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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

183-GHz Radiometer Handbook - November 2006  

SciTech Connect (OSTI)

The G-Band Vapor Radiometer (GVR) provides time-series measurements of brightness temperatures from four double sideband channels centered at ± 1, ± 3, ± 7, and ± 14 GHz around the 183.31-GHz water vapor line. Atmospheric emission in this spectral region is primarily due to water vapor, with some influence from liquid water. The 183.31 ± 14-GHz channel is particularly sensitive to the presence of liquid water. The sensitivity to water vapor of the 183.31-GHz line is approximately 30 times higher than at the frequencies of the two-channel microwave radiometer (MWR) for a precipitable water vapor (PWV) amount of less than 2.5 mm. Measurements from this nstrument are therefore especially useful during low-humidity conditions (PWV < 5 mm).

MP Cadeddu

2006-11-30T23:59:59.000Z

3

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

4

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

5

Ground-Based Microwave Radiometer Measurements  

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

Ground-Based Microwave Radiometer Measurements Ground-Based Microwave Radiometer Measurements and Radiosonde Comparisons During the WVIOP2000 Field Experiment D. Cimini University of L'Aquila L'Aquil, Italy E. R. Westwater Cooperative Institute for Research in the Environmental Sciences University of Colorado National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado Y. Han Science System Applications National Aeronautics Space Administration Goddard Space Flight Center Greenbelt, Maryland S. Keihm Jet Propulsion Laboratory California Institute of Technology Pasadena, California Introduction During September to October 2000, a water vapor intensive operational period (WVIOP) was conducted at the Atmospheric Radiation Measurement (ARM) Program's Southern Great Plains (SGP) Cloud and

6

Differential Microwave Radiometer and the Cosmic Microwave Background |  

Office of Science (SC) Website

Differential Differential Microwave Radiometer and the Cosmic Microwave Background Laboratory Policy and Evaluation (LPE) LPE Home Staff M&O Contracts SC Laboratory Appraisal Process Laboratory Planning Process Work for Others in the Office of Science Laboratory Directed Research and Development (LDRD) DOE's Philosophy on LDRD Frequently Asked Questions Success Stories Brochures Additional Information LDRD Program Contacts Technology Transfer DOE National Laboratories Contact Information Laboratory Policy and Evaluation U.S. Department of Energy SC-32/Forrestal Building 1000 Independence Ave., SW Washington, DC 20585 P: (202) 586-5447 F: (202) 586-3119 Success Stories Differential Microwave Radiometer and the Cosmic Microwave Background Print Text Size: A A A RSS Feeds FeedbackShare Page

7

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)

MEASUREMENTS AND RETRIEVALS FROM A NEW 183-GHz WATER VAPOR RADIOMETER IN MEASUREMENTS AND RETRIEVALS FROM A NEW 183-GHz WATER VAPOR RADIOMETER IN THE ARCTIC Cadeddu, Maria Argonne National Laboratory Category: Instruments A new G-band (183 GHz) vapor radiometer (GVR), developed and built by Prosensing Inc. (http://www.prosensing.com), was deployed in Barrow, Alaska, in April 2005. The radiometer was deployed as part of the ongoing Atmospheric Radiation Measurement (ARM) program's effort to improve water vapor retrievals in the cold, dry Arctic environment. The instrument measures brightness temperatures from four double sideband channels centered at 1, 3, 7, and 14 GHz from the 183.31-GHz water vapor line. Atmospheric emission in this spectral region is primarily due to water vapor, with some influence from liquid water. The GVR will remain in Barrow

8

Microwave interferometer using 94-GHz solid-state sources  

SciTech Connect (OSTI)

A 94-GHz microwave interferometer has been designed for the Tandem Mirror Experiment Upgrade and the Mirror Fusion Test Facility to replace the 140-GHz system. The new system is smaller and has modular single-channel units designed for high reliability. It is magnetically shielded and can be mounted close to the machine, which allows the use of lower power solid-state sources. Test results of the 94-GHz prototype indicate that the phase resolution is better than 1/sup 0/, the Impatt FM noise is 5 MHz wide, and the Gunn FM noise is 6 kHz wide. This paper presents the antenna designs along with the test results and discusses the unique problems associated with diagnosing a high electron temperature plasma in the presence of electron cyclotron resonant heating.

Coffield, F.E.; Thomas, S.R.; Lang, D.D.; Stever, R.D.

1983-11-14T23:59:59.000Z

9

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

10

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

11

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

12

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)

Satellite-Derived Liquid Water Paths Using Satellite-Derived Liquid Water Paths Using ARM SGP Microwave Radiometers M. M. Khaiyer and J. Huang Analytical Services & Materials, Inc. Hampton, Virginia P. Minnis, B. Lin, and W. L. Smith, Jr. National Aeronautics and Space Administration Langley Research Center Hampton, Virginia A. Fan Science Applications International Corporation Hampton, Virginia A. Rapp Colorado State University Fort Collins, Colorado Introduction Satellites are useful for monitoring climatological parameters over large domains. They are especially useful for measuring various cloud microphysical and radiative parameters where ground-based instruments are not available. The geostationary operational environmental satellite (GOES) has been used to retrieve cloud and radiative properties over an extended domain centered on the Atmospheric

13

On the challenges of tomography retrievals of a 2D water vapor field using ground-based microwave radiometers: An observation system simulation experiment  

Science Journals Connector (OSTI)

Two-dimensional water vapor fields were retrieved by simulated measurements from multiple ground-based microwave radiometers using a tomographic approach. The goal of this paper was to investigate how the various aspects of the instrument set-up (...

Véronique Meunier; David D. Turner; Pavlos Kollias

14

Microwave Properties of Ice-Phase Hydrometeors for Radar and Radiometers: Sensitivity to Model Assumptions  

Science Journals Connector (OSTI)

A simplified framework is presented for assessing the qualitative sensitivities of computed microwave properties, satellite brightness temperatures, and radar reflectivities to assumptions concerning the physical properties of ice-phase ...

Benjamin T. Johnson; Grant W. Petty; Gail Skofronick-Jackson

2012-12-01T23:59:59.000Z

15

G-Band Vapor Radiometer Profiler (GVRP) Handbook  

SciTech Connect (OSTI)

The G-Band Vapor Radiometer Profiler (GVRP) provides time-series measurements of brightness temperatures from 15 channels between 170 and 183.310 GHz. Atmospheric emission in this spectral region is primarily due to water vapor, with some influence from liquid water. Channels between 170.0 and 176.0 GHz are particularly sensitive to the presence of liquid water. The sensitivity to water vapor of the 183.31-GHz line is approximately 30 times higher than at the frequencies of the two-channel microwave radiometer (MWR) for a precipitable water vapor (PWV) amount of less than 2.5 mm. Measurements from the GVRP instrument are therefore especially useful during low-humidity conditions (PWV < 5 mm). In addition to integrated water vapor and liquid water, the GVRP can provide low-resolution vertical profiles of water vapor in very dry conditions.

Caddeau, MP

2010-06-23T23:59:59.000Z

16

A 250 GHz microwave interferometer for divertor experiments on DIII-D  

SciTech Connect (OSTI)

A new 250 GHz, two-frequency microwave interferometer system has been developed to diagnose divertor plasmas on DIII-D. This diagnostic will measure the line-averaged density across both the inner and outer, lower divertor legs. With a cut-off density of over 7 {times} 10{sup 14} cm{sup {minus}3}, temporal measurements of ELMs, MARFs and plasma detachment are expected. The outer leg system will use a double pass method while the inner leg system will be single pass. Two special 3D carbon composite tiles are used, one to protect the microwave antennas mounted directly under the strike point and the other as the outer leg reflecting surface. Performance, design constraints, and the thermalmechanical design of the 3D carbon composite tiles are discussed.

James, R.A.; Nilson, D.G.; Stever, R.D.; Hill, D.N.; Casper, T.A.

1994-01-31T23:59:59.000Z

17

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)

Monitoring of Precipitable Water Vapor and Cloud Liquid Monitoring of Precipitable Water Vapor and Cloud Liquid Path from Scanning Microwave Radiometers During the 2003 Cloudiness Inter-Comparison Experiment V. Mattioli Department of Electronic and Information Engineering University of Perugia Perugia, Italy E. R. Westwater Cooperative Institute for Research in Environmental Sciences University of Colorado National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado V. Morris Pacific Northwest National Laboratory Richland, Washington Introduction Ground-based microwave radiometers (MWR) are widely used to measure atmospheric precipitable water vapor (PWV) and cloud liquid path (CLP). Comparisons of PWV derived from MWRs with water vapor retrievals from instruments like radiosondes, Global Positioning System (GPS) and Raman

18

Development of a simple 2.45 GHz microwave plasma with a repulsive double hexapole configuration  

SciTech Connect (OSTI)

A simple and inexpensive 2.45 GHz microwave plasma source with a repulsive double hexapole configuration is described and characterized. In this work, the operation of the source is shown to be flexible in terms of electron density, electron temperature, and plasma uniformity even at low-pressures (approximately millitorr). It allows for easy control of the electron temperature (2-3.8 eV) and density ({approx}10{sup 9}-10{sup 10} cm{sup -3}) by removing either of the two hexapoles or by varying the separation distance between the two hexapoles. Characterization was done via information gathered from the usual Langmuir probe measurements for electron temperature and density. The source makes a resonant surface with its repulsive double hexapole magnetic configuration providing an additional longitudinal confinement near the walls midway between the two hexapoles. Magnetic field maps are presented for varying double hexapole distances. Power delivery for various settings is also presented.

Arciaga, Marko; Ulano, April; Lee, Henry Jr.; Lledo, Rumar; Ramos, Henry [National Institute of Physics, College of Science, University of the Philippines, Diliman, Quezon City 1101 (Philippines); Tumlos, Roy [Department of Physical Science and Mathematics, College of Arts and Sciences, University of the Philippines, Manila 1000 (Philippines)

2008-09-15T23:59:59.000Z

19

MWRRET (Microwave Radiometer Retrievals)  

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

Plus Plus Plus Andy Vogelmann, Dave Turner Andy Vogelmann, Dave Turner & Jennifer Comstock & Jennifer Comstock Min Min Susanne Crewell Susanne Crewell Ulrich L Ulrich L ö ö rnard rnard Jim Liljegren Jim Liljegren John Ogre John Ogre . Y. Matrosov . Y. Matrosov Sally McFarlane Sally McFarlane Warren Wiscombe, Christine Chiu, Sasha Marshak, Maria Warren Wiscombe, Christine Chiu, Sasha Marshak, Maria Cadeddu, Qilong Min, Susanne Crewell, Ulrich L Cadeddu, Qilong Min, Susanne Crewell, Ulrich L ö ö hnert, Mandy hnert, Mandy M. Khaiyer, Greg McFarquhar , Chuck Long, Bill O M. Khaiyer, Greg McFarquhar , Chuck Long, Bill O ' ' Hirok, Bin Hirok, Bin Lin, Connor Flynn, Eli Mlawer, Graham Feingold, Jim Barnard, Lin, Connor Flynn, Eli Mlawer, Graham Feingold, Jim Barnard,

20

IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS, VOL. 19, NO. 6, JUNE 2009 407 A 0.15 GHz Cryogenic SiGe MMIC LNA  

E-Print Network [OSTI]

IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS, VOL. 19, NO. 6, JUNE 2009 407 A 0.1­5 GHz Cryogenic for operation at cryogenic temperatures is presented. At room temperature, the cir- cuit provides greater than and the first matched wideband cryogenic integrated circuit LNA that covers frequencies as low as 0.1 GHz. Index

Weinreb, Sander

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

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

22

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

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

A wind speed retrieval algorithm by combining 6 and 10 GHz data from Advanced Microwave Scanning Radiometer: Wind speed inside hurricanes  

Science Journals Connector (OSTI)

A wind speed retrieval algorithm was developed using 6 and ... aboard AQUA, for the purpose of retrieving wind speed inside rainstorms, primarily hurricanes and typhoons. ... because the brightness temperature se...

Akira Shibata

2006-06-01T23:59:59.000Z

25

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

26

Comparison of diamond-like carbon films synthesized by 2.45 \\{GHz\\} microwave and 13.56 \\{MHz\\} multi-jet radiofrequency plasma sources  

Science Journals Connector (OSTI)

Diamond-like carbon films (DLC) were grown by two different plasma deposition systems: the RF–MW system employing a radio frequency (RF) powered substrate holder with an additional 2.45 \\{GHz\\} slot antenna (SLAN) microwave (MW) plasma source and the RF–RF system employing a RF powered substrate holder with an additional RF (13.56 MHz) jet matrix plasma source (JeMPS). Helium and methane were used as carrier gas and carbon source, respectively. When operating the RF–MW system, ion densities approached 4×1010 cm?3. Because of the large working distance used in our experiments the MW plasma did not contribute significantly to the charged particle density. In the RF–RF system substantially higher ion concentrations of up to 1.6×1011 cm?3 were measured. Optical and structural properties of the coatings deposited were compared using ellipsometry, Raman spectroscopy and Fourier transform infrared (FTIR). When depositing with the RF–MW system a gradual and controllable change from polymer-like to DLC-based films with increasing substrate RF-power was obtained. This is reflected by a refractive index variation from 1.6 to 2.1. Furthermore, the film growth rates decreased with increasing RF-bias. Typical growth rates were 30 nm min?1 at ?400 to ?500 V bias. A similar change of the films deposited in the RF–RF system was not observed. Instead, DLC films were produced in all cases. The growth rate peaked at 70–80 nm min?1 when using ?350 to ?450 V bias. The refractive index (at ?=632 nm) and Vickers hardness were approximately 2.3 and 30 GPa, respectively.

G. Fedosenko; D. Korzec; A. Schwabedissen; J. Engemann; E. Braca; J.M. Kenny

2001-01-01T23:59:59.000Z

27

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

28

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

29

G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) Value-Added Product  

SciTech Connect (OSTI)

The G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) value-added product (VAP) computes precipitable water vapor using neural network techniques from data measured by the GVR. The GVR reports time-series measurements of brightness temperatures for four channels located at 183.3 ± 1, 3, 7, and 14 GHz.

Koontz, A; Cadeddu, M

2012-12-05T23:59:59.000Z

30

GVR (G-Band Vapor Radiometer) M.P. Cadeddu and J.C. Liljegren Argonne Natl. Laboratory  

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

MWR status MWR status M.P. Cadeddu New radiometers New radiometers ECO-00664 (MWR procurement) open Specifications have been written and submitted Draft of specifications sent to vendors last month A few changes were incorporated after vendors feedback. Final specification document will be sent next week. ECO-00664 (MWR procurement) open Specifications have been written and submitted Draft of specifications sent to vendors last month A few changes were incorporated after vendors feedback. Final specification document will be sent next week. PWV-LWP: 12 2-channel MWR Temperature-humidity profile: 2 profilers operating Low LWP-PWV: 2 183-GHz radiometers Low LWP: 2 90/150-GHz radiometers PWV-LWP: 12 2-channel MWR Temperature-humidity profile: 2 profilers

31

Lighting Research Group: Facilities: Spectro-Radiometer  

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

Spectro-Radiometer Spectro-Radiometer Spectro-Radiometer spectro-radiometer Gonio-photometer | Integrating sphere | Power analyzer | Spectro-radiometer The spectro-radiometer is used to measure the light output of a light source at each wavelength. The part that looks like a video camera (to the far right in the picture) can look at each wavelength separately. The spectro-radiometer can also be used as a standard light meter and measure all visible wavelengths at once to obtain the total light output of a source. The console portion of the spectro-radiometer is used to display the meter readings and also to adjust measurement settings like the sensitivity. The computer is interfaced with the spectro-radiometer and is used to send commands to the machine and receive, store, and analyze the data.

32

Theoretical and experimental study of 2.45 GHz rectifying antennas  

E-Print Network [OSTI]

This thesis presents a study on 2.45 GHz rectifying antennas (rectennas). The rectenna is a major component in a microwave power transmission system. The main feature is the conversion efficiency from microwave power to direct current (DC) power...

McSpadden, James Oliver

2012-06-07T23:59:59.000Z

33

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

34

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

35

Scanning multichannel microwave radiometer snow water equivalent assimilation  

E-Print Network [OSTI]

(AMSR-E) observing system. Many investi- gators have carefully evaluated the accuracy of remotely sensed

Walker, Jeff

36

Design and Demonstration of an Interference Suppressing Microwave Radiometer  

E-Print Network [OSTI]

spectrum. For L-band systems, 27 MHz is protected from 1400-1427 MHz, but bandwidths on the order of 100 Kinnear Rd., Columbus, OH 43212 hampson.8, johnson.1374 @osu.edu *Department of Electrical and Computer MHz of spectrum and applies real-time RFI mitigation tech- niques using FPGAs. A field test

Ellingson, Steven W.

37

Conduction-electron spin resonance in aluminum at 79 GHz  

Science Journals Connector (OSTI)

Conduction-electron spin resonance in aluminum has been studied by the microwave transmission technique at 79 GHz over the temperature range 4-80 K. At low temperatures the g value and linewidth show the same type of anomalous temperature dependence as reported earlier at 35 GHz. At high temperatures, where the linewidth reflects the spin-flip scattering rate from thermal phonons, a strong and unexpected frequency dependence is observed with the linewidth being proportional to the applied frequency.

G. L. Dunifer and M. R. Pattison

1976-08-01T23:59:59.000Z

38

Integration of Global Positioning System and Scanning Water Vapor Radiometers for Precipitable Water Vapor and Cloud Liquid Path Estimates  

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

Integration of Global Positioning System and Scanning Integration of Global Positioning System and Scanning Water Vapor Radiometers for Precipitable Water Vapor and Cloud Liquid Path Estimates V. Mattioli and P. Basili Department of Electronic and Information Engineering University of Perugia Perugia, Italy E. R. Westwater Cooperative Institute for Research in Environmental Sciences University of Colorado National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado Introduction In recent years the Global Positioning System (GPS) has proved to be a reliable instrument for measuring precipitable water vapor (PWV) (Bevis et al. 1992), offering an independent source of information on water vapor when compared with microwave radiometers (MWRs), and/or radiosonde

39

Ground-Based and Airborne (PMS 2-D Probe Canister-Mounted) 183 GHz Water  

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

Ground-Based and Airborne (PMS 2-D Probe Canister-Mounted) 183 GHz Water Ground-Based and Airborne (PMS 2-D Probe Canister-Mounted) 183 GHz Water Vapor Radiometer Pazmany, Andrew ProSensing Inc. Category: Instruments ProSensing Inc. has developed a G-band (183 GHz, 1.5 mm wavelength) water vapor radiometer (GVR) for the measurement of low concentrations of atmospheric water vapor and liquid water. The instrument's precipitable water vapor measurement precision is approximately 0.01 mm in dry (<2 mm vapor column) conditions. The ground-based version of the instrument was first deployed at ProSensing's facility in Amherst, MA in February 2005, then at the North Slope of Alaska DOE ARM site in Barrow AK in April 2005, where it has been continuously operating since. An airborne version, designed to operate from a standard PMS 2-D probe canister, is now being

40

Tropospheric Water Vapor Profiles Retrieved from Pressure-Broadened Emission Spectra at 22 GHz  

Science Journals Connector (OSTI)

The authors present the analysis and the evaluation of the retrieval of tropospheric water vapor profiles from pressure-broadened emission spectra at 22 GHz measured with a ground-based microwave spectroradiometer. The spectra have a bandwidth of ...

Alexander Haefele; Niklaus Kämpfer

2010-01-01T23:59:59.000Z

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.


41

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

42

Validation and Development of Melting Layer Models Using Constraints by Active/Passive Microwave Observations of Rain and the Wind-Roughened Ocean Surface  

Science Journals Connector (OSTI)

A physically based method is developed to estimate the microphysical structure of the melting layer in stratiform rain using airborne observations by a dual-frequency radar and a 10.7-GHz radiometer. The method employs a nonlinear optimal ...

Shannon T. Brown; Christopher S. Ruf

2007-04-01T23:59:59.000Z

43

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

44

Crookes's radiometers: a train of thought manifest  

Science Journals Connector (OSTI)

...radiant molecular energy of solar masses may at last be found...considered viscosity of the residual gas, and one of the Royal Society...He then described a little turbine radiometer not blacked at all...the warmer side, while the gas creeps around the edges from...

2010-01-01T23:59:59.000Z

45

Electrically calibrated absolute radiometer suitable for measurement automation  

Science Journals Connector (OSTI)

New electrically calibrated absolute radiometers (ESRs) were developed having fast response and high responsivity; these ESRs are specially useful for measurement automation. They are...

Boivin, Louis-Philippe; McNeely, Francis T

1986-01-01T23:59:59.000Z

46

Optical control of microwaves with semiconductor n?i?p?i structures  

Science Journals Connector (OSTI)

We control the microwave transmission of a GaAsn?i?p?i structure by illuminating it with a cw argon ion laser. Tests in a broadband microwave modulator wave spectrometer show that an optical intensity of 800 mW/cm2 produces a 50% change in transmission for microwaves between 10 and 50 GHz.

Alan Kost; Linda West; T. C. Hasenberg; Jeffrey O. White; Mehran Matloubian; George C. Valley

1993-01-01T23:59:59.000Z

47

The Quest for Ultimate Broadband High Power Microwaves  

E-Print Network [OSTI]

Paper describes High Power Microwave research of combining GW peak power to achieve MV/m and GV/m radiated fields in 1 to 500 GHz band. To achieve such fields multiple independently triggered broadband GW sources, supplying power to multiple spatially distributed broadband radiators/antennas are used. Single TW array is used as an ultimate microwave weapon in 1 to 5 GHz range while multiple TW arrays provide GV/m radiating field at plasma frequencies in 300 GHz range leading to fusion power.

Podgorski, Andrew S

2014-01-01T23:59:59.000Z

48

OH number densities and plasma jet behavior in atmospheric microwave plasma jets operating with different plasma gases (Ar, Ar/N2, and Ar/O2)  

Science Journals Connector (OSTI)

OH radical number density in multiple atmospheric pressure microwave plasma jets is measured using UV cavity ringdown ... 0–0) band at 308 nm. The plasma cavity was excited by a 2.45 GHz microwave plasma source a...

C. Wang; N. Srivastava

2010-12-01T23:59:59.000Z

49

GVR (G-Band Vapor Radiometer) M.P. Cadeddu and J.C. Liljegren Argonne Natl. Laboratory  

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

ARM 90/150 GHz data at ARM 90/150 GHz data at COPS M.P. Cadeddu, A. Vogelmann, D.D. Turner, S. Crewell, U. Lönhert MWRHF (90/150) data Data available at archives from 06/22 to 12/31 Challenges associated with instrument: New instrument - new technology We still need to learn about calibration Spectral region (WV continuum) still uncertain in models Data available at archives from 06/22 to 12/31 Challenges associated with instrument: New instrument - new technology We still need to learn about calibration Spectral region (WV continuum) still uncertain in models Weather conditions were not ideal for the initial testing of the instrument. The radiometer did not calibrate from 06/30 until 10/13 The few calibrations in June may have been affected by dew formation Calibration of summer data is

50

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

51

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

52

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

53

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 45, NO. 6, JUNE 1997 963 Planar Microwave Integrated Phase-Shifter Design  

E-Print Network [OSTI]

Microwave Integrated Phase-Shifter Design with High Purity Ferroelectric Material Franco De Flaviis, N. G a change in the dielectric constant. A phase shift of 165 was obtained at 2.4 GHz, with an insertion loss of ferroelectric materials (FEM's) in ceramic form for the realization of a phase shifter operating at 2.4 GHz

De Flaviis, Franco

54

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

55

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

56

Calibrations of filter radiometers for determination of atmospheric optical depth  

Science Journals Connector (OSTI)

Atmospheric optical depths are determined by relating ground-based measurements of direct solar radiation to the extraterrestrial value, I0, that a filter radiometer would read outside the atmosphere. Usually I0 is determined by the Langley extrapolation technique from a high-altitude site, where clear and highly stable atmospheric conditions may be found. Alternatively, I0 can be measured in situ from a stratospheric balloon experiment. We have employed both methods and found agreement to better than 1 %. Filter radiometers tend to change over time, especially when used operationally outdoors. Absolute calibrations in the laboratory are used to monitor the radiometric stability of filter radiometers at the Physikalisch-Meteorologisches Observatorium Davos (PMOD/WRC, Switzerland). A spectral calibration facility based on a calibrated trap detector from the Physikalisch-Technische Bundesanstalt (PTB, Germany) is used to relate the filter radiometer to an accurate and long-term traceable standard. An FEL-lamp-based standard, previously used for several years, was compared with the new trap standard via a filter radiometer at four wavelengths between 368 nm and 862 nm and revealed a systematic difference of the order of 5 %. The link between radiometric and I0 calibration is the value of the extraterrestrial solar spectrum at the filter radiometer wavelengths which can be determined from these two calibrations and compared with published values.

Ch Wehrli

2000-01-01T23:59:59.000Z

57

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.

58

Constraints on the microwave opacity of gaseous methane and water vapor in the Jovian atmosphere  

SciTech Connect (OSTI)

Gaseous NH/sub 3/'s microwave absorption in the Jovian atmosphere appears too great to be due to a solar abundance of this gas. The additional capacity of microwave absorption is presently sought in measurements of the microwave absorption of CH/sub 4/ and H/sub 2/O under simulated Jovian conditions at 2.25 GHz, 8.5 GHz, 21.7 GHz; due to large error bars, measurements represent upper limits on the microwave opacity generated by H/sub 2/O and CH/sub 4/. The results obtained are consistent with theoretical expressions for microwave opacity in a Jovian atmosphere at the specified frequencies. The presence of an NH/sub 3/ abundance exceeding the solar level by a factor of 1.5 is indicated by test results. 16 references.

Jenkins, J.M.; Steffes, P.G.

1988-11-01T23:59:59.000Z

59

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

60

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

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

Ground-based Microwave Cloud Tomography  

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

Microwave Cloud Tomography Microwave Cloud Tomography Experiment, SGP, May 15-June 15, 2009 Lead Scientist Dong Huang, BNL Co-Investigators Al Gasiewski, UC Boulder Maria Cadeddu, ANL Warren Wiscombe, BNL Radiation Processes Working Group March 30, 2009 multiple radiometers All good cloud radiation modelers should close their airplane window shades so as not to be corrupted by the spectacle of real 3D clouds. - Roger Davies In case you forget to do this, you see 3/30/2009 ARM RPWG 2 Effects of cloud structure on radiation 3/30/2009 ARM RPWG 3 Typical climate model - Cloud fraction & mean water content - Horizontally uniform clouds, no side radiation - Assumption on overlap Courtesy of Bernhard Mayer Cloud structure important to radiation - Cumulus (Benner & Evans 2001, Pincus et al. 2005), deep convection (DiGiuseppe &

62

Exhaust gas treatment by an atmospheric pressure microwave plasma  

Science Journals Connector (OSTI)

A microwave process for treating exhaust gases from internal combustion engines is presented. The exhaust gases are ionised by microwave energy at 2.45 GHz and the resultant plasma jet discharges into ambient air and exhaust gas environment. A gas analyser was used to measure the change in exhaust gas composition due to the influence of the plasma. Large decreases in CO2, CO and hydrocarbon levels, accompanied by an increase in NO levels, were found.

Carlos A. Destefani; Elias Siores

2002-01-01T23:59:59.000Z

63

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.

64

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

65

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

66

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

67

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

68

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

69

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

70

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

71

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

72

Wind Speed Retrieval Based on Sea Surface Roughness Measurements from Spaceborne Microwave Radiometers  

Science Journals Connector (OSTI)

Wind speed is the main factor responsible for the increase in ocean thermal emission because sea surface emissivity strongly depends on surface roughness. An alternative approach to estimate the surface wind speed (SWS) as a function of surface ...

Sungwook Hong; Inchul Shin

2013-02-01T23:59:59.000Z

73

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

E-Print Network [OSTI]

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

Ruf, Christopher

74

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

75

Spectroscopic temperature measurements of air breakdown plasma using a 110 GHz megawatt gyrotron beam  

SciTech Connect (OSTI)

Temperature measurements are presented of a non-equilibrium air breakdown plasma using optical emission spectroscopy. A plasma is created with a focused 110 GHz 3 {mu}s pulse gyrotron beam in air that produces power fluxes exceeding 1 MW/cm{sup 2}. Rotational and vibrational temperatures are spectroscopically measured over a pressure range of 1-100 Torr as the gyrotron power is varied above threshold. The temperature dependence on microwave field as well as pressure is examined. Rotational temperature measurements of the plasma reveal gas temperatures in the range of 300-500 K and vibrational temperatures in the range of 4200-6200 K. The vibrational and rotational temperatures increase slowly with increasing applied microwave field over the range of microwave fields investigated.

Hummelt, J. S.; Shapiro, M. A.; Temkin, R. J. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2012-12-15T23:59:59.000Z

76

Phase 2 microwave concrete decontamination results  

SciTech Connect (OSTI)

The authors report on the results of the second phase of a four-phase program at Oak Ridge National Laboratory to develop a system to decontaminate concrete using microwave energy. The microwave energy is directed at the concrete surface through the use of an optimized wave guide antenna, or applicator, and this energy rapidly heats the free water present in the interstitial spaces of the concrete matrix. The resulting steam pressure causes the surface to burst in much the same way popcorn pops in a home microwave oven. Each steam explosion removes several square centimeters of concrete surface that are collected by a highly integrated wave guide and vacuum system. The authors call this process the microwave concrete decontamination, or MCD, process. In the first phase of the program the principle of microwaves concrete removal concrete surfaces was demonstrated. In these experiments, concrete slabs were placed on a translator and moved beneath a stationary microwave system. The second phase demonstrated the ability to mobilize the technology to remove the surfaces from concrete floors. Area and volume concrete removal rates of 10.4 cm{sup 2}/s and 4.9 cm{sup 3}/S, respectively, at 18 GHz were demonstrated. These rates are more than double those obtained in Phase 1 of the program. Deeper contamination can be removed by using a longer residence time under the applicator to create multiple explosions in the same area or by taking multiple passes over previously removed areas. Both techniques have been successfully demonstrated. Small test sections of painted and oil-soaked concrete have also been removed in a single pass. Concrete with embedded metal anchors on the surface has also been removed, although with some increased variability of removal depth. Microwave leakage should not pose any operational hazard to personnel, since the observed leakage was much less than the regulatory standard.

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

1995-04-01T23:59:59.000Z

77

Microwave radiation by a relativistic electron beam propagation through low?pressure air  

Science Journals Connector (OSTI)

Intense relativistic electron beams fired into air at varying pressures display a wide range of microwave signatures. These experiments held beam current energy and pulse length constant while varying gas pressure. Our observing window is 10 to 40 GHz. At low pressures (generated plasma frequencies. Power falls linearly with pressure above 20 mTorr until electron?Neutral collisions damp the emission at a few Torr. However weak 10 GHz emission appears at full atmospheric pressure.

S. Jordan; A. Ben?Amar Baranga; G. Benford; D. Tzach; K. Kato

1985-01-01T23:59:59.000Z

78

ARM - Facility News Article  

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

New Microwave Radiometer Makes Water Vapor Measurements in the Arid Cold a New Microwave Radiometer Makes Water Vapor Measurements in the Arid Cold a Snap Bookmark and Share The 183 GHz radiometer, protected inside an insulated enclosure (inset), is installed on the roof of the primary instrument shelter at Barrow. To prevent snow from accumulating on the mylar window, a blower mounted beneath the radiometer directs air through a duct to a standard Y-shaped fitting mounted on top of the radiometer. The 183 GHz radiometer, protected inside an insulated enclosure (inset), is installed on the roof of the primary instrument shelter at Barrow. To prevent snow from accumulating on the mylar window, a blower mounted beneath the radiometer directs air through a duct to a standard Y-shaped fitting mounted on top of the radiometer.

79

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

80

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

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

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

82

Microwave Plasma Sources for Gas Processing  

SciTech Connect (OSTI)

In this paper atmospheric pressure microwave discharge methods and devices used for producing the non-thermal plasmas for processing of gases are presented. The main part of the paper concerns the microwave plasma sources (MPSs) for environmental protection applications. A few types of the MPSs, i.e. waveguide-based surface wave sustained MPS, coaxial-line-based and waveguide-based nozzle-type MPSs, waveguide-based nozzleless cylinder-type MPS and MPS for microdischarges are presented. Also, results of the laboratory experiments on the plasma processing of several highly-concentrated (up to several tens percent) volatile organic compounds (VOCs), including Freon-type refrigerants, in the moderate (200-400 W) waveguide-based nozzle-type MPS (2.45 GHz) are presented. The results showed that the microwave discharge plasma fully decomposed the VOCs at relatively low energy cost. The energy efficiency of VOCs decomposition reached 1000 g/kWh. This suggests that the microwave discharge plasma can be a useful tool for environmental protection applications. In this paper also results of the use of the waveguide-based nozzleless cylinder-type MPS to methane reforming into hydrogen are presented.

Mizeraczyk, J. [Centre for Plasma and Laser Engineering, Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Sciences, Fiszera 14, 80-952 Gdansk (Poland); Department of Marine Electronics, Gdynia Martime University, Morska 83, 81-225 Gdynia (Poland); Jasinski, M.; Dors, M.; Zakrzewski, Z. [Centre for Plasma and Laser Engineering, Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Sciences, Fiszera 14, 80-952 Gdansk (Poland)

2008-03-19T23:59:59.000Z

83

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

84

Working Group Reports A Short-Wave Radiometer Array Across  

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

9 9 Working Group Reports A Short-Wave Radiometer Array Across the Tropical Pacific Ocean as a Component of the TOGA-TAO Buoy Array R. M. Reynolds Brookhaven National Laboratory Upton, New York Introduction The purpose of this document is to bring together pertinent information concerning the NOAA TOGA-TAO buoy array so that a decision can be made for the following questions: 1. Are the scientific gains from an array of short-wave radiation sensors in the equatorial Pacific Ocean sufficiently impelling that DOE/ARM should provide financial and material support to NOAA/PMEL to install and operate this array? 2. What scientists and/or scientific studies would directly benefit from such a data set? 3. What should that array look like? That is, what sub-set of buoys should be so implemented given the per-buoy

85

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

86

Gantmakher-Kaner oscillations at 79 GHz in single-crystal copper plates  

Science Journals Connector (OSTI)

Thin plates of high-purity, single-crystal copper have been investigated with the microwave transmission technique at 79 GHz with the utilization of a magnetic field perpendicular to the sample surfaces and parallel to the ?100?, ?110?, and ?111? crystal axes. The observed Gantmakher-Kaner oscillations are compared with a theoretical model first proposed by Phillips, Baraff, and Schmidt to explain their data in copper at 35 GHz for a ?100? orientation. With the aid of their model we find two classes of signals: (a) those arising from a sharp cutoff of the topological effectiveness, and (b) those due to an extremal helical trajectory. The generally excellent agreement between observation and the predictions of the model for all three crystal orientations confirms the physical significance of the model, although it is lacking a rigorous mathematical derivation.

T. M. Hsu and G. L. Dunifer

1983-07-15T23:59:59.000Z

87

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

88

The Usage of Screen-Level Parameters and Microwave Brightness Temperature for Soil Moisture Analysis  

Science Journals Connector (OSTI)

This study focuses on testing two different soil moisture analysis systems based on screen-level parameters (2-m temperature T2m, 2-m relative humidity RH2m) and 1.4-GHz passive microwave brightness temperatures TB. First, a simplified extended ...

G. Seuffert; H. Wilker; P. Viterbo; M. Drusch; J-F. Mahfouf

2004-06-01T23:59:59.000Z

89

The BOOMERANG North America Instrument: A Balloon-borne Bolometric Radiometer Optimized for Measurements of Cosmic Background Radiation Anisotropies from 03 to 4°  

Science Journals Connector (OSTI)

We describe the BOOMERANG North America instrument, a balloon-borne bolometric radiometer designed to map the cosmic microwave background (CMB) radiation with 03 resolution over a significant portion of the sky. This receiver employs new technologies in bolometers, readout electronics, millimeter-wave optics and filters, cryogenics, scan, and attitude reconstruction. All these subsystems are described in detail in this paper. The system has been fully calibrated in flight using a variety of techniques, which are described and compared. Using this system, we have obtained a measurement of the first peak in the CMB angular power spectrum in a single, few hour long balloon flight. The instrument described here was a prototype of the BOOMERANG Long Duration Balloon experiment.

F. Piacentini; P. A. R. Ade; R. S. Bhatia; J. J. Bock; A. Boscaleri; P. Cardoni; B. P. Crill; P. de Bernardis; H. Del Castillo; G. De Troia; P. Farese; M. Giacometti; E. F. Hivon; V. V. Hristov; A. Iacoangeli; A. E. Lange; S. Masi; P. D. Mauskopf; L. Miglio; C. B. Netterfield; P. Palangio; E. Pascale; A. Raccanelli; S. Rao; G. Romeo; J. Ruhl; F. Scaramuzzi

2002-01-01T23:59:59.000Z

90

Measurement of Boundary-Layer Temperature Profiles by a Scanning 5-MM Radiometer During the 1999 Winter NSA/AAO Radiometer Exp  

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

Boundary-Layer Temperature Profiles by Boundary-Layer Temperature Profiles by a Scanning 5-MM Radiometer During the 1999 Winter NSA/AAO Radiometer Experiment and WVIOP 2000 V. Y. Leuski and E. R. Westwater Cooperative Institute for Research in the Environmental Sciences National Oceanic and Atmospheric Administration Environmental Technology Laboratory University of Colorado Boulder, Colorado Introduction A scanning 5-mm-wavelength radiometer was deployed during two Intensive Operational Periods (IOPs) at the Atmospheric Radiation Measurement (ARM) Program's Cloud and Radiation Testbed (CART) facilities. The first was conducted at the North Slope of Alaska (NSA) and Adjacent arctic Ocean (AAO) site near Barrow, Alaska, during March 1999. One goal was to evaluate the ability of an

91

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

92

Ocean Aerosols: The Marine Fast-Rotating Shadow-Band Radiometer Network  

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

Ocean Aerosols: The Marine Fast-Rotating Ocean Aerosols: The Marine Fast-Rotating Shadow-Band Radiometer Network M. A. Miller, R. M. Reynolds, and J. J. Bartholomew Brookhaven National Laboratory Upton, New York Introduction A network of ship-mounted marine fast-rotating shadow-band radiometers (FRSRs) and broadband radiometers have been deployed over the fast four years on several backbone ships, funded jointly by Atmospheric Radiation Measurement (ARM) and National Aeronautic and Space Administration's (NASA's) Sensor Intercomparison and Merger for Biological and Interdisciplinary Studies (SIMBIOS). These radiometers operate continuously and automatically during daylight hours. There fundamental measurements made by the FRSRs in the network are the direct-normal irradiance

93

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

94

Graphene Integrated Microwave Photonics  

Science Journals Connector (OSTI)

This paper proposes and analyzes the incorporation of graphene to integrated waveguides and circuits for application to the field of microwave photonics (MWP). We discuss the main...

Capmany, José; Doménech, David; Muñoz, Pascual

2014-01-01T23:59:59.000Z

95

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

96

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 cyclotron heating required in fusion devices. A short pulse gyrotron based on the industrial tube design was built at MIT for experimental studies. The experiments are the first demonstration of such high powers at 110 GHz. Using a 96 kV, 40 A electron beam, over 1.4 MW was axially extracted in the design (TE22,6) mode in 3 ?s pulses, corresponding to a microwave efficiency of 37%. The beam alpha, the ratio of transverse to axial velocity in the electron beam, was measured with a probe. At the high efficiency operating point the beam alpha was measured as 1.33. This value of alpha is less than the design value of 1.4, possibly accounting for the slightly reduced experimental efficiency. The output power and efficiency, as a function of magnetic field, beam voltage, and beam current, are in...

Anderson, J P

2005-01-01T23:59:59.000Z

97

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

98

Microwave Observation of Detonation  

Science Journals Connector (OSTI)

... We have recently developed a technique for measuring the velocity of detonation of various high explosives under contained conditions by means of the reflexion of microwaves from ... contained conditions by means of the reflexion of microwaves from a region travelling with the detonation front. The technique differs substantially from that of Koch2 and the recent development of ...

JOHN L. FARRANDS; G. F. CAWSEY

1956-01-07T23:59:59.000Z

99

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

100

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

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

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

102

The Q/U Imaging Experiment: Polarization Measurements of Radio Sources at 43 and 95 GHz  

E-Print Network [OSTI]

We present polarization measurements of extragalactic radio sources observed during the Cosmic Microwave Background polarization survey of the Q/U Imaging Experiment (QUIET), operating at 43 GHz (Q-band) and 95 GHz (W-band). We examine sources selected at 20 GHz from the public, $>$40 mJy catalog of the Australia Telescope (AT20G) survey. There are $\\sim$480 such sources within QUIET's four low-foreground survey patches, including the nearby radio galaxies Centaurus A and Pictor A. The median error on our polarized flux density measurements is 30--40 mJy per Stokes parameter. At S/N $> 3$ significance, we detect linear polarization for seven sources in Q-band and six in W-band; only $1.3 \\pm 1.1$ detections per frequency band are expected by chance. For sources without a detection of polarized emission, we find that half of the sources have polarization amplitudes below 90 mJy (Q-band) and 106 mJy (W-band), at 95% confidence. Finally, we compare our polarization measurements to intensity and polarization meas...

Huffenberger, K M; Bischoff, C; Buder, I; Chinone, Y; Cleary, K; Kusaka, A; Monsalve, R; Næss, S K; Newburgh, L B; Reeves, R; Ruud, T M; Wehus, I K; Zwart, J T L; Dickinson, C; Eriksen, H K; Gaier, T; Gundersen, J O; Hasegawa, M; Hazumi, M; Miller, A D; Radford, S J E; Readhead, A C S; Staggs, S T; Tajima, O; Thompson, K L

2014-01-01T23:59:59.000Z

103

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

104

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

105

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

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

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 Quasi-optical...

106

Microwaves and Bacteria  

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

Microwaves and Bacteria Microwaves and Bacteria Name: mike Location: N/A Country: N/A Date: N/A Question: Do the microwaves in a microwave kill bacteria or is it the heat that kills the bacteria? I am wondering this because i have a science fair project and i am searching for a project dealing with bacteria. Replies: As far as I'm aware it is the heat that kill bacteria in a microwave, and they need quite some time to be dead. The spores that some kind of bacteria make to survive harsh conditions do not contain much water and they might survive microwaves. I'm not sure what bacteria do that can survive high dosis of radiation, like Deinococcus radiodurans. They can do this by a very efficient repair system for their DNA. My guess is that they would also be killed by the heat generated in a microwave but I haven't found any data on this.

107

Speciation Analysis for Organotin Compounds in Biomaterials after Integrated Dissolution, Extraction, and Derivatization in a Focused Microwave Field  

Science Journals Connector (OSTI)

A Microdigest Model A301 (2.45 GHz, maximum power 200 W) microwave digester (Prolabo, Fontenay-sous-bois, France) equipped with a TX32 programmer was used. ... Some silanized glass wool was inserted in the tip of the pipet and on the top of the alumina plug. ... Samples were digested by refluxing for 16 h with ... ...

Isaac Rodriguez Pereiro; Vincent O. Schmitt; Joanna Szpunar; Olivier F. X. Donard; Ryszard ?obi?ski

1996-12-01T23:59:59.000Z

108

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

109

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

110

Microwave power thin film resistors for high frequency and high power load applications  

Science Journals Connector (OSTI)

The authors report a power-dividing-based microwave power thin film resistor (MPTFR) that exhibits high operating frequency and high power load. The MPTFR is comprised of substrate ground electrodes two TaN resistive films power dividing circuit and signal input port. The experimental results show that the voltage standing wave ratio of the MPTFR is lower than 1.6 in the band of 3.4–7.4 GHz and 8.2–9.8 GHz. The power load of the MPTFR is 200 W. The experimental data are in good agreement with the electromagnetic simulations.

H. C. Jiang; X. Si; W. L. Zhang; C. J. Wang; B. Peng; Y. R. Li

2010-01-01T23:59:59.000Z

111

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

112

Microwave Quantum Illumination  

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

2014-10-15T23:59:59.000Z

113

Microwave Quantum Illumination  

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 transmit...

Barzanjeh, Shabir; Weedbrook, Christian; Vitali, David; Shapiro, Jeffrey H; Pirandola, Stefano

2014-01-01T23:59:59.000Z

114

Recent Progress in Retrieving Air Temperature Profiles and Air-Sea Temperature Differences from Infrared and Microwave Scan...  

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

Recent Progress in Retrieving Air Temperature Profiles Recent Progress in Retrieving Air Temperature Profiles and Air-Sea Temperature Differences from Infrared and Microwave Scanning Radiometer Data D. Cimini University of L'Aquila L'Aquila, Italy J. A. Shaw Department of Electrical and Computer Engineering Montana State University Bozeman, Montana E. R. Westwater Cooperative Institute for Research in the Environmental Sciences University of Colorado National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado Introduction A system of two scanning radiometers has been developed by National Oceanic and Atmospheric Administration (NOAA) Environmental Technology Laboratory (ETL) and deployed on the NOAA Ron H. Brown (RHB) Research Vessel (RV) during the Nauru99 cruise in the Tropical Western Pacific,

115

Classification of GHZ-type, W-type and GHZ-W-type multiqubit entanglements  

E-Print Network [OSTI]

We propose the concept of SLOCC-equivalent basis (SEB) in the multiqubit space. In particular, two special SEBs, the GHZ-type and the W-type basis are introduced. They can make up a more general family of multiqubit states, the GHZ-W-type states, which is a useful kind of entanglement for quantum teleporatation and error correction. We completely characterize the property of this type of states, and mainly classify the GHZ-type states and the W-type states in a regular way, which is related to the enumerative combinatorics. Many concrete examples are given to exhibit how our method is used for the classification of these entangled states.

Lin Chen; Yi-Xin Chen

2006-05-23T23:59:59.000Z

116

Non-fusion applications of RF and microwave technology  

SciTech Connect (OSTI)

The processing of materials using rf and/or microwave power is a broad area that has grown significantly in the past few years. The authors have applied rf and microwave technology in the areas of ceramic sintering, plasma processing, and waste processing. The sintering of ceramics in the frequency range of 50 MHz-28 GHz has lead to unique material characteristics compared to materials that have been sintered conventionally. It has been demonstrated that sintering can be achieved in a variety of materials, including alumina, zirconia, silicon carbide, and boron carbide. In the area of plasma processing, progress has been made in the development and understanding of high density plasma sources, including inductively coupled plasma (ICP) sources. The effects of processing conditions on the ion energy distribution at the substrate surface (a critical processing issue) have been determined for a variety of process gases. The relationship between modeling and experiment is being established. Microwave technology has also been applied to the treatment of radioactive and chemical waste. The application of microwaves to the removal of contaminated concrete has been demonstrated. Details of these programs and other potential application areas are discussed.

Caughman, J.B.O.; Baity, F.W.; Bigelow, T.S.; Gardner, W.L.; Hoffman, D.J.; Forrester, S.C.; White, T.L.

1995-12-01T23:59:59.000Z

117

Measurements of atmospheric water vapor above Mauna Kea using an infrared radiometer  

E-Print Network [OSTI]

Measurements of atmospheric water vapor above Mauna Kea using an infrared radiometer David A in atmospheric water vapor that distort the phase coherence of incoming celestial signals. The signal received water vapor, this paper presents results obtained with a second generation IRMA operating at the James

Naylor, David A.

118

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

119

Oxidative Degradation of Trichloroethylene Adsorbed on Active Carbons: Use of Microwave Energy  

E-Print Network [OSTI]

OXIDATIVE DEGRADATION OF TRICHLOROETHYLENE ADSORBED ON ACTIVE CARBONS: USE OF MICROWAVE ENERGY R. VARMA, S. P. NANDI, D. CLEAVELAND, K. M. MYLES, D. R. VISSERS, AND P. A. NELSON Chemist Chemical Technology Division Argonne National... Laboratory Argonne, Illinois ABSTRACT Trichloroethylene (TCE) adsorbed on different types of active carbons was exposed to a dry and moist air stream in the presence of 2.45 GHz micro wave radiation. Active carbon beds were used becauae they absorb...

Varma, R.; Nandi, S. P.; Cleaveland, D.; Myles, K. M.; Vissers, D. R.; Nelson, P. A.

120

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 ...

Note: This page contains sample records for the topic "ghz microwave radiometer" from the National Library of EnergyBeta (NLEBeta).
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121

Millimeter wave scattering and diffraction in 110 GHz air breakdown plasma  

SciTech Connect (OSTI)

We present measurements of the scattering, reflection, absorption, and transmission of a 1.5 MW, 110 GHz quasioptical gyrotron beam by a self-induced air breakdown plasma. The breakdown forms a periodic array of plasma filaments, oriented parallel to the incident electric field polarization that propagates toward the microwave source. For incident intensity of 3 MW/cm{sup 2}, calorimetric measurements show that as much as 45% of the full beam power is absorbed by the plasma, averaged over the pulse, 1% is reflected backward, and the remainder is transmitted and also scattered into a wide angular spread. We observe that approximately 10 times more power is scattered in the direction perpendicular to the filaments than parallel. The far-field angular distribution of transmitted power exhibits a diffraction pattern that changes throughout the 2-{mu}s life of the plasma.

Cook, Alan M.; Hummelt, Jason S.; Shapiro, Michael A.; Temkin, Richard J. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2013-04-15T23:59:59.000Z

122

Microwave | OpenEI  

Open Energy Info (EERE)

Microwave Microwave Dataset Summary Description The following data-set is for a benchmark residential home for all TMY3 locations across all utilities in the US. The data is indexed by utility service provider which is described by its "unique" EIA ID ( Source National Renewable Energy Laboratory Date Released April 05th, 2012 (2 years ago) Date Updated April 06th, 2012 (2 years ago) Keywords AC apartment CFL coffeemaker Computer cooling cost demand Dishwasher Dryer Furnace gas HVAC Incandescent Laptop load Microwave model NREL Residential television tmy3 URDB Data text/csv icon Residential Cost Data for Common Household Items (csv, 14.5 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Annually Time Period License License Open Data Commons Public Domain Dedication and Licence (PDDL)

123

PHOTOCHEMISTRY IN THE MICROWAVE FIELD  

E-Print Network [OSTI]

. The objective of microwave-assisted photochemistry is frequently, but not irreplaceably, connected. EDLs Hg-EDLs: I2- and P-EDLs S-EDL vs. solar radiation flux Literature: 1. P. Kl�n V. C�rkva, Microwave in the MW field. � No evidence for nonthermal microwave effects was observed. Outlook � MW-assisted

Cirkva, Vladimir

124

Studies of 2.45 GHz Microwave Induced Plasma Abatement of CF4  

Science Journals Connector (OSTI)

by plasma reaction with oxygen, but CF4, an undesirable byproduct, is produced. ... without CF4 formation. ... neutral species kinetics favor the formation of CF4 over COF2, while the opposite is true at high temp. ...

Marilena T. Radoiu

2003-07-25T23:59:59.000Z

125

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

126

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

127

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

128

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

129

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

130

Microwave spectroscopy of Lambda-doublet transitions in the ground state of CH  

E-Print Network [OSTI]

The Lambda-doublet transitions in CH at 3.3 and 0.7 GHz are unusually sensitive to variations in the fine-structure constant and the electron-to-proton mass ratio. We describe methods used to measure the frequencies of these transitions with Hz-level accuracy. We produce a pulsed supersonic beam of cold CH by photodissociation of CHBr3, and we measure the microwave transition frequencies as the molecules propagate through a parallel-plate transmission line resonator. We use the molecules to map out the amplitude and phase of the standing wave field inside the transmission line. We investigate velocity-dependent frequency shifts, showing that they can be strongly suppressed through careful timing of the microwave pulses. We measure the Zeeman and Stark effects of the microwave transitions, and reduce systematic shifts due to magnetic and electric fields to below 1 Hz. We also investigate other sources of systematic uncertainty in the experiment.

Truppe, S; Tokunaga, S K; Hinds, E A; Tarbutt, M R

2014-01-01T23:59:59.000Z

131

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

132

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

133

A microwave impedance meter  

E-Print Network [OSTI]

A MICROWAVE IMPEDANCE METER A Thesis Virgil Layfaette 8oaz Submitted to the Graduate School of the Agricultural and Mechanical College oi' Texas in partial fulfillment of the requirements for the degree of MASTER OF SC I ENCE August 1 g61... and advice of Dr. J. P, German who suggested the research proj ct and rendered assistance when necessary. Further thanks are extended to the Electrical Engineering Faculty and Staff for their patience and suggestions, 1v CONTENTS LIST OF FIGURES...

Boaz, Virgil Layfaette

2012-06-07T23:59:59.000Z

134

Cryogenic Microwave Anisotropic Artificial Frank Trang  

E-Print Network [OSTI]

Cryogenic Microwave Anisotropic Artificial Materials by Frank Trang B.S., University of California entitled: Cryogenic Microwave Anisotropic Artificial Materials written by Frank Trang has been approved.D., Electrical Engineering) Cryogenic Microwave Anisotropic Artificial Materials Thesis directed by Professor

Popovic, Zoya

135

Metamaterial microwave holographic imaging system  

Science Journals Connector (OSTI)

We demonstrate a microwave imaging system that combines advances in metamaterial aperture design with emerging computational imaging techniques. The flexibility inherent to...

Hunt, John; Gollub, Jonah; Driscoll, Tom; Lipworth, Guy; Mrozack, Alex; Reynolds, Matthew S; Brady, David J; Smith, David R

2014-01-01T23:59:59.000Z

136

Microwave and optical saturable absorption in graphene  

Science Journals Connector (OSTI)

We report on the first experiments on saturable absorption in graphene at microwave frequency band. Almost independent of the incident frequency, microwave absorbance of graphene...

Zheng, Zhiwei; Zhao, Chujun; Lu, Shunbin; Chen, Yu; Li, Ying; Zhang, Han; Wen, Shuangchun

2012-01-01T23:59:59.000Z

137

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

138

Microwave and Pulsed Power  

SciTech Connect (OSTI)

The goals of the Microwave and Pulsed Power thrust area are to identify realizable research and development efforts and to conduct high-quality research in those pulse power and microwave technologies that support existing and emerging programmatic requirements at Lawrence Livermore National Laboratory (LLNL). Our main objective is to work on nationally important problems while enhancing our basic understanding of enabling technologies such as component design and testing, compact systems packaging, exploratory physics experiments, and advanced systems integration and performance. During FY-92, we concentrated our research efforts on the six project areas described in this report. (1) We are investigating the superior electronic and thermal properties of diamond that may make it an ideal material for a high-power, solid-state switch. (2) We are studying the feasibility of using advanced Ground Penetrating Imaging Radar technology for reliable non-destructive evaluation of bridges and other high-value concrete structures. These studies include conceptual designs, modeling, experimental verifications, and image reconstruction of simulated radar data. (3) We are exploring the efficiency of pulsed plasma processing techniques used for the removal of NO{sub x} from various effluent sources. (4) We have finished the investigation of the properties of a magnetically delayed low-pressure gas switch, which was designed here at LLNL. (5) We are applying statistical electromagnetic theory techniques to help assess microwave effects on electronic subsystems, by using a mode stirred chamber as our measurement tool. (6) We are investigating the generation of perfluoroisobutylene (PFIB) in proposed CFC replacement fluids when they are subjected to high electrical stresses and breakdown environments.

Freytag, E.K.

1993-03-01T23:59:59.000Z

139

ARM - Instrument - mwrhf  

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

govInstrumentsmwrhf govInstrumentsmwrhf Documentation MWRHF : Handbook MWRHF : Instrument Mentor Monthly Summary (IMMS) reports MWRHF : Data Quality Assessment (DQA) reports ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Instrument : Microwave Radiometer - High Frequency (MWRHF) Instrument Categories Radiometric, Cloud Properties, Atmospheric Profiling Picture of the Microwave Radiometer-High Frequency (MWRHF) Picture of the Microwave Radiometer-High Frequency (MWRHF) General Overview The Microwave Radiometer-High Frequency (MWRHF) 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.

140

Partial Discharge Location using Unsynchronized Radiometer Network for Condition Monitoring in HV Substations - A Proposed Approach  

Science Journals Connector (OSTI)

A location estimation system for online Partial Discharge (PD) detection is proposed as a low-cost approach to real-time condition monitoring, asset management and operation optimization in future smart grid. Some early progress in the development of subsystems (specifically the antenna, radiometer device, PD emulator and PD generator) for a proof-of-principle prototype system is described. The proposed PD Wireless Sensor Network (WSN) uses a novel approach to PD location which obviates the need for synchronization between sensors thereby improving scalability.

J M R de Souza Neto (IEEE member); E C T de Macedo; J S da Rocha Neto (IEEE senior member); E G da Costa; S A Bhatti; I A Glover

2012-01-01T23:59:59.000Z

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.


141

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

142

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

143

A near-field scanning microwave microscope based on a superconducting resonator for low power measurements  

E-Print Network [OSTI]

We report on the design and performance of a cryogenic (300 mK) near-field scanning microwave microscope. It uses a microwave resonator as the near-field sensor, operating at a frequency of 6 GHz and microwave probing amplitudes down to 100 uV, approaching low enough photon population (N~1000) of the resonator such that coherent quantum manipulation becomes feasible. The resonator is made out of a miniaturized distributed fractal superconducting circuit that is integrated with the probing tip, micromachined to be compact enough such that it can be mounted directly on a quartz tuning-fork, and used for parallel operation as an atomic force microscope (AFM). The resonator is magnetically coupled to a transmission line for readout, and to achieve enhanced sensitivity we employ a Pound-Drever-Hall measurement scheme to lock to the resonance frequency. We achieve a well localized near-field around the tip such that the microwave resolution is comparable to the AFM resolution, and a capacitive sensitivity down to 6.4x10^-20 F/rtHz, limited by mechanical noise. We believe that the results presented here are a significant step towards probing quantum systems at the nanoscale using near-field scanning microwave microscopy.

S. E. de Graaf; A. V. Danilov; A. Adamyan; S. E. Kubatkin

2014-04-02T23:59:59.000Z

144

Microwave plasma source for remote low energy ion stream  

Science Journals Connector (OSTI)

A plasma source capable of delivering a narrow (2 to 3?in. diameter) low ion energy (10–30 eV) plasma stream has been designed and tested. Microwave plasmas were excited in a 3?in.?diam chamber by cw electromagnetic waves (2.45 GHz 200–1000 W) in the presence of static axial magnetic fields of 875–930 G. Plasma was delivered to the sample via a 12?in.?long 2?in.?diam?metal tube. Ion current densities of several hundred ?A/cm2 at gas pressures 1–3×10? 4 Torr (N2 Xe) were achieved at distances of 15–16 in. from the source output.

Oleg A. Popov; William Hale; August O. Westner

1990-01-01T23:59:59.000Z

145

Microwave interferometer for plasma-density measurement on TMX Upgrade  

SciTech Connect (OSTI)

A four-channel microwave interferometer operating at 140 GHz has been designed for installation on the upgrade to the Tandem Mirror Experiment (TMX Upgrade). The instrument can be used to measure plasma density simultaneously at four locations: by reconnecting the waveguide runs, density can be measured at other locations of interest. The design is an outgrowth of a system used on TMX, but includes some newly developed hardware. An over-mode circular waveguide system is used to transport the signals over long distances with only moderate losses. Several precautions have been taken to limit the effect of possible interference from the electron cyclotron resonant heating (ECRH) system used to heat the plasma. A high-resolution linear phase comparator has been designed that will operate over the wide range of signals expected. A CAMAC-based data-acquisition system provides for automatic data sampling and archival after each shot.

Coffield, F.E.; Stever, R.D.; Lund, N.P.

1981-09-25T23:59:59.000Z

146

Measurement of a Peak in the Cosmic Microwave Background Power  

Science Journals Connector (OSTI)

We describe a measurement of the angular power spectrum of anisotropies in the cosmic microwave background (CMB) at scales of 03 to 5° from the North American test flight of the Boomerang experiment. Boomerang is a balloon-borne telescope with a bolometric receiver designed to map CMB anisotropies on a long-duration balloon flight. During a 6 hr test flight of a prototype system in 1997, we mapped more than 200 deg2 at high Galactic latitudes in two bands centered at 90 and 150 GHz with a resolution of 26' and 165 FWHM, respectively. Analysis of the maps gives a power spectrum with a peak at angular scales of 1° with an amplitude 70 ?KCMB.

P. D. Mauskopf; P. A. R. Ade; P. de Bernardis; J. J. Bock; J. Borrill; A. Boscaleri; B. P. Crill; G. DeGasperis; G. De Troia; P. Farese; P. G. Ferreira; K. Ganga; M. Giacometti; S. Hanany; V. V. Hristov; A. Iacoangeli; A. H. Jaffe; A. E. Lange; A. T. Lee; S. Masi; A. Melchiorri; F. Melchiorri; L. Miglio; T. Montroy; C. B. Netterfield; E. Pascale; F. Piacentini; P. L. Richards; G. Romeo; J. E. Ruhl; E. Scannapieco; F. Scaramuzzi; R. Stompor; N. Vittorio

2000-01-01T23:59:59.000Z

147

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

148

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

149

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

150

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

151

Measurement of the dielectric properties of high-purity sapphire at 1.865 GHZ from 2-10 Kelvin  

SciTech Connect (OSTI)

A dielectric test cavity was designed and tested to measure the microwave dielectric properties of ultrapure sapphire at cryogenic temperatures. Measurements were performed by placing a large cylindrical crystal of sapphire in a Nb superconducting cavity operating in the TE01 mode at 1.865 GHz. The dielectric constant, heat capacity, and loss tangent were all calculated using experimental data and RF modeling software. The motivation for these measurements was to determine if such a sapphire could be used as a dielectric lens to focus the magnetic field onto a sample wafer in a high field wafer test cavity. The measured properties have been used to finalize the design of the wafer test cavity.

N. Pogue, P. McIntyre, Akhdiyor Sattarov, Charles Reece

2012-06-01T23:59:59.000Z

152

Profiles of ion beams and plasma parameters on a multi-frequencies microwaves large bore electron cyclotron resonance ion source with permanent magnets  

SciTech Connect (OSTI)

In order to contribute to various applications of plasma and beams based on an electron cyclotron resonance, a new concept on magnetic field with all magnets on plasma production and confinement has been proposed with enhanced efficiency for broad and dense ion beam. The magnetic field configuration consists of a pair of comb-shaped magnet surrounding plasma chamber cylindrically. Resonance zones corresponding for 2.45 GHz and 11-13 GHz frequencies are positioned at spatially different positions. We launch simultaneously multiplex frequencies microwaves operated individually, try to control profiles of the plasma parameters and the extracted ion beams, and to measure them in detail.

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

2012-02-15T23:59:59.000Z

153

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...

154

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

155

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

156

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

157

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

158

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

159

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

160

SLOW MAGNETOACOUSTIC OSCILLATIONS IN THE MICROWAVE EMISSION OF SOLAR FLARES  

SciTech Connect (OSTI)

Analysis of the microwave data, obtained in the 17 GHz channel of the Nobeyama Radioheliograph during the M1.6 flare on 2010 November 4, revealed the presence of 12.6 minute oscillations of the emitting plasma density. The oscillations decayed with the characteristic time of about 15 minutes. Similar oscillations with the period of about 13.8 minutes and the decay time of 25 minutes are also detected in the variation of EUV emission intensity measured in the 335 A channel of the Solar Dynamics Observatory/Atmospheric Imaging Assembly. The observed properties of the oscillations are consistent with the oscillations of hot loops observed by the Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation (SUMER) in the EUV spectra in the form of periodic Doppler shift. Our analysis presents the first direct observations of the slow magnetoacoustic oscillations in the microwave emission of a solar flare, complementing accepted interpretations of SUMER hot loop oscillations as standing slow magnetoacoustic waves.

Kim, S.; Shibasaki, K. [Nobeyama Solar Radio Observatory/NAOJ, Nagano 384-1305 (Japan); Nakariakov, V. M., E-mail: sjkim@nro.nao.ac.jp [Physics Department, University of Warwick, Coventry, CV4 7AL (United Kingdom)

2012-09-10T23:59:59.000Z

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.


161

Maria Cadeddu, James C. Liljegren, and Andrew Pazmany Decision and Information Sciences Division, Argonne National Laboratory, Argonne, IL  

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

and Retrievals from a New 183-GHz Water Vapor Radiometer in the Arctic and Retrievals from a New 183-GHz Water Vapor Radiometer in the Arctic Maria Cadeddu, James C. Liljegren, and Andrew Pazmany Decision and Information Sciences Division, Argonne National Laboratory, Argonne, IL Prosensing, Inc., Amherst, MA This work was supported by the Climate Change Research Division, U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research, under contract W-31-109-Eng-38, as part of the DOE Atmospheric Radiation Measurement (ARM) Program. Argonne National Laboratory is managed by The University of Chicago for the U.S. Department of Energy. The two-channels microwave water vapor radiometer (MWR) shown in Fig. 1 measures brightness temperatures at the microwave frequencies of 23.8 and 31.4 GHz. Brightness

162

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

163

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

164

Modeling and characterization of a cantilever-based near-field scanning microwave impedance microscope  

Science Journals Connector (OSTI)

This paper presents a detailed modeling and characterization of a microfabricated cantilever-based scanning microwave probe with separated excitation and sensing electrodes. Using finite-element analysis we model the tip-sample interaction as small impedance changes between the tip electrode and the ground at our working frequencies near 1 GHz . The equivalent lumped elements of the cantilever can be determined by transmission line simulation of the matching network which routes the cantilever signals to 50 ? feed lines. In the microwave electronics the background common-mode signal is canceled before the amplifier stage so that high sensitivity (below 1 aF capacitance changes) is obtained. Experimental characterization of the microwavemicroscope was performed on ion-implanted Si wafers and patterned semiconductor samples. Pure electrical or topographical signals can be obtained from different reflection modes of the probe.

K. Lai; W. Kundhikanjana; M. Kelly; Z. X. Shen

2008-01-01T23:59:59.000Z

165

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

166

A near-field scanning microwave microscope based on a superconducting resonator for low power measurements  

E-Print Network [OSTI]

We report on the design and performance of a cryogenic (300 mK) near-field scanning microwave microscope. It uses a microwave resonator as the near-field sensor, operating at a frequency of 6 GHz and microwave probing amplitudes down to 100 uV, approaching low enough photon population (N~1000) of the resonator such that coherent quantum manipulation becomes feasible. The resonator is made out of a miniaturized distributed fractal superconducting circuit that is integrated with the probing tip, micromachined to be compact enough such that it can be mounted directly on a quartz tuning-fork, and used for parallel operation as an atomic force microscope (AFM). The resonator is magnetically coupled to a transmission line for readout, and to achieve enhanced sensitivity we employ a Pound-Drever-Hall measurement scheme to lock to the resonance frequency. We achieve a well localized near-field around the tip such that the microwave resolution is comparable to the AFM resolution, and a capacitive sensitivity down to 6...

de Graaf, S E; Adamyan, A; Kubatkin, S E

2014-01-01T23:59:59.000Z

167

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

168

Thermodynamics of water superheated in the microwave oven  

Science Journals Connector (OSTI)

Water is conveniently heated above its normal boiling point in a microwave oven in a glass microwave oven teapot. ...

B. H. Erné; Penny Snetsinger

2000-10-01T23:59:59.000Z

169

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

170

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

171

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

172

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

173

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

174

Fault tolerant deterministic quantum communications using GHZ states over collective-noise channels  

Science Journals Connector (OSTI)

This study proposes two new coding functions for a GHZ state and a GHZ-like state, respectively. Based on these coding functions, two fault tolerant deterministic quantum communication (DQC) protocols are proposed. Each of the new DQC's is robust under ... Keywords: Collective noise, Deterministic quantum communication, GHZ state, Quantum cryptography

Chun-Wei Yang; Chia-Wei Tsai; Tzonelih Hwang

2013-09-01T23:59:59.000Z

175

Cloud Properties Working Group Low Clouds Update  

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

Cloud Properties Working Group Cloud Properties Working Group Low Clouds Update Low Clouds Update Jennifer Comstock Jennifer Comstock Dave Turner Dave Turner Andy Andy Vogelmann Vogelmann Instruments Instruments 90/150 GHz microwave radiometer 90/150 GHz microwave radiometer Deployed during COPS AMF Deployed during COPS AMF Exploring calibration w/ DPR ( Exploring calibration w/ DPR ( Crewell Crewell & & L L ö ö hnert hnert ) ) See COPS Breakout, Wednesday evening See COPS Breakout, Wednesday evening 183 GHz (GVR) deployed at the NSA 183 GHz (GVR) deployed at the NSA Neural network algorithm to retrieve PWV & LWP (Maria Neural network algorithm to retrieve PWV & LWP (Maria Cadeddu Cadeddu ) ) Potential VAP candidate (RPWG) Potential VAP candidate (RPWG)

176

Remotely Controlled, Continuous Observations of Infrared Radiance with the CSIRO/ARM Mark II Radiometer at the SGP CART Site  

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

Remotely Controlled, Continuous Observations of Remotely Controlled, Continuous Observations of Infrared Radiance with the CSIRO/ARM Mark II Radiometer at the SGP CART Site C. M. R. Platt and R. T. Austin Department of Atmospheric Science Colorado State University Fort Collins, Colorado C. M. R. Platt and J. A. Bennett Commonwealth Scientific and Industrial Research Organization Atmospheric Research Aspendale, Victoria, Australia Abstract The Commonwealth Scientific and Industrial Research Organization/Atmospheric Radiation Measurement (CSIRO/ARM) Program Mark II infrared (IR) filter radiometer operated continuously at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site for a period of five weeks. Data of high quality were obtained by remote operation and data transfer with no evidence of spurious

177

Microwave scattering from laser spark in air  

SciTech Connect (OSTI)

In this paper, microwave Mie scattering from a laser-induced plasma in atmospheric air is computed. It shows that the scattered microwave transitions from coherent Rayleigh scattering to Mie scattering based on the relative transparency of the laser-induced plasma at the microwave frequency. The microwave penetration in the plasma alters from total transparency to partial shielding due to the sharp increase of the electron number density within the avalanche ionization phase. The transition from Rayleigh scattering to Mie scattering is verified by both the temporal evolution of the scattered microwave and the homogeneity of polar scattering plots.

Sawyer, Jordan; Zhang Zhili [Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Shneider, Mikhail N. [Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

2012-09-15T23:59:59.000Z

178

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

179

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

180

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

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

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

182

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

183

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

184

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

185

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

186

ARM - Instrument Handbooks  

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

Ground Radiometers on Stand for Upwelling Radiation (Draft) GNDRAD 2004 Infrared Thermometer IRT 2006 Micropulse Lidar MPL 2012 Microwave Radiometer MWR 2006 Microwave...

187

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

188

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

189

314 IEEE MICROWAVE AND GUIDED WAVE LETTERS, VOL. 9, NO. 8, AUGUST 1999 39-GHz GaN-Based Microwave Power  

E-Print Network [OSTI]

As-based counterparts of the same sizes. Index Terms--Amplifier, field-effect transistors, gallium-nitride (Ga

York, Robert A.

190

28 GHz Gyrotron and 4.6 GHz Klystron Heating Options for LDX P. P. Woskov1, A. C. Boxer1, J. L. Ellsworth1, D. T. Garnier2, J. Kesner1, M. E. Mauel2, P. C. Michael1  

E-Print Network [OSTI]

magnetic configuration. Adding 28 GHz gyrotron and 4.6 GHz klystron electron cyclotron heating using cyclotron fundamental and harmonics. 28 GHz Gyrotron Heating 4.6 GHz Klystron Heating 100 mA B AB 10 cm i to the magnetic field. The heating beam would be directed at the fundamental and 2nd harmonic electron cyclotron

191

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

192

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

193

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

194

BOOMERANG: A Balloon-borne Millimeter Wave Telescope and Total Power Receiver for Mapping Anisotropy in the Cosmic Microwave Background  

E-Print Network [OSTI]

We describe BOOMERANG; a balloon-borne microwave telescope designed to map the Cosmic Microwave Background (CMB) at a resolution of 10' from the Long Duration Balloon (LDB) platform. The millimeter-wave receiver employs new technology in bolometers, readout electronics, cold re-imaging optics, millimeter-wave filters, and cryogenics to obtain high sensitivity to CMB anisotropy. Sixteen detectors observe in 4 spectral bands centered at 90, 150, 240 and 410 GHz. The wide frequency coverage, the long duration flight, the optical design and the observing strategy provide strong rejection of systematic effects. We report the flight performance of the instrument during a 10.5 day stratospheric balloon flight launched from McMurdo Station, Antarctica that mapped ~2000 square degrees of the sky.

B. P. Crill; P. A. R. Ade; D. R. Artusa; R. S. Bhatia; J. J. Bock; A. Boscaleri; P. Cardoni; S. E. Church; K. Coble; P. deBernardis; G. deTroia; P. Farese; K. M. Ganga; M. Giacometti; C. V. Haynes; E. Hivon; V. V. Hristov; A. Iacoangeli; W. C. Jones; A. E. Lange; L. Martinis; S. Masi; P. V. Mason; P. D. Mauskopf; L. Miglio; T. Montroy; C. B. Netterfield; C. G. Paine; E. Pascale; F. Piacentini; G. Polenta; F. Pongetti; G. Romeo; J. E. Ruhl; F. Scaramuzzi; D. Sforna; A. D. Turner

2002-06-14T23:59:59.000Z

195

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

196

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

197

Microwave solidification development for Rocky Flats waste  

SciTech Connect (OSTI)

The Microwave Engineering Team at the Rocky Flats Plant has developed a production-scale system for the treatment of hazardous, radioactive, and mixed wastes using microwave energy. The system produces a vitreous final form which meets the acceptance criteria for shipment and disposal. The technology also has potential for application on various other waste streams from the public and private sectors. Technology transfer opportunities are being identified and pursued for commercialization of the microwave solidification technology.

Dixon, D.; Erle, R.; Eschen, V. [and others

1994-04-01T23:59:59.000Z

198

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

199

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

200

Simultaneous acoustic and microwave backscattering from the sea surface  

Science Journals Connector (OSTI)

Simultaneous and coincident measurements of acoustic and microwavebackscatter from the air/sea interface were obtained during Phase II of the SAXON-FPN experiment in December 1992 and again in March 1993. The acoustic and microwave grazing angles were both set to 17° and the wavelengths were matched being set to 2.14 3.00 and 5.66 cm corresponding to respectively acoustic frequencies of 26.5 50 and 70 kHz and microwave frequencies of 5.3 10 and 14 GHz. Backscattering cross sections normalized by ensonified area for the acoustic (? 0 a ) and microwave (? 0 m ) returns were determined and their dependence on wind speed was investigated. The acoustic scattering strength is defined as 10? log 10 (? 0 a ) and the microwavescattering strength is defined as 10? log 10 (? 0 m )?10? log 10 (4?). The results of these experiments show that the two scattering strengths are comparable at wind speeds below about 3 m/s but that the acoustic scattering strength increases much faster than the microwavescattering strength with increasing wind speed until reaching saturation. If these wind-speed dependencies are represented by a power law U n then n is 5–6 for ? 0 a and 2–4 for ? 0 m for wind speeds between 2 and 7 m/s. This difference is ascribed to the effect of bubbles on the acoustic backscatter. The more rapid increase of ? 0 a compared to ? 0 m implies that for our 17° grazing angle acoustic scattering from the surface is negligible at all but the lowest wind speeds. Therefore a simple model is used for bubble scattering to fit the acoustic data as a function of wind speed for all three acoustic frequencies. The bubble densities required to fit the data agree well with previous measurements of near-surface bubble distributions. The model predicts an overshoot of the acoustic scattering strength (above the saturation level) at moderate wind speeds which is clearly seen in the data at 26.5 and 70 kHz. Finally a composite surface scatteringmodel is utilized for the pure surface scattering component along with the bubble model to predict the wind-speed dependence of the acoustic scattering strength at a 45° grazing angle and compare the results with earlier measurements.

Peter H. Dahl; William J. Plant; Bernd Nützel; Anke Schmidt; Heinz Herwig; Eugene A. Terray

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.


201

Calibrated nanoscale dopant profiling using a scanning microwave microscope  

SciTech Connect (OSTI)

The scanning microwave microscope is used for calibrated capacitance spectroscopy and spatially resolved dopant profiling measurements. It consists of an atomic force microscope combined with a vector network analyzer operating between 1-20 GHz. On silicon semiconductor calibration samples with doping concentrations ranging from 10{sup 15} to 10{sup 20} atoms/cm{sup 3}, calibrated capacitance-voltage curves as well as derivative dC/dV curves were acquired. The change of the capacitance and the dC/dV signal is directly related to the dopant concentration allowing for quantitative dopant profiling. The method was tested on various samples with known dopant concentration and the resolution of dopant profiling determined to 20% while the absolute accuracy is within an order of magnitude. Using a modeling approach the dopant profiling calibration curves were analyzed with respect to varying tip diameter and oxide thickness allowing for improvements of the calibration accuracy. Bipolar samples were investigated and nano-scale defect structures and p-n junction interfaces imaged showing potential applications for the study of semiconductor device performance and failure analysis.

Huber, H. P.; Hochleitner, M.; Hinterdorfer, P. [University of Linz, Christian Doppler Laboratory for Nanoscopic Methods in Biophysics, Altenbergerstrasse 69, 4040 Linz (Austria); Humer, I.; Smoliner, J. [Technical University of Vienna, Institute for Solid State Electronics, 1040 Vienna (Austria); Fenner, M.; Moertelmaier, M.; Rankl, C.; Tanbakuchi, H.; Kienberger, F. [Agilent Technologies, Inc., 5301 Stevens Creek Blvd., Santa Clara, California 95051 (United States); Imtiaz, A.; Wallis, T. M.; Kabos, P. [National Institute for Standards and Technology, Electromagnetic Division, 325 Broadway, Boulder, Colorado 80305-3337 (United States); Kopanski, J. J. [National Institute of Standards and Technology, Semiconductor Measurements Division, Gaithersburg, Maryland 20899-8120 (United States)

2012-01-01T23:59:59.000Z

202

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

203

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

204

Expanded Capacity Microwave-Cleaned Diesel Particulate Filter...  

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

Expanded Capacity Microwave-Cleaned Diesel Particulate Filter Expanded Capacity Microwave-Cleaned Diesel Particulate Filter 2002 DEER Conference Presentation: Industrial Ceramic...

205

New Energy Efficiency Standards for Microwave Ovens to Save Consumers...  

Energy Savers [EERE]

New Energy Efficiency Standards for Microwave Ovens to Save Consumers on Energy Bills New Energy Efficiency Standards for Microwave Ovens to Save Consumers on Energy Bills May 31,...

206

Energy Efficiency Standards for Microwave Ovens Saves Consumers...  

Energy Savers [EERE]

Energy Efficiency Standards for Microwave Ovens Saves Consumers Energy and Updates the Social Cost of Carbon Energy Efficiency Standards for Microwave Ovens Saves Consumers Energy...

207

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

208

Modeling Results for Proposed NSTX 28 GHz and EBWH System  

SciTech Connect (OSTI)

A 28 GHz electron cyclotron heating (ECH) and electron Bernstein wave heating (EBWH) system has been proposed for installation on the National Spherical Torus Experiment (NSTX). A 350 kW gyrotron connected to a fixed horn antenna is proposed for ECH-assisted solenoid-free plasma startup. Modeling predicts strong first pass on-axis EC absorption, even for low electron temperature, Te ~ 20 eV, Coaxial Helicity Injection (CHI) startup plasmas. ECH will heat the CHI plasma to Te ~ 300 eV, providing a suitable target plasma for 30 MHz high-harmonic fast wave heating. A second gyrotron and steered O-X-B mirror launcher is proposed for EBWH experiments. Radiometric measurements of thermal EBW emission detected via B-X-O coupling on NSTX support implementation of the proposed system. 80% B-X-O coupling efficiency was measured in L-mode plasmas and 60% B-X-O coupling efficiency was recently measured in H-mode plasmas conditioned with evaporated lithium. Modeling predicts local on-axis EBW heating and current drive using 28 GHz power in ? ~ 20% NSTX plasmas should be possible, with current drive efficiencies ~ 40 kA/MW.

Taylor, G; Ellis, R A; Fredd, E; Greenough, N; Hosea, J C; Wilgen, J B; Harvey, R W; Smirnov, A P; Preinhaelter, J; Urban, J

2008-03-20T23:59:59.000Z

209

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

210

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

211

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

212

han-99.PDF  

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

Tip Cal Methods for Ground-Based Microwave Tip Cal Methods for Ground-Based Microwave Radiometric Sensing of Water Vapor and Clouds Y. Han and E. R. Westwater CIRES, University of Colorado National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado Introduction Ground-based Microwave Radiometers (MWRs) have been widely used to measure atmospheric water vapor and cloud liquid water. Frequencies on the 22.235-GHz water vapor absorption band and in the 31-GHz absorption window region are commonly used in these systems. These frequency channels differ in their response to water vapor and cloud liquid water and provide brightness temperature measurements from which precipitable water vapor (PWV) and integrated cloud liquid water are derived. Absolute calibration of the radiometer is fundamental in determining the accuracies of these

213

QUASI-PERIODIC WIGGLES OF MICROWAVE ZEBRA STRUCTURES IN A SOLAR FLARE  

SciTech Connect (OSTI)

Quasi-periodic wiggles of microwave zebra pattern (ZP) structures with periods ranging from about 0.5 s to 1.5 s are found in an X-class solar flare on 2006 December 13 at the 2.6-3.8 GHz with the Chinese Solar Broadband Radio Spectrometer (SBRS/Huairou). Periodogram and correlation analysis show that the wiggles have two to three significant periodicities and are almost in phase between stripes at different frequencies. The Alfvén speed estimated from the ZP structures is about 700 km s{sup –1}. We find the spatial size of the wave-guiding plasma structure to be about 1 Mm with a detected period of about 1 s. This suggests that the ZP wiggles can be associated with the fast magnetoacoustic oscillations in the flaring active region. The lack of a significant phase shift between wiggles of different stripes suggests that the ZP wiggles are caused by a standing sausage oscillation.

Yu, Sijie; Tan, Baolin; Yan, Yihua [Key Laboratory of Solar Activity, National Astronomical Observatories Chinese Academy of Sciences, Beijing 100012 (China); Nakariakov, V. M.; Selzer, L. A., E-mail: sjyu@nao.cas.cn [Centre for Fusion, Space and Astrophysics, Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom)

2013-11-10T23:59:59.000Z

214

Polarization of the Atmosphere as a Foreground for Cosmic Microwave Background Polarization Experiments  

E-Print Network [OSTI]

We quantify the level of polarization of the atmosphere due to Zeeman splitting of oxygen in the Earth's magnetic field and compare it to the level of polarization expected from the polarization of the cosmic microwave background radiation. The analysis focuses on the effect at mid-latitudes and at large angular scales. We find that from stratospheric balloon borne platforms and for observations near 100 GHz the atmospheric linear and circular polarized intensities is about 10^{-12} and 100 x 10^{-9} K, respectively, making the atmosphere a negligible source of foreground. From the ground the linear and circular polarized intensities are about 10^{-9} and 100 x 10^{-6} K, making the atmosphere a potential source of foreground for the CMB E (B) mode signal if there is even a 1% (0.01%) conversion of circular to linear polarization in the instrument.

Shaul Hanany; Philip Rosenkranz

2003-07-02T23:59:59.000Z

215

Mapping Observations of 6.7GHz Methanol Masers with the Japanese VLBI Network  

Science Journals Connector (OSTI)

......figure 12) is a CO condensation at a distance of...12.2GHz and the water maser at 22GHz...detection rate, flux recovery, and small fringe...compared with that of water masers. Given this...observation, the atmospheric fluctuation is a...Strong absorption by water vapor in the atmosphere......

Koichiro Sugiyama; Kenta Fujisawa; Akihiro Doi; Mareki Honma; Hideyuki Kobayashi; Takeshi Bushimata; Nanako Mochizuki; Yasuhiro Murata

2008-02-25T23:59:59.000Z

216

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

217

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.

218

Special Sensor Microwave/Imager (SSM/I) and Special Sensor Microwave Imager  

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

Special Sensor Microwave/Imager (SSM/I) and Special Sensor Microwave Imager Special Sensor Microwave/Imager (SSM/I) and Special Sensor Microwave Imager Sounder (SSMIS) Global Gridded Products Agriculture Community Menu DATA APPS EVENTS DEVELOPER STATISTICS COLLABORATE ABOUT Agriculture You are here Data.gov » Communities » Agriculture » Data Special Sensor Microwave/Imager (SSM/I) and Special Sensor Microwave Imager Sounder (SSMIS) Global Gridded Products Dataset Summary Description The SSM/I products are useful for evaluating the mean climate state, it's interannual and seasonal variations, and the detection of anomalies associated with ENSO and regional climatic variations. The Hydrology Team has assembled a time series of the entire SSM/I archive, now entering it's 16th year, which includes data from July 1987 to the present. Monthly average products are produced for precipitation, cloud liquid water, total precipitable water, snow cover, sea-ice cover, and oceanic surface wind speed.

219

Microwave concrete decontamination - Phase II results  

SciTech Connect (OSTI)

This report documents the results of the second phase of a four-phase development program to develop a system to decontaminate concrete using microwave energy. In the first phase of the program the feasibility of using microwaves to remove concrete surfaces was demonstrated. In the first phase experiments, concrete slabs were placed on a translator and moved beneath a stationery microwave system. The second phase demonstrated the ability to mobilize the technology to remove the surfaces from concrete floors. Phases III and IV will further develop the technology to be remotely operated and capable of removing concrete from floors as well as from vertical surfaces.

White, T.L.; Foster, D. Jr.

1994-06-01T23:59:59.000Z

220

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

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

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

222

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......

223

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

224

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

225

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

226

Validation of Geolocation of Measurements of the Clouds and the Earth’s Radiant Energy System (CERES) Scanning Radiometers aboard Three Spacecraft  

Science Journals Connector (OSTI)

The Clouds and the Earth’s Radiant Energy System (CERES) instrument is a scanning radiometer for measuring Earth-emitted and -reflected solar radiation to understand Earth’s energy balance. One CERES instrument was placed into orbit aboard the ...

G. Louis Smith; Kory J. Priestley; Phillip C. Hess; Chris Currey; Peter Spence

2009-11-01T23:59:59.000Z

227

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

228

Container evaluation for microwave solidification project  

SciTech Connect (OSTI)

This document discusses the development and testing of a suitable waste container and packaging arrangement to be used with the Microwave Solidification System (MSS) and Bagless Posting System (BPS). The project involves the Rocky Flats Plant.

Smith, J.A.

1994-08-01T23:59:59.000Z

229

Testing maser-based evolutionary schemes: A new search for 37.7-GHz methanol masers  

E-Print Network [OSTI]

We have used the Australia Telescope National Facility Mopra 22-m antenna to search for 37.7-GHz (7(-2) - 8(-1}E) methanol masers towards a sample of thirty six class II methanol masers. The target sources are the most luminous class II methanol masers not previously searched for this transition, with isotropic peak 12.2-GHz maser luminosity greater than 250 Jy/kpc^2 and isotropic peak 6.7-GHz maser luminosity greater than 800 Jy/kpc^2. Seven new 37.7-GHz methanol masers were detected as a result of the search. The detection rate for 37.7-GHz methanol masers towards a complete sample of all such class II methanol maser sites south of declination -20 deg is at least 30 percent. The relatively high detection rate for this rare methanol transition is in line with previous predictions that the 37.7-GHz transition is associated with a late stage of the class II methanol maser phase of high-mass star formation. We find that there is a modest correlation between the ratio of the 6.7- and 37.7-GHz maser peak intensit...

Ellingsen, S P; Voronkov, M A; Dawson, J R

2012-01-01T23:59:59.000Z

230

Wide-open, high-resolution microwave/millimeter-wave Doppler frequency shift estimation using photonics technology  

E-Print Network [OSTI]

Today, wide-open, high-resolution Doppler frequency shift (DFS) estimation is essential for radar, microwave/millimeter-wave, and communication systems. Using photonics technology, an effective approach is proposed and experimentally demonstrated, providing a high-resolution and frequency-independent solution. In the approach consisting of two cascaded opto-electronic modulators, DFS between the transmitted microwave/ millimeter-wave signal and the received echo signal is mapped into a doubled spacing between two target optical sidebands. Subsequently, the DFS is then estimated through the spectrum analysis of a generated low-frequency electrical signal, with an improved resolution by a factor of 2. In experiments, DFSs from -90 to 90 KHz are successfully estimated for microwave/millimeter-wave signals at 10, 15, and 30 GHz, where estimation errors keep lower than +/- 5e-10 Hz. For radial velocity measurement, these results reveal a range from 0 to 900 m/s (0 to 450 m/s) and a resolution of 1e-11 m/s (5e-12 m...

Zou, Xihua; Lu, Bing; Pan, Wei; Yan, Lianshan; Shao, Liyang

2014-01-01T23:59:59.000Z

231

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

232

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

233

A Novel Technique Enabling the Realisation of 60 GHz Body Area Networks  

Science Journals Connector (OSTI)

This paper presents a novel technique to enable over-body propagation at 60 GHz. A flexible material has been created that enables the propagation of surface waves around the body without the need of repeaters, high powers or high gain antennas. The ... Keywords: Surface wave, metamaterial, propagation, Zenneck wave, on-body propagation, personal area network, body area network, wireless technologies, mHealth, mobile health, 60 GHz

Janice E. Turner; Michael S. Jessup; Kin-Fai Tong

2012-05-01T23:59:59.000Z

234

The microwave background anisotropies:?Observations  

Science Journals Connector (OSTI)

...imposes limits on energy-producing processes...modes, so more energy can be collected...CMBR source. The disadvantages of bolometeric detectors...course, the main advantage of interferometer...demonstrated the many advantages of using experiments...and 106 GHz. The solar panels (shown deployed...

David Wilkinson

1998-01-01T23:59:59.000Z

235

Effects of Microwave Radiation on Oil Recovery  

Science Journals Connector (OSTI)

A variety of oil recovery methods have been developed and applied to mature and depleted reservoirs in order to improve the efficiency. Microwave radiation oil recovery method is a relatively new method and has been of great interest in the recent years. Crude oil is typically co?mingled with suspended solids and water. To increase oil recovery it is necessary to remove these components. The separation of oil from water and solids using gravitational settling methods is typically incomplete. Oil?in?water and oil?water?solid emulsions can be demulsified and separated into their individual layers by microwave radiation. The data also show that microwave separation is faster than gravity separation and can be faster than conventional heating at many conditions. After separation of emulsion into water and oil layers water can be discharged and oil is collected. High?frequency microwave recycling process can recover oil and gases from oil shale residual oil drill cuttings tar sands oil contaminated dredge/sediments tires and plastics with significantly greater yields and lower costs than are available utilizing existing known technologies. This process is environmentally friendly fuel?generating recycler to reduce waste cut emissions and save energy. This paper presents a critical review of Microwave radiation method for oil recovery.

2011-01-01T23:59:59.000Z

236

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?...

237

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

238

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

239

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

240

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

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

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

242

On the radiative and thermodynamic properties of the Cosmic Microwave Background radiation using COBE FIRAS instrument data  

E-Print Network [OSTI]

Use formulas to describe the monopole and dipole spectra of the Cosmic Microwave Background (CMB) radiation, the exact expressions for the temperature dependences of the radiative and thermodynamic functions, such as the total radiation power per unit area, total energy density, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume, pressure, enthalpy density, and internal energy density in the finite range of frequencies are obtained. Since the dependence of temperature upon the redshift z is known, the obtained expressions can be simply presented in z representation. Utilizing experimental data for the monopole and dipole spectra measured by the COBE FIRAS instrument in the 60 - 600 GHz frequency interval at the temperature T = 2.728 K, the values of the radiative and thermodynamic functions, as well as the radiation density constant a and the Stefan-Boltzmann constant are calculated. In the case of the dipole spectrum, the constants a and the Stefan-Bol...

Fisenko, Anatoliy I

2014-01-01T23:59:59.000Z

243

Ion beams extraction and measurements of plasma parameters on a multi-frequencies microwaves large bore ECRIS with permanent magnets  

SciTech Connect (OSTI)

We have developed an all-permanent magnet large bore electron cyclotron resonance ion source (ECRIS) for broad ion beam processing. The cylindrically comb-shaped magnetic field configuration is adopted for efficient plasma production and good magnetic confinement. To compensate for disadvantages of fixed magnetic configuration, a traveling wave tube amplifier (TWTA) is used. In the comb-shaped ECRIS, it is difficult to achieve controlling ion beam profiles in the whole inside the chamber by using even single frequency-controllable TWTA (11-13GHz), because of large bore size with all-magnets. We have tried controlling profiles of plasma parameters and then those of extracted ion beams by launching two largely different frequencies simultaneously, i.e., multi-frequencies microwaves. Here we report ion beam profiles and corresponding plasma parameters under various experimental conditions, dependence of ion beams against extraction voltages, and influence of different electrode positions on the electron density profile.

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

2012-11-06T23:59:59.000Z

244

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

245

ARM - Datastreams - gvrp  

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

Datastreamsgvrp Datastreamsgvrp Documentation Data Quality Plots Citation DOI: 10.5439/1025199 [ What is this? ] Generate Citation ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Datastream : GVRP G-band (183 GHz) Vapor Radiometer profiler: 15 microwave brightness temperatures from 170.0 to 183.3 GHz Active Dates 2008.04.01 - 2014.01.09 Measurement Categories Radiometric Originating Instrument G-band (183 GHz) Vapor Radiometer Profiler (GVRP) Measurements Only measurements considered scientifically relevant are shown below by default. Show all measurements Measurement Units Variable Mean radiating temperature K MRT ( frequency ) Noise diode temperature at Tkbb = 290 K K Tnd ( frequency ) Non-linearity correction coefficient None alpha ( frequency )

246

A 250 GHz Survey of High Redshift QSOs from the Sloan Digital Sky Survey  

E-Print Network [OSTI]

We present observations at 250 GHz (1.2 mm), 43 GHz, and 1.4 GHz of a sample of 41 QSOs at z > 3.7 found in the Sloan Digital Sky Survey. We detect 16 sources with a 250 GHz flux density greater than 1.4 mJy. The combination of centimeter and millimeter wavelength observations indicates that the 250 GHz emission is most likely thermal dust emission. Assuming a dust temperature of 50 K, the implied dust masses for the 16 detected sources are in the range 1.5e8 to 5.9e8 Msun, and the dust emitting regions are likely to be larger than 1 kpc in extent. The radio-through-optical spectral energy distributions for these sources are within the broad range defined by lower redshift, lower optical luminosity QSOs. We consider possible dust heating mechanisms, including UV emission from the active nucleus (AGN) and a starburst concurrent with the AGN, with implied star formation rates between 500 and 2000 Msun/year.

Carilli, C L; Rupen, M P; Fan, X; Strauss, M A; Menten, K M; Kreysa, E; Schneider, D P; Bertarini, A; Yun, M S; Zylka, R; Fan, Xiaohui; Strauss, Michael A.; Schneider, Donald P.

2001-01-01T23:59:59.000Z

247

Analysis of Microwave Propagation In Plasma  

E-Print Network [OSTI]

Analysis of Microwave Propagation In Plasma Elaine Chung Advisor: Dr. John Rodgers #12;Plasma OverviewPlasma Overview · Plasma ­ ionized gas htt[p://www.noaa.gov http://www.photoeverywhere.co.uk http://sohowww.nascom.nasa.gov/ #12;Experimental Plasma · Formed by collisional excitation of gas in an electric field Electrode Non

Anlage, Steven

248

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

249

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

250

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

251

Results of a new OCTOPUS'' ECR ion source at 6. 4 GHz  

SciTech Connect (OSTI)

The first OCTOPUS electron cyclstron resonance (ECR) multicharged heavy ion source was built in 1985 at the Centre de Recherches du Cyclotron of the University of Louvain (Belgium). This first source used an ECR frequency of 14.3 GHz in the injector stage and 8.5 GHz in the main confinement stage. A new OCTOPUS source has now been built for a new cyclotron to be installed at the Japan Atomic Energy Research Institute (JAERI). The design of this new OCTOPUS source is identical to the first OCTOPUS source, but uses an ECR frequency of 6.4 GHz in the main confinement stage. The experimental results are described, and a comparison is made between the two sources. However, the available data does not allow any clear conclusion to be drawn on frequency scaling.

Dupont, C.; Jongen, Y. (IBA, Chemin du Cyclotron,2, B-1348 Louvain 1a Neuve, Belgium (BE)); Arakawa, K.; Yokota, W. (JAERI, Takasaki, (Japan)); Satoh, T.; Tachikawa, T. (Sumitomo Heavy Industries, Tokyo, (Japan))

1990-01-01T23:59:59.000Z

252

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

253

Enhanced production of ECR plasma by using pulse mode microwaves on a large bore ECRIS with permanent magnets  

SciTech Connect (OSTI)

In order to enhance the efficiency of an electron cyclotron resonance (ECR) plasma for a broad and dense ion beam source at low pressure, the magnetic field configuration is constructed by all permanent magnets. By using the pulse mode, we aim at the generation of plasma with parameters that cannot be achieved in the CW mode at microwave frequencies of 11-13GHz, under the constraint of the same average incident microwave powers. It is found that the total beam currents are increased by the pulse mode operation compared with the case of the CW mode. According to probe measurements of the ECR plasma, it is found that the electron density in the pulse mode is larger than that in the CW mode, while the electron temperatures in the pulse mode are lower than that in the CW mode. These results are discussed from the viewpoint of relaxation times obtained on plasma parameters and ECR efficiency. The cause of the beam current increment and operational windows spread due to the pulse mode are also discussed on these parameters suitable to production of molecular/cluster ions.

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

2012-11-06T23:59:59.000Z

254

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

255

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

256

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

257

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.

258

A container for heat treating materials in microwave ovens  

DOE Patents [OSTI]

The efficiency of a microwave oven of a conventional two-source configuration and energy level is increased by providing the oven with a container for housing a refractory material to be treated. The container is formed to top and bottom walls transparent to microwaves while the sidewalls, in a circular configuration, are formed of a nonmetallic material opaque to microwave radiation for reflecting the radiation penetrating the top and bottom walls radially inwardly into the center of the container wherein a casket of heat-insulating material is provided for housing the material to be heat treated. The reflection of the microwave radiation from the sidewalls increases the concentration of the microwaves upon the material being heat treated while the concentration of the microwaves upon the material being heat treated while the casket retains the heat to permit the heating of the material to a substantially higher temperature than achievable in the oven without the container.

Holcombe, C.E.; Dykes, N.L.; Kimrey, H.D. Jr.; Mills, J.E.

1988-01-26T23:59:59.000Z

259

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

260

Generation of 20 GHz, sub-40 fs pulses at 960 nm via repetition-rate multiplication  

E-Print Network [OSTI]

Generation of 20 GHz, sub-40 fs pulses at 960 nm via repetition-rate multiplication M. S. Kirchner of Physics, University of Colorado, 2000 Colorado Avenue, Boulder, Colorado 80309, USA 2 National Institute­Pérot cavity in a double-pass configuration provides a broad cavity coupling bandwidth / 10% and large

Purdue University

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

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

262

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

263

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

264

Status of KSTAR 170 GHz, 1 MW Electron Cyclotron Heating and Current Drive System  

SciTech Connect (OSTI)

A 170 GHz Electron Cyclotron Heating and Current Drive (ECH/CD) system on KSTAR is designed to launch total 2.4 MW of power for up to 300 sec into the plasma. At present the first 1 MW ECH/CD system is under installation and commissioning for 2011 KSTAR campaign. The 170 GHz, 1 MW, 300 sec gyrotron and the matching optics unit (MOU) will be provided from JAEA under collaboration between NFRI and JAEA. The transmission line consists of MOU and 70 m long 63.5 mm ID corrugated waveguides with the eight miter bends. The 1 MW, 10 sec launcher is developed based on the existing two-mirror front-end launcher in collaboration with Princeton Plasma Physics Laboratory and Pohang University of Science and Technology, and is installed on the low field side in the KSTAR equatorial plane. The mirror pivot is located at 30 cm below from the equatorial plane. 3.6 MVA power supply system is manufactured and now is under commissioning to meet the triode gun operation of JAEA gyrotron. The power supply consists of 66 kV/55 A cathode power supply, mode-anode system, and 50 kV/160 mA body power supply. In this paper, the current status of KSTAR 170 GHz, 1 MW ECH/CD system will be presented as well as the experimental plan utilizing 170 GHz new ECH/CD system.

Joung, M.; Bae, Y. S.; Jeong, J. H.; Park, S.; Kim, H. J.; Yang, H. L. [National Fusion Research Institute, Daejeon (Korea, Republic of); Park, H.; Cho, M. H.; Namkung, W. [Pohang University of Science and Technology, Pohang (Korea, Republic of); Hosea, J.; Ellis, R. [Princeton Plasma Physics Laboratory, Princeton (United States); Sakamoto, K.; Kajiwara, K. [Japan Atomic Energy Agency, Ibaraki (Japan); Doane, J. [General Atomics, San Diego (United States)

2011-12-23T23:59:59.000Z

265

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

266

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

267

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

268

Cavity Microwave Searches for Cosmological Axions  

SciTech Connect (OSTI)

This chapter will cover the search for dark matter axions based on microwave cavity experiments proposed by Pierre Sikivie. We will start with a brief overview of halo dark matter and the axion as a candidate. The principle of resonant conversion of axions in an external magnetic field will be described as well as practical considerations in optimizing the experiment as a signal-to-noise problem. A major focus of this chapter will be the two complementary strategies for ultra-low noise detection of the microwave photons--the 'photon-as-wave' approach (i.e. conventional heterojunction amplifiers and soon to be quantum-limited SQUID devices), and 'photon-as-particle' (i.e. Rydberg-atom single-quantum detection). Experimental results will be presented; these experiments have already reached well into the range of sensitivity to exclude plausible axion models, for limited ranges of mass. The section will conclude with a discussion of future plans and challenges for the microwave cavity experiment.

Carosi, G; van Bibber, K

2007-01-22T23:59:59.000Z

269

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

270

Gas Chromatography—Microwave-Induced Plasma for the Determination of Halogenated Hydrocarbons  

Science Journals Connector (OSTI)

......microwave-induced plasma detector. The...generator (2450 MHz frequency) was...microwave-induced plasma in helium at atmospheric pressure as an...compounds with atmospheric pressure helium microwave induced plasma-atomic emission......

M.M. Abdillahi

1990-12-01T23:59:59.000Z

271

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...

272

Product Standards for Microwaves (Japan) | Open Energy Information  

Open Energy Info (EERE)

Product Standards for Microwaves (Japan) Product Standards for Microwaves (Japan) Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Product Standards for Microwaves (Japan) Focus Area: Appliances & Equipment Topics: Policy Impacts Website: www.eccj.or.jp/top_runner/pdf/tr_microwaveoven.pdf Equivalent URI: cleanenergysolutions.org/content/product-standards-microwaves-japan Language: English Policies: "Deployment Programs,Regulations" is not in the list of possible values (Deployment Programs, Financial Incentives, Regulations) for this property. DeploymentPrograms: Industry Codes & Standards Regulations: Appliance & Equipment Standards and Required Labeling This Energy Conservation Center Japan (ECCJ) document was created as a guide in response to its newly established set of standards and labelling

273

Microwave heating for adsorbents regeneration and oil sands coke activation.  

E-Print Network [OSTI]

??Microwave heating has unique advantages compared to convection-radiation heating methods including fast heating rate and selective heating of objects. This thesis studied two applications of… (more)

Chen, Heng

2010-01-01T23:59:59.000Z

274

Posters Preliminary Analysis of Ground-Based Microwave and Infrared...  

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

3 Posters Preliminary Analysis of Ground-Based Microwave and Infrared Radiance Observations During the Pilot Radiation OBservation Experiment E. R. Westwater, Y. Han, J. H....

275

Microwave-Assisted Polymerizations: Recent Status and Future Perspectives  

Science Journals Connector (OSTI)

Microwave heating is frequently used in the synthesis of polymers owing to the precise temperature and pressure control when using monomodal microwave synthesizer. ... Nguyen et al. investigated the homopolymerization of vinylcyclicsilazanes as well as their ability to be used in block copolymerizations with St.(19) The usage of microwave heating allowed the synthesis of higher molar mass polyvinylsilazanes (H-PVSZ) with an excellent control over the polymerization compared to conventional heating, which was attributed to the superior dielectric properties of the PVSZ mixture obtained by microwave irradiation. ... Time- and energy-consuming synthetic pathways that usually involve the use of volatile, flammable or toxic org. ...

Kristian Kempe; C. Remzi Becer; Ulrich S. Schubert

2011-07-13T23:59:59.000Z

276

Structure and microwave dielectric characteristics of lithium-excess Ca0.6Nd0.8/3TiO3/(Li0.5Nd0.5)TiO3 ceramics  

Science Journals Connector (OSTI)

Abstract Compositions based on (1?x)Ca0.6Nd8/3TiO3?x(Li1/2Nd1/2)TiO3 + yLi (CNLNTx + yLi, x = 0.30–0.60, y = 0–0.05), suitable for microwave applications have been developed by systematically adding excess lithium in order to tune the microwave dielectric properties and lower sintering temperature. Addition of 0.03 excess-Li simultaneously reduced the sintering temperature and improved the relative density of sintered \\{CNLNTx\\} ceramics. The excess Li addition can compensate the evaporation of Li during sintering process and decrease the secondary phase content. The \\{CNLNTx\\} (x = 0.45) ceramics with 0.03 Li excess sintered at 1190 °C have single phase orthorhombic perovskite structure, together with the optimum combination of microwave dielectric properties of ?r = 129, Q × f = 3600 GHz, ?f = 38 ppm/°C. Obviously, excess-Li addition can efficiently decrease the sintering temperature and improve the microwave dielectric properties. The high permittivity and relatively low sintering temperatures of lithium-excess Ca0.6Nd0.8/3TiO3/(Li0.5Nd0.5)TiO3 ceramics are ideal for the development of low cost ultra-small dielectric loaded antenna.

Changrong Zhou; Guohua Chen; Zhenyong Cen; Changlai Yuan; Yun Yang; Weizhou Li

2013-01-01T23:59:59.000Z

277

Radiometer Calibration Trends  

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

Wilcox, T. L. Stoffel, and D. R. Myers National Renewable Energy Laboratory Golden, Colorado Abstract Calibrations of Atmospheric Radiation Measurement (ARM) broadband...

278

Inexpensive photovoltaic solar radiometer  

Science Journals Connector (OSTI)

Using a solar cell as a sensor a low?cost instrument can be constructed which measures both the instantaneous and integrated value of solar flux. The process of constructing and calibrating the instrument constitutes an excellent undergraduate experimental project affording the student an opportunity to examine a variety of aspects associated with solar energy measurements.

Fritz Kissner

1981-01-01T23:59:59.000Z

279

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

280

Gas breakdown driven by L band short-pulse high-power microwave  

SciTech Connect (OSTI)

High power microwave (HPM) driven gas breakdown is a major factor in limiting the radiation and transmission of HPM. A method that HPM driven gas breakdown could be obtained by changing the aperture of horn antenna is studied in this paper. Changing the effective aperture of horn antenna can adjust the electric field in near field zone, leading to gas breakdown. With this method, measurements of air and SF{sub 6} breakdowns are carried out on a magnetically insulated transmission-line oscillators, which is capable of generating HPM with pulse duration of 30 ns, and frequency of 1.74 GHz. The typical breakdown waveforms of air and SF{sub 6} are presented. Besides, the breakdown field strengths of the two gases are derived at different pressures. It is found that the effects of air and SF{sub 6} breakdown on the transmission of HPM are different: air breakdown mainly shortens the pulse width of HPM while SF{sub 6} breakdown mainly reduces the peak output power of HPM. The electric field threshold of SF{sub 6} is about 2.4 times larger than that of air. These differences suggest that gas properties have a great effect on the transmission characteristic of HPM in gases.

Yang Yiming; Yuan Chengwei; Qian Baoliang [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

2012-12-15T23:59:59.000Z

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.
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to obtain the most current and comprehensive results.


281

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

282

Microwave short-pulse bed-level detector. Annual report, January 1-December 31, 1981  

SciTech Connect (OSTI)

A short-pulse microwave system for measuring the bed-level within a fluidized-bed combustor, has been designed, built, and laboratory tested on static beds. The system is a short-pulse radar which operates in the frequency region of 6.75 to 10.95 GHz as a time-domain measurement system. Laboratory measurements of static bed-levels, for smooth and corrugated surfaces of metal plates and limestone sand, agree to an average of 2.0% of the actual heights. Additionally, the system was tested with a dielectric thermal protector, which did not compromise the accuracy of the measurements. Analytical models have been formulated to provide insight into the operation of the system on a wide range of simulated targets without the necessity of performing expensive and difficult laboratory experiments. Two formulations have been used to describe electromagnetic scattering by a rough surface as a function of frequency: the space harmonic model and the physical optics model. A reconstruction technique has been devised which uses the scattering models and the spectrum of the transmitted pulse to synthesize the reflected pulse. The data generated by the models compare well to previously published data and to experimental results.

Balanis, C.A.; Delauder, D.M.

1981-01-01T23:59:59.000Z

283

Microwave characterisation of CaF2 at cryogenic temperatures using a dielectric resonator technique  

E-Print Network [OSTI]

Properties of calcium fluoride (CaF2) have been well researched at UV, visible and IR range of frequencies, but not at ultra high frequencies. In this work we report the loss tangent and the real part of relative permittivity of CaF2, measured in the temperatures range of 15 - 81 K and the frequency of 29.25 GHz. The loss tangent and the real part of relative permittivity were determined by measurements of the resonant frequency and the Qo - factor of a TE011 mode cylindrical copper cavity with superconducting plates containing the sample under test. The measured real part of relative permittivity of CaF2 was found to change from 6.484 to 6.505, and the loss tangent from 3.1x10^(-6) to 22.7x10^(-6), when the temperature was varied from 15 to 81 K. Due to the low losses CaF2 can be useful in construction of high Q-factor microwave circuits and devices, operating at the cryogenic temperatures.

Jacob, Mohan V; Ledenyov, Dimitri O; Krupka, Jerzy; 10.1016/S0955-2219(03)00183-3

2012-01-01T23:59:59.000Z

284

Effect of a chameleon scalar field on the cosmic microwave background  

Science Journals Connector (OSTI)

We show that a direct coupling between a chameleonlike scalar field and photons can give rise to a modified Sunyaev-Zel’dovich (SZ) effect in the cosmic microwave background (CMB). The coupling induces a mixing between chameleon particles and the CMB photons when they pass through the magnetic field of a galaxy cluster. Both the intensity and the polarization of the radiation are modified. The degree of modification depends strongly on the properties of the galaxy cluster such as magnetic field strength and electron number density. Existing SZ measurements of the Coma cluster enable us to place constraints on the photon-chameleon coupling. The constrained conversion probability in the cluster is PComa(204??GHz)<6.2×10-5 at 95% confidence, corresponding to an upper bound on the coupling strength of geff(cell)<2.2×10-8??GeV-1 or geff(Kolmo)<(7.2–32.5)×10-10??GeV-1, depending on the model that is assumed for the cluster magnetic field structure. We predict the radial profile of the chameleonic CMB intensity decrement. We find that the chameleon effect extends farther toward the edges of the cluster than the thermal SZ effect. Thus we might see a discrepancy between the x-ray emission data and the observed SZ intensity decrement. We further predict the expected change to the CMB polarization arising from the existence of a chameleonlike scalar field. These predictions could be verified or constrained by future CMB experiments.

Anne-Christine Davis; Camilla A. O. Schelpe; Douglas J. Shaw

2009-09-10T23:59:59.000Z

285

The microwave spectrum and structure of the CH[sub 3]OH-CO dimer  

SciTech Connect (OSTI)

The reaction mechanism involved in the conversion of methanol to gasoline (MTG) over a zeolite catalyst (MTG process) has generated considerable interest, although much controversy still remains over the particular steps which lead to the formation of the first C-C bond. The rotational spectrum of CH[sub 3]OH-CO has been observed in the region 7--18 GHz with a pulsed-beam Fabry-Perot cavity Fourier-transform microwave spectrometer. In order to obtain detailed structural information the spectra of CH[sub 3]OH, CH[sub 3]OD, CD[sub 3]OH, and CD[sub 3]OD combined with CO and [sup 13]CO were examined. Each of the isotopic species studied exhibits two states, which are interpreted as A and E symmetry states arising from internal rotation of the methyl group. The E-state assignments were verified by observing their first-order Stark effect. The structure of the complex is a bent hydrogen bond of the carbon atom of CO at a distance of 2.41 [angstrom] from the hydroxyl hydrogen of methanol and planar heavy atoms. The effective barrier to internal rotation for CH[sub 3]OH-CO, V[sub 3] = 183.0 cm[sup [minus]1], is one-half of the value for the methanol monomer.

Lovas, F.J.; Belov, S.P.; Tretyakov, M.Yu.; Ortigoso, J.; Suenram, R.D. (National Inst. of Standards and Technology, Gaithersburg, MD (United States). Molecular Physics Division)

1994-09-01T23:59:59.000Z

286

A broadband microwave Corbino spectrometer at $^3$He temperatures and high magnetic fields  

E-Print Network [OSTI]

We present the technical details of a broadband microwave spectrometer for measuring the complex conductance of thin films covering the range from 50 MHz up to 16 GHz in the temperature range 300 mK to 6 K and at applied magnetic fields up to 8 Tesla. We measure the complex reflection from a sample terminating a coaxial transmission line and calibrate the signals with three standards with known reflection coefficients. Thermal isolation of the heat load from the inner conductor is accomplished by including a section of NbTi superconducting cable (transition temperature around 8 $-$ 9 K) and hermetic seal glass bead adapters. This enables us to stabilize the base temperature of the sample stage at 300 mK. However, the inclusion of this superconducting cable complicates the calibration procedure. We document the effects of the superconducting cable on our calibration procedure and the effects of applied magnetic fields and how we control the temperature with great repeatability for each measurement. We have suc...

Liu, Wei; Armitage, N P

2014-01-01T23:59:59.000Z

287

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...

288

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...

289

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...

290

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

291

Microsoft Word - cimini-d.doc  

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

Microwave Radiative Models Study Microwave Radiative Models Study Based on Ground-Based Multichannel Radiometer Observations in the 20-60 GHz Band C. Cimini, F. S. Marzano, and P. Ciotti Center of Excellence CETEMPS Universita' dell'Aquila L'Aquila, Italy D. Cimini Science and Technology Corporation Hampton, Virginia E. R. Westwater Cooperative Institute for Research in Environmental Sciences University of Colorado National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado Y. Han National Oceanic and Atmospheric Administration National Environmental Satellite, Data, and Information Service Office of Research and Application Camp Springs, Maryland S. J. Keihm National Aeronautics and Space Administration Jet Propulsion Laboratory

292

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

293

Gun Injection into a Microwave Plasma J. C. Sprott  

E-Print Network [OSTI]

Gun Injection into a Microwave Plasma by J. C. Sprott May, 1970 Plasma Studies University high densities by rapid pulsed gun injection. TIlis no te describes measurements made -Cwo years ago in which a gun plasma was injected into a background microwave plasma of variable density in the toroidal

Sprott, Julien Clinton

294

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

295

Tunable negative-tap photonic microwave filter based on a  

E-Print Network [OSTI]

Tunable negative-tap photonic microwave filter based on a cladding-mode coupler and an optically injected laser of large detuning Sze-Chun Chan,* Qing Liu, Zhu Wang, and Kin Seng Chiang Department: A tunable negative-tap photonic microwave filter using a cladding-mode coupler together with optical

Chan, Sze-Chun

296

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

297

Thermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby  

E-Print Network [OSTI]

, there is a considerable motivation to develop practical means to ignite pure thermites. Laser beams were found effectiveThermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby Faculty of Engineering 2012 Keywords: Thermite Microwave heating Hotspots Thermal runaway Ignition a b s t r a c t This paper

Jerby, Eli

298

Thermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby  

E-Print Network [OSTI]

, there is a considerable motivation to develop practical means to ignite pure thermites. Laser beams were found effectiveThermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby Faculty of Engineering Keywords: Thermite Microwave heating Hotspots Thermal runaway Ignition a b s t r a c t This paper presents

Jerby, Eli

299

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

300

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

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

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

302

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

303

Microwave Plasma Monitoring System For Real-Time Elemental Analysis  

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

Microwave Plasma Monitoring System For Real-Time Elemental Analysis Microwave Plasma Monitoring System For Real-Time Elemental Analysis Microwave Plasma Monitoring System For Real-Time Elemental Analysis The invention apparatus can also be used to monitor for the presence of halogens, sulfur and silicon. Available for thumbnail of Feynman Center (505) 665-9090 Email Microwave Plasma Monitoring System For Real-Time Elemental Analysis There has been invented a process for analyzing ambient air in a microwave induced plasma without use of an additional carrier gas. There has also been invented an apparatus for analyzing ambient air, other sample gas, or nebulized and desolvated liquids wherein a novel arrangement of plasma gas and sample gas conduits is used to enhance dependability of the plasma. This apparatus embodiment of the invention has a concentric arrangement of

304

Container for heat treating materials in microwave ovens  

DOE Patents [OSTI]

The efficiency of a microwave oven of a conventional two-source configuration and energy level is increased by providing the oven with a container for housing a refractory material to be treated. The container is formed of top and bottom walls transparent to microwaves while the sidewalls, in a circular configuration, are formed of a nonmetallic material opaque to microwave radiation reflecting the radiation penetrating the top and bottom walls radially inwardly into the center of the container wherein a casket of heat-insulating material is provided for housing the material to be heat treated. The reflection of the microwave radiation from the sidewalls increases the concentration of the microwaves upon the material being heat treated while the casket retains the heat to permit the heating of the material to a substantially higher temperature than achieveable in the oven without the container.

Holcombe, Cressie E. (Farragut, TN); Dykes, Norman L. (Oak Ridge, TN); Kimrey, Jr., Harold D. (Knoxville, TN); Mills, James E. (Knoxville, TN)

1989-01-01T23:59:59.000Z

305

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

306

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

307

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

308

A Preliminary Study Towards Consistent Soil Moisture from AMSR2  

Science Journals Connector (OSTI)

A preliminary study towards consistent soil moisture products from the Advanced Microwave Scanning Radiometer 2 (AMSR2) is presented. Its predecessor, the Advanced Microwave Scanning Radiometer – Earth Observing System (AMSR-E), has provided Earth ...

Robert M. Parinussa; Thomas R.H. Holmes; Niko Wanders; Wouter A. Dorigo; Richard A.M. de Jeu

309

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

310

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

311

A 10 GHz electron-cyclotron-resonance (ECR) ion source for ion-electron and ion-atom collision studies  

Science Journals Connector (OSTI)

In order to extend our investigations in the field of electronion collision studies involving ions in high charge states, we decided to build a newly designed 10 GHz Electron-Cyclotron-Resonance Ion Source. The n...

M. Liehr; M. Schlapp; E. Salzborn

1991-01-01T23:59:59.000Z

312

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

313

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

314

Energy Efficiency Standards for Microwave Ovens Saves Consumers Energy and Updates the Social Cost of Carbon  

Office of Energy Efficiency and Renewable Energy (EERE)

EERE's new microwave standards will reduce carbon pollution and save consumers money on their energy bills.

315

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

316

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

317

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

318

High-Efficiency, Magnetized, Virtual-Cathode Microwave Generator  

Science Journals Connector (OSTI)

Microwave generation by electron beams in virtual-cathode configurations can achieve significant power levels. However, most designs inherently have two competing mechanisms generating microwaves: the oscillating virtual cathode and the reflexing electrons. These mechanisms interfere destructively with each other. This paper reports investigation of a novel idea of using an external axial magnetic field and a thick anode with an appropriate collimating slot to extract the electron beam and to suppress the reflexing electrons. It was found that high-power, narrow-band, monochromatic microwaves could be generated with efficiency of 10% to 20%.

Thomas J. T. Kwan

1986-10-13T23:59:59.000Z

319

S. Crewell  

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

the ARM Mobile Facilities deployment in the Black forest, Germany, additional microwave radiometers and lidars were operated in the Murg Valley in order to Microwave radiometry and...

320

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

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

Information Gains from Cosmic Microwave Background Experiments  

E-Print Network [OSTI]

To shed light on the fundamental problems posed by Dark Energy and Dark Matter, a large number of experiments have been performed and combined to constrain cosmological models. We propose a novel way of quantifying the information gained by updates on the parameter constraints from a series of experiments which can either complement earlier measurements or replace them. For this purpose, we use the Kullback-Leibler divergence or relative entropy from information theory to measure differences in the posterior distributions in model parameter space from a pair of experiments. We apply this formalism to a historical series of Cosmic Microwave Background experiments ranging from Boomerang to WMAP, SPT, and Planck. Considering different combinations of these experiments, we thus estimate the information gain in units of bits and distinguish contributions from the reduction of statistical errors and the `surprise' corresponding to a significant shift of the parameters' central values. For this experiment series, we...

Seehars, Sebastian; Refregier, Alexandre; Paranjape, Aseem; Akeret, Joël

2014-01-01T23:59:59.000Z

322

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

323

ARM - Field Campaign - Arctic Winter Water Vapor IOP  

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

govCampaignsArctic Winter Water Vapor IOP govCampaignsArctic Winter Water Vapor IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Arctic Winter Water Vapor IOP 2004.03.09 - 2004.04.09 Lead Scientist : Ed Westwater Data Availability http://www.etl.noaa.gov/programs/2004/wviop/data will contain quicklooks of all of the data. For data sets, see below. Summary During the IOP, the Ground-based Scanning Radiometer of NOAA/ETL, and the ARM MicroWave Radiometer and Microwave Profiler, yielded excellent data over a range of conditions. In all, angular-scanned and calibrated radiometric data from 22.345 to 380 GHz were taken. The Precipitable Water Vapor varied about an order of magnitude from 1 to 10 mm, and surface temperatures varied from about -10 to -40 deg. Celcius. Vaisala RS90

324

Slide 1  

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

Illinois, Champaign, IL Illinois, Champaign, IL October 14-16, 2008 ARM AVP Workshop The Profiling Radiometer for Atmospheric and Cloud Observation PRACO Marian Klein, Vladimir Irisov, Vladimir Leuski University of Illinois, Champaign, IL October 14-16, 2008 ARM AVP Workshop BEST * Established in 2006 * Passive microwave remote sensing * Long experience with airborne, ship-borne, ground based microwave radiometers University of Illinois, Champaign, IL October 14-16, 2008 ARM AVP Workshop 60 GHz Boundary Layer Temperature Profiler Retrieved Boundary Layer Profile (ºK) ~ 2 days Successful operation in several extreme environments: Ship, Aircraft, Ice- breaker, Arctic ground site, and Dirigible University of Illinois, Champaign, IL October 14-16, 2008 ARM AVP Workshop Coastal Ocean Probing

325

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

326

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

327

High-precision optical and microwave signal synthesis and distribution  

E-Print Network [OSTI]

In this thesis, techniques for high-precision synthesis of optical and microwave signals and their distribution to remote locations are presented. The first topic is ultrafast optical pulse synthesis by coherent superposition ...

Kim, Jung-Won, 1976-

2007-01-01T23:59:59.000Z

328

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

329

Standoff concealed weapon detection using a 350 GHz radar imaging system  

SciTech Connect (OSTI)

The Pacific Northwest National Laboratory is currently developing a 350 GHz, active, wideband, three-dimensional, radar imaging system to evaluate the feasibility of active sub-mm imaging for standoff concealed weapon detection. The prototype radar imaging system is based on a wideband, heterodyne, frequency-multiplier-based transceiver system coupled to a quasi-optical focusing system and high-speed rotating conical scanner. The wideband operation of this system provides accurate ranging information, and the images obtained are fully three-dimensional. Recent improvements to the system include increased imaging speed using improved balancing techniques, wider bandwidth, and image display techniques.

Sheen, David M.; Hall, Thomas E.; Severtsen, Ronald H.; McMakin, Douglas L.; Hatchell, Brian K.; Valdez, Patrick LJ

2010-04-01T23:59:59.000Z

330

Photon-pair generation in photonic crystal fibrebre with a 1.5GHz modelocked VECSEL  

E-Print Network [OSTI]

Four-wave mixing (FWM) in optical fibre is a leading technique for generating high-quality photon pairs. We report the generation of photon pairs by spontaneous FWM in photonic crystal fibre pumped by a 1.5 GHz repetition-rate vertical-external-cavity surface-emitting laser (VECSEL). The photon pairs exhibit high count rates and a coincidence-to-accidental ratio of over 80. The VECSEL's high repetition-rate, high average power, tunability, and small footprint make this an attractive source for quantum key distribution and photonic quantum-state engineering.

Oliver J. Morris; Robert J. A. Francis-Jones; Keith G. Wilcox; Anne C. Tropper; Peter J. Mosley

2014-09-09T23:59:59.000Z

331

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

332

VLBI observations at 147 GHz: first detection of transatlantic fringes in bright AGN  

E-Print Network [OSTI]

At 147 GHz (2mm wavelength), we detected three prominent AGN (NRAO150, 3C279, 1633+382) with Very Long Baseline Interferometry (VLBI) with an angular resolution of only 18 micro-arcseconds on the baseline between two antennas in Arizona (10m HHT and 12m KittPeak) and the IRAM 30m antenna on Pico Veleta in Spain. This is a new world record in radio interferometry and astronomical imaging and opens fascinating future possibilities to directly image and study the innermost regions in Quasars and other Active Galactic Nuclei.

T. P. Krichbaum; D. A. Graham; W. Alef; A. Polatidis; U. Bach; A. Witzel; J. A. Zensus; A. Greve; M. Grewing; S. Doeleman; R. Phillips; A. E. E. Rogers; M. Titus; H. Fagg; P. Strittmatter; T. L. Wilson; L. Ziurys; R. Freund; P. K"on"onen; J. Peltonen; S. Urpo; F. Rantakyro; J. Conway; R. S. Booth

2002-07-01T23:59:59.000Z

333

VLBI observations at 147 GHz first detection of transatlantic fringes in bright AGN  

E-Print Network [OSTI]

At 147 GHz (2mm wavelength), we detected three prominent AGN (NRAO150, 3C279, 1633+382) with Very Long Baseline Interferometry (VLBI) with an angular resolution of only 18 micro-arcseconds on the baseline between two antennas in Arizona (10m HHT and 12m KittPeak) and the IRAM 30m antenna on Pico Veleta in Spain. This is a new world record in radio interferometry and astronomical imaging and opens fascinating future possibilities to directly image and study the innermost regions in Quasars and other Active Galactic Nuclei.

Krichbaum, T P; Alef, W; Polatidis, A; Bach, U; Witzel, A; Zensus, J A; Greve, A; Grewing, M; Doeleman, S; Phillips, R; Rogers, A E E; Titus, M; Fagg, H; Strittmatter, P A; Wilson, T L; Ziurys, L M; Freund, R W; Könönen, P; Peltonen, J; Urpo, S; Rantakyro, F; Conway, J; Booth, R S

2002-01-01T23:59:59.000Z

334

Transatlantic Transport of Fermilab 3.9 GHZ Cryomodule to DESY  

SciTech Connect (OSTI)

In an exchange of technology agreement, Fermilab has built and delivered a 3.9 GHz (3rd harmonic) cryomodule to Deutsches Elektron-Synchrotron (DESY) Laboratory to be installed in the TTF/FLASH beamline. Transport to Hamburg, Germany was completed via a combination of flatbed air ride truck and commercial aircraft, while minimizing transition or handling points. Initially, destructive testing of fragile components, transport and corresponding alignment stability studies were performed in order to assess the risk associated with transatlantic travel of a fully assembled cryomodule. Data logged triaxial acceleration results of the transport with a comparison to the transport study predicted values are presented.

McGee, M.W.; Grimm, C.; Olis, D.; Schappert, Warren; /Fermilab

2009-05-01T23:59:59.000Z

335

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

336

Study of CERC using newly installed 77 GHz Gyrotron in LHD  

SciTech Connect (OSTI)

We have investigated the transition to Core Electron-Root Confinement (CERC) using the 77 GHz ECRH system, which was newly installed in the Large Helical Device (LHD). The focal point scan of the ECRH was carried out shot by shot in the same poloidal surface along the magnetic field of 2.75 T, which is the fundamental resonance surface for 77 GHz ECRH. The formation of the steep gradient in the electron temperature and the change of the radial electric field from negative to positive value in the plasma core region were observed by the ECRH injection to {rho}<0.5. The foot point of the peaked profile of the electron temperature appeared near the m/n = 2/1 rational surface, which was located at {rho}{approx}0.5. These results imply that localized ECRH in the inner region within the lower order rational surface and/or the electron heat flux across the rational surface play important roles for the transition to CERC. We also confirmed that the calculated radial electric field from a neoclassical theory qualitatively agreed with the experimental results.

Takahashi, H.; Shimozuma, T.; Yokoyama, M.; Ido, T.; Kubo, S.; Shimizu, A.; Yoshimura, Y.; Igami, H.; Mutoh, T. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan)

2009-11-26T23:59:59.000Z

337

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

338

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

339

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

E-Print Network [OSTI]

indirectly, using satellite-borne observations of the scattering of upwelling microwave radiation by precipitation sized ice and satellite-borne observations of lightning. The observations are then compared to tropical cyclone intensity and the resulting...

Cecil, Daniel Joseph

2012-06-07T23:59:59.000Z

340

Application of a Microwave-Induced Helium Plasma Detector at Atmospheric Pressure for Gas Chromatographic Capillary Columns  

Science Journals Connector (OSTI)

......microwave-induced plasma emission detector...microwave- induced plasma that operates at atmospheric pressure using helium...to within 1 cm of the plasma discharge. The quartz...Raytheon PGM-10X2 2450 MHz microwave power supply......

Stanley P. Wasik; Frederick P. Schwarz

1980-12-01T23:59:59.000Z

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

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

342

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

343

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

344

ARM - Facility News Article  

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

Arctic Winter Water Vapor IOP Starts; Microwave Radiometer Profiler Arctic Winter Water Vapor IOP Starts; Microwave Radiometer Profiler Deployed Bookmark and Share Some of the instruments collecting data during the Arctic Winter Water Vapor IOP include ARM's microwave radiometer profiler (left) and microwave radiometer (right), and NOAA's ground-based scanning radiometer (middle). Some of the instruments collecting data during the Arctic Winter Water Vapor IOP include ARM's microwave radiometer profiler (left) and microwave radiometer (right), and NOAA's ground-based scanning radiometer (middle). The Arctic Winter Water Vapor Intensive Operational Period (IOP), a collaborative effort with the National Oceanic and Atmospheric Administration (NOAA) Environmental Technology Laboratory, began on March 10 in Barrow, Alaska. The major goal of the Arctic Winter Water Vapor IOP

345

Ignition characteristics of methane/air premixed mixture by microwave-enhanced laser-induced breakdown plasma  

Science Journals Connector (OSTI)

A microwave-enhanced plasma generation technique was combined with laser-induced ignition to improve ignition characteristics. A locally intensified microwave field was formed near the...

Nishiyama, Atsushi; Moon, Ahsa; Ikeda, Yuji; Hayashi, Jun; Akamatsu, Fumiteru

2013-01-01T23:59:59.000Z

346

Integration of microwave and thermographic NDT methods for corrosion detection  

Science Journals Connector (OSTI)

Infrastructure health monitoring is an important issue in the transportation industry. For the case of cement-based structures in particular detection of corrosion on reinforcing steel bars (rebar) is an ongoing problem for aging infrastructure. There have been a number of techniques that have shown promise in this area including microwave nondestructive testing (NDT) and thermography. Thermography is quite advantageous as it is an established method and can be utilized for large inspection areas with intuitive results. Typical heat sources include induction heating and flash lamps but these are not without drawbacks. Microwave nondestructive testing has also been successful at detecting corroded rebar but at the cost of lengthy scan times. This paper presents an investigation into the potential of utilizing aspects of microwave NDT and thermography to create a hybrid NDT method herein referred to as Active Microwave Thermography (AMT). AMT takes advantage of the electromagnetically lossy nature of corrosion byproducts and uses microwave energy to induce heat in the corrosion. Subsequently the resultant heat profile is captured using an infrared camera. This paper presents initial simulations and measurements that highlight the potential of AMT to detect corroded rebar.

2014-01-01T23:59:59.000Z

347

Reduction of Metal Oxides by Microwave Heating of Multi-walled...  

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

Reduction of Metal Oxides by Microwave Heating of Multi-walled Carbon Nanotubes Microwave heating of a metal oxide in the presence of multi-walled carbon nanotubes may result in...

348

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...

349

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

350

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

351

Attosecond timing jitter modelocked lasers and ultralow phase noise photonic microwave oscillators  

E-Print Network [OSTI]

Photonic microwave oscillator based on optical frequency comb and ultrastable optical reference cavity represents the state-of-the-art solution to generate X-band microwaves of ultralow phase noise. Such high-quality ...

Li, Duo, Ph. D. Massachusetts Institute of Technology

2014-01-01T23:59:59.000Z

352

Pyrolysis of Municipal Solid Waste for Syngas Production by Microwave Irradiation  

Science Journals Connector (OSTI)

In the present study, we discuss the application of microwave-irradiated pyrolysis of municipal solid waste (MSW) for total recovery of useful gases and energy. The MSW pyrolysis under microwave irradiation hi...

Vidyadhar V. Gedam; Iyyaswami Regupathi

2012-03-01T23:59:59.000Z

353

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,...

354

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

355

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

356

Observation of plasma array dynamics in 110 GHz millimeter-wave air breakdown  

SciTech Connect (OSTI)

We present dynamical measurements of self-organizing arrays of plasma structures in air induced by a 110 GHz millimeter-wave beam with linear or circular polarization. The formation of the individual plasmas and the growth of the array pattern are studied using a fast-gated (5-10 ns) intensified camera. We measure the time-dependent speed at which the array pattern propagates in discrete steps toward the millimeter-wave source, observing a peak speed greater than 100 km/s. We observe the expansion of an initially spherical plasma into a disk or an elongated filament, depending on the polarization of the incident beam. The results show good agreement with one-dimensional ionization-diffusion theory and two-dimensional simulations.

Cook, Alan M.; Hummelt, Jason S.; Shapiro, Michael A.; Temkin, Richard J. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, 167 Albany St., Cambridge, Massachusetts 02139 (United States)

2011-10-15T23:59:59.000Z

357

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

358

VERY LARGE ARRAY DETECTION OF THE 36 GHz ZEEMAN EFFECT IN DR21W REVISITED  

SciTech Connect (OSTI)

We report on the observation of the 36 GHz methanol maser line in the star-forming region DR21W to accurately measure the Zeeman effect. The Zeeman signature reported by Fish et al. became suspicious after an instrumental effect was discovered in the early days of the commissioning of the Very Large Array Wide-band Digital Architecture correlator. We conclude that the previously reported magnetic field strength of 58 mG (1.7 Hz mG{sup -1}/z) is instrumental in nature and thus incorrect. With the improved performance of the array, we now deduce a 3{sigma} limit of -4.7 to +0.4 mG (1.7 Hz mG{sup -1}/z) for the line-of-sight component of the magnetic field strength in DR21W.

Momjian, Emmanuel; Sjouwerman, Lorant O. [National Radio Astronomy Observatory, P.O. Box O, 1003 Lopezville Road, Socorro, NM 87801 (United States); Fish, Vincent L., E-mail: emomjian@nrao.edu [MIT Haystack Observatory, Route 40, Westford, MA 01886 (United States)

2012-09-20T23:59:59.000Z

359

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.

360

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

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

In situ RF/microwave remediation of soil experiment overview  

SciTech Connect (OSTI)

Contaminant plumes are significant waste problems that require remediation in both the government and private sectors. The authors are developing an in situ process that uses RF/microwave stimulation to remove pollutants from contaminated soils. This process is more efficient than existing technologies, creates less secondary pollution, and is applicable to situations that are not amenable to treatment by existing technologies. Currently, the most commonly used process is soil vapor extraction. However, even when it is successful, this technology is energy inefficient. The authors objective is to combine RF/microwave energy application with soil vapor extraction to help mobilize and efficiently remove the soil contaminants, specifically demonstrating the viability of RF/microwave induced, in situ, soil remediation of light and dense non-aqueous phase liquids (LNAPL, DNAPL) contaminants.

Regan, A.H.; Palomares, M.E.; Polston, C.; Rees, D.E.; Roybal, W.T. [Los Alamos National Lab., NM (United States); Ross, T.J. [Univ. of New Mexico, Albuquerque, NM (United States)

1995-09-01T23:59:59.000Z

362

Purcell effect with microwave drive: Suppression of qubit relaxation rate  

E-Print Network [OSTI]

We analyze the Purcell relaxation rate of a superconducting qubit coupled to a resonator, which is coupled to a transmission line and pumped by an external microwave drive. Considering the typical regime of the qubit measurement, we focus on the case when the qubit frequency is significantly detuned from the resonator frequency. Surprisingly, the Purcell rate decreases when the strength of the microwave drive is increased. This suppression becomes significant in the nonlinear regime. In the presence of the microwave drive, the loss of photons to the transmission line also causes excitation of the qubit; however, the excitation rate is typically much smaller than the relaxation rate. Our analysis also applies to a more general case of a two-level quantum system coupled to a cavity.

Eyob A. Sete; Jay M. Gambetta; Alexander N. Korotkov

2014-01-22T23:59:59.000Z

363

Application of microwave solidification technology to radioactive waste  

SciTech Connect (OSTI)

The EPA has declared vitrification to be the Best Available Demonstrated Technology (BDAT) for High Level Radioactive Waste (40 CFR 268.42). Vitrification has been chosen as the method of choice for treating a number of radioactive residues and wastes in the DOE complex. Vitrification offers advantages of waste volume reduction, the ability to handle changing waste forms, and a stable, nonleachable final waste form. Microwave heating is a superior method for vitrification of radioactive wastes. Advantages of microwave heating include: (1) direct waste heating, eliminates need for electrodes, refractories and other consumables; (2) ``in-can`` processing allows for treatment of the material in its final container, (3) a mechanically simple system where the microwaves are generated away from the treatment area and transmitted to the treatment applicator by a wave guide, thus minimizing worker exposure to radiation; (4) easier equipment maintenance; and (5) a high degree of public acceptance.

Harris, M.; Sprenger, G.; Roushey, B.; Fenner, G.; Nieweg, R.

1995-09-28T23:59:59.000Z

364

Design ad Modeling of a 17 GHz Photcxxthode RF Gun C. L. Lin, S. C. Chen, J. S. U'urtele, H. Temkin, 13. Danly *  

E-Print Network [OSTI]

Design ad Modeling of a 17 GHz Photcxxthode RF Gun C. L. Lin, S. C. Chen, J. S. U'urtele, H. Temkin of a high-frequencv(l7GHz), high accel- erating gradirnt(250hlv/rrl) photocathode RF gun is stud- ied in conventional DC guns followed by RF bunchers have reached their intrin- sic limitations and do not meet

Wurtele, Jonathan

365

Differential Damage in Bacterial Cells by Microwave Radiation on the Basis of Cell Wall Structure  

Science Journals Connector (OSTI)

...consistent when the microwave radiation was repeated. Changes in the...NaCl was exposed to microwave radiation at 600 W, and its temperature...U200; Hitachi Co., Tokyo, Japan). All the experiments were...cells were treated by microwave radiation, the shape of the cells was...

Im-Sun Woo; In-Koo Rhee; Heui-Dong Park

2000-05-01T23:59:59.000Z

366

Microwave and EUV Observations of an Erupting Filament and Associated Flare and Coronal Mass Ejections  

Science Journals Connector (OSTI)

......feature was 5.51 MHz at 07:48 UT, and...High-Temperature Plasma to the Microwave...microwave emission from plasma below this temperature...case of a stratified atmosphere; then, the integrations...high- temperature plasma to the microwave...operating at 5743 MHz (5.2 cm), observed......

Costas E. Alissandrakis; Alexey A. Kochanov; Spiros Patsourakos; Alexander T. Altyntsev; Sergey V. Lesovoi; Nadya N. Lesovoya

2013-12-05T23:59:59.000Z

367

Microwave-assisted sample preparation of coal and coal fly ash for subsequent metal determination  

SciTech Connect (OSTI)

The aim of this paper is to review microwave-assisted digestion of coal and coal fly ash. A brief description of microwave heating principles is presented. Microwave-assisted digestion appears currently to be the most popular preparation technique, possibly due to the comparatively rapid sample preparation and the reduction of contamination, compared to the conventional hot-plate digestion methods.

Srogi, K. [Inst. of Chemical Processing of Coal, Zabrze (Poland)

2007-01-15T23:59:59.000Z

368

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

369

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

370

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

371

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

372

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

373

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

374

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.

375

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

376

Pressure History Measurement in a Microwave Beaming Thruster  

Science Journals Connector (OSTI)

In a microwave beaming thruster with a 1?dimensional nozzle plasma and shock wave propagates in the nozzle absorbing microwave power. In this study pressure histories in the thruster are measured using pressure gauges. Measured pressure history at the thruster wall shows constant pressure during plasma propagation in the nozzle. The result of measurement of the propagating velocities of shock wave and plasma shows that both propagate in the same velocity. These result shows that thrust producing model of analogy of pulse detonation engine is successful for the 1D thruster.

Yasuhisa Oda; Masato Ushio; Kimiya Komurasaki; Koji Takahashi; Atsushi Kasugai; Keishi Sakamoto

2006-01-01T23:59:59.000Z

377

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

378

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

379

Cryogenic resonant microwave cavity searches for hidden sector photons  

E-Print Network [OSTI]

The hidden sector photon is a weakly interacting hypothetical particle with sub-eV mass that kinetically mixes with the photon. We describe a microwave frequency light shining through a wall experiment where a cryogenic resonant microwave cavity is used to try and detect photons that have passed through an impenetrable barrier, a process only possible via mixing with hidden sector photons. For a hidden sector photon mass of 53 $\\mu$eV we limit the hidden photon kinetic mixing parameter $\\chi cryogenic detector cavity to place new limits on the kinetic mixing parameter for hidden sector photons as a form of cold dark matter.

Parker, Stephen R; Povey, Rhys G; Tobar, Michael E

2014-01-01T23:59:59.000Z

380

Cryogenic resonant microwave cavity searches for hidden sector photons  

E-Print Network [OSTI]

The hidden sector photon is a weakly interacting hypothetical particle with sub-eV mass that kinetically mixes with the photon. We describe a microwave frequency light shining through a wall experiment where a cryogenic resonant microwave cavity is used to try and detect photons that have passed through an impenetrable barrier, a process only possible via mixing with hidden sector photons. For a hidden sector photon mass of 53 $\\mu$eV we limit the hidden photon kinetic mixing parameter $\\chi cryogenic detector cavity to place new limits on the kinetic mixing parameter for hidden sector photons as a form of cold dark matter.

Stephen R. Parker; John G. Hartnett; Rhys G. Povey; Michael E. Tobar

2014-10-20T23:59:59.000Z

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

Cryogenic resonant microwave cavity searches for hidden sector photons  

Science Journals Connector (OSTI)

The hidden sector photon is a weakly interacting hypothetical particle with sub-eV mass that kinetically mixes with the photon. We describe a microwave frequency light shining through a wall experiment, where a cryogenic resonant microwave cavity is used to try and detect photons that have passed through an impenetrable barrier, a process only possible via mixing with hidden sector photons. For a hidden sector photon mass of 53???eV, we limit the hidden photon kinetic mixing parameter ?cryogenic detector cavity to place new limits on the kinetic mixing parameter for hidden sector photons as a form of cold dark matter.

Stephen R. Parker; John G. Hartnett; Rhys G. Povey; Michael E. Tobar

2013-12-03T23:59:59.000Z

382

Non-absorbing high-efficiency counter for itinerant microwave photons  

E-Print Network [OSTI]

Detecting an itinerant microwave photon with high efficiency is an outstanding problem in microwave photonics and its applications. We present a scheme to detect an itinerant microwave photon in a transmission line via the nonlinearity provided by a transmon in a driven microwave resonator. With a single transmon we achieve 84% distinguishability between zero and one microwave photons and 90% distinguishability with two cascaded transmons by performing continuous measurements on the output field of the resonator. We also show how the measurement diminishes coherence in the photon number basis thereby illustrating a fundamental principle of quantum measurement: the higher the measurement efficiency, the faster is the decoherence.

Bixuan Fan; Göran Johansson; Joshua Combes; G. J. Milburn; Thomas M. Stace

2014-03-18T23:59:59.000Z

383

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

384

Electrically long vertical interconnects for microwave circuits and antennas  

E-Print Network [OSTI]

. . . . . 2 . . . . 3 . . . . 4 . 4 . 4 . 5 . . . . 5 . . . . 6 . . . . 7 A. Transmission Line Interconnects. . B. Electromagnetically Coupled lnterconnects . . . . . C. Conclusions . . . . . . 8 . . . 10 III FIDELITY SIMULATION 12 A. B. C. D... interconnects satisfying specifications set by Raytheon Systems Co. This research was sponsored by Raytheon Systems Co. RF/Microwave Division. A vertical interconnect couples transmission lines, antennas, and components between vertically spaced layers...

Coutant, Matthew Richard

2012-06-07T23:59:59.000Z

385

Multi-modal transmission of microwaves through hole arrays  

E-Print Network [OSTI]

. R. Evans, and J. R. Sambles, "Experimental verification of designer surface plasmons," Science 308Multi-modal transmission of microwaves through hole arrays James D. Edmunds,1,* Euan Hendry,1(5722), 670­672 (2005). 8. S. A. Maier, S. R. Andrews, L. Martín-Moreno, and F. J. García-Vidal, "Terahertz

Exeter, University of

386

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

387

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

388

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

389

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

390

Controlling Nanoparticle Aggregation in Colloidal Microwave Absorbers via Interface Chemistry  

E-Print Network [OSTI]

Controlling Nanoparticle Aggregation in Colloidal Microwave Absorbers via Interface Chemistry Brian ABSTRACT Interface chemistry can be implemented to modulate the aggregation and dispersion of nanoparticles of superparamagnetic magnetite nanoparticles in organic and aqueous solutions. With decrease in solution pH, individual

Stowell, Michael

391

Metal slits and liquid crystals at microwave frequencies  

Science Journals Connector (OSTI)

...the possible use of dual frequency materials to allow drive-on as well as drive-off. Unfortunately such dual-frequency materials have reduced...T Nomoto2002Microwave variable delay line using dual-frequency switching-mode liquid...

2006-01-01T23:59:59.000Z

392

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

393

Enhancement of RF Breakdown Threshold of Microwave Cavities by Magnetic Insulation  

SciTech Connect (OSTI)

Limitations on the maximum achievable accelerating gradient of microwave cavities can influence the performance, length, and cost of particle accelerators. Gradient limitations are believed to be initiated by electron emission from the cavity surfaces. Here, we show that field emission is effectively suppressed by applying a tangential magnetic field to the cavity walls, so higher gradients can be achieved. Numerical simulations indicate that the magnetic field prevents electrons leaving these surfaces and subsequently picking up energy from the electric field. Our results agree with current experimental data. Two specific examples illustrate the implementation of magnetic insulation into prospective particle accelerator applications. The ultimate goal of several research efforts is to integrate high-gradient radio-frequency (rf) structures into next generation particle accelerators. For instance, the Muon Accelerator Program is looking at developing low-frequency cavities for muon cooling, and the International Linear Collider is optimizing the performance of 1.3 GHz rf structures aimed at designing a 1 TeV electron-positron collider. Furthermore, the High Gradient RF Collaboration is examining high frequency (f > 10 GHz) structures intended for an electron-positron collider operating at energies in the TeV range. In all this research, the accelerating gradient will be one of the crucial parameters affecting their design, construction, and cost. Limitations from rf breakdown strongly influence the development of accelerators since it limits the machine's maximum gradient. The emission of electrons from the cavity surfaces seemingly is a necessary stage in the breakdown process, acting either as a direct cause of breakdown or as precursor for other secondary effects. Typically, electron currents arise from sharp edges or cracks on the cavities surfaces, where the strength of the electric field is strongly enhanced compared to that of the nominal field when the surfaces of the cavity are perfect planes. Subsequently, a stream of emitted electrons can be accelerated by the rf electric field toward the opposing cavity walls. Upon impact, they heat a localized region, resulting in the eventual breakdown by a variety of secondary mechanisms. Therefore, it is advantageous to develop techniques that could suppress field emission within rf cavities. It has been proposed that high voltages up to about a gigavolt range may be sustained in voltage transformers, by adopting the principle of magnetic insulation in ultrahigh vacuum. The basic idea is to suppress field emission by applying a suitably directed magnetic field of sufficient strength to force the electrons orbits back on to the rf emitting surface. More recently, it was shown that magnetic insulation could be very effective in suppressing field emission and multipacting in rectangular coupler waveguides. Hence, the question arises whether the same principle is applicable to rf accelerating structures. In this Letter, we shall consider application of the concept to low-frequency (201-805 MHz) muon accelerator cavities.

Stratakis, D.; Gallardo, J.; Palmer, R.B.

2011-03-28T23:59:59.000Z

394

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

395

1  

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

Technique for Retrieving Liquid Water Path over Land Technique for Retrieving Liquid Water Path over Land using Satellite Microwave Observations M.N. Deeter and J. Vivekanandan Research Applications Library National Center for Atmospheric Research Boulder, Colorado Abstract 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 (∆ε), surface temperature, liquid water path (LWP), and precipitable water vapor

396

Effects of water addition on OH radical generation and plasma properties in an atmospheric argon microwave plasma jet  

SciTech Connect (OSTI)

Water vapor was added to the feeding gas of a continuous atmospheric argon (Ar) microwave plasma jet to study its influence on plasma shape, plasma gas temperature, and OH radical concentrations. The plasma jet was created by a 2.45 GHz microwave plasma source operating at constant power of 104 W with H{sub 2}O-Ar mixture flow rate of 1.7 standard liter per minute (slm). With an increase in the H{sub 2}O/Ar ratio from 0.0 to 1.9%, the plasma jet column length decreased from 11 mm to 4 mm, and the plasma jet became unstable when the ratio was higher than 1.9%; elevation of plasma gas temperature up to 330 K was observed in the plasma temperature range of 420-910 K. Optical emission spectroscopy showed that the dominant plasma emissions changed from N{sub 2} in the pure Ar plasma jet to OH with the addition of water vapor, and simulations of emission spectra suggested non-Boltzmann distribution of the rotational levels in the OH A-state (v'=0). Spatially resolved absolute OH number densities along the plasma jet axis were measured using UV cavity ringdown spectroscopy of the OH (A-X) (0-0) band in the H{sub 2}O/Ar ratio range of 0.0-1.9%. The highest OH number density is consistently located in the vicinity of the plasma jet tip, regardless of the H{sub 2}O/Ar ratio. OH number density in the post-tip region follows approximately an exponential decay along the jet axis with the fastest decay constant of 3.0 mm in the H{sub 2}O/Ar ratio of 1.5%. Given the low gas temperature of 420-910 K and low electron temperature of 0.5-5 eV along the jet axis, formation of the OH radical is predominantly due to electron impact induced dissociation of H{sub 2}O and dissociative recombination of H{sub 2}O{sup +} resulting from the Penning ionization process.

Srivastava, Nimisha; Wang Chuji [Department of Physics and Astronomy and the Energy Institute, Mississippi State University, Mississippi State, Mississippi 39762 (United States)

2011-09-01T23:59:59.000Z

397

STRUCTURE OF THE INNER JET OF OJ287 FROM VLBA DATA AT 15 GHz IN SUPER-RESOLUTION MODE  

SciTech Connect (OSTI)

In this work we show the results obtained from the Very Long Baseline Array data at 15 GHz of OJ287 in super-resolution mode. The data showed a jet configuration in the form of a 'fork' where superluminal components emerge via stationary components at the northwest and the southeast close to the core to form parallel trajectories along the southwest direction in the plane of sky. This agrees with a source structure of an extended, broad morphology of OJ287.

Tateyama, Claudio E. [CEA-Instituto Nacional de Pesquisas Espaciais (INPE), Av. dos Astronautas 1758, 12201-970 Sao Jose dos Campos, SP, Brazil. (Brazil)] [CEA-Instituto Nacional de Pesquisas Espaciais (INPE), Av. dos Astronautas 1758, 12201-970 Sao Jose dos Campos, SP, Brazil. (Brazil)

2013-04-01T23:59:59.000Z

398

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

399

Mapping the Central Region of the PPN CRL 618 at Sub-arcsecond Resolution at 350 GHz  

E-Print Network [OSTI]

CRL 618 is a well-studied pre-planetary nebula. We have mapped its central region in continuum and molecular lines with the Submillimeter Array at 350 GHz at ~ 0.3" to 0.5" resolutions. Two components are seen in 350 GHz continuum: (1) a compact emission at the center tracing the dense inner part of the H II region previously detected in 23 GHz continuum and it may trace a fast ionized wind at the base, and (2) an extended thermal dust emission surrounding the H II region, tracing the dense core previously detected in HC3N at the center of the circumstellar envelope. The dense core is dusty and may contain mm-sized dust grains. It may have a density enhancement in the equatorial plane. It is also detected in carbon chain molecules HC3N and HCN, and their isotopologues, with higher excitation lines tracing closer to the central star. It is also detected in C2H3CN toward the innermost part. Most of the emission detected here arises within ~ 630 AU (~0.7") from the central star. A simple radiative transfer model...

Lee, Chin-Fei; Sahai, Raghvendra; Contreras, Carmen Sanchez

2013-01-01T23:59:59.000Z

400

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

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

ARM - Facility News Article  

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

15, 2007 [Facility News] 15, 2007 [Facility News] Microwave Radiometers Put to the Test in Germany Bookmark and Share A 2-channel microwave radiometer (left) and a 12-channel microwave radiometer profiler (right) are part of a larger collection of instruments deployed at the ARM Mobile Facility site in Heselbach, Germany, in 2007. A 2-channel microwave radiometer (left) and a 12-channel microwave radiometer profiler (right) are part of a larger collection of instruments deployed at the ARM Mobile Facility site in Heselbach, Germany, in 2007. Microwave radiometers (MWRs) are instruments used to measure emissions of water vapor and liquid water molecules in the atmosphere at specific microwave frequencies. Different MWRs are used to measure various frequencies, but the accuracy of all their retrievals is somewhat suspect,

402

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

403

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

404

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

405

Microwave studies of weak localization and antilocalization in epitaxial graphene  

SciTech Connect (OSTI)

A microwave detection method was applied to study weak localization and antilocalization in epitaxial graphene sheets grown on both polarities of SiC substrates. Both coherence and scattering length values were obtained. The scattering lengths were found to be smaller for graphene grown on C-face of SiC. The decoherence rate was found to depend linearly on temperature, showing the electron-electron scattering mechanism.

Drabi?ska, Aneta; Kami?ska, Maria [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warsaw (Poland); Wo?o?, Agnieszka [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warsaw, Poland and Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Strupinski, Wlodek [Institute of Electronic Materials Technology, ul. Wólczyñska 133, 01-919 Warsaw (Poland); Baranowski, J. M. [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warsaw, Poland and Institute of Electronic Materials Technology, ul. Wólczyñska 133, 01-919 Warsaw (Poland)

2013-12-04T23:59:59.000Z

406

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

407

Microwaves and Chemistry: The Catalysis of an Exciting Marriage  

E-Print Network [OSTI]

of microwave catalysts employed. We should emphasize that water as a reactant is in the adsorbed state Oil the catalyst's sUlfaces. Indeed, both the hydrocarbon and water are adsorbed on the surfaces and the primary reaction of the oxidation takes place.... For this reason, it is important to realize that the methods of introducing and maintaining the concentrations of adsorbed water on the surfaces effectively control the efficiency and the selectivity of the oxidation products. This is equally true...

Wan, J.

408

Measuring plasma turbulence using low coherence microwave radiation  

SciTech Connect (OSTI)

Low coherence backscattering (LCBS) is a proposed diagnostic technique for measuring plasma turbulence and fluctuations. LCBS is an adaptation of optical coherence tomography, a biomedical imaging technique. Calculations and simulations show LCBS measurements can achieve centimeter-scale spatial resolution using low coherence microwave radiation. LCBS measurements exhibit several advantages over standard plasma turbulence measurement techniques including immunity to spurious reflections and measurement access in hollow density profiles. Also, LCBS is scalable for 1-D profile measurements and 2-D turbulence imaging.

Smith, D. R. [Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2012-02-20T23:59:59.000Z

409

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

410

Propagation in 3D of microwaves through density perturbations  

E-Print Network [OSTI]

Simulations using 3D and 2D full-wave codes have shown that edge filaments in tokamak plasmas can significantly affect the propagation of microwaves across a broad frequency spectrum, resulting in scattering angles of up to 46 degrees. Parameter scans were carried out for density perturbations comparable in width and amplitude to MAST filaments and the effect on the measured emission was calculated. 3D effects were discovered in the case of an obliquely incident beam. In general, the problem of EM propagation past wavelength-sized 3D inhomogeneities is not well understood, yet is of importance for both heating and diagnostic applications in the electron cyclotron frequency range for tokamaks, as well as atmospheric physics. To improve this understanding, a new cold-plasma code, EMIT-3D, was written to extend full-wave microwave simulations in magnetized plasmas to 3D, and make comparisons to the existing 2D code IPF-FDMC. This work supports MAST experiments using the SAMI diagnostic to image microwave emissio...

Williams, T R N; O'Brien, M R; Vann, R G L

2013-01-01T23:59:59.000Z

411

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

412

Assessment of microwave power flow for reflectometry measurements in tokamak plasmas  

E-Print Network [OSTI]

measurements in tokamak plasmas P. -A. Gourdain a , W. A.are widely employed in tokamak fusion plasmas, and are alsoresearch devices, such as tokamaks, microwave reflectometry

Gourdain, P-A; Peebles, W. A.

2008-01-01T23:59:59.000Z

413

Microwave Regenerated DPF for Auxiliary Power Units and Diesel Hybrid Vehicles  

Broader source: Energy.gov [DOE]

Microwave regeneration of the DPF can be done without diesel fuel or a catalyst in less than 5 minutes with the engine off.

414

Electric Kettle Takes Down Microwave in Final Round of #EnergyFaceoff  

Broader source: Energy.gov [DOE]

The final round of #EnergyFaceoff goes to the electric kettle! See how much it can save compared to a microwave when heating water.

415

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

416

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...

417

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

Broader source: Energy.gov [DOE]

In the final #EnergyFaceoff round, the electric kettle takes on the microwave for the honor of heating your water.

418

Microwave cavity searches for dark-matter axions  

Science Journals Connector (OSTI)

Recent determinations of cosmological parameters point to a flat Universe, whose total energy density is composed of about two-thirds vacuum energy and one-third matter. Ordinary baryonic matter is relegated to a small fraction of the latter, within which the luminous part is an order of magnitude smaller yet. Particle dark matter, i.e., one or more relic particle species from the big bang, is thus strongly suggested as the dominant component of matter in the Universe. The axion, a hypothetical elementary pseudoscalar arising from the Peccei-Quinn solution to the strong-CP problem, is a well-motivated candidate. If the axion exists, it must be extremely light, in the mass range of 10-6–10-3 eV, and possess extraordinarily feeble couplings to matter and radiation. Nevertheless, as proposed by Sikivie in 1983, the axion’s two-photon coupling lends itself to a feasible search strategy with currently available technology. In this scheme, axions resonantly convert to single microwave photons by a Primakoff interaction, in a tunable microwave cavity permeated by a strong magnetic field. Present experiments utilizing heterostructure transistor microwave amplifiers have achieved total system noise temperatures of ?3 K and represent the world’s quietest spectral radio receivers. Exclusion regions have already been published well into the band of realistic axion model couplings, within the lowest decade of mass range. Recent breakthroughs in the development of near-quantum-limited superconducting quantum interference device amplifiers should reduce the system noise temperature to ?100 mK or less. Ongoing research into using Rydberg-atom single-quantum detectors as the detector in a microwave cavity experiment could further reduce the effective noise temperature. In parallel with improvements in amplifier technology, promising concepts for higher-frequency cavity resonators are being explored to open up the higher decades in mass range. Definitive experiments to find or exclude the axion may therefore be at hand in the next few years. As the microwave cavity technique measures the total energy of the axion, a positive discovery could well reveal fine structure of the signal due to flows of nonthermalized axions. Manifesting diurnal and sidereal modulation, such detailed features would contain a wealth of information about the history, structure, and dynamics of our Milky Way galaxy.

Richard Bradley; John Clarke; Darin Kinion; Leslie J Rosenberg; Karl van Bibber; Seishi Matsuki; Michael Mück; Pierre Sikivie

2003-06-12T23:59:59.000Z

419

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

420

Connecting the Time Series of Microwave Sounding Observations from AMSU to ATMS for Long-Term Monitoring of Climate  

Science Journals Connector (OSTI)

The measurements from the Microwave Sounding Unit (MSU) and the Advanced Microwave Sounding Unit-A (AMSU-A) on board NOAA polar-orbiting satellites have been extensively utilized for detecting atmospheric temperature trend during the last several ...

Xiaolei Zou; Fuzhong Weng; H. Yang

2014-10-01T23:59:59.000Z

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.


421

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.

422

Passive and active circuits in cmos technology for rf, microwave and millimeter wave applications  

E-Print Network [OSTI]

) and -5.2 dBm in the centre of band 2 (from 5.8 to 8 GHz) with input return loss less than 10 dB throughout the two bands of operation....

Chirala, Mohan Krishna

2009-05-15T23:59:59.000Z

423

Elemental analysis by microwave-assisted laser-induced breakdown spectroscopy: Evaluation on ceramics  

E-Print Network [OSTI]

,2 These sources are usually flames or plasmas: arcs, sparks, plasma jets, inductively coupled plasma (ICP), high demonstrated the signal enhancement ability of their LAMPS (Laser-Assisted Microwave Plasma Spectroscopy utilizing interaction between microwave radiation and laser-induced plasma has been evaluated. Experimental

Richardson, Martin C.

424

Microwave applicator for in-drum processing of radioactive waste slurry  

DOE Patents [OSTI]

A microwave applicator for processing of radioactive waste slurry uses a waveguide network which splits an input microwave of TE.sub.10 rectangular mode to TE.sub.01 circular mode. A cylindrical body has four openings, each receiving 1/4 of the power input. The waveguide network includes a plurality of splitters to effect the 1/4 divisions of power.

White, Terry L. (Oak Ridge, TN)

1994-01-01T23:59:59.000Z

425

Microwave Photon Counter Based on Josephson Junctions Y.-F. Chen,1,* D. Hover,1  

E-Print Network [OSTI]

Microwave Photon Counter Based on Josephson Junctions Y.-F. Chen,1,* D. Hover,1 S. Sendelbach,1 L on the current-biased Josephson junction. The junction is tuned to absorb single microwave photons from optical photon counters, it is natural to consider the Josephson junction--a nonlinear, nondissipative

Saffman, Mark

426

Selective Conversion of Biomass Hemicellulose to Furfural Using Maleic Acid with Microwave Heating  

Science Journals Connector (OSTI)

Selective Conversion of Biomass Hemicellulose to Furfural Using Maleic Acid with Microwave Heating ... With the aim to develop an ecological method to convert xylose into furfural without the use of inorganic acids, a ... ... Sulfonated lignin was converted to phenol and phenolic compounds using a conventional batch or a microwave reactor. ...

Eurick S. Kim; Shuo Liu; Mahdi M. Abu-Omar; Nathan S. Mosier

2012-01-10T23:59:59.000Z

427

Eric Moulton, Ferri Hassani, Pejman Nekoovaght Microwave-Assisted Heating in Rock  

E-Print Network [OSTI]

Eric Moulton, Ferri Hassani, Pejman Nekoovaght Microwave-Assisted Heating in Rock INTRODUCTION to expensive replacements. Expansive heating through microwaves breaks up the rock, which reduces the stress the mechanisms and parameters governing the heating rate of a material. Department of Mining and Materials

Barthelat, Francois

428

Microwave and EUV Observations of an Erupting Filament and Associated Flare and Coronal Mass Ejections  

Science Journals Connector (OSTI)

......observes below 16 MHz that corresponds...to at least 30 kHz, well into the...feature was 5.51 MHz at 07:48 UT...High-Temperature Plasma to the Microwave...of a stratified atmosphere; then, the integrations...temperature plasma to the microwave...operating at 5743 MHz (5.2 cm......

Costas E. Alissandrakis; Alexey A. Kochanov; Spiros Patsourakos; Alexander T. Altyntsev; Sergey V. Lesovoi; Nadya N. Lesovoya

2013-12-05T23:59:59.000Z

429

Microwave-assisted preparation of zeolite KH from alumatrane and Mathavee Sathupunya a  

E-Print Network [OSTI]

-loaded zeolite was synthesized for the first time, via sol­gel processing and microwave heating techniques Elsevier Inc. All rights reserved. Keywords: Alumatrane; Silatrane; Microwave technique; Sol­gel process; K by hydrothermal crystallization under alkaline conditions using an amorphous aluminosilicate gel as the starting

Gulari, Erdogan

430

Comparative study of microwave tomography segmentation techniques based on GMM and KNN in breast cancer detection  

Science Journals Connector (OSTI)

Microwave Tomography Imaging (MTI) is a new technology for early breast cancer detection. Compared to other methods such as X-ray, Magnetic Resonance Imaging (MRI) and ultrasound, the MTI technology is almost radiation-free, and low cost. However, the ... Keywords: gaussian mixture model, microwave tomography imaging, segmentation

Chunqiu Wang, Wei Wang, Sung Shin, Soon I. Jeon

2014-10-01T23:59:59.000Z

431

Method and apparatus for measuring butterfat and protein content using microwave absorption techniques  

DOE Patents [OSTI]

A self calibrating method and apparatus for measuring butterfat and protein content based on measuring the microwave absorption of a sample of milk at several microwave frequencies. A microwave energy source injects microwave energy into the resonant cavity for absorption and reflection by the sample undergoing evaluation. A sample tube is centrally located in the resonant cavity passing therethrough and exposing the sample to the microwave energy. A portion of the energy is absorbed by the sample while another portion of the microwave energy is reflected back to an evaluation device such as a network analyzer. The frequency at which the reflected radiation is at a minimum within the cavity is combined with the scatter coefficient S.sub.11 as well as a phase change to calculate the butterfat content in the sample. The protein located within the sample may also be calculated in a likewise manner using the frequency, S.sub.11 and phase variables. A differential technique using a second resonant cavity containing a reference standard as a sample will normalize the measurements from the unknown sample and thus be self-calibrating. A shuttered mechanism will switch the microwave excitation between the unknown and the reference cavities. An integrated apparatus for measuring the butterfat content in milk using microwave absorption techniques is also presented.

Fryer, Michael O. (Roberts, ID); Hills, Andrea J. (Iowa City, IA); Morrison, John L. (Idaho Falls, ID)

2000-01-01T23:59:59.000Z

432

Microwave accelerated one-minute synthesis of luminescent ZnO quantum dots  

Science Journals Connector (OSTI)

In this paper we present microwave assisted non-aqueous synthesis of ZnO quantum dots (QDs) by hydrolyzing zinc acetate with lithium hydroxide in ethanol under microwave heating. The processing time for QDs was reduced to few minutes when compared with time consuming sol–gel chemistry. The prepared QDs show good colloidal stability along with stable visible emission.

Adersh Asok; A. R. Kulkarni; Mayuri N. Gandhi

2013-01-01T23:59:59.000Z

433

Experimental Study on Microwave Pyrolysis of an Indonesian Low-Rank Coal  

Science Journals Connector (OSTI)

Microwave pyrolysis of an Indonesian lignite is investigated in this study. ... About half of the world’s coal reserves are low-rank coals. ... Considerable amts. of 3,4-dihydro-1(2H)-naphthalenone (alpha-tetralone) were found in the oil fractions of lignites treated by microwave energy. ...

Nan Wang; Jianglong Yu; Arash Tahmasebi; Yanna Han; John Lucas; Terry Wall; Yu Jiang

2013-10-14T23:59:59.000Z

434

Design of a Microwave-Initiated Pulsed Plasma Thruster Jian F. Li, Class of 2006  

E-Print Network [OSTI]

and departments: · Prof. Edgar Choueiri of the Princeton University Electric Propulsion and Plasma Dynamics and Plasma Dynamics Laboratory. · Prof. Miles and Princeton Applied Physics Group for microwave leak detector of the Princeton University Electric Propulsion and Plasma Dynamics Laboratory for his insight into microwave

Choueiri, Edgar

435

Beamfilling correction study for retrieval of oceanic rain from passive microwave observations  

E-Print Network [OSTI]

Constant in R-T relationship????????????.??..?.??. 6 2 Spatial resolution for each TMI channel?????????????... 7 3 ARMAR system parameters ?????????.????????... 13 4 The impact of path averaging on STD of rain rate ??????..??? 21 5... except for TMI 19 GHz channel ???????????. 8 3 Same as Fig. 1 except for TMI 10 GHz channel ..????????.??.. 8 4 Comparison between Chiu?s BCF formula and real data BCF calculations???????????????????????.??.. 10 5 ARMAR observational...

Chen, Ruiyue

2004-09-30T23:59:59.000Z

436

Sub-degree Scale Microwave Anisotropies from Cosmic Defects  

E-Print Network [OSTI]

If current ideas about unified field theories are correct, macroscopic cosmic defects may well exist. The observation of such an entity would have enormous significance for our understanding of fundamental physics. This paper points out a novel observable signature of cosmic texture and global monopoles, namely strong hot spots in the cosmic microwave anisotropy pattern on subdegree scales. This signal should be readily detectable by the next generation of anisotropy mapping experiments. The signature arises from overdensities in the photon-baryon fluid generated by the gravitational attraction of the defects. The angular power spectrum of the anisotropy fluctuations on subdegree scales is also calculated, for cosmic string, global monopoles, and texture.

Neil Turok

1996-06-16T23:59:59.000Z

437

Translational invariance and the anisotropy of the cosmic microwave background  

SciTech Connect (OSTI)

Primordial quantum fluctuations produced by inflation are conventionally assumed to be statistically homogeneous, a consequence of translational invariance. In this paper we quantify the potentially observable effects of a small violation of translational invariance during inflation, as characterized by the presence of a preferred point, line, or plane. We explore the imprint such a violation would leave on the cosmic microwave background anisotropy, and provide explicit formulas for the expected amplitudes of the spherical-harmonic coefficients.

Carroll, Sean M.; Tseng, C.-Y.; Wise, Mark B. [California Institute of Technology, Pasadena, California 91125 (United States)

2010-04-15T23:59:59.000Z

438

Nanoparticle plasma ejected directly from solid copper by localized microwaves  

SciTech Connect (OSTI)

A plasma column ejected directly from solid copper by localized microwaves is studied. The effect stems from an induced hotspot that melts and emits ionized copper vapors as a confined fire column. Nanoparticles of {approx}20-120 nm size were revealed in the ejected column by in situ small-angle x-ray scattering. Optical spectroscopy confirmed the dominance of copper particles in the plasma column originating directly from the copper substrate. Nano- and macroparticles of copper were verified also by ex situ scanning electron microscopy. The direct conversion of solid metals to nanoparticles is demonstrated and various applications are proposed.

Jerby, E.; Golts, A.; Shamir, Y.; Wonde, S.; Ashkenazi, D.; Eliaz, N. [Faculty of Engineering, Tel Aviv University, Ramat Aviv 69978 (Israel); Mitchell, J. B. A.; LeGarrec, J. L. [IPR., U.M.R. No. 6251 du C.N.R.S., Universite de Rennes I, 35042 Rennes (France); Narayanan, T.; Sztucki, M. [European Synchrotron Radiation Facility, BP-220, 38043 Grenoble (France); Barkay, Z. [Wolfson Applied Materials Research Center, Tel Aviv University, Ramat-Aviv 69978 (Israel)

2009-11-09T23:59:59.000Z

439

A 100-kc modulation system for an EPR microwave spectrometer  

E-Print Network [OSTI]

A 100-kc FIELD MODULATION SYSTEM FOR AN EPR MICROWAVE SPECTROMETER A Thesis By Frank Edwin Stewart Approved as to style and content by: /I i r Chairman of Committee C ead of Dep rtment Member ember August 1964 ACM ONLEDGi PENT... LIST OF FIGURES FIGURE PAGE II-1 Molecular Structure of DPPH 22 II-2 11-3 III-1 IV-1 Hyperfine Splitting in the DPPH EPR Spectrum . 25 Hyperfine Splitting in the Mn EpR Spectrum , . 27 100-kc Field Modulation and Detection System . 4I Typical...

Stewart, Frank Edwin

2012-06-07T23:59:59.000Z

440

One-way glass for microwaves using nonreciprocal metamaterials  

Science Journals Connector (OSTI)

We introduce a class of nonreciprocal metamaterials based on composite assemblies of metallic and biased ferrimagnetic elements. We show that such structures act as ultrathin one-way glasses due to the competition between two modes at the surface of the ferrimagnetic elements—a low-loss surface wave that transmits the signal on the other side of the structure and a surface spin-wave resonance that produces strong isolation levels. These findings can be adapted to existing metamaterial geometries, offering a blueprint to achieve unidirectional propagation in a variety of artificial media at radio, microwave, and millimeter wave frequencies.

A. Degiron and D. R. Smith

2014-05-27T23:59:59.000Z

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

Wide band cryogenic ultra-high vacuum microwave absorber  

DOE Patents [OSTI]

An absorber wave guide assembly for absorbing higher order modes of microwave energy under cryogenic ultra-high vacuum conditions, that absorbs wide-band multi-mode energy. The absorber is of a special triangular shape, made from flat tiles of silicon carbide and aluminum nitride. The leading sharp end of the absorber is located in a corner of the wave guide and tapers to a larger cross-sectional area whose center is located approximately in the center of the wave guide. The absorber is relatively short, being of less height than the maximum width of the wave guide.

Campisi, Isidoro E. (Newport News, VA)

1992-01-01T23:59:59.000Z

442

The Cosmic Microwave Background: Beyond the Power Spectrum  

E-Print Network [OSTI]

Much recent work on the cosmic microwave background (CMB) has focussed on the angular power spectrum of temperature anisotropies and particularly on the recovery of cosmological parameters from acoustic peaks in the power spectrum. However, there is more that can conceivably be done with CMB measurements. Here I briefly survey a few such ideas: cross-correlation with other cosmic backgrounds as a probe of the density of the Universe; CMB polarization as a gravitational-wave detector; secondary anisotropies and the ionization history of the Universe; tests of alternative-gravity theories; polarization, the Sunyaev-Zeldovich effect, and cosmic variance; and tests for a neutrino mass.

Marc Kamionkowski

1998-09-24T23:59:59.000Z

443

A 2-MeV microwave thermionic gun  

SciTech Connect (OSTI)

A high-gradient, S-band microwave gun with a thermionic cathode is being developed in a collaborative effort by AET, Varian, and SSRL. A prototype design using an upgraded Varian dispenser cathode mounted with thermal isolation directly in the first half-cell of a 1-1/2 cell, side-coupled, standing-wave cavity has been fabricated and is being tested. Optimization of the cavity shape and beam formation was done using SUPERFISH, MASK, and PARMELA. An overview of design details, as well as the status of in-progress beam tests, will be presented. 9 refs., 6 figs.

Tanabe, E.; Borland, M.; Green, M.C.; Miller, R.H.; Nelson, L.V.; Weaver, J.N.; Wiedemann, H.

1989-08-01T23:59:59.000Z

444

Wide band cryogenic ultra-high vacuum microwave absorber  

DOE Patents [OSTI]

An absorber waveguide assembly for absorbing higher order modes of microwave energy under cryogenic ultra-high vacuum conditions, that absorbs wide-band multi-mode energy. The absorber is of a special triangular shape, made from flat tiles of silicon carbide and aluminum nitride. The leading sharp end of the absorber is located in a corner of the waveguide and tapers to a larger cross-sectional area whose center is located approximately in the center of the wave guide. The absorber is relatively short, being of less height than the maximum width of the waveguide. 11 figs.

Campisi, I.E.

1992-05-12T23:59:59.000Z

445

Compact hot-nozzle fourier-transform microwave spectormeter  

E-Print Network [OSTI]

, the observed signal (the voltage at the input to the analog-to-digital converter (ADC), for example, see Fig. 2), may be written as Scc(~Qv>“~~!f(Po,To,D,r~,...), (2) where v,Q, and V are, respectively, the microwave frequency, quality factor... dipole moment for the resonant molecular states. For the Fabry-Perot cavity, Q scales with reflector separation (d),6 so (QV) r” introduces (I X Z3) “’ = I”, scaling with linear dimension 1. But in practice Q is often determined by input...

Harmony, Marlin D.; Ratzlaff, Kenneth L.; Angst, D. M.; Beren, K. A.

1995-11-01T23:59:59.000Z

446

Polycrystal diamond growth in a microwave plasma torch  

SciTech Connect (OSTI)

Diamond films of different structures were deposited on quartz, WC-Co, and molybdenum substrates in a microwave plasma torch discharge in an argon-hydrogen-methane gas mixture in a sealed chamber at pressures close to atmospheric by using the chemical vapor deposition technique. Images of diamond polycrystal films and separate crystals, as well as results of Raman spectroscopy, are presented. The spectra of optical plasma radiation recorded during film deposition demonstrate the presence of intense H{sub {alpha}} hydrogen and C{sub 2} radical bands known as Swan bands.

Sergeichev, K. F.; Lukina, N. A.; Bolshakov, A. P.; Ralchenko, V. G.; Arutyunyan, N. R.; Vlasov, I. I. [Russian Academy of Sciences, Prokhorov Institute of General Physics (Russian Federation)

2010-12-15T23:59:59.000Z

447

Journal of Microwaves, Optoelectronics and Electromagnetic Applications, Vol. X, No. Y, Month 2010 Numerical treatment of rounded and sharp  

E-Print Network [OSTI]

Journal of Microwaves, Optoelectronics and Electromagnetic Applications, Vol. X, No. Y, Month 2010 the corners for any value of . For a precise definition, refer to [2]. Brazilian Microwave and Optoelectronics in "journal of microwaves, optoelectronics and electromagnetic applications 10, 1 (2011) 66-81" DOI : 10

Boyer, Edmond

448

Microsoft PowerPoint - Microwave Off-gas srnlTechBriefp1.ppt  

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

Microwave Off-Gas Treatment Microwave Off-Gas Treatment System at a glance  simple design  compact and portable  easy to operate  can be remotely operated  low cost, low maintenance  scalable for large and small volume operations  U.S. patent 6,534,754 The Microwave Off-Gas Treatment System uses microwave energy and high temperatures to treat off- gas emissions to reduce contaminants to acceptable or nondetectable levels. This allows the treated gaseous waste stream to be safety discharged to the atmosphere. New method Scientists at Savannah River National Laboratory (SRNL), working with colleagues from the University of Florida (UF), have invented a unique system to treat off-gas emissions from safe discharge into the atmosphere. The compact and portable Microwave Off-Gas Treatment System is designed to

449

Method of nitriding, carburizing, or oxidizing refractory metal articles using microwaves  

DOE Patents [OSTI]

A method of nitriding an article of refractory-nitride-forming metal or metalloids. A consolidated metal or metalloid article is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid to an article of refractory nitride. in addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.

Holcombe, C.E.; Dykes, N.L.; Tiegs, T.N.

1992-10-13T23:59:59.000Z

450

Method of nitriding, carburizing, or oxidizing refractory metal articles using microwaves  

DOE Patents [OSTI]

A method of nitriding an article of refractory-nitride-forming metal or metalloids. A consolidated metal or metalloid article is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid to an article of refractory nitride. in addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.

Holcombe, Cressie E. (Knoxville, TN); Dykes, Norman L. (Oak Ridge, TN); Tiegs, Terry N. (Lenoir City, TN)

1992-01-01T23:59:59.000Z

451

Abstract--In electrically substituted radiometers, the ultra low noise control of the temperature is required. In this framework, we present results dedicated to the temperature regulation of copper plates, 3 cm diameter and 1 mm thick, using YBa2Cu3O7-d  

E-Print Network [OSTI]

Abstract--In electrically substituted radiometers, the ultra low noise control of the temperature wide band absolute thermometers, with mK accuracy, also needs very efficient but convenient control of the sample holder. A temperature resolution well below the mK has to be reached in that case. We present here

Paris-Sud XI, Université de

452

DEEP 1.4 GHz FOLLOW-UP OF THE STEEP SPECTRUM RADIO HALO IN A521  

SciTech Connect (OSTI)

In a recent paper, we reported on the discovery of a radio halo with very steep spectrum in the merging galaxy cluster A521 through observations with the Giant Metrewave Radio Telescope. We showed that the steep spectrum of the halo is inconsistent with a secondary origin of the relativistic electrons and supports a turbulent acceleration scenario. At that time, due to the steep spectrum, the available observations at 1.4 GHz (archival NRAO-Very Large Array-VLA-CnB-configuration data) were not adequate to accurately determine the flux density associated with the radio halo. In this paper, we report the detection at 1.4 GHz of the radio halo in A521 using deep VLA observations in the D configuration. We use these new data to confirm the steep spectrum of the object. We consider A521 the prototype of a population of very steep spectrum halos. This population is predicted assuming that turbulence plays an important role in the acceleration of relativistic particles in galaxy clusters, and we expect it will be unveiled by future surveys at low frequencies with the LOFAR and LWA radio telescopes.

Dallacasa, D.; Macario, G.; Setti, G. [Dipartimento di Astronomia, Universita di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Brunetti, G.; Cassano, R.; Venturi, T. [INAF-Istituto di Radioastronomia, via Gobetti 101, I-40129 Bologna (Italy); Giacintucci, S. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Kassim, N. E.; Lane, W. [Naval Research Laboratory, Code 7213, Washington, DC 20375-5320 (United States)

2009-07-10T23:59:59.000Z

453

HIGH POWER TEST OF A 3.9 GHZ 5-CELL DEFLECTING-MODE CAVITY IN A CRYOGENIC OPERATION  

SciTech Connect (OSTI)

A 3.9 GHz deflecting mode (S, TM110) cavity has been long used for six-dimensional phase-space beam manipulation tests [1-5] at the A0 Photo-Injector Lab (16 MeV) in Fermilab and their extended applications with vacuum cryomodules are currently planned at the Advanced Superconducting Test Accelerator (ASTA) user facility (> 50 MeV). Despite the successful test results, the cavity, however, demonstrated limited RF performance during liquid nitrogen (LN2) ambient operation that was inferior to theoretical prediction. We have been performing full analysis of the designed cavity by analytic calculation and comprehensive system simulation analysis to solve complex thermodynamics and mechanical stresses. The re-assembled cryomodule is currently under the test with a 50 kW klystron at the Fermilab A0 beamline, which will benchmark the modeling analysis. The test result will be used to design vacuum cryomodules for the 3.9 GHz deflecting mode cavity that will be employed at the ASTA facility for beam diagnostics and phase-space control.

Shin, Young-Min; Church, Michael

2013-11-24T23:59:59.000Z

454

High Power Test Of A 3.9 GHz 5-cell Deflecting-mode Cavity In A Cryogenic Operation  

E-Print Network [OSTI]

A 3.9 GHz deflecting mode (pi, TM110) cavity has been long used for six-dimensional phase-space beam manipulation tests at the A0 Photo-Injector Lab (16 MeV) in Fermilab and their extended applications with vacuum cryomodules are currently planned at the Advanced Superconducting Test Accelerator (ASTA) user facility (> 50 MeV). Despite the successful test results, the cavity, however, demonstrated limited RF performance during liquid nitrogen (LN2) ambient operation that was inferior to theoretical prediction. We have been performing full analysis of the designed cavity by analytic calculation and comprehensive system simulation analysis to solve complex thermodynamics and mechanical stresses. The re-assembled cryomodule is currently under the test with a 50 kW klystron at the Fermilab A0 beamline, which will benchmark the modeling analysis. The test result will be used to design vacuum cryomodules for the 3.9 GHz deflecting mode cavity that will be employed at the ASTA facility for beam diagnostics and phase...

Shin, Young-Min

2014-01-01T23:59:59.000Z

455

Low-pressure microwave plasma ultraviolet lamp for water purification  

Science Journals Connector (OSTI)

Low-pressure mercury lamps are commonly used for germicidal applications. The germicidal effect is due to the emission of light at 254 nm, which leads to the destruction of the most waterborne bacteria and viruses. The microwave plasma ultraviolet (UV) lamp (MPUVL) is a new technology for generating a high-intensity UV light and that can be also controlled to operate at 185 nm; irradiation is in air at this wavelength produces ozone. The microwave power is injected into a resonant cavity and the surface wave excitation takes place within the cavity through that part of the discharge tube (fused silica) protruding inside it. The MPUVL has many advantages over conventional lamps, which are limited to an output power in the region of 30 W m-1, while MPUVL can deliver any amount of power per unit length and the tube can be of any shape, length or diameter. This paper describes the design of the MPUVL and compares its efficiency with that of conventional lamps through spectral analysis. Other results, which include the effects of temperature and different power inputs, are also discussed.

A I Al-Shamma'a; I Pandithas; J Lucas

2001-01-01T23:59:59.000Z

456

Emission of Microwave Photon Pairs by a Tunnel Junction  

E-Print Network [OSTI]

Generation and control of non-classical electromagnetic fields is of crucial importance for quantum information physics. While usual methods for the production of such fields rely on a non-linearity (of a crystal, a Josephson junction, etc.), a recent experiment performed on a normal conductor, a tunnel junction under microwave irradiation, has unveiled an alternative: the use of electron shot noise in a quantum conductor\\cite{PAN_squeezing}. Here we show that such a device can emit \\emph{pairs of microwave photons} of different frequencies with a rate as high as that of superconducting Josephson junctions\\cite{Flurin}. This results in intensity fluctuations of the photon field at two different frequencies being correlated below the photon shot noise,i.e. two-mode amplitude squeezing. Our experiment constitutes a fundamental step towards the understanding of electronic noise in terms of quantum optics, and shows that even a normal conductor could be used as a resource for quantum information processing.

Jean-Charles Forgues; Christian Lupien; Bertrand Reulet

2014-03-21T23:59:59.000Z

457

Optic-microwave mixing velocimeter for superhigh velocity measurement  

SciTech Connect (OSTI)

The phenomenon that a light beam reflected off a moving object experiences a Doppler shift in its frequency underlies practical interferometric techniques for remote velocity measurements, such as velocity interferometer system for any reflector (VISAR), displacement interferometer system for any reflector (DISAR), and photonic Doppler velocimetry (PDV). While VISAR velocimeters are often bewildered by the fringe loss upon high-acceleration dynamic process diagnosis, the optic-fiber velocimeters such as DISAR and PDV, on the other hand, are puzzled by high velocity measurement over 10 km/s, due to the demand for the high bandwidth digitizer. Here, we describe a new optic-microwave mixing velocimeter (OMV) for super-high velocity measurements. By using currently available commercial microwave products, we have constructed a simple, compact, and reliable OMV device, and have successfully obtained, with a digitizer of bandwidth 6 GH only, the precise velocity history of an aluminum flyer plate being accelerated up to 11.2 km/s in a three stage gas-gun experiment.

Weng Jidong; Wang Xiang; Tao Tianjiong; Liu Cangli; Tan Hua [Laboratory for Shock Waves and Detonation Physics Research, Institute of Fluid Physics, P.O. Box 919-102, Mianyang, Sichuan 621900 (China)

2011-12-15T23:59:59.000Z

458

Microwave calcination for plutonium immobilization and residue stabilization  

SciTech Connect (OSTI)

In the late 1980`s development was begun on a process using microwave energy to vitrify low level mixed waste sludge and transuranic mixed waste sludge generated in Building 374 at Rocky Flats. This process was shown to produce a dense, highly durable waste form. With the cessation of weapons production at Rocky Flats, the emphasis has changed from treatment of low level and TRU wastes to stabilizaiton of plutonium oxide and residues. This equipment is versatile and can be used as a heat source to calcine, react or vitrify many types of residues and oxides. It has natural economies in that it heats only the material to be treated, significantly reducing cycle times over conventional furnaces. It is inexpensive to operate in that most of the working components remain outside of any necessary contamination enclosure and therefore can easily be maintained. Limited testing has been successfully performed on cerium oxide (as a surrogate for plutonium oxide), surrogate electrorefining salts, surrogate residue sludge and residue ash. Future plans also include tests on ion exchange resins. In an attempt to further the usefullness of this technology, a mobile, self-contained microwave melting system is currently under development and expected to be operational at Rocky Flats Enviromental Technology Site by the 4th quarter of FY96.

Harris, M.J.; Rising, T.L.; Roushey, W.J.; Sprenger, G.S. [Kaiser-Hill Co., Golden, CO (United States)

1995-12-01T23:59:59.000Z

459

ARM - Data Announcements Article  

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

Bookmark and Share An example plot from the MWRRET VAP for 1192007 at Black Forest, Germany: (top) Brightness temperatures measured by the microwave radiometer (MWR). Orange and...

460

ARM - Black Forest News  

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

News Campaign Images Black Forest News ARM Mobile Facility Completes Field Campaign in Germany January 15, 2008 Microwave Radiometers Put to the Test in Germany September 15, 2007...

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

ARM - Publications: Science Team Meeting Documents  

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

Continued Evaluation of the Microwave Radiometer Profiler Liljegren, J.C., Argonne National Laboratory Twelfth Atmospheric Radiation Measurement (ARM) Science Team Meeting Final...

462

Sep08.doc  

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

scanning, compact microwave radiometer, are needed to initialize and validate numerical weather and climate models. The finely resolved measurements will, in theory, provide more...

463

ARM - Publications: Science Team Meeting Documents  

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

Radar and Microwave Radiometer Data from the Southern Great Plains (SGP) Multi-Angle Satellite Retrieval of Cumulus Thickness at the ARM TWP Site: Validation Tests Stochastic...

464

Microsoft PowerPoint - DongHuang_ARMposter2008.ppt [Compatibility...  

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

dimensional Tomography of Cloud Microphysics by Combining Microwave Radar and Radiometer Measurements Dong Huang, Yangang Liu, and Warren Wiscombe Summary Retrieving cloud liquid...

465

Abstract--At present, the vast majority of ground-based and airborne microwave remote sensing instrumentation is produced  

E-Print Network [OSTI]

have a demonstrated ability to monitor atmospheric water vapor density in a spatial volume under nearly to enable development of a new generation of radiometers. This paper describes the design of a prototype Miniaturized Water Vapor Profiler for the 3-D measurement of tropospheric water vapor using a four

Reising, Steven C.

466

Using a cloud resolving model to generate the beam-filling correction for microwave retrieval of oceanic rainfall  

E-Print Network [OSTI]

from the CRM along a sloping radiometer view path is conducted to calculate the beam-filling corrections. The best resolution of the CRM we can get is 3km and the beam-filling corrections based on radar data come from another member of our group, Roy...

Feng, Kai

2003-01-01T23:59:59.000Z

467

A New Microwave Temperature Profiler Â… First Measurements in Polar Regions  

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

Microwave Temperature Profiler - First Microwave Temperature Profiler - First Measurements in Polar Regions E. N. Kadygrov, A. V. Koldaev, and A. S. Viazankin Central Aerological Observatory Moscow, Russia A. Argentini, and A. Conidi Institute of Atmospheric Physics CNR, Italy Introduction Temperature inversions are a ubiquitous feature of the high latitude atmospheric boundary layer (ABL). In Polar Regions, the temperature inversion is a complicated phenomenon involving interactions between surface radiative cooling, subsidence and warm air advection. In the period 1997-2002, several microwave temperature profilers were used to measure temperature inversion parameters at one of the three sites of the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM)

468

Microwave Absorption and Radiation from Large-area Multilayer CVD Graphene  

E-Print Network [OSTI]

the emergence of reproducible large-area synthesis of graphene by chemical coplanar waveguides [21–23], rectangular waveguides [24], ve been carried out in the microwave transisto t and dyn osed [36]. multilayer graphene is also of great interest as a h... metamaterial in the THz regime [37]. Microwave absorption of graphene composites have been experimentally studied to design microwave absorbing mate- * Corresponding author. C A R B O N 7 7 ( 2 0 1 4 ) 8 1 4 –8 2 2 Avai lab le at www.sc iencedi rect .com...

Wu, Bian; Tuncer, Hatice M.; Katsounaros, Anestis; Wu, Weiping; Cole, Matthew T.; Ying, Kai; Zhang, Lianhong; Milne, William I.; Hao, Yang

469

Analysis and estimation of the threshold for a microwave "pellicle mirror" parametric oscillator, via energy conservation  

E-Print Network [OSTI]

An experiment is proposed to observe the dynamical Casimir effect by means of two tandem, high Q, superconducting microwave cavities, which are separated from each other by only a very thin wall consisting of a flexible superconducting membrane that can be driven into motion by means of resonant "pump" microwaves injected into the left cavity. Degenerate "signal" and "idler" microwave signals can then be generated by the exponential amplification of vacuum fluctuations in the initially empty right cavity, above a certain threshold. The purpose of this paper is calculate the threshold for this novel kind of opto-mechanical parametric oscillation, using energy considerations.

Chiao, Raymond Y

2012-01-01T23:59:59.000Z

470

Modelling the transmission of a 40-Gbit s{sup -1} NRZ-ADPSK signal in 50-GHz networks  

SciTech Connect (OSTI)

We study numerically the effect of linear and nonlinear distortions on the transmission of a 40-Gbit s{sup -1} NRZ-ADPSK signal. The results of the numerical simulation coincide within the measurement accuracy with the experimental data, which indicates the adequacy of the mathematical model of the communication line, transmitter and receiver. We have found experimentally and numerically that in communication systems based on a standard telecommunication fibre negative dispersion (approximately -160 ps nm{sup -1}) introduced into the signal being transmitted provides an increase in the maximum admissible signal power coupled into a span and in the value of the admissible attenuation of the spans at 2 dB. It is established that nonlinear distortions caused by the presence of adjacent channels in a frequency network with a step of 50 and 100 GHz (crosstalks) are insignificant in comparison with the interchannel nonlinear distortions. (optical information transmission)

Gurkin, N V; Kapin, Yu A; Nanii, Oleg E; Novikov, A G; Pavlov, V N; Plaksin, S O; Plotskii, A Yu; Treshchikov, V N

2013-06-30T23:59:59.000Z

471

Beam Measurement of 11.424 GHz X-Band Linac for Compton Scattering X-ray Source  

SciTech Connect (OSTI)

An inverse Compton scattering X-ray source for medical applications, consisting of an X-band (11.424 GHz) linac and Q-switched Nd:YAG laser, is currently being developed at the University of Tokyo. This system uses an X-band 3.5-cell thermionic cathode RF gun for electron beam generation. We can obtain a multi-bunch electron beam with this gun. The beam is accelerated to 30 MeV by a traveling-wave accelerating tube. So far, we have verified stable beam generation (around 2.3 MeV) by using the newly designed RF gun and we have succeeded in beam transportation to a beam dump.

Natsui, Takuya; Mori, Azusa; Masuda, Hirotoshi; Uesaka, Mitsuru [Nuclear Professional School, School of Engineering, University of Tokyo, 22-2 Shirane-shirakata, Tokai, Naka, Ibaraki 319-1188 (Japan); Sakamoto, Fumito [Akita National College of Technology, 1-1 Iijima-bunkyo, Akita city, Akita 011-8511 (Japan)

2010-11-04T23:59:59.000Z

472

Remote sensing of heart rate and patterns of respiration on a stationary subject using 94 GHz millimeter wave interferometry.  

SciTech Connect (OSTI)

Using continuous wave, 94-GHz millimeter-wave interferometry, a signal representing chest wall motion can be obtained that contains both the heart rate and respiration patterns of a human subject. These components have to be separated from each other in the received signal. Our method was to use the quadrature and in-phase components of the signal, after removing the mean of each, to find the phase, unwrap it, and convert it to a displacement measurement. Using this, the power spectrum was examined for peaks, which corresponded to the heart rate and respiration rate. The displacement waveform of the chest was also analyzed for discrete heartbeats using a novel wavelet decomposition technique.

Mikhelson, I. V.; Bakhtiari, S.; Elmer, T. W.; Sahakian, A. V. (Nuclear Engineering Division); (Northwestern University)

2011-06-01T23:59:59.000Z

473

Design of a high-power, high-gain, 2nd harmonic, 22.848 GHz gyroklystron  

SciTech Connect (OSTI)

In this paper we consider the design of a four-cavity, high-gain K-band gyroklystron experiment for high gradient structure testing. The frequency doubling gyroklystron utilizes a beam voltage of 500 kV and a beam current of 200 A from a magnetron injection gun (MIG) originally designed for a lower-frequency device. The microwave circuit features input and gain cavities in the circular TE{sub 011} mode and penultimate and output cavities that operate at the second harmonic in the TE{sub 021} mode. We investigate the MIG performance and study the behavior of the circuit for different values of perpendicular to parallel velocity ratio (?= V{sub ?}/ V{sub z}). This microwave tube is expected to be able to produce at least 20 MW of power in 1?s pulses at a repetition rate of at least 120 Hz. A maximum efficiency of 26% and a large signal gain of 58 dB under zero-drive stable conditions were simulated for a velocity ratio equal to 1.35.

Veale, M. [University of California, Berkeley, CA, 24720 (United States)] [University of California, Berkeley, CA, 24720 (United States); Purohit, P. [Qualcomm Technologies, Inc. USA (United States)] [Qualcomm Technologies, Inc. USA (United States); Lawson, W. [University of Maryland, College Park, MD 20742 (United States)] [University of Maryland, College Park, MD 20742 (United States)

2013-08-15T23:59:59.000Z

474

Testing gaussianity, homogeneity and isotropy with the cosmic microwave background  

E-Print Network [OSTI]

We review the basic hypotheses which motivate the statistical framework used to analyze the cosmic microwave background, and how that framework can be enlarged as we relax those hypotheses. In particular, we try to separate as much as possible the questions of gaussianity, homogeneity and isotropy from each other. We focus both on isotropic estimators of non-gaussianity as well as statistically anisotropic estimators of gaussianity, giving particular emphasis on their signatures and the enhanced "cosmic variances" that become increasingly important as our putative Universe becomes less symmetric. After reviewing the formalism behind some simple model-independent tests, we discuss how these tests can be applied to CMB data when searching for large scale "anomalies"

L. Raul Abramo; Thiago S. Pereira

2010-05-13T23:59:59.000Z

475

Microwave impregnation of porous materials with thermal energy storage materials  

DOE Patents [OSTI]

A method for impregnating a porous, non-metallic construction material with a solid phase-change material is described. The phase-change material in finely divided form is spread onto the surface of the porous material, after which the porous material is exposed to microwave energy for a time sufficient to melt the phase-change material. The melted material is spontaneously absorbed into the pores of the porous material. A sealing chemical may also be included with the phase-change material (or applied subsequent to the phase-change material) to seal the surface of the porous material. Fire retardant chemicals may also be included with the phase-change materials. The treated construction materials are better able to absorb thermal energy and exhibit increased heat storage capacity.

Benson, David K. (Golden, CO); Burrows, Richard W. (Conifer, CO)

1993-01-01T23:59:59.000Z

476

Enhancement of accelerating field of microwave cavities by magnetic insulation  

SciTech Connect (OSTI)

Limitations on the maximum achievable accelerating gradient of microwave cavities can strongly influence the performance, length, and cost of particle accelerators. Gradient limitations are widely believed to be initiated by electron emission from the cavity surfaces. Here, we show that the deleterious effects of field emission are effectively suppressed by applying a tangential magnetic field to the cavity walls. With the aid of numerical simulations we compute the field strength required to insulate an 805 MHz cavity and estimate the cavity's tolerances to typical experimental errors such as magnet misalignments and positioning errors. Then, we review an experimental program, currently under progress, to further study the concept. Finally, we report on two specific examples that illustrate the feasibility of magnetic insulation into prospective particle accelerator applications.

Stratakis, D.; Gallardo, J.; Palmer, R.B.

2011-04-15T23:59:59.000Z

477

Determining cosmic microwave background anisotropies in the presence of foregrounds  

E-Print Network [OSTI]

Separating foregrounds from the signal is one of the big challenges in cosmic microwave background (CMB) experiments. A simple way to estimate the CMB temperature in a given pixel is to fit for the amplitudes of the CMB and the various foreground components. The variance squared of this estimator is shown to be equal to $[(FDF)^2\\ \\sigzt + \\sigsh^2]$, where $\\sigz$ is the variance in the absence of foregrounds; $\\sigsh$ is the variance due to the uncertainty in the shapes of the foreground components; and FDF is the {\\it foreground degradation factor}. This one number, the FDF, gives a good indication of the ability of a given experiment to disentangle the CMB from foreground sources. A variety of applications relating to the planning and analyzing of experiments is presented.

Scott Dodelson

1995-12-05T23:59:59.000Z

478

"Magic" radio-frequency dressing for trapped atomic microwave clocks  

E-Print Network [OSTI]

It has been proposed to use magnetically trapped atomic ensembles to enhance the interrogation time in microwave clocks. To mitigate the perturbing effects of the magnetic trap, "near-magic field" configurations are employed, where the involved clock transition becomes independent of the atoms potential energy to first order. Still, higher order effects are a dominating source for dephasing, limiting the perfomance of this approach. Here we propose a simple method to cancel the energy dependence to both, first and second order, using weak radio-frequency dressing. We give values for dressing frequencies, amplitudes, and trapping fields for 87Rb atoms and investigate quantitatively the robustness of these "second-order magic" conditions to variations of the system parameters. We conclude that radio-frequency dressing can suppress field-induced dephasing by at least one order of magnitude for typical experimental parameters.

Kazakov, Georgy A

2014-01-01T23:59:59.000Z

479

Development of microwave foaming method for phenolic insulation foams  

Science Journals Connector (OSTI)

Many types of foams are used for thermal insulation in building, frozen food industries and LNG containment systems. Low thermal conductivity, low density and low flammability are required for thermal insulation. Among many foams, phenolic foams are preferred for thermal insulation due to its lower flammability and lower gas generation than any other polymer insulation foams. However, it takes long time to manufacture large size phenolic foams and the environmental regulation limits the use of blowing agents. Urethane foams and polystyrene foams are widely used in spite of their high flammability and toxic gas generation because conventional phenolic foams usually have higher thermal conductivity than expected. In this work, a foaming method for the resole-type phenolic foams was developed using microwave and air instead of blowing agents, and its thermal and mechanical properties were measured. From the measured results, it was found that the phenolic foams developed had low thermal conductivity and low density suitable for insulation foams.

Bu Gi Kim; Dai Gil Lee

2008-01-01T23:59:59.000Z

480

Microwave impregnation of porous materials with thermal energy storage materials  

DOE Patents [OSTI]

A method for impregnating a porous, non-metallic construction material with a solid phase-change material is described. The phase-change material in finely divided form is spread onto the surface of the porous material, after which the porous material is exposed to microwave energy for a time sufficient to melt the phase-change material. The melted material is spontaneously absorbed into the pores of the porous material. A sealing chemical may also be included with the phase-change material (or applied subsequent to the phase-change material) to seal the surface of the porous material. Fire retardant chemicals may also be included with the phase-change materials. The treated construction materials are better able to absorb thermal energy and exhibit increased heat storage capacity.

Benson, D.K.; Burrows, R.W.

1993-04-13T23:59:59.000Z

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.


481

Weighing the Universe with the Cosmic Microwave Background  

E-Print Network [OSTI]

Variations in $\\Omega$, the total density of the Universe, leave a clear and distinctive imprint on the power spectrum of temperature fluctuations in the cosmic microwave background (CMB). This signature is virtually independent of other cosmological parameters or details of particular cosmological models. We evaluate the precision with which $\\Omega$ can be determined by a CMB map as a function of sky coverage, pixel noise, and beam size. For example, assuming only that the primordial density perturbations were adiabatic and with no prior information on the values of any other cosmological parameters, a full-sky CMB map at $0.5^\\circ$ angular resolution and a noise level of $15\\,\\mu{\\rm K}$ per pixel can determine $\\Omega$ with a variance of 5\\%. If all other cosmological parameters are fixed, $\\Omega$ can be measured to better than 1\\%.

Gerard Jungman; Marc Kamionkowski; Arthur Kosowsky; David N. Spergel

1995-07-21T23:59:59.000Z

482

CRYOGENIC 1.5-4.5 GHz ULTRA LOW NOISE AMPLIFIER Niklas Wadefalk*, Anders Mellberg, Iltcho Angelov, Emmanuil Choumas**, Erik Kollberg,  

E-Print Network [OSTI]

CRYOGENIC 1.5-4.5 GHz ULTRA LOW NOISE AMPLIFIER Niklas Wadefalk*, Anders Mellberg, Iltcho Angelov Trading AG, Truebbach, Switzerland Abstract - This paper describes cryogenic broadband amplifier with very the channel at the mesa edge and thereby decreased the gate leakage current. Index Terms ­ cryogenic low noise

483

FUNDAMENTAL MIXING AT 9.05 GHz USING INDIUM MICR0BRIDGES+ W.H. Howard, M.B. Stern and Y.H. Kao  

E-Print Network [OSTI]

FUNDAMENTAL MIXING AT 9.05 GHz USING INDIUM MICR0BRIDGES+ W.H. Howard, M.B. Stern and Y.H. Kao made on single-bridge samples and on series arrays of microbridges. INTRODUCTION.- Josephson point by a micro- bridge array. The rod was then mounted in the wave- guide parallel to.the short dimension, so

Paris-Sud XI, Université de

484

Millimeter-wave InP/InGaAs HPT optoelectronic mixers and their application to 60GHz bi-directional radio-on-fiber systems  

E-Print Network [OSTI]

#12;Millimeter-wave InP/InGaAs HPT optoelectronic mixers and their application to 60GHz bi demonstrate the use of InP/InGaAs heterojunction phototransistors as optoelectronic mixers for bi are frequency up-converted to millimeter-wave band signals in InP HPT optoelectronic mixer with remotely

Choi, Woo-Young

485

Optoelectronic Mixers for Fiber-fed 60-GHz Wireless Systems Woo-Young Choi, Jae-Young Kim and Myung-Jae Lee  

E-Print Network [OSTI]

#12;Optoelectronic Mixers for Fiber-fed 60-GHz Wireless Systems Woo-Young Choi, Jae-Young Kim investigated millimeter-wave fiber-fed wireless systems using optoelectronic mixers based on hetero-effective optoelectronic (O/E) mixer, which performs photo- detection and frequency conversion functions simultaneously. We

Choi, Woo-Young

486

Nitroxide Side-Chain Dynamics in a Spin-Labeled Helix-Forming Peptide Revealed by High-Frequency (139.5-GHz) EPR Spectroscopy  

E-Print Network [OSTI]

-Frequency (139.5-GHz) EPR Spectroscopy M. Bennati,* G. J. Gerfen, G. V. Martinez, R. G. Griffin,*, § D. J. Singel High-frequency electron paramagnetic resonance (EPR) spec- troscopy has been performed on a nitroxide sulfur. The spin sensitivity of high-frequency EPR is excel- lent with less than 20 pmol of sample

Griffin, Robert G.

487

Pulsed Electron-Nuclear Double Resonance (ENDOR) at 140 GHz M. Bennati,* C. T. Farrar,* J. A. Bryant,* S. J. Inati,* V. Weis,* G. J. Gerfen,  

E-Print Network [OSTI]

Pulsed Electron-Nuclear Double Resonance (ENDOR) at 140 GHz M. Bennati,* C. T. Farrar,* J. A-selective Davies-ENDOR. � 1999 Academic Press INTRODUCTION Electron nuclear double resonance (ENDOR) spectroscopy by the g-dispersion. Thus, micro- wave pulsed irradiation at arbitrary field positions in the EPR line

Griffin, Robert G.

488

New Energy Efficiency Standards for Microwave Ovens to Save Consumers on  

Broader source: Energy.gov (indexed) [DOE]

Energy Efficiency Standards for Microwave Ovens to Save Energy Efficiency Standards for Microwave Ovens to Save Consumers on Energy Bills New Energy Efficiency Standards for Microwave Ovens to Save Consumers on Energy Bills May 31, 2013 - 3:26pm Addthis NEWS MEDIA CONTACT (202) 586-4940 WASHINGTON - U.S. Energy Secretary Ernest Moniz announced today that the Energy Department has finalized new energy efficiency standards for microwave ovens that will save consumers nearly $3 billion on their energy bills through 2030. Over the next 30 years, it will dramatically reduce harmful carbon pollution, equivalent to taking over 12 million new cars off the road for one year. "Appliance efficiency standards represent a huge opportunity to help families save money by saving energy, while still delivering high quality

489

Simulation of Wind-Vector Estimation — Design Evaluation of Microwave Scatterometer -  

Science Journals Connector (OSTI)

One of several representative features of the microwave scatterometer(SCAT), which has been being developed by NASDA since 1979, is in its higher capability of wind alias removal by providing three differently mo...

Masanobu Shimada; Masao Sasanuma

1985-01-01T23:59:59.000Z

490

Monitoring Agricultural Risk in Canada Using L-Band Passive Microwave Soil Moisture from SMOS  

Science Journals Connector (OSTI)

Soil moisture from Soil Moisture Ocean Salinity (SMOS) passive microwave satellite data was assessed as an information source for identifying regions experiencing climate-related agricultural risk for a period from 2010-2013. Both absolute soil ...

Catherine Champagne; Andrew Davidson; Patrick Cherneski; Jessika L’Heureux; Trevor Hadwen

491

Microwave-induced thermoacoustic tomography: applications and corrections for the effects of acoustic heterogeneities  

E-Print Network [OSTI]

This research is primarily focused on developing potential applications for microwaveinduced thermoacoustic tomography and correcting for image degradations caused by acoustic heterogeneities. Microwave-induced thermoacoustic tomography was first...

Jin, Xing

2009-05-15T23:59:59.000Z

492