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Sample records for measuring energy deposition

  1. Calorimetric sensors for energy deposition measurements

    SciTech Connect

    Langenbrunner, J.; Cooper, R.; Morgan, G.

    1998-12-31

    A calorimetric sensor with several novel design features has been developed. These sensors will provide an accurate sampling of thermal power density and energy deposition from proton beams incident on target components of accelerator-based systems, such as the Accelerator Production of Tritium Project (APT) and the Spallation Neutron Source (SNS). A small, solid slug (volume = 0.347 cc) of target material is suspended by kevlar fibers and surrounded by an adiabatic enclosure in an insulating vacuum canister of stainless steel construction. The slug is in thermal contact with a low-mass, calibrated, 100-k{Omega} thermistor. Power deposition caused by the passage of radiation through the slug is calculated from the rate of temperature rise of the slug. The authors have chosen slugs composed of Pb, Al, and LiAl.

  2. Energy deposition rates by charged particles measured during the energy budget campaign

    NASA Technical Reports Server (NTRS)

    Urban, A.; Torkar, K. M.; Bjordal, J.; Lundblad, J. A.; Soraas, F.; Grandal, B.; Smith, L. G.; Ulwick, J. C.; Vancour, R. P.

    1982-01-01

    Measurements of the precipitation of electrons and positive ions (in the keV to MeV range) detected aboard eight rockets launched from Northern Scandinavia are reported together with corresponding satellite data. The downgoing integral fluxes indicate the temporal fluctuations during each flight. Height profiles of the energy deposition into the atmosphere at different levels of geomagnetic disturbance are given.

  3. Energy deposition rates by charged particles measured during the energy budget campaign

    NASA Technical Reports Server (NTRS)

    Urban, A.; Torkar, K. M.; Bjordal, J.; Lundblad, J. A.; Soraas, F.; Grandal, B.; Smith, L. G.; Ulwick, J. C.; Vancour, R. P.

    1982-01-01

    Measurements of the precipitation of electrons and positive ions (in the keV to MeV range) detected aboard eight rockets launched from Northern Scandinavia are reported together with corresponding satellite data. The downgoing integral fluxes indicate the temporal fluctuations during each flight. Height profiles of the energy deposition into the atmosphere at different levels of geomagnetic disturbance are given.

  4. 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''.

  5. 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.

  6. 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.

  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. Measuring internal energy deposition in collisional activation using hydrated ion nanocalorimetry to obtain peptide dissociation energies and entropies.

    PubMed

    Demireva, Maria; Williams, Evan R

    2010-07-01

    The internal energy deposited in both on- and off-resonance collisional activation in Fourier transform ion cyclotron resonance mass spectrometry is measured with ion nanocalorimetry and is used to obtain information about the dissociation energy and entropy of a protonated peptide. Activation of Na(+)(H(2)O)(30) results in sequential loss of water molecules, and the internal energy of the activated ion can be obtained from the abundances of the product ions. Information about internal energy deposition in on-resonance collisional activation of protonated peptides is inferred from dissociation data obtained under identical conditions for hydrated ions that have similar m/z and degrees-of-freedom. From experimental internal energy deposition curves and Rice-Ramsperger-Kassel-Marcus (RRKM) theory, dissociation data as a function of collision energy for protonated leucine enkephalin, which has a comparable m/z and degrees-of-freedom as Na(+)(H(2)O)(30), are modeled. The threshold dissociation energies and entropies are correlated for data acquired at a single time point, resulting in a relatively wide range of threshold dissociation energies (1.1 to 1.7 eV) that can fit these data. However, this range of values could be significantly reduced by fitting data acquired at different dissociation times. By measuring the internal energy of an activated ion, the number of fitting parameters necessary to obtain information about the dissociation parameters by modeling these data is reduced and could result in improved accuracy for such methods.

  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. 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.

  14. 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.

  15. A Template-Matching Method For Measuring Energy Depositions In TES Films

    NASA Astrophysics Data System (ADS)

    Shank, Benjamin; Yen, Jeffrey; Cabrera, Blas; Kreikebaum, John Mark; Moffatt, Robert; Redl, Peter; Young, Betty; Brink, Paul; Cherry, Matthew; Tomada, Astrid

    2014-03-01

    Transition edge sensors (TES) have a wide variety of applications in particle ∖astrophysics for detecting incoming particles with high energy resolution. In TES design, the need for sufficient heat capacity to avoid saturation limits the ultimate energy resolution. Building on the TES model developed for SuperCDMS by Yen et al. for tungsten TESs deposited next to aluminum collection fins, we outline a time-domain non-linear optimal filter method for reconstructing energy depositions in TES films. This allows us to operate devices into their saturation region while taking into account changing noise performance and loss of energy collection. We show how this method has improved our understanding of quasiparticle diffusion and energy collection in our superconducting sensors.

  16. 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.

  17. Measurement of Runaway Electron Plateau Final Loss Energy Deposition into Wall of DIII-D

    NASA Astrophysics Data System (ADS)

    Hollmann, E. M.; Bykov, I.; Moyer, R. A.; Rudakov, D. L.; Commaux, N.; Shiraki, D.; Lasnier, C.; Martin-Solis, R.; Cooper, C.; Eidietis, N.; Parks, P.; Paz-Soldan, C.

    2016-10-01

    Intentional runaway electron (RE) plateau-wall strikes with different initial impurity levels are used to study the effect of background plasma relativistic electron Z (as well as plasma resistivity for slow electrons) on RE-wall loss dynamics. RE wall loss time is found to be close to the avalanche time (meC/eE| |) 1 nλ √{ 3 (Z + 5) / π } , consistent with REs being lost by a series of MHD reconnection events, with timescale limited by current profile filling via avalanche. Local kinetic energy deposition is estimated with both hard x-ray emission and with infra-red imaging. At higher plasma impurity levels Z 10 , energy deposition appears to be consistent with power balance estimates, as long as collisional dissipation during the final loss event is included. At low impurity levels Z 1 , however, local energy deposition appears around 10 × less than expected, indicating that the energy dissipation at low Z is still poorly understood. Work supported by the US DOE under DE-FG02-07ER54917, DE-AC05-00OR22725, DE-AC52-07NA27344, DE-FC02-04ER54698.

  18. Multiple measurements of time of flight, position and energy deposit of ionizing particles by solid state detectors.

    NASA Astrophysics Data System (ADS)

    Codino, Antonio

    1997-03-01

    A telescope made of silicon strip detectors performing simultaneous measurements of position, time and energy deposit has been constructed and operated. The telescope has been tested with a pion beam of 4 GeV/c at the CERN Proton Synchrotron. The intrinsic time resolution of the telescope measured in the beam test is 61+/-7 ps. This unprecedented time resolution is achieved by the multiple sampling of the time of flight. Future developments of this telescope aiming at the construction of a new, analogous instrument of large sensitive area are considered (LATIN project).

  19. 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

  20. Development of a Dual-Energy Computed Tomography Scoring System for Measurement of Urate Deposition in Gout.

    PubMed

    Bayat, Sara; Aati, Opetaia; Rech, Jürgen; Sapsford, Mark; Cavallaro, Alexander; Lell, Michael; Araujo, Elizabeth; Petsch, Christina; Stamp, Lisa K; Schett, Georg; Manger, Bernhard; Dalbeth, Nicola

    2016-06-01

    To develop a semiquantitative dual-energy computed tomography (DECT) scoring system for measurement of urate deposition in gout. Following a structured review of images, a semiquantitative DECT urate scoring method for foot/ankle scans was developed for testing. This method included 4 regions, each scored 0-3, with a maximum total DECT urate score of 12. DECT scans from 224 patients (182 with gout, 42 without gout) were scored by 2 independent readers. Automated urate volumes were also measured. Paired scans from 8 patients receiving pegloticase were analyzed, and a timing exercise was undertaken. The properties of the DECT urate score were analyzed according to the Outcome Measures in Rheumatology (OMERACT) filter. The interreader intraclass correlation coefficient (95% confidence interval) for the DECT urate score was 0.98 (0.97-0.98). All scored regions contributed to the total DECT urate score. DECT urate scores and volumes were highly correlated (r = 0.91, P < 0.0001). Both DECT urate scores and volumes discriminated between gout and nongout control participants and between the tophaceous gout, nontophaceous gout, and control groups. Compared with urate volume, the DECT urate score had greater ability to discriminate between responders and nonresponders to pegloticase therapy (P < 0.001 for DECT urate score and P > 0.05 for volume). The mean ± SD time required for the DECT urate score was 121 ± 2 seconds and for urate volume was 240 ± 2 seconds (P = 2 × 10(-31) ). We have developed a novel semiquantitative DECT scoring method for measurement of urate deposition in the feet/ankles. This method fulfills many aspects of the OMERACT filter. © 2016, American College of Rheumatology.

  1. 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.

  2. CAN THE DIFFERENTIAL EMISSION MEASURE CONSTRAIN THE TIMESCALE OF ENERGY DEPOSITION IN THE CORONA?

    SciTech Connect

    Guennou, C.; Auchere, F.; Bocchialini, K.; Parenti, S.

    2013-09-01

    In this paper, the ability of the Hinode/EIS instrument to detect radiative signatures of coronal heating is investigated. Recent observational studies of active region cores suggest that both the low and high frequency heating mechanisms are consistent with observations. Distinguishing between these possibilities is important for identifying the physical mechanism(s) of the heating. The differential emission measure (DEM) tool is one diagnostic that allows us to make this distinction, through the amplitude of the DEM slope coolward of the coronal peak. It is therefore crucial to understand the uncertainties associated with these measurements. Using proper estimations of the uncertainties involved in the problem of DEM inversion, we derive confidence levels on the observed DEM slope. Results show that the uncertainty in the slope reconstruction strongly depends on the number of lines constraining the slope. Typical uncertainty is estimated to be about {+-}1.0 in the more favorable cases.

  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. 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.

  6. 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

    SciTech Connect

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

    2016-04-15

    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.

  7. 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.

  8. Ionizing Energy Depositions After Fast Neutron Interactions in Silicon

    DOE PAGES

    Bergmann, Benedikt; Pospisil, Stanislav; Caicedo, Ivan; ...

    2016-06-01

    In our study we present the ionizing energy depositions in a 300 μm thick silicon layer after fast neutron impact. With the Time-of-Flight (ToF) technique, the ionizing energy deposition spectra of recoil silicons and secondary charged particles were assigned to (quasi-)monoenergetic neutron energies in the range from 180 keV to hundreds of MeV. We also show and interpret representative measured energy spectra. By separating the ionizing energy losses of the recoil silicon from energy depositions by products of nuclear reactions, the competition of ionizing (IEL) and non-ionizing energy losses (NIEL) of a recoil silicon within the silicon lattice was investigated.more » Furthermore, the data give supplementary information to the results of a previous measurement and are compared with different theoretical predictions.« less

  9. Ionizing Energy Depositions After Fast Neutron Interactions in Silicon

    SciTech Connect

    Bergmann, Benedikt; Pospisil, Stanislav; Caicedo, Ivan; Kierstead, James; Takai, Helio; Frojdh, Erik

    2016-06-01

    In our study we present the ionizing energy depositions in a 300 μm thick silicon layer after fast neutron impact. With the Time-of-Flight (ToF) technique, the ionizing energy deposition spectra of recoil silicons and secondary charged particles were assigned to (quasi-)monoenergetic neutron energies in the range from 180 keV to hundreds of MeV. We also show and interpret representative measured energy spectra. By separating the ionizing energy losses of the recoil silicon from energy depositions by products of nuclear reactions, the competition of ionizing (IEL) and non-ionizing energy losses (NIEL) of a recoil silicon within the silicon lattice was investigated. Furthermore, the data give supplementary information to the results of a previous measurement and are compared with different theoretical predictions.

  10. Ionizing Energy Depositions After Fast Neutron Interactions in Silicon

    SciTech Connect

    Bergmann, Benedikt; Pospisil, Stanislav; Caicedo, Ivan; Kierstead, James; Takai, Helio; Frojdh, Erik

    2016-06-01

    In our study we present the ionizing energy depositions in a 300 μm thick silicon layer after fast neutron impact. With the Time-of-Flight (ToF) technique, the ionizing energy deposition spectra of recoil silicons and secondary charged particles were assigned to (quasi-)monoenergetic neutron energies in the range from 180 keV to hundreds of MeV. We also show and interpret representative measured energy spectra. By separating the ionizing energy losses of the recoil silicon from energy depositions by products of nuclear reactions, the competition of ionizing (IEL) and non-ionizing energy losses (NIEL) of a recoil silicon within the silicon lattice was investigated. Furthermore, the data give supplementary information to the results of a previous measurement and are compared with different theoretical predictions.

  11. 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.

  12. 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.

  13. 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.

  14. Asteroid fragmentation approaches for modeling atmospheric energy deposition

    NASA Astrophysics Data System (ADS)

    Register, Paul J.; Mathias, Donovan L.; Wheeler, Lorien F.

    2017-03-01

    During asteroid entry, energy is deposited in the atmosphere through thermal ablation and momentum-loss due to aerodynamic drag. Analytic models of asteroid entry and breakup physics are used to compute the energy deposition, which can then be compared against measured light curves and used to estimate ground damage due to airburst events. This work assesses and compares energy deposition results from four existing approaches to asteroid breakup modeling, and presents a new model that combines key elements of those approaches. The existing approaches considered include a liquid drop or "pancake" model where the object is treated as a single deforming body, and a set of discrete fragment models where the object breaks progressively into individual fragments. The new model incorporates both independent fragments and aggregate debris clouds to represent a broader range of fragmentation behaviors and reproduce more detailed light curve features. All five models are used to estimate the energy deposition rate versus altitude for the Chelyabinsk meteor impact, and results are compared with an observationally derived energy deposition curve. Comparisons show that four of the five approaches are able to match the overall observed energy deposition profile, but the features of the combined model are needed to better replicate both the primary and secondary peaks of the Chelyabinsk curve.

  15. Note: the influence of exploding foil shape on energy deposition.

    PubMed

    Zeng, Qingxuan; Lv, Junjun; Li, Mingyu

    2013-06-01

    The main influence factors of exploding bridge foil were studied in order to improve energy utilization of the explosion foil initiator. "Square" and "curving" shaped bridge foils were fabricated using magnetron sputtering and chemical etching techniques, and the key dimension of the bridge foil was measured using surface profiler. Commercial software MATLAB was employed to calculate the burst current, burst voltage, and energy deposition. Simulation results were in good agreement with experiment data. In this study, the energy deposition ratio of "square" shaped bridge is between 45%-50%, while the value of "curving" shaped bridge is between 55%-75%.

  16. 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.

  17. Spectrum of energy depositions in the Auger Water Cherenkov Detector

    NASA Astrophysics Data System (ADS)

    Salazar, Humberto

    1999-08-01

    The measured spectrum of energy depositions in a Water Cherenkov Detector (WCD) prototype for the Pierre Auger Observatory is presented. A WCD (area 10 m2 )is located in the Puebla University campus at a depth of 800 g/cm2 (2200 m above sea level). Differential and integral spectra in a wide energy deposition range (0.5 - 150 of vertical equivalent muons) are presented. The problem of the WCD "self calibration" procedure (by rate of the muon events) is discussed. The characteristic change of the slopes of the differential spectrum at the transition from single muon signals to EAS signals is also discussed. The measured energy deposition spectrum at extreme signals is used to estimate the linearity of the response of the WCD PMTs. Key words: Auger array, water Cherenkov detector, extensive air showers

  18. 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.

  19. Measuring the scintillation decay time for different energy deposited by γ-rays and neutrons in a Cs2LiYCl6:Ce3+ detector

    NASA Astrophysics Data System (ADS)

    Wen, Xianfei; Enqvist, Andreas

    2017-05-01

    In nuclear safeguards and homeland security applications, it is greatly beneficial to simultaneously detect γ-rays, thermal neutrons, and fast neutrons using a single detector with reasonable pulse shape discrimination capability, energy resolution comparable with or even better than NaI(Tl) detectors, and high detection efficiency. Cs2LiYCl6:Ce3+(CLYC) scintillation detectors have been proven to be one promising candidate to meet these requirements. In this work, the decay time and fraction of each scintillation component for different energy deposition and incident particle type (γ-ray, thermal neutron, and fast neutron) were investigated based on fitting the PMT anode output with exponential functions. For γ-rays, four components were determined with ultrafast decay time of less than one nanosecond and slow time in the order of magnitude of microsecond. It was found that the dependence on the energy deposited by γ-rays of the fraction as well as the decay time of the three slow components was small. However, significant dependence was observed for the ultrafast component. Two or three components were determined for thermal neutrons and fast neutrons without observing a component with fast decay time. To verify the approach used it was first applied to scintillation pulses induced by γ-rays in a NaI(Tl) detector. The results were consistent with well-known data already published in the literature.

  20. Temporal and spatial characteristics of auroral energy deposition

    NASA Astrophysics Data System (ADS)

    Hampton, D. L.; Conde, M.

    2015-12-01

    Auroral electron precipitation forms a complex and dynamic energy input into the high-latitude ionosphere and thermopshere. Rapid changes in plasma density due to electron impact ionization create correspondingly rapid changes in conductivity which in turn change the magnitude and altitude profile of magnetospheric current closure in the E- and F-region. Modeling these changes in the ionosphere and their effects on the local or regional upper atmosphere requires detailed input over wide regions. In support of the AMISR PINOT campaign and several rocket campaigns (CASCADES-2, MICA, ASSP) we have developed and tested a method to determine the characteristics of auroral energy input using purely ground-based optical measurements in geometries away from magnetic zenith. Using the N2+ first negative emissions at 427.8 nm reproduces the total energy flux over a wide region, but alone does not indicate the altitude profile of this energy deposition. Using temperature maps of the E-region collected by a Scanning Doppler Imager (SDI) observing the auroral green-line emission is a proxy for the characteristic energy of the precipitating electrons. While in some cases the energy determination underestimates the average energy it still is a good proxy for understanding when the electron distribution changes. We examine two seasons worth of auroral observations and determine the spatial and temporal variability of auroral energy deposition in comparison to solar wind and geophysical activity parameters. We also compare the results with well-known empirical models of electron energy deposition and show that they underestimate the peak local energy deposition rates by as much as a factor of 30.

  1. Automated deposit-measuring device (ADMD)

    SciTech Connect

    Stavinoha, L.L.; McInnis, L.A.

    1995-04-01

    The Automated Deposit-Measuring Device (ADMD) was developed and fabricated for the evaluation of lacquer-type fuel and lubricant deposits on Jet Fuel Thermal Oxidation Test (JFTOT), ASTM D 3241, heater test tubes. The ADMD employs commercially available components that provide enhanced speed and accuracy of data acquisition as well as improved maintainability, as compared to the prototype Deposit-Measuring Device (DMD) developed in an Army/Navy program. Application of power to the ADMD automatically brings up an operator selection menu on the vacuum fluorescent display. One of five modes of operation can be selected, including both short and long JFTOT tube length and transference of data from random access memory (RAM) to a personal computer (PC) diskette, if the ADMD is already attached to a PC. Maximum breakdown voltage for the DMD is 1,500 volts, compared to 1,372 volts in the ADMD. This difference in voltage will affect maximum measurable volume of deposit, causing the ADMD to sometimes yield a smaller total volume than the DMD. This fact is a problem only with the thicker deposits. The repeatability of the ADMD is at least as reliable as that of the DMD. Comparison of the ADMD values with the old and current values of the DMD reveals a compatibility between the two devices. The correlation between the volume of deposit of the ADMD and carbon burnoff is superior to the correlation between the volume of deposit of the DMD and carbon burnoff. The ADMD is a viable and reliable instrument for measuring deposit on JFTOT standard and long test tubes. This report describes the ADMD features and compares correlations to DMD data and carbon burnoff data. Advantages and limitations of ADMD-derived data are demonstrated and discussed.

  2. Motor Energy Conservation Measures

    SciTech Connect

    Ian Metzger, Jesse Dean

    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.

  3. Interaction region design driven by energy deposition

    NASA Astrophysics Data System (ADS)

    Martin, Roman; Besana, Maria Ilaria; Cerutti, Francesco; Langner, Andy; Tomás, Rogelio; Cruz-Alaniz, Emilia; Dalena, Barbara

    2017-08-01

    The European Strategy Group for High Energy Physics recommends to study collider designs for the post-LHC era. Among the suggested projects there is the circular 100 TeV proton-proton collider FCC-hh. Starting from LHC and its proposed upgrade HL-LHC, this paper outlines the development of the interaction region design for FCC-hh. We identify energy deposition from debris of the collision events as a driving factor for the layout and draft the guiding principles to unify protection of the superconducting final focus magnets from radiation with a high luminosity performance. Furthermore, we offer a novel strategy to mitigate the lifetime limitation of the first final focus magnet due to radiation load, the Q1 split.

  4. 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.

  5. Energy deposition calculated by PHITS code in Pb spallation target

    NASA Astrophysics Data System (ADS)

    Yu, Quanzhi

    2016-01-01

    Energy deposition in a Pb spallation target irradiated by high energetic protons was calculated by PHITS2.52 code. The validation of the energy deposition and neutron production calculated by PHITS code was performed. Results show good agreements between the simulation results and the experimental data. Detailed comparison shows that for the total energy deposition, PHITS simulation result was about 15% overestimation than that of the experimental data. For the energy deposition along the length of the Pb target, the discrepancy mainly presented at the front part of the Pb target. Calculation indicates that most of the energy deposition comes from the ionizations of the primary protons and the produced secondary particles. With the event generator mode of PHITS, the deposit energy distribution for the particles and the light nulclei is presented for the first time. It indicates that the primary protons with energy more than 100 MeV are the most contributors to the total energy deposition. The energy depositions peaking at 10 MeV and 0.1 MeV, are mainly caused by the electrons, pions, d, t, 3He and also α particles during the cascade process and the evaporation process, respectively. The energy deposition density caused by different proton beam profiles are also calculated and compared. Such calculation and analyses are much helpful for better understanding the physical mechanism of energy deposition in the spallation target, and greatly useful for the thermal hydraulic design of the spallation target.

  6. Energy deposition rates by charged particles. [in upper atmosphere

    NASA Technical Reports Server (NTRS)

    Torkar, K. M.; Urban, A.; Bjordal, J.; Lundblad, J. A.; Soraas, F.; Smith, L. G.; Dumbs, A.; Grandal, B.; Ulwick, J. C.; Vancour, R. P.

    1985-01-01

    A summary of measurements of the precipitation of electrons and positive ions (in the keV-MeV range) detected aboard eight rockets launched within the Energy Budget Campaign from Northern Scandinavia is given, together with corresponding satellite data. In some cases strong temporal variations of the downgoing integral fluxes were observed. The fluxes provide the background for the calculated ion production rates and altitude profiles of the energy deposition into the atmosphere at different levels of geomagnetic disturbance and cosmic noise absorption. The derived ion production rates by eneretic particles are compared to other night-time ionisation sources.

  7. Energy deposition rates by charged particles. [in upper atmosphere

    NASA Technical Reports Server (NTRS)

    Torkar, K. M.; Urban, A.; Bjordal, J.; Lundblad, J. A.; Soraas, F.; Smith, L. G.; Dumbs, A.; Grandal, B.; Ulwick, J. C.; Vancour, R. P.

    1985-01-01

    A summary of measurements of the precipitation of electrons and positive ions (in the keV-MeV range) detected aboard eight rockets launched within the Energy Budget Campaign from Northern Scandinavia is given, together with corresponding satellite data. In some cases strong temporal variations of the downgoing integral fluxes were observed. The fluxes provide the background for the calculated ion production rates and altitude profiles of the energy deposition into the atmosphere at different levels of geomagnetic disturbance and cosmic noise absorption. The derived ion production rates by eneretic particles are compared to other night-time ionisation sources.

  8. Laser energy deposition in crossing shock interaction

    NASA Astrophysics Data System (ADS)

    Yan, H.; Knight, D.; Elliott, G.

    A combined computational and experimental study was performed to investigate the effect of a single laser energy pulse on the transition from a Mach Reflection (MR) to a Regular Reflection (RR) in the Dual Solution Domain (DSD). The freestream Mach number is 3.45 and two oblique shock waves are formed by two symmetric 22° wedges. These conditions correspond to a point midway within the DSD wherein either an MR or an RR is possible. A steady MR was first obtained experimentally and numerically, then a single laser pulse was deposited above the horizontal center plane. The experiment showed that the Mach stem height decreased to 30% of its original height due to the interaction with the thermal spot generated by the laser pulse and then returned to its original height by 300μs. That the Mach stem returned to its original height was most likely due to freestream turbulence in the wind tunnel. The numerical simulation successfully predicted the reverse transition from a stable MR to a stable RR and the stable RR persisted across the span. This study showed the capability of a laser energy pulse to control the reverse transition of MR → RR within the Dual Solution Domain.

  9. 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

  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. 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...

  12. The calculation of proportional counter energy-deposition spectra from experimental data.

    NASA Technical Reports Server (NTRS)

    Steigerwalt, J. E.; Baily, N. A.

    1973-01-01

    The experimental approach considered requires the measurement of energy-absorption distributions for a set of pathlengths which define a biological volume. A suitable folding procedure is necessary to produce composite energy-absorption distributions. The investigation is concerned with the quality of the prediction of energy-deposition distributions, taking into account distributions measured with a proportional counter.

  13. Charge state dependent energy deposition by ion impact.

    PubMed

    Lake, R E; Pomeroy, J M; Grube, H; Sosolik, C E

    2011-08-05

    We report on a measurement of craters in thin dielectric films formed by Xe(Q+) (26 ≤ Q ≤ 44) projectiles. Tunnel junction devices with ion-irradiated barriers were used to amplify the effect of charge-dependent cratering through the exponential dependence of tunneling conductance on barrier thickness. Electrical conductance of a crater σ(c)(Q) increased by 4 orders of magnitude (7.9 × 10(-4) μS to 6.1 μS) as Q increased, corresponding to crater depths ranging from 2 to 11 Å. By employing a heated spike model, we determine that the energy required to produce the craters spans from 8 to 25 keV over the investigated charge states. Considering energy from preequilibrium nuclear and electronic stopping as well as neutralization, we find that at least (27 ± 2)% of available projectile neutralization energy is deposited into the thin film during impact.

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

    PubMed

    Stefik, Morgan

    2016-07-07

    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.

  15. Energy and momentum deposited into a QCD medium by a jet shower.

    PubMed

    Qin, G-Y; Majumder, A; Song, H; Heinz, U

    2009-10-09

    For a hard parton moving through a dense QCD medium, we compute self-consistently the energy loss and the fraction deposited into the medium due to showering and rescattering of the shower, assuming weak coupling between probe and medium. The same transport coefficients thus determine both the energy loss and its deposition into the medium. This allows a parameter free calculation of the latter once the former are computed or measured. We compute them for a weakly interacting medium. Assuming a short thermalization time for the deposited energy, we determine the medium's hydrodynamical response and obtain a conical pattern that is strongly enhanced by showering.

  16. 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.

  17. Energy deposition study of low-energy cosmic radiation at sea level

    NASA Astrophysics Data System (ADS)

    Wijesinghe, Pushpa

    In this dissertation work, a computer simulation model based on the Geant4 simulation package has been designed and developed to study the energy deposition and track structures of cosmic muons and their secondary electrons in tissue-like materials. The particle interactions in a cubic water volume were first simulated. To analyze the energy deposition and tracks in small structures, with the intention of studying the energy localization in nanometric structures such as DNA, the chamber was sliced in three dimentions. Validation studies have been performed by comparing the results with experimental, theoretical, and other simulation results to test the accuracy of the simulation model. A human body phantom in sea-level muon environment was modeled to measure the yearly dose to a human from cosmic muons. The yearly dose in this phantom is about 22 millirems. This is close to the accepted value for the yearly dose from cosmic radiation at sea level. Shielding cosmic muons with a concrete slab from 0 to 2 meters increased the dose received by the body. This dissertation presents an extensive study on the interactions of secondary electrons created by muons in water. Index words. Radiation Dosimetry Simulation, Track Structures, Sea-Level muon Flux, Energy Deposition

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  19. Effect of layer thickness setting on deposition characteristics in direct energy deposition (DED) process

    NASA Astrophysics Data System (ADS)

    Shim, Do-Sik; Baek, Gyeong-Yun; Seo, Jin-Seon; Shin, Gwang-Yong; Kim, Kee-Poong; Lee, Ki-Yong

    2016-12-01

    Direct energy deposition is an additive manufacturing technique that involves the melting of metal powder with a high-powered laser beam and is used to build a variety of components. In laser-assisted metal deposition, the mechanical and metallurgical properties achieved are influenced by many factors. This paper addresses methods for selecting an appropriate layer thickness setting, which is an important parameter in layer-by-layer deposition manufacturing. A new procedure is proposed for determining the layer thickness setting for use in slicing of a part based on the single-layer height for a given depositing condition. This procedure was compared with a conventional method that uses an empirically determined layer thickness and with a feedback control method. The micro-hardness distribution, location of the melting pool, and microstructures of the deposited layers after deposition of a simple target shape were investigated for each procedure. The experimental results show that even though the feedback control method is the most effective method for obtaining the desired geometry, the deposited region was characterized by inhomogeneity of micro-hardness due to the time-variable depositing conditions involved. The largest dimensional error was associated with the conventional deposition procedure, which produced a rise in the melting zone due to over-deposition with respect to the slicing thickness, especially at the high laser power level considered. In contrast, the proposed procedure produced a stable melting zone position during deposition, which resulted in the deposited part having reasonable dimensional accuracy and uniform micro-hardness throughout the deposited region.

  20. Energy deposition model for I-125 photon radiation in water

    NASA Astrophysics Data System (ADS)

    Fuss, M. C.; Muñoz, A.; Oller, J. C.; Blanco, F.; Limão-Vieira, P.; Williart, A.; Huerga, C.; Téllez, M.; García, G.

    2010-10-01

    In this study, an electron-tracking Monte Carlo algorithm developed by us is combined with established photon transport models in order to simulate all primary and secondary particle interactions in water for incident photon radiation. As input parameters for secondary electron interactions, electron scattering cross sections by water molecules and experimental energy loss spectra are used. With this simulation, the resulting energy deposition can be modelled at the molecular level, yielding detailed information about localization and type of single collision events. The experimental emission spectrum of I-125 seeds, as used for radiotherapy of different tumours, was used for studying the energy deposition in water when irradiating with this radionuclide.

  1. 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.

  2. 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.

  3. Energy deposition in low power coaxial plasma thrusters

    NASA Astrophysics Data System (ADS)

    Myers, Roger Metcalf

    The energy deposition in steady-state, low power, coaxial plasma thrusters operated between 10 and 30 kW with argon and nitrogen propellants was studied experimentally and analytically. The major energy sinks were found to be electrode losses (primarily anode), propellant ionization, and thrust. Performance measurements showed the efficiency and specific impulse to vary between two and ten percent and 500 and 1200 seconds, respectively, as functions of thruster current level, propellant flow rate, and thruster geometry. Thrust was found to increase quadratically with current, in agreement with theoretical models of self-field electromagnetic thrusters. Spectroscopic studies of the plasma exhaust with argon propellant showed it to consist primarily of singly and doubly ionized argon, with an electron temperature between 1.2 and 1.7 eV and electron densities between 2 x 10 (exp 13) cu cm and 5 x 10 (exp 13) cu cm. Floating potential measurements showed the anode fall voltage to be between 65 and 95 percent of the total thruster voltage depending on thruster geometry, propellant, and current level. Non-intrusive cathode surface temperature and erosion measurements revealed that the cathode energy balance was governed by electron cooling, surface radiation and conduction through the cathode base. Comparisons of these new results with data from megawatt class, quasi-steady magnetoplasmadynamic thrusters revealed similarities between the plasma properties and acceleration mechanisms of the devices, but showed they have dramatically different anode power fractions. Attempts to increase thruster efficiency by decreasing the chamber radius were not successful, indicating that major changes in thruster design and/or power level will be required to achieve high efficiency, high specific impulse operation.

  4. ENERGY DEPOSITION PROFILES AND ENTROPY IN GALAXY CLUSTERS

    SciTech Connect

    Chaudhuri, Anya; Majumdar, Subhabrata; Nath, Biman B. E-mail: subha@tifr.res.in

    2012-11-10

    We report the results of our study of fractional entropy enhancement in the intracluster medium (ICM) of the clusters from the representative XMM-Newton cluster structure survey. We compare the observed entropy profile of these clusters with that expected for the ICM without any feedback, as well as with the introduction of preheating and cooling. We make the first estimate of the total, as well as radial, non-gravitational energy deposition up to r {sub 500} for this large, nearly flux-limited, sample of clusters. We find that the total energy deposition corresponding to the entropy enhancement is proportional to the cluster temperature (and hence cluster mass). The energy deposition per particle scaled by T {sub sp}, {Delta}E/T {sub sp} has a similar profile in all clusters, and is more pronounced in the central regions. Our results support models of entropy enhancement through active galactic nucleus feedback.

  5. Energy deposition in discharge chamber of lightning protection multichamber system

    NASA Astrophysics Data System (ADS)

    Pinchuk, M. E.; Budin, A. V.; Kumkova, I. I.; Bogomaz, A. A.; Sivaev, A. D.; Chusov, A. N.; Zaynalov, R. I.

    2016-11-01

    The experimental data of energy deposition distribution along discharge chamber of lightning protection multichamber system in initial stage of discharge process aimed to model lightning current impulse up to 10 kA is presented. A multichamber system is a series connection of discharge chambers. According to our experiments the shock wave formation occurs during the breakdown phase between electrodes located at the bottom of discharge chamber. The consequent energy deposition during discharge development goes in the whole volume bounded by shock wave front.

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

    USGS Publications Warehouse

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

    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.

  7. Mechanical characteristics of a tool steel layer deposited by using direct energy deposition

    NASA Astrophysics Data System (ADS)

    Baek, Gyeong Yun; Shin, Gwang Yong; Lee, Eun Mi; Shim, Do Sik; Lee, Ki Yong; Yoon, Hi-Seak; Kim, Myoung Ho

    2017-07-01

    This study focuses on the mechanical characteristics of layered tool steel deposited using direct energy deposition (DED) technology. In the DED technique, a laser beam bonds injected metal powder and a thin layer of substrate via melting. In this study, AISI D2 substrate was hardfaced with AISI H13 and M2 metal powders for mechanical testing. The mechanical and metallurgical characteristics of each specimen were investigated via microstructure observation and hardness, wear, and impact tests. The obtained characteristics were compared with those of heat-treated tool steel. The microstructures of the H13- and M2-deposited specimens show fine cellular-dendrite solidification structures due to melting and subsequent rapid cooling. Moreover, the cellular grains of the deposited M2 layer were smaller than those of the H13 structure. The hardness and wear resistance were most improved in the M2-deposited specimen, yet the H13-deposited specimen had higher fracture toughness than the M2-deposited specimen and heat-treated D2.

  8. 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.

  9. 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.

  10. Steam System Energy Conservation Measures

    SciTech Connect

    Ian Metzger, Jesse Dean

    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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Improvements to the FLASH Laser Energy Deposition Package

    NASA Astrophysics Data System (ADS)

    Flocke, Norbert; Bachan, J.; Couch, S.; Daley, C.; Dubey, A.; Fatenejad, M.; Graziani, C.; Lamb, Don; Lee, Dongwook; Scopatz, A.; Tzeferacos, P.; Weide, K.

    2012-10-01

    FLASH is an open source, compressible, spatially-adaptive, radiation magnetohydrodynamics code that is currently used at a number of institutions for simulating laser-driven HEDP experiments. FLASH uses ray-tracing to model laser energy deposition via the inverse-Bremsstrahlung process on an Eulerian block-structured mesh. We describe recent improvements to the laser ray-tracing package in FLASH which have led to increased accuracy and performance. A ``3D-in-2D'' ray-trace model has been developed which transports rays in three-dimensions when FLASH is configured to run in 2D cylindrical geometry. Several options have been added which allow users greater flexibility in choosing the initial ray placement. These options can be used to reduce the number of rays needed to accurately represent the energy deposition. Several models have been added to FLASH for smoothing the deposited laser energy to reduce numerical noise. The laser package has also been modified to use threading and mesh-replication for parallelization to improve computational performance. Finally, we will present the results of FLASH simulations that use these improvements and compare results using different laser options.

  17. Latest Developments to the FLASH Laser Energy Deposition Package

    NASA Astrophysics Data System (ADS)

    Flocke, Norbert; Daley, Chris; Fatenejad, Milad; Tzeferacos, Petros; Lamb, Don Q.

    2013-10-01

    We describe recent improvements to the FLASH laser energy deposition package. FLASH is an open source, compressible, spatially-adaptive, radiation hydro/MHD code based on an Eulerian AMR grid. Laser energy deposition is modeled using geometric optics ray-tracing algorithms and the inverse-Bremsstrahlung process. A large variety of options exist for users, which allows for a flexible setup of the laser. Several domain geometries are possible (1D, 2D cartesian and cylindrical, 3D in 2D ray-tracing, 3D cartesian) and several beam cross-sections are available (ray placements on square, radial or statistical grids). The original treatment is based on the Kaiser algorithm, which represents the electron number density as a cell-by-cell, piece-wise linear continuous function. We have added a second option that uses cubic interpolation of the electron number density, resulting in a smoother distribution of the energy deposition. We have also improved the computational performance of the package through threading and asynchronous communication when rays cross a block boundary. We present the results of performance and verification tests of the improved package. This work was supported by DOE NNSA ASC.

  18. Mathematical modelling of energy expenditure during tissue deposition.

    PubMed

    Hall, Kevin D

    2010-07-01

    Predicting the magnitude and rate of weight gain for a given increase of energy intake requires a model of whole-body energy expenditure that includes the energy cost of tissue deposition. Here, I introduce a mathematical framework for modelling energy expenditure that elucidates conceptual problems with the classical Kielanowski method for estimating the efficiencies of body fat and protein deposition. An alternative approach uses the theoretical biochemical efficiencies for protein and fat synthesis in combination with models of energy expenditure that include body fat and protein turnover costs. I illustrate this alternative approach using a simple mathematical model applied to previously published data from growing rats and human infants and compare the simple model results with the classical Kielanowski model. While both models fit the data reasonably well (R2>0.87 in rats and R2>0.67 in infants), the Kielanowski method resulted in parameter estimates that varied widely across experiments, had poor precision, and occasionally produced efficiency estimates greater than 1. In contrast, the new method provided precise parameter values and revealed consistencies across different experiments. The proposed mathematical framework has implications for interpreting studies of animal nutrition as well as providing a roadmap for future modelling efforts.

  19. On the Measurement of Dewfall and Fog-Droplet Deposition

    NASA Astrophysics Data System (ADS)

    Price, J. D.; Clark, R.

    2014-09-01

    An observational study has been conducted concerning atmospheric dewfall and fog-droplet deposition with application to the formation and maintenance of fog layers. The relationship between dew and fog is discussed together with the challenges and requirements to measure representative values of their deposition to the surface. A practical instrument developed at the UK Met Office Research Unit, Cardington, is described. The instrument is a small portable device that uses a load cell to measure the weight of a pan upon which various types of natural and artificial canopies can be placed, and can measure dewfall and fog-droplet deposition to an accuracy of 0.0005 mm. Dewfall results from this device are shown for a selection of nights under varying conditions. On a given night the overriding factor determining the amount of dew deposition appears to be location. Several dewmeter devices were placed at different locations around the 18 ha Cardington field site for various clear nights and it was found that dew amounts varied significantly, depending on location: canopies with a more open aspect experienced more deposition by up to a factor of two. The results also suggest that the hygroscopic effect of a canopy, whereby water is absorbed into the canopy and topsoil layer before dew formation begins, is also important for the removal of atmospheric water vapour. Results indicate this effect can be of a similar magnitude to dew deposition. Measurements of fog-droplet deposition showed total water deposition rates did not change when thin radiation fog formed. When optically thick adiabatic fog formed, deposition rates were seen to decrease with time or be generally lower than for thinner radiation fog. Further observations are required to establish if the behaviours found are typical for all fogs.

  20. Energy deposition in the ionosphere derived from LEO satellite observations

    NASA Astrophysics Data System (ADS)

    Stolle, Claudia; Park, Jaeheung; Buchert, Stephan; Trulik, Vladimir; Bilitza, Dieter

    2014-05-01

    Ten years of successful operation of the multi-instrument CHAMP satellite mission at a unique orbit altitude of about 400 km revealed many interesting features of the coupling between the thermosphere and ionosphere. Different processes contribute to the deposition of solar and magnetospheric energy into the thermosphere. One important venue is heating through thermal electrons transferring energy by collisions with ions and neutrals. In the ionospheric F region thermal electrons are heated primarily through photoelectrons by local or non-local processes. At high latitudes soft precipitation and electromagnetic heating play a major role. The energy deposition can be quantified by a family of chemo-physical equations (Schunk and Nagy, 2009) that depend on plasma and neutral densities and temperatures. One important indicator for the energy transfer is the difference between electron and ion- and neutral- temperatures. Electron cooling leads to thermospheric heating and and we expect that this process leads to a local enhancement of mass density (air drag). Sizable electron cooling rates in the F region have been published from EISCAT radar observations in the ionospheric cusp. Based on CHAMP observation of electron density and temperature we estimate the energy deposit in the F-region through cooling of the thermal electron gas caused by elastic and inelastic processes. We find that a significant deposition is present during day at mid latitudes. At low latitudes the energy flux remains important until midnight. Observed heating rates depend on the satellite altitudes, but they are globally available from the CHAMP data. Missing observations in the CHAMP dataset, e.g., ion temperature, are derived from empirical models as IRI or MSIS. We investigate the global distribution of the electron cooling rate, we quantify the contributions of the different processes (equations) to the total energy transfer, e.g., depending on height, and we intend to compare our results

  1. 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.

  2. 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.

  3. Experimental Measurement of ECH Deposition Broadening: Beyond Anomalous Transport

    NASA Astrophysics Data System (ADS)

    Brookman, M. W.; Austin, M. E.; Gentle, K. W.; Petty, C. C.; Ernst, D. E.; Peysson, Y.; Decker, J.; Barada, K.

    2017-07-01

    This work provides a first experimental measurement of broadened ECH deposition on the DIIID tokamak. As seen in theory[1] and simulation[2], refraction by edge density fluctuations shifts the path of RF waves, altering ECH and ECCD deposition. This paper reports on an initial experimental confirmation of broadened ECH deposition on DIII-D tokamak. Te measurements from a 48 channel 2nd Harmonic ECE Radiometer digitized at 500 kHz are used with a set of broadened trial ECH deposition functions to calculate time-dependent, modulation-induced heat fluxes. The fitting of convective and diffusive transport to these fluxes allows different ECH deposition profiles to be compared. The best-fit ECH deposition produces reasonable transport coefficients which compare favorably with simulation. This method is applied to a set of L- and H- mode DIII-D discharges. Accounting for diffusive, convective, and coupled transport, the ECH deposition profile is found to be 2 to 3 times wider than predicted by TORAY-GA ray tracing.

  4. Preliminary Results from a Mercury Dry Deposition Measurement Methods Intercomparison

    NASA Astrophysics Data System (ADS)

    Marsik, F. J.; Brooks, S.; Gustin, M. S.; Holsen, T.; Landis, M.; Prestbo, E. M.; Poissant, L.

    2009-12-01

    Over the past fifteen years, a number of intensive field campaigns and measurement networks have provided valuable information on the estimated rates of mercury wet deposition to sensitive ecosystems throughout the world. In contrast, the ability to place bounds on the rates of mercury dry deposition has been hampered by the relative lack of direct measurements of this process. Recently, a number of researchers have performed measurements of mercury dry deposition using a variety of direct and indirect measurement techniques. While these studies have provided important information regarding the potential rates of mercury dry deposition to natural surfaces, little is known about the comparability of the results utilizing these different measurement approaches. During the month of August 2008, a mercury dry deposition measurement methods comparison was conducted in Ann Arbor, Michigan over a nine-day period. Seven research groups participated in the study, with the following measurement approaches: water, cation exchange membrane, chemically treated filter and turf surrogate surfaces; and several micrometeorological modeling methods. Continuous monitoring was conducted for ambient meteorological conditions and elemental, oxidized and particulate mercury concentrations. Preliminary results suggest that study-average mercury dry deposition estimates ranged from 0.17 to 0.59 ng/m2/hour for the group of pure-water surrogate surfaces, the cation exchange membrane and a micrometeorological flux gradient approach. The turf surrogate surface, BrCl spiked-water surface and a gold-coated quartz fiber filter surface resulted in significantly higher mercury dry deposition estimates, with the latter two approaches having been designed to measure total mercury dry deposition. Given that the turf surrogate surface and the cation exchange membrane samplers were designed for long-term deployment (up to one week), these methods were deployed for an additional series of four one

  5. Thickness measurement of JFTOT tube deposits by ellipsometry

    SciTech Connect

    Baker, C.; David, P.; Taylor, S.E.; Woodward, A.J.

    1995-04-01

    Thickness measurement of Jet Fuel Thermal Oxidation Test (JFTOT) tube deposits has long been a desirable goal to characterize better the thermal stability of jet fuels. The current visual rating method used for specification purposes suffers from the drawback of operator subjectivity and provides little information on the thickness and volume of deposits, parameters which are far more meaningful for characterizing fuels for users and suppliers. Ellipsometry has been identified as a suitable technique for measuring the thickness of JFTOT tubes. Such a system would be robust and non-destructive; cover the important thickness range with regard to visual ratings; provide quick and easy absolute measurement of thickness; enable single spot and profiling measurements; and there would be no restriction on minimum deposit thickness.

  6. 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.

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

    SciTech Connect

    Brambrink, E.; Audebert, P.; Schlegel, T.; Malka, G.; Aleonard, M. M.; Claverie, G.; Gerbaux, M.; Gobet, F.; Hannachi, F.; Scheurer, J. N.; Tarisien, M.; Amthor, K. U.; Meot, V.; Morel, P.

    2007-06-15

    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.

  8. 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.

  9. Energy deposition in ultrathin extreme ultraviolet resist films: extreme ultraviolet photons and keV electrons

    NASA Astrophysics Data System (ADS)

    Kyser, David F.; Eib, Nicholas K.; Ritchie, Nicholas W. M.

    2016-07-01

    The absorbed energy density (eV/cm3) deposited by extreme ultraviolet (EUV) photons and electron beam (EB) high-keV electrons is proposed as a metric for characterizing the sensitivity of EUV resist films. Simulations of energy deposition are used to calculate the energy density as a function of the incident aerial flux (EUV: mJ/cm2, EB: μC/cm2). Monte Carlo calculations for electron exposure are utilized, and a Lambert-Beer model for EUV absorption. The ratio of electron flux to photon flux which results in equivalent energy density is calculated for a typical organic chemically amplified resist film and a typical inorganic metal-oxide film. This ratio can be used to screen EUV resist materials with EB measurements and accelerate advances in EUV resist systems.

  10. 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...

  11. 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...

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. Changes in the frequency distribution of energy deposited in short pathlengths as a function of energy degradation of the primary beam.

    NASA Technical Reports Server (NTRS)

    Baily, N. A.; Steigerwalt, J. E.; Hilbert, J. W.

    1972-01-01

    The frequency distributions of event size in the deposition of energy over small pathlengths have been measured after penetration of 44.3 MeV protons through various thicknesses of tissue-equivalent material. Results show that particle energy straggling of an initially monoenergetic proton beam after passage through an absorber causes the frequency distributions of energy deposited in short pathlengths of low atomic number materials to remain broad. In all cases investigated, the ratio of the most probable to the average energy losses has been significantly less than unity.

  6. Energy deposition in low-power coaxial plasma thrusters

    NASA Technical Reports Server (NTRS)

    Myers, R. M.; Kelly, A. J.; Jahn, R. G.

    1991-01-01

    An experimental examination of energy deposition in self-field, coaxial plasma thrusters revealed that the thrust efficiency ranged from 2-9 percent and that the dominant losses resulted from electrode heating and propellant ionization. Sensible enthalpy and radiative losses were negligible. Thruster specific impulse increased with current, ranging from 550-1750 seconds. Spectroscopic studies of the plume plasma showed that the electron temperature ranged from 0.5-2.5 eV and that the dominant species were singly and doubly ionized argon. Attempts to raise thruster efficiency by increasing the chamber pressure resulted in reduced electrode losses and lowered I(sp), but the thrust efficiency decreased because of a current redistribution that lowered the thrust beyond expectations.

  7. 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.

  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. Energy deposition in low-power coaxial plasma thrusters

    NASA Technical Reports Server (NTRS)

    Myers, R. M.; Kelly, A. J.; Jahn, R. G.

    1991-01-01

    An experimental examination of energy deposition in self-field, coaxial plasma thrusters revealed that the thrust efficiency ranged from 2-9 percent and that the dominant losses resulted from electrode heating and propellant ionization. Sensible enthalpy and radiative losses were negligible. Thruster specific impulse increased with current, ranging from 550-1750 seconds. Spectroscopic studies of the plume plasma showed that the electron temperature ranged from 0.5-2.5 eV and that the dominant species were singly and doubly ionized argon. Attempts to raise thruster efficiency by increasing the chamber pressure resulted in reduced electrode losses and lowered I(sp), but the thrust efficiency decreased because of a current redistribution that lowered the thrust beyond expectations.

  10. Finite-difference electromagnetic deposition/thermoregulatory model: comparison between theory and measurements

    SciTech Connect

    Spiegel, R.J.; Fatmi, M.B.; Ward, T.R.

    1987-01-01

    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 monkeys under similar exposure conditions were obtained using Vitek probes. Calculations exhibit reasonable correlation with the measured data, especially for the rise in colonic temperature.

  11. Energy deposition, heat flow, and rapid solidification during laser and electron beam irradiation of materials

    SciTech Connect

    White, C.W.; Aziz, M.J.

    1985-10-01

    The fundamentals of energy deposition, heat flow, and rapid solidification during energy deposition from lasers and electron beams is reviewed. Emphasis is placed on the deposition of energy from pulsed sources (10 to 100 ns pulse duration time) in order to achieve high heating and cooling rates (10/sup 8/ to 10/sup 10/ /sup 0/C/s) in the near surface region. The response of both metals and semiconductors to pulsed energy deposition is considered. Guidelines are presented for the choice of energy source, wavelength, and pulse duration time.

  12. Measured and modeled dry deposition velocities over the ESCOMPTE area

    NASA Astrophysics Data System (ADS)

    Michou, M.; Laville, P.; Serça, D.; Fotiadi, A.; Bouchou, P.; Peuch, V.-H.

    2005-03-01

    Measurements of the dry deposition velocity of ozone have been made by the eddy correlation method during ESCOMPTE (Etude sur Site pour COntraindre les Modèles de Pollution atmosphérique et de Transport d'Emissions). The strong local variability of natural ecosystems was sampled over several weeks in May, June and July 2001 for four sites with varying surface characteristics. The sites included a maize field, a Mediterranean forest, a Mediterranean shrub-land, and an almost bare soil. Measurements of nitrogen oxide deposition fluxes by the relaxed eddy correlation method have also been carried out at the same bare soil site. An evaluation of the deposition velocities computed by the surface module of the multi-scale Chemistry and Transport Model MOCAGE is presented. This module relies on a resistance approach, with a detailed treatment of the stomatal contribution to the surface resistance. Simulations at the finest model horizontal resolution (around 10 km) are compared to observations. If the seasonal variations are in agreement with the literature, comparisons between raw model outputs and observations, at the different measurement sites and for the specific observing periods, are contrasted. As the simulated meteorology at the scale of 10 km nicely captures the observed situations, the default set of surface characteristics (averaged at the resolution of a grid cell) appears to be one of the main reasons for the discrepancies found with observations. For each case, sensitivity studies have been performed in order to see the impact of adjusting the surface characteristics to the observed ones, when available. Generally, a correct agreement with the observations of deposition velocities is obtained. This advocates for a sub-grid scale representation of surface characteristics for the simulation of dry deposition velocities over such a complex area. Two other aspects appear in the discussion. Firstly, the strong influence of the soil water content to the plant

  13. Distinctive features of kinetics of plasma at high specific energy deposition

    NASA Astrophysics Data System (ADS)

    Lepikhin, Nikita; Popov, Nikolay; Starikovskaia, Svetlana

    2016-09-01

    A nanosecond capillary discharge in pure nitrogen at moderate pressures is used as an experimental tool for plasma kinetics studies at conditions of high specific deposited energy up to 1 eV/molecule. Experimental observations based on electrical (back current shunts, capacitive probe) and spectroscopic measurements (quenching rates; translational, rotational and vibrational temperature measurements) demonstrate that high specific deposited energy, at electric fields of 200-300 Td, can significantly change gas kinetics in the discharge and in the afterglow. The numerical calculations in 1D axially symmetric geometry using experimental data as input parameters show that changes in the plasma kinetics are caused by extremely high excitation degree: up to 10% of molecular nitrogen is electronically excited at present conditions. Distinctive features of kinetics of plasma at high specific energy deposition as well as details of the experimental technique and numerical calculations will be present. The work was partially supported by French National Agency, ANR (PLASMAFLAME Project, 2011 BS09 025 01), AOARD AFOSR, FA2386-13-1-4064 grant (Program Officer Prof. Chiping Li), LabEx Plas@Par and Linked International Laboratory LIA KaPPA (France-Russia).

  14. Correlation between energy deposition and AlN crystal growth induced by ion bombardment

    NASA Astrophysics Data System (ADS)

    Kenzo, Kobayashi; Masaya, Iwaki; Takanobu, Fujihana

    1991-07-01

    A study has been made of the effects of ion (He, O, N and Ne) bombardment on the crystallization of AlN. AlN 0.8 thin films 100 nm thick were deposited on Si (111) wafers by an activated reactive evaporation method in a nitrogen atmosphere. He, O, N and Ne ions were bombarded onto films at room temperature to a dose of 5 × 10 17 ions/cm 2, using an energy of 150 keV. This energy was chosen to place the average projected range of the ions in the substrate interior. XRD measurements were carried out using CuK α radiation (40 keV, 30 mA). The quantities of energy deposited in the films, through ionization and by recoil atoms, were calculated using TRIM-88. It is concluded that ion bombardment of AlN 0.8 thin films causes crystal growth of AlN, with the c-axis oriented perpendicular to the substrate plane, near to room temperature without any thermal annealing. Energy deposition through the ionization plays an essential role in the crystallization of AlN in AlN x thin films.

  15. Control of MR to RR Transition by Pulsed Energy Deposition

    NASA Astrophysics Data System (ADS)

    Yan, Hong; Adelgren, Russell; Elliott, Gregory; Knight, Doyle

    2003-11-01

    This paper presents a study of the effect of a single laser energy pulse on the transition from a Mach Reflection (MR) to a Regular Reflection (RR) in the Dual Solution Domain (DSD). The freestream Mach number is 3.45 and two oblique shock waves are formed by two symmetric 22 degree wedges. These conditions correspond to a point midway within the DSD. A steady MR was first obtained experimentally and numerically, then a single laser pulse was deposited above the horizontal center plane. For the steady MR, the simulation showed the variation of Mach stem height along the span due to side effects. The predicted spanwise averaged Mach stem height was 1.96 mm within 2 percent of the experimental value of 2 mm. The experiment showed that the Mach stem height decreased to 30 percent of its original height due to the interaction with the laser spot and then returned to its original height by 300 microsec. That the Mach stem returned to its original height was most likely due to freestream turbulence in the wind tunnel. The numerical simulation successfully predicted the reverse transition from a stable MR to a stable RR and the stable RR persisted across the span. This study showed the capability of a laser energy pulse to control the reverse transition of MR -> RR within the Dual Solution Domain.

  16. Aligned deposition and electrical measurements on single DNA molecules

    NASA Astrophysics Data System (ADS)

    Eidelshtein, Gennady; Kotlyar, Alexander; Hashemi, Mohtadin; Gurevich, Leonid

    2015-11-01

    A reliable method of deposition of aligned individual dsDNA molecules on mica, silicon, and micro/nanofabricated circuits is presented. Complexes of biotinylated double stranded poly(dG)-poly(dC) DNA with avidin were prepared and deposited on mica and silicon surfaces in the absence of Mg2+ ions. Due to its positive charge, the avidin attached to one end of the DNA anchors the complex to negatively charged substrates. Subsequent drying with a directional gas flow yields DNA molecules perfectly aligned on the surface. In the avidin-DNA complex only the avidin moiety is strongly and irreversibly bound to the surface, while the DNA counterpart interacts with the substrates much more weakly and can be lifted from the surface and realigned in any direction. Using this technique, avidin-DNA complexes were deposited across platinum electrodes on a silicon substrate. Electrical measurements on the deposited DNA molecules revealed linear IV-characteristics and exponential dependence on relative humidity.

  17. Energy Deposition and Condition of the Metal Core in Exploding Wire Experiments

    NASA Astrophysics Data System (ADS)

    Sarkisov, G. S.; Rosenthal, S. E.; Struve, K. W.; McDaniel, D. H.; Waisman, E. M.; Sasorov, P. V.

    2002-11-01

    Measurements of the Joule energy deposition into exploding wire and its relation with condition of the expanding wire core are presented. Wires of nine different metals with diameters of 10-30 microns, have been exploded by fast 150A/ns and slow 20A/ns pulses, in vacuum and in air. It has been shown by interferometry and light emission that expanding wire core has different conditions. The substances with small atomization enthalpy (Ag, Al, Cu, Au) demonstrate full vaporization of the wire core. The refractory metals (Ti, Pt, Mo, W) demonstrates that core consists from vapor and small and hot microparticles. In this case we observe "firework effect" when large radiation from the wire exceed the energy deposition time in a three order of magnitude. For non-refractory metals radiation dropping fast in 100 ns time scale due to effective adiabatic cooling. It is possible if main part of the metal core was vaporized. The interferometrical investigation of the refraction coefficient of expanding metal core is proof this conclusion. It has been shown that energy deposition before surface breakdown dependent strongly from current rate, surface coatings, environment, wire diameter and radial electric field. The regime of wire explosion in vacuum without shunting plasma shell has been realized for fast exploding mode. In this case we observe anomaly high energy deposition in to the wire core exceeding regular value in almost 20 times. The experimental results for Al wire have been compared with ALEGRA 2D MHD simulations. *Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL8500.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. A lithium depth-marker technique for rapid erosion and deposition measurements

    NASA Astrophysics Data System (ADS)

    Sullivan, R. M.; Pang, A.; Martinez-Sanchez, M.; Whyte, D. G.

    2014-01-01

    A novel, high-resolution technique has been developed for the measurement of erosion and deposition in solid material surfaces. The technique uses a combination of nuclear reaction analysis (NRA) and Rutherford backscattering spectrometry (RBS) to determine the change in depth of a previously implanted marker layer consisting of 7Li. A scoping study shows that 7Li is an ideal marker candidate due to a high Q (∼18 MeV) nuclear reaction, 7Li(p,α)4He. Net erosion or deposition is measured by NRA of modified alpha energy passing through the bulk material. The reaction's high cross-section provides for the fast time resolution needed to measure erosion from high flux plasmas, and a highly penetrating proton beam provides for a large range of erosion/deposition measurements. Additionally, the implantation of low-Z Li leads to relatively low vacancy concentrations in the solid material due to implantation. This technique thus provides greater assurance that the measured erosion rate is indicative of the solid material: due to both the low vacancy production and the fact that no films or deposits are involved. Validation was performed by comparing the measured and predicted amount of erosion based on previously measured sputtering yields; the two were found to agree, within the uncertainty of the experiment. The depth resolution of the techniques is ∼60 nm at a net erosion depth of about 1 μm. The benefits of this technique are summarized as: short time scales (minutes) to obtain results, the marker layer can be used in any solid material, greater assurance that the measured erosion is indicative of the unperturbed solid material, and the continuous monitoring of the surface composition for contaminants and/or identification of deposited species using RBS simultaneous with the NRA.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Measuring the Stratigraphic Filter in Ancient Deltaic Deposits

    NASA Astrophysics Data System (ADS)

    Trampush, S. M.; Hajek, E. A.

    2014-12-01

    Internal or autogenic sedimentary-system dynamics act as a filter that can dampen or obliterate signals of environmental perturbations, such as changes in climate and tectonics. Additionally, the transfer of material into the sedimentary archive can further degrade environmental signals. Presently we have a poor understanding of the rates, scales, and types of sedimentary processes that influence the stratigraphic filter in natural systems. A set of statistical tools has been developed for estimating the spatial and temporal scales over which the sedimentary filter operates from preserved stratigraphy. These tools, such as the compensation index, have been applied to experimental data and numerical models, with only limited use on outcrop data. Experimental datasets commonly have several orders of magnitude more data than even the most well exposed ancient outcrops; consequently, the ability to confidently use tools in natural systems is limited. Here we present an evaluation of the suitability of the compensation index for measuring and interpreting sedimentary outcrops. In order to constrain uncertainty due to data-set-size limitations, we model the degree to which measurement error, small data sets, and incomplete sampling influence attempts to quantify stratigraphic architecture. We demonstrate the potential for measuring the stratigraphic filter in ancient deposits by evaluating well-exposed deltaic deposits in the Cretaceous Western Interior Seaway that have been interpreted as having different degrees of to wave, tide, and river influence. Ultimately our results underscore how powerful quantitative tools developed in experimental and model datasets must be applied and interpreted with care in ancient deposits where data availability is limited.

  12. Energy-dependent deposition processes of size-selected Ag nanoclusters on highly-oriented pyrolytic graphite

    NASA Astrophysics Data System (ADS)

    Yamaguchi, W.; Yoshimura, K.; Tai, Y.; Maruyama, Y.; Igarashi, K.; Tanemura, S.; Murakami, J.

    2000-06-01

    Singly charged cations of silver atoms and clusters (Agn+, n=1,3,5,7,9) were deposited on highly oriented pyrolytic graphite substrates at well-controlled, various collision energies. The total amount of Ag atoms remaining on the substrates after collision was quantified by measuring the Ag3d5/2 photoelectron intensities. The collision energy dependence of the amount of deposited Ag atoms revealed that, for all the species, there are three distinct energy regions, for which soft landing, rebounding, or implantation is a dominant process, and that the energy ranges for the processes strongly depend on the cluster size. The deposition efficiency vs collision energy curve for each cluster is well fitted to that for Ag1, by considering the difference between the contact area of Ag1 with the surface and that of the cluster, reflecting the compactness of the clusters. Boundaries between the different deposition regimes for the clusters were less distinct than those for Ag1. Considering anisotropy in shape of a cluster, deposition efficiency around the implantation threshold was calculated, which well explains the indistinctness of the threshold observed in the experimental data. This supports the picture that the energy given to a unit surface area determines the collision process.

  13. Influence of deposited energy on shock wave induced by underwater pulsed current discharge

    NASA Astrophysics Data System (ADS)

    Li, Xian-Dong; Liu, Yi; Liu, Si-Wei; Li, Zhi-Yuan; Zhou, Gu-Yue; Li, Hua; Lin, Fu-Chang; Pan, Yuan

    2016-10-01

    In this paper, an integrated experimental system is established to study the influence of deposited energy on the intensity of the shock wave induced by underwater pulse discharge. Considering the time varying behavior of the arc, the calculation methods of the deposited energy into the plasma channel and the average arc resistance are proposed and presented. The effect of the breakdown process on the deposited energy and the shock wave is analyzed. It can be concluded that the shock wave intensity can be improved by depositing more energy in the first half oscillation period and increasing the arc resistance. It is also found that the energy deposition and the shock wave intensity are significantly influenced by the breakdown time delay and the shape of the initial plasma channel.

  14. 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.

  15. Activation energy measurements of cheese

    USDA-ARS?s Scientific Manuscript database

    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 ...

  16. 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.

  17. 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.

  18. Effects of deposited nuclear and electronic energy on the hardness of R7T7-type containment glass

    NASA Astrophysics Data System (ADS)

    Peuget, S.; Noël, P.-Y.; Loubet, J.-L.; Pavan, S.; Nivet, P.; Chenet, A.

    2006-05-01

    The effects of elastic and inelastic interactions induced by cumulative alpha decay on the hardness of R7T7-type nuclear containment glass were investigated on actinide-doped glass specimens and by external irradiation of inactive glass by light and heavy ions. Vickers microindentation and nanoindentation hardness measurements showed that in the deposited energy range investigated (below 3 × 10 22 keV/cm 3) inelastic effects have no influence on the plastic response of the glass. Conversely, identical hardness variations versus the nuclear energy deposited in the material were observed on curium-doped glass and on glass irradiated by ion bombardment. The observed hardness variation stabilized after the deposited energy reached about 3 × 10 20 keV nucl/cm 3. These findings indicate that the change in the plastic response of the glass is a consequence of ballistic effects.

  19. 19 CFR 351.212 - Assessment of antidumping and countervailing duties; provisional measures deposit cap; interest...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... duties; provisional measures deposit cap; interest on certain overpayments and underpayments. 351.212... countervailing duties; provisional measures deposit cap; interest on certain overpayments and underpayments. (a... regarding the assessment of duties, the provisional measures deposit cap, and interest on over- or...

  20. CalloseMeasurer: a novel software solution to measure callose deposition and recognise spreading callose patterns

    PubMed Central

    2012-01-01

    Background Quantification of callose deposits is a useful measure for the activities of plant immunity and pathogen growth by fluorescence imaging. For robust scoring of differences, this normally requires many technical and biological replicates and manual or automated quantification of the callose deposits. However, previously available software tools for quantifying callose deposits from bioimages were limited, making batch processing of callose image data problematic. In particular, it is challenging to perform large-scale analysis on images with high background noise and fused callose deposition signals. Results We developed CalloseMeasurer, an easy-to-use application that quantifies callose deposition, a plant immune response triggered by potentially pathogenic microbes. Additionally, by tracking identified callose deposits between multiple images, the software can recognise patterns of how a given filamentous pathogen grows in plant leaves. The software has been evaluated with typical noisy experimental images and can be automatically executed without the need for user intervention. The automated analysis is achieved by using standard image analysis functions such as image enhancement, adaptive thresholding, and object segmentation, supplemented by several novel methods which filter background noise, split fused signals, perform edge-based detection, and construct networks and skeletons for extracting pathogen growth patterns. To efficiently batch process callose images, we implemented the algorithm in C/C++ within the Acapella™ framework. Using the tool we can robustly score significant differences between different plant genotypes when activating the immune response. We also provide examples for measuring the in planta hyphal growth of filamentous pathogens. Conclusions CalloseMeasurer is a new software solution for batch-processing large image data sets to quantify callose deposition in plants. We demonstrate its high accuracy and usefulness for two

  1. CalloseMeasurer: a novel software solution to measure callose deposition and recognise spreading callose patterns.

    PubMed

    Zhou, Ji; Spallek, Thomas; Faulkner, Christine; Robatzek, Silke

    2012-12-17

    Quantification of callose deposits is a useful measure for the activities of plant immunity and pathogen growth by fluorescence imaging. For robust scoring of differences, this normally requires many technical and biological replicates and manual or automated quantification of the callose deposits. However, previously available software tools for quantifying callose deposits from bioimages were limited, making batch processing of callose image data problematic. In particular, it is challenging to perform large-scale analysis on images with high background noise and fused callose deposition signals. We developed CalloseMeasurer, an easy-to-use application that quantifies callose deposition, a plant immune response triggered by potentially pathogenic microbes. Additionally, by tracking identified callose deposits between multiple images, the software can recognise patterns of how a given filamentous pathogen grows in plant leaves. The software has been evaluated with typical noisy experimental images and can be automatically executed without the need for user intervention. The automated analysis is achieved by using standard image analysis functions such as image enhancement, adaptive thresholding, and object segmentation, supplemented by several novel methods which filter background noise, split fused signals, perform edge-based detection, and construct networks and skeletons for extracting pathogen growth patterns. To efficiently batch process callose images, we implemented the algorithm in C/C++ within the Acapella™ framework. Using the tool we can robustly score significant differences between different plant genotypes when activating the immune response. We also provide examples for measuring the in planta hyphal growth of filamentous pathogens. CalloseMeasurer is a new software solution for batch-processing large image data sets to quantify callose deposition in plants. We demonstrate its high accuracy and usefulness for two applications: 1) the

  2. 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.

  3. 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

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

    SciTech Connect

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

    2016-05-15

    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.

  5. 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)

  6. High Energy Laser Techniques In Industrial Measurements

    NASA Astrophysics Data System (ADS)

    Erdelyi, Laszlo; Fagan, William F.

    1984-03-01

    High energy lasers are used for industrial measurements in connection with additional instrumentations. The most advanced system for this purposes is the Image Derotator. This system in combination with high energy laser systems is a powerful engeneering and scientific tool in the field of holographic interferometry and speckle photography. Traditional measurements complete the application range of the Image Derotator.

  7. Comparison of Calibration of Sensors Used for the Quantification of Nuclear Energy Rate Deposition

    SciTech Connect

    Brun, J.; Reynard-Carette, C.; Tarchalski, M.; Pytel, K.; Lyoussi, A.; Fourmentel, D.; Villard, J.F.; Jagielski, J.

    2015-07-01

    This present work deals with a collaborative program called GAMMA-MAJOR 'Development and qualification of a deterministic scheme for the evaluation of GAMMA heating in MTR reactors with exploitation as example MARIA reactor and Jules Horowitz Reactor' between the National Centre for Nuclear Research of Poland, the French Atomic Energy and Alternative Energies Commission and Aix Marseille University. One of main objectives of this program is to optimize the nuclear heating quantification thanks to calculation validated from experimental measurements of radiation energy deposition carried out in irradiation reactors. The quantification of the nuclear heating is a key data especially for the thermal, mechanical design and sizing of irradiation experimental devices in specific irradiated conditions and locations. The determination of this data is usually performed by differential calorimeters and gamma thermometers such as used in the experimental multi-sensors device called CARMEN 'Calorimetric en Reacteur et Mesures des Emissions Nucleaires'. In the framework of the GAMMA-MAJOR program a new calorimeter was designed for the nuclear energy deposition quantification. It corresponds to a single-cell calorimeter and it is called KAROLINA. This calorimeter was recently tested during an irradiation campaign inside MARIA reactor in Poland. This new single-cell calorimeter differs from previous CALMOS or CARMEN type differential calorimeters according to three main points: its geometry, its preliminary out-of-pile calibration, and its in-pile measurement method. The differential calorimeter, which is made of two identical cells containing heaters, has a calibration method based on the use of steady thermal states reached by simulating the nuclear energy deposition into the calorimeter sample by Joule effect; whereas the single-cell calorimeter, which has no heater, is calibrated by using the transient thermal response of the sensor (heating and cooling steps). The paper will

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

    NASA Astrophysics Data System (ADS)

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

    2013-08-01

    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 SiH4 to an H2 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 SiH3+, i.e., a change from H3+ 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, mitigating the detrimental effects of an

  9. 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

  10. Comprehensive Energy Balance Measurements in Mice.

    PubMed

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

    2016-09-01

    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. Copyright © 2016 John Wiley & Sons, Inc.

  11. Energy and energy width measurement in the FNAL antiproton accumulator

    SciTech Connect

    Church, M.; Hsueh, S.; Rapidis, P.; Werkema, S.

    1991-10-01

    The Fermilab Antiproton Accumulator has recently been used to produce Charmonium resonances (charm quark, anti-charm quark bound states) in proton-antiproton annihilations using an internal H{sub 2} gas jet target. A measurement of the resonance mass and width may be obtained from a precise knowledge of the antiproton beam energy and energy spread. The beam energy is measured to an accuracy of 1 part in 10{sup 4} in the range 6.3 Gev to 4.1 Gev by measuring the orbit length and revolution frequency of the beam. The beam momentum spread is measured to an accuracy of 10% by measuring the beam frequency spread and the parameter {eta} = (P{sub beam}/F{sub rev}){center_dot}(dF{sub rev}/dP{sub beam}). These two measurement techniques are described in this report.

  12. 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.

  13. Measuring energy savings for modernization projects

    SciTech Connect

    Cowan, J.D.; Schiller, S. |

    1997-08-01

    Energy savings are often used to help finance a facility`s modernization program. The process of determining these savings has come under the microscope as facility owners often pay energy service companies based on savings measurements. Unfortunately, financiers and facility owners usually do not appreciate that determination of savings is an Art, subject to discretion. To them, savings are determined by accountants subtracting one year`s costs from another year`s costs. For those wishing to properly quantify avoided cost, engineering judgments must be added to this simplistic subtraction process. How do you measure something you don`t have? This is the challenge in measuring energy savings. The absence of energy use cannot be measured. However, energy savings can be determined indirectly, using measurements of the presence of energy use, engineering judgment and analysis. This article summarizes the state of the art in savings measurement, particularly as it may be applied by an energy service company (ESCO) in an energy performance contract.

  14. Three methods to measure RH bond energies

    NASA Astrophysics Data System (ADS)

    Berkowitz, Joseph; Ellison, G. Barney; Gutman, David

    1993-03-01

    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.

  15. 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.

  16. 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

  17. 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

  18. The role of Energy Deposition in the Epitaxial Layer in Triggering SEGR in Power MOSFETs

    NASA Technical Reports Server (NTRS)

    Selva, L.; Swift, G.; Taylor, W.; Edmonds, L.

    1999-01-01

    In these SEGR experiments, three identical-oxide MOSFET types were irradiated with six ions of significantly different ranges. Results show the prime importance of the total energy deposited in the epitaxial layer.

  19. The role of Energy Deposition in the Epitaxial Layer in Triggering SEGR in Power MOSFETs

    NASA Technical Reports Server (NTRS)

    Selva, L.; Swift, G.; Taylor, W.; Edmonds, L.

    1999-01-01

    In these SEGR experiments, three identical-oxide MOSFET types were irradiated with six ions of significantly different ranges. Results show the prime importance of the total energy deposited in the epitaxial layer.

  20. A Complete Reporting of MCNP6 Validation Results for Electron Energy Deposition in Single-Layer Extended Media for Source Energies <= 1-MeV

    SciTech Connect

    Dixon, David A.; Hughes, Henry Grady

    2016-05-04

    In this paper, we expand on previous validation work by Dixon and Hughes. That is, we present a more complete suite of validation results with respect to to the well-known Lockwood energy deposition experiment. Lockwood et al. measured energy deposition in materials including beryllium, carbon, aluminum, iron, copper, molybdenum, tantalum, and uranium, for both single- and multi-layer 1-D geometries. Source configurations included mono-energetic, mono-directional electron beams with energies of 0.05-MeV, 0.1-MeV, 0.3- MeV, 0.5-MeV, and 1-MeV, in both normal and off-normal angles of incidence. These experiments are particularly valuable for validating electron transport codes, because they are closely represented by simulating pencil beams incident on 1-D semi-infinite slabs with and without material interfaces. Herein, we include total energy deposition and energy deposition profiles for the single-layer experiments reported by Lockwood et al. (a more complete multi-layer validation will follow in another report).

  1. 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

  2. Monte Carlo simulation and analysis of proton energy-deposition patterns in the Bragg peak

    NASA Astrophysics Data System (ADS)

    González-Muñoz, Gloria; Tilly, Nina; Fernández-Varea, José M.; Ahnesjö, Anders

    2008-06-01

    The spatial pattern of energy depositions is crucial for understanding the mechanisms that modify the relative biological effectiveness of different radiation qualities. In this paper, we present data on energy-deposition properties of mono-energetic protons (1-20 MeV) and their secondary electrons in liquid water. Proton-impact ionization was described by means of the Hansen-Kocbach-Stolterfoht doubly differential cross section (DDCS), thus modelling both the initial energy and angle of the emitted electron. Excitation by proton impact was included to account for the contribution of this interaction channel to the electronic stopping power of the projectile. Proton transport was implemented assuming track-segment conditions, whereas electrons were followed down to 50 eV by the Monte Carlo code PENELOPE. Electron intra-track energy-deposition properties, such as slowing-down and energy-imparted spectra of electrons, were calculated. Furthermore, the use of DDCSs enabled the scoring of electron inter-track properties. We present novel results for 1, 5 and 20 MeV single-proton-track frequencies of distances between the nearest inter- (e--e-, e--H+) and intra-track (e--e-, e--H+, H+-H+) energy-deposition events. By setting a threshold energy of 17.5 eV, commonly employed as a surrogate to discriminate for elementary damage in the DNA, the variation in these frequencies was studied as well. The energy deposited directly by the proton represents a large amount of the total energy deposited along the track, but when an energy threshold is adopted the relative contribution of the secondary electrons becomes larger for increasing energy of the projectile. We found that the frequencies of closest energy-deposition events per nanometre decrease with proton energy, i.e. for lower proton energies a denser ionization occurs, following the trend of the characteristic LET curves. In conclusion, considering the energy depositions due to the delta electrons and at the core of the

  3. Monte Carlo simulation and analysis of proton energy-deposition patterns in the Bragg peak.

    PubMed

    González-Muñoz, Gloria; Tilly, Nina; Fernández-Varea, José M; Ahnesjö, Anders

    2008-06-07

    The spatial pattern of energy depositions is crucial for understanding the mechanisms that modify the relative biological effectiveness of different radiation qualities. In this paper, we present data on energy-deposition properties of mono-energetic protons (1-20 MeV) and their secondary electrons in liquid water. Proton-impact ionization was described by means of the Hansen-Kocbach-Stolterfoht doubly differential cross section (DDCS), thus modelling both the initial energy and angle of the emitted electron. Excitation by proton impact was included to account for the contribution of this interaction channel to the electronic stopping power of the projectile. Proton transport was implemented assuming track-segment conditions, whereas electrons were followed down to 50 eV by the Monte Carlo code PENELOPE. Electron intra-track energy-deposition properties, such as slowing-down and energy-imparted spectra of electrons, were calculated. Furthermore, the use of DDCSs enabled the scoring of electron inter-track properties. We present novel results for 1, 5 and 20 MeV single-proton-track frequencies of distances between the nearest inter- (e(-)-e(-), e(-)-H+) and intra-track (e(-)-e(-), e(-)-H+, H+-H+) energy-deposition events. By setting a threshold energy of 17.5 eV, commonly employed as a surrogate to discriminate for elementary damage in the DNA, the variation in these frequencies was studied as well. The energy deposited directly by the proton represents a large amount of the total energy deposited along the track, but when an energy threshold is adopted the relative contribution of the secondary electrons becomes larger for increasing energy of the projectile. We found that the frequencies of closest energy-deposition events per nanometre decrease with proton energy, i.e. for lower proton energies a denser ionization occurs, following the trend of the characteristic LET curves. In conclusion, considering the energy depositions due to the delta electrons and at the

  4. Study of hot electron spatial energy deposition in spherical targets relevant to shock ignition

    NASA Astrophysics Data System (ADS)

    Zhang, Shu; Wei, M. S.; Krauland, C.; Reynolds, H.; Hoppe, M.; Peebles, J.; Beg, F. N.; Theobald, W.; Borwick, E.; Li, J.; Ren, C.; Stoeckl, C.; Seka, W.; Betti, R.; Campbell, M.

    2016-10-01

    Understanding hot electron generation and coupling is important for the high-intensity shock ignition (SI) inertial confinement fusion concept. Recent hard x-ray experimental data from a SI-relevant platform on OMEGA-60 suggest that <100 keV hot electrons may augment shock pressure by depositing their energy in the solid density region behind the ablation front. These results deduced from simulation are convincing support for electron assisted SI. To further investigate beneficial hot electron characteristics from both high intensity UV and IR lasers in this relevant regime, we performed a joint OMEGA-60/OMEGA EP experiment in the spherical geometry. 60 UV laser beams (18 kJ, 1.8 ns, up to 1015 W/cm2) irradiated a low-density Cu foam ball target with a CH ablator followed by a single IR short pulse laser (2.6 kJ, 100 ps, 1017 W/cm2) at various delays. The electron spatial energy deposition was diagnosed via imaging Cu K α emission with a spherical crystal imager; total K α photon yield and bremsstrahlung radiation were also measured to infer electron spectra. Experimental results are compared with radiation hydrodynamic modeling and will be presented at the meeting. Work supported by the U.S. DOE under contracts DE-NA0002730 (NLUF) and DE-SC0014666.

  5. Deposition of Chromium Thin Films on Stainless Steel-304 Substrates Using a Low Energy Plasma Focus Device

    NASA Astrophysics Data System (ADS)

    Javadi, S.; Ghoranneviss, M.; Hojabri, A.; Habibi, M.; Hosseinnejad, M. T.

    2012-06-01

    In this paper, we study thin films of chromium deposited on stainless steel-304 substrates using a low energy (1.6 kJ) plasma focus device. The films of chromium are likewise deposited with 25 focus shots each at various axial distances from the top of the anode (3, 5, 7, 9 and 11 cm). We also consider different angular positions with respect to the anode axis (0°, 15° and 30°) at a distance of 5 cm from the anode tip to deposit the chromium films on the stainless steel substrates. To characterize the structural properties of the films, we benefit from X-ray diffraction (XRD) analysis. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are applied as well to study the surface morphology of these deposited films. Furthermore, we make use of Vicker's micro-hardness measurements to investigate the mechanical properties of chromium thin films. The XRD results show that the degree of crystallinity of chromium thin films depends on the substrate axial and angular positions. The AFM images illustrate that the film deposited at the distance of 5 cm and the angular position of 0° has quite a uniform surface with homogeneous distribution of grains on the film surface. From the hardness results, we observe that the sample deposited at the axial distance of 5 cm from the anode tip and at the angle of 0° with respect to the anode axis, is harder than the other deposited films.

  6. 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.

  7. Direct Measurement of the Surface Energy of Graphene.

    PubMed

    van Engers, Christian D; Cousens, Nico E A; Babenko, Vitaliy; Britton, Jude; Zappone, Bruno; Grobert, Nicole; Perkin, Susan

    2017-06-14

    Graphene produced by chemical vapor deposition (CVD) is a promising candidate for implementing graphene in a range of technologies. In most device configurations, one side of the graphene is supported by a solid substrate, wheras the other side is in contact with a medium of interest, such as a liquid or other two-dimensional material within a van der Waals stack. In such devices, graphene interacts on both faces via noncovalent interactions and therefore surface energies are key parameters for device fabrication and operation. In this work, we directly measured adhesive forces and surface energies of CVD-grown graphene in dry nitrogen, water, and sodium cholate using a modified surface force balance. For this, we fabricated large (∼1 cm(2)) and clean graphene-coated surfaces with smooth topography at both macro- and nanoscales. By bringing two such surfaces into contact and measuring the force required to separate them, we measured the surface energy of single-layer graphene in dry nitrogen to be 115 ± 4 mJ/m(2), which was similar to that of few-layer graphene (119 ± 3 mJ/m(2)). In water and sodium cholate, we measured interfacial energies of 83 ± 7 and 29 ± 6 mJ/m(2), respectively. Our work provides the first direct measurement of graphene surface energy and is expected to have an impact both on the development of graphene-based devices and contribute to the fundamental understanding of surface interactions.

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

    NASA Astrophysics Data System (ADS)

    Xu, Yan; Wu, SiZhong; Zheng, WuDi

    2015-04-01

    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.

  9. A fragment-cloud model for asteroid breakup and atmospheric energy deposition

    NASA Astrophysics Data System (ADS)

    Wheeler, Lorien F.; Register, Paul J.; Mathias, Donovan L.

    2017-10-01

    As asteroids break up during atmospheric entry, they deposit energy that can be seen in flares of light and, if substantial enough, can produce damaging blast waves. Analytic models of asteroid breakup and energy deposition processes are needed in order to assess potential airburst hazards, and to enable inferences about asteroid properties or breakup physics to be made from comparisons with observed meteors. This paper presents a fragment-cloud model (FCM) that is able to represent a broad range of breakup behaviors and the resulting variations in energy deposition in ways that make it a useful tool for both applications. Sensitivity studies are performed to investigate how variations the model's fragmentation parameters affect the energy deposition results for asteroids 20-500 m in diameter. The model is also used to match observational data from the Chelyabinsk meteor and infer potential asteroid properties and representative modeling parameter ranges. Results illustrate how the model's fragmentation parameters can introduce different energy deposition features, and how much they affect the overall energy deposition rates, magnitudes, and altitudes that would drive ground damage for risk assessment applications.

  10. 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.

  11. Fluorocarbon thin-film deposition on polymer surfaces from low-energy polyatomic ion beams

    NASA Astrophysics Data System (ADS)

    Wijesundara, Muthu Bandage Jayathilaka

    Low energy polyatomic ion deposition is attractive for selective surface modification of advanced materials. Surface modification by fluorocarbon (FC) thin film deposition is widely used for many technological applications. Thus, polymer surface modification by FC thin film deposition was carried out using mass-separated low energy FC ion beams. X-ray photoelectron spectroscopy, atomic force microscopy and air/water contact angles were employed to examine how the FC film chemistry, morphology, and long term stability depend on incident ion structure, kinetic energy, and fluence. Molecular dynamics simulations were performed to support experimental data. 25--100 eV CF3+ and C3F 5+ ion deposition on polystyrene (PS) surface was examined. CF3+ and C3F5+ each formed a distribution of different FC functional groups on PS in amounts dependent upon the incident ion energy, structure, and fluence. Both ions deposited mostly intact upon the surface at 25 eV. The total fluorine and fluorinated carbon content were increased with ion energy. The fluorination efficiency was higher for the larger ion. The simulations revealed that the fragmentation behavior depends on the incident ion structure and its energy. The simulations also confirmed that FC ions only penetrated a few angstroms into the surface. The compositional changes of 25--100 eV CF3+ and C3F5+ ion-modified PS surfaces were examined after being exposed to atmosphere for four and eight weeks. The FC films oxidized in atmospheric conditions. Oxygen incorporation into the ion-modified surfaces increased with ion energy due to higher surface bond breakage and active site formation at high collision energy. Overall, the aging process of these ion-deposited films appeared similar to that of plasma-deposited films. Mass-selected 50 eV C3F5+ ion deposition was employed to create chemical gradient thin films on polymethylmethacrylate (PMMA) by variation of the ion fluence across the substrate surface. The surface chemistry

  12. 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.

  13. Engineering Properties of Superhard Films with Ion Energy and Post-Deposition Processing

    SciTech Connect

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

    2003-08-26

    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.

  14. 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.

  15. Application of a single crystal chemical vapor deposition diamond detector for deuteron plasma neutron measurement

    NASA Astrophysics Data System (ADS)

    Xie, Xufei; Yuan, Xi; Zhang, Xing; Chen, Zhongjing; Peng, Xingyu; Du, Tengfei; Li, Tao; Hu, Zhimeng; Cui, Zhiqiang; Chen, Jinxiang; Li, Xiangqing; Zhang, Guohui; Fan, Tieshuan; Yuan, Guoliang; Yang, Jinwei; Yang, Qingwei

    2014-10-01

    A single crystal chemical vapor deposition (scCVD) diamond detector has been characterized and employed for the neutron measurement at the HL-2A tokamak device. The scCVD diamond detector has been deposited with 5 μm of lithium fluoride (LiF) layer to enhance the sensitivity to thermal neutrons. Time stability of the detector has been studied with α-source and good performance has been found for more than 12 h. Neutron irradiations have been performed in four quasi-monoenergetic neutron fields in the energy range from 2.50 MeV to 16.03 MeV. The measured response function of the scCVD diamond detector to 14.13 MeV neutrons shows a narrow 12C (n, α)9Be reaction peak which is well isolated from other structures by about 1 MeV in energy, indicating the great potential as a fast neutron spectrometer. Neutron measurement of deuterium plasma discharge was established at the HL-2A tokamak device, and good consistence has been revealed among this detector signal and other related signals.

  16. Energy deposition profile in human skin upon irradiation with a 1,342 nm Nd:YAP laser.

    PubMed

    Milanič, Matija; Majaron, Boris

    2013-01-01

    Nd:YAP laser emitting at 1,342 nm appears promising for nonablative skin rejuvenation treatment, based on favorable absorption properties of water and melanin in this part of the spectrum. A quantitative determination of energy deposition characteristics of Nd:YAP in normal human skin should enable design of a safe and effective treatment protocol for future human studies. Energy deposition profile of a prototype Nd:YAP laser was determined using pulsed photothermal radiometry. This technique involves time-resolved measurement of mid-infrared emission from a sample after pulsed laser irradiation. The laser-induced temperature depth profile is reconstructed from the radiometric transients using a custom optimization algorithm, developed and tested earlier in our group. Measurements were performed on the extremities of four healthy volunteers at low radiant exposure (2.8 J/cm(2) ). For the purpose of comparison, energy deposition characteristics of commercial Nd:YAG and KTP lasers (at 1,064 and 532 nm, respectively), were also determined at the same test sites. On average, the Nd:YAP laser deposits 50% of the absorbed energy within the top 0.36 mm of skin and 90% within 0.86 mm, which is significantly shallower than the Nd:YAG laser. The ratio between the dermal versus epidermal heating is more favorable and shows a smaller inter- and intra-patient variance as compared to both Nd:YAG and KTP laser. Energy deposition characteristics of the 1,342 nm Nd:YAP laser are very suitable for controlled heating of the upper dermis, as required for nonablative skin rejuvenation. The risks of overheating the epidermis or subcutis should be significantly reduced in comparison with the 1,064 nm Nd:YAG laser. Copyright © 2012 Wiley Periodicals, Inc.

  17. Study of Z scaling of runaway electron plateau final loss energy deposition into wall of DIII-D

    NASA Astrophysics Data System (ADS)

    Hollmann, E. M.; Commaux, N.; Eidietis, N. W.; Lasnier, C. J.; Rudakov, D. L.; Shiraki, D.; Cooper, C.; Martin-Solis, J. R.; Parks, P. B.; Paz-Soldan, C.

    2017-06-01

    Controlled runaway electron (RE) plateau-wall strikes with different initial impurity levels are used to study the effect of background plasma ion charge Z (resistivity) on RE-wall loss dynamics. It is found that Joule heating (magnetic to kinetic energy conversion) during the final loss does not go up monotonically with increasing Z but peaks at intermediate Z ˜ 6. Joule heating and overall time scales of the RE final loss are found to be reasonably well-described by a basic 0D coupled-circuit model, with only the loss time as a free parameter. This loss time is found to be fairly well correlated with the avalanche time, possibly suggesting that the RE final loss rate is limited by the avalanche rate. First attempts at measuring total energy deposition to the vessel walls by REs during the final loss are made. At higher plasma impurity levels Z > 5, energy deposition to the wall appears to be consistent with modeling, at least within the large uncertainties of the measurement. At low impurity levels Z < 5, however, local energy deposition appears around 5-20× less than expected, suggesting that the RE energy dissipation at low Z is not fully understood.

  18. Power deposition measurements at 800 MeV-direct proton beam heating of target materials

    SciTech Connect

    Quintana, D.L.; Langenbrunner, J.; Morgan, G.

    1999-07-01

    A slug calorimetric sensor with several novel design features was developed to measure the power deposition in a cylindrical test article with lead, aluminum, polyethylene and tungsten components. A small, solid slug (volume = 347.5 mm{sup 3}) was suspended by Kevlar fibers and surrounded by an adiabatic enclosure in an insulating vacuum canister of stainless steel construction. A small, calibrated, 100-kOhm thermistor was placed in the slug to monitor the temperature. Power deposition caused by the passage of radiation through the slug was measured from the rate of temperature rise. Lead, tungsten, and Inconel-718 slugs were placed on the beam axis of the test article and were irradiated with an 800 MeV proton beam. The data from these sensors will provide an accurate determination of thermal power density and energy deposition from proton beams incident on target/blanket components of accelerator-based systems, such as the Accelerator Production of Tritium (APT) and the Spallation Neutron Source (SNS).

  19. 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

  20. 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

  1. 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.

  2. How energy conservation limits our measurements.

    PubMed

    Navascués, Miguel; Popescu, Sandu

    2014-04-11

    Observations in quantum mechanics are subject to complex restrictions arising from the principle of energy conservation. Determining such restrictions, however, has been so far an elusive task, and only partial results are known. In this Letter, we discuss how constraints on the energy spectrum of a measurement device translate into limitations on the measurements which we can effect on a target system with a nonconstant energy operator. We provide efficient algorithms to characterize such limitations and, in case the target is a two-level quantum system, we quantify them exactly. Our Letter, thus, identifies the boundaries between what is possible or impossible to measure, i.e., between what we can see or not, when energy conservation is at stake.

  3. 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.

  4. 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.

  5. High energy cosmic ray charge and energy spectra measurements

    NASA Technical Reports Server (NTRS)

    Chappell, J. H.; Webber, W. R.

    1981-01-01

    In 1976, 1977, and 1978, a series of three balloon flights was conducted to measure the energy spectra of cosmic ray nuclei. A gas Cerenkov detector with different gas thresholds of 8.97, 13.12, and 17.94 GeV/n was employed to extend these measurements to high energies. The total collection factor for these flights is more than 20 sq m ster-hr. Individual charge resolution was achieved over the charge range Z equals 4-26, and overlapping differential spectra were obtained from the three flights up to approximately 100.0 GeV/n.

  6. Analysis of mechanical-hydraulic bedload deposition control measures

    NASA Astrophysics Data System (ADS)

    Schwindt, S.; Franca, M. J.; De Cesare, G.; Schleiss, A. J.

    2017-10-01

    During floods, the bedload transport of steep headwaters can exceed the hydraulic transport capacity of milder downstream reaches where settlements are often situated. Therefore, sediment retention barriers are typically installed upstream of such sensible areas. These barriers trigger bedload trapping via two control mechanisms, either hydraulic or mechanical. Both deposition controls, pertaining to instream sediment trapping structures, are analyzed experimentally in this study. Bedload trapping by hydraulically controlled barriers is prone to sediment flushing, i.e., the remobilization of formerly deposited sediment, in particular when the barrier is simultaneously under- and overflown. In this case, the remobilization rate is close to the bedload transport capacity of the nonconstricted channel. Mechanical deposition control by screens is in turn sensible to the grain size. Thus, both deposition control concepts may fail, and bedload may be transported downstream at a rate corresponding to the transport capacity of headwaters, thereby endangering urban areas. This study shows that the combination of both deposition control concepts is suitable for improving the control of bedload retention. With this combination, undesired sediment flushing of upstream deposits in the channel caused by insufficient hydraulic control is prevented. Furthermore, the uncertainty related to the estimation of the representative grain size in the design of mechanical control barriers is reduced.

  7. 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

  8. Efficient Energy Deposition for an Electron Beam Pumped KrF Laser

    NASA Astrophysics Data System (ADS)

    Hegeler, F.; Myers, M. C.; Friedman, M.; Sethian, J. D.; Swanekamp, S. B.; Rose, D. V.; Welch, D. R.

    2002-11-01

    Electra is a repetitively pulsed, electron beam pumped krypton fluoride (KrF) laser that will develop the technologies that can meet the Inertial Fusion Energy (IFE) requirements for durability, efficiency, and cost. The Electra laser is pumped with two opposing electron beams each with parameters of 500 kV, 90 kA, with a 100 ns flat-top pulse duration, and a cathode area of 27 x 97 cm^2. The e-beam propagates through a hibachi structure, which supports a thin foil that isolates the vacuum diode from the high-pressure (>1 atm) laser gas. It has been demonstrated that segmenting the beam into strips to miss the hibachi support ribs significantly increases the electron beam deposition efficiency. The energy deposition efficiency is defined as the ratio of energy deposited in the laser gas over the vacuum diode e-beam energy. Energy deposition efficiencies of 75have been achieved with a 500 keV e-beam. In addition, 1-D and 3-D codes have simulated the e-beam propagation through the hibachi, and 1-D codes predict a maximum energy deposition efficiency of 81

  9. Mechanisms of ignition by transient energy deposition: Regimes of combustion wave propagation

    NASA Astrophysics Data System (ADS)

    Kiverin, A. D.; Kassoy, D. R.; Ivanov, M. F.; Liberman, M. A.

    2013-03-01

    Regimes of chemical reaction wave propagating in reactive gaseous mixtures, whose chemistry is governed by chain-branching kinetics, are studied depending on the characteristics of a transient thermal energy deposition localized in a finite volume of reactive gas. Different regimes of the reaction wave propagation are initiated depending on the amount of deposited thermal energy, power of the source, and the size of the hot spot. The main parameters which define regimes of the combustion waves facilitated by the transient deposition of thermal energy are acoustic time scale, duration of the energy deposition, ignition time scale, and size of the hot spot. The interplay between these parameters specifies the role of gasdynamical processes, the formation and steepness of the temperature gradient, and speed of the spontaneous wave. The obtained results show how ignition of one or another combustion regime depends on the value of energy, rate of the energy deposition, and size of the hot spot, which is important for the practical use and for risk assessment.

  10. 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.

  11. 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.

  12. On the role of energy deposition in triggering SEGR in power MOSFETs

    SciTech Connect

    Selva, L.E.; Swift, G.M.; Taylor, W.A.; Edmonds, L.D.

    1999-12-01

    Single event gate rupture (SEGR) was studied using three types of power MOSFET devices with ions having incident linear energy transfers (LETs) in silicon from 26 to 82 MeV{center{underscore}dot}cm{sup 2}/mg. Results are: (1) consistent with Wrobel's oxide breakdown for V{sub DS} = 0 volts (for both normal incidence and angle); and (2) when V{sub GS} = 0 volts, energy deposited near the Si/SiO{sub 2} interface is more important than the energy deposited deeper in the epi.

  13. 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.

  14. 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.

  15. Advanced Materials Enabled by Atomic Layer Deposition for High Energy Density Rechargeable Batteries

    NASA Astrophysics Data System (ADS)

    Chen, Lin

    In order to meet the ever increasing energy needs of society and realize the US Department of Energy (DOE)'s target for energy storage, acquiring a fundamental understanding of the chemical mechanisms in batteries for direct guidance and searching novel advanced materials with high energy density are critical. To realize rechargeable batteries with superior energy density, great cathodes and excellent anodes are required. LiMn2O4 (LMO) has been considered as a simpler surrogate for high energy cathode materials like NMC. Previous studies demonstrated that Al2O3 coatings prepared by atomic layer deposition (ALD) improved the capacity of LMO cathodes. This improvement was attributed to a reduction in surface area and diminished Mn dissolution. However, here we propose a different mechanism for ALD Al 2O3 on LMO based on in-situ and ex-situ investigations coupled with density functional theory calculations. We discovered that Al2O 3 not only coats the LMO, but also dopes the LMO surface with Al leading to changes in the Mn oxidation state. Different thicknesses of Al2O 3 were deposited on nonstoichiometric LiMn2O4 for electrochemical measurements. The LMO treated with one cycle of ALD Al2O3 (1xAl 2O3 LMO) to produce a sub-monolayer coating yielded a remarkable initial capacity, 16.4% higher than its uncoated LMO counterpart in full cells. The stability of 1xAl2O3 LMO is also much better as a result of stabilized defects with Al species. Furthermore, 4xAl 2O3 LMO demonstrates remarkable capacity retention. Stoichiometric LiMn2O4 was also evaluated with similar improved performance achieved. All superior results, accomplished by great stability and reduced Mn dissolution, is thanks to the synergetic effects of Al-doping and ALD Al2O 3 coating. Turning our attention to the anode, we again utilized aluminum oxide ALD to form conformal films on lithium. We elaborately designed and studied, for the first time, the growth mechanism during Al2O3 ALD on lithium metal in

  16. 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.

  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. 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.

  19. 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.

  20. Calculation of energy deposition, photon and neutron production in proton therapy of thyroid gland using MCNPX.

    PubMed

    Mowlavi, Ali Asghar; Fornasie, Maria Rosa; de Denaro, Mario

    2011-01-01

    In this study, the MCNPX code has been used to simulate a proton therapy in thyroid gland, in order to calculate the proton energy deposition in the target region. As well as, we have calculated the photon and neutron production spectra due to proton interactions with the tissue. We have considered all the layers of tissue, from the skin to the thyroid gland, and an incident high energy pencil proton beam. The results of the simulation show that the best proton energy interval, to cover completely the thyroid tissue, is from 42 to 54 MeV, assuming that the thyroid gland has a 14 mm thickness and is located 11.2mm under the skin surface. The most percentage of deposited energy (78%) is related to the 54 MeV proton energy beam. Total photon and neutron production are linear and polynomial second order functions of the proton energy, respectively.

  1. Photon Energy Deposition in Strong-Field Single Ionization of Multielectron Molecules.

    PubMed

    Zhang, Wenbin; Li, Zhichao; Lu, Peifen; Gong, Xiaochun; Song, Qiying; Ji, Qinying; Lin, Kang; Ma, Junyang; He, Feng; Zeng, Heping; Wu, Jian

    2016-09-02

    Molecules exposed to strong laser fields may coherently absorb multiple photons and deposit the energy into electrons and nuclei, triggering the succeeding dynamics as the primary stage of the light-molecule interaction. We experimentally explore the electron-nuclear sharing of the absorbed photon energy in above-threshold multiphoton single ionization of multielectron molecules. Using CO as a prototype, vibrational and orbital resolved electron-nuclear sharing of the photon energy is observed. Different from the simplest one- or two-electron systems, the participation of the multiple orbitals and the coupling of various electronic states in the strong-field ionization and dissociation processes alter the photon energy deposition dynamics of the multielectron molecule. The population of numerous vibrational states of the molecular cation as the energy reservoir in the ionization process plays an important role in photon energy sharing between the emitted electron and the nuclear fragments.

  2. Optimal algorithm to improve the calculation accuracy of energy deposition for betavoltaic MEMS batteries design

    NASA Astrophysics Data System (ADS)

    Li, Sui-xian; Chen, Haiyang; Sun, Min; Cheng, Zaijun

    2009-11-01

    Aimed at improving the calculation accuracy when calculating the energy deposition of electrons traveling in solids, a method we call optimal subdivision number searching algorithm is proposed. When treating the energy deposition of electrons traveling in solids, large calculation errors are found, we are conscious of that it is the result of dividing and summing when calculating the integral. Based on the results of former research, we propose a further subdividing and summing method. For β particles with the energy in the entire spectrum span, the energy data is set only to be the integral multiple of keV, and the subdivision number is set to be from 1 to 30, then the energy deposition calculation error collections are obtained. Searching for the minimum error in the collections, we can obtain the corresponding energy and subdivision number pairs, as well as the optimal subdivision number. The method is carried out in four kinds of solid materials, Al, Si, Ni and Au to calculate energy deposition. The result shows that the calculation error is reduced by one order with the improved algorithm.

  3. Relationship between energy deposition and shock wave phenomenon in an underwater electrical wire explosion

    NASA Astrophysics Data System (ADS)

    Han, Ruoyu; Zhou, Haibin; Wu, Jiawei; Qiu, Aici; Ding, Weidong; Zhang, Yongmin

    2017-09-01

    An experimental study of pressure waves generated by an exploding copper wire in a water medium is performed. We examined the effects of energy deposited at different stages on the characteristics of the resulting shock waves. In the experiments, a microsecond time-scale pulsed current source was used to explode a 300-μm-diameter, 4-cm-long copper wire with initial stored energies ranging from 500 to 2700 J. Our experimental results indicated that the peak pressure (4.5-8.1 MPa) and energy (49-287 J) of the shock waves did not follow a simple relationship with any electrical parameters, such as peak voltage or deposited energy. Conversely, the impulse had a quasi-linear relationship with the parameter Π. We also found that the peak pressure was mainly influenced by the energy deposited before separation of the shock wave front and the discharge plasma channel (DPC). The decay time constant of the pressure waveform was affected by the energy injection after the separation. These phenomena clearly demonstrated that the deposited energy influenced the expansion of the DPC and affected the shock wave characteristics.

  4. 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.

  5. 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.

  6. The effect of energy deposition on pattern resolution in electron beam lithography

    NASA Astrophysics Data System (ADS)

    Raghunathan, Ananthan

    Electron beam lithography is one of the most important tools for nanofabrication. Electron beam lithography has consistently been able to offer higher resolution, typically better than 10 nm or so, compared to other techniques. In this work the contribution of electron-substrate interaction to pattern resolution is investigated. In electron beam lithography the incident beam is scattered in the resist-substrate stack by a combination of elastic and inelastic events which is described by the point spread function. Using a Vistec VB300 Gaussian beam lithography tool operating at 100 keV the experimental point spread function is investigated by a technique called point exposure distribution measurements. The experimental results indicate that the scattering in the sub-100 nm range shows several orders of the magnitude difference with that obtained via Monte Carlo simulations. In high energy electron beam lithography where forward scattering in small, contribution of secondary electrons generated by the primary beam must be taken into account. The chemical change leading to resist exposure is through bond scission, which is typically a low energy event between 3 -- 5 eV. Compared to the primary beam, the secondary electrons have a significantly higher probability of scission due to their lower energy. These secondary electrons are also generated with large emission angles and can travel several nanometers, leading to an increase in observed line widths compared to the size of the beam. An analytical model developed here, that considers the energy deposited by the secondary electrons, is able to predict the dependence of dose on observed diameter to within a reasonable accuracy. This technique used in conjunction with the knowledge of resist contrast is also indicative of pattern resolution limits in high energy electron beam lithography. It is also found that for negative resists, backscatter effects and resist contrast significantly degrade the resolution for large

  7. 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

    2014-07-18

    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.

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

    PubMed Central

    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 (Xe22+ to Xe30+) 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

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

    NASA Astrophysics Data System (ADS)

    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.

    2014-07-01

    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 (Xe22+ to Xe30+) 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.

  10. Measurements of dry-deposition parameters for the California acid-deposition monitoring program. Final report

    SciTech Connect

    Watson, J.G.; Chow, J.C.; Egami, R.T.; Bowen, J.L.; Frazier, C.A.

    1991-06-01

    The State of California monitors the concentrations of acidic gases and particles at 10 sites throughout the state. Seven sites represent urban areas (South Coast Air Basin - three sites, San Francisco Bay Area, Bakersfield, Santa Barbara, and Sacramento) and three represent forested areas (Sequoia National Park, Yosemite National Park, and Gasquet). Several sites are collocated with monitoring instruments for other air quality and forest response networks. Continuous monitors for the dry deposition network collect hourly average values for ozone, wind speed, wind direction, atmospheric stability, temperature, dew point, time of wetness, and solar radiation. A newly-designed gas/particle sampler collects daytime (6 a.m. to 6 p.m.) and nighttime (6 p.m. to 6 a.m.) samples every sixth day for sulfur dioxide, ammonia, nitrogen dioxide, and nitric acid. Particles are collected on the same day/night schedule in PM(10) and PM(2.5) size ranges, and are analyzed for mass, sulfate, nitrate, chloride, ammonium, sodium, magnesium, potassium, and calcium ions. The sampling schedule follows the regulatory schedule adopted by the EPA and ARB for suspended particulate matter. Wet deposition data are collected at or nearby the dry deposition stations. The first year of the monitoring program included installation of the network, training of technicians, acquisition and validation of data, and transfer of the sampling and analysis technology to Air Resources Board operating divisions. Data have been validated and stored for the period May, 1988 through September, 1989.

  11. 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

  12. 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.

  13. 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

  14. Effect of Mach number on the efficiency of microwave energy deposition in supersonic flow

    NASA Astrophysics Data System (ADS)

    Lashkov, V. A.; Karpenko, A. G.; Khoronzhuk, R. S.; Mashek, I. Ch.

    2016-05-01

    The article is devoted to experimental and numerical studies of the efficiency of microwave energy deposition into a supersonic flow around the blunt cylinder at different Mach numbers. Identical conditions for energy deposition have been kept in the experiments, thus allowing to evaluate the pure effect of varying Mach number on the pressure drop. Euler equations are solved numerically to model the corresponding unsteady flow compressed gas. The results of numerical simulations are compared to the data obtained from the physical experiments. It is shown that the momentum, which the body receives during interaction of the gas domain modified by microwave discharge with a shock layer before the body, increases almost linearly with rising of Mach number and the efficiency of energy deposition also rises.

  15. Void formation in amorphous germanium due to high electronic energy deposition

    SciTech Connect

    Gaertner, K.; Joehrens, J.; Steinbach, T.; Schnohr, C. S.; Wesch, W.; Ridgway, M. C.

    2011-06-01

    The effect of high electronic energy deposition in amorphous germanium has been studied experimentally by Au irradiation with ion energies of up to 185 MeV and different angles of incidence and by molecular dynamics computer simulations. In both cases, the energy deposition leads to void formation accompanied by strong swelling of the amorphous germanium. The simulation results prove that the formation of the voids is mainly based on a shock wave mechanism and the swelling is determined by the competing processes of the formation and growth of voids on the one hand and the shrinking and annihilation of voids on the other hand. In full agreement between experiment and simulation, the amount of the swelling is a linear function of the total energy deposited into electronic processes and there exists a threshold value of the electronic energy loss per ion and depth for swelling. A comparison of the threshold values obtained by the experiment and the simulation suggests that approximately 20% of the energy deposited into electronic processes is converted into atomic motion.

  16. 19 CFR 351.212 - Assessment of antidumping and countervailing duties; provisional measures deposit cap; interest...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... duties; provisional measures deposit cap; interest on certain overpayments and underpayments. 351.212 Section 351.212 Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE ANTIDUMPING AND... countervailing duties; provisional measures deposit cap; interest on certain overpayments and underpayments. (a...

  17. 19 CFR 351.212 - Assessment of antidumping and countervailing duties; provisional measures deposit cap; interest...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... duties; provisional measures deposit cap; interest on certain overpayments and underpayments. 351.212 Section 351.212 Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE ANTIDUMPING AND... countervailing duties; provisional measures deposit cap; interest on certain overpayments and underpayments. (a...

  18. 19 CFR 351.212 - Assessment of antidumping and countervailing duties; provisional measures deposit cap; interest...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... duties; provisional measures deposit cap; interest on certain overpayments and underpayments. 351.212 Section 351.212 Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE ANTIDUMPING AND... countervailing duties; provisional measures deposit cap; interest on certain overpayments and underpayments. (a...

  19. 19 CFR 351.212 - Assessment of antidumping and countervailing duties; provisional measures deposit cap; interest...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... duties; provisional measures deposit cap; interest on certain overpayments and underpayments. 351.212 Section 351.212 Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE ANTIDUMPING AND... countervailing duties; provisional measures deposit cap; interest on certain overpayments and underpayments. (a...

  20. 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.

  1. 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.

  2. Nonlinear Material Response to Very Rapid Energy Deposition

    DTIC Science & Technology

    1990-03-23

    including optical windows, geophysical solids, polymers , composites, etc.) to intense impulsive loading is central to many Air Force pro- grams and...picture of dielectric breakdown at dc to optical frequencies has dramatically changed in the last five years due to the work of Fischetti, DiMaria, Cartier ...and co-workers at IBM and our group at Washington State University. Cartier et al.6 were able to measure the electron-photon scattering rates in

  3. 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.

  4. Extended bulk defects induced by low-energy ions during partially ionized beam deposition

    SciTech Connect

    Lee, W.I.; Wong, J.; Borrego, J.M.; Lu, T.

    1988-08-15

    The study of possible defects generated by low-energy ions during partially ionized beam (PIB) depositions was performed. No defects were observed when acceleration voltage was set lower than 1 kV. Surprisingly, several deep levels were detected up to the depth of 4000 A in the 3-kV sample. However, these levels can be annealed out at a relatively low temperature of 400 /sup 0/C. It is concluded in this study that, by properly choosing the ion energy range, PIB deposition will not cause severe damage to the substrate and can be a viable technique for growing heterostructures.

  5. Energy deposition in the earth's atmosphere due to impact of solar activity-generated disturbances

    NASA Technical Reports Server (NTRS)

    Wu, S. T.; Kan, L. C.; Tandberg-Hanssen, E.; Dryer, M.

    1979-01-01

    Energy deposition in and dynamic responses of the terrestrial atmosphere to solar flare-generated shocks and other physical processes - such as particle precipitation and local heating - are investigated self-consistently in the context of hydrodynamics, the problem being treated as an initial boundary-value problem. It is extremely difficult to construct a general model for the line solar activity-magnetosphere-atmosphere; however, a limited model for this link is possible. The paper describes such a model, and presents some results on energy deposition into the earth's atmosphere due to solar activity-generated disturbances. Results from the present calculations are presented and discussed.

  6. Amorphization due to electronic energy deposition in defective strontium titanate

    DOE PAGES

    Xue, Haizhou; Zarkadoula, Eva; Liu, Peng; ...

    2017-01-27

    The synergistic interaction of electronic energy loss by ions with ion-induced defects created by elastic nuclear scattering processes has been investigated for single crystal SrTiO3. An initial pre-damaged defect state corresponding to a relative disorder level of 0.10–0.15 sensitizes the SrTiO3 to amorphous track formation along the ion path of 12 and 20 MeV Ti, 21 MeV Cl and 21 MeV Ni ions, where Ti, Cl and Ni ions otherwise do not produce amorphous or damage tracks in pristine SrTiO3. The electronic stopping power threshold for amorphous ion track formation is found to be 6.7 keV/nm for the pre-damaged defectmore » state studied in this work. Lastly, these results suggest the possibility of selectively producing nanometer scale, amorphous ion tracks in thin films of epitaxial SrTiO3.« less

  7. 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...

  8. 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...

  9. Odor measurements for manure spreading using a subsurface deposition applicator.

    PubMed

    Lau, Anthony; Bittman, Shabtai; Lemus, Gladis

    2003-03-01

    Odor emissions during manure spreading events have become a source of concern, particularly where farms are located nearby urban areas. The objective of the present study was to compare odor concentrations and odor emission rates due to pig manure application using two different types of applicators, a sub-surface deposition system and a conventional splash-plate applicator. Air samples were collected using a Surface Isolation Flux Chamber and the "bag-in-vacuum chamber" techniques, at 0.5, 1.5 and 2.5 hours after manure application. A three-station forced-choice dynamic dilution olfactometer was used by an odor panel for determining odor concentration. Preliminary results indicated that with the sub-surface deposition system applicator odor emission rate was reduced by 8% to 38% compared to that of the conventional splash-plate applicator. The highest reduction in odor strength and odor emission rate was observed in the most offensive period after manure application. The sub-surface deposition system may be a solution for hog producers who wish to reduce odor complaints from applying manure without the cost and problems associated with deep injection systems.

  10. Diffusion enhancement due to low-energy ion bombardment during sputter etching and deposition

    NASA Astrophysics Data System (ADS)

    Eltoukhy, A. H.; Greene, J. E.

    1980-08-01

    The effects of low-energy ion bombardment on enhancing elemental diffusion rates at both heterojunction interfaces during film deposition and over the compositionally altered layer created during sputter etching alloy targets have been considered. Depth dependent enhanced interdiffusion coefficients, expressed as D*(x)=D*(0) exp(-x/Ld), where D*(0) is more than five orders of magnitude greater than thermal diffusion values, were measured in InSb/GaSb multilayer structures deposited by multitarget bias sputering. D*(0) was determined from the amplitude u of the compositional modulation in the multilayered films (layer thicknesses between 20 and 45 Å) as measured by superlattice x-ray diffraction techniques. The value of D*(0) was found to increase from 3×10-17 to 1×10-16 cm2/sec as the applied substrate bias was increased from 0 to -75 V. However even at Va=0, the diffusion coefficient was enhanced owing to an induced substrate potential with respect to the positive space-charge region in the Ar discharge. The diffusion length of Ld of the ion bombardment created defects was ˜1000 Å. Enhanced diffusion also has a significiant effect on the altered layer thickness xe and the total sputtering time te (or ion dose) required to reach steady state during ion etching of multielement targets. The effects of using an exponentially depth dependent versus a constant value of the enhanced diffusion coefficient on calculated values of xe and te in single-phase binary alloys were considered. The results show that both xe and te are considerably larger using a depth dependent D*(x), when Ld

  11. Pulse energy measurement at the SXR instrument

    SciTech Connect

    Moeller, Stefan; Brown, Garth; Dakovski, Georgi; Hill, Bruce; Holmes, Michael; Loos, Jennifer; Maida, Ricardo; Paiser, Ernesto; Schlotter, William; Turner, Joshua J.; Wallace, Alex; Jastrow, Ulf; Kreis, Svea; Sorokin, Andrey A.; Tiedtke, Kai

    2015-04-14

    A gas monitor detector was implemented and characterized at the Soft X-ray Research (SXR) instrument to measure the average, absolute and pulse-resolved photon flux of the LCLS beam in the energy range between 280 and 2000 eV. The detector is placed after the monochromator and addresses the need to provide reliable absolute pulse energy as well as pulse-resolved measurements for the various experiments at this instrument. This detector provides a reliable non-invasive measurement for determining flux levels on the samples in the downstream experimental chamber and for optimizing signal levels of secondary detectors and for the essential need of data normalization. The design, integration into the instrument and operation are described, and examples of its performance are given.

  12. Measurements of low energy auroral ions

    NASA Astrophysics Data System (ADS)

    Urban, A.

    1981-12-01

    Ion measurements in the energy range 0.1-30 keV observed during the 'Substorm Phenomena' and 'Porcupine' campaigns are summarized. Acceleration of the ions by an electrostatic field aligned parallel to the magnetic field is identified and found to be accompanied by intense electron precipitation. On the other hand, deceleration of the ions is observed in other field-aligned current sheets which are indicated by the electron and magnetic field measurements. Temporal successive monoenergetic ion variations suggest energy dispersion and a location of the source region at 9 earth radii. What is more, ion fluxes higher than those of the electrons are measured at pitch angles parallel to the magnetic field. It is noted that each of the examples was observed during different flights.

  13. Pulse energy measurement at the SXR instrument

    PubMed Central

    Moeller, Stefan; Brown, Garth; Dakovski, Georgi; Hill, Bruce; Holmes, Michael; Loos, Jennifer; Maida, Ricardo; Paiser, Ernesto; Schlotter, William; Turner, Joshua J.; Wallace, Alex; Jastrow, Ulf; Kreis, Svea; Sorokin, Andrey A.; Tiedtke, Kai

    2015-01-01

    A gas monitor detector was implemented and characterized at the Soft X-ray Research (SXR) instrument to measure the average, absolute and pulse-resolved photon flux of the LCLS beam in the energy range between 280 and 2000 eV. The detector is placed after the monochromator and addresses the need to provide reliable absolute pulse energy as well as pulse-resolved measurements for the various experiments at this instrument. This detector provides a reliable non-invasive measurement for determining flux levels on the samples in the downstream experimental chamber and for optimizing signal levels of secondary detectors and for the essential need of data normalization. The design, integration into the instrument and operation are described, and examples of its performance are given. PMID:25931075

  14. Pulse energy measurement at the SXR instrument

    DOE PAGES

    Moeller, Stefan; Brown, Garth; Dakovski, Georgi; ...

    2015-04-14

    A gas monitor detector was implemented and characterized at the Soft X-ray Research (SXR) instrument to measure the average, absolute and pulse-resolved photon flux of the LCLS beam in the energy range between 280 and 2000 eV. The detector is placed after the monochromator and addresses the need to provide reliable absolute pulse energy as well as pulse-resolved measurements for the various experiments at this instrument. This detector provides a reliable non-invasive measurement for determining flux levels on the samples in the downstream experimental chamber and for optimizing signal levels of secondary detectors and for the essential need of datamore » normalization. The design, integration into the instrument and operation are described, and examples of its performance are given.« less

  15. Plasma engineering of silicon quantum dots and their properties through energy deposition and chemistry.

    PubMed

    Sahu, Bibhuti Bhusan; Yin, Yongyi; Gauter, Sven; Han, Jeon Geon; Kersten, Holger

    2016-09-21

    The characterization of plasma and atomic radical parameters along with the energy influx from plasma to the substrate during plasma enhanced chemical vapor deposition (PECVD) of Si quantum dot (QD) films is presented and discussed. In particular, relating to the Si QD process optimization and control of film growth, the necessity to control the deposition environment by inducing the effect of the energy of the key plasma species is realized. In this contribution, we report dual frequency PECVD processes for the low-temperature and high-rate deposition of Si QDs by chemistry and energy control of the key plasma species. The dual frequency plasmas can effectively produce a very high plasma density and atomic H and N densities, which are found to be crucial for the growth and nucleation of QDs. Apart from the study of plasma chemistry, the crucial role of the energy imparted due to these plasma activated species on the substrate is determined in light of QD formation. Various plasma diagnostics and film analysis methods are integrated to correlate the effect of plasma and energy flux on the properties of the deposited films prepared in the reactive mixtures of SiH4/NH3 at various pressures. The present results are highly relevant to the development of the next-generation plasma process for devices that rely on effective control of the QD size and film properties.

  16. Energy intensity ratios as net energy measures of United States energy production and expenditures

    NASA Astrophysics Data System (ADS)

    King, C. W.

    2010-10-01

    In this letter I compare two measures of energy quality, energy return on energy invested (EROI) and energy intensity ratio (EIR) for the fossil fuel consumption and production of the United States. All other characteristics being equal, a fuel or energy system with a higher EROI or EIR is of better quality because more energy is provided to society. I define and calculate the EIR for oil, natural gas, coal, and electricity as measures of the energy intensity (units of energy divided by money) of the energy resource relative to the energy intensity of the overall economy. EIR measures based upon various unit prices for energy (e.g. /Btu of a barrel of oil) as well as total expenditures on energy supplies (e.g. total dollars spent on petroleum) indicate net energy at different points in the supply chain of the overall energy system. The results indicate that EIR is an easily calculated and effective proxy for EROI for US oil, gas, coal, and electricity. The EIR correlates well with previous EROI calculations, but adds additional information on energy resource quality within the supply chain. Furthermore, the EIR and EROI of oil and gas as well as coal were all in decline for two time periods within the last 40 years, and both time periods preceded economic recessions.

  17. 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

  18. 10 CFR 436.104 - Energy conservation measures and standards.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Energy conservation measures and standards. 436.104 Section 436.104 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION FEDERAL ENERGY MANAGEMENT AND PLANNING PROGRAMS Guidelines for General Operations Plans § 436.104 Energy conservation measures and standards....

  19. 10 CFR 436.104 - Energy conservation measures and standards.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Energy conservation measures and standards. 436.104 Section 436.104 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION FEDERAL ENERGY MANAGEMENT AND PLANNING PROGRAMS Guidelines for General Operations Plans § 436.104 Energy conservation measures and standards....

  20. 10 CFR 436.104 - Energy conservation measures and standards.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Energy conservation measures and standards. 436.104 Section 436.104 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION FEDERAL ENERGY MANAGEMENT AND PLANNING PROGRAMS Guidelines for General Operations Plans § 436.104 Energy conservation measures and standards....

  1. 10 CFR 436.104 - Energy conservation measures and standards.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Energy conservation measures and standards. 436.104 Section 436.104 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION FEDERAL ENERGY MANAGEMENT AND PLANNING PROGRAMS Guidelines for General Operations Plans § 436.104 Energy conservation measures and standards....

  2. 10 CFR 436.104 - Energy conservation measures and standards.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Energy conservation measures and standards. 436.104 Section 436.104 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION FEDERAL ENERGY MANAGEMENT AND PLANNING PROGRAMS Guidelines for General Operations Plans § 436.104 Energy conservation measures and standards....

  3. Hiking down the energy landscape: progress toward the Kauzmann temperature via vapor deposition.

    PubMed

    Kearns, Kenneth L; Swallen, Stephen F; Ediger, M D; Wu, Tian; Sun, Ye; Yu, Lian

    2008-04-24

    Physical vapor deposition was employed to prepare amorphous samples of indomethacin and 1,3,5-(tris)naphthylbenzene. By depositing onto substrates held somewhat below the glass transition temperature and varying the deposition rate from 15 to 0.2 nm/s, glasses with low enthalpies and exceptional kinetic stability were prepared. Glasses with fictive temperatures that are as much as 40 K lower than those prepared by cooling the liquid can be made by vapor deposition. As compared to an ordinary glass, the most stable vapor-deposited samples moved about 40% toward the bottom of the potential energy landscape for amorphous materials. These results support the hypothesis that enhanced surface mobility allows stable glass formation by vapor deposition. A comparison of the enthalpy content of vapor-deposited glasses with aged glasses was used to evaluate the difference between bulk and surface dynamics for indomethacin; the dynamics in the top few nanometers of the glass are about 7 orders of magnitude faster than those in the bulk at Tg - 20 K.

  4. Strain and Cohesive Energy of TiN Deposit on Al(001) Surface: Density Functional Calculation

    NASA Astrophysics Data System (ADS)

    Ren, Yuan; Liu, Xuejie

    2016-07-01

    To apply the high hardness of TiN film to soft and hard multilayer composite sheets, we constructed a new type of composite structural material with ultra-high strength. The strain of crystal and cohesive energy between the atoms in the eight structures of N atom, Ti atom, 2N2Ti island and TiN rock salt deposited on the Al(001) surface were calculated with the first-principle ultra-soft pseudopotential approach of the plane wave based on the density functional theory. The calculations of the cohesive energy showed that N atoms could be deposited in the face-centered-cubic vacancy position of the Al(001) surface and results in a cubic structure AlN surface. The TiN film could be deposited on the interface of β-AlN. The calculations of the strains showed that the strain in the TiN film deposited on the Al(001) surface was less than that in the 2N2Ti island deposited on the Al(001) surface. The diffusion behavior of interface atom N was investigated by a nudged elastic band method. Diffusion energy calculation showed that the N atom hardly diffused to the substrate Al layer.

  5. Energy gaps measured by scanning tunneling microscopy

    NASA Astrophysics Data System (ADS)

    Wang, Chen; Giambattista, B.; Slough, C. G.; Coleman, R. V.; Subramanian, M. A.

    1990-11-01

    A scanning tunneling microscope (STM) has been used to measure energy gaps in the charge-density-wave (CDW) phases of the layer-structure dichalcogenides and in the high-temperature superconductor Bi2Sr2CaCu2O8. Measured values of ΔCDW at 4.2 K for 2H-TaSe2, 2H-TaS2, and 2H-NbSe2 are 80, 50, and 34 meV giving values of 2ΔCDW/kBTc equal to 15.2, 15.4, and 23.9, indicating strong coupling in these CDW systems. Measured values of ΔCDW at 4.2 K in 1T-TaSe2 and 1T-TaS2 are ~150 meV for both materials giving 2ΔCDW/kBTc~=5.8. STM scans of Bi2Sr2CaCu2O8 at 4.2 K resolve atoms on the BiOx layer and show possible variations in electronic structure. The energy gap determined from I versus V and dI/dV versus V curves is in the range 30-35 meV giving values of 2Δ/kBTc~=8. Spectroscopy measurements with the STM can exhibit large zero-bias anomalies which complicate the analysis of the energy-gap structure, but adequate separation has been accomplished.

  6. 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.

  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. Energy Deposition and Shielding Study of the Front End for the Neutrino Factory

    SciTech Connect

    Snopok, Pavel; Neuffer, David; Rogers, Chris

    2013-06-01

    In the Neutrino Factory and Muon Collider muons are produced by firing high energy protons onto a target to produce pions. The pions decay to muons which are then accelerated. This method of pion production results in significant background from protons and electrons, which may result in heat deposition on superconducting materials and activation of the machine preventing manual handling. In this paper we discuss the design of a secondary particle handling system. The system comprises a solenoidal chicane that filters high momentum particles, followed by a proton absorber that reduces the energy of all particles, resulting in the rejection of low energy protons that pass through the solenoid chicane. We detail the design and optimization of the system and energy deposition and shielding analysis in MARS15.

  9. Energy deposition through radiative processes in absorbers irradiated by electron beams

    NASA Astrophysics Data System (ADS)

    Tatsuo, Tabata; Pedro, Andreo; Kunihiko, Shinoda; Rinsuke, Ito

    1994-09-01

    The component of energy deposition due to radiative processes (bremsstrahlung component) in absorbers irradiated by electron beams has been computed together with the total energy deposition by using the ITS Monte Carlo system version 3.0. Plane-parallel electron beams with energies from 0.1 to 100 MeV have been assumed to be incident normally on the slab absorber, whose thickness is 2.5 times the continuous slowing-down approximation (csda) range of the incident electrons. Absorber materials considered are elemental solids with atomic numbers between 4 and 92 (Be, C, Al, Cu, Ag, Au and U). An analytic formula is given to express the depth profile of the bremsstrahlung component as a function of scaled depth (depth in units of the csda range), incident-electron energy and absorber atomic number. It is also applicable to compounds.

  10. 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.

  11. Energy bandgap variation in oblique angle-deposited indium tin oxide

    SciTech Connect

    Kim, Kyurin; Kim, Hyunsoo; Cho, Jaehee; Park, Jun Hyuk; Kim, Jong Kyu; Fred Schubert, E.

    2016-01-25

    Indium tin oxide (ITO) thin films deposited using the oblique angle deposition (OAD) technique exhibit a strong correlation between structural and optical properties, especially the optical bandgap energy. The microstructural properties of ITO thin films are strongly influenced by the tilt angle used during the OAD process. When changing the tilt angle, the refractive index, porosity, and optical bandgap energy of ITO films also change due to the existence of a preferential growth direction at the interface between ITO and the substrate. Experiments reveal that the ITO film's optical bandgap varies from 3.98 eV (at normal incident deposition) to 3.87 eV (at a 60° tilt angle)

  12. 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.

  13. Reduced energy bandgap of a-Si:H films deposited by PECVD at elevating temperatures

    NASA Astrophysics Data System (ADS)

    Cahyono, Yoyok; Maslakah, Umi; Muttaqin, Fuad Darul; Darminto

    2017-01-01

    The hydrogenated amorphous silicon (a-Si:H) films with the thickness of several hundreds nanometer have successfully been grown on the glass substrates by plasma enhanced (PE) chemical vapor deposition (CVD), employing SiH4 gas with H2 dilution. The deposition temperatures being set from 150°C up to 250°C was intended to induce nanocrystalline clusters in the amorphous structure, to reduce dangling bond and to recover defect states in the gap, in order to obtain films with reduced energy band gap. The X-ray diffractometry, UV-Vis spectrometric and atomic force microscopic examinations were conducted to structurally study the samples. The reduction of energy bandgap from 1.89 eV down to 1.03 eV was obtained from the deposited films.

  14. HETDEX: Measuring Dark Energy at High Redshift

    NASA Astrophysics Data System (ADS)

    Gebhardt, Karl; Hill, G.; Komatsu, E.; Drory, N.; DePoy, D.; Ciardullo, R.; Gronwall, C.; Fabricius, M.; Wisotzki, L.; HETDEX Collaboration

    2012-01-01

    The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) is a blind spectroscopic survey to map the evolution of dark energy using Lyman-alpha emitting galaxies as tracers. The survey instrument, VIRUS, consists of 75 IFUs distributed across the 22-arcmin field of the upgraded 9.2-m HET. Each 50x50 sq. arcsec IFU is made up of 448 1.5-arcsec fibers, and feeds a pair of spectrographs with a fixed bandpass of 350-550 nm and resolving power R 700. Each exposure gathers 33,600 spectra. The baseline survey will deliver spectra of 0.8M LAEs in a 9 cubic Gpc volume with 1.9 < z < 3.5, and 1M [OII] emitters with z < 0.48. We expect to measure both the Hubble parameter and angular diameter distance to better than 1%. HETDEX will provide a unique window on the evolution of dark energy.

  15. Energy harvesting in high voltage measuring techniques

    NASA Astrophysics Data System (ADS)

    Żyłka, Pawel; Doliński, Marcin

    2016-02-01

    The paper discusses selected problems related to application of energy harvesting (that is, generating electricity from surplus energy present in the environment) to supply autonomous ultra-low-power measurement systems applicable in high voltage engineering. As a practical example of such implementation a laboratory model of a remote temperature sensor is presented, which is self-powered by heat generated in a current-carrying busbar in HV- switchgear. Presented system exploits a thermoelectric harvester based on a passively cooled Peltier module supplying micro-power low-voltage dc-dc converter driving energy-efficient temperature sensor, microcontroller and a fibre-optic transmitter. Performance of the model in laboratory simulated conditions are presented and discussed.

  16. NEMVP: North American energy measurement and verification protocol

    SciTech Connect

    1996-03-01

    This measurement and verification protocol discusses procedures that,when implemented, allow buyers, sellers, and financiers of energy projects to quantify energy conservation measure performance and savings.

  17. Effects of acidic deposition and other energy emissions on wildlife: a compendium

    SciTech Connect

    Newman, J.R.; Schreiber, R.K.

    1985-10-01

    Energy emissions, including acidic depositions, pose potential problems for wildlife populations. Historical and recent events show both direct, acute effects and indirect, chronic effects from a variety of airborne pollutants. Information on effects of selected gaseous and particulate energy emissions on domestic animals and livestock and on wildlife is compared. Our understanding of wildlife effects can be improved by the evaluation of veterinary toxicological information and research on the ecological equivalents of domestic and laboratory animals. 42 references.

  18. Neutron Energy Measurements in Emergency Response Applications

    SciTech Connect

    Sanjoy Mukhopadhyay, Paul Guss, Michael Hornish, Scott Wilde, Tom Stampahar, Michael Reed

    2009-09-11

    We present significant results in recent advances in the measurement of neutron energy. Neutron energy measurements are a small but significant part of radiological emergency response applications. Mission critical information can be obtained by analyzing the neutron energy given off from radioactive materials. In the case of searching for special nuclear materials, neutron energy information from an unknown source can be of importance. At the Remote Sensing Laboratory (RSL) of National Security Technologies, LLC, a series of materials, viz., liquid organic scintillator (LOS), Lithium Gadolinium Borate (LGB) or Li6Gd(BO3)3 in a plastic matrix, a recently developed crystal of Cesium Lithium Yttrium Chloride, Cs2LiYCl6: Ce (called CLYC)[1], and normal plastic scintillator (BC-408) with 3He tubes have been used to study their effectiveness as a portable neutron energy spectrometer. Comparisons illustrating the strengths of the various materials will be provided. Of these materials, LGB offers the ability to tailor its response to the neutron spectrum by varying the isotopic composition of the key constituents (Lithium, Gadolinium [Yttrium], and Boron). All three of the constituent elements possess large neutron capture cross section isotopes for highly exothermic reactions. These compounds of composition Li6Gd(Y)(BO3)3 can be activated by Cerium ions Ce3+. CLYC, on the other hand, has a remarkable gamma response in addition to superb neutron discrimination, comparable to that of Europium-doped Lithium Iodide (6LiI: Eu). Comparing these two materials, CLYC has higher light output (4500 phe/MeV) than that from 6LiI: Eu and shows better energy resolution for both gamma and neutron pulse heights. Using CLYC, gamma energy pulses can be discriminated from the neutron signals by simple pulse height separation. For the cases of both LGB and LOS, careful pulse shape discrimination is needed to separate the gamma energy signals from neutron pulses. Both analog and digital

  19. Neutron energy measurements in emergency response applications

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Sanjoy; Guss, Paul; Hornish, Michael; Wilde, Scott; Stampahar, Tom; Reed, Michael

    2009-08-01

    We present significant results in recent advances in the measurement of neutron energy. Neutron energy measurements are a small but significant part of radiological emergency response applications. Mission critical information can be obtained by analyzing the neutron energy given off from radioactive materials. In the case of searching for special nuclear materials, neutron energy information from an unknown source can be of importance. At the Remote Sensing Laboratory (RSL) of National Security Technologies, LLC, a series of materials, viz., liquid organic scintillator (LOS), Lithium Gadolinium Borate (LGB) or Li6Gd(BO3)3 in a plastic matrix, a recently developed crystal of Cesium Lithium Yttrium Chloride, Cs2LiYCl6: Ce (called CLYC)[1], and normal plastic scintillator (BC-408) with 3He tubes have been used to study their effectiveness as a portable neutron energy spectrometer. Comparisons illustrating the strengths of the various materials will be provided. Of these materials, LGB offers the ability to tailor its response to the neutron spectrum by varying the isotopic composition of the key constituents (Lithium, Gadolinium [Yttrium], and Boron). All three of the constituent elements possess large neutron capture cross section isotopes for highly exothermic reactions. These compounds of composition Li6Gd(Y)(BO3)3 can be activated by Cerium ions Ce3+. CLYC, on the other hand, has a remarkable gamma response in addition to superb neutron discrimination, comparable to that of Europium-doped Lithium Iodide (6LiI: Eu). Comparing these two materials, CLYC has higher light output (4500 phe/MeV) than that from 6LiI: Eu and shows better energy resolution for both gamma and neutron pulse heights. Using CLYC, gamma energy pulses can be discriminated from the neutron signals by simple pulse height separation. For the cases of both LGB and LOS, careful pulse shape discrimination is needed to separate the gamma energy signals from neutron pulses. Both analog and digital

  20. Recent Development of Advanced Electrode Materials by Atomic Layer Deposition for Electrochemical Energy Storage.

    PubMed

    Guan, Cao; Wang, John

    2016-10-01

    Electrode materials play a decisive role in almost all electrochemical energy storage devices, determining their overall performance. Proper selection, design and fabrication of electrode materials have thus been regarded as one of the most critical steps in achieving high electrochemical energy storage performance. As an advanced nanotechnology for thin films and surfaces with conformal interfacial features and well controllable deposition thickness, atomic layer deposition (ALD) has been successfully developed for deposition and surface modification of electrode materials, where there are considerable issues of interfacial and surface chemistry at atomic and nanometer scale. In addition, ALD has shown great potential in construction of novel nanostructured active materials that otherwise can be hardly obtained by other processing techniques, such as those solution-based processing and chemical vapor deposition (CVD) techniques. This review focuses on the recent development of ALD for the design and delivery of advanced electrode materials in electrochemical energy storage devices, where typical examples will be highlighted and analyzed, and the merits and challenges of ALD for applications in energy storage will also be discussed.

  1. 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.

  2. Recent Development of Advanced Electrode Materials by Atomic Layer Deposition for Electrochemical Energy Storage

    PubMed Central

    2016-01-01

    Electrode materials play a decisive role in almost all electrochemical energy storage devices, determining their overall performance. Proper selection, design and fabrication of electrode materials have thus been regarded as one of the most critical steps in achieving high electrochemical energy storage performance. As an advanced nanotechnology for thin films and surfaces with conformal interfacial features and well controllable deposition thickness, atomic layer deposition (ALD) has been successfully developed for deposition and surface modification of electrode materials, where there are considerable issues of interfacial and surface chemistry at atomic and nanometer scale. In addition, ALD has shown great potential in construction of novel nanostructured active materials that otherwise can be hardly obtained by other processing techniques, such as those solution‐based processing and chemical vapor deposition (CVD) techniques. This review focuses on the recent development of ALD for the design and delivery of advanced electrode materials in electrochemical energy storage devices, where typical examples will be highlighted and analyzed, and the merits and challenges of ALD for applications in energy storage will also be discussed. PMID:27840793

  3. Atmospheric Breakup and Energy Deposition Modeling for Asteroid Impact Risk Assessmen

    NASA Astrophysics Data System (ADS)

    Wheeler, L.; Mathias, D.

    2016-12-01

    The Asteroid Threat Assessment Project (ATAP) team at NASA Ames Research Center is developing physics-based models to assess the risk posed by potential asteroid strikes on Earth. As part of this effort, an analytic asteroid fragmentation model has been developed to model the atmospheric energy deposition of asteroids with a range of compositional properties and entry conditions. The resulting energy deposition profiles are used to estimate airburst altitudes and blast overpressure damage on the ground. The model approach combines successive fragmentation of larger independent pieces with the release of aggregate clouds of debris. A wide range of potential breakup behaviors can be assessed by varying the number and masses of fragments produced, the fraction of mass released as debris clouds, and the size-strength scaling used to increase the durability of smaller fragments. The initial asteroid body can also be seeded with a distribution of independent fragment sizes and remaining debris mass to represent a variety of structural types, from rubble piles to coherent monoliths. The model is able to reproduce key energy deposition features, such as multiple flares, high-altitude regolith blow-off, or initial disruption of loosely bound conglomerations followed by more energetic breakup of the constituent boulders. These capabilities provide a means to investigate sensitivities of energy deposition to potential variations in asteroid structure, while also maintaining a level of fidelity appropriate for the large numbers of cases needed for statistical risk assessment.

  4. Energy deposition in scintillation detectors and the triggers formation in the GAMMA-400 experiment

    NASA Astrophysics Data System (ADS)

    Arkhangelskaja, Irene; Yurkin, Yuri T.; Arkhangelsky, Andrey; Topchiev, Nikolay; Kheymits, Maxim; Chasovikov, Evgeniy; Galper, Arkady; Chistyakov, Pavel

    In this paper, some details of the GAMMA-400 trigger system construction are presented. The comparison between relativistic electron, proton, and gamma-ray energy deposition is described and methods of on-board triggers and trigger markers formation for discrimination between each of other are proposed.

  5. Experimental Measurement of Low Energy Neutrino Interactions

    SciTech Connect

    Scholberg, Kate

    2011-11-23

    Neutrino interactions in the few to few tens of MeV range are of importance for several physics topics, including solar, supernova and reactor neutrinos, as well as future proposed oscillation and Standard Model test experiments. Although interaction cross-sections for some simple targets are well understood, very little experimental data exist for interactions with nuclei. This talk will discuss the motivation for measuring low energy neutrino interactions, the state of knowledge, and possible future strategies.

  6. Collective flow measurements at RHIC energies

    NASA Astrophysics Data System (ADS)

    Esumi, Shinichi

    2017-04-01

    Recent experimental results on collective flow measurements from relativistic heavy-ion collider (RHIC) are presented and discussed to study high-temperature and high-density quark-nuclear matter, Quark Gluon Plasma (QGP) especially focusing on bulk properties, such as freeze-out parameters, temperature, chemical potential, collective expansion, azimuthal event anisotropy measurements. Their relations to the various correlation and fluctuation studies are also discussed, including initial geometrical and E- and B-field conditions as well as possible collective flow evolution that could even be developed in small systems. Current results and understandings from the beam energy scan program (BES) and future plans are discussed and reviewed.

  7. 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)

  8. Methods for measuring atmospheric nitrogen deposition inputs in arid and montane ecosystems of western North America

    Treesearch

    M.E. Fenn; J.O. Sickman; A. Bytnerowicz; D.W. Clow; N.P. Molotch; J.E. Pleim; G.S. Tonnesen; K.C. Weathers; P.E. Padgett; D.H. Campbell.

    2009-01-01

    Measuring atmospheric deposition in arid and snow-dominated regions presents unique challenges. Throughfall, the flux of nutrients transported in solution to the forest floor, is generally the most practical method of estimating below-canopy deposition, particularly when monitoring multiple forest sites or over multiple years. However, more studies are needed to relate...

  9. 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...

  10. Gravity measurements useful in the preliminary evaluation of the Nimiuktuk barite deposit, Alaska.

    USGS Publications Warehouse

    Barnes, D.F.; Mayfield, C.F.; Morin, R.L.; Brynn, S.

    1982-01-01

    Measurements taken in 1979 are used to assess the Nimiuktuk deposit; combined models suggest that the orebody contains a total mass of >1.5M metric tons of high-grade barite. The anomaly associated with Nimiuktuk suggests that gravity exploration could locate other massive deposits.-after Authors

  11. 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...

  12. Gravimetric measurements with use of a cantilever for controlling of electrochemical deposition processes

    NASA Astrophysics Data System (ADS)

    Prokaryn, Piotr; Janus, Pawel; Zajac, Jerzy; Sierakowski, Andrzej; Domanski, Krzysztof; Grabiec, Piotr

    2016-11-01

    In this paper we describe the method for monitoring the progress of electrochemical deposition process. The procedure allows to control the deposition of metals as well as conductive polymers on metallic seed layer. The method is particularly useful to very thin layers (1-10 nm) of deposited medium which mechanical or optical methods are troublesome for. In this method deposit is grown on the target and on the test silicon micro-cantilever with a metal pad. Galvanic deposition on the cantilever causes the change of its mass and consequently the change of its resonance frequency. Changes of the frequency is measured with laser vibro-meter then the layer thicknesses can be estimated basing on the cantilever calibration curve. Applying this method for controlling of gold deposition on platinum seed layer, for improving the properties of the biochemical sensors, is described in this paper.

  13. Measurements of Cloud Droplet Size and Fog Water Deposition

    NASA Astrophysics Data System (ADS)

    Fernandez, D.; Lee, T.; Torregrosa, A.; Underwood, J.; Andersen, D.

    2013-12-01

    The size of cloud droplets is a factor in the variability of coastal low clouds and fog. The relationship between cloud droplet size and volume of fog water collected as a function of position over land may provide useful information for fog related mechanisms such as water deposition via fog drip, aerosol scavenging, and cloud top radiation flux. We derive landscape-level estimates of cloud top droplet size through the application of a three channel-based algorithm on geostationary operational environmental satellite (GOES) data. The result retrieves cloud top droplet size, cloud top temperature, cloud optical depth, emissivity, and cloud top height. Comparable information on droplet size has been used for years in ocean experiments accompanied by observations from ships and aircraft, but it has not been explored for use in coastal environments. Retrievals are still experimental and are confined to daytime hours of about 1000 - 1600 hours local time. We are exploring the use of cloud-top GOES derived droplet size data to better understand fog water deposition along the central California coast through comparative analysis with 1) ground-based volumetric fog water data collected from several 1.00 square meter fog collectors deployed in Marina, CA and active fog water samplers inland at Pepperwood Preserve ; 2) droplet size distributions (between 2 - 50 μm) sampled with an optical spectrometer along a coast to inland transect, and 3) trajectory swaths from the three cloud-aerosol LIDAR instrument system (CALIPSO) coincident in location with #1 and #2. Satellite-derived coastal drop size data show large droplet size at the coast and smaller droplet sizes inland. The data observed may provide information on the relationship between the fog droplet diameter and the volume of fog water collected as a function of location from the coast.

  14. 76 FR 74050 - Measured Building Energy Performance Data Taxonomy

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-30

    ... Office of Energy Efficiency and Renewable Energy Measured Building Energy Performance Data Taxonomy... related to a measured building energy performance data taxonomy. DOE has created this measured building energy performance data taxonomy as part of its DOE Buildings Performance Database project. This...

  15. Energy harvesting based on piezoelectric AlN and AlScN thin films deposited by high rate sputtering

    NASA Astrophysics Data System (ADS)

    Frach, Peter; Barth, Stephan; Bartzsch, Hagen; Gloess, Daniel

    2017-05-01

    Aluminum nitride (AlN) is a piezoelectric material often used as thin film in SAW/BAW devices. Furthermore, there is an increasing interest in its use for energy harvesting applications. Despite it has a relatively low piezoelectric coefficient, it is a suitable choice for energy harvesting applications and due to its low dielectric constant and good mechanical properties. In addition, it is a lead-free material. The films were deposited by reactive pulsed magnetron sputtering using the Double Ring Magnetron DRM 400. This sputter source together with suitable powering and process control allows depositing piezoelectric AlN very homogeneously on 8" substrates with deposition rates of up to 200 nm/min. With the developed technology, film thicknesses of several ten microns are technically and economically feasible. Moreover, by adjusting process parameters accordingly, it is possible to tune properties, like film stress, to application specific requirements. Additionally, it is known that the doping of AlN with Scandium results in a significantly increased piezoelectric coefficient. The influence of process parameters and Sc concentration on film properties were determined by piezometer, pulse echo, SEM, XRD, EDS and nanoindentation measurements. Energy harvesting measurements were done using an electromechanical shaker system for the excitation of defined vibrations and a laservibrometer for determination of the displacement of the samples. The generated power was measured as function of electric load at resonance. An rms power of up to 140μW using AlN films and of 350μW using AlScN films was generated on Si test pieces of 8x80mm2. Furthermore, energy harvesting measurements using manually bended steel strips of 75x25mm2 coated with AlScN were carried out as well. When using only a single actuation, energy of up to 8μJ could be measured. By letting the system vibrate freely, the damped vibration at resonance 50Hz resulted in a measured energy of 420μJ.

  16. Kinetic-energy induced smoothening and delay of epitaxial breakdown in pulsed-laser deposition

    SciTech Connect

    Shin, Byungha; Aziz, Michael J.

    2007-08-15

    We have isolated the effect of kinetic energy of depositing species from the effect of flux pulsing during pulsed-laser deposition (PLD) on surface morphology evolution of Ge(001) homoepitaxy at low temperature (100 deg. C). Using a dual molecular beam epitaxy (MBE) PLD chamber, we compare morphology evolution from three different growth methods under identical experimental conditions except for the differing nature of the depositing flux: (a) PLD with average kinetic energy 300 eV (PLD-KE); (b) PLD with suppressed kinetic energy comparable to thermal evaporation energy (PLD-TH); and (c) MBE. The thicknesses at which epitaxial breakdown occurs are ranked in the order PLD-KE>MBE>PLD-TH; additionally, the surface is smoother in PLD-KE than in MBE. The surface roughness of the films grown by PLD-TH cannot be compared due to the early epitaxial breakdown. These results demonstrate convincingly that kinetic energy is more important than flux pulsing in the enhancement of epitaxial growth, i.e., the reduction in roughness and the delay of epitaxial breakdown.

  17. Fast electron energy deposition in a magnetized plasma: Kinetic theory and particle-in-cell simulation

    SciTech Connect

    Robiche, J.; Rax, J.-M.; Bonnaud, G.; Gremillet, L.

    2010-03-15

    The collisional dynamics of a relativistic electron jet in a magnetized plasma are investigated within the framework of kinetic theory. The relativistic Fokker-Planck equation describing slowing down, pitch angle scattering, and cyclotron rotation is derived and solved. Based on the solution of this Fokker-Planck equation, an analytical formula for the root mean square spot size transverse to the magnetic field is derived and this result predicts a reduction in radial transport. Some comparisons with particle-in-cell simulation are made and confirm striking agreement between the theory and the simulation. For fast electron with 1 MeV typical kinetic energy interacting with a solid density hydrogen plasma, the energy deposition density in the transverse direction increases by a factor 2 for magnetic field of the order of 1 T. Along the magnetic field, the energy deposition profile is unaltered compared with the field-free case.

  18. 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.

  19. 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

  20. 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.

  1. Direct measurements of atmospheric iron, cobalt, and aluminum-derived dust deposition at Kerguelen Islands

    NASA Astrophysics Data System (ADS)

    Heimburger, A.; Losno, R.; Triquet, S.; Dulac, F.; Mahowald, N.

    2012-12-01

    Atmospheric deposition is one of the major sources of nutrients bringing trace metals to remote marine biota. In this study, total atmospheric deposition and crustal aerosol concentrations were monitored at Kerguelen Islands (49°18'S; 70°07'E) in the Southern Ocean during a short campaign in early 2005 and then continuously for about 2 years (2009-2010). Results show very low levels of atmospheric dust and trace metals concentrations but higher deposition fluxes than expected. The averaged total dust deposition flux as derived from Al deposition measurements is 659 μg m-2 d-1. Simultaneously measured Fe and Co deposition fluxes are respectively 29 μg m-2 d-1 (520 nmol m-2 d-1) and 0.014 μg m-2 d-1 (0.24 nmol m-2 d-1), giving typically crustal elemental ratios to Al of 0.54 and 2.6 10-4. Measured dust deposition is in relatively good agreement with those simulated by current atmospheric models, but suggest that previous indirect calculations from field experiments are too low by a factor of 20. Observations and model results show that dust is transported above the marine atmospheric boundary layer to Kerguelen Islands, and thus that surface concentrations are not representative of the total dust column. Indeed, using surface concentrations leads to very large computed wet scavenging ratios, and to the conclusion that it is not appropriate to derive deposition fluxes from surface concentrations at remote ocean sites.

  2. Energy gaps measured by scanning tunneling microscopy

    SciTech Connect

    Wang, C.; Giambattista, B.; Slough, C.G.; Coleman, R.V. ); Subramanian, M.A. )

    1990-11-15

    A scanning tunneling microscope (STM) has been used to measure energy gaps in the charge-density-wave (CDW) phases of the layer-structure dichalcogenides and in the high-temperature superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8}. Measured values of {Delta}{sub CDW} at 4.2 K for 2{ital H}-TaSe{sub 2}, 2{ital H}-TaS{sub 2}, and 2{ital H}-NbSe{sub 2} are 80, 50, and 34 meV giving values of 2{Delta}{sub CDW}/{ital k}{sub {ital B}T{ital c}} equal to 15.2, 15.4, and 23.9, indicating strong coupling in these CDW systems. Measured values of {Delta}{sub CDW} at 4.2 K in 1{ital T}-TaSe{sub 2} and 1{ital T}-TaS{sub 2} are {approximately}150 meV for both materials giving 2{Delta}{sub CDW}/{ital k}{sub {ital B}T{ital c}}{approx}5.8. STM scans of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} at 4.2 K resolve atoms on the BiO{sub {ital x}} layer and show possible variations in electronic structure. The energy gap determined from {ital I} versus {ital V} and {ital dI}/{ital dV} versus {ital V} curves is in the range 30--35 meV giving values of 2{Delta}/{ital k}{sub {ital B}T{ital c}}{approx}8. Spectroscopy measurements with the STM can exhibit large zero-bias anomalies which complicate the analysis of the energy-gap structure, but adequate separation has been accomplished.

  3. Precision energy measurement using the MAJORANA DEMONSTRATOR

    NASA Astrophysics Data System (ADS)

    Guinn, Ian

    2016-09-01

    The MAJORANA DEMONSTRATOR is seeking neutrinoless double beta decay (0 νββ) in 76Ge. The 0 νββ signal consists of a peak in a 4 keV region of interest (ROI) at the 76Ge double-beta decay Q-value of 2039 keV. The DEMONSTRATOR will consist of an array of high purity germanium (HPGe) detectors with a P-type point contact (PPC) geometry. The experiment's goal is to reduce the background in the ROI to < 3 counts/ROI-tonne-yr. Precise calculation of the energy of each event can help to shrink the size of the ROI, thus reducing the background counts. A precise measurement of the response function of the detectors is important for calculating the ROI and controlling systematic errors on the limits produced. This presentation will describe the measurement of the response function using calibration data, along with several techniques used to improve the energy calculations, such as correcting for charge trapping in detectors and digitizer non-linearities. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics Program of the National Science Foundation, and the Sanford Underground Research Facility.

  4. Modeling reaction pathways of low energy particle deposition on thiophene via ab initio calculations

    NASA Astrophysics Data System (ADS)

    Crenshaw, Jasmine D.; Phillpot, Simon R.; Iordanova, Nedialka; Sinnott, Susan B.

    2011-07-01

    Chemical reactions of thiophene with organic molecules are of interest to modify thermally deposited coatings of conductive polymers. Here, energy barriers for reactions involving thiophene and small hydrocarbon radicals are identified. Enthalpies of formation involving reactants are also calculated using the B3LYP, BMK, and B98 hybrid functionals within the G AUSSIAN03 program. Experimental values, G3, and CBS-QB3 calculations are used as standards, due to their accurate thermochemistry parameters. The BMK functional is found to perform best for the selected organic molecules. These results provide insights into the reactivity of several polymerization and deposition processes.

  5. Lime-mud layers in high-energy tidal channels: A record of hurricane deposition

    USGS Publications Warehouse

    Shinn, E.A.; Steinen, R.P.; Dill, R.F.; Major, R.

    1993-01-01

    During or immediately following the transit of Hurricane Andrew (August 23-24, 1992) across the northern part of the Great Bahama Bank, thin laminated beds of carbonate mud were deposited in high-energy subtidal channels (4 m depth) through the ooid shoals of south Cat Cay and Joulters Cays. Thicker, more cohesive (and therefore older) mud beds and angular mud fragments associated with ooids from Joulters Cays have similar characteristics but lack fresh plant fragments. We infer that these older beds were similarly deposited and thus record the passage of previous hurricanes or tropical storms. -from Authors

  6. Cell to Cell Variability of Radiation-Induced Foci: Relation between Observed Damage and Energy Deposition.

    PubMed

    Gruel, Gaëtan; Villagrasa, Carmen; Voisin, Pascale; Clairand, Isabelle; Benderitter, Marc; Bottollier-Depois, Jean-François; Barquinero, Joan Francesc

    2016-01-01

    Most studies that aim to understand the interactions between different types of photon radiation and cellular DNA assume homogeneous cell irradiation, with all cells receiving the same amount of energy. The level of DNA damage is therefore generally determined by averaging it over the entire population of exposed cells. However, evaluating the molecular consequences of a stochastic phenomenon such as energy deposition of ionizing radiation by measuring only an average effect may not be sufficient for understanding some aspects of the cellular response to this radiation. The variance among the cells associated with this average effect may also be important for the behaviour of irradiated tissue. In this study, we accurately estimated the distribution of the number of radiation-induced γH2AX foci (RIF) per cell nucleus in a large population of endothelial cells exposed to 3 macroscopic doses of gamma rays from 60Co. The number of RIF varied significantly and reproducibly from cell to cell, with its relative standard deviation ranging from 36% to 18% depending on the macroscopic dose delivered. Interestingly, this relative cell-to-cell variability increased as the dose decreased, contrary to the mean RIF count per cell. This result shows that the dose effect, in terms of the number of DNA lesions indicated by RIF is not as simple as a purely proportional relation in which relative SD is constant with dose. To analyse the origins of this observed variability, we calculated the spread of the specific energy distribution for the different target volumes and subvolumes in which RIF can be generated. Variances, standard deviations and relative standard deviations all changed similarly from dose to dose for biological and calculated microdosimetric values. This similarity is an important argument that supports the hypothesis of the conservation of the association between the number of RIF per nucleus and the specific energy per DNA molecule. This comparison allowed us to

  7. Assessing Locations of Energy Transfer/Deposit in the Ionosphere-Thermosphere System

    NASA Astrophysics Data System (ADS)

    Tu, J.; Song, P.

    2014-12-01

    It has long been believed that most of energy transferred from the magnetosphere and deposited in the ionosphere-thermosphere system occurs in the auroral zone, the region of strong field-aligned current density. Recent observations of the Poynting flux to the ionosphere and theoretical investigations of the magnetosphere-ionosphere coupling show that the strongest energy transfer may be in the polar cap proper where the plasma flow speed is high and not where the flow reverses. This implies that the field-aligned current is not the primary agent of the energy transfer into the ionosphere-thermosphere system and that other physical progresses are at play. Recent simulation studies using an inductive-dynamic approach (including self-consistent solutions of Faraday's law and retaining inertia terms in the ion momentum equations) on the magnetosphere-ionosphere-thermosphere coupling indicate that the energy transfer is through Alfven waves propagating to the ionosphere/thermosphere and the energy deposition is via the frictional heating caused by relative motion between ions and neutrals. In this study we assess the locations of the energy transfer and deposition by employing a self-consistent inductive-dynamic ionosphere-thermosphere model. In a 2-D numerical simulation (dawn-dusk meridian plane), we solve the continuity, momentum, and energy equations for multiple species of ions and neutrals including photochemistry and Maxwell's equations. By simulating responses of the ionosphere-thermosphere system to enhanced magnetosphere convection, we show that the strongest energy transfer occurs in the polar cap proper instead of the auroral zone.

  8. 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.

  9. High energy conversion efficiency in laser-proton acceleration by controlling laser-energy deposition onto thin foil targets

    NASA Astrophysics Data System (ADS)

    Brenner, C. M.; Robinson, A. P. L.; Markey, K.; Scott, R. H. H.; Gray, R. J.; Rosinski, M.; Deppert, O.; Badziak, J.; Batani, D.; Davies, J. R.; Hassan, S. M.; Lancaster, K. L.; Li, K.; Musgrave, I. O.; Norreys, P. A.; Pasley, J.; Roth, M.; Schlenvoigt, H.-P.; Spindloe, C.; Tatarakis, M.; Winstone, T.; Wolowski, J.; Wyatt, D.; McKenna, P.; Neely, D.

    2014-02-01

    An all-optical approach to laser-proton acceleration enhancement is investigated using the simplest of target designs to demonstrate application-relevant levels of energy conversion efficiency between laser and protons. Controlled deposition of laser energy, in the form of a double-pulse temporal envelope, is investigated in combination with thin foil targets in which recirculation of laser-accelerated electrons can lead to optimal conditions for coupling laser drive energy into the proton beam. This approach is shown to deliver a substantial enhancement in the coupling of laser energy to 5-30 MeV protons, compared to single pulse irradiation, reaching a record high 15% conversion efficiency with a temporal separation of 1 ps between the two pulses and a 5 μm-thick Au foil. A 1D simulation code is used to support and explain the origin of the observation of an optimum pulse separation of ˜1 ps.

  10. 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.

  11. 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

  12. Laser energy density, structure and properties of pulsed-laser deposited zinc oxide films

    NASA Astrophysics Data System (ADS)

    Tsoutsouva, M. G.; Panagopoulos, C. N.; Kompitsas, M.

    2011-05-01

    Zinc oxide thin films were deposited on soda lime glass substrates by pulsed laser deposition in an oxygen-reactive atmosphere at 20 Pa and a constant substrate temperature at 300 °C. A pulsed KrF excimer laser, operated at 248 nm with pulse duration 10 ns, was used to ablate the ceramic zinc oxide target. The structure, the optical and electrical properties of the as-deposited films were studied in dependence of the laser energy density in the 1.2-2.8 J/cm 2 range, with the aid of X-ray Diffraction, Atomic Force Microscope, Transmission Spectroscopy techniques, and the Van der Pauw method, respectively. The results indicated that the structural and optical properties of the zinc oxide films were improved by increasing the laser energy density of the ablating laser. The surface roughness of the zinc oxide film increased with the decrease of laser energy density and both the optical bang gap and the electrical resistivity of the film were significantly affected by the laser energy density.

  13. Influence of emitter temperature on the energy deposition in a low-pressure plasma

    SciTech Connect

    Levko, Dmitry; Raja, Laxminarayan L.

    2016-03-15

    The influence of emitter temperature on the energy deposition into low-pressure plasma is studied by the self-consistent one-dimensional Particle-in-Cell Monte Carlo Collisions model. Depending on the emitter temperature, different modes of discharge operation are obtained. The mode type depends on the plasma frequency and does not depend on the ratio between the densities of beam and plasma electrons. Namely, plasma is stable when the plasma frequency is small. For this plasma, the energy transfer from emitted electrons to plasma electrons is inefficient. The increase in the plasma frequency results first in the excitation of two-stream electron instability. However, since the thermal velocity of plasma electrons is smaller than the electrostatic wave velocity, the resonant wave-particle interaction is inefficient for the energy deposition into the plasma. Further increase in the plasma frequency leads to the distortion of beam of emitted electrons. Then, the electrostatic wave generated due to two-stream instability decays into multiple slower waves. Phase velocities of these waves are comparable with the thermal velocity of plasma electrons which makes possible the resonant wave-particle interaction. This results in the efficient energy deposition from emitted electrons into the plasma.

  14. Evolution of energy deposition during glass cutting with pulsed femtosecond laser radiation

    NASA Astrophysics Data System (ADS)

    Kalupka, C.; Großmann, D.; Reininghaus, M.

    2017-05-01

    We report on investigations of the energy deposition in the volume of thin glass during an ablation cutting process with pulsed femtosecond laser radiation by time-resolved pump-probe shadowgraphy. For a single laser pulse, the temporal evolution of the transient electronic excitation of the glass volume is imaged up to 10 ps after initial excitation. For an increasing number of laser pulses, the spatial excitation of the glass volume significantly changes compared to single pulse irradiation. Sharp spikes are observed, which reduce the transmission of the illuminating probe pulse. This indicates local maxima of the absorption and, therefore, energy deposition of the pump pulse energy in the glass volume. Furthermore, for an increasing number of pulses, different shapes of the surface ablation crater are observed. To study the correlation between the shape of the surface ablation crater and the energy deposition in the glass volume, simulations of the spatial intensity distribution of the pump pulse are executed by means of linear beam propagation method. We show that the transient excitation spikes observed by pump-probe shadowgraphy can be explained by refraction and diffraction of the laser radiation at the surface ablation crater. Our results provide an experimental validation for the physical reason of an ablation stop for an ablation cutting process. Moreover, the simulations allow for the prediction of damage inside the glass volume.

  15. Energy fluxes in a radio-frequency magnetron discharge for the deposition of superhard cubic boron nitride coatings

    SciTech Connect

    Bornholdt, S.; Kersten, H.; Ye, J.; Ulrich, S.

    2012-12-15

    Energy flux measurements by a calorimetric probe in a rf-magnetron plasma used for the deposition of super-hard c-BN coatings are presented and discussed. Argon as working gas is used for sputtering a h-BN target. Adding a certain amount of N{sub 2} is essential for the formation of stoichiometric BN films, since a lack of nitrogen will lead to boron rich films. Subsequently, the contributions of different plasma species, surface reactions, and film growth to the resulting variation of the substrate temperature in dependence on nitrogen admixture are estimated and discussed. In addition, SRIM simulations are performed to estimate the energy influx by sputtered neutral atoms. The influence of magnetron target power and oxygen admixture (for comparison with nitrogen) to the process gas on the total energy flux is determined and discussed qualitatively, too. The results indicate that variation of the energy influx due to additional nitrogen flow, which causes a decrease of electron and ion densities, electron temperature and plasma potential, is negligible, while the admixture of oxygen leads to a drastic increase of the energy influx. The typical hysteresis effect which can be observed during magnetron sputtering in oxygen containing gas mixtures has also been confirmed in the energy influx measurements for the investigated system. However, the underlying mechanism is not understood yet, and will be addressed in further investigations.

  16. Energy fluxes in a radio-frequency magnetron discharge for the deposition of superhard cubic boron nitride coatings

    NASA Astrophysics Data System (ADS)

    Bornholdt, S.; Ye, J.; Ulrich, S.; Kersten, H.

    2012-12-01

    Energy flux measurements by a calorimetric probe in a rf-magnetron plasma used for the deposition of super-hard c-BN coatings are presented and discussed. Argon as working gas is used for sputtering a h-BN target. Adding a certain amount of N2 is essential for the formation of stoichiometric BN films, since a lack of nitrogen will lead to boron rich films. Subsequently, the contributions of different plasma species, surface reactions, and film growth to the resulting variation of the substrate temperature in dependence on nitrogen admixture are estimated and discussed. In addition, SRIM simulations are performed to estimate the energy influx by sputtered neutral atoms. The influence of magnetron target power and oxygen admixture (for comparison with nitrogen) to the process gas on the total energy flux is determined and discussed qualitatively, too. The results indicate that variation of the energy influx due to additional nitrogen flow, which causes a decrease of electron and ion densities, electron temperature and plasma potential, is negligible, while the admixture of oxygen leads to a drastic increase of the energy influx. The typical hysteresis effect which can be observed during magnetron sputtering in oxygen containing gas mixtures has also been confirmed in the energy influx measurements for the investigated system. However, the underlying mechanism is not understood yet, and will be addressed in further investigations.

  17. Energy deposition model based on electron scattering cross section data from water molecules

    NASA Astrophysics Data System (ADS)

    Muñoz, A.; Oiler, J. C.; Blanco, F.; Gorfinkiel, J. D.; Limão-Vieira, P.; Maira-Vidal, A.; Borge, M. J. G.; Tengblad, O.; Huerga, C.; Téllez, M.; García, G.

    2008-10-01

    A complete set of electrons scattering cross sections by water molecules over a broad energy range, from the me V to the Me V ranges, is presented in this study. These data have been obtained by combining experiments and calculations and cover most relevant processes, both elastic and inelastic, which can take place in the considered energy range. A new Monte Carlo simulation programme has been developed using as input parameter these cross sectional data as well as experimental energy loss spectra. The simulation procedure has been applied to obtain electron tracks and energy deposition plots in water when irradiated by a Ru-106 plaque as those used for brachyteraphy of ocular tumours. Finally, the low energy electron tracks provided by the present model have been compared with those obtained with other codes available in the literature

  18. In-situ monitoring by reflective high energy electron diffraction during pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Blank, Dave H. A.; Rijnders, Guus J. H. M.; Koster, Gertjan; Rogalla, Horst

    1999-01-01

    Pulsed laser deposition (PLD) has developed during the past decade from a fast but limited preparation tool towards a competitive thin film deposition technique. One of the advantages above other techniques is the possibility of growth at relative high background pressure. There is a large freedom in choosing which kind of gas. Moreover, in a number of applications, the gaseous species in the background pressure are part of the elements to be grown, e.g., oxygen in the case of high Tc superconductors. However, the advantage of relative high pressures leads to restrictions of using standard diagnostics and monitoring of the film growth, e.g., reflective high energy electron diffraction (RHEED). Here, a PLD chamber including an in-situ RHEED system is presented, which makes it possible to monitor and study the growth at standard PLD parameters. Using a two-stages differential pumped, magnetically shielded, extension tube mounted at the electron gun side and a special designed phosphor screen including CCD camera, real time monitoring by observation of RHEED oscillations could be established at pressures up to 50 Pa. In this paper the latest results on applying this technique on SrTiO 3 and YBa 2Cu 3O 7 will be presented. Additional to the usual diagnostics performed with RHEED, another phenomena can be observed. The pulsed way of deposition, characteristic for PLD, leads to relaxations in the intensity of the diffracted pattern due to the mobility of the deposited material. These relaxation times give extra information about relaxation, crystallization, and nucleation of the deposited material. The presented technique leads to a better understanding of the growth during pulsed laser deposition and, because of the possibility to monitor the growth, will make PLD competitive with other deposition techniques.

  19. Deposition of carbonate mud beds within high-energy subtidal sand Dunes, Bahamas

    SciTech Connect

    Dill, R.F.; Steinen, R.P.

    1988-01-01

    Laminated, carbonate mud beds are being deposited in the interisland channels of the Exuma Cays in the Bahamas. They are associated with stromatolites and interbedded with ooid sands that form large migrating subtidal dunes on flood tidal deltas and bars. Currents up to 3 knots sweep in and out of the 4-8 m deep channels 3 hours out of every 6 hours, creating a high-energy bank margin environment not usually considered to be the site of mud-sized particle deposition. Mud deposits reach thicknesses of 1 m and have individual beds 2-5 cm thick. When exposed to flowing seawater, bed surfaces become encrusted with carbonate cement and algal mats. The white interior of mud beds between the crusts appears homogeneous, is soft, and has the consistency of ''tooth paste.'' Loose uncemented ooid sand is found above and below the mud beds, showing that both are occupying the same depositional environment. Rip-up clasts of the crusted mud beds, formed by scour of underlying sands, are carried throughout the channels and accumulate as a lag deposit within the troughs of migrating dunes. Some clasts are colonized by algal mats that trap ooid and skeletal sands forming stromatolite structures that can grow up to 2 m high.

  20. Characteristic properties of the Casimir free energy for metal films deposited on metallic plates

    NASA Astrophysics Data System (ADS)

    Klimchitskaya, G. L.; Mostepanenko, V. M.

    2016-04-01

    The Casimir free energy and pressure of thin metal films deposited on metallic plates are considered using the Lifshitz theory and the Drude and plasma model approaches to the role of conduction electrons. The bound electrons are taken into account by using the complete optical data of film and plate metals. It is shown that for films of several tens of nanometers thickness the Casimir free energy and pressure calculated using these approaches differ by hundreds and thousands percent and can be easily discriminated experimentally. According to our results, the free energy of a metal film does not vanish in the limiting case of ideal metal if the Drude model approach is used in contradiction with the fact that the fluctuating field cannot penetrate in its interior. Numerical computations of the Casimir free energy and pressure of Ag and Au films deposited on Cu and Al plates have been performed using both theoretical approaches. It is shown that the free energy of a film can be both negative and positive depending on the metals used. For a Au film on a Ag plate and vice versa the Casimir energy of a film changes its sign with increasing film thickness. Applications of the obtained results for resolving the Casimir puzzle and the problem of stability of thin films are discussed.

  1. 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.

  2. 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.

  3. Measurement of the cleavage energy of graphite

    PubMed Central

    Wang, Wen; Dai, Shuyang; Li, Xide; Yang, Jiarui; Srolovitz, David J.; Zheng, Quanshui

    2015-01-01

    The basal plane cleavage energy (CE) of graphite is a key material parameter for understanding many of the unusual properties of graphite, graphene and carbon nanotubes. Nonetheless, a wide range of values for the CE has been reported and no consensus has yet emerged. Here we report the first direct, accurate experimental measurement of the CE of graphite using a novel method based on the self-retraction phenomenon in graphite. The measured value, 0.37±0.01 J m−2 for the incommensurate state of bicrystal graphite, is nearly invariant with respect to temperature (22 °C≤T≤198 °C) and bicrystal twist angle, and insensitive to impurities from the atmosphere. The CE for the ideal ABAB graphite stacking, 0.39±0.02 J m−2, is calculated based on a combination of the measured CE and a theoretical calculation. These experimental measurements are also ideal for use in evaluating the efficacy of competing theoretical approaches. PMID:26314373

  4. 1-D Van der Waals Foams Heated by Ion Beam Energy Deposition

    SciTech Connect

    Zylstra, A; Barnard, J J; More, R M

    2010-03-19

    One dimensional simulations of various initial average density aluminum foams (modeled as slabs of solid metal separated by low density regions) heated by volumetric energy deposition are conducted with a Lagrangian hydrodynamics code using a van der Waals equation of state (EOS). The resulting behavior is studied to facilitate the design of future warm dense matter (WDM) experiments at LBNL. In the simulations the energy deposition ranges from 10 to 30 kJ/g and from 0.075 to 4.0 ns total pulse length, resulting in temperatures from approximately 1 to 4 eV. We study peak pressures and temperatures in the foams, expansion velocity, and the phase evolution. Five relevant time scales in the problem are identified. Additionally, we present a method for characterizing the level of inhomogeneity in a foam target as it is heated and the time it takes for a foam to homogenize.

  5. 1-D Van der Waals Foams Heated by Ion Beam Energy Deposition

    SciTech Connect

    Zylstra, A. B.; Barnard, J. J.; More, R. M.

    2009-12-23

    One dimensional simulations of various initial average density aluminum foams (modeled as slabs of solid metal separated by low density regions) heated by volumetric energy deposition are conducted with a Lagrangian hydrodynamics code using a van der Waals equation of tate (EOS). The resulting behavior is studied to facilitate the design of future warm dense matter (WDM) experiments at LBNL. In the simulations the energy deposition ranges from 10 to 30 kJ/g and from 0.075 to 4.0 ns total pulse length, resulting in temperatures from approximately 1 o 4 eV. We study peak pressures and temperatures in the foams, expansion velocity, and the phase evolution. Five relevant time scales in the problem are identified. Additionally, we present a method for characterizing the level of inhomogeneity in a foam target as it is heated and the time it takes for a foam to homogenize.

  6. Energy deposited in the high luminosity inner triplets of the LHC by collision debris

    SciTech Connect

    Wildner, E.; Broggi, F.; Cerutti, F.; Ferrari, A.; Hoa, C.; Koutchouk, J.-P.; Mokhov, N.V.; /Fermilab

    2008-06-01

    The 14 TeV center of mass proton-proton collisions in the LHC produce not only debris interesting for physics but also showers of particles ending up in the accelerator equipment, in particular in the superconducting magnet coils. Evaluations of this contribution to the heat, that has to be transported by the cryogenic system, have been made to guarantee that the energy deposition in the superconducting magnets does not exceed limits for magnet quenching and the capacity of the cryogenic system. The models of the LHC base-line are detailed and include description of, for energy deposition, essential elements like beam-pipes and corrector magnets. The evaluations made using the Monte-Carlo code FLUKA are compared to previous studies using MARS. For the consolidation of the calculations, a dedicated comparative study of these two codes was performed for a reduced setup.

  7. Energy Deposition into a Collisional Gas from Optical Lattices Formed in an Optical Cavity (PREPRINT)

    DTIC Science & Technology

    2008-07-02

    pp. 1344-1347 2 Kuga et al., “Novel Optical Trap of Atoms with a Doughnut Beam,” Physical Review Letters 78, (1997), pp. 4713-4716 3 Dotsenko et...other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a ...Technical Paper 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Energy Deposition into a Collisional Gas from

  8. Ion mass and energy selective hyperthermal ion-beam assisted deposition setup

    NASA Astrophysics Data System (ADS)

    Gerlach, J. W.; Schumacher, P.; Mensing, M.; Rauschenbach, S.; Cermak, I.; Rauschenbach, B.

    2017-06-01

    For the synthesis of high-quality thin films, ion-beam assisted deposition (IBAD) is a frequently used technique providing precise control over several substantial film properties. IBAD typically relies on the use of a broad-beam ion source. Such ion sources suffer from the limitation that they deliver a blend of ions with different ion masses, each of them possessing a certain distribution of kinetic energy. In this paper, a compact experimental setup is presented that enables the separate control of ion mass and ion kinetic energy in the region of hyperthermal energies (few 1 eV - few 100 eV). This ion energy region is of increasing interest not only for ion-assisted film growth but also for the wide field of preparative mass spectrometry. The setup consists of a constricted glow-discharge plasma beam source and a tailor-made, compact quadrupole system equipped with entry and exit ion optics. It is demonstrated that the separation of monoatomic and polyatomic nitrogen ions (N+ and N2+) is accomplished. For both ion species, the kinetic energy is shown to be selectable in the region of hyperthermal energies. At the sample position, ion current densities are found to be in the order of 1 μA/cm2 and the full width at half maximum of the ion beam profile is in the order of 10 mm. Thus, the requirements for homogeneous deposition processes in sufficiently short periods of time are fulfilled. Finally, employing the described setup, for the first time in practice epitaxial GaN films were deposited. This opens up the opportunity to fundamentally study the influence of the simultaneous irradiation with hyperthermal ions on the thin film growth in IBAD processes and to increase the flexibility of the technique.

  9. Overview of strontium-89,90 deposition measurements in Finland 1963-2005.

    PubMed

    Paatero, Jussi; Saxén, Ritva; Buyukay, Murat; Outola, Iisa

    2010-04-01

    In Finland the deposition of strontium-89 (90Sr) and strontium-90 (90Sr) has been monitored since the early 1960s. The measured cumulative 90Sr deposition in 1963-2005 is on average 1200 Bq m(-2), of which 150 Bq m(-2) originates from the Chernobyl accident. Adding to this the deposition in 1945-1962 produces a value of 2040 Bq m(-2) for the cumulative deposition in Finland. The nuclear explosion-derived deposition up to 1985 obtained in this study, 1850 Bq m(-2), is in good agreement with the zonal 90Sr deposition of 1740 Bq m(-2) in the 60 degrees N-70 degrees N latitude band estimated by UNSCEAR. The regional deposition patterns of 89Sr and 90Sr following the Chernobyl accident resemble those of the refractory nuclides such as 239,240Pu and 95Zr. The total deposition of Chernobyl-derived 90Sr in Finland was about 5.3 x 10(13) Bq. This activity corresponds to 0.027% of the reactor core inventory and 0.66% of the atmospheric emissions from the accident. The corresponding figures for 89Sr are 4.5 x 10(14) Bq, 0.023% and 0.56%, respectively. Copyright 2010 Elsevier Ltd. All rights reserved.

  10. Energy deposition of heavy ions in the regime of strong beam-plasma correlations.

    PubMed

    Gericke, D O; Schlanges, M

    2003-03-01

    The energy loss of highly charged ions in dense plasmas is investigated. The applied model includes strong beam-plasma correlation via a quantum T-matrix treatment of the cross sections. Dynamic screening effects are modeled by using a Debye-like potential with a velocity dependent screening length that guarantees the known low and high beam velocity limits. It is shown that this phenomenological model is in good agreement with simulation data up to very high beam-plasma coupling. An analysis of the stopping process shows considerably longer ranges and a less localized energy deposition if strong coupling is treated properly.

  11. Monte Carlo calculations of the energy deposited in biological samples and shielding materials

    NASA Astrophysics Data System (ADS)

    Akar Tarim, U.; Gurler, O.; Ozmutlu, E. N.; Yalcin, S.

    2014-03-01

    The energy deposited by gamma radiation from the Cs-137 isotope into body tissues (bone and muscle), tissue-like medium (water), and radiation shielding materials (concrete, lead, and water), which is of interest for radiation dosimetry, was obtained using a simple Monte Carlo algorithm. The algorithm also provides a realistic picture of the distribution of backscattered photons from the target and the distribution of photons scattered forward after several scatterings in the scatterer, which is useful in studying radiation shielding. The presented method in this work constitutes an attempt to evaluate the amount of energy absorbed by body tissues and shielding materials.

  12. Lines of Energy Deposition for Supersonic/Hypersonic Temperature/ Drag-Reduction and Vehicle Control

    DTIC Science & Technology

    2009-10-06

    amount of energy to deposit along the cone axis in order to open up low-density cylindrical cores of various radii. The reason behind modeling the...for a 15° half- angle cone and up to 96% for a 45° half-angle cone . The energy retum ratio [thrust (power) saved]:[invested power] of this...addresses the r ~q .•-.~~,~.~ .• ~.~.~.~, ~.~.~. (a) X ·2 · $ ·4 ·3 ·~ · 1 0 I l 3 4 5 6 (c) X FIGURE 3: A low-density core streaming over the cone

  13. Front end energy deposition and collimation studies for IDS-NF

    SciTech Connect

    Rogers, C.; Neuffer, D.; Snopok, P.; /IIT, Chicago /Fermilab

    2011-03-01

    The function of the Neutrino Factory front end is to reduce the energy spread and size of the muon beam to a manageable level that will allow reasonable throughput to subsequent system components. Since the Neutrino Factory is a tertiary machine (protons to pions to muons), there is an issue of large background from the pion-producing target. The implications of energy deposition in the front end lattice for the Neutrino Factory are addressed. Several approaches to mitigating the effect are proposed and discussed, including proton absorbers, chicanes, beam collimation, and shielding.

  14. 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.

  15. Simulation of submarine gas hydrate deposits as a sustainable energy source and CO2 storage

    NASA Astrophysics Data System (ADS)

    Janicki, G.; Hennig, T.; Schlüter, S.; Deerberg, G.

    2012-04-01

    Being aware that conventionally exploitable natural gas resources are limited, research concentrates on the development of new technologies for the extraction of methane from gas hydrate deposits in subsea sediments. The quantity of methane stored in hydrate form is considered to be a promising means to overcome future shortages in energy resources. In combination with storing carbon dioxide (CO2) as hydrates in the deposits chances for sustainable energy supply systems are given. The combustion of hydrate-based natural gas can contribute to the energy supply, but the coupled CO2 emissions cause climate change effects. At present, the possible options to capture and subsequently store CO2 (CCS-Technology) become of particular interest. To develop a sustainable hydrate-based energy supply system, the production of natural gas from hydrate deposits has to be coupled with the storage of CO2. Hence, the simultaneous storage of CO2 in hydrate deposits has to be developed. Decomposition of methane hydrate in combination with CO2 sequestration appears to be promising because CO2 hydrate is stable within a wider range of pressure and temperature than methane hydrate. As methane hydrate provides structural integrity and stability in its natural formation, incorporating CO2 hydrate as substitute for methane hydrate will help to preserve the natural sediments' stability. Regarding the technological implementation, many problems have to be overcome. Especially heat and mass transfer in the deposits are limiting factors causing very long process times. Within the scope of the German research project »SUGAR«, different technological approaches are evaluated and compared by means of dynamic system simulations and analysis. Detailed mathematical models for the most relevant chemical and physical effects are developed. The basic mechanisms of gas hydrate formation/dissociation and heat and mass transport in porous media are considered and implemented into simulation programs like

  16. Hall measurements on carbon nanotube paper modified with electroless deposited platinum.

    PubMed

    Petrik, Leslie; Ndungu, Patrick; Iwuoha, Emmanuel

    2009-09-18

    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.

  17. 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.

  18. Monte Carlo calculations of energy deposition distributions of electrons below 20 keV in protein.

    PubMed

    Tan, Zhenyu; Liu, Wei

    2014-05-01

    The distributions of energy depositions of electrons in semi-infinite bulk protein and the radial dose distributions of point-isotropic mono-energetic electron sources [i.e., the so-called dose point kernel (DPK)] in protein have been systematically calculated in the energy range below 20 keV, based on Monte Carlo methods. The ranges of electrons have been evaluated by extrapolating two calculated distributions, respectively, and the evaluated ranges of electrons are compared with the electron mean path length in protein which has been calculated by using electron inelastic cross sections described in this work in the continuous-slowing-down approximation. It has been found that for a given energy, the electron mean path length is smaller than the electron range evaluated from DPK, but it is large compared to the electron range obtained from the energy deposition distributions of electrons in semi-infinite bulk protein. The energy dependences of the extrapolated electron ranges based on the two investigated distributions are given, respectively, in a power-law form. In addition, the DPK in protein has also been compared with that in liquid water. An evident difference between the two DPKs is observed. The calculations presented in this work may be useful in studies of radiation effects on proteins.

  19. Kinetic treatment of alpha-particle loss and energy deposition in ELMO Bumpy Torus

    SciTech Connect

    Fenstermacher, M.E.; Uckan, N.A.

    1982-12-01

    A formalism has been developed in terms of a drift kinetic equation with a Fokker-Planck collision operator to calculate alpha particle loss and energy deposition rate coefficients for one position in space and for steady-state operating conditions. A bounce-averaged drift kinetic equation for an ELMO Bumpy Torus (EBT) is expressed in invariant variables E = v/sup 2//2 and lambda = v/sub perpendicular//sup 2/B/sub MID//v/sup 2/B(l) and is used with energy scattering and pitch angle scattering terms in the collision operator. The alpha particle distribution function is expanded in terms of energy coefficients and pitch angle eigenfunctions. For the case of a square well magnetic field shape, the pitch angle eigenfunctions are the Legendre polynominals. With an expression for the distribution function the particle loss and energy deposition rates are calculated by taking the zeroth and first-order energy moments, respectively, of the kinetic equation.

  20. Measurements of the deposition rates of radon daughters on indoor surfaces

    SciTech Connect

    Toohey, R.E.; Essling, M.A.; Rundo, J.; Hengde, W.

    1983-01-01

    The deposition rates of radon daughters on indoor surfaces have been measured by exposing the window of a proportional counter to the air of a house with high concentrations of radon and its daughters. Deposition velocities for unattached RaA and RaB of approximately 4 mm sec/sup -1/ were obtained by dividing the deposition rates by the concentrations of unattached daughters in the air. These results agree with those obtained by other workers but are dependent on the assumptions made about the fractions of the daughters which are attached to the atmospheric aerosol.

  1. An APL program for the distribution of energy deposition by charged particles passing through thin absorbers

    NASA Technical Reports Server (NTRS)

    Howell, L. W.

    1985-01-01

    An APL program which numerically evaluates the probability density function (PDF) for the energy deposited in a thin absorber by a charged particle is proposed, with application to the construction, pointing, and control of spacecraft. With this program, the PDF of the restricted energy loss distribution of Watts (1973) is derived, and Vavilov's (1957) distribution is obtained by proper parameter selection. The method is demonstrated with the example of the effect of charged particle induced radiation on the Hubble Space Telescope (HST) pointing accuracy. A Monte Carlo study simulates the photon noise caused by charged particles passing through the photomultiplier tube window, and the stochastic variation of energy loss is introduced into the simulation by generating random energy losses from a power law distribution. The program eliminates annoying loop procedures, and model parameter sensitivity can be studied using the graphical output.

  2. HUBBLE PARAMETER MEASUREMENT CONSTRAINTS ON DARK ENERGY

    SciTech Connect

    Farooq, Omer; Mania, Data; Ratra, Bharat E-mail: mania@phys.ksu.edu

    2013-02-20

    We use 21 Hubble parameter versus redshift data points from Simon et al., Gaztanaga et al., Stern et al., and Moresco et al. to place constraints on model parameters of constant and time-evolving dark energy cosmologies. The inclusion of the eight new measurements results in H(z) constraints more restrictive than those derived by Chen and Ratra. These constraints are now almost as restrictive as those that follow from current Type Ia supernova (SNIa) apparent magnitude versus redshift data, which now more carefully account for systematic uncertainties. This is a remarkable result. We emphasize, however, that SNIa data have been studied for a longer time than the H(z) data, possibly resulting in a better estimate of potential systematic errors in the SNIa case. A joint analysis of the H(z), baryon acoustic oscillation peak length scale, and SNIa data favors a spatially flat cosmological model currently dominated by a time-independent cosmological constant but does not exclude slowly evolving dark energy.

  3. The dry-deposition of speciated mercury to the Florida Everglades: Measurements and modeling

    NASA Astrophysics Data System (ADS)

    Marsik, Frank J.; Keeler, Gerald J.; Landis, Matthew S.

    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 (Cladium jamaicense) and cattail (Typha domingensis) stand within the Florida Everglades. Measurement intensives were performed during 24 February-04 March 1999 and 05-21 June 2000, which corresponded to the climatological dry and wet seasons in South Florida, respectively. During these intensives, direct measurements of mercury dry-deposition were made using a newly developed surrogate water surface technique. These direct measurements were compared with modeled estimates of mercury dry-deposition to the site that were obtained through the use of an inferential or "bigleaf" model that was modified for use with speciated mercury. On-site measurements of ambient speciated mercury concentrations and numerous micrometeorological variables were used as input to the model. The average mercury dry-deposition measured during the 1999 FEDDS measurement intensive was 13.3±4.0 ng m -2 day -1, while the modeled deposition for this period was 3.4±2.3 ng m -2 day -1. The average mercury dry-deposition measured during the 2000 FEDDS measurement intensive was lower, 5.9±2.8 ng m -2 day -1, while the average modeled deposition for this period was 1.8±0.6 ng m -2 day -1. A least-squares linear regression suggests that the model was able to explain 74% and 73% of the variability in the datasets for the 1999 and 2000 FEDDS intensives, respectively. While reported reductions in total mercury emissions across South Florida between study periods could explain the reductions in both the measured and predicted mercury dry-deposition estimates, the increased presence of cumulus convection during the summer-intensive could have also resulted in a removal of reactive and particulate mercury species within the

  4. Determination of deposited flux and energy of sputtered tungsten atoms on every stages of transport in HiPIMS discharge

    NASA Astrophysics Data System (ADS)

    Desecures, M.; de Poucques, L.; Bougdira, J.

    2017-02-01

    A time-resolved tunable diode-laser (DL) induced fluorescence (TR-TDLIF) technique has been used to identify different populations of atoms (on different stages of transport) to determine their corresponding deposited energy and flux. The temporal dimension permits the splitting of the processes of sputtering during the discharge and particles transport in the post-discharge where atoms and flux velocity distribution functions (AVDF, FVDF) of each population were measured varying the discharge parameters (power, voltage, pressure, and distance from target). Tungsten (W) was chosen, being an interesting case in terms of sputtered atom transport, considering its weight which implies weak changes of directivity or energy transfer after collisions with the buffer gas. The high temporal and spectral resolutions of TR-TDLIF are the keys for the distinction of the atoms populations and the stage corresponding to the transition from the ballistic to diffusive regime of transport was observed for the first time and named quasi-diffusive regime. Thus, the ability to dissociate populations of atoms and to determine their deposited flux and energy may be of great interest to adjust film properties as desired for applications.

  5. The influence of energy deposition parameters on laser plasma drag reduction

    NASA Astrophysics Data System (ADS)

    Dou, Zhiguo; Liu, Zhun; Yao, Honglin; Li, Xiuqian

    2013-09-01

    Laser plasma drag reduction is a new method to reduce the wave drag of hypersonic flight. The research of the laser plasma drag reduction performance is an important work. The purpose of this paper is investigating laser plasma drag reduction by numerical simulation to enhance the understanding of the drag reduction mechanism, get the drag reduction performance in different conditions, and provide references for laser plasma drag reduction experiment in the future. Based on summarizing correlative references systematically, through building the model of energy deposition and comparison the simulated results to the empirical formula and computation results to verify the program correctness, the influence of laser energy parameters to laser plasma drag reduction were simulated numerically for optimize the performance. The follow conclusions were got by numerical simulation: The computation program can well simulate the interacting of LSDW(laser supported detonation wave) to the bow shock in front of the blunt body. Results indicate that the blunt body drag could be decreased by injecting laser energy into the incoming hypersonic flow. The correctness of program was verified by compare result to the experiment and computation results. Blunt body drag will be greatly decreased with injected laser power increased, The bigger laser power is injected, the more drag decreases. There's an energy saturation value for each laser power level, the injecting laser power effectiveness values are never quite high for all laser power level. There is an optimized energy deposition location in upstream flow, this location is right ahead of the blunt body. When the distance from deposition location to the surface of blunt body is 5 times the blunt radius, blunt body drag decreased the most. This paper investigated the parameters which primary influence the performance of drag reduction. The numerical simulation data and obtained results are meaningful for laser plasma drag reduction

  6. 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

  7. 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.

  8. 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.

  9. Low-Energy Plasma Spray (LEPS) Deposition of Hydroxyapatite/Poly-ɛ-Caprolactone Biocomposite Coatings

    NASA Astrophysics Data System (ADS)

    Garcia-Alonso, Diana; Parco, Maria; Stokes, Joseph; Looney, Lisa

    2012-01-01

    Thermal spraying is widely employed to deposit hydroxyapatite (HA) and HA-based biocomposites on hip and dental implants. For thick HA coatings (>150 μm), problems are generally associated with the build-up of residual stresses and lack of control of coating crystallinity. HA/polymer composite coatings are especially interesting to improve the pure HA coatings' mechanical properties. For instance, the polymer may help in releasing the residual stresses in the thick HA coatings. In addition, the selection of a bioresorbable polymer may enhance the coatings' biological behavior. However, there are major challenges associated with spraying ceramic and polymeric materials together because of their very different thermal properties. In this study, pure HA and HA/poly-ɛ-caprolactone (PCL) thick coatings were deposited without significant thermal degradation by low-energy plasma spraying (LEPS). PCL has never been processed by thermal spraying, and its processing is a major achievement of this study. The influence of selected process parameters on microstructure, composition, and mechanical properties of HA and HA/PCL coatings was studied using statistical design of experiments (DOE). The HA deposition rate was significantly increased by the addition of PCL. The average porosity of biocomposite coatings was slightly increased, while retaining or even improving in some cases their fracture toughness and microhardness. Surface roughness of biocomposites was enhanced compared with HA pure coatings. Cell culture experiments showed that murine osteoblast-like cells attach and proliferate well on HA/PCL biocomposite deposits.

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

    Treesearch

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

    2014-01-01

    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...

  11. Breath-by-breath measurement of particle deposition in the lung of spontaneously breathing rats.

    PubMed

    Karrasch, S; Eder, G; Bolle, I; Tsuda, A; Schulz, H

    2009-10-01

    A number of deposition models for humans, as well as experimental animals, have been described. However, no breath-by-breath deposition measurement in rats has been reported to date. The objective of this study is to determine lung deposition of micrometer-sized particles as a function of breathing parameters in the adult rat lung. A new aerosol photometry system was designed to measure deposition of nonhygroscopic, 2-mum sebacate particles in anesthetized, intubated, and spontaneously breathing 90-day-old Wistar-Kyoto rats placed in a size-adjusted body plethysmograph box. Instrumental dead space of the system was minimized down to 310 microl (i.e., approximately 20% of respiratory dead space). The system allows continuous monitoring of particle concentration in the respired volume. Breathing parameters, such as respiratory rate (f), tidal volume (Vt), as well as inspiration/expiration times, were also monitored at different levels of anesthesia. The results showed that Vt typically varied between 1.5 and 4.0 ml for regular breathing and between 4.0 and 10.0 ml for single-sigh breaths; f ranged from 40 to 200 breaths/min. Corresponding deposition values varied between 5 and 50%, depending on breath-by-breath breathing patterns. The best fit of deposition (D) was achieved by a bilinear function of Vt and f and found to be D = 11.0 - 0.09.f + 3.75.Vt. We conclude that our approach provides more realistic conditions for the measurement of deposition than conventional models using ventilated animals and allows us to analyze the correlation between breath-specific deposition and spontaneous breathing patterns.

  12. Correlation between energy deposition and molecular damage from Auger electrons: A case study of ultra-low energy (5–18 eV) electron interactions with DNA

    PubMed Central

    Rezaee, Mohammad; Hunting, Darel J.; Sanche, Léon

    2015-01-01

    Purpose The present study introduces a new method to establish a direct correlation between biologically related physical parameters (i.e., stopping and damaging cross sections, respectively) for an Auger-electron emitting radionuclide decaying within a target molecule (e.g., DNA), so as to evaluate the efficacy of the radionuclide at the molecular level. These parameters can be applied to the dosimetry of Auger electrons and the quantification of their biological effects, which are the main criteria to assess the therapeutic efficacy of Auger-electron emitting radionuclides. Methods Absorbed dose and stopping cross section for the Auger electrons of 5–18 eV emitted by 125I within DNA were determined by developing a nanodosimetric model. The molecular damages induced by these Auger electrons were investigated by measuring damaging cross section, including that for the formation of DNA single- and double-strand breaks. Nanoscale films of pure plasmid DNA were prepared via the freeze-drying technique and subsequently irradiated with low-energy electrons at various fluences. The damaging cross sections were determined by employing a molecular survival model to the measured exposure–response curves for induction of DNA strand breaks. Results For a single decay of 125I within DNA, the Auger electrons of 5–18 eV deposit the energies of 12.1 and 9.1 eV within a 4.2-nm3 volume of a hydrated or dry DNA, which results in the absorbed doses of 270 and 210 kGy, respectively. DNA bases have a major contribution to the deposited energies. Ten-electronvolt and high linear energy transfer 100-eV electrons have a similar cross section for the formation of DNA double-strand break, while 100-eV electrons are twice as efficient as 10 eV in the induction of single-strand break. Conclusions Ultra-low-energy electrons (<18 eV) substantially contribute to the absorbed dose and to the molecular damage from Auger-electron emitting radionuclides; hence, they should be considered in the

  13. Correlation between energy deposition and molecular damage from Auger electrons: A case study of ultra-low energy (5–18 eV) electron interactions with DNA

    SciTech Connect

    Rezaee, Mohammad Hunting, Darel J.; Sanche, Léon

    2014-07-15

    Purpose: The present study introduces a new method to establish a direct correlation between biologically related physical parameters (i.e., stopping and damaging cross sections, respectively) for an Auger-electron emitting radionuclide decaying within a target molecule (e.g., DNA), so as to evaluate the efficacy of the radionuclide at the molecular level. These parameters can be applied to the dosimetry of Auger electrons and the quantification of their biological effects, which are the main criteria to assess the therapeutic efficacy of Auger-electron emitting radionuclides. Methods: Absorbed dose and stopping cross section for the Auger electrons of 5–18 eV emitted by{sup 125}I within DNA were determined by developing a nanodosimetric model. The molecular damages induced by these Auger electrons were investigated by measuring damaging cross section, including that for the formation of DNA single- and double-strand breaks. Nanoscale films of pure plasmid DNA were prepared via the freeze-drying technique and subsequently irradiated with low-energy electrons at various fluences. The damaging cross sections were determined by employing a molecular survival model to the measured exposure–response curves for induction of DNA strand breaks. Results: For a single decay of{sup 125}I within DNA, the Auger electrons of 5–18 eV deposit the energies of 12.1 and 9.1 eV within a 4.2-nm{sup 3} volume of a hydrated or dry DNA, which results in the absorbed doses of 270 and 210 kGy, respectively. DNA bases have a major contribution to the deposited energies. Ten-electronvolt and high linear energy transfer 100-eV electrons have a similar cross section for the formation of DNA double-strand break, while 100-eV electrons are twice as efficient as 10 eV in the induction of single-strand break. Conclusions: Ultra-low-energy electrons (<18 eV) substantially contribute to the absorbed dose and to the molecular damage from Auger-electron emitting radionuclides; hence, they should

  14. Correlation between energy deposition and molecular damage from Auger electrons: A case study of ultra-low energy (5-18 eV) electron interactions with DNA.

    PubMed

    Rezaee, Mohammad; Hunting, Darel J; Sanche, Léon

    2014-07-01

    The present study introduces a new method to establish a direct correlation between biologically related physical parameters (i.e., stopping and damaging cross sections, respectively) for an Auger-electron emitting radionuclide decaying within a target molecule (e.g., DNA), so as to evaluate the efficacy of the radionuclide at the molecular level. These parameters can be applied to the dosimetry of Auger electrons and the quantification of their biological effects, which are the main criteria to assess the therapeutic efficacy of Auger-electron emitting radionuclides. Absorbed dose and stopping cross section for the Auger electrons of 5-18 eV emitted by(125)I within DNA were determined by developing a nanodosimetric model. The molecular damages induced by these Auger electrons were investigated by measuring damaging cross section, including that for the formation of DNA single- and double-strand breaks. Nanoscale films of pure plasmid DNA were prepared via the freeze-drying technique and subsequently irradiated with low-energy electrons at various fluences. The damaging cross sections were determined by employing a molecular survival model to the measured exposure-response curves for induction of DNA strand breaks. For a single decay of(125)I within DNA, the Auger electrons of 5-18 eV deposit the energies of 12.1 and 9.1 eV within a 4.2-nm(3) volume of a hydrated or dry DNA, which results in the absorbed doses of 270 and 210 kGy, respectively. DNA bases have a major contribution to the deposited energies. Ten-electronvolt and high linear energy transfer 100-eV electrons have a similar cross section for the formation of DNA double-strand break, while 100-eV electrons are twice as efficient as 10 eV in the induction of single-strand break. Ultra-low-energy electrons (<18 eV) substantially contribute to the absorbed dose and to the molecular damage from Auger-electron emitting radionuclides; hence, they should be considered in the dosimetry calculation of such

  15. Magnetic field effects on the energy deposition spectra of MV photon radiation.

    PubMed

    Kirkby, C; Stanescu, T; Fallone, B G

    2009-01-21

    Several groups worldwide have proposed various concepts for improving megavoltage (MV) radiotherapy that involve irradiating patients in the presence of a magnetic field-either for image guidance in the case of hybrid radiotherapy-MRI machines or for purposes of introducing tighter control over dose distributions. The presence of a magnetic field alters the trajectory of charged particles between interactions with the medium and thus has the potential to alter energy deposition patterns within a sub-cellular target volume. In this work, we use the MC radiation transport code PENELOPE with appropriate algorithms invoked to incorporate magnetic field deflections to investigate electron energy fluence in the presence of a uniform magnetic field and the energy deposition spectra within a 10 microm water sphere as a function of magnetic field strength. The simulations suggest only very minor changes to the electron fluence even for extremely strong magnetic fields. Further, calculations of the dose-averaged lineal energy indicate that a magnetic field strength of at least 70 T is required before beam quality will change by more than 2%.

  16. Energy deposition around swift proton tracks in polymethylmethacrylate: How much and how far

    NASA Astrophysics Data System (ADS)

    Dapor, Maurizio; Abril, Isabel; de Vera, Pablo; Garcia-Molina, Rafael

    2017-08-01

    The use of proton beams in several modern technologies to probe or modify the properties of materials, such as proton beam lithography or ion beam cancer therapy, requires us to accurately know the extent to which the energy lost by the swift projectiles in the medium is redistributed radially around their tracks, since this determines several endpoints, such as the resolution of imaging or manufacturing techniques, or even the biological outcomes of radiotherapy. In this paper, the radial distribution of the energy deposited around swift-proton tracks in polymethylmethacrylate (PMMA) by the transport of secondary electrons is obtained by means of a detailed Monte Carlo simulation. The initial energy and angular distributions of the secondary electrons generated by proton impact, as well as the electronic cross sections for the ejection of these electrons, are reliably calculated in the framework of the dielectric formalism, where a realistic electronic excitation spectrum of PMMA is accounted for. The cascade of all secondary electrons generated in PMMA is simulated taking into account the main interactions that occur between these electrons and the condensed phase target. After analyzing the influence that several angular distributions of the electrons generated by the proton beam have on the resulting radial profiles of deposited energy, we conclude that the widely used Rudd and Kim formula should be replaced by the simpler isotropic angular distribution, which leads to radial energy distributions comparable to the ones obtained from more realistic angular distributions. By studying the dependence of the radial dose on the proton energy we recommend lower proton energies than previously published for reducing proximity effects around a proton track. The obtained results are of relevance for assessing the resolution limits of proton beam based imaging and manufacturing techniques.

  17. Calculation of the Frequency Distribution of the Energy Deposition in DNA Volumes by Heavy Ions

    NASA Technical Reports Server (NTRS)

    Plante, Ianik; Cicinotta, Francis A.

    2012-01-01

    Radiation quality effects are largely determined by energy deposition in small volumes of characteristic sizes less than 10 nm representative of short-segments of DNA, the DNA nucleosome, or molecules initiating oxidative stress in the nucleus, mitochondria, or extra-cellular matrix. On this scale, qualitatively distinct types of molecular damage are possible for high linear energy transfer (LET) radiation such as heavy ions compared to low LET radiation. Unique types of DNA lesions or oxidative damages are the likely outcome of the energy deposition. The frequency distribution for energy imparted to 1-20 nm targets per unit dose or particle fluence is a useful descriptor and can be evaluated as a function of impact parameter from an ions track. In this work, the simulation of 1-Gy irradiation of a cubic volume of 5 micron by: 1) 450 (1)H(+) ions, 300 MeV; 2) 10 (12)C(6+) ions, 290 MeV/amu and 3) (56)Fe(26+) ions, 1000 MeV/amu was done with the Monte-Carlo simulation code RITRACKS. Cylindrical targets are generated in the irradiated volume, with random orientation. The frequency distribution curves of the energy deposited in the targets is obtained. For small targets (i.e. <25 nm size), the probability of an ion to hit a target is very small; therefore a large number of tracks and targets as well as a large number of histories are necessary to obtain statistically significant results. This simulation is very time-consuming and is difficult to perform by using the original version of RITRACKS. Consequently, the code RITRACKS was adapted to use multiple CPU on a workstation or on a computer cluster. To validate the simulation results, similar calculations were performed using targets with fixed position and orientation, for which experimental data are available [5]. Since the probability of single- and double-strand breaks in DNA as function of energy deposited is well know, the results that were obtained can be used to estimate the yield of DSB, and can be extended

  18. Enhancement of X-ray Energy Deposition via Heavy Element Sensitization in Biological Environments

    NASA Astrophysics Data System (ADS)

    Lim, Sara; Pradhan, Anil; Nahar, Sultana; Barth, Rolf

    2015-05-01

    Energy (dose) deposition by low vs. high energy x-rays (LEX & HEX), approximately E ~ 100 keV and E > 1 MeV respectively, was studied in biological matter sensitized with heavy elements (high-Z or HZ) to improve radiation therapy of cancer. Computations and simulations show that LEX interact favorably with HZ sensitizers by depositing more dose than HEX. LEX photons effectively photoionize deep inner electronic shells and release cell-killing Auger electrons near malignant cells embedded with HZ atoms. HEX photons predominantly Compton scatter with little interaction, even with HZ elements. Monte Carlo simulations show that in comparison to unsensitized tissue, LEX irradiation of HZ-sensitized models resulted in up to a factor of 2 increase in dose deposition relative to HEX. To validate the studies, in vitro experiments were performed using 2 distinct cancer cell types treated with Pt-based sensitizers, then irradiated with a LEX 160 KV x-ray source and a HEX 6 MV LINAC employed in radiation therapy. The experiments support numerical simulations, and demonstrate several factors lower survival of HZ-sensitized cells irradiated with LEX compared with HEX.

  19. Measuring energy efficiency in economics: Shadow value approach

    NASA Astrophysics Data System (ADS)

    Khademvatani, Asgar

    For decades, academic scholars and policy makers have commonly applied a simple average measure, energy intensity, for studying energy efficiency. In contrast, we introduce a distinctive marginal measure called energy shadow value (SV) for modeling energy efficiency drawn on economic theory. This thesis demonstrates energy SV advantages, conceptually and empirically, over the average measure recognizing marginal technical energy efficiency and unveiling allocative energy efficiency (energy SV to energy price). Using a dual profit function, the study illustrates how treating energy as quasi-fixed factor called quasi-fixed approach offers modeling advantages and is appropriate in developing an explicit model for energy efficiency. We address fallacies and misleading results using average measure and demonstrate energy SV advantage in inter- and intra-country energy efficiency comparison. Energy efficiency dynamics and determination of efficient allocation of energy use are shown through factors impacting energy SV: capital, technology, and environmental obligations. To validate the energy SV, we applied a dual restricted cost model using KLEM dataset for the 35 US sectors stretching from 1958 to 2000 and selected a sample of the four sectors. Following the empirical results, predicted wedges between energy price and the SV growth indicate a misallocation of energy use in stone, clay and glass (SCG) and communications (Com) sectors with more evidence in the SCG compared to the Com sector, showing overshoot in energy use relative to optimal paths and cost increases from sub-optimal energy use. The results show that energy productivity is a measure of technical efficiency and is void of information on the economic efficiency of energy use. Decomposing energy SV reveals that energy, capital and technology played key roles in energy SV increases helping to consider and analyze policy implications of energy efficiency improvement. Applying the marginal measure, we also

  20. 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.

  1. MEASUREMENT OF THE INHERENT GROWTH ENERGY OF TISSUES

    PubMed Central

    Carrel, Alexis

    1923-01-01

    1. The residual growth energy of fibroblasts is expressed by the extent of their migration and multiplication in a non-nutrient medium. 2. The residual energy of fibroblasts is related to their inherent energy and the variations of the inherent energy can be ascertained by the measurement of the residual energy. PMID:19868807

  2. Differential heating: A versatile method for thermal conductivity measurements in high-energy-density matter

    DOE PAGES

    Ping, Y.; Fernandez-Panella, A.; Sio, H.; ...

    2015-09-04

    We propose a method for thermal conductivity measurements of high energy density matter based on differential heating. A temperature gradient is created either by surface heating of one material or at an interface between two materials by different energy deposition. The subsequent heat conduction across the temperature gradient is observed by various time-resolved probing techniques. Conceptual designs of such measurements using laser heating, proton heating, and x-ray heating are presented. As a result, the sensitivity of the measurements to thermal conductivity is confirmed by simulations.

  3. Differential heating: A versatile method for thermal conductivity measurements in high-energy-density matter

    NASA Astrophysics Data System (ADS)

    Ping, Y.; Fernandez-Panella, A.; Sio, H.; Correa, A.; Shepherd, R.; Landen, O.; London, R. A.; Sterne, P. A.; Whitley, H. D.; Fratanduono, D.; Boehly, T. R.; Collins, G. W.

    2015-09-01

    We propose a method for thermal conductivity measurements of high energy density matter based on differential heating. A temperature gradient is created either by surface heating of one material or at an interface between two materials by different energy deposition. The subsequent heat conduction across the temperature gradient is observed by various time-resolved probing techniques. Conceptual designs of such measurements using laser heating, proton heating, and x-ray heating are presented. The sensitivity of the measurements to thermal conductivity is confirmed by simulations.

  4. Differential heating: A versatile method for thermal conductivity measurements in high-energy-density matter

    SciTech Connect

    Ping, Y.; Fernandez-Panella, A.; Correa, A.; Shepherd, R.; Landen, O.; London, R. A.; Sterne, P. A.; Whitley, H. D.; Fratanduono, D.; Collins, G. W.; Sio, H.; Boehly, T. R.

    2015-09-15

    We propose a method for thermal conductivity measurements of high energy density matter based on differential heating. A temperature gradient is created either by surface heating of one material or at an interface between two materials by different energy deposition. The subsequent heat conduction across the temperature gradient is observed by various time-resolved probing techniques. Conceptual designs of such measurements using laser heating, proton heating, and x-ray heating are presented. The sensitivity of the measurements to thermal conductivity is confirmed by simulations.

  5. The effect of laser energy on V2O5 thin film growth prepared by laser assisted molecular beam deposition

    NASA Astrophysics Data System (ADS)

    Abdel Samad, B.; Ashrit, P. V.

    2014-09-01

    Vanadium pentoxide V2O5 thin films were grown on glass substrates by the LAMBD deposition system with different laser energies. The structure, composition and optical properties of the films have been investigated with atomic force microscopy, x-ray photoemission spectroscopy, ellipsometry and the transmittance analysis. Upon the increase of laser energy, the results showed that the changes in the optical constants are consistent with the thickness changes of the film. The refractive index increases and the absorption coefficient increases when the laser energy increases. The AFM analysis showed a change of the roughness and structure of the deposited films at different laser energies. The prepared films deposited by LAMBD showed interesting properties with correct V2O5 phase without need of annealing after deposition.

  6. Applications of Ion-Beam Milling and Deposition Techniques to HEL (High Energy Laser) Optics.

    DTIC Science & Technology

    1981-11-23

    using a Twyman -Green interferometer with one leg in the vacuum deposition chamber ........ ...................... .. 14 Figure 3. Deomonstration of...of beam current and voltage. 13 b) I Figure 2. Photographs of interference pattern produced using a Twyman -Green interferometer with one leg in the...Measurements of optical surface roughness were made versus milling depth for various ion beam conditions and geometry arrangements. A Twyman -Green

  7. Hydrodynamic planetary thermosphere model: 2. Coupling of an electron transport/energy deposition model

    NASA Astrophysics Data System (ADS)

    Tian, Feng; Solomon, Stanley C.; Qian, Liying; Lei, Jiuhou; Roble, Raymond G.

    2008-07-01

    An electron transport/energy deposition model is expanded to include atomic nitrogen and is coupled with a 1-D hydrodynamic thermosphere model. The coupled model is used to investigate the response of the Earth's thermosphere under extreme solar EUV conditions and is compared with previous studies. It is found that (1) the parameterization of Swartz and Nisbet (1972) underestimates the ambient electron heating by photoelectrons significantly in the upper thermosphere of the Earth under conditions with greater than 3 times the present solar EUV irradiance; (2) the transition of the Earth's thermosphere from a hydrostatic equilibrium regime to a hydrodynamic regime occurs at a smaller solar EUV flux condition when enhanced, more realistic, and self-consistent, ambient electron heating by photoelectrons is accounted for; (3) atomic nitrogen becomes the dominant neutral species in the upper thermosphere (competing against atomic oxygen) under extreme solar EUV conditions, and the electron impact processes of atomic nitrogen are important for both the chemistry and energetics in the corresponding thermosphere/ionosphere; (4) N+ remains a minor ion compared to O+, even when atomic nitrogen dominates the exobase; and (5) adiabatic cooling does not play an important role in electron gas energy budget. These findings highlight the importance of an electron transport/energy deposition model when investigating the thermosphere and ionosphere of terrestrial planets in their early evolutionary stages.

  8. Experimental measurements and computational predictions of regional particle deposition in a sectional nasal model.

    PubMed

    Schroeter, Jeffry D; Tewksbury, Earl W; Wong, Brian A; Kimbell, Julia S

    2015-02-01

    Knowledge of the regional deposition of inhaled particles in the nose is important for drug delivery and assessment of the toxicity of inhaled materials. In this study, computational fluid dynamics (CFD) predictions and experimental measurements in a nasal replica cast were used to study regional deposition of inhaled microparticles. The replica cast was sectioned into six regions of interest based on nasal anatomy: the nasal vestibule, nasal valve, anterior turbinates, olfactory region, turbinates, and nasopharynx. Monodisperse fluorescein particles with aerodynamic diameters of 2.6-14.3 μm were passed through the assembled cast in the presence of steady inspiratory airflow at 15 L/min. After each experiment, the cast was disassembled and the deposited fluorescein in each region was washed out and quantified with fluorescence spectrometry. A nasal CFD model was developed from the same magnetic resonance imaging scans that were used to construct the replica cast. Steady-state inspiratory airflow and particle deposition calculations were conducted in the CFD model using Fluent(™) at flow rates producing Stokes numbers comparable to experimental conditions. Total and regional particle deposition predictions from the CFD model were compared with experimental measurements from the replica cast. Overall, good agreement was observed between CFD predictions and experimental measurements with similar deposition trends in each region of interest. CFD predictions in central nasal regions demonstrated well-defined maximum values of 15%, 7%, and 12% in the anterior turbinates, olfactory, and turbinates regions, respectively, at particle sizes of 10-11 μm. These results demonstrate the use of a sectioned nasal CFD model based on anatomical regions of interest for nasal drug delivery to elucidate patterns of regional deposition within a human nasal cavity.

  9. Quantum cascade laser-based measurement of metal alkylamide density during atomic layer deposition.

    PubMed

    Maslar, James E; Kimes, William A; Sperling, Brent A

    2012-03-01

    An in situ gas-phase diagnostic for the metal alkylamide compound tetrakis(ethylmethylamido) hafnium (TEMAH), Hf[N(C(2)H(5))(CH(3))](4), was demonstrated. This diagnostic is based on direct absorption measurement of TEMAH vapor using an external cavity quantum cascade laser emitting at 979 cm(-1), coinciding with the most intense TEMAH absorption in the mid-infrared spectral region, and employing 50 kHz amplitude modulation with synchronous detection. Measurements were performed in a single-pass configuration in a research-grade atomic layer deposition (ALD) chamber. To examine the detection limit of this technique for use as a TEMAH delivery monitor, this technique was demonstrated in the absence of any other deposition reactants or products, and to examine the selectivity of this technique in the presence of deposition products that potentially interfere with detection of TEMAH vapor, it was demonstrated during ALD of hafnium oxide using TEMAH and water. This technique successfully detected TEMAH at molecular densities present during simulated industrial ALD conditions. During hafnium oxide ALD using TEMAH and water, absorbance from gas-phase reaction products did not interfere with TEMAH measurements while absorption by reaction products deposited on the optical windows did interfere, although interfering absorption by deposited reaction products corresponded to only ≈4% of the total derived TEMAH density. With short measurement times and appropriate signal averaging, estimated TEMAH minimum detectable densities as low as ≈2 × 10(12) molecules/cm(3) could be obtained. While this technique was demonstrated specifically for TEMAH delivery and hafnium oxide ALD using TEMAH and water, it should be readily applicable to other metal alkylamide compounds and associated metal oxide and nitride deposition chemistries, assuming similar metal alkylamide molar absorptivity and molecular density in the measurement chamber. © 2012 Society for Applied Spectroscopy

  10. Implementation and Rejection of Industrial Steam System Energy Efficiency Measures

    SciTech Connect

    Therkelesen, Peter; McKane, Aimee

    2013-05-01

    Steam systems consume approximately one third of energy applied at U.S. industrial facilities. To reduce energy consumption, steam system energy assessments have been conducted on a wide range of industry types over the course of five years through the Energy Savings Assessment (ESA) program administered by the U.S. Department of Energy (U.S. DOE). ESA energy assessments result in energy efficiency measure recommendations that are given potential energy and energy cost savings and potential implementation cost values. Saving and cost metrics that measure the impact recommended measures will have at facilities, described as percentages of facility baseline energy and energy cost, are developed from ESA data and used in analyses. Developed savings and cost metrics are examined along with implementation and rejection rates of recommended steam system energy efficiency measures. Based on analyses, implementation of steam system energy efficiency measures is driven primarily by cost metrics: payback period and measure implementation cost as a percentage of facility baseline energy cost (implementation cost percentage). Stated reasons for rejecting recommended measures are primarily based upon economic concerns. Additionally, implementation rates of measures are not only functions of savings and cost metrics, but time as well.

  11. Mesoscale energy deposition footprint model for kiloelectronvolt cluster bombardment of solids.

    PubMed

    Russo, Michael F; Garrison, Barbara J

    2006-10-15

    Molecular dynamics simulations have been performed to model 5-keV C60 and Au3 projectile bombardment of an amorphous water substrate. The goal is to obtain detailed insights into the dynamics of motion in order to develop a straightforward and less computationally demanding model of the process of ejection. The molecular dynamics results provide the basis for the mesoscale energy deposition footprint model. This model provides a method for predicting relative yields based on information from less than 1 ps of simulation time.

  12. The influence of different 192Ir sources geometries to the energy deposition

    NASA Astrophysics Data System (ADS)

    Santos, W. S.; Gonalves, P. E.; Belinato, W.; Caldas, L. V. E.; Perini, A. P.; Neves, L. P.

    2016-07-01

    In this paper, various simplifications of the HDR source Varian VariSource Classic model, in which 192Ir as a radionuclide is used, were compared. These simplifications were carried out by Monte Carlo simulations, using the MCNPX 2.7.0 code. The different sources were compared through a distribution of energy deposition in a water phantom. Our results indicated that small simplifications will present no influence on the source response, and the removal of the entire capsule surrounding the radionuclide will present a difference of just 0.53% in the final response.

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Role of suprathermal electrons during nanosecond laser energy deposit in fused silica

    SciTech Connect

    Grua, P.; Hébert, D.; Lamaignère, L.; Rullier, J.-L.

    2014-08-25

    An accurate description of interaction between a nanosecond laser pulse and a wide band gap dielectric, such as fused silica, requires the understanding of energy deposit induced by temperature changes occurring in the material. In order to identify the fundamental processes involved in laser-matter interaction, we have used a 1D computational model that allows us to describe a wide set of physical mechanisms and intended for comparison with specially designed “1D experiments.” We have pointed out that suprathermal electrons are very likely implicated in heat conduction, and this assumption has allowed the model to reproduce the experiments.

  15. 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.

  16. The measurement of dry deposition and surface runoff to quantify urban road pollution in Taipei, Taiwan.

    PubMed

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

    2013-10-16

    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/m(2) · 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.

  17. Ultraviolet absorption measurements of CF2 in the parallel plate pyrolytic chemical vapour deposition process

    NASA Astrophysics Data System (ADS)

    Cruden, Brett A.; Gleason, Karen K.; Sawin, Herbert H.

    2002-03-01

    Polytetrafluoroethylene films have been deposited for use as low dielectric constant materials. Deposition is performed through pyrolysis of hexafluoropropylene oxide (HFPO) to produce CF2, which can then polymerize and deposit as a thin film. The variation of CF2 concentration as a function of reactor conditions has been characterized by ultraviolet absorption spectroscopy. CF2 concentration is observed to go through a maximum with respect to both pressure and pyrolysis temperature when it is present in large amounts (~1014 cm-3). A one-dimensional model including known kinetic reactions for HFPO decomposition and CF2 recombination and multi-component diffusive transport has been applied to the parallel plate system. The result is seen to overestimate the measured concentration and does not capture the maxima observed versus pressure and temperature. An additional mechanism of particle formation, by CF2 insertion into (CF2)n oligomers, has been introduced to produce a kinetic model that explains the CF2 concentration measurements.

  18. Characterization of nanosecond, femtosecond and dual pulse laser energy deposition in air for flow control and diagnostic applications

    NASA Astrophysics Data System (ADS)

    Limbach, Christopher M.

    The non-resonant heating of gases by laser irradiation and plasma formation has been under investigation since the development of 100 megawatt peak power, Q-switched, nanosecond pulse duration lasers and the commensurate discovery of laser air sparks. More recently, advances in mode-locking and chirped pulse amplification have led to commercially available 100 gigawatt peak power, femtosecond pulse duration lasers with a rapidly increasing number of applications including remote sensing, laser spectroscopy, aerodynamic flow control, and molecular tagging velocimetry and thermometry diagnostics. This work investigates local energy deposition and gas heating produced by focused, non-resonant, nanosecond and femtosecond laser pulses in the context of flow control and laser diagnostic applications. Three types of pulse configurations were examined: single nanosecond pulses, single femtosecond pulses and a dual pulse approach whereby a femtosecond pre-ionizing pulse is followed by a nanosecond pulse. For each pulse configuration, optical and laser diagnostic techniques were applied in order to qualitatively and quantitatively measure the plasmadynamic and hydrodynamic processes accompanying laser energy deposition. Time resolved imaging of optical emission from the plasma and excited species was used to qualitatively examine the morphology and decay of the excited gas. Additionally, Thomson scattering and Rayleigh scattering diagnostics were applied towards measurements of electron temperature, electron density, gas temperature and gas density. Gas heating by nanosecond and dual pulse laser plasmas was found to be considerably more intense than femtosecond plasmas, irrespective of pressure, while the dual pulse approach provided substantially more controllability than nanosecond pulses alone. In comparison, measurements of femtosecond laser heating showed a strong and nonlinearly dependence on focusing strength. With comparable pulse energy, measurements of maximum

  19. Sensing for directed energy deposition and powder bed fusion additive manufacturing at Penn State University

    NASA Astrophysics Data System (ADS)

    Nassar, Abdalla R.; Reutzel, Edward W.; Brown, Stephen W.; Morgan, John P.; Morgan, Jacob P.; Natale, Donald J.; Tutwiler, Rick L.; Feck, David P.; Banks, Jeffery C.

    2016-04-01

    Additive manufacturing of metal components through directed energy deposition or powder bed fusion is a complex undertaking, often involving hundreds or thousands of individual laser deposits. During processing, conditions may fluctuate, e.g. material feed rate, beam power, surrounding gas composition, local and global temperature, build geometry, etc., leading to unintended variations in final part geometry, microstructure and properties. To assess or control as-deposited quality, researchers have used a variety of methods, including those based on sensing of melt pool and plume emission characteristics, characteristics of powder application, and layer-wise imaging. Here, a summary of ongoing process monitoring activities at Penn State is provided, along with a discussion of recent advancements in the area of layer-wise image acquisition and analysis during powder bed fusion processing. Specifically, methods that enable direct comparisons of CAD model, build images, and 3D micro-tomographic scan data will be covered, along with thoughts on how such analyses can be related to overall process quality.

  20. Energy Measurement in a Plasma Wakefield Accelerator

    SciTech Connect

    Ischebeck, R

    2007-07-06

    In the E-167 plasma wakefield acceleration experiment, electrons with an initial energy of 42GeV are accelerated in a meter-scale lithium plasma. Particles are leaving plasma with a large energy spread. To determine the spectrum of the accelerated particles, a two-plane spectrometer has been set up.

  1. A database of frequency distributions of energy depositions in small-size targets by electrons and ions.

    PubMed

    Nikjoo, H; Uehara, S; Emfietzoglou, D; Pinsky, L

    2011-02-01

    Linear energy transfer (LET) is an average quantity, which cannot display the stochastics of the interactions of radiation tracks in the target volume. For this reason, microdosimetry distributions have been defined to overcome the LET shortcomings. In this paper, model calculations of frequency distributions for energy depositions in nanometre size targets, diameters 1-100 nm, and for a 1 μm diameter wall-less TEPC, for electrons, protons, alpha particles and carbon ions are reported. Frequency distributions for energy depositions in small-size targets with dimensions similar to those of biological molecules are useful for modelling and calculations of DNA damage. Monte Carlo track structure codes KURBUC and PITS99 were used to generate tracks of primary electrons 10 eV to 1 MeV, and ions 1 keV µm(-1) to 300 MeV µm(-1) energies. Distribution of absolute frequencies of energy depositions in volumes with diameters of 1-100 nm randomly positioned in unit density water irradiated with 1 Gy of the given radiation was obtained. Data are presented for frequency of energy depositions and microdosimetry quantities including mean lineal energy, dose mean lineal energy, frequency mean specific energy and dose mean specific energy. The modelling and calculations presented in this work are useful for characterisation of the quality of radiation beam in biophysical studies and in radiation therapy.

  2. High voltage electrophoretic deposition for electrochemical energy storage and other applications

    NASA Astrophysics Data System (ADS)

    Santhanagopalan, Sunand

    High voltage electrophoretic deposition (HVEPD) has been developed as a novel technique to obtain vertically aligned forests of one-dimensional nanomaterials for efficient energy storage. The ability to control and manipulate nanomaterials is critical for their effective usage in a variety of applications. Oriented structures of one-dimensional nanomaterials provide a unique opportunity to take full advantage of their excellent mechanical and electrochemical properties. However, it is still a significant challenge to obtain such oriented structures with great process flexibility, ease of processing under mild conditions and the capability to scale up, especially in context of efficient device fabrication and system packaging. This work presents HVEPD as a simple, versatile and generic technique to obtain vertically aligned forests of different one-dimensional nanomaterials on flexible, transparent and scalable substrates. Improvements on material chemistry and reduction of contact resistance have enabled the fabrication of high power supercapacitor electrodes using the HVEPD method. The investigations have also paved the way for further enhancements of performance by employing hybrid material systems and AC/DC pulsed deposition. Multi-walled carbon nanotubes (MWCNTs) were used as the starting material to demonstrate the HVEPD technique. A comprehensive study of the key parameters was conducted to better understand the working mechanism of the HVEPD process. It has been confirmed that HVEPD was enabled by three key factors: high deposition voltage for alignment, low dispersion concentration to avoid aggregation and simultaneous formation of holding layer by electrodeposition for reinforcement of nanoforests. A set of suitable parameters were found to obtain vertically aligned forests of MWCNTs. Compared with their randomly oriented counterparts, the aligned MWCNT forests showed better electrochemical performance, lower electrical resistance and a capability to

  3. 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.

  4. Investigating oceanic tidal energy dissipation on deep time scales using short tidal deposit sequences

    NASA Astrophysics Data System (ADS)

    Coughenour, C.

    2012-12-01

    One of the enduring problems in physical oceanography has been that of tidal dynamics and the effective tidal torque that serves to slow Earth's axial rotation. In the late 20th century, with the aid of satellite altimetry and other technologies, a suite of reliable estimates was finally placed on the magnitude of this torque and other, related parameters in the current epoch. Tidal drag accounts for a 20 microsecond/year increase in mean day length, a 3.5 terawatt dissipation of energy in the oceans (Kantha et al., 1998), and a lunar retreat rate of 3.82 cm/yr (Dickey et al., 1994). Despite these significant advances, however, the problem of tidal dissipation in the geologic past remains largely unresolved. This is due, in part, to difficulties in numerical modeling of past tidal regimes that stem from uncertainties in ocean basin configurations and lunar distances. Tidal deposits can record, to high resolution, the primary astronomical periodicities responsible for the generation of the tidal currents under which transport and deposition occur. With reliable lunar orbital period data obtained from tidal deposits, the past Earth-Moon distance and length of day can be calculated. This task requires careful spectral analysis and consideration of sedimentological factors that may add noise and/or discontinuities to the signal. For deposits representing less than one year of deposition, the necessary assumptions are that Earth's moment of inertia has not changed significantly over the time interval of interest and that the solar component of tidal dissipation can be well-approximated. With consideration of the total angular momentum of the Earth-Moon couplet, we derive a method to calculate lunar distance and length of day. The efficacy of this method and its assumptions is tested via the multi-year sequence of data obtained from the late Precambrian Elatina Formation of Australia and comparing results obtained from the full suite of data by Williams (2000). We go on

  5. Monte-Carlo Simulations of the Nuclear Energy Deposition Inside the CARMEN-1P Differential Calorimeter Irradiated into OSIRIS Reactor

    SciTech Connect

    Amharrak, H.; Reynard-Carette, C.; Carette, M.; Lemaire, M.; Vaglio-Gaudard, C.; Fourmentel, D.; Lyoussi, A.

    2015-07-01

    carried out. A preliminary analysis shows that the numerical results overestimate the measurements by about 20 %. A new approach has been developed in order to estimate the nuclear heating by two methods (energy deposition or KERMA) by considering the whole complete geometry of the sensor. This new approach will contribute to the interpretation of the irradiation campaign and will be useful to improve the out-of-pile calibration procedure of the sensor and its thermal response during irradiations. The aim of this paper is to present simulations made by using MCNP5 Monte-Carlo transport code (using ENDF/B-VI nuclear data library) for the nuclear heating inside the different parts of the calorimeter (head, rod and base). Calculations into two steps will be realized. We will use as an input source in the model new spectra (neutrons, prompt-photons and delayed-photons) calculated with the Monte Carlo code TRIPOLI-4{sup R} inside different experimental channels (water) located into the OSIRIS periphery and used during the CARMEN-1P irradiation campaign. We will consider Neutrons- Photons-Electrons and Photons-Electrons modes. We will begin by a brief description of the differential-calorimeter device geometry. Then the MCNP5 model used for the calculations of nuclear heating inside the calorimeter elements will be introduced. The energy deposition due to the prompt-gamma, delayed-gamma and neutrons, the neutron-activation of the device will be considered. The different components of the nuclear heating inside the different parts of the calorimeter will be detailed. Moreover, a comparison between KERMA and nuclear energy deposition estimations will be given. Finally, a comparison between this total nuclear heating Calculation and Experiment in graphite sample will be determined. (authors)

  6. Model of enhanced energy deposition in a Z-pinch plasma

    SciTech Connect

    Velikovich, A. L.; Davis, J.; Thornhill, J. W.; Giuliani, J. L. Jr.; Rudakov, L. I.; Deeney, C.

    2000-08-01

    In numerous experiments, magnetic energy coupled to strongly radiating Z-pinch plasmas exceeds the thermalized kinetic energy, sometimes by a factor of 2-3. An analytical model describing this additional energy deposition based on the concept of macroscopic magnetohydrodynamic (MHD) turbulent pinch heating proposed by Rudakov and Sudan [Phys. Reports 283, 253 (1997)] is presented. The pinch plasma is modeled as a foam-like medium saturated with toroidal ''magnetic bubbles'' produced by the development of surface m=0 Rayleigh-Taylor and MHD instabilities. As the bubbles converge to the pinch axis, their magnetic energy is converted to thermal energy of the plasma through pdV work. Explicit formulas for the average dissipation rate of this process and the corresponding contribution to the resistance of the load, which compare favorably to the experimental data and simulation results, are presented. The possibility of using this enhanced (relative to Ohmic heating) dissipation mechanism to power novel plasma radiation sources and produce high K-shell yields using long current rise time machines is discussed. (c) 2000 American Institute of Physics.

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

    PubMed

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

    2016-04-14

    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.

  8. Energy deposition and radiation quality of radon and radon daughters. Final report

    SciTech Connect

    Karam, L.R.; Caswell, R.S.

    1996-09-09

    This program was aimed at creating a quantitative physical description, at the micrometer and nanometer levels, of the physical interactions of the alpha particles from radon and its daughters with cells at risk in the bronchial epithelium. The authors calculated alpha-particle energy spectra incident upon the cells and also energy deposition spectra in micrometer- and nanometer-sized sites as a function of cell depth, site size, airway diameter, activities of {sup 218}Po and {sup 214}Po, and other parameters. These data are now being applied, using biophysical models of radiation effects, to predict cell killing, mutations, and cell transformation. The model predictions are then compared to experimental biophysical, biochemical, and biological information. These studies contribute to a detailed understanding of the mechanisms of the biological effectiveness of the radiations emitted by radon and its progeny.

  9. Deposition of silicon oxynitride films by low energy ion beam assisted nitridation at room temperature

    NASA Astrophysics Data System (ADS)

    Youroukov, S.; Kitova, S.; Danev, G.

    2008-05-01

    The possibility is studied of growing thin silicon oxynitride films by e-gun evaporation of SiO and SiO2 together with concurrent bombardment with low energy N2+ ions from a cyclotron resonance (ECR) source at room temperature of substrates. The degree of nitridation and oxidation of the films is investigated by means of X-ray spectroscopy. The optical characteristics of the films, their environmental stability and adhesion to different substrates are examined. The results obtained show than the films deposited are transparent. It is found that in the case of SiO evaporation with concurrent N2+ ion bombardment, reactive implantation of nitrogen within the films takes place at room temperature of the substrate with the formation of a new silicon oxynitride compound even at low ion energy (150-200 eV).

  10. Measurements and Modeling to Enhance Estimates of NH3 Total Deposition

    EPA Science Inventory

    Values for the total (wet + dry) deposition of ammonia are needed as input to nitrogen budget studies and ecological assessments. Concentrations of ammonia are measured at NADP’s Ammonia Monitoring Network (AMoN) sites. Research is focusing on the use of the concentration...

  11. Measurement of ion energy distributions using a combined energy and mass analyzer.

    PubMed

    Walton, S G; Fernsler, R F; Leonhardt, D

    2007-08-01

    A method is described for measuring ion energy distributions using a commercially available, combined energy analyzer/mass spectrometer. The distributions were measured at an electrode located adjacent to pulsed, electron beam-generated plasmas produced in argon. The method uses energy-dependent tuning and was tested for various plasma conditions. The results indicate an improved collection efficiency of low-energy ions when compared to conventional approaches in measuring ion energy distributions.

  12. REFLEX: An energy deposition code that models the effects of electron reflection during electron beam heating tests

    SciTech Connect

    Stone, C.A. IV; Croessmann, C.D.; Whitley, J.B.

    1988-01-01

    This report describes an energy coupling model that considers electron reflection losses during electron beam heating experiments. This model is embodied on the REFLEX computer code, written in standard FORTRAN 77. REFLEX currently models energy deposition phenomena in three different sample geometries. These configurations include flat, cylindrical shell, and hemispherical shell surfaces. Given the electron beam operating parameters, REFLEX calculates the heat flux profile over a sample's surface, the total amount of energy deposited into a sample, and the percentage of the electron beam energy that is transferred to a sample. This document describes the energy deposition equations used in the REFLEX code; the program is described and detailed instructions are given regarding the input. Results are given for each geometry and possible experimental applications are presented. 3 refs., 20 figs., 11 tabs.

  13. Monte Carlo simulation of energy-deposit clustering for ions of the same LET in liquid water.

    PubMed

    Francis, Z; Incerti, S; Ivanchenko, V; Champion, C; Karamitros, M; Bernal, M A; El Bitar, Z

    2012-01-07

    This work presents a Monte Carlo study of energy depositions due to protons, alpha particles and carbon ions of the same linear-energy-transfer (LET) in liquid water. The corresponding track structures were generated using the Geant4-DNA toolkit, and the energy deposition spatial distributions were analyzed using an adapted version of the DBSCAN clustering algorithm. Combining the Geant4 simulations and the clustering algorithm it was possible to compare the quality of the different radiation types. The ratios of clustered and single energy depositions are shown versus particle LET and frequency-mean lineal energies. The estimated effect of these types of radiation on biological tissues is then discussed by comparing the results obtained for different particles with the same LET.

  14. Enhancement of the maximum energy density in atomic layer deposited oxide based thin film capacitors

    NASA Astrophysics Data System (ADS)

    Spahr, Holger; Nowak, Christine; Hirschberg, Felix; Reinker, Johannes; Kowalsky, Wolfgang; Hente, Dirk; Johannes, Hans-Hermann

    2013-07-01

    Thin film capacitors on areas up to 6 mm2 have been measured regarding capacitance density, relative permittivity, and electrical breakdown. The maximum storable energy density of the thin film capacitors will be discussed as a parameter to evaluate the thin film capacitors applicability. Therefore the measurements of the layer thickness, capacitance density, and the breakdown voltage were combined to achieve the maximum storable areal and volume energy density depending on the dielectric layer thickness. Thickness dependent volume energy densities of up to 50 J/cm3 for pure Al2O3 and 60 J/cm3 for Al2O3/TiO2 nanolaminates were reached.

  15. Development and deposition of resilin in energy stores for locust jumping.

    PubMed

    Burrows, Malcolm

    2016-08-15

    Locusts jump by using a catapult mechanism in which energy produced by slow contractions of the extensor tibiae muscles of the hind legs is stored in distortions of the exoskeleton, most notably (1) the two semi-lunar processes at each knee joint and (2) the tendons of the extensor muscles themselves. The energy is then suddenly released from these stores to power the rapid, propulsive movements of the hind legs. The reliance on the mechanical storage of energy is likely to impact on jumping because growth occurs by a series of five moults, at each of which the exoskeleton is replaced by a new one. All developmental stages (instars) nevertheless jump as a means of forward locomotion, or as an escape movement. Here, I show that in each instar, resilin is added to the semi-lunar processes and to the core of the extensor tendons so that their thickness increases. As the next moult approaches, a new exoskeleton forms within the old one, with resilin already present in the new semi-lunar processes. The old exoskeleton, the tendons and their resilin are discarded at moulting. The resilin of the semi-lunar processes and tendons of the new instar is initially thin, but a similar pattern of deposition results in an increase of their thickness. In adults, resilin continues to be deposited so that at 4 weeks old the thickness in the semi-lunar processes has increased fourfold. These changes in the energy stores accompany changes in jumping ability and performance during each moulting cycle.

  16. Atomic-layer-deposition-assisted formation of carbon nanoflakes on metal oxides and energy storage application.

    PubMed

    Guan, Cao; Zeng, Zhiyuan; Li, Xianglin; Cao, Xiehong; Fan, Yu; Xia, Xinhui; Pan, Guoxiang; Zhang, Hua; Fan, Hong Jin

    2014-01-29

    Nanostructured carbon is widely used in energy storage devices (e.g., Li-ion and Li-air batteries and supercapacitors). A new method is developed for the generation of carbon nanoflakes on various metal oxide nanostructures by combining atomic layer deposition (ALD) and glucose carbonization. Various metal oxide@nanoflake carbon (MO@f-C) core-branch nanostructures are obtained. For the mechanism, it is proposed that the ALD Al2 O3 and glucose form a composite layer. Upon thermal annealing, the composite layer becomes fragmented and moves outward, accompanied by carbon deposition on the alumina skeleton. When tested as electrochemical supercapacitor electrode, the hierarchical MO@f-C nanostructures exhibit better properties compared with the pristine metal oxides or the carbon coating without ALD. The enhancement can be ascribed to increased specific surface areas and electric conductivity due to the carbon flake coating. This peculiar carbon coating method with the unique hierarchical nanostructure may provide a new insight into the preparation of 'oxides + carbon' hybrid electrode materials for energy storage applications.

  17. Initial studies of Bremsstrahlung energy deposition in small-bore superconducting undulator structures in linac environments

    SciTech Connect

    Cremer, T.; Tatchyn, R.

    1995-12-31

    One of the more promising technologies for developing minimal-length insertion devices for linac-driven, single-pass Free Electron Lasers (FELs) operating in the x-ray range is based on the use of superconducting (SC) materials. In recent FEL simulations, for example, a bifilar helical SC device with a 2 cm period and 1.8 T field was found to require a 30 m saturation length for operation at 1.5{Angstrom} on a 15 GeV linac, more than 40% shorter than an alternative hybrid/permanent magnet (hybrid/PM) undulator. AT the same time, however, SC technology is known to present characteristic difficulties for insertion device design, both in engineering detail and in operation. Perhaps the most critical problem, as observed, e.g., by Madey and co-workers in their initial FEL experiments, was the frequent quenching induced by scattered electrons upstream of their (bifilar) device. Postulating that this quenching was precipitated by directly-scattered or bremsstrahlung-induced particle energy deposited into the SC material or into material contiguous with it, the importance of numerical and experimental characterizations of this phenomenon for linac-based, user-facility SC undulator design becomes evident. In this paper we discuss selected prior experimental results and report on initial EGS4 code studies of scattered and bremsstrahlung induced particle energy deposition into SC structures with geometries comparable to a small-bore bifilar helical undulator.

  18. Use of energy deposition spectrometer Liulin for individual monitoring of aircrew.

    PubMed

    Ploc, O; Pachnerová Brabcová, K; Spurny, F; Malušek, A; Dachev, T

    2011-03-01

    Silicon energy deposition spectrometer Liulin was primarily developed for cosmic radiation monitoring onboard spacecrafts. Nowadays, Liulin type detectors are also used to characterise radiation field on board aircraft, at alpine observatories and behind the shielding of heavy ion accelerators. In this work, experiments and calibrations performed in these radiation fields are presented and the method developed for calculation of ambient dose equivalent H*(10) on board aircraft is described. Since 2001, a simple method employing the energy deposition spectra had been used to determine H*(10) on board aircraft but, in 2004, it became clear that the resulting values were strongly biased at locations close to Earth's equator. An improved method for the determination of H*(10) on board aircraft using the Liulin detector was developed. It took into account the composition of the radiation field via the ratio of absorbed doses D(low) and D(neut) reflecting the contributions from low-LET particles and neutrons, respectively. It resulted in much better agreement with the EPCARD computer code for all aircraft locations; relative differences were within 11 % for low-LET and 20 % for neutron components of H*(10).

  19. Production of High Energy Particles Using the Pd/D Co-Deposition Process

    NASA Astrophysics Data System (ADS)

    Mosier-Boss, Pamela A.; Szpak, Stanislaw; Gordon, Frank E.

    2007-03-01

    Using the Pd/D co-deposition technique, we have obtained evidence (i.e., heat generation, hot spots, mini-explosions, radiation, and tritium production) suggestive that nuclear reactions can and do occur within the Pd lattice. It was found that these reactions are enhanced in the presence of either an external electric or magnetic field. SEM analysis of the cathodes shows morphological features suggestive of localized melting of the palladium. EDX analysis of these features show the presence of new elements which result form transmutation. To verify that these new elements are indeed nuclear in origin, experiments have been conducted using CR-39 detectors, a commonly used etch-track detector for recording the emission of high energy particles such as alphas and protons. When the co-deposition reaction was conducted in either an external electric or magnetic field, numerous tracks due to high energy particles were clearly observed on the CR-39 detector in those areas where the cathode is in direct contact with the detector. S. Szpak et al, J. Electroanal. Chem., v 580, 284(2005). S. Szpak et al, Naturwissenschaften, v 92, 394-397(2005).

  20. Buoyancy driven mixing of miscible fluids by volumetric energy deposition of microwaves.

    PubMed

    Wachtor, Adam J; Mocko, Veronika; Williams, Darrick J; Goertz, Matthew P; Jebrail, Farzaneh F

    2013-01-01

    An experiment that seeks to investigate buoyancy driven mixing of miscible fluids by microwave volumetric energy deposition is presented. The experiment involves the use of a light, non-polar fluid that initially rests on top of a heavier fluid which is more polar. Microwaves preferentially heat the polar fluid, and its density decreases due to thermal expansion. As the microwave heating continues, the density of the lower fluid eventually becomes less than that of the upper, and buoyancy driven Rayleigh-Taylor mixing ensues. The choice of fluids is crucial to the success of the experiment, and a description is given of numerous fluid combinations considered and characterized. After careful consideration, the miscible pair of toluene/tetrahydrofuran (THF) was determined as having the best potential for successful volumetric energy deposition buoyancy driven mixing. Various single fluid calibration experiments were performed to facilitate the development of a heating theory. Thereafter, results from two-fluid mixing experiments are presented that demonstrate the capability of this novel Rayleigh-Taylor driven experiment. Particular interest is paid to the onset of buoyancy driven mixing and unusual aspects of the experiment in the context of typical Rayleigh-Taylor driven mixing.

  1. Comparison of Energy Deposition in the Auroral Oval and Cap Regions for Cases Where Transpolar Structures Exist

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

    For several cases where the full auroral zone is imaged and transpolar structures exist, we compare the total energy input to the auroral oval with the total energy input in the polar cap. This comparison is made for cases where auroral intensification near local midnight is and is not observed. Temporal evolution of the energy balance between the energy deposited in the oval and polar cap can be used to understand the mechanism that triggers substorms.

  2. Procedure for Measuring and Reporting Commercial Building Energy Performance

    SciTech Connect

    Barley, D.; Deru, M.; Pless, S.; Torcellini, P.

    2005-10-01

    This procedure is intended to provide a standard method for measuring and characterizing the energy performance of commercial buildings. The procedure determines the energy consumption, electrical energy demand, and on-site energy production in existing commercial buildings of all types. The performance metrics determined here may be compared against benchmarks to evaluate performance and verify that performance targets have been achieved.

  3. 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.

  4. 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.

  5. A concentration rebound method for measuring particle penetrationand deposition in the indoor environment

    SciTech Connect

    tlthatcher@lbl.gov

    2002-09-01

    Continuous, size resolved particle measurements were performed in two houses in order to determine size-dependent particle penetration and deposition in the indoor environment. The experiments consisted of three parts: (1) measurement of the particle loss rate following artificial elevation of indoor particle concentrations, (2) rapid reduction in particle concentration through induced ventilation by pressurization of the houses with HEPA-filtered air, and (3) measurement of the particle concentration rebound after house pressurization stopped. During the particle concentration decay period, when indoor concentrations are very high, losses due to deposition are large compared to gains due to particle infiltration. During the concentration rebound period, the opposite is true. The large variation in indoor concentration allows the effects of penetration and deposition losses to be separated by the transient, two-parameter model we employed to analyze the data. We found penetration factors between 0.3 and 1 and deposition loss rates between 0.1 and 5 h{sup -1}, for particles between 0.1 and 10 {micro}m.

  6. Energy deposition of quasi-two temperature relativistic electrons in fast-shock ignition scenario

    NASA Astrophysics Data System (ADS)

    Ghasemi, Seyed Abolfazl; Farahbod, Amir Hossein

    2016-10-01

    Previous calculations from Solodov et al. (2008) indicate that classical stopping and scattering dominate electrons energy deposition and transport when the electrons reach the dense plasma in FSI inertial confinement fusion concept [1]. Our calculations show that, by using quasi- two temperature electrons energy distribution function [2] in comparison with exponential [3] or monoenergetic distribution function and also increasing fast electrons energy to about 7 MeV, the ratio of beam blooming to straggling definitely decreases. Our analytical analysis shows that for fuel mass more than 1 mg and for fast ignitor wavelength λif > 0.53 μ m, straggling and beam blooming increases. Meanwhile, by reducing fast ignitor wavelength from 0.53 to 0.35 micron, and for fuel mass about 2 mg, electron penetration into the dense fuel slightly increases. Therefore, reduction of scattering (blooming and straggling) of electrons and enhancement of electron penetration into the dense fuel, can be obtained in relativistic regime with high energy fast electrons of the order of 5 Mev and more. Such derivations can be used in theoretical studies of the ignition conditions and PIC simulations of the electron transport in fast ignition scenario.

  7. Wet atmospheric deposition of nitrogen: 20 years measurement in Shenzhen City, China.

    PubMed

    Huang, Yilong; Lu, XiXi; Chen, Kai

    2013-01-01

    We presented measurements of wet deposition of NH(4)(+)-N and NO(3)(-)-N from 1986 to 2006 in Shenzhen City, China. Over the past 20 years, NO(3)(-)-N concentration had significantly increased, but a reverse trend was found for NH(4)(+)-N. The main form of total inorganic nitrogen (TIN) was NH(4)(+)-N and the average NH(4)(+)-N/NO(3)(-)-N ratio was 1.57 in this area. The contribution of NO(3)(-)-N to TIN increased from 28-42% in the period of 1986-2000 to 50-63% during 2001-2006. The increased deposition flux of NO(3)(-)-N resulted in the increasing trend of TIN, although NH(4)(+)-N showed a decreasing trend over time. Average deposition flux of TIN during 1986-2006 was 13.24 kg/ha/year, with a minimum value of 6.03kg/ha/year in 1988 and a maximum value of 20.52 kg/ha/year in 1997. Wet deposition fluxes of N appeared to vary with season, 81% occurred in the warm season (from April to September). The wet deposition of TIN to the Shenzhen Reservoir reached 8,902 kg in 2006, which contributed 9.95% of the total nonpoint pollution to the reservoir and will be increased in the future.

  8. 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.

  9. Inkwells for on-demand deposition rate measurement in aerosol-jet based 3D printing

    NASA Astrophysics Data System (ADS)

    Gu, Yuan; Gutierrez, David; Das, Siddhartha; Hines, D. R.

    2017-09-01

    Aerosol-jet printing (AJP) is an important direct-write printing technology based on additive manufacturing methods. Numerous research groups have utilized AJP for the fabrication of electronic circuits and devices. However, there has not been any real-time or even any on-demand method for quantitatively measuring and/or setting the deposition rate of an AJ ink stream. In this paper, we present a method for measuring the deposition rate of an AJ ink stream by printing into an array of inkwells that were fabricated using photolithography and were characterized using x-ray tomography and optical profilometry. These inkwell arrays were then used to establish a set of deposition rates namely 0.0011, 0.0024, 0.0035, 0.0046 and 0.0059 mm3 s-1 that were subsequently compared with independently-measured deposition rates obtained by printing the ink stream into a weighing pan for a specified time and calculating the resulting deposition rate from the weight of the printed sample. From this comparison, it is observed that, for a human operator, the error in setting a specific deposition rate is less for inkwell fill times greater than 3 s and greater for fill times less than 3 s. This observation indicates that the average volume of an inkwell array should be at least three times the desired deposition rate (V inkwell  >  3R). It was also observed that when the diameter of the inkwell was only slightly larger than the ink stream diameter, the ink uniformly wets the sidewall of the inkwell and results in a well filled inkwell for which the point at which it is just fully filled is easily observable. Finally, the interactions of the ink with both ‘philic’ and ‘phobic’ inkwells were studied illustrating the ability to use inkwells of various materials for setting the desired deposition rates for a variety of AJ printable inks.

  10. Volatile-rich Crater Interior Deposits on Mars: An Energy Balance Model of Modification

    NASA Technical Reports Server (NTRS)

    Russell, Patrick S.; Head, James W.; Hecht, Michael H.

    2003-01-01

    Several craters on Mars are partially filled by material emplaced by post-impact processes. Populations of such craters include those in the circumsouth polar cap region, in Arabia Terra, associated with the Medusae Fossae Formation, and in the northern lowlands proximal to the north polar cap. In this study, crater fill material refers to an interior mound, generally separated from the interior walls of the crater by a trough that may be continuous along the crater s circumference (i.e. a ring-shaped trough), or may only partially contact the crater walls (i.e. a crescent-shaped trough). The fill deposit is frequently off-center from the crater center and may be asymmetric, (i.e. not circular) in plan view shape. Here we test the hypothesis that asymmetries in volatile fill shape, profile, and center-location within a crater result from asymmetries in local energy balance within the crater due mainly to variation of solar insolation and radiative effects of the crater walls over the crater interior. We first focus on Korolev crater in the northern lowlands. We can then apply this model to other craters in different regions. If asymmetry in morphology and location of crater fill are consistent with radiative-dominated asymmetries in energy budget within the crater, then 1) the volatile-rich composition of the fill is supported (this process should not be effective at shaping volcanic or sedimentary deposits), and 2) the dominant factor determining the observed shape of volatile-rich crater fill is the local radiative energy budget within the crater (and erosive processes such as eolian deflation are not necessary).

  11. Volatile-rich Crater Interior Deposits on Mars: An Energy Balance Model of Modification

    NASA Technical Reports Server (NTRS)

    Russell, Patrick S.; Head, James W.; Hecht, Michael H.

    2003-01-01

    Several craters on Mars are partially filled by material emplaced by post-impact processes. Populations of such craters include those in the circumsouth polar cap region, in Arabia Terra, associated with the Medusae Fossae Formation, and in the northern lowlands proximal to the north polar cap. In this study, crater fill material refers to an interior mound, generally separated from the interior walls of the crater by a trough that may be continuous along the crater s circumference (i.e. a ring-shaped trough), or may only partially contact the crater walls (i.e. a crescent-shaped trough). The fill deposit is frequently off-center from the crater center and may be asymmetric, (i.e. not circular) in plan view shape. Here we test the hypothesis that asymmetries in volatile fill shape, profile, and center-location within a crater result from asymmetries in local energy balance within the crater due mainly to variation of solar insolation and radiative effects of the crater walls over the crater interior. We first focus on Korolev crater in the northern lowlands. We can then apply this model to other craters in different regions. If asymmetry in morphology and location of crater fill are consistent with radiative-dominated asymmetries in energy budget within the crater, then 1) the volatile-rich composition of the fill is supported (this process should not be effective at shaping volcanic or sedimentary deposits), and 2) the dominant factor determining the observed shape of volatile-rich crater fill is the local radiative energy budget within the crater (and erosive processes such as eolian deflation are not necessary).

  12. Solar energy control system. [temperature measurement

    NASA Technical Reports Server (NTRS)

    Currie, J. R. (Inventor)

    1981-01-01

    A solar energy control system for a hot air type solar energy heating system wherein thermocouples are arranged to sense the temperature of a solar collector, a space to be heated, and a top and bottom of a heat storage unit is disclosed. Pertinent thermocouples are differentially connected together, and these are employed to effect the operation of dampers, a fan, and an auxiliary heat source. In accomplishing this, the differential outputs from the thermocouples are amplified by a single amplifier by multiplexing techniques. Additionally, the amplifier is corrected as to offset by including as one multiplex channel a common reference signal.

  13. Thermal smoothing and hydrodynamical compensation of the nonuniformities of laser energy deposition in a direct-driven target

    NASA Astrophysics Data System (ADS)

    Gus'kov, S.; Rozanov, V.; Lebo, I.; Vergunova, G.; Tishkin, V.; Zmitrenko, N.; Kozubskaya, T.; Popov, I.; Nikishin, V.

    1996-05-01

    Design of the LIGHT target based on an electron heat conductivity smoothing and hydrodynamical compensation of the nonuniformities of energy deposition of a small quantity laser beams is discussed. 2D distribution of absorbed laser energy deposition in an undercritical low-Z absorber of LIGHT target under propagation of a super sonic electron heat conductivity waves and 2D implosion of target with ablator having special initially given distributions of mass are presented. Numerical simulations show the flexibility of LIGHT target ignition at the laser energy of (200-300) kJ and quantity of beams 6.

  14. Auroral energy deposition and neutral composition changes observed simultaneously by ESRO 4 and AE-C at different altitudes

    NASA Technical Reports Server (NTRS)

    Trinks, H.; Mayr, H. G.; Kayser, D. C.; Potter, W. E.

    1977-01-01

    Neutral composition data obtained simultaneously from ESRO 4 and AE-C during geomagnetically disturbed conditions at different altitudes (160 and 230 km) are used to investigate the atmospheric response to geomagnetic storms and to infer information regarding the excitation mechanism. The data are compared with a theoretical model that estimates the composition effects in terms of wind induced diffusion. A parametric study was conducted bearing on the influence of energy deposition at different altitudes and with varying latitudinal extent. In one of the observed events the composition effects at 160 km are substantially smaller than at 230 km for which we inferred by comparison with the theory that the energy mainly was deposited at 150 km altitude over a wide latitude range. Another event required energy deposition at somewhat lower altitudes near 120 km with a more localized energy source. Significant variations of the turbopause level were not necessary to explain the observed variations.

  15. Uncertainty Estimation Improves Energy Measurement and Verification Procedures

    SciTech Connect

    Walter, Travis; Price, Phillip N.; Sohn, Michael D.

    2014-05-14

    Implementing energy conservation measures in buildings can reduce energy costs and environmental impacts, but such measures cost money to implement so intelligent investment strategies require the ability to quantify the energy savings by comparing actual energy used to how much energy would have been used in absence of the conservation measures (known as the baseline energy use). Methods exist for predicting baseline energy use, but a limitation of most statistical methods reported in the literature is inadequate quantification of the uncertainty in baseline energy use predictions. However, estimation of uncertainty is essential for weighing the risks of investing in retrofits. Most commercial buildings have, or soon will have, electricity meters capable of providing data at short time intervals. These data provide new opportunities to quantify uncertainty in baseline predictions, and to do so after shorter measurement durations than are traditionally used. In this paper, we show that uncertainty estimation provides greater measurement and verification (M&V) information and helps to overcome some of the difficulties with deciding how much data is needed to develop baseline models and to confirm energy savings. We also show that cross-validation is an effective method for computing uncertainty. In so doing, we extend a simple regression-based method of predicting energy use using short-interval meter data. We demonstrate the methods by predicting energy use in 17 real commercial buildings. We discuss the benefits of uncertainty estimates which can provide actionable decision making information for investing in energy conservation measures.

  16. Additive Manufacturing of AlSi10Mg Alloy Using Direct Energy Deposition: Microstructure and Hardness Characterization

    NASA Astrophysics Data System (ADS)

    Javidani, M.; Arreguin-Zavala, J.; Danovitch, J.; Tian, Y.; Brochu, M.

    2016-12-01

    This paper aims to study the manufacturing of the AlSi10Mg alloy with direct energy deposition (DED) process. Following fabrication, the macro- and microstructural evolution of the as-processed specimens was initially investigated using optical microscopy and scanning electron microscopy. Columnar dendritic structure was the dominant solidification feature of the deposit; nevertheless, detailed microstructural analysis revealed cellular morphology near the substrate and equiaxed dendrites at the top end of the deposit. Moreover, the microstructural morphology in the melt pool boundary of the deposit differed from the one in the core of the layers. The remaining porosity of the deposit was evaluated by Archimedes' principle and by image analysis of the polished surface. Crystallographic texture in the deposit was also assessed using electron backscatter diffraction and x-ray diffraction analysis. The dendrites were unidirectionally oriented at an angle of 80° to the substrate. EPMA line scans were performed to evaluate the compositional variation and elemental segregation in different locations. Eventually, microhardness (HV) tests were conducted in order to study the hardness gradient in the as-DED-processed specimen along the deposition direction. The presented results, which exhibited a deposit with an almost defect free structure, indicate that the DED process can suitable for the deposition of Al-Si-based alloys with a highly consolidated structure.

  17. Additive Manufacturing of AlSi10Mg Alloy Using Direct Energy Deposition: Microstructure and Hardness Characterization

    NASA Astrophysics Data System (ADS)

    Javidani, M.; Arreguin-Zavala, J.; Danovitch, J.; Tian, Y.; Brochu, M.

    2017-04-01

    This paper aims to study the manufacturing of the AlSi10Mg alloy with direct energy deposition (DED) process. Following fabrication, the macro- and microstructural evolution of the as-processed specimens was initially investigated using optical microscopy and scanning electron microscopy. Columnar dendritic structure was the dominant solidification feature of the deposit; nevertheless, detailed microstructural analysis revealed cellular morphology near the substrate and equiaxed dendrites at the top end of the deposit. Moreover, the microstructural morphology in the melt pool boundary of the deposit differed from the one in the core of the layers. The remaining porosity of the deposit was evaluated by Archimedes' principle and by image analysis of the polished surface. Crystallographic texture in the deposit was also assessed using electron backscatter diffraction and x-ray diffraction analysis. The dendrites were unidirectionally oriented at an angle of 80° to the substrate. EPMA line scans were performed to evaluate the compositional variation and elemental segregation in different locations. Eventually, microhardness (HV) tests were conducted in order to study the hardness gradient in the as-DED-processed specimen along the deposition direction. The presented results, which exhibited a deposit with an almost defect free structure, indicate that the DED process can suitable for the deposition of Al-Si-based alloys with a highly consolidated structure.

  18. Instrumentation for measuring energy inputs to implements

    SciTech Connect

    Tompkins, F.D.; Wilhelm, L.R.

    1981-01-01

    A microcomputer-based instrumentation system for monitoring tractor operating parameters and energy inputs to implements was developed and mounted on a 75-power-takeoff-KW tractor. The instrumentation system, including sensors and data handling equipment, is discussed. 10 refs.

  19. Calorimetric measurement of energy of ultrasonic cleaners

    SciTech Connect

    Harding, W.B.

    1994-11-01

    The development of a calorimeter that measured the power within an ultrasonic cleaning tank is presented. The principle involved is explained. Several types of calorimeter that were tested are described. Measurement of the power in an ultrasonic cleaner permits: (1) comparing different ultrasonic cleaners; (2) monitoring the performance of a specific cleaner; (3) measuring the distribution of power in a cleaning tank, and (4) evaluating the effects of process variables on the power.

  20. Measuring atomic oxygen densities and electron properties in an Inductively Coupled Plasma for thin film deposition

    NASA Astrophysics Data System (ADS)

    Meehan, David; Gibson, Andrew; Booth, Jean-Paul; Wagenaars, Erik

    2016-09-01

    Plasma Enhanced Pulsed Laser Deposition (PE-PLD) is an advanced way of depositing thin films of oxide materials by using a laser to ablate a target, and passing the resulting plasma plume through a background Inductively-Coupled Plasma (ICP), instead of a background gas as is done in traditional PLD. The main advantage of PE-PLD is the control of film stoichiometry via the direct control of the reactive oxygen species in the ICP instead of relying on a neutral gas background. The aim is to deposit zinc oxide films from a zinc metal target and an oxygen ICP. In this work, we characterise the range of compositions of the reactive oxygen species achievable in ICPs; in particular the atomic oxygen density. The density of atomic oxygen has been determined within two ICPs of two different geometries over a range of plasma powers and pressures with the use of Energy Resolved Actinometry (ERA). ERA is a robust diagnostic technique with determines both the dissociation degree and average electron energy by comparing the excitation ratios of two oxygen and one argon transition. Alongside this the electron densities have been determined with the use of a hairpin probe. This work received financial support from the EPSRC, and York-Paris CIRC.

  1. 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.

  2. Influence of normal daytime fat deposition on laboratory measurements of torpor use in territorial versus nonterritorial hummingbirds.

    PubMed

    Powers, Donald R; Brown, Alison R; Van Hook, Jessamyn A

    2003-01-01

    Fat deposition and torpor use in hummingbirds exhibiting distinct foraging styles should vary. We predicted that dominant territorial hummingbirds will use torpor less than subordinate nonterritorial species because unrestricted access to energy by territory owners allows for fat storage. Entry into torpor was monitored using open-flow respirometry on hummingbirds allowed to accumulate fat normally during the day. Fat accumulation was measured by solvent fat extraction. Territorial blue-throated hummingbirds (Lampornis clemenciae) had the highest fat accumulation and used torpor only 17% of the time. Fat storage by L. clemenciae averaged 26% of lean dry mass (LDM) in 1995 and 18% in 1996, similar to that measured for other nonmigratory birds. Fat storage by magnificent hummingbirds (Eugenes fulgens; trapliner) and black-chinned hummingbirds (Archilochus alexandri; nectar robber) averaged 19% and 16% of LDM, respectively, and they used torpor frequently (64% and 92% of the time, respectively). All species initiated torpor if total body fat dropped below 10% of LDM, indicating the existence of a torpor threshold. The ability of L. clemenciae to store enough fat to support nighttime metabolism is likely an important benefit of territoriality. Likewise, frequent torpor use by subordinates suggests that natural restrictions to energy intake can impact their energy budget, necessitating energy conservation by use of torpor.

  3. Chemically deposited thin films of sulfides and selenides of antimony and bismuth as solar energy materials

    NASA Astrophysics Data System (ADS)

    Nair, M. T.; Nair, Padmanabhan K.; Garcia, V. M.; Pena, Y.; Arenas, O. L.; Garcia, J. C.; Gomez-Daza, O.

    1997-10-01

    Chemical bath deposition techniques for bismuth sulfide, bismuth selenide, antimony sulfide, and antimony selenide thin films of about 0.20 - 0.25 micrometer thickness are reported. All these materials may be considered as solar absorber films: strong optical absorption edges, with absorption coefficient, (alpha) , greater than 104 cm-1, are located at 1.31 eV for Bi2Se3, 1.33 eV for Bi2S3, 1.8 eV for Sb2S3, and 1.35 eV for Sb2Se3. As deposited, all the films are nearly amorphous. However, well defined crystalline peaks matching bismuthinite (JCPDS 17- 0320), paraguanajuatite (JCPDS 33-0214), and stibnite (JCPDS 6-0474) and antimony selenide (JCPDS 15-0861) for Bi2S3, Bi2Se3, Sb2S3 and Sb2Se3 respectively, are observed when the films are annealed in nitrogen at 300 degrees Celsius. This is accompanied by a substantial modification of the electrical conductivity in the films: from 10-7 (Omega) -1 cm-1 (in as prepared films) to 10 (Omega) -1 cm-1 in the case of bismuth sulfide and selenide films, and enhancement of photosensitivity in the case of antimony sulfide films. The chemical deposition of a CuS/CuxSe film on these Vx- VIy films and subsequent annealing at 300 degrees Celsius for 1 h at 1 torr of nitrogen leads to the formation of p-type films (conductivity of 1 - 100 (Omega) -1 cm-1) of multinary composition. Among these, the formation of Cu3BiS3 (JCPDS 9-0488) and Cu3SbS4 (JCPDS 35- 0581), CuSbS2 (JCPDS 35-0413) have been clearly detected. Solar energy applications of these films are suggested.

  4. Fast electron transport and spatial energy deposition in imploded fast ignition cone-in-shell targets

    NASA Astrophysics Data System (ADS)

    Jarrott, Leonard

    2014-10-01

    We report on the first experimental observation and model validation of the spatial energy deposition of fast electrons into the imploded, high-density core of integrated cone-in-shell fast ignition experiments on OMEGA. Spatial energy deposition was characterized via fast electron produced K α fluorescence from a Cu tracer added to the CD shell. 2-D images of the Cu K α fluorescence were obtained using a spherically bent Bragg crystal imager. 54 of the 60 OMEGA beams (18 kJ) were used for fuel assembly, and the high intensity EP beam (10 ps, 0.5--1.5 kJ, Ip >1019 W/cm2) , was focused onto the inner cone tip to produce fast electrons. Cu K α emission from a 300 μm region surrounding the cone tip correlated well with the predicted core size from radiation-hydrodynamic simulations of the shell implosion. The emission also emanated from as far back as 100 μm from the cone tip, indicative of an electron source position with a large standoff distance from the cone tip, consistent with the presence of an extended pre-plasma from the EP pre-pulse. We observed a simultaneous increase in both K α yield (up to 70%) and thermal neutron number (up to 2×) with increasing EP beam energy. K α yield data also show an improved energy coupling using the high contrast EP pulse. Comprehensive simulations of the electron production within the cone and subsequent transport into the imploded core have been performed using the implicit PIC code LSP and the hybrid-PIC code ZUMA. These simulations explain the observed K α shape and yield trends and identify parameters that constrain energy coupling into the compressed core. This work was performed under the auspices of U.S. DOE under Contracts DE-FC02-04ER54789 (FSC), DE-FG02-05ER54834 (ACE) and DE-NA0000854 (NLUF).

  5. Beta measurements at Department of Energy facilities

    SciTech Connect

    Rathbun, L.A.; Swinth, K.L.; Haggard, D.L.

    1987-08-01

    Pacific Northwest Laboratory performed a two-step process to characterize the current beta measurement practices at DOE facilities. PNL issued a survey questionnaire on beta measurement practices to DOE facilities and reported the results. PNL measured beta doses and spectra at seven selected DOE facilities and compared selected measurement techniques in the facility environment. This report documents the results of the radiation field measurements and the comparison of measurement techniques at the seven facilities. Data collected included beta dose and spectral measurements at seven DOE facilities that had high beta-to-gamma ratios (using a silicon surface barrier spectrometer, a plastic scintillator spectrometer, and a multielement beta dosimeter). Other dosimeters and survey meters representative of those used at DOE facilities or under development were also used for comparison. Field spectra were obtained under two distinct conditions. Silicon- and scintillation-based spectrometer systems were used under laboratory conditions where high beta-to-gamma dose ratios made the beta spectra easier to observe and analyze. In the second case, beta spectrometers were taken into actual production and maintenance areas of DOE facilities. Analyses of beta and gamma spectra showed that /sup 234/Th- /sup 234m/Pa, /sup 231/Th, /sup 137/Cs, and /sup 90/Sr//sup 90/Y were the major nuclides contributing to beta doses at the facilities visited. Beta doses from other fission products and /sup 60/Co were also measured, but the potential for exposure was less significant. 21 refs., 64 figs., 18 tabs.

  6. Role of low-energy ion irradiation in the formation of an aluminum germanate layer on a germanium substrate by radical-enhanced atomic layer deposition

    SciTech Connect

    Fukuda, Yukio Yamada, Daichi; Yokohira, Tomoya; Yanachi, Kosei; Yamamoto, Chiaya; Yoo, Byeonghak; Sato, Tetsuya; Yamanaka, Junji; Takamatsu, Toshiyuki; Okamoto, Hiroshi

    2016-03-15

    Radical-enhanced atomic layer deposition uses oxygen radicals generated by a remote microwave-induced plasma as an oxidant to change the surface reactions of the alternately supplied trimethylaluminum precursor and oxygen radicals on a Ge substrate, which leads to the spontaneous formation of an aluminum germanate layer. In this paper, the effects that low-energy ions, supplied from a remote microwave plasma to the substrate along with the oxygen radicals, have on the surface reactions were studied. From a comparative study of aluminum oxide deposition under controlled ion flux irradiation on the deposition surface, it was found that the ions enhance the formation of the aluminum germanate layer. The plasma potential measured at the substrate position by the Langmuir probe method was 5.4 V. Assuming that the kinetic energy of ions arriving at the substrate surface is comparable to that gained by this plasma potential, such ions have sufficient energy to induce exchange reactions of surface-adsorbed Al atoms with the underlying Ge atoms without causing significant damage to the substrate. This ion-induced exchange reaction between Al and Ge atoms is inferred to be the background kinetics of the aluminum germanate formation by radical-enhanced atomic layer deposition.

  7. Tidal inlet processes and deposits along a low energy coastline: easter Barataria Bight, Louisiana

    SciTech Connect

    Moslow, T.F.; Levin, D.R.

    1985-01-01

    Historical, seismic and vibracore data were used to determine the geologic framework of sand deposits along the predominantly muddy coastline of eastern Barataria Bight, Louisiana. Three inlet types with distinct sand body geometries and morphologies were identified and are found 1) at flanking barrier island systems spread laterally across the front of interdistributary bays; 2) in old distributary channels; 3) at overwash breaches; or 4) combination of these. Barataria Bight, a sheltered barrier island shoreline embayment with limited sand supply, minimal tidal range (36 cm) and low wave energies (30 cm) can be used to show examples of each inlet type. Barataria Pass and Quatre Bayou Pass are inlets located in old distributary channels. However, Barataria Pass has also been affected by construction between barrier islands. Pass Ronquille is located where the coastline has transgressed a low area in the delta plain. This breach is situated in a hydraulically efficient avenue between the Gulf and Bay Long behind it. Pass Abel is a combination of a low-profile barrier breach and the reoccupation of an old distributary channel. Shelf and shoreline sands are reworked from abandoned deltaic distributaries and headlands. Inner shelf sands are concentrated in thick (10 m) shore-normal relict distributary channels with fine grained cross-bedded and ripple laminated sand overlain by burrowed shelf muds. Shoreface sand deposits occur as 2-3 m thick, fine-grained, coarsening upward and burrowed ebb-tidal delta sequences and shore-parallel relict tidal inlet channels filled through lateral accretion.

  8. Single-molecule imaging of DNA curtains reveals intrinsic energy landscapes for nucleosome deposition

    PubMed Central

    Visnapuu, Mari-Liis; Greene, Eric C.

    2009-01-01

    Here we use single-molecule imaging to determine coarse-grained intrinsic energy landscapes for nucleosome deposition on model DNA substrates. Our results reveal distributions that are correlated with recent in silico predictions, reinforcing the hypothesis that DNA contains some intrinsic positioning information. We also show that cis-regulatory sequences in human DNA coincide with peaks in the intrinsic landscape, whereas valleys correspond to non-regulatory regions, and we present evidence arguing that nucleosome deposition in vertebrates is influenced by factors not accounted for by current theory. Finally, we demonstrate that intrinsic landscapes of nucleosomes containing the centromere-specific variant CenH3 are correlated with patterns observed for canonical nucleosomes, arguing that CenH3 does not alter sequence preferences of centromeric nucleosomes. However, the non-histone protein Scm3 alters the intrinsic landscape of CenH3-containing nucleosomes, enabling them to overcome the otherwise exclusionary effects of poly(dA–dT) tracts, which are enriched in centromeric DNA. PMID:19734899

  9. High-performance energy harvester fabricated with aerosol deposited PMN-PT material

    NASA Astrophysics Data System (ADS)

    Chen, C. T.; Lin, S. C.; Lin, T. K.; Wu, W. J.

    2016-11-01

    This paper reports a high-performance piezoelectric energy harvester (EH) fabricated with xPb(Mg1/3Nb2/3)-(l-x)PbTiO3 (PMN-PT) by aerosol deposition method. The result indicates that PMN-PT based EH owns 1.8 times output power which is higher than traditional PbZrxTi1- xO3 (PZT) based EH. In order to compare the output performance of EH fabricated with PMN- PT compared with PZT, the similar thickness of PMN-PT and PZT thin film is deposited on stainless steel subtracted. The experimental results show that PZT-based EH had a maximum output power of 4.65 μW with 1.11 Vp-p output voltage excited at 94.4 Hz under 0.5g base excitation, while the PMN-PT based device has a maximum output power of 8.42 μW with 1.49 Vp-p output voltage at a vibration frequency of 94.8 Hz and the same base excitation level. The volumetric power density was 82.95 μW/mm3 and 48.05 μW/mm3 for the device based on PMN- PT and PZT materials, respectively. All the results demonstrate that PMN-PT has better output performance than PZT.

  10. Lime-mud layers in high-energy tidal channels: A record of hurricane deposition

    NASA Astrophysics Data System (ADS)

    Shinn, Eugene A.; Steinen, Randolph P.; Dill, Robert F.; Major, Richard

    1993-07-01

    During or immediately following the transit of Hurricane Andrew (August 23-24, 1992) across the northern part of the Great Bahama Bank, thin laminated beds of carbonate mud were deposited in high-energy subtidal channels (4 m depth) through the ooid shoals of south Cat Cay and Joulters Cays. During our reconnaissance seven weeks later, we observed lime-mud beds exposed in the troughs of submarine oolite dunes and ripples. The mud layers were underlain and locally covered by ooid sand. The mud beds were lenticular and up to 5 cm thick. Their bases cast the underlying rippled surface. The layers were composed of soft silt- and sand-sized pellets and peloids and in some areas contained freshly preserved Thalassia blades and other organic debris along planes of lamination. The beds had a gelatinous consistency and locally had been penetrated by burrowers and plants. Layers of lime mud had also settled on bioturbated, plant-stabilized flats and in lagoonal settings but were quickly reworked and made unrecognizable by the burrowing of organisms. Thicker, more cohesive (and therefore older) mud beds and angular mud fragments associated with ooids from Joulters Cays have similar characteristics but lack fresh plant fragments. We infer that these older beds were similarly deposited and thus record the passage of previous hurricanes or tropical storms. Storm layers are preserved within channel sediments because migrating ooids prevent attack by the burrowing activity off organisms.

  11. Measuring and Managing Cleanroom Energy Use

    SciTech Connect

    Tschudi, William; Mills, Evan; Xu, Tenfang; Rumsey, Peter

    2005-11-15

    Combining high air-recirculation rates and energy-intensive processes, cleanrooms are 20 to 100 times as costly to operate on a per-square-foot basis as conventional commercial buildings. Additionally, they operate 24 hr a day, seven days a week, which means their electricity demand always is contributing to peak utility-system demand, an important fact given increasing reliance on time-dependent tariffs.

  12. 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

  13. Three-dimensional Čerenkov tomography of energy deposition from ionizing radiation beams.

    PubMed

    Glaser, Adam K; Voigt, William H A; Davis, Scott C; Zhang, Rongxiao; Gladstone, David J; Pogue, Brian W

    2013-03-01

    Since its discovery during the 1930s the Čerenkov effect (light emission from charged particles traveling faster than the local speed of light in a dielectric medium) has been paramount in the development of high-energy physics research. The ability of the emitted light to describe a charged particle's trajectory, energy, velocity, and mass has allowed scientists to study subatomic particles, detect neutrinos, and explore the properties of interstellar matter. However, to our knowledge, all applications of the process to date have focused on the identification of particles themselves, rather than their effect upon the surroundings through which they travel. Here we explore a novel application of the Čerenkov effect for the recovery of the spatial distribution of ionizing radiation energy deposition in a medium and apply it to the issue of dose determination in medical physics. By capturing multiple projection images of the Čerenkov light induced by a medical linear accelerator x-ray photon beam, we demonstrate the successful three-dimensional tomographic reconstruction of the imparted dose distribution.

  14. Three-dimensional Čerenkov tomography of energy deposition from ionizing radiation beams

    PubMed Central

    Glaser, Adam K.; Voigt, William H.A.; Davis, Scott C.; Zhang, Rongxiao; Gladstone, David J.; Pogue, Brian W.

    2013-01-01

    Since its discovery during the 1930’s, the Čerenkov effect (light emission from charged particles traveling faster than the local speed of light in a dielectric medium) has been paramount in the development of high-energy physics research. The ability of the emitted light to describe a charged particle’s trajectory, energy, velocity, and mass has allowed scientists to study subatomic particles, detect neutrinos, and explore the properties of interstellar matter. However, all applications of the process to date have focused on identification of particle’s themselves, rather than their effect upon the surroundings through which they travel. Here, we explore a novel application of the Čerenkov effect for the recovery of the spatial distribution of ionizing radiation energy deposition in a medium, and apply it to the issue of dose determination in medical physics. By capturing multiple projection images of the Čerenkov light induced by a medical linear accelerator (LINAC) x-ray photon beam, we demonstrate the successful three-dimensional (3D) tomographic reconstruction of the imparted dose distribution for the first time. PMID:23455248

  15. Pulsed laser deposition of HfO2 thin films on indium zinc oxide: Band offsets measurements

    NASA Astrophysics Data System (ADS)

    Craciun, D.; Craciun, V.

    2017-04-01

    One of the most used dielectric films for amorphous indium zinc oxide (IZO) based thin films transistor is HfO2. The estimation of the valence band discontinuity (ΔEV) of HfO2/IZO heterostructure grown using the pulsed laser deposition technique, with In/(In + Zn) = 0.79, was obtained from X-ray photoelectron spectroscopy (XPS) measurements. The binding energies of Hf 4d5, Zn 2p3 and In 3d5 core levels and valence band maxima were measured for thick pure films and for a very thin HfO2 film deposited on a thick IZO film. A value of ΔEV = 1.75 ± 0.05 eV was estimated for the heterostructure. Taking into account the measured HfO2 and IZO optical bandgap values of 5.50 eV and 3.10 eV, respectively, a conduction band offset ΔEC = 0.65 ± 0.05 eV in HfO2/IZO heterostructure was then obtained.

  16. A new method for measuring lung deposition efficiency of airborne nanoparticles in a single breath

    NASA Astrophysics Data System (ADS)

    Jakobsson, Jonas K. F.; Hedlund, Johan; Kumlin, John; Wollmer, Per; Löndahl, Jakob

    2016-11-01

    Assessment of respiratory tract deposition of nanoparticles is a key link to understanding their health impacts. An instrument was developed to measure respiratory tract deposition of nanoparticles in a single breath. Monodisperse nanoparticles are generated, inhaled and sampled from a determined volumetric lung depth after a controlled residence time in the lung. The instrument was characterized for sensitivity to inter-subject variability, particle size (22, 50, 75 and 100 nm) and breath-holding time (3-20 s) in a group of seven healthy subjects. The measured particle recovery had an inter-subject variability 26-50 times larger than the measurement uncertainty and the results for various particle sizes and breath-holding times were in accordance with the theory for Brownian diffusion and values calculated from the Multiple-Path Particle Dosimetry model. The recovery was found to be determined by residence time and particle size, while respiratory flow-rate had minor importance in the studied range 1-10 L/s. The instrument will be used to investigate deposition of nanoparticles in patients with respiratory disease. The fast and precise measurement allows for both diagnostic applications, where the disease may be identified based on particle recovery, and for studies with controlled delivery of aerosol-based nanomedicine to specific regions of the lungs.

  17. A new method for measuring lung deposition efficiency of airborne nanoparticles in a single breath

    PubMed Central

    Jakobsson, Jonas K. F.; Hedlund, Johan; Kumlin, John; Wollmer, Per; Löndahl, Jakob

    2016-01-01

    Assessment of respiratory tract deposition of nanoparticles is a key link to understanding their health impacts. An instrument was developed to measure respiratory tract deposition of nanoparticles in a single breath. Monodisperse nanoparticles are generated, inhaled and sampled from a determined volumetric lung depth after a controlled residence time in the lung. The instrument was characterized for sensitivity to inter-subject variability, particle size (22, 50, 75 and 100 nm) and breath-holding time (3–20 s) in a group of seven healthy subjects. The measured particle recovery had an inter-subject variability 26–50 times larger than the measurement uncertainty and the results for various particle sizes and breath-holding times were in accordance with the theory for Brownian diffusion and values calculated from the Multiple-Path Particle Dosimetry model. The recovery was found to be determined by residence time and particle size, while respiratory flow-rate had minor importance in the studied range 1–10 L/s. The instrument will be used to investigate deposition of nanoparticles in patients with respiratory disease. The fast and precise measurement allows for both diagnostic applications, where the disease may be identified based on particle recovery, and for studies with controlled delivery of aerosol-based nanomedicine to specific regions of the lungs. PMID:27819335

  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

    2016-04-04

    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.

  19. Benchmark study for charge deposition by high energy electrons in thick slabs

    NASA Technical Reports Server (NTRS)

    Jun, I.

    2002-01-01

    The charge deposition profiles created when highenergy (1, 10, and 100 MeV) electrons impinge ona thick slab of elemental aluminum, copper, andtungsten are presented in this paper. The chargedeposition profiles were computed using existing representative Monte Carlo codes: TIGER3.0 (1D module of ITS3.0) and MCNP version 4B. The results showed that TIGER3.0 and MCNP4B agree very well (within 20% of each other) in the majority of the problem geometry. The TIGER results were considered to be accurate based on previous studies. Thus, it was demonstrated that MCNP, with its powerful geometry capability and flexible source and tally options, could be used in calculations of electron charging in high energy electron-rich space radiation environments.

  20. Atomic layer deposition of nanostructured materials for energy and environmental applications.

    PubMed

    Marichy, Catherine; Bechelany, Mikhael; Pinna, Nicola

    2012-02-21

    Atomic layer deposition (ALD) is a thin film technology that in the past two decades rapidly developed from a niche technology to an established method. It proved to be a key technology for the surface modification and the fabrication of complex nanostructured materials. In this Progress Report, after a short introduction to ALD and its chemistry, the versatility of the technique for the fabrication of novel functional materials will be discussed. Selected examples, focused on its use for the engineering of nanostructures targeting applications in energy conversion and storage, and on environmental issues, will be discussed. Finally, the challenges that ALD is now facing in terms of materials fabrication and processing will be also tackled.

  1. Cluster-assembled Tb-Fe nanostructured films produced by low energy cluster beam deposition.

    PubMed

    Zhao, Shifeng; Bi, Feng; Wan, Jian-Guo; Han, Min; Song, Fengqi; Liu, Jun-Ming; Wang, Guanghou

    2007-07-04

    Cluster-assembled Tb-Fe nanostructured films were prepared by the low energy cluster beam deposition method. The microstructure, magnetization and magnetostriction were investigated for the films. It is shown that the film is assembled by monodisperse spherical nanoparticles with average diameter of ∼30 nm which are distributed uniformly. The cluster-assembled Tb-Fe nanostructured films exhibit good magnetization and possess giant magnetostriction with saturation value of ∼1060 × 10(-6), much higher than that of the common Tb-Fe films. The origin of good magnetization and giant magnetostriction for the cluster-assembled Tb-Fe nanostructured film was discussed. The present work opens a new avenue to produce the nanostructured magnetostrictive alloy in application of a nano-electro-mechanical system.

  2. Comparison of MCNPX and Geant4 proton energy deposition predictions for clinical use

    PubMed Central

    Titt, U.; Bednarz, B.; Paganetti, H.

    2012-01-01

    Several different Monte Carlo codes are currently being used at proton therapy centers to improve upon dose predictions over standard methods using analytical or semi-empirical dose algorithms. There is a need to better ascertain the differences between proton dose predictions from different available Monte Carlo codes. In this investigation Geant4 and MCNPX, the two most-utilized Monte Carlo codes for proton therapy applications, were used to predict energy deposition distributions in a variety of geometries, comprising simple water phantoms, water phantoms with complex inserts and in a voxelized geometry based on clinical CT data. The gamma analysis was used to evaluate the differences of the predictions between the codes. The results show that in the all cases the agreement was better than clinical acceptance criteria. PMID:22996039

  3. Surface free energy of non-stick coatings deposited using closed field unbalanced magnetron sputter ion plating

    NASA Astrophysics Data System (ADS)

    Sun, Chen-Cheng; Lee, Shih-Chin; Dai, Shyue-Bin; Tien, Shein-Long; Chang, Chung-Chih; Fu, Yaw-Shyan

    2007-02-01

    Semiconductor IC packaging molding dies require wear resistance, corrosion resistance and non-sticking (with a low surface free energy). The molding releasing capability and performance are directly associated with the surface free energy between the coating and product material. The serious sticking problem reduces productivity and reliability. Depositing TiN, TiMoS, ZrN, CrC, CrN, NiCr, NiCrN, CrTiAlN and CrNiTiAlN coatings using closed field unbalanced magnetron sputter ion plating, and characterizing their surface free energy are the main object in developing a non-stick coating system for semiconductor IC molding tools. The contact angle of water, diiodomethane and ethylene glycol on the coated surfaces were measured at temperature in 20 °C using a Dataphysics OCA-20 contact angle analyzer. The surface free energy of the coatings and their components (dispersion and polar) were calculated using the Owens-Wendt geometric mean approach. The surface roughness was investigated by atomic force microscopy (AFM). The adhesion force of these coatings was measured using direct tensile pull-off test apparatus. The experimental results showed that NiCrN, CrN and NiCrTiAlN coatings outperformed TiN, ZrN, NiCr, CiTiAlN, CrC and TiMoS coatings in terms of non-sticking, and thus have the potential as working layers for injection molding industrial equipment, especially in semiconductor IC packaging molding applications.

  4. Research of the temperature measurement of high-energy laser energy meter and energy loss compensation technique

    NASA Astrophysics Data System (ADS)

    Yu, Xun; Wang, Hui; Wu, Ji'an; Wang, Fang; Li, Qian

    2009-11-01

    The energy measurement of high energy laser is converts incident laser energy into heat energy, calculates energy utilizing absorber temperature rise, thus the energy value can be gained. Temperature measurement of high-energy laser energy meter and energy loss compensation during the course of the measurement were studied here. Firstly, temperature-resistance characteristics of resistance wire was analyzed, which was winded on exterior surface of the absorbing cavity of high-energy laser energy meter and used in temperature measurement. Least square method was used to process experiment data and a compensation model was established to calibrate the relationship of temperature vs. resistance. Experiment proved that, error between resistance wire and Pt100 is less than 0.01Ω and temperature error is less than 0.02°C. This greatly improves accuracy of the high energy meter measurement result. Secondly, aimed to the compensation of laser energy loss caused by absorbing cavity's heat exchange, the heat energy loss of absorbing cavity, resulted from thermal radiation, heat convection and heat conduction was analyzed based on heat transfer theory. Its mathematics model was established. Least square method was used to fit a curve of experiment data in order to compensate energy loss. Repetitiveness of measurement is 0.7%, which is highly improved.

  5. Microdosimetry measurements for low-energy particles using a mini TEPC with removable plug

    NASA Astrophysics Data System (ADS)

    Cho, I.-Chun; Wen, Wan-Hsin; Chao, Tsi-Chian; Tung, Chuan-Jong

    2017-08-01

    Knowledge about the single-event energy deposition in a subcellular biological target, e.g. cell nucleus, is required in order to understand the radiation action and the biological effectiveness of ionizing radiation. This energy deposition can be measured using a tissue equivalent proportional counter (TEPC). Such measurements are particularly useful to find the microdosimetric spectra for mixed radiation fields comprising different radiation types and energies. In the present work, several mixed radiation fields were generated by irradiating a mini TEPC, containing a small plug inserted into the hole on the counter wall, with reactor neutrons. The plug, made of A150, boron, nitrogen, lithium or cadmium mixture, was designed to generate different ionizing particles under the neutron irradiation. The measured spectra separated the contributions to the absorbed dose from electrons (photons), protons (neutrons) and heavy ions. The lineal energy spectra demonstrated that three distinct regions of lineal energy y, were identified, i.e. the region from heavy ions at y>100 keV/μm, the region for recoil protons at 10measurements, the proton edge and the electron edge were used as marking points to calibrate the lineal energies. The relative magnitudes of the measured spectra in each y region depended on the yields and stopping powers of nuclear reaction products. For instance, lineal energy peaks were identified at y>100 keV/μm due to the 10B (n, α)7Li reaction. If one substitutes the plug material by a radionuclide, microdosimetry spectra could be measured for internal dosimetry applications.

  6. Down to Earth Solar Energy Measurement

    ERIC Educational Resources Information Center

    Oppegard, Milo

    1975-01-01

    Describes the construction of a calorimeter to be used in an experiment which consists of measuring the rate at which ground level solar radiation raises the temperature of the metal in the calorimeter. (GS)

  7. Energy deposition and non-equilibrium infared radiation of energetic auroral electrons

    NASA Astrophysics Data System (ADS)

    Wu, Yadong; Gao, Bo; Zhu, Guangsheng; Li, Ziguang

    2016-07-01

    Infrared radiation caused by energetic auroral electrons plays an important role in the thermospheric hear budget, and may be seen as background by infrared surveillance sensors. The auroral electron deposition leads to the ionization, excitation, and dissociation of neutral species(N2,O2,and O), and initiates a series of chemical reaction in the upper atmosphere, finally causes the optical emission of infared excited emitters. In this study, the whole progress from the initial auroral electrons energy deposition to the final infrared emissions has been modeled, which including space plasma, atmospheric physical chemistry, and radiative transfer. The initial atmosphere parameters before auroral disturbing are given by MSIS00 model. The primary electron flux at the top of atmosphere is given by a statistical fitting with the sum of three distribution terms, a power law, a Maxwellian and a Guassian. A semi-emprical model is used in the calculation of energy depositon of single primary electron. The total integral ion pairs production rate is obtained after combining with the initial primary electron flux. The production rate and flux of secondary electrons are modeled with a continuous slow down approximation, using different excitation, ionization, dissociation cross sections of N2, O2, and O to electrons. The photochemical reactions with auroral disturbance is analysed, and its calculation model is established. A "three-step" calculation method is created to obtain number densities of eleven species in the hight between 90-160 km, which containing N2+, O2+, O+, O2+(a4Π), O+(2D), O+(2P), N2(A3Σ), N(2D), N(4S), NO+, and N+. Number densities of different vibraional levels of NO and NO+ are got with steady state assumption, considering 1-12 vibrational levels of NO and 1-14 vibrational levels of NO+. The infared emissions and the spectral lines of the two radiating bodies are calculated with a fuzzy model of spectral band.

  8. Deposition of mass-selected clusters studied by thermal energy atom scattering and low-temperature scanning tunneling microscopy: An experimental setup

    NASA Astrophysics Data System (ADS)

    Jödicke, Harald; Schaub, Renald; Bhowmick, Ashok; Monot, René; Buttet, Jean; Harbich, Wolfgang

    2000-07-01

    We present an experimental setup for the investigation of the processes occurring during the deposition of mass-selected clusters on a well-defined surface. The sample is analyzed in situ by two complementary methods: thermal energy atom scattering (TEAS) and scanning tunneling microscopy (STM). TEAS is used to study the dynamical processes during the deposition and to gather statistical information about the resulting structures on the surface. Subsequent STM measurements allow us to investigate the collision outcome on an atomic scale. The setup is highly versatile and guarantees ultra-high-vacuum conditions and cryogenic temperatures (≈30 K) of the sample at all times even during sample transfer. Clusters are produced in a CORDIS-type cluster source. A new compact multichannel effusive He source in combination with a new Wien-filter-based He detector are used for TEAS measurements. The new low-temperature STM allows measurements in a temperature range between 8 and 450 K. Atomic resolution on the Pt(111) surface is regularly observed at Tsample=8 K. The performances of the setup are illustrated by STM images obtained after the deposition of Ag7+ clusters with Ekin=95 and 1000 eV on bare Pt(111) and by measurements made of the deposition of Ag7+ clusters with Ekin=20 eV in a Xe-rare-gas matrix adsorbed on Pt(111).

  9. 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.

  10. Shaping thin film growth and microstructure pathways via plasma and deposition energy: a detailed theoretical, computational and experimental analysis.

    PubMed

    Sahu, Bibhuti Bhusan; Han, Jeon Geon; Kersten, Holger

    2017-02-15

    Understanding the science and engineering of thin films using plasma assisted deposition methods with controlled growth and microstructure is a key issue in modern nanotechnology, impacting both fundamental research and technological applications. Different plasma parameters like electrons, ions, radical species and neutrals play a critical role in nucleation and growth and the corresponding film microstructure as well as plasma-induced surface chemistry. The film microstructure is also closely associated with deposition energy which is controlled by electrons, ions, radical species and activated neutrals. The integrated studies on the fundamental physical properties that govern the plasmas seek to determine their structure and modification capabilities under specific experimental conditions. There is a requirement for identification, determination, and quantification of the surface activity of the species in the plasma. Here, we report a detailed study of hydrogenated amorphous and crystalline silicon (c-Si:H) processes to investigate the evolution of plasma parameters using a theoretical model. The deposition processes undertaken using a plasma enhanced chemical vapor deposition method are characterized by a reactive mixture of hydrogen and silane. Later, various contributions of energy fluxes on the substrate are considered and modeled to investigate their role in the growth of the microstructure of the deposited film. Numerous plasma diagnostic tools are used to compare the experimental data with the theoretical results. The film growth and microstructure are evaluated in light of deposition energy flux under different operating conditions.

  11. 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

  12. High Energy Measurement of the Deuteron Photodisintegration Differential Cross Section

    SciTech Connect

    Schulte, Elaine

    2002-05-01

    New measurements of the high energy deuteron photodisintegration differential cross section were made at the Thomas Jefferson National Accelerator Facility in Newport News, Virginia. Two experiments were performed. Experiment E96-003 was performed in experimental Hall C. The measurements were designed to extend the highest energy differential cross section values to 5.5 GeV incident photon energy at forward angles. This builds upon previous high energy measurements in which scaling consistent with the pQCD constituent counting rules was observed at 90 degrees and 70 degrees in the center of mass. From the new measurements, a threshold for the onset of constituent counting rule scaling seems present at transverse momentum approximately 1.3 GeV/c. The second experiment, E99-008, was performed in experimental Hall A. The measurements were designed to explore the angular distribution of the differential cross section at constant energy. The measurements were made symmetric about 90 degrees

  13. Measuring industrial energy efficiency: Physical volume versus economic value

    SciTech Connect

    Freeman, S.L.; Niefer, M.J.; Roop, J.M.

    1996-12-01

    This report examines several different measures of industrial output for use in constructing estimates of industrial energy efficiency and discusses some reasons for differences between the measures. Estimates of volume-based measures of output, as well as 3 value-based measures of output (value of production, value of shipments, and value added), are evaluated for 15 separate 4-digit industries. Volatility, simple growth rate, and trend growth rate estimates are made for each industry and each measure of output. Correlations are made between the volume- and value-based measures of output. Historical energy use data are collected for 5 of the industries for making energy- intensity estimates. Growth rates in energy use, energy intensity, and correlations between volume- and value-based measures of energy intensity are computed. There is large variability in growth trend estimates both long term and from year to year. While there is a high correlation between volume- and value-based measures of output for a few industries, typically the correlation is low, and this is exacerbated for estimates of energy intensity. Analysis revealed reasons for these low correlations. It appears that substantial work must be done before reliable measures of trends in the energy efficiency of industry can be accurately characterized.

  14. Measuring energy efficiency in the United States` economy: A beginning

    SciTech Connect

    1995-10-01

    Energy efficiency is a vital component of the Nation`s energy strategy. One of the Department of Energy`s missions are to promote energy efficiency to help the Nation manage its energy resources. The ability to define and measure energy efficiency is essential to this objective. In the absence of consistent defensible measures, energy efficiency is a vague, subjective concept that engenders directionless speculation and confusion rather than insightful analysis. The task of defining and measuring energy efficiency and creating statistical measures as descriptors is a daunting one. This publication is not a final product, but is EIA`s first attempt to define and measure energy efficiency in a systematic and robust manner for each of the sectors and the United States economy as a whole. In this process, EIA has relied on discussions, customer reviews, in-house reviews, and seminars that have focused on energy efficiency in each of the sectors. EIA solicits the continued participation of its customers in further refining this work.

  15. Measured Energy Performance of New and Retrofitted Schools.

    ERIC Educational Resources Information Center

    Gardiner, Betsy L.

    1985-01-01

    The Building Energy Data Group at Lawrence Berkeley Laboratory, Berkeley, California, compiles measured energy data on retrofitted buildings and new buildings designed to be energy-efficient. Currently in the database are data from 89 elementary schools, 31 secondary schools, and 14 colleges. (MLF)

  16. Measured Energy Performance of New and Retrofitted Schools.

    ERIC Educational Resources Information Center

    Gardiner, Betsy L.

    1985-01-01

    The Building Energy Data Group at Lawrence Berkeley Laboratory, Berkeley, California, compiles measured energy data on retrofitted buildings and new buildings designed to be energy-efficient. Currently in the database are data from 89 elementary schools, 31 secondary schools, and 14 colleges. (MLF)

  17. Establishing Measurement Criteria for an Energy Literacy Questionnaire

    ERIC Educational Resources Information Center

    DeWaters, Jan; Powers, Susan

    2013-01-01

    Energy literacy is a broad term encompassing content knowledge as well as a citizenship understanding of energy that includes affective and behavioral aspects. This article presents explicit criteria that will serve as a foundation for developing measurable objectives for energy literacy in three dimensions: cognitive (knowledge, cognitive…

  18. Inverse modeling of the Chernobyl source term using atmospheric concentration and deposition measurements

    NASA Astrophysics Data System (ADS)

    Evangeliou, Nikolaos; Hamburger, Thomas; Cozic, Anne; Balkanski, Yves; Stohl, Andreas

    2017-07-01

    This paper describes the results of an inverse modeling study for the determination of the source term of the radionuclides 134Cs, 137Cs and 131I released after the Chernobyl accident. The accident occurred on 26 April 1986 in the Former Soviet Union and released about 1019 Bq of radioactive materials that were transported as far away as the USA and Japan. Thereafter, several attempts to assess the magnitude of the emissions were made that were based on the knowledge of the core inventory and the levels of the spent fuel. More recently, when modeling tools were further developed, inverse modeling techniques were applied to the Chernobyl case for source term quantification. However, because radioactivity is a sensitive topic for the public and attracts a lot of attention, high-quality measurements, which are essential for inverse modeling, were not made available except for a few sparse activity concentration measurements far from the source and far from the main direction of the radioactive fallout. For the first time, we apply Bayesian inversion of the Chernobyl source term using not only activity concentrations but also deposition measurements from the most recent public data set. These observations refer to a data rescue attempt that started more than 10 years ago, with a final goal to provide available measurements to anyone interested. In regards to our inverse modeling results, emissions of 134Cs were estimated to be 80 PBq or 30-50 % higher than what was previously published. From the released amount of 134Cs, about 70 PBq were deposited all over Europe. Similar to 134Cs, emissions of 137Cs were estimated as 86 PBq, on the same order as previously reported results. Finally, 131I emissions of 1365 PBq were found, which are about 10 % less than the prior total releases. The inversion pushes the injection heights of the three radionuclides to higher altitudes (up to about 3 km) than previously assumed (≈ 2.2 km) in order to better match both

  19. Measurements of alpha particle energy using nuclear tracks in solids methodology.

    PubMed

    Espinosa, G; Amero, C; Gammage, R B

    2002-01-01

    In this paper we present a method for the measurement of alpha particle energy using polycarbonate materials as nuclear track detectors (NTDs). This method is based on the interaction of the radiation with the solid-state materials, using the relationship between the energy deposited in the material by the ionising particle and the track developed after an established chemical process. The determination of the geometrical parameters of the formed track, such as major axis, minor axis and overall track length, permit determination of the energy of the alpha particle. The track analysis is performed automatically using a digital image system, and the data are processed in a PC with commercial software. In this experiment 148Gd, 238U, 230Th, 239Pu and 244Cm alpha particle emitters were used. The values for alpha particle energy resolution, the linear response to energy, the confidence in the results and the automatisation of the procedure make this method a promising analysis system.

  20. Saving money with energy conservation: economic analysis of conservation measures

    SciTech Connect

    Bailey, J.E.; Roller, D.A.; Moor, W.C.

    1980-01-01

    The basic tools for performing simple economic analyses of energy-conservation measures are reviewed. Energy accounting establishes energy-utilization patterns and performance goals. Directions for analyzing the utility bill are presented. Part 2 introduces ways to calculate the payback period, return on investment, and present worth of energy-conservation measures. Examples are given for reducing parking lot and indoor lighting, adding storm windows, reducing ventilation-fan running time, recycling boiler condensate, and shifting electrical-demand peak. A discussion of the inflation, depreciation, and income-tax ramifications of energy conservation is offered.

  1. Measurement of Wet Deposition of Inorganic and Organic Nitrogen in a Forest Environment

    NASA Astrophysics Data System (ADS)

    Hill, K. A.; Shepson, P. B.; Galbavy, E. S.; Anastasio, C.

    2004-12-01

    Nitrogen is often the limiting nutrient for tree growth. Wet deposition is a major source of nitrogen to a forest. Few previous studies have included organic nitrogen as part of the assessment of atmospheric inputs of nitrogen to forest ecosystems. A significant fraction of wet and dry deposited nitrogen is organic, and several studies have shown that organic nitrogen can thermally or photochemically degrade into inorganic nitrogen as well as be directly taken up by leaves, thereby making it a viable source of nitrogen to forests. Our hypothesis is that organic nitrogen is a significant fraction of nitrogen deposited via wet deposition to a forest, and that this nitrogen can be utilized by the trees. Dissolved inorganic and organic nitrogen were measured in precipitation at the University of Michigan Biological Station (UMBS) in an open field and under the forest canopy. Precipitation was collected on an event basis. The rainwater collectors were deployed just prior to a rain event and were retrieved immediately after the rain finished. The collection bottles were surrounded with dry ice to freeze the precipitation upon collection, preventing degradation of any nitrogen species either by bacteria or by chemical reactions. The samples were analyzed for nitrate, ammonium, and organic nitrogen content. The results of the frozen, single event sampling were compared with samples collected unfrozen over a one-week period in order to investigate sample stability issues. Canopy retention of nitrogen in precipitation will also be discussed.

  2. Interpretation of energy deposition data from historical operation of the transient test facility (TREAT)

    DOE PAGES

    DeHart, Mark D.; Baker, Benjamin A.; Ortensi, Javier

    2017-07-27

    The Transient Test Reactor (TREAT) at Idaho National Laboratory will resume operations in late 2017 after a 23 year hiatus while maintained in a cold standby state. Over that time period, computational power and simulation capabilities have increased substantially and now allow for new multiphysics modeling possibilities that were not practical or feasible for most of TREAT's operational history. Hence the return of TREAT to operational service provides a unique opportunity to apply state-of-the-art software and associated methods in the modeling and simulation of general three-dimensional steady state and kinetic behavior for reactor operation, and for coupling of the coremore » power transient model to experiment simulations. However, measurements taken in previous operations were intended to predict power deposition in experimental samples, with little consideration of three-dimensional core power distributions. Hence, interpretation of data for the purpose of validation of modern methods can be challenging. For the research discussed herein, efforts are described for the process of proper interpretation of data from the most recent calibration experiments performed in the core, the M8 calibration series (M8-CAL). These measurements were taken between 1990 and 1993 using a set of fission wires and test fuel pins to estimate the power deposition that would be produced in fast reactor test fuel pins during the M8 experiment series. Because of the decision to place TREAT into a standby state in 1994, the M8 series of transients were never performed. However, potentially valuable information relevant for validation is available in the M8-CAL measurement data, if properly interpreted. This article describes the current state of the process of recovery of useful data from M8-CAL measurements and quantification of biases and uncertainties to potentially apply to the validation of multiphysics methods.« less

  3. 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.

  4. Measurements of natural deposition ice nuclei in Córdoba, Argentina

    NASA Astrophysics Data System (ADS)

    López, M. L.; Ávila, E. E.

    2012-12-01

    Ice nucleation in the atmosphere is of practical and fundamental importance since ice crystals influence the release of snow, rain and hail. Suspended aerosols in the atmosphere can initiate freezing at temperatures below -15 °C. In this work we describe an experimental device designed to measure the concentration of natural ice nuclei under controlled temperature and supersaturation conditions. The measurements were performed at Córdoba City, for temperatures between -15 °C and -30 °C and the sampled air was supersaturated with respect to ice and subsaturated with respect to liquid water; under these conditions the deposition ice nuclei were quantified. There are few studies reported in the literature regarding measurements of deposition ice nuclei concentration and, to our knowledge, there are no previous laboratory data of this kind of ice nuclei for T < -20 °C. The results show that the number of deposition ice nuclei increases at colder temperatures and higher supersaturations. These results are in general in good agreement with results previously reported by other authors. A fitting function which depends on temperature and supersaturation is proposed to parameterize the results obtained in the present work.

  5. Measurements of natural deposition ice nuclei in Córdoba, Argentina

    NASA Astrophysics Data System (ADS)

    López, M. L.; Ávila, E. E.

    2013-03-01

    Ice nucleation in the atmosphere is of practical and fundamental importance since ice crystals influence the release of snow, rain and hail. Suspended aerosols in the atmosphere typically initiate freezing at temperatures below -15 °C; although occasionally freezing occurs at higher temperatures. In this work we describe an experimental device designed to measure the concentration of natural ice nuclei under controlled temperature and supersaturation conditions. The measurements were performed at Córdoba City, for temperatures between -15 °C and -30 °C and the sampled air was supersaturated with respect to ice and subsaturated with respect to liquid water; under these conditions the deposition ice nuclei were quantified. There are few studies reported in the literature regarding measurements of deposition ice nuclei concentration and, to our knowledge, there are no previous laboratory data of this kind of ice nuclei for T < -20 °C. The results show that the number of deposition ice nuclei increases at colder temperatures and higher supersaturations. These results are in general in good agreement with results previously reported by other authors. A fitting function which depends on temperature and supersaturation is proposed to parameterize the results obtained in the present work.

  6. Energy deposition of H and He ion beams in hydroxyapatite films: A study with implications for ion-beam cancer therapy

    NASA Astrophysics Data System (ADS)

    Limandri, Silvina; de Vera, Pablo; Fadanelli, Raul C.; Nagamine, Luiz C. C. M.; Mello, Alexandre; Garcia-Molina, Rafael; Behar, Moni; Abril, Isabel

    2014-02-01

    Ion-beam cancer therapy is a promising technique to treat deep-seated tumors; however, for an accurate treatment planning, the energy deposition by the ions must be well known both in soft and hard human tissues. Although the energy loss of ions in water and other organic and biological materials is fairly well known, scarce information is available for the hard tissues (i.e., bone), for which the current stopping power information relies on the application of simple additivity rules to atomic data. Especially, more knowledge is needed for the main constituent of human bone, calcium hydroxyapatite (HAp), which constitutes 58% of its mass composition. In this work the energy loss of H and He ion beams in HAp films has been obtained experimentally. The experiments have been performed using the Rutherford backscattering technique in an energy range of 450-2000 keV for H and 400-5000 keV for He ions. These measurements are used as a benchmark for theoretical calculations (stopping power and mean excitation energy) based on the dielectric formalism together with the MELF-GOS (Mermin energy loss function-generalized oscillator strength) method to describe the electronic excitation spectrum of HAp. The stopping power calculations are in good agreement with the experiments. Even though these experimental data are obtained for low projectile energies compared with the ones used in hadron therapy, they validate the mean excitation energy obtained theoretically, which is the fundamental quantity to accurately assess energy deposition and depth-dose curves of ion beams at clinically relevant high energies. The effect of the mean excitation energy choice on the depth-dose profile is discussed on the basis of detailed simulations. Finally, implications of the present work on the energy loss of charged particles in human cortical bone are remarked.

  7. Investigation of the surface free energy of the ITO thin films deposited under different working pressure

    SciTech Connect

    Özen, Soner Pat, Suat; Korkmaz, Şadan; Şenay, Volkan

    2016-03-25

    This study discusses the influence of working pressure on the surface energy of the ITO thin films produced by radio frequency magnetron sputtering method. Optical tensiometer (Attension Theta Lite) is used for evaluating wetting behavior of the water droplet on the film surface and Equation of State method was selected to determine surface free energy for this study. Equation of state method does not divide the surface tension into different components such as polar, dispersive, acid-base. It is calculated the surfaces’ free energy measuring the contact angle with a single liquid. The surface free energy value was in the range of 15-31 mN/m. Also, the transmittances were determined in the wavelength range between 200 and 1000 nm using the UNICO 4802 UV-Vis double beam spectrophotometer. Transmittances of the produced ITO thin films are greater than %70 in the visible range.

  8. Measurement of photon-energy albedo from stratified shielding materials.

    PubMed

    Sinha, A K; Bhattacharjee, A

    1991-11-01

    In the conventional method of measuring photon-energy albedo using a scintillation detector coupled with a multichannel analyzer, tedious efficiency correction by the inverse matrix method was needed. The indigenously designed proportional-response photon counter, with its detection efficiency proportional to energy of incident photons, was used in the present investigation. Use of the proportional-response photon counter makes the measurement straightforward and more accurate. Measurements of energy albedo from stratified layers of aluminum, iron, lead, and concrete using 662-keV and 1250-keV photon energies are reported.

  9. A direct measurement of shear fracture energy in rocks

    NASA Astrophysics Data System (ADS)

    Cox, S. J. D.; Scholz, C. H.

    Shear fracture energy has been measured for a granite and a limestone using a torsional method. We monitor failure with periodic stiffness determinations and measure strain energy released by integrating the load-displacement record. Values of strain energy release rate (G3C) obtained for zero normal stress lie in the range 10²-10³ Jm-2. These fall between the values of G1C from tensile experiments and of shear fracture energy measured under high normal stress in triaxial tests.

  10. Observation of enhanced thermal lensing due to near-Gaussian pump energy deposition in a laser-diode side-pumped Nd:YAG laser

    NASA Technical Reports Server (NTRS)

    Welford, David; Rines, David M.; Dinerman, Bradley J.; Martinsen, Robert

    1992-01-01

    The authors report operation of a laser-diode side-pumped Nd:YAG laser with a novel pumping geometry that ensures efficient conversion of pump energy into the TEM00 mode. Significant enhancement of thermally induced lensing due to the near-Gaussian energy deposition profile of the pump radiation was observed. An induced lens of approximately 3.2-m focal length was measured at average incident pump powers of only 3.2 W (corresponding to a 0.6 W heat load).

  11. Integrating Energy Efficiency and Renewable Energy Measures in the Air Quality Planning Process

    EPA Pesticide Factsheets

    This guidance provides state and local air quality officials with valuable information on how to incorporate energy efficiency and renewable energy (EE/RE) measures into their air quality plan, also known as the State Implementation Plan (SIP).

  12. Integrating Energy Efficiency and Renewable Energy Measures in the Air Quality Planning Process

    EPA Pesticide Factsheets

    This guidance provides state and local air quality officials with valuable information on how to incorporate energy efficiency and renewable energy (EE/RE) measures into their air quality plan, also known as the State Implementation Plan (SIP).

  13. Measuring proton energies and fluxes using EIT (SOHO) CCD areas outside the solar disk images

    NASA Astrophysics Data System (ADS)

    Didkovsky, L. V.; Judge, D. L.; Jones, A. R.; Rhodes, E. J., Jr.; Gurman, J. B.

    2006-05-01

    An indirect proton flux measuring tool based on discrimination of the energy deposited by protons in 128×128 pixel EIT CCD areas outside the solar disk images is presented. Single pixel intensity events are converted into proton incident energy flux using modeled energy deposition curves for angles of incidence ± 60° in four EIT spatial areas with different proton stopping power. The extracted proton flux is corrected for both the loss of one-pixel events in the range of angles of incidence as well as for the contribution to the single pixel events resulting from scattered middle-energy protons (low-energy or high-energy particles are stopped by the EIT components or pass through them, accordingly). A simple geometrical approach was found and applied to correct for a non-unique relation between the proton-associated CCD output signal and the incident proton energy. With this geometrical approximation four unique proton incident energy ranges were determined as 45-49, 145-154, 297-335, and 390-440 MeV. The indirect proton flux measuring tool has been tested by comparing Solar Energetic Particles (SEP) flux temporal profiles extracted from the EIT CCD frames and downloaded from the GOES database for the Bastille Day (BD) of 2000 July 14 and the more recent 2005 January 20 events. The SEP flux temporal profiles and proton spectra extracted from the EIT in the relatively narrow energy ranges between 45 and 440 MeV reported here are consistent with the related GOES profiles. The four additional EIT extracted ranges provide higher energy resolution of the SEP data.

  14. Enhancing the Number of High-Energy Electrons Deposited to a Compressed Pellet via Double Cones in Fast Ignition

    SciTech Connect

    Cai Hongbo; Mima, Kunioki; Zhou Weimin; Jozaki, Tomoyuki; Nagatomo, Hideo; Sunahara, Atsushi; Mason, Rodney J.

    2009-06-19

    Particle-in-cell simulations aimed at improving the coupling efficiency of input laser energy deposited to a compressed core by using a double cone are described. It is found that the number of high-energy electrons escaping from the sides of the cone is greatly reduced by the vacuum gap inside the wing of the double cone. Two main mechanisms to confine high-energy electrons are found. These mechanisms are the sheath electric field at the rear of the inner cone wing and the quasistatic magnetic field inside the vacuum gap. The generation mechanism for the quasistatic magnetic fields is discussed in detail. It is found that the quasistatic fields continue to confine the high-energy electrons for longer than a few picoseconds. The double cones provide confinement and focusing of about 15% of the input energy for deposition in the compressed core.

  15. Energy subtraction computed tomography measured by current-mode detector

    NASA Astrophysics Data System (ADS)

    Kanno, I.; Imamura, R.; Mikami, K.; Hashimoto, M.; Ohtaka, M.; Ara, K.; Nomiya, S.; Onabe, H.

    2009-10-01

    For the reduction of exposure dose in contrast media detection with X-ray transmission measurements, the energy measurement of X-rays and the energy subtraction (ES) method have been shown to be effective. To make the ES method applicable, a novel detector for unfolding the X-ray energy distribution was proposed by the authors. As an application of this novel detector, a CT image was reconstructed with ES data and compared with the image reconstructed using electric current data.

  16. Neutron Energy Measurements in Radiological Emergency Response Applications

    SciTech Connect

    Sanjoy Mukhopadhyay, Paul Guss, Michael Hornish, Scott Wilde, Tom Stampahar, Michael Reed

    2009-04-30

    We present significant results in recent advances in the determination of neutron energy. Neutron energy measurements are a small but very significant part of radiological emergency response applications. Mission critical information can be obtained by analyzing the neutron energy given off from radioactive materials. In the case of searching for special nuclear materials, neutron energy information from an unknown source can be of paramount importance.

  17. Measurement of total lung aerosol deposition as an index of lung abnormality.

    PubMed

    Kim, C S; Lewars, G A; Sackner, M A

    1988-04-01

    Total aerosol deposition in the lung was measured in 100 subjects with various lung conditions. The subjects consisted of 40 normals (N), 15 asymptomatic smokers (S), 10 smokers with small airway disease (SAD), 20 with chronic simple bronchitis (SB), and 15 with chronic obstructive bronchitis (COPD), and a relationship of total aerosol deposition to degree of lung abnormality was investigated. The subjects were categorized by medical history and a battery of pulmonary function tests, including spirometry, body plethysmography, and single and multiple N2 washout measurements. Subjects repeatedly breathed a monodisperse test aerosol (1.0 micron diam) from a collapsible rebreathing bag (0.5 liter volume) at a rate of 30 breaths/min, while inhaled and exhaled aerosol concentrations were continuously monitored by a laser aerosol photometer in situ and recorded on a strip-chart recorder. The number of rebreathing breaths resulting in 90% aerosol loss from the bag (N90) was determined, and percent predicted N90 values were then determined from the results of computer simulation and used as a deposition index. The percent predicted N90 values were 99.7 +/- 14, 86.5 +/- 15, 66.9 +/- 17, 51 +/- 12, and 30.9 +/- 9, respectively, for N, S, SAD, SB, and COPD. All of these values were significantly different from each other (P less than 0.05). There was no difference between male and female but percent predicted N90 values were slightly higher in young than in old normals. Percent predicted N90 values showed a strong linear correlation with spirometric measurements of forced expiratory volume in 1 s and maximum midexpiratory flow rate. However, many of the SAD and SB with normal spirometry showed abnormal N90. These results suggest that total lung aerosol deposition is a sensitive index of lung abnormality and may be of potential use for nonspecific general patient screening.

  18. Point-by-point near-field optical energy deposition around plasmonic nanospheres in absorbing media.

    PubMed

    Harrison, R K; Ben-Yakar, Adela

    2015-08-01

    Here we investigate the effects of absorbing media on plasmon-enhanced near-field optical energy deposition. We find that increasing absorption by the medium results in increased particle scattering at the expense of particle absorption, and that much of this increased particle scattering is absorbed by the medium close to the particle surface. We present an analytical method for evaluating the spatial distribution of near-field enhanced absorption surrounding plasmonic metal nanospheres in absorbing media using a new point-by-point method. We propose criteria to define relevant near-field boundaries and calculate the properties of the local absorption enhancement, which redistributes absorption to the near-field and decays asymptotically as a function of the distance from the particle to background levels. Using this method, we performed a large-scale parametric study to understand the effect of particle size and wavelength on the near-field absorption for gold nanoparticles in aqueous media and silicon, and identified conditions that are relevant to enhanced local infrared absorption in silicon. The presented approach provides insight into the local energy transfer around plasmonic nanoparticles for predicting near-field effects for advanced concepts in optical sensing, thin-film solar cells, nonlinear imaging, and photochemical applications.

  19. A mechanism of wave drag reduction in the thermal energy deposition experiments

    SciTech Connect

    Markhotok, A.

    2015-06-15

    Many experimental studies report reduced wave drag when thermal energy is deposited in the supersonic flow upstream of a body. Though a large amount of research on this topic has been accumulated, the exact mechanism of the drag reduction is still unknown. This paper is to fill the gap in the understanding connecting multiple stages of the observed phenomena with a single mechanism. The proposed model provides an insight on the origin of the chain of subsequent transformations in the flow leading to the reduction in wave drag, such as typical deformations of the front, changes in the gas pressure and density in front of the body, the odd shapes of the deflection signals, and the shock wave extinction in the plasma area. The results of numerical simulation based on the model are presented for three types of plasma parameter distribution. The spherical and cylindrical geometry has been used to match the data with the experimental observations. The results demonstrate full ability of the model to exactly explain all the features observed in the drag reduction experiments. Analytical expressions used in the model allow separating out a number of adjustment parameters that can be used to optimize thermal energy input and thus achieve fundamentally lower drag values than that of conventional approaches.

  20. 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.

  1. Effects of Seismological and Soil Parameters on Earthquake Energy demand in Level Ground Sand Deposits

    NASA Astrophysics Data System (ADS)

    nabili, sara; shahbazi majd, nafiseh

    2013-04-01

    Liquefaction has been a source of major damages during severe earthquakes. To evaluate this phenomenon there are several stress, strain and energy based approaches. Use of the energy method has been more focused by researchers due to its advantages with respect to other approaches. The use of the energy concept to define the liquefaction potential is validated through laboratory element and centrifuge tests as well as field studies. This approach is based on the hypothesis that pore pressure buildup is directly related to the dissipated energy in sands which is the accumulated areas between the stress-strain loops. Numerous investigations were performed to find a relationship which correlates the dissipated energy to the soil parameters, but there are not sufficient studies to relate this dissipated energy, known as demand energy, concurrently, to the seismological and the soil parameters. The aim of this paper is to investigate the dependency of the demand energy in sands to seismological and the soil parameters. To perform this task, an effective stress analysis has been executed using FLAC finite difference program. Finn model, which is a built-in constitutive model implemented in FLAC program, was utilized. Since an important stage to predict the liquefaction is the prediction of excess pore water pressure at a given point, a simple numerical framework is presented to assess its generation during a cyclic loading in a given centrifuge test. According to the results, predicted excess pore water pressures did not closely match to the measured excess pore water pressure values in the centrifuge test but they can be used in the numerical assessment of excess pore water pressure with an acceptable degree of preciseness. Subsequently, the centrifuge model was reanalyzed using several real earthquake acceleration records with different seismological parameters such as earthquake magnitude and Hypocentral distance. The accumulated energies (demand energy) dissipated in

  2. Investigation of various energy deposition kernel refinements for the convolution/superposition method

    PubMed Central

    Huang, Jessie Y.; Eklund, David; Childress, Nathan L.; Howell, Rebecca M.; Mirkovic, Dragan; Followill, David S.; Kry, Stephen F.

    2013-01-01

    Purpose: Several simplifications used in clinical implementations of the convolution/superposition (C/S) method, specifically, density scaling of water kernels for heterogeneous media and use of a single polyenergetic kernel, lead to dose calculation inaccuracies. Although these weaknesses of the C/S method are known, it is not well known which of these simplifications has the largest effect on dose calculation accuracy in clinical situations. The purpose of this study was to generate and characterize high-resolution, polyenergetic, and material-specific energy deposition kernels (EDKs), as well as to investigate the dosimetric impact of implementing spatially variant polyenergetic and material-specific kernels in a collapsed cone C/S algorithm. Methods: High-resolution, monoenergetic water EDKs and various material-specific EDKs were simulated using the EGSnrc Monte Carlo code. Polyenergetic kernels, reflecting the primary spectrum of a clinical 6 MV photon beam at different locations in a water phantom, were calculated for different depths, field sizes, and off-axis distances. To investigate the dosimetric impact of implementing spatially variant polyenergetic kernels, depth dose curves in water were calculated using two different implementations of the collapsed cone C/S method. The first method uses a single polyenergetic kernel, while the second method fully takes into account spectral changes in the convolution calculation. To investigate the dosimetric impact of implementing material-specific kernels, depth dose curves were calculated for a simplified titanium implant geometry using both a traditional C/S implementation that performs density scaling of water kernels and a novel implementation using material-specific kernels. Results: For our high-resolution kernels, we found good agreement with the Mackie et al. kernels, with some differences near the interaction site for low photon energies (<500 keV). For our spatially variant polyenergetic kernels, we

  3. Investigation of various energy deposition kernel refinements for the convolution/superposition method

    SciTech Connect

    Huang, Jessie Y.; Howell, Rebecca M.; Mirkovic, Dragan; Followill, David S.; Kry, Stephen F.; Eklund, David; Childress, Nathan L.

    2013-12-15

    Purpose: Several simplifications used in clinical implementations of the convolution/superposition (C/S) method, specifically, density scaling of water kernels for heterogeneous media and use of a single polyenergetic kernel, lead to dose calculation inaccuracies. Although these weaknesses of the C/S method are known, it is not well known which of these simplifications has the largest effect on dose calculation accuracy in clinical situations. The purpose of this study was to generate and characterize high-resolution, polyenergetic, and material-specific energy deposition kernels (EDKs), as well as to investigate the dosimetric impact of implementing spatially variant polyenergetic and material-specific kernels in a collapsed cone C/S algorithm.Methods: High-resolution, monoenergetic water EDKs and various material-specific EDKs were simulated using the EGSnrc Monte Carlo code. Polyenergetic kernels, reflecting the primary spectrum of a clinical 6 MV photon beam at different locations in a water phantom, were calculated for different depths, field sizes, and off-axis distances. To investigate the dosimetric impact of implementing spatially variant polyenergetic kernels, depth dose curves in water were calculated using two different implementations of the collapsed cone C/S method. The first method uses a single polyenergetic kernel, while the second method fully takes into account spectral changes in the convolution calculation. To investigate the dosimetric impact of implementing material-specific kernels, depth dose curves were calculated for a simplified titanium implant geometry using both a traditional C/S implementation that performs density scaling of water kernels and a novel implementation using material-specific kernels.Results: For our high-resolution kernels, we found good agreement with the Mackie et al. kernels, with some differences near the interaction site for low photon energies (<500 keV). For our spatially variant polyenergetic kernels, we found

  4. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Evaluation of energy deposition and secondary particle production in proton therapy of brain using a slab head phantom

    PubMed Central

    Jia, Sayyed Bijan; Hadizadeh, Mohammad Hadi; Mowlavi, Ali Asghar; Loushab, Mahdy Ebrahimi

    2014-01-01

    Aim Evaluation of energy deposition of protons in human brain and calculation of the secondary neutrons and photons produced by protons in proton therapy. Background Radiation therapy is one of the main methods of treating localized cancer tumors. The use of high energy proton beam in radiotherapy was proposed almost 60 years ago. In recent years, there has been a revival of interest in this subject in the context of radiation therapy. High energy protons suffer little angular deflection and have a well-defined penetration range, with a sharp increase in the energy loss at the end of their trajectories, namely the Bragg peak. Materials and methods A slab head phantom was used for the purpose of simulating proton therapy in brain tissue. In this study simulation was carried out using the Monte Carlo MCNPX code. Results By using mono energetic proton pencil beams, energy depositions in tissues, especially inside the brain, as well as estimating the neutron and photon production as a result of proton interactions in the body, together with their energy spectra, were calculated or obtained. The amount of energy escaped from the head by secondary neutrons and photons was determined. Conclusions It was found that for high energy proton beams the amount of escaped energy by neutrons is almost 10 times larger than that by photons. We estimated that at 110 MeV beam energy, the overall proton energy “leaked” from the head by secondary photons and neutrons to be around 1%. PMID:25337410

  6. Energy measurement using flow computers and chromatography

    SciTech Connect

    Beeson, J.

    1995-12-01

    Arkla Pipeline Group (APG), along with most transmission companies, went to electronic flow measurement (EFM) to: (1) Increase resolution and accuracy; (2) Real time correction of flow variables; (3) Increase speed in data retrieval; (4) Reduce capital expenditures; and (5) Reduce operation and maintenance expenditures Prior to EFM, mechanical seven day charts were used which yielded 800 pressure and differential pressure readings. EFM yields 1.2-million readings, a 1500 time improvement in resolution and additional flow representation. The total system accuracy of the EFM system is 0.25 % compared with 2 % for the chart system which gives APG improved accuracy. A typical APG electronic measurement system includes a microprocessor-based flow computer, a telemetry communications package, and a gas chromatograph. Live relative density (specific gravity), BTU, CO{sub 2}, and N{sub 2} are updated from the chromatograph to the flow computer every six minutes which provides accurate MMBTU computations. Because the gas contract length has changed from years to monthly and from a majority of direct sales to transports both Arkla and its customers wanted access to actual volumes on a much more timely basis than is allowed with charts. The new electronic system allows volumes and other system data to be retrieved continuously, if EFM is on Supervisory Control and Data Acquisition (SCADA) or daily if on dial up telephone. Previously because of chart integration, information was not available for four to six weeks. EFM costs much less than the combined costs of telemetry transmitters, pressure and differential pressure chart recorders, and temperature chart recorder which it replaces. APG will install this equipment on smaller volume stations at a customers expense. APG requires backup measurement on metering facilities this size. It could be another APG flow computer or chart recorder, or the other companies flow computer or chart recorder.

  7. Carbon Deposition in the Inner JET Divertor Measured by Means of Quartz Microbalance

    NASA Astrophysics Data System (ADS)

    Esser, H. G.; Philipps, V.; Freisinger, M.; Coad, P.; Matthews, G. F.; Neill, G.; JET EFDA Contributors

    A Quartz Microbalance (QMB) system was implemented in the inner divertor region of JET in order to measure in situ and time resolved (minimum exposure time ≥0.1 s) material fluxes (mainly carbon) and layer deposition. The system has been developed to operate at temperatures up to 200°C. The aim is to investigate carbon transport to the remote areas, and hence the tritium retention in dependence on plasma conditions. This question is still a major concern for the ITER operation. The mass sensitivity of the system is Sm = 1.5 A~— 10-8 [g/Hz cm2]. First reliable measurements were made during the C5 campaign (March–May 2002; â‰e1000 plasma discharges). The results presented are based on 74 selected exposures (694 s) under various conditions (strike point position, input power, neutral pressure, ELM frequency). Most influencing on the carbon deposition in the remote area seems to be the geometry i.e. the strike point position on the divertor tiles. In average 1.9 A~— 10-4 C-atom are deposited per deuterium ion flowing into the inner divertor.

  8. Field comparison of methods for the measurement of gaseous and particulate contributors to acidic dry deposition

    SciTech Connect

    Sickles, J.E.; Hodson, L.L.; McClenny, W.A.; Paur, R.J.; Ellestad, T.G.

    1990-01-01

    A field study was conducted to compare methods for sampling and analysis of atmospheric constituents that are important contributors to acidic dry deposition. Three multicomponent samplers were used: the Canadian filter pack (FP), the annular denuder system (ADS), and the transition flow reactor (TFR). A tunable diode laser absorption spectrometer (TDLAS) provided continuous reference measurements of NO2 and HNO3. Nitrogen dioxide was also monitored with continuous luminol-based chemiluminescence monitors and with passive sampling devices (PSDs). The study was designed to provide a database for statistical comparison of the various methods with emphasis on the multicomponent samplers under consideration for use in a national dry deposition network. The study was conducted at the EPA dry deposition station in Research Triangle Park, NC between 29 September and 12 October, 1986. Daily averaging and/or sampling times were employed for the 13-day study; weekly samples were also collected, but results from these samples are not compared in the paper. Different measurements of ambient concentrations of the following constituents are compared: total particulate and gaseous NO3(-), HNO3, NO2, total particulate NH4(-), NH3, total particulate SO4(-), and SO2.

  9. 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.

  10. A new experimental procedure of outgassing rate measurement to obtain more precise deposition properties of materials

    NASA Astrophysics Data System (ADS)

    Miyazaki, Eiji; Shimazaki, Kazunori; Numata, Osamu; Waki, Miyuki; Yamanaka, Riyo; Kimoto, Yugo

    2016-09-01

    Outgassing rate measurement, or dynamic outgassing test, is used to obtain outgassing properties of materials, i.e., Total Mass Loss, "TML," and Collected Volatile Condensed Mass, "CVCM." The properties are used as input parameters for executing contamination analysis, e.g., calculating a prediction of deposition mass on a surface in a spacecraft caused by outgassed substances from contaminant sources onboard. It is likely that results obtained by such calculations are affected by the input parameters. Thus, it is important to get a sufficient experimental data set of outgassing rate measurements for extract good outgassing parameters of materials for calculation. As specified in the standard, ASTM E 1559, TML is measured by a QCM sensor kept at cryogenic temperature; CVCMs are measured at certain temperatures. In the present work, the authors propose a new experimental procedure to obtain more precise VCMs from one run of the current test time with the present equipment. That is, two of four CQCMs in the equipment control the temperature to cool step-by-step during the test run. It is expected that the deposition rate, that is sticking coefficient, with respect to temperature could be discovered. As a result, the sticking coefficient can be obtained directly between -50 and 50 degrees C with 5 degrees C step. It looks like the method could be used as an improved procedure for outgassing rate measurement. The present experiment also specified some issues of the new procedure. It will be considered in future work.

  11. Measuring and modelling the radiological impact of a phosphogypsum deposition site on the surrounding environment.

    PubMed

    Bituh, Tomislav; Petrinec, Branko; Skoko, Božena; Vučić, Zlatko; Marović, Gordana

    2015-03-01

    Phosphogypsum (PG) is a waste product (residue) from the production of phosphoric acid characterized by technologically enhanced natural radioactivity. Croatia's largest PG deposition site is situated at the edge of Lonjsko Polje Nature Park, a sensitive ecosystem possibly endangered by PG particles. This field study investigates two aspects relevant for the general radiological impact of PG: risk assessment for the environment and risk assessment for occupationally exposed workers and local inhabitants. Activity concentrations of natural radionuclides ((238)U, (235)U, (232)Th, (226)Ra, (210)Pb, and (40)K) were measured in the PG (at the deposition site), soil, and grass samples (in the vicinity of the site). The ERICA Assessment Tool was used to estimate the radiological impact of PG particles on non-human biota of the Lonjsko Polje Nature Park. The average annual effective dose for occupationally exposed workers was 0.4 mSv which was within the worldwide range.

  12. 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.

  13. 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

  14. Gas hydrates as potential resource of energy and pathfinders for conventional type hydrocarbon deposits

    SciTech Connect

    Krason, J. )

    1991-03-01

    Solid compounds of water and gaseous hydrocarbons are known as gas hydrates, clathrates, or cryohydrates. They occur naturally in offshore and terrestrial environments, in the areas where temperature is at least seasonally low (i.e. close to or below freezing), bathymetric, geostatic, ice, or permafrost pressure is sufficiently high, and the source of hydrocarbons is available. These factors (regional and local geological conditions of 21 locations grouped into 13 study regions worldwide offshore and one in permafrost environments with proven, reported, and inferred presence of gas hydrates) have been recently researched by Geoexplorers International, Inc. Conservative estimations from Geoexplorers International suggest that the world's total gas hydrates may contain 7,000 to 50,000 tcf of natural gas. Although at this time exploitation of gas trapped in the hydrate zone and below is not economically viable, because estimated reserves are enormous, they should be seriously considered as potential energy resource. Smaller, but less dispersed massive gas hydrate deposits associated with fault zones may be the first offshore gas resource to become economic. This research, particularly of the Messoyakh gas field, has proved that the presence of gas hydrates provides very useful information in exploration for conventional oil and gas deposits. Gas hydrates indicate ongoing hydrocarbon generation in the sediments. Hydrates are valuable to assess the present heat flow and thermal history of a region. Since gas hydrates exist only under a very limited range of pressure and temperature, deviation in patterns of their occurrence can be related to changes in pore water chemistry, hydrocarbon composition, or pressure and temperature gradient anomalies.

  15. Super-Eddington stellar winds driven by near-surface energy deposition

    NASA Astrophysics Data System (ADS)

    Quataert, Eliot; Fernández, Rodrigo; Kasen, Daniel; Klion, Hannah; Paxton, Bill

    2016-05-01

    We develop analytic and numerical models of the properties of super-Eddington stellar winds, motivated by phases in stellar evolution when super-Eddington energy deposition (via, e.g. unstable fusion, wave heating, or a binary companion) heats a region near the stellar surface. This appears to occur in the giant eruptions of luminous blue variables (LBVs), Type IIn supernovae progenitors, classical novae, and X-ray bursts. We show that when the wind kinetic power exceeds Eddington, the photons are trapped and behave like a fluid. Convection does not play a significant role in the wind energy transport. The wind properties depend on the ratio of a characteristic speed in the problem v_crit˜ (dot{E} G)^{1/5} (where dot{E} is the heating rate) to the stellar escape speed near the heating region vesc(rh). For vcrit ≳ vesc(rh), the wind kinetic power at large radii dot{E}_w ˜ dot{E}. For vcrit ≲ vesc(rh), most of the energy is used to unbind the wind material and thus dot{E}_w ≲ dot{E}. Multidimensional hydrodynamic simulations without radiation diffusion using FLASH and one-dimensional hydrodynamic simulations with radiation diffusion using MESA are in good agreement with the analytic predictions. The photon luminosity from the wind is itself super-Eddington but in many cases the photon luminosity is likely dominated by `internal shocks' in the wind. We discuss the application of our models to eruptive mass-loss from massive stars and argue that the wind models described here can account for the broad properties of LBV outflows and the enhanced mass-loss in the years prior to Type IIn core-collapse supernovae.

  16. Instrument to measure energy and charge of low energy interplanetary particles

    NASA Technical Reports Server (NTRS)

    Tums, E.; Gloeckler, G.; Cain, J.; Sciambi, R.; Fan, C. Y.

    1974-01-01

    An experiment to measure the charge composition and energy spectra of ultra low energy charged particles in interplanetary space has been developed and launched on the IMP 8 (Explorer 50) satellite on Oct. 26, 1973. The instrument consists of two separate sensors sharing common electronics. One of these sensors uses a thin window gas proportional counter to measure the rate of energy loss and a totally depleted silicon surface barrier detector to measure total energy of incoming particles. The energy range for two dimensional analysis extends from 300 KeV to 2.5 MeV for protons and 60 KeV/nucleon to 25 MeV/nucleon for iron with excellent resolution of individual chemical elements. The other sensor combines electrostatic deflection with total energy measurements in silicon surface barrier detectors to give the ionic charge and kinetic energy of the particle.

  17. Modeling dose deposition and DNA damage due to low-energy β(-) emitters.

    PubMed

    Alloni, D; Cutaia, C; Mariotti, L; Friedland, W; Ottolenghi, A

    2014-09-01

    One of the main issues of low-energy internal emitters concerns the very short ranges of the beta particles, versus the dimensions of the biological targets. Depending on the chemical form, the radionuclide may be more concentrated either in the cytoplasm or in the nucleus of the target cell. Consequently, since in most cases conventional dosimetry neglects this issue it may overestimate or underestimate the dose to the nucleus and hence the biological effects. To assess the magnitude of these deviations and to provide a realistic evaluation of the localized energy deposition by low-energy internal emitters, the biophysical track-structure code PARTRAC was used to calculate nuclear doses, DNA damage yields and fragmentation patterns for different localizations of radionuclides in human interphase fibroblasts. The nuclides considered in the simulations were tritium and nickel-63, which emit electrons with average energies of 5.7 (range in water of 0.42 μm) and 17 keV (range of 5 μm), respectively, covering both very short and medium ranges of beta-decay products. The simulation results showed that the largest deviations from the conventional dosimetry occur for inhomogeneously distributed short-range emitters. For uniformly distributed radionuclides selectively in the cytoplasm but excluded from the cell nucleus, the dose in the nucleus is 15% of the average dose in the cell in the case of tritium but 64% for nickel-63. Also, the numbers of double-strand breaks (DSBs) and the distributions of DNA fragments depend on subcellular localization of the radionuclides. In the low- and medium-dose regions investigated here, DSB numbers are proportional to the nuclear dose, with about 50 DSB/Gy for both studied nuclides. In addition, DSB numbers on specific chromosomes depend on the radionuclide localization in the cell as well, with chromosomes located more peripherally in the cell nucleus being more damaged by short-ranged emitters in cytoplasm compared with chromosomes

  18. A Framework for Comparative Assessments of Energy Efficiency Policy Measures

    SciTech Connect

    Blum, Helcio; Atkinson, Barbara; Lekov, Alex

    2011-05-24

    When policy makers propose new policies, there is a need to assess the costs and benefits of the proposed policy measures, to compare them to existing and alternative policies, and to rank them according to their effectiveness. In the case of equipment energy efficiency regulations, comparing the effects of a range of alternative policy measures requires evaluating their effects on consumers’ budgets, on national energy consumption and economics, and on the environment. Such an approach should be able to represent in a single framework the particularities of each policy measure and provide comparable results. This report presents an integrated methodological framework to assess prospectively the energy, economic, and environmental impacts of energy efficiency policy measures. The framework builds on the premise that the comparative assessment of energy efficiency policy measures should (a) rely on a common set of primary data and parameters, (b) follow a single functional approach to estimate the energy, economic, and emissions savings resulting from each assessed measure, and (c) present results through a set of comparable indicators. This framework elaborates on models that the U.S. Department of Energy (DOE) has used in support of its rulemakings on mandatory energy efficiency standards. In addition to a rigorous analysis of the impacts of mandatory standards, DOE compares the projected results of alternative policy measures to those projected to be achieved by the standards. The framework extends such an approach to provide a broad, generic methodology, with no geographic or sectoral limitations, that is useful for evaluating any type of equipment energy efficiency market intervention. The report concludes with a demonstration of how to use the framework to compare the impacts estimated for twelve policy measures focusing on increasing the energy efficiency of gas furnaces in the United States.

  19. Energy deposition of multi-MeV protons in compressed targets of fast-ignition inertial confinement fusion.

    PubMed

    Mahdavi, M; Koohrokhi, T

    2012-01-01

    The energy loss and penetration of multi-megelectronvolt protons into a uniform deuterium-tritium (DT) plasma has been calculated. The effects of nuclear elastic scattering and Coulomb interactions are treated from a unified point of view. In general, multiple scattering enhances the proton linear-energy transfer along the initial proton direction, thus the energy deposition increases near the end of its range. The net effect of multiple scattering is to reduce the penetration from 1.20 to 1.02 g cm-2 for 12 MeV protons in a ρ=500 g cm-3 plasma at T=5 keV. These results should have relevance to proton fast ignition, specifically to energy deposition calculations that critically assess quantitative ignition requirements.

  20. Effect of the interplanetary magnetic field orientation and intensity in the mass and energy deposition on the Hermean surface

    NASA Astrophysics Data System (ADS)

    Varela, J.; Pantellini, F.; Moncuquet, M.

    2016-09-01

    The aim of the present study is to simulate the interaction between the solar wind and the Hermean magnetosphere. We use the MHD code PLUTO in spherical coordinates with an axisymmetric multipolar expansion of the Hermean magnetic field, to perform a set of simulations with different interplanetary magnetic field orientations and intensities. We fix the hydrodynamic parameters of the solar wind to study the distortions driven by the interplanetary magnetic field in the topology of the Hermean magnetosphere, leading to variations of the mass and energy deposition distributions, the integrated mass deposition, the oval aperture, the area covered by open magnetic field lines and the regions of efficient particle sputtering on the planet surface. The simulations show a correlation between the reconnection regions and the local maxima of plasma inflow and energy deposition on the planet surface.

  1. Mitigation technologies and measures in energy sector of Kazakstan

    SciTech Connect

    Pilifosova, O.; Danchuk, D.; Temertekov, T.

    1996-12-31

    An important commitment in the UN Framework Convention on Climate Change is to conduct mitigation analysis and to communicate climate change measures and policies. In major part reducing CO{sub 2} as well as the other greenhouse gas emissions in Kazakstan, can be a side-product of measures addressed to increasing energy efficiency. Since such measures are very important for the national economy, mitigation strategies in the energy sector of Kazakstan are directly connected with the general national strategy of the energy sector development. This paper outlines the main measures and technologies in energy sector of Kazakstan which can lead to GHG emissions reduction and presents the results of current mitigation assessment. The mitigation analysis is addressed to energy production sector. A baseline and six mitigation scenarios were developed to evaluate the most attractive mitigation options, focusing on specific technologies which have been already included in sustainable energy programs. According to the baseline projection, Kazakstan`s CO{sub 2} emissions will not exceed their 1990 level until 2005. The potential for CO{sub 2} emission reduction is estimated to be about 11 % of the base line emission level by the end of considered period (in 2020). The main mitigation options in the energy production sector in terms of mitigation potential and technical and economical feasibility include rehabilitation of thermal power plants aimed to increasing efficiency, use of nuclear energy and further expansion in the use of hydro energy based on small hydroelectric power plants.

  2. Measurement of bandgap energies in low-k organosilicates

    SciTech Connect

    Nichols, M. T.; Li, W.; Pei, D.; Shohet, J. L.; Antonelli, G. A.; Lin, Q.; Banna, S.; Nishi, Y.

    2014-03-07

    In this work, experimental measurements of the electronic band gap of low-k organosilicate dielectrics will be presented and discussed. The measurement of bandgap energies of organosilicates will be made by examining the onset of inelastic energy loss in core-level atomic spectra using X-ray photoelectron spectroscopy. This energy serves as a reference point from which many other facets of the material can be understood, such as the location and presence of defect states in the bulk or at the interface. A comparison with other measurement techniques reported in the literature is presented.

  3. Ion energy analyzer for measurement of ion turbulent transport

    NASA Astrophysics Data System (ADS)

    Sokolov, V.; Sen, A. K.

    2012-10-01

    For local measurement of radial ion thermal transport, we developed a novel time-resolved gridded ion energy analyzer. The turbulent thermal flux is obtained by correlating fluctuations of ion temperature, plasma density and plasma velocity. The simultaneous measurement of the ion current fluctuations from an ion energy analyzer tilde I_{IEA} (t) and the fluctuation of ion saturation current from a conventional Langmuir probe tilde I_{LP} (t) allow us to determine local fluctuations of ion temperature tilde T_i (t). To reduce the effect of plasma potential fluctuations in the energy analyzer measurements, we use special a compensative circuit loop.

  4. Measuring Conformational Energy Differences Using Pulsed-Jet Microwave Spectroscopy

    NASA Astrophysics Data System (ADS)

    Funderburk, Cameron M.; Gaster, Sydney A.; Taylor, Tiffany R.; Brown, Gordon G.

    2017-06-01

    The conformational energy differences of various chemicals have been measured using chirped-pulse Fourier transform microwave (CP-FTMW) spectroscopy. The hypothesis is that the relative intensities measured in a pulsed-jet instrument are proportional to the conformer populations present before the expansion occurs. Therefore, by measuring the relative intensities in a CP-FTMW spectrum, we aim to determine the relative energy difference between conformers. Experimentally, pulsed-jet CP-FTMW data will be compared to energy differences reported in the literature and to room-temperature CP-FTMW data acquired at Coker College. Results from ab initio calculations will also be used for comparison.

  5. An Artificial Turf-Based Surrogate Surface Collector for the Direct Measurement of Atmospheric Mercury Dry Deposition

    EPA Science Inventory

    This paper describes the development of a new artificial turf surrogate surface (ATSS) sampler for use in the measurement of mercury (Hg) dry deposition. In contrast to many existing surrogate surface designs, the ATSS utilizes a three-dimensional deposition surface that may more...

  6. Atmospheric deposition of inorganic nitrogen in Spanish forests of Quercus ilex measured with ion-exchange resins and conventional collectors

    Treesearch

    Héctor García-Gomez; Sheila Izquieta-Rojano; Laura Aguillaume; Ignacio González-Fernández; Fernando Valiño; David Elustondo; Jesús M. Santamaría; Anna Àvila; Mark E. Fenn; Rocío Alonso

    2016-01-01

    Atmospheric nitrogen deposition is one of the main threats for biodiversity and ecosystem functioning. Measurement techniques like ion-exchange resin collectors (IECs), which are less expensive and time-consuming than conventional methods, are gaining relevance in the study of atmospheric deposition and are recommended to expand monitoring networks. In the present work...

  7. An Artificial Turf-Based Surrogate Surface Collector for the Direct Measurement of Atmospheric Mercury Dry Deposition

    EPA Science Inventory

    This paper describes the development of a new artificial turf surrogate surface (ATSS) sampler for use in the measurement of mercury (Hg) dry deposition. In contrast to many existing surrogate surface designs, the ATSS utilizes a three-dimensional deposition surface that may more...

  8. Nanostructured Thin Film Synthesis by Aerosol Chemical Vapor Deposition for Energy Storage Applications

    NASA Astrophysics Data System (ADS)

    Chadha, Tandeep S.

    Renewable energy sources offer a viable solution to the growing energy demand while mitigating concerns for greenhouse gas emissions and climate change. This has led to a tremendous momentum towards solar and wind-based energy harvesting technologies driving efficiencies higher and costs lower. However, the intermittent nature of these energy sources necessitates energy storage technologies, which remain the Achilles heel in meeting the renewable energy goals. This dissertation focusses on two approaches for addressing the needs of energy storage: first, targeting direct solar to fuel conversion via photoelectrochemical water-splitting and second, improving the performance of current rechargeable batteries by developing new electrode architectures and synthesis processes. The aerosol chemical vapor deposition (ACVD) process has emerged as a promising single-step approach for nanostructured thin film synthesis directly on substrates. The relationship between the morphology and the operating parameters in the process is complex. In this work, a simulation based approach has been developed to understand the relationship and acquire the ability of predicting the morphology. These controlled nanostructured morphologies of TiO2 , compounded with gold nanoparticles of various shapes, are used for solar water-splitting applications. Tuning of light absorption in the visible-light range along with reduced electron-hole recombination in the composite structures has been demonstrated. The ACVD process is further extended to a novel single-step synthesis of nanostructured TiO2 electrodes directly on the current collector for applications as anodes in lithium-ion batteries, mainly for electric vehicles and hybrid electric vehicles. The effect of morphology of the nanostructures has been investigated via experimental studies and electrochemical transport modelling. Results demonstrate the exceptional performance of the single crystal one-dimensional nanostructures over granular

  9. Acoustic measurement and morphological features of organic sediment deposits in combined sewer networks.

    PubMed

    Carnacina, Iacopo; Larrarte, Frédérique; Leonardi, Nicoletta

    2017-04-01

    The performance of sewer networks has important consequences from an environmental and social point of view. Poor functioning can result in flood risk and pollution at a large scale. Sediment deposits forming in sewer trunks might severely compromise the sewer line by affecting the flow field, reducing cross-sectional areas, and increasing roughness coefficients. In spite of numerous efforts, the morphological features of these depositional environments remain poorly understood. The interface between water and sediment remains inefficiently identified and the estimation of the stock of deposit is frequently inaccurate. In part, this is due to technical issues connected to difficulties in collecting accurate field measurements without disrupting existing morphologies. In this paper, results from an extensive field campaign are presented; during the campaign a new survey methodology based on acoustic techniques has been tested. Furthermore, a new algorithm for the detection of the soil-water interface, and therefore for the correct esteem of sediment stocks is proposed. Finally, results in regard to bed topography, and morphological features at two different field sites are presented and reveal that a large variability in bed forms is present along sewer networks.

  10. Calorimetric Measurements of Laser Energy and Power- 1975 Supplement

    DTIC Science & Technology

    1975-07-30

    Bolometer Volume Absorption Partial Reflectance Absorptance Measurement Test Comparison Pages: 00021 Cataloged Date: Dec 07,1992 Document Type: HC...Hollow-Sphere Calorimeters 4 Bolometer Calorimeters 5 Volume- Absorption Calorimeters 5 Partial- Absorption Calorimeters 7 Reflectance and... Absorptance Measurements 7 Test and Comparison Procedures 7 Miscellany 7 References 14 -in- CALORIMETRIC MEASUREMENTS OF LASER ENERGY AND

  11. Lawrence Livermore National Laboratory?s Book of Minimum Detectable Activity for Direct Measurement of Internally Deposited Radionuclides in Radiation Workers

    SciTech Connect

    Hickman, D P

    2008-10-08

    Lawrence Livermore National Laboratory maintains an in vivo measurement program designed to identify and evaluate the activity of radionuclides deposited in the body. Two types of systems are primarily used for the routine monitoring of radiation workers, the lung counting system and the scanning bed whole body counting system. The lung counting system is comprised of two Canberra ACTII detector sets. Each ACTII set contains two planar germanium detectors with carbon composite end windows optimized to measure low energy photon emitting radionuclides. The ACTII detectors are placed on the upper torso over the lungs for the direct measurement of internally deposited radionuclides in the lungs that emit low energy photons. A correction for the thickness of the chest wall is applied to the efficiency. Because the thickness of the chest wall is a key factor in the measurement of low energy photon emitting radionuclides in the lung, the minimum detectable activity is a function of the chest wall thickness. The scanning bed whole body counting system is comprised of a thin air mattress on top of a carbon fiber bed that slowly scans over four high purity germanium detectors. The scanning system is designed to minimize variations in detected activity due to radionuclide distribution in the body. The scanning bed detection system is typically used for the measurement of internally deposited radionuclides that emit photons above 100 to 200 keV. MDAs have been generated for radionuclides that provide energies above 80 keV since the lowest calibration energy for the system is approximately 86 keV. The following charts and table provide best determination of minimum detectable activity using human subjects as controls for the background contributions. A wide variety of radionuclides are used throughout the laboratory and the following pages represent several of the radionuclides that have been encountered at the Whole Body and Spectroscopy Laboratories within Hazards Control.

  12. Energy Efficiency Measures to Incorporate into Remodeling Projects

    SciTech Connect

    Liaukus, C.

    2014-12-01

    Energy improvements in a home are often approached as one concerted effort, beginning with a simple walk-through assessment or more in-depth energy audit and followed by the installation of recommended energy measures. While this approach allows for systems thinking to guide the efforts, comprehensive energy improvements of this nature are undertaken by a relatively small number of the households in our nation compared to more piecemeal remodeling efforts. Even when programs like the Weatherization Assistance Program and Home Performance with ENERGY STAR are considered, homes that have had a comprehensive energy makeover still represent a small fraction of the 111.1 million households. In this report, the U.S Department of Energy Building America Retrofit Alliance research team looks at the improvement of a home's energy performance in an opportunistic way: it examines what can be done to incorporate energy efficiency measures into general remodeling work and home repair projects. This allows for the possibility for people who would not normally pursue energy efficiency but will remodel their kitchen or re-side their home to improve their home's performance at the same time. There are challenges to this approach, not the least of which being that the work will take place over time in potentially many separate projects. The opportunity to improve a home's energy efficiency at one time expands or contracts with the scope of the remodel. As such, guidance on how to do each piece thoughtfully and with consideration for potential future projects, is critical.

  13. Studies of Niobium Thin Film Produced by Energetic Vacuum Deposition

    SciTech Connect

    Genfa Wu; Anne-Marie Valente; H. Phillips; Haipeng Wang; Andy Wu; T. J. Renk; P Provencio

    2004-05-01

    An energetic vacuum deposition system has been used to study deposition energy effects on the properties of niobium thin films on coppe