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1

Microwave Radiometer (MWR) Handbook  

SciTech Connect (OSTI)

The Microwave Radiometer (MWR) provides time-series measurements of column-integrated amounts of water vapor and liquid water. The instrument itself is essentially a sensitive microwave receiver. That is, it is tuned to measure the microwave emissions of the vapor and liquid water molecules in the atmosphere at specific frequencies.

Morris, VR

2006-08-01T23:59:59.000Z

2

Microwave Radiometer-High Frequency (MWRHF) Handbook  

SciTech Connect (OSTI)

The 90/150-GHz Vapor Radiometer provides time-series measurements of brightness temperatures from two channels centered at 90 and 150 GHz. These two channels are sensitive to the presence of liquid water and precipitable water vapor.

Caddedu, MP

2011-03-17T23:59:59.000Z

3

Microwave Radiometer – 3 Channel (MWR3C) Handbook  

SciTech Connect (OSTI)

The microwave radiometer 3-channel (MWR3C) provides time-series measurements of brightness temperatures from three channels centered at 23.834, 30, and 89 GHz. These three channels are sensitive to the presence of liquid water and precipitable water vapor.

Cadeddu, MP

2012-05-04T23:59:59.000Z

4

ARM: Microwave Radiometer data (MWR Profiles - QME), water vapor, temp, cloud liquid water, precip water retrievals  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

Microwave Radiometer data (MWR Profiles - QME), water vapor, temp, cloud liquid water, precip water retrievals

Cadeddu, Maria

5

ARM - Field Campaign - Microwave Radiometer Profiler Evaluation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD) by Microtops Atmospheric Optical Depth (AOD) by Microtops ARM Data DiscoverygovCampaignsMicrowave

6

Preliminary separation of galactic and cosmic microwave emission for the COBE Differential Microwave Radiometer  

SciTech Connect (OSTI)

Preliminary models of microwave emission from the Milky Way Galaxy based on COBE and other data are constructed for the purpose of distinguishing cosmic and Galactic signals. Differential Microwave Radiometer (DMR) maps, with the modeled Galactic emission removed, are fitted for a quadrupole distribution. Autocorrelation functions for individual Galactic components are presented. When Galactic emission is removed from the DMR data, the residual fluctuations are virtually unaffected, and therefore they are not dominated by any known Galactic emission component. 42 refs.

Bennet, C.L.; Smoot, G.F.; Hinshaw, G.; Wright, E.L.; Kogut, A.; De Amici, G.; Meyer, S.S.; Weiss, R.; Wilkinson, D.T.; Gulkis, S. (NASA, Goddard Space Flight Center, Greenbelt, MD (United States) Lawrence Berkeley Laboratory, CA (United States) California, University, Berkeley (United States) Universities Space Research Association, Boulder, CO (United States) California, University, Los Angeles (United States) MIT, Cambridge, MA (United States) Princeton University, NJ (United States) JPL, Pasadena, Ca (United States))

1992-09-01T23:59:59.000Z

7

Measurements of the cosmic microwave background temperature at 1. 47 GHz  

SciTech Connect (OSTI)

A radiofrequency-gain total power radiometer measured the intensity of the cosmic microwave background (CMB) at a frequency of 1.47 GHz (20.4 cm wavelength) from White Mountain, California, in September 1988 and from the South Pole, Antarctica, in December 1989. The CMB thermodynamic temperature, TCMB, is 2.27 {plus minus} 0.25 K (68% C.L.) measured from White Mountain and 2.26 {plus minus} 0.21 K from the South Pole site. The combined result is 2.27 {plus minus} 0.19 K. The correction for galactic emission has been derived from scaled low-frequency maps and constitutes the main source, of error. The atmospheric signal is found by extrapolation from zenith scan measurements at higher frequencies. The result is consistent with previous low-frequency measurements, including a measurement at 1.41 GHz (Levin et al. 1988) made with an earlier version of this instrument. The result is {approximately}2.5 {sigma} ({approximately}l% probability) from the 2.74 {plus minus} 0.02,K global average CMB temperature.

Bensadoun, M.J.

1991-11-01T23:59:59.000Z

8

Measurements of the cosmic microwave background temperature at 1.47 GHz  

SciTech Connect (OSTI)

A radiofrequency-gain total power radiometer measured the intensity of the cosmic microwave background (CMB) at a frequency of 1.47 GHz (20.4 cm wavelength) from White Mountain, California, in September 1988 and from the South Pole, Antarctica, in December 1989. The CMB thermodynamic temperature, TCMB, is 2.27 {plus_minus} 0.25 K (68% C.L.) measured from White Mountain and 2.26 {plus_minus} 0.21 K from the South Pole site. The combined result is 2.27 {plus_minus} 0.19 K. The correction for galactic emission has been derived from scaled low-frequency maps and constitutes the main source, of error. The atmospheric signal is found by extrapolation from zenith scan measurements at higher frequencies. The result is consistent with previous low-frequency measurements, including a measurement at 1.41 GHz (Levin et al. 1988) made with an earlier version of this instrument. The result is {approximately}2.5 {sigma} ({approximately}l% probability) from the 2.74 {plus_minus} 0.02,K global average CMB temperature.

Bensadoun, M.J.

1991-11-01T23:59:59.000Z

9

ARM - Midlatitude Continental Convective Clouds Microwave Radiometer Profiler (jensen-mwr)  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

A major component of the Mid-latitude Continental Convective Clouds Experiment (MC3E) field campaign was the deployment of an enhanced radiosonde array designed to capture the vertical profile of atmospheric state variables (pressure, temperature, humidity wind speed and wind direction) for the purpose of deriving the large-scale forcing for use in modeling studies. The radiosonde array included six sites (enhanced Central Facility [CF-1] plus five new sites) launching radiosondes at 3-6 hour sampling intervals. The network will cover an area of approximately (300)2 km2 with five outer sounding launch sites and one central launch location. The five outer sounding launch sites are: S01 Pratt, KS [ 37.7oN, 98.75oW]; S02 Chanute, KS [37.674, 95.488]; S03 Vici, Oklahoma [36.071, -99.204]; S04 Morris, Oklahoma [35.687, -95.856]; and S05 Purcell, Oklahoma [34.985, -97.522]. Soundings from the SGP Central Facility during MC3E can be retrieved from the regular ARM archive. During routine MC3E operations 4 radiosondes were launched from each of these sites (approx. 0130, 0730, 1330 and 1930 UTC). On days that were forecast to be convective up to four additional launches were launched at each site (approx. 0430, 1030, 1630, 2230 UTC). There were a total of approximately 14 of these high frequency launch days over the course of the experiment. These files contain brightness temperatures observed at Purcell during MC3E. The measurements were made with a 5 channel (22.235, 23.035, 23.835, 26.235, 30.000GHz) microwave radiometer at one minute intervals. The results have been separated into daily files and the day of observations is indicated in the file name. All observations were zenith pointing. Included in the files are the time variables base_time and time_offset. These follow the ARM time conventions. Base_time is the number seconds since January 1, 1970 at 00:00:00 for the first data point of the file and time_offset is the offset in seconds from base_time.

Jensen, Mike

10

ARM - Midlatitude Continental Convective Clouds Microwave Radiometer Profiler (jensen-mwr)  

SciTech Connect (OSTI)

A major component of the Mid-latitude Continental Convective Clouds Experiment (MC3E) field campaign was the deployment of an enhanced radiosonde array designed to capture the vertical profile of atmospheric state variables (pressure, temperature, humidity wind speed and wind direction) for the purpose of deriving the large-scale forcing for use in modeling studies. The radiosonde array included six sites (enhanced Central Facility [CF-1] plus five new sites) launching radiosondes at 3-6 hour sampling intervals. The network will cover an area of approximately (300)2 km2 with five outer sounding launch sites and one central launch location. The five outer sounding launch sites are: S01 Pratt, KS [ 37.7oN, 98.75oW]; S02 Chanute, KS [37.674, 95.488]; S03 Vici, Oklahoma [36.071, -99.204]; S04 Morris, Oklahoma [35.687, -95.856]; and S05 Purcell, Oklahoma [34.985, -97.522]. Soundings from the SGP Central Facility during MC3E can be retrieved from the regular ARM archive. During routine MC3E operations 4 radiosondes were launched from each of these sites (approx. 0130, 0730, 1330 and 1930 UTC). On days that were forecast to be convective up to four additional launches were launched at each site (approx. 0430, 1030, 1630, 2230 UTC). There were a total of approximately 14 of these high frequency launch days over the course of the experiment. These files contain brightness temperatures observed at Purcell during MC3E. The measurements were made with a 5 channel (22.235, 23.035, 23.835, 26.235, 30.000GHz) microwave radiometer at one minute intervals. The results have been separated into daily files and the day of observations is indicated in the file name. All observations were zenith pointing. Included in the files are the time variables base_time and time_offset. These follow the ARM time conventions. Base_time is the number seconds since January 1, 1970 at 00:00:00 for the first data point of the file and time_offset is the offset in seconds from base_time.

Jensen, Mike

2012-02-01T23:59:59.000Z

11

3742 IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 47, NO. 11, NOVEMBER 2009 Microwave Radiometer Radio-Frequency  

E-Print Network [OSTI]

Radiometer Radio-Frequency Interference Detection Algorithms: A Comparative Study Sidharth Misra, Priscilla N is with Halliburton Energy Services, Houston, TX 77032 USA. J. R. Piepmeier is with the Microwave Instrument growth recently in satellite telecommunica- tion, in high-bandwidth point-to-point terrestrial wireless

Ruf, Christopher

12

Hydrologic data assimilation of multi-resolution microwave radiometer and radar measurements using ensemble smoothing  

E-Print Network [OSTI]

Previously, the ensemble Kalman filter (EnKF) has been used to estimate soil moisture and related fluxes by merging noisy low frequency microwave observations with forecasts from a conventional though uncertain land surface ...

Dunne, Susan Catherine

2006-01-01T23:59:59.000Z

13

The Microwave Air Yield Beam Experiment (MAYBE): measurement of GHz radiation for Ultra-High Energy Cosmic Rays detection  

E-Print Network [OSTI]

We present first measurements by MAYBE of microwave emission from an electron beam induced air plasma, performed at the electron Van de Graaff facility of the Argonne National Laboratory. Coherent radio Cherenkov, a major background in a previous beam experiment, is not produced by the 3 MeV beam, which simplifies the interpretation of the data. Radio emission is studied over a wide range of frequencies between 3 and 12 GHz. This measurement provides further insight on microwave emission from extensive air showers as a novel detection technique for Ultra-High Energy Cosmic Rays.

M. Monasor; M. Bohacova; C. Bonifazi; G. Cataldi; S. Chemerisov; J. R. T. De Mello Neto; P. Facal San Luis; B. Fox; P. W. Gorham; C. Hojvat; N. Hollon; R. Meyhandan; L. C. Reyes; B. Rouille D'Orfeuil; E. M. Santos; J. Pochez; P. Privitera; H. Spinka; V. Verzi; C. Williams; J. Zhou

2011-08-31T23:59:59.000Z

14

SECOND SEASON QUIET OBSERVATIONS: MEASUREMENTS OF THE COSMIC MICROWAVE BACKGROUND POLARIZATION POWER SPECTRUM AT 95 GHz  

SciTech Connect (OSTI)

The Q/U Imaging ExperimenT (QUIET) has observed the cosmic microwave background (CMB) at 43 and 95 GHz. The 43 GHz results have been published in a previous paper, and here we report the measurement of CMB polarization power spectra using the 95 GHz data. This data set comprises 5337 hr of observations recorded by an array of 84 polarized coherent receivers with a total array sensitivity of 87 {mu}K{radical}s. Four low-foreground fields were observed, covering a total of {approx}1000 deg{sup 2} with an effective angular resolution of 12.'8, allowing for constraints on primordial gravitational waves and high signal-to-noise measurements of the E-modes across three acoustic peaks. The data reduction was performed using two independent analysis pipelines, one based on a pseudo-C {sub l} (PCL) cross-correlation approach, and the other on a maximum-likelihood (ML) approach. All data selection criteria and filters were modified until a predefined set of null tests had been satisfied before inspecting any non-null power spectrum. The results derived by the two pipelines are in good agreement. We characterize the EE, EB, and BB power spectra between l = 25 and 975 and find that the EE spectrum is consistent with {Lambda}CDM, while the BB power spectrum is consistent with zero. Based on these measurements, we constrain the tensor-to-scalar ratio to r = 1.1{sup +0.9} {sub -0.8} (r < 2.8 at 95% C.L.) as derived by the ML pipeline, and r = 1.2{sup +0.9} {sub -0.8} (r < 2.7 at 95% C.L.) as derived by the PCL pipeline. In one of the fields, we find a correlation with the dust component of the Planck Sky Model, though the corresponding excess power is small compared to statistical errors. Finally, we derive limits on all known systematic errors, and demonstrate that these correspond to a tensor-to-scalar ratio smaller than r = 0.01, the lowest level yet reported in the literature.

Araujo, D.; Dumoulin, R. N.; Newburgh, L. B.; Zwart, J. T. L. [Department of Physics and Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Bischoff, C.; Brizius, A.; Buder, I.; Kusaka, A. [Kavli Institute for Cosmological Physics, Department of Physics, Enrico Fermi Institute, The University of Chicago, Chicago, IL 60637 (United States); Chinone, Y. [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Cleary, K.; Reeves, R. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, 1200 E. California Blvd M/C 249-17, Pasadena, CA 91125 (United States); Monsalve, R.; Bustos, R. [Department of Physics, University of Miami, 1320 Campo Sano Drive, Coral Gables, FL 33146 (United States); Naess, S. K.; Eriksen, H. K. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway); Wehus, I. K. [Department of Astrophysics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Bronfman, L. [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Church, S. E. [Kavli Institute for Particle Astrophysics and Cosmology and Department of Physics, Stanford University, Varian Physics Building, 382 Via Pueblo Mall, Stanford, CA 94305 (United States); Dickinson, C. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Gaier, T., E-mail: ibuder@uchicago.edu [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Collaboration: QUIET Collaboration; and others

2012-12-01T23:59:59.000Z

15

MWRRET Value-Added Product: The Retrieval of Liquid Water Path and Precipitable Water Vapor from Microwave Radiometer (MWR) Data Sets (Revision 2)  

SciTech Connect (OSTI)

This report provides a short description of the Atmospheric Radiation Measurement (ARM) Climate Research Facility microwave radiometer (MWR) Retrieval (MWRRET) value-added product (VAP) algorithm. This algorithm utilizes a complementary physical retrieval method and applies brightness temperature offsets to reduce spurious liquid water path (LWP) bias in clear skies resulting in significantly improved precipitable water vapor (PWV) and LWP retrievals. We present a general overview of the technique, input parameters, output products, and describe data quality checks. A more complete discussion of the theory and results is given in Turner et al. (2007b).

Gaustad, KL; Turner, DD; McFarlane, SA

2011-07-25T23:59:59.000Z

16

MWRRET (Microwave Radiometer Retrievals)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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17

Stress effect on magnetoimpedance (MI) in amorphous wires at GHz frequencies and application to stress-tunable microwave composite materials  

E-Print Network [OSTI]

The effect of tensile stress on magnetoimpedance (MI) in CoMnSiB amorphous wires at microwave frequencies (0.5-3 GHz) is investigated both experimentally and theoretically. In the presence of the dc bias magnetic field of the order of the anisotropy field, the impedance shows very large and sensitive change when the wire is subjected to a tensile stress: 100% and 60% per 180 MPa for frequencies 500 MHz and 2.5 GHz, respectively. It is demonstrated that this behavior owes mainly to the directional change in the equilibrium magnetization caused by the applied stress and field, which agrees well with the theoretical results for the surface impedance. This stress effect on MI is proposed to use for creating microwave stress-tunable composite materials containing short magnetic wires. The analysis of the dielectric response from such materials shows that depending on the stress level in the material, the dispersion of the effective permittivity can be of a resonant or relaxation type with a considerable change in its values (up to 100% at 600 MPa). This media can be used for structural stress monitoring by microwave contrast imaging.

L. V. Panina; S. I. Sandacci; D. P. Makhnovskiy

2004-11-18T23:59:59.000Z

18

FOREGROUND PREDICTIONS FOR THE COSMIC MICROWAVE BACKGROUND POWER SPECTRUM FROM MEASUREMENTS OF FAINT INVERTED RADIO SOURCES AT 5 GHz  

SciTech Connect (OSTI)

We present measurements of a population of matched radio sources at 1.4 and 5 GHz down to a flux limit of 1.5 mJy in 7 deg{sup 2} of the NOAO Deep Field South. We find a significant fraction of sources with inverted spectral indices that all have 1.4 GHz fluxes less than 10 mJy and are therefore too faint to have been detected and included in previous radio source count models that are matched at multiple frequencies. Combined with the matched source population at 1.4 and 5 GHz in 1 deg{sup -2} in the ATESP survey, we update models for the 5 GHz differential number counts and distributions of spectral indices in 5 GHz flux bins that can be used to estimate the unresolved point source contribution to the cosmic microwave background temperature anisotropies. We find a shallower logarithmic slope in the 5 GHz differential counts than in previously published models for fluxes {approx}< 100 mJy as well as larger fractions of inverted spectral indices at these fluxes. Because the Planck flux limit for resolved sources is larger than 100 mJy in all channels, our modified number counts yield at most a 10% change in the predicted Poisson contribution to the Planck temperature power spectrum. For a flux cut of 5 mJy with the South Pole Telescope and a flux cut of 20 mJy with the Atacama Cosmology Telescope, we predict a {approx}30% and {approx}10% increase, respectively, in the radio source Poisson power in the lowest frequency channels of each experiment relative to that predicted by previous models.

Schneider, Michael D. [Lawrence Livermore National Laboratory, P.O. Box 808 L-210, Livermore, CA 94551 (United States); Becker, Robert H. [Department of Physics, University of California, One Shields Avenue, Davis, CA 08991 (United States); De Vries, Willem [Lawrence Livermore National Laboratory, P.O. Box 808 L-211, Livermore, CA 94551 (United States); White, Richard L., E-mail: schneider42@llnl.gov [Space Telescope Science Institute, Baltimore, MD 21218 (United States)

2012-05-10T23:59:59.000Z

19

Empirical Evaluation of Four Microwave Radiative Forward Models Based on Ground-Based Radiometer Data Near 20 and 30 GHz  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing Zirconia Nanoparticles asSecond stage of theEMI SIGTrends inSub-Urban

20

Behavior of microwave-heated silicon carbide particles at frequencies of 2.0–13.5?GHz  

SciTech Connect (OSTI)

Silicon carbide is a key material in microwave (MW) processing and is used widely as a thermal insulator and catalytic agent. In this study, we experimentally investigated the temperature dependence of the MW-absorption properties of SiC particles at frequencies of 2.0–13.5?GHz. We heated SiC particles of different sizes using MW radiation. The heating behaviors of the particles were then compared with their MW-absorption properties. The heating behavior of the particles was dependent on their radii; this result was in keeping with theoretical predictions. Furthermore, the ?-SiC particles exhibited anomalous behaviors when subjected to microwave heating at temperatures of 1100?°C and higher. These behaviors were attributable to the transformation of ?-SiC into the ?-phase. The underlying mechanism for this transformation is discussed on the basis of the results of X-ray diffraction analysis.

Sugawara, H.; Hayashi, M.; Ishihara, S. [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro, Tokyo 152-8552 (Japan); Kashimura, K., E-mail: kashimura@isc.chubu.ac.jp [Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi 487-8501 (Japan); Mitani, T.; Shinohara, N. [Kyoto University, Gokasyo, Uji, Kyoto 611-0011 (Japan)

2014-07-21T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

IMPROVED MICROWAVE REMOTE SENSING OF HURRICANE WIND SPEED AND RAIN RATES USING THE HURRICANE IMAGING RADIOMETER (HIRAD)  

E-Print Network [OSTI]

IMPROVED MICROWAVE REMOTE SENSING OF HURRICANE WIND SPEED AND RAIN RATES USING THE HURRICANE) that measures wind speed and rain rate along the ground track directly beneath the aircraft. This paper presents are presented, which illustrate wind speed and rain rate measurement spatial resolutions and swath coverage. 1

Ruf, Christopher

22

High spatial resolution upgrade of the electron cyclotron emission radiometer for the DIII-D tokamak  

SciTech Connect (OSTI)

The 40-channel DIII-D electron cyclotron emission (ECE) radiometer provides measurements of T{sub e}(r,t) at the tokamak midplane from optically thick, second harmonic X-mode emission over a frequency range of 83–130 GHz. The frequency spacing of the radiometer's channels results in a spatial resolution of ?1–3 cm, depending on local magnetic field and electron temperature. A new high resolution subsystem has been added to the DIII-D ECE radiometer to make sub-centimeter (0.6–0.8 cm) resolution T{sub e} measurements. The high resolution subsystem branches off from the regular channels’ IF bands and consists of a microwave switch to toggle between IF bands, a switched filter bank for frequency selectivity, an adjustable local oscillator and mixer for further frequency down-conversion, and a set of eight microwave filters in the 2–4 GHz range. Higher spatial resolution is achieved through the use of a narrower (200 MHz) filter bandwidth and closer spacing between the filters’ center frequencies (250 MHz). This configuration allows for full coverage of the 83–130 GHz frequency range in 2 GHz bands. Depending on the local magnetic field, this translates into a “zoomed-in” analysis of a ?2–4 cm radial region. Expected uses of these channels include mapping the spatial dependence of Alfven eigenmodes, geodesic acoustic modes, and externally applied magnetic perturbations. Initial T{sub e} measurements, which demonstrate that the desired resolution is achieved, are presented.

Truong, D. D., E-mail: dtruong@wisc.edu [Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Austin, M. E. [Institute for Fusion Studies, University of Texas, Austin, Texas, 78712 (United States)

2014-11-15T23:59:59.000Z

23

Application of microwave heating to ceramic processing: Design and initial operation of a 2.45-GHz single-mode furnace  

SciTech Connect (OSTI)

High-power microwave and millimeter-wave sources are currently being applied to ceramic processing studies at the Naval Research Laboratory (NRL). A single-mode cavity microwave furnace, operating in the TE{sub 103} mode at 2.45 GHz, is operational and is being used to investigate sintering of nanocrystalline ceramics. This paper reports the design of the 2.45-GHz furnace and its use in initial microwave sintering experiments on nanocrystalline alumina and titania compacts. The high purity Al{sub 2}O{sub 3} and TiO{sub 2} nanocrystalline powders used in the sintering experiments were prepared by the sol-gel method. These powders were first uniaxially pressed to 14 MPa, cold isostatically pressed (CIP`ed) to various pressures {ge}420 MPa, and finally sectioned into wafers. The density of the green compacts was 30 to 38% theoretical density (TD). The compacts were placed in insulating fiberboard caskets which were sufficiently lossy to provide hybrid heating at room temperature. The compacts were heated in the microwave furnace for up to three hours at temperatures {ge}1720 C. The temperature of the workpiece was monitored using an optical pyrometer. Final densities up to 80% TD have been obtained to date for Al{sub 2}O{sub 3} and up to 52% TD for TiO{sub 2}. The sintered compacts were characterized by X-ray diffraction and by scanning electron microscopy (SEM) to determine the phase and grain size.

Fliflet, A.W. [Naval Research Lab., Washington, DC (United States)] [Naval Research Lab., Washington, DC (United States); Bruce, R.W.; Kinkead, A.K. [Sachs/Freeman Associates Inc., Landover, MD (United States)] [and others] [Sachs/Freeman Associates Inc., Landover, MD (United States); and others

1996-06-01T23:59:59.000Z

24

Broadband radiometer  

DOE Patents [OSTI]

A broadband radiometer is disclosed including (a) an optical integrating sphere having generally spherical integrating chamber and an entry port for receiving light (e.g., having visible and ultraviolet fractions), (b) a first optical radiation detector for receiving light from the sphere and producing an electrical output signal corresponding to broadband radiation, (c) a second optical radiation detector for receiving light from the sphere and producing an electrical output signal corresponding to a predetermined wavelength fraction of the broadband radiation, and (d) an output for producing an electrical signal which is proportional to the difference between the two electrical output signals. The radiometer is very useful, for example, in measuring the absolute amount of ultraviolet light present in a given light sample. 8 figs.

Cannon, T.W.

1994-07-26T23:59:59.000Z

25

DRAFT Microwave Radiometer Profiler Handbook  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phases onOrganizationElectronic2005-2007 Budget Dear2, 2011 DRAFT MEETING

26

Selected applications of microwave radiometric techniques  

E-Print Network [OSTI]

Measurements at 31. 4 GHz of an Oil Film on a Water Surface 75 80 93 96 97 114 122 126 127 132 LIST OF FIGURES ~Fi ure ~Pa e III-1 Laboratory measurements of the dielectric properties of moist sand 24 III-2 III-3 III-4 Effects of increasing.... Based on the characteristic of all bodies to radiate electromagnetic energy at a rate depen- dent upon their temperature, surface structure, and elec- tromagnetic properties, the microwave radiometer provides an all-weather, day-night means...

Jean, Buford Randall

1971-01-01T23:59:59.000Z

27

Influence of microwave driver coupling design on plasma density at Testbench for Ion sources Plasma Studies, a 2.45 GHz Electron Cyclotron Resonance Plasma Reactor  

SciTech Connect (OSTI)

A comparative study of two microwave driver systems (preliminary and optimized) for a 2.45 GHz hydrogen Electron Cyclotron Resonance plasma generator has been conducted. The influence on plasma behavior and parameters of stationary electric field distribution in vacuum, i.e., just before breakdown, along all the microwave excitation system is analyzed. 3D simulations of resonant stationary electric field distributions, 2D simulations of external magnetic field mapping, experimental measurements of incoming and reflected power, and electron temperature and density along the plasma chamber axis have been carried out. By using these tools, an optimized set of plasma chamber and microwave coupler has been designed paying special attention to the optimization of stationary electric field value in the center of the plasma chamber. This system shows a strong stability on plasma behavior allowing a wider range of operational parameters and even sustaining low density plasma formation without external magnetic field. In addition, the optimized system shows the capability to produce values of plasma density four times higher than the preliminary as a consequence of a deeper penetration of the magnetic resonance surface in relative high electric field zone by keeping plasma stability. The increment of the amount of resonance surface embedded in the plasma under high electric field is suggested as a key factor.

Megía-Macías, A.; Vizcaíno-de-Julián, A. [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain)] [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain); Cortázar, O. D., E-mail: dcortazar@essbilbao.org [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain); Universidad de Castilla-La Mancha, ETSII, C.J. Cela s/n, 13170 Ciudad Real (Spain)

2014-03-15T23:59:59.000Z

28

FIRST SEASON QUIET OBSERVATIONS: MEASUREMENTS OF COSMIC MICROWAVE BACKGROUND POLARIZATION POWER SPECTRA AT 43 GHz IN THE MULTIPOLE RANGE 25 {<=} l {<=} 475  

SciTech Connect (OSTI)

The Q/U Imaging ExperimenT (QUIET) employs coherent receivers at 43 GHz and 94 GHz, operating on the Chajnantor plateau in the Atacama Desert in Chile, to measure the anisotropy in the polarization of the cosmic microwave background (CMB). QUIET primarily targets the B modes from primordial gravitational waves. The combination of these frequencies gives sensitivity to foreground contributions from diffuse Galactic synchrotron radiation. Between 2008 October and 2010 December, over 10,000 hr of data were collected, first with the 19 element 43 GHz array (3458 hr) and then with the 90 element 94 GHz array. Each array observes the same four fields, selected for low foregrounds, together covering Almost-Equal-To 1000 deg{sup 2}. This paper reports initial results from the 43 GHz receiver, which has an array sensitivity to CMB fluctuations of 69 {mu}K{radical}s. The data were extensively studied with a large suite of null tests before the power spectra, determined with two independent pipelines, were examined. Analysis choices, including data selection, were modified until the null tests passed. Cross-correlating maps with different telescope pointings is used to eliminate a bias. This paper reports the EE, BB, and EB power spectra in the multipole range l = 25-475. With the exception of the lowest multipole bin for one of the fields, where a polarized foreground, consistent with Galactic synchrotron radiation, is detected with 3{sigma} significance, the E-mode spectrum is consistent with the {Lambda}CDM model, confirming the only previous detection of the first acoustic peak. The B-mode spectrum is consistent with zero, leading to a measurement of the tensor-to-scalar ratio of r = 0.35{sup +1.06}{sub -0.87}. The combination of a new time-stream 'double-demodulation' technique, side-fed Dragonian optics, natural sky rotation, and frequent boresight rotation leads to the lowest level of systematic contamination in the B-mode power so far reported, below the level of r = 0.1.

Bischoff, C.; Brizius, A.; Buder, I.; Kusaka, A.; Smith, K. M. [Kavli Institute for Cosmological Physics, Department of Physics, Enrico Fermi Institute, University of Chicago, Chicago, IL 60637 (United States); Chinone, Y. [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Cleary, K.; Reeves, R. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Dumoulin, R. N.; Newburgh, L. B.; Zwart, J. T. L. [Department of Physics and Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Monsalve, R.; Bustos, R. [Department of Physics, University of Miami, Coral Gables, FL 33146 (United States); Naess, S. K.; Eriksen, H. K. [Institute of Theoretical Astrophysics, University of Oslo, N-0315 Oslo (Norway); Wehus, I. K. [Department of Physics, University of Oslo, N-0316 Oslo (Norway); Zuntz, J. A. [Department of Astrophysics, University of Oxford, Oxford OX1 3RH (United Kingdom); Bronfman, L. [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Church, S. E. [Kavli Institute for Particle Astrophysics and Cosmology and Department of Physics, Stanford University, Varian Physics Building, Stanford, CA 94305 (United States); Dickinson, C., E-mail: akito@kicp.uchicago.edu [Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom)

2011-11-10T23:59:59.000Z

29

Circularly polarized microwaves for magnetic resonance study in the GHz range: application to nitrogen-vacancy in diamonds  

E-Print Network [OSTI]

The ability to create time-dependent magnetic fields of controlled polarization is essential for many experiments with magnetic resonance. We describe a microstrip circuit that allows us to generate strong magnetic field at microwave frequencies with arbitrary adjusted polarization. The circuit performance is demonstrated by applying it to an optically detected magnetic resonance and Rabi nutation experiments in nitrogen-vacancy color centers in diamond. Thanks to high efficiency of the proposed microstrip circuit and degree of circular polarization of 85% it is possible to address the specific spin states of a diamond sample using a low power microwave generator.

Mrozek, Mariusz; Rudnicki, Daniel S; Gawlik, Wojciech

2015-01-01T23:59:59.000Z

30

Cloud fraction, liquid and ice water contents derived from long-term radar, lidar, and microwave radiometer data are systematically compared to models to quantify and  

E-Print Network [OSTI]

Cloud fraction, liquid and ice water contents derived from long-term radar, lidar, and microwave a systematic evaluation of clouds in forecast models. Clouds and their associated microphysical processes for end users of weather forecasts, who may be interested not only in cloud cover, but in other variables

Hogan, Robin

31

ARM - Field Campaign - Microwave Radiometer Profiler Evaluation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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32

Ground-Based Microwave Radiometer Measurements  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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33

Microwave and Millimeter-Wave Radiometric Studies of Temperature, Water Vapor and Clouds  

SciTech Connect (OSTI)

The importance of accurate measurements of column amounts of water vapor and cloud liquid has been well documented by scientists within the Atmospheric Radiation Measurement (ARM) Program. At the North Slope of Alaska (NSA), both microwave radiometers (MWR) and the MWRProfiler (MWRP), been used operationally by ARM for passive retrievals of the quantities: Precipitable Water Vapor (PWV) and Liquid Water Path (LWP). However, it has been convincingly shown that these instruments are inadequate to measure low amounts of PWV and LWP. In the case of water vapor, this is especially important during the Arctic winter, when PWV is frequently less than 2 mm. For low amounts of LWP (< 50 g/m{sup 2}), the MWR and MWRP retrievals have an accuracy that is also not acceptable. To address some of these needs, in March-April 2004, NOAA and ARM conducted the NSA Arctic Winter Radiometric Experiment - Water Vapor Intensive Operational Period at the ARM NSA/Adjacent Arctic Ocean (NSA/AAO) site. After this experiment, the radiometer group at NOAA moved to the Center for Environmental Technology (CET) of the Department of Electrical and Computer Engineering of the University of Colorado at Boulder. During this 2004 experiment, a total of 220 radiosondes were launched, and radiometric data from 22.235 to 380 GHz were obtained. Primary instruments included the ARM MWR and MWRP, a Global Positioning System (GPS), as well as the CET Ground-based Scanning Radiometer (GSR). We have analyzed data from these instruments to answer several questions of importance to ARM, including: (a) techniques for improved water vapor measurements; (b) improved calibration techniques during cloudy conditions; (c) the spectral response of radiometers to a variety of conditions: clear, liquid, ice, and mixed phase clouds; and (d) forward modeling of microwave and millimeter wave brightness temperatures from 22 to 380 GHz. Many of these results have been published in the open literature. During the third year of this contract, we participated in another ARM-sponsored experiment at the NSA during February-March 2007. This experiment is called the Radiative Heating in Underexplored Bands Campaign (RHUBC) and the GSR was operated successfully for the duration of the campaign. One of the principal goals of the experiment was to provide retrievals of water vapor during PWV amounts less than 2 mm and to compare GSR data with ARM radiometers and radiosondes. A secondary goal was to compare the radiometric response of the microwave and millimeter wavelength radiometers to water and ice clouds. In this final report, we will include the separate progress reports for each of the three years of the project and follow with a section on major accomplishments of the project.

Westwater, Edgeworth

2011-05-06T23:59:59.000Z

34

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 47, NO. 8, AUGUST 1999 1457 A Planar 4.5-GHz DCDC Power Converter  

E-Print Network [OSTI]

. The need for discrete magnetic components, including inductors and isolation transformers, is the main.5-GHz DC­DC Power Converter Slavko Djuki´c, Dragan Maksimovi´c, Member, IEEE, and Zoya Popovi´c, Senior a maximum power-added efficiency of 86%, corresponding drain efficiency of 95%, and 120 mW of output power

Popovic, Zoya

35

Microwave Sensors Active and David G. Long  

E-Print Network [OSTI]

waves up through high energy gamma waves. Microwaves extend over an important part of the elec be classified as either passive (radiometers) or active (radars). Each sensor class provides unique insight instruments can be divided into two broad classes: pas- sive, known as radiometers, and active, known

Long, David G.

36

Characterization and calibration of 8-channel E-band heterodyne radiometer system for SST-1 tokamak  

SciTech Connect (OSTI)

An 8-channel E-band heterodyne radiometer system (74–86 GHz) is designed, characterized, and calibrated to measure the radial electron temperature profile by measuring Electron Cyclotron Emission spectrum at SST-1 Tokamak. The developed radiometer has a noise equivalent temperature of 1 eV and sensitivity of 5 × 10{sup 9} V/W. In order to precisely measure the absolute value of electron temperature, a calibration measurement of the radiometer system is performed using hot-cold Dicke switch method, which confirms the system linearity.

Siju, Varsha; Kumar, Dharmendra; Shukla, Praveena; Pathak, S. K. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)] [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)

2014-05-15T23:59:59.000Z

37

Radiometer Characterization System  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared at 278, 298, and 323Program2 Radiometer Characterization System

38

Simultaneous Retreival of Surface Wind Speed and Rain Rate using Radar and Radiometer Measurements  

E-Print Network [OSTI]

to simultaneously retrieve the vertical profile of precipitation and the near-surface wind speed. ResultsSimultaneous Retreival of Surface Wind Speed and Rain Rate using Radar and Radiometer Measurements simultaneously estimates the over ocean near-surface wind speed and rain rate profile using data from a 10.7 GHz

Ruf, Christopher

39

6, 54275456, 2006 Passive microwave  

E-Print Network [OSTI]

ACPD 6, 5427­5456, 2006 Passive microwave 3-D polarization effects from rainy clouds A. Battaglia radiometers A. Battaglia 1 , C. Simmer 1 , and H. Czekala 2 1 Meteorological Institute, University of Bonn April 2006 ­ Published: 27 June 2006 Correspondence to: A. Battaglia (batta@uni-bonn.de) 5427 #12;ACPD 6

Boyer, Edmond

40

A 16-channel heterodyne electron cyclotron emission radiometer on J-TEXT  

SciTech Connect (OSTI)

To study equilibrium temporal dynamics and the mechanisms of magnetohydrodynamic instabilities, a 16-channel heterodyne electron cyclotron emission (ECE) radiometer has been developed to view the J-TEXT tokamak from the low field side. The ECE radiometer detects second-harmonic extraordinary mode in the frequency band of 94-125 GHz which corresponds to resonances from 1.8 T to 2.2 T. This ECE system consists of an ECE transmission line, a radio frequency unit, and two 8-channel intermediate frequency units. An in situ blackbody calibration source is applied for system calibration by comparison of hot and cold sources in order to provide an absolute temperature measurement.

Yang, Z. J.; Zhuang, G.; Xiao, J. S.; Wang, Z. J. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Key Laboratory of Fusion and Advanced Electromagnetic Technology Ministry of Education, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Phillips, P. E.; Huang, H.; Rowan, W. L. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)

2012-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Spectroscopy with Multichannel Correlation Radiometers  

E-Print Network [OSTI]

Correlation radiometers make true differential measurements in power with high accuracy and small systematic errors. This receiver architecture has been used in radio astronomy for measurements of continuum radiation for over 50 years; this article examines spectroscopy over broad bandwidths using correlation techniques. After general discussions of correlation and the choice of hybrid phase, experimental results from tests with a simple laboratory multi-channel correlation radiometer are shown. Analysis of the effect of the input hybrid's phase shows that a 90 degree hybrid is likely to be the best general choice for radio astronomy, depending on its amplitude match and phase flatness with frequency. The laboratory results verify that the combination of the correlation architecture and an analog lag correlator is an excellent method for spectroscopy over very wide bandwidths.

A. I. Harris

2005-04-20T23:59:59.000Z

42

New Technique for Retrieving Liquid Water Path over Land using Satellite Microwave Observations  

SciTech Connect (OSTI)

We present a new methodology for retrieving liquid water path over land using satellite microwave observations. As input, the technique exploits the Advanced Microwave Scanning Radiometer for earth observing plan (EOS) (AMSR-E) polarization-difference signals at 37 and 89 GHz. Regression analysis performed on model simulations indicates that over variable atmospheric and surface conditions the polarization-difference signals can be simply parameterized in terms of the surface emissivity polarization difference ({Delta}{var_epsilon}), surface temperature, liquid water path (LWP), and precipitable water vapor (PWV). The resulting polarization-difference parameterization (PDP) enables fast and direct (noniterative) retrievals of LWP with minimal requirements for ancillary data. Single- and dual-channel retrieval methods are described and demonstrated. Data gridding is used to reduce the effects of instrumental noise. The methodology is demonstrated using AMSR-E observations over the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site during a six day period in November and December, 2003. Single- and dual-channel retrieval results mostly agree with ground-based microwave retrievals of LWP to within approximately 0.04 mm.

Deeter, M.N.; Vivekanandan, J.

2005-03-18T23:59:59.000Z

43

Microwave-induced thermoacoustic tomography: reconstruction by synthetic aperture  

E-Print Network [OSTI]

-induced thermoacoustic tomography (LMTT) based on focused transducers. Two microwave sources, which had frequencies of 9 GHz and 3 GHz, respectively, were used in the experiments for comparison. The 3-GHz system had a much larger imaging depth but a lower signal...

Feng, Dazi

2001-01-01T23:59:59.000Z

44

Microwave radiative transfer in the mixed-phase regions of tropical rainfall  

E-Print Network [OSTI]

on an RTM. To accomplish this, we examined data taken by the Convair-580 aircraft during the KWAJEX (Kwajalein Experiment). In order to calculate radiative transfer, the AMMR (Airborne Multi-channel Microwave Radiometer) data were combined with radiosonde...

Jin, Kyoung-Wook

2001-01-01T23:59:59.000Z

45

Potential Soil Moisture Products from the Aquarius Radiometer and Scatterometer Using an Observing System Simulation Experiment  

SciTech Connect (OSTI)

Using an observing system simulation experiment (OSSE), we investigate the potential soil moisture retrieval capability of the National Aeronautics and Space Administration (NASA) Aquarius radiometer (L-band 1.413 GHz) and scatterometer (L-band, 1.260 GHz). We estimate potential errors in soil moisture retrievals and identify the sources that could cause those errors. The OSSE system includes (i) a land surface model in the NASA Land Information System, (ii) a radiative transfer and backscatter model, (iii) a realistic orbital sampling model, and (iv) an inverse soil moisture retrieval model. We execute the OSSE over a 1000 2200 km2 region in the central United States, including the Red and Arkansas river basins. Spatial distributions of soil moisture retrieved from the radiometer and scatterometer are close to the synthetic truth. High root mean square errors (RMSEs) of radiometer retrievals are found over the heavily vegetated regions, while large RMSEs of scatterometer retrievals are scattered over the entire domain. The temporal variations of soil moisture are realistically captured over a sparely vegetated region with correlations 0.98 and 0.63, and RMSEs 1.28% and 8.23% vol/vol for radiometer and scatterometer, respectively. Over the densely vegetated region, soil moisture exhibits larger temporal variation than the truth, leading to correlation 0.70 and 0.67, respectively, and RMSEs 9.49% and 6.09% vol/vol respectively. The domain-averaged correlations and RMSEs suggest that radiometer is more accurate than scatterometer in retrieving soil moisture. The analysis also demonstrates that the accuracy of the retrieved soil moisture is affected by vegetation coverage and spatial aggregation.

Luo, Yan [I.M. Systems Group at NOAA/NCEP/EMC; Feng, Xia [George Mason University; Houser, Paul [George Mason University; Anantharaj, Valentine G [ORNL; Fan, Xingang [Western Kentucky University, Bowling Green; De Lannoy, Gabrielle [Ghent University, Belgium; Zhan, Xiwu [NOAA/NESDIS Center for Satellite Applications and Research; Dabbiru, Lalitha [Mississippi State University (MSU)

2013-01-01T23:59:59.000Z

46

Remote monitoring of soil moisture using airborne microwave radiometers  

E-Print Network [OSTI]

) site G (b) site H I V-6 i IV- 7 'IV- 8 iV- I iV- 2 ! iV-3 Chickasha test site I V-4 Ground cover for Chickasha sites: site A (b) site B 62 63 64 67 68 69 71 X1 I I' I giirc I';i g| c Ground cover I or Chickashn sites: (n) site C (b...O bd rn 4I cb ccb U 0 0 U cd C4 Cd 0 44 E cd Itt g bb 0 cd cd E cjoy Gl U W t:t cd U cd 4 0 cb ?0 I M cct U Q rt M with the internal calibration which gives the slope or difference in temperature scale, the absolute reading...

Kroll, Charles Lindsey

2012-06-07T23:59:59.000Z

47

ARM - Field Campaign - Long-Term Microwave Radiometer Intercomparison  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience4AJ01)3,CloudgovCampaignsIR Cloud

48

Experimental study of a 1.5-MW, 110-GHz gyrotron oscillator  

E-Print Network [OSTI]

This thesis reports the design, construction and testing of a 1.5 MW, 110 GHz gyrotron oscillator. This high power microwave tube has been proposed as the next evolutionary step for gyrotrons used to provide electron ...

Anderson, James P. (James Paul), 1972-

2005-01-01T23:59:59.000Z

49

IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, VOL. 53, NO. 8, AUGUST 2006 1647 Multistatic Adaptive Microwave Imaging for Early  

E-Print Network [OSTI]

, and the backscattered energy distribution is calculated coherently. The advantages of UWB CMI include high to the microwave radiometry [8], [9], which uses radiometers to measure temperature differences between the normal

Xie, Yao

50

Anomalous Microwave Emission  

E-Print Network [OSTI]

Improved knowledge of diffuse Galactic emission is important to maximize the scientific return from scheduled CMB anisotropy missions. Cross-correlation of microwave maps with maps of the far-IR dust continuum show a ubiquitous microwave emission component whose spatial distribution is traced by far-IR dust emission. The spectral index of this emission, beta_{radio} = -2.2 (+0.5 -0.7) is suggestive of free-free emission but does not preclude other candidates. Comparison of H-alpha and microwave results show that both data sets have positive correlations with the far-IR dust emission. Microwave data, however, are consistently brighter than can be explained solely from free-free emission traced by H-alpha. This ``anomalous'' microwave emission can be explained as electric dipole radiation from small spinning dust grains. The anomalous component at 53 GHz is 2.5 times as bright as the free-free emission traced by H-alpha, providing an approximate normalization for models with significant spinning dust emission.

A. Kogut

1999-02-22T23:59:59.000Z

51

Novel Cyclotron-Based Radiometal Production  

SciTech Connect (OSTI)

Accomplishments: (1) Construction of prototype solution target for radiometal production; (2) Testing of prototype target for production of following isotopes: a. Zr-89. Investigation of Zr-89 production from Y-89 nitrate solution. i. Defined problems of gas evolution and salt precipitation. ii. Solved problem of precipitation by addition of nitric acid. iii. Solved gas evolution problem with addition of backpressure regulator and constant degassing of target during irradiations. iv. Investigated effects of Y-89 nitrate concentration and beam current. v. Published abstracts at SNM and ISRS meetings; (3) Design of 2nd generation radiometal solution target. a. Included reflux chamber and smaller target volume to conserve precious target materials. b. Included aluminum for prototype and tantalum for working model. c. Included greater varicosities for improved heat transfer; and, (4) Construction of 2nd generation radiometal solution target started.

DeGrado, Timothy R. [Mayo Clinic] [Mayo Clinic (United States)

2013-10-31T23:59:59.000Z

52

Modification of the collective Thomson scattering radiometer in the search for parametric decay on TEXTOR  

SciTech Connect (OSTI)

Strong scattering of high-power millimeter waves at 140 GHz has been shown to take place in heating and current-drive experiments at TEXTOR when a tearing mode is present in the plasma. The scattering signal is at present supposed to be generated by the parametric decay instability. Here we describe the heterodyne detection system used to characterize the newly discovered signal measured at TEXTOR, and we present spectral shapes in which the signal can appear under different conditions. The radiation is collected by the receiver through a quasi-optical transmission line that is independent of the electron cyclotron resonance heating transmission line, and so the scattering geometry is variable. The signal is detected with 42 frequency channels ranging from 136 to 142 GHz. We demonstrate that the large signal does not originate from gyrotron spurious radiation. The measured signal agrees well with independent backscattering radiometer data.

Nielsen, S. K.; Salewski, M.; Korsholm, S. B.; Leipold, F.; Meo, F.; Michelsen, P.; Stejner, M. [Association EURATOM - DTU, Department of Physics, Technical University of Denmark, Risoe Campus, DK-4000 Roskilde (Denmark); Bongers, W.; Moseev, D.; Westerhof, E. [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, Association EURATOM - FOM, Nieuwegein (Netherlands); Oosterbeek, J. W. [Department of Applied Physics, Science and Technology of Nuclear Fusion, Eindhoven University of Technology, NL-5600 MB Eindhoven (Netherlands)

2012-11-15T23:59:59.000Z

53

Millimeter-wave Radiometer for High Sensitivity Water Vapor Profiling in Arid Regions  

SciTech Connect (OSTI)

Abstract - ProSensing Inc. has developed a G-band (183 GHz) water Vapor Radiometer (GVR) for long-term, unattended measurements of low concentrations of atmospheric water vapor and liquid water. Precipitable water vapor and liquid water path are estimated from zenith brightness temperatures measured from four double-sideband receiver channels, centered at 183.31 1, 3 and 7, and 14 GHz. A prototype ground-based version of the instrument was deployed at the DOE ARM program?s North Slope of Alaska site near Barrow AK in April 2005, where it collected data continuously for one year. A compact, airborne version of this instrument, packaged to operate from a standard 2-D PMS probe canister, has been tested on the ground and is scheduled for test flights in the summer of 2006. This paper presents design details, laboratory test results and examples of retrieved precipitable water vapor and liquid water path from measured brightness temperature data.

Pazmany, Andrew

2006-11-09T23:59:59.000Z

54

Development of multichannel intermediate frequency system for electron cyclotron emission radiometer on KSTAR Tokamak  

SciTech Connect (OSTI)

Plasma experiments on KSTAR are scheduled to start up this year (2008). We have developed an electron cyclotron emission (ECE) radiometer to measure the radial electron temperature profiles in KSTAR experiments. The radiometer system consists, briefly, of two downconversion stages, amplifiers, bandpass filter banks, and video detectors. These components are made commercially or developed in house. The system detects ECE power in the frequency range from 110 to 196 GHz, the detected signal being resolved by means of 48 frequency windows. Before installation of this system on KSTAR, we installed a part of this system on large helical device (LHD) to study the system under similar plasma conditions. In this experiment, the signal amplitude, considered to be proportional to the electron temperature, is measured. The time-dependent traces of the electron temperature measured by this radiometer are in good agreement with those provided by the LHD Michelson spectrometer. The system noise level which limits the minimum measurable temperature (converted to the electron temperature) is about 30 eV.

Kogi, Yuichiro; Sakoda, Takuya; Mase, Atsushi; Ito, Naoki; Yokota, Yuya [Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga Fukuoka 816-8580 (Japan); Yamaguchi, Soichiro; Nagayama, Yoshio; Kawahata, Kazuo [National Institute for Fusion Science, Toki Gifu 509-5292 (Japan); Jeong, Seung H. [Korea Atomic Energy Research Institute, 1045 Daedeokdaero Daejeon (Korea, Republic of); Kwon, Myeun [National Fusion Research Institute, 113 Gwahangno Daejeon (Korea, Republic of)

2008-10-15T23:59:59.000Z

55

Low density inorganic foams fabricated using microwaves  

SciTech Connect (OSTI)

The objective of our work was to determine if high temperature foams could be made using microwave heating; and if so, to investigate some of their properties. Several foams were made and their compressive strengths, tensile strengths and densities were determined. Foams were made of glass, metal-glass, glass-fiber, metal-glass-fiber, and fly ash. The microwave source used was a Litton model 1521 microwave oven which operated at 2.45 GHz and had an output of 700 watts.

Meek, T.T.; Blake, R.D.; Gregory, T.G.

1985-01-01T23:59:59.000Z

56

MEASUREMENTS AND RETRIEVALS FROM A NEW 183-GHz WATER VAPOR RADIOMETER IN  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and InterfacesAdministration -Lowell L. Wood,3, BPA earned net3rdKSTHE

57

Broadband patterned magnetic microwave absorber  

SciTech Connect (OSTI)

It is a tough task to greatly improve the working bandwidth for the traditional flat microwave absorbers because of the restriction of available material parameters. In this work, a simple patterning method is proposed to drastically broaden the absorption bandwidth of a conventional magnetic absorber. As a demonstration, an ultra-broadband microwave absorber with more than 90% absorption in the frequency range of 4–40 GHz is designed and experimentally realized, which has a thin thickness of 3.7?mm and a light weight equivalent to a 2-mm-thick flat absorber. In such a patterned absorber, the broadband strong absorption is mainly originated from the simultaneous incorporation of multiple ?/4 resonances and edge diffraction effects. This work provides a facile route to greatly extend the microwave absorption bandwidth for the currently available absorbing materials.

Li, Wei; Wu, Tianlong; Wang, Wei; Guan, Jianguo, E-mail: guanjg@whut.edu.cn [State Key Lab of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Zhai, Pengcheng [School of Science, Wuhan University of Technology, Wuhan 430070 (China)

2014-07-28T23:59:59.000Z

58

A new radiometer for earth radiation budget studies  

SciTech Connect (OSTI)

A critical need for the US Global Change Research Program is to provide continuous, well-calibrated radiometric data for radiation balance studies. This paper describes a new, compact, relatively light-weight, adaptable radiometer which will provide both spectrally integrated measurements and data in selected spectral bands. The radiometer design is suitable for use on (small) satellites, aircraft, or Unmanned Aerospace Vehicles (UAVs). Some considerations for the implementation of this radiometer on a small satellite are given. 17 refs.

Weber, P.G.

1992-05-01T23:59:59.000Z

59

Microwave detector  

DOE Patents [OSTI]

A microwave detector (10) is provided for measuring the envelope shape of a microwave pulse comprised of high-frequency oscillations. A biased ferrite (26, 28) produces a magnetization field flux that links a B-dot loop (16, 20). The magnetic field of the microwave pulse participates in the formation of the magnetization field flux. High-frequency insensitive means (18, 22) are provided for measuring electric voltage or current induced in the B-dot loop. The recorded output of the detector is proportional to the time derivative of the square of the envelope shape of the microwave pulse.

Meldner, Heiner W. (Moss Beach, CA); Cusson, Ronald Y. (Chapel Hill, NC); Johnson, Ray M. (San Ramon, CA)

1986-01-01T23:59:59.000Z

60

Microwave detector  

DOE Patents [OSTI]

A microwave detector is provided for measuring the envelope shape of a microwave pulse comprised of high-frequency oscillations. A biased ferrite produces a magnetization field flux that links a B-dot loop. The magnetic field of the microwave pulse participates in the formation of the magnetization field flux. High-frequency insensitive means are provided for measuring electric voltage or current induced in the B-dot loop. The recorded output of the detector is proportional to the time derivative of the square of the envelope shape of the microwave pulse.

Meldner, H.W.; Cusson, R.Y.; Johnson, R.M.

1985-02-08T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Mobile system for microwave removal of concrete surfaces  

DOE Patents [OSTI]

A method and apparatus are disclosed for the microwave removal of contaminated concrete surfaces. The apparatus comprises a housing adapted to pass over a support surface. The housing includes a waveguide for directing microwave energy to the surface at an angle maximizing absorption of microwave energy by the surface. The apparatus is further provided with a source of microwave energy operably associated with the waveguide, wherein the microwave energy has a frequency of between about 10.6 GHz and about 24 GHz and acts to remove the uppermost layer from the surface. The apparatus further includes a debris containment assembly comprising a vacuum assembly operably associated with the housing. The vacuum assembly is adapted to remove debris from the area adjacent the surface. 7 figs.

White, T.L.; Bigelow, T.S.; Schaich, C.R.; Foster, D. Jr.

1997-06-03T23:59:59.000Z

62

Mobile system for microwave removal of concrete surfaces  

DOE Patents [OSTI]

A method and apparatus for the microwave removal of contaminated concrete surfaces. The apparatus comprises a housing adapted to pass over a support surface. The housing includes a waveguide for directing microwave energy to the surface at an angle maximizing absorption of microwave energy by the surface. The apparatus is further provided with a source of microwave energy operably associated with the waveguide, wherein the microwave energy has a frequency of between about 10.6 GHz and about 24 GHz and acts to remove the uppermost layer from the surface. The apparatus further includes a debris containment assembly comprising a vacuum assembly operably associated with the housing. The vacuum assembly is adapted to remove debris from the area adjacent the surface.

White, Terry L. (Oak Ridge, TN); Bigelow, Timothy S. (Knoxville, TN); Schaich, Charles R. (Lenoir City, TN); Foster, Jr., Don (Knoxville, TN)

1997-01-01T23:59:59.000Z

63

Single scattering parameters of randomly oriented snow particles at microwave frequencies  

E-Print Network [OSTI]

can affect earth energy balance through the surface albedo change. Ground-based radars have been used] Millimeter-wave radiometers operating at frequencies greater than 90 GHz have been employed to estimate, 2004; Kim, 2004] because of their high sensitivity to scattering by snow in the atmosphere

Houze Jr., Robert A.

64

The Anisotropy in the Cosmic Microwave Background At Degree Angular Scales.  

E-Print Network [OSTI]

are 36­39.5, 39.5­43, 43­46 GHz. The six channels in each radiometer view the sky in a single­axis parabola. The FWHM beam in K a band is 1:42 \\Sigma 0:02 ffi and in Q band is 1:04 \\Sigma 0:02 ffi . After

65

Microwave sintering of nanocrystalline ceramics  

SciTech Connect (OSTI)

A single-mode cavity microwave furnace, operating in the TE{sub 103} mode at 2.45 GHz, has been set up at the Naval Research Laboratory (NRL) and is currently being used to investigate sintering of nanocrystalline ceramics. This presentation will discuss the apparatus used and the results obtained to date. The high purity Al{sub 2}O{sub 3} and TiO{sub 2} nanocrystalline powders were prepared by the sol-gel method. These powders were first uniaxially pressed to 14 MPa, CIP`ed to various pressures > 420 MPa and finally sectioned into wafers. The density of the green wafers was 30 to 38% TD. The wafers were heated in the microwave furnace for up to three hours at temperatures {<=} 1720{degrees}C. The temperature of the workpiece was monitored using an optical pyrometer. Final densities up to 80% TD have been obtained to date for Al{sub 2}O{sub 3} and up to 52% TD for TiO{sub 2}. Work is ongoing to characterize the sintered compacts, optimize the casketing for this furnace, and lay the groundwork for new studies using a 35 GHz gyrotron and quasioptical gyrotron tunable from 85 to 120 GHz.

Bruce, R.W. [United States Naval Academy, Annapolis, MD (United States); Rayne, R.; Chow, G.M. [Naval Research Lab., Washington, DC (United States)] [and others

1995-12-31T23:59:59.000Z

66

Microfluidic Radiometal Labeling Systems for Biomolecules  

SciTech Connect (OSTI)

In a typical labeling procedure with radiometals, such as Cu-64 and Ga-68; a very large (~ 100-fold) excess of the non-radioactive reactant (precursor) is used to promote rapid and efficient incorporation of the radioisotope into the PET imaging agent. In order to achieve high specific activities, careful control of reaction conditions and extensive chromatographic purifications are required in order to separate the labeled compounds from the cold precursors. Here we propose a microfluidic approach to overcome these problems, and achieve high specific activities in a more convenient, semi-automated fashion and faster time frame. Microfluidic reactors, consisting of a network of micron-sized channels (typical dimensions in the range 10 â�� 300 �¼m), filters, separation columns, electrodes and reaction loops/chambers etched onto a solid substrate, are now emerging as an extremely useful technology for the intensification and miniaturization of chemical processes. The ability to manipulate, process and analyze reagent concentrations and reaction interfaces in both space and time within the channel network of a microreactor provides the fine level of reaction control that is desirable in PET radiochemistry practice. These factors can bring radiometal labeling, specifically the preparation of radio-labeled biomolecules such as antibodies, much closer to their theoretical maximum specific activities.

Reichert, D E; Kenis, P J. A.

2011-12-29T23:59:59.000Z

67

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. ???, XXXX, DOI:10.1029/, Sea Ice Remote Sensing Using AMSR-E 89 GHz Channels  

E-Print Network [OSTI]

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. ???, XXXX, DOI:10.1029/, Sea Ice Remote Sensing Using AMSR progress in sea ice concentration remote sensing by satellite microwave radiometers has been stimulated models, e.g. the heat flux between ocean and atmosphere, especially near coast- lines and in polynyas. (2

Bremen, Universität

68

Plasma Physics Challenges of MMPlasma Physics Challenges of MM--toto--THz and High Power MicrowaveTHz and High Power Microwave  

E-Print Network [OSTI]

Solid StateSolid State Microwave Power ElectronicsMicrowave Power Electronics · Both convert kinetic Devices (Avg) Vacuum HPM (Peak) Solid State Lasers (Peak) Solid State Devices (Avg) Power(W) (Single ...BUT ... For f > 100 GHz VEDs frontier 1/f2P High power limit for Solid State 1/f 2 and HPM Frontier

69

Four absolute cavity radiometer (pyrheliometer) intercomparisons at New River, Arizona: radiometer standards  

SciTech Connect (OSTI)

Four detailed intercomparisons were made for a number of models of cavity-type self-calibrating radiometers (pyrheliometers). Each intercomparison consisted of simultaneous readings of pyrheliometers at 30-second intervals in runs of 10 minutes, with at least 15 runs per intercomparison. Twenty-seven instruments were in at least one intercomparison, and five were in all four. Summarized results and all raw data are provided from the intercomparisons.

Estey, R.S.; Seaman, C.H.

1981-07-01T23:59:59.000Z

70

Microwave generator  

DOE Patents [OSTI]

A microwave generator is provided for generating microwaves substantially from virtual cathode oscillation. Electrons are emitted from a cathode and accelerated to an anode which is spaced apart from the cathode. The anode has an annular slit there through effective to form the virtual cathode. The anode is at least one range thickness relative to electrons reflecting from the virtual cathode. A magnet is provided to produce an optimum magnetic field having the field strength effective to form an annular beam from the emitted electrons in substantial alignment with the annular anode slit. The magnetic field, however, does permit the reflected electrons to axially diverge from the annular beam. The reflected electrons are absorbed by the anode in returning to the real cathode, such that substantially no reflexing electrons occur. The resulting microwaves are produced with a single dominant mode and are substantially monochromatic relative to conventional virtual cathode microwave generators. 6 figs.

Kwan, T.J.T.; Snell, C.M.

1987-03-31T23:59:59.000Z

71

Satellite Microwave remote sensing of contrasting surface water inundation changes within the ArcticBoreal Region  

E-Print Network [OSTI]

-atmosphere water, energy and carbon (CO2, CH4) fluxes, and potential feedbacks to climate change. Here we report fractional open water (Fw) cover from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E). The AMSR ) of regions above 49°N (Brown et al., 1998). Although permafrost is widespread at high latitudes due to low

Montana, University of

72

Passive microwave soil moisture downscaling using evaporative fraction Olivier Merlin1  

E-Print Network [OSTI]

stations (METFLUX) and six flights of the L-band Push Broom Microwave Radiometer (PBMR). For each PBMR fraction (EF), which is the ratio of the evapotranspiration to the total energy available at the surface, especially for high soil moisture values. Those results illustrate the potential use of high

Paris-Sud XI, Université de

73

Dr. Sandra L. Cruz Pol INEL 6069 Microwave Remote Sensing, Dr.  

E-Print Network [OSTI]

of Microwaves · Sensor types: passive/active · Radiometers · RADARS · Electromagnetic Spectrum · Atmospheric into ground (more into dry than wet soil). Visible and IR sensors can sometimes be used to complement · Absorbed energy is transformed · into thermal energy. · Thermodynamic balance · through emission

Cruz-Pol, Sandra L.

74

Photonic microwave generation with high-power photodiodes  

E-Print Network [OSTI]

We utilize and characterize high-power, high-linearity modified uni-traveling carrier (MUTC) photodiodes for low-phase-noise photonic microwave generation based on optical frequency division. When illuminated with picosecond pulses from a repetition-rate-multiplied gigahertz Ti:sapphire modelocked laser, the photodiodes can achieve 10 GHz signal power of +14 dBm. Using these diodes, a 10 GHz microwave tone is generated with less than 500 attoseconds absolute integrated timing jitter (1 Hz-10 MHz) and a phase noise floor of -177 dBc/Hz. We also characterize the electrical response, amplitude-to-phase conversion, saturation and residual noise of the MUTC photodiodes.

Fortier, Tara M; Hati, Archita; Nelson, Craig; Taylor, Jennifer A; Fu, Yang; Campbell, Joe; Diddams, Scott A

2013-01-01T23:59:59.000Z

75

ARM: Broadband Radiometer Station (BRS) broadband shortwave and longwave 1-min radiation data with Dutton correction  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

Broadband Radiometer Station (BRS) broadband shortwave and longwave 1-min radiation data with Dutton correction

Stoffel, Tom; Kay, Bev; Habte, Aron; Anderberg, Mary; Kutchenreiter, Mark

76

Effect of Microwave Frequency on Hydrothermal Synthesis of Nanocrystalline Tetragonal Barium Titanate  

E-Print Network [OSTI]

Effect of Microwave Frequency on Hydrothermal Synthesis of Nanocrystalline Tetragonal Barium) with particle sizes ranging from 30 to 100 nm were synthesized via microwave-hydrothermal routes at various, but increased gradually with extended aging time in variable frequency (3-5.5 GHz to 1 s) processing

Dutta, Prabir K.

77

Microwave furnace having microwave compatible dilatometer  

DOE Patents [OSTI]

An apparatus for measuring and monitoring a change in the dimension of a sample being heated by microwave energy is described. The apparatus comprises a microwave heating device for heating a sample by microwave energy, a microwave compatible dilatometer for measuring and monitoring a change in the dimension of the sample being heated by microwave energy without leaking microwaves out of the microwave heating device, and a temperature determination device for measuring and monitoring the temperature of the sample being heated by microwave energy.

Kimrey, Jr., Harold D. (Knoxville, TN); Janney, Mark A. (Knoxville, TN); Ferber, Mattison K. (Oak Ridge, TN)

1992-01-01T23:59:59.000Z

78

Microwave furnace having microwave compatible dilatometer  

DOE Patents [OSTI]

An apparatus for measuring and monitoring a change in the dimension of a sample being heated by microwave energy is described. The apparatus comprises a microwave heating device for heating a sample by microwave energy, a microwave compatible dilatometer for measuring and monitoring a change in the dimension of the sample being heated by microwave energy without leaking microwaves out of the microwave heating device, and a temperature determination device for measuring and monitoring the temperature of the sample being heated by microwave energy. 2 figs.

Kimrey, H.D. Jr.; Janney, M.A.; Ferber, M.K.

1992-03-24T23:59:59.000Z

79

Correlation of globe thermometer response and a YSI radiometer response  

E-Print Network [OSTI]

CORRELATION OF GLOBE THERMOMETER RESPONSE AND A YSI RADIOMETER RESPONSE A Thesis by ROBERT HOWARD FRANKNECHT Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE May 1979 Major Subjects Industrial Hygiene CORRELATION OF GLOBE THERMOMETER RESPONSE AND A YSI RADIOMETER RESPONSE A Thesis by ROBERT HOMARD FRANKNECHT Approved as to sty1e and content by: C'6~& . ~ Chairman of Committee ead...

Franknecht, Robert Howard

1979-01-01T23:59:59.000Z

80

Multifilter Rotating Shadowband Radiometer (MFRSR) Handbook  

SciTech Connect (OSTI)

The visible Multifilter Rotating Shadowband Radiometer (MFRSR) is a passive instrument that measures global and diffuse components of solar irradiance at six narrowband channels and one open, or broadband, channel (Harrison et al. 1994). Direct irradiance is not a primary measurement, but is calculated using the diffuse and global measurements. To collect one data record, the MFRSR takes measurements at four different shadowband positions. The first measurement is taken with the shadowband in the nadir (home) position. The next three measurements are, in order, the first side-band, sun-blocked, and second side-band. The side-band measurements are used to correct for the portion of the sky obscured by the shadowband. The nominal wavelengths of the narrowband channels are 415, 500, 615, 673, 870, and 940 nm. From such measurements, one may infer the atmosphere's aerosol optical depth at each wavelength. In turn, these optical depths may be used to derive information about the column abundances of ozone and water vapor (Michalsky et al. 1995), as well as aerosol (Harrison and Michalsky 1994) and other atmospheric constituents.

Hodges, GB; Michalsky, JJ

2011-02-07T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Making Maps from Planck LFI 30GHz Data  

E-Print Network [OSTI]

This paper is one of a series describing the performance and accuracy of map-making codes as assessed by the Planck CTP working group. We compare the performance of multiple codes written by different groups for making polarized maps from Planck-sized, all-sky cosmic microwave background (CMB) data. Three of the codes are based on destriping algorithm, whereas the other three are implementations of a maximum-likelihood algorithm. Previous papers in the series described simulations at 100 GHz (Poutanen et al. 2006) and 217 GHz (Ashdown et al. 2006). In this paper we make maps (temperature and polarisation) from the simulated one-year observations of four 30 GHz detectors of Planck Low Frequency Instrument (LFI). We used Planck Level S simulation pipeline to produce the observed time-ordered-data streams (TOD). Our previous studies considered polarisation observations for the CMB only. For this paper we increased the realism of the simulations and included polarized galactic foregrounds to our sky model. Our simulated TODs comprised of dipole, CMB, diffuse galactic emissions, extragalactic radio sources, and detector noise. The strong subpixel signal gradients arising from the foreground signals couple to the output map through the map-making and cause an error (signal error) in the maps. Destriping codes have smaller signal error than the maximum-likelihood codes. We examined a number of schemes to reduce this error. On the other hand, the maximum-likelihood map-making codes can produce maps with lower residual noise than destriping codes.

M. A. J. Ashdown; C. Baccigalupi; A. Balbi; J. G. Bartlett; J. Borrill; C. Cantalupo; G. de Gasperis; K. M. Gorski; V. Heikkila; E. Hivon; E. Keihanen; H. Kurki-Suonio; C. R. Lawrence; P. Natoli; T. Poutanen; S. Prunet; M. Reinecke; R. Stompor; B. Wandelt

2007-02-19T23:59:59.000Z

82

INTEGRATED GHz VOLTAGE CONTROLLED OSCILLATORS  

E-Print Network [OSTI]

INTEGRATED GHz VOLTAGE CONTROLLED OSCILLATORS Peter Kinget Bell Labs - Lucent Technologies Murray Hill, NJ (USA) Abstract The voltage controlled oscillator (VCO) is a critical sub. We focus on the de- sign of a critical sub-block: the voltage controlled oscillator (VCO). We review

Kinget, Peter

83

Active radiometer for self-calibrated furnace temperature measurements  

DOE Patents [OSTI]

Radiometer with a probe beam superimposed on its field-of-view for furnace temperature measurements. The radiometer includes a heterodyne millimeter/submillimeter-wave receiver including a millimeter/submillimeter-wave source for probing. The receiver is adapted to receive radiation from a surface whose temperature is to be measured. The radiation includes a surface emission portion and a surface reflection portion which includes the probe beam energy reflected from the surface. The surface emission portion is related to the surface temperature and the surface reflection portion is related to the emissivity of the surface. The simultaneous measurement of surface emissivity serves as a real time calibration of the temperature measurement.

Woskov, Paul P. (Bedford, MA); Cohn, Daniel R. (Chestnut Hill, MA); Titus, Charles H. (Newtown Square, PA); Wittle, J. Kenneth (Chester Springs, PA); Surma, Jeffrey E. (Kennewick, WA)

1996-01-01T23:59:59.000Z

84

Method and device for microwave sintering large ceramic articles  

DOE Patents [OSTI]

A microwave sintering system and method are provided for extremely uniform sintering of large and/or irregular shaped ceramic articles at microwave frequencies of at least 28 GHz in the hundreds of kilowatts power range in an untuned cavity. A 28 GHz, 200 kw gyrotron with variable power output is used as the microwave source connected to an untuned microwave cavity formed of an electrically conductive housing through an overmoded waveguide arrangement which acts in conjunction with a mode promoter within the cavity to achieve unexpected field uniformity. The part to be sintered is placed in the cavity and supported on a removable high temperature table in a central location within the cavity. The part is surrounded by a microwave transparent bulk insulating material to reduce thermal heat loss at the part surfaces and maintain more uniform temperature. The cavity may be operated at a high vacuum to aid in preventing arcing. The system allows controlled increased heating rates of greater than 200.degree. C./min to provide rapid heating of a ceramic part to a selected sintering temperature where it is maintained by regulating the microwave power applied to the part. As a result of rapid heating, the extent of non-isothermal processes such as segregation of impurities to the grain boundaries are minimized and exaggerated grain growth is reduced, thereby strengthening the mechanical properties of the ceramic part being sintered.

Kimrey, Jr., Harold D. (Knoxville, TN)

1990-01-01T23:59:59.000Z

85

Evaluation of Radiometers Deployed at the National Renewable Energy Laboratory's Solar Radiation Research Laboratory  

SciTech Connect (OSTI)

This study analyzes the performance of various commercially available radiometers used for measuring global horizontal irradiances and direct normal irradiances. These include pyranometers, pyrheliometers, rotating shadowband radiometers, and a pyranometer with fixed internal shading and are all deployed at the National Renewable Energy Laboratory's Solar Radiation Research Laboratory. Data from 32 global horizontal irradiance and 19 direct normal irradiance radiometers are presented. The radiometers in this study were deployed for one year (from April 1, 2011, through March 31, 2012) and compared to measurements from radiometers with the lowest values of estimated measurement uncertainties for producing reference global horizontal irradiances and direct normal irradiances.

Habte, A.; Wilcox, S.; Stoffel, T.

2014-02-01T23:59:59.000Z

86

Surface soil moisture estimation with the electrically scanning microwave radiometer (ESMR)  

E-Print Network [OSTI]

, Mr. Theis was stationed at Dyess AFB, Texas where he performed the duties of wing weather officer, weather forecaster, and radar coordinator. In September 1977, he entered the Graduate College at Texas ASM University. His permanent address is Route...

Theis, Sidney Wayne

2012-06-07T23:59:59.000Z

87

Ocean Water Vapor and Cloud Burden Trends Derived from the Topex Microwave Radiometer  

E-Print Network [OSTI]

algorithm is a log-linear regression algorithm with coefficients that are stratified by wind speed and water. TMR OBSERVATIONS The TMR flew in a 10-day non-sun-synchronous exact repeat orbit with an inclination

Ruf, Christopher

88

Determination of an Amazon Hot Reference Target for the On-Orbit Calibration of Microwave Radiometers  

E-Print Network [OSTI]

, University of Michigan, Ann Arbor, Michigan (Manuscript received 12 May 2004, in final form 14 January 2005-surface winds, ocean surface roughness, sea ice concentration, land surface vegetation and soil mois- ture, Corresponding author address: Chris Ruf, University of Michi- gan, 2455 Hayward St., Ann Arbor, MI 48109-2143. E

Ruf, Christopher

89

Validation of Satellite-Derived Liquid Water Paths Using ARM SGP Microwave Radiometers  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism inS-4500II FieldVacancy-InducedCloud Properties

90

Improved Retrievals of Temperature and Water Vapor Profiles Using a Twelve-Channel Microwave Radiometer  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching.348 270 300 219 255Retrievals of Temperature and Water

91

Dielectric and microwave attenuation properties of graphene nanoplatelet–epoxy composites  

SciTech Connect (OSTI)

Graphene nanoplatelet (GNP)–epoxy composites were fabricated for the investigation of the dielectric permittivity and microwave absorption in a frequency range from 8 to 20 GHz. The intrinsically conductive GNP particles and polarized interfacial centers in the composites contribute to the microwave absorption. A minimum reflection loss of ?14.5 dB at 18.9 GHz is observed for the GNP–epoxy composites with 15 wt. % GNP loading, which is mainly attributed to electric conductivity and the charge multipoles at the polarized interfaces in the GNP–epoxy composites.

Wang, Zhou; Luo, Jia; Zhao, Guang–Lin, E-mail: guang-lin-zhao@subr.edu [Department of Physics, Southern University and A and M college, Baton Rouge, LA 70813 (United States)] [Department of Physics, Southern University and A and M college, Baton Rouge, LA 70813 (United States)

2014-01-15T23:59:59.000Z

92

An Experimental Study of Waveguide Coupled Microwave Heating with Conventional Multicusp Negative Ion Source  

E-Print Network [OSTI]

Negative ion production with conventional multicusp plasma chambers utilizing 2.45 GHz microwave heating is demonstrated. The experimental results were obtained with the multicusp plasma chambers and extraction systems of the RFdriven RADIS ion source and the filament driven arc discharge ion source LIISA. A waveguide microwave coupling system, which is almost similar to the one used with the SILHI ion source, was used. The results demonstrate that at least one third of negative ion beam obtained with inductive RF-coupling (RADIS) or arc discharge (LIISA) can be achieved with 1 kW of 2.45 GHz microwave power in CW mode without any modification of the plasma chamber. The co-extracted electron to H^- ratio and the optimum pressure range were observed to be similar for both heating methods. The behaviour of the plasma implies that the energy transfer from the microwaves to the plasma electrons is mainly an off-resonance process.

Komppula, J; Koivisto, H; Laulainen, J; Tarvainen, O

2015-01-01T23:59:59.000Z

93

Quantitative Analysis of Spectral Impacts on Silicon Photodiode Radiometers  

SciTech Connect (OSTI)

Inexpensive broadband pyranometers with silicon photodiode detectors have a non-uniform spectral response over the spectral range of 300-1100 nm. The response region includes only about 70% to 75% of the total energy in the terrestrial solar spectral distribution from 300 nm to 4000 nm. The solar spectrum constantly changes with solar position and atmospheric conditions. Relative spectral distributions of diffuse hemispherical irradiance sky radiation and total global hemispherical irradiance are drastically different. This analysis convolves a typical photodiode response with SMARTS 2.9.5 spectral model spectra for different sites and atmospheric conditions. Differences in solar component spectra lead to differences on the order of 2% in global hemispherical and 5% or more in diffuse hemispherical irradiances from silicon radiometers. The result is that errors of more than 7% can occur in the computation of direct normal irradiance from global hemispherical irradiance and diffuse hemispherical irradiance using these radiometers.

Myers, D. R.

2011-01-01T23:59:59.000Z

94

Quantitative Analysis of Spectral Impacts on Silicon Photodiode Radiometers: Preprint  

SciTech Connect (OSTI)

Inexpensive broadband pyranometers with silicon photodiode detectors have a non-uniform spectral response over the spectral range of 300-1100 nm. The response region includes only about 70% to 75% of the total energy in the terrestrial solar spectral distribution from 300 nm to 4000 nm. The solar spectrum constantly changes with solar position and atmospheric conditions. Relative spectral distributions of diffuse hemispherical irradiance sky radiation and total global hemispherical irradiance are drastically different. This analysis convolves a typical photodiode response with SMARTS 2.9.5 spectral model spectra for different sites and atmospheric conditions. Differences in solar component spectra lead to differences on the order of 2% in global hemispherical and 5% or more in diffuse hemispherical irradiances from silicon radiometers. The result is that errors of more than 7% can occur in the computation of direct normal irradiance from global hemispherical irradiance and diffuse hemispherical irradiance using these radiometers.

Myers, D. R.

2011-04-01T23:59:59.000Z

95

Narrow Field of View Zenith Radiometer (NFOV) Handbook  

SciTech Connect (OSTI)

The two-channel narrow field-of-view radiometer (NFOV2) is a ground-based radiometer that looks straight up and measures radiance directly above the instrument at wavelengths of 673 and 870 nm. The field-of-view of the instrument is 1.2 degrees, and the sampling time resolution is one second. Measurements of the NFOV2 have been used to retrieve optical properties for overhead clouds that range from patchy to overcast. With a one-second sampling rate of the NFOV2, faster than almost any other ARM Climate Research Facility (ACRF) instrument, we are able, for the first time, to capture changes in cloud optical properties at the natural time scale of cloud evolution.

Chiu, C; Marshak, A; Hodges, G; Barnard, JC; Schmelzer, J

2008-11-01T23:59:59.000Z

96

ARM Multi-Filter Rotating Shadowband Radiometer (MFRSR): irradiances  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

The multifilter rotating shadowband radiometer (MFRSR) takes spectral measurements of direct normal, diffuse horizontal and total horizontal solar irradiances. These measurements are at nominal wavelengths of 415, 500, 615, 673, 870, and 940 nm. The measurements are made at a user-specified time interval, usually about one minute or less. The sampling rate for the Atmospheric Radiation Measurement (ARM) Climate Research Facility MFRSRs is 20 seconds. From such measurements, one may infer the atmosphere's optical depth at the wavelengths mentioned above. In turn, these optical depths may be used to derive information about the column abundances of ozone and water vapor (Michalsky et al. 1995), as well as aerosol (Michalsky et al. 1994) and other atmospheric constituents. A silicon detector is also part of the MFRSR. This detector provides a measure of the broadband direct normal, diffuse horizontal and total horizontal solar irradiances. A MFRSR head that is mounted to look vertically downward can measure upwelling spectral irradiances. In the ARM system, this instrument is called a multifilter radiometer (MFR). At the Southern Great Plains (SGP) there are two MFRs; one mounted at the 10-m height and the other at 25 m. At the North Slope of Alaska (NSA) sites, the MFRs are mounted at 10 m. MFRSR heads are also used to measure normal incidence radiation by mounting on a solar tracking device. These are referred to as normal incidence multi-filter radiometers (NIMFRs) and are located at the SGP and NSA sites. Another specialized use for the MFRSR is the narrow field of view (NFOV) instrument located at SGP. The NFOV is a ground-based radiometer (MFRSR head) that looks straight up.

Hodges, Gary

97

The multi-filter rotating shadowband radiometer (MFRSR) - precision infrared radiometer (PIR) platform in Fairbanks: Scientific objectives  

SciTech Connect (OSTI)

The multi-filter rotating shadowband radiometer (MFRSR) and precision infrared radiometer (PIR) have been employed at the Geophysical Institute in Fairbanks to check their performance under arctic conditions. Drawing on the experience of the previous measurements in the Arctic, the PIR was equipped with a ventilator to prevent frost and moisture build-up. We adopted the Solar Infrared Observing Sytem (SIROS) concept from the Southern Great Plains Cloud and Radiation Testbed (CART) to allow implementation of the same data processing software for a set of radiation and meteorological instruments. To validate the level of performance of the whole SIROS prior to its incorporation into the North Slope of Alaska (NSA) Cloud and Radiation Testbed Site instrumental suite for flux radiatin measurements, the comparison between measurements and model predictions will be undertaken to assess the MFRSR-PIR Arctic data quality.

Stamnes, K.; Leontieva, E. [Univ. of Alaska, Fairbanks (United States)

1996-04-01T23:59:59.000Z

98

FIVE-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE OBSERVATIONS: SOURCE CATALOG  

SciTech Connect (OSTI)

We present the list of point sources found in the Wilkinson Microwave Anisotropy Probe (WMAP) five-year maps. The technique used in the first-year and three-year analyses now finds 390 point sources, and the five-year source catalog is complete for regions of the sky away from the Galactic plane to a 2 Jy limit, with SNR >4.7 in all bands in the least covered parts of the sky. The noise at high frequencies is still mainly radiometer noise, but at low frequencies the cosmic microwave background (CMB) anisotropy is the largest uncertainty. A separate search of CMB-free V-W maps finds 99 sources of which all but one can be identified with known radio sources. The sources seen by WMAP are not strongly polarized. Many of the WMAP sources show significant variability from year to year, with more than a 2:1 range between the minimum and maximum fluxes.

Wright, E. L.; Chen, X. [UCLA Physics and Astronomy, P.O. Box 951547, Los Angeles, CA 90095-1547 (United States); Odegard, N.; Hill, R. S.; Weiland, J. L. [Adnet Systems, Inc., 7515 Mission Dr., Suite A100, Lanham, MD 20706 (United States); Bennett, C. L.; Gold, B.; Larson, D. [Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218-2686 (United States); Hinshaw, G.; Wollack, E.; Kogut, A. [Code 665, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Jarosik, N.; Page, L.; Dunkley, J. [Department of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544-0708 (United States); Komatsu, E. [Department of Astronomy, University of Texas, Austin, 2511 Speedway, RLM 15.306, Austin, TX 78712 (United States); Nolta, M. R. [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George St., Toronto, ON M5S 3H8 (Canada); Spergel, D. N. [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544-1001 (United States); Halpern, M. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Limon, M. [Columbia Astrophysics Laboratory, 550 W. 120th St., Mail Code 5247, New York, NY 10027-6902 (United States); Meyer, S. S. [Departments of Astrophysics and Physics, KICP and EFI, University of Chicago, Chicago, IL 60637 (United States)], E-mail: wright@astro.ucla.edu (and others)

2009-02-15T23:59:59.000Z

99

Characterization of low-temperature microwave loss of thin aluminum oxide formed by plasma oxidation  

SciTech Connect (OSTI)

We report on the characterization of microwave loss of thin aluminum oxide films at low temperatures using superconducting lumped resonators. The oxide films are fabricated using plasma oxidation of aluminum and have a thickness of 5?nm. We measure the dielectric loss versus microwave power for resonators with frequencies in the GHz range at temperatures from 54 to 303?mK. The power and temperature dependence of the loss are consistent with the tunneling two-level system theory. These results are relevant to understanding decoherence in superconducting quantum devices. The obtained oxide films are thin and robust, making them suitable for capacitors in compact microwave resonators.

Deng, Chunqing, E-mail: cdeng@uwaterloo.ca; Otto, M.; Lupascu, A., E-mail: alupascu@uwaterloo.ca [Institute for Quantum Computing, Department of Physics and Astronomy, and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

2014-01-27T23:59:59.000Z

100

High brightness microwave lamp  

DOE Patents [OSTI]

An electrodeless microwave discharge lamp includes a source of microwave energy, a microwave cavity, a structure configured to transmit the microwave energy from the source to the microwave cavity, a bulb disposed within the microwave cavity, the bulb including a discharge forming fill which emits light when excited by the microwave energy, and a reflector disposed within the microwave cavity, wherein the reflector defines a reflective cavity which encompasses the bulb within its volume and has an inside surface area which is sufficiently less than an inside surface area of the microwave cavity. A portion of the reflector may define a light emitting aperture which extends from a position closely spaced to the bulb to a light transmissive end of the microwave cavity. Preferably, at least a portion of the reflector is spaced from a wall of the microwave cavity. The lamp may be substantially sealed from environmental contamination. The cavity may include a dielectric material is a sufficient amount to require a reduction in the size of the cavity to support the desired resonant mode.

Kirkpatrick, Douglas A.; Dolan, James T.; MacLennan, Donald A.; Turner, Brian P.; Simpson, James E.

2003-09-09T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Microwave hemorrhagic stroke detector  

DOE Patents [OSTI]

The microwave hemorrhagic stroke detector includes a low power pulsed microwave transmitter with a broad-band antenna for producing a directional beam of microwaves, an index of refraction matching cap placed over the patients head, and an array of broad-band microwave receivers with collection antennae. The system of microwave transmitter and receivers are scanned around, and can also be positioned up and down the axis of the patients head. The microwave hemorrhagic stroke detector is a completely non-invasive device designed to detect and localize blood pooling and clots or to measure blood flow within the head or body. The device is based on low power pulsed microwave technology combined with specialized antennas and tomographic methods. The system can be used for rapid, non-invasive detection of blood pooling such as occurs with hemorrhagic stroke in human or animal patients as well as for the detection of hemorrhage within a patient's body.

Haddad, Waleed S. (Dublin, CA); Trebes, James E. (Livermore, CA)

2002-01-01T23:59:59.000Z

102

Microwave hemorrhagic stroke detector  

DOE Patents [OSTI]

The microwave hemorrhagic stroke detector includes a low power pulsed microwave transmitter with a broad-band antenna for producing a directional beam of microwaves, an index of refraction matching cap placed over the patients head, and an array of broad-band microwave receivers with collection antennae. The system of microwave transmitter and receivers are scanned around, and can also be positioned up and down the axis of the patients head. The microwave hemorrhagic stroke detector is a completely non-invasive device designed to detect and localize blood pooling and clots or to measure blood flow within the head or body. The device is based on low power pulsed microwave technology combined with specialized antennas and tomographic methods. The system can be used for rapid, non-invasive detection of blood pooling such as occurs with hemorrhagic stoke in human or animal patients as well as for the detection of hemorrhage within a patient's body.

Haddad, Waleed S. (Dublin, CA); Trebes, James E. (Livermore, CA)

2007-06-05T23:59:59.000Z

103

Ferrite-ferroelectric layered structures for electrically and magnetically tunable microwave resonators  

E-Print Network [OSTI]

Ferrite-ferroelectric layered structures for electrically and magnetically tunable microwave It is demonstrated experimentally that a layered structure consisting of ferrite and ferroelectric thin films can constant , and a bias magnetic field to the ferrite layer. The resonator having central frequency f0 5 GHz

Demokritov, S.O.

104

Rapid and Mass Production of Porous Materials Using a Continuous Microwave Equipment  

E-Print Network [OSTI]

% of the maximum power of the oven (Wmax = 1200 watts, frequency = 2.45 GHz, Pmax = 800 psi). The fiber optic probe aluminosilicate gel with a nanoseed solution obtained under microwave irradiation, and pumped continuously irradiation. In the case of NaY zeolite, the precursor gel without nanoseeds was also introduced into the CME

Kim, Ji Man

105

Microwave Dielectric Heating of Drops in Microfluidic Devices  

E-Print Network [OSTI]

We present a technique to locally and rapidly heat water drops in microfluidic devices with microwave dielectric heating. Water absorbs microwave power more efficiently than polymers, glass, and oils due to its permanent molecular dipole moment that has a large dielectric loss at GHz frequencies. The relevant heat capacity of the system is a single thermally isolated picoliter drop of water and this enables very fast thermal cycling. We demonstrate microwave dielectric heating in a microfluidic device that integrates a flow-focusing drop maker, drop splitters, and metal electrodes to locally deliver microwave power from an inexpensive, commercially available 3.0 GHz source and amplifier. The temperature of the drops is measured by observing the temperature dependent fluorescence intensity of cadmium selenide nanocrystals suspended in the water drops. We demonstrate characteristic heating times as short as 15 ms to steady-state temperatures as large as 30 degrees C above the base temperature of the microfluidic device. Many common biological and chemical applications require rapid and local control of temperature, such as PCR amplification of DNA, and can benefit from this new technique.

David Issadore; Katherine J. Humphry; Keith A. Brown; Lori Sandberg; David Weitz; Robert M. Westervelt

2009-01-09T23:59:59.000Z

106

Design of a differential radiometer for atmospheric radiative flux measurements  

SciTech Connect (OSTI)

The Hemispherical Optimized NEt Radiometer (HONER) is an instrument under development at the Los Alamos National Laboratory for deployment on an unmanned aerospace vehicle as part of the Atmospheric Radiation Measurements (ARM/UAV) program. HONER is a differential radiometer which will measure the difference between the total upwelling and downwelling fluxes and is intended to provide a means of measuring the atmospheric radiative flux divergence. Unlike existing instruments which measure the upwelling and downwelling fluxes separately, HONER will achieve an optical difference by chopping the two fluxes alternately onto a common pyroelectric detector. HONER will provide data resolved into two spectral bands; one covering the solar dominated region from less than 0.4 micrometer to approximately 4.5 micrometers and the other covering the region from approximately 4.5 micrometers to greater than 50 micrometers, dominated by thermal radiation. The means of separating the spectral regions guarantees seamless summation to calculate the total flux. The fields-of-view are near-hemispherical, upward and downward. The instrument can be converted, in flight, from the differential mode to absolute mode, measuring the upwelling and downwelling fluxes separately and simultaneously. The instrument also features continuous calibration from on-board sources. We will describe the design and operation of the sensor head and the on-board reference sources as well as the means of deployment.

LaDelfe, P.C.; Weber, P.G.; Rodriguez, C.W.

1994-11-01T23:59:59.000Z

107

ECE RADIOMETER UPGRADE ON THE DIII-D TOKAMAK  

SciTech Connect (OSTI)

OAK A271 ECE RADIOMETER UPGRADE ON THE DIII-D TOKAMAK. The electron cyclotron emission (ECE) heterodyne radiometer diagnostic on DIII-D has been upgraded with the addition of eight channels for a total of 40. The new, higher frequency channels allow measurements of electron temperature into the magnetic axis in discharges at maximum field, 2.15 T. The complete set now extends over the full usable range of second harmonic emission frequencies at 2.0 T covering radii from the outer edge inward to the location of third harmonic overlap on the high field side. Full coverage permits the measurement of heat pulses and magnetohydrodynamic (MHD) fluctuations on both sides of the magnetic axis. In addition, the symmetric measurements are used to fix the location of the magnetic axis in tokamak magnetic equilibrium reconstructions. Also, the new higher frequency channels have been used to determine central T{sub e} with good time resolution in low field, high density discharges using third harmonic ECE in the optically gray and optically thick regimes.

AUSTIN, ME; LOHR, J

2002-08-01T23:59:59.000Z

108

A Comparison of Direct Heating During Radiofrequency and Microwave Ablation in Ex Vivo Liver  

SciTech Connect (OSTI)

This study was designed to determine the magnitude and spatial distribution of temperature elevations when using 480 kHz RF and 2.45 GHz microwave energy in ex vivo liver models. A total of 60 heating cycles (20 s at 90 W) were performed in normal, RF-ablated, and microwave-ablated liver tissues (n = 10 RF and n = 10 microwave in each tissue type). Heating cycles were performed using a 480-kHz generator and 3-cm cooled-tip electrode (RF) or a 2.45-GHz generator and 14-gauge monopole (microwave) and were designed to isolate direct heating from each energy type. Tissue temperatures were measured by using fiberoptic thermosensors 5, 10, and 15 mm radially from the ablation applicator at the depth of maximal heating. Power delivered, sensor location, heating rates, and maximal temperatures were compared using mixed effects regression models. No significant differences were noted in mean power delivered or thermosensor locations between RF and microwave heating groups (P > 0.05). Microwaves produced significantly more rapid heating than RF at 5, 10, and 15 mm in normal tissue (3.0 vs. 0.73, 0.85 vs. 0.21, and 0.17 vs. 0.09 Degree-Sign C/s; P < 0.05); and at 5 and 10 mm in ablated tissues (2.3 {+-} 1.4 vs. 0.7 {+-} 0.3, 0.5 {+-} 0.3 vs. 0.2 {+-} 0 Degree-Sign C/s, P < 0.05). The radial depth of heating was {approx}5 mm greater for microwaves than RF. Direct heating obtained with 2.45-GHz microwave energy using a single needle-like applicator is faster and covers a larger volume of tissue than 480-kHz RF energy.

Andreano, Anita; Brace, Christopher L., E-mail: clbrace@wisc.edu [University of Wisconsin, Department of Radiology (United States)

2013-04-15T23:59:59.000Z

109

Ten channel background alpha radiometer for nondestructive analysis of low activity samples  

SciTech Connect (OSTI)

The description of a ten-channel alpha-radiometer based on large-area semiconductor detectors is presented in this paper. The radiometer is intended for determination of soil pollution by alpha-active radionuclides using thick samples. The analysis of isotopes is also provided. The concentrations of Pu and Am isotopes in soil samples are determined.

Pugatch, V.M.; Pavlenko, Y.N.; Vasiliev, Y.O.; Nenakhov, A.N.; Tkatch, N.M.; Barabash, L.I.; Berdnichenko, S.V.; Litovchenko, P.G.; Rosenfeld, A.B.; Zinets, O.S. (Inst. for Nuclear Research, Kiev (USSR))

1992-10-01T23:59:59.000Z

110

Calibration of a Solar Absolute Cavity Radiometer with Traceability to the World Radiometric Reference  

SciTech Connect (OSTI)

This report describes the present method of establishing traceability of absolute cavity radiometers to the World Radiometric Reference (WRR) through the process employed in the International Pyrheliometer Comparisons (IPC). This method derives the WRR reduction factor for each of the participating cavity radiometers. An alternative method is proposed, described, and evaluated as a way to reduce the uncertainty in the comparison process. The two methods are compared using a sample of data from the recent IPC-VIII conducted from September 25th to October 13th, 1995 at the World Radiation Center in Davos, Switzerland. A description of absolute cavity radiometers is also included, using a PMO-6 as an example of active cavity radiometers, and a HF as an example of passive cavity radiometers.

Reda, I.

1996-01-01T23:59:59.000Z

111

Global, exact cosmic microwave background data analysis using Gibbs sampling  

SciTech Connect (OSTI)

We describe an efficient and exact method that enables global Bayesian analysis of cosmic microwave background (CMB) data. The method reveals the joint posterior density (or likelihood for flat priors) of the power spectrum C{sub l} and the CMB signal. Foregrounds and instrumental parameters can be simultaneously inferred from the data. The method allows the specification of a wide range of foreground priors. We explicitly show how to propagate the non-Gaussian dependency structure of the C{sub l} posterior through to the posterior density of the parameters. If desired, the analysis can be coupled to theoretical (cosmological) priors and can yield the posterior density of cosmological parameter estimates directly from the time-ordered data. The method does not hinge on special assumptions about the survey geometry or noise properties, etc., It is based on a Monte Carlo approach and hence parallelizes trivially. No trace or determinant evaluations are necessary. The feasibility of this approach rests on the ability to solve the systems of linear equations which arise. These are of the same size and computational complexity as the map-making equations. We describe a preconditioned conjugate gradient technique that solves this problem and demonstrate in a numerical example that the computational time required for each Monte Carlo sample scales as n{sub p}{sup 3/2} with the number of pixels n{sub p}. We use our method to analyze the data from the Differential Microwave Radiometer on the Cosmic Background Explorer and explore the non-Gaussian joint posterior density of the C{sub l} from the Differential Microwave Radiometer on the Cosmic Background Explorer in several projections.

Wandelt, Benjamin D. [Department of Physics, UIUC, 1110 W Green Street, Urbana, Illinois 61801 (United States); Department of Astronomy, UIUC, 1002 W Green Street, Urbana, Illinois 61801 (United States); Larson, David L.; Lakshminarayanan, Arun [Department of Physics, UIUC, 1110 W Green Street, Urbana, Illinois 61801 (United States)

2004-10-15T23:59:59.000Z

112

The Planck/LFI Radiometer Electronics Box Assembly  

E-Print Network [OSTI]

The Radiometer Electronics Box Assembly (REBA) is the control and data processing on board computer of the Low Frequency Instrument (LFI) of the Planck mission (ESA). The REBA was designed and built incorporating state of the art processors, communication interfaces and real time operating system software in order to meet the scientific performance of the LFI. We present a technical summary of the REBA, including a physical, functional, electrical, mechanical and thermal description. Aspects of the design and development, the assembly, the integration and the verification of the equipment are provided. A brief description of the LFI on board software is given including the Low-Level Software and the main functionalities and architecture of the Application Software. The compressor module, which has been developed as an independent product, later integrated in the application, is also described in this paper. Two identical engineering models EM and AVM, the engineering qualification model EQM, the flight model ...

Herreros, J M; Rebolo, R; Chulani, H; Rubino-Martin, J A; Hildebrandt, S R; Bersanelli, M; Butler, R C; Miccolis, M; Pena, A; Pereira, M; Torrero, F; Franceschet, C; Lopez, M; Alcala, C; 10.1088/1748-0221/4/12/T12008

2010-01-01T23:59:59.000Z

113

Design evaluation of a ground based radiometer system  

E-Print Network [OSTI]

, maximum Mixer Double balanced; utilizing low-noise, high reliability Schottky diodes. Conversion. Loss about 7. 6 dB. Matched to the preamplifier. IF Pream lifier Frequency Range 1. 4 ? 1. 6 GHz 36 dB Ripple Noise Figure USWR 0. 3 dB, maximum 4.... . . . . . . . . . . . . . . . . . 110 New Mixer Theoretical Noise Improvement . . . . . 110 Measured X-Band. Sensitivity . . . . . . . . . . . 113 Error Due to the Temperature-Limited Diode Noise Source. . . . . . . . . . . . . . . . 116 VI. CONCLUSIONS AND RECOMMENDATIONS...

McClellan, Wallace Roy

2012-06-07T23:59:59.000Z

114

Variable frequency microwave heating apparatus  

DOE Patents [OSTI]

A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a multi-mode microwave cavity (34) for testing or other selected applications. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a high-power microwave oscillator (14). A power supply (22) is provided for operation of the high-power microwave oscillator (14) or microwave amplifier (20). A directional coupler (24) is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity (34). A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

Bible, Don W. (Clinton, TN); Lauf, Robert J. (Oak Ridge, TN); Johnson, Arvid C. (Lake in the Hills, IL); Thigpen, Larry T. (Angier, NC)

1999-01-01T23:59:59.000Z

115

Microwave processing of ceramics  

SciTech Connect (OSTI)

Recent work in the areas of microwave processing and joining of ceramics is briefly reviewed. Advantages and disadvantages of microwave processing as well as some of the current issues in the field are discussed. Current state and potential for future commercialization of this technology is also addressed.

Katz, J.D.

1993-04-01T23:59:59.000Z

116

Microwave processing of ceramics  

SciTech Connect (OSTI)

Recent work in the areas of microwave processing and joining of ceramics is briefly reviewed. Advantages and disadvantages of microwave processing as well as some of the current issues in the field are discussed. Current state and potential for future commercialization of this technology is also addressed.

Katz, J.D.

1993-01-01T23:59:59.000Z

117

Two-frequency heating technique at the 18 GHz electron cyclotron resonance ion source of the National Institute of Radiological Sciences  

E-Print Network [OSTI]

The two-frequency heating technique was studied to increase the beam intensities of highly charged ions provided by the high-voltage extraction configuration (HEC) ion source at the National Institute of Radiological Sciences (NIRS). The observed dependences on microwave power and frequency suggested that this technique improved plasma stability but it required precise frequency tuning and more microwave power than was available before 2013. Recently, a new, high-power (1200 W) wide bandwidth (17.1-18.5 GHz) travelling-wave-tube amplifier (TWTA) was installed. After some single tests with klystron and TWT amplifiers the simultaneous injection of the two microwaves has been successfully realized. The dependence of highly charged ions (HCI) currents on the superposed microwave power was studied by changing only the output power of one of the two amplifiers, alternatively. While operating the klystron on its fixed 18.0 GHz, the frequency of the TWTA was swept within its full limits (17.1-18.5 GHz), and the effec...

Biri, S; Muramatsu, M; Drentje, A G; Rácz, R; Yano, K; Kato, Y; Sasaki, N; Takasugi, W

2015-01-01T23:59:59.000Z

118

Two-gigawatt burst-mode operation of the intense microwave prototype (IMP) free-electron laser (FEL) for the microwave tokamak experiment (MTX)  

SciTech Connect (OSTI)

The MTX explored the plasma heating effects of 140 GHz microwaves from both Gyrotrons and from the IMP FEL wiggler. The Gyrotron was long pulse length (0.5 seconds maximum) and the FEL produced short-pulse length, high-peak power, single and burst modes of 140 GHZ microwaves. Full-power operations of the IMP FEL wiggler were commenced in April of 1992 and continued into October of 1992. The Experimental Test Accelerator H (ETA-II) provided a 50-nanosecond, 6-MeV, 2--3 kAmp electron beam that was introduced co-linear into the IMP FEL with a 140 GHz Gyrotron master oscillator (MO). The FEL was able to amplify the MO signal from approximately 7 kW to peaks consistently in the range of 1--2 GW. This microwave pulse was transmitted into the MTX and allowed the exploration of the linear and non-linear effects of short pulse, intense power in the MTX plasma. Single pulses were used to explore and gain operating experience in the parameter space of the IMP FEL, and finally evaluate transmission and absorption in the MTX. Single-pulse operations were repeatable. After the MTX was shut down burst-mode operations were successful at 2 kHz. This paper will describe the IMP FEL, Microwave Transmission System to MTX, the diagnostics used for calorimetric measurements, and the operations of the entire Microwave system. A discussion of correlated and uncorrelated errors that affect FEL performance will be made Linear and non-linear absorption data of the microwaves in the MTX plasma will be presented.

Felker, B.; Allen, S.; Bell, H. [and others

1993-10-06T23:59:59.000Z

119

17 GHz High Gradient Accelerator Research  

SciTech Connect (OSTI)

This is a report on the MIT High Gradient Accelerator Research program which has included: Operation of the 17 GHz, 25 MeV MIT/Haimson Research Corp. electron accelerator at MIT, the highest frequency, stand-alone accelerator in the world; collaboration with members of the US High Gradient Collaboration, including the design and test of novel structures at SLAC at 11.4 GHz; the design, construction and testing of photonic bandgap structures, including metallic and dielectric structures; the investigation of the wakefields in novel structures; and the training of the next generation of graduate students and postdoctoral associates in accelerator physics.

Temkin, Richard J. [MIT] [MIT; Shapiro, Michael A. [MIT] [MIT

2013-07-10T23:59:59.000Z

120

Compact microwave ion source for industrial applications  

SciTech Connect (OSTI)

A 2.45 GHz microwave ion source for ion implanters has many good properties for industrial application, such as easy maintenance and long lifetime, and it should be compact for budget and space. But, it has a dc current supply for the solenoid and a rf generator for plasma generation. Usually, they are located on high voltage platform because they are electrically connected with beam extraction power supply. Using permanent magnet solenoid and multi-layer dc break, high voltage deck and high voltage isolation transformer can be eliminated, and the dose rate on targets can be controlled by pulse duty control with semiconductor high voltage switch. Because the beam optics does not change, beam transfer components, such as focusing elements and beam shutter, can be eliminated. It has shown the good performances in budget and space for industrial applications of ion beams.

Cho, Yong-Sub; Kim, Dae-Il; Kim, Han-Sung; Seol, Kyung-Tae; Kwon, Hyeok-Jung; Hong, In-Seok [Proton Engineering Frontier Project, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of)

2012-02-15T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

A novel wideband 140 GHz gyrotron amplifier  

E-Print Network [OSTI]

The theory, design and experimental results of a wideband 140 GHz, 1 kW pulsed gyro-traveling wave amplifier are presented. The gyro- TWA operates in the HE(0,6) mode of a novel cylindrical confocal waveguide using a ...

Joye, Colin D., 1980-

2008-01-01T23:59:59.000Z

122

Design of a 250 GHz gyrotron amplifier  

E-Print Network [OSTI]

A design is presented of a 250 GHz, 1 kW gyrotron traveling wave tube (gyro-TWT) amplifier with gain exceeding 50 dB. Calculations show that the amplifier will operate at 32 kV, 1 A with a saturated gain of 60 dB, an output ...

Nanni, Emilio A. (Emilio Alessandro)

2010-01-01T23:59:59.000Z

123

Microwave coupler and method  

DOE Patents [OSTI]

The present invention is directed to a microwave coupler for enhancing the heating or metallurgical treatment of materials within a cold-wall, rapidly heated cavity as provided by a microwave furnace. The coupling material of the present invention is an alpha-rhombohedral-boron-derivative-structure material such as boron carbide or boron silicide which can be appropriately positioned as a susceptor within the furnace to heat other material or be in powder particulate form so that composites and structures of boron carbide such as cutting tools, grinding wheels and the like can be rapidly and efficiently formed within microwave furnaces.

Holcombe, C.E.

1984-11-29T23:59:59.000Z

124

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 50, NO. 10, OCTOBER 2002 2305 A Reduced-Size Silicon Micromachined  

E-Print Network [OSTI]

communication systems, the need for high-performance, low-cost, low-power, and small-size RF/microwave circuits, IEEE, and John Papapolymerou, Member, IEEE Abstract--This paper depicts the progress toward a novel. Digital Object Identifier 10.1109/TMTT.2002.803428. around 200 MHz­1.5 GHz ( ), but their fabrication

Papapolymerou, Ioannis "John"

125

Sea surface temperature for climate from the along-track scanning radiometers   

E-Print Network [OSTI]

This thesis describes the construction of a sea surface temperature (SST) dataset from Along-Track Scanning Radiometer (ATSR) observations suitable for climate applications. The algorithms presented here are now used at ...

Embury, Owen

2014-06-30T23:59:59.000Z

126

Evaluating Solar Resource Data Obtained from Multiple Radiometers Deployed at the National Renewable Energy Laboratory: Preprint  

SciTech Connect (OSTI)

Solar radiation resource measurements from radiometers are used to predict and evaluate the performance of photovoltaic and concentrating solar power systems, validate satellite-based models for estimating solar resources, and advance research in solar forecasting and climate change. This study analyzes the performance of various commercially available radiometers used for measuring global horizontal irradiances (GHI) and direct normal irradiances (DNI). These include pyranometers, pyrheliometers, rotating shadowband irradiometers, and a pyranometer with a shading ring deployed at the National Renewable Energy Laboratory's Solar Radiation Research Laboratory (SRRL). The radiometers in this study were deployed for one year (from April 1, 2011, through March 31, 2012) and compared to measurements from radiometers with the lowest values of estimated measurement uncertainties for producing reference GHI and DNI.

Habte, A.; Sengupta, M.; Andreas, A.; Wilcox, S.; Stoffel, T.

2014-09-01T23:59:59.000Z

127

High Field W-Band (95 GHz) EPR | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

High Field W-Band (95 GHz) EPR High Field W-Band (95 GHz) EPR The W-band pulsed EPR spectrometer, introduced in 2011, is one of only two of its design worldwide. It uses a...

128

Emitron: microwave diode  

DOE Patents [OSTI]

The invention comprises a new class of device, driven by electron or other charged particle flow, for producing coherent microwaves by utilizing the interaction of electromagnetic waves with electron flow in diodes not requiring an external magnetic field. Anode and cathode surfaces are electrically charged with respect to one another by electron flow, for example caused by a Marx bank voltage source or by other charged particle flow, for example by a high energy charged particle beam. This produces an electric field which stimulates an emitted electron beam to flow in the anode-cathode region. The emitted electrons are accelerated by the electric field and coherent microwaves are produced by the three dimensional spatial and temporal interaction of the accelerated electrons with geometrically allowed microwave modes which results in the bunching of the electrons and the pumping of at least one dominant microwave mode.

Craig, G.D.; Pettibone, J.S.; Drobot, A.T.

1982-05-06T23:59:59.000Z

129

A 915 MHz/2. 45 GHz ECR plasma source for large area ion beam and plasma processing  

SciTech Connect (OSTI)

The technology for producing uniform, high density (10{sup 11}--10{sup 12}/cm{sup 3}) microwave discharges over cross sections of 50 cm{sup 2} is well established. The present challenge is to extend the high density, and electrodeless benefits of microwave discharges to produce uniform densities over an area of 300--700 cm{sup 2}. Such discharges have important applications for 6 to 8-in. single wafer processing and as large surface, broad beam, high current density ion sources. The design principles for scaling the 18 cm diam MPDR ECR cavity applicator technology to 38--47 cm diam are reviewed. Microwave discharges with diameters of 20--30 cm can be created when these applicators are excited with either 2.45 GHz or 915 MHz. The design and construction of a prototype cavity applicator with a 20 cm diam discharge is described. The discharge is enclosed with a 12-pole multicusp static magnetic field produced by 2-in. by 2-in. by 1-in. rare-earth magnets. Each magnet has a pole face field strength of 3 kG. The experimental test of this plasma source in argon gas excited with 2.45 GHz energy is reviewed.

Asmussen, J.; Hopwood, J.; Sze, F.C. (Department of Electrical Engineering, Michigan State University, East Lansing, Michigan 48824-1226 (US))

1990-01-01T23:59:59.000Z

130

High power microwave generator  

DOE Patents [OSTI]

A microwave generator efficiently converts the energy of an intense relativistic electron beam (REB) into a high-power microwave emission using the Smith-Purcell effect which is related to Cerenkov radiation. Feedback for efficient beam bunching and high gain is obtained by placing a cylindrical Smith-Purcell transmission grating on the axis of a toroidal resonator. High efficiency results from the use of a thin cold annular highly-magnetized REB that is closely coupled to the resonant structure.

Ekdahl, C.A.

1983-12-29T23:59:59.000Z

131

THE COMPACT STEEP SPECTRUM AND GHZ PEAKED SPECTRUM RADIO SOURCES  

E-Print Network [OSTI]

THE COMPACT STEEP SPECTRUM AND GHZ PEAKED SPECTRUM RADIO SOURCES Christopher P. O'Dea Space@stsci.edu ABSTRACT I review the radio to X­ray properties of GHz Peaked Spectrum (GPS) and Compact Steep Spectrum The GHz Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) radio sources make up significant fractions

132

Microwaves and particle accelerators: a fundamental link  

SciTech Connect (OSTI)

John Cockcroft's splitting of the atom and Ernest Lawrence's invention of the cyclotron in the first half of the twentieth century ushered in the grand era of ever higher energy particle accelerators to probe deeper into matter. It also forged a link, bonding scientific discovery with technological innovation that continues today in the twenty first century. The development of radar and high power vacuum electronics, especially microwave power tubes like the magnetrons and the klystrons in the pre-second world war era, was instrumental in the rapid development of circular and linear charged particle accelerators in the second half of the twentieth century. We had harnessed the powerful microwave radio-frequency sources from few tens of MHz to up to 90 GHz spanning L-band to W-band frequencies. Simultaneously in the second half of the twentieth century, lasers began to offer very first opportunities of controlling charged particles at smaller resolutions on the scale of wavelengths of visible light. We also witnessed in this period the emergence of the photon and neutron sciences driven by accelerators built-by-design producing tailored and ultra-bright pulses of bright photons and neutrons to probe structure and function of matter from aggregate to individual molecular and atomic scales in unexplored territories in material and life sciences. As we enter the twenty first century, the race for ever higher energies, brightness and luminosity to probe atto-metric and atto-second domains of the ultra-small structures and ultra-fast processes continues. These developments depend crucially on yet further advancements in the production and control of high power and high frequency microwaves and light sources, often intricately coupled in their operation to the high energy beams themselves. We give a glimpse of the recent developments and innovations in the electromagnetic production and control of charged particle beams in the service of science and society. (author)

Chattopadhyay, Swapan [Universities of Lancaster, Liverpool and Manchester and Cockcroft Institute, Cheshire (United Kingdom)

2011-07-01T23:59:59.000Z

133

SEVENTH HARMONIC 20 GHz CO-GENERATOR  

SciTech Connect (OSTI)

To satisfy the need for multi-MW rf sources in frequency ranges where commercial sources do not exist, a study was undertaken on a class of devices based on gyro-harmonic frequency multiplication. This mechanism relies upon adding energy in gyrating motion to a linear electron beam that traverses a rotating-mode TE111-mode drive cavity in a dc magnetic field. The beam then drifts along the magnetic field into a second cavity, operating in the TEn11-mode tuned to the nth harmonic of the drive cavity. Studies of this configuration have been carried out for 2 < n < 7. Results are given for multi-MW, efficient operation of a 7th harmonic device operating at 20 GHz, and a 2nd harmonic device operating at 22.4 GHz.

Hirshfield, Jay L

2014-04-08T23:59:59.000Z

134

Microwave Emission by Dust: Mechanisms, Properties and Prospects for ISM Studies  

E-Print Network [OSTI]

I review my work with Bruce Draine on dust emissivity at microwave frequencies (3 cm - 3 mm). This emissivity explains the recently detected "anomalous" component of the galactic foreground emission. Both small (a<0.001 micron) and large grains contribute to this emission. Small grains have electric dipole moments and emit while they rotate; the microwave emission of large grains is mostly due to magneto-dipole radiation. Most efficient magneto-dipole emitters are strongly magnetic, e.g. ferrimagnetic or ferromagnetic, materials. The relative role of the two mechanisms can be established through observations of microwave emissivity from dark clouds. New microwave window is a window of opportunity for interstellar studies. Magnetic fields inside dark clouds may be successfully studied via microwave polarization. Microwave emissivity constrains the abundance of strongly magnetic materials. For instance, the available data at 90 GHz indicate that not more than 5% of interstellar Fe is in the form of metallic iron grains or inclusions (e.g., in ``GEMS''). Future missions, e.g. MAP and PLANCK, will bring a wealth of microwave data that can be successfully used to study ISM. Such a study would be appreciated by cosmologists who franticly try to remove all foregrounds from their data.

Lazarian A

1998-11-03T23:59:59.000Z

135

Evaluation of Radiometers in Full-Time Use at the National Renewable Energy Laboratory Solar Radiation Research Laboratory  

SciTech Connect (OSTI)

This report describes the evaluation of the relative performance of the complement of solar radiometers deployed at the National Renewable Energy Laboratory (NREL) Solar Radiation Research Laboratory (SRRL).

Wilcox, S. M.; Myers, D. R.

2008-12-01T23:59:59.000Z

136

Microwave and Radio Frequency Workshop  

Broader source: Energy.gov [DOE]

At the Microwave and Radio Frequency Workshop (held in Long Beach, CA, on July 25, 2012), academic and industry experts discussed the existing and emerging electrotechnologies – such as microwave ...

137

Intermediate frequency band digitized high dynamic range radiometer system for plasma diagnostics and real-time Tokamak control  

SciTech Connect (OSTI)

An intermediate frequency (IF) band digitizing radiometer system in the 100-200 GHz frequency range has been developed for Tokamak diagnostics and control, and other fields of research which require a high flexibility in frequency resolution combined with a large bandwidth and the retrieval of the full wave information of the mm-wave signals under investigation. The system is based on directly digitizing the IF band after down conversion. The enabling technology consists of a fast multi-giga sample analog to digital converter that has recently become available. Field programmable gate arrays (FPGA) are implemented to accomplish versatile real-time data analysis. A prototype system has been developed and tested and its performance has been compared with conventional electron cyclotron emission (ECE) spectrometer systems. On the TEXTOR Tokamak a proof of principle shows that ECE, together with high power injected and scattered radiation, becomes amenable to measurement by this device. In particular, its capability to measure the phase of coherent signals in the spectrum offers important advantages in diagnostics and control. One case developed in detail employs the FPGA in real-time fast Fourier transform (FFT) and additional signal processing. The major benefit of such a FFT-based system is the real-time trade-off that can be made between frequency and time resolution. For ECE diagnostics this corresponds to a flexible spatial resolution in the plasma, with potential application in smart sensing of plasma instabilities such as the neoclassical tearing mode (NTM) and sawtooth instabilities. The flexible resolution would allow for the measurement of the full mode content of plasma instabilities contained within the system bandwidth.

Bongers, W. A.; Beveren, V. van; Westerhof, E.; Goede, A. P. H.; Krijger, B.; Berg, M. A. van den; Graswinckel, M. F.; Schueller, F. C. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Thoen, D. J. [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Nuij, P. J. W. M. [Eindhoven University of Technology, Control Systems Technology Group, and Applied Physics Department, PO Box 513, NL-5600 MB Eindhoven (Netherlands); Baar, M. R. de; Donne, A. J. H.; Hennen, B. A. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Eindhoven University of Technology, Control Systems Technology Group, and Applied Physics Department, PO Box 513, NL-5600 MB Eindhoven (Netherlands); Kantor, M. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Forschungszentrum Juelich GMBH, Institute of Energy and Climate research, Plasma Physics, Association EURATOM-FZJ, Trilateral Euregio Cluster, 52425 Juelich (Germany); Ioffe Institute, RAS, Saint-Petersburg, 195256 (Russian Federation)

2011-06-15T23:59:59.000Z

138

On the detection of point sources in Planck LFI 70 GHz CMB maps based on cleaned K-map  

E-Print Network [OSTI]

We use the Planck LFI 70GHz data to further probe point source detection technique in the sky maps of the cosmic microwave background (CMB) radiation. The method developed by Tegmark et al. for foreground reduced maps and the Kolmogorov parameter as the descriptor are adopted for the analysis of Planck satellite CMB temperature data. Most of the detected points coincide with point sources already revealed by other methods. However, we have also found 9 source candidates for which still no counterparts are known.

Khachatryan, H G; Poghosyan, E; Yegoryan, G

2015-01-01T23:59:59.000Z

139

Controllable microwave three-wave mixing via a single three-level superconducting quantum circuit  

E-Print Network [OSTI]

Three-wave mixing in second-order nonlinear optical processes cannot occur in atomic systems due to the electric-dipole selection rules. In contrast, we demonstrate that second-order nonlinear processes can occur in a superconducting quantum circuit (i.e., a superconducting artificial atom) when the inversion symmetry of the potential energy is broken by simply changing the applied magnetic flux. In particular, we show that difference- and sum-frequencies (and second harmonics) can be generated in the microwave regime in a controllable manner by using a single three-level superconducting flux quantum circuit (SFQC). For our proposed parameters, the frequency tunability of this circuit can be achieved in the range of about 17 GHz for the sum-frequency generation, and around 42 GHz (or 26 GHz) for the difference-frequency generation. Our proposal provides a simple method to generate second-order nonlinear processes within current experimental parameters of SFQCs.

Yu-xi Liu; Hui-Chen Sun; Z. H. Peng; Adam Miranowicz; J. S. Tsai; Franco Nori

2014-12-21T23:59:59.000Z

140

Floating data acquisition system for microwave calorimeter measurements on MTX  

SciTech Connect (OSTI)

A microwave calorimeter has been designed for making 140-GHz absorption measurements on the MTX. Measurement of the intensity and spatial distribution of the FEL-generated microwave beam on the inner wall will indicate the absorption characteristics of the plasma when heated with a 140 GHz FEL pulse. The calorimeter works by monitoring changes of temperature in silicon carbide tiles located on the inner wall of the tokamak. Thermistors are used to measure the temperature of each tile. The tiles are located inside the tokamak about 1 cm outside of the limiter radius at machine potential. The success of this measurement depends on our ability to float the data acquisition system near machine potential and isolate it from the rest of the vault ground system. Our data acquisition system has 48 channels of thermistor signal conditioning, a multiplexer and digitizer section, a serial data formatter, and a fiber-optic transmitter to send the data out. Additionally, we bring timing signals to the interface through optical fibers to tell it when to begin measurement, while maintaining isolation. The receiver is an HP 200 series computer with a serial data interface; the computer provides storage and local display for the shot temperature profile. Additionally, the computer provides temporary storage of the data until it can be passed to a shared resource management system for archiving. 2 refs., 6 figs.

Sewall, N.R.; Meassick, S. (Lawrence Livermore National Lab., CA (USA))

1989-09-13T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
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141

AUSTRALIAN WORKSHOP ON MICROWAVE PHOTONICS  

E-Print Network [OSTI]

-mail: kamituna@aecl.ntt.co.jp Abstract -- We have investigated 60GHz radio-on-fiber systems using remote up

Choi, Woo-Young

142

Variable frequency microwave furnace system  

DOE Patents [OSTI]

A variable frequency microwave furnace system (10) designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity (34) for testing or other selected applications. The variable frequency microwave furnace system (10) includes a microwave signal generator (12) or microwave voltage-controlled oscillator (14) for generating a low-power microwave signal for input to the microwave furnace. A first amplifier (18) may be provided to amplify the magnitude of the signal output from the microwave signal generator (12) or the microwave voltage-controlled oscillator (14). A second amplifier (20) is provided for processing the signal output by the first amplifier (18). The second amplifier (20) outputs the microwave signal input to the furnace cavity (34). In the preferred embodiment, the second amplifier (20) is a traveling-wave tube (TWT). A power supply (22) is provided for operation of the second amplifier (20). A directional coupler (24) is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

Bible, Don W. (Clinton, TN); Lauf, Robert J. (Oak Ridge, TN)

1994-01-01T23:59:59.000Z

143

Variable frequency microwave furnace system  

DOE Patents [OSTI]

A variable frequency microwave furnace system designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity for testing or other selected applications. The variable frequency microwave furnace system includes a microwave signal generator or microwave voltage-controlled oscillator for generating a low-power microwave signal for input to the microwave furnace. A first amplifier may be provided to amplify the magnitude of the signal output from the microwave signal generator or the microwave voltage-controlled oscillator. A second amplifier is provided for processing the signal output by the first amplifier. The second amplifier outputs the microwave signal input to the furnace cavity. In the preferred embodiment, the second amplifier is a traveling-wave tube (TWT). A power supply is provided for operation of the second amplifier. A directional coupler is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter is provided for measuring the power delivered to the microwave furnace. A second power meter detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load. 5 figs.

Bible, D.W.; Lauf, R.J.

1994-06-14T23:59:59.000Z

144

Local microwave background radiation  

E-Print Network [OSTI]

An inquiry on a possible local origin for the Microwave Background Radiation is made. Thermal MBR photons are contained in a system called {\\it magnetic bottle} which is due to Earth magnetic field and solar wind particles, mostly electrons. Observational tests are anticipated.

Domingos Soares

2014-11-13T23:59:59.000Z

145

A 5364-GHz SiGe Up-Conversion Mixer with 4-GHz IF Bandwidth  

E-Print Network [OSTI]

), Germany wchoi@yonsei.ac.kr Abstract -- A Gilbert-cell direct up-conversion mixer is realized for 57­64-GHz mixers is important for the overall system performance of direct-conversion transmitters. In particular-to-RF isolation is necessary due to in- band LO leakage in direct-conversion transmitters. In this paper

Choi, Woo-Young

146

SYNCHROTRON SPECTRAL CURVATURE FROM 22 MHz TO 23 GHz  

SciTech Connect (OSTI)

We combine surveys of the radio sky at frequencies 22 MHz to 1.4 GHz with data from the ARCADE-2 instrument at frequencies 3 GHz to 10 GHz to characterize the frequency spectrum of diffuse synchrotron emission in the Galaxy. The radio spectrum steepens with frequency from 22 MHz to 10 GHz. The projected spectral index at 23 GHz derived from the low-frequency data agrees well with independent measurements using only data at frequencies 23 GHz and above. Comparing the spectral index at 23 GHz to the value from previously published analyses allows extension of the model to higher frequencies. The combined data are consistent with a power-law index {beta} = -2.64 {+-} 0.03 at 0.31 GHz, steepening by an amount of {Delta}{beta} = 0.07 every octave in frequency. Comparison of the radio data to models including the cosmic-ray energy spectrum suggests that any break in the synchrotron spectrum must occur at frequencies above 23 GHz.

Kogut, A., E-mail: Alan.J.Kogut@nasa.gov [Code 665, Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-07-10T23:59:59.000Z

147

The microwave electro-thermal (MET) thruster: A new technology for satellite propulsion and attitude control  

SciTech Connect (OSTI)

This paper discusses the current research status of the MET (Microwave Electro-Thermal) thruster. In the MET thruster, an electrodeless, vortex stabilized, plasma is produced in a microwave resonator cavity for the purpose of heating gaseous fuel to produce a high temperature rocket exhaust for space propulsion. The higher specific impulse (momentum transfer per unit weight) of these heated gases offers advantages over traditional chemical rockets in terms of reduced fuel mass. In MET devices, dense plasmas have been produced in various possible fuel gases, nitrogen, hydrogen, and ammonia, using 600 to 2200 Watts of microwave power at a frequency of 2.45 GHz. Ammonia has been found to give a specific impulse of 550 sec. It has been found that the plasma is a 98{percent} absorber of microwave power leading to negligible reflection of power back to the microwave source and making the cavity operate at low {ital Q}. Taking advantage of this effect, it has been found that a very compact MET thruster design could be operated, with the magnetron microwave source and resonator cavity joined in one unit. The MET can run at a variety of power levels and use many fuels, including H{sub 2}O. {copyright} {ital 1996 American Institute of Physics.}

Brandenburg, J.E. [Principle Research Scientist, Research Support Instruments, Washington Operations, 4325-B Forbes Boulevard, Lanham, Maryland 20706 (United States); Micci, M.M. [Assoc. Professor of Aerospace Eng., Propulsion Engineering Research Center, Department of Aerospace Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

1996-03-01T23:59:59.000Z

148

Highly conducting SrMoO{sub 3} thin films for microwave applications  

SciTech Connect (OSTI)

We have measured the microwave resistance of highly conducting perovskite oxide SrMoO{sub 3} thin film coplanar waveguides. The epitaxial SrMoO{sub 3} thin films were grown by pulsed laser deposition and showed low mosaicity and smooth surfaces with a root mean square roughness below 0.3?nm. Layer-by-layer growth could be achieved for film thicknesses up to 400?nm as monitored by reflection high-energy electron diffraction and confirmed by X-ray diffraction. We obtained a constant microwave resistivity of 29???·cm between 0.1 and 20?GHz by refining the frequency dependence of the transmission coefficients. Our result shows that SrMoO{sub 3} is a viable candidate as a highly conducting electrode material for all-oxide microwave electronic devices.

Radetinac, Aldin, E-mail: aldin@oxide.tu-darmstadt.de; Mani, Arzhang; Ziegler, Jürgen; Alff, Lambert; Komissinskiy, Philipp, E-mail: komissinskiy@oxide.tu-darmstadt.de [Institute of Materials Science, TU Darmstadt, Alarich-Weiss-Str. 2, 64287 Darmstadt (Germany); Melnyk, Sergiy; Nikfalazar, Mohammad; Zheng, Yuliang; Jakoby, Rolf [Institute for Microwave Engineering and Photonics, TU Darmstadt, Merckstraße 25, 64283 Darmstadt (Germany)

2014-09-15T23:59:59.000Z

149

Outgassing, Temperature Gradients and the Radiometer Effect in LISA: A Torsion Pendulum Investigation  

E-Print Network [OSTI]

Thermal modeling of the LISA gravitational reference sensor (GRS) includes such effects as outgassing from the proof mass and its housing and the radiometer effect. Experimental data in conditions emulating the LISA GRS are required to confidently predict the GRS performance. Outgassing and the radiometer effect are similar in characteristics and are difficult to decouple experimentally. The design of our torsion balance allows us to investigate differential radiation pressure, the radiometer effect, and outgassing on closely separated conducting surfaces with high sensitivity. A thermally controlled split copper plate is brought near a freely hanging plate-torsion pendulum.We have varied the temperature on each half of the copper plate and have measured the resulting forces on the pendulum. We have determined that to first order the current GRS model for the radiometer effect, outgassing, and radiation pressure are mostly consistent with our torsion balance measurements and therefore these thermal effects do not appear to be a large hindrance to the LISA noise budget. However, there remain discrepancies between the predicted dependence of these effects on the temperature of our apparatus.

Scott E Pollack; Stephan Schlamminger; Jens H Gundlach

2007-02-08T23:59:59.000Z

150

Experimental test of a microwave ion beam source in oxygen  

SciTech Connect (OSTI)

Recent experiments have demonstrated a microwave (2.45 GHz) plasma disk ion source operating with inert gases both with and without an applied static magnetic field. Earlier results were reported using a preliminary, multicusp static magnetic field configuration produced by alternating pole, small, --2.5 kG rare earth magnets surrounding the microwave discharge zone. This electrodeless ion source has been rebuilt incorporating several improvements and has been experimentally tested with different discharge diffusion lengths. The improvements include removing the rare earth magnets from the inside of the microwave cavity and embedding them in the cavity walls. The placement and strength of the magnets allows electron cyclotron resonant surfaces (--875 G) to lie entirely within the discharge zone. Discharges with different diffusion lengths were created by varying the thickness of the disk-shaped discharge zone. The experimental performance with and without a static magnetic field is discussed at the low flow rates of 2--10 sccm and using a 2.5 cm diam double grid set. Experimental test results are compared to similar ion beam sources in oxygen that employ a dc discharge. The expected lifetime, startup, and shutdown problems and maintenance are also reviewed.

Asmussen, J.; Dahimene, M.

1987-01-01T23:59:59.000Z

151

GHz Resonant Cavity Enhanced Schottky Photodiodes  

E-Print Network [OSTI]

Resonant Cavity Enhanced (RCE) photodiodes are promising candidates for applications in optical communications and interconnects where ultrafast high-efficiency detection is desirable. We have designed and fabricated RCE Schottky photodiodes in the (Al,In)GaAs material system for 900nm wavelength. The observed temporal response with 10 ps pulse width was limited by the measurement setup and a conservative estimation of the bandwidth corresponds to more than 100 GHz. A direct comparison of RCE versus conventional detector performance was performed by high speed measurements under optical excitation at resonant wavelength (895 nm) and at 840 nm where the device functions as a single pass conventional photodiode. A more than two-fold bandwidth enhancement with the RCE detection scheme was demonstrated. Index Terms--- Resonant cavity enhancement, high-speed, photodetector, Schottky photodiode. 1 I. INTRODUCTION High speed photodetectors for today's high performance optical co...

Onat Gokkavas Ozbay; B. M. Onat; M. Gokkavas; E. P. Ata; E. Towe; M. S

152

A continuous-wave second harmonic gyrotron oscillator at 460 GHz  

E-Print Network [OSTI]

We report the short pulse and CW operation of a 460 GHz gyrotron oscillator both at the fundamental (near 230 GHz) and second harmonic (near 460 GHz) of electron cyclotron resonance. During operation in a complete CW regime ...

Hornstein, Melissa K. (Melissa Kristen), 1977-

2005-01-01T23:59:59.000Z

153

A Permanent-Magnet Microwave Ion Source for a Compact High-Yield Neutron Generator  

SciTech Connect (OSTI)

We present recent work on the development of a microwave ion source that will be used in a high-yield compact neutron generator for active interrogation applications. The sealed tube generator will be capable of producing high neutron yields, 5x1011 n/s for D-T and ~;;1x1010 n/s for D-D reactions, while remaining transportable. We constructed a microwave ion source (2.45 GHz) with permanent magnets to provide the magnetic field strength of 87.5 mT necessary for satisfying the electron cyclotron resonance (ECR) condition. Microwave ion sources can produce high extracted beam currents at the low gas pressures required for sealed tube operation and at lower power levels than previously used RF-driven ion sources. A 100 mA deuterium/tritium beam will be extracted through a large slit (60x6 mm2) to spread the beam power over a larger target area. This paper describes the design of the permanent-magnet microwave ion source and discusses the impact of the magnetic field design on the source performance. The required equivalent proton beam current density of 40 mA/cm2 was extracted at a moderate microwave power of 400 W with an optimized magnetic field.

Waldmann, Ole; Ludewigt, Bernhard

2010-10-11T23:59:59.000Z

154

InGaAs/InP DHBTs with 120-nm Collector Having Simultaneously High ft,fmax > 450 GHz  

E-Print Network [OSTI]

Simultaneously High f , f max 450 GHz Zach Grif?th, Mark J.devices exhibit a maximum 450 GHz and 490 GHz max , which iscollector. Here, we report a 450 GHz and 490 InP DHBT—the ?

2005-01-01T23:59:59.000Z

155

Microwave hematoma detector  

DOE Patents [OSTI]

The Microwave Hematoma Detector is a non-invasive device designed to detect and localize blood pooling and clots near the outer surface of the body. While being geared towards finding sub-dural and epi-dural hematomas, the device can be used to detect blood pooling anywhere near the surface of the body. Modified versions of the device can also detect pneumothorax, organ hemorrhage, atherosclerotic plaque in the carotid arteries, evaluate perfusion (blood flow) at or near the body surface, body tissue damage at or near the surface (especially for burn assessment) and be used in a number of NDE applications. The device is based on low power pulsed microwave technology combined with a specialized antenna, signal processing/recognition algorithms and a disposable cap worn by the patient which will facilitate accurate mapping of the brain and proper function of the instrument. The invention may be used for rapid, non-invasive detection of sub-dural or epi-dural hematoma in human or animal patients, detection of hemorrhage within approximately 5 cm of the outer surface anywhere on a patient's body.

Haddad, Waleed S. (Dublin, CA); Trebes, James E. (Livermore, CA); Matthews, Dennis L. (Moss Beach, CA)

2001-01-01T23:59:59.000Z

156

Development of a new radiometer for the thermodynamic measurement of high temperature fixed points  

SciTech Connect (OSTI)

The National Physical Laboratory (NPL) has developed a new radiometer to measure the thermodynamic melting point temperatures of high temperature fixed points with ultra-low uncertainties. In comparison with the NPL's Absolute Radiation Thermometer (ART), the 'THermodynamic Optical Radiometer' (THOR) is more portable and compact, with a much lower size-of-source effect and improved performance in other parameters such as temperature sensitivity. It has been designed for calibration as a whole instrument via the radiance method, removing the need to calibrate the individual subcomponents, as required by ART, and thereby reducing uncertainties. In addition, the calibration approach has been improved through a new integrating sphere that has been designed to have greater uniformity.

Dury, M. R.; Goodman, T. M.; Lowe, D. H.; Machin, G.; Woolliams, E. R. [National Physical Laboratory, Teddington (United Kingdom)] [National Physical Laboratory, Teddington (United Kingdom)

2013-09-11T23:59:59.000Z

157

Electron cyclotron emission radiometer upgrade on the Joint European Torus (JET) tokamak  

SciTech Connect (OSTI)

The capabilities of the Joint European Torus (JET) electron cyclotron emission (ECE) diagnostics have recently been extended with an upgrading of the heterodyne radiometer. The number of channels has been doubled to 96 channels, with a frequency separation corresponding to <1 cm for JET magnetic field gradient, and with a frequency response of 1 MHz. This enhancement has increased the radial coverage of the ECE electron temperature measurements in JET to approximately the full plasma column (limited at R>2.6 m for the X-mode due to harmonic overlap) at almost all magnetic field values used at JET (1.7 Tradiometer is presented along with some results showing its performance.

Luna, E. de la; Sanchez, J.; Tribaldos, V.; Conway, G.; Suttrop, W.; Fessey, J.; Prentice, R.; Gowers, C.; Chareau, J. M. [Asociacion EURATOM-CIEMAT para Fusion, CIEMAT, Madrid (Spain); IPP-EURATOM Association, Garching (Germany); EURATOM-UKAEA Fusion Associations, Culham Science Centre, Abingdon (United Kingdom); European Commission, Institute for Transuranium Elements, Karlsruhe (Germany)

2004-10-01T23:59:59.000Z

158

Calibration of a 32 channel electron cyclotron emission radiometer on the HL-2A tokamak  

SciTech Connect (OSTI)

A novel 32-channel electron cyclotron emission radiometer has been designed and tested for the measurement of electron temperature profiles on the HL-2A tokamak. This system is based on the intermediate frequency filter detection technique, and has the features of wide working frequency range and high spatial resolution. Two relative calibration methods have been investigated: sweeping the toroidal magnetic field and hopping the output frequency of the local oscillator. Preliminary results show that both methods can ensure reasonable profiles.

Shi, Z. B., E-mail: shizb@swip.ac.cn; Jiang, M.; Huang, X. L.; Zhong, W. L.; Chen, W.; Che, Y. L.; Liu, Z. T.; Ding, X. T.; Yang, Q. W.; Duan, X. R. [Southwestern Institute of Physics, P. O. Box 432, Chengdu 610041 (China)] [Southwestern Institute of Physics, P. O. Box 432, Chengdu 610041 (China)

2014-02-15T23:59:59.000Z

159

Using a cold radiometer to measure heat loads and survey heat leaks  

SciTech Connect (OSTI)

We have developed an inexpensive cold radiometer for use in thermal/vacuum chambers to measure heat loads, characterize emissivity and specularity of surfaces and to survey areas to evaluate stray heat loads. We report here the results of two such tests for the James Webb Space Telescope to measure heat loads and effective emissivities of 2 major pieces of optical ground support equipment that will be used in upcoming thermal vacuum testing of the Telescope.

DiPirro, M.; Tuttle, J.; Hait, T.; Shirron, P. [Cryogenics and Fluids Branch, NASA/Goddard Space Flight Center, Greenbelt MD 20771 (United States)

2014-01-29T23:59:59.000Z

160

Broadband sample holder for microwave spectroscopy of superconducting qubits  

SciTech Connect (OSTI)

We present a practical design and implementation of a broadband sample holder suitable for microwave experiments with superconducting integrated circuits at millikelvin temperatures. Proposed design can be easily integrated in standard dilution cryostats, has flat pass band response in a frequency range from 0 to 32 GHz, allowing the RF testing of the samples with substrate size up to 4 × 4 mm{sup 2}. The parasitic higher modes interference in the holder structure is analyzed and prevented via design considerations. The developed setup can be used for characterization of superconducting parametric amplifiers, bolometers, and qubits. We tested the designed sample holder by characterizing of a superconducting flux qubit at 20 mK temperature.

Averkin, A. S.; Karpov, A.; Glushkov, E.; Abramov, N. [National University of Science and Technology (MISIS), Leninskiy prosp. 4, Moscow, 119049 (Russian Federation); Shulga, K. [National University of Science and Technology (MISIS), Leninskiy prosp. 4, Moscow, 119049 (Russian Federation); Russian Quantum Center (RQC), 100 Novaya St., Skolkovo, Moscow region, 143025 (Russian Federation); Huebner, U. [Leibniz Institute of Photonic Technology (IPHT), PO Box 100239, D-07702 Jena (Germany); Il'ichev, E. [Russian Quantum Center (RQC), 100 Novaya St., Skolkovo, Moscow region, 143025 (Russian Federation); Leibniz Institute of Photonic Technology (IPHT), PO Box 100239, D-07702 Jena (Germany); Ustinov, A. V. [National University of Science and Technology (MISIS), Leninskiy prosp. 4, Moscow, 119049 (Russian Federation); Russian Quantum Center (RQC), 100 Novaya St., Skolkovo, Moscow region, 143025 (Russian Federation); Physikalisches Institut, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe (Germany)

2014-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

EPR, Bell, GHZ, and Hardy theorems, and quantum mechanics  

E-Print Network [OSTI]

We review the theorems of Einstein-Podolsky-Rosen (EPR), Bell, Greenberger-Horne-Zeilinger (GHZ), and Hardy, and present arguments supporting the idea that quantum mechanics is a complete, causal, non local, and non separable theory.

Miguel Socolovsky

2005-08-09T23:59:59.000Z

162

Application of vane-type resonator to microwave powered electrodeless HID lamp  

SciTech Connect (OSTI)

A cavity resonator has been generally used as microwave applicator for an electrodeless high intensity discharge (HID) lamp. The size of a cavity resonator is determined by the wavelength of a microwave applied. For example, for a microwave of 2.45 GHz, an inner diameter of more than about 76 mm is necessary for obtaining a microwave resonant field, and then the size of a plasma arc capable of maintaining a stable discharge is experimentally limited at about 15 mm and above. Accordingly the microwave powered electrodeless HID lamp device using cavity resonator is inappropriate in applications where a point light source is required. A vane-type resonator is generally known as an anode of a magnetron, which decides the oscillation frequency of the magnetron. The authors used 3-D finite element method simulation for a design of a vane-type resonator with parabolic reflector to obtain a desired resonant frequency. According to the results of the simulation, the sizes of a 4-vanes resonator with the parabolic reflector were decided, and the resonator made of aluminum and copper was prepared. An electrodeless lamp with InBr and Ar gas enclosed in a spherical quartz glass tube having an inner diameter of about 4 mm was also prepared, and was set at center portion of the resonator. The total luminous flux was about 2,150 lm at microwave input of 27 W. Incidentally, the CRI and Tc for this lamp were 93 and 10,200 K, respectively. Thus, it becomes possible to efficiently couple microwave energy with a smaller-sized electrodeless HID lamp than conventional.

Hochi, Akira; Takeda, Mamoru

1999-07-01T23:59:59.000Z

163

60 GHz ecrh system for the PPL PDX machine  

SciTech Connect (OSTI)

A 60-GHz kW Electron Cyclotron Resonance (ECR) heating system for the PDX machine is now under construction. It will use two of the pulse-type 60 GHz gyrotrons now being developed by Varian for the U.S. Department of Energy under a subcontract for Oak Ridge National Laboratory. The system will be used for various temperature profile, start-up, and heating experiments. This paper describes the design of the system and its physical configuration.

Bowen, N.; Doane, J.; Newman, W.

1981-01-01T23:59:59.000Z

164

Power combination of two phase-locked high power microwave beams from a new coaxial microwave source based on dual beams  

SciTech Connect (OSTI)

The new coaxial high power microwave source based on dual beams has demonstrated two phase-locked output microwave beams generated by its two sub-sources. In order to achieve a single higher output power, we present a three-port waveguide-based power combiner to combine the two microwave beams. Particle-in-cell simulation results show that when the diode voltage is 675?kV and the guiding magnetic field is 0.8?T, a combined microwave with an average power of about 4.0?GW and a frequency of 9.74 GHz is generated; the corresponding power conversion efficiency is 29%. The combination effect of the combiner is further validated in the diode voltage range from 675?kV to 755?kV as well as in the pulse regime. The simulations indicate that the maximum surface axial electric field strength of the electrodynamic structure is 720?kV/cm, which is relatively low corresponding to an output power of 4.0?GW. The stable combined output suggests the probability of long-pulse operation for the combined source.

Li, Yangmei; Zhang, Xiaoping, E-mail: plinafly@163.com; Zhang, Jiande; Dang, Fangchao; Yan, Xiaolu [College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

2014-10-15T23:59:59.000Z

165

Temperature and density evolution during decay in a 2.45 GHz hydrogen electron cyclotron resonance plasma: Off-resonant and resonant cases  

SciTech Connect (OSTI)

Time resolved electron temperature and density measurements during the decay stage in a hydrogen electron cyclotron resonance (ECR) plasma are presented for a resonance and off-resonance magnetic field configurations. The measurements are conducted on a ECR plasma generator excited at 2.45 GHz denominated test-bench for ion-sources plasma studies at ESS Bilbao. The plasma parameters evolution is studied by Langmuir probe diagnostic with synchronized sample technique developed for repetitive pulsed plasmas with a temporal resolution of 200 ns in typical decay processes of about 40 ?s. An afterglow transient is clearly observed in the reflected microwave power signal from the plasma. Simultaneously, the electron temperature evolution shows rebounding peaks that may be related to the interplay between density drop and microwave coupling with deep impact on the Electron Energy Distribution Function. The correlation of such structures with the plasma absorbed power and the coupling quality is also reported.

Cortázar, O. D. [ESS Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain) [ESS Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain); Universidad de Castilla-La Mancha, ETSII, C.J. Cela s/n, 13170 Ciudad Real (Spain); Megía-Macías, A.; Vizcaíno-de-Julián, A. [ESS Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain)] [ESS Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain)

2013-09-15T23:59:59.000Z

166

Gigatron microwave amplifier  

DOE Patents [OSTI]

An electron tube for achieving high power at high frequency with high efficiency, including an input coupler, a ribbon-shaped electron beam and a traveling wave output coupler. The input coupler is a lumped constant resonant circuit that modulates a field emitter array cathode at microwave frequency. A bunched ribbon electron beam is emitted from the cathode in periodic bursts at the desired frequency. The beam has a ribbon configuration to eliminate limitations inherent in round beam devices. The traveling wave coupler efficiently extracts energy from the electron beam, and includes a waveguide with a slot therethrough for receiving the electron beam. The ribbon beam is tilted at an angle with respect to the traveling wave coupler so that the electron beam couples in-phase with the traveling wave in the waveguide. The traveling wave coupler thus extracts energy from the electron beam over the entire width of the beam.

McIntyre, Peter M. (611 Montclair, College Station, TX 77840)

1993-01-01T23:59:59.000Z

167

Gigatron microwave amplifier  

DOE Patents [OSTI]

An electron tube for achieving high power at high frequency with high efficiency is described, including an input coupler, a ribbon-shaped electron beam and a traveling wave output coupler. The input coupler is a lumped constant resonant circuit that modulates a field emitter array cathode at microwave frequency. A bunched ribbon electron beam is emitted from the cathode in periodic bursts at the desired frequency. The beam has a ribbon configuration to eliminate limitations inherent in round beam devices. The traveling wave coupler efficiently extracts energy from the electron beam, and includes a waveguide with a slot there through for receiving the electron beam. The ribbon beam is tilted at an angle with respect to the traveling wave coupler so that the electron beam couples in-phase with the traveling wave in the waveguide. The traveling wave coupler thus extracts energy from the electron beam over the entire width of the beam.

McIntyre, P.M.

1993-07-13T23:59:59.000Z

168

Cosmic Microwave Background Polarization  

E-Print Network [OSTI]

Cosmic microwave background (CMB) anisotropy is our richest source of cosmological information; the standard cosmological model was largely established thanks to study of the temperature anisotropies. By the end of the decade, the Planck satellite will close this important chapter and move us deeper into the new frontier of polarization measurements. Numerous ground--based and balloon--borne experiments are already forging into this new territory. Besides providing new and independent information on the primordial density perturbations and cosmological parameters, polarization measurements offer the potential to detect primordial gravity waves, constrain dark energy and measure the neutrino mass scale. A vigorous experimental program is underway worldwide and heading towards a new satellite mission dedicated to CMB polarization.

James G. Bartlett

2006-04-18T23:59:59.000Z

169

Microwave Regenerated DPF for Auxiliary Power Units and Diesel...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Microwave Regenerated DPF for Auxiliary Power Units and Diesel Hybrid Vehicles Microwave Regenerated DPF for Auxiliary Power Units and Diesel Hybrid Vehicles Microwave regeneration...

170

Relative Accuracy of 1-Minute and Daily Total Solar Radiation Data for 12 Global and 4 Direct Beam Solar Radiometers: Preprint  

SciTech Connect (OSTI)

This report evaluates the relative performance of 12 global and four direct beam solar radiometers deployed at a single site over a 12-month period. Test radiometer irradiances were compared with a reference irradiance consisting of either an absolute cavity radiometer (during calibrations) or a low uncertainty thermopile pyrheliometer (during the evaluation period) for pyrheliometers; and for pyranometers a reference global irradiance computed from the reference pyrheliometer and diffuse irradiance from a shaded pyranometer.

Myers, D. R.; Wilcox, S. M.

2009-03-01T23:59:59.000Z

171

Microwave sintering of pure and doped nanocrystalline alumina compacts  

SciTech Connect (OSTI)

A single-mode cavity microwave furnace, operating in the TE{sub 103} mode at 2.45 GHz is being used to investigate sintering of pure and doped nanocrystalline alumina. The purpose of these experiments is to determine the effect of additives on the sintering process in the nanocrystalline regime. Using the sol-gel method, high purity Al{sub 2}O{sub 3} nanocrystalline powders were synthesized. These powders were calcined at 700 C and then CIP`ed to 414 MPa, producing 0.4 in. diameter, 0.25 in. high cylindrical compacts. The compacts were heated in the microwave furnace to temperatures between 1,100 C to approximately 1,800 C and were then brought back to room temperature using a triangular heating profile of about 30 minutes duration. A two-color IR pyrometer was used to monitor the surface temperature of the workpiece. The additives tested in this work lowered the temperature needed for densification but this effect was offset by increased grain growth. Initial grain growth from <5 nm to {approximately}50 nm was closely correlated with the {gamma} to {alpha}-alumina phase transition.

Bruce, R.W. [SFA, Inc., Largo, MD (United States); Fliflet, A.W.; Lewis, D. III; Rayne, R.J.; Bender, B.A.; Chow, G.M.; Schoen, P.E. [Naval Research Lab., Washington, DC (United States); Kurihara, L.K. [Georgetown Univ., Washington, DC (United States). Dept. of Biochemistry

1996-12-31T23:59:59.000Z

172

Microwave coupling of frequency-locked Josephson junction arrays  

SciTech Connect (OSTI)

A high temperature superconducting YBa{sub 2}Cu{sub 3}O{sub y} array of five Josephson junctions designed with additional coupling lines has been developed to demonstrate the effects of frequency locking and impedance matching for applications such as oscillators, mixers, and detectors. The Josephson self-radiation power was directly detected by a superheterodyne receiver, and Shapiro steps were also measured. The Josephson self-radiation properties reveal good quality of phase locking and microwave coupling with external circuits. The maximum self-radiation power of our array is about 50 pW which is several ten times higher than that of a single Josephson junction, and its peak point exactly satisfies the Josephson current-voltage relation. The Shapiro-step measurements show that the behavior of current-voltage curve depends on the effective inductance of coupling lines which affects the total impedance of Josephson junction array and microwave coupling. The Josephson oscillation frequency was obtained up to about 880 GHz which is 73{percent} of the maximum available frequency calculated from the characteristic voltage of the Josephson junctions. Experimental results show that this type of Josephson junction array can improve the Josephson self-radiation power and increase the maximum detectable frequency. {copyright} {ital 1997 American Institute of Physics.}

Song, I.; Eom, Y.; Park, G. [Department of Physics, Sogang University, Seoul 100-611 (Korea)] [Department of Physics, Sogang University, Seoul 100-611 (Korea); Lee, E.; Park, S. [Electronic Materials Laboratory, Samsung Advanced Institute of Technology, Suwon (Korea)] [Electronic Materials Laboratory, Samsung Advanced Institute of Technology, Suwon (Korea)

1997-06-01T23:59:59.000Z

173

Microwave power spectral density and its effects on exciting electrodeless high intensity discharge lamps  

SciTech Connect (OSTI)

The effects of a microwave source generating a spectrally dense power spectrum on the operation of an electrodeless high intensity discharge lamp were measured. Spectrally pure sources operating within ISM bands at 915 MHz and 2.45 GHz produce stable capacitively coupled discharges useful for producing flicker-free light for numerous applications. The internal plasma temperature distribution and lamp geometry define acoustic resonance modes within the lamp which can be excited with power sidebands. The operation of lamps with commercially available power sources and custom built generators are discussed. Estimates of the spectral purity required for stable operation are provided.

Butler, S.J.; Goss, H.H.; Lapatovich, W.P. [Osram Sylvania Inc., Salem, MA (United States)

1995-12-31T23:59:59.000Z

174

STATISTICAL PROPERTIES OF 12.2 GHz METHANOL MASERS ASSOCIATED WITH A COMPLETE SAMPLE OF 6.7 GHz METHANOL MASERS  

SciTech Connect (OSTI)

We present definitive detection statistics for 12.2 GHz methanol masers toward a complete sample of 6.7 GHz methanol masers detected in the Methanol Multibeam survey south of declination -20{sup 0}. In total, we detect 250 12.2 GHz methanol masers toward 580 6.7 GHz methanol masers. This equates to a detection rate of 43.1%, which is lower than that of previous significant searches of comparable sensitivity. Both the velocity ranges and the flux densities of the target 6.7 GHz sources surpass that of their 12.2 GHz companion in almost all cases. Eighty percent of the detected 12.2 GHz methanol maser peaks are coincident in velocity with the 6.7 GHz maser peak. Our data support an evolutionary scenario whereby the 12.2 GHz sources are associated with a somewhat later evolutionary stage than the 6.7 GHz sources devoid of this transition. Furthermore, we find that the 6.7 GHz and 12.2 GHz methanol sources increase in luminosity as they evolve. In addition to this, evidence for an increase in velocity range with evolution is presented. This implies that it is not only the luminosity but also the volume of gas conducive to the different maser transitions that increases as the sources evolve. Comparison with GLIMPSE mid-infrared sources has revealed a coincidence rate between the locations of the 6.7 GHz methanol masers and GLIMPSE point sources similar to that achieved in previous studies. Overall, the properties of the GLIMPSE sources with and without 12.2 GHz counterparts are similar. There is a higher 12.2 GHz detection rate toward those 6.7 GHz methanol masers that are coincident with extended green objects.

Breen, S. L.; Caswell, J. L.; Green, J. A.; Voronkov, M. A. [CSIRO Astronomy and Space Science, P.O. Box 76, Epping, NSW 1710 (Australia); Ellingsen, S. P. [School of Mathematics and Physics, University of Tasmania, Private Bag 37, Hobart, Tasmania 7001 (Australia); Fuller, G. A.; Quinn, L. J.; Avison, A., E-mail: Shari.Breen@csiro.au [Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom)

2011-06-01T23:59:59.000Z

175

OAK 270 - The use of Lidar/radiometer (LIRAD) in the ARM program to obtain optical properties and microphysics of high and midlevel clouds  

SciTech Connect (OSTI)

OAK 270 - The use of Lidar/Radiometer (LIRAD) in the ARM program to obtain optical properties and microphysics of high and midlevel clouds

C.M.R. Platt; R.T. Austin; S.A. Young; and G.L. Stephens

2002-12-13T23:59:59.000Z

176

An Assessment of Microwave Absorption Models and Retrievals of Cloud Liquid Water Using Clear-Sky Data  

SciTech Connect (OSTI)

Passive microwave radiometers have a long history in the remote sensing of atmospheric liquid and water vapor. Retrievals of these quantities are sensitive to variations in pressure and temperature of the liquid and water vapor. Rather than use a statistical or climatological approach to account for the natural variability in atmospheric pressure and temperature, additional information on the atmospheric profile at the time of the radiometer measurements can be directly incorporated into the retrieval process. Such an approach has been referred to in the literature as a “physical-iterative” solution. This paper presents an assessment of the accuracy of the column liquid water path that can be expected using such an iterative technique as a result of uncertainties in the microwave emissions from oxygen and water vapor. It is shown that the retrieval accuracy is influenced by the accuracy of the instrument measurements and the quality of the atmospheric profiles of temperature and pressure, as one would expect. But also critical is the uncertainty in the absorption coefficients used in the underlying microwave radiative transfer model. The uncertainty in the absorption coefficients is particularly problematic in that it may well bias the liquid water retrieval. The differences between 3 absorption models examined in this paper are equivalent to a bias of 15 to 30 g/m2, depending on the total column water vapor. An examination of typical liquid water paths from the Southern Great Plains region of the United States shows that errors of this magnitude have significant implications for shortwave radiation and retrievals of cloud effective particle size.

Marchand, Roger T.; Ackerman, Thomas P.; Westwater, Ed R.; Clough, Shepard A.; Cady-Pereira, Karen; Liljegren, James C.

2003-12-19T23:59:59.000Z

177

On the mechanism of electromagnetic microwave absorption in superfluid helium  

SciTech Connect (OSTI)

In experiments on electromagnetic (EM) wave absorption in the microwave range in superfluid (SF) helium [1-3], a narrow EM field absorption line with a width on the order of (20-200) kHz was observed against the background of a wide absorption band with a width of 30-40 GHz at frequencies f{sub 0} Almost-Equal-To 110-180 GHz corresponding to the roton gap energy {Delta}{sub r}(T) in the temperature range 1.4-2.2 K. Using the so-called flexoelectric mechanism of polarization of helium atoms ({sup 4}He) in the presence of density gradients in SF helium (HeII), we show that nonresonance microwave absorption in the frequency range 170-200 GHz can be due to the existence of time-varying local density gradients produced by roton excitations in the bulk HeII. The absorption bandwidth is determined by the roton-roton scattering time in an equilibrium Boltzmann gas of rotons, which is t{sub r-r} Almost-Equal-To 3.4 Multiplication-Sign 10{sup -11} s at T = 1.4 K and decreases upon heating. We propose that the anomalously narrow microwave resonance absorption line in HeII at the roton frequency f{sub 0}(T) = {Delta}r(T)/2{pi}h appears due to the following two factors: (i) the discrete structure of the spectrum of the surface EM resonator modes in the form of a periodic sequence of narrow peaks and (ii) the presence of a stationary dipole layer in HeII near the resonator surface, which forms due to polarization of {sup 4}He atoms under the action of the density gradient associated with the vanishing of the density of the SF component at the solid wall. For this reason, the relaxation of nonequilibrium rotons generated in such a surface dipole layer is strongly suppressed, and the shape and width of the microwave resonance absorption line are determined by the roton density of states, which has a sharp peak at the edge of the roton gap in the case of weak dissipation. The effective dipole moments of rotons in the dipole layer can be directed either along or across the normal to the resonator surface, which explains the experimentally observed symmetric doublet splitting of the resonance absorption line in an external dc electric field perpendicular to the resonator surface. We show that negative absorption (induced emission) of EM field quanta observed after triggering a Kapitza 'heat gun' occurs when the occupation numbers for roton states due to 'pumping' of rotons exceed the occupation numbers of EM field photons in the resonator.

Pashitskii, E. A., E-mail: pashitsk@iop.kiev.ua; Pentegov, V. I. [National Academy of Sciences of Ukraine, Institute of Physics (Ukraine)

2012-08-15T23:59:59.000Z

178

Development of a Permanent-Magnet Microwave Ion Source for a Sealed-Tube Neutron Generator  

SciTech Connect (OSTI)

A microwave ion source has been designed and constructed for use with a sealed-tube, high-yield neutron generator. When operated with a tritium-deuterium gas mixture the generator will be capable of producing 5*1011 n/s in non-proliferation applications. Microwave ion sources are well suited for such a device because they can produce high extracted beam currents with a high atomic fraction at low gas pressures of 0.2-0.3 Pa required for sealed tube operation. The magnetic field strength for achieving electron cyclotron resonance (ECR) condition, 87.5 mT at 2.45 GHz microwave frequency, was generated and shaped with permanent magnets surrounding the plasma chamber and a ferromagnetic plasma electrode. This approach resulted in a compact ion source that matches the neutron generator requirements. The needed proton-equivalent extracted beam current density of 40 mA/cm^2 was obtained at moderate microwave power levels of 400 W. Results on magnetic field design, pressure dependency and atomic fraction measured for different wall materials are presented.

Waldmann, Ole; Ludewigt, Bernhard

2011-03-31T23:59:59.000Z

179

Towards hard X-ray imaging at GHz frame rate  

SciTech Connect (OSTI)

Gigahertz (GHz) imaging using hard X-rays ({approx}> 10 keV) can be useful to high-temperature plasma experiments, as well as research using coherent photons from synchrotron radiation and X-ray free electron lasers. GHz framing rate can be achieved by using multiple cameras through multiplexing. The advantages and trade-offs of single-photon detection mode, when no more than one X-ray photon is detected per pixel, are given. Two possible paths towards X-ray imaging at GHz frame rates using a single camera are (a) Avalanche photodiode arrays of high-Z materials and (b) Microchannel plate photomultipliers in conjunction with materials with large indices of refraction.

Wang, Zhehui [Los Alamos National Laboratory; Morris, Christopher [Los Alamos National Laboratory; Luo, Shengnian [Los Alamos National Laboratory; Kwiatkowski, Kris K. [Los Alamos National Laboratory; Kapustinsky, Jon S. [Los Alamos National Laboratory

2012-05-02T23:59:59.000Z

180

Towards hard x-ray imaging at GHz frame rate  

SciTech Connect (OSTI)

Gigahertz (GHz) imaging using hard x-rays ( Greater-Than-Or-Equivalent-To 10 keV) can be useful to high-temperature plasma experiments, as well as research and applications using coherent photons from synchrotron radiation and x-ray free electron lasers. GHz framing rate can be achieved by using multiple cameras through multiplexing. The advantages and trade-offs of single-photon detection mode, when no more than one x-ray photon is detected per pixel, are given. Two possible paths towards x-ray imaging at GHz frame rates using a single camera are: (a) avalanche photodiode arrays of high-Z materials and (b) microchannel plate photomultipliers in conjunction with materials with large indices of refraction.

Wang Zhehui; Morris, C. L.; Kapustinsky, J. S.; Kwiatkowski, K.; Luo, S.-N. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2012-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Macrocyclic polyaminocarboxylates for stable radiometal antibody conjugates for therapy, spect and pet imaging  

DOE Patents [OSTI]

A simple method for the synthesis of 1,4,7, 10-tetraazacyclododecane N,N'N",N'"-tetraacetic acid and 1,4,8,11-tetraazacyclotetradecane N,N',N",N'"-tetraacetic acid involves cyanomethylating 1,4,7, 10-tetraazacyclododecane or 1,4,8,11-tetraazacyclotetradecane to form a tetranitrile and hydrolyzing the tetranitrile. These macrocyclic compounds are functionalized through one of the carboxylates and then conjugated to various biological molecules including monoclonal antibodies. The resulting conjugated molecules are labeled with radiometals for SPECT and PET imaging and for radiotherapy.

Mease, Ronnie C. (Fairfax, VA); Mausner, Leonard F. (Stony Brook, NY); Srivastava, Suresh C. (Setauket, NY)

1997-06-17T23:59:59.000Z

182

Macrocyclic polyaminocarboxylates for stable radiometal antibody conjugates for therapy, SPECT and PET imaging  

DOE Patents [OSTI]

A simple method for the synthesis of 1,4,7, 10-tetraazacyclododecane N,N{prime}N{double_prime},N{prime}{double_prime}-tetraacetic acid and 1,4,8,11-tetraazacyclotetradecane N,N{prime},N{double_prime},N{prime}{double_prime}-tetraacetic acid involves cyanomethylating 1,4,7,10-tetraazacyclododecane or 1,4,8,11-tetraazacyclotetradecane to form a tetranitrile and hydrolyzing the tetranitrile. These macrocyclic compounds are functionalized through one of the carboxylates and then conjugated to various biological molecules including monoclonal antibodies. The resulting conjugated molecules are labeled with radiometals for SPECT and PET imaging and for radiotherapy. 4 figs.

Mease, R.C.; Mausner, L.F.; Srivastava, S.C.

1997-06-17T23:59:59.000Z

183

SLAC All Access: Vacuum Microwave Device Department  

ScienceCinema (OSTI)

The Vacuum Microwave Device Department (VMDD) builds the devices that make SLAC's particle accelerators go. These devices, called klystrons, generate intense waves of microwave energy that rocket subatomic particles up to nearly the speed of light.

Haase, Andy

2014-06-13T23:59:59.000Z

184

Ignition methods and apparatus using microwave energy  

DOE Patents [OSTI]

An ignition apparatus for a combustor includes a microwave energy source that emits microwave energy into the combustor at a frequency within a resonant response of the combustor, the combustor functioning as a resonant cavity for the microwave energy so that a plasma is produced that ignites a combustible mixture therein. The plasma preferably is a non-contact plasma produced in free space within the resonant cavity spaced away from with the cavity wall structure and spaced from the microwave emitter.

DeFreitas, Dennis Michael (Oxford, NY); Migliori, Albert (Santa Fe, NM)

1997-01-01T23:59:59.000Z

185

Microwavable thermal energy storage material  

DOE Patents [OSTI]

A microwavable thermal energy storage material is provided which includes a mixture of a phase change material and silica, and a carbon black additive in the form of a conformable dry powder of phase change material/silica/carbon black, or solid pellets, films, fibers, moldings or strands of phase change material/high density polyethylene/ethylene-vinyl acetate/silica/carbon black which allows the phase change material to be rapidly heated in a microwave oven. The carbon black additive, which is preferably an electrically conductive carbon black, may be added in low concentrations of from 0.5 to 15% by weight, and may be used to tailor the heating times of the phase change material as desired. The microwavable thermal energy storage material can be used in food serving applications such as tableware items or pizza warmers, and in medical wraps and garments.

Salyer, Ival O. (Dayton, OH)

1998-09-08T23:59:59.000Z

186

Microwavable thermal energy storage material  

DOE Patents [OSTI]

A microwavable thermal energy storage material is provided which includes a mixture of a phase change material and silica, and a carbon black additive in the form of a conformable dry powder of phase change material/silica/carbon black, or solid pellets, films, fibers, moldings or strands of phase change material/high density polyethylene/ethylene vinyl acetate/silica/carbon black which allows the phase change material to be rapidly heated in a microwave oven. The carbon black additive, which is preferably an electrically conductive carbon black, may be added in low concentrations of from 0.5 to 15% by weight, and may be used to tailor the heating times of the phase change material as desired. The microwavable thermal energy storage material can be used in food serving applications such as tableware items or pizza warmers, and in medical wraps and garments. 3 figs.

Salyer, I.O.

1998-09-08T23:59:59.000Z

187

Multi-Spectral Pushbroom Imaging Radiometer (MPIR) for remote sensing studies  

SciTech Connect (OSTI)

A Multi-spectral Pushbroom Imaging Radiometer (MPIR) has been developed as a well-calibrated, imaging radiometer for studies of cloud properties from an unmanned aerospace vehicle platform. The instrument is designed to fly at altitudes up to 20 km and produce data from nine spectral detector modules. Each module has its own telescope optics, linear detector array, spectral filter, and necessary electronics. Cryogenic cooling for the long-wavelength infrared modules, as well as temperature regulation of the short- wavelength modules, is provided by a liquid nitrogen system designed to operate for multi-day missions. Pre- and post-flight calibration, combined with an on-board calibration chopper, provide an instrument with state-of-the-art radiometric measurement accuracies. Each module has a {+-}40{degree} across-track field-of-view and images a curved footprint onto its linear detector array. The long-wavelength array types have 256 detector elements while the short-wavelength arrays can have 512 elements. A modular design allows individual spectral bands to be changed to match the requirements for a particular mission.

Phipps, GS; Grotbeck, CL

1996-05-01T23:59:59.000Z

188

Multi Spectral Pushbroom Imaging Radiometer (MPIR) for remote sensing cloud studies  

SciTech Connect (OSTI)

A Multi Spectral Pushbroom Imaging Radiometer (MPIR) has been developed as are relatively inexpensive ({approximately}$IM/copy), well-calibrated,imaging radiometer for aircraft studies of cloud properties. The instrument is designed to fly on an Unmanned Aerospace Vehicle (UAV) platform at altitudes from the surface up to 20 km. MPIR is being developed to support the Unmanned Aerospace Vehicle portion of the Department of Energy`s Atmospheric Radiation Measurements program (ARM/UAV). Radiation-cloud interactions are the dominant uncertainty in the current General Circulation Models used for atmospheric climate studies. Reduction of this uncertainty is a top scientific priority of the US Global Change Research Program and the ARM program. While the DOE`s ARM program measures a num-ber of parameters from the ground-based Clouds and Radiation Testbed sites, it was recognized from the outset that other key parameters are best measured by sustained airborne data taking. These measurements are critical in our understanding of global change issues as well as for improved atmospheric and near space weather forecasting applications.

Phipps, G.S.; Grotbeck, C.L.

1995-10-01T23:59:59.000Z

189

Microwave assisted centrifuge and related methods  

DOE Patents [OSTI]

Centrifuge samples may be exposed to microwave energy to heat the samples during centrifugation and to promote separation of the different components or constituents of the samples using a centrifuge device configured for generating microwave energy and directing the microwave energy at a sample located in the centrifuge.

Meikrantz, David H. (Idaho Falls, ID) [Idaho Falls, ID

2010-08-17T23:59:59.000Z

190

An Assessment of MultiAngle Imaging SpectroRadiometer (MISR) Stereo-Derived Cloud Top Heights and cloud top winds using ground-based radar, lidar, and microwave radiometers  

SciTech Connect (OSTI)

Clouds are of tremendous importance to climate because of their direct radiative effects and because of their role in atmospheric dynamics and the hydrological cycle. The value of satellite imagery in monitoring cloud properties on a global basis can hardly be understated. One cloud property that satellites are in an advantageous position to monitor is cloud top height. Cloud top height retrievals are especially important for MISR because the derived height field is used to co-register the measured radiances. In this presentation we show the results of an ongoing comparison between ground-based millimeter-wave cloud radar and lidar measurements of cloud top and MISR stereo-derived cloud top height. This comparison is based on data from three radar systems located in the U.S Southern Great Plains (Lamont, Oklahoma), the Tropical Western Pacific (Nauru Island) and the North Slope of Alaska (Barrow, Alaska). These radars are operated as part of the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program. The MISR stereo height algorithm is performing largely as expected for most optically thick clouds. As with many satellite retrievals, the stereo-height retrieval has difficulty with optically thin clouds or ice clouds with little optical contrast near cloud top.

Marchand, Roger T.; Ackerman, Thomas P.; Moroney, C.

2007-03-17T23:59:59.000Z

191

Retrieval of Optical And Size Parameters of Aerosols Utilizing a Multi-Filter Rotating Shadowband Radiometer and Inter-Comparison with CIMEL Sun Photometer and  

E-Print Network [OSTI]

Radiometer and Inter-Comparison with CIMEL Sun Photometer and MICROTOPS Sun Photometer Antonio Aguirre Radiometer (MFRSR) and comparing with data from a CIMEL Sun Photometer and a MICROTOPS Sun Photometer. Using the inverse cosine of the angle between the sun and the vertical. A Langley plot provides a linear regression

192

Microwave treatment of vulcanized rubber  

DOE Patents [OSTI]

A process and resulting product is provided in which a vulcanized solid particulate, such as vulcanized crumb rubber, has select chemical bonds broken by microwave radiation. The direct application of microwaves in combination with uniform heating of the crumb rubber renders the treated crumb rubber more suitable for use in new rubber formulations. As a result, larger particle sizes and/or loading levels of the treated crumb rubber can be used in new rubber mixtures to produce recycled composite products with good properties.

Wicks, George G. (Aiken, SC); Schulz, Rebecca L. (Aiken, SC); Clark, David E. (Gainesville, FL); Folz, Diane C. (Gainesville, FL)

2002-07-16T23:59:59.000Z

193

Carbon Nanotube GHz Nano-Resonator Shengdong Li1  

E-Print Network [OSTI]

Carbon Nanotube GHz Nano-Resonator Shengdong Li1 , Zhen Yu1 , Sheng-Feng Yen1 , Peter J. Burke1 walled carbon nanotube. Both semiconducting and metallic nanotubes are measured. Using a semiconducting signal processing components based on carbon nanotubes. Index Terms -- Nanotechnology, Resonators, Tuning

Tang, William C

194

Validation and analysis of microwave-derived rainfall over the tropics. Master's thesis  

SciTech Connect (OSTI)

A recently developed single channel microwave rain rate retrieval algorithm exists to measure global precipitation over the data-sparse tropical oceans. The objective of this study is to retrieve and validate rainfall using this algorithm, followed by an analysis of the derived rainfall fields. Retrieval consists of applying the algorithm technique to the extraction of four years worth of achieved data from the Electrically Scanning Microwave Radiometer (ESMR) instrument flown aboard the NIMBUS 5 satellite. The Pacific Atoll Raingage Data Set is chosen as a ground truth measure to validate the ESMR-Derived rainfall data against, comparing slope, intercept and correlation between 5 deg x 5 deg area average. Despite limitations imposed by the comparison of point measurements to area-averaged rainfall, results show a 0.80 correlation. Monthly and quarterly climatological mean rainfall estimates are produced, with a consequent analysis of prominent signals, especially in the Intertropical Convergence Zone (ITCZ), South Pacific Convergence Zone (SPCZ) and the Indian monsoon. Latent heat flux is computed, using the ESMR-derived rainfall, and plotted to show qualitatively where seasonal latent thermodynamic energy sources and sinks exist in the atmosphere. A comparison of the summer and winter quarterly composites of the above products with previously compiled climatologies and Outgoing Longwave Radiation (OLR) showed only minor discrepancies in location and intensity, which are discussed in some detail.

Fleishauer, R.P.

1993-01-01T23:59:59.000Z

195

Adhesive bonding using variable frequency microwave energy  

DOE Patents [OSTI]

Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy.

Lauf, Robert J. (Oak Ridge, TN); McMillan, April D. (Knoxville, TN); Paulauskas, Felix L. (Oak Ridge, TN); Fathi, Zakaryae (Cary, NC); Wei, Jianghua (Raleigh, NC)

1998-01-01T23:59:59.000Z

196

Adhesive bonding using variable frequency microwave energy  

DOE Patents [OSTI]

Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy. 26 figs.

Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L.; Fathi, Z.; Wei, J.

1998-09-08T23:59:59.000Z

197

Adhesive bonding using variable frequency microwave energy  

DOE Patents [OSTI]

Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy. 26 figs.

Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L.; Fathi, Z.; Wei, J.

1998-08-25T23:59:59.000Z

198

Scanning tip microwave near field microscope  

DOE Patents [OSTI]

A microwave near field microscope has a novel microwave probe structure wherein the probing field of evanescent radiation is emitted from a sharpened metal tip instead of an aperture or gap. This sharpened tip, which is electrically and mechanically connected to a central electrode, extends through and beyond an aperture in an endwall of a microwave resonating device such as a microwave cavity resonator or a microwave stripline resonator. Since the field intensity at the tip increases as the tip sharpens, the total energy which is radiated from the tip and absorbed by the sample increases as the tip sharpens. The result is improved spatial resolution without sacrificing sensitivity.

Xiang, Xiao-Dong (Alameda, CA); Schultz, Peter G. (Oakland, CA); Wei, Tao (Albany, CA)

1998-01-01T23:59:59.000Z

199

Making Maps from Planck LFI 30GHz Data with Asymmetric Beams and Cooler Noise  

E-Print Network [OSTI]

J. Ashdown et al. : Making Maps from Planck LFI 30GHz DataJ. Ashdown et al. : Making Maps from Planck LFI 30GHz Datain this study. The hit map is shown in the ecliptic (left)

Ashdown, M.A.J.

2010-01-01T23:59:59.000Z

200

Microwave sintering of boron carbide  

DOE Patents [OSTI]

A method for forming boron carbide into a particular shape and densifying the green boron carbide shape. Boron carbide in powder form is pressed into a green shape and then sintered, using a microwave oven, to obtain a dense boron carbide body. Densities of greater than 95% of theoretical density have been obtained. 1 tab.

Blake, R.D.; Katz, J.D.; Petrovic, J.J.; Sheinberg, H.

1988-06-10T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Controlled zone microwave plasma system  

DOE Patents [OSTI]

An apparatus and method for initiating a process gas plasma. A conductive plate having a plurality of conductive fingers is positioned in a microwave applicator. An arc forms between the conductive fingers to initiate the formation of a plasma. A transport mechanism may convey process materials through the plasma. A spray port may be provided to expel processed materials.

Ripley, Edward B. (Knoxville, TN); Seals, Roland D. (Oak Ridge, TN); Morrell, Jonathan S. (Knoxville, TN)

2009-10-20T23:59:59.000Z

202

Handheld reader Incident wave Microwave  

E-Print Network [OSTI]

for Moisture Detection Utilizing Carbon Nanotube Arnaud Vena, A. Ali Babar, Lauri Sydänheimo and Leena Ukkonen-printing a dual rhombic loop scatterer on a flexible substrate having a size of 4x2cm2 only. This sensor operates in the ISM band at 2.45 GHz. The scatterer is doped with a thin layer of carbon nanotube- based organic ink

Tentzeris, Manos

203

Effect of Land Surface Heterogeneity on Satellite Near-  

E-Print Network [OSTI]

in regulating the energy and water balance at the soil surface and it is therefore a crucial variable for many. SMOS will carry an L-band (1.4GHz) microwave radiometer and will provide near-surface soil moisture highly heterogeneous land surface conditions. The principal objectives of this research are to (i) test

Walker, Jeff

204

MONITORING POWER PLANT EFFICIENCY USING THE MICROWAVE-EXCITED PHOTOACOUSTIC EFFECT TO MEASURE UNBURNED CARBON  

SciTech Connect (OSTI)

Three test instruments are being evaluated to determine the feasibility of using photoacoustic technology for measuring unburned carbon in fly ash. The first test instrument is a single microwave frequency system previously constructed to measure photo-acoustic signals in an off-line configuration. This system was assembled and used to test parameters thought important to photo-acoustic signal output. A standard modulation frequency was chosen based upon signal to noise data gained from experimentation. Sample heterogeneity was tested and found not to be influential. Further testing showed that sample compression and photo-acoustic volume do affect photo-acoustic signal with photoacoustic volume being the most influential. Testing in the fifth quarter focused on microwave power stability. Simultaneously, a second instrument is being constructed based in part on lessons learned with the first instrument, but also expands the capabilities of the first instrument by allowing a spectrum of microwave frequencies to be tested up to 10 GHz. The power amplifiers for this second instrument were completed and tested. Improvements were made to the current leveling loop, which will stabilize the microwave power. This loop is currently in operation with the single frequency cell. Discriminatory measurements are continuing in an attempt to differentiate between magnetic contaminants such as iron and non-magnetic contaminants such as carbon. A short coaxial test fixture was fabricated and tested showing the promise of another microwave based test method for determining carbon content in fly ash. Preliminary design iterations for the third on-line instrument (based on the experiences of the first two instruments) have begun.

Robert C. Brown; Robert J. Weber; Andrew A. Suby

2003-01-01T23:59:59.000Z

205

Solar Irradiances Measured using SPN1 Radiometers: Uncertainties and Clues for Development  

SciTech Connect (OSTI)

The fast development of solar radiation and energy applications, such as photovoltaic and solar thermodynamic systems, has increased the need for solar radiation measurement and monitoring, not only for the global component but also the diffuse and direct. End users look for the best compromise between getting close to state-of-the-art measurements and keeping capital, maintenance and operating costs to a minimum. Among the existing commercial options, SPN1 is a relatively low cost solar radiometer that estimates global and diffuse solar irradiances from seven thermopile sensors under a shading mask and without moving parts. This work presents a comprehensive study of SPN1 accuracy and sources of uncertainty, which results from laboratory experiments, numerical modeling and comparison studies between measurements from this sensor and state-of-the art instruments for six diverse sites. Several clues are provided for improving the SPN1 accuracy and agreement with state-of-the-art measurements.

Badosa, Jordi; Wood, John; Blanc, Philippe; Long, Charles N.; Vuilleumier, Laurent; Demengel, Dominique; Haeffelin, Martial

2014-12-08T23:59:59.000Z

206

Informal Preliminary Report on Comparisons of Prototype SPN-1 Radiometer to PARSL Measurements  

SciTech Connect (OSTI)

The prototype SPN-1 has been taking measurements for several months collocated with our PNNL Atmospheric Remote Sensing Laboratory (PARSL) solar tracker mounted instruments at the Pacific Northwest National Laboratory (PNNL) located in Richland, Washington, USA. The PARSL radiometers used in the following comparisons consist of an Eppley Normal Incident Pyrheliometer (NIP) and a shaded Eppley model 8-48 “Black and White” pyrgeometer (B&W) to measure the direct and diffuse shortwave irradiance (SW), respectively. These instruments were calibrated in mid-September by comparison to an absolute cavity radiometer directly traceable to the world standard group in Davos, Switzerland. The NIP calibration was determined by direct comparison, while the B&W was calibrated using the shade/unshade technique. All PARSL data prior to mid-September have been reprocessed using the new calibration factors. The PARSL data are logged as 1-minute averages from 1-second samples. Data used in this report span the time period from June 22 through December 1, 2006. All data have been processed through the QCRad code (Long and Shi, 2006), which itself is a more elaborately developed methodology along the lines of that applied by the Baseline Surface Radiation Network (BSRN) Archive (Long and Dutton, 2004), for quality control. The SPN-1 data are the standard total and diffuse SW values obtained from the analog data port of the instrument. The comparisons use only times when both the PARSL and SPN-1 data passed all QC testing. The data were further processed and analyzed by application of the SW Flux Analysis methodology (Long and Ackerman, 2000; Long and Gaustad, 2004, Long et al., 2006) to detect periods of clear skies, calculate continuous estimates of clear-sky SW irradiance and the effect of clouds on the downwelling SW, and estimate fractional sky cover.

Long, Charles N.

2014-06-17T23:59:59.000Z

207

Global longterm passive microwave satellitebased retrievals of vegetation optical depth  

E-Print Network [OSTI]

with those observed in the Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation the Advanced Very High Resolution Radiometer (AVHRR) extending back to 1981. The NDVI is derived by subtracting in the hydrological, energy and carbon cycles, through influences of land cover change on hydrologic responses

Evans, Jason

208

Materials for freeform fabrication of GHz tunable dielectric photonic crystals.  

SciTech Connect (OSTI)

Photonic crystals are of interest for GHz transmission applications, including rapid switching, GHz filters, and phased-array technology. 3D fabrication by Robocasting enables moldless printing of high solid loading slurries into structures such as the ''woodpile'' structures used to fabricate dielectric photonic band gap crystals. In this work, tunable dielectric materials were developed and printed into woodpile structures via solid freeform fabrication (SFF) toward demonstration of tunable photonic crystals. Barium strontium titanate ceramics possess interesting electrical properties including high permittivity, low loss, and high tunability. This paper discusses the processing route and dielectric characterization of (BaxSr1-XTiO3):MgO ceramic composites, toward fabrication of tunable dielectric photonic band gap crystals.

Niehaus, Michael Keith; Lewis, Jennifer A. (University of Illinois, Urbana, IL); Smay, James Earl; Clem, Paul Gilbert; Lin, Shawn-Yu; Cesarano, Joseph, III (,; ); Carroll, James F.

2003-01-01T23:59:59.000Z

209

Detection of two histidyl ligands to Cu[sub A] of cytochrome oxidase by 35-GHz ENDOR. [sup 14,15]N and [sup 63,65]Cu ENDOR studies of the Cu[sub A] site in bovine heart cytochrome aa[sub 3] and cytochromes caa[sub 3] and ba[sub 3] from Thermus thermophilus  

SciTech Connect (OSTI)

To study the ligation of the Cu[sub A] site of heme-copper terminal oxidases, we have performed ENDOR measurements at X-band (9-GHz) and 35-GHz microwave frequencies on the three titled enzymes. The 35-GHz measurements provide complete spectral separation of the [sup 1]H and [sup 14]N resonances and permit analysis of the field dependence of the [sup 14]N ENDOR for each enzyme. The results indicate that two nitrogenous ligands were quite unequal hyperfine couplings are ligated to Cu[sub A] in each of the enzymes studied. We have also examined cytochrome caa[sub 3] isolated from His Thermus cells grown in the presence of D,L,-[[delta],[epsilon]-[sup 15]N[sub 2

Gurbiel, R.J. (Northwestern Univ., Evanston, IL (United States) Jagiellonian Univ., Krakow (Poland)); Fann, Y.C.; Werst, M.M.; Doan, P.E.; Hoffman, B.M. (Northwestern Univ., Evanston, IL (United States)); Surerus, K.K. (Los Alamos National Lab., NM (United States)); Musser, S.M.; Chan, S.I. (California Inst. of Technology, Pasadena, CA (United States)); Fee, J.A. (Los Alamos National Lab., NM (United States) Univ. of California, La Jolla, CA (United States))

1993-11-17T23:59:59.000Z

210

The number counts, luminosity functions and evolution of microwave-selected (WMAP) blazars and radio galaxies  

E-Print Network [OSTI]

(Abridged) We carried out an extensive search to identify the counterparts of all the sources listed in the WMAP 3-yr catalogue using literature and archival data. Our work led to the identification of 309 WMAP sources, 98% of which are blazars, radio quasars or radio galaxies. At present, 15 objects still remain without identification due to the lack of optical spectroscopic data or a clear radio counterpart. Our results allow us to define a flux limited sample of 203 high Galactic latitude microwave sources ($f_{41GHz} \\ge 1$ Jy, $|b_{\\rm II}| > 15^\\circ$) which is virtually completely identified (99%). The microwave band is ideally suited for blazar statistical studies since this is the part of the em spectrum that is least affected by the superposition of spectral components of different origin. Using this data-set we derived number counts, luminosity functions and cosmological evolution of blazars and radio galaxies at microwave frequencies. Our results are in good agreement with those found at radio fre...

Giommi, P; Padovani, P; Gasparrini, D; Cavazzuti, E; Cutini, S

2009-01-01T23:59:59.000Z

211

Future Directions in the Microwave Cavity Search for Dark Matter Axions  

E-Print Network [OSTI]

The axion is a light pseudoscalar particle which suppresses CP-violating effects in strong interactions and also happens to be an excellent dark matter candidate. Axions constituting the dark matter halo of our galaxy may be detected by their resonant conversion to photons in a microwave cavity permeated by a magnetic field. The current generation of the microwave cavity experiment has demonstrated sensitivity to plausible axion models, and upgrades in progress should achieve the sensitivity required for a definitive search, at least for low mass axions. However, a comprehensive strategy for scanning the entire mass range, from 1-1000 $\\mu$eV, will require significant technological advances to maintain the needed sensitivity at higher frequencies. Such advances could include sub-quantum-limited amplifiers based on squeezed vacuum states, bolometers, and/or superconducting microwave cavities. The Axion Dark Matter eXperiment at High Frequencies (ADMX-HF) represents both a pathfinder for first data in the 20-100 $\\mu$eV range ($\\sim$5-25 GHz), and an innovation test-bed for these concepts.

T. M. Shokair; J. Root; K. A. Van Bibber; B. Brubaker; Y. V. Gurevich; S. B. Cahn; S. K. Lamoreaux; M. A. Anil; K. W. Lehnert; B. K. Mitchell; A. Reed; G. Carosi

2014-05-14T23:59:59.000Z

212

Sub-optical wavelength acoustic wave modulation of integrated photonic resonators at microwave frequencies  

E-Print Network [OSTI]

Light-sound interactions have long been exploited in various acousto-optic devices based on bulk crystalline materials. Conventionally these devices operate in megahertz frequency range where the acoustic wavelength is much longer than the optical wavelength and a long interaction length is required to attain significant coupling. With nanoscale transducers, acoustic waves with sub-optical wavelengths can now be excited to induce strong acousto-optic coupling in nanophotonic devices. Here we demonstrate microwave frequency surface acoustic wave transducers co-integrated with nanophotonic resonators on piezoelectric aluminum nitride substrates. Acousto-optic modulation of the resonance modes at above 10 GHz with the acoustic wavelength significantly below the optical wavelength is achieved. The phase and modal matching conditions in this scheme are investigated for efficient modulation. The new acousto-optic platform can lead to novel optical devices based on nonlinear Brillouin processes and provides a direct, wideband link between optical and microwave photons for microwave photonics and quantum optomechanics.

Semere Ayalew Tadesse; Mo Li

2014-10-04T23:59:59.000Z

213

Microwave assisted hard rock cutting  

DOE Patents [OSTI]

An apparatus for the sequential fracturing and cutting of subsurface volume of hard rock (102) in the strata (101) of a mining environment (100) by subjecting the volume of rock to a beam (25) of microwave energy to fracture the subsurface volume of rock by differential expansion; and , then bringing the cutting edge (52) of a piece of conventional mining machinery (50) into contact with the fractured rock (102).

Lindroth, David P. (Apple Valley, MN); Morrell, Roger J. (Bloomington, MN); Blair, James R. (Inver Grove Heights, MN)

1991-01-01T23:59:59.000Z

214

Note: Cryogenic coaxial microwave filters  

SciTech Connect (OSTI)

The careful filtering of microwave electromagnetic radiation is critical for controlling the electromagnetic environment for experiments in solid-state quantum information processing and quantum metrology at millikelvin temperatures. We describe the design and fabrication of a coaxial filter assembly and demonstrate that its performance is in excellent agreement with theoretical modelling. We further perform an indicative test of the operation of the filters by making current-voltage measurements of small, underdamped Josephson junctions at 15 mK.

Tancredi, G.; Meeson, P. J. [Department of Physics, Royal Holloway, University of London, Egham TW20 0EX (United Kingdom)] [Department of Physics, Royal Holloway, University of London, Egham TW20 0EX (United Kingdom); Schmidlin, S. [Department of Physics, Royal Holloway, University of London, Egham TW20 0EX (United Kingdom) [Department of Physics, Royal Holloway, University of London, Egham TW20 0EX (United Kingdom); National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom)

2014-02-15T23:59:59.000Z

215

Process for microwave sintering boron carbide  

DOE Patents [OSTI]

A method of microwave sintering boron carbide comprises leaching boron carbide powder with an aqueous solution of nitric acid to form a leached boron carbide powder. The leached boron carbide powder is coated with a glassy carbon precursor to form a coated boron carbide powder. The coated boron carbide powder is consolidated in an enclosure of boron nitride particles coated with a layer of glassy carbon within a container for microwave heating to form an enclosed coated boron carbide powder. The enclosed coated boron carbide powder is sintered within the container for microwave heating with microwave energy.

Holcombe, C.E.; Morrow, M.S.

1993-10-12T23:59:59.000Z

216

Process for microwave sintering boron carbide  

DOE Patents [OSTI]

A method of microwave sintering boron carbide comprises leaching boron carbide powder with an aqueous solution of nitric acid to form a leached boron carbide powder. The leached boron carbide powder is coated with a glassy carbon precursor to form a coated boron carbide powder. The coated boron carbide powder is consolidated in an enclosure of boron nitride particles coated with a layer of glassy carbon within a container for microwave heating to form an enclosed coated boron carbide powder. The enclosed coated boron carbide powder is sintered within the container for microwave heating with microwave energy.

Holcombe, Cressie E. (440 Sugarwood Dr., Knoxville, TN 37922); Morrow, Marvin S. (Rte. #3, Box 113, Kingston, TN 37763)

1993-01-01T23:59:59.000Z

217

New opportunities in microwave electronics with ferromagnetic nanowires  

SciTech Connect (OSTI)

A series of monolithic tunable microwave band-stop filters and phase shifters have been designed, fabricated, and characterized on arrays of ferromagnetic nanowires (FMNWs) constituted of Ni, Co, CoFeB, and NiFe alloy embedded in anodic alumina templates (AAO). The aim of the present investigation is to significantly boost the operating frequency of devices in very low applied magnetic field. The stop-band response can cover from 8 to 40?GHz with an applied magnetic field up to 5 kOe using these materials. In addition, we observed a substantial increase in frequency tunability (>110%) for Ni and NiFe alloy based filter. Frequency bandwidth/linewidth can be tuned with the proper choice of magnetic material, broad band for Co nanowires to narrow band for CoFeB nanowires. The amorphous nature of CoFeB reduces linewidth considerably and hence increases resonance absorption. It is also observed that the frequency linewidth (?f) decreases with increasing applied magnetic field. The same filter can be used as a tunable phase shifter. For Ni nanowire based phase shifter, a maximum shift of 75°/cm at 4 kOe was observed.

Sharma, Monika, E-mail: monikasharma1604@gmail.com; Sharma, Manish; Basu, Ananjan [Centre for Applied Research in Electronics, Indian Institute of Technology, Delhi 110016 (India); Kuanr, Bijoy K. [Special Centre for Nanoscience, Jawaharlal Nehru University, New Delhi 110067 (India)

2014-05-07T23:59:59.000Z

218

Monitoring of Precipitable Water Vapor and Cloud Liquid Path from Scanning Microwave Radiometers During the 2003 Cloudiness Inter-Comparison Experiment  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment SurfacesResource ProgramModification andinterface of water.OrganicNov 4 5

219

Comparison of Historical Satellite-Based Estimates of Solar Radiation Resources with Recent Rotating Shadowband Radiometer Measurements: Preprint  

SciTech Connect (OSTI)

The availability of rotating shadow band radiometer measurement data at several new stations provides an opportunity to compare historical satellite-based estimates of solar resources with measurements. We compare mean monthly daily total (MMDT) solar radiation data from eight years of NSRDB and 22 years of NASA hourly global horizontal and direct beam solar estimates with measured data from three stations, collected after the end of the available resource estimates.

Myers, D. R.

2009-03-01T23:59:59.000Z

220

Comment on Quantum teleportation via GHZ-like state  

E-Print Network [OSTI]

Recently Yang et al. [Int. J. Theo. Phys. 48 (2009) 516] have shown that an unknown qubit can be teleported by using a particular GHZ-like state as quantum channel. However, there are several errors in the calculation which lead to incorrect conclusions. The errors have been indicated and corrected. It is also noted that their scheme and the independently proposed teleportation scheme of Zhang et al. [Int. J. Theo. Phys. 48 (2009) 3331] uses quantum channel from the same family and any state of that family may be used for teleportation.

Anindita Banerjee; Kamal Patel; Anirban Pathak

2010-06-08T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

A 300 GHz collective scattering diagnostic for low temperature plasmas  

SciTech Connect (OSTI)

A compact and portable 300 GHz collective scattering diagnostic employing a homodyne detection scheme has been constructed and installed on the hot helicon experiment (HELIX). Verification of the homodyne detection scheme was accomplished with a rotating grooved aluminum wheel to Doppler shift the interaction beam. The HELIX chamber geometry and collection optics allow measurement of scattering angles ranging from 60 deg. to 90 deg. Artificially driven ion-acoustic waves are also being investigated as a proof-of-principle test for the diagnostic system.

Hardin, Robert A.; Scime, Earl E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Heard, John [Department of Physics, Clarion University, Clarion, Pennsylvania 16214 (United States)

2008-10-15T23:59:59.000Z

222

A reactionless, bearingless linear shutter mechanism for the multispectral pushbroom imaging radiometer  

SciTech Connect (OSTI)

The Atmospheric Radiation Measurement Program is a multi-laboratory, interagency program as part of DOE`s principal entry into the US Global Change Research Program. Two issues addressed are the radiation budget and its spectral dependence, and radiative and other properties of clouds. Measures of solar flux divergence and energy exchanges between clouds, the earth, its oceans, and the atmosphere through various altitudes are sought. Additionally, the program seeks to provide measurements to calibrate satellite radiance products and validate their associated flux retrieval algorithms. Unmanned Aerospace Vehicles fly long, extended missions. MPIR is one of the primary instruments on the ARM-UAV campaigns. A shutter mechanism has been developed and flown as part of an airborne imaging radiometer having application to spacecraft or other applications requiring low vibration, high reliability, and long life. The device could be employed in other cases where a reciprocating platform is needed. Typical shutters and choppers utilize a spinning disc, or in very small instruments, a vibrating vane to continually interrupt incident light or radiation that enters the system. A spinning disk requires some sort of bearings that usually have limited life, and at a minimum introduce issues of reliability. Friction, lubrication and contamination always remain critical areas of concern, as well as the need for power to operate. Dual vibrating vanes may be dynamically well balanced as a set and are frictionless. However, these are limited by size in a practical sense. In addition, multiples of these devices are difficult to synchronize.

Krumel, L.J.

1996-12-31T23:59:59.000Z

223

Method to Calculate Uncertainty Estimate of Measuring Shortwave Solar Irradiance using Thermopile and Semiconductor Solar Radiometers  

SciTech Connect (OSTI)

The uncertainty of measuring solar irradiance is fundamentally important for solar energy and atmospheric science applications. Without an uncertainty statement, the quality of a result, model, or testing method cannot be quantified, the chain of traceability is broken, and confidence cannot be maintained in the measurement. Measurement results are incomplete and meaningless without a statement of the estimated uncertainty with traceability to the International System of Units (SI) or to another internationally recognized standard. This report explains how to use International Guidelines of Uncertainty in Measurement (GUM) to calculate such uncertainty. The report also shows that without appropriate corrections to solar measuring instruments (solar radiometers), the uncertainty of measuring shortwave solar irradiance can exceed 4% using present state-of-the-art pyranometers and 2.7% using present state-of-the-art pyrheliometers. Finally, the report demonstrates that by applying the appropriate corrections, uncertainties may be reduced by at least 50%. The uncertainties, with or without the appropriate corrections might not be compatible with the needs of solar energy and atmospheric science applications; yet, this report may shed some light on the sources of uncertainties and the means to reduce overall uncertainty in measuring solar irradiance.

Reda, I.

2011-07-01T23:59:59.000Z

224

Microwave-triggered laser switch  

DOE Patents [OSTI]

A high-repetition rate switch is described for delivering short duration, high-powered electrical pulses from a pulsed-charged dc power supply. The present invention utilizes a microwave-generating device such as a magnetron that is capable of producing high-power pulses at high-pulse repetition rates and fast-pulse risetimes for long periods with high reliability. The rail-gap electrodes provide a large surface area that reduces induction effects and minimizes electrode erosion. Additionally, breakdown is initiated in a continuous geometric fashion that also increases operating lifetime of the device.

Piltch, M.S.

1982-05-19T23:59:59.000Z

225

Microwave-triggered laser switch  

DOE Patents [OSTI]

A high-repetition rate switch for delivering short duration, high-power electrical pulses from a pulsed-charged dc power supply. The present invention utilizes a microwave-generating device such as a magnetron that is capable of producing high-power pulses at high-pulse repetition rates and fast-pulse risetimes for long periods with high reliability. The rail-gap electrodes provide a large surface area that reduces induction effects and minimizes electrode erosion. Additionally, breakdown is initiated in a continuous geometric fashion that also increases operating lifetime of the device.

Piltch, Martin S. (Los Alamos, NM)

1984-01-01T23:59:59.000Z

226

Microwave-enhanced chemical processes  

DOE Patents [OSTI]

A process is disclosed for the disposal of toxic wastes including chlorinated hydrocarbons, comprising, establishing a bed of non-metallic particulates having a high dielectric loss factor. Intimate contact of the particulates and the toxic wastes at a temperature in excess of about 400 C in the presence of microwave radiation for a time sufficient breaks the hydrocarbon chlorine bonds. Detoxification values in excess of 80 are provided and further detoxification of the bed is followed by additional disposal of toxic wastes. 1 figure.

Varma, R.

1990-06-19T23:59:59.000Z

227

Microwave Meals in a Hurry.  

E-Print Network [OSTI]

of time to prepare complete meals. Select dishes that are family favorites and use tested recipes . Learning to adapt recipes for microwave cooking comes. later with experience. In general, advance meal planning is the key to getting the most out.... For example, whole carrots stay hot longer than sliced carrots. Cooking and then serving food in the same dish extends holding time. So does wrapping or cov ering the food in plastic wrap or foil, or covering it with a lid. Cook foods with a long holding...

Haggard, Marilyn A.

1981-01-01T23:59:59.000Z

228

Microwave drying of ferric oxide pellets  

SciTech Connect (OSTI)

The application of microwave energy for the drying of ferric oxide pellets has been investigated and evaluated. It is shown that the microwave drying rates are much higher than those observed in the conventional process. Also there is some potential for improved quality of the product. As a stand-alone technology it is unlikely that microwave drying would be economical for pellets due to the low cost of conventional fuels. However, based on an understanding of the drying mechanisms in the conventional process and in the microwave process, it is shown that microwave-assisted drying offers considerable potential. In this hybrid process, the advantages of the two drying techniques are combined to provide an improved drying process.

Pickles, C.A.; Xia, D.K. [Queens` Univ., Kingston, Ontario (Canada). Dept. of Materials and Metallurgical Engineering

1997-12-31T23:59:59.000Z

229

Electrodeless lamp energized by microwave energy  

SciTech Connect (OSTI)

This patent describes an electrodeless lamp. It comprises: a microwave cavity; a source of microwaves in communication with the cavity; a lamp envelope containing a plasma-forming medium mounted within the microwave cavity; a gas manifold for feeding gas to at least one gas passageway for directing a stream of gas to the outer surface of the envelope; a gas leak passageway leading from the gas manifold; a conductive mesh assembly for retaining microwaves within the cavity and permitting light to be emitted from the cavity. The assembly including gas flow blocking means for preventing the flow of gas through the gas leak passageway when the screen is in place in the lamp; and means for shutting off the source of microwaves when the gas pressure in the manifold drops below a predetermined value.

Ervin, R.M.; Perret, J.

1990-01-16T23:59:59.000Z

230

Microwave generated plasma light source apparatus  

SciTech Connect (OSTI)

A microwave generated plasma light source including a microwave generator, a microwave cavity having a light reflecting member forming at least a portion of the cavity, and a member transparent to light and opaque to microwaves disposed across an opening of the cavity opposite the feeding opening through which the microwave generator is coupled. An electrodeless discharge bulb is disposed at a position in the cavity such that the cavity operates as a resonant cavity at least when the bulb is emitting light. In the bulb is encapsulated at least one discharge light emissive substance. The bulb has a shape and is sufficiently small that the bulb acts substantially as a point light source.

Yoshizawa, K.; Ito, H.; Kodama, H.; Komura, H.; Minowa, Y.

1985-02-05T23:59:59.000Z

231

Tandem microwave waste remediation and decontamination system  

DOE Patents [OSTI]

The invention discloses a tandem microwave system consisting of a primary chamber in which microwave energy is used for the controlled combustion of materials. A second chamber is used to further treat the off-gases from the primary chamber by passage through a susceptor matrix subjected to additional microwave energy. The direct microwave radiation and elevated temperatures provide for significant reductions in the qualitative and quantitative emissions of the treated off gases. The tandem microwave system can be utilized for disinfecting wastes, sterilizing materials, and/or modifying the form of wastes to solidify organic or inorganic materials. The simple design allows on-site treatment of waste by small volume waste generators.

Wicks, George G. (North Aiken, SC); Clark, David E. (Gainesville, FL); Schulz, Rebecca L. (Gainesville, FL)

1999-01-01T23:59:59.000Z

232

30 GHz Zeno-based Graphene Electro-optic Modulator  

E-Print Network [OSTI]

Graphene has generated exceptional interest as an optoelectronic material because its high carrier mobility and broadband absorption promise to make extremely fast and broadband electro-optic devices possible. Electro-optic graphene modulators reported to date, however, have been limited in bandwidth to a few GHz because of the large capacitance required to achieve reasonable voltage swings. Here we demonstrate a graphene electro-optic modulator based on the classical Zeno effect that shows drastically increased speed and efficiency. Our device operates with a 30 GHz bandwidth, over an order of magnitude faster than prior work, and a state-of-the-art modulation efficiency of 1.5 dB/V. We also show the first high-speed large-signal operation in a graphene modulator, paving the way for fast digital communications using this platform. The modulator uniquely uses silicon nitride waveguides, an otherwise completely passive material platform, with promising applications for ultra-low-loss broadband structures and n...

Phare, Christopher T; Cardenas, Jaime; Lipson, Michal

2014-01-01T23:59:59.000Z

233

Microwave processing for carbide ceramics  

SciTech Connect (OSTI)

The US Bureau of Mines (USBM) has developed a process for synthesizing carbide ceramics in a microwave-induced plasma (MIP). For example, the process forms tungsten carbide with only 0.04% free carbon impurity at an average particle size of 0.05 {mu}m. Starting materials are tungsten oxide, carbon, and carbon monoxide. Commercial methods to produce tungsten carbide require heating to 1,500 C for up to 7 hours. Using the USBM method, tungsten carbide can be produced in approximately 10 minutes using a 30 kW, 915 mHz microwave unit. The reaction is carried out in a short-circuited waveguide to create a standing wave. Reactants rest on a carbon pedestal inside a closed zirconia crucible filled with carbon monoxide. The crucible is place at a field maximum within the waveguide. The waveguide was filled with helium to protect the waveguide. A procedure for producing carbide on a larger scale is described. Other ceramic compounds have been produced using this method, including silicon carbide and titanium carbide.

Tolley, W.K.; Church, R.H. [Bureau of Mines, Salt Lake City, UT (United States). Salt Lake City Research Center

1995-08-01T23:59:59.000Z

234

A microwave resonator for limiting depth sensitivity for electron paramagnetic resonance spectroscopy of surfaces  

SciTech Connect (OSTI)

A microwave Surface Resonator Array (SRA) structure is described for use in Electron Paramagnetic Resonance (EPR) spectroscopy. The SRA has a series of anti-parallel transmission line modes that provides a region of sensitivity equal to the cross-sectional area times its depth sensitivity, which is approximately half the distance between the transmission line centers. It is shown that the quarter-wave twin-lead transmission line can be a useful element for design of microwave resonators at frequencies as high as 10 GHz. The SRA geometry is presented as a novel resonator for use in surface spectroscopy where the region of interest is either surrounded by lossy material, or the spectroscopist wishes to minimize signal from surrounding materials. One such application is in vivo spectroscopy of human finger-nails at X-band (9.5 GHz) to measure ionizing radiation dosages. In order to reduce losses associated with tissues beneath the nail that yield no EPR signal, the SRA structure is designed to limit depth sensitivity to the thickness of the fingernail. Another application, due to the resonator geometry and limited depth penetration, is surface spectroscopy in coating or material science. To test this application, a spectrum of 1.44 ?M of Mg{sup 2+} doped polystyrene 1.1 mm thick on an aluminum surface is obtained. Modeling, design, and simulations were performed using Wolfram Mathematica (Champaign, IL; v. 9.0) and Ansys High Frequency Structure Simulator (HFSS; Canonsburg, PA; v. 15.0). A micro-strip coupling circuit is designed to suppress unwanted modes and provide a balanced impedance transformation to a 50 ? coaxial input. Agreement between simulated and experimental results is shown.

Sidabras, Jason W.; Varanasi, Shiv K.; Hyde, James S. [Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53211 (United States); Mett, Richard R. [Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53211 (United States); Department of Physics and Chemistry, Milwaukee School of Engineering, Milwaukee, Wisconsin 53202 (United States); Swarts, Steven G. [Department of Radiation Oncology, University of Florida, Gainesville, Florida, 32610 (United States); Swartz, Harold M. [Department of Radiology, Geisel Medical School at Dartmouth, Hanover, New Hampshire 03755 (United States)

2014-10-15T23:59:59.000Z

235

The R/V Discoverer cruise to Manus Island. The BNL Portable Radiometer Package (PRP) evaluation  

SciTech Connect (OSTI)

Brookhaven National Laboratory installed and operated a Portable Radiation Package (PRP) on the NOAA ship R/V DISCOVERER as part of the Combined Sensor Program cruise in the Tropical Western Pacific Ocean. The DISCOVERER transported a collection of radiation and atmospheric instrumentation to positions offshore of manus Island to compare cloud and radiation fields to like instruments measured from a station on the island. The ship sailed NW from Pago Pago, American Samoa, on 14 March 1996 to a latitude of 1{degree}S then due West until it approached manus Island (2{degree}S and 148{degree}E) on approximately 7 April. The ship then turned SW and approached Manus Island in three steps. This route was reversed during the ship`s return to Hawaii. The PRP package is a compact low-power integration of simple sensors that measure long- and short-wave irradiance from moving platforms. A rapid rotating shadowband radiometer that is designed to provide good estimates of diffuse (sky) radiation even from moving buoys or ships was being evaluated. The PRP provided the only means of making diffuse (sky) radiation measurements from the ship. The CSP cruise provided an excellent opportunity to intercompare the PRP with other like instruments in the TWP locale. The unit was located on the starboard flying bridge which was fully exposed to direct sunlight during the ship`s westward transit. When the ship was at its closest approach to manus, the PRP was moved to the island where careful intercomparison with the Manus instrumentation was conducted.

Reynolds, R.M.; Smith, S.

1996-05-24T23:59:59.000Z

236

Chiral-field microwave antennas (Chiral microwave near fields for far-field radiation)  

E-Print Network [OSTI]

In a single-element structure we obtain a radiation pattern with a squint due to chiral microwave near fields originated from a magnetostatic-mode ferrite disk. At the magnetostatic resonances, one has strong subwavelength localization of energy of microwave radiation. Magnetostatic oscillations in a thin ferrite disk are characterized by unique topological properties: the Poynting-vector vortices and the field helicity. The chiral-topology near fields allow obtaining unique phase structure distribution for far-field microwave radiation.

Kamenetskii, E O; Shavit, R

2015-01-01T23:59:59.000Z

237

Gauging the cosmic microwave background  

E-Print Network [OSTI]

We provide a new derivation of the anisotropies of the cosmic microwave background (CMB), and find an exact expression that can be readily expanded perturbatively. Close attention is paid to gauge issues, with the motivation to examine the effect of super-Hubble modes on the CMB. We calculate a transfer function that encodes the behaviour of the dipole, and examine its long-wavelength behaviour. We show that contributions to the dipole from adiabatic super-Hubble modes are strongly suppressed, even in the presence of a cosmological constant, contrary to claims in the literature. We also introduce a naturally defined CMB monopole, which exhibits closely analogous long-wavelength behaviour. We discuss the geometrical origin of this super-Hubble suppression, pointing out that it is a simple reflection of adiabaticity, and hence argue that it will occur regardless of the matter content.

J. P. Zibin; Douglas Scott

2008-12-21T23:59:59.000Z

238

Planar slot coupled microwave hybrid  

DOE Patents [OSTI]

A symmetrical 180.degree. microwave hybrid is constructed by opening a slot line in a ground plane below a conducting strip disposed on a dielectric substrate, creating a slot coupled conductor. Difference signals propagating on the slot coupled conductor are isolated on the slot line leaving sum signals to propagate on the microstrip. The difference signal is coupled from the slot line onto a second microstrip line for transmission to a desired location. The microstrip branches in a symmetrical fashion to provide the input/output ports of the 180.degree. hybrid. The symmetry of the device provides for balance and isolation between sum and difference signals, and provides an advantageous balance between the power handling capabilities and the bandwidth of the device.

Petter, Jeffrey K. (Williston, VT)

1991-01-01T23:59:59.000Z

239

E-Print Network 3.0 - assessment south microwave Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Process Christopher Marion Supervisor: Prof Kristian Waters Summary: microwaves) Optimization of the microwave pre-treatment process Assess the effect of the microwave pre......

240

Optoelectronic Oscillators and Their Applications to 60-GHz Fiber-Fed  

E-Print Network [OSTI]

Optoelectronic Oscillators and Their Applications to 60-GHz Fiber-Fed Wireless Systems Kwang;Optoelectronic Oscillators and Their Applications to 60-GHz Fiber-Fed Wireless Systems by Kwang-Hyun Lee-1-2. Oscillator phase noise limited by resonator's Q.............................4 1-2. Optoelectronic oscillators

Choi, Woo-Young

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

THE CELESTIAL REFERENCE FRAME AT 24 AND 43 GHz. I. ASTROMETRY  

SciTech Connect (OSTI)

We present astrometric results for compact extragalactic objects observed with the Very Long Baseline Array at radio frequencies of 24 and 43 GHz. Data were obtained from ten 24 hr observing sessions made over a five-year period. These observations were motivated by the need to extend the International Celestial Reference Frame (ICRF) to higher radio frequencies to enable improved deep space navigation after 2016 and to improve state-of-the-art astrometry. Source coordinates for 268 sources were estimated at 24 GHz and for 131 sources at 43 GHz. The median formal uncertainties of right ascension and declination at 24 GHz are 0.08 and 0.15 mas, respectively. Median formal uncertainties at 43 GHz are 0.20 and 0.35 mas, respectively. Weighted root-mean-square differences between the 24 and 43 GHz positions and astrometric positions based on simultaneous 2.3 and 8.4 GHz Very Long Baseline Interferometry observations, such as the ICRF, are less than about 0.3 mas in both coordinates. With observations over five years we have achieved a precision at 24 GHz approaching that of the ICRF but unaccounted systematic errors limit the overall accuracy of the catalogs.

Lanyi, G. E.; Jacobs, C. S.; Naudet, C. J.; Sovers, O. J.; Zhang, L. D. [Jet Propulsion Laboratory, Caltech, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States); Boboltz, D. A.; Fey, A. L. [U.S. Naval Observatory, 3450 Massachusetts Ave., NW, Washington, DC 20392-5420 (United States); Charlot, P. [Universite de Bordeaux, Observatoire Aquitain des Sciences de l'Univers, BP 89, 33271 Floirac Cedex (France); Fomalont, E. B. [National Radio Astronomy Observatory, 520 Edgemont Rd., Charlottesville, VA 22903 (United States); Geldzahler, B. J. [National Aeronautics and Space Administration, 300 E. St., SW, Washington, DC 20546 (United States); Gordon, D. [NVI Inc./NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Ma, C. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Romney, J. D. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States)

2010-05-15T23:59:59.000Z

242

Sub-GHz UWB Biomedical Communication Mark Stoopman and Wouter A. Serdijn  

E-Print Network [OSTI]

Sub-GHz UWB Biomedical Communication Mark Stoopman and Wouter A. Serdijn Biomedical Electronics and lower power consuming wireless link compared to other biomedical communications today. An operating to the conventional 50 interface. Index Terms--Sub-GHz, UWB, biomedical, wireless commu- nication, implantable

Serdijn, Wouter A.

243

Dependence of ion beam current on position of mobile plate tuner in multi-frequencies microwaves electron cyclotron resonance ion source  

SciTech Connect (OSTI)

We are constructing a tandem-type electron cyclotron resonance ion source (ECRIS). The first stage of this can supply 2.45 GHz and 11-13 GHz microwaves to plasma chamber individually and simultaneously. We optimize the beam current I{sub FC} by the mobile plate tuner. The I{sub FC} is affected by the position of the mobile plate tuner in the chamber as like a circular cavity resonator. We aim to clarify the relation between the I{sub FC} and the ion saturation current in the ECRIS against the position of the mobile plate tuner. We obtained the result that the variation of the plasma density contributes largely to the variation of the I{sub FC} when we change the position of the mobile plate tuner.

Kurisu, Yosuke; Kiriyama, Ryutaro; Takenaka, Tomoya; Nozaki, Dai; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2012-02-15T23:59:59.000Z

244

Synthesis of zinc oxide particles coated multiwalled carbon nanotubes: Dielectric properties, electromagnetic interference shielding and microwave absorption  

SciTech Connect (OSTI)

Graphical abstract: A resistor–capacitor model could well describe the relationships between the structure and the dielectric properties, electromagnetic interference shielding and microwave-absorption of the composites in the frequency range of 2–18 GHz. The resonant behavior associated with the multiwalled carbon nanotubes/zinc oxide (MWCNTs/ZnO) interface greatly broadens the absorption band. Highlights: ? ZnO-immobilized on multiwalled carbon nanotubes (MWCNTs/ZnO) have resonant behavior. ? A resistor–capacitor model describes the relation between the structure and properties. ? The composite with 40 wt% MWCNTs/ZnO has good electromagnetic interference shielding. ? Two different types of absorption peaks are found in the MWCNTs/ZnO composites. ? The existence of MWCNTs/ZnO interface broadens the absorption band. -- Abstract: Zinc oxide (ZnO) nanoparticles were coated on the surfaces of multiwalled carbon nanotubes (MWCNTs). High resolution transmission electron microscopy images show that the wurtzite ZnO immobilized on the MWCNTs is single-crystalline with a preferential [0 0 0 2] growth direction. A capacitor was generated by the interface of ZnO and MWCNTs, and a resistor–capacitor model could well describe the relationships between the structure and the dielectric properties, electromagnetic interference shielding and microwave-absorption of the composites in the frequency range of 2–18 GHz. The network built by ZnO-immobilized MWCNTs could contribute to the improvement of electrical properties. Resonant peaks associated with the capacitor formed by the interface were observed in the microwave absorption spectra, which suggest that reflection–loss peaks greatly broadens the absorption bandwidth.

Song, Wei-Li [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China)] [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Cao, Mao-Sheng, E-mail: caomaosheng@bit.edu.cn [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China)] [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Wen, Bo; Hou, Zhi-Ling; Cheng, Jin [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China)] [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Yuan, Jie, E-mail: yuanjie4000@sina.com [School of Information Engineering, Central University for Nationality, Beijing 100081 (China)] [School of Information Engineering, Central University for Nationality, Beijing 100081 (China)

2012-07-15T23:59:59.000Z

245

Modulated microwave microscopy and probes used therewith  

DOE Patents [OSTI]

A microwave microscope including a probe tip electrode vertically positionable over a sample and projecting downwardly from the end of a cantilever. A transmission line connecting the tip electrode to the electronic control system extends along the cantilever and is separated from a ground plane at the bottom of the cantilever by a dielectric layer. The probe tip may be vertically tapped near or at the sample surface at a low frequency and the microwave signal reflected from the tip/sample interaction is demodulated at the low frequency. Alternatively, a low-frequency electrical signal is also a non-linear electrical element associated with the probe tip to non-linearly interact with the applied microwave signal and the reflected non-linear microwave signal is detected at the low frequency. The non-linear element may be semiconductor junction formed near the apex of the probe tip or be an FET formed at the base of a semiconducting tip.

Lai, Keji; Kelly, Michael; Shen, Zhi-Xun

2012-09-11T23:59:59.000Z

246

Continuous, real time microwave plasma element sensor  

DOE Patents [OSTI]

Microwave-induced plasma is described for continuous, real time trace element monitoring under harsh and variable conditions. The sensor includes a source of high power microwave energy and a shorted waveguide made of a microwave conductive, refractory material communicating with the source of the microwave energy to generate a plasma. The high power waveguide is constructed to be robust in a hot, hostile environment. It includes an aperture for the passage of gases to be analyzed and a spectrometer is connected to receive light from the plasma. Provision is made for real time in situ calibration. The spectrometer disperses the light, which is then analyzed by a computer. The sensor is capable of making continuous, real time quantitative measurements of desired elements, such as the heavy metals lead and mercury. 3 figs.

Woskov, P.P.; Smatlak, D.L.; Cohn, D.R.; Wittle, J.K.; Titus, C.H.; Surma, J.E.

1995-12-26T23:59:59.000Z

247

Results of First Outdoor Comparison Between Absolute Cavity Pyrgeometer (ACP) and Infrared Integrating Sphere (IRIS) Radiometer at PMOD (Presentation)  

SciTech Connect (OSTI)

The ACP and IRIS are developed to establish a world reference for calibrating pyrgeometers with traceability to SI units. The two radiometers are unwindowed with negligible spectral dependence, and traceable to SI units through the temperature scale (ITS-90). The first outdoor comparison between the two designs was held from January 28 to February 8, 2013 at the Physikalisch-Metorologisches Observatorium Davos (PMOD). The difference between the irradiance measured by ACP and that of IRIS was within 1 W/m2. A difference of 5 W/m2 was observed between the irradiance measured by ACP&IRIS and that of the interim World Infrared Standard Group (WISG).

Reda, I.; Grobner, J.; Wacker, S.; Stoffel, T.

2013-03-01T23:59:59.000Z

248

Synthesis of macrocyclic polyaminocarboxylates and their use for preparing stable radiometal antibody immunoconjugates for therapy, spect and pet imaging  

DOE Patents [OSTI]

A simple method for the synthesis of 1,4,7,10-tetraazacyclododecane N,N'N",N'"-tetraacetic acid and 1,4,8,11-tetraazacyclotetradecane N,N',N",N'"-tetraacetic acid involves cyanomethylating 1,4,7,10-tetraazacyclododecane or 1,4,8,11-tetraazacyclotetradecane to form a tetranitrile and hydrolyzing the tetranitrile. These macrocyclic compounds are functionalized through one of the carboxylates and then conjugated to various biological molecules including monoclonal antibodies. The resulting conjugated molecules are labeled with radiometals for SPECT and PET imaging and for radiotherapy.

Mease, Ronnie C. (Fairfax, VA); Mausner, Leonard F. (Stony Brook, NY); Srivastava, Suresh C. (Setauket, NY)

1995-06-27T23:59:59.000Z

249

Synthesis of macrocyclic polyaminocarboxylates and their use for preparing stable radiometal antibody immunoconjugates for therapy, SPECT and PET imaging  

DOE Patents [OSTI]

A simple method for the synthesis of 1,4,7,10-tetraazacyclododecane N,N{prime}N{double_prime},N{prime}{double_prime}-tetraacetic acid and 1,4,8,11-tetraazacyclotetradecane N,N{prime},N{double_prime},N{prime}{double_prime}-tetraacetic acid involves cyanomethylating 1,4,7,10-tetraazacyclododecane or 1,4,8,11-tetraazacyclotetradecane to form a tetranitrile and hydrolyzing the tetranitrile. These macrocyclic compounds are functionalized through one of the carboxylates and then conjugated to various biological molecules including monoclonal antibodies. The resulting conjugated molecules are labeled with radiometals for SPECT and PET imaging and for radiotherapy. 4 figs.

Mease, R.C.; Mausner, L.F.; Srivastava, S.C.

1995-06-27T23:59:59.000Z

250

Quantum Illumination at the Microwave Wavelengths  

E-Print Network [OSTI]

Quantum illumination is a quantum-optical sensing technique in which an entangled source is exploited to improve the detection of a low-reflectivity object that is immersed in a bright thermal background. Here we describe and analyze a system for applying this technique at microwave frequencies, a more appropriate spectral region for target detection than the optical, due to the naturally-occurring bright thermal background in the microwave regime. We use an electro-optomechanical converter to entangle microwave signal and optical idler fields, with the former being sent to probe the target region and the latter being retained at the source. The microwave radiation collected from the target region is then phase conjugated and upconverted into an optical field that is combined with the retained idler in a joint-detection quantum measurement. The error probability of this microwave quantum-illumination system, or quantum radar, is shown to be superior to that of any classical microwave radar of equal transmitted energy.

Shabir Barzanjeh; Saikat Guha; Christian Weedbrook; David Vitali; Jeffrey H. Shapiro; Stefano Pirandola

2015-01-31T23:59:59.000Z

251

EXPANDED VERY LARGE ARRAY DETECTION OF 36.2 GHz CLASS I METHANOL MASERS IN SAGITTARIUS A  

E-Print Network [OSTI]

We report on the interferometric detection of 36.2 GHz Class I methanol emission with the new 27-40 GHz Ka-band receivers available on the Expanded Very Large Array (EVLA). The brightness temperatures of the interferometric ...

Sjouwerman, Loránt O.

252

Failure and Redemption of Multifilter Rotating Shadowband Radiometer (MFRSR)/Normal Incidence Multifilter Radiometer (NIMFR) Cloud Screening: Contrasting Algorithm Performance at Atmospheric Radiation Measurement (ARM) North Slope of Alaska (NSA) and Southern Great Plains (SGP) Sites  

SciTech Connect (OSTI)

Well-known cloud-screening algorithms, which are designed to remove cloud-contaminated aerosol optical depths (AOD) from AOD measurements, have shown great performance at many middle-to-low latitude sites around the world. However, they may occasionally fail under challenging observational conditions, such as when the sun is low (near the horizon) or when optically thin clouds with small spatial inhomogeneity occur. Such conditions have been observed quite frequently at the high-latitude Atmospheric Radiation Measurement (ARM) North Slope of Alaska (NSA) sites. A slightly modified cloud-screening version of the standard algorithm is proposed here with a focus on the ARM-supported Multifilter Rotating Shadowband Radiometer (MFRSR) and Normal Incidence Multifilter Radiometer (NIMFR) data. The modified version uses approximately the same techniques as the standard algorithm, but it additionally examines the magnitude of the slant-path line of sight transmittance and eliminates points when the observed magnitude is below a specified threshold. Substantial improvement of the multi-year (1999-2012) aerosol product (AOD and its Angstrom exponent) is shown for the NSA sites when the modified version is applied. Moreover, this version reproduces the AOD product at the ARM Southern Great Plains (SGP) site, which was originally generated by the standard cloud-screening algorithms. The proposed minor modification is easy to implement and its application to existing and future cloud-screening algorithms can be particularly beneficial for challenging observational conditions.

Kassianov, Evgueni I.; Flynn, Connor J.; Koontz, Annette S.; Sivaraman, Chitra; Barnard, James C.

2013-09-11T23:59:59.000Z

253

Neural networks and separation of Cosmic Microwave Background and astrophysical signals in sky maps  

E-Print Network [OSTI]

The Independent Component Analysis (ICA) algorithm is implemented as a neural network for separating signals of different origin in astrophysical sky maps. Due to its self-organizing capability, it works without prior assumptions on the signals, neither on their frequency scaling, nor on the signal maps themselves; instead, it learns directly from the input data how to separate the physical components, making use of their statistical independence. To test the capabilities of this approach, we apply the ICA algorithm on sky patches, taken from simulations and observations, at the microwave frequencies, that are going to be deeply explored in a few years on the whole sky, by the Microwave Anisotropy Probe (MAP) and by the {\\sc Planck} Surveyor Satellite. The maps are at the frequencies of the Low Frequency Instrument (LFI) aboard the {\\sc Planck} satellite (30, 44, 70 and 100 GHz), and contain simulated astrophysical radio sources, Cosmic Microwave Background (CMB) radiation, and Galactic diffuse emissions from thermal dust and synchrotron. We show that the ICA algorithm is able to recover each signal, with precision going from 10% for the Galactic components to percent for CMB; radio sources are almost completely recovered down to a flux limit corresponding to $0.7\\sigma_{CMB}$, where $\\sigma_{CMB}$ is the rms level of CMB fluctuations. The signal recovering possesses equal quality on all the scales larger then the pixel size. In addition, we show that the frequency scalings of the input signals can be partially inferred from the ICA outputs, at the percent precision for the dominant components, radio sources and CMB.

C. Baccigalupi; L. Bedini; C. Burigana; G. De Zotti; A. Farusi; D. Maino; M. Maris; F. Perrotta; E. Salerno; L. Toffolatti; A. Tonazzini

2000-06-21T23:59:59.000Z

254

A Wideband 77GHz, 17.5dBm Power Amplifier in Silicon Abbas Komijani and Ali Hajimiri  

E-Print Network [OSTI]

such as short-range communication (e.g., 60GHz band) and automotive radar (e.g., 77GHz band) [1 integrated 77GHz power amplifier in silicon. II. FREQUENCY BAND In a collision-avoidance automotive radar copper layers and a thick 4µm aluminum layer as top metal for low-loss interconnects. The breakdown

Hajimiri, Ali

255

Results of Second Outdoor Comparison Between Absolute Cavity Pyrgeometer (ACP) and Infrared Integrating Sphere (IRIS) Radiometer at PMOD (Presentation)  

SciTech Connect (OSTI)

The Absolute Cavity Pyrgeometer (ACP) and InfraRed Integrating Sphere radiometer (IRIS) are developed to establish a world reference for calibrating pyrgeometers with traceability to SI units. The two radiometers are un-windowed with negligible spectral dependence, and traceable to SI units through the temperature scale (ITS-90). The second outdoor comparison between the two designs was held from September 30 to October 11, 2013 at the Physikalisch-Metorologisches Observatorium Davos (PMOD). The difference between the irradiance measured by ACP and that of the IRIS was within 1 W/m2 (3 IRISs: PMOD + Australia + Germany). From the first and second comparisons, a difference of 4-6 W/m2 was observed between the irradiance measured by ACP&IRIS and that of the interim World Infrared Standard Group (WISG). This presentation includes results from the first and second comparison in an effort to establish the world reference for pyrgeometer calibrations, a key deliverable for the World Meteorological Organization (WMO), and the DOE-ASR.

Reda, I.; Grobner, J.; Wacker, S.

2014-01-01T23:59:59.000Z

256

Progress toward a MEMS fabricated 100 GHz oscillator.  

SciTech Connect (OSTI)

This report summarizes an LDRD effort which looked at the feasibility of building a MEMS (Micro-Electro-Mechanical Systems) fabricated 100 GHz micro vacuum tube. PIC Simulations proved to be a very useful tool in investigating various device designs. Scaling parameters were identified. This in turn allowed predictions of oscillator growth based on beam parameters, cavity geometry, and cavity loading. The electron beam source was identified as a critical element of the design. FEA's (Field Emission Arrays) were purchased to be built into the micro device. Laboratory testing of the FEA's was also performed which pointed out care and handling issues along with maximum current capabilities. Progress was made toward MEMS fabrication of the device. Techniques were developed and successfully employed to build up several of the subassemblies of the device. However, the lower wall fabrication proved to be difficult and a successful build was not completed. Alternative approaches to building this structure have been identified. Although these alternatives look like good solutions for building the device, it was not possible to complete a redesign and build during the timeframe of this effort.

Loubriel, Guillermo Manuel; Lemp, Thomas; Weyn, Mark L.; Coleman, Phillip Dale; Rowley, James E. (SAIC, Albuquerque, NM)

2006-02-01T23:59:59.000Z

257

Global estimation of precipitation using opaque microwave bands  

E-Print Network [OSTI]

This thesis describes the use of opaque microwave bands for global estimation of precipitation rate. An algorithm was developed for estimating instantaneous precipitation rate for the Advanced Microwave Sounding Unit (AMSU) ...

Chen, Frederick Wey-Min, 1975-

2004-01-01T23:59:59.000Z

258

Microwave vs. Electric Kettle: Which Appliance Is in Hot Water...  

Energy Savers [EERE]

Microwave vs. Electric Kettle: Which Appliance Is in Hot Water in EnergyFaceoff Round 4? Microwave vs. Electric Kettle: Which Appliance Is in Hot Water in EnergyFaceoff Round 4?...

259

Development of a microwave ion and plasma source immersed in a multicusp electron-cyclotron-resonant magnetic field  

SciTech Connect (OSTI)

Experimental development and test of an electrodeless microwave (2.45 GHz)-generated plasma and ion source in a discharge pressure range of 6 x 10 /sup -4/-5 x 10/sup -1/ Torr and relatively low power (80-350 W CW) are presented. Also presented is a semi-empirical model applicable to low-pressure microwave discharges with no static magnetic field. Initial experiments studied the properties of variable diffusion length (0.43-1.22 cm) disk-shaped discharges generated and maintained in a cylindrical microwave resonant-cavity applicator for argon and oxygen gases without a static magnetic field. These discharges were characterized by measuring plasma densities and electron temperatures using a Langmuir double probe for different experimental conditions. The measured plasma densities and electron temperatures ranged for 8 x 10/sup 10/ to 5 x 10 /sup 11/ cm/sup -3/ and 2 x 10/sup 4/ to 8 x 10/sup 4/ /sup 0/K, respectively. The ion temperature was less than 500 /sup 0/K. Ion beams were extracted from these discharges using single and double grids. Argon ion-beam currents densities were measured to be 3.0 mA/cm/sup 2/ for the single grid and 5.8 mA/cm/sup 2/ for the double grids with a maximum extraction voltage of 1.7 kV. This applicator was then retrofitted with magnets to study the effect of a multicusp static magnetic field. Using this concept, a new cylindrical microwave applicator was designed and tested.

Dahimene, M.

1987-01-01T23:59:59.000Z

260

Microwave off-gas treatment apparatus and process  

DOE Patents [OSTI]

The invention discloses a microwave off-gas system in which microwave energy is used to treat gaseous waste. A treatment chamber is used to remediate off-gases from an emission source by passing the off-gases through a susceptor matrix, the matrix being exposed to microwave radiation. The microwave radiation and elevated temperatures within the combustion chamber provide for significant reductions in the qualitative and quantitative emissions of the gas waste stream.

Schulz, Rebecca L. (Aiken, SC); Clark, David E. (Gainesville, FL); Wicks, George G. (North Aiken, SC)

2003-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

The Strongest 100 Point Radio Sources in the LMC at 1.4 GHz  

E-Print Network [OSTI]

We present the 100 strongest 1.4 GHz point sources from a new mosaic image in the direction of the Large Magellanic Cloud (LMC). The observations making up the mosaic were made over a ten year period and were combined with Parkes single dish data at 1.4 GHz to complete the image for short spacing. An initial list of co-identifications within 10" at 0.843, 4.8 and 8.6 GHz consisted of 2682 sources. Elimination of extended objects and artifact noise allowed the creation of a refined list containing 1988 point sources. Most of these are presumed to be background objects seen through the LMC; a small portion may represent compact H II regions, young SNRs and radio planetary nebulae. We find an average spectral index of -0.53 and present a 1.4 GHz image showing source location in the direction of the LMC.

Payne, J L; Filipovic, M D; Crawford, E J; De Horta, A Y

2009-01-01T23:59:59.000Z

262

Calculation of wakefields in a 17 GHz beam-driven photonic band-gap accelerator structure  

E-Print Network [OSTI]

We present the theoretical analysis and computer simulation of the wakefields in a 17 GHz photonic band-gap (PBG) structure for accelerator applications. Using the commercial code CST Particle Studio, the fundamental ...

Hu, Min

263

Microwave accelerator E-beam pumped laser  

DOE Patents [OSTI]

A device and method for pumping gaseous lasers by means of a microwave accelerator. The microwave accelerator produces a relativistic electron beam which is applied along the longitudinal axis of the laser through an electron beam window. The incident points of the electron beam on the electron beam window are varied by deflection coils to enhance the cooling characteristics of the foil. A thyratron is used to reliably modulate the microwave accelerator to produce electron beam pulses which excite the laser medium to produce laser pulse repetition frequencies not previously obtainable. An aerodynamic window is also disclosed which eliminates foil heating problems, as well as a magnetic bottle for reducing laser cavity length and pressures while maintaining efficient energy deposition.

Brau, Charles A. (Los Alamos, NM); Stein, William E. (Los Alamos, NM); Rockwood, Stephen D. (Los Alamos, NM)

1980-01-01T23:59:59.000Z

264

Integrated microwave and millimeter-wave phased-array designs in silicon technologies  

E-Print Network [OSTI]

for 2-GHz WCDMA direct-conversion transceiver,” IEEE J.for 2-GHz WCDMA direct-conversion transceiver,” IEEE J.

Koh, Kwang-Jin

2008-01-01T23:59:59.000Z

265

Apparatus for microwave heat treatment of manufactured components  

DOE Patents [OSTI]

An apparatus for heat treating manufactured components using microwave energy and microwave susceptor material. Heat treating medium such as eutectic salts may be employed. A fluidized bed introduces process gases which may include carburizing or nitriding gases. The process may be operated in a batch mode or continuous process mode. A microwave heating probe may be used to restart a frozen eutectic salt bath.

Babcock & Wilcox Technical Services Y-12, LLC (Oak Ridge, TN)

2008-04-15T23:59:59.000Z

266

Methods for microwave heat treatment of manufactured components  

DOE Patents [OSTI]

An apparatus for heat treating manufactured components using microwave energy and microwave susceptor material. Heat treating medium such as eutectic salts may be employed. A fluidized bed introduces process gases which may include carburizing or nitriding gases. The process may be operated in a batch mode or continuous process mode. A microwave heating probe may be used to restart a frozen eutectic salt bath.

Ripley, Edward B. (Knoxville, TN)

2010-08-03T23:59:59.000Z

267

Microwave joining of SiC  

SciTech Connect (OSTI)

The purpose of this work is to optimize the properties of SiC-SiC joints made using microwave energy. The current focus is on identification of the most effective joining methods for scale-up to large tube assemblies, including joining using SiC produced in situ from chemical precursors. During FY 1996, a new microwave applicator was designed, fabricated and tested that provides the capability for vacuum baking of the specimens and insulation and for processing under inert environment. This applicator was used to join continuous fiber-reinforced (CFCC) SiC/SiC composites using a polymer precursor to form a SiC interlayer in situ.

Silberglitt, R.; Ahmad, I.; Tian, Y.L. [FM Technologies, Inc., Fairfax, VA (United States)] [and others

1997-04-01T23:59:59.000Z

268

International Conference on Microwave and High Frequency Heating Nottingham, UK, September 2013 Scaling Up Reactors for Microwave-Assisted  

E-Print Network [OSTI]

2013 316 Scaling Up Reactors for Microwave-Assisted Chemistry via ANN Optimization Andrew O. Holmesa by demonstrating that a particular microwave reactor can be designed with the help of computer optimization optimization technique to a microwave reactor. This technique is used here to optimize the geometry of a system

Yakovlev, Vadim

269

Optimized ECR plasma apparatus with varied microwave window thickness  

DOE Patents [OSTI]

The present invention describes a technique to control the radial profile of microwave power in an ECR plasma discharge. In order to provide for a uniform plasma density to a specimen, uniform energy absorption by the plasma is desired. By controlling the radial profile of the microwave power transmitted through the microwave window of a reactor, the profile of the transmitted energy to the plasma can be controlled in order to have uniform energy absorption by the plasma. An advantage of controlling the profile using the window transmission characteristics is that variations to the radial profile of microwave power can be made without changing the microwave coupler or reactor design. 9 figs.

Berry, L.A.

1995-11-14T23:59:59.000Z

270

Farinon microwave end of life cycle  

SciTech Connect (OSTI)

This engineering report evaluates alternatives for the replacement of the Farinon microwave radio system. The system is beyond its expected life cycle and has decreasing maintainability. Principal applications supported by the Farinon system are two electrical utility monitor and control systems, the Integrated Transfer Trip System (ITTS), and the Supervisory Control and Data Acquisition (SCADA) system.

Poe, R.C.

1996-06-24T23:59:59.000Z

271

MICROWAVE PHOTOREACTOR FOR PHOTOCHEMICAL SYNTHESIS Milan Hajeka  

E-Print Network [OSTI]

and a IR pyrometer or fiber optic thermometer (Nortech), according to Figure 1. A round part (200 mm of the reaction mixture is monitored by the IR pyrometer or fiber optic thermometer. The MW photoreactor has been scientific discipline and microwave (MW) irradiation represents a new way to increase the efficiency of many

Cirkva, Vladimir

272

Environmental assessment: South microwave communication facilities  

SciTech Connect (OSTI)

Western Area Power Administration (Western) is proposing to construct, operate, and maintain eight microwave repeater stations in southwestern Colorado, southeastern Utah, and northern Arizona, in order to meet the minimum fade criteria established by the Western Systems Coordinating Council (WSCC) for the operation and protection of electric power systems. The proposed microwave facilities would increase the reliability of communication. This environmental assessment (EA) describes the existing environmental conditions and the impacts from construction of the eight microwave communication facilities. The EA was prepared in compliance with the National Environmental Policy Act of 1969, the Council on Environmental Quality Regulations (40 CFR 1500-1508), and the Department of Energy Guidelines (52 FR 47662, December 15, 1987). The proposed project would consist of constructing eight microwave facilities, each of which would include a self-supported lattice tower, an equipment building, a propane tank, distribution lines to provide electric power to the sites, and access roads to the sites. The facilities would be constructed in San Miguel and Montezuma Counties in Colorado, San Juan County, Utah, and Navajo, Apache, Coconino, and Yavapai Counties in Arizona. 20 refs., 2 figs., 2 tabs.

Not Available

1989-06-01T23:59:59.000Z

273

Planar controlled zone microwave plasma system  

DOE Patents [OSTI]

An apparatus and method for initiating a process gas plasma. A conductive plate having a plurality of conductive fingers is positioned in a microwave applicator. An arc forms between the conductive fingers to initiate the formation of a plasma. A transport mechanism may convey process materials through the plasma. A spray port may be provided to expel processed materials.

Ripley, Edward B. (Knoxville, TN); Seals, Roland D. (Oak Ridge, TN); Morrell, Jonathan S. (Knoxvlle, TN)

2011-10-04T23:59:59.000Z

274

High-power microwave transmission systems for electron-cyclotron-resonance plasma heating  

SciTech Connect (OSTI)

This progress report is for the sixth year of a grant from the US Department of Energy for the design, development, and fabrication of ECRH transmission and mode conversion systems to transport microwave power from a gyrotron to a magnetically confined plasma. The design and low-power testing of new and improved components for such systems and development of underlying theory is the focus of this project. Devising and improving component testing and diagnostic techniques is also an important part of this effort. The development of possible designs for sections of gyrotrons themselves, such as tapers or Vlasov-type launchers, in support of the Varian gyrotron development program is also considered when appropriate. We also provide support to other groups working on ECR heating of magnetically confined plasmas such as the groups at General Atomics, the University of Texas at Austin, and Lawrence Livermore National Laboratory. During the last year, we designed and had fabricated a two-dimensional Vlasov antenna system for a 110 GHz TE{sub 15,2} mode gyrotron for possible use at General Atomics. The system included the launcher section, a visor, main reflector, and focusing reflector. Programs to generate the tool-path profiles to cut the General Atomics'' Vlasov components on a milling machine were developed. We have also developed state-of-the art theory and programs for three-dimensional whispering-gallery-mode Vlasov antenna systems. A design for a 110 GHz TE{sub 01}-TE{sub 15,2} mode converter system for cold testing WGM Vlasov antenna systems was developed and is currently being fabricated also.

Vernon, R.J.

1991-08-01T23:59:59.000Z

275

Distinctive plume formation in atmospheric Ar and He plasmas in microwave frequency band and suitability for biomedical applications  

SciTech Connect (OSTI)

Distinctive discharge formation in atmospheric Ar and He plasmas was observed in the microwave frequency band using coaxial transmission line resonators. Ar plasmas formed a plasma plume whereas He formed only confined plasmas. As the frequency increased from 0.9 GHz to 2.45 GHz, the Ar plasma exhibited contraction and filamentation, and the He plasmas were constricted. Various powers and gas flow rates were applied to identify the effect of the electric field and gas flow rate on plasma plume formation. The He plasmas were more strongly affected by the electric field than the Ar plasmas. The breakdown and sustain powers yielded opposite results from those for low-frequency plasmas (?kHz). The phenomena could be explained by a change in the dominant ionization process with increasing frequency. Penning ionization and the contribution of secondary electrons in sheath region reduced as the frequency increased, leading to less efficient ionization of He because its ionization and excitation energies are higher than those of Ar. The emission spectra showed an increase in the NO and N{sub 2} second positive band in both the Ar and He plasmas with increasing frequency whereas the hydroxyl radical and atomic O peaks did not increase with increasing frequency but were highest at particular frequencies. Further, the frequency effect of properties such as the plasma impedance, electron density, and device efficiency were presented. The study is expected to be helpful for determining the optimal conditions of plasma systems for biomedical applications.

Lee, H. Wk.; Kang, S. K.; Won, I. H.; Kim, H. Y.; Kwon, H. C.; Sim, J. Y.; Lee, J. K. [Department of Electrical Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)] [Department of Electrical Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

2013-12-15T23:59:59.000Z

276

Investigation into the feasibility of a linear microwave oscillator design  

E-Print Network [OSTI]

. Phase Response of the Final Overall Filter From 9. 5 GHz to 10. 5 GHz . 7. 1. The Tee Coupler 7. 2. Microstrip-Stripline Transition to Construct a Broadside Coupler 7. 3. The Lange Coupler 7. 4. A Microstrip Directional Coupler Modified with a...

McCoy, Jody Arnold

1986-01-01T23:59:59.000Z

277

Apparatus and method for microwave processing of materials  

DOE Patents [OSTI]

Disclosed is a variable frequency microwave heating apparatus designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity for testing or other selected applications. The variable frequency heating apparatus is used in the method of the present invention to monitor the resonant processing frequency within the furnace cavity depending upon the material, including the state thereof, from which the workpiece is fabricated. The variable frequency microwave heating apparatus includes a microwave signal generator and a high-power microwave amplifier or a microwave voltage-controlled oscillator. A power supply is provided for operation of the high-power microwave oscillator or microwave amplifier. A directional coupler is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity. A first power meter is provided for measuring the power delivered to the microwave furnace. A second power meter detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load. 10 figs.

Johnson, A.C.; Lauf, R.J.; Bible, D.W.; Markunas, R.J.

1996-05-28T23:59:59.000Z

278

Apparatus and method for microwave processing of materials  

DOE Patents [OSTI]

A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity (34) for testing or other selected applications. The variable frequency heating apparatus (10) is used in the method of the present invention to monitor the resonant processing frequency within the furnace cavity (34) depending upon the material, including the state thereof, from which the workpiece (36) is fabricated. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a microwave voltage-controlled oscillator (14). A power supply (22) is provided for operation of the high-power microwave oscillator (14) or microwave amplifier (20). A directional coupler (24) is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity (34). A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

Johnson, Arvid C. (Lake in the Hills, IL); Lauf, Robert J. (Oak Ridge, TN); Bible, Don W. (Clinton, TN); Markunas, Robert J. (Chapel Hill, NC)

1996-01-01T23:59:59.000Z

279

Fabrication of an optically driven 10 GHz ring resonator on a gallium arsenide substrate  

E-Print Network [OSTI]

/D converters, optical detectors, dc to rf converters, and millimeter-wave or microwave generators. Photoconductors can be easily integrated with microelectronic devices as well as microwave circuits. Recently, an optically excited photoconductive switch... is the barrier height and y, is the electron affinity for the semiconductor. Current flow at a metal-semiconductor barrier is due mainly to majority carriers. The four major current transport methods are thermionic emission over the barrier, quantum...

McGregor, Douglas Scott

1989-01-01T23:59:59.000Z

280

Diagnostics of fast formation of distributed plasma discharges using X-band microwaves  

SciTech Connect (OSTI)

We present measurements of high power (25.7?kW), pulsed (800?ns), X-band (9.382?GHz) microwave breakdown plasmas, including reflected power measurements, mixer reflected amplitude and phase measurements, optical emission spectroscopy (OES) measurements, and an analysis that estimates the average electron density and electron temperature. In addition, a six-region, 1-D model was used to determine plasma parameters and compare with the experimental results. The experimental results show that using a 43?Hz repetition rate with an 800?ns pulse, fast (<300?ns) breakdown occurs in neon measured between 50?Torr and 250?Torr, producing plasma that lasts for over 7??s. It also leads to large microwave reflections (70%) and an on-axis transmission attenuation of ?15?dB. Moreover, a comparison between a 1-D model and mixer measurements shows that at 100?Torr, the neon plasma electron density peaked at 2?×?10{sup 12}?cm{sup ?3}, and the electron temperature peaked at 2.5?eV assuming a Maxwellian distribution. The addition of 2% Ar in Ne reduced the breakdown time and allowed OES measurements to determine the effective electron temperature. OES measurements of mixed (Ne/Ar: 98/2) argon line ratios (420.1?nm/419.8?nm) were used to determine the average effective electron temperature T{sub e(eff)}?=?1.2?eV, averaged over the entire 7?s plasma lifetime. They indicate that the electron energy distribution was not Maxwellian but, instead, tended towards a Druyvesteyn character.

Xiang, X., E-mail: xxiang3@wisc.edu; Kupczyk, B.; Booske, J.; Scharer, J. [Department of Electrical and Computer Engineering, University of Wisconsin, Madison, Wisconsin 53705 (United States)

2014-02-14T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Electromagnetic properties of microwave sintered ferromagnetic-ferroelectric composites for application in low temperature co-fired ceramic devices  

SciTech Connect (OSTI)

In this paper, microwave sintering (MS) technology has been applied in the preparation of ferromagnetic-ferroelectric composites. Several kinds of (Ni{sub 0.3}Zn{sub 0.6}Cu{sub 0.1})Fe{sub 2}O{sub 4} (NiCuZn) ferrite with different contents of BaTiO{sub 3}(BT) have been fabricated by MS technology. We found that the sintering time and temperature were significantly reduced from 22 h and 1100 deg. C for the conventional sintering (CS) process to 2 h and 840 deg. C for MS process, respectively. Experiments show that MS treated NiCuZn-BT composites possess both excellent ferromagnetic and ferroelectric properties. For the composites of NiCuZn added with 15% BaTiO{sub 3}, the real part of permittivity is larger than 50 below 20 MHz and the real part of dielectric constant is larger than 18 below 1 GHz. Our results indicate that the microwave sintering method is a potential important technique in LTCC technology.

Yang Qinghui; Zhang Huaiwu; Wen Qiye; Liu Yingli [State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chendu 610054, Sichuan (China)

2011-04-01T23:59:59.000Z

282

Nonlinear multiferroic phase shifters for microwave frequencies  

SciTech Connect (OSTI)

A nonlinear microwave phase shifter based on a planar multiferroic composite has been studied. The multiferroic structure is fabricated in the form of a bilayer consisting of yttrium iron garnet and barium strontium titanate. The principle of operation of the device is based on the linear and nonlinear control of the phase shift of the hybrid spin-electromagnetic waves propagating in the bilayer. The linear control is realized with magnetic and electric fields. The nonlinear control is provided by the input power of microwave signal. The device showed a nonlinear phase shift up to 250°, electric field induced phase shift up to 330°, and magnetic field induced phase shift of more than 180°.

Ustinov, Alexey B.; Kalinikos, Boris A. [Department of Physical Electronics and Technology, St. Petersburg Electrotechnical University, St. Petersburg 197376 (Russian Federation); Srinivasan, G. [Department of Physics, Oakland University, Rochester, Michigan 48309 (United States)

2014-02-03T23:59:59.000Z

283

Hybrid Microwave-Cavity Heat Engine  

E-Print Network [OSTI]

We propose and analyze the use of hybrid microwave cavities as quantum heat engines. A possible realization consists of two macroscopically separated quantum dot conductors coupled capacitively to the fundamental mode of a microwave cavity. We demonstrate that an electrical current can be induced in one conductor through cavity-mediated processes by heating up the other conductor. The heat engine can reach Carnot efficiency with optimal conversion of heat to work. When the system delivers the maximum power, the efficiency can be a large fraction of the Carnot efficiency. The heat engine functions even with moderate electronic relaxation and dephasing in the quantum dots. We provide detailed estimates for the electrical current and output power using realistic parameters.

Christian Bergenfeldt; Peter Samuelsson; Björn Sothmann; Christian Flindt; Markus Büttiker

2014-02-27T23:59:59.000Z

284

Rare Earth ? N = N* fs fGHZ fp nH fl  

E-Print Network [OSTI]

Rare Earth ? #12;N to date N = N* fs fGHZ fp nH fl ·N* = 4 x 1011 ·fs = 0.2 ·fGHZ = 0.1 ·fp = 0.8 ·nH = 2 ·fl = 1.0 N = 1.3 x 1010 #12;The Goldilocks Effect Earth is "Just Right" Yes, life on Earth has adapted to Earth, but ... Earth has just the right mass to be ·Tectonically-active ·Retain

Walter, Frederick M.

285

Cosmic Microwave Background: Past, Future, and Present  

E-Print Network [OSTI]

I explain the origin and evolution of anisotropies in the Cosmic Microwave Background (CMB) and argue that upcoming experiments will measure cosmological and fundamental parameters very accurately. Most of the paper focuses on present data, which strongly suggest that the universe is flat. Several arguments are given to prove that present data sets are not contaminated by systematics. New techniques to compare different experiments visually are introduced. These are illustrated for two years of the MSAM and Python experiments.

Scott Dodelson

1999-12-22T23:59:59.000Z

286

ARM - Measurement - Microwave narrowband brightness temperature  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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287

Quantum and Wave Dynamical Chaos in Superconducting Microwave Billiards  

E-Print Network [OSTI]

Experiments with superconducting microwave cavities have been performed in our laboratory for more than two decades. The purpose of the present article is to recapitulate some of the highlights achieved. We briefly review (i) results obtained with flat, cylindrical microwave resonators, so-called microwave billiards, concerning the universal fluctuation properties of the eigenvalues of classically chaotic systems with no, a threefold and a broken symmetry; (ii) summarize our findings concerning the wave-dynamical chaos in three-dimensional microwave cavities; (iii) present a new approach for the understanding of the phenomenon of dynamical tunneling which was developed on the basis of experiments that were performed recently with unprecedented precision, and finally, (iv) give an insight into an ongoing project, where we investigate universal properties of (artificial) graphene with superconducting microwave photonic crystals that are enclosed in a microwave resonator, i.e., so-called Dirac billiards.

B. Dietz; A. Richter

2015-04-16T23:59:59.000Z

288

Quantum and Wave Dynamical Chaos in Superconducting Microwave Billiards  

E-Print Network [OSTI]

Experiments with superconducting microwave cavities have been performed in our laboratory for more than two decades. The purpose of the present article is to recapitulate some of the highlights achieved. We briefly review (i) results obtained with flat, cylindrical microwave resonators, so-called microwave billiards, concerning the universal fluctuation properties of the eigenvalues of classically chaotic systems with no, a threefold and a broken symmetry; (ii) summarize our findings concerning the wave-dynamical chaos in three-dimensional microwave cavities; (iii) present a new approach for the understanding of the phenomenon of dynamical tunneling which was developed on the basis of experiments that were performed recently with unprecedented precision, and finally, (iv) give an insight into an ongoing project, where we investigate universal properties of (artificial) graphene with superconducting microwave photonic crystals that are enclosed in a microwave resonator, i.e., so-called Dirac billiards.

B. Dietz; A. Richter

2015-04-17T23:59:59.000Z

289

Issues in microwave power systems engineering  

SciTech Connect (OSTI)

The key issues in microwave power system engineering are beam safety, frequency allocation, and affordability. These major issues are presented, discussed, and suggestions for resolving them are offered. The issue of beam safety can be captured in the phrase ``Fear of Frying.`` Can a properly engineered beamed power safety system allay the public perception of microwave radiation dangers? Openness, visibility, and education may be keys to resolving this issue satisfactorily. ``Not in my Spectrum`` is a phrase that is frequently encountered in connection with the issue of where can the microwave power beam frequency be located. International cooperation may provide a part of the solution to this issue. ``Wow, that much?`` is a phrase encountered when dealing with the issue of economic affordability of large beamed power systems. A phased engineering approach for multiple uses even during construction is presented to aid in garnering revenue during the system build phase. Also, dual mode dc-RF converters are encouraged for bi-directional power flow utility and economies of scale in production.

Dickinson, R.M. [California Inst. of Tech., Pasadena, CA (United States). Jet Propulsion Lab.

1996-12-31T23:59:59.000Z

290

Joining of thermoplastic substrates by microwaves  

DOE Patents [OSTI]

A method for joining two or more items having surfaces of thermoplastic material includes the steps of depositing an electrically-conductive material upon the thermoplastic surface of at least one of the items, and then placing the other of the two items adjacent the one item so that the deposited material is in intimate contact with the surfaces of both the one and the other items. The deposited material and the thermoplastic surfaces contacted thereby are then exposed to microwave radiation so that the thermoplastic surfaces in contact with the deposited material melt, and then pressure is applied to the two items so that the melted thermoplastic surfaces fuse to one another. Upon discontinuance of the exposure to the microwave energy, and after permitting the thermoplastic surfaces to cool from the melted condition, the two items are joined together by the fused thermoplastic surfaces. The deposited material has a thickness which is preferably no greater than a skin depth, .delta..sub.s, which is related to the frequency of the microwave radiation and characteristics of the deposited material in accordance with an equation.

Paulauskas, Felix L. (Oak Ridge, TN); Meek, Thomas T. (Knoxville, TN)

1997-01-01T23:59:59.000Z

291

A 58.4mW Solid-State Power Amplifier at 220 GHz using InP HBTs Abstract --A 220 GHz solid state power amplifier MMIC is  

E-Print Network [OSTI]

A 58.4mW Solid-State Power Amplifier at 220 GHz using InP HBTs Abstract -- A 220 GHz solid state, Solid State Power Amplifier (SSPA). I. INTRODUCTION Future high resolution imaging systems and high bandwidth communications systems will benefit from the continued development of solid-state power amplifiers

Rodwell, Mark J. W.

292

E-Print Network 3.0 - argon microwave plasma Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Vortex Stabilization of Microwave PlasmaMicrowave... Plasma a b 2 1 3 5 4 6 7 1- quartz tube of microwave plasma torch; 2 -original tangential gas feeder; 3... Numerical Simulation...

293

Microwave-Assisted Ignition for Improved Internal Combustion Engine Efficiency  

E-Print Network [OSTI]

J. B. (1988) Internal Combustion Engine Fundamentals.novel microwave internal combustion engine ignition source,in the Internal Combustion Engine." SAE Technical Paper

DeFilippo, Anthony Cesar

2013-01-01T23:59:59.000Z

294

Hydrogen recovery from extraterrestrial materials using microwave energy  

SciTech Connect (OSTI)

The feasibility of recovering hydrogen from extraterrestrial materials (lunar and Martian soils, asteroids) using microwave energy is presented. Reasons for harvesting and origins and locations of hydrogen are reviewed. Problems of hydrogen recovery are discussed in terms of hydrogen release characteristics and microwave coupling to insulating materials. From results of studies of hydrogen diffusivities (oxides, glasses) and tritium release (oxides) as well as studies of microwave coupling to ilmenite, alkali basalt and ceramic oxides it is concluded that using microwave energy in hydrogen recovery from extraterrestrial materials could be the basis for a workable process.

Tucker, D.S.; Vaniman, D.T.; Anderson, J.L.; Clinard, F.W. Jr.; Feber, R.C. Jr.; Frost, H.M.; Meek, T.T.; Wallace, T.C.

1984-01-01T23:59:59.000Z

295

Method and apparatus for thickness measurement using microwaves  

DOE Patents [OSTI]

The method for measuring the thickness of a material which transmits a detectable amount of microwave radiation includes irradiating the material with coherent microwave radiation tuned over a frequency range. Reflected microwave radiation is detected, the reflected radiation having maxima and minima over the frequency range as a result of coherent interference of microwaves reflected from reflecting surfaces of the material. The thickness of the material is determined from the period of the maxima and minima along with knowledge of the index of refraction of the material.

Woskov, Paul (Bedford, MA) [Bedford, MA; Lamar, David A. (West Richland, WA) [West Richland, WA

2001-01-01T23:59:59.000Z

296

advanced microwave circuits: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

transition of photons in circuit quantum electrodynamics electrodynamics QED , superconduct- ing qubits are coupled with microwave photons in a trans- mission line and a...

297

Microwave-Assisted Ignition for Improved Internal Combustion Engine Efficiency  

E-Print Network [OSTI]

of Emissions from HCCI Engines using a Consistent 3-Zoneof Microwave Plasma Combustion Engine (Part I: Concept ofPlasma Combustion Engine (Part II: Engine Performance of

DeFilippo, Anthony Cesar

2013-01-01T23:59:59.000Z

298

Assessment of the Performance of the Chilbolton 3-GHz Advanced Meteorological Radar for Cloud-Top-Height Retrieval  

E-Print Network [OSTI]

. The potential for this radar to make useful measurements of low-altitude liquid water cloud structure is investigated. To assess the cloud-height assignment capabilities of the 3-GHz radar, low-level cloudAssessment of the Performance of the Chilbolton 3-GHz Advanced Meteorological Radar for Cloud

299

Analysis of cloud layer structure in Shouxian, China using RS92 radiosonde aided by 95 GHz cloud radar  

E-Print Network [OSTI]

Analysis of cloud layer structure in Shouxian, China using RS92 radiosonde aided by 95 GHz cloud to analyze cloud vertical structure over this area by taking advantage of the first direct measurements of cloud vertical layers from the 95 GHz radar. Singlelayer, twolayer, and threelayer clouds account for 28

Li, Zhanqing

300

High-Frequency (140-GHz) Time Domain EPR and ENDOR Spectroscopy: The Tyrosyl Radical-Diiron Cofactor in  

E-Print Network [OSTI]

High-Frequency (140-GHz) Time Domain EPR and ENDOR Spectroscopy: The Tyrosyl Radical EPR and ENDOR have been employed to characterize the tyrosyl radical (Y·)-diiron cofactor in the Y2 of 140-GHz time domain EPR and ENDOR to examine this system and demonstrates the capabilities

Griffin, Robert G.

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Low temperature charge transport and microwave absorption of carbon coated iron nanoparticles–polymer composite films  

SciTech Connect (OSTI)

Highlights: ? Carbon coated Fe nanoparticle–PVC composite films were prepared by solution casting method. ? A low electrical percolation threshold of 2.2 was achieved. ? The low temperature electrical conductivity follows variable range hopping type conduction. ? An EMI shielding of 18 dB was achieved in 200 micron thick film. -- Abstract: In this paper, the low temperature electrical conductivity and microwave absorption properties of carbon coated iron nanoparticles–polyvinyl chloride composite films are investigated for different filler fractions. The filler particles are prepared by the pyrolysis of ferrocene at 980 °C and embedded in polyvinyl chloride matrix. The high resolution transmission electron micrographs of the filler material have shown a 5 nm thin layer graphitic carbon covering over iron particles. The room temperature electrical conductivity of the composite film changes by 10 orders of magnitude with the increase of filler concentration. A percolation threshold of 2.2 and an electromagnetic interference shielding efficiency (EMI SE) of ?18.6 dB in 26.5–40 GHz range are observed for 50 wt% loading. The charge transport follows three dimensional variable range hopping conduction.

Prasad, V., E-mail: vishnu@physics.iisc.ernet.in [Department of Physics, Indian Institute of Science, Bangalore 560 012 (India)

2012-06-15T23:59:59.000Z

302

A compact micro-wave synthesizer for transportable cold-atom interferometers  

SciTech Connect (OSTI)

We present the realization of a compact micro-wave frequency synthesizer for an atom interferometer based on stimulated Raman transitions, applied to transportable inertial sensing. Our set-up is intended to address the hyperfine transitions of {sup 87}Rb at 6.8 GHz. The prototype is evaluated both in the time and the frequency domain by comparison with state-of-the-art frequency references developed at Laboratoire national de métrologie et d'essais?Systémes de référence temps espace (LNE-SYRTE). In free-running mode, it features a residual phase noise level of ?65 dB rad{sup 2} Hz{sup ?1} at 10 Hz offset frequency and a white phase noise level in the order of ?120 dB rad{sup 2} Hz{sup ?1} for Fourier frequencies above 10 kHz. The phase noise effect on the sensitivity of the atomic interferometer is evaluated for diverse values of cycling time, interrogation time, and Raman pulse duration. To our knowledge, the resulting contribution is well below the sensitivity of any demonstrated cold atom inertial sensors based on stimulated Raman transitions. The drastic improvement in terms of size, simplicity, and power consumption paves the way towards field and mobile operations.

Lautier, J.; Lours, M.; Landragin, A., E-mail: arnaud.landragin@obspm.fr [LNE-SYRTE, Observatoire de Paris, CNRS, UPMC, 61 avenue de l’Observatoire, 75014 Paris (France)

2014-06-15T23:59:59.000Z

303

Optimizing a microwave gas ion source for continuous-flow accelerator mass spectrometry  

SciTech Connect (OSTI)

A 2.45 GHz microwave ion source coupled with a magnesium charge exchange canal (C x C) has been successfully adapted to a large acceptance radiocarbon accelerator mass spectrometry system at the National Ocean Sciences Accelerator Mass Spectrometry (AMS) Facility, Woods Hole Oceanographic Institution. CO{sub 2} samples from various preparation sources are injected into the source through a glass capillary at 370 {mu}l/min. Routine system parameters are about 120-140 {mu}A of negative {sup 12}C current after the C x C, leading to about 400 {sup 14}C counts per second for a modern sample and implying a system efficiency of 0.2%. While these parameters already allow us to perform high-quality AMS analyses on large samples, we are working on ways to improve the output of the ion source regarding emittance and efficiency. Modeling calculations suggest modifications in the extraction triode geometry, shape, and size of the plasma chamber could improve emittance and, hence, ion transport efficiency. Results of experimental tests of these modifications are presented.

Reden, K. F. von; Roberts, M. L.; Burton, J. R.; Beaupre, S. R. [Geology and Geophysics Department, Woods Hole Oceanographic Institution (WHOI), Woods Hole, Massachusetts 02543 (United States)

2012-02-15T23:59:59.000Z

304

A Polarization Sensitive Bolometric Detector for Observations of the Cosmic Microwave Background  

E-Print Network [OSTI]

We have developed a bolometric detector that is intrinsically sensitive to linear polarization which is optimized for making measurements of the polarization of the cosmic microwave background radiation. The receiver consists of a pair of co-located silicon nitride micromesh absorbers which couple anisotropically to linearly polarized radiation through a corrugated waveguide structure. This system allows simultaneous background limited measurements of the Stokes I and Q parameters over ~ 30% bandwidths at frequencies from ~ 60 to 600 GHz. Since both linear polarizations traverse identical optical paths from the sky to the point of detection, the susceptibility to systematic effects is minimized. The amount of uncorrelated noise between the two polarization senses is limited to the quantum limit of thermal and photon shot noise, while drifts in the relative responsivity to orthogonal polarizations are limited to the effect of non-uniformity in the thin film deposition of the leads and the intrinsic thermistor properties. Devices using NTD Ge thermistors have achieved NEPs of 2 x 10^{-17} W/sqrt{Hz} with a 1/f knee below 100 mHz at a base temperature of 270 mK. Numerical modelling of the structures has been used to optimize the bolometer geometry and coupling to optics. Comparisons of numerical results and experimental data are made. A description of how the quantities measured by the device can be interpreted in terms of the Stokes parameters is presented. The receiver developed for the Boomerang and Planck HFI focal planes is presented in detail.

W. C. Jones; R. S. Bhatia; J. J. Bock; A. E. Lange

2002-09-08T23:59:59.000Z

305

A COSMIC MICROWAVE BACKGROUND LENSING MASS MAP AND ITS CORRELATION WITH THE COSMIC INFRARED BACKGROUND  

SciTech Connect (OSTI)

We use a temperature map of the cosmic microwave background (CMB) obtained using the South Pole Telescope at 150 GHz to construct a map of the gravitational convergence to z {approx} 1100, revealing the fluctuations in the projected mass density. This map shows individual features that are significant at the {approx}4{sigma} level, providing the first image of CMB lensing convergence. We cross-correlate this map with Herschel/SPIRE maps covering 90 deg{sup 2} at wavelengths of 500, 350, and 250 {mu}m. We show that these submillimeter (submm) wavelength maps are strongly correlated with the lensing convergence map, with detection significances in each of the three submm bands ranging from 6.7{sigma} to 8.8{sigma}. We fit the measurement of the cross power spectrum assuming a simple constant bias model and infer bias factors of b = 1.3-1.8, with a statistical uncertainty of 15%, depending on the assumed model for the redshift distribution of the dusty galaxies that are contributing to the Herschel/SPIRE maps.

Holder, G. P.; De Haan, T.; Dobbs, M. A.; Dudley, J. [Department of Physics, McGill University, Montreal, Quebec H3A 2T8 (Canada); Viero, M. P.; Bock, J. [California Institute of Technology, Pasadena, CA 91125 (United States); Zahn, O. [Berkeley Center for Cosmological Physics, Department of Physics, University of California, and Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Aird, K. A. [University of Chicago, Chicago, IL 60637 (United States); Benson, B. A.; Bhattacharya, S.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T. [Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States); Brodwin, M. [Department of Physics and Astronomy, University of Missouri, Kansas City, MO 64110 (United States); Cho, H-M. [NIST Quantum Devices Group, Boulder, CO 80305 (United States); Conley, A. [Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309 (United States); George, E. M. [Department of Physics, University of California, Berkeley, CA 94720 (United States); Halverson, N. W. [Department of Astrophysical and Planetary Sciences and Department of Physics, University of Colorado, Boulder, CO 80309 (United States); and others

2013-07-01T23:59:59.000Z

306

Demonstration of a 140-GHz 1-kW Confocal Gyro-Traveling-Wave Amplifier  

E-Print Network [OSTI]

The theory, design, and experimental results of a wideband 140-GHz 1-kW pulsed gyro-traveling-wave amplifier (gyro-TWA) are presented. The gyro-TWA operates in the HE [subscript 06] mode of an overmoded quasi-optical ...

Temkin, Richard J.

307

Planning of Low-Cost 77-GHz Radar Transceivers for Automotive Applications  

E-Print Network [OSTI]

Planning of Low-Cost 77-GHz Radar Transceivers for Automotive Applications H. Ameri, A. Attaran & M. Moghavvemi University ofMalaya INTRODUCTION The use of electronics in the automotive industry will reach (or the position and speed as with other components used in the automotive industry, radars will find widespread

Paris-Sud XI, Université de

308

AUTOMATED RETRIEVALS OF PRECIPITATION PARAMETERS USING NON-RAYLEIGH SCATTERING AT 95-GHZ  

E-Print Network [OSTI]

(dependency on the sixth power of the raindrop diameter), radar measurement geometry and several known-GHz) profiling radars. The technique capitalizes on non- Rayleigh resonance signatures found-1 ). Low-level DSD slope parameter retrievals are shown in agreement (bias of -1.48 cm-1 and rms

309

Elastic properties of transparent nano-polycrystalline diamond measured by GHz-ultrasonic interferometry and resonant  

E-Print Network [OSTI]

Elastic properties of transparent nano-polycrystalline diamond measured by GHz-ultrasonic interferometry Sphere resonance Nano-polycrystalline diamond NPD Elastic properties Superhard materials a b s t r a c t The sound velocities and elastic moduli of transparent nano-polycrystalline diamond (NPD) have

Jacobsen, Steven D.

310

EXPERIMENTAL DEMONSTRATION OF WAKEFIELD EFFECTS IN A 250 GHZ PLANAR DIAMOND ACCELERATING STRUCTURE*  

E-Print Network [OSTI]

of a rectangular waveguide loaded with polycrystalline CVD diamond plates as an accelerating structure. It should polycrystalline diamond plates loaded in a 6 cm long waveguide (Fig. 2). The beam gap was 200 microns (Fig. TM11EXPERIMENTAL DEMONSTRATION OF WAKEFIELD EFFECTS IN A 250 GHZ PLANAR DIAMOND ACCELERATING STRUCTURE

Brookhaven National Laboratory

311

Physics Design of a 28 GHz Electron Heating System for the National Spherical Torus Experiment Upgrade  

SciTech Connect (OSTI)

A megawatt-level, 28 GHz electron heating system is being designed to support non-inductive (NI) plasma current (I{sub p}) start-up and local heating and current drive (CD) in H-mode discharges in the National Spherical Torus Experiment Upgrade (NSTX-U). The development of fully NI I{sub p} start-up and ramp-up is an important goal of the NSTX-U research program. 28 GHz electron cyclotron (EC) heating is predicted to rapidly increase the central electron temperature (T{sub e}(0)) of low density NI plasmas generated by Coaxial Helicity Injection (CHI). The increased T{sub e}(0) will significantly reduce the Ip decay rate of CHI plasmas, allowing the coupling of fast wave heating and neutral beam injection. Also 28 GHz electron Bernstein wave (EBW) heating and CD can be used during the I{sub p} flat top in NSTX-U discharges when the plasma is overdense. Ray tracing and Fokker-Planck numerical simulation codes have been used to model EC and EBW heating and CD in NSTX-U. This paper presents a pre-conceptual design for the 28 GHz heating system and some of the results from the numerical simulations.

none,

2013-07-09T23:59:59.000Z

312

Physics design of a 28 GHz electron heating system for the National Spherical Torus experiment upgrade  

SciTech Connect (OSTI)

A megawatt-level, 28 GHz electron heating system is being designed to support non-inductive (NI) plasma current (I{sub p}) start-up and local heating and current drive (CD) in H-mode discharges in the National Spherical Torus Experiment Upgrade (NSTX-U). The development of fully NI I{sub p} start-up and ramp-up is an important goal of the NSTXU research program. 28 GHz electron cyclotron (EC) heating is predicted to rapidly increase the central electron temperature (T{sub e}(0)) of low density NI plasmas generated by Coaxial Helicity Injection (CHI). The increased T{sub e}(0) will significantly reduce the I{sub p} decay rate of CHI plasmas, allowing the coupling of fast wave heating and neutral beam injection. Also 28 GHz electron Bernstein wave (EBW) heating and CD can be used during the I{sub p} flat top in NSTX-U discharges when the plasma is overdense. Ray tracing and Fokker-Planck numerical simulation codes have been used to model EC and EBW heating and CD in NSTX-U. This paper presents a pre-conceptual design for the 28 GHz heating system and some of the results from the numerical simulations.

Taylor, G.; Bertelli, N.; Ellis, R. A.; Gerhardt, S. P.; Hosea, J. C.; Poli, F. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Harvey, R. W. [CompX, Del Mar, California 92014 (United States); Raman, R. [University of Washington, Seattle, Washington 98195 (United States); Smirnov, A. P. [M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

2014-02-12T23:59:59.000Z

313

1. ABSTRACT A 1.4-GHz LC voltage-controlled oscillator has  

E-Print Network [OSTI]

1. ABSTRACT A 1.4-GHz LC voltage-controlled oscillator has been implemented in a MOSIS 0.5-µm CMOS integrated, low noise, low power voltage-controlled oscillator (VCO). For higher quality receivers, an LC the overall phase noise. In this paper, we present such an LC voltage-controlled oscillator fabricated through

Lee, Thomas H.

314

A 100 MHz 2.5 GHz Direct Conversion CMOS Transceiver for SDR Applications  

E-Print Network [OSTI]

A 100 MHz ­ 2.5 GHz Direct Conversion CMOS Transceiver for SDR Applications Gio Cafaro, Tom frequency switching and phase noise of ­123 dBc/Hz at 25 KHz offset. Index Terms -- CMOS, Direct Conversion are not practical in today's technology [5]-[7]. Direct conversion is preferred for this reason, but it has some

Ellingson, Steven W.

315

Superconducting quantum interference device as a near-quantum-limited amplifier at 0.5 GHz  

E-Print Network [OSTI]

Superconducting quantum interference device as a near-quantum-limited amplifier at 0.5 GHz Michael 94720 Received 10 October 2000; accepted for publication 14 December 2000 A dc superconducting quantum, for example, superconducting transition-edge sensors for infrared, optical, and ultraviolet wavelengths,2

Le Roy, Robert J.

316

A 5-WATT, 37-GHz MONOLITHIC GRID AMPLIFIER Blythe Deckman1  

E-Print Network [OSTI]

of the fabricated active grid. Thermal Management Previous grid amplifiers lacked a heat spreader, so Figure 1A 5-WATT, 37-GHz MONOLITHIC GRID AMPLIFIER Blythe Deckman1 , Donald S. Deakin, Jr.2 , Emilio Sovero has been demonstrated. The area of the grid am- plifier is 1 cm2, and there are 512 transistors

317

MISO time reversal and delay spread compression for FWA channels at 5GHz  

E-Print Network [OSTI]

MISO time reversal and delay spread compression for FWA channels at 5GHz Persefoni Kyritsi, Member (MISO) can reduce the delay spread of the channel impulse response by a factor of 2-3, depending transmitter instead. The paper is structured as follows. Section II describes the concept of TR in a MISO

Papanicolaou, George C.

318

BEHAVIOUR OF A HIGHLY PRESSURISED TANK OF GHz, SUBMITTED TO A THERMAL OR MECHANICAL IMPACT  

E-Print Network [OSTI]

2000-41 BEHAVIOUR OF A HIGHLY PRESSURISED TANK OF GHz, SUBMITTED TO A THERMAL OR MECHANICAL IMPACT will significantly reduce the volume of the necessary tank(s). Whatever this pressure and whatever the volume of the tank(s), the storage System must be designed in such a way that the consequences of an accident

Paris-Sud XI, Université de

319

E-Print Network 3.0 - advanced microwave scanning Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

measurements. Near-field microwave reflectometer... -field microwave probe and signal processing section. This automated scanning 12;platform is easy to use... scanning...

320

E-Print Network 3.0 - active microwave medium Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

MA: Artech House, 1981... . 41 F. Ulaby, R. Moore, and A. K. Fung, Microwave Remote Sensing: Active and Passive, vol. 3. Norwood... Sat Passive Microwave Polarimetric...

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

E-Print Network 3.0 - analogue microwave photonics Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Engineering ; Materials Science 6 Abstract--A novel approach to generating a frequency-tunable microwave or sub-terahertz wave based on time-delayed Summary: , microwave...

322

E-Print Network 3.0 - aura microwave limb Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

measured by the Aura Microwave Limb Sounder (MLS) version 2... of the greenhouse effect. Nature, 342, 758-761. Read, W. G., and Coauthors, 2007: Aura Microwave Limb...

323

International Conference on Microwave and High Frequency Heating Nottingham, UK, September 2013 Underwater Microwave Ignition of  

E-Print Network [OSTI]

-cost operation [4, 5]. Thermite reaction as a self-propagated, high-temperature synthesis (SHS) process, Localized microwave heating, underwater ignition, combustion. INTRODUCTION Self-propagated thermite reactions between metal-oxide and metals typically burn at high flame temperatures, and require high

Jerby, Eli

324

Broadband microwave burst produced by electron beams  

E-Print Network [OSTI]

Theoretical and experimental study of fast electron beams attracts a lot of attention in the astrophysics and laboratory. In the case of solar flares the problem of reliable beam detection and diagnostics is of exceptional importance. This paper explores the fact that the electron beams moving oblique to the magnetic field or along the field with some angular scatter around the beam propagation direction can generate microwave continuum bursts via gyrosynchrotron mechanism. The characteristics of the microwave bursts produced by beams differ from those in case of isotropic or loss-cone distributions, which suggests a new tool for quantitative diagnostics of the beams in the solar corona. To demonstrate the potentiality of this tool, we analyze here a radio burst occurred during an impulsive flare 1B/M6.7 on 10 March 2001 (AR 9368, N27W42). Based on detailed analysis of the spectral, temporal, and spatial relationships, we obtained firm evidence that the microwave continuum burst is produced by electron beams. For the first time we developed and applied a new forward fitting algorithm based on exact gyrosynchrotron formulae and employing both the total power and polarization measurements to solve the inverse problem of the beam diagnostics. We found that the burst is generated by a oblique beam in a region of reasonably strong magnetic field ($\\sim 200-300$ G) and the burst is observed at a quasi-transverse viewing angle. We found that the life time of the emitting electrons in the radio source is relatively short, $\\tau_l \\approx 0.5$ s, consistent with a single reflection of the electrons from a magnetic mirror at the foot point with the stronger magnetic field. We discuss the implications of these findings for the electron acceleration in flares and for beam diagnostics.

A. T. Altyntsev; G. D. Fleishman; G. -L. Huang; V. F. Melnikov

2007-12-16T23:59:59.000Z

325

Microwave sintering of single plate-shaped articles  

DOE Patents [OSTI]

Apparatus and method are disclosed for high temperature sintering of plate-shaped articles of alumina, magnesia, silica, yttria, zirconia, and mixtures thereof using microwave radiation. An article is placed within a sintering structure located within a sintering container which is placed in a microwave cavity for heating. The rates at which heating and cooling take place is controlled. 2 figs.

Katz, J.D.; Blake, R.D.

1995-07-11T23:59:59.000Z

326

Noise properties of mutually sustained microwave-optoelectronic oscillator pair  

E-Print Network [OSTI]

Noise properties of mutually sustained microwave-optoelectronic oscillator pair E. Shumakher and G microwave-optoelectronic oscillator pair are described. The two oscillators have different spectral purities and exhibits low phase noise and highly suppressed spurious modes. Optoelectronic oscillators are employed

Eisenstein, Gadi

327

Tailoring The Microwave Permittivity And Permeability Of Composite Materials  

E-Print Network [OSTI]

1 Tailoring The Microwave Permittivity And Permeability Of Composite Materials Kenneth M. Bober/Lowell, Lowell, MA 01854 ABSTRACT The microwave permittivity( r ) and permeability( r ) of composite materials. Polynomials are also used for the ferrite composites because it was determined that the MG theory was unable

Massachusetts at Lowell, University of

328

Microwave sintering of sol-gel derived abrasive grain  

DOE Patents [OSTI]

A method is provided for making microwave-sintered, free flowing alpha alumina-based ceramic abrasive grain, under conditions effective to couple microwaves with calcined alpha alumina-based abrasive gain precursor and sinter it at a temperature of at least about 1150.degree. C.

Plovnick, Ross (St. Louis Park, MN); Celikkaya, Ahmet (Woodbury, MN); Blake, Rodger D. (Tuscon, AZ)

1997-01-01T23:59:59.000Z

329

MICROWAVE-BASED NDE OF FRP-JACKETED CONCRETE STRUCTURES  

E-Print Network [OSTI]

MICROWAVE-BASED NDE OF FRP-JACKETED CONCRETE STRUCTURES Yoo Jin Kim, Franco De Flaviis University are presented in this paper. KEY WORDS: Microwave, Non-Destructive Evaluation (NDE), FRP Jacket, Imaging Technol not be visually observed. Various nondestructive evaluation (NDE) techniques have been studied to detect cracks

De Flaviis, Franco

330

RF and Microwave Amplifier Design With ESD Protection  

E-Print Network [OSTI]

A 3.1 to 8.2 GHz direct conversion receiver for MB- OFDM UWBnaturally employ direct conversion, that is, zero-IF.Such a direct conversion 3-band OFDM UWB transceiver has

Lin, Lin

2010-01-01T23:59:59.000Z

331

Microwave photonics with Josephson junction arrays  

E-Print Network [OSTI]

We introduce an architecture for a photonic crystal in the microwave regime based on superconducting transmission lines interrupted by Josephson junctions. A study of the scattering properties of a single junction in the line shows that the junction behaves as a perfect mirror when the photon frequency matches the Josephson plasma frequency. We generalize our calculations to periodic arrangements of junctions, demonstrating that they can be used for tunable band engineering, forming what we call a quantum circuit crystal. As a relevant application, we discuss the creation of stationary entanglement between two superconducting qubits interacting through a disordered media.

Zueco, David; Solano, Enrique; García-Ripoll, Juan José

2011-01-01T23:59:59.000Z

332

New physics from the Cosmic Microwave Background  

E-Print Network [OSTI]

I review the present status of the Cosmic Microwave Background, with some emphasis on the current and future implications for particle physics. Conclusions are: gravitational instability in a dark matter dominated universe grew today's structure; the Universe remained neutral until z<~50; the CMB power spectrum peaks at 150<~l<~350; the large-scale structure of spacetime appears to be simple; something like inflation is something like proven; we will learn a great deal about cosmology, astrophysics and particle physics from MAP and Planck.

Douglas Scott

1999-11-17T23:59:59.000Z

333

Cosmic Microwave Background Tests of Inflation  

E-Print Network [OSTI]

Inflation provides a unified paradigm for understanding the isotropy of the cosmic microwave background (CMB), the flatness problem, and the origin of large-scale structure. Although the physics responsible for inflation is not yet well understood, slow-roll inflation generically makes several predictions: a flat Universe, primordial adiabatic density perturbations, and a stochastic gravity-wave background. Inflation further predicts specific relations between the amplitudes and shapes of the spectrum of density perturbations and gravity waves. There are now excellent prospects for testing precisely these predictions with forthcoming CMB temperature and polarization maps. Here I discuss these new CMB tests of inflation.

Marc Kamionkowski

1998-03-14T23:59:59.000Z

334

Ground-based Microwave Cloud Tomography  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun with Big Sky LearningGetGraphene's 3DRise |EnergyVehiclesMeasurementMicrowave

335

Manipulating microwaves with magnetic-dipolar-mode vortices  

SciTech Connect (OSTI)

There has been a surge of interest in the subwavelength confinement of electromagnetic fields. It is well known that, in optics, subwavelength confinement can be obtained from surface plasmon (quasielectrostatic) oscillations. In this article, we propose to realize subwavelength confinement in microwaves by using dipolar-mode (quasimagnetostatic) magnon oscillations in ferrite particles. Our studies of interactions between microwave electromagnetic fields and small ferrite particles with magnetic-dipolar-mode (MDM) oscillations show strong localization of electromagnetic energy. MDM oscillations in a ferrite disk are at the origin of topological singularities resulting in Poynting vector vortices and symmetry breakings of the microwave near fields. We show that new subwavelength microwave structures can be realized based on a system of interacting MDM ferrite disks. Wave propagation of electromagnetic signals in such structures is characterized by topological phase variations. Interactions of microwave fields with an MDM ferrite disk and MDM-disk arrays open a perspective for creating engineered electromagnetic fields with unique symmetry properties.

Kamenetskii, E. O.; Sigalov, M.; Shavit, R. [Department of Electrical and Computer Engineering, Ben Gurion University of the Negev, IL-84 105 Beer Sheva (Israel)

2010-05-15T23:59:59.000Z

336

Microwave characterization of high-temperature superconductors  

SciTech Connect (OSTI)

Thick (10-15 {mu}m) Tl-Ba-Ca-Cu-O films have been deposited onto yttria-stabilized zirconia and Ag substrates by d.c. magnetron sputtering techniques. Direct deposition onto 1'' diameter yttria-stabilized zirconia yields films with typical 22 GHz surface resistance (R{sub s}) values of 5.2 {plus minus} 2 m{Omega} and 52 {plus minus} 2 m{Omega} at 10 K and 77 K, respectively. For comparison, R{sub s} of Cu at this same frequency is 10 m{Omega} at 4 K and 22 m{Omega} at 77 K. Tl-Ba-Ca-Cu-O films have also been deposited onto 1'' diameter Ag substrates using Au/Cu, Cu, and BaF{sub 2} buffer layers. The lowest R{sub s} values were obtained on films with a BaF{sub 2} buffer layer, typical values being 7.8 {plus minus} 2 m{Omega} and 30.6 {plus minus} 2 m{Omega} (measured at 22 GHz) at 10 K and 77 K, respectively. Larger films (1.5'' diameter) with similar R{sub s} values were prepared using this same technique, demonstrating that the fabrication process can be scaled to larger surface areas. These films are promising for radiofrequency cavity applications because they are thick (50-75 times the London penetration depth), have relatively large surface areas, are fabricated on metallic substrates, and have R{sub s} values that are competitive with Cu at 77 K and are lower than Cu at 4 K. Because they are polycrystalline and unoriented, it is anticipated that their R{sub s} values can be lowered by improving the processing technique. High-quality films of YBa{sub 2}Cu{sub 3}O{sub 7} have been electron-beam deposited onto 1'' LaGaO{sub 3} and 1.5'' LaAlO{sub 3} substrates. The 1'' sample is characterized by R{sub s} values of 0.2 {plus minus} 0.1 m{Omega} at 4 K and 18.6 {plus minus} 2 m{Omega} at 77 K. The 4-K value is only 2-4 times higher than Nb. The 1.5'' sample has R{sub s} values (measured at 18 GHz) of 0.93 {plus minus} 2 m{Omega} and 71 {plus minus} 3 m{Omega} at 10 K and 77 K, respectively. 18 refs., 8 figs.

Cooke, D.W.; Gray, E.R.; Arendt, P.N.; Beery, J.G.; Bennett, B.L.; Brown, D.R.; Houlton, R.J.; Jahan, M.S.; Klapetzky, A.J.; Maez, M.A.; Raistrick, I.D.; Reeves, G.A.; Rusnak, B.

1989-01-01T23:59:59.000Z

337

60 GHz Harmonic Optoelectronic Up-Conversion Using an InAlAs/InGaAs Metamorphic High-Electron-Mobility Transistor on a GaAs Substrate  

E-Print Network [OSTI]

60 GHz Harmonic Optoelectronic Up-Conversion Using an InAlAs/InGaAs Metamorphic High optoelectronic up-conversion using an InAlAs/InGaAs metamorphic high-electron-mobility transistor (HEMT) on a Ga 1 GHz signals into a 60 GHz band. After investigating the dependences of optoelectronic mixing

Choi, Woo-Young

338

Microwaves, hyperthermia, and human leukocyte function  

SciTech Connect (OSTI)

The objective of this study is to determine whether exposure to microwaves (2450 MHz) affects the function of human leukocytes in the resting state and during antigenic or mitogenic challenge. This publication is a summary report of the construction and calibration of a waveguide exposure facility for in vitro irradiation of human leukocytes. Calorimetric determinations of specific absorption rates (SAR) were made using heating curves measured with a microwave transparent Vitek 101 Electrothermia Monitor. The correlation between SAR and forward power was highly significant (r=0.95). At a forward power of 0.55 W the average SAR was approximately 33 mW/ml. However, inhomogeneity and significant resonance absorption were noted in the dual vial waveguide exposure facility. A 30-point measurement of SAR distribution revealed that the SAR at any of the measured points could range between 0.12- and 3.94-fold of the average SAR within the given vial. Measurements indicated that this variability in SAR values did not create significant thermal gradients within the vials when external agitation was applied.

Roberts, N.J. Jr; Lu, S.; Michaelson, S.M.

1981-05-01T23:59:59.000Z

339

Pattern formation and propagation during microwave breakdown  

SciTech Connect (OSTI)

During microwave breakdown at atmospheric pressure, a sharp plasma front forms and propagates toward the microwave source at high velocities. Experiments show that the plasma front may exhibit a complex dynamical structure or pattern composed of plasma filaments aligned with the wave electric field and apparently moving toward the source. In this paper, we present a model of the pattern formation and propagation under conditions close to recent experiments. Maxwell's equations are solved together with plasma fluid equations in two dimensions to describe the space and time evolution of the wave field and plasma density. The simulation results are in excellent agreement with the experimental observations. The model provides a physical interpretation of the pattern formation and dynamics in terms of ionization-diffusion and absorption-reflection mechanisms. The simulations allow a good qualitative and quantitative understanding of different features such as plasma front velocity, spacing between filaments, maximum plasma density in the filaments, and influence of the discharge parameters on the development of well-defined filamentary plasma arrays or more diffuse plasma fronts.

Chaudhury, Bhaskar [Laboratoire Plasma et Conversion d'Energie (LAPLACE), INPT, UPS, Universite de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); Boeuf, Jean-Pierre [Laboratoire Plasma et Conversion d'Energie (LAPLACE), INPT, UPS, Universite de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); LAPLACE, CNRS, F-31062 Toulouse (France); Zhu, Guo Qiang [Laboratoire Plasma et Conversion d'Energie (LAPLACE), INPT, UPS, Universite de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); Northwestern Polytechnique University, Xi'an 710072 (China)

2010-12-15T23:59:59.000Z

340

Relationships between tropical cyclone intensity and satellite based indicators of inner core convection: 85 GHz ice scattering signature and lightning  

E-Print Network [OSTI]

. REFERENCES. . . . . VITA. . . 116 119 125 LIST OF FIGURES FIGURE I Typhoon Oscar 85 GHz PCT iield at 2117 UTC 15 September 1995. . . . , Page 2 Correlations between 0-1' radius PCT parameters and hurricane/typhoon intensity at the time of SSM... miniinum PCT and lightning in Hurricane Barbara. . 79 46 Typhoon Oscar best track, 12 IJTC 7 September - 0 UTC 18 September 1995. . 81 47 Oscar 85 GHz PCT field at 2014 UTC 12 September 1995. . . . . . 48 Oscar 85 GHz PCT field at 2112 IJTC 13 September...

Cecil, Daniel Joseph

1997-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Peak effect in laser ablated DyBa2Cu3O7-d films at microwave frequencies at subcritical currents  

E-Print Network [OSTI]

In this paper we report the observation of a peak in the microwave surface resistance (at frequencies ~10GHz) of laser ablated DyBa2Cu3O7-d films in magnetic field ranging from 2 to 9kOe (||c) close to the superconducting transition temperature (Tc(H)). The exact nature of peak is sample dependent but it follows a general behaviour. The peak shifts to lower temperature when the magnetic field is increased. It has strong frequency dependence and the peak is pronounced at frequencies close to the depinning frequency of the flux line lattice. From the observed temperature and field dependence we argue that this peak is associated with the order disorder transition of the flux line lattice close to Tc(H).

A. R. Bhangale; P. Raychaudhuri; T. Banerjee; R. Pinto; V. S. Shirodhkar

2000-11-16T23:59:59.000Z

342

Analysis and control of the thermal runaway of ceramic slab under microwave heating  

E-Print Network [OSTI]

Analysis and control of the thermal runaway of ceramic slab under microwave heating Changjun Liu of the dielectrics during microwave heating, in which there is a big jump of the steady-state temperature while the applied microwave power varies slightly. It hinders engineers in the applications of microwave heating

Sheen, Dongwoo

343

Ultrafast Microwave Hydrothermal Synthesis of BiFeO3 Nanoplates Riad Nechache,  

E-Print Network [OSTI]

hydrothermal processes while requiring significantly less time and energy. In addition, we show that microwaveUltrafast Microwave Hydrothermal Synthesis of BiFeO3 Nanoplates Shun Li, Riad Nechache,§ Ivan and very rapid (1­2 min) microwave-assisted hydrothermal approach. We show that the microwave treatment

344

Astrometry of the stellar image of U Her amplified by the circumstellar 22 GHz water masers  

E-Print Network [OSTI]

The 22 GHz H_2O masers in the circumstellar envelope of the Mira variable star U Her have been observed with MERLIN using a phase referencing technique to determine accurate astrometric positions. The positions were compared with the optical positions obtained with the Hipparcos satellite to an accuracy of 18 mas. The absolute radio position of the brightest H_2O maser spot is found to match the optical position, indicating that this spot is the stellar image amplified by the maser screen in front of it. The occurrence of an amplified image in the 22 GHz maser can be used to accurately determine the positions of the H_2O with respect to the star as well as with respect to the SiO and OH masers. Our observations seem to indicate that the star is not in the centre of the distribution of maser spots, which has been interpreted as a ring.

W. H. T. Vlemmings; H. J. van Langevelde; P. J. Diamond

2002-08-09T23:59:59.000Z

345

Portable microwave instrument for non-destructive evaluation of structural characteristics  

DOE Patents [OSTI]

A portable microwave instrument for evaluating characteristics of a structural member includes a source of microwave energy, a transmitter coupled to the source of microwave energy for transmitting a microwave signal at the structural member, and a receiver positioned on the same side of the structural member as the transmitter and being disposed to receive a microwave signal reflected by the structural member. A phase angle difference is determined between the transmitted microwave signal and the received microwave signal using a signal splitter and a balanced mixer. The difference in phase angle varies in accordance with differences in size, shape and locations of constituent materials within the structural member.

Bible, Don W. (Clinton, TN); Crutcher, Richard I. (Knoxville, TN); Sohns, Carl W. (Oak Ridge, TN); Maddox, Stephen R. (Loudon, TN)

1995-01-01T23:59:59.000Z

346

Portable microwave instrument for non-destructive evaluation of structural characteristics  

DOE Patents [OSTI]

A portable microwave instrument for evaluating characteristics of a structural member includes a source of microwave energy, a transmitter coupled to the source of microwave energy for transmitting a microwave signal at the structural member, and a receiver positioned on the same side of the structural member as the transmitter and being disposed to receive a microwave signal reflected by the structural member. A phase angle difference is determined between the transmitted microwave signal and the received microwave signal using a signal splitter and a balanced mixer. The difference in phase angle varies in accordance with differences in size, shape and locations of constituent materials within the structural member. 6 figures.

Bible, D.W.; Crutcher, R.I.; Sohns, C.W.; Maddox, S.R.

1995-01-24T23:59:59.000Z

347

Making Maps from Planck LFI 30GHz Data with Asymmetric Beams and Cooler Noise  

SciTech Connect (OSTI)

The Planck satellite will observe the full sky at nine frequencies from 30 to 857 GHz. Temperature and polarization frequency maps made from these observations are prime deliverables of the Planck mission. The goal of this paper is to examine the effects of four realistic instrument systematics in the 30 GHz frequency maps: non-axially-symmetric beams, sample integration, sorption cooler noise, and pointing errors. They simulated one year long observations of four 30 GHz detectors. The simulated timestreams contained CMB, foreground component (both galactic and extra-galactic), instrument nolise (correlated and white), and the four instrument systematic effects. They made maps from the timelines and examined the magnitudes of the systematics effects in the maps and their angular power spectra. They also compared the maps of different mapmaking codes to see how they performed. They used five mapmaking codes (two destripers and three optimal codes). None of their mapmaking codes makes an attempt to deconvolve the beam from its output map. Therefore all our maps had similar smoothing due to beams and sample integration. This is a complicated smoothing, because every map pixel has its own effective beam. Temperature to polarization cross-coupling due to beam mismatch causes a detectable bias in the TE spectrum of the CMB map. The effects of cooler noise and pointing errors did not appear to be major concerns for the 30 GHz channel. The only essential difference found so far between mapmaking codes that affects accuracy (in terms of residual RMS) is baseline length. All optimal codes give essentially indistiguishable results. A destriper gives the same result as the optimal codes when the baseline is set short enough (Madam). For longer baselines destripers (Springtide and Madam) require less computing resources but deliver a noisier map.

The Planck CTP Working Group; Ashdown, M.A.J.; Baccigalupi, C.; Bartlett, J.G.; Borrill, J.; Cantalupo, C.; de Gasperis, G.; Gorski, K.M.; Hivon, E.; Huffenberger, K.; Keihanen, E.; Keskitalo, R.; Kisner, T.; Hurki-Suonio, H.; Lawrence, C.R.; Natoli, P.; Poutanen, T.; Prezeau, G.; Reinecke, M.; Rocha, G.; Sandri, M.; Stompor, R..; Villa, F.; Wandelt, B.; de Troia, G.

2008-06-19T23:59:59.000Z

348

Making Maps from Planck LFI 30GHz Data with Asymmetric Beams and Cooler Noise  

E-Print Network [OSTI]

The Planck satellite will observe the full sky at nine frequencies from 30 to 857 GHz. The goal of this paper is to examine the effects of four realistic instrument systematics in the 30 GHz frequency maps: non-axially-symmetric beams, sample integration, sorption cooler noise, and pointing errors. We simulated one year long observations of four 30 GHz detectors. The simulated timestreams contained CMB, foreground components (both galactic and extra-galactic), instrument noise (correlated and white), and the four instrument systematic effects. We made maps from the timelines and examined the magnitudes of the systematics effects in the maps and their angular power spectra. We also compared the maps of different mapmaking codes to see how they performed. We used five mapmaking codes (two destripers and three optimal codes). None of our mapmaking codes makes an attempt to deconvolve the beam from its output map. Therefore all our maps had similar smoothing due to beams and sample integration. Temperature to polarization cross-coupling due to beam mismatch causes a detectable bias in the TE spectrum of the CMB map. The effects of cooler noise and pointing errors did not appear to be major concerns for the 30 GHz channel. The only essential difference found so far between mapmaking codes that affects accuracy (in terms of residual RMS) is baseline length. All optimal codes give essentially indistinguishable results. A destriper gives the same result as the optimal codes when the baseline is set short enough. For longer baselines destripers require less computing resources but deliver a noisier map.

M. A. J. Ashdown; C. Baccigalupi; J. G. Bartlett; J. Borrill; C. Cantalupo; G. de Gasperis; G. de Troia; K. M. Gorski; E. Hivon; K. Huffenberger; E. Keihanen; R. Keskitalo; T. Kisner; H. Kurki-Suonio; C. R. Lawrence; P. Natoli; T. Poutanen; G. Prezeau; M. Reinecke; G. Rocha; M. Sandri; R. Stompor; F. Villa; B. Wandelt

2009-04-09T23:59:59.000Z

349

Design of a Shadowband Spectral Radiometer for the Retrieval of Thin Cloud Optical Depth, Liquid Water Path, and the Effective Radius  

SciTech Connect (OSTI)

The design and operation of a Thin-Cloud Rotating Shadowband Radiometer (TCRSR) described here was used to measure the radiative intensity of the solar aureole and enable the simultaneous retrieval of cloud optical depth, drop effective radius, and liquid water path. The instrument consists of photodiode sensors positioned beneath two narrow metal bands that occult the sun by moving alternately from horizon to horizon. Measurements from the narrowband 415-nm channel were used to demonstrate a retrieval of the cloud properties of interest. With the proven operation of the relatively inexpensive TCRSR instrument, its usefulness for retrieving aerosol properties under cloud-free skies and for ship-based observations is discussed.

Bartholomew M. J.; Reynolds, R. M.; Vogelmann, A. M.; Min, Q.; Edwards, R.; Smith, S.

2011-11-01T23:59:59.000Z

350

Modeling and design of compact microwave components and systems for wireless communications and power transmission  

E-Print Network [OSTI]

-band. Measured insertion loss (IL) K-band loop is under 0.4dB. The K- and W-band antenna array measured broadside gains are 23.6dB at 24.125GHz and 25dB at 76.5GHz with return loss under 9.54dB from 24 to 24.4GHz and 12 dB from 75.1 to 77.3GHz, respectively. Also...

Zepeda, Paola

2004-09-30T23:59:59.000Z

351

Final Report on "Development and Testing of Advanced Accelerator Structures and Technologies at 11.424 GHz"  

SciTech Connect (OSTI)

This is the final report on the research program ?Development and Testing of Advanced Accelerator Structures and Technologies at 11.424 GHz,? which was carried out by the Naval Research Laboratory (NRL) under Interagency Agreement DE?AI02?01ER41170 with the Department of Energy. The period covered by this report is 15 July 2010 ? 14 July 2013. The program included two principal tasks. Task 1 involved a study of the key physics issues related to the use of high gradient dielectric-loaded accelerating (DLA) structures in rf linear accelerators and was carried out in collaboration with Argonne National Laboratory (ANL) and Euclid Techlabs LLC. Task 2 involved a study of high power active microwave pulse compressors and was carried out in collaboration with Omega-P, Inc. and the Institute of Applied Physics of the Russian Academy of Sciences in Nizhny Novgorod. The studies under Task 1 were focused on rf-induced multipactor and breakdown in externally driven DLA structures at the 200-ns timescale. Suppression of multipactor and breakdown are essential to the practical application of dielectric structures in rf linear accelerators. The structures that were studied were developed by ANL and Euclid Techlabs and their performance was evaluated at high power in the X-band Magnicon Laboratory at NRL. Three structures were designed, fabricated, and tested, and the results analyzed in the first two years of the program: a clamped quartz traveling-wave (TW) structure, a externally copper-coated TW structure, and an externally copper-coated dielectric standing-wave (SW) structure. These structures showed that rf breakdown could be largely eliminated by eliminating dielectric joints in the structures, but that the multipactor loading was omnipresent. In the third year of the program, the focus of the program was on multipactor suppression using a strong applied axial magnetic field, as proposed by Chang et al. [C. Chang et al., J. Appl. Phys. 110, 063304 (2011).], and a successful experiment was carried out that demonstrated suppression of multipactor in the uniform-field region of a TW DLA structure. However, in accordance with theory, the multipactor was enhanced in regions of the structure with lower values of axial magnetic field. Under Task 2, there were two two-month experimental runs at NRL that were used to characterize the performance of high power two-channel dual-mode active microwave pulse compressor configurations that used electron-beam triggered switch cavities. The pulse compressors were designed and fabricated by Omega-P, Inc. and the Russian Institute of Applied Physics and tested in the Magnicon Laboratory at NRL. These pulse compressors made use of an electron beam discharge from a cylindrical knife-edged Mo cathode coated with a CVD diamond film that was driven by a ?100 kV, 100 ns high voltage pulse. The electron beam was used to change the resonant frequency of the switch cavities in order to create the output microwave pulse. The compressor channels included a TE01 input and output section and a TE02 energy storage cavity, followed by a switch assembly that controlled the coupling between the TE01 and TE02 modes. In the initial state, the switch cavity was in resonance, the reflection from the cavity was out of phase, and the mode conversion was only ~2-3%, allowing the energy storage cavity to fill. When the electron beam was discharged into the switch cavity, the cavity was shifted out of resonance, causing the phase of the reflection to change by ~?. As a result of the change in the reflection phase, the mode coupling in the conical taper was greatly increased, and could approach ~100%, permitting the energy storage cavity to empty in one cavity round trip time of the TE02 mode to produce a high power output pulse. The second experiment runs demonstrated a 190 MW, ~20 ns compressed pulse at 25.7 gain and ~50% efficiency, using a 7.4 MW, 1 ?s drive pulse from the magnicon. The success of this experiment suggests a path to future high gain active versions of the SLED 2 pulse compressor at SLAC.

Gold, Steven H. [Naval Research Laboratory

2013-10-13T23:59:59.000Z

352

Using Radar, Lidar, and Radiometer measurements to Classify Cloud Type and Study Middle-Level Cloud Properties  

SciTech Connect (OSTI)

The project is mainly focused on the characterization of cloud macrophysical and microphysical properties, especially for mixed-phased clouds and middle level ice clouds by combining radar, lidar, and radiometer measurements available from the ACRF sites. First, an advanced mixed-phase cloud retrieval algorithm will be developed to cover all mixed-phase clouds observed at the ACRF NSA site. The algorithm will be applied to the ACRF NSA observations to generate a long-term arctic mixed-phase cloud product for model validations and arctic mixed-phase cloud processes studies. To improve the representation of arctic mixed-phase clouds in GCMs, an advanced understanding of mixed-phase cloud processes is needed. By combining retrieved mixed-phase cloud microphysical properties with in situ data and large-scale meteorological data, the project aim to better understand the generations of ice crystals in supercooled water clouds, the maintenance mechanisms of the arctic mixed-phase clouds, and their connections with large-scale dynamics. The project will try to develop a new retrieval algorithm to study more complex mixed-phase clouds observed at the ACRF SGP site. Compared with optically thin ice clouds, optically thick middle level ice clouds are less studied because of limited available tools. The project will develop a new two wavelength radar technique for optically thick ice cloud study at SGP site by combining the MMCR with the W-band radar measurements. With this new algorithm, the SGP site will have a better capability to study all ice clouds. Another area of the proposal is to generate long-term cloud type classification product for the multiple ACRF sites. The cloud type classification product will not only facilitates the generation of the integrated cloud product by applying different retrieval algorithms to different types of clouds operationally, but will also support other research to better understand cloud properties and to validate model simulations. The ultimate goal is to improve our cloud classification algorithm into a VAP.

Wang, Zhien

2010-06-29T23:59:59.000Z

353

Electrical detection of microwave assisted magnetization reversal by spin pumping  

SciTech Connect (OSTI)

Microwave assisted magnetization reversal has been investigated in a bilayer system of Pt/ferromagnet by detecting a change in the polarity of the spin pumping signal. The reversal process is studied in two material systems, Pt/CoFeB and Pt/NiFe, for different aspect ratios. The onset of the switching behavior is indicated by a sharp transition in the spin pumping voltage. At a threshold value of the external field, the switching process changes from partial to full reversal with increasing microwave power. The proposed method provides a simple way to detect microwave assisted magnetization reversal.

Rao, Siddharth; Subhra Mukherjee, Sankha; Elyasi, Mehrdad; Singh Bhatia, Charanjit; Yang, Hyunsoo, E-mail: eleyang@nus.edu.sg [Department of Electrical and Computer Engineering and NUSNNI, National University of Singapore, Singapore 117576 (Singapore)

2014-03-24T23:59:59.000Z

354

Method and apparatus for component separation using microwave energy  

DOE Patents [OSTI]

A method for separating and recovering components includes the steps of providing at least a first component bonded to a second component by a microwave absorbent adhesive bonding material at a bonding area to form an assembly, the bonding material disposed between the components. Microwave energy is directly and selectively applied to the assembly so that substantially only the bonding material absorbs the microwave energy until the bonding material is at a debonding state. A separation force is applied while the bonding material is at the debonding state to permit disengaging and recovering the components. In addition, an apparatus for practicing the method includes holders for the components.

Morrow, Marvin S. (Kingston, TN); Schechter, Donald E. (Ten Mile, TN); Calhoun, Jr., Clyde L. (Knoxville, TN)

2001-04-03T23:59:59.000Z

355

Functional and shunt states of bacteriorhodopsin resolved by 250 GHz dynamic nuclear polarization-enhanced solid-state NMR  

E-Print Network [OSTI]

Observation and structural studies of reaction intermediates of proteins are challenging because of the mixtures of states usually present at low concentrations. Here, we use a 250 GHz gyrotron (cyclotron resonance maser) ...

Bajaj, Vikram S.

356

2D microwave imaging reflectometer electronics  

SciTech Connect (OSTI)

A 2D microwave imaging reflectometer system has been developed to visualize electron density fluctuations on the DIII-D tokamak. Simultaneously illuminated at four probe frequencies, large aperture optics image reflections from four density-dependent cutoff surfaces in the plasma over an extended region of the DIII-D plasma. Localized density fluctuations in the vicinity of the plasma cutoff surfaces modulate the plasma reflections, yielding a 2D image of electron density fluctuations. Details are presented of the receiver down conversion electronics that generate the in-phase (I) and quadrature (Q) reflectometer signals from which 2D density fluctuation data are obtained. Also presented are details on the control system and backplane used to manage the electronics as well as an introduction to the computer based control program.

Spear, A. G.; Domier, C. W., E-mail: cwdomier@ucdavis.edu; Hu, X.; Muscatello, C. M.; Ren, X.; Luhmann, N. C. [Electrical and Computer Engineering, University of California, Davis, California 95616 (United States); Tobias, B. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2014-11-15T23:59:59.000Z

357

Quantum chaotic scattering in microwave resonators  

SciTech Connect (OSTI)

In a frequency range where a microwave resonator simulates a chaotic quantum billiard, we have measured moduli and phases of reflection and transmission amplitudes in the regimes of both isolated and of weakly overlapping resonances and for resonators with and without time-reversal invariance. Statistical measures for S-matrix fluctuations were determined from the data and compared with extant and/or newly derived theoretical results obtained from the random-matrix approach to quantum chaotic scattering. The latter contained a small number of fit parameters. The large data sets taken made it possible to test the theoretical expressions with unprecedented accuracy. The theory is confirmed by both a goodness-of-fit-test and the agreement of predicted values for those statistical measures that were not used for the fits, with the data.

Dietz, B.; Miski-Oglu, M.; Schaefer, F. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Friedrich, T. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); GSI Helmholzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Harney, H. L.; Weidenmueller, H. A. [Max-Planck-Institut fuer Kernphysik, D-69029 Heidelberg (Germany); Richter, A. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); ECT, Villa Tambosi, I-38100 Villazzano (Trento) (Italy)

2010-03-15T23:59:59.000Z

358

Anisotropies in the Cosmic Microwave Background: Theory  

E-Print Network [OSTI]

Anisotropies in the Cosmic Microwave Background (CMB) contain a wealth of information about the past history of the universe and the present values of cosmological parameters. I ouline some of the theoretical advances of the last few years. In particular, I emphasize that for a wide class of cosmological models, theorists can accurately calculate the spectrum to better than a percent. The specturm of anisotropies today is directly related to the pattern of inhomogeneities present at the time of recombination. This recognition leads to a powerful argument that will enable us to distinguish inflationary models from other models of structure formation. If the inflationary models turn out to be correct, the free parameters in these models will be determined to unprecedented accuracy by the upcoming satellite missions.

Scott Dodelson

1997-02-14T23:59:59.000Z

359

The Cosmic Microwave Background and Particle Physics  

E-Print Network [OSTI]

In forthcoming years, connections between cosmology and particle physics will be made increasingly important with the advent of a new generation of cosmic microwave background (CMB) experiments. Here, we review a number of these links. Our primary focus is on new CMB tests of inflation. We explain how the inflationary predictions for the geometry of the Universe and primordial density perturbations will be tested by CMB temperature fluctuations, and how the gravitational waves predicted by inflation can be pursued with the CMB polarization. The CMB signatures of topological defects and primordial magnetic fields from cosmological phase transitions are also discussed. Furthermore, we review current and future CMB constraints on various types of dark matter (e.g. massive neutrinos, weakly interacting massive particles, axions, vacuum energy), decaying particles, the baryon asymmetry of the Universe, ultra-high-energy cosmic rays, exotic cosmological topologies, and other new physics.

Marc Kamionkowski; Arthur Kosowsky

1999-04-09T23:59:59.000Z

360

mm-WAVE Op-Amps FOR LOW DISTORTION AMPLIFICATION WITH HIGH OIP3/PDC RATIO > 100 AT 2 GHz  

E-Print Network [OSTI]

mm-WAVE Op-Amps FOR LOW DISTORTION AMPLIFICATION WITH HIGH OIP3/PDC RATIO > 100 AT 2 GHz Zach in bandwidth for an op-amp of any kind, as well as 3Ã? betterment in OIP3/PDC ratio at fs = 2-3 GHz, when dissipation PDC. This very high ratio of third-order-intercept power to DC power consumption POIP 3/PDC > 100

Rodwell, Mark J. W.

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Microwave-Regenerated Diesel Exhaust Particulate Filter  

SciTech Connect (OSTI)

Development of a microwave-regenerated particulate filter system has evolved from bench scale work to actual diesel engine experimentation. The filter system was initially evaluated on a stationary mounted 1.2-L diesel engine and was able to remove a significant amount of carbon particles from the exhaust. The ability of the microwave energy to regenerate or clean the filter was also demonstrated on this engine under idle conditions. Based on the 1.2-L experiments, improvements to the filter design and materials were implemented and the system was re-evaluated on a vehicle equipped with a 7.3-L diesel engine. The 7.3-L engine was selected to achieve heavy filter loading in a relatively short period of time. The purpose of these experiments was to evaluate filter-loading capacity, power requirements for regeneration, and filter regeneration efficiency. A more detailed evaluation of the filter was performed on a stationary mounted 1.9-L diesel engine. The effect of exhaust flow rate, loading, transients, and regeneration on filter efficiency was evaluated with this setup. In addition, gaseous exhaust emissions were investigated with and without an oxidation catalyst on the filter cartridge during loading and regeneration. (SAE Paper SAE-2001-01-0903 © 2001 SAE International. This paper is published on this website with permission from SAE International. As a user of this website, you are permitted to view this paper on-line, download this pdf file and print one copy of this paper at no cost for your use only. The downloaded pdf file and printout of this SAE paper may not be copied, distributed or forwarded to others or for the use of others.)

Nixdorf, Richard D. (Industrial Ceramic Solution, LLC); Green, Johney Boyd; Story, John M.; Wagner, Robert M. (Oak Ridge National Laboratory)

2001-03-05T23:59:59.000Z

362

Radiometer Calibration Trends  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared at 278, 298, and 323Program

363

A Novel Retrieval Algorithm for Cloud Optical Properties from the Atmopsheric Radiation Measurement Program's Two-Channel Narrow-Field-of-View Radiometer  

SciTech Connect (OSTI)

Cloud optical depth is the most important of all cloud optical properties, and vital for any cloud-radiation parameterization. To estimate cloud optical depth, the atmospheric science community has widely used ground-based flux measurements from either broadband or narrowband radiometers in the past decade. However, this type of technique is limited to overcast conditions and, at best, gives us an "effective" cloud optical depth instead of its "local" value. Unlike flux observations, monochromatic narrow-field-of-view (NFOV) radiance measurements contain information of local cloud properties, but unfortunately, the use of radiance to interpret optical depth suffers from retrieval ambiguity. We have pioneered an algorithm to retrieve cloud optical depth in a fully three-dimensional cloud situation using new Atmospheric Radiation Measurement (ARM) ground-based passive two-channel (673 and 870 nm) NFOV measurements. The underlying principle of the algorithm is that these two channels have similar cloud properties but strong spectral contrast in surface reflectance. This algorthm offers the first opportunity to illustrate cloud evolution with high temporal resolution retrievals. A combination of two-channel NFOV radiances with multi-filter rotating shadowband radiometer (MFRSR) fluxes for the retrieval of cloud optical properties is also discussed.

Wiscombe, Warren J.; Marshak, A.; Chiu, J.-Y. C.; Knyazikhin, Y.; Barnard, James C.; Luo, Yi

2005-03-14T23:59:59.000Z

364

Method for curing polymers using variable-frequency microwave heating  

DOE Patents [OSTI]

A method for curing polymers incorporating a variable frequency microwave furnace system designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity is disclosed. By varying the frequency of the microwave signal, non-uniformities within the cavity are minimized, thereby achieving a more uniform cure throughout the workpiece. A directional coupler is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter is provided for measuring the power delivered to the microwave furnace. A second power meter detects the magnitude of reflected power. The furnace cavity may be adapted to be used to cure materials defining a continuous sheet or which require compressive forces during curing. 15 figs.

Lauf, R.J.; Bible, D.W.; Paulauskas, F.L.

1998-02-24T23:59:59.000Z

365

Method for curing polymers using variable-frequency microwave heating  

DOE Patents [OSTI]

A method for curing polymers (11) incorporating a variable frequency microwave furnace system (10) designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity (34). By varying the frequency of the microwave signal, non-uniformities within the cavity (34) are minimized, thereby achieving a more uniform cure throughout the workpiece (36). A directional coupler (24) is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. The furnace cavity (34) may be adapted to be used to cure materials defining a continuous sheet or which require compressive forces during curing.

Lauf, Robert J. (Oak Ridge, TN); Bible, Don W. (Clinton, TN); Paulauskas, Felix L. (Oak Ridge, TN)

1998-01-01T23:59:59.000Z

366

Slotted Ground Structures and Their Applications to Various Microwave Components  

E-Print Network [OSTI]

(LPF) using slotted ground structure (SGS) with dumbbell shape is designed and measured to validate its theories. By using SGS techniques presented in this thesis, some other RF/microwave components such as a periodic structure, ultra-wideband bandpass...

Jung, Dong

2010-01-16T23:59:59.000Z

367

Temperature Modeling for Reaction Development in Microwave-Assisted Chemistry  

E-Print Network [OSTI]

made to evaluate and classify the effects of microwave irradiation. While it is commonly acknowledged energy, such as materials processing and food technologies, one can observe an expanding use

Yakovlev, Vadim

368

Analytical scanning evanescent microwave microscope and control stage  

DOE Patents [OSTI]

A scanning evanescent microwave microscope (SEMM) that uses near-field evanescent electromagnetic waves to probe sample properties is disclosed. The SEMM is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The SEMM has the ability to map dielectric constant, loss tangent, conductivity, electrical impedance, and other electrical parameters of materials. Such properties are then used to provide distance control over a wide range, from to microns to nanometers, over dielectric and conductive samples for a scanned evanescent microwave probe, which enable quantitative non-contact and submicron spatial resolution topographic and electrical impedance profiling of dielectric, nonlinear dielectric and conductive materials. The invention also allows quantitative estimation of microwave impedance using signals obtained by the scanned evanescent microwave probe and quasistatic approximation modeling. The SEMM can be used to measure electrical properties of both dielectric and electrically conducting materials.

Xiang, Xiao-Dong; Gao, Chen; Duewer, Fred; Yang, Hai Tao; Lu, Yalin

2013-01-22T23:59:59.000Z

369

Virtual cathode microwave generator having annular anode slit  

DOE Patents [OSTI]

A microwave generator is provided for generating microwaves substantially from virtual cathode oscillation. Electrons are emitted from a cathode and accelerated to an anode which is spaced apart from the cathode. The anode has an annular slit therethrough effective to form the virtual cathode. The anode is at least one range thickness relative to electrons reflecting from the virtual cathode. A magnet is provided to produce an optimum magnetic field having the field strength effective to form an annular beam from the emitted electrons in substantial alignment with the annular anode slit. The magnetic field, however, does permit the reflected electrons to axially diverge from the annular beam. The reflected electrons are absorbed by the anode in returning to the real cathode, such that substantially no reflexing electrons occur. The resulting microwaves are produced with a single dominant mode and are substantially monochromatic relative to conventional virtual cathode microwave generators.

Kwan, Thomas J. T. (Los Alamos, NM); Snell, Charles M. (Los Alamos, NM)

1988-01-01T23:59:59.000Z

370

Microwave mode shifting antenna system for regenerating particulate filters  

DOE Patents [OSTI]

A regeneration system comprises a particulate matter (PM) filter including a microwave energy absorbing surface, and an antenna system comprising N antennas and an antenna driver module that sequentially drives the antenna system in a plurality of transverse modes of the antenna system to heat selected portions of the microwave absorbing surface to regenerate the PM filter, where N is an integer greater than one. The transverse modes may include transverse electric (TE) and/or transverse magnetic (TM) modes.

Gonze, Eugene V [Pinckney, MI; Kirby, Kevin W [Calabasas Hills, CA; Phelps, Amanda [Malibu, CA; Gregoire, Daniel J [Thousand Oaks, CA

2011-04-26T23:59:59.000Z

371

Mathematical and experimental modelling of heat pump assisted microwave drying  

SciTech Connect (OSTI)

Drying is one of the most energy intensive operations in industry and agriculture. In the quest to increase drying efficiency and product quality, new technologies and methods are constantly being sought. Of these technologies, heat pump assisted drying and microwave drying have proved to be the most promising contenders. In order to achieve a better understanding and provide a computer design tool for heat pump assisted convective and microwave drying, both mathematical modelling and experimental investigations of heat pump assisted microwave dryers have been undertaken in this study. A mathematical model has been developed to predict the steady-state performance of a heat pump assisted continuous microwave dryer, with emphasis on the simulation of heat and mass transfer processes in the evaporator and drying chamber. The model is intend to serve as a design tool in the study of heat pump dryers. To achieve the optimum design, the influences of the key design and operating parameters, as well as the comparison of different drying configurations, have been examined. Based on investigation results, several methods have been proposed to improve the performance of heat pump assisted microwave drying, such as the use of a recuperator. To validate the above mathematical model, extensive drying tests using foam rubber as the test material have been conducted on a prototype heat pump assisted microwave dryer. The prototype heat pump input power was 5 kW with a maximum microwave input power of 10 kW. The experimental performance data confirmed the veracity of the simulation model. The experimental results on drying test materials indicate that with careful design heat pump assisted microwave drying is comparable to convective drying in energy consumption while with a much higher drying speed.

Xiguo Jia (Univ. of Queensland (Australia))

1993-01-01T23:59:59.000Z

372

Proposal for an Optomechanical Microwave Sensor at the Subphoton Level  

E-Print Network [OSTI]

Because of their low energy content, microwave signals at the single-photon level are extremely challenging to measure. Guided by recent progress in single-photon optomechanics and hybrid optomechanical systems, we propose a multimode optomechanical transducer that can detect intensities significantly below the single-photon level via adiabatic transfer of the microwave signal to the optical frequency domain where the measurement is then performed. The influence of intrinsic quantum and thermal fluctuations is also discussed.

Keye Zhang; Francesco Bariani; Ying Dong; Weiping Zhang; Pierre Meystre

2015-03-17T23:59:59.000Z

373

Optomechanical microwave sensor at the sub-photon level  

E-Print Network [OSTI]

Due to their low energy content microwave signals at the single-photon level are extremely challenging to measure. Guided by recent progress in single-photon optomechanics and hybrid optomechanical systems, we propose a multimode optomechanical transducer that can detect intensities significantly below the single-photon level via adiabatic transfer of the microwave signal to the optical frequency domain where the measurement is then performed. The influence of intrinsic quantum and thermal fluctuations is also discussed.

Keye Zhang; Francesco Bariani; Ying Dong; Weiping Zhang; Pierre Meystre

2014-09-30T23:59:59.000Z

374

Injection locking of laser diodes for microwave signal generation  

E-Print Network [OSTI]

INJECTION LOCKING OF LASER DIODES FOR MICROWAVE SIGNAL GENERATION A Thesis by BEN-MOU YU Submitted to the Graduate College of Texas ARM University in partial fulfillment. of the requirement. for the degree of MASTER OF SCIENCE August 1987... Major Subject: Electrical Engineering INJECTION LOCKING OF LASER DIODES FOR MICROWAVE SIGNAL GENERATION A Thesis BEN. -MOU YU Approved as to style and content by: Taylor, Henry . (E. E. ) (Chairman of Committee) Chang, Kai (E. E. ) (Member) 0...

Yu, Ben-Mou

2012-06-07T23:59:59.000Z

375

Fuel gas production by microwave plasma in liquid  

SciTech Connect (OSTI)

We propose to apply plasma in liquid to replace gas-phase plasma because we expect much higher reaction rates for the chemical deposition of plasma in liquid than for chemical vapor deposition. A reactor for producing microwave plasma in a liquid could produce plasma in hydrocarbon liquids and waste oils. Generated gases consist of up to 81% hydrogen by volume. We confirmed that fuel gases such as methane and ethylene can be produced by microwave plasma in liquid.

Nomura, Shinfuku; Toyota, Hiromichi; Tawara, Michinaga; Yamashita, Hiroshi; Matsumoto, Kenya [Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790-8577 (Japan); Shikoku Industry and Technology Promotion Center, 2-5 Marunouchi, Takamatsu, Kagawa 760-0033 (Japan)

2006-06-05T23:59:59.000Z

376

Microwave processing of ceramic oxide filaments. Annual report, FY1997  

SciTech Connect (OSTI)

The objective of the microwave filament processing project is to develop microwave techniques to manufacture continuous ceramic oxide filaments. Microwave processing uses the volumetric absorption of microwave power in oxide filament tows to drive off process solvents, to burn out organic binders, and to sinter the dried fibers to produce flexible, high-strength ceramic filaments. The technical goal is to advance filament processing technology by microwave heating more rapidly with less energy and at a lower cost than conventional processing, but with the same quality as conventional processing. The manufacturing goal is to collaborate with the 3M Company, a US manufacturer of ceramic oxide filaments, to evaluate the technology using a prototype filament system and to transfer the microwave technology to the 3M Company. Continuous ceramic filaments are a principal component in many advanced high temperature materials like continuous fiber ceramic composites (CFCC) and woven ceramic textiles. The use of continuous ceramic filaments in CFCC radiant burners, gas turbines, waste incineration, and hot gas filters in U.S. industry and power generation is estimated to save at least 2.16 quad/yr by year 2010 with energy cost savings of at least $8.1 billion. By year 2010, continuous ceramic filaments and CFCC`s have the potential to abate pollution emissions by 917,000 tons annually of nitrous oxide and 118 million tons annually of carbon dioxide (DOE Report OR-2002, February, 1994).

Vogt, G.J.

1998-12-31T23:59:59.000Z

377

Investigating the effective range of vacuum ultraviolet-mediated breakdown in high-power microwave metamaterials  

SciTech Connect (OSTI)

Metamaterials and periodic structures operating under high-power excitations are susceptible to breakdown. It was recently demonstrated that a localized breakdown created in a given region of a periodic structure can facilitate breakdown in other regions of the structure where the intensity of the incident electromagnetic fields may not be high enough to cause breakdown under normal circumstances. It was also demonstrated that this phenomenon is due to the generation of vacuum ultraviolet radiation at the location of the initial discharge, which propagates to the neighboring regions (e.g., other unit cells in a periodic structure) and facilitates the generation of a discharge at a lower incident power level. In this paper, we present the results of an experimental study conducted to determine the effective range of this physical phenomenon for periodic structures that operate in air and in pure nitrogen gas at atmospheric pressure levels. It is demonstrated that when breakdown is induced in a periodic structure using a high-power pulse with a frequency of 9.382 GHz, duration of 0.8??s, and peak power level of 25?kW, this phenomenon is highly likely to happen in radii of approximately 16–17?mm from the location of the initial discharge under these test conditions. The results of this study are significant in designing metamaterials and periodic structures for high-power microwave applications as they suggest that a localized discharge created in such a periodic structure with a periodicity less than 16–17?mm can spread over a large surface and result in a distributed discharge.

Liu, Chien-Hao, E-mail: cliu82@wisc.edu; Neher, Joel D., E-mail: jdneher@wisc.edu; Booske, John H., E-mail: booske@engr.wisc.edu; Behdad, Nader, E-mail: behdad@wisc.edu [Department of Electrical and Computer Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, Wisconsin 53706 (United States)

2014-10-14T23:59:59.000Z

378

Phenomenological method of calculating microwave longitudinal coupling impedances  

SciTech Connect (OSTI)

A previous paper described an investigation of the longitudinal coupling impedance of the TM/sub olm/ modes in the ISA vacuum chamber. A method was developed for calculating these impedances by using the data derived from pertubation measurements. This method gave accurate results between 2.6 and 2.8 GHz, but above 2.8 GHz measurements became difficult because of the mixing of the TM/sub olm/ modes with other modes. This paper presents a phenomenological approach for calculating these impedances based on previously developed concepts.

Giordano, S.; Votruba, J.

1980-05-01T23:59:59.000Z

379

Vertical and horizontal test results of 3.9-GHz accelerating cavities at FNAL  

SciTech Connect (OSTI)

The 3rd harmonic 3.9GHz accelerating cavity was proposed to improve the beam performance of the VUV FEL, FLASH. In the frame of a collaborative agreement, Fermilab will provide DESY with a cryomodule containing a string of four cavities. Seven 9-cell Nb cavities were tested and six of them did reach accelerating gradient up to 24 MV/m almost twice more than design value of 14 MV/m. Two of these cavities are with new HOM couplers with improved design. In this paper we present all results of the vertical and horizontal tests.

Khabiboulline, T.; Edwards, H.; Foley, M.; Harms, E.; Hocker, James Andrew; Mitchell, D.; Rowe, A.; Solyak, N.; /Fermilab

2008-06-01T23:59:59.000Z

380

Note: Efficient generation of optical sidebands at GHz with a high-power tapered amplifier  

SciTech Connect (OSTI)

Two methods using a laser-diode tapered amplifier to produce high-power, high-efficiency optical frequency sidebands over a wide tunable frequency range are studied and compared. For a total output of 500 mW at 811 nm, 20% of the power can be placed in each of the first-order sidebands. Functionality and characterization are presented within the sideband frequency region of 0.8–2.3 GHz, and it is shown that both methods can be applied beyond this frequency range. These methods provide a versatile and effective tool for atomic physics experiments.

Zappala, J. C.; Lu, Z.-T. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States) [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics and Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States); Bailey, K.; O’Connor, T. P.; Jiang, W., E-mail: wjiang@phy.anl.gov [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2014-04-15T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Statistics of Cosmic Microwave Background Polarization  

E-Print Network [OSTI]

We present a formalism for analyzing a full-sky temperature and polarization map of the cosmic microwave background. Temperature maps are analyzed by expanding over the set of spherical harmonics to give multipole moments of the two-point correlation function. Polarization, which is described by a second-rank tensor, can be treated analogously by expanding in the appropriate tensor spherical harmonics. We provide expressions for the complete set of temperature and polarization multipole moments for scalar and tensor metric perturbations. Four sets of multipole moments completely describe isotropic temperature and polarization correlations; for scalar metric perturbations one set is identically zero, giving the possibility of a clean determination of the vector and tensor contributions. The variance with which the multipole moments can be measured in idealized experiments is evaluated, including the effects of detector noise, sky coverage, and beam width. Finally, we construct coordinate-independent polarization two-point correlation functions, express them in terms of the multipole moments, and derive small-angle limits.

Marc Kamionkowski; Arthur Kosowsky; Albert Stebbins

1996-11-15T23:59:59.000Z

382

Cosmic Microwave Background Anisotropy Window Functions Revisited  

E-Print Network [OSTI]

The primary results of most observations of cosmic microwave background (CMB) anisotropy are estimates of the angular power spectrum averaged through some broad band, called band-powers. These estimates are in turn what are used to produce constraints on cosmological parameters due to all CMB observations. Essential to this estimation of cosmological parameters is the calculation of the expected band-power for a given experiment, given a theoretical power spectrum. Here we derive the "band power" window function which should be used for this calculation, and point out that it is not equivalent to the window function used to calculate the variance. This important distinction has been absent from much of the literature: the variance window function is often used as the band-power window function. We discuss the validity of this assumed equivalence, the role of window functions for experiments that constrain the power in {\\it multiple} bands, and summarize a prescription for reporting experimental results. The analysis methods detailed here are applied in a companion paper to three years of data from the Medium Scale Anisotropy Measurement.

Lloyd Knox

1999-09-28T23:59:59.000Z

383

First Season QUIET Observations: Measurements of CMB Polarization Power Spectra at 43 GHz in the Multipole Range 25 <= ell <= 475  

E-Print Network [OSTI]

The Q/U Imaging ExperimenT (QUIET) employs coherent receivers at 43GHz and 95GHz, operating on the Chajnantor plateau in the Atacama Desert in Chile, to measure the anisotropy in the polarization of the CMB. QUIET primarily targets the B modes from primordial gravitational waves. The combination of these frequencies gives sensitivity to foreground contributions from diffuse Galactic synchrotron radiation. Between 2008 October and 2010 December, >10,000hours of data were collected, first with the 19-element 43GHz array (3458hours) and then with the 90-element 95GHz array. Each array observes the same four fields, selected for low foregrounds, together covering ~1000deg^2. This paper reports initial results from the 43GHz receiver which has an array sensitivity to CMB fluctuations of 69uK sqrt(s). The data were extensively studied with a large suite of null tests before the power spectra, determined with two independent pipelines, were examined. Analysis choices, including data selection, were modified until th...

Bischoff, C; Buder, I; Chinone, Y; Cleary, K; Dumoulin, R N; Kusaka, A; Monsalve, R; Næss, S K; Newburgh, L B; Reeves, R; Smith, K M; Wehus, I K; Zuntz, J A; Zwart, J T L; Bronfman, L; Bustos, R; Church, S E; Dickinson, C; Eriksen, H K; Ferreira, P G; Gaier, T; Gundersen, J O; Hasegawa, M; Hazumi, M; Huffenberger, K M; Jones, M E; Kangaslahti, P; Kapner, D J; Lawrence, C R; Limon, M; May, J; McMahon, J J; Miller, A D; Nguyen, H; Nixon, G W; Pearson, T J; Piccirillo, L; Radford, S J E; Readhead, A C S; Richards, J L; Samtleben, D; Seiffert, M; Shepherd, M C; Staggs, S T; Tajima, O; Thompson, K L; Vanderlinde, K; Williamson, R; Winstein, B

2010-01-01T23:59:59.000Z

384

A 77 GHz Transceiver for Automotive Radar System Using a120nm In AlAs/In GaAs Metamorphic HEMTs  

E-Print Network [OSTI]

A 77 GHz Transceiver for Automotive Radar System Using a120nm 0.4 0.35 In AlAs/In GaAs Metamorphic-mail:ykwon@snu.ac.kr) Abstract -- In this work, we demonstrate a compact 77GHz single-chip transceiver for an automotive radar at the transmitter and a 5dB conversion gain at the receiver. Index Terms -- Automotive radar, 77GHz, MHEMT, MMIC

Kwon, Youngwoo

385

High quality Y-type hexaferrite thick films for microwave applications by an economical and environmentally benign crystal growth technique  

SciTech Connect (OSTI)

Thick barium hexaferrite Ba{sub 2}Zn{sub 2}Fe{sub 12}O{sub 22} (i.e., Zn{sub 2}Y) films having thicknesses of ?100??m were epitaxially grown on MgO (111) substrates using an environmentally benign ferrite-salt mixture by vaporizing the salt. X-ray diffraction pole figure analyses showed (00l) crystallographic alignment with little in plane dispersion confirming epitaxial growth. Saturation magnetization, 4?M{sub s}, was measured for as-grown films to be 2.51?±?0.1?kG with an out of plane magnetic anisotropy field H{sub A} of 8.9?±?0.1?kOe. Ferromagnetic resonance linewidth, as the peak-to-peak power absorption derivative at 9.6?GHz, was measured to be 62?Oe. These properties demonstrate a rapid, convenient, cost-effective, and nontoxic method of growing high quality thick crystalline ferrite films which could be used widely for microwave device applications.

Hu, Bolin; Chen, Yajie, E-mail: y.chen@neu.edu; Gillette, Scott; Su, Zhijuan; Harris, Vincent G. [Center for Microwave Magnetic Materials and Integrated Circuits and Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts 02115 (United States); Wolf, Jason; McHenry, Michael E. [Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)

2014-02-17T23:59:59.000Z

386

Detection of lower hybrid waves in the scrape-off layer of tokamak plasmas with microwave backscattering  

SciTech Connect (OSTI)

Microwave backscattering experiments have been performed on the Alcator C-Mod tokamak in order to investigate the propagation of lower hybrid (LH) waves in reactor-relevant, high-density plasmas. When the line-averaged density is raised above 1?×?10{sup 20} m{sup –3}, lower hybrid current drive efficiency is found to be lower than expected [Wallace et al., Phys. Plasmas 19, 062505 (2012)] and LH power is thought to be dissipated at the plasma edge. Using a single channel (60 GHz) ordinary-mode (O-mode) reflectometer system, we demonstrate radially localized LH wave measurements in the scrape-off layer of high density plasmas (n{sup ¯}{sub e}???0.9×10{sup 20}?m{sup ?3}). Measured backscattered O-mode power varies depending on the magnetic field line mapping, suggesting the resonance cone propagation of LH waves. Backscattered power is also sensitive to variations in plasma density and the launched parallel refractive index of the LH waves. LH ray-tracing simulations have been carried out to interpret the observed variations. To understand the measured LH waves in regions not magnetically connected to the launcher, two hypotheses are examined. One is the weak single pass absorption and the other is scattering of LH waves by non-linear effects.

Baek, S. G., E-mail: sgbaek@mit.edu; Shiraiwa, S.; Parker, R. R.; Bonoli, P. T.; Marmar, E. S.; Wallace, G. M.; Lau, C. [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States)] [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Dominguez, A.; Kramer, G. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2014-01-15T23:59:59.000Z

387

Development of a high-temperature oven for the 28 GHz electron cyclotron resonance ion source  

SciTech Connect (OSTI)

We have been developing the 28 GHz ECR ion source in order to accelerate high-intensity uranium beams at the RIKEN RI-beam Factory. Although we have generated U{sup 35+} beams by the sputtering method thus far, we began developing a high-temperature oven with the aim of increasing and stabilizing the beams. Because the oven method uses UO{sub 2}, a crucible must be heated to a temperature higher than 2000?°C to supply an appropriate amount of UO{sub 2} vapor to the ECR plasma. Our high-temperature oven uses a tungsten crucible joule-heated with DC current of approximately 450 A. Its inside dimensions are ?11 mm × 13.5 mm. Since the crucible is placed in a magnetic field of approximately 3 T, it is subject to a magnetic force of approximately 40 N. Therefore, we used ANSYS to carefully design the crucible, which was manufactured by machining a tungsten rod. We could raise the oven up to 1900?°C in the first off-line test. Subsequently, UO{sub 2} was loaded into the crucible, and the oven was installed in the 28 GHz ECR ion source and was tested. As a result, a U{sup 35+} beam current of 150 ?A was extracted successfully at a RF power of approximately 3 kW.

Ohnishi, J., E-mail: ohnishi@riken.jp; Higurashi, Y.; Kidera, M.; Ozeki, K.; Nakagawa, T. [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan)] [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan)

2014-02-15T23:59:59.000Z

388

THE 5 GHz ARECIBO SEARCH FOR RADIO FLARES FROM ULTRACOOL DWARFS  

SciTech Connect (OSTI)

We present the results of a 4.75 GHz survey of 33 brown dwarfs and one young exoplanetary system for flaring radio emission, conducted with the 305 m Arecibo radio telescope. The goal of this program was to detect and characterize the magnetic fields of objects cooler than spectral type L3.5, the coolest brown dwarf detected prior to our survey. We have also attempted to detect flaring radio emission from the HR 8799 planetary system, guided by theoretical work indicating that hot, massive exoplanets may have strong magnetic fields capable of generating radio emission at GHz frequencies. We have detected and confirmed radio flares from the T6.5 dwarf 2MASS J10475385+2124234. This detection dramatically extends the temperature range over which brown dwarfs appear to be at least sporadic radio-emitters, from 1900 K (L3.5) down to 900 K (T6.5). It also demonstrates that the utility of radio detection as a unique tool to study the magnetic fields of substellar objects extends to the coolest dwarfs, and, plausibly to hot, massive exoplanets. We have also identified a single, 3.6{sigma} flare from the L1 dwarf, 2MASS J1439284+192915. This detection is tentative and requires confirmation by additional monitoring observations.

Route, Matthew; Wolszczan, Alexander, E-mail: mroute@astro.psu.edu, E-mail: alex@astro.psu.edu [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)

2013-08-10T23:59:59.000Z

389

A Megawatt-level 28z GHz Heating System For The National Spherical Torus Experiment Upgrade  

SciTech Connect (OSTI)

The National Spherical Torus Experiment Upgrade (NSTX-U) will operate at axial toroidal fields of < 1 T and plasma currents, Ip < 2 MA. The development of non-inductive (NI) plasmas is a major long-term research goal for NSTX-U. Time dependent numerical simulations of 28 GHz electron cyclotron (EC) heating of low density NI start-up plasmas generated by Coaxial Helicity Injection (CHI) in NSTX-U predict a significant and rapid increase of the central electron temperature (Te(0)) before the plasma becomes overdense. The increased Te(0) will significantly reduce the Ip decay rate of CHI plasmas, allowing the coupling of fast wave heating and neutral beam injection. A megawatt-level, 28 GHz electron heating system is planned for heating NI start-up plasmas in NSTX-U. In addition to EC heating of CHI start-up discharges, this system will be used for electron Bernstein wave (EBW) plasma start-up, and eventually for EBW heating and current drive during the Ip flattop.

Taylor, Gary [PPPL

2014-04-01T23:59:59.000Z

390

Microwave-Assisted Synthesis of II-VI Semiconductor Micro- and Nanoparticles towards Sensor Applications  

E-Print Network [OSTI]

leads to slow heating and allows decomposition of reagents or products over time. Microwave-assisted heating provides faster, localized heating at the molecular level with near instantaneous control over reaction parameters. In this work, microwave...

Majithia, Ravish

2013-01-15T23:59:59.000Z

391

be virtually impossible to construct land lines and microwave networks in the  

E-Print Network [OSTI]

) with a microwave radio transmission tail is not suit- able for very harsh terrain, or for locations that are more. The use of microwave repeater towers, requiring line- of-sight from one tower to the next, was ruled out

Brewer, Eric A.

392

Journal of Microwaves and Optoelectronics, Vol. 2, N.o 6, December 2002.  

E-Print Network [OSTI]

Journal of Microwaves and Optoelectronics, Vol. 2, N.o 6, December 2002. Copyright SBMO ISSN 1516 one metric is not #12;Journal of Microwaves and Optoelectronics, Vol. 2, N.o 6, December 2002

Coello, Carlos A. Coello

393

Journal of Microwaves and Optoelectronics, Vol. 2, N.o 6, December 2002.  

E-Print Network [OSTI]

Journal of Microwaves and Optoelectronics, Vol. 2, N.o 6, December 2002. Copyright SBMO ISSN 1516 investigation is subsequently #12;Journal of Microwaves and Optoelectronics, Vol. 2, N.o 6, December 2002

Coello, Carlos A. Coello

394

Electric Kettle Takes Down Microwave in Final Round of #EnergyFaceoff...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Electric Kettle Takes Down Microwave in Final Round of EnergyFaceoff Electric Kettle Takes Down Microwave in Final Round of EnergyFaceoff November 24, 2014 - 12:13pm Addthis The...

395

Letter to the Editor Microwave assisted exfoliation and reduction of graphite  

E-Print Network [OSTI]

Letter to the Editor Microwave assisted exfoliation and reduction of graphite oxide yet versatile method to simultaneously achieve the exfoliation and reduction of graphite oxide of crumpled, few-layer thick and electronically conductive graphitic sheets. Using the microwave exfoliated

396

E-Print Network 3.0 - argon-helium microwave plasma Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and Medicine 63 Development of a Permanent-Magnet Microwave Ion Source for a Sealed-Tube Neutron Generator Summary: to efficiently couple the microwave energy into the plasma,...

397

THE STAR FORMATION IN RADIO SURVEY: GBT 33 GHz OBSERVATIONS OF NEARBY GALAXY NUCLEI AND EXTRANUCLEAR STAR-FORMING REGIONS  

SciTech Connect (OSTI)

We present 33 GHz photometry of 103 galaxy nuclei and extranuclear star-forming complexes taken with the Green Bank Telescope as part of the Star Formation in Radio Survey. Among the sources without evidence for an active galactic nucleus, and also having lower frequency radio data, we find a median thermal fraction at 33 GHz of Almost-Equal-To 76% with a dispersion of Almost-Equal-To 24%. For all sources resolved on scales {approx}<0.5 kpc, the thermal fraction is even larger, being {approx}>90%. This suggests that the rest-frame 33 GHz emission provides a sensitive measure of the ionizing photon rate from young star-forming regions, thus making it a robust star formation rate (SFR) indicator. Taking the 33 GHz SFRs as a reference, we investigate other empirical calibrations relying on different combinations of warm 24 {mu}m dust, total infrared (IR; 8-1000 {mu}m), H{alpha} line, and far-UV continuum emission. The recipes derived here generally agree with others found in the literature, albeit with a large dispersion that most likely stems from a combination of effects. Comparing the 33 GHz to total IR flux ratios as a function of the radio spectral index, measured between 1.7 and 33 GHz, we find that the ratio increases as the radio spectral index flattens which does not appear to be a distance effect. Consequently, the ratio of non-thermal to total IR emission appears relatively constant, suggesting only moderate variations in the cosmic-ray electron injection spectrum and ratio of synchrotron to total cooling processes among star-forming complexes. Assuming that this trend solely arises from an increase in the thermal fraction sets a maximum on the scatter of the non-thermal spectral indices among the star-forming regions of {sigma}{sub {alpha}{sup N}{sup T}}{approx}<0.13.

Murphy, E. J. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Bremseth, J. [Department of Physics and Astronomy, Pomona College, Claremont, CA 91711 (United States); Mason, B. S.; Condon, J. J. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Schinnerer, E. [Max Planck Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Aniano, G. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Armus, L. [Spitzer Science Center, California Institute of Technology, MC 314-6, Pasadena, CA 91125 (United States); Helou, G. [California Institute of Technology, MC 100-22, Pasadena, CA 91125 (United States); Turner, J. L. [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095 (United States); Jarrett, T. H., E-mail: emurphy@obs.carnegiescience.edu [Infrared Processing and Analysis Center, California Institute of Technology, MC 100-22, Pasadena, CA 91125 (United States)

2012-12-20T23:59:59.000Z

398

0.6 cu. ft. (17 litre) capacity microwave 700 watts of cooking power  

E-Print Network [OSTI]

. Installation/yearly maintenance not included. Danby ENERGY STAR Mini Fridge (DCR88WDD) Danby Microwave (DMW608W

Lotze, Heike K.

399

One piece microwave container screens for electrodeless lamps  

DOE Patents [OSTI]

A microwave powered electrodeless lamp includes an improved screen unit having mesh and solid sections with an internal reflector to reflect light into a light-transmitting chamber defined in the lamp microwave cavity by the reflector and the mesh section. A discharge envelope of a bulb is disposed in the light-transmitting chamber. Light emitted from the envelope is prevented by the reflector from entering the cavity portion bounded by the solid section of the screen. Replacing mesh material by solid metal material as part of the screen unit significantly reduces leakage of microwave energy from the lamp. The solid section has multiple compliant fingers defined therein for engaging the periphery of a flange on the waveguide unit so that a hose clamp can easily secure the screen to the assembly. Screen units of this type having different mesh section configurations can be interchanged in the lamp assembly to produce different respective illumination patterns.

Turner, Brian (Myersville, MD); Ury, Michael (Bethesda, MD)

1998-01-01T23:59:59.000Z

400

Spectral properties of microwave graphs with local absorption  

E-Print Network [OSTI]

The influence of absorption on the spectra of microwave graphs has been studied experimentally. The microwave networks were made up of coaxial cables and T junctions. First, absorption was introduced by attaching a 50 Ohm load to an additional vertex for graphs with and without time-reversal symmetry. The resulting level-spacing distributions were compared with a generalization of the Wigner surmise in the presence of open channels proposed recently by Poli et al. [Phys. Rev. Lett. 108, 174101 (2012)]. Good agreement was found using an effective coupling parameter. Second, absorption was introduced along one individual bond via a variable microwave attenuator, and the influence of absorption on the length spectrum was studied. The peak heights in the length spectra corresponding to orbits avoiding the absorber were found to be independent of the attenuation, whereas, the heights of the peaks belonging to orbits passing the absorber once or twice showed the expected decrease with increasing attenuation.

M. Allgaier; S. Gehler; S. Barkhofen; H. -J. Stöckmann; U. Kuhl

2014-03-30T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

The Electrodeless Discharge Lamps Coated with the Titania Thin Film for Photocatalysis in a Microwave Field  

E-Print Network [OSTI]

photochemical and photocatalytic reactions for degradation of organic pollutants. The electrodeless discharge lamp (EDL) generates UV/VIS radiation when placed into the microwave field and is connected to the objective of microwave photochemistry [1]. The degradation of mono-chloroacetic acid (MCAA) by microwave

Cirkva, Vladimir

402

CAD Technique for Microwave Chemistry Reactors with Energy Efficiency Optimized for Different Reactants  

E-Print Network [OSTI]

CAD Technique for Microwave Chemistry Reactors with Energy Efficiency Optimized for Different in experimental development of large- scale and highly-productive reactors. This paper proposes to address this issue by developing microwave chemistry reactors as microwave systems, rather than as black

Yakovlev, Vadim

403

Apparatus with moderating material for microwave heat treatment of manufactured components  

DOE Patents [OSTI]

An apparatus for heat treating manufactured components using microwave energy and microwave susceptor material. Heat treating medium such as eutectic salts may be employed. A fluidized bed introduces process gases which may include carburizing or nitriding gases The process may be operated in a batch mode or continuous process mode. A microwave heating probe may be used to restart a frozen eutectic salt bath.

Ripley, Edward B. (Knoxville, TN)

2011-05-10T23:59:59.000Z

404

Microwaves and Chemistry: The Catalysis of an Exciting Marriage  

E-Print Network [OSTI]

. Product distrihution of microwave catalysis of carbon dioxide and water. Product Relative % yield Methane 55.1 Methanol 5.5 Acetone 4.7 C J alcohols 5.8 C 4 alcohols 28.4 o.5,------------------ 0.4 'C v >= 0.3 !i ;:I '" 0.2 &1... our first major success in cracking methane to ethylene and hydrogen [1,2], lhe destruction of chlorinated hydrocarbons [3,4], the hydrodesulfurization of hydrocracked pitch [5], and the microwave treatment of some Alberta oil sands and bitumens...

Wan, J.

405

Ultra high vacuum broad band high power microwave window  

DOE Patents [OSTI]

An improved high vacuum microwave window has been developed that utilizes high density polyethylene coated on two sides with SiOx, SiNx, or a combination of the two. The resultant low dielectric and low loss tangent window creates a low outgassing, low permeation seal through which broad band, high power microwave energy may be passed. No matching device is necessary and the sealing technique is simple. The features of the window are broad band transmission, ultra-high vacuum compatibility with a simple sealing technique, low voltage standing wave ratio, high power transmission and low cost.

Nguyen-Tuong, Viet (Seaford, VA); Dylla, III, Henry Frederick (Yorktown, VA)

1997-01-01T23:59:59.000Z

406

Ultra high vacuum broad band high power microwave window  

DOE Patents [OSTI]

An improved high vacuum microwave window has been developed that utilizes high density polyethylene coated on two sides with SiOx, SiNx, or a combination of the two. The resultant low dielectric and low loss tangent window creates a low outgassing, low permeation seal through which broad band, high power microwave energy may be passed. No matching device is necessary and the sealing technique is simple. The features of the window are broad band transmission, ultra-high vacuum compatibility with a simple sealing technique, low voltage standing wave ratio, high power transmission and low cost. 5 figs.

Nguyen-Tuong, V.; Dylla, H.F. III

1997-11-04T23:59:59.000Z

407

Ceramic-glass-metal seal by microwave heating  

DOE Patents [OSTI]

A method for producing a ceramic-glass-metal seal by microwaving, mixes a slurry of glass sealing material and coupling agent and applies same to ceramic and metal workpieces. The slurry and workpieces are then insulated and microwaved at a power, time and frequency sufficient to cause a liquid-phase reaction in the slurry. The reaction of the glass sealing material forms a chemically different seal than that which would be formed by conventional heating because it is formed by diffusion rather than by wetting of the reactants.

Meek, T.T.; Blake, R.D.

1983-10-04T23:59:59.000Z

408

Applications for Microwave Generators in the Process Industries  

E-Print Network [OSTI]

. 14. Fix, S. R. "Microwave Devulcanization of Rub ber." (Goodyear Tire and Rubber Co., lincoln, NE, USA). US 4,104,205, Elastomerics, Vol. 112, No.6, pp. 1980, 38-40 (Eng). 15. Yamashita, I., Yamamoto, N., and Mima, S., "Decomposition of Waste... August 1978. 18. Novotny, D. S., et al. "Devulcanization of Sulfer-Vulcanized Elastomers." (Goodyear Tire and Rubber Co.) Ger. Offen. 2,700,306, 18 August 1977, US Appl. 646,821, 6 January 1976. 19. "Microwave Hardenable Molding Sand." (Ko matsu...

Humphrey, J. L.; Vasilakos, N. P.

1983-01-01T23:59:59.000Z

409

15 GHz Monitoring of the Gravitational Lens MG 0414+0534  

E-Print Network [OSTI]

We report the results of monitoring the four images of the gravitational lens MG 0414+0534 at 15 GHz. In 35 VLA maps spanning 180 days, we measure root-mean-square variations in the image light curves of ~3.5% mostly due to variations in the flux density calibration. The flux ratios, which are independent of flux density calibration variations, show root-mean-square variability of 1-3%. Extensive simulations of the data analysis process show that the observed variations in the flux ratios are likely to be due entirely to errors in the deconvolution process. It is possible that some of the observed variation is due to the source; however, the signal-to-noise ratio is too small to make a time delay determination using a data set of this size.

Christopher B. Moore; Jacqueline N. Hewitt

1997-08-08T23:59:59.000Z

410

MAJOR STRUCTURES OF THE INNER GALAXY DELINEATED BY 6.7 GHz METHANOL MASERS  

SciTech Connect (OSTI)

We explore the longitude-velocity distribution of 6.7 GHz methanol masers in the context of the inner structure of our Galaxy. We analyze the correlation in velocities within this distribution and identify density enhancements indicating large-scale regions of enhanced star formation. These are interpreted as the starting points of the spiral arms and the interaction of the Galactic bar with the 3 kpc arms. The methanol masers support the presence of a long thin bar with a 45{sup 0} orientation. Signatures of the full 3 kpc arm structure are seen, including a prominent tangent at approximately -22{sup 0} Galactic longitude. We compare this distribution with existing models of the gas dynamics of our Galaxy. The 3 kpc arm structure appears likely to correspond to the radius of corotation resonance of the bar, with the bar on its inner surface and the starting points of the spiral arms on its outer surface.

Green, J. A.; Caswell, J. L.; McClure-Griffiths, N. M.; Breen, S. L.; Voronkov, M. A. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia); Avison, A.; Fuller, G. A.; Gray, M. D. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, University of Manchester, Manchester, M13 9PL (United Kingdom); Burton, M. G. [School of Physics, University of New South Wales, Sydney, NSW 2052 (Australia); Ellingsen, S. P. [School of Mathematics and Physics, University of Tasmania, Private Bag 37, Hobart, TAS 7001 (Australia); Pestalozzi, M. [INAF/IFSI, via del Fosso del Cabaliere 100, I-00133 Roma (Italy); Thompson, M. A. [Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, College Lane, Hatfield, AL10 9AB (United Kingdom)

2011-05-20T23:59:59.000Z

411

The generation of shared cryptographic keys through channel impulse response estimation at 60 GHz.  

SciTech Connect (OSTI)

Methods to generate private keys based on wireless channel characteristics have been proposed as an alternative to standard key-management schemes. In this work, we discuss past work in the field and offer a generalized scheme for the generation of private keys using uncorrelated channels in multiple domains. Proposed cognitive enhancements measure channel characteristics, to dynamically change transmission and reception parameters as well as estimate private key randomness and expiration times. Finally, results are presented on the implementation of a system for the generation of private keys for cryptographic communications using channel impulse-response estimation at 60 GHz. The testbed is composed of commercial millimeter-wave VubIQ transceivers, laboratory equipment, and software implemented in MATLAB. Novel cognitive enhancements are demonstrated, using channel estimation to dynamically change system parameters and estimate cryptographic key strength. We show for a complex channel that secret key generation can be accomplished on the order of 100 kb/s.

Young, Derek P.; Forman, Michael A.; Dowdle, Donald Ryan

2010-09-01T23:59:59.000Z

412

A 2.45 GHz ECR ion source for production of medium charge states ions  

SciTech Connect (OSTI)

At the Lawrence Berkeley National Laboratory we are constructing an ECR ion source test facility for nuclear science as well as industrial applications experiments. For these purposes, a single-stage 2.45 GHz electron cyclotron resonance ion source has been designed and constructed. It features an axial magnetic field with a mirror ratio of up to six and a hexapole field produced by a simple Nd{endash}Fe{endash}B permanent magnet assembly. In order to enhance the ion confinement time, the source plasma volume has been enlarged as much as possible while still maintaining a high mirror ratio. This paper describes the design of the ion source, the extraction system and the test stand. First, operational experience and experimental results with an argon discharge are presented. {copyright} {ital 1998 American Institute of Physics.}

Wutte, D.C.; Leitner, M.A.; Williams, M.D.; Leung, K.N.; Gough, R.A. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Saadatmand, K.; Benveniste, V. [Eaton Corporation, Beverly, Massachusetts 01915 (United States)] [Eaton Corporation, Beverly, Massachusetts 01915 (United States)

1998-02-01T23:59:59.000Z

413

EVN observations of 6.7 GHz methanol masers from Medicina survey  

E-Print Network [OSTI]

We report VLBI observations of methanol masers in the brightest 5(1)-6(0) A+ transition at 6.7 GHz in NGC 281W, 18151-1208 and 19388+2357. Using the fringe rate method absolute positions were obtained for all observed sources. A linear ordered structure with a velocity gradient was revealed in NGC 281W. Under assumption that such structure is an edge-on Keplerian disk around the central object with a mass of 30Msun located at a distance of 3.5 kpc from the Sun, we estimated that methanol masers are situated at the distance about 400 a.u. from the center of the disk. A second epoch of observations was reported for L1206, GL2789 and 20062+3550. The upper limits on the relative motions of maser spots are estimated to be 4.7 km/s and 28 km/s for L1206 and GL2789 respectively.

Voronkov, M A; Palagi, F; Tofani, G

2002-01-01T23:59:59.000Z

414

EVN observations of 6.7 GHz methanol masers from Medicina survey  

E-Print Network [OSTI]

We report VLBI observations of methanol masers in the brightest 5(1)-6(0) A+ transition at 6.7 GHz in NGC 281W, 18151-1208 and 19388+2357. Using the fringe rate method absolute positions were obtained for all observed sources. A linear ordered structure with a velocity gradient was revealed in NGC 281W. Under assumption that such structure is an edge-on Keplerian disk around the central object with a mass of 30Msun located at a distance of 3.5 kpc from the Sun, we estimated that methanol masers are situated at the distance about 400 a.u. from the center of the disk. A second epoch of observations was reported for L1206, GL2789 and 20062+3550. The upper limits on the relative motions of maser spots are estimated to be 4.7 km/s and 28 km/s for L1206 and GL2789 respectively.

M. A. Voronkov; V. I. Slysh; F. Palagi; G. Tofani

2002-05-31T23:59:59.000Z

415

LARP LHC 4.8 GHZ Schottky System Initial Commissioning with Beam  

SciTech Connect (OSTI)

The LHC Schottky system consists for four independent 4.8 GHz triple down conversion receivers with associated data acquisition systems. Each system is capable of measuring tune, chromaticity, momentum spread in either horizontal or vertical planes; two systems per beam. The hardware commissioning has taken place from spring through fall of 2010. With nominal bunch beam currents of 10{sup 11} protons, the first incoherent Schottky signals were detected and analyzed. This paper will report on these initial commissioning results. A companion paper will report on the data analysis curve fitting and remote control user interface of the system. The Schottky system for the LHC was proposed in 2004 under the auspices of the LARP collaboration. Similar systems were commissioned in 2003 in the Fermilab Tevatron and Recycler accelerators as a means of measuring tunes noninvasively. The Schottky detector is based on the stochastic cooling pickups that were developed for the Fermilab Antiproton Source Debuncher cooling upgrade completed in 2002. These slotted line waveguide pickups have the advantage of large aperture coupled with high beam coupling characteristics. For stochastic cooling, wide bandwidths are integral to cooling performance. The bandwidth of slotted waveguide pickups can be tailored by choosing the length of the pickup and slot spacing. The Debuncher project covered the 4-8 GHz band with eight bands of pickups, each with approximately 500 MHz of bandwidth. For use as a Schottky detector, bandwidths of 100-200 MHz are required for gating, resulting in higher transfer impedance than those used for stochastic cooling. Details of hardware functionality are reported previously.

Pasquinelli, Ralph J.; /Fermilab; Jansson, Andreas; /ESS, Lund; Jones, O.Rhodri; Caspers, Fritz; /CERN

2011-03-18T23:59:59.000Z

416

A 220GHz InP HBT Solid-State Power Amplifier MMIC with at 8.2dB Compressed Gain  

E-Print Network [OSTI]

A 220GHz InP HBT Solid-State Power Amplifier MMIC with 90mW POUT at 8.2dB Compressed Gain Thomas B, CA, USA 91360 zgriffith@teledyne-si.com Abstract -- A 220 GHz Solid State Power Amplifer MMIC, Solid State Power Amplifier (SSPA). I. INTRODUCTION Future synthetic aperture radars and high resolution

Rodwell, Mark J. W.

417

A 180mW InP HBT Power Amplifier MMIC at 214 GHz Thomas B. Reed1  

E-Print Network [OSTI]

-- A solid state power amplifer MMIC is demonstrated with 180mW of saturated output power at 214GHz, from, MMICs, Power amplifier, Solid State Power Amplifier (SSPA). I. INTRODUCTION Active interest in increasing the saturated output power of solid-state power amplifiers has continued due to growing interest

Rodwell, Mark J. W.

418

A 75 GHz silicon metal-semiconductor-metal Schottky photodiode Sotiris Alexandrou, Chia-Chi Wang, and Thomas Y. Hsiang  

E-Print Network [OSTI]

A 75 GHz silicon metal-semiconductor-metal Schottky photodiode Sotiris Alexandrou, Chia-Chi Wang-semiconductor-metal (MSM) photodiodes with 300 nm finger width and spacing were measured with a subpicosecond electro of silicon MSM photodiodes. A configuration is suggested to improve the speed of these detectors at long

419

Characteristics of InP HEMT Harmonic Optoelectronic Mixers and Their Application to 60GHz Radio-on-Fiber Systems  

E-Print Network [OSTI]

. #12;Characteristics of InP HEMT Harmonic Optoelectronic Mixers and Their Application to 60GHz device characteristics of InP HEMT as a harmonic optoelectronic mixer. A single InP HEMT device performs is successfully demonstrated using InP HEMT harmonic optoelectronic mixer. Index Terms -- millimeter-wave, radio

Choi, Woo-Young

420

Comparison of Airborne and Spaceborne 95-GHz Radar Reflectivities and Evaluation of Multiple Scattering Effects in Spaceborne Measurements  

E-Print Network [OSTI]

of coincident measurements collected by an airborne 95-GHz radar during the African Monsoon Multidisci- plinary radar calibration is assessed. Collocated measurements of the spaceborne and airborne radars within the CloudSat measurements have to be corrected for this effect, if one wants to derive accurate level 2

Protat, Alain

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Concurrent Circuit-Level/System-Level Optimization of a 24 GHz Mixer for Automotive Applications Using a Hybrid  

E-Print Network [OSTI]

radar sensor can easily measure both the true ground speed of the vehicles and the relative speedConcurrent Circuit-Level/System-Level Optimization of a 24 GHz Mixer for Automotive Applications mixer is presented. The benchmarking geometry is a low-cost mixer for a Doppler Radar Sensor, built

Tentzeris, Manos

422

SP 23.6: A 1.8GHz CMOS Voltage-Controlled Oscillator BehzadRazavi  

E-Print Network [OSTI]

SP 23.6: A 1.8GHz CMOS Voltage-Controlled Oscillator BehzadRazavi University of California, Los that limit the tuning range of monolithic LC voltage-controlled oscillators (VCOs), especially at low supply voltages, and introduces circuit techniques that alle- viate this problem. Incorporating such techniques

Razavi, Behzad

423

>300GHz Fixed-Frequency and Voltage-Controlled Fundamental Oscillators in an InP DHBT Process  

E-Print Network [OSTI]

>300GHz Fixed-Frequency and Voltage-Controlled Fundamental Oscillators in an InP DHBT Process, 93106, USA Abstract -- We report fundamental fixed-frequency and voltage-controlled oscillators bandwidth. Index Terms -- Millimeter-wave oscillators, voltage-controlled oscillators, MMIC oscillators. I

Rodwell, Mark J. W.

424

SPECTRAL ANALYSIS OF A PHASE LOCKED LASER AT 891 GHz, AN APPLICATION OF JOSEPHSON JUNCTIONS IN THE FAR INFRARED  

E-Print Network [OSTI]

285 SPECTRAL ANALYSIS OF A PHASE LOCKED LASER AT 891 GHz, AN APPLICATION OF JOSEPHSON JUNCTIONS. Abstract. 2014 We have used a Josephson junction to investigate the spectral purity of an HCN laser which take advantage of the unique properties of the Josephson junction as a frequency multiplier and mixer

Paris-Sud XI, Université de

425

A Wideband Single-balanced Down-mixer for the 60 GHz Band in 65 nm CMOS  

E-Print Network [OSTI]

en- gineering today is the design of low-power low-cost sili- con transceiver front performance [2], [3]. This paper presents the design and implementation of one of the basic building blocks on a differential pair employing the current bleeding technique. An integrated 60 GHz wideband passive balun allows

Boyer, Edmond

426

Design and RF measurements of a 5 GHz 500 kW window for the ITER LHCD system  

E-Print Network [OSTI]

CEA/IRFM is conducting R\\&D efforts in order to validate the critical RF components of the 5 GHz ITER LHCD system, which is expected to transmit 20 MW of RF power to the plasma. Two 5 GHz 500 kW BeO pill-box type window prototypes have been manufactured in 2012 by the PMB Company, in close collaboration with CEA/IRFM. Both windows have been validated at low power, showing good agreement between measured and modeling, with a return loss better than 32 dB and an insertion loss below 0.05 dB. This paper reports on the window RF design and the low power measurements. The high power tests up to 500kW have been carried out in March 2013 in collaboration with NFRI. Results of these tests are also reported. In the current ITER LHCD design, 20 MW Continuous Wave (CW) of Radio-Frequency power at 5 GHz are expected to be generated and transmitted to the plasma. In order to separate the vacuum vessel pressure from the cryostat waveguide pressure, forty eight 5 GHz 500kW CW windows are to be assembled on the waveguide...

Hillairet, Julien; Dechambre, N; Delpech, L; Ekedahl, A; Faure, N; Goniche, M; Kim, J; Larroque, S; Magne, R; Marfisi, L; Namkung, W; Park, H; Park, S; Poli, S; Vulliez, K

2015-01-01T23:59:59.000Z

427

X-Band EPR Spectrometer with Customizable Arbitrary Waveform Generator based on a 1 GHz DAC Board  

E-Print Network [OSTI]

X-Band EPR Spectrometer with Customizable Arbitrary Waveform Generator based on a 1 GHz DAC Board-4120 , Email: songi@chem.ucsb.edu Abstract We present an EPR spectrometer featuring an arbitrary waveform of pulsed electron paramagnetic resonance (EPR) and enable new experiments. It generates shaped X

Martinis, John M.

428

Fractal-Shape 40 GHz Microstrip Bandpass Filter on High-Resistivity Si for Suppression of the 2nd  

E-Print Network [OSTI]

Fractal-Shape 40 GHz Microstrip Bandpass Filter on High-Resistivity Si for Suppression of the 2nd, the Koch fractal shape is applied for the first time to microstrip bandpass filters integrated on a high. To reduce the silicon substrate loss, high resistivity silicon (HRS) can be used. Several fractal geometries

Tentzeris, Manos

429

Impacts of Mobile Radar and Telecommunications Sys-tems on Earth Remote Sensing in the 22-27 GHz Range  

E-Print Network [OSTI]

) vehicular radar systems operating in the 22-27 GHz fre- quency range a technical assessment on the potential (GRSS) Technical Committee on Frequency Alloca- tion in Remote Sensing (FARS) is charged with providing suggests that inter- ference to the passive services at power levels several or- ders of magnitude above

Ruf, Christopher

430

Low Power Body Sensor Network for Wireless ECG Based on Relaying of Creeping Waves at 2.4GHz1  

E-Print Network [OSTI]

Low Power Body Sensor Network for Wireless ECG Based on Relaying of Creeping Waves at 2.4GHz1 Engineering Rochester Institute of Technology Abstract- A wireless communication platform for ECG operating applications that demand higher data rates than ECG.1 I. INTRODUCTION The Electrocardiogram (ECG) [1

Tsouri, Gill

431

Environmental assessment for the Satellite Power System (SPS) Concept Development and Evaluation Program (CDEP). [Microwave and non-microwave health and ecological assessment  

SciTech Connect (OSTI)

In the satellite power system (SPS), satellites in geosynchronous earth orbit would collect solar energy in space, convert it to microwaves, and transmit the microwaves to receiving antennas (rectennas) on earth. At the rectennas, the microwave energy would be converted to electricity. This SPS environmental assessment considers the microwave and nonmicrowave effects on the terrestrial environment and human health, atmospheric effects, and effects on electromagnetic systems. No environmental problem has been identified that would preclude the continued study of SPS technology. To increase the certainty of the assessment, some research has been initiated and long-term research is being planned.

Valentino, A.R.

1980-08-01T23:59:59.000Z

432

TGRS-2009-00082.R2 1 Abstract--The emission of bare soils at microwave L-band (1  

E-Print Network [OSTI]

will use a combined radiometer and high- resolution radar to measure surface soil moisture and freeze- thaw with sparse or no vegetation, the amount of this energy exchange is fundamentally linked with the moisture

Boyer, Edmond

433

ECRH microwave beam broadening in the edge turbulent plasma  

SciTech Connect (OSTI)

The influence of turbulent plasma density fluctuations on angular and spatial beam width is treated analytically in the framework of WKB based eikonal method. Reasonable agreement of analytical and numerical treatment results is demonstrated within the domain of quasi-optical approximation validity. Significant broadening of microwave beams is predicted for future ECRH experiments at ITER.

Sysoeva, E. V.; Gusakov, E. Z.; Popov, A. Yu. [Ioffe Institute, St. Petersburg, Russia and RL PAT SPbSPU, St. Petersburg (Russian Federation); Silva, F. da [Institute of Plasmas and Nuclear Fusion, IST, Lisbon (Portugal); Heuraux, S. [IJL UMR-7198 CNRS-Université de Lorraine, BP70239, 54506 Vandoeuvre Cedex (France)

2014-02-12T23:59:59.000Z

434

Use of passive microwave remote sensing to monitor soil moisture  

E-Print Network [OSTI]

January 1998) Abstract - Surface soil moisture is a key variable to describe the water and energy soil layer) is a key variable in the water and energy exchanges at the land surfaceReview Use of passive microwave remote sensing to monitor soil moisture Jean-Pierre Wignerona

Paris-Sud XI, Université de

435

Engineering of Ferrite-Graphite Composite Media for Microwave Shields  

E-Print Network [OSTI]

Engineering of Ferrite-Graphite Composite Media for Microwave Shields Marina Koledintseva, PoornaAA@mpei.ru Abstract-- An electromagnetic shielding of objects using ferrite-graphite composites is considered- shielding; dielectric base material; ferrite- graphite composite, Maxwell Garnett formulation I

Koledintseva, Marina Y.

436

Experimental Investigation of Microwave Vulnerabilities in CMOS Inverters  

E-Print Network [OSTI]

Experimental Investigation of Microwave Vulnerabilities in CMOS Inverters Agis A. Iliadis effects on single CMOS inverters, the fundamental building block of logic ICs, consisting of an NMOS and a PMOS transistor. The inverters were designed in our group and fabricated in the AMI-1.5µm MOSIS line

Anlage, Steven

437

Azimuth Variation in Microwave Backscatter over the Greenland Ice Sheet  

E-Print Network [OSTI]

Azimuth Variation in Microwave Backscatter over the Greenland Ice Sheet Ivan S. Ashcraft and David backscatter measurements are becoming an important tool for monitoring the dynamic behavior of the Greenland ice sheet. However, most Greenland studies assume constant backscatter for varying azimuth angles

Long, David G.

438

International Microwave Power Institute 127 ANALYSIS OF OPERATIONAL REGIMES  

E-Print Network [OSTI]

for microwave heating. KEY WORDS: Electric field, dissipated power, micro- wave power, model, permittivity heating systems oper ating at 915 MHz is a standard feature protecting the magnetron from reflections LOAD E. Eves and V. Yakovlev Reflections, electric field and dissipated power of a 915 MHz water load

Yakovlev, Vadim

439

Microwave properties of nanodiamond particles Daniel Slocombe,1,2  

E-Print Network [OSTI]

at microwave frequencies using a cavity perturbation technique, and results were compared with UV Raman detonation nanodiamond powders were sourced from PlasmaChem GmbH (G01 grade). This mate- rial is purified measured, designated U in what follows. Samples were then oxidised by burning the powders in air

Paris-Sud XI, Université de

440

Microwave-assisted synthesis of transition metal phosphide  

SciTech Connect (OSTI)

A method of synthesizing transition metal phosphide. In one embodiment, the method has the steps of preparing a transition metal lignosulfonate, mixing the transition metal lignosulfonate with phosphoric acid to form a mixture, and subjecting the mixture to a microwave radiation for a duration of time effective to obtain a transition metal phosphide.

Viswanathan, Tito

2014-12-30T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

A SIMPLIFIED ANALYSIS FOR HIGH POWER MICROWAVE BANDPASS FILTER STRUCTURES  

E-Print Network [OSTI]

and wireless diplexers. An exact analysis of the voltage/power distribution inside a filter involves the 3D is derived. This transformation is then used to relate the actual voltage distribution inside a transmissionA SIMPLIFIED ANALYSIS FOR HIGH POWER MICROWAVE BANDPASS FILTER STRUCTURES Apu Sivadas, Ming Yu

Yu, Ming

442

Flexible Graphene Field-Effect Transistors for Microwave Electronics  

E-Print Network [OSTI]

Flexible Graphene Field-Effect Transistors for Microwave Electronics Inanc Meric , Nicholas Petrone-frequency characteristics of graphene field-effect transistors (GFETs) has received significant interest due the very high carrier velocities in graphene. In addition to excellent electronic performance, graphene possesses

Shepard, Kenneth

443

Statistical Isotropy of the Cosmic Microwave Background Anisotropy  

E-Print Network [OSTI]

Statistical Isotropy of the Cosmic Microwave Background Anisotropy Amir Hajian #3; I.U.C.A.A., Pune to be statistically isotropic, i.e., statistical expectation values of the temperature #29;uctuations are preserved under rotations of the sky. Only under statistical isotropy does the widely used angular power spectrum

Souradeep, Tarun

444

Thermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby  

E-Print Network [OSTI]

- propagating high-temperature synthesis (SHS) for sintering of ceramic composites [14]. The magnetic (H, the microwave energy is supplied locally to the powder. It creates a confined hotspot, and initiates a self-propagating the powder prior to its ignition is simulated theoretically, taking into account the powder's temperature

Jerby, Eli

445

A NOVEL MICROWAVE CAMERA FOR NDE OF CONCRETE STRUCTURES  

E-Print Network [OSTI]

A NOVEL MICROWAVE CAMERA FOR NDE OF CONCRETE STRUCTURES By Maria Q. Feng1 , Yoo Jin Kim2 , Franco De Flaviis3 , and Luis Jofre 4 ABSTRACT: Nondestructive assessment of concrete structures heavily and cracks inside concrete caused by aging, deterioration, and seismic loading. The authors have developed

De Flaviis, Franco

446

Polymer Surface Modification Using Microwave-Oven-Generated Plasma  

E-Print Network [OSTI]

, diameter 160 mm) are from Fisher Scientific. Compressed oxygen and ethanol (100%) are from Air Products with plasma is a frequently used technique to accomplish surface modifi- cations that affect chemical products. Our approach relies on an unmodified "kitchen microwave oven" and standard laboratory glassware

Steinbock, Oliver

447

System to continuously produce carbon fiber via microwave assisted plasma processing  

DOE Patents [OSTI]

A method for continuously processing carbon fiber including establishing a microwave plasma in a selected atmosphere contained in an elongated chamber having a microwave power gradient along its length defined by a lower microwave power at one end and a higher microwave power at the opposite end of the elongated chamber. The elongated chamber having an opening in each of the ends of the chamber that are adapted to allow the passage of the fiber tow while limiting incidental gas flow into or out of said chamber. A continuous fiber tow is introduced into the end of the chamber having the lower microwave power. The fiber tow is withdrawn from the opposite end of the chamber having the higher microwave power. The fiber to is subjected to progressively higher microwave energy as the fiber is being traversed through the elongated chamber.

White, Terry L; Paulauskas, Felix L; Bigelow, Timothy S

2014-03-25T23:59:59.000Z

448

Microwave-emitting rotor, separator apparatus including same, methods of operation and design thereof  

DOE Patents [OSTI]

An apparatus for use in separating, at least in part, a mixture, including at least one chamber and at least one microwave generation device configured for communicating microwave energy into the at least one chamber is disclosed. The rotor assembly may comprise an electric generator for generating electricity for operating the microwave generation device. At least one microwave generation device may be positioned within a tubular interior shaft extending within the rotor assembly. At least a portion of the tubular interior shaft may be substantially transparent to microwave energy. Microwave energy may be emitted in an outward radial direction or toward an anticipated boundary surface defined between a mixture and a separated constituent thereof. A method including flowing a mixture through at least one chamber and communicating microwave energy into the at least one chamber while rotating same is disclosed. Methods of operating a centrifugal separator and design thereof are disclosed.

Meikrantz, David H.

2006-12-19T23:59:59.000Z

449

422 IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS, VOL. 19, NO. 6, JUNE 2009 Instantaneous Microwave Frequency Measurement  

E-Print Network [OSTI]

. I. INTRODUCTION MICROWAVE receiver for radar and other electronic warfare applications require of Information and Electronic Engineering, Zhejiang University, Hangzhou 310027, China (e-mail: chihao@zju.edu.cn). J. Yao is with the Department of Information and Electronic Engineering, Zhejiang University

Yao, Jianping

450

Comparing Optical and Microwave Remote Sensing-based Vegetation Density over Mongolia for 1988-2006  

E-Print Network [OSTI]

Vegetation Index (NDVI), derived from the Advanced Very High Resolution Radiometer (AVHRR) series.vandijk@csiro.au Abstract ­ Vegetation density plays an important role in water and energy balance. Satellite-based optical product (Tucker et al., 2005). It can provide a relatively high spatial resolution product (up to 1km

Evans, Jason

451

A New Upper Limit on the Large Angular Scale Polarization of the Cosmic Microwave Background Radiation  

E-Print Network [OSTI]

, dark matter, and dark energy to the overall energy density of the universe. In addition to being of a new breed of highly-sensitive instruments that will one day map out this interesting property knowledge, Brian Keat- ing, also deserves much credit. Thanks to him I have finally memorized the radiometer

Timbie, Peter

452

Efficient protocols for deterministic secure quantum communication using GHZ-like states  

E-Print Network [OSTI]

Two protocols for deterministic secure quantum communication (DSQC) using GHZ-like states have been proposed. It is shown that one of these protocols can be modified to an equivalent but more efficient protocol of quantum secure direct communication (QSDC). Security and efficiency of the proposed protocols are analyzed in detail and are critically compared with the existing protocols. It is shown that the proposed protocols are highly efficient. It is also shown that all the physical systems where dense coding is possible can be used to design maximally efficient protocol of DSQC and QSDC. Further, it is shown that dense coding is sufficient but not essential for DSQC and QSDC protocols of the present kind. We have shown that there exist a large class of quantum state which can be used to design maximally efficient DSQC and QSDC protocols of the present kind. It is further, observed that maximally efficient QSDC protocols are more efficient than their DSQC counterparts. This additional efficiency arises at the cost of message transmission rate.

Anindita Banerjee; Anirban Pathak

2012-01-18T23:59:59.000Z

453

Simulation Study of Current Drive Efficiency for KSTAR 5 GHz LHCD  

SciTech Connect (OSTI)

Theoretical 5 GHz lower hybrid current drive (LHCD) efficiency using power spectrum given by 0-D Brambilla code and Lower Hybrid Simulation Code (LSC) have been studied for KSTAR. In LSC simulation, RF-driven current and current drive efficiency has been found to be deeply dependent on the profiles of the plasma density and temperature as well as on current profile in order to obtain hollow current profile favorable for advance tokamak operation mode and steady state operation. The peaked density and broad temperature profile control has been found to be efficient in current drive with maximum RF-driven current larger than 400 kA/MW with very high efficiency when the peak plasma density is ranged from 0.2 to 2.0x1020 m-3, and the peak electron temperature range of 2-20 keV together with toroidal field 2-3.5 T and Ip = 0.5-2 MA. The on-/off-axis current profile controllability is also investigated through parametric scan, and small negative magnetic shear is seen at the narrow region of the off-axis for very high temperature regime and for high BT and I{sub p}. In order to achieve the same for lower temperature regime Ip has to be lower and also for higher LH-power compromising with CD efficiency in this case.

Aria, A. K.; Bae, Y. S.; Yang, H. L.; Kwon, M. [National Fusion Research Institute, Gwahangno 113, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Do, H. J.; Namkung, W.; Cho, M. H.; Park, H. [Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Pohang 790-784 (Korea, Republic of)

2011-12-23T23:59:59.000Z

454

Microwave generated electrodeless lamp for producing bright output  

SciTech Connect (OSTI)

A microwave generated electrodeless light source for producing a bright output comprising a lamp structure including a microwave chamber and a plasma medium-containing lamp envelope having a maximum dimension which is substantially less than a wavelength disposed therein. To provide the desired radiation output the interior of the chamber is coated with a UV-reflective material and the chamber has an opening for allowing UV radiation to exit, which is covered with a metallic mesh. The chamber is arranged to be near-resonant at a single wavelength, and the lamp envelope has a fill including mercury at an operating pressure of 1-2 atmospheres, while a power density of at least 250-300 (watts/cm/sup 3/) is coupled to the envelope to result in a relatively high deep UV output at a relatively high brightness.

Wood, Ch. H.; Ury, M. G.

1985-03-26T23:59:59.000Z

455

Microwave measurement of the mass of frozen hydrogen pellets  

DOE Patents [OSTI]

A nondestructive apparatus and method for measuring the mass of a moving object, based on the perturbation of the dielectric character of a resonant microwave cavity caused by the object passing through the cavity. An oscillator circuit is formed with a resonant cavity in a positive feedback loop of a microwave power amplifier. The moving object perturbs the resonant characteristics of the cavity causing a shift in the operating frequency of the oscillator proportional to the ratio of the pellet volume to the volume of the cavity. Signals from the cavity oscillation are mixed with a local oscillator. Then the IF frequency from the mixer is measured thereby providing a direct measurement of pellet mass based upon known physical properties and relationships. This apparatus and method is particularly adapted for the measurement of frozen hydrogen pellets.

Talanker, Vera (Golden, CO); Greenwald, Martin (Belmont, MA)

1990-01-01T23:59:59.000Z

456

Fabrication and characterization of aluminum airbridges for superconducting microwave circuits  

SciTech Connect (OSTI)

Superconducting microwave circuits based on coplanar waveguides (CPW) are susceptible to parasitic slotline modes which can lead to loss and decoherence. We motivate the use of superconducting airbridges as a reliable method for preventing the propagation of these modes. We describe the fabrication of these airbridges on superconducting resonators, which we use to measure the loss due to placing airbridges over CPW lines. We find that the additional loss at single photon levels is small, and decreases at higher drive powers.

Chen, Zijun; Kelly, J.; Barends, R.; Bochmann, J.; Chen, Yu; Chiaro, B.; Dunsworth, A.; Jeffrey, E.; Mutus, J. Y.; O'Malley, P. J. J.; Neill, C.; Roushan, P.; Sank, D.; Vainsencher, A.; Wenner, J.; White, T. C. [Department of Physics, University of California, Santa Barbara, California 93106-9530 (United States); Megrant, A. [Department of Physics, University of California, Santa Barbara, California 93106-9530 (United States); Department of Materials, University of California, Santa Barbara, California 93106 (United States); Cleland, A. N.; Martinis, John M., E-mail: martinis@physics.ucsb.edu [Department of Physics, University of California, Santa Barbara, California 93106-9530 (United States); California NanoSystems Institute, University of California, Santa Barbara, California 93106-9530 (United States)

2014-02-03T23:59:59.000Z

457

Microwave plasma CVD of NANO structured tin/carbon composites  

DOE Patents [OSTI]

A method for forming a graphitic tin-carbon composite at low temperatures is described. The method involves using microwave radiation to produce a neutral gas plasma in a reactor cell. At least one organo tin precursor material in the reactor cell forms a tin-carbon film on a supporting substrate disposed in the cell under influence of the plasma. The three dimensional carbon matrix material with embedded tin nanoparticles can be used as an electrode in lithium-ion batteries.

Marcinek, Marek (Warszawa, PL); Kostecki, Robert (Lafayette, CA)

2012-07-17T23:59:59.000Z

458

Effect of microwave radiation on Jayadhar cotton fibers: WAXS studies  

SciTech Connect (OSTI)

Thermal effect in the form of micro wave energy on Jayadhar cotton fiber has been investigated. Microstructural parameters have been estimated using wide angle x-ray scattering (WAXS) data and line profile analysis program developed by us. Physical properties like tensile strength are correlated with X-ray results. We observe that the microwave radiation do affect significantly many parameters and we have suggested a multivariate analysis of these parameters to arrive at a significant result.

Niranjana, A. R., E-mail: arnphysics@gmail.com; Mahesh, S. S., E-mail: arnphysics@gmail.com; Divakara, S., E-mail: arnphysics@gmail.com; Somashekar, R., E-mail: arnphysics@gmail.com [Department of Studies in Physics, University of Mysore, Mysore-570006 (India)

2014-04-24T23:59:59.000Z

459

Microwave-Assisted Synthesis of Fluorescent Carbon Nanoparticles  

E-Print Network [OSTI]

MICROWAVE-ASSITED SYNTHESIS OF FLUORESCENT CARBON NANOPARTICLES A Thesis by BONNIE CHEN Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree...-(hydroxymethyl) furfural (5- HMF) derivatives, which are major products of glucose decomposition. iv ACKNOWLEDGEMENTS This thesis was completed in my fourth year at Texas A&M University as a master's student, and analyzes, discusses and displays...

Chen, Bonnie

2014-08-19T23:59:59.000Z

460

Novel Birefringent Frequency Discriminator for Microwave Photonic Links  

E-Print Network [OSTI]

NOVEL BIREFRINGENT FREQUENCY DISCRIMINATOR FOR MICROWAVE PHOTONIC LINKS A Dissertation by JAE HYUN KIM Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree...-Division Multiplexing OPD Optical Path Length Different OVA Optical Vector Network Analyzer PBS Polarization Beam Splitter PM Phase Modulation PD Photodiode PDL Polarization Dependent Loss PLC Planar Lightwave Circuit QWP Quarter Wave Plate RAMZI Ring...

Kim, Jae Hyun

2013-04-22T23:59:59.000Z

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Beam Shaping for Short-Range Wireless Sensor Application at 2.4GHz using 0.18 Micrometer Technology  

E-Print Network [OSTI]

Beam Shaping for Short-Range Wireless Sensor Application at 2.4GHz using 0.18 ?m Technology Utkarshkrishna Unnikrishna, Sudipta Saha, Priyam Khanna, and Talal Al-Attar Department of Electrical Engineering, Center for Analog Design... SHAPING USING AMPLITUDE TAPERING In order to control the directivity of the array beam, we adjust the amplitude of each array element by scaling it. Thus for a 5x5 array, we would have 25 coefficients, one for each element and all scaled...

Saha, S.; Unnikrishna, U.; Khanna, P.; Al-Attar, T.

2010-01-01T23:59:59.000Z

462

Interfacing microwave qubits and optical photons via spin ensembles  

E-Print Network [OSTI]

A protocol is discussed which allows one to realize a transducer for single photons between the optical and the microwave frequency range. The transducer is a spin ensemble, where the individual emitters possess both an optical and a magnetic-dipole transition. Reversible frequency conversion is realized by combining optical photon storage, by means of EIT, with the controlled switching of the coupling between the magnetic-dipole transition and a superconducting qubit, which is realized by means of a microwave cavity. The efficiency is quantified by the global fidelity for transferring coherently a qubit excitation between a single optical photon and the superconducting qubit. We test various strategies and show that the total efficiency is essentially limited by the optical quantum memory: It can exceed 80% for ensembles of NV centers and approaches 99% for cold atomic ensembles, assuming state-of-the-art experimental parameters. This protocol allows one to bridge the gap between the optical and the microwave regime so to efficiently combine superconducting and optical components in quantum networks.

Susanne Blum; Christopher O'Brien; Nikolai Lauk; Pavel Bushev; Michael Fleischhauer; Giovanna Morigi

2015-01-23T23:59:59.000Z

463

The contribution of microbunching instability to solar flare emission in the GHz to THz range of frequencies  

SciTech Connect (OSTI)

Recent solar flare observations in the sub-terahertz range have provided evidence of a new spectral component with fluxes increasing for larger frequencies, separated from the well-known microwave emission that maximizes in the gigahertz range. Suggested interpretations explain the terahertz spectral component but do not account for the simultaneous microwave component. We present a mechanism for producing the observed "double spectra." Based on coherent enhancement of synchrotron emission at long wavelengths in laboratory accelerators, we consider how similar processes may occur within a solar flare. The instability known as microbunching arises from perturbations that produce electron beam density modulations, giving rise to broadband coherent synchrotron emission at wavelengths comparable to the characteristic size of the microbunch structure. The spectral intensity of this coherent synchrotron radiation (CSR) can far exceed that of the incoherent synchrotron radiation (ISR), which peaks at a higher frequency, thus producing a double-peaked spectrum. Successful CSR simulations are shown to fit actual burst spectral observations, using typical flaring physical parameters and power-law energy distributions for the accelerated electrons. The simulations consider an energy threshold below which microbunching is not possible because of Coulomb repulsion. Only a small fraction of the radiating charges accelerated to energies above the threshold is required to produce the microwave component observed for several events. The ISR/CSR mechanism can occur together with other emission processes producing the microwave component. It may bring an important contribution to microwaves, at least for certain events where physical conditions for the occurrence of the ISR/CSR microbunching mechanism are possible.

Klopf, J. Michael [William and Mary College; Kaufmann, Pierre; Raulin, Jean-Pierre; Szpigel, Sergio

2014-07-01T23:59:59.000Z

464

Multi-MW 22.8 GHz Harmonic Multiplier - RF Power Source for High-Gradient Accelerator R&D  

SciTech Connect (OSTI)

Electrodynamic and particle simulation studies have been carried out to optimize design of a two-cavity harmonic frequency multiplier, in which a linear electron beam is energized by rotating fields near cyclotron resonance in a TE111 cavity in a uniform magnetic field, and in which the beam then radiates coherently at the nth harmonic into a TEn11 output cavity. Examples are worked out in detail for 7th and 2nd harmonic converters, showing RF-to-RF conversion efficiencies of 45% and 88%, respectively at 19.992 GHz (K-band) and 5.712 GHz (C-band), for a drive frequency of 2.856 GHz. Details are shown of RF infrastructure (S-band klystron, modulator) and harmonic converter components (drive cavity, output cavities, electron beam source and modulator, beam collector) for the two harmonic converters to be tested. Details are also given for the two-frequency (S- and C-band) coherent multi-MW test stand for RF breakdown and RF gun studies.

Jay L. Hirshfield

2012-07-26T23:59:59.000Z

465

An angular power spectrum analysis of the DRAO 1.4 GHz polarization survey: implications for CMB observations  

E-Print Network [OSTI]

The aim of the present analysis is to improve the knowledge of the statistical properties of the Galactic diffuse synchrotron emission, which constrains sensitive CMB anisotropy measurements. We have analysed the new DRAO 1.4 GHz polarization survey together with the Stockert 1.4 GHz total intensity survey and derived the angular power spectra (APSs) of the total intensity, the polarized emission, and their cross-correlation for the entire surveys and for three low-intensity regions. The APSs of the diffuse synchrotron emission are modelled by power laws. For the $E$ and $B$ modes, a slope of $\\alpha \\sim [-3.0,-2.5]$ for the multipole range $\\sim [30,300]$ is found. By the extrapolation of these results to 70 GHz, we can estimate the Galactic synchrotron contamination of CMB anisotropies, and we find results that are compatible with the ones coming from WMAP 3-yr data. In the low-intensity regions, the cosmological primordial B~mode peak at $\\ell \\sim 100$ should be clearly observable for a tensor-to-scalar ...

La Porta, L; Reich, W; Reich, P

2006-01-01T23:59:59.000Z

466

A microwave tomography system using a tunable mirror for beam steering  

SciTech Connect (OSTI)

Microwave tomography is a fast-growing technique in the fields of NDE and medical industry. This paper presents a new microwave tomography system which reduces the complexities of conventional microwave imaging systems by utilizing a reconfigurable mirror, a tunable reflectarray antenna. In order to build a tunable reflectarray with beam steering capabilities, the unit cell characteristics should dynamically alter. Modelling and experimental results of a single unit cell are presented in this work.

Tayebi, A. [Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 (United States); Non-Destructive Evaluation Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physic (United States); Tang, J. [Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 (United States); Paladhi, P. Roy; Udpa, L.; Udpa, S. [Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 (United States); Non-Destructive Evaluation Laboratory, Michigan State University, East Lansing, MI 48824 (United States)

2014-02-18T23:59:59.000Z

467

Design and testing of an internal mode converter for a 1.5 MW, 110 GHz gyrotron with a depressed collector  

E-Print Network [OSTI]

We report experimental results on a 1.5 MW, 110 GHz, 3 microsecond pulsed gyrotron with a single-stage depressed collector. A simplified mode converter with smooth mirror surfaces has been installed in the tube. The converter ...

Tax, David Samuel

468

Temperature and pore pressure distribution in a concrete slab during the microwave decontamination process  

SciTech Connect (OSTI)

As an application of microwave engineering, the new technology of concrete decontamination and decommissioning using microwave energy has been recently developed. The temperature and pore pressure within the concrete are studied theoretically in this paper. The heat and mass transfer within the porous concrete, coupled with temperature dependent dielectric property are investigated. The effects of microwave frequency (f), microwave power intensity (Q{sub 0,ave}), concrete porosity ({phi}) on the temperature and pore pressure distributions and their variations are fully discussed. The effects of the variation of complex dielectric permittivity ({epsilon}) and presentation of different steel reinforcements are also illustrated.

Li, W.; Ebadian, M.A. [Florida International Univ., Miami, FL (United States). Dept. of Mechanical Engineering; White, T.L.; Grubb, R.G.; Foster, D. Jr. [Oak Ridge National Lab., TN (United States)

1994-10-01T23:59:59.000Z

469

Electron cyclotron resonant multicusp magnetic field microwave plasma source for electric propulsion  

SciTech Connect (OSTI)

The development of electrodeless microwave ion and plasma sources has been a recent, very active research project at Michigan State University. The results are efficient, compact microwave discharge configurations that operate at low pressures (0.5 mtorr to 100 mtorr) and efficiently produce low energy ions and free radicals and broad ion beams for oxidation, deposition, and etching experiments. The microwave discharge technology developed for these applications may be useful for application in electric propulsion. This paper reviews this microwave applicator technology and indicates how it may be extended to higher power levels and applied to electric propulsion systems. 12 references.

Dahimene, M.; Mahoney, L.; Asmussen, J.

1987-05-01T23:59:59.000Z

470

Production of large resonant plasma volumes in microwave electron cyclotron resonance ion sources  

DOE Patents [OSTI]

Microwave injection methods are disclosed for enhancing the performance of existing electron cyclotron resonance (ECR) ion sources. The methods are based on the use of high-power diverse frequency microwaves, including variable-frequency, multiple-discrete-frequency, and broadband microwaves. The methods effect large resonant ``volume`` ECR regions in the ion sources. The creation of these large ECR plasma volumes permits coupling of more microwave power into the plasma, resulting in the heating of a much larger electron population to higher energies, the effect of which is to produce higher charge state distributions and much higher intensities within a particular charge state than possible in present ECR ion sources. 5 figs.

Alton, G.D.

1998-11-24T23:59:59.000Z

471

E-Print Network 3.0 - atmospheric pressure microwave Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

carbon as a reducing agent under a nitro- gen ... Source: Agrawal, Dinesh - Microwave Processing and Engineering Center, Pennsylvania State University Collection: Materials...

472

E-Print Network 3.0 - advanced microwave processing Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

RF Phase Shifter Yu Yan and Jianping Yao... , Senior Member, IEEE Abstract--A novel tunable photonic microwave filter ... Source: Yao, Jianping - School of Information...

473

E-Print Network 3.0 - aces microwave link Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Microw. Theory Tech., vol... 1 Abstract-- A novel approach to generating a frequency- tunable microwave or sub-terahertz wave... a dispersive fiber. By applying these optical...

474

Using Radar, Lidar and Radiometer Data from NSA and SHEBA to Quantify Cloud Property Effects on the Surface Heat Budget in the Arctic  

SciTech Connect (OSTI)

Cloud and radiation data from two distinctly different Arctic areas are analyzed to study the differences between coastal Alaskan and open Arctic Ocean region clouds and their respective influence on the surface radiation budget. The cloud and radiation datasets were obtained from (1) the DOE North Slope of Alaska (NSA) facility in the coastal town of Barrow, Alaska, and (2) the SHEBA field program, which was conducted from an icebreaker frozen in, and drifting with, the sea-ice for one year in the Western Arctic Ocean. Radar, lidar, radiometer, and sounding measurements from both locations were used to produce annual cycles of cloud occurrence and height, atmospheric temperature and humidity, surface longwave and shortwave broadband fluxes, surface albedo, and cloud radiative forcing. In general, both regions revealed a similar annual trend of cloud occurrence fraction with minimum values in winter (60-75%) and maximum values during spring, summer and fall (80-90%). However, the annual average cloud occurrence fraction for SHEBA (76%) was lower than the 6-year average cloud occurrence at NSA (92%). Both Arctic areas also showed similar annual cycle trends of cloud forcing with clouds warming the surface through most of the year and a period of surface cooling during the summer, when cloud shading effects overwhelm cloud greenhouse effects. The greatest difference between the two regions was observed in the magnitude of the cloud cooling effect (i.e., shortwave cloud forcing), which was significantly stronger at NSA and lasted for a longer period of time than at SHEBA. This is predominantly due to the longer and stronger melt season at NSA (i.e., albedo values that are much lower coupled with Sun angles that are somewhat higher) than the melt season observed over the ice pack at SHEBA. Longwave cloud forcing values were comparable between the two sites indicating a general similarity in cloudiness and atmospheric temperature and humidity structure between the two regions.

Janet Intrieri; Mathhew Shupe

2005-01-01T23:59:59.000Z

475

IEEE TRANSACTIONS ON TERAHERTZ SCIENCE AND TECHNOLOGY, VOL. 3, NO. 4, JULY 2013 453 Prototype 250 GHz Bandwidth Chip to Chip  

E-Print Network [OSTI]

), and relatively low attenuation. Our achieved performance with a power loss of 5.8 dB/m approaches that needed a power loss of 260 dB/100 ft (equivalent to 8.5 dB/m) at 50 GHz.1 This loss is mainly due to the PTFE with frequency to a loss of 85 dB/m at 500 GHz. This power loss has been previously measured to be 278 d

Oklahoma State University

476

Superconducting hot-electron nanobolometer with microwave bias and readout  

E-Print Network [OSTI]

We propose a new detection technique based on radio-frequency (RF) bias and readout of an antenna-coupled superconducting nanobolometer. This approach is suitable for Frequency-Division-Multiplexing (FDM) readout of large arrays using broadband low-noise RF amplifier. We call this new detector RFTES. This feasibility study was made on demonstrator devices which are made in all-Nb technology and operate at 4.2 K. The studied RFTES devices consist of an antenna-coupled superconducting nanobolometer made of ultrathin niobium films with transition temperature Tc = 5.2 K. The 0.65-THz antenna and nanobolometer are embedded as a load into a GHz-range coplanar niobium resonator (Tc = 8.9 K, Q = 4000). To heat the superconducting Nb nanobolometer close to the Tc, the RF power at resonator frequency f = 5.8 GHz is applied via a transmission line which is weakly coupled (-11 dB) to the loaded resonator. The THz-antenna of RFTES was placed in the focus of a sapphire immersion lens inside a He4-cryostat equipped with an ...

Kuzmin, A A; Shitov, S V; Abramov, N N; Ermakov, A B; Arndt, M; Wuensch, S H; Ilin, K S; Ustinov, A V; Siegel, M

2014-01-01T23:59:59.000Z

477

Remote three-dimensional temperature sensing using planar laser induced fluorescence : development and applications to microwave heated liquids  

E-Print Network [OSTI]

Microwave heating is an important technology that has been hampered in application by difficulties in measuring temperatures and temperature distributions during the microwave heating process. This thesis describes the ...

Finegan, Timothy Michael

2004-01-01T23:59:59.000Z

478

Modelling microwave cooking; theory and experiment C.J. Budd, Centre for Nonlinear Mechanics, University of Bath, UK,  

E-Print Network [OSTI]

is that they reveal that the fields in a typical microwave cavity (such as a domestic cooker) are very sensitive a microwave cooker and a scenario used for experimental testing is shown in Figure. ??. PICTURE OF THE COOKER

Burton, Geoffrey R.

479

S162 july 2008| AcknowledgmentS. Over 300 individuals from  

E-Print Network [OSTI]

Acquisition System AVHRR Advanced Very High Resolution Radiometer AVISO Archiving, Validating: Acronyms A Anticyclonic days ACC Antarctic Circumpolar Current ACE NOAA's Accumulated Cyclone Energy Index Multidecadal Mode AMO Atlantic Multidecadal Oscillation AMSR-E Advanced Microwave Scanning Radiometer for Earth

480

2068 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 54, NO. 5, MAY 2006 Modeling of Realistic Rectangular -Coaxial Lines  

E-Print Network [OSTI]

the microwave spectrum can benefit from such lines. For example, Alessandri et al. [5] demonstrated a high

Popovic, Zoya

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