, Andrew; Cravens, Tom; Dandouras, Iannis; Shemansky, Don

    2008-01-01

    Most of Titan's atmospheric organic and nitrogen chemistry, aerosol formation, and atmospheric loss are driven from external energy sources such as Solar UV, Saturn's magnetosphere, solar wind and galactic cosmic rays. The Solar UV tends to dominate the energy input at lower altitudes of approximately 1100 km but which can extend down to approximately 400 km, while the plasma interaction from Saturn's magnetosphere, Saturn's magnetosheath or solar wind are more important at higher altitudes of approximately 1400 km, but the heavy ion plasma [O(+)] of approximately 2 keV and energetic ions [H(+)] of approximately 30 keV or higher from Saturn's magnetosphere can penetrate below 950km. Cosmic rays with energies of greater than 1 GeV can penetrate much deeper into Titan's atmosphere with most of its energy deposited at approximately 100 km altitude. The haze layer tends to dominate between 100 km and 300 km. The induced magnetic field from Titan's interaction with the external plasma can be very complex and will tend to channel the flow of energy into Titan's upper atmosphere. Cassini observations combined with advanced hybrid simulations of the plasma interaction with Titan's upper atmosphere show significant changes in the character of the interaction with Saturn local time at Titan's orbit where the magnetosphere displays large and systematic changes with local time. The external solar wind can also drive sub-storms within the magnetosphere which can then modify the magnetospheric interaction with Titan. Another important parameter is solar zenith angle (SZA) with respect to the co-rotation direction of the magnetospheric flow. Titan's interaction can contribute to atmospheric loss via pickup ion loss, scavenging of Titan's ionospheric plasma, loss of ionospheric plasma down its induced magnetotail via an ionospheric wind, and non-thermal loss of the atmosphere via heating and sputtering induced by the bombardment of magnetospheric keV ions and electrons. This

  11. Measurements and modeling of reactive nitrogen deposition in southeast Brazil.

    PubMed

    Allen, A G; Machado, C M D; Cardoso, A A

    2011-05-01

    Increased reactive nitrogen (Nr) deposition due to expansion of agro-industry was investigated considering emission sources, atmospheric transport and chemical reactions. Measurements of the main inorganic nitrogen species (NO2, NH3, HNO3, and aerosol nitrate and ammonium) were made over a period of one year at six sites distributed across an area of ∼130,000 km2 in southeast Brazil. Oxidized species were estimated to account for ∼90% of dry deposited Nr, due to the region's large emissions of nitrogen oxides from biomass burning and road transport. NO2-N was important closer to urban areas, however overall HNO3-N represented the largest component of dry deposited Nr. A simple mathematical modeling procedure was developed to enable estimates of total Nr dry deposition to be made from knowledge of NO2 concentrations. The technique, whose accuracy here ranged from <1% to 29%, provides a useful new tool for the mapping of reactive nitrogen deposition. PMID:21354679

  12. Experimental measurements of the thermal conductivity of ash deposits: Part 1. Measurement technique

    SciTech Connect

    A. L. Robinson; S. G. Buckley; N. Yang; L. L. Baxter

    2000-04-01

    This paper describes a technique developed to make in situ, time-resolved measurements of the effective thermal conductivity of ash deposits formed under conditions that closely replicate those found in the convective pass of a commercial boiler. Since ash deposit thermal conductivity is thought to be strongly dependent on deposit microstructure, the technique is designed to minimize the disturbance of the natural deposit microstructure. Traditional techniques for measuring deposit thermal conductivity generally do not preserve the sample microstructure. Experiments are described that demonstrate the technique, quantify experimental uncertainty, and determine the thermal conductivity of highly porous, unsintered deposits. The average measured conductivity of loose, unsintered deposits is 0.14 {+-} 0.03 W/(m K), approximately midway between rational theoretical limits for deposit thermal conductivity.

  13. Deposition measurement of particulate matter in connection with corrosion studies.

    PubMed

    Ferm, Martin; Watt, John; O'Hanlon, Samantha; De Santis, Franco; Varotsos, Costas

    2006-03-01

    A new passive particle collector (inert surrogate surface) that collects particles from all directions has been developed. It was used to measure particle deposition at 35 test sites as part of a project that examined corrosion of materials in order that variation in particulate material could be used in development of dose-response functions in a modern multi-pollutant environment. The project, MULTI-ASSESS, was funded by the EU to examine the effects of air pollution on cultural heritage. Passive samplers were mounted rain-protected, and both in wind-protected and wind-exposed positions, to match the exposure of the samples for corrosion studies. The particle mass and its chemical content (nitrate, ammonium, sulfate, calcium, sodium, chloride, magnesium and potassium) were analysed. The loss of light reflectance on the surrogate surface was also measured. Very little ammonium and potassium was found, and one or more anions are missing in the ion balance. There were many strong correlations between the analysed species. The mass of analysed water-soluble ions was fairly constant at 24% of the total mass. The particle mass deposited to the samplers in the wind-protected position was about 25% of the particles deposited to an openly exposed sampler. The Cl-/Na+ ratios indicate a reaction between HNO(3) and NaCl. The deposited nitrate flux corresponds to the missing chloride. The Ca2+ deposition equals the SO4(2-) deposition and the anion deficiency. The SO4(2-) deposition most likely originates from SO2 that has reacted with basic calcium-containing particles either before or after they were deposited. The particle depositions at the urban sites were much higher than in nearby rural sites. The deposited mass correlated surprisingly well with the PM(10) concentration, except at sites very close to traffic. PMID:16518649

  14. Preliminary Strength Measurements of High Temperature Ash Filter Deposits

    SciTech Connect

    Kang, B.S.; Johnson, E.K.; Mallela, R.; Barberio, J.F.

    1996-12-31

    The objective of this study is to develop and evaluate preliminary strength measurement techniques for high temperature candle filter ash deposits. The efficient performance of a high temperature gas filtering system is essential for many of the new thermal cycles being proposed for power plants of the future. These new cycles hold the promise of higher thermal efficiency and lower emissions of pollutants. Many of these cycles involve the combustion or gasification of coal to produce high temperature gases to eventually be used in gas turbines. These high temperature gases must be relatively free of particulates. Today, the candle filter appears to be the leading candidate for high temperature particulate removal. The performance of a candle filter depends on the ash deposits shattering into relatively large particles during the pulse cleaning (back flushing) of the filters. These relatively large particles fall into the ash hopper and are removed from the system. Therefore, these 1247 particles must be sufficiently large so that they will not be re-entrained by the gas flow. The shattering process is dictated by the strength characteristics of the ash deposits. Consequently, the objective of this research is to develop measurements for the desired strength characteristics of the ash deposits. Experimental procedures were developed to measure Young`s modulus of the ash deposit at room temperature and the failure tensile strain of ash deposits from room temperature to elevated temperatures. Preliminary data has been obtained for both soft and hard ash deposits. The qualifier ``preliminary`` is used to indicate that these measurements are a first for this material, and consequently, the measurement techniques are not perfected. In addition, the ash deposits tested are not necessarily uniform and further tests are needed in order to obtain meaningful average data.

  15. Electron energy deposition in carbon monoxide gas

    NASA Technical Reports Server (NTRS)

    Liu, Weihong; Victor, G. A.

    1994-01-01

    A comprehensive set of electron impact cross sections for carbon monoxide molecules is presented on the basis of the most recent experimental measurements and theoretical calculations. The processes by which energetic electrons lose energy in CO gas are analyzed with these input cross sections. The efficiencies are computed of vibrational and electronic excitation, dissociation, ionization, and heating for CO gas with fractional ionization ranging from 0% to 10%. The calculated mean energy per ion pair for neutral CO gas is 32.3 eV, which is in excellent agreement with the experimental value of 32.2 eV. It increases to 35.6 eV at a fractional ionization of 1%, typical of supernovae ejecta.

  16. MEASUREMENT AND MODELING OF THE DRY DEPOSITION OF PEROXIDES

    EPA Science Inventory

    Measurements of the dry deposition velocity (Vd) of hydrogen peroxide (H2O2) and total organic peroxides (ROOH) were made during four experiments at three forested sites. Details and uncertainties associated with the measurement of peroxide...

  17. Energy deposition of corpuscular radiation in the middle atmosphere

    NASA Technical Reports Server (NTRS)

    Kudela, K.

    1989-01-01

    Main components of corpuscular radiation contributing to energy deposition (ED in eV/cu cm/s) in the atmosphere (10 to 100 km) are cosmic ray nuclei (CR - galactic and solar) and high energy electrons (HEE), mainly of magnetospheric origin. Galactic CR depending on solar cycle phase and latitude are dominant source of ED by corpuscular radiation below 50 to 60 km. Below 20 km secondaries must be assumed. More accurate treatment need assuming of individual HE solar flare particles, cut off rigidities in geomagnetic field and their changes during magnetospheric disturbances. Electrons E sub e greater than 30 keV of magnetospheric origin penetrating to atmosphere contribute to production rate below 100 km especially on night side. High temporal variability, local time dependence and complicated energy spectra lead to complicated structure of electron ED rate. Electrons of MeV energy found at geostationary orbit, pronouncing relation to solar and geomagnetic activity, cause maximum ED at 40 to 60 km. Monitoring the global distribution of ED by corpuscular radiation in middle atmosphere need continuing low altitude satellite measurements of both HEE and x ray BS from atmosphere as well as measurements of energy spectra and charge composition of HE solar flare particles.

  18. Estimated variability of National Atmospheric Deposition Program/Mercury Deposition Network measurements using collocated samplers

    USGS Publications Warehouse

    Wetherbee, G.A.; Gay, D.A.; Brunette, R.C.; Sweet, C.W.

    2007-01-01

    The National Atmospheric Deposition Program/Mercury Deposition Network (MDN) provides long-term, quality-assured records of mercury in wet deposition in the USA and Canada. Interpretation of spatial and temporal trends in the MDN data requires quantification of the variability of the MDN measurements. Variability is quantified for MDN data from collocated samplers at MDN sites in two states, one in Illinois and one in Washington. Median absolute differences in the collocated sampler data for total mercury concentration are approximately 11% of the median mercury concentration for all valid 1999-2004 MDN data. Median absolute differences are between 3.0% and 14% of the median MDN value for collector catch (sample volume) and between 6.0% and 15% of the median MDN value for mercury wet deposition. The overall measurement errors are sufficiently low to resolve between NADP/MDN measurements by ??2 ng??l-1 and ??2 ????m-2?? year-1, which are the contour intervals used to display the data on NADP isopleths maps for concentration and deposition, respectively. ?? Springer Science+Business Media B.V. 2007.

  19. Atomic Layer Deposition of Bismuth Vanadates for Solar Energy Materials.

    PubMed

    Stefik, Morgan

    2016-07-01

    The fabrication of porous nanocomposites is key to the advancement of energy conversion and storage devices that interface with electrolytes. Bismuth vanadate, BiVO4 , is a promising oxide for solar water splitting where the controlled fabrication of BiVO4 layers within porous, conducting scaffolds has remained a challenge. Here, the atomic layer deposition of bismuth vanadates is reported from BiPh3 , vanadium(V) oxytriisopropoxide, and water. The resulting films have tunable stoichiometry and may be crystallized to form the photoactive scheelite structure of BiVO4 . A selective etching process was used with vanadium-rich depositions to enable the synthesis of phase-pure BiVO4 after spinodal decomposition. BiVO4 thin films were measured for photoelectrochemical performance under AM 1.5 illumination. The average photocurrents were 1.17 mA cm(-2) at 1.23 V versus the reversible hydrogen electrode using a hole-scavenging sulfite electrolyte. The capability to deposit conformal bismuth vanadates will enable a new generation of nanocomposite architectures for solar water splitting. PMID:27246652

  20. Rapid Ammonia Deposition Measured Near Concentrated Animal Feeding Operations

    NASA Astrophysics Data System (ADS)

    Stanton, L. G.; Pan, D.; Sun, K.; Golston, L.; Tao, L.; Zondlo, M. A.

    2014-12-01

    Concentrated animal feeding operations (CAFOs) emit massive amounts of ammonia (NH3) to the atmosphere. Current measurements of NH3 are generally conducted far away from the sources (satellites, airplanes, etc.). There is insufficient knowledge about the dry deposition rate of NH3 near the sources, which might contribute to the large discrepancies between measured concentrations at CAFOs and those from models. During the 2014 NASA DISCOVER-AQ campaign, we designed a series of tests to measure the deposition rate of NH3 by utilizing a suite of sensors, including a LICOR LI-7700 methane sensor and Princeton University's custom open path NH3 sensor, which was mounted on top of a small SUV. Our mobile sampling technique enables us to follow feedlot emission plumes to see how ambient NH3 concentration decays as gases moves away from the CAFO. The mobile platform is used to perform upwind and downwind sampling to characterize the NH3 emission source. We tracked the change of the enhancement of NH3 concentration relative to the enhancement of CH4 concentration (ΔNH3:ΔCH4), while transecting the plume of individual cattle feedlots. Measured data shows that the high concentration of NH3 seen at the source decreases quickly as one moves further downwind from it. A time constant of approximately ten minutes has been calculated from the decay of the ΔNH3:ΔCH4 ratios while moving away from the sources. We also will compare our measurements with those of NASA's P-3B aerosol measurements to show that the majority must be lost to dry deposition. This rapid deposition suggests that large amounts of NH3 are being deposited in very close proximity to these CAFOs, which is consistent with previous findings of locally high soil pH near NH3 sources. Our results will be used to better characterize nitrogen deposition from cattle feedlots and estimate NH3 lifetime.

  1. Energy deposition characteristics of nanosecond dielectric barrier discharge plasma actuators: Influence of dielectric material

    NASA Astrophysics Data System (ADS)

    Correale, G.; Winkel, R.; Kotsonis, M.

    2015-08-01

    An experimental study aimed at the characterization of energy deposition of nanosecond Dielectric Barrier Discharge (ns-DBD) plasma actuators was carried out. Special attention was given on the effect of the thickness and material used for dielectric barrier. The selected materials for this study were polyimide film (Kapton), polyamide based nylon (PA2200), and silicone rubber. Schlieren measurements were carried out in quiescent air conditions in order to observe density gradients induced by energy deposited. Size of heated area was used to qualify the energy deposition coupled with electrical power measurements performed using the back-current shunt technique. Additionally, light intensity measurements showed a different nature of discharge based upon the material used for barrier, for a fixed thickness and frequency of discharge. Finally, a characterisation study was performed for the three tested materials. Dielectric constant, volume resistivity, and thermal conductivity were measured. Strong trends between the control parameters and the energy deposited into the fluid during the discharge were observed. Results indicate that efficiency of energy deposition mechanism relative to the thickness of the barrier strongly depends upon the material used for the dielectric barrier itself. In general, a high dielectric strength and a low volumetric resistivity are preferred for a barrier, together with a high heat capacitance and a low thermal conductivity coefficient in order to maximize the efficiency of the thermal energy deposition induced by an ns-DBD plasma actuator.

  2. X-ray reflectivity measurements of vacuum deposited thin films

    SciTech Connect

    Chason, M.; Chason, E.

    1992-12-31

    X-ray reflectivity using energy dispersive X-ray detection, a nondestructive probe of surface roughness over the region of {approximately} 1--50 {Angstrom}, has been used to investigate the characteristicsof vacuum deposited thin films. With a surface roughness sensitivity better than 1 {Angstrom} X-ray reflectivity is sensitive to interfaces between different materials for sample thicknesses up to approximately2000 {Angstrom} (depending on material density). We have investigated discrete Cr/Al deposits on quartz substrates and determined the surface roughness at the interfaces. We have also monitored the evolution ofthe Cr/Al interface following annealing. The experimental data is presented and discussed. The use of the technique for studying thin film deposits is addressed.

  3. X-ray reflectivity measurements of vacuum deposited thin films

    SciTech Connect

    Chason, M. ); Chason, E. )

    1992-01-01

    X-ray reflectivity using energy dispersive X-ray detection, a nondestructive probe of surface roughness over the region of [approximately] 1--50 [Angstrom], has been used to investigate the characteristicsof vacuum deposited thin films. With a surface roughness sensitivity better than 1 [Angstrom] X-ray reflectivity is sensitive to interfaces between different materials for sample thicknesses up to approximately2000 [Angstrom] (depending on material density). We have investigated discrete Cr/Al deposits on quartz substrates and determined the surface roughness at the interfaces. We have also monitored the evolution ofthe Cr/Al interface following annealing. The experimental data is presented and discussed. The use of the technique for studying thin film deposits is addressed.

  4. MCNPX benchmark of in-beam proton energy deposition

    SciTech Connect

    Corzine, K.; Ferguson, P.; Morgan, G.; Quintana, D.; Waters, L.; Cooper, R.; Liljestrand, R.; Whiteson, A.

    2000-07-01

    The MCNPX code is being used to calculate energy deposition in the accelerator production of tritium (APT) target/blanket system components. To ensure that these components are properly designed, the code must be validated. An energy deposition experiment was designed to aid in the code validation using thermocouple sensors in-beam and thermistor-type sensors in decoupler- and blanketlike regions. This paper focuses on the in-beam thermocouple sensors.

  5. Experimental measurements of the thermal conductivity of ash deposits: Part 2. Effects of sintering and deposit microstructure

    SciTech Connect

    A. L. Robinson; S. G. Buckley; N. Yang; L. L. Baxter

    2000-04-01

    The authors report results from an experimental study that examines the influence of sintering and microstructure on ash deposit thermal conductivity. The measurements are made using a technique developed to make in situ, time-resolved measurements of the effective thermal conductivity of ash deposits formed under conditions that closely replicate those found in the convective pass of a commercial boiler. The technique is designed to minimize the disturbance of the natural deposit microstructure. The initial stages of sintering and densification are accompanied by an increase in deposit thermal conductivity. Subsequent sintering continues to densify the deposit, but has little effect on deposit thermal conductivity. SEM analyses indicates that sintering creates a layered deposit structure with a relatively unsintered innermost layer. They hypothesize that this unsintered layer largely determines the overall deposit thermal conductivity. A theoretical model that treats a deposit as a two-layered material predicts the observed trends in thermal conductivity.

  6. FINITE-DIFFERENCE ELECTROMAGNETIC DEPOSITION/THERMOREGULATORY MODEL: COMPARISON BETWEEN THEORY AND MEASUREMENTS (JOURNAL VERSION)

    EPA Science Inventory

    The rate of the electromagnetic energy deposition and the resultant thermoregulatory response of a block model of a squirrel monkey exposed to plane-wave fields at 350 MHz were calculated using a finite-difference procedure. Noninvasive temperature measurements in live squirrel m...

  7. Global Auroral Energy Deposition during Substorm Onset Compared with Local Time and Solar Wind IMF Conditions

    NASA Technical Reports Server (NTRS)

    Spann, J. F.; Brittnacher, M.; Fillingim, M. O.; Germany, G. A.; Parks, G. K.

    1998-01-01

    The global images made by the Ultraviolet Imager (UVI) aboard the IASTP/Polar Satellite are used to derive the global auroral energy deposited in the ionosphere resulting from electron precipitation. During a substorm onset, the energy deposited and its location in local time are compared to the solar wind IMF conditions. Previously, insitu measurements of low orbiting satellites have made precipitating particle measurements along the spacecraft track and global images of the auroral zone, without the ability to quantify energy parameters, have been available. However, usage of the high temporal, spatial, and spectral resolution of consecutive UVI images enables quantitative measurement of the energy deposited in the ionosphere not previously available on a global scale. Data over an extended period beginning in January 1997 will be presented.

  8. Study of the energy deposit of muon bundles in the NEVOD detector

    NASA Astrophysics Data System (ADS)

    Bogdanov, A. G.; Dushkin, L. I.; Khokhlov, S. S.; Khomyakov, V. A.; Kindin, V. V.; Kokoulin, R. P.; Kovylyaeva, E. A.; Mannocchi, G.; Petrukhin, A. A.; Saavedra, O.; Shutenko, V. V.; Trinchero, G.; Yashin, I. I.

    2015-08-01

    In several cosmic ray experiments, an excess of multi-muon events in comparison with calculations performed in frame of the widely used hadron interaction models was found. In order to solve this puzzle, investigations of muon energy characteristics in EAS are required. An experiment on the measurement of the energy deposit of muon bundles in water has been started with the NEVOD-DECOR experimental complex. The results of the analysis of the first experimental data are discussed. It has been found that the average specific energy deposit in the Cherenkov calorimeter appreciably increases with zenith angle, thus reflecting the increase of the mean muon energy in the bundles. A possible evidence for an increase of the energy deposit at primary energies above 1017 eV is observed.

  9. Anode power deposition in quasi-steady MPD arcs. [accelerator anode heat flux measurement

    NASA Technical Reports Server (NTRS)

    Saber, A. J.; Jahn, R. G.

    1973-01-01

    The power deposited in the anode of a quasi-steady MPD accelerator has been measured directly by thermocouples attached to the inside surface of a shell anode which provide a local measurement of anode heat flux. The results over a range of arc currents from 5.5 to 44 kiloamperes and argon mass flows from 1 g/sec to 48 g/sec show that the fraction of the total input power deposited in the anode decreases drastically from 50% at an arc power of 200 kW to 10% at 20 MW, and that anode power is not uniformly deposited in the anode. A theoretical model of the anode heat transfer, including effects of anode work function, electron thermal energy, and anode sheath, can be brought into reasonable agreement with the measurements, provided the effective range of the conduction electrons from within the discharge plasma to the anode surface is properly acknowledged.

  10. Simulation of proton-induced energy deposition in integrated circuits

    NASA Technical Reports Server (NTRS)

    Fernald, Kenneth W.; Kerns, Sherra E.

    1988-01-01

    A time-efficient simulation technique was developed for modeling the energy deposition by incident protons in modern integrated circuits. To avoid the excessive computer time required by many proton-effects simulators, a stochastic method was chosen to model the various physical effects responsible for energy deposition by incident protons. Using probability density functions to describe the nuclear reactions responsible for most proton-induced memory upsets, the simulator determines the probability of a proton hit depositing the energy necessary for circuit destabilization. This factor is combined with various circuit parameters to determine the expected error-rate in a given proton environment. An analysis of transient or dose-rate effects is also performed. A comparison to experimental energy-disposition data proves the simulator to be quite accurate for predicting the expected number of events in certain integrated circuits.

  11. Single crystal chemical vapor deposit diamond detector for energetic plasma measurement in space

    NASA Astrophysics Data System (ADS)

    Ogasawara, K.; Broiles, T. W.; Coulter, K. E.; Dayeh, M. A.; Desai, M. I.; Livi, S. A.; McComas, D. J.; Walther, B. C.

    2015-03-01

    This study reports the performance of single crystal chemical vapor deposit diamond detectors for measuring space plasma and energetic particles: ~7 keV energy resolution for protons with a 14 keV threshold level, and good response linearity for ions and electrons as expected from Monte-Carlo calculations of primary particle energy loss. We investigated that these diamond detectors are able to operate at high temperature (> 70 ° C) and have fast response times (< 1 ns rise time). While silicon detectors have proven capability over this energy range for space plasma measurements, diamond detectors offer a faster response, higher temperature operation, greater radiation tolerance, and immunity to light.

  12. In situ measurement of conductivity during nanocomposite film deposition

    NASA Astrophysics Data System (ADS)

    Blattmann, Christoph O.; Pratsinis, Sotiris E.

    2016-05-01

    Flexible and electrically conductive nanocomposite films are essential for small, portable and even implantable electronic devices. Typically, such film synthesis and conductivity measurement are carried out sequentially. As a result, optimization of filler loading and size/morphology characteristics with respect to film conductivity is rather tedious and costly. Here, freshly-made Ag nanoparticles (nanosilver) are made by scalable flame aerosol technology and directly deposited onto polymeric (polystyrene and poly(methyl methacrylate)) films during which the resistance of the resulting nanocomposite is measured in situ. The formation and gas-phase growth of such flame-made nanosilver, just before incorporation onto the polymer film, is measured by thermophoretic sampling and microscopy. Monitoring the nanocomposite resistance in situ reveals the onset of conductive network formation by the deposited nanosilver growth and sinternecking. The in situ measurement is much faster and more accurate than conventional ex situ four-point resistance measurements since an electrically percolating network is detected upon its formation by the in situ technique. Nevertheless, general resistance trends with respect to filler loading and host polymer composition are consistent for both in situ and ex situ measurements. The time lag for the onset of a conductive network (i.e., percolation) depends linearly on the glass transition temperature (Tg) of the host polymer. This is attributed to the increased nanoparticle-polymer interaction with decreasing Tg. Proper selection of the host polymer in combination with in situ resistance monitoring therefore enable the optimal preparation of conductive nanocomposite films.

  13. Transonic flow control by means of local energy deposition

    NASA Astrophysics Data System (ADS)

    Aul'Chenko, S. M.; Zamuraev, V. P.; Kalinina, A. P.

    2011-11-01

    Experimental data for the feasibility of transonic flow control by means of energy deposition are generalized. Energy supplied to the immediate vicinity of a body in stream before a compression shock is found to result in the nonlinear interaction of introduced disturbances with the shock and the surface in zones extended along the surface. A new, explosive gasdynamic mechanism behind the shift of the compression shock is discovered. It is shown that the nonlinear character of the interaction may considerably decrease the wave resistance of, e.g., transonic airfoils. It is found that energy supply from without stabilizes a transonic flow about an airfoil—the effect similar to the Khristianovich stabilization effect. The dependence of the energy deposition optimal frequency on the energy source parameters and Mach number of the incoming flow at which the resistance drops to the greatest extent is obtained. The influence of the real thermodynamic properties and viscosity of air is studied.

  14. DESIGN AND IMPLEMENTATION OF A TRANSPORTABLE SYSTEM FOR DIRECT MEASUREMENT OF DRY DEPOSITION FLUXES

    EPA Science Inventory

    Dry deposition of air pollutants is expensive and difficult to measure. icks et al. (1985) proposed the dry deposition inferential model determines dry deposition fluxes as the product of a measured concentration and a modeled deposition velocity. eposition velocity is calculated...

  15. Gamma-ray transfer and energy deposition in supernovae

    NASA Technical Reports Server (NTRS)

    Swartz, Douglas A.; Sutherland, Peter G.; Harkness, Robert P.

    1995-01-01

    Solutions to the energy-independent (gray) radiative transfer equations are compared to results of Monte Carlo simulations of the Ni-56 and Co-56 decay gamma-ray energy deposition in supernovae. The comparison shows that an effective, purely absorptive, gray opacity, kappa(sub gamma) approximately (0. 06 +/- 0.01)Y(sub e) sq cm/g, where Y is the total number of electrons per baryon, accurately describes the interaction of gamma-rays with the cool supernova gas and the local gamma-ray energy deposition within the gas. The nature of the gamma-ray interaction process (dominated by Compton scattering in the relativistic regime) creates a weak dependence of kappa(sub gamma) on the optical thickness of the (spherically symmetric) supernova atmosphere: The maximum value of kappa(sub gamma) applies during optically thick conditions when individual gamma-rays undergo multiple scattering encounters and the lower bound is reached at the phase characterized by a total Thomson optical depth to the center of the atmosphere tau(sub e) approximately less than 1. Gamma-ray deposition for Type Ia supernova models to within 10% for the epoch from maximum light to t = 1200 days. Our results quantitatively confirm that the quick and efficient solution to the gray transfer problem provides an accurate representation of gamma-ray energy deposition for a broad range of supernova conditions.

  16. Nuclear stopping and energy deposition into the central rapidity region

    SciTech Connect

    Zingman, J.A.

    1987-08-03

    Nuclear stopping and energy deposition into the central rapidity region of ultrarelativistic heavy-ion collisions are studied through the application of a model incorporating hydrodynamic baryon flow coupled to a self-consistent field calculated in the flux tube model. Ultrarelativistic heavy ion collisions are modeled in which the nuclei have passed through each other and as a result are charged and heated.

  17. Energy deposition via magnetoplasmadynamic acceleration: I. Experiment

    NASA Astrophysics Data System (ADS)

    Gilland, James; Mikellides, Pavlos; Marriott, Darin

    2009-02-01

    The expansion of a high-temperature fusion plasma through an expanding magnetic field is a process common to most fusion propulsion concepts. The propulsive efficiency of this process has a strong bearing on the overall performance of fusion propulsion. In order to simulate the expansion of a fusion plasma, a concept has been developed in which a high velocity plasma is first stagnated in a converging magnetic field to high (100s of eV) temperatures, then expanded though a converging/diverging magnetic nozzle. As a first step in constructing this experiment, a gigawatt magnetoplasmadynamic plasma accelerator was constructed to generate the initial high velocity plasma and has been characterized. The source is powered by a 1.6 MJ, 1.6 ms pulse forming network. The device has been operated with currents up to 300 kA and power levels up to 200 MWe. These values are among the highest levels reached in an magnetoplasmadynamic thruster. The device operation has been characterized by quasi-steady voltage and current measurements for helium mass flow rates from 0.5 to 27 g s-1. Probe results for downstream plasma density and electron temperature are also presented. The source behavior is examined in terms of current theories for magnetoplasmadynamic thrusters.

  18. Laboratory measurements of parameters affecting wet deposition of methyl iodide

    SciTech Connect

    Maeck, W.J.; Honkus, R.J.; Keller, J.H.; Voilleque, P.G.

    1984-09-01

    The transfer of gaseous methyl iodide (CH/sub 3/I) to raindrops and the initial retention by vegetation of CH/sub 3/I in raindrops have been studied in a laboratory experimental program. The measured air-to-drop transfer parameters and initial retention factors both affect the wet deposition of methyl iodide onto vegetation. No large effects on the air-to-drop transfer due to methyl iodide concentration, temperature, acidity, or rain type were observed. Differences between laboratory measurements and theoretical values of the mass transfer coefficient were found. Pasture grass, lettuce, and alfalfa were used to study the initial retention of methyl iodide by vegetation. Only a small fraction of the incident CH/sub 3/I in raindrops was held by any of the three vegetation types.

  19. Energy deposition via magnetoplasmadynamic acceleration: II. modeling and performance predictions

    NASA Astrophysics Data System (ADS)

    Mikellides, P. G.; England, B.; Gilland, J. H.

    2009-02-01

    A time-dependent, two-dimensional, axisymmetric magnetohydrodynamics code is employed to model, validate and extend the experimentally-limited performance characteristics of a gigawatt-level plasma source that utilized magnetoplasmadynamic (MPD) acceleration for gas energy deposition. Accurate modeling required an upgrade of the code's circuit routines to properly capture the pulse-forming-network current waveform which also serves as the primary variable for validation. Comparisons with experimentally deduced current waveforms were in good agreement for all power levels. The simulations also produced values for the plasma voltage which were compared with the measured voltage across the electrodes. The trend agreement was encouraging while the magnitude of the discrepancy is approximately constant and interpreted as a representation of the electrode fall voltage. Force computations captured the expected electromagnetic acceleration trends and serve as further verification. They also allow examination of the device as a very high power MPD thruster operating at power levels in excess of 180 MW. The computations offer insights into the plasma's characteristics at different power levels through two-dimensional distributions of pertinent parameters and identify design guidelines for effective stagnation temperature values as a function of the mass-flow rate.

  20. System to quantify gamma-ray radial energy deposition in semiconductor detectors

    DOEpatents

    Kammeraad, Judith E.; Blair, Jerome J.

    2001-01-01

    A system for measuring gamma-ray radial energy deposition is provided for use in conjunction with a semiconductor detector. The detector comprises two electrodes and a detector material, and defines a plurality of zones within the detecting material in parallel with the two electrodes. The detector produces a charge signal E(t) when a gamma-ray interacts with the detector. Digitizing means are provided for converting the charge signal E(t) into a digitized signal. A computational means receives the digitized signal and calculates in which of the plurality of zones the gamma-ray deposited energy when interacting with the detector. The computational means produces an output indicating the amount of energy deposited by the gamma-ray in each of the plurality of zones.

  1. Auroral energy deposition rate, characteristic electron energy, and ionospheric parameters derived from Dynamics Explorer 1 images

    NASA Technical Reports Server (NTRS)

    Rees, M. H.; Lummerzheim, D.; Roble, R. G.; Winningham, J. D.; Craven, J. D.

    1988-01-01

    Auroral images obtained by the Spin Scan Auroral Imager (SAI) aboard the DE-1 satellite were used to derive auroral energy deposition rate, characteristic electron energy, and ionospheric parameters. The principles involved in the imaging technique and the physical mechanisms that underlie the relationship between the spectral images and the geophysical parameters are discussed together with the methodology for implementing such analyses. It is shown that images obtained with the SAI provide global parameters at 12-min temporal resolution; the spatial resolution is limited by the field of view of a pixel. The analysis of the 12-min images presented yielded a representation of ionospheric parameters that was better than can be obtained using empirical models based on local measurements averaged over long periods of time.

  2. BEAM INDUCED ENERGY DEPOSITION IN MUON STORAGE RINGS.

    SciTech Connect

    MOKHOV,N.V.; JOHNSTONE,C.J.; PARKER,B.L.

    2001-06-18

    Beam-induced radiation effects have been simulated for 20 and 50 GeV muon storage rings designed for a Neutrino Factory. It is shown that by appropriately shielding the superconducting magnets, quench stability, acceptable dynamic heat loads, and low residual dose rates can be achieved. Alternatively, if a specially-designed skew focusing magnet without superconducting coils on the magnet's mid-plane is used, then the energy is deposited preferentially in the warm iron yoke or outer cryostat layers and internal shielding may not be required. In addition to the component irradiation analysis, shielding studies have been performed. Calculations of the external radiation were done for both designs but the internal energy deposition calculations for the 20 GeV Study-2 lattice are still in progress.

  3. Beam-induced energy deposition in muon storage rings

    SciTech Connect

    Nikolai V. Mokhov; Carol J. Johnstone; Brett Parker

    2001-06-22

    Beam-induced radiation effects have been simulated for 20 and 50 GeV muon storage rings designed for a Neutrino Factory. It is shown that by appropriately shielding the superconducting magnets, quench stability, acceptable dynamic heat loads, and low residual dose rates can be achieved. Alternatively, if a specially-designed skew focusing magnet without superconducting coils on the magnet's mid-plane is used, then the energy is deposited preferentially in the warm iron yoke or outer cryostat layers and internal shielding may not be required. In addition to the component irradiation analysis, shielding studies have been performed. Calculations of the external radiation were done for both designs but the internal energy deposition calculations for the 20 GeV Study-2 lattice are still in progress.

  4. Critical energy deposit in heavy ion complete fusion

    SciTech Connect

    Fonte, R.; Insolia, A. Dipartimento di Fisica dell'Universita di Catania corso Italia, 57-95129 Catania, Italy)

    1991-07-01

    In the framework of an {ital l}-window model for complete fusion reactions within a sharp cutoff approximation, the problem of the maximum excitation energy which can be deposited in a compound nucleus is discussed. Predictions about the spin distribution of the compound nucleus are compared with the conclusions of a recent analysis of the {sup 28}Si+{sup 28}Si fusion reaction.

  5. Effect of energy deposition rate on plasma expansion characteristics and nanoparticle generation by electrical explosion of conductors

    NASA Astrophysics Data System (ADS)

    Sahoo, Somanand; Saxena, Alok K.; Kaushik, Trilok C.; Gupta, Satish C.

    2015-12-01

    The process of electrical explosion of metal conductors has been used to produce nano particles under normal atmospheric conditions. The impact of average rate of energy deposition, overheat factor on size distribution of particles and expansion characteristics of plasma generated from exploding conductors have been experimentally investigated. The particle size was characterized by TEM and XRD while expansion rate was measured using streak photography.The geometric mean diameter of size distribution was found to be influenced by rate of energy deposition in the conductors. It is observed that higher the rate of energy deposition, higher will be the expansion velocity, and smaller will be the size of particles formed.

  6. Monte Carlo simulation of energy deposition by low-energy electrons in molecular hydrogen

    NASA Technical Reports Server (NTRS)

    Heaps, M. G.; Furman, D. R.; Green, A. E. S.

    1975-01-01

    A set of detailed atomic cross sections has been used to obtain the spatial deposition of energy by 1-20-eV electrons in molecular hydrogen by a Monte Carlo simulation of the actual trajectories. The energy deposition curve (energy per distance traversed) is quite peaked in the forward direction about the entry point for electrons with energies above the threshold of the electronic states, but the peak decreases and broadens noticeably as the electron energy decreases below 10 eV (threshold for the lowest excitable electronic state of H2). The curve also assumes a very symmetrical shape for energies below 10 eV, indicating the increasing importance of elastic collisions in determining the shape of the curve, although not the mode of energy deposition.

  7. Steam System Energy Conservation Measures

    Energy Science and Technology Software Center (ESTSC)

    2010-12-31

    This software requires inputs of simple system inventory information and calculates the energy and cost benefits of various retrofit opportunities. This tool includes energy conservation measures for: fixing steam leaks. This tool calculates energy savings, demand reduction, cost savings, and building life cycle costs including: simple payback, discounted payback, net-present value, and savings to investment ratio. In addition this tool also displays the environmental benefits of a project.

  8. Estimating the energy deposition in the mesosphere from anisotropic electron fluxes during REP events

    NASA Astrophysics Data System (ADS)

    Stadsnes, Johan; Sandanger, Marit; Nesse Tyssoy, Hilde; Odegaard, Linn-Kristine; Asnes, Arne

    Data from the MEPED particle spectrometers on the Polar Orbiting Operational Environmental Satellites (POES) are often used for estimating the energy deposition in the upper atmosphere from electrons in the energy range 30 keV - 2.5 MeV. MEPED includes two collimated electron detectors, which are pointing approximately towards zenith (0 degree detector) and in the horizontal plane (90 degree detector). At medium and high geomagnetic latitudes the 0 degree detector measures particles within a limited part of the bounce loss cone and the 90 degree detector measures particles outside or near the edge of the loss cone. The electron fluxes often show strong pitch angle anisotropy which causes large uncertainty in the estimate of energy deposition based on these measurements. An upper estimate is derived from the 90 degree detector and a lower estimate from the 0 degree detector. The electron anisotropy is to a large extent determined by wave-particle interactions causing pitch angle diffusion driving electrons into the bounce loss cone. The pitch angle anisotropy is dependent on the strength of the diffusion. We are developing a method for calculating the flux versus pitch angle in the loss cone based on the measured electron fluxes and modeled flux profiles from pitch angle scattering by whistler mode waves. We will present results from calculation of the energy deposition using the derived anisotropic flux distribution during a REP event in 2008.

  9. Time resolved measurements of deposition and dust in NSTX

    NASA Astrophysics Data System (ADS)

    Skinner, C. H.; Biewer, T. M.; Nishino, N.; Parker, C. V.

    2005-10-01

    Tritium codeposition and dust accumulation will impact the operation of next-step devices such as ITER and measurements in contemporary tokamaks are important to gain a predictive understanding that can help mitigate the associated risk. We will discuss results from three diagnostics that address these issues. Incandescent particles have been observed by fast cameras moving at 10-100 m/s in some NSTX plasmas. The particle trajectories appear to be complex including velocity reversal, and particle breakup. We also have developed a novel electrostatic device to detect dust on remote surfaces[1,2]. Recent laboratory work with ultra-fine 25 µm trace spacing has shown 1 μg/cm2 sensitivity with information on the particle size in the detected waveform. Quartz crystal microbalances have been deployed in NSTX to measure pulse-by-pulse deposition at various locations[3] and observations from the current campaign will be reported. [1] A. Bader et al., Rev. Sci. Instrum., 75, (2004) 370. [2] C. Voinier et al., J. Nucl. Mater. in press (2005) [3] C. H. Skinner et al., J. Nucl. Mater., 337-339 (2005) 129.

  10. Direct ion flux measurements at high-pressure-depletion conditions for microcrystalline silicon deposition

    SciTech Connect

    Bronneberg, A. C.; Kang, X.; Palmans, J.; Janssen, P. H. J.; Lorne, T.; Creatore, M.; Sanden, M. C. M. van de

    2013-08-14

    The contribution of ions to the growth of microcrystalline silicon thin films has been investigated in the well-known high-pressure-depletion (HPD) regime by coupling thin-film analysis with plasma studies. The ion flux, measured by means of a capacitive probe, has been studied in two regimes, i.e., the amorphous-to-microcrystalline transition regime and a low-to-high power regime; the latter regime had been investigated to evaluate the impact of the plasma power on the ion flux in collisional plasmas. The ion flux was found not to change considerably under the conditions where the deposited material undergoes a transition from the amorphous to the microcrystalline silicon phase; for solar-grade material, an ion-to-Si deposition flux of ∼0.30 has been determined. As an upper-estimation of the ion energy, a mean ion energy of ∼19 eV has been measured under low-pressure conditions (<1 mbar) by means of a retarding field energy analyzer. Combining this upper-estimate with an ion per deposited Si atom ratio of ∼0.30, it is concluded that less than 6 eV is available per deposited Si atom. The addition of a small amount of SiH{sub 4} to an H{sub 2} plasma resulted in an increase of the ion flux by about 30% for higher power values, whereas the electron density, deduced from optical emission spectroscopy analysis, decreased. The electron temperature, also deduced from optical emission spectroscopy analysis, reveals a slight decrease with power. Although the dominant ion in the HPD regime is SiH{sub 3}{sup +}, i.e., a change from H{sub 3}{sup +} in pure hydrogen HPD conditions, the measured larger ion loss can be explained by assuming steeper electron density profiles. These results, therefore, confirm the results reported so far: the ion-to-Si deposition flux is relatively large but has neither influence on the microcrystalline silicon film properties nor on the phase transition. Possible explanations are the reported high atomic hydrogen to deposition flux ratio

  11. Heterogeneous Shock Energy Deposition in Shock Wave Consolidation of Metal Powders.

    NASA Astrophysics Data System (ADS)

    Mutz, Andrew Howard

    Shock wave consolidation of powder is a high deformation rate process in which a shock wave generated by an explosive or a colliding projectile rapidly densifies and bonds together the powder particles into a solid compact. The deposition of the shock energy during this process is highly inhomogeneous on the powder particle scale. Evidence of the extent and pattern of the energy deposition was provided by recovery experiments performed using a crystalline metallic glass forming alloy, and analyzed using a heat flow model. The energy deposited during the shock wave passage was best modeled as deposited partly into the particle bulk and partly onto particle surfaces. To investigate this inhomogeneity, and the powder parameters which influence it, a propellant driven gas gun was designed, built and utilized. The planarity of the shock waves produced using the targets designed for the gun was established. Powder - powder thermocouples were impacted with powders of varying sizes to establish the effect of particle size on energy deposition. Small particles in contact with large ones were inferred to absorb the greater fraction of shock energy. Hardened and unhardened steel powder was shocked to investigate the effect of particle hardness on energy distribution. The recovered compacts were not measurably affected by the initial hardness. Compaction experiments were performed on a Ni based super-alloy and on a SiC reinforced Ti matrix composite to test some of the practical applications of the process and the target designs developed. Superior tensile properties were observed in the shock consolidated and heat treated Ni based 718 alloy. The SiC reinforced composite was recovered in the intended net shape with no macro-cracks in the compact body, but with fractured SiC particles.

  12. Evaluation of eruptive energy of a pyroclastic deposit applying fractal geometry to fragment size distributions

    NASA Astrophysics Data System (ADS)

    Paredes Marino, Joali; Morgavi, Daniele; Di Vito, Mauro; de Vita, Sandro; Sansivero, Fabio; Perugini, Diego

    2016-04-01

    Fractal fragmentation theory has been applied to characterize the particle size distribution of pyroclastic deposits generated by volcanic explosions. Recent works have demonstrated that fractal dimension on grain size distributions can be used as a proxy for estimating the energy associated with volcanic eruptions. In this work we seek to establish a preliminary analytical protocol that can be applied to better characterize volcanic fall deposits and derive the potential energy for fragmentation that was stored in the magma prior/during an explosive eruption. The methodology is based on two different techniques for determining the grain-size distribution of the pyroclastic samples: 1) dry manual sieving (particles larger than 297μm), and 2) automatic grain size analysis via a CamSizer-P4®device, the latter measure the distribution of projected area, obtaining a cumulative distribution based on volume fraction for particles up to 30mm. Size distribution data have been analyzed by applying the fractal fragmentation theory estimating the value of Df, i.e. the fractal dimension of fragmentation. In order to test our protocol we studied the Cretaio eruption, Ischia island, Italy. Results indicate that size distributions of pyroclastic fall deposits follow a fractal law, indicating that the fragmentation process of these deposits reflects a scale-invariant fragmentation mechanism. Matching the results from manual and automated techniques allows us to obtain a value of the "fragmentation energy" from the explosive eruptive events that generate the Cretaio deposits. We highlight the importance of these results, based on fractal statistics, as an additional volcanological tool for addressing volcanic risk based on the analyses of grain size distributions of natural pyroclastic deposits. Keywords: eruptive energy, fractal dimension of fragmentation, pyroclastic fallout.

  13. Internal energy deposition with silicon nanoparticle-assisted laser desorption/ionization (SPALDI) mass spectrometry

    NASA Astrophysics Data System (ADS)

    Dagan, Shai; Hua, Yimin; Boday, Dylan J.; Somogyi, Arpad; Wysocki, Ronald J.; Wysocki, Vicki H.

    2009-06-01

    The use of silicon nanoparticles for laser desorption/ionization (LDI) is a new appealing matrix-less approach for the selective and sensitive mass spectrometry of small molecules in MALDI instruments. Chemically modified silicon nanoparticles (30 nm) were previously found to require very low laser fluence in order to induce efficient LDI, which raised the question of internal energy deposition processes in that system. Here we report a comparative study of internal energy deposition from silicon nanoparticles to previously explored benzylpyridinium (BP) model compounds during LDI experiments. The internal energy deposition in silicon nanoparticle-assisted laser desorption/ionization (SPALDI) with different fluorinated linear chain modifiers (decyl, hexyl and propyl) was compared to LDI from untreated silicon nanoparticles and from the organic matrix, [alpha]-cyano-4-hydroxycinnamic acid (CHCA). The energy deposition to internal vibrational modes was evaluated by molecular ion survival curves and indicated that the ions produced by SPALDI have an internal energy threshold of 2.8-3.7 eV. This is slightly lower than the internal energy induced using the organic CHCA matrix, with similar molecular survival curves as previously reported for LDI off silicon nanowires. However, the internal energy associated with desorption/ionization from the silicon nanoparticles is significantly lower than that reported for desorption/ionization on silicon (DIOS). The measured survival yields in SPALDI gradually decrease with increasing laser fluence, contrary to reported results for silicon nanowires. The effect of modification of the silicon particle surface with semifluorinated linear chain silanes, including fluorinated decyl (C10), fluorinated hexyl (C6) and fluorinated propyl (C3) was explored too. The internal energy deposited increased with a decrease in the length of the modifier alkyl chain. Unmodified silicon particles exhibited the highest analyte internal energy

  14. Energy Deposition and Radiological Studies for the LBNF Hadron Absorber

    SciTech Connect

    Rakhno, I. L.; Mokhov, N. V.; Tropin, I. S.; Eidelman, Y. I.

    2015-06-25

    Results of detailed Monte Carlo energy deposition and radiological studies performed for the LBNF hadron absorber with the MARS15 code are described. The model of the entire facility, that includes a pion-production target, focusing horns, target chase, decay channel, hadron absorber system – all with corresponding radiation shielding – was developed using the recently implemented ROOT-based geometry option in the MARS15 code. Both normal operation and accidental conditions were studied. Results of detailed thermal calculations with the ANSYS code helped to select the most viable design options.

  15. Detailed modeling of microwave energy deposition in EBT devices

    SciTech Connect

    Batchelor, D.B.; Rasmussen, D.A.; Goldfinger, R.C.

    1983-08-01

    Ray-tracing studies have been combined with a simple wave power balance model to provide a complete, albeit approximate, description of microwave power deposition in the ELMO Bumpy Torus (EBT-I), EBT-Scale (EBT-S), and EBT Proof-of-Principle (EBT-P) devices. Electron cyclotron absorption of ordinary and extraordinary waves by the combined core plasma and relativistic annuli is calculated using a fully relativistic damping package developed for the RAYS geometrical optics code. The rays are traced in finite-beta bumpy cylinder plasma equilibria that are obtained from the Oak Ridge National Laboratory (ORNL) two-dimensional (2-D) equilibrium code. These results for direct, single-pass absorption are combined with results from a statistical model for the deposition of multiply reflected and mode-converted waves to obtain estimates of the power deposited in the core, surface, and annulus plasma components. Wave absorption by the annuli and by the core components at the fundamental and second harmonic resonances, reflection and Budden tunneling of the extraordinary mode at the right-hand cutoff, and conversion between ordinary and extraordinary modes upon wall reflection are the processes included in the power balance model. Experimental measurements of wave power flux on the cavity wall in EBT-S made with a simple microwave calorimeter are in good agreement with predictions of the model for a variety of operating configurations.

  16. Fossil fuel energy resources of Ethiopia: Oil shale deposits

    NASA Astrophysics Data System (ADS)

    Wolela, Ahmed

    2006-10-01

    The energy crisis affects all countries in the world. Considering the price scenarios, many countries in Africa have begun to explore various energy resources. Ethiopia is one of the countries that depend upon imported petroleum products. To overcome this problem, geological studies suggest a significant occurrence of oil shale deposits in Ethiopia. The Inter-Trappean oil shale-bearing sediments are widely distributed on the South-Western Plateau of Ethiopia in the Delbi-Moye, Lalo-Sapo, Sola, Gojeb-Chida and Yayu Basins. The oil shale-bearing sediments were deposited in fluviatile and lacustrine environments. The oil shales contain mixtures of algal, herbaceous and higher plant taxa. They are dominated by algal-derived liptinite with minor amounts of vitrinite and inertinite. The algal remains belong to Botryococcus and Pediastrum. Laboratory results confirm that the Ethiopian oil shales are dominated by long-chain aliphatic hydrocarbons and have a low sulphur content. Type-II and Type-I kerogen dominated the studied oil shales. Type-II and Type-I are good source rocks for oil and gas generation. Hydrogen index versus Tmax value plots indicated that most of the oil shale samples fall within the immature-early mature stage for hydrocarbon generation, consistent with the Ro values that range from 0.3% to 0.64%. Pyrolysis data of the oil shales sensu stricto indicate excellent source rocks with up to 61.2% TOC values. Calorific value ranges from 400 to 6165 cal/g. Palynological studies confirmed that the oil shale-bearing sediments of Ethiopia range from Eocene to Miocene in age. A total of about 253,000,000 ton of oil shale is registered in the country. Oil shale deposits in Ethiopia can be used for production of oil and gas.

  17. Hot-Jupiter Inflation due to Deep Energy Deposition

    NASA Astrophysics Data System (ADS)

    Ginzburg, Sivan; Sari, Re'em

    2015-04-01

    Some extrasolar giant planets in close orbits—“hot Jupiters”—exhibit larger radii than that of a passively cooling planet. The extreme irradiation {{L}eq} these hot Jupiters receive from their close in stars creates a thick isothermal layer in their envelopes, which slows down their convective cooling, allowing them to retain their inflated size for longer. This is still insufficient to explain the observed sizes of the most inflated planets. Some models invoke an additional power source, deposited deep in the planet's envelope. Here, we present an analytical model for the cooling of such irradiated and internally heated gas giants. We show that a power source {{L}dep}, deposited at an optical depth {{τ }dep}, creates an exterior convective region, between optical depths {{L}eq}/{{L}dep} and {{τ }dep}, beyond which a thicker isothermal layer exists, which in extreme cases may extend to the center of the planet. This convective layer, which occurs only for {{L}dep}{{τ }dep}\\gt {{L}eq}, further delays the cooling of the planet. Such a planet is equivalent to a planet irradiated with {{L}eq}{{(1+{{L}dep}{{τ }dep}/{{L}eq})}β }, where β ≈ 0.35 is an effective power-law index describing the radiative energy density as a function of the optical depth for a convective planet U\\propto {{τ }β }. Our simple analytical model reproduces the main trends found in previous numerical works and provides an intuitive understanding. We derive scaling laws for the cooling rate of the planet, its central temperature, and radius. These scaling laws can be used to estimate the effects of tidal or Ohmic dissipation, wind shocks, or any other mechanism involving energy deposition on the sizes of hot Jupiters.

  18. Hot-electron energy deposition around unsupported laser targets

    SciTech Connect

    Eidmann, K.; Maaswinkel, A.; Sigel, R.; Witkowski, S.; Amiranoff, F.; Fabbro, R.; Hares, J.D.; Kilkenny, J.D.

    1983-09-01

    Free-falling spheres, released by a simple mechanism, are used as laser targets. Hot-electron energy transport upon one-sided irradiation with 300-ps iodine laser pulses (6 x 10/sup 15/ W cm/sup -2/) is studied by various methods, including x-ray pinhole photography and time-resolved shadowgraphy. Spatial energy deposition is consistent with hot-electron spreading in the presence of self-generated magnetic fields, as suggested by recent experiments and simulations. The insensitivity of the results to the presence of a supporting stalk is attributed to inductive decoupling of the target. Free-falling targets open the possibility of highly symmetric implosion experiments.

  19. Effect of Energy Input on the Characteristic of AISI H13 and D2 Tool Steels Deposited by a Directed Energy Deposition Process

    NASA Astrophysics Data System (ADS)

    Park, Jun Seok; Park, Joo Hyun; Lee, Min-Gyu; Sung, Ji Hyun; Cha, Kyoung Je; Kim, Da Hye

    2016-05-01

    Among the many additive manufacturing technologies, the directed energy deposition (DED) process has attracted significant attention because of the application of metal products. Metal deposited by the DED process has different properties than wrought metal because of the rapid solidification rate, the high thermal gradient between the deposited metal and substrate, etc. Additionally, many operating parameters, such as laser power, beam diameter, traverse speed, and powder mass flow rate, must be considered since the characteristics of the deposited metal are affected by the operating parameters. In the present study, the effect of energy input on the characteristics of H13 and D2 steels deposited by a direct metal tooling process based on the DED process was investigated. In particular, we report that the hardness of the deposited H13 and D2 steels decreased with increasing energy input, which we discuss by considering microstructural observations and thermodynamics.

  20. Deposition Measurements From the Full-Scale Radiological Dispersal Device Field Trials.

    PubMed

    Erhardt, Lorne; Lebel, Luke; Korpach, Ed; Berg, Rodney; Inrig, Elizabeth; Watson, Ian; Liu, Chuanlei; Gilhuly, Colleen; Quayle, Debora

    2016-05-01

    In 2012, Defence Research and Development Canada led a series of experiments, titled the Full-Scale Radiological Dispersal Device Field Trials, in which short-lived radioactive material was explosively dispersed and the resulting plume and deposition were characterized through a variety of methods. Presented here are the results of a number of measurements that were taken to characterize the radioactive ground deposition. These included in situ gamma measurements, deposition filter samples, and witness plate measurements that were taken in situ with handheld beta survey meters. The results from the different measurement techniques are compared to each other and to a simple deposition model. Results showed that approximately 3% of the original source activity was deposited in the immediate vicinity of ground zero, and an additional 15-30% of the original activity was deposited within 450 m of ground zero. Implications of these results for emergency response are discussed. PMID:27023032

  1. Measuring Dark Energy with CHIME

    NASA Astrophysics Data System (ADS)

    Newburgh, Laura; Chime Collaboration

    2015-04-01

    The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a new radio transit interferometer currently being built at the Dominion Radio Astrophysical Observatory (DRAO) in Penticton, BC, Canada. We will use the 21 cm emission line of neutral hydrogen to map baryon acoustic oscillations between 400-800 MHz across 3/4 of the sky. These measurements will yield sensitive constraints on the dark energy equation of state between redshifts 0.8 - 2.5, a fascinating but poorly probed era corresponding to when dark energy began to impact the expansion history of the Universe. I will describe theCHIME instrument, the analysis challenges, the calibration requirements, and current status.

  2. Modeling Planetary Atmospheric Energy Deposition By Energetic Ions

    NASA Astrophysics Data System (ADS)

    Parkinson, Christopher; Bougher, Stephen; Gronoff, Guillaume; Barthelemy, Mathieu

    2016-07-01

    The structure, dynamics, chemistry, and evolution of planetary upper atmospheres are in large part determined by the available sources of energy. In addition to the solar EUV flux, the solar wind and solar energetic particle (SEP) events are also important sources. Both of these particle populations can significantly affect an atmosphere, causing atmospheric loss and driving chemical reactions. Attention has been paid to these sources from the standpoint of the radiation environment for humans and electronics, but little work has been done to evaluate their impact on planetary atmospheres. At unmagnetized planets or those with crustal field anomalies, in particular, the solar wind and SEPs of all energies have direct access to the atmosphere and so provide a more substantial energy source than at planets having protective global magnetic fields. Additionally, solar wind and energetic particle fluxes should be more significant for planets orbiting more active stars, such as is the case in the early history of the solar system for paleo-Venus and Mars. Therefore quantification of the atmospheric energy input from the solar wind and SEP events is an important component of our understanding of the processes that control their state and evolution. We have applied a full Lorentz motion particle transport model to study the effects of particle precipitation in the upper atmospheres of Mars and Venus. Such modeling has been previously done for Earth and Mars using a guiding center precipitation model. Currently, this code is only valid for particles with small gyroradii in strong uniform magnetic fields. There is a clear necessity for a Lorentz formulation, hence, a systematic study of the ionization, excitation, and energy deposition has been conducted, including a comparison of the influence relative to other energy sources (namely EUV photons). The result is a robust examination of the influence of energetic ion transport on the Venus and Mars upper atmosphere which

  3. Modeling Atmospheric Energy Deposition (by energetic ions): New Results

    NASA Astrophysics Data System (ADS)

    Parkinson, C.; Brain, D. A.; Lillis, R. J.; Liemohn, M. W.; Bougher, S. W.

    2012-12-01

    deposition is conducted including a comparison of the influence relative to other energy sources (namely EUV photons) and previous efforts using the guiding center approximation.

  4. POLLUTANT SAMPLER FOR MEASUREMENTS OF ATMOSPHERIC ACIDIC DRY DEPOSITION

    EPA Science Inventory

    An acidic pollutant sampler for dry deposition monitoring has been designed and evaluated in laboratory and field studies. The system, which is modular and simple to operate, samples gaseous HNO3, NH3, SO2 and NO2 and particulate SO4(-2), NO3(1-) and NH4(1+) and is made of Teflon...

  5. AN EXAMINATION OF SOME MICROMETEOROLOGICAL METHODS FOR MEASURING DRY DEPOSITION

    EPA Science Inventory

    Dry deposition on natural surfaces is one of the major removal pathways for air pollutants. In order to develop mathematical descriptions for the numerical simulation of the transport, removal, and ecological impact of pollutant gases and aerosols, the dependence of dry depositio...

  6. Distributions of deposited energy and ionization clusters around ion tracks studied with Geant4 toolkit

    NASA Astrophysics Data System (ADS)

    Burigo, Lucas; Pshenichnov, Igor; Mishustin, Igor; Hilgers, Gerhard; Bleicher, Marcus

    2016-05-01

    The Geant4-based Monte Carlo model for Heavy-Ion Therapy (MCHIT) was extended to study the patterns of energy deposition at sub-micrometer distance from individual ion tracks. Dose distributions for low-energy 1H, 4He, 12C and 16O ions measured in several experiments are well described by the model in a broad range of radial distances, from 0.5 to 3000 nm. Despite the fact that such distributions are characterized by long tails, a dominant fraction of deposited energy (∼80%) is confined within a radius of about 10 nm. The probability distributions of clustered ionization events in nanoscale volumes of water traversed by 1H, 2H, 4He, 6Li, 7Li, and 12C ions are also calculated. A good agreement of calculated ionization cluster-size distributions with the corresponding experimental data suggests that the extended MCHIT can be used to characterize stochastic processes of energy deposition to sensitive cellular structures.

  7. Energetic particle energy deposition in Titan's upper atmosphere

    NASA Astrophysics Data System (ADS)

    Westlake, J. H.; Smith, H. T.; Mitchell, D. G.; Paranicas, C. P.; Rymer, A. M.; Bell, J. M.; Waite, J. H., Jr.; Mandt, K. E.

    2012-04-01

    Titan’s upper atmosphere has been observed to be variable on a pass-by-pass basis. During the nominal mission where the Cassini Ion and Neutral Mass Spectrometer (INMS) only sampled the northern hemisphere this variability was initially believed to be tied to solar drivers manifest in latitudinal variations in the thermal structure of the upper atmosphere. However, when Cassini delved into the southern hemisphere the latitudinal dependence was not present in the data. Recently, Westlake et al. (2011) showed that the pass-by-pass variability is correlated with the deviations in the plasma environment as identified by Rymer et al. (2009) and Simon et al. (2010). Furthermore, the studies of Westlake et al. (2011) and Bell et al. (2011) showed that Titan’s upper atmosphere responds to changes in the ambient magnetospheric plasma on timescales of roughly one Titan day (16 Earth days). We report on recent studies of energy deposition in Titan’s upper atmosphere. Previous studies by Smith et al. (2009), Cravens et al. (2008), Tseng et al. (2008), and Shah et al. (2009) reported on energetic proton and oxygen ion precipitation. Back of the envelope calculations by Sittler et al. (2009) showed that magnetospheric energy inputs are expected to be of the order of or greater than the solar processes. We report on further analysis of the plasma environment around Titan during the flybys that the INMS has good data. We utilize data from the Magnetospheric Imaging Instrument to determine how the magnetospheric particle population varies from pass to pass and how this influences the net magnetospheric energy input prior to the flyby. We also report on enhanced energetic neutral atom emissions during select highly energetic passes. References: Bell, J., et al.: “Simulating the time-dependent response of Titan's upper atmosphere to periods of magnetospheric forcing”. Geophys. Res. Lett., Vol. 38, L06202, 2011. Rymer, A. M., et al.: “Discrete classification and electron

  8. Energy deposition studies for the LBNE beam absorber

    SciTech Connect

    Rakhno, Igor L.; Mokhov, Nikolai V.; Tropin, Igor S.

    2015-01-29

    Results of detailed Monte Carlo energy deposition studies performed for the LBNE absorber core and the surrounding shielding with the MARS15 code are described. The model of the entire facility, that includes a pion-production target, focusing horns, target chase, decay channel, hadron absorber system – all with corresponding radiation shielding – was developed using the recently implemented ROOT-based geometry option in the MARS15 code. This option provides substantial flexibility and automation when developing complex geometry models. Both normal operation and accidental conditions were studied. Various design options were considered, in particular the following: (i) filling the decay pipe with air or helium; (ii) the absorber mask material and shape; (iii) the beam spoiler material and size. Results of detailed thermal calculations with the ANSYS code helped to select the most viable absorber design options.

  9. Hypersonic Flow Control Using Upstream Focused Energy Deposition

    NASA Technical Reports Server (NTRS)

    Riggins David W.; Nelson, H. F.

    1999-01-01

    A numerical study of centerline and off-centerline power deposition at a point upstream of a two-dimensional blunt body at Mach 6.5 at 30 km altitude are presented. The full Navier-Stokes equations are used. Wave drag, lift, and pitching moment are presented as a function of amount of power absorbed in the flow and absorption point location. It is shown that wave drag is considerably reduced. Modifications to the pressure distribution in the flow field due to the injected energy create lift and a pitching moment when the injection is off-centerline. This flow control concept may lead to effective ways to improve the performance and to stabilize and control hypersonic vehicles.

  10. Enhancement of fast electron energy deposition by external magnetic fields

    NASA Astrophysics Data System (ADS)

    Honrubia, J. J.; Murakami, M.; Mima, K.; Johzaki, T.; Sunahara, A.; Nagatomo, H.; Fujioka, S.; Shiraga, H.; Azechi, H.

    2016-03-01

    Recently, generation of external magnetic fields of a few kT has been reported [Fujioka et al. Scientific Reports 2013 3 1170]. These fields can be used in fast ignition to mitigate the large fast electron divergence. In this summary, two fast ignition applications are briefly outlined. The first one deals with electron guiding by external B-fields applied at the end of the shell implosion of a re-entrant cone target. Preliminary results show that the B-field strength at the time of peak ρR may be sufficiently high for fast electron guiding. The second application deals with guiding of fast electrons in magnetized wires surrounded by plasma. Results show a significant enhancement of electron energy deposition at the end of the wire, which is particularly important for low-Z wires.

  11. Energy level alignment in polymer organic solar cells at donor-acceptor planar junction formed by electrospray vacuum deposition

    SciTech Connect

    Kim, Ji-Hoon; Hong, Jong-Am; Kwon, Dae-Gyeon; Seo, Jaewon; Park, Yongsup

    2014-04-21

    Using ultraviolet photoelectron spectroscopy (UPS), we have measured the energy level offset at the planar interface between poly(3-hexylthiophene) (P3HT) and C{sub 61}-butyric acid methylester (PCBM). Gradual deposition of PCBM onto spin-coated P3HT in high vacuum was made possible by using electrospray vacuum deposition (EVD). The UPS measurement of EVD-prepared planar interface resulted in the energy level offset of 0.91 eV between P3HT HOMO and PCBM LUMO, which is considered as the upper limit of V{sub oc} of the organic photovoltaic cells.

  12. Direct evidence of strongly inhomogeneous energy deposition in target heating with laser-produced ion beams.

    PubMed

    Brambrink, E; Schlegel, T; Malka, G; Amthor, K U; Aléonard, M M; Claverie, G; Gerbaux, M; Gobet, F; Hannachi, F; Méot, V; Morel, P; Nicolai, P; Scheurer, J N; Tarisien, M; Tikhonchuk, V; Audebert, P

    2007-06-01

    We report on strong nonuniformities in target heating with intense, laser-produced proton beams. The observed inhomogeneity in energy deposition can strongly perturb equation of state (EOS) measurements with laser-accelerated ions which are planned in several laboratories. Interferometric measurements of the target expansion show different expansion velocities on the front and rear surfaces, indicating a strong difference in local temperature. The nonuniformity indicates at an additional heating mechanism, which seems to originate from electrons in the keV range. PMID:17677318

  13. Energy deposition in parallel-plate plasma accelerators. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Dicapua, M. S.

    1971-01-01

    To appraise the ratio of energy deposition into kinetic and thermal modes in plasma accelerators, a parallel-plate plasma accelerator has been operated in the quasi-steady mode with current pulses in the range of 10 to 100 kilo-amperes (kA), durations of the order of one millisecond, and argon mass flows up to 100 grams/sec. From photographic observations, spectroscopic measurements of velocity and electron density, and pressure measurements with a fast-rise piezoelectric transducer it is found that, for currents between 50 and 90 kA, the accelerated argon plasma is supersonic with ion velocities of 5 to 6 kilometers/sec.

  14. Directed energy deflection laboratory measurements

    NASA Astrophysics Data System (ADS)

    Brashears, Travis; Lubin, Phillip; Hughes, Gary B.; Meinhold, Peter; Suen, Jonathan; Batliner, Payton; Motta, Caio; Griswold, Janelle; Kangas, Miikka; Johansson, Isbella; Alnawakhtha, Yusuf; Prater, Kenyon; Lang, Alex; Madajian, Jonathan

    2015-09-01

    We report on laboratory studies of the effectiveness of directed energy planetary defense as a part of the DESTAR (Directed Energy System for Targeting of Asteroids and exploRation) program. DE-STAR [1][5][6] and DE-STARLITE [2][5][6] are directed energy "stand-off" and "stand-on" programs, respectively. These systems consist of a modular array of kilowatt-class lasers powered by photovoltaics, and are capable of heating a spot on the surface of an asteroid to the point of vaporization. Mass ejection, as a plume of evaporated material, creates a reactionary thrust capable of diverting the asteroid's orbit. In a series of papers, we have developed a theoretical basis and described numerical simulations for determining the thrust produced by material evaporating from the surface of an asteroid [1][2][3][4][5][6]. In the DE-STAR concept, the asteroid itself is used as the deflection "propellant". This study presents results of experiments designed to measure the thrust created by evaporation from a laser directed energy spot. We constructed a vacuum chamber to simulate space conditions, and installed a torsion balance that holds an "asteroid" sample. The sample is illuminated with a fiber array laser with flux levels up to 60 MW/m2 which allows us to simulate a mission level flux but on a small scale. We use a separate laser as well as a position sensitive centroid detector to readout the angular motion of the torsion balance and can thus determine the thrust. We compare the measured thrust to the models. Our theoretical models indicate a coupling coefficient well in excess of 100 μN/Woptical, though we assume a more conservative value of 80 μN/Woptical and then degrade this with an optical "encircled energy" efficiency of 0.75 to 60 μN/Woptical in our deflection modeling. Our measurements discussed here yield about 45 μN/Wabsorbed as a reasonable lower limit to the thrust per optical watt absorbed.

  15. Vapor-deposited porous films for energy conversion

    DOEpatents

    Jankowski, Alan F.; Hayes, Jeffrey P.; Morse, Jeffrey D.

    2005-07-05

    Metallic films are grown with a "spongelike" morphology in the as-deposited condition using planar magnetron sputtering. The morphology of the deposit is characterized by metallic continuity in three dimensions with continuous and open porosity on the submicron scale. The stabilization of the spongelike morphology is found over a limited range of the sputter deposition parameters, that is, of working gas pressure and substrate temperature. This spongelike morphology is an extension of the features as generally represented in the classic zone models of growth for physical vapor deposits. Nickel coatings were deposited with working gas pressures up 4 Pa and for substrate temperatures up to 1000 K. The morphology of the deposits is examined in plan and in cross section views with scanning electron microscopy (SEM). The parametric range of gas pressure and substrate temperature (relative to absolute melt point) under which the spongelike metal deposits are produced appear universal for other metals including gold, silver, and aluminum.

  16. Comparisons of Solar Wind Coupling Parameters with Auroral Energy Deposition Rates

    NASA Technical Reports Server (NTRS)

    Elsen, R.; Brittnacher, M. J.; Fillingim, M. O.; Parks, G. K.; Germany G. A.; Spann, J. F., Jr.

    1997-01-01

    Measurement of the global rate of energy deposition in the ionosphere via auroral particle precipitation is one of the primary goals of the Polar UVI program and is an important component of the ISTP program. The instantaneous rate of energy deposition for the entire month of January 1997 has been calculated by applying models to the UVI images and is presented by Fillingim et al. In this session. A number of parameters that predict the rate of coupling of solar wind energy into the magnetosphere have been proposed in the last few decades. Some of these parameters, such as the epsilon parameter of Perrault and Akasofu, depend on the instantaneous values in the solar wind. Other parameters depend on the integrated values of solar wind parameters, especially IMF Bz, e.g. applied flux which predicts the net transfer of magnetic flux to the tail. While these parameters have often been used successfully with substorm studies, their validity in terms of global energy input has not yet been ascertained, largely because data such as that supplied by the ISTP program was lacking. We have calculated these and other energy coupling parameters for January 1997 using solar wind data provided by WIND and other solar wind monitors. The rates of energy input predicted by these parameters are compared to those measured through UVI data and correlations are sought. Whether these parameters are better at providing an instantaneous rate of energy input or an average input over some time period is addressed. We also study if either type of parameter may provide better correlations if a time delay is introduced; if so, this time delay may provide a characteristic time for energy transport in the coupled solar wind-magnetosphere-ionosphere system.

  17. Field measurement of critical shear stress for erosion and deposition of fine muddy sediments

    NASA Astrophysics Data System (ADS)

    Salehi, M.; Strom, K. B.; Field Study

    2010-12-01

    The movement of muddy sediment from one region to another is linked to the fate and transport of pollutants that can be attached to this sediment. Important in understanding this movement is the need to know the critical conditions for erosion and deposition of the fine muddy sediment. For non-cohesion sediment, such as sands and gravels, reasonable estimates for the critical conditions can often be made theoretically without in situ measurements of the critical fluid condition or sediment transport rate. However, the shear stress needed for the incipient motion of the mud (cohesive sediments) is inherently difficult to calculate theoretically or in research flumes due to the influence of (1) flow history; (2) local sediment composition; (3) biological activity within the bed; (4) water content of the bed; and (5) salinity of the water column. The complexity of the combination of these factors makes the field measurement necessary. A field experiment was conducted under tidal flow in the region surrounding the Houston Ship Channel (near Houston, TX) to determine these conditions. Observations were made using single point, simultaneous, in situ measurement of turbulent flow and suspended sediment concentration within bottom boundary layer. Measurements were primarily made with a 6 MHz Nortek Vector velocimeter (ADV). The ADV was programmed to record 3-minute turbulent velocity with 32 Hz frequency every 10 minute. The suspended sediment concentration (SSC) was measured using the calibration of acoustic backscatter recorded by ADV against sample derived SSC. Different methods such as turbulent kinetic energy (TKE), TKEw and direct covariance method (COV) are compared together. TKE showed much more reasonable estimation on bed shear stress. Combination of time varying SSC, distance from the bed to the sampling volume recorded by ADV and calculation of shear stress made the determination of critical conditions for erosion and deposition possible.

  18. Athermal Energy Loss from X-rays Deposited in Thin Superconducting Films on Solid Substrates

    NASA Technical Reports Server (NTRS)

    Kozorezov, Alexander G.; Lambert, Colin J.; Bandler, Simon R.; Balvin, Manuel A.; Busch, Sarah E.; Sagler, Peter N.; Porst, Jan-Patrick; Smith, Stephen J.; Stevenson, Thomas R.; Sadleir, John E.

    2013-01-01

    When energy is deposited in a thin-film cryogenic detector, such as from the absorption of an X-ray, an important feature that determines the energy resolution is the amount of athermal energy that can be lost to the heat bath prior to the elementary excitation systems coming into thermal equilibrium. This form of energy loss will be position-dependent and therefore can limit the detector energy resolution. An understanding of the physical processes that occur when elementary excitations are generated in metal films on dielectric substrates is important for the design and optimization of a number of different types of low temperature detector. We have measured the total energy loss in one relatively simple geometry that allows us to study these processes and compare measurements with calculation based upon a model for the various di.erent processes. We have modeled the athermal phonon energy loss in this device by finding an evolving phonon distribution function that solves the system of kinetic equations for the interacting system of electrons and phonons. Using measurements of device parameters such as the Debye energy and the thermal di.usivity we have calculated the expected energy loss from this detector geometry, and also the position-dependent variation of this loss. We have also calculated the predicted impact on measured spectral line-shapes, and shown that they agree well with measurements. In addition, we have tested this model by using it to predict the performance of a number of other types of detector with di.erent geometries, where good agreement is also found.

  19. Influence of Surface Free Energy on Adhesion of CrN Thin Film Deposited by AIP Method

    NASA Astrophysics Data System (ADS)

    Nouda, Hikaru; Oda, Hiroatsu; Yonekura, Daisuke; Murakami, Ri-Ichi

    The purpose of this study is to examine the relationship between adhesion of CrN thin film and the surface free energy of substrate. CrN film was deposited on JIS SKH2 high speed tool steel by arc ion plating (AIP) method. The surface free energy of the substrate was measured with/without ion bombardment process using nitrogen and argon gas under various gas flow rate before CrN deposition. The surface free energy was measured by the sessile drop method using distilled water and methylene iodide. The adhesion was evaluated by scratch testing and the relationship between a critical load and the surface free energy in each ion bombardment condition was discussed. As a result, it was found that the adhesion increased with decreasing the surface free energy, in particular the polar component strongly affects the adhesion.

  20. Unloading Versus Driven Processes Derived from Auroral Energy Deposition and Polar Cap Size

    NASA Technical Reports Server (NTRS)

    Brittnacher, M. J.; Parks, G. K.; Fillingim, M. O.; Elsen, R.; Chua, D.; Germany, G. A.; Spann, J. F., Jr.

    1998-01-01

    The intensity of far ultraviolet auroral emissions at all local times during the three substorm phases has been monitored by the Ultraviolet Imager (UVI) on the Polar spacecraft for many substorms. Changes in the energy flux and characteristic energy of the precipitating electrons can be derived from these observations by modeling of the spectral emission processes. The global and local energy deposition is a new parameter that can be used in substorm studies since it provides a measure of energy transfer from the tail to the ionosphere due to precipitating electrons at a time resolution of three minutes. The polar cap area and area of auroral emissions can also be determined at high time resolution during substorms from the UVI images. An example of a substorm that appears to be driven by solar wind dynamic pressure alone will be presented. The polar cap area and other parameters do not indicate a growth phase prior to substorm onset. In another example, the slow growth phase followed by a very rapid increase in energy deposition during the expansion phase will be shown. This substorm was preceded by a southward IMF orientation. In these two examples, the role the solar wind in determining polar cap area is discussed. The time development of the area of auroral emissions is also discussed in relation to substorm phase and energy deposition. If the auroral emissions occur on closed field lines then the area of auroral emissions may provide an indication of changes in the thickness of the plasma sheet during each substorm phase.

  1. A calorimetric measurement of the heat deposition in the vicinity of a spallation neutron target

    SciTech Connect

    Fischer, W.E.; Moritz, L.; Spitzer, H.; Thorson, I.M.

    1986-07-01

    An experiment to measure the heat deposition in various materials in the vicinity of a spallation neuron target is described. This experiment has been performed at the Thermal Neutron Facility, TRIUMF. In the analysis of the data, the contributions to the heat deposition from (n,..gamma..) capture processes, fast neutron, and prompt gamma-ray scattering are separated.

  2. THE DRY DEPOSITION OF SPECIATED MERCURY TO THE FLORIDA EVERGLADES: MEASUREMENTS AND MODELING

    EPA Science Inventory

    The Florida Everglades Dry-Deposition Study (FEDDS) was designed to test the viability of using new and existing measurement techniques in the estimation of the dry-depositional loading of speciated mercury (elemental gaseous, reactive gaseous and particulate) to a mixed sawgrass...

  3. Halite depositional facies in a solar salt pond: A key to interpreting physical energy and water depth in ancient deposits

    SciTech Connect

    Handford, C.R. )

    1990-08-01

    Subaqueous deposits of aragonite, gypsum, and halite are accumulating in shallow solar salt ponds constructed in the Pekelmeer, a sea-level salina on Bonaire, Netherlands Antilles. Several halite facies are deposited in the crystallizer ponds in response to difference in water depth and wave energy. Cumulate halite, which originates as floating rafts, is present only along the protected, upwind margins of ponds where low-energy conditions foster their formation and preservation. Cornet crystals with peculiar mushroom- and mortarboard-shaped caps precipitate in centimetre-deep brine sheets within a couple of metres of the upwind or low-energy margins. Downwind from these margins, cornet and chevron halite precipitate on the pond floors in water depths ranging from a few centimetres to {approximately} 60 cm. Halite pisoids with radial-concentric structure are precipitated in the swash zone along downwind high-energy shorelines where they form pebbly beaches. This study suggests that primary halite facies are energy and/or depth dependent and that some primary features, if preserved in ancient halite deposits, can be used to infer physical energy conditions, subenvironments such as low- to high-energy shorelines, and extremely shallow water depths in ancient evaporite basins.

  4. Deposition of dopant impurities and pulsed energy drive-in

    DOEpatents

    Wickboldt, Paul; Carey, Paul G.; Smith, Patrick M.; Ellingboe, Albert R.

    1999-01-01

    A semiconductor doping process which enhances the dopant incorporation achievable using the Gas Immersion Laser Doping (GILD) technique. The enhanced doping is achieved by first depositing a thin layer of dopant atoms on a semiconductor surface followed by exposure to one or more pulses from either a laser or an ion-beam which melt a portion of the semiconductor to a desired depth, thus causing the dopant atoms to be incorporated into the molten region. After the molten region recrystallizes the dopant atoms are electrically active. The dopant atoms are deposited by plasma enhanced chemical vapor deposition (PECVD) or other known deposition techniques.

  5. Deposition of dopant impurities and pulsed energy drive-in

    DOEpatents

    Wickboldt, Paul; Carey, Paul G.; Smith, Patrick M.; Ellingboe, Albert R.

    2008-01-01

    A semiconductor doping process which enhances the dopant incorporation achievable using the Gas Immersion Laser Doping (GILD) technique. The enhanced doping is achieved by first depositing a thin layer of dopant atoms on a semiconductor surface followed by exposure to one or more pulses from either a laser or an ion-beam which melt a portion of the semiconductor to a desired depth, thus causing the dopant atoms to be incorporated into the molten region. After the molten region recrystallizes the dopant atoms are electrically active. The dopant atoms are deposited by plasma enhanced chemical vapor deposition (PECVD) or other known deposition techniques.

  6. Deposition of dopant impurities and pulsed energy drive-in

    DOEpatents

    Wickboldt, P.; Carey, P.G.; Smith, P.M.; Ellingboe, A.R.

    1999-06-29

    A semiconductor doping process which enhances the dopant incorporation achievable using the Gas Immersion Laser Doping (GILD) technique is disclosed. The enhanced doping is achieved by first depositing a thin layer of dopant atoms on a semiconductor surface followed by exposure to one or more pulses from either a laser or an ion-beam which melt a portion of the semiconductor to a desired depth, thus causing the dopant atoms to be incorporated into the molten region. After the molten region recrystallizes the dopant atoms are electrically active. The dopant atoms are deposited by plasma enhanced chemical vapor deposition (PECVD) or other known deposition techniques. 2 figs.

  7. Direct Measurement of EGR Cooler Deposit Thermal Properties for Improved Understanding of Cooler Fouling

    SciTech Connect

    Wang, Hsin; Sluder, Scott; Storey, John Morse

    2009-01-01

    Exhaust gas recirculation (EGR) cooler fouling has become a significant issue for compliance with NOX emissions standards. This paper reports results of a study of fundamental aspects of EGR cooler fouling. An apparatus and procedure were developed to allow surrogate EGR cooler tubes to be exposed to diesel engine exhaust under controlled conditions. The resulting fouled tubes were removed and analyzed. Volatile and non-volatile deposit mass was measured for each tube. Thermal diffusivity of the deposited soot cake was measured by milling a window into the tube and using the Xenon flash lamp method. The heat capacity of the deposit was measured at temperatures up to 430 C and was slightly higher than graphite, presumably due to the presence of hydrocarbons. These measurements were combined to allow calculation of the deposit thermal conductivity, which was determined to be 0.041 W/mK, only ~1.5 times that of air and much lower than the 304 stainless steel tube (14.7 W/mK). The main determinant of the deposit thermal conductivity is density, which was measured to be just 2% that of the density of the primary soot particles (or 98% porous). The deposit layer thermal resistance was calculated and compared with estimates of the thermal resistance calculated from gas temperature data during the experiment. The deposit properties were also used to further analyze the temperature data collected during the experiment.

  8. Dry deposition of peroxyacetyl nitrate (PAN): Determination of its deposition velocity at night from measurements of the atmospheric PAN and 222Radon concentration gradient

    NASA Astrophysics Data System (ADS)

    Schrimpf, Wolfram; Lienaerts, Karlheinz; Müller, Klaus Peter; Rudolph, Jochen; Neubert, Rolf; Schüßler, Wolfram; Levin, Ingeborg

    During the field campaign POPCORN (Photooxidant Formation by Plant Emitted Compounds and OH-Radicals in North-Eastern Germany) in August 1994 we measured the nighttime deposition velocities of PAN above a corn field. These are the first absolute measurements of PAN deposition velocities in the field. The deposition velocities were derived using a novel method, which uses measurements of the gradients of PAN and 222Rn and of the emission rates of 222Rn from the soil. A unique data set of about 250 field measurements of the PAN deposition velocity at night was thus obtained. The deposition velocity at night proved to be highly variable with an average of 0.54 cm/s and a standard deviation of 0.94 cm/s. Recent presumptions by Shepson et al. [1992] that the PAN deposition velocity is strongly reduced with increasing relative humidity could not be confirmed by our measurements.

  9. The activation energy for nanocrystalline diamond films deposited from an Ar/H2/CH4 hot-filament reactor.

    PubMed

    Barbosa, D C; Melo, L L; Trava-Airoldi, V J; Corat, E J

    2009-06-01

    In this work we have investigated the effect of substrate temperature on the growth rate and properties of nanocrystalline diamond thin films deposited by hot filament chemical vapor deposition (HFCVD). Mixtures of 0.5 vol% CH4 and 25 vol% H2 balanced with Ar at a pressure of 50 Torr and typical deposition time of 12 h. We present the measurement of the activation energy by accurately controlling the substrate temperature independently of other CVD parameters. Growth rates have been measured in the temperature range from 550 to 800 degrees C. Characterization techniques have involved Raman spectroscopy, high resolution X-ray difractometry and scanning electron microscopy. We also present a comparison with most activation energy for micro and nanocrystalline diamond determinations in the literature and propose that there is a common trend in most observations. The result obtained can be an evidence that the growth mechanism of NCD in HFCVD reactors is very similar to MCD growth. PMID:19504946

  10. Neutron energy spectrum adjustment using deposited metal films on Teflon in the miniature neutron source reactor.

    PubMed

    Nassan, L; Abdallah, B; Omar, H; Sarheel, A; Alsomel, N; Ghazi, N

    2016-01-01

    The focus of this article was on the experimental estimation of the neutron energy spectrum in the inner irradiation site of the miniature neutron source reactor (MNSR), using, for the first time, a selected set of deposited metal films on Teflon (DMFTs) neutron detectors. Gold, copper, zinc, titanium, aluminum, nickel, silver, and chromium were selected because of the dependence of their neutron cross-sections on neutron energy. Emphasis was placed on the usability of this new type of neutron detectors in the total neutron energy spectrum adjustment. The measured saturation activities per target nucleus values of the DMFTs, and the calculated neutron spectrum in the inner irradiation site using the MCNP-4C code were used as an input for the STAY'SL computer code during the adjustment procedure. The agreement between the numerically calculated and experimentally adjusted spectra results was discussed. PMID:26562448

  11. Measurements of carbon and tungsten erosion/deposition in the DIII-D divertor

    SciTech Connect

    Bastasz, R.; Wampler, W.R.; Cuthbertson, J.W.; Buchenauer, D.A.; Brooks, N.; Junge, R.; West, W.P.; Wong, C.P.C.

    1994-08-01

    Net erosion/deposition rates of carbon and tungsten were measured at the outer strike point of the divertor plasma on the floor of the DIII-D tokamak during deuterium H-mode operation at a peak power deposition of about 40 W/cm{sup 2}. For carbon, net erosion rates of up to 4 nm/s were found. For a tungsten film, no appreciable erosion was detected. However, measurements of deposited tungsten on adjacent carbon surfaces indicated a net W erosion rate of 0.06 nm/s.

  12. Fissible Deposit Characterization at the Former Oak Ridge K-25 Gaseous Diffusion Plant by {sup 252}CF-Source-Driven Measurements

    SciTech Connect

    Hannon, T.F.; Mihalczo, J.T.; Mullens, J.A.; Uckan, T.; Valentine, T.E.; Wyatt, M.S.

    1998-05-01

    The Deposit Removal Project was undertaken with the support of the U. S. Department of Energy at the East Tennessee Technology Park (ETTP) formerly the Oak Ridge K-25 Site. The project team performed the safe removal of the hydrated uranyl fluoride (UO{sub 2}F{sub 2}) deposits from the K-29 Building of the former Oak Ridge Gaseous Diffusion Plant. The deposits had developed as a result of air leakage into UF{sub 6} gas process pipes; UO{sub 2}F{sub 2} became hydrated by moisture from the air and deposited inside the pipes. The mass, its distribution, and the hydrogen content [that is, the ratio of H to U (H/U)], were the key parameters that controlled the nuclear criticality safety of the deposits. Earlier gamma-ray spectrometry measurements in K-29 had identified the largest deposits in the building. The first and third largest deposits in the building were measured in this program. The first deposit, found in the Unit 2, Cell 7, B-Line Outlet process pipe (called the ''Hockey Stick'') was about 1,300 kg ({+-} 50% uncertainty) at 3.34 wt% {sup 235}U enrichment ({+-}50% uncertainty) and according to the gamma-ray spectroscopy was uniformly distributed. The second deposit (the third-largest deposit in the building), found in the Unit 2, Cell 6, A-Line Outlet process pipe (called the ''Tee-Pipe''), had a uranium deposit estimated to be about 240 kg ({+-} 50% uncertainty) at 3.4 wt % {sup 235}U enrichment ({+-} 20% uncertainty). Before deposit removal activities began, the Deposit Removal Project team needed to survey the inside of the pipes intrusively to assess the nuclear criticality safety of the deposits. Therefore, the spatial distribution of the deposits, the total uranium deposit mass, and the moderation level resulting from hydration of the deposits, all of which affect nuclear criticality safety were required. To perform the task safely and effectively, the Deposit Removal Project team requested that Oak Ridge National Laboratory (ORNL) characterize the two

  13. Insitu Measurements and Modeling of Carbon Nanotube Array Growth Kinetics during Chemical Vapor Deposition

    SciTech Connect

    Puretzky, Alexander A; Geohegan, David B; Jesse, Stephen; Ivanov, Ilia N; Eres, Gyula

    2005-01-01

    Direct measurements of carbon nanotube growth kinetics are described based upon time-resolved reflectivity (TRR) of a HeNe laser beam from vertically aligned nanotube arrays (VANTAs) as they grow during chemical vapor deposition (CVD). Growth rates and terminal lengths were measured in situ for VANTAs growing during CVD between 535 C and 900 C on Si substrates with evaporated Al/Fe/Mo multi-layered catalysts and acetylene feedstock at different feedstock partial pressures. Methods of analysis of the TRR signals are presented to interpret catalyst particle formation and oxidation, as well as the porosity of the VANTAs. A rate-equation model is developed to describe the measured kinetics in terms of activation energies and rate constants for surface carbon formation and diffusion on the catalyst nanoparticle, nanotube growth, and catalyst over-coating. Taken together with the TRR data, this model enables basic understanding and optimization of growth conditions for any catalyst/feedstock combination. The model lends insight into the main processes responsible for the growth of VANTAs, the measured number of walls in the nanotubes at different temperatures, conditions for growth of single-wall carbon nanotube arrays, and likely catalyst poisoning mechanisms responsible for the sharp decline in growth rates observed at high temperatures.

  14. Global inorganic nitrogen dry deposition inferred from ground- and space-based measurements

    PubMed Central

    Jia, Yanlong; Yu, Guirui; Gao, Yanni; He, Nianpeng; Wang, Qiufeng; Jiao, Cuicui; Zuo, Yao

    2016-01-01

    Atmospheric nitrogen (N) dry deposition is an important component in total N deposition. However, uncertainty exists in the assessment of global dry deposition. Here, we develop empirical models for estimating ground N concentrations using NO2 satellite measurements from the Ozone Monitoring Instrument (OMI) and ground measurements from 555 monitoring sites. Global patterns and trends in the fluxes of NO2, HNO3, NH4+, and NO3− were assessed for 2005–2014. Moreover, we estimated global NH3 dry deposition directly using data from 267 monitoring sites. Our results showed that East Asia, the United States, and Europe were important regions of N deposition, and the total annual amount of global inorganic N deposition was 34.26 Tg N. The dry deposition fluxes were low in Africa and South America, but because of their large area, the total amounts in these regions were comparable to those in Europe and North America. In the past decade, the western United States and Eurasia, particularly eastern China, experienced the largest increases in dry deposition, whereas the eastern United States, Western Europe, and Japan experienced clear decreases through control of NOx and NH3 emissions. These findings provide a scientific background for policy-makers and future research into global changes. PMID:26813440

  15. Global inorganic nitrogen dry deposition inferred from ground- and space-based measurements.

    PubMed

    Jia, Yanlong; Yu, Guirui; Gao, Yanni; He, Nianpeng; Wang, Qiufeng; Jiao, Cuicui; Zuo, Yao

    2016-01-01

    Atmospheric nitrogen (N) dry deposition is an important component in total N deposition. However, uncertainty exists in the assessment of global dry deposition. Here, we develop empirical models for estimating ground N concentrations using NO2 satellite measurements from the Ozone Monitoring Instrument (OMI) and ground measurements from 555 monitoring sites. Global patterns and trends in the fluxes of NO2, HNO3, NH4(+), and NO3(-) were assessed for 2005-2014. Moreover, we estimated global NH3 dry deposition directly using data from 267 monitoring sites. Our results showed that East Asia, the United States, and Europe were important regions of N deposition, and the total annual amount of global inorganic N deposition was 34.26 Tg N. The dry deposition fluxes were low in Africa and South America, but because of their large area, the total amounts in these regions were comparable to those in Europe and North America. In the past decade, the western United States and Eurasia, particularly eastern China, experienced the largest increases in dry deposition, whereas the eastern United States, Western Europe, and Japan experienced clear decreases through control of NOx and NH3 emissions. These findings provide a scientific background for policy-makers and future research into global changes. PMID:26813440

  16. Global inorganic nitrogen dry deposition inferred from ground- and space-based measurements

    NASA Astrophysics Data System (ADS)

    Jia, Yanlong; Yu, Guirui; Gao, Yanni; He, Nianpeng; Wang, Qiufeng; Jiao, Cuicui; Zuo, Yao

    2016-01-01

    Atmospheric nitrogen (N) dry deposition is an important component in total N deposition. However, uncertainty exists in the assessment of global dry deposition. Here, we develop empirical models for estimating ground N concentrations using NO2 satellite measurements from the Ozone Monitoring Instrument (OMI) and ground measurements from 555 monitoring sites. Global patterns and trends in the fluxes of NO2, HNO3, NH4+, and NO3- were assessed for 2005-2014. Moreover, we estimated global NH3 dry deposition directly using data from 267 monitoring sites. Our results showed that East Asia, the United States, and Europe were important regions of N deposition, and the total annual amount of global inorganic N deposition was 34.26 Tg N. The dry deposition fluxes were low in Africa and South America, but because of their large area, the total amounts in these regions were comparable to those in Europe and North America. In the past decade, the western United States and Eurasia, particularly eastern China, experienced the largest increases in dry deposition, whereas the eastern United States, Western Europe, and Japan experienced clear decreases through control of NOx and NH3 emissions. These findings provide a scientific background for policy-makers and future research into global changes.

  17. Measurements of stress evolution during thin film deposition

    SciTech Connect

    Chason, E.; Floro, J.A.

    1996-05-01

    We have developed a technique for measuring thin film stress during growth by monitoring the wafer curvature. By measuring the deflection of multiple parallel laser beams with a CCD detector, the sensivity to vibration is reduced and a radius of curvature limit of 4 km has been obtained in situ. This technique also enables us to obtain a 2-dimensional profile of the surface curvature from the simultaneous reflection of a rectangular array of beams. Results from the growth of SiG alloy films are presented to demonstrate the unique information that can be obtained during growth.

  18. Long-term elemental dry deposition fluxes measured around Lake Michigan with an automated dry deposition sampler

    SciTech Connect

    Shahin, U. Yi, S.M.; Paode, R.D.; Holsen, T.M.

    2000-05-15

    Long-term measurements of mass and elemental dry deposition (MG, Al, V, Cr, Mn, Ni, Co, Cu, Zn, As, Sr, Mo, Cd, Sb, Ba, and Pb) were made with an automated dry deposition sampler (Eagle II) containing knife-edge surrogate surfaces during the Lake Michigan Mass Balance/Mass Budget Study. Measurements were made over a roughly 700-day period in Chicago, IL; in South Haven and Sleeping Bear Dunes, MI; and over Lake Michigan on the 68th Street drinking water intake cribs from December 1993 to October 1995. Average mass fluxes in Chicago, South Haven, Sleeping Bear Dunes, and the 68th Street crib were 65, 10, 3.6, and 12 mg m{sup {minus}2} day{sup {minus}1}, respectively. Primarily crustal elemental fluxes were significantly smaller than the mass fluxes but higher than primarily anthropogenic elemental fluxes. For example, the average elemental flux of Al in Chicago, South Haven, Sleeping Bear Dunes, and the 68th Street crib were 1.0, 0.34, 0.074, and 0.34 mg m{sup {minus}2}day{sup {minus}1}, respectively. The average Pb fluxes in Chicago, South Haven, Sleeping Bear Dunes, and the 68th Street crib were 0.038, 0.023, 0.035, and 0.032 mg m{sup {minus}2}day{sup {minus}1}, respectively. The measured fluxes at the various sites were used to calculate the dry deposition loadings to the lake. These estimated fluxes were highest for Mg and lowest for Cd.

  19. Experiments measuring particle deposition from fully developed turbulent flow in ventilation ducts

    SciTech Connect

    Sippola, Mark R.; Nazaroff, William W.

    2003-08-01

    Particle deposition in ventilation ducts influences particle exposures of building occupants and may lead to a variety of indoor air quality concerns. Experiments have been performed in a laboratory to study the effects of particle size and air speed on deposition rates of particles from turbulent air flows in galvanized steel and internally insulated ducts with hydraulic diameters of 15.2 cm. The duct systems were constructed of materials typically found in commercial heating, ventilating and air conditioning (HVAC) systems. In the steel duct system, experiments with nominal particle sizes of 1, 3, 5, 9 and 16 {micro}m were conducted at each of three nominal air speeds: 2.2, 5.3 and 9.0 m/s. In the insulated duct system, deposition rates of particles with nominal sizes of 1, 3, 5, 8 and 13 {micro}m were measured at nominal air speeds of 2.2, 5.3 and 8.8 m/s. Fluorescent techniques were used to directly measure the deposition velocities of monodisperse fluorescent particles to duct surfaces (floor, wall and ceiling) at two straight duct sections where the turbulent flow profile was fully developed. In steel ducts, deposition rates were higher to the duct floor than to the wall, which were, in turn, greater than to the ceiling. In insulated ducts, deposition was nearly the same to the duct floor, wall and ceiling for a given particle size and air speed. Deposition to duct walls and ceilings was greatly enhanced in insulated ducts compared to steel ducts. Deposition velocities to each of the three duct surface orientations in both systems were found to increase with increasing particle size or air velocity over the ranges studied. Deposition rates measured in the current experiments were in general agreement with the limited observations of similar systems by previous researchers.

  20. Hall Measurements on Carbon Nanotube Paper Modified With Electroless Deposited Platinum

    PubMed Central

    2010-01-01

    Carbon nanotube paper, sometimes referred to as bucky paper, is a random arrangement of carbon nanotubes meshed into a single robust structure, which can be manipulated with relative ease. Multi-walled carbon nanotubes were used to make the nanotube paper, and were subsequently modified with platinum using an electroless deposition method based on substrate enhanced electroless deposition. This involves the use of a sacrificial metal substrate that undergoes electro-dissolution while the platinum metal deposits out of solution onto the nanotube paper via a galvanic displacement reaction. The samples were characterized using SEM/EDS, and Hall-effect measurements. The SEM/EDS analysis clearly revealed deposits of platinum (Pt) distributed over the nanotube paper surface, and the qualitative elemental analysis revealed co-deposition of other elements from the metal substrates used. When stainless steel was used as sacrificial metal a large degree of Pt contamination with various other metals was observed. Whereas when pure sacrificial metals were used bimetallic Pt clusters resulted. The co-deposition of a bimetallic system upon carbon nanotubes was a function of the metal type and the time of exposure. Hall-effect measurements revealed some interesting fluctuations in sheet carrier density and the dominant carrier switched from N- to P-type when Pt was deposited onto the nanotube paper. Perspectives on the use of the nanotube paper as a replacement to traditional carbon cloth in water electrolysis systems are also discussed. PMID:20651913

  1. Measurements of the Near-Surface Column Structure of Lunar Pyroclastic Deposits

    NASA Astrophysics Data System (ADS)

    Carter, Lynn M.; Ghent, R. R.; Bandfield, J. L.

    2013-10-01

    Pyroclastic deposits on the Moon are associated with many types of volcanic constructs, including rilles, pits and linear fractures, and small domes. Prior radar data have revealed buried flows and rocks within some pyroclastics deposits (e.g. Aristarchus), while other deposits have radar polarimetry values that suggest very thick mounds of fine (centimeter-or-less sized) material (Campbell et. al., Geology, 36, 135, 2008; Carter et al., JGR, 114, E11004, doi:10.1029/2009JE003406, 2009). Radar can detect buried blocks or buried structures and provide a measure of roughness, while thermal infrared data provides complimentary information on the surface and near-surface rock abundance. The two wavelength ranges are also sensitive to different sized rocks, and the combined data sets provide the best way to make quantitative measurements of the upper structure of pyroclastic deposits. We use imaging radar data from Arecibo Observatory and the Green Bank Telescope, Lunar Reconnaissance Orbiter (LRO) Mini-RF data, and LRO Diviner rock abundance and regolith temperature maps, to investigate a range of pyroclastic deposits associated with different types of volcanic structures, including Aristarchus, Rima Hyginus, and domes in Mare Tranquillitatis. Thick pyroclastic deposits have low rock abundance in both radar and infrared data, but in many cases (e.g. lunar domes, Aristarchus buried flows), the radar reveals rocks and structures that are not visible in the Diviner data sets. The derived column structure maps will provide an improved estimate of the thickness and degree of regolith mixing of pyroclastic deposits.

  2. Nuclear data processing for energy release and deposition calculations in the MC21 Monte Carlo code

    SciTech Connect

    Trumbull, T. H.

    2013-07-01

    With the recent emphasis in performing multiphysics calculations using Monte Carlo transport codes such as MC21, the need for accurate estimates of the energy deposition-and the subsequent heating - has increased. However, the availability and quality of data necessary to enable accurate neutron and photon energy deposition calculations can be an issue. A comprehensive method for handling the nuclear data required for energy deposition calculations in MC21 has been developed using the NDEX nuclear data processing system and leveraging the capabilities of NJOY. The method provides a collection of data to the MC21 Monte Carlo code supporting the computation of a wide variety of energy release and deposition tallies while also allowing calculations with different levels of fidelity to be performed. Detailed discussions on the usage of the various components of the energy release data are provided to demonstrate novel methods in borrowing photon production data, correcting for negative energy release quantities, and adjusting Q values when necessary to preserve energy balance. Since energy deposition within a reactor is a result of both neutron and photon interactions with materials, a discussion on the photon energy deposition data processing is also provided. (authors)

  3. Beam-induced energy deposition issues in the Very Large Hadron Collider

    SciTech Connect

    Nikolai V. Mokhov; Alexandr I. Drozhdin; G. William Foster

    2001-06-26

    Energy deposition issues are extremely important in the Very Large Hadron Collider (VLHC) with huge energy stored in its 20 TeV (Stage-1) and 87.5 TeV (Stage-2) beams. The status of the VLHC design on these topics, and possible solutions of the problems are discussed. Protective measures are determined based on the operational and accidental beam loss limits for the prompt radiation dose at the surface, residual radiation dose, ground water activation, accelerator components radiation damage and quench stability. The beam abort and beam collimation systems are designed to protect accelerator from accidental and operational beam losses, IP region quadrupoles from irradiation by the products of beam-beam collisions, and to reduce the accelerator-induced backgrounds in the detectors.

  4. In-Situ Silver Acetylide Silver Nitrate Explosive Deposition Measurements Using X-Ray Fluorescence.

    SciTech Connect

    Covert, Timothy Todd

    2014-09-01

    The Light Initiated High Explosive facility utilized a spray deposited coating of silver acetylide - silver nitrate explosive to impart a mechanical shock into targets of interest. A diagnostic was required to measure the explosive deposition in - situ. An X - ray fluorescence spectrometer was deployed at the facility. A measurement methodology was developed to measure the explosive quantity with sufficient accuracy. Through the use of a tin reference material under the silver based explosive, a field calibration relationship has been developed with a standard deviation of 3.2 % . The effect of the inserted tin material into the experiment configuration has been explored.

  5. Monte Carlo approach to the spatial deposition of energy by electrons in molecular hydrogen

    NASA Technical Reports Server (NTRS)

    Heaps, M. G.; Green, A. E. S.

    1974-01-01

    The Monte Carlo (MC) and continuous slowdown approximation (CSDA) approaches to the spatial deposition of energy by electrons are compared using the same detailed atomic cross section (DACS). It is found that the CSDA method overestimates the amount of energy that is deposited near the end of the path for electrons above a few hundred electron volts. The MC results are in approximate agreement with experimental data in such a way as to be relatively independent of the actual gas used. Our MC results are extended to obtain the three-dimensional deposition of energy by sub-keV electrons in molecular hydrogen.

  6. Measurement techniques for respiratory tract deposition of airborne nanoparticles: a critical review.

    PubMed

    Löndahl, Jakob; Möller, Winfried; Pagels, Joakim H; Kreyling, Wolfgang G; Swietlicki, Erik; Schmid, Otmar

    2014-08-01

    Determination of the respiratory tract deposition of airborne particles is critical for risk assessment of air pollution, inhaled drug delivery, and understanding of respiratory disease. With the advent of nanotechnology, there has been an increasing interest in the measurement of pulmonary deposition of nanoparticles because of their unique properties in inhalation toxicology and medicine. Over the last century, around 50 studies have presented experimental data on lung deposition of nanoparticles (typical diameter≤100 nm, but here≤300 nm). These data show a considerable variability, partly due to differences in the applied methodologies. In this study, we review the experimental techniques for measuring respiratory tract deposition of nano-sized particles, analyze critical experimental design aspects causing measurement uncertainties, and suggest methodologies for future studies. It is shown that, although particle detection techniques have developed with time, the overall methodology in respiratory tract deposition experiments has not seen similar progress. Available experience from previous research has often not been incorporated, and some methodological design aspects that were overlooked in 30-70% of all studies may have biased the experimental data. This has contributed to a significant uncertainty on the absolute value of the lung deposition fraction of nanoparticles. We estimate the impact of the design aspects on obtained data, discuss solutions to minimize errors, and highlight gaps in the available experimental set of data. PMID:24151837

  7. Measurement Techniques for Respiratory Tract Deposition of Airborne Nanoparticles: A Critical Review

    PubMed Central

    Möller, Winfried; Pagels, Joakim H.; Kreyling, Wolfgang G.; Swietlicki, Erik; Schmid, Otmar

    2014-01-01

    Abstract Determination of the respiratory tract deposition of airborne particles is critical for risk assessment of air pollution, inhaled drug delivery, and understanding of respiratory disease. With the advent of nanotechnology, there has been an increasing interest in the measurement of pulmonary deposition of nanoparticles because of their unique properties in inhalation toxicology and medicine. Over the last century, around 50 studies have presented experimental data on lung deposition of nanoparticles (typical diameter≤100 nm, but here≤300 nm). These data show a considerable variability, partly due to differences in the applied methodologies. In this study, we review the experimental techniques for measuring respiratory tract deposition of nano-sized particles, analyze critical experimental design aspects causing measurement uncertainties, and suggest methodologies for future studies. It is shown that, although particle detection techniques have developed with time, the overall methodology in respiratory tract deposition experiments has not seen similar progress. Available experience from previous research has often not been incorporated, and some methodological design aspects that were overlooked in 30–70% of all studies may have biased the experimental data. This has contributed to a significant uncertainty on the absolute value of the lung deposition fraction of nanoparticles. We estimate the impact of the design aspects on obtained data, discuss solutions to minimize errors, and highlight gaps in the available experimental set of data. PMID:24151837

  8. Energy deposition and middle atmosphere electrodynamic response to a highly relativistic electron precipitation event

    NASA Astrophysics Data System (ADS)

    Goldberg, R. A.; Baker, D. N.; Herrero, F. A.; McCarthy, S. P.; Twigg, P. A.; Croskey, C. L.; Hale, L. C.

    1994-10-01

    Rocket data have been used to evaluate the characteristics of precipitating relativistic electrons and their effects on the electrodynamic structure of the middle atmosphere. These data were obtained at Poker Flat, Alaska, on May 13 and 14, 1990, during a midday, highly relativistic electron (HRE) precipitation event. Solid state detectors were used to measure the electron fluxes and their energy spectra. An X ray scintillator was included on each flight to measure bremsstrahlung X rays produced by energetic electrons impacting on the upper atmosphere. However, these were found the be of negligible importance for this particular event. The energy deposition by the electrons has been determined from the flux measurements and compared with in situ measurements of the atmospheric electrical response. The electrodynamic measurements were obtained by the same rockets and additionally on May 13, with an accompanying rocket. The impact flux was highly irregular, containing short-lived bursts of relativistic electrons, mainly with energies below 0.5 MeV and with fluxes most enhanced between pitch angles of 0 deg - 20 deg. Although the geostationary counterpart of this measured event was considered to be of relatively low intensity and hardness, energy deposition peaked near 75 km with fluxes approaching an ion pair production rate in excess of 100/cu cm s. This exceeds peak fluxes in relativistic electron precipitation (REP) events as observed by us in numerous rocket soundings since 1976. Conductivity measurements from a blunt probe showed that negative electrical conductivities exceeded positive conductivities down to 50 km or lower, consistent with steady ionization by precipitating electrons above 1 MeV. These findings imply that the electrons from the outer radiation zone can modulate the electrical properties of the middle atmosphere to altitudes below 50 km. During the decline and activity minimum of the current solar cycle, we anticipate the occurence of similar

  9. Energy deposition and middle atmosphere electrodynamic response to a highly relativistic electron precipitation event

    NASA Technical Reports Server (NTRS)

    Goldberg, R. A.; Baker, D. N.; Herrero, F. A.; Mccarthy, S. P.; Twigg, P. A.; Croskey, C. L.; Hale, L. C.

    1994-01-01

    Rocket data have been used to evaluate the characteristics of precipitating relativistic electrons and their effects on the electrodynamic structure of the middle atmosphere. These data were obtained at Poker Flat, Alaska, on May 13 and 14, 1990, during a midday, highly relativistic electron (HRE) precipitation event. Solid state detectors were used to measure the electron fluxes and their energy spectra. An X ray scintillator was included on each flight to measure bremsstrahlung X rays produced by energetic electrons impacting on the upper atmosphere. However, these were found the be of negligible importance for this particular event. The energy deposition by the electrons has been determined from the flux measurements and compared with in situ measurements of the atmospheric electrical response. The electrodynamic measurements were obtained by the same rockets and additionally on May 13, with an accompanying rocket. The impact flux was highly irregular, containing short-lived bursts of relativistic electrons, mainly with energies below 0.5 MeV and with fluxes most enhanced between pitch angles of 0 deg - 20 deg. Although the geostationary counterpart of this measured event was considered to be of relatively low intensity and hardness, energy deposition peaked near 75 km with fluxes approaching an ion pair production rate in excess of 100/cu cm s. This exceeds peak fluxes in relativistic electron precipitation (REP) events as observed by us in numerous rocket soundings since 1976. Conductivity measurements from a blunt probe showed that negative electrical conductivities exceeded positive conductivities down to 50 km or lower, consistent with steady ionization by precipitating electrons above 1 MeV. These findings imply that the electrons from the outer radiation zone can modulate the electrical properties of the middle atmosphere to altitudes below 50 km. During the decline and activity minimum of the current solar cycle, we anticipate the occurence of similar

  10. Overall dry deposition velocities of trace elements measured at harbor and traffic site in central Taiwan.

    PubMed

    Fang, Guor-Cheng; Wu, Yuh-Shen; Chang, Shih-Yu; Lin, Jum-Bo; Lin, Jhih-Guang

    2007-03-01

    For reasonable and convenient assessments of the characteristics of the dry deposition velocities between Taichung harbor site and Wuchi town site in central Taiwan, the overall dry deposition velocities of several metallic elements were calculated as the particulate diameter (D(p)) distributions of large particles (D(p) > 10 microm), coarse particles (10 microm < D(p) < 2.5 microm), and fine particles (D(p) < 2.5 microm) based on the ambient measurements during March-December of 2004. In this work, the dry deposition fluxes showed the higher correlation with coarse particle concentrations than large particle concentrations; however, the least well correlation was observed between the dry deposition fluxes and the fine particle concentrations. The calculated best-fit overall dry deposition velocities obtained using coarse particle concentrations varied from approximately 0.2 cm s(-1) for Cr to 1.5 cm s(-1) for Pb and 0.2 cm s(-1) for Fe to 2.6 cm s(-1) for Pb at Taichung harbor and Wuchi town site, respectively. In general, the crustal elements had higher deposition velocities than anthropogenic elements. In addition, overall dry deposition velocities for crustal elements were higher in Wuchi town site than in Taichung harbor site. The results identified the dry deposition flux was mainly contributed from large and coarse particles due to their high deposition velocities. The results also indicated that the best approach to estimate overall dry deposition was by depending on the characteristics of particles with diameters larger than 2.5 microm. PMID:17166552

  11. Energy deposition evaluation for ultra-low energy electron beam irradiation systems using calibrated thin radiochromic film and Monte Carlo simulations.

    PubMed

    Matsui, S; Mori, Y; Nonaka, T; Hattori, T; Kasamatsu, Y; Haraguchi, D; Watanabe, Y; Uchiyama, K; Ishikawa, M

    2016-05-01

    For evaluation of on-site dosimetry and process design in industrial use of ultra-low energy electron beam (ULEB) processes, we evaluate the energy deposition using a thin radiochromic film and a Monte Carlo simulation. The response of film dosimeter was calibrated using a high energy electron beam with an acceleration voltage of 2 MV and alanine dosimeters with uncertainty of 11% at coverage factor 2. Using this response function, the results of absorbed dose measurements for ULEB were evaluated from 10 kGy to 100 kGy as a relative dose. The deviation between the responses of deposit energy on the films and Monte Carlo simulations was within 15%. As far as this limitation, relative dose estimation using thin film dosimeters with response function obtained by high energy electron irradiation and simulation results is effective for ULEB irradiation processes management. PMID:27250416

  12. Validation of model calculation of ammonia deposition in the neighbourhood of a poultry farm using measured NH 3 concentrations and N deposition

    NASA Astrophysics Data System (ADS)

    Sommer, S. G.; Østergård, H. S.; Løfstrøm, P.; Andersen, H. V.; Jensen, L. S.

    Substantial emission of ammonia (NH 3) from animal houses and the related high local deposition of NH 3-N are a threat to semi-natural nitrogen-deficient ecosystems situated near the NH 3 source. In Denmark, there are regulations limiting the level of NH 3 emission from livestock houses near N-deficient ecosystems that are likely to change due to nitrogen (N) enrichment caused by NH 3 deposition. The models used for assessing NH 3 emission from livestock production, therefore, need to be precise, as the regulation will affect both the nature of the ecosystem and the economy of the farmer. Therefore a study was carried out with the objective of validating the Danish model used to monitor NH 3 transport, dispersion and deposition from and in the neighbourhood of a chicken farm. In the study we measured NH 3 emission with standard flux measuring methods, NH 3 concentrations at increasing distances from the chicken houses using passive diffusion samplers and deposition using 15N-enriched biomonitors and field plot studies. The dispersion and deposition of NH 3 were modelled using the Danish OML-DEP model. It was also shown that model calculations clearly reflect the measured NH 3 concentration and N deposition. Deposition of N measured by biomonitors clearly reflected the variation in NH 3 concentrations and showed that deposition was not significantly different from zero ( P < 0.05) at distances greater than 150-200 m from these chicken houses. Calculations confirmed this, as calculated N deposition 320 m away from the chicken farm was only marginally affected by the NH 3 emission from the farm. There was agreement between calculated and measured deposition showing that the model gives true estimates of the deposition in the neighbourhood of a livestock house emitting NH 3.

  13. Beryllium-7 and (210)Pb atmospheric deposition measured in moss and dependence on cumulative precipitation.

    PubMed

    Krmar, M; Mihailović, D T; Arsenić, I; Radnović, D; Pap, I

    2016-01-15

    This paper focuses on analysis of the time series of (7)Be and (210)Pb activity measured in moss, and the amount, as well as duration of precipitation, to gain a better understanding of the possible relationships between airborne radionuclide deposition and precipitation. Here we consider whether the amount of these airborne radionuclides in moss samples is a cumulative measure of radionuclide deposition and decay, and a new approach for analyses of the relationships between precipitation and moss activity concentrations is suggested. Through these analyses it was shown that comparison of cumulative activity measured at one location using moss, normalized by values of cumulative amount or duration of precipitation, showed different regimes of airborne radionuclide deposition. PMID:26461139

  14. A multilayer model for inferring dry deposition using standard meteorological measurements

    NASA Astrophysics Data System (ADS)

    Meyers, Tilden P.; Finkelstein, Peter; Clarke, John; Ellestad, Thomas G.; Sims, Pamela F.

    1998-09-01

    In this paper, we describe the latest version of the dry deposition inferential model, which is used to estimate the deposition velocities (Vd) for SO2, O3, HNO3, and particles with diameters less than 2 μm. The dry deposition networks operated by the National Oceanic and Atmospheric Administration (NOAA) and the Environmental Protection Agency (EPA) use this model to estimate dry deposition on a weekly basis. This model uses a multilayer approach, discretizing the vegetated canopy into 20 layers. The use of canopy radiative transfer and simple wind profile models allows for estimates of stomatal (rs) and leaf boundary layer (rb) resistances to be determined at each layer in the plant canopy for both sunlit and shaded leaves. The effect of temperature, water stress, and vapor pressure deficits on the stomatal resistance (rs) have been included. Comparisons of modeled deposition velocities are made with extensive direct measurements performed at three different locations with different crops. The field experiment is discussed in some detail. Overall, modeled O3 deposition velocities are in good agreement with measured values with the average mean bias for all surfaces of the order of 0.01 cm/s or less. For SO2, mean biases range from -0.05 for corn to 0.15 cm/s for soybeans, while for HNO3, they range from 0.09 for corn to 0.47 cm/s for pasture.

  15. Energy loss measurement of cosmic ray muons

    NASA Astrophysics Data System (ADS)

    Unger, Joseph

    1993-02-01

    Measurements of energy losses of high energy cosmic ray muons in an ionization chamber are presented. The chamber consists of 16 single gap layers, and the liquid tetra methyl silane (TMS) was used as active medium. The absolute energy loss and the relativistic rise were measured and compared with theoretical calculations. The importance of the measurements within the framework of the cosmic ray experiment KASCADE (German acronym for Karlsruhe Shower Core and Array Detector) are discussed, especially with respect to energy calibration of hadrons and high energy muons above 1 TeV.

  16. MCNPX benchmark of out-of-beam energy deposition in LiAl

    SciTech Connect

    Corzine, K.; Ferguson, P.; Morgan, G.; Quintana, D.; Waters, L.; Cooper, R.; Liljestrand, R.; Whiteson, A.

    2000-07-01

    The MCNPX code is currently being used to calculate energy deposition in the accelerator production of tritium (APT) target/blanket system components. To ensure that these components are properly designed, the code must be validated. An energy deposition experiment was designed to aid in the code validation using thermocouple sensors in-beam and thermistor-type sensors in decoupler- and blanketlike regions. This paper focuses on the out-of-beam thermistor sensors constructed of LiAl.

  17. Dry Deposition of Fine Aerosol Nitrogen to an Agricultural Field Measured by Eddy-Correlation Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Gonzales, D. A.; Allen, J. O.; Smith, K. A.; Hope, D.

    2004-12-01

    In urban areas high emissions of reactive nitrogen species cause an increase in atmospheric aerosol nitrogen formation and deposition. This nitrogen is eventually removed from the atmosphere by wet or dry deposition, with dry deposition often accounting for more than half of the total deposition of particulate nitrate (Lovett, 1994). Total N deposition is not adequately characterized, in part because dry deposition is difficult to measure or model. For example measured fine particle deposition to a forest canopy differs from predicted values by an order of magnitude (Gallagher et al., 1997). The eddy-correlation technique is a micrometeorological method used to directly measure fluxes from measurements made above the surface (Wesely and Hicks, 2000). Eddy-correlation mass spectrometry (ECMS) has been developed to directly measure aerosol particle deposition velocities from fast response aerosol concentration and wind velocity measurements. Using an Aerodyne Aerosol Mass Spectrometer (AMS) (Jayne et al., 2000), the size and composition of ambient aerosols is measured at a high frequency. The AMS signal is proportional to non-refractory PM1.0 mass. Aerosol deposition fluxes for a given averaging period are then calculated directly as the covariance of the vertical wind velocity with the AMS signal (F = -/line{w'S'}). A field study was conducted to measure aerosol nitrogen dry deposition to an agricultural field immediately downwind of the Phoenix metropolitan area using eddy-correlation mass spectrometry. The study was supplemented with aerosol composition measurements including bulk deposition collectors and filter bank samplers. Bulk deposition samples and 24-hour filter samples were analyzed for ammonia and nitrogen. Here we compare the results of the flux estimates from bulk collection with inferential measurements (filter samples and modeled deposition velocities) and direct micrometeorological measurements (ECMS) in order to improve N deposition estimates.

  18. Engineering properties of superhard films with ion energy and post-deposition processing

    SciTech Connect

    Monteiro, Othon R.; Delplancke-Ogletree, Mari-Paule

    2002-10-14

    Recent developments in plasma synthesis of hard materials using energetic ions are described. Metal Plasma Immersion Ion Implantation and Deposition (MePIIID) has been used to prepare several hard films: from diamondlike carbon (DLC) to carbides, from nitrides to oxides. The energy of the depositing species is controlled to maximize adhesion as well as to change the physical and chemical properties of the films. Adhesion is promoted by the creation of a graded interface between the film and the substrate. The energy of the depositing ions is also used to modify and control the intrinsic stresses and the microstructure of the films. The deposition is carried out at room temperature, which is important for temperature sensitive substrates. A correlation between intrinsic stresses and the energetics of the deposition is presented for the case of DLC films, and means to reduce stress levels are discussed.

  19. Laser energy deposition and its dynamic uniformity for direct-drive capsules

    SciTech Connect

    Xu, Yan; Wu, SiZhong; Zheng, WuDi

    2015-04-15

    The total laser energy deposition of multi-laser-beam irradiation is not only associated with the dynamic behavior of capsule but also the time-dependent angular distribution of the energy deposition of each beam around its axis. The dynamic behavior of laser energy deposition does not linearly respond to the dynamic behavior of laser irradiation. The laser energy deposition uniformity determines the symmetry of implosion. The dynamic behavior of laser energy deposition non-uniformity in OMEGA for laser with square beam shape intensity profile is investigated. In the case of smaller laser spot, the initial non-uniformity caused by laser beam overlap is very high. The shell asymmetry caused by the high initial laser irradiation non-uniformity is estimated by the extent of distortion of shock front which is not as severe as expected before the shock driven by main pulse arrives. This suggests that the large initial non-uniformity due to smaller laser spot is one of the elements that seed disturbance before the main pulse. The rms of laser energy deposition during the main pulse remains above 2%. Since the intensity of main driving pulse usually is several times higher than that of picket pulses, the non-uniformity in main pulse period may jeopardize the symmetrical implosion. When dynamic behavior of capsule is considered, the influence of beam pointing error, the target positioning error, and beam-to-beam power unbalance is quite different for the case of static capsule.

  20. Study of microdosimetric energy deposition patterns in tissue-equivalent medium due to low-energy neutron fields using a graphite-walled proportional counter.

    PubMed

    Waker, A J; Aslam

    2011-06-01

    To improve radiation protection dosimetry for low-energy neutron fields encountered in nuclear power reactor environments, there is increasing interest in modeling neutron energy deposition in metrological instruments such as tissue-equivalent proportional counters (TEPCs). Along with these computational developments, there is also a need for experimental data with which to benchmark and test the results obtained from the modeling methods developed. The experimental work described in this paper is a study of the energy deposition in tissue-equivalent (TE) medium using an in-house built graphite-walled proportional counter (GPC) filled with TE gas. The GPC is a simple model of a standard TEPC because the response of the counter at these energies is almost entirely due to the neutron interactions in the sensitive volume of the counter. Energy deposition in tissue spheres of diameter 1, 2, 4 and 8 µm was measured in low-energy neutron fields below 500 keV. We have observed a continuously increasing trend in microdosimetric averages with an increase in neutron energy. The values of these averages decrease as we increase the simulated diameter at a given neutron energy. A similar trend for these microdosimetric averages has been observed for standard TEPCs and the Rossi-type, TE, spherical wall-less counter filled with propane-based TE gas in the same energy range. This implies that at the microdosimetric level, in the neutron energy range we employed in this study, the pattern of average energy deposited by starter and insider proton recoil events in the gas is similar to those generated cumulatively by crosser and stopper events originating from the counter wall plus starter and insider recoil events originating in the sensitive volume of a TEPC. PMID:21476858

  1. Stabilizing laser energy density on a target during pulsed laser deposition of thin films

    DOEpatents

    Dowden, Paul C.; Jia, Quanxi

    2016-05-31

    A process for stabilizing laser energy density on a target surface during pulsed laser deposition of thin films controls the focused laser spot on the target. The process involves imaging an image-aperture positioned in the beamline. This eliminates changes in the beam dimensions of the laser. A continuously variable attenuator located in between the output of the laser and the imaged image-aperture adjusts the energy to a desired level by running the laser in a "constant voltage" mode. The process provides reproducibility and controllability for deposition of electronic thin films by pulsed laser deposition.

  2. Activation energy measurements of cheese

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Temperature sweeps of cheeses using small amplitude oscillatory shear tests produced values for activation energy of flow (Ea) between 30 and 44 deg C. Soft goat cheese and Queso Fresco, which are high-moisture cheeses and do not flow when heated, exhibited Ea values between 30 and 60 kJ/mol. The ...

  3. Assessment of the local role of a steel making plant by POPs deposition measurements.

    PubMed

    Rada, E C; Ragazzi, M; Schiavon, M

    2014-09-01

    Atmospheric depositions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were monitored at three sites in the vicinity of a steel making plant, located in an Italian alpine valley. A high variability in the deposition of PCDD/Fs was observed. The influence of the plant was noticeable at two of the sampling sites. However, as the congener profiles demonstrated, wood burning for domestic heating is an additional source of PCDD/Fs for the area under investigation, and this interferes with the characterization of the emissions from the steel plant. The influence of the plant, in terms of PCDD/F deposition, was not noticeable at the most distant site (2km), where an extremely high peak of PCDD/F deposition was measured during the period from 12 January-22 February 2012. The comparison between the congener distribution of PCDD/Fs observed in this sample and the fingerprints of different sources could justify the attribution of this anomalous peak to a possible episode of domestic waste combustion. In order to find a better correlation between the deposition to soil and emissions from the plant, the congener distribution of PCBs was studied. The PCB profiles observed at the three sites well reproduced the average profile found in samples of ash retained by the bag filter of the plant. Thus the monitoring of PCB deposition is an interesting starting point to calibrate dispersion models to assess the impact of steel making activities. PMID:24880599

  4. Linear energy transfer spectrum measurement experiment (P0006)

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Parnell, T. A.

    1984-01-01

    The linear energy transfer (LET) is the energy deposited per unit path length of charged particle traversing matter. For estimating the rate of damage from single-hit phenomena, the quantity that best combines the radiation environment, orbital situation, and spacecraft shielding is the linear energy transfer (LET) spectrum at the device location. This experiment will measure the LET spectrum behind different shielding configurations for approximately 1 year. The shielding will be increased in increments of approximately 1 G/sq cm up to a maximum shieldng of 16 G/sq cm. In addition to providing critical information to future spacecraft designers, these measurements will also provide data that will be extremely valuable to other experiments on LDEF.

  5. Linear energy transfer spectrum measurement experiment (P0006)

    SciTech Connect

    Benton, E.V.; Parnell, T.A.

    1984-02-01

    The linear energy transfer (LET) is the energy deposited per unit path length of charged particle traversing matter. For estimating the rate of damage from single-hit phenomena, the quantity that best combines the radiation environment, orbital situation, and spacecraft shielding is the linear energy transfer (LET) spectrum at the device location. This experiment will measure the LET spectrum behind different shielding configurations for approxmately 1 year. The shielding will be increased in increments of approximately 1 G/sq cm up to a maximum shieldng of 16 G/sq cm. In addition to providing critical information to future spacecraft designers, these measurements will also provide data that will be extremely valuable to other experiments on LDEF.

  6. Dry Deposition of Fine Aerosol Nitrogen to an Agricultural Field Measured by Eddy-Correlation Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Gonzales, D. A.; Allen, J. O.

    2005-12-01

    In urban areas high emissions of reactive nitrogen species cause an increase in atmospheric aerosol nitrogen formation and deposition. This nitrogen is eventually removed from the atmosphere by wet or dry deposition, with dry deposition often accounting for more than half of the total deposition of particulate nitrate. Total N deposition is not adequately characterized, in part because dry deposition is difficult to measure or model. For example measured fine particle deposition to a forest canopy differs from predicted values by an order of magnitude. The eddy-correlation technique is a micrometeorological method used to directly measure fluxes from measurements made above the surface. Eddy-correlation mass spectrometry (ECMS) has been developed to directly measure aerosol particle deposition velocities from fast response aerosol concentration and wind velocity measurements. Using an Aerodyne Aerosol Mass Spectrometer (AMS), the size and composition of ambient aerosols were measured at 10~Hz. The AMS signal is proportional to non-refractory PM1.0 mass. Aerosol deposition fluxes for a given averaging period are then calculated directly as the covariance of the vertical wind velocity with the AMS signal (F = -\\overline{w'S'}). A field study was conducted to measure aerosol nitrogen dry deposition to an agricultural field immediately downwind of the Phoenix metropolitan area using eddy-correlation mass spectrometry. The study was supplemented with aerosol composition measurements including bulk deposition collectors and filter bank samplers. Here we compare the results of the flux estimates from bulk collection with inferential measurements (filter samples and modeled deposition velocities) and direct micrometeorological measurements (ECMS) in order to improve nitrogen deposition estimates.

  7. Biological characterization of low-energy ions with high-energy deposition on human cells.

    PubMed

    Saha, Janapriya; Wilson, Paul; Thieberger, Peter; Lowenstein, Derek; Wang, Minli; Cucinotta, Francis A

    2014-09-01

    During space travel, astronauts are exposed to cosmic radiation that is comprised of high-energy nuclear particles. Cancer patients are also exposed to high-energy nuclear particles when treated with proton and carbon beams. Nuclear interactions from high-energy particles traversing shielding materials and tissue produce low-energy (<10 MeV/n) secondary particles of high-LET that contribute significantly to overall radiation exposures. Track structure theories suggest that high charge and energy (HZE) particles and low-energy secondary ions of similar LET will have distinct biological effects for cellular and tissue damage endpoints. We investigated the biological effects of low-energy ions of high LET utilizing the Tandem Van de Graaff accelerator at the Brookhaven National Laboratory (BNL), and compared these to experiments with HZE particles, that mimic the space environment produced at NASA Space Radiation Laboratory (NSRL) at BNL. Immunostaining for DNA damage response proteins was carried out after irradiation with 5.6 MeV/n boron (LET 205 keV/μm), 5.3 MeV/n silicon (LET 1241 keV/μm), 600 MeV/n Fe (LET 180 keV/μm) and 77 MeV/n oxygen (LET 58 keV/μm) particles. Low-energy ions caused more persistent DNA damage response (DDR) protein foci in irradiated human fibroblasts and esophageal epithelial cells compared to HZE particles. More detailed studies comparing boron ions to Fe particles, showed that boron-ion radiation resulted in a stronger G2 delay compared to Fe-particle exposure, and boron ions also showed an early recruitment of Rad51 at double-strand break (DSB) sites, which suggests a preference of homologous recombination for DSB repair in low-energy albeit high-LET particles. Our experiments suggest that the very high-energy radiation deposition by low-energy ions, representative of galactic cosmic radiation and solar particle event secondary radiation, generates massive but localized DNA damage leading to delayed DSB repair, and distinct cellular

  8. Four studies on effects of environmental factors on the quality of National Atmospheric Deposition Program measurements

    USGS Publications Warehouse

    Wetherbee, Gregory A.; Latysh, Natalie E.; Lehmann, Christopher M.B.; Rhodes, Mark F.

    2011-01-01

    Selected aspects of National Atmospheric Deposition Program / National Trends Network (NADP/NTN) protocols are evaluated in four studies. Meteorological conditions have minor impacts on the error in NADP/NTN sampling. Efficiency of frozen precipitation sample collection is lower than for liquid precipitation samples. Variability of NTN measurements is higher for relatively low-intensity deposition of frozen precipitation than for higher-intensity deposition of liquid precipitation. Urbanization of the landscape surrounding NADP/NTN sites is not affecting trends in wet-deposition chemistry data to a measureable degree. Five NADP siting criteria intended to preserve wet-deposition sample integrity have varying degrees of effectiveness. NADP siting criteria for objects within the 90 degrees cones and trees within the 120 degrees cones projected from the collector bucket to sky are important for protecting sample integrity. Tall vegetation, fences, and other objects located within 5 meters of the collectors are related to the frequency of visible sample contamination, indicating the importance of these factors in NADP siting criteria.

  9. CLUST - EVAP Monte Carlo Simulation Applications for Determining Effective Energy Deposition in Silicon by High Energy Protons

    NASA Technical Reports Server (NTRS)

    ONeill, Pat M.

    2000-01-01

    The CLUST-EVAP is a Monte Carlo simulation of the interaction of high energy (25 - 400 MeV) protons with silicon nuclei. The initial nuclear cascade stage is modeled using the CLUST model developed by Indiana University over 30 years ago. The second stage, in which the excited nucleus evaporates particles in random directions, is modeled according to the evaporation algorithm provided by H. H. K. Tang of IBM. Using the CLUST-EVAP code to model fragment produ6tion and the Vavilov-Landau theory to model fluctuations in direct ionization in thin silicon layers, we have predicted energy deposition in silicon components for various geometrical configurations. We have compared actual measurements with model predictions for geometry's such as single, thin silicon particle detectors, telescopic particle detectors flown in space to measure the environment, and thin sensitive volumes of modern micro-electronic components. We have recently compared the model predictions with actual measurements made by the DOSTEL spectrometer flown in the Shuttle payload bay on STS-84. The model faithfully reproduces the features and aids in interpretation of flight results of this instrument. We have also applied the CLUST-EVAP model to determine energy deposition in the thin sensitive volumes of modern micro-electronic components. We have accessed the ability of high energy (200 MeV) protons to induce latch-up in certain devices that are known to latch up in heavy ion environments. However, some devices are not nearly as susceptible to proton induced latch-up as expected according to their measured heavy ion latch-up cross sections. The discrepancy is believed to be caused by the limited range of the proton-silicon interaction fragments. The CLUST-EV AP model was used to determine a distribution of these fragments and their range and this is compared to knowledge of the ranges required based on the known device structure. This information is especially useful in accessing the risk to on

  10. Ultrafast triggered transient energy storage by atomic layer deposition into porous silicon for integrated transient electronics

    NASA Astrophysics Data System (ADS)

    Douglas, Anna; Muralidharan, Nitin; Carter, Rachel; Share, Keith; Pint, Cary L.

    2016-03-01

    Here we demonstrate the first on-chip silicon-integrated rechargeable transient power source based on atomic layer deposition (ALD) coating of vanadium oxide (VOx) into porous silicon. A stable specific capacitance above 20 F g-1 is achieved until the device is triggered with alkaline solutions. Due to the rational design of the active VOx coating enabled by ALD, transience occurs through a rapid disabling step that occurs within seconds, followed by full dissolution of all active materials within 30 minutes of the initial trigger. This work demonstrates how engineered materials for energy storage can provide a basis for next-generation transient systems and highlights porous silicon as a versatile scaffold to integrate transient energy storage into transient electronics.Here we demonstrate the first on-chip silicon-integrated rechargeable transient power source based on atomic layer deposition (ALD) coating of vanadium oxide (VOx) into porous silicon. A stable specific capacitance above 20 F g-1 is achieved until the device is triggered with alkaline solutions. Due to the rational design of the active VOx coating enabled by ALD, transience occurs through a rapid disabling step that occurs within seconds, followed by full dissolution of all active materials within 30 minutes of the initial trigger. This work demonstrates how engineered materials for energy storage can provide a basis for next-generation transient systems and highlights porous silicon as a versatile scaffold to integrate transient energy storage into transient electronics. Electronic supplementary information (ESI) available: (i) Experimental details for ALD and material fabrication, ellipsometry film thickness, preparation of gel electrolyte and separator, details for electrochemical measurements, HRTEM image of VOx coated porous silicon, Raman spectroscopy for VOx as-deposited as well as annealed in air for 1 hour at 450 °C, SEM and transient behavior dissolution tests of uniformly coated VOx on

  11. Development of a microbalance suitable for space application. [mass measurement device for particulate and vapor deposition measurements

    NASA Technical Reports Server (NTRS)

    Patashnick, H.; Rupprecht, G.

    1977-01-01

    The tapered element oscillating microbalance (TEOM), an ultrasensitive mass measurement device which is suitable for both particulate and vapor deposition measurements is described. The device can be used in contamination measurements, surface reaction studies, particulate monitoring systems or any microweighing activity where either laboratory or field monitoring capability is desired. The active element of the TEOM consists of a tube or reed constructed of a material with high mechanical quality factor and having a special taper. The element is firmly mounted at the wide end while the other end supports a substrate surface which can be composed of virtually any material. The tapered element with the substrate at the free (narrow) end is set into oscillation in a clamped free mode. A feedback system maintains the oscillation whose natural frequency will change in relation to the mass deposited on the substrate.

  12. In vivo measurement of 241Am in the lungs confounded by activity deposited in other organs.

    PubMed

    Lobaugh, Megan L; Spitz, Henry B; Glover, Samuel E

    2015-01-01

    Radioactive material deposited in multiple organs of the body is likely to confound a result of an in vivo measurement performed over the lungs, the most frequently monitored organ for occupational exposure. The significance of this interference was evaluated by measuring anthropometric torso phantoms containing lungs, liver, skeleton, and axillary lymph nodes, each with a precisely known quantity of 241Am uniformly distributed in the organs. Arrays of multiple high-resolution germanium detectors were positioned over organs within the torso phantom containing 241Am or over proximal organs without activity to determine the degree of measurement confounding due to photons emitted from other source organs. A set of four mathematical response functions describes the measured count rate with detectors positioned over each of the relevant organs and 241Am contained in the measured organ or one of the other organs selected as a confounder. Simultaneous solution of these equations by matrix algebra, where the diagonal terms of the matrix are calibration factors for a direct measurement of activity in an organ and the off-diagonal terms reflect the contribution (i.e., interference or cross-talk) produced by 241Am in a confounding organ, yields the activity deposited in each of the relevant organs. The matrix solution described in this paper represents a method for adjusting a result of 241Am measured directly in one organ for interferences that may arise from 241Am deposited elsewhere and represents a technically valid procedure to aid in evaluating internal dose based upon in vivo measurements for those radioactive materials known to deposit in multiple organs. PMID:25437522

  13. Auroral Energy and Energy Flux Measurements using GUVI

    NASA Astrophysics Data System (ADS)

    Holley, K. E.; McHarg, M. G.; Paxton, L.; Zhang, Y.; Morrison, D.

    2003-12-01

    We present estimates of the average characteristic energy and energy flux of energetic precipitating auroral particles. These estimates are derived from irradiance data measured on the Global Ultraviolet Imager (GUVI) flying on the TIMED satellite. We will present both the average and standard deviation of global maps of the energy and energy flux during the first year of GUVI data. We will compare results of the GUVI derived measurements to previous estimates of Hardy who used in-situ particle measurements from the Defense Meteorological Support Satellite (DMSP) program.

  14. Review of the ITER diagnostics suite for erosion, deposition, dust and tritium measurements

    NASA Astrophysics Data System (ADS)

    Reichle, R.; Andrew, P.; Bates, P.; Bede, O.; Casal, N.; Choi, C. H.; Barnsley, R.; Damiani, C.; Bertalot, L.; Dubus, G.; Ferreol, J.; Jagannathan, G.; Kocan, M.; Leipold, F.; Lisgo, S. W.; Martin, V.; Palmer, J.; Pearce, R.; Philipps, V.; Pitts, R. A.; Pampin, R.; Passedat, G.; Puiu, A.; Suarez, A.; Shigin, P.; Shu, W.; Vayakis, G.; Veshchev, E.; Walsh, M.

    2015-08-01

    Dust and tritium inventories in the vacuum vessel have upper limits in ITER that are set by nuclear safety requirements. Erosion, migration and re-deposition of wall material together with fuel co-deposition will be largely responsible for these inventories. The diagnostic suite required to monitor these processes, along with the set of the corresponding measurement requirements is currently under review given the recent decision by the ITER Organization to eliminate the first carbon/tungsten (C/W) divertor and begin operations with a full-W variant Pitts et al. [1]. This paper presents the result of this review as well as the status of the chosen diagnostics.

  15. A "TEST OF CONCEPT" COMPARISON OF AERODYNAMIC AND MECHANICAL RESUSPENSION MECHANISMS FOR PARTICLES DEPOSITED ON FIELD RYE GRASS (SECALS CERCELE). PART 2. THRESHOLD MECHANICAL ENERGIES FOR RESUSPENSION PARTICLE FLUXES

    EPA Science Inventory

    Kinetic energy from the oscillatory impacts of the grass stalk against a stationary object was measured with a kinetic energy measuring device. These energy inputs were measured as part of a resuspension experiment of uniform latex microspheres deposited on a single rye grass see...

  16. Eddy Correlation Measurements of the Dry Deposition of Particles in Wintertime.

    NASA Astrophysics Data System (ADS)

    Duan, B.; Fairall, C. W.; Thomson, D. W.

    1988-05-01

    Eddy correlation measurements of the vertical fluxes of particles, momentum, heat and water vapor, were conducted over a partially snow covered field in central Pennsylvania during December 1985. The PMS ASASP-300 and CSASP-100-HV optical counters were used as sensors to measure particle-number fluxes. Overall, average dry deposition velocities for 28 half-hour runs were found to be 0.034 ± 0.014 and 0.021 ± 0.005 cm s1 for particles in two size ranges, 0.15-30 and 0.5-1.0 m, respectively. The average deposition velocity was close to results from prior wind-tunnel and theoretical investigations. These results were also comparable with those reported by other authors over grass. Relatively large sampling rates reduced the effects of counting noise on deposition measurements of 0.5-;1.0 m particles. Small correlation coefficients between vertical velocity and the particle concentration were found even after corrections for the effects of counting noise. The normalized average surface deposition velocity vds/u( for particles in diameter of 0.15-0.30 and 0.5-1.0 m appeared to be 0.006 and 0.002, respectively, in nearly neutral and stable conditions.

  17. Comprehensive Energy Balance Measurements in Mice.

    PubMed

    Moir, Lee; Bentley, Liz; Cox, Roger D

    2016-01-01

    In mice with altered body composition, establishing whether it is food intake or energy expenditure, or both, that is the major determinant resulting in changed energy balance is important. In order to ascertain where the imbalance is, the acquisition of reproducible data is critical. Therefore, here we provide detailed descriptions of how to determine energy balance in mice. This encompasses protocols for establishing energy intake from home cage measurement of food intake, determining energy lost in feces using bomb calorimetry, and using equations to calculate parameters such as energy intake (EI), digested energy intake (DEI), and metabolisable energy intake (MEI) to determine overall energy balance. We also discuss considerations that should be taken into account when planning these experiments, including diet and sample sizes. © 2016 by John Wiley & Sons, Inc. PMID:27584551

  18. On the Total Energy Deposition Between Periodically Occurring Activations of the Aurora

    NASA Technical Reports Server (NTRS)

    Spann, James F., Jr.; Germany, G. A.; Parks, G. K.; Brittnacher, M. J.; Winglee, R. W.

    1998-01-01

    Total energy deposition in the northern latitudes is used in models to determine the state of the magnetosphere. It is known that on occasion, a series of intensifications of the aurora occur that are regularly spaced. The energy profile of the total energy deposited reflects this occurance. What can be said of the state of the magnetosphere based on these profiles. We present the result of a study which looks at several of these periods when a series of intensifications occur. Conclusions as to what the magnetosphere may be doing are presented.

  19. Numerical Laser Energy Deposition on Supersonic Cavity Flow and Sensor Placement Strategies to Control the Flow

    PubMed Central

    Aradag, Selin

    2013-01-01

    In this study, the impact of laser energy deposition on pressure oscillations and relative sound pressure levels (SPL) in an open supersonic cavity flow is investigated. Laser energy with a magnitude of 100 mJ is deposited on the flow just above the cavity leading edge and up to 7 dB of reduction is obtained in the SPL values along the cavity back wall. Additionally, proper orthogonal decomposition (POD) method is applied to the x-velocity data obtained as a result of computational fluid dynamics simulations of the flow with laser energy deposition. Laser is numerically modeled using a spherically symmetric temperature distribution. By using the POD results, the effects of laser energy on the flow mechanism are presented. A one-dimensional POD methodology is applied to the surface pressure data to obtain critical locations for the placement of sensors for real time flow control applications. PMID:24363612

  20. Numerical laser energy deposition on supersonic cavity flow and sensor placement strategies to control the flow.

    PubMed

    Yilmaz, Ibrahim; Aradag, Selin

    2013-01-01

    In this study, the impact of laser energy deposition on pressure oscillations and relative sound pressure levels (SPL) in an open supersonic cavity flow is investigated. Laser energy with a magnitude of 100 mJ is deposited on the flow just above the cavity leading edge and up to 7 dB of reduction is obtained in the SPL values along the cavity back wall. Additionally, proper orthogonal decomposition (POD) method is applied to the x-velocity data obtained as a result of computational fluid dynamics simulations of the flow with laser energy deposition. Laser is numerically modeled using a spherically symmetric temperature distribution. By using the POD results, the effects of laser energy on the flow mechanism are presented. A one-dimensional POD methodology is applied to the surface pressure data to obtain critical locations for the placement of sensors for real time flow control applications. PMID:24363612

  1. Experiment of Flow Control Using Laser Energy Deposition Around High Speed Propulsion System

    NASA Astrophysics Data System (ADS)

    Lee, HyoungJin; Jeung, InSeuck; Lee, SangHun; Kim, Seihwan

    2011-11-01

    An experimental investigation was conducted to examine the effect of a pulsed Nd:YAG laser energy deposition on the shock structures in supersonic/hypersonic flow and quiescent air. The effect of the laser energy and pressure in the blast wave generation were also investigated. As a result, the strength of plasma and blast wave becomes stronger as pressure or laser energy increase. And the breakdown threshold of air by laser energy deposition is 0.015 bar at 508 mJ laser energy, the blast wave threshold generation in air by laser energy deposition is 0.100 bar at same laser energy. As qualitative analysis, schlieren images are also obtained. After the series of experiments, the effect of laser energy deposition (LED) on high speed flow around the shock—shock interaction created by a wedge and blunt body. By LED, the structure of shock—shock interaction was collapsed momentary and the pressure of the stagnation point was fluctuated while interference of wave.

  2. Three methods to measure RH bond energies

    SciTech Connect

    Berkowitz, J.; Ellison, G.B.; Gutman, D.

    1993-03-21

    In this paper the authors compare and contrast three powerful methods for experimentally measuring bond energies in polyatomic molecules. The methods are: radical kinetics; gas phase acidity cycles; and photoionization mass spectroscopy. The knowledge of the values of bond energies are a basic piece of information to a chemist. Chemical reactions involve the making and breaking of chemical bonds. It has been shown that comparable bonds in polyatomic molecules, compared to the same bonds in radicals, can be significantly different. These bond energies can be measured in terms of bond dissociation energies.

  3. An experimental approach to measure particle deposition in large circular ventilation ducts.

    PubMed

    Da, Guillaume; Géhin, Evelyne; Ben-Othmane, Mourad; Havet, Michel; Solliec, Camille; Motzkus, Charles

    2015-04-01

    The topic of this study is related to airborne particle dynamics in indoor environments. Lab-scale experiments have been performed to investigate particle deposition velocity to six different surfaces orientations (with respect to gravity) for fully developed turbulent flow in horizontal large circular ventilation ducts. Monodispersed aerosol particles (1-6 μm) were used in the deposition experiments. A very low particle mass (40 ng) was measured reliably above background level on duct surfaces by a means of a nondestructive stencil technique associated with fluorescence analysis. For 2-6 μm particles (diffusion and impaction regime), deposition rates to floors were much greater than rates to the ceiling and greater than rates to the wall. For 1-μm particles, the effect of surface orientation to particle deposition was not significant. Results were compared to the very few similar and published studies. This work was conducted in the frame of the CleanAirNet project which aimed at producing new knowledge, models, and techniques to help controlling the safety food stuffs, through a better control of aerosol particle (bioaerosols) transport and deposition in the ventilation networks of the food industry. PMID:24756675

  4. Labor and energy impacts of energy-conservation measures

    SciTech Connect

    Not Available

    1980-01-01

    Three papers are presented discussing the labor and energy impacts of energy-conservation measures, namely: Generation of the Industry/Occupation Wage Matrix and Related Matters, by Carole Green; Job Shifts from Energy Conservation (Salary Distribution Effects), by Robert A. Herendeen; and Energy and Labor Implication of Improving Thermal Integrity of New Houses, by John Joseph Nangle. A separate abstract was prepared for each paper.

  5. Moderation of near-field pressure over a supersonic flight model using laser-pulse energy deposition

    NASA Astrophysics Data System (ADS)

    Furukawa, D.; Aoki, Y.; Iwakawa, A.; Sasoh, A.

    2016-05-01

    The impact of a thermal bubble produced by energy deposition on the near-field pressure over a Mach 1.7 free-flight model was experimentally investigated using an aeroballistic range. A laser pulse from a transversely excited atmospheric (TEA) CO2 laser was sent into a test chamber with 68 kPa ambient pressure, focused 10 mm below the flight path of a conically nosed cylinder with a diameter of 10 mm. The pressure history, which was measured 150 mm below the flight path along the acoustic ray past the bubble, exhibited precursory pressure rise and round-off peak pressure, thereby demonstrating the proof-of-concept of sonic boom alleviation using energy deposition.

  6. Effect of Low-Energy Ions on Plasma-Enhanced Deposition of Cubic Boron Nitride

    NASA Astrophysics Data System (ADS)

    Torigoe, M.; Fukui, S.; Teii, K.; Matsumoto, S.

    2015-09-01

    The effect of low-energy ions on deposition of cubic boron nitride (cBN) films in an inductively coupled plasma with the chemistry of fluorine is studied in terms of ion energy, ion flux, and ion to boron flux ratio onto the substrate. The ion energy and the ion to boron flux ratio are determined from the sheath potential and the ratio of incident ion flux to net deposited boron flux, respectively. For negative substrate biases where sp2-bonded BN phase only or no deposit is formed, both the ion energy and the ion to boron flux ratio are high. For positive substrate biases where cBN phase is formed, the ion energy and the ion to boron flux ratio are estimated in the range of a few eV to 35 eV and 100 to 130, respectively. The impact of negative ions is presumed to be negligible due to their low kinetic energy relative to the sheath potential over the substrate surface. The impact of positive ions with high ion to boron flux ratios is primarily responsible for reduction of the ion energy for cBN film deposition. Work supported in part by a Grant-in-Aid for Scientific Research (B), a Funding Program for Next Generation World-Leading Researchers, and an Industrial Technology Research Grant Program 2008.

  7. Measurements of size-fractionated concentration and bulk dry deposition of atmospheric particulate bound mercury

    NASA Astrophysics Data System (ADS)

    Fang, G. C.; Zhang, L.; Huang, C. S.

    2012-12-01

    Daily samples of size-fractionated (18, 10, 2.5 and 1.0 μm) particulate-bound mercury Hg(p) were collected using Micro-Orifice Uniform Deposition Impactors (MOUDI), on randomly selected days each month between November 2010 and July 2011, at a traffic site (Hungkuang), a wetland site (Gaomei), and an industrial site (Quanxing) in central Taiwan. Bulk dry deposition was also collected simultaneously using a surrogate surface. The nine-month average (±standard deviation) Hg(p) concentrations were 0.57 (±0.90), 0.17 (±0.27), and 0.94 (±0.92) ng m-3 at Hungkuang, Gaomei, and Quanxing, respectively. Concentrations in November and December were much higher than in the other months due to a combination of high local emissions and meteorological conditions. PM1.0 contributed more than 50% to the bulk concentration at the traffic and the industrial sites, but only contributed 25% at the wetland site. PM1.0-2.5 contributed 25%-50%, depending on location, to the bulk mass. Coarse fraction (PM2.5-18) contributed 7% at Hungkuang, 25% at Gaomei, and 19% at Quanxing. Samples with very high bulk concentrations had large fine fractions. Annual dry deposition estimated from the surrogate surface measurements was in the range of 30-85 μg m-2 yr-1 at the three sites. Coarse particulate Hg(p) were estimated to contribute 50-85% of the total Hg(p) dry deposition. Daily dry deposition velocities (Vd) ranged from 0.01 to 7.7 cm s-1. The annual Vd generated from the total measured fluxes was 0.34, 0.60 and 0.29 cm s-1 at Hungkuang, Gaomei, and Quanxing, respectively. These values can be reasonably reproduced using a size-resolved model and measured size fractions.

  8. In situ gas phase measurements during metal alkylamide atomic layer deposition.

    PubMed

    Maslar, J E; Kimes, W A; Sperling, B A

    2011-09-01

    Metal alkylamide compounds, such as tetrakis(ethylmethylamido) hafnium (TEMAH), represent a technologically important class of metalorganic precursors for the deposition of metal oxides and metal nitrides via atomic layer deposition (ALD) or chemical vapor deposition. The development of in situ diagnostics for processes involving these compounds could be beneficial in, e.g., developing deposition recipes and validating equipment-scale simulations. This report describes the performance of the combination of two techniques for the simultaneous, rapid measurement of the three major gas phase species during hafnium oxide thermal ALD using TEMAH and water: TEMAH, water, and methylethyl amine (MEA), the only major reaction by-product. For measurement of TEMAH and MEA, direct absorption methods based on a broadband infrared source with different mid-IR bandpass filters and utilizing amplitude modulation and synchronous detection were developed. For the measurement of water, wavelength modulation spectroscopy utilizing a near-IR distributed feedback diode laser was used. Despite the relatively simple reactor geometry employed here (a flow tube), differences were easily observed in the time-dependent species distributions in 300 mL/min of a helium carrier gas and in 1000 mL/min of a nitrogen carrier gas. The degree of TEMAH entrainment was lower in 300 mL/min of helium compared to that in 1000 mL/min of nitrogen. The capability to obtain detailed time-dependent species concentrations during ALD could potentially allow for the selection of carrier gas composition and flow rates that would minimize parasitic wall reactions. However, when nitrogen was employed at the higher flow rates, various flow effects were observed that, if detrimental to a deposition process, would effectively limit the upper range of useful flow rates. PMID:22097559

  9. Stochastic spatial energy deposition profiles for MeV protons and keV electrons

    NASA Astrophysics Data System (ADS)

    Udalagama, C.; Bettiol, A. A.; Watt, F.

    2009-12-01

    With the rapid advances being made in novel high-energy ion-beam techniques such as proton beam writing, single-ion-event effects, ion-beam-radiation therapy, ion-induced fluorescence imaging, proton/ion microscopy, and ion-induced electron imaging, it is becoming increasingly important to understand the spatial energy-deposition profiles of energetic ions as they penetrate matter. In this work we present the results of comprehensive yet straightforward event-by-event Monte Carlo calculations that simulate ion/electron propagation and secondary electron ( δ ray) generation to yield spatial energy-deposition data. These calculations combine SRIM/TRIM features, EEDL97 data and volume-plasmon-localization models with a modified version of one of the newer δ ray generation models, namely, the Hansen-Kocbach-Stolterfoht. The development of the computer code DEEP (deposition of energy due to electrons and protons) offers a unique means of studying the energy-deposition/redistribution problem while still retaining the important stochastic nature inherent in these processes which cannot be achieved with analytical modeling. As an example of an application of DEEP we present results that compare the energy-deposition profiles of primary MeV protons and primary keV electrons in polymethymethacrylate. Such data are important when comparing proximity effects in the direct write lithography processes of proton-beam writing and electron-beam writing. Our calculations demonstrate that protons are able to maintain highly compact spatial energy-deposition profiles compared with electrons.

  10. Procedure to Measure Indoor Lighting Energy Performance

    SciTech Connect

    Deru, M.; Blair, N.; Torcellini, P.

    2005-10-01

    This document provides standard definitions of performance metrics and methods to determine them for the energy performance of building interior lighting systems. It can be used for existing buildings and for proposed buildings. The primary users for whom these documents are intended are building energy analysts and technicians who design, install, and operate data acquisition systems, and who analyze and report building energy performance data. Typical results from the use of this procedure are the monthly and annual energy used for lighting, energy savings from occupancy or daylighting controls, and the percent of the total building energy use that is used by the lighting system. The document is not specifically intended for retrofit applications. However, it does complement Measurement and Verification protocols that do not provide detailed performance metrics or measurement procedures.

  11. Energy deposition dynamics of femtosecond pulses in water

    SciTech Connect

    Minardi, Stefano Pertsch, Thomas; Milián, Carles; Couairon, Arnaud; Majus, Donatas; Tamošauskas, Gintaras; Dubietis, Audrius; Gopal, Amrutha

    2014-12-01

    We exploit inverse Raman scattering and solvated electron absorption to perform a quantitative characterization of the energy loss and ionization dynamics in water with tightly focused near-infrared femtosecond pulses. A comparison between experimental data and numerical simulations suggests that the ionization energy of water is 8 eV, rather than the commonly used value of 6.5 eV. We also introduce an equation for the Raman gain valid for ultra-short pulses that validates our experimental procedure.

  12. Wet Deposition Measurements across the Continent: Observations from The National Ecological Observatory Network

    NASA Astrophysics Data System (ADS)

    Taylor, J. R.; Goodman, K. J.; Luo, H.; Roehm, C. L.

    2013-12-01

    The National Ecological Observatory Network (NEON) is responsible for making observations of terrestrial, aquatic, and organismal ecology at 106 sites in 20 different eco-climatic domains across the North American continent. NEON will provide data on key local, meteorological, climate, and chemical variables, as well as their associated biogeochemical and biotic responses, in an effort to better understand and predict the effects of climate change, land-use change, and invasive species. The volume of data collected is expected to exceed hundreds of Terabytes per year and will be freely available via a web portal for use by researchers, educators, and policy makers. Chemical scavenging by wet deposition is a principle means of chemical inputs into an ecosystem. By the time NEON becomes fully operational in 2017; wet deposition will be collected and measured at 55 sites across the US. It is expected that these measurements will capture, among other compounds, the deposition of sulfate, ammonium, and nitrate spanning gradients and 'hot spots' across terrestrial and aquatic ecosystems. This poster will highlight the network planning for these measurements, the instrumentation and observational details, as well as opportunities to link these data products with external networks. Particular emphasis will be placed on how these measurements complement and link with other biogeochemical and climatological data products at NEON.

  13. Biological consequences of nanoscale energy deposition near irradiated heavy atom nanoparticles

    NASA Astrophysics Data System (ADS)

    McMahon, Stephen J.; Hyland, Wendy B.; Muir, Mark F.; Coulter, Jonathan A.; Jain, Suneil; Butterworth, Karl T.; Schettino, Giuseppe; Dickson, Glenn R.; Hounsell, Alan R.; O'Sullivan, Joe M.; Prise, Kevin M.; Hirst, David G.; Currell, Fred J.

    2011-06-01

    Gold nanoparticles (GNPs) are being proposed as contrast agents to enhance X-ray imaging and radiotherapy, seeking to take advantage of the increased X-ray absorption of gold compared to soft tissue. However, there is a great discrepancy between physically predicted increases in X-ray energy deposition and experimentally observed increases in cell killing. In this work, we present the first calculations which take into account the structure of energy deposition in the nanoscale vicinity of GNPs and relate this to biological outcomes, and show for the first time good agreement with experimentally observed cell killing by the combination of X-rays and GNPs. These results are not only relevant to radiotherapy, but also have implications for applications of heavy atom nanoparticles in biological settings or where human exposure is possible because the localised energy deposition high-lighted by these results may cause complex DNA damage, leading to mutation and carcinogenesis.

  14. Biological consequences of nanoscale energy deposition near irradiated heavy atom nanoparticles

    PubMed Central

    McMahon, Stephen J.; Hyland, Wendy B.; Muir, Mark F.; Coulter, Jonathan A.; Jain, Suneil; Butterworth, Karl T.; Schettino, Giuseppe; Dickson, Glenn R.; Hounsell, Alan R.; O'Sullivan, Joe M.; Prise, Kevin M.; Hirst, David G.; Currell, Fred J.

    2011-01-01

    Gold nanoparticles (GNPs) are being proposed as contrast agents to enhance X-ray imaging and radiotherapy, seeking to take advantage of the increased X-ray absorption of gold compared to soft tissue. However, there is a great discrepancy between physically predicted increases in X-ray energy deposition and experimentally observed increases in cell killing. In this work, we present the first calculations which take into account the structure of energy deposition in the nanoscale vicinity of GNPs and relate this to biological outcomes, and show for the first time good agreement with experimentally observed cell killing by the combination of X-rays and GNPs. These results are not only relevant to radiotherapy, but also have implications for applications of heavy atom nanoparticles in biological settings or where human exposure is possible because the localised energy deposition high-lighted by these results may cause complex DNA damage, leading to mutation and carcinogenesis. PMID:22355537

  15. Study on deposition rate and laser energy efficiency of Laser-Induction Hybrid Cladding

    NASA Astrophysics Data System (ADS)

    Wang, DengZhi; Hu, QianWu; Zheng, YinLan; Xie, Yong; Zeng, XiaoYan

    2016-03-01

    Laser-Induction Hybrid Cladding (LIHC) was introduced to prepare metal silicide based composite coatings, and influence of different factors such as laser type, laser power, laser scan speed and induction preheating temperature on the coating deposition rate and laser energy efficiency was studied systematically. Compared with conventional CO2 laser cladding, fiber laser-induction hybrid cladding improves the coating deposition rate and laser energy efficiency by 3.7 times. When a fiber laser with laser power of 4 kW was combined with an induction preheating temperature of 850 °C, the maximum coating deposition rate and maximum laser energy efficiency reaches 71 g/min and 64% respectively.

  16. Particle production and energy deposition studies for the neutrino factory target station

    NASA Astrophysics Data System (ADS)

    Back, John J.; Densham, Chris; Edgecock, Rob; Prior, Gersende

    2013-02-01

    We present FLUKA and MARS simulation studies of the pion production and energy deposition in the Neutrino Factory baseline target station, which consists of a 4 MW proton beam interacting with a liquid mercury jet target within a 20 T solenoidal magnetic field. We show that a substantial increase in the shielding is needed to protect the superconducting coils from too much energy deposition. Investigations reveal that it is possible to reduce the magnetic field in the solenoid capture system without adversely affecting the pion production efficiency. We show estimates of the amount of concrete shielding that will be required to protect the environment from the high radiation doses generated by the target station facility. We also present yield and energy deposition results for alternative targets: gallium liquid jet, tungsten powder jet, and solid tungsten bars.

  17. The Measurement of Dry Deposition and Surface Runoff to Quantify Urban Road Pollution in Taipei, Taiwan

    PubMed Central

    Wang, Yunn-Jinn; Chen, Chi-Feng; Lin, Jen-Yang

    2013-01-01

    Pollutants deposited on road surfaces and distributed in the environment are a source of nonpoint pollution. Field data are traditionally hard to collect from roads because of constant traffic. In this study, in cooperation with the traffic administration, the dry deposition on and road runoff from urban roads was measured in Taipei City and New Taipei City, Taiwan. The results showed that the dry deposition is 2.01–5.14 g/m2·day and 78–87% of these solids are in the 75–300 µm size range. The heavy metals in the dry deposited particles are mainly Fe, Zn, and Na, with average concentrations of 34,978, 1,519 and 1,502 ppm, respectively. Elevated express roads show the highest heavy metal concentrations. Not only the number of vehicles, but also the speed of the traffic should be considered as factors that influence road pollution, as high speeds may accelerate vehicle wear and deposit more heavy metals on road surfaces. In addition to dry deposition, the runoff and water quality was analyzed every five minutes during the first two hours of storm events to capture the properties of the first flush road runoff. The sample mean concentration (SMC) from three roads demonstrated that the first flush runoff had a high pollution content, notably for suspended solid (SS), chemical oxygen demand (COD), oil and grease, Pb, and Zn. Regular sweeping and onsite water treatment facilities are suggested to minimize the pollution from urban roads. PMID:24135820

  18. Long period gratings coated with hafnium oxide by plasma-enhanced atomic layer deposition for refractive index measurements.

    PubMed

    Melo, Luis; Burton, Geoff; Kubik, Philip; Wild, Peter

    2016-04-01

    Long period gratings (LPGs) are coated with hafnium oxide using plasma-enhanced atomic layer deposition (PEALD) to increase the sensitivity of these devices to the refractive index of the surrounding medium. PEALD allows deposition at low temperatures which reduces thermal degradation of UV-written LPGs. Depositions targeting three different coating thicknesses are investigated: 30 nm, 50 nm and 70 nm. Coating thickness measurements taken by scanning electron microscopy of the optical fibers confirm deposition of uniform coatings. The performance of the coated LPGs shows that deposition of hafnium oxide on LPGs induces two-step transition behavior of the cladding modes. PMID:27137052

  19. Absolute reflectivity measurements at 44.79 A of sputter deposited multilayer x-ray mirrors.

    PubMed

    Arbaoui, M; Barchewitz, R; Sella, C; Youn, K B

    1990-02-01

    Multilayer x-ray mirrors have been deposited using a dc triode sputtering system, which incorporates an accurate method of thickness monitoring based on the dependence of the deposition rate on the target current. Thickness can be controlled with an accuracy of better than 0.1 A. High efficiency W-C and Ni-C multilayer mirrors have been synthesized and tested at 1.54-A (CuKoalpha) and 44.79-A (CKalpha). Absolute reflectivity measurements at lambda = 44.79-A (CKalpha) have been carried out. In this case the incident beam is previously polarized by a premonochromator equipped with a pair of parallel-plane multilayer mirrors fixed at an angle close to the Brewster (theta ? 45 degrees ). Thus the measured reflectivities are not affected by a progressive variation of the P-component. PMID:20556133

  20. Energy deposition at the bone-tissue interface from nuclear fragments produced by high-energy nucleons

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Hajnal, Ferenc; Wilson, John W.

    1990-01-01

    The transport of nuclear fragmentation recoils produced by high-energy nucleons in the region of the bone-tissue interface is considered. Results for the different flux and absorbed dose for recoils produced by 1 GeV protons are presented in a bidirectional transport model. The energy deposition in marrow cavities is seen to be enhanced by recoils produced in bone. Approximate analytic formulae for absorbed dose near the interface region are also presented for a simplified range-energy model.

  1. Measurement of the Critical Deposition Velocity in Slurry Transport through a Horizontal Pipe

    SciTech Connect

    Erian, Fadel F.; Furfari, Daniel J.; Kellogg, Michael I.; Park, Walter R.

    2001-03-01

    Critical Deposition Velocity (CDV) is an important design and operational parameter in slurry transport. Almost all existing correlations that are used to predict this parameter have been obtained experimentally from slurry transport tests featuring single solid species in the slurry mixture. No correlations have been obtained to describe this parameter when the slurry mixture contains more than one solid species having a wide range of specific gravities, particle size distributions, and volume concentrations within the overall slurry mixture. There are no physical or empirical bases that can justify the extrapolation or modification of the existing single species correlations to include all these effects. New experiments must be carried out to obtain new correlations that would be suited for these types of slurries, and that would clarify the mechanics of solids deposition as a function of the properties of the various solid species. Our goal in this paper is to describe a robust experimental technique for the accurate determination of the critical deposition velocity associated with the transport of slurries in horizontal or slightly inclined pipes. Because of the relative difficulty encountered during the precise determination of this useful operational parameter, it has been the practice to connect it with some transitional behavior of more easily measurable flow parameters such as the pressure drop along the slurry pipeline. In doing so, the critical deposition velocity loses its unique and precise definition due to the multitude of factors that influence such transitional behaviors. Here, data has been obtained for single species slurries made up of washed garnet and water and flowing through a 1- inch clear pipe. The selected garnet had a narrow particle size distribution with a mean diameter of 100 mm, approximately. The critical deposition velocity was measured for garnet/water slurries of 10, 20, and 30 percent solids concentration by volume.

  2. Microparticle impact sensor measures energy directly

    NASA Technical Reports Server (NTRS)

    Alexander, W. M.; Berg, O. E.

    1965-01-01

    Construction of a capacitor sensor consisting of a dielectric layer between two conductive surface layers and connected across a potential source through a sensing resistor permits measurement of energy of impinging particles without degradation of sensitivity. A measurable response is produced without penetration of the dielectric layer.

  3. Predicting wetland contamination from atmospheric deposition measurements of pesticides in the Canadian Prairie Pothole region

    NASA Astrophysics Data System (ADS)

    Messing, Paul G.; Farenhorst, Annemieke; Waite, Don T.; McQueen, D. A. Ross; Sproull, James F.; Humphries, David A.; Thompson, Laura L.

    2011-12-01

    Although it has been suggested that atmospheric deposition alone can result in detectable levels of pesticides in wetlands of the Pairie Pothole Region of Canada, this is the first field study to compare the masses of pesticides entering wetlands by atmospheric deposition with those concentrations of pesticides detected in the water-column of prairie wetlands. Weekly air and bulk deposition samples were collected from May 26th to Sept. 15th, 2008 at the Manitoba Zero Tillage Research Association (MZTRA) Farm, Brandon, Manitoba, with four on-site wetlands (approximate sizes 0.15-0.45 ha) monitored every second week. Twelve pesticides were detected in the air, with MCPA (one of the three pesticides applied on the farm in 2008 in addition to clopyralid and glyphosate), triallate, and γ-HCH being detected every week. Calculations were performed to predict wetland pesticide concentrations based on bulk deposits alone for those pesticides that had detectable concentrations in the bulk deposition samples (in order of the highest total seasonal deposition mass to the lowest): MCPA, glyphosate, 2,4-D, clopyralid, bromoxynil, atrazine, dicamba, metolachlor, and mecoprop. The estimated concentrations were closest to actual concentrations for MCPA (Pearson correlation coefficient's = 0.91 to 0.98; p-values < 0.001) and predictions were also reasonable for a range of other herbicides, but a source other than atmospheric deposition was clearly relevant to detections of clopyralid in the wetland water-column. Although the types and levels of pesticides detected in the wetlands of the current study suggest that regional pesticide applications can contribute to pesticide surface water contamination following atmospheric transport and deposition, the greater frequency and concentrations of clopyralid, MCPA, and glyphosate detections in wetlands confirm that on-farm pesticide applications have a greater impact on on-site water quality. Beneficial management practices that reduce

  4. Measured Black Carbon Deposition on the Sierra Nevada Snow Pack and Implication for Snow Pack Retreat

    SciTech Connect

    Hadley, O.L.; Corrigan, C.E.; Kirchstetter, T.W.; Cliff, S.S.; Ramanathan, V.

    2010-01-12

    Modeling studies show that the darkening of snow and ice by black carbon deposition is a major factor for the rapid disappearance of arctic sea ice, mountain glaciers and snow packs. This study provides one of the first direct measurements for the efficient removal of black carbon from the atmosphere by snow and its subsequent deposition to the snow packs of California. The early melting of the snow packs in the Sierras is one of the contributing factors to the severe water problems in California. BC concentrations in falling snow were measured at two mountain locations and in rain at a coastal site. All three stations reveal large BC concentrations in precipitation, ranging from 1.7 ng/g to 12.9 ng/g. The BC concentrations in the air after the snow fall were negligible suggesting an extremely efficient removal of BC by snow. The data suggest that below cloud scavenging, rather than ice nuclei, was the dominant source of BC in the snow. A five-year comparison of BC, dust, and total fine aerosol mass concentrations at multiple sites reveals that the measurements made at the sampling sites were representative of large scale deposition in the Sierra Nevada. The relative concentration of iron and calcium in the mountain aerosol indicates that one-quarter to one-third of the BC may have been transported from Asia.

  5. Identification of cost effective energy conservation measures

    NASA Technical Reports Server (NTRS)

    Bierenbaum, H. S.; Boggs, W. H.

    1978-01-01

    In addition to a successful program of readily implemented conservation actions for reducing building energy consumption at Kennedy Space Center, recent detailed analyses have identified further substantial savings for buildings representative of technical facilities designed when energy costs were low. The techniques employed for determination of these energy savings consisted of facility configuration analysis, power and lighting measurements, detailed computer simulations and simulation verifications. Use of these methods resulted in identification of projected energy savings as large as $330,000 a year (approximately two year break-even period) in a single building. Application of these techniques to other commercial buildings is discussed

  6. Investigation of Mn-implanted n-Si by low-energy ion beam deposition

    NASA Astrophysics Data System (ADS)

    Liu, Lifeng; Chen, Nuofu; Song, Shulin; Yin, Zhigang; Yang, Fei; Chai, Chunlin; Yang, Shaoyan; Liu, Zhikai

    2005-01-01

    Mn ions were implanted to n-type Si(0 0 1) single crystal by low-energy ion beam deposition technique with an energy of 1000 eV and a dose of 7.5×10 17 cm -2. The samples were held at room temperature and at 300 °C during implantation. Auger electron spectroscopy depth profiles of samples indicate that the Mn ions reach deeper in the sample implanted at 300 °C than in the sample implanted at room temperature. X-ray diffraction measurements show that the structure of the sample implanted at room temperature is amorphous while that of the sample implanted at 300 °C is crystallized. There are no new phases found except silicon both in the two samples. Atomic force microscopy images of samples indicate that the sample implanted at 300 °C has island-like humps that cover the sample surface while there is no such kind of characteristic in the sample implanted at room temperature. The magnetic properties of samples were investigated by alternating gradient magnetometer (AGM). The sample implanted at 300 °C shows ferromagnetic behavior at room temperature.

  7. The measurement of bicycle exercising energy transfer

    NASA Astrophysics Data System (ADS)

    Cho, Hung-Pin; Jian, Zi-Jie; Jwo, Ching-Song; Wang, Jiun-Yau; Chen, Sih-Li

    2010-08-01

    The main study purpose is to develop a device capable of translating exercise energy into hot or icy drinkable water. This device can accurately measure energy consumption during exercise, transform it, and apply it to a heating and refrigerating system. Traditional energy measurements were based on the amount of exercise load from the human body. The research tapped into this non-electric form of energy transmission to run a heating and refrigerating system. The energy requirement was 50.6 kcal. When compared to 57.9 kcal, which the body consumes based actual calorie test, the difference was within a 15% striking range. In terms of energy comparisons, this study demonstrates potential R & D value with this innovative design. It complied with carbon emission requirements by producing 2,000 cc of energy at 47°C of hot water and 1,300 cc of energy at 6.6°C of ice water, all without the use of conventional energy sources. As the paper shows, this device is an innovative and environmentally conscious design. In an upcoming low-carbon emissions future, its research potential is definitely worth evaluating.

  8. Energy deposition and thermal effects of runaway electrons in ITER-FEAT plasma facing components

    NASA Astrophysics Data System (ADS)

    Maddaluno, G.; Maruccia, G.; Merola, M.; Rollet, S.

    2003-03-01

    The profile of energy deposited by runaway electrons (RAEs) of 10 or 50 MeV in International Thermonuclear Experimental Reactor-Fusion Energy Advanced Tokamak (ITER-FEAT) plasma facing components (PFCs) and the subsequent temperature pattern have been calculated by using the Monte Carlo code FLUKA and the finite element heat conduction code ANSYS. The RAE energy deposition density was assumed to be 50 MJ/m 2 and both 10 and 100 ms deposition times were considered. Five different configurations of PFCs were investigated: primary first wall armoured with Be, with and without protecting CFC poloidal limiters, both port limiter first wall options (Be flat tile and CFC monoblock), divertor baffle first wall, armoured with W. The analysis has outlined that for all the configurations but one (port limiter with Be flat tile) the heat sink and the cooling tube beneath the armour are well protected for both RAE energies and for both energy deposition times. On the other hand large melting (W, Be) or sublimation (C) of the surface layer occurs, eventually affecting the PFCs lifetime.

  9. Experimental investigation on the energy deposition and expansion rate under the electrical explosion of aluminum wire in vacuum

    SciTech Connect

    Shi, Zongqian; Wang, Kun; Shi, Yuanjie; Wu, Jian; Han, Ruoyu

    2015-12-28

    Experimental investigations on the electrical explosion of aluminum wire using negative polarity current in vacuum are presented. Current pulses with rise rates of 40 A/ns, 80 A/ns, and 120 A/ns are generated for investigating the influence of current rise rate on energy deposition. Experimental results show a significant increase of energy deposition into the wire before the voltage breakdown with the increase of current rise rate. The influence of wire dimension on energy deposition is investigated as well. Decreasing the wire length allows more energy to be deposited into the wire. The energy deposition of a 0.5 cm-long wire explosion is ∼2.5 times higher than the energy deposition of a 2 cm-long wire explosion. The dependence of the energy deposition on wire diameter demonstrates a maximum energy deposition of 2.7 eV/atom with a diameter of ∼18 μm. Substantial increase in energy deposition is observed in the electrical explosion of aluminum wire with polyimide coating. A laser probe is applied to construct the shadowgraphy, schlieren, and interferometry diagnostics. The morphology and expansion trajectory of exploding products are analyzed based on the shadowgram. The interference phase shift is reconstructed from the interferogram. Parallel dual wires are exploded to estimate the expansion velocity of the plasma shell.

  10. Experimental investigation on the energy deposition and expansion rate under the electrical explosion of aluminum wire in vacuum

    NASA Astrophysics Data System (ADS)

    Shi, Zongqian; Wang, Kun; Shi, Yuanjie; Wu, Jian; Han, Ruoyu

    2015-12-01

    Experimental investigations on the electrical explosion of aluminum wire using negative polarity current in vacuum are presented. Current pulses with rise rates of 40 A/ns, 80 A/ns, and 120 A/ns are generated for investigating the influence of current rise rate on energy deposition. Experimental results show a significant increase of energy deposition into the wire before the voltage breakdown with the increase of current rise rate. The influence of wire dimension on energy deposition is investigated as well. Decreasing the wire length allows more energy to be deposited into the wire. The energy deposition of a 0.5 cm-long wire explosion is ˜2.5 times higher than the energy deposition of a 2 cm-long wire explosion. The dependence of the energy deposition on wire diameter demonstrates a maximum energy deposition of 2.7 eV/atom with a diameter of ˜18 μm. Substantial increase in energy deposition is observed in the electrical explosion of aluminum wire with polyimide coating. A laser probe is applied to construct the shadowgraphy, schlieren, and interferometry diagnostics. The morphology and expansion trajectory of exploding products are analyzed based on the shadowgram. The interference phase shift is reconstructed from the interferogram. Parallel dual wires are exploded to estimate the expansion velocity of the plasma shell.

  11. Energy Balance, Evapo-transpiration and Dew deposition in the Dead Sea Valley

    NASA Astrophysics Data System (ADS)

    Metzger, Jutta; Corsmeier, Ulrich

    2016-04-01

    The Dead Sea is a unique place on earth. It is a terminal hypersaline lake, located at the lowest point on earth with a lake level of currently -429 m above mean sea level (amsl). It is located in a transition zone of semiarid to arid climate conditions, which makes it highly sensible to climate change (Alpert1997, Smiatek2011). The Virtual Institute DEad SEa Research Venue (DESERVE) is an international project funded by the German Helmholtz Association and was established to study coupled atmospheric hydrological, and lithospheric processes in the changing environment of the Dead Sea. At the moment the most prominent environmental change is the lake level decline of approximately 1 m / year due to anthropogenic interferences (Gertman, 2002). This leads to noticeable changes in the fractions of the existing terrestrial surfaces - water, bare soil and vegetated areas - in the valley. Thus, the partitioning of the net radiation in the valley changes as well. To thoroughly study the atmospheric and hydrological processes in the Dead Sea valley, which are driven by the energy balance components, sound data of the energy fluxes of the different surfaces are necessary. Before DESERVE no long-term monitoring network simultaneously measuring the energy balance components of the different surfaces in the Dead Sea valley was available. Therefore, three energy balance stations were installed at three characteristic sites at the coast-line, over bare soil, and within vegetation, measuring all energy balance components by using the eddy covariance method. The results show, that the partitioning of the energy into sensible and latent heat flux on a diurnal scale is totally different at the three sites. This results in gradients between the sites, which are e.g. responsible for the typical diurnal wind systems at the Dead Sea. Furthermore, driving forces of evapo-transpiration at the sites were identified and a detailed analysis of the daily evaporation and dew deposition rates

  12. Comparing i-Tree modeled ozone deposition with field measurements in a periurban Mediterranean forest.

    PubMed

    Morani, A; Nowak, D; Hirabayashi, S; Guidolotti, G; Medori, M; Muzzini, V; Fares, S; Mugnozza, G Scarascia; Calfapietra, C

    2014-12-01

    Ozone flux estimates from the i-Tree model were compared with ozone flux measurements using the Eddy Covariance technique in a periurban Mediterranean forest near Rome (Castelporziano). For the first time i-Tree model outputs were compared with field measurements in relation to dry deposition estimates. Results showed generally a good agreement between predicted and measured ozone fluxes (least sum square=5.6 e(-4)) especially when cumulative values over the whole measurement campaign are considered. However at daily and hourly time-step some overestimations were observed in estimated values especially in hot dry periods. The use of different m values in the Ball-Berry formula in the different periods, produced the best fit between predicted and measured ozone fluxes. This suggests that a variable value for the coefficient m accounting for water availability may be appropriate to improve model estimates for Mediterranean and drought prone regions. PMID:25247877

  13. An in-situ technique to measure erosion and deposition in fusion devices

    NASA Astrophysics Data System (ADS)

    Ruzic, David N.; Gerdin, Glenn A.

    1987-02-01

    Erosion or deposition of sub-micron layers of graphite or other materials can be measured by bombarding a sub-surface layer of 10B or 6Li with thermal neutrons and observing with a surface-barrier detector the energy loss of the prompt alphas or tritons produced. To demonstrate the feasibility of this technique, a (5250 ± 250) Å layer of boron and a (1.25 ± 0.05) μm layer of Li 2B 4O 7 were electron-beam evaporated onto graphite substrates and exposed to a thermal neutron flux of (8.0 ± 0.5) × 10 5 cm -2 s -1. The (n,α) reactions of the 10B produce a 1.78 MeV α, a 1.48 MeV α, and a 0.848 MeV 7Li. The reactions of 6Li produce a 2.73 MeV 3H and a 2.05 MeV α. Carbon coatings of (600 ± 25) Å, (8250 ± 500) Å, (2.0 ± 0.2) μm, and (4.0 ± 0.4) μm were placed between the active layers and a surface barrier detector in vacuuo. The thinner layers shifted the 1.48 MeV α peak by (31.7 ± 4.5) keV and (431 ± 43) keV respectively. The thicker layers shifted the 2.73 MeV 3H peak by (206 ± 15) keV and (346 ± 20) keV respectfully. Therefore, utilizing boron implants, 100 Å to 1 μm of graphite erosion or redeposition can be determined. Utilizing lithium implants, thicknesses in the range of 1 μm to 10 μm can be determined. Theoretical energy shifts, thermal diffusion, and the feasibility of this technique as a between shot diagnostic for limiters, divertor plates, and/or first-wall armor are discussed.

  14. Strong shock generation by fast electron energy deposition

    SciTech Connect

    Fox, T. E.; Pasley, J.; Robinson, A. P. L.

    2013-12-15

    It has been suggested that fast electrons may play a beneficial role in the formation of the ignitor shock in shock ignition owing to the high areal density of the fuel at the time of the ignitor pulse. In this paper, we extend previous studies which have focused on monoenergetic electron sources to populations with extended energy distributions. In good agreement with analytic scalings, we show that strong shocks can be produced with peak pressures of a few hundred Mbar to over 1 Gbar using fast electron intensities of 1–10 PW/cm{sup 2} in a uniform deuterium-tritium plasma at 10 g/cm{sup 3}. However, the length required for shock formation increases with fast electron temperature. As this shock formation distance becomes comparable to the target size, the shock is not able to fully develop, and this implies a limit on the ability of fast electrons to aid shock formation.

  15. Modelling heavy-ion energy deposition in extended media

    NASA Astrophysics Data System (ADS)

    Mishustin, I.; Pshenichnov, I.; Greiner, W.

    2010-10-01

    We present recent developments of the Monte Carlo model for heavy-ion therapy (MCHIT), which is currently based on the Geant4 toolkit of version 9.2. The major advancement of the model concerns the modelling of violent fragmentation reactions by means of the Fermi break-up model, which is used to simulate decays of hot fragments created after the first stage of nucleus-nucleus collisions. By means of MCHIT we study the dose distributions from therapeutic beams of carbon nuclei in tissue-like materials, like water and PMMA. The contributions to the total dose from primary beam nuclei and from charged secondary fragments produced in nuclear fragmentation reactions are calculated. The build-up of secondary fragments along the beam axis is calculated and compared with available experimental data. Finally, we demonstrate the impact of violent multifragment decays on energy distributions of secondary neutrons produced by carbon nuclei in water.

  16. Nighttime auroral energy deposition in the middle atmosphere

    NASA Technical Reports Server (NTRS)

    Goldberg, R. A.; Jackman, C. H.; Barcus, J. R.; Soraas, F.

    1984-01-01

    Ionospheric rocket sounding data for eight nighttime auroral events are used to characterize relativistic electron showers and their effects on atmospheric ozone. The rockets were launched from the Poker Flat Research Range in Alaska and from Andoya, Norway over the period 1976-82. Energetic fluxes were always detected but were of insufficient magnitude to produce significant changes in stratospheric ozone. However, middle atmospheric energy sources were found to be dominated by relativistic electrons and X-ray bremmstrahlung, the latter from 40-55 km and the former from 55-60 km altitudes. The ionizing radiation is concluded to be a significant factor in mesospheric ion conductivity, mobility, electric field structure and analytical models for the ion-neutral chemistry.

  17. Measuring Income and Projecting Energy Use

    SciTech Connect

    Pitcher, Hugh M.

    2009-11-01

    Abstract: Energy is a key requirement for a healthy, productive life and a major driver of the emissions leading to an increasingly warm planet. The implications of a doubling and redoubling of per capita incomes over the remainder of this century for energy use are a critical input into understanding the magnitude of the carbon management problem. A substantial controversy about how the Special Report on Emssions Scenarios (SRES) measured income and the potential implications of how income was measured for long term levels of energy use is revisited again in the McKibbin, Pearce and Stegman article appearing elsewhere in this issue. The recent release of a new set of purchasing power estimates of national income, and the preparations for creating new scenarios to support the IPCC’s fifth assessment highlight the importance of the issues which have arisen surrounding income and energy use. Comparing the 1993 and 2005 ICP results on Purchasing Power Parity (PPP) based measures of income reveals that not only do the 2005 ICP estimates share the same issue of common growth rates for real income as measured by PPP and US $, but the lack of coherence in the estimates of PPP incomes, especially for developing countries raises yet another obstacle to resolving the best way to measure income. Further, the common use of an income term to mediate energy demand (as in the Kaya identity) obscures an underlying reality about per capita energy demands, leading to unreasonable estimates of the impact of changing income measures and of the recent high GDP growth rates in India and China. Significant new research is required to create both a reasonable set of GDP growth rates and long term levels of energy use.

  18. Comparison of methods for measuring atmospheric deposition of arsenic, cadmium, nickel and lead.

    PubMed

    Aas, Wenche; Alleman, Laurent Y; Bieber, Elke; Gladtke, Dieter; Houdret, Jean-Luc; Karlsson, Vuokko; Monies, Christian

    2009-06-01

    A comprehensive field intercomparison at four different types of European sites (two rural, one urban and one industrial) comparing three different collectors (wet only, bulk and Bergerhoff samplers) was conducted in the framework of the European Committee for Standardization (CEN) to create an European standard for the deposition of the four elements As, Cd, Ni and Pb. The purpose was to determine whether the proposed methods lead to results within the uncertainty required by the EU's daughter directive (70%). The main conclusion is that a different sampling strategy is needed for rural and industrial sites. Thus, the conclusions on uncertainties and sample approach are presented separately for the different approaches. The wet only and bulk collector ("bulk bottle method") are comparable at wet rural sites where the total deposition arises mainly from precipitation, the expanded uncertainty when comparing these two types of sampler are below 45% for As, Cd and Pb, 67% for Ni. At industrial sites and possibly very dry rural and urban sites it is necessary to use Bergerhoff samplers or a "bulk bottle+funnel method". It is not possible to address the total deposition estimation with these methods, but they will give the lowest estimate of the total deposition. The expanded uncertainties when comparing the Bergerhoff and the bulk bottle+funnel methods are below 50% for As and Cd, and 63% for Pb. The uncertainty for Ni was not addressed since the bulk bottle+funnel method did not include a full digestion procedure which is necessary for sites with high loads of undissolved metals. The lowest estimate can however be calculated by comparing parallel Bergerhoff samplers where the expanded uncertainty for Ni was 24%. The reproducibility is comparable to the between sampler/method uncertainties. Sampling and sample preparation were proved to be the main factors in the uncertainty budget of deposition measurements. PMID:19513460

  19. Chemical vapour deposition of thermochromic vanadium dioxide thin films for energy efficient glazing

    SciTech Connect

    Warwick, Michael E.A.; Binions, Russell

    2014-06-01

    Vanadium dioxide is a thermochromic material that undergoes a semiconductor to metal transitions at a critical temperature of 68 °C. This phase change from a low temperature monoclinic structure to a higher temperature rutile structure is accompanied by a marked change in infrared reflectivity and change in resistivity. This ability to have a temperature-modulated film that can limit solar heat gain makes vanadium dioxide an ideal candidate for thermochromic energy efficient glazing. In this review we detail the current challenges to such glazing becoming a commercial reality and describe the key chemical vapour deposition technologies being employed in the latest research. - Graphical abstract: Schematic demonstration of the effect of thermochromic glazing on solar radiation (red arrow represents IR radiation, black arrow represents all other solar radiation). - Highlights: • Vanadium dioxide thin films for energy efficient glazing. • Reviews chemical vapour deposition techniques. • Latest results for thin film deposition for vanadium dioxide.

  20. Noncatalytic thermocouple coatings produced with chemical vapor deposition for flame temperature measurements.

    PubMed

    Bahlawane, N; Struckmeier, U; Kasper, T S; Osswald, P

    2007-01-01

    Chemical vapor deposition (CVD) and metal-organic chemical vapor deposition (MOCVD) have been employed to develop alumina thin films in order to protect thermocouples from catalytic overheating in flames and to minimize the intrusion presented to the combustion process. Alumina films obtained with a CVD process using AlCl(3) as the precursor are dense, not contaminated, and crystallize in the corundum structure, while MOCVD using Al(acetyl acetone)(3) allows the growth of corundum alumina with improved growth rates. These films, however, present a porous columnar structure and show some carbon contamination. Therefore, coated thermocouples using AlCl(3)-CVD were judged more suitable for flame temperature measurements and were tested in different fuels over a typical range of stoichiometries. Coated thermocouples exhibit satisfactory measurement reproducibility, no temporal drifts, and do not suffer from catalytic effects. Furthermore, their increased radiative heat loss (observed by infrared spectroscopy) allows temperature measurements over a wider range when compared to uncoated thermocouples. A flame with a well-known temperature profile established with laser-based techniques was used to determine the radiative heat loss correction to account for the difference between the apparent temperature measured by the coated thermocouple and the true flame temperature. The validity of the correction term was confirmed with temperature profile measurements for several flames previously studied in different laboratories with laser-based techniques. PMID:17503931

  1. Noncatalytic thermocouple coatings produced with chemical vapor deposition for flame temperature measurements

    NASA Astrophysics Data System (ADS)

    Bahlawane, N.; Struckmeier, U.; Kasper, T. S.; Oßwald, P.

    2007-01-01

    Chemical vapor deposition (CVD) and metal-organic chemical vapor deposition (MOCVD) have been employed to develop alumina thin films in order to protect thermocouples from catalytic overheating in flames and to minimize the intrusion presented to the combustion process. Alumina films obtained with a CVD process using AlCl3 as the precursor are dense, not contaminated, and crystallize in the corundum structure, while MOCVD using Al(acetylwidth="0.3em"/>acetone)3 allows the growth of corundum alumina with improved growth rates. These films, however, present a porous columnar structure and show some carbon contamination. Therefore, coated thermocouples using AlCl3-CVD were judged more suitable for flame temperature measurements and were tested in different fuels over a typical range of stoichiometries. Coated thermocouples exhibit satisfactory measurement reproducibility, no temporal drifts, and do not suffer from catalytic effects. Furthermore, their increased radiative heat loss (observed by infrared spectroscopy) allows temperature measurements over a wider range when compared to uncoated thermocouples. A flame with a well-known temperature profile established with laser-based techniques was used to determine the radiative heat loss correction to account for the difference between the apparent temperature measured by the coated thermocouple and the true flame temperature. The validity of the correction term was confirmed with temperature profile measurements for several flames previously studied in different laboratories with laser-based techniques.

  2. In-situ measurement of conducting polymers on evaporated and electrochemically deposited Au surfaces

    NASA Astrophysics Data System (ADS)

    Bohn, Clayton C.; Pyo, Myoungho; Sadki, Said; Smela, Elisabeth; Reynolds, John R.; Brennan, Anthony B.

    2002-07-01

    By utilizing strain gage technology it is possible to directly and continuously measure the electrochemically induced strain response of EAP actuators. Strain sensitive actuators were constructed by directly vapor depositing gold (EvAu) on polyimide strain gages which are capable of measuring strain with an accuracy of +/- 1(mu) (epsilon) . Strain sensitive actuators were used to evaluate the strain response of polypyrrole (PPy), poly(3,4-ethylenedioxypyrrole) (PEDOP) and poly(3,6-bis(2-(3,4-ethylenedioxy)thienyl)-N-carbazole) (PBEDOT-Cz). PPy was shown to produce significantly higher strain when compared to PEDOP and PBEDOT-Cz. The resulting overall strain for the materials was: 236, 33, and 35 (mu) (epsilon) respectively. From the initial investigation, adhesion of the EAP to the EvAu layer was identified as a major factor in the resulting lifetime and strain response of these actuators. Therefore an electrochemically deposited Au layer (EcAu) was deposited on top of the EvAu layer to improve the adhesion of the EAP to the working electrode. By changing the surface roughness from requals3.43 (EvAu) to requals8.26 and 18.00 (EcAu) the normalized strain response after 2000 cycles increases from 45% to 60% and 68% respectively. Also by changing the surface roughness from 5 to 23, the resulting strain response increases from ~100 (mu) (epsilon) to 600-800 (mu) (epsilon) for Ppy.

  3. Measurements and modeling of emissions, dispersion and dry deposition of ammonia from swine facilities

    NASA Astrophysics Data System (ADS)

    Bajwa, Kanwardeep Singh

    Ammonia has recently gained importance for its increasing atmospheric concentrations and its role in the formation of aerosols. Studies have shown increasing atmospheric concentration levels of NH3 and NH 4+, especially in the regions of concentrated animal feeding operations. Atmospheric inputs of reduced nitrogen as ammonia and ammonium by dry and wet deposition may represent a substantial contribution to the acidification of semi natural ecosystems and could also affect sensitive coastal ecosystems and estuaries. The anaerobic lagoon and spray method, commonly used for waste storage and disposal in confined animal feeding operations (CAFO), is a significant source of ammonia emissions. An accurate emission model for ammonia from aqueous surfaces can help in the development of emission factors. Study of dispersion and dry deposition patterns of ammonia downwind of a hog farm will help us to understand how much ammonia gets dry deposited near the farm, and how remaining ammonia gets transported farther away. An experimental and modeling study is conducted of emissions, dispersion and dry deposition of ammonia taking one swine farm as a unit. Measurements of ammonia flux were made at 11 swine facilities in North Carolina using dynamic flow-through chamber system over the anaerobic waste treatment lagoons. Continuous measurements of ammonia flux, meteorological and lagoon parameters were made for 8-10 days at each farm during each of the warm and cold seasons. Ammonia concentrations were continuously measured in the chamber placed over the lagoon using a Thermo Environmental Instrument Incorporated (TECO) Model 17c chemiluminescnce ammonia analyzer. A similar ammonia analyzer was used to measure ammonia concentrations at selected locations on the farm. Barn emissions were measured using open-path Fourier transform infrared (OP-FTIR) spectroscopy. A 10 m meteorological tower was erected at each site to measure wind speed and direction, temperature, relative humidity

  4. A generalized framework for in-line energy deposition during steady-state Monte Carlo radiation transport

    SciTech Connect

    Griesheimer, D. P.; Stedry, M. H.

    2013-07-01

    A rigorous treatment of energy deposition in a Monte Carlo transport calculation, including coupled transport of all secondary and tertiary radiations, increases the computational cost of a simulation dramatically, making fully-coupled heating impractical for many large calculations, such as 3-D analysis of nuclear reactor cores. However, in some cases, the added benefit from a full-fidelity energy-deposition treatment is negligible, especially considering the increased simulation run time. In this paper we present a generalized framework for the in-line calculation of energy deposition during steady-state Monte Carlo transport simulations. This framework gives users the ability to select among several energy-deposition approximations with varying levels of fidelity. The paper describes the computational framework, along with derivations of four energy-deposition treatments. Each treatment uses a unique set of self-consistent approximations, which ensure that energy balance is preserved over the entire problem. By providing several energy-deposition treatments, each with different approximations for neglecting the energy transport of certain secondary radiations, the proposed framework provides users the flexibility to choose between accuracy and computational efficiency. Numerical results are presented, comparing heating results among the four energy-deposition treatments for a simple reactor/compound shielding problem. The results illustrate the limitations and computational expense of each of the four energy-deposition treatments. (authors)

  5. SPECTRAL REFLECTANCE METHOD TO MEASURE ACID DEPOSITION EFFECTS ON BUILDING STONE.

    USGS Publications Warehouse

    Kingston, Marguerite J.; Ager, Cathy M.

    1985-01-01

    As part of the National Acid Precipitation Assessment Program (NAPAP), the U. S. Geological Survey is cooperating with other agencies to test the effects of acid deposition on building stone. A 10-year test-site study has been organized for the purpose of correlating possible stone deterioration with environmental factors. In Summer 1984, slabs of building stone, 3 by 2 by 2 inches, were exposed to the atmosphere at four test sites where the pH of precipitation and other meteorological variables are continuously monitored. This paper examines the development of one experimental technique used in this study - the application of diffuse spectral reflectance methods for laboratory and in situ measurement of those properties of stone which may be affected by acid deposition.

  6. Measurement of pyrotechnic ignition energy by thermography

    SciTech Connect

    Mohler, J.H.; Abney, L.D.; Chow, T.S.

    1985-01-01

    Measuring the laser energy required to ignite pyrotechnic pellets is complicated by several factors that are difficult to control or predict. These include reflection of part of the incident laser energy, reemission from the heated sample, and heat conduction away from the ignition site. In addition to these factors, it is often difficult to control and/or measure the incident laser power. High-speed thermographic recording of the temperature distribution in the test sample makes it possible to calculate the heat content of the test pellet at any instant. Thus, one can actually observe the laser heating and on-set of reaction in the pellet and avoid having to make measurements or assumptions to account for possible energy losses.

  7. Analysis of CRRES PHA Data for Low-Energy-Deposition Events

    NASA Technical Reports Server (NTRS)

    McNulty, P. J.; Hardage, Donna

    2004-01-01

    This effort analyzed the low-energy deposition Pulse Height Analyzer (PHA) data from the Combined Release and Radiation Effects Satellite (CRRES). The high-energy deposition data had been previously analyzed and shown to be in agreement with spallation reactions predicted by the Clemson University Proton Interactions in Devices (CUPID) simulation model and existing environmental and orbit positioning models (AP-8 with USAF B-L coordinates). The scope of this project was to develop and improve the CUPID model by increasing its range to lower incident particle energies, and to expand the modeling to include contributions from elastic interactions. Before making changes, it was necessary to identify experimental data suitable for benchmarking the codes; then, the models to the CRRES PHA data could be applied. It was also planned to test the model against available low-energy proton or neutron SEU data obtained with mono-energetic beams.

  8. Effect of forage energy intake and supplementation on marbling deposition in growing beef cattle.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glucose is the primary carbon source for fatty acid synthesis in intramuscular fat, whereas, acetate is primarily utilized by subcutaneous fat. Our objective was to examine the effect of forage energy intake and type of fermentation on marbling deposition by stocker cattle grazing dormant native ra...

  9. Low energy, low latitude wave-dominated shallow marine depositional systems: examples from northern Borneo

    NASA Astrophysics Data System (ADS)

    Lambiase, Joseph J.; Suraya Tulot

    2013-12-01

    The depositional environments of the wave-dominant successions in the middle to late Miocene Belait and Sandakan Formations in northwestern and northern Borneo, respectively, were determined based on grain size distributions, sedimentary structures and facies successions, as well as trace and microfossil assemblages. Generally, progradational shoreface successions in the Belait Formation were deposited in very low wave energy environments where longshore currents were too weak to generate trough cross-bedding. Shoreface sands are laterally continuous for several km and follow the basin contours, suggesting attached beaches similar to the modern Brunei coastline. In contrast, trough cross-bedding is common in the coarser Sandakan Formation and back-barrier mangrove swamp deposits cap the progradational succession as on the modern northern Dent Peninsula coastline, indicating barrier development and higher wave energy conditions than in the Belait Formation. The Borneo examples indicate that barrier systems that include significant tidal facies form under higher wave energy conditions than attached beaches with virtually no tidal facies. Also, Borneo's low latitude climate promotes back-barrier mangrove which reduces tidal exchange and reduces tidal influence relative to comparable temperate climate systems. The results of the study indicate that depositional systems on low energy, wave-dominated coasts are highly variable, as are the sand bodies and facies associations they generate.

  10. Interferometric technique for determining the energy deposition in gas-flow nuclear-pumped lasers

    SciTech Connect

    Pikulev, A A

    2001-06-30

    An interference technique is developed for determining the energy deposition in gas-flow lasers pumped by uranium fission fragments. It is shown that four types of interference patterns may be formed. Algorithms are presented for determining the type of interference and for enumerating the maxima in interference pattern. (lasers, active media)

  11. Energy deposition by heavy ions: additivity of kinetic and potential energy contributions in hillock formation on CaF2.

    PubMed

    Wang, Y Y; Grygiel, C; Dufour, C; Sun, J R; Wang, Z G; Zhao, Y T; Xiao, G Q; Cheng, R; Zhou, X M; Ren, J R; Liu, S D; Lei, Y; Sun, Y B; Ritter, R; Gruber, E; Cassimi, A; Monnet, I; Bouffard, S; Aumayr, F; Toulemonde, M

    2014-01-01

    Modification of surface and bulk properties of solids by irradiation with ion beams is a widely used technique with many applications in material science. In this study, we show that nano-hillocks on CaF2 crystal surfaces can be formed by individual impact of medium energy (3 and 5 MeV) highly charged ions (Xe(22+) to Xe(30+)) as well as swift (kinetic energies between 12 and 58 MeV) heavy xenon ions. For very slow highly charged ions the appearance of hillocks is known to be linked to a threshold in potential energy (Ep) while for swift heavy ions a minimum electronic energy loss per unit length (Se) is necessary. With our results we bridge the gap between these two extreme cases and demonstrate, that with increasing energy deposition via Se the Ep-threshold for hillock production can be lowered substantially. Surprisingly, both mechanisms of energy deposition in the target surface seem to contribute in an additive way, which can be visualized in a phase diagram. We show that the inelastic thermal spike model, originally developed to describe such material modifications for swift heavy ions, can be extended to the case where both kinetic and potential energies are deposited into the surface. PMID:25034006

  12. Young's modulus and density measurements of thin atomic layer deposited films using resonant nanomechanics

    NASA Astrophysics Data System (ADS)

    Ilic, B.; Krylov, S.; Craighead, H. G.

    2010-08-01

    Material properties of atomic layer deposited (ALD) thin films are of interest for applications ranging from wear resistance to high-k dielectrics in electronic circuits. We demonstrate the ability to simultaneously measure Young's modulus (E) and density (ρ) of 21.2-21.5 nm ALD hafnia, alumina, and aluminum nitride ultrathin films by observing vibrations of nanomechanical cantilever beams. The nanomechanical structures were fabricated from a 250 nm thick single crystal silicon layer with varying length and width ranging from 6 μm to 10 μm and 45 nm to 1 μm, respectively. Our approach is based on an optical excitation and interferometric detection of in-plane and out-of plane vibrational spectra of single crystal silicon cantilevers before and after a conformal coating deposition of an ALD thin film. In conjunction with three-dimensional numerical finite element analysis, measurements of resonance carried out prior to the ALD revealed that while the influence of clamping compliance arising from the undercut of the sacrificial layer is significant for wider beams, the effect is less pronounced for both, narrower cantilevers and the in-plane vibrational response. Following the deposition, higher stiffness alumina films (E >ESi) showed an increase in the resonant frequency whereas lower stiffness (E measured spectral response, material properties were extracted using simple expressions for E and ρ in terms of measured in-plane and out-of-plane frequencies shifts. The derived model was based on an ideally clamped Euler-Bernoulli beam with effective bending stiffness and effective mass per unit length. In-plane and out-of-plane frequency measurements provided two equations that enabled simultaneous extraction of E and ρ. Three-dimensional finite element analysis showed that residual stress, nonideal clamping conditions, and the mismatch in the Poisson's ratio between the deposited

  13. The fractal energy measurement and the singularity energy spectrum analysis

    NASA Astrophysics Data System (ADS)

    Xiong, Gang; Zhang, Shuning; Yang, Xiaoniu

    2012-12-01

    The singularity exponent (SE) is the characteristic parameter of fractal and multifractal signals. Based on SE, the fractal dimension reflecting the global self-similar character, the instantaneous SE reflecting the local self-similar character, the multifractal spectrum (MFS) reflecting the distribution of SE, and the time-varying MFS reflecting pointwise multifractal spectrum were proposed. However, all the studies were based on the depiction of spatial or differentiability characters of fractal signals. Taking the SE as the independent dimension, this paper investigates the fractal energy measurement (FEM) and the singularity energy spectrum (SES) theory. Firstly, we study the energy measurement and the energy spectrum of a fractal signal in the singularity domain, propose the conception of FEM and SES of multifractal signals, and investigate the Hausdorff measure and the local direction angle of the fractal energy element. Then, we prove the compatibility between FEM and traditional energy, and point out that SES can be measured in the fractal space. Finally, we study the algorithm of SES under the condition of a continuous signal and a discrete signal, and give the approximation algorithm of the latter, and the estimations of FEM and SES of the Gaussian white noise, Fractal Brownian motion and the multifractal Brownian motion show the theoretical significance and application value of FEM and SES.

  14. Low-bay Lighting Energy Conservation Measures

    Energy Science and Technology Software Center (ESTSC)

    2010-12-31

    This software requires inputs of simple low-bay lighting system inventory information and calculates the energy and cost benefits of various retrofit opportunities. This tool includes energy conservation measures for: Low-wattage T8 lighting retrofit, T12 to T8 lighting retrofit, LED Exit signs retrofit, Occupancy sensors, Screw-in lighting retrofit, and central lighting controls. This tool calculates energy savings, demand reduction, cooling load reduction, heating load increases, cost savings, building life cycle costs including: Simple payback, discounted payback,more » net-present value, and savings to investment ratio. In addition this tool also displays the environmental benefits of a project.« less

  15. Energy Savings Measure Packages. Existing Homes

    SciTech Connect

    Casey, Sean; Booten, Chuck

    2011-11-01

    This document presents the most cost effective Energy Savings Measure Packages (ESMP) for existing mixed-fuel and all electric homes to achieve 15% and 30% savings for each BetterBuildings grantee location across the United States. These packages are optimized for minimum cost to homeowners for source energy savings given the local climate and prevalent building characteristics (i.e. foundation types). Maximum cost savings are typically found between 30% and 50% energy savings over the reference home; this typically amounts to $300 - $700/year.

  16. Energy Savings Measure Packages: Existing Homes

    SciTech Connect

    Casey, S.; Booten, C.

    2011-11-01

    This document presents the most cost effective Energy Savings Measure Packages (ESMP) for existing mixed-fuel and all electric homes to achieve 15% and 30% savings for each BetterBuildings grantee location across the US. These packages are optimized for minimum cost to homeowners for given source energy savings given the local climate and prevalent building characteristics (i.e. foundation types). Maximum cost savings are typically found between 30% and 50% energy savings over the reference home. The dollar value of the maximum annual savings varies significantly by location but typically amounts to $300 - $700/year.

  17. Low-bay Lighting Energy Conservation Measures

    SciTech Connect

    Ian Metzger, Jesse Dean

    2010-12-31

    This software requires inputs of simple low-bay lighting system inventory information and calculates the energy and cost benefits of various retrofit opportunities. This tool includes energy conservation measures for: Low-wattage T8 lighting retrofit, T12 to T8 lighting retrofit, LED Exit signs retrofit, Occupancy sensors, Screw-in lighting retrofit, and central lighting controls. This tool calculates energy savings, demand reduction, cooling load reduction, heating load increases, cost savings, building life cycle costs including: Simple payback, discounted payback, net-present value, and savings to investment ratio. In addition this tool also displays the environmental benefits of a project.

  18. High-bay Lighting Energy Conservation Measures

    SciTech Connect

    Ian Metzger, Jesse Dean

    2010-12-31

    This software requires inputs of simple high-bay lighting system inventory information and calculates the energy and cost benefits of various retrofit opportunities. This tool includes energy conservation measures for: 1000 Watt to 750 Watt High-pressure Sodium lighting retrofit, 400 Watt to 360 Watt High Pressure Sodium lighting retrofit, High Intensity Discharge to T5 lighting retrofit, High Intensity Discharge to T8 lighting retrofit, and Daylighting. This tool calculates energy savings, demand reduction, cost savings, building life cycle costs including: simple payback, discounted payback, net-present value, and savings to investment ratio. In addition this tool also displays the environmental benefits of a project.

  19. Power Measurement Methods for Energy Efficient Applications

    PubMed Central

    Calandrini, Guilherme; Gardel, Alfredo; Bravo, Ignacio; Revenga, Pedro; Lázaro, José L.; Toledo-Moreo, F. Javier

    2013-01-01

    Energy consumption constraints on computing systems are more important than ever. Maintenance costs for high performance systems are limiting the applicability of processing devices with large dissipation power. New solutions are needed to increase both the computation capability and the power efficiency. Moreover, energy efficient applications should balance performance vs. consumption. Therefore power data of components are important. This work presents the most remarkable alternatives to measure the power consumption of different types of computing systems, describing the advantages and limitations of available power measurement systems. Finally, a methodology is proposed to select the right power consumption measurement system taking into account precision of the measure, scalability and controllability of the acquisition system. PMID:23778191

  20. Residual energy deposition in dental enamel during IR laser ablation at 2.79, 2.94, 9.6, and 10.6 μm

    NASA Astrophysics Data System (ADS)

    Ragadio, Jerome N.; Lee, Christian K.; Fried, Daniel

    2000-03-01

    The objective of this study was to measure the residual heat deposition during laser ablation at those IR laser wavelengths best suited for the removal of dental caries. The principal factor limiting the rate of laser ablation of dental hard tissue is the risk of excessive heat accumulation in the tooth, which has the potential for causing damage to the pulp. Optimal laser ablation systems minimize the residual energy deposition in the tooth by transferring deposited laser energy to kinetic and internal energy of ejected tissue components. The residual heat deposition in the tooth was measured at laser wavelengths of 2.79, 2.94, 9.6 and 10.6 micrometer and pulse widths of 150 ns - 150 microsecond(s) . The residual energy was at a minimum for fluences well above the ablation threshold where it saturates at values from 25 - 70% depending on pulse duration and wavelength for the systems investigated. The lowest values of the residual energy were measured for short (less than 20 microseconds) CO2 laser pulses at 9.6 micrometer and for Q-switched erbium laser pulses. This work was supported by NIH/NIDCR R29DE12091 and the Center for Laser Applications in Medicine, DOE DEFG0398ER62576.

  1. Frequency modulation in shock wave-boundary layer interaction by repetitive-pulse laser energy deposition

    NASA Astrophysics Data System (ADS)

    Tamba, T.; Pham, H. S.; Shoda, T.; Iwakawa, A.; Sasoh, A.

    2015-09-01

    Modulation of shock foot oscillation due to energy deposition by repetitive laser pulses in shock wave-boundary layer interaction over an axisymmetric nose-cylinder-flare model in Mach 1.92 flow was experimentally studied. From a series of 256 schlieren images, density oscillation spectra at each pixel were obtained. When laser pulses of approximately 7 mJ were deposited with a repetition frequency, fe, of 30 kHz or lower, the flare shock oscillation had a peak spectrum equivalent to the value of fe. However, with fe of 40 kHz-60 kHz, it experienced frequency modulation down to lower than 20 kHz.

  2. Precision timing measurements for high energy photons

    SciTech Connect

    Anderson, Dustin; Apreysan, Artur; Bornheim, Adi; Duarte, Javier; Newman, Harvey; Pena, Cristian; Ronzhin, Anatoly; Spiropulu, Maria; Trevor, Jason; Xie, Si; Zhu, Ren-Yuan

    2014-11-21

    Particle colliders operating at high luminosities present challenging environments for high energy physics event reconstruction and analysis. We discuss how timing information, with a precision on the order of 10 ps, can aid in the reconstruction of physics events under such conditions. We present calorimeter based timing measurements from test beam experiments in which we explore the ultimate timing precision achievable for high energy photons or electrons of 10 GeV and above. Using a prototype calorimeter consisting of a 1.7×1.7×1.7 cm3 lutetium–yttrium oxyortho-silicate (LYSO) crystal cube, read out by micro-channel plate photomultipliers, we demonstrate a time resolution of 33.5±2.1 ps for an incoming beam energy of 32 GeV. In a second measurement, using a 2.5×2.5×20 cm3 LYSO crystal placed perpendicularly to the electron beam, we achieve a time resolution of 59±11 ps using a beam energy of 4 GeV. We also present timing measurements made using a shashlik-style calorimeter cell made of LYSO and tungsten plates, and demonstrate that the apparatus achieves a time resolution of 54±5 ps for an incoming beam energy of 32 GeV.

  3. Precision timing measurements for high energy photons

    NASA Astrophysics Data System (ADS)

    Anderson, Dustin; Apreysan, Artur; Bornheim, Adi; Duarte, Javier; Newman, Harvey; Pena, Cristian; Ronzhin, Anatoly; Spiropulu, Maria; Trevor, Jason; Xie, Si; Zhu, Ren-Yuan

    2015-07-01

    Particle colliders operating at high luminosities present challenging environments for high energy physics event reconstruction and analysis. We discuss how timing information, with a precision on the order of 10 ps, can aid in the reconstruction of physics events under such conditions. We present calorimeter based timing measurements from test beam experiments in which we explore the ultimate timing precision achievable for high energy photons or electrons of 10 GeV and above. Using a prototype calorimeter consisting of a 1.7×1.7×1.7 cm3 lutetium-yttrium oxyortho-silicate (LYSO) crystal cube, read out by micro-channel plate photomultipliers, we demonstrate a time resolution of 33.5±2.1 ps for an incoming beam energy of 32 GeV. In a second measurement, using a 2.5×2.5×20 cm3 LYSO crystal placed perpendicularly to the electron beam, we achieve a time resolution of 59±11 ps using a beam energy of 4 GeV. We also present timing measurements made using a shashlik-style calorimeter cell made of LYSO and tungsten plates, and demonstrate that the apparatus achieves a time resolution of 54±5 ps for an incoming beam energy of 32 GeV.

  4. Mechanical properties improvement of pulsed laser-deposited hydroxyapatite thin films by high energy ion-beam implantation

    NASA Astrophysics Data System (ADS)

    Nelea, V.; Pelletier, H.; Müller, D.; Broll, N.; Mille, P.; Ristoscu, C.; Mihailescu, I. N.

    2002-01-01

    Major problems in the hydroxyapatite (HA), Ca 5(PO 4) 3OH, thin films processing still keep the poor mechanical properties and the lack in density. We present a study on the feasibility of high energy ion-beam implantation technique to densify HA bioceramic films. Crystalline HA films were grown by pulsed laser deposition (PLD) method using an excimer KrF ∗ laser ( λ=248 nm, τ FWHM≥20 ns). The films were deposited on Ti-5Al-2.5Fe alloys substrates previously coated with a ceramic TiN buffer layer. After deposition the films were implanted with Ar + ions at high energy. Optical microscopy (OM), white light confocal microscopy (WLCM), grazing incidence X-ray diffraction (GIXRD) and Berkovich nanoindentation in normal and scratch options have been applied for the characterization of the obtained structures. We put into evidence an enhancement of the mechanical characteristics after implantation, while GIXRD measurements confirm that the crystalline structure of HA phase is preserved. The improvement in mechanical properties is an effect of a densification after ion treatment as a result of pores elimination and grains regrowth.

  5. PRODUCTIVITY BENEFITS OF INDUSTRIAL ENERGY EFFICIENCY MEASURES

    EPA Science Inventory

    A journal article by: Ernst Worrell1, John A. Laitner, Michael Ruth, and Hodayah Finman Abstract: We review the relationship between energy efficiency improvement measures and productivity in industry. We review over 70 industrial case studies from widely available published dat...

  6. Thermal Conductivity Measurement of an Electron-Beam Physical-Vapor-Deposition Coating

    PubMed Central

    Slifka, A. J.; Filla, B. J.

    2003-01-01

    An industrial ceramic thermal-barrier coating designated PWA 266, processed by electron-beam physical-vapor deposition, was measured using a steady-state thermal conductivity technique. The thermal conductivity of the mass fraction 7 % yttria-stabilized zirconia coating was measured from 100 °C to 900 °C. Measurements on three thicknesses of coatings, 170 μm, 350 μm, and 510 μm resulted in thermal conductivity in the range from 1.5 W/(m·K) to 1.7 W/(m·K) with a combined relative standard uncertainty of 20 %. The thermal conductivity is not significantly dependent on temperature.

  7. Simple measurement of deposition velocities and wall reaction probabilities in denuder tubes

    NASA Astrophysics Data System (ADS)

    Topalova, I.; Katsanos, N. A.; Kapolos, J.; Vassilakos, Ch.

    The diffusion column in the Reversed-Flow Gas Chromatography (RF-3C) technique is replaced by a simple denuder tube and the theoretical analysis based on this experimental set-up is developed for measurement of deposition velocities and reaction probabilities of an injected gaseous analyte on the denuder wall coating. The mathematical formulation of the problem is based on a general mass balance equation of the analyte, which is solved by the method of Laplace transforms, under nonsteady-state conditions. The final result gives the height of the sample peaks of RF-GC method as a function of time of flow reversal, thus describing mathematically the diffusion band for each analyte, in the form of a sum (or difference) of four exponential functions of time. A simple PC program, based on nonlinear regression analysis, permits the calculation of both the pre-exponential factor and the exponential coefficient of all four functions from the experimental diffusion band. From these factors and coefficients, five physicochemical parameters for the denuder operation are calculated in seven different ways by another simple PC program. Consistent results are obtained by the seven methods of calculation, the mean values of the five parameters and their standard error also being printed. The physicochemical parameters are the initial deposition velocity of the analyte on the tube wall, the rate constant for its desorption, the rate constant for surface reaction, the final deposition velocity and the wall reaction probability. The method has been applied to propene in synthetic air depositing on silica gel, aluminium oxide and marble powder, and also to hydrogen sulphide in air on silver foil.

  8. Method for controlling energy density for reliable pulsed laser deposition of thin films

    SciTech Connect

    Dowden, P. C. E-mail: qxjia@lanl.gov; Bi, Z.; Jia, Q. X. E-mail: qxjia@lanl.gov

    2014-02-15

    We have established a methodology to stabilize the laser energy density on a target surface in pulsed laser deposition of thin films. To control the focused laser spot on a target, we have imaged a defined aperture in the beamline (so called image-focus) instead of focusing the beam on a target based on a simple “lens-focus.” To control the laser energy density on a target, we have introduced a continuously variable attenuator between the output of the laser and the imaged aperture to manipulate the energy to a desired level by running the laser in a “constant voltage” mode to eliminate changes in the lasers’ beam dimensions. This methodology leads to much better controllability/reproducibility for reliable pulsed laser deposition of high performance electronic thin films.

  9. A precise ionization method for determination of the energy deposited in small sites of irradiated objects

    SciTech Connect

    Bigildeev, E.A.; Lappa, A.V.

    1994-09-01

    The ionization method for determination of the energy deposited in sensitive sites of irradiated objects is usually used with the assumption that deposited energy is directly proportional to the number of ionization in a site. This assumption fails in two cases important for nanometer-sized sites: (1) when the fluctuation characteristics of deposited energy such as higher moments, probability distributions, etc. are determined instead of the mean value; (2) when the radiation field in a site is spatially non-uniform. In this paper both cases are investigated. Exact formulae connecting energy and ionization quantities (moments, cumulants, probability distributions) are established as well as practical procedures to obtain energy quantities from those of ionization. The validity of the direct proportionality principle is analyzed and approximate methods to correct it are propose. Some microdosimetric results are presented. The solution of these problems required that we refine some known notions and introduce new terms. In particular, in the paper the necessity of distinguishing two distinct types of events and correspondingly two sets of microdosimetric quantities is noted; new radiation parameters such as the fluctuation W value and non-equivalence factor for the events are defined and investigated numerically. 12 refs., 5 figs.

  10. Measurement of LHCD edge power deposition through modulation techniques on Alcator C-Mod

    NASA Astrophysics Data System (ADS)

    Faust, I. C.; Brunner, D.; LaBombard, B.; Parker, R. R.; Baek, S. G.; Chilenksi, M. A.; Edlund, E.; Hubbard, A.; Hughes, J. W.; Terry, J. L.; Shiraiwa, S.; Walk, J. R.; Wallace, G. M.; Whyte, D. G.

    2015-12-01

    The efficiency of LHCD on Alcator C-Mod drops exponentially with line average density. At reactor relevant densities (> 1 . 1020 [m-3]) no measurable current is driven. While a number of causes have been suggested, no specific mechanism has been shown to be responsible for the loss of current drive at high density. Fast modulation of the LH power was used to isolate and quantify the LHCD deposition within the plasma. Measurements from these plasmas provide unique evidence for determining a root cause. Modulation of LH power in steady plasmas exhibited no correlated change in the core temperature. A correlated, prompt response in the edge suggests that the loss in efficiency is related to a edge absorption mechanism. This follows previous results which found the generation of n||-independent SOL currents. Multiple Langmuir probe array measurements of the conducted heat conclude that the lost power is deposited near the last closed flux surface. The heat flux induced by LH waves onto the outer divertor is calculated. Changes in the neutral pressure, ionization and hard X-ray emission at high density highlight the importance of the active divertor in the loss of efficiency. Results of this study implicate a mechanism which may occur over multiple passes, leading to power absorption near the LCFS.