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Note: This page contains sample records for the topic "radio frequency electromagnetic" 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.


1

Program on Technology Innovation: Frequently Asked Questions (FAQ) on Radio-Frequency Electromagnetic Fields  

Science Conference Proceedings (OSTI)

The number of sources of radio-frequency (RF) electromagnetic fields in our midst has increased dramatically in the past three decades. From cordless phones, to cellular phones and their base stations, to pagers and walkie-talkies, to WiFi in public venues, such as coffee shops and airports, and to smart meters and other wireless components of the smart grid. Of course, since the advent of broadcast radio and TV during the 20th century, radio-frequency electromagnetic fields have been an ...

2012-11-05T23:59:59.000Z

2

Enhancement of electromagnetic propagation through complex media for Radio Frequency Identification  

E-Print Network (OSTI)

In this thesis, I present and examine the fundamental limitations involved in Radio Frequency Identification (RFID) as well as provide a means to improve reader-tag communication in ultra high frequency RFID systems. The ...

Marti, Uttara P

2005-01-01T23:59:59.000Z

3

Electromagnetic and mechanical design of gridded radio-frequency cavity windows  

SciTech Connect

Electromagnetic, thermal and structural analyses of radio-frequency (RF) cavities were performed as part of a developmental RF cavity program for muon cooling. RF cavities are necessary to provide longitudinal focusing of the muons and to compensate for their energy loss. Closing the cavity ends by electrically conducting windows reduces the power requirement and increases the on-axis electric field for a given maximum surface electric field. Many factors must be considered in the design of RF cavity windows. RF heating can cause the windows to deform in the axial direction of the cavity. The resulting thermal stresses in the window must be maintained below the yield stress of the window material. The out-of-plane deflection must be small enough so that the consequent frequency shift is tolerable. For example, for an 805 MHz cavity, the out-of-plane deflection must be kept below 25 microns to prevent the frequency of the cavity from shifting more than 10 kHz. In addition, the window design should yield smooth electric and magnetic fields, terminate field leakage beyond the window, and minimize beam scattering. In the present thesis, gridded-tube window designs were considered because of their high structural integrity. As a starting point in the analysis, a cylindrical pillbox cavity was considered as a benchmark problem. Analytical and finite element solutions were obtained for the electric and magnetic fields, power loss density, and temperature profile. Excellent agreement was obtained between the analytical and finite element results. The finite element method was then used to study a variety of gridded-tube windows. It was found that cooling of the gridded-tube windows by passing helium gas inside the tubes significantly reduces the out-of-plane deflection and the thermal stresses. Certain tube geometries and grid patterns were found to satisfy all of the design requirements.

Alsharoa, Mohammad M.; /IIT, Chicago /Fermilab

2004-12-01T23:59:59.000Z

4

Stabilized radio frequency quadrupole  

DOE Patents (OSTI)

Disclosed is a long-vane stabilized radio frequency resonator for accelerating charged particles and including means defining a radio frequency resonator cavity, a plurality of long vanes mounted in the defining means for dividing the cavity into sections, and means interconnecting opposing ones of the plurality of vanes for stabilizing the resonator. 5 figs.

Lancaster, H.D.; Fugitt, J.A.; Howard, D.R.

1984-12-25T23:59:59.000Z

5

Radio Frequency Engineering, MDE, Accelerator Operations and...  

NLE Websites -- All DOE Office Websites (Extended Search)

Home Teams Low-Level Radio Frequency Magnet Power Supplies, Pulsed Power Radio Frequency, High Voltage Technologies Radio Frequency Operations CONTACTS Group Leader Dan Rees Deputy...

6

Radio frequency sustained ion energy  

SciTech Connect

Electromagnetic (E.M.) energy injection method and apparatus for producing and sustaining suprathermal ordered ions in a neutral, two-ion-species, toroidal, bulk equilibrium plasma. More particularly, the ions are produced and sustained in an ordered suprathermal state of existence above the average energy and velocity of the bulk equilibrium plasma by resonant rf energy injection in resonance with the natural frequency of one of the ion species. In one embodiment, the electromagnetic energy is injected to clamp the energy and velocity of one of the ion species so that the ion energy is increased, sustained, prolonged and continued in a suprathermal ordered state of existence containing appreciable stored energy that counteracts the slowing down effects of the bulk equilibrium plasma drag. Thus, selective deuteron absorption may be used for ion-tail creation by radio-frequency excitation alone. Also, the rf can be used to increase the fusion output of a two-component neutral injected plasma by selective heating of the injected deuterons.

Jassby, Daniel L. (Princeton, NJ); Hooke, William M. (Princeton, NJ)

1977-01-01T23:59:59.000Z

7

Development of Radio Frequency Exposure Standards  

Science Conference Proceedings (OSTI)

While unconfirmed claims of adverse human health effects from electromagnetic radiation date to the 1930s, development of modern safety standards did not begin until the 1952 Hirsch study of eye damage at a microwave power density of 100 mW/cm2. Early work on standards focused on microwave frequencies due to rapid development of radar and microwave communications links. In the years since 1952, radio frequency (RF) exposure standards have kept pace with those technological advancements. While refinements...

2004-11-01T23:59:59.000Z

8

Radio frequency coaxial feedthrough  

DOE Patents (OSTI)

An improved radio frequency coaxial transmission line vacuum feed-through provided based on the use of a half-wavelength annular dielectric pressure barrier disk, or multiple disks comprising an effective half wavelength structure to eliminate reflections from the barrier surfaces. Gas-tight seals are formed about the outer and inner diameter surfaces of the barrier disk using a sealing technique which generates radial forces sufficient to form seals by forcing the conductor walls against the surfaces of the barrier disks in a manner which does not deform the radii of the inner and outer conductors, thereby preventing enhancement of the electric field at the barrier faces which limits voltage and power handling capabilities of a feedthrough.

Owens, Thomas L. (Kingston, TN)

1989-01-17T23:59:59.000Z

9

Stabilized radio-frequency quadrupole  

DOE Patents (OSTI)

A long-vane stabilized radio frequency resonator for accelerating charged particles and including means defining a radio frequency resonator cavity, a plurality of long vanes mounted in the defining means for dividing the cavity into sections, and means interconnecting opposing ones of the plurality of vanes for stabilizing the resonator.

Lancaster, H.D.; Fugitt, J.A.; Howard, D.R.

1982-09-29T23:59:59.000Z

10

Radio frequency coaxial feedthrough device  

DOE Patents (OSTI)

A radio frequency coaxial vacuum feedthrough is provided which utilizes a cylindrical ceramic vacuum break formed of an alumina ceramic. The cylinder is coaxially disposed and brazed between tapered coaxial conductors to form a vacuum sealed connection between a pressurized upstream coaxial transmission line and a utilization device located within a vacuum container. The feedthrough provides 50 ohm matched impedance RF feedthrough up to about 500 MHz at power levels in the multimegawatt range.

Owens, Thomas L. (Kingston, TN); Baity, Frederick W. (Oak Ridge, TN); Hoffman, Daniel J. (Oak Ridge, TN); Whealton, John H. (Oak Ridge, TN)

1987-01-01T23:59:59.000Z

11

Cerenkov radio pulses from electromagnetic showers in the time domain  

Science Conference Proceedings (OSTI)

The electric field of the Cerenkov radio pulse produced by a single charged particle track in a dielectric medium is derived from first principles. An algorithm is developed to obtain the pulse in the time domain for numerical calculations. The algorithm is implemented in a Monte Carlo simulation of electromagnetic showers in dense media (specifically designed for coherent radio emission applications) as might be induced by interactions of ultrahigh energy neutrinos. The coherent Cerenkov radio emission produced by such showers is obtained simultaneously both in the time and frequency domains. A consistency check performed by Fourier transforming the pulse in time and comparing it to the frequency spectrum obtained directly in the simulations yields, as expected, fully consistent results. The reversal of the time structure inside the Cerenkov cone and the signs of the corresponding pulses are addressed in detail. The results, besides testing algorithms used for reference calculations in the frequency domain, shed new light into the properties of the radio pulse in the time domain. The shape of the pulse in the time domain is directly related to the depth development of the excess charge in the shower and its width to the observation angle with respect to the Cerenkov direction. This information can be of great practical importance for interpreting actual data.

Alvarez-Muniz, Jaime; Romero-Wolf, Andres; Zas, Enrique [Depto. de Fisica de Particulas and Instituto Galego de Fisica de Altas Enerxias, Universidade de Santiago de Compostela, 15782 Santiago de Compostela (Spain); Department of Physics and Astronomy, University of Hawaii at Manoa, Honolulu, Hawaii 96822 (United States); Depto. de Fisica de Particulas and Instituto Galego de Fisica de Altas Enerxias, Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain)

2010-06-15T23:59:59.000Z

12

A radio frequency coaxial feedthrough  

DOE Patents (OSTI)

An improved radio frequency coaxial transmission line vacuum feedthrough is provided based on the use of a half-wavelength annular dielectric pressure barrier disk, or multiple disks comprising an effective half wavelength structure to eliminate reflection from the barrier surfaces. Gas-tight seals are formed about the outer and inner diameter surfaces of the barrier disk using a sealing technique which generates radial forces sufficient to form seals by forcing the conductor walls against the surfaces of the barrier disks in a manner which does not deform the radii of the inner and outer conductors, thereby preventing enhancement of the electric field at the barrier faces which limits the voltage and power handling capabilities of a feedthrough.

Owens, T.L.

1987-12-07T23:59:59.000Z

13

Integrally formed radio frequency quadrupole  

DOE Patents (OSTI)

An improved radio frequency quadrupole (10) is provided having an elongate housing (11) with an elongate central axis (12) and top, bottom and two side walls (13a-d) symmetrically disposed about the axis, and vanes (14a-d) formed integrally with the walls (13a-d), the vanes (14a-d) each having a cross-section at right angles to the central axis (12) which tapers inwardly toward the axis to form electrode tips (15a-d) spaced from each other by predetermined distances. Each of the four walls (13a-d), and the vanes (14a-d) integral therewith, is a separate structural element having a central lengthwise plane (16) passing through the tip of the vane, the walls (13a-d) having flat mounting surfaces (17, 18) at right angles to and parallel to the control plane (16), respectively, which are butted together to position the walls and vane tips relative to each other.

Abbott, Steven R. (Concord, CA)

1989-01-01T23:59:59.000Z

14

High power radio frequency attenuation device  

DOE Patents (OSTI)

A resistor device for attenuating radio frequency power includes a radio frequency conductor connected to a series of fins formed of high relative magnetic permeability material. The fins are dimensional to accommodate the skin depth of the current conduction therethrough, as well as an inner heat conducting portion where current does not travel. Thermal connections for air or water cooling are provided for the inner heat conducting portions of each fin. Also disclosed is a resistor device to selectively alternate unwanted radio frequency energy in a resonant cavity.

Kerns, Quentin A. (Bloomingdale, IL); Miller, Harold W. (Winfield, IL)

1984-01-01T23:59:59.000Z

15

Security approaches for Radio Frequency Identification systems  

E-Print Network (OSTI)

In this thesis, I explore the challenges related to the security of the Electronic Product Code (EPC) class of Radio Frequency Identification (RFID) tags and associated data. RFID systems can be used to improve supply chain ...

Foley, Joseph Timothy, 1976-

2007-01-01T23:59:59.000Z

16

Radio Frequency Identification : regulating information privacy protection  

E-Print Network (OSTI)

As applications of Radio Frequency Identification (RFID) become more profuse, the technology itself is stirring up some controversy. Due to its potential for amassing large amounts of information about both people and ...

Laufer, Deanna (Deanna Raquel)

2007-01-01T23:59:59.000Z

17

Electromagnetic Compatibility from a Time-Frequency Perspective  

E-Print Network (OSTI)

Abstract — In wireless communication, interference between two radio systems may occur when they operate at close frequency bands, sharing the same environment at the same time. Such systems coexist if both of them perform correctly in the presence of the other. To ensure their coexistence, Electromagnetic Compatibility (EMC) is used to specify rules within standardization bodies. According to current EMC standards, the radio spectrum has been divided into non-overlapping bands often with exclusive access. However, nowadays there is a proliferation of new digital systems sharing common frequency bands because the spectrum is a limited resource. Many of them are operating in unlicensed bands regulated by The International Telecommunications Union (ITU), for example the 2.45 GHz Industrial, Scientific and Medical (ISM) band. The frequency allocation is also changing with the emergence of digital systems and this is the case for white spaces in the broadcast television (TV) spectrum. To avoid high interference levels, it is necessary to consider some parameters related to signal variations, representing more accurately the environment. Some techniques have been proposed in the literature to reduce interference levels but they are applied to specific sharing studies. Hence, we evaluate in this paper the impact of time-frequency considerations for radio coexistence. We show that EMC studies are more precise and more representative of the reality when additional parameters relevant to the time domain are taken into account in the analysis framework. We illustrate these concepts through a specific study case. We evaluate the results for different system parameters, first considering that both of them occupy the same band and then assuming that they use overlapping but non-equal frequency bands. Index Terms — Radio coexistence, electromagnetic compatibility, frequency-domain analysis, time-domain analysis.

Najett Neji; Raul De Lacerda; Alain Azoulay; Thierry Letertre

2013-01-01T23:59:59.000Z

18

Radio frequency communication system utilizing radiating transmission lines  

DOE Patents (OSTI)

A radio communication system for use in tunnels, mines, buildings or other shielded locations in which a pair of radiating transmission lines (30), (31) extend through such location in spaced coextensive relation to each other. Each transmission line (30), (31) has at least one unidirectional amplifier (32), (33) interposed therein with the sense of the unidirectional amplifier (32) of one transmission line (30) being opposite to the sense of the unidirectional amplifier (33) of the other transmission line (31). Each of the amplifiers (32), (33) has a gain which is less than the coupling loss between the transmission lines (30), (31). Two or more mobile transceivers (35) in the location served by the system are coupled to the transmission lines (30), (31) by electromagnetic wave propagation in space in order to communicate directly with each other at a given radio frequency within the frequency range of the system.

Struven, Warren C. (San Carlos, CA)

1984-01-01T23:59:59.000Z

19

Resonant circuit which provides dual-frequency excitation for rapid cycling of an electromagnet  

DOE Patents (OSTI)

Disclosed is a novel ring-magnet control circuit that permits synchrotron repetition rates much higher than the frequency of the sinusoidal guide field of the ring magnet during particle acceleration. The control circuit generates sinusoidal excitation currents of different frequencies in the half waves. During radio-frequency acceleration of the synchrotron, the control circuit operates with a lower frequency sine wave and, thereafter, the electromagnets are reset with a higher-frequency half sine wave.

Praeg, W.F.

1982-03-09T23:59:59.000Z

20

On Digital Radio Receiver Performance in Electromagnetic Interference Environments  

E-Print Network (OSTI)

adiated emission from electronic equipment, co-located to a digital radio receiver, can affect receiving performance. It is therefore of great importance that this undesired emission be considered in the early design phase of a system containing radio equipment. For this purpose, methods to estimate the performance degradation on digital radio receivers in such environment must be available. From a military point of view, such methods are necessary for at least two important situations; 1) The communication system is not subject to interference from hostile jammers. In this case, undesired electromagnetic interference will decrease the operating range of the radio link. 2) The communication system is subject to interference from hostile jammers. In this case, the ability to withstand jamming is degraded by the undesired interference, as the latter degrades the signal protection devices in the communication system. A tactical consequence of this is that the jammer can obtain the same ...

Peter Stenumgaard; Peter Stenumgaard; Isrn Kth/rst/r--/ --se

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

Home monitoring using wearable radio frequency transmitters  

Science Conference Proceedings (OSTI)

Background: Location tracking of a wearable radio frequency (RF) transmitter in a wireless network is a potentially useful tool for the home monitoring of patients in clinical applications. However, the problem of converting RF signals into accurate ... Keywords: Gaussian mixture models, Home monitoring, Motion tracking, Wireless network

Anthony Almudevar; Adrian Leibovici; Aleksey Tentler

2008-02-01T23:59:59.000Z

22

Overview of Personal Radio Frequency Communication Technologies  

Science Conference Proceedings (OSTI)

The growth of wireless electronic communication devices and their applications is creating an increasingly complex radio frequency (RF) environment in the workplace and home. Personal communication applications discussed in this report include cordless telephones, analog cellular telephones, digital cellular telephones, and a dozen more. Depending on the specific wireless device, different frequency ranges, modulation types, multiple access types, and power levels can be encountered. The significant grow...

2008-09-09T23:59:59.000Z

23

A Power-efficient Radio Frequency Energy-harvesting Circuit .  

E-Print Network (OSTI)

??This work aims to demonstrate the design and simulation of a Radio Frequency (RF) energy-harvesting circuit, from receiving antenna to the point of charge collection.… (more)

Khoury, Philip

2013-01-01T23:59:59.000Z

24

Definition: Frequency-Domain Electromagnetics Survey | Open Energy  

Open Energy Info (EERE)

Frequency-Domain Electromagnetics Survey Frequency-Domain Electromagnetics Survey Jump to: navigation, search Dictionary.png Frequency-Domain Electromagnetics Survey Frequency-domain electromagnetic techniques are continuous wave field methods which enable the mapping of the electrical conductivity of the subsurface through electromagnetic induction.[1] View on Wikipedia Wikipedia Definition Electromagnetic induction is the production of a potential difference (voltage) across a conductor when it is exposed to a varying magnetic field. Michael Faraday is generally credited with the discovery of induction in 1831 though it may have been anticipated by the work of Francesco Zantedeschi in 1829. Around 1830 to 1832, Joseph Henry made a similar discovery, but did not publish his findings until later. Faraday's

25

Macroscopic Diversity in Frequency Reuse Radio Systems  

Science Conference Proceedings (OSTI)

Macroscopic diversity is a technique that can facilitate high quality and ubiquitous communications between low-power portable radiotelephones and data terminals, and radio base stations (ports) that are connected to the local network. It uses radio ...

R. Bernhardt

2006-09-01T23:59:59.000Z

26

Definition: Frequency-Domain Electromagnetic Survey | Open Energy  

Open Energy Info (EERE)

Electromagnetic Survey Electromagnetic Survey Jump to: navigation, search Dictionary.png Frequency-Domain Electromagnetic Survey Frequency-domain electromagnetic techniques are continuous wave field methods which enable the mapping of the electrical conductivity of the subsurface through electromagnetic induction.[1] Also Known As Controlled-Source EM References ↑ http://library.seg.org/doi/pdf/10.1190/1.1441531 Ret LikeLike UnlikeLike You like this.Sign Up to see what your friends like. rieved from "http://en.openei.org/w/index.php?title=Definition:Frequency-Domain_Electromagnetic_Survey&oldid=591411" Category: Definitions What links here Related changes Special pages Printable version Permanent link Browse properties About us Disclaimers Energy blogs Linked Data Developer services

27

Trirotron: triode rotating beam radio frequency amplifier  

DOE Patents (OSTI)

High efficiency amplification of radio frequencies to very high power levels including: establishing a cylindrical cloud of electrons; establishing an electrical field surrounding and coaxial with the electron cloud to bias the electrons to remain in the cloud; establishing a rotating electrical field that surrounds and is coaxial with the steady field, the circular path of the rotating field being one wavelength long, whereby the peak of one phase of the rotating field is used to accelerate electrons in a beam through the bias field in synchronism with the peak of the rotating field so that there is a beam of electrons continuously extracted from the cloud and rotating with the peak; establishing a steady electrical field that surrounds and is coaxial with the rotating field for high-energy radial acceleration of the rotating beam of electrons; and resonating the rotating beam of electrons within a space surrounding the second field, the space being selected to have a phase velocity equal to that of the rotating field to thereby produce a high-power output at the frequency of the rotating field.

Lebacqz, Jean V. (Stanford, CA)

1980-01-01T23:59:59.000Z

28

Chips, tags and scanners: Ethical challenges for radio frequency identification  

Science Conference Proceedings (OSTI)

Radio Frequency Identification (RFID) systems identify and track objects, animals and, in principle, people. The ability to gather information obtained by tracking consumer goods, government documents, monetary transactions and human beings raises a ... Keywords: RFID, business ethics, ethics, privacy, radio frequency identification, surveillance

Dara J. Glasser; Kenneth W. Goodman; Norman G. Einspruch

2007-07-01T23:59:59.000Z

29

Method and apparatus for radio frequency ceramic sintering  

DOE Patents (OSTI)

Radio frequency energy is used to sinter ceramic materials. A coaxial waveguide resonator produces a TEM mode wave which generates a high field capacitive region in which a sample of the ceramic material is located. Frequency of the power source is kept in the range of radio frequency, and preferably between 60-80 MHz. An alternative embodiment provides a tunable radio frequency circuit which includes a series input capacitor and a parallel capacitor, with the sintered ceramic connected by an inductive lead. This arrangement permits matching of impedance over a wide range of dielectric constants, ceramic volumes, and loss tangents. 6 figures.

Hoffman, D.J.; Kimrey, H.D. Jr.

1993-11-30T23:59:59.000Z

30

Method and apparatus for radio frequency ceramic sintering  

DOE Patents (OSTI)

Radio frequency energy is used to sinter ceramic materials. A coaxial waveguide resonator produces a TEM mode wave which generates a high field capacitive region in which a sample of the ceramic material is located. Frequency of the power source is kept in the range of radio frequency, and preferably between 60-80 MHz. An alternative embodiment provides a tunable radio frequency circuit which includes a series input capacitor and a parallel capacitor, with the sintered ceramic connected by an inductive lead. This arrangement permits matching of impedance over a wide range of dielectric constants, ceramic volumes, and loss tangents.

Hoffman, Daniel J. (Oak Ridge, TN); Kimrey, Jr., Harold D. (Knoxville, TN)

1993-01-01T23:59:59.000Z

31

High-power radio-frequency attenuation device  

DOE Patents (OSTI)

A resistor device for attenuating radio frequency power includes a radio frequency conductor connected to a series of fins formed of high relative magnetic permeability material. The fins are dimensional to accommodate the skin depth of the current conduction therethrough, as well as an inner heat conducting portion where current does not travel. Thermal connections for air or water cooling are provided for the inner heat conducting portions of each fin. Also disclosed is a resistor device to selectively alternate unwanted radio frequency energy in a resonant cavity.

Kerns, Q.A.; Miller, H.W.

1981-12-30T23:59:59.000Z

32

RFIDSim : a discrete event simulator for Radio Frequency Identification systems  

E-Print Network (OSTI)

This thesis presents RFIDSim, a discrete event process-oriented simulator designed to model Radio Frequency Identification (RFID) communication. The simulator focuses on the discovery and identification process of passive ...

Yu, Kenneth Kwan-Wai, 1979-

2003-01-01T23:59:59.000Z

33

Radio-frequency spectroscopy of ultracold atomic Fermi gases  

E-Print Network (OSTI)

This thesis presents experiments investigating the phase diagram of ultracold atomic Fermi gases using radio-frequency spectroscopy. The tunability of many experimental parameters including the temperature, the interparticle ...

Schirotzek, Andre

2010-01-01T23:59:59.000Z

34

Frequency-Domain Electromagnetic Survey | Open Energy Information  

Open Energy Info (EERE)

Frequency-Domain Electromagnetic Survey Frequency-Domain Electromagnetic Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Frequency-Domain Electromagnetic Survey Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Electromagnetic Profiling Techniques Information Provided by Technique Lithology: Detection of high-conductivity bodies in the subsurface. Stratigraphic/Structural: Hydrological: Thermal: Detection of the presence of a thermal anomaly through its resistivity signature. Cost Information Low-End Estimate (USD): 2,928.38292,838 centUSD 2.928 kUSD 0.00293 MUSD 2.92838e-6 TUSD / mile Median Estimate (USD): 4,505.20450,520 centUSD

35

Radio frequency fingerprinting commercial communication devices to enhance electronic security  

Science Conference Proceedings (OSTI)

There is a current shift toward protecting against unauthorised network access at the open systems interconnection physical layer by exploiting radio frequency characteristics that are difficult to mimic. This work addresses the use of RF 'fingerprints' ... Keywords: Fisher linear discriminant, OSI, PHY layer authentication, RF fingerprinting, RF forensics, SEI, access authorisation, anti-spoofing, burst detection, commercial communication devices, electronic security, feature generation, multiple discriminant analysis, network access, physical layer authentication, radio frequency fingerprinting, signal features, specific emitter identification, transient detection

William C. Suski II; Michael A. Temple; Michael J. Mendenhall; Robert F. Mills

2008-10-01T23:59:59.000Z

36

Radio Frequency Identification Tags - Active Tags ...  

Selectable, license free, RF frequency bands; Ultra low power sleep mode; Miniaturized, encapsulated bendable packaging;

37

Multi-dimensional ultra-high frequency passive radio frequency identification tag antenna designs  

E-Print Network (OSTI)

In this thesis, we present the design, simulation, and empirical evaluation of two novel multi-dimensional ultra-high frequency (UHF) passive radio frequency identification (RFID) tag antennas, the Albano-Dipole antenna ...

Delichatsios, Stefanie Alkistis

2006-01-01T23:59:59.000Z

38

Overview of Personal Radio Frequency Communication Technologies  

Science Conference Proceedings (OSTI)

Personal wireless communication devices seem to be everywhere. Cell phones, Blackberries, Wi-Fi Internet connections and many other similar devices are in constant use, often simultaneously by a single person. As the proliferation of wireless products expands, their ubiquity raises questions concerning their effects on each other and the people who use them. The effects of one communications device on another one nearby fall under the category of electromagnetic compatibility. Compatibility issues arise ...

2009-07-17T23:59:59.000Z

39

Resonant circuit which provides dual frequency excitation for rapid cycling of an electromagnet  

DOE Patents (OSTI)

Disclosed is a ring magnet control circuit that permits synchrotron repetition rates much higher than the frequency of the cosinusoidal guide field of the ring magnet during particle acceleration. the control circuit generates cosinusoidal excitation currents of different frequencies in the half waves. During radio frequency acceleration of the particles in the synchrotron, the control circuit operates with a lower frequency cosine wave and thereafter the electromagnets are reset with a higher frequency half cosine wave. Flat-bottom and flat-top wave shaping circuits maintain the magnetic guide field in a relatively time-invariant mode during times when the particles are being injected into the ring magnets and when the particles are being ejected from the ring magnets.

Praeg, Walter F. (Palos Park, IL)

1984-01-01T23:59:59.000Z

40

Method and Apparatus for Pasteurizing Shell Eggs Using Radio Frequency  

NLE Websites -- All DOE Office Websites (Extended Search)

Method and Apparatus for Pasteurizing Shell Eggs Using Radio Frequency Method and Apparatus for Pasteurizing Shell Eggs Using Radio Frequency Heating" Inventors..--.. Christopher D. Brunkhorst, David J. Geveke, Andrew B. W. Bigley. This disclosure is directed to a system for pasteurizing shell eggs. The system includes an egg rotating assembly structured to rotate the egg, and electrodes that are in contact with the egg. The system is structured so that, as the rotating assembly rotates the egg, radio frequency energy is directed to the egg to pasteurize it. Nearly 200 million "shell eggs" are consumed in the United States (US) each day. "Shell eggs" are non-powdered conventional eggs that are naturally produced by hens. Shell eggs are among the most nutritious foods on earth and can be part of a healthy diet. However, some unbroken, clean, fresh

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

Radio frequency dc-dc power conversion  

E-Print Network (OSTI)

THIS THESIS addresses the development of system architectures and circuit topologies for dc-dc power conversion at very high frequencies. The systems architectures that are developed are structured to overcome limitations ...

Rivas, Juan, 1976-

2007-01-01T23:59:59.000Z

42

Plasma ignition schemes for the SNS radio-frequency driven H- source  

E-Print Network (OSTI)

on the Spallation Neutron Source (SNS) Project,” EPAC ‘98,ignition schemes for the SNS radio-frequency driven H -the Spallation Neutron Source (SNS) is a cesiated, radio-

2001-01-01T23:59:59.000Z

43

Towards Optimization of Probe Placement for Radio-Frequency Ablation  

E-Print Network (OSTI)

's electric potential and of the steady state of the heat distribution during RF ablation. The optimization of the optimization to artificial data and a comparison to a real RF ablation are presented. 1 Introduction on Cartesian or tetrahedral grids. In this work we consider the radio-frequency (RF) ablation of liver tumors

Preusser, Tobias

44

Radio-Frequency Identification (RFID) applications: A brief introduction  

Science Conference Proceedings (OSTI)

This short paper introduces the key concepts behind RFID technology and presents a brief historical perspective. Examples of RFID applications are also given to highlight the developing popularity of the technology in many sectors. This paper will provide ... Keywords: Antenna, Radio-Frequency Identification, Reader, Tagging, Tracking, Transponder

Konstantinos Domdouzis; Bimal Kumar; Chimay Anumba

2007-10-01T23:59:59.000Z

45

Method for imaging with low frequency electromagnetic fields  

DOE Patents (OSTI)

A method for imaging with low frequency electromagnetic fields, and for interpreting the electromagnetic data using ray tomography, in order to determine the earth conductivity with high accuracy and resolution. The imaging method includes the steps of placing one or more transmitters, at various positions in a plurality of transmitter holes, and placing a plurality of receivers in a plurality of receiver holes. The transmitters generate electromagnetic signals which diffuse through a medium, such as earth, toward the receivers. The measured diffusion field data H is then transformed into wavefield data U. The traveltimes corresponding to the wavefield data U, are then obtained, by charting the wavefield data U, using a different regularization parameter .alpha. for each transform. The desired property of the medium, such as conductivity, is then derived from the velocity, which in turn is constructed from the wavefield data U using ray tomography.

Lee, Ki H. (Lafayette, CA); Xie, Gan Q. (Berkeley, CA)

1994-01-01T23:59:59.000Z

46

Computer simulation of low-frequency electromagnetic data acquisition  

DOE Green Energy (OSTI)

Computer simulation of low frequency electromagnetic (LFEM) digital data acquisition in the presence of natural field noise demonstrates several important limitations and considerations. Without the use of a remote reference noise removal scheme it is difficult to obtain an adequate ratio of signal to noise below 0.1 Hz for frequency domain processing and below 0.3 Hz base frequency for time domain processing for a typical source-receiver configuration. A digital high-pass filter substantially facilitates rejection of natural field noise above these frequencies but, at lower frequencies where much longer stacking times are required, it becomes ineffective. Use of a remote reference to subtract natural field noise extends these low-frequency limits a decade, but this technique is limited by the resolution and dynamic range of the instrumentation. Gathering data in short segments so that natural field drift can be offset for each segment allows a higher gain setting to minimize dynamic range problems.

SanFilipo, W.A.; Hohmann, G.W.

1982-02-01T23:59:59.000Z

47

Power System Electromagnetic Compatibility  

Science Conference Proceedings (OSTI)

The potential for man-made electromagnetic interference has existed since the construction of the first electric power system. As the use of electricity expanded during the first few decades of the twentieth century, the number of sources of electromagnetic interference, as well as the number of receptors, burgeoned. With the proliferation of sources and receptors, the engineering study of electromagnetic interference--sometimes called radio noise, electrical noise, or radio-frequency interference--becam...

2000-12-19T23:59:59.000Z

48

Tubular Radio Frequency (RF) Cage Field Confinement Cavity (IN-05-107)  

Scientists at Argonne National Laboratory have created innovations in the design and fabrication of radio frequency (RF) cavities that improve ...

49

Electronic Radio-Frequency (Electrodeless) Induction Lamps: A Fluorescent Technology  

Science Conference Proceedings (OSTI)

This EPRI Technical Update addresses an expanding energy efficient light source electronic radio-frequency (electrodeless) induction lamps. Business and technical market factors (Chapter 2) use the past and future growth of the CFL market to illustrate the potential for the induction lighting market while emphasizing future technical improvements. Discussion of the importance of utility involvement in helping their customers consider induction lamps for high-efficiency fluorescent applications with long-...

2007-12-20T23:59:59.000Z

50

Ross Ice Shelf in situ radio-frequency ice attenuation  

E-Print Network (OSTI)

We have measured the in situ average electric field attenuation length for radio-frequency signals broadcast vertically through the Ross Ice Shelf. We chose a location, Moore Embayment, south of Minna Bluff, known for its high reflectivity at the ice-sea interface. We confirmed specular reflection and used the return pulses to measure the average attenuation length from 75-1250 MHz over the round-trip distance of 1155 m. We find the average electric field attenuation length to vary from 500 m at 75 MHz to 300 m at 1250 MHz, with an experimental uncertainty of 55 to 15 m. We discuss the implications for neutrino telescopes that use the radio technique and include the Ross Ice Shelf as part of their sensitive volume.

Taylor Barrella; Steven Barwick; David Saltzberg

2010-11-02T23:59:59.000Z

51

Low-Frequency Electromagnetic Backscatter from Buried Tunnels  

Science Conference Proceedings (OSTI)

This progress report is submitted under a contract between the Special Project Office of DARPA and Lawrence Livermore National Laboratory. The Project Manager at DARPA is Dr. Michael Zatman. Our purpose under this contract is to investigate interactions between electromagnetic waves and a class of buried targets located in multilayered media with rough interfaces. In this report, we investigate three preliminary problems. In each case our specific goal is to understand various aspects of the electromagnetic wave interaction mechanisms with targets in layered media. The first problem, discussed in Section 2, is that of low-frequency electromagnetic backscattering from a tunnel that is cut into a lossy dielectric half-space. In this problem, the interface between the upper (free space) region and the lower (ground) region is smooth. The tunnel is assumed to be a cylindrical free-space region of infinite extent in its axial direction and with a diameter that is small in comparison to the free-space wavelength. Because its diameter is small, the tunnel can be modeled as a buried ''wire'' described by an equivalent impedance per unit length. In Section 3 we extend the analysis to include a statistically rough interface between the air and ground regions. The interface is modeled as a random-phase screen. Such a screen reduces the coherent power in a plane wave that is transmitted through it, scattering some of the total power into an incoherent field. Our analysis of this second problem quantifies the reduction in the coherent power backscattered from the buried tunnel that is caused by the roughness of the air-ground interface. The problem of low-frequency electromagnetic backscattering from two buried tunnels, parallel to each other but at different locations in the ground, is considered in Section 4. In this analysis, we wish to determine the conditions under which the presence of more than one tunnel can be detected via backscattering. Section 5 concludes the report with a summary of the investigations discussed herein and recommendations for future work on problems of this class.

Casey, K; Pao, H

2006-06-21T23:59:59.000Z

52

Design and characterization of a radio-frequency dc/dc power converter  

E-Print Network (OSTI)

The use of radio-frequency (RF) amplifier topologies in dc/dc power converters allows the operating frequency to be increased by more than two orders of magnitude over the frequency of conventional converters. This enables ...

Jackson, David A. (David Alexander)

2005-01-01T23:59:59.000Z

53

Radio-Frequency Interference (RFI) From Extra-High- Voltage (EHV) Transmission Lines  

E-Print Network (OSTI)

The subject of radio-frequency interference (RFI) generated by high-voltage transmission lines has long been of both academic and commercial interest because of concerns about

Patrick C. Crane

2010-01-01T23:59:59.000Z

54

ARG-US RADIO FREQUENCY IDENTIFICATION (RFID) Technology (IN-08-046)  

For years, radio frequency identification (RFID) technology has been used in a variety of applications, from passports to inventory tracking in retail ...

55

RFQ (radio-frequency quadrupole) acceleration section and its optimization  

SciTech Connect

The acceleration section is a crucial component of any radio- frequency quadrupole (RFQ). It is common a practice to design this section with a constant modulation factor equal to its value at the end of the gentle buncher. A new method of design is proposed in this paper. The algorithm is based on the fact that the transverse space-charge current limit (TCL) is approximately proportional to the instantaneous velocity of the accelerated particle and the longitudinal space-charge current limit (LCL) is nearly independent of the velocity in the acceleration section. The modulation factor is increased such that the TCL is slightly larger than the double of the design current. Simulation using this method shows that transmission efficiency and emittances are the same as the conventional design. The advantage gained is a 50-75% increase in accelerating rate. The optimization of the length of this section is also discussed. 3 refs., 4 figs., 1 tab.

Raparia, D.

1988-01-01T23:59:59.000Z

56

Superconducting radio-frequency modules test faciilty operating experience  

Science Conference Proceedings (OSTI)

Fermilab is heavily engaged and making strong technical contributions to the superconducting radio-frequency research and development program (SRF R&D). Four major SRF test areas are being constructed to enable vertical and horizontal cavity testing, as well as cryomodule testing. The existing Fermilab cryogenic infrastructure has been modified to service Fermilab SRF R&D needs. The first stage of the project has been successfully completed, which allows for distribution of cryogens for a single cavity cryomodule using the existing Cryogenic Test Facility (CTF) that houses three Tevatron satellite refrigerators. The cooling capacity available for cryomodule testing at MDB results from the liquefaction capacity of the CTF cryogenic system. The cryogenic system for a single 9-cell cryomodule is currently operational. The paper describes the status, challenges and operational experience of the initial phase of the project.

Soyars, W.; Bossert, R.; Darve, C.; Degraff, B.; Klebaner, A.; Martinez, A.; Pei, L.; Theilacker, J.; /Fermilab

2007-07-01T23:59:59.000Z

57

Plenary lecture I: electromagnetic low frequency radiation from natural phenomena - data analysis and modelling  

Science Conference Proceedings (OSTI)

Can severe weather conditions, volcanic eruptions or even earthquakes be predicted from monitoring and analyzing electromagnetic radiation especially in very and ultra low frequency ranges? What signatures in this frequency range leave solar wind, solar ...

Ernst D. Schmitter

2008-07-01T23:59:59.000Z

58

Automatic collecting technique of low frequency electromagnetic signals and its application in earthquake study  

Science Conference Proceedings (OSTI)

Two methods to automatically collect disturbed ultra low frequency electromagnetic signals before strong earthquakes were developed in this paper, in which one is only related to the spectrum intensity of electric field, and another is additionally combined ... Keywords: Chile earthquake, DEMETER, fractal property, multi parameters, ultra low frequency electromagnetic emission

Xuemin Zhang; Roberto Battiston; Xuhui Shen; Zhima Zeren; Xinyan Ouyang; Jiadong Qian; Jing Liu; Jianping Huang; Yuanqing Miao

2010-09-01T23:59:59.000Z

59

A Study of Microfluidic Reconfiguration Mechanisms Enabled by Functionalized Dispersions of Colloidal Material for Radio Frequency Applications  

E-Print Network (OSTI)

Communication and reconnaissance systems are requiring increasing flexibility concerning functionality and efficiency for multiband and broadband frequency applications. Circuit-based reconfiguration mechanisms continue to promote radio frequency (RF) application flexibility; however, increasing limitations have resulted in hindering performance. Therefore, the implementation of a "wireless" reconfiguration mechanism provides the required agility and amicability for microwave circuits and antennas without local overhead. The wireless reconfiguration mechanism in this thesis integrates dynamic, fluidic-based material systems to achieve electromagnetic agility and reduce the need for "wired" reconfiguration technologies. The dynamic material system component has become known as electromagnetically functionalized colloidal dispersions (EFCDs). In a microfluidic reconfiguration system, they provide electromagnetic agility by altering the colloidal volume fraction of EFCDs - their name highlights the special considerations we give to material systems in applied electromagnetics towards lowering loss and reducing system complexity. Utilizing EFCDs at the RF device-level produced the first circuit-type integration of this reconfiguration system; this is identified as the coaxial stub microfluidic impedance transformer (COSMIX). The COSMIX is a small hollowed segment of transmission line with results showing a full reactive loop (capacitive to inductive tuning) around the Smith chart over a 1.2 GHz bandwidth. A second microfluidic application demonstrates a novel antenna reconfiguration mechanism for a 3 GHz microstrip patch antenna. Results showed a 300 MHz downward frequency shift by dielectric colloidal dispersions. Magnetic material produced a 40 MHz frequency shift. The final application demonstrates the dynamically altering microfluidic system for a 3 GHz 1x2 array of linearly polarized microstrip patch antennas. The parallel microfluidic capillaries were imbedded in polydimethylsiloxane (PDMS). Both E- and H-plane designs showed a 250 MHz frequency shift by dielectric colloidal dispersions. Results showed a strong correlation between decreasing electrical length of the elements and an increase of the volume fraction, causing frequency to decrease and mutual coupling to increase. Measured, modeled, and analytical results for impedance, voltage standing wave ratio (VSWR), and radiation behavior (where applicable) are provided.

Goldberger, Sean A.

2009-05-01T23:59:59.000Z

60

Free-Free Emission at Low Radio Frequencies  

E-Print Network (OSTI)

We discuss free-free radio emission from ionized gas in the intergalactic medium. Because the emissivity is proportional to the square of the electron density, the mean background is strongly sensitive to the spatial clumping of free electrons. Using several existing models for the clumping of ionized gas, we find that the expected free-free distortion to the cosmic microwave background (CMB) blackbody spectrum is at a level detectable with upcoming experiments such as the Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE). However, the dominant contribution to the distortion comes from clumpy gas at z free-free background and the extent to which these anisotropies confuse the search for fluctuations in 21 cm line emission from neutral hydrogen during and prior to reionization. This background is smooth in frequency space and hence can be removed through frequency differencing, but only so long as the 21 cm signal and the free-free emission are uncorrelated. We show that, because the free-free background is generated primarily at low redshifts, the cross-correlation between the two fields is smaller than a few percent. Thus, multifrequency cleaning should be an effective way to eliminate the free-free confusion.

Asantha Cooray; Steven Furlanetto

2004-02-10T23:59:59.000Z

Note: This page contains sample records for the topic "radio frequency electromagnetic" from the National Library of EnergyBeta (NLEBeta).
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61

Investigation of an Electromagnetic Interference (EMI) Problem Involving Light-Emitting Diode Streetlights and an Amateur Radio Tran sceiver  

Science Conference Proceedings (OSTI)

Any type of electronic device is susceptible to energy from the electromagnetic environment. This technical update describes an investigation of electromagnetic interference (EMI) problems associated with amateur radio, distribution hardware, and streetlights at a customer's home in Camden, Tennessee. Because light-emitting diode (LED) streetlights were deemed the direct cause of the EMI problem, an investigational plan involving a two-level effort was customized to fit the situation. First, field observ...

2011-10-06T23:59:59.000Z

62

Economics of shale oil production by radio frequency heating  

DOE Green Energy (OSTI)

A conceptual facility for the production of shale oil by radio frequency(rf) heating has been designed to evaluate the economic feasibility of this technique. In the proposed procedure, the shale is processed in situ without being rubbed or explosively fractured. Metal electrodes inserted in a set of vertical drill holes are energized by a group of rf oscillators. The holes bound a block of shale that is to be retorted. The electric field is developed in such a way that heating within the block is almost uniform, and heating outside the block is very low. Retorting of the shale results in a pressure buildup of the hydrocarbon fluids. The oil and gas move horizontally (parallel to bedding planes), then down the electrode holes to a collection manifold. The facility schedule is planned so that off-peak electric power from existing generating stations can be used to operate the oscillators. Thus, the cost of power and the capital requirements for the facility are held to a minimum. Oil production costs and capital requirements indicate that the proposed procedure is economically attractive. The two principal costs are purchase of electric power and mining operations. The largest capital requirement is oscillators and associated electrical equipment.

Mallon, R.G.

1980-05-07T23:59:59.000Z

63

Energy Saving Glass Lamination via Selective Radio Frequency Heating  

DOE Green Energy (OSTI)

Ceralink Inc. developed FastFuse™, a rapid, new, energy saving process for lamination of glass and composites using radio frequency (RF) heating technology. The Inventions and Innovations program supported the technical and commercial research and development needed to elevate the innovation from bench scale to a self-supporting technology with significant potential for growth. The attached report provides an overview of the technical and commerical progress achieved for FastFuse™ during the course of the project. FastFuse™ has the potential to revolutionize the laminate manufacturing industries by replacing energy intensive, multi-step processes with an energy efficient, single-step process that allows higher throughput. FastFuse™ transmits RF energy directly into the interlayer to generate heat, eliminating the need to directly heat glass layers and the surrounding enclosures, such as autoclaves or vacuum systems. FastFuse™ offers lower start-up and energy costs (up to 90% or more reduction in energy costs), and faster cycles times (less than 5 minutes). FastFuse™ is compatible with EVA, TPU, and PVB interlayers, and has been demonstrated for glass, plastics, and multi-material structures such as photovoltaics and transparent armor.

Shawn M. Allan; Patricia M. Strickland; Holly S. Shulman

2009-11-11T23:59:59.000Z

64

Method of making radio frequency ion source antenna  

DOE Patents (OSTI)

In the method, the radio frequency (RF) antenna is made by providing a clean coil made of copper tubing or other metal conductor, which is coated with a tacky organic binder, and then with a powdered glass frit, as by sprinkling the frit uniformly over the binder. The coil is then heated internally in an inert gas atmosphere, preferably by passing an electrical heating current along the coil. Initially, the coil is internally heated to about 200.degree. C. to boil off the water from the binder, and then to about 750.degree. C.-850.degree. C. to melt the glass frit, while also burning off the organic binder. The melted frit forms a molten glass coating on the metal coil, which is then cooled to solidify the glass, so that the metal coil is covered with a thin continuous homogeneous impervious glass coating of substantially uniform thickness. The glass coating affords complete electrical insulation and complete dielectric protection for the metal coil of the RF antenna, to withstand voltage breakdown and to prevent sputtering, while also doubling the plasma generating efficiency of the RF antenna, when energized with RF power in the vacuum chamber of an ion source for a particle accelerator or the like. The glass frit preferably contains apprxoimately 45% lead oxide.

Ehlers, Kenneth W. (Alamo, CA); Leung, Ka-Ngo (Hercules, CA)

1988-01-01T23:59:59.000Z

65

Algorithms for irreducible infeasible subset detection in CSP - Application to frequency planning and graph k-coloring.  

E-Print Network (OSTI)

??The frequency assignment (FAP) consists in assigning the frequency on the radio links of a network which satisfiesthe electromagnetic interference among the links. Given the… (more)

Hu, Jun

2012-01-01T23:59:59.000Z

66

Proposal for the Purchase, Without a Call for Tenders, of a Fourth Radio-Frequency Transmission Line for the SPS  

E-Print Network (OSTI)

Proposal for the Purchase, Without a Call for Tenders, of a Fourth Radio-Frequency Transmission Line for the SPS

1977-01-01T23:59:59.000Z

67

Energy Saving Glass Lamination via Selective Radio-Frequency Heating  

SciTech Connect

This Inventions and Innovations program supported the technical and commercial research and development needed to elevate Ceralink's energy saving process for flat glass lamination from bench scale to a self-supporting technology with significant potential for growth. Radio-frequency heating was any un-explored option for laminating glass prior to this program. With significant commercial success through time and energy savings in the wood, paper, and plastics industries, RF heating was found to have significant promise for the energy intensive glass lamination industry. A major technical goal of the program was to demonstrate RF lamination across a wide range of laminate sizes and materials. This was successfully accomplished, dispelling many skeptics' concerns about the abilities of the technology. Ceralink laminated panels up to 2 ft x 3 ft, with four sets processed simultaneously, in a 3 minute cycle. All major categories of interlayer materials were found to work with RF lamination. In addition to laminating glass, other materials including photovoltaic silicon solar cells, light emitting diodes, metallized glass, plastics (acrylic and polycarbonate), and ceramics (alumina) were found compatible with the RF process. This opens up a wide range of commercial opportunities beyond the initially targeted automotive industry. The dramatic energy savings reported for RF lamination at the bench scale were found to be maintained through the scale up of the process. Even at 2 ft x 3 ft panel sizes, energy savings are estimated to be at least 90% compared to autoclaving or vacuum lamination. With targeted promotion through conference presentations, press releases and internet presence, RF lamination has gained significant attention, drawing large audiences at American Ceramic Society meetings. The commercialization success of the project includes the establishment of a revenue-generating business model for providing process development and demonstrations for potential RF lamination users. A path to industrial energy benefits and revenue through industrial equipment sales was established in a partnership with Thermex Thermatron, a manufacturer of RF equipment.

Shulman, Holly S.; Allan, Shawn M.

2009-11-11T23:59:59.000Z

68

H- radio frequency source development at the Spallation Neutron Source  

Science Conference Proceedings (OSTI)

The Spallation Neutron Source (SNS) now routinely operates nearly 1 MW of beam power on target with a highly persistent {approx}38 mA peak current in the linac and an availability of {approx}90%. H{sup -} beam pulses ({approx}1 ms, 60 Hz) are produced by a Cs-enhanced, multicusp ion source closely coupled with an electrostatic low energy beam transport (LEBT), which focuses the 65 kV beam into a radio frequency quadrupole accelerator. The source plasma is generated by RF excitation (2 MHz, {approx}60 kW) of a copper antenna that has been encased with a thickness of {approx}0.7 mm of porcelain enamel and immersed into the plasma chamber. The ion source and LEBT normally have a combined availability of {approx}99%. Recent increases in duty-factor and RF power have made antenna failures a leading cause of downtime. This report first identifies the physical mechanism of antenna failure from a statistical inspection of {approx}75 antennas which ran at the SNS, scanning electron microscopy studies of antenna surface, and cross sectional cuts and analysis of calorimetric heating measurements. Failure mitigation efforts are then described which include modifying the antenna geometry and our acceptance/installation criteria. Progress and status of the development of the SNS external antenna source, a long-term solution to the internal antenna problem, are then discussed. Currently, this source is capable of delivering comparable beam currents to the baseline source to the SNS and, an earlier version, has briefly demonstrated unanalyzed currents up to {approx}100 mA (1 ms, 60 Hz) on the test stand. In particular, this paper discusses plasma ignition (dc and RF plasma guns), antenna reliability, magnet overheating, and insufficient beam persistence.

Welton, Robert F [ORNL; Pennisi, Terry R [ORNL; Roseberry, Ron T [ORNL; Stockli, Martin P [ORNL

2012-01-01T23:59:59.000Z

69

Adaptive-rate techniques for frequency-hop multiple-access packet-radio networks  

E-Print Network (OSTI)

The effects of adaptive-rate transmissions and routing on the total throughput of a slow-frequency-hop packet-radio network are considered. Adaptive rates are achieved through the use of error-control coding with perfect ...

Block, Frederick J., IV

70

A Radio Frequency Identification (RFID) evaluation strategy for customer fulfillment centers  

E-Print Network (OSTI)

Radio Frequency Identification (RFID) is a wireless technology that can be used to track inventory labeled with microchip-embedded identifiers communicating passively with scanners without operator involvement. This ...

Shen, Howard H. (Howard Hao)

2006-01-01T23:59:59.000Z

71

Radio Frequency Station - Beam Dynamics Interaction in Circular Accelerators  

Science Conference Proceedings (OSTI)

The longitudinal beam dynamics in circular accelerators is mainly defined by the interaction of the beam current with the accelerating Radio Frequency (RF) stations. For stable operation, Low Level RF (LLRF) feedback systems are employed to reduce coherent instabilities and regulate the accelerating voltage. The LLRF system design has implications for the dynamics and stability of the closed-loop RF systems as well as for the particle beam, and is very sensitive to the operating range of accelerator currents and energies. Stability of the RF loop and the beam are necessary conditions for reliable machine operation. This dissertation describes theoretical formalisms and models that determine the longitudinal beam dynamics based on the LLRF implementation, time domain simulations that capture the dynamic behavior of the RF station-beam interaction, and measurements from the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC) that validate the models and simulations. These models and simulations are structured to capture the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They also provide the opportunity to study diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Coupled-bunch instabilities and RF station power were the performance limiting effects for PEP-II. The sensitivity of the instabilities to individual LLRF parameters, the effectiveness of alternative operational algorithms, and the possible tradeoffs between RF loop and beam stability were studied. New algorithms were implemented, with significant performance improvement leading to a world record current during the last PEP-II run of 3212 mA for the Low Energy Ring. Longitudinal beam emittance growth due to RF noise is a major concern for LHC. Simulations studies and measurements were conducted that clearly show the correlation between RF noise and longitudinal bunch emittance, identify the major LLRF noise contributions, and determine the RF component dominating this effect. With these results, LHC upgrades and alternative algorithms are evaluated to reduce longitudinal emittance growth during operations. The applications of this work are described with regard to future machines and analysis of new technical implementations, as well as to possible future work which would continue the directions of this dissertation.

Mastoridis, Themistoklis; /Stanford U., Elect. Eng. Dept. /SLAC

2011-03-01T23:59:59.000Z

72

Energy Saving Glass Lamination via Selective Radio Frequency Heating  

SciTech Connect

This project focused on advancing radio-frequency (RF) lamination technology closer to commercial implementation, in order to reduce the energy intensity of glass lamination by up to 90%. Lamination comprises a wide range of products including autoglass, architectural safety and innovative design glass, transparent armor (e.g. bullet proof glass), smart glass, mirrors, and encapsulation of photovoltaics. Lamination is also the fastest growing segment of glass manufacturing, with photovoltaics, architectural needs, and an anticipated transition to laminated side windows in vehicles. The state-of-the-art for glass lamination is to use autoclaves, which apply heat and uniform gas pressure to bond the laminates over the course of 1 to 18 hours. Laminates consist of layers of glass or other materials bonded with vinyl or urethane interlayers. In autoclaving, significant heat energy is lost heating the chamber, pressurized air, glass racks, and the glass. In RF lamination, the heat is generated directly in the vinyl interlayer, causing it to heat and melt quickly, in just 1 to 10 minutes, without significantly heating the glass or the equipment. The main purpose of this project was to provide evidence that low energy, rapid RF lamination quality met the same standards as conventionally autoclaved windows. The development of concepts for laminating curved glass with RF lamination was a major goal. Other primary goals included developing a stronger understanding of the lamination product markets described above, and to refine the potential benefits of commercial implementation. The scope of the project was to complete implementation concept studies in preparation for continuation into advanced development, pilot studies, and commercial implementation. The project consisted of 6 main tasks. The first dealt with lamination with poly-vinyl butyral (PVB) interlayers, which prior work had shown difficulties in achieving good quality laminates, working with Pilkington North America. The second task dealt with a study of current lamination processes in the various laminate industries, and development of concepts for integrating RF lamination into new or existing processes. The third task explored the use of a non-destructive technique for analyzing laminate adhesion with the University of Illinois at Urbana-Champaign. The fourth task focused on developing concepts for curved glass lamination using RF lamination. The fifth and sixth tasks together comprised an analysis of laminate product markets, ranking for applicability and commercialization potential, and the development of commercialization strategies for those products. In addition, throughout the project as new experimental data and conventional process data were obtained, the benefits analysis of RF lamination was refined. The goals of the project described above were achieved, positioning RF lamination for the next stage growth envisioned in the original Industrial Grand Challenge proposal. Working with Pilkington North America, lamination of flat autoglass with PVB was achieved, meeting all 16 stringent industry tests. In particular, PVB laminates made with RF lamination passed environmental tests including the high temperature, 120 C bake test, without significant formation of bubbles (defects). The adhesion of PVB to glass was measured using the pummel method. Adhesion values ranging from 1 to 7 out of 10 were obtained. The significant process parameters affecting the environmental and adhesion performance were identified through a designed experiment. Pre-lamination process variables including PVB storage humidity and the de-airing process (vacuum or nip rolling) were significant, as well as the level of pressure applied to the laminate during the RF process. Analysis of manufacturing with RF lamination equipment, based on the processes developed indicated that 3 RF presses could replace a typical auto-industry autoclave to achieve equal or greater throughput with possibly less capital cost and smaller footprint. Concepts for curved lamination identifying castable molds for

Allan, Shawn M.

2012-02-27T23:59:59.000Z

73

Energy Saving Glass Lamination via Selective Radio Frequency Heating  

SciTech Connect

This project focused on advancing radio-frequency (RF) lamination technology closer to commercial implementation, in order to reduce the energy intensity of glass lamination by up to 90%. Lamination comprises a wide range of products including autoglass, architectural safety and innovative design glass, transparent armor (e.g. bullet proof glass), smart glass, mirrors, and encapsulation of photovoltaics. Lamination is also the fastest growing segment of glass manufacturing, with photovoltaics, architectural needs, and an anticipated transition to laminated side windows in vehicles. The state-of-the-art for glass lamination is to use autoclaves, which apply heat and uniform gas pressure to bond the laminates over the course of 1 to 18 hours. Laminates consist of layers of glass or other materials bonded with vinyl or urethane interlayers. In autoclaving, significant heat energy is lost heating the chamber, pressurized air, glass racks, and the glass. In RF lamination, the heat is generated directly in the vinyl interlayer, causing it to heat and melt quickly, in just 1 to 10 minutes, without significantly heating the glass or the equipment. The main purpose of this project was to provide evidence that low energy, rapid RF lamination quality met the same standards as conventionally autoclaved windows. The development of concepts for laminating curved glass with RF lamination was a major goal. Other primary goals included developing a stronger understanding of the lamination product markets described above, and to refine the potential benefits of commercial implementation. The scope of the project was to complete implementation concept studies in preparation for continuation into advanced development, pilot studies, and commercial implementation. The project consisted of 6 main tasks. The first dealt with lamination with poly-vinyl butyral (PVB) interlayers, which prior work had shown difficulties in achieving good quality laminates, working with Pilkington North America. The second task dealt with a study of current lamination processes in the various laminate industries, and development of concepts for integrating RF lamination into new or existing processes. The third task explored the use of a non-destructive technique for analyzing laminate adhesion with the University of Illinois at Urbana-Champaign. The fourth task focused on developing concepts for curved glass lamination using RF lamination. The fifth and sixth tasks together comprised an analysis of laminate product markets, ranking for applicability and commercialization potential, and the development of commercialization strategies for those products. In addition, throughout the project as new experimental data and conventional process data were obtained, the benefits analysis of RF lamination was refined. The goals of the project described above were achieved, positioning RF lamination for the next stage growth envisioned in the original Industrial Grand Challenge proposal. Working with Pilkington North America, lamination of flat autoglass with PVB was achieved, meeting all 16 stringent industry tests. In particular, PVB laminates made with RF lamination passed environmental tests including the high temperature, 120 ���°C bake test, without significant formation of bubbles (defects). The adhesion of PVB to glass was measured using the pummel method. Adhesion values ranging from 1 to 7 out of 10 were obtained. The significant process parameters affecting the environmental and adhesion performance were identified through a designed experiment. Pre-lamination process variables including PVB storage humidity and the de-airing process (vacuum or nip rolling) were significant, as well as the level of pressure applied to the laminate during the RF process. Analysis of manufacturing with RF lamination equipment, based on the processes developed indicated that 3 RF presses could replace a typical auto-industry autoclave to achieve equal or greater throughput with possibly less capital cost and smaller footprint. Concepts for curved lamination id

Allan, Shawn M.; Baranova, Inessa; Poley, Joseph; Reis, Henrique

2012-02-27T23:59:59.000Z

74

Narrowband high temperature superconducting receiver for low frequency radio waves  

DOE Patents (OSTI)

An underground communicating device has a low-noise SQUID using high temperature superconductor components connected to detect a modulated external magnetic flux for outputting a voltage signal spectrum that is related to the varying magnetic flux. A narrow bandwidth filter may be used to select a portion of the voltage signal spectrum that is relatively free of power line noise to output a relatively low noise output signal when operating in a portion of the electromagnetic spectra where such power line noise exists. A demodulator outputs a communication signal, which may be an FM signal, indicative of a modulation on the modulated external magnetic flux.

Reagor, David W. (Los Alamos, NM)

2001-01-01T23:59:59.000Z

75

Low frequency electromagnetic oscillations in dense degenerate electron-positron pair plasma, with and without ions  

SciTech Connect

Quantum plasma oscillations are studied in a strongly magnetized, ultra-dense plasma with degenerate electrons and positrons. The dispersive role of electron and positron quantum effects on low frequency (in comparison to electron cyclotron frequency) shear electromagnetic wave is investigated by employing hydrodynamic formulation. In the presence of ions, the density balance changes, and the electromagnetic wave (with frequency lower than the ion cyclotron frequency) is shown to couple with electrostatic ion mode under certain conditions. For such low frequency waves, it is also seen that the contribution of electron and positron degeneracy pressure is dominant as compared to their diffraction effects. The results are analyzed numerically for illustrative purpose pointing out their relevance to the dense laboratory (e.g., super-intense laser-dense matter interactions) and astrophysical plasmas.

Khan, S. A. [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 45320 (Pakistan); Ayub, M. K. [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 45320 (Pakistan); Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); Pohang University of Science and Technology (POSTECH), Pohang, Gyunbuk 790-784 (Korea, Republic of); Ahmad, Ali [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 45320 (Pakistan); Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan)

2012-10-15T23:59:59.000Z

76

Low frequency electromagnetic prospecting system. [Grass Valley, KGRA  

DOE Green Energy (OSTI)

A prototype portable electromagnetic sounding system was assembled and depth sounding survey was conducted in Grass Valley, Nevada, as a part of a program to evaluate geophysical techniques in geothermal exploration. A horizontal loop transmitter of radius 50 meters operating between .01 Hz and 100 Hz was used in conjunction with a SQUID magnetometer. A digital synchronous detector was used for on site processing of magnetometer output. This detector allowed useful data acquisition with transmitter-receiver separation of up to 2 km with power requirements of less than 72 watts. Conductive sediments (1 to 10 ohm-m) of thicknesses of up to 1.5 km were well resolved with this system, and the interpreted sections compared very well with dc resistivity measurements made with much heavier equipment and larger arrays in the same area.

Jain, B.K.

1978-04-01T23:59:59.000Z

77

UTag: Long-range Ultra-wideband Passive Radio Frequency Tags  

SciTech Connect

Long-range, ultra-wideband (UWB), passive radio frequency (RF) tags are key components in Radio Frequency IDentification (RFID) system that will revolutionize inventory control and tracking applications. Unlike conventional, battery-operated (active) RFID tags, LLNL's small UWB tags, called 'UTag', operate at long range (up to 20 meters) in harsh, cluttered environments. Because they are battery-less (that is, passive), they have practically infinite lifetimes without human intervention, and they are lower in cost to manufacture and maintain than active RFID tags. These robust, energy-efficient passive tags are remotely powered by UWB radio signals, which are much more difficult to detect, intercept, and jam than conventional narrowband frequencies. The features of long range, battery-less, and low cost give UTag significant advantage over other existing RFID tags.

Dowla, F

2007-03-14T23:59:59.000Z

78

UTag: Long-range Ultra-wideband Passive Radio Frequency Tags  

SciTech Connect

Long-range, ultra-wideband (UWB), passive radio frequency (RF) tags are key components in Radio Frequency IDentification (RFID) system that will revolutionize inventory control and tracking applications. Unlike conventional, battery-operated (active) RFID tags, LLNL's small UWB tags, called 'UTag', operate at long range (up to 20 meters) in harsh, cluttered environments. Because they are battery-less (that is, passive), they have practically infinite lifetimes without human intervention, and they are lower in cost to manufacture and maintain than active RFID tags. These robust, energy-efficient passive tags are remotely powered by UWB radio signals, which are much more difficult to detect, intercept, and jam than conventional narrowband frequencies. The features of long range, battery-less, and low cost give UTag significant advantage over other existing RFID tags.

Dowla, F

2007-03-14T23:59:59.000Z

79

Measurements of time average series resonance effect in capacitively coupled radio frequency discharge plasma  

Science Conference Proceedings (OSTI)

Self-excited plasma series resonance is observed in low pressure capacitvely coupled radio frequency discharges as high-frequency oscillations superimposed on the normal radio frequency current. This high-frequency contribution to the radio frequency current is generated by a series resonance between the capacitive sheath and the inductive and resistive bulk plasma. In this report, we present an experimental method to measure the plasma series resonance in a capacitively coupled radio frequency argon plasma by modifying the homogeneous discharge model. The homogeneous discharge model is modified by introducing a correction factor to the plasma resistance. Plasma parameters are also calculated by considering the plasma series resonances effect. Experimental measurements show that the self-excitation of the plasma series resonance, which arises in capacitive discharge due to the nonlinear interaction of plasma bulk and sheath, significantly enhances both the Ohmic and stochastic heating. The experimentally measured total dissipation, which is the sum of the Ohmic and stochastic heating, is found to increase significantly with decreasing pressure.

Bora, B.; Bhuyan, H.; Favre, M.; Wyndham, E.; Chuaqui, H. [Facultad de Fisica, Pontificia Universidad Catolica de Chile, Ave. Vicuna Mackenna 4860, Santiago 22 (Chile); Kakati, M. [Thermal Plasma Processed Materials Laboratory, Centre of Plasma Physics, Institute for Plasma Research, Sonapur 782 402, Assam (India)

2011-10-15T23:59:59.000Z

80

Low frequency electrostatic and electromagnetic modes in nonuniform cold quantum plasmas  

SciTech Connect

The low frequency electrostatic and electromagnetic linear modes in a nonuniform cold quantum electron-ion plasma are studied. The effect of stationary dust on an electrostatic mode is also investigated. The quantum corrections in the linear dispersion relations of a cold dense plasma are presented with possible applications.

Saleem, H.; Ahmad, Ali [Theoretical Plasma Physics Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Khan, S. A. [Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Department of Physics, Government College Bagh AJK (Pakistan)

2008-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

A Perspective on Radio-Frequency Exposure Associated With Residential Automatic Meter Reading Technology  

Science Conference Proceedings (OSTI)

Advanced Metering Infrastructure (AMI) is rapidly expanding to improve the service quality and efficiency of our electrical power systems. This short paper focuses on questions that have arisen with regard to residential radio-frequency exposure from Automatic Meter Reading technology (or the use of so-called Smart Meters), a component of AMI, which over time is replacing conventional electrical meters.

2010-02-22T23:59:59.000Z

82

A new method for indoor location base on radio frequency identification  

Science Conference Proceedings (OSTI)

In recent years, there has dramatic proliferation of research concerned with Radio Frequency Identification (RFID). The RFID technologies are getting considerable attentions not only academic research but also the applications of enterprise. One of most ... Keywords: LANDMRC, RFID, RSS, indoor position location, location identification, powel level

Rung-Ching Chen; Sheng-Ling Huang

2009-07-01T23:59:59.000Z

83

The effect of radio frequency plasma processing reactor circuitry on plasma characteristics  

E-Print Network (OSTI)

, developed an equivalent circuit model of the plasma reactor using this data, and later devel- oped a sheath was supported by the National Institute of Standards and Technology, Air Force Office of Scientific ResearchThe effect of radio frequency plasma processing reactor circuitry on plasma characteristics Shahid

Kushner, Mark

84

Self-focusing of intense high frequency electromagnetic waves in a collisional magnetoactive plasma  

Science Conference Proceedings (OSTI)

The self-focusing of an intense electromagnetic beam in a collisional magnetoactive plasma has been investigated by the perturbation method. Considering the relativistic and ponderomotive nonlinearities and the first three terms of perturbation expansion for the electron density and velocity, the nonlinear wave equation is obtained. This wave equation is solved by applying the source dependent expansion method and the evolution of electromagnetic beam spot-size is discussed. It is shown that the laser spot-size decreases with increasing the collision frequency and external magnetic field strength.

Niknam, A. R.; Hashemzadeh, M. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Evin, Tehran (Iran, Islamic Republic of); Aliakbari, A.; Majedi, S. [Physics Department, Faculty of Science, Tafresh University, Tafresh (Iran, Islamic Republic of); Haji Mirzaei, F. [Physics Department, Islamic Azad University, Arak Branch, Arak (Iran, Islamic Republic of)

2011-11-15T23:59:59.000Z

85

Contributions to Radio Frequency Identification (RFID) research: An assessment of SCI-, SSCI-indexed papers from 2004 to 2008  

Science Conference Proceedings (OSTI)

The research literature on Radio Frequency Identification (RFID) has grown exponentially in recent years. In a domain where new concepts and techniques are constantly being introduced, it is of interest to analyze recent trends in this literature. Although ... Keywords: Citation analysis, Radio Frequency Identification (RFID), Science Citation Index (SCI), Social Science Citation Index (SSCI)

Wei-Pang Liao; Tom M. Y. Lin; Shu-Hsien Liao

2011-01-01T23:59:59.000Z

86

Radio frequency circuits for wireless receiver front-ends  

E-Print Network (OSTI)

The beginning of the 21st century sees great development and demands on wireless communication technologies. Wireless technologies, either based on a cable replacement or on a networked environment, penetrate our daily life more rapidly than ever. Low operational power, low cost, small form factor, and function diversity are the crucial requirements for a successful wireless product. The receiver??s front-end circuits play an important role in faithfully recovering the information transmitted through the wireless channel. Bluetooth is a short-range cable replacement wireless technology. A Bluetooth receiver architecture was proposed and designed using a pure CMOS process. The front-end of the receiver consists of a low noise ampli?er (LNA) and mixer. The intermediate frequency was chosen to be 2MHz to save battery power and alleviate the low frequency noise problem. A conventional LNA architecture was used for reliability. The mixer is a modi?ed Gilbert-cell using the current bleeding technique to further reduce the low frequency noise. The front-end draws 10 mA current from a 3 V power supply, has a 8.5 dB noise ?gure, and a voltage gain of 25 dB and -9 dBm IIP3. A front-end for dual-mode receiver is also designed to explore the capability of a multi-standard application. The two standards are IEEE 802.11b and Bluetooth. They work together making the wireless experience more exciting. The front-end is designed using BiCMOS technology and incorporating a direct conversion receiver architecture. A number of circuit techniques are used in the front-end design to achieve optimal results. It consumes 13.6 mA from a 2.5 V power supply with a 5.5 dB noise ?gure, 33 dB voltage gain and -13 dBm IIP3. Besides the system level contributions, intensive studies were carried out on the development of quality LNA circuits. Based on the multi-gated LNA structure, a CMOS LNA structure using bipolar transistors to provide linearization is proposed. This LNA con?guration can achieve comparable linearity to its CMOS multi-gated counterpart and work at a higher frequency with less power consumption. A LNA using an on-chip transformer source degeneration is proposed to realize input impedance matching. The possibility of a dual-band cellular application is studied. Finally, a study on ultra-wide band (UWB) LNA implementation is performed to explore the possibility and capability of CMOS technology on the latest UWB standard for multimedia applications.

Xin, Chunyu

2004-08-01T23:59:59.000Z

87

Low-cost electromagnetic tagging : design and implementation  

E-Print Network (OSTI)

Several implementations of chipless RFID (Radio Frequency Identification) tags are presented and discussed as low-cost alternatives to chip-based RFID tags and sensors. An overview of present-day near-field electromagnetic ...

Fletcher, Richard R. (Richard Ribon)

2002-01-01T23:59:59.000Z

88

FREQUENCY DEPENDENCE OF THE POWER-LAW INDEX OF SOLAR RADIO BURSTS  

Science Conference Proceedings (OSTI)

We process solar flare observations of Nobeyama Radio Polarimeters with an improved maximum likelihood method developed recently by Clauset et al. The method accurately extracts power-law behaviors of the peak fluxes in 486 radio bursts at six frequencies (1-35 GHz) and shows an excellent performance in this study. The power-law indices on 1-35 GHz given by this study vary around 1.74-1.87, which is consistent with earlier statistics in different solar cycles and very close to the simulations of the avalanche model by Lu.

Song Qiwu; Huang Guangli [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Tan Baolin, E-mail: songqw@pmo.ac.cn, E-mail: glhuang@pmo.ac.cn, E-mail: bltan@bao.ac.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

2012-05-10T23:59:59.000Z

89

Characterization of Radio Frequency Emissions From Two Models of Wireless Smart Meters  

Science Conference Proceedings (OSTI)

Concomitant with the widespread deployment of Advanced Metering Infrastructure (AMI) is the need to characterize radio-frequency (RF) emissions from wireless smart meters. A previous EPRI Technical Report (1021126) provided a detailed characterization of RF emissions from one type of wireless smart meter deployed across several service territories in the U.S. This report describes emissions from wireless smart meters produced by two manufacturers that are currently in operation within a large service ter...

2011-12-08T23:59:59.000Z

90

First Spectroscopic Imaging Observations of the Sun at Low Radio Frequencies with the Murchison Widefield Array Prototype  

E-Print Network (OSTI)

We present the first spectroscopic images of solar radio transients from the prototype for the Murchison Widefield Array, observed on 2010 March 27. Our observations span the instantaneous frequency band 170.9–201.6 MHz. ...

Oberoi, Divya

91

Interaction of extremely-low-frequency electromagnetic fields with living systems  

SciTech Connect

The sources and physical properties of extremely-low-frequency (ELF) electromagnetic fields are described in this paper. Biological effects and mechanisms through which ELF fields interact with humans and other organisms are discussed, including several aspects of this subject that are presently under active laboratory investigation. Studies on the potential health effects of ELF fields present in the home and workplace are also summarized, including a critical evaluation of evidence for a possible linkage between exposure to ELF fields and cancer risk. 53 refs.

Tenforde, T.S.

1991-11-01T23:59:59.000Z

92

Effect of electron density profile on power absorption of high frequency electromagnetic waves in plasma  

SciTech Connect

Considering different typical electron density profiles, a multi slab approximation model is built up to study the power absorption of broadband (0.75-30 GHz) electromagnetic waves in a partially ionized nonuniform magnetized plasma layer. Based on the model, the power absorption spectra for six cases are numerically calculated and analyzed. It is shown that the absorption strongly depends on the electron density fluctuant profile, the background electron number density, and the collision frequency. A potential optimum profile is also analyzed and studied with some particular parameters.

Xi Yanbin; Liu Yue [MOE Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2012-07-15T23:59:59.000Z

93

Frequency Selective Surfaces as Near Infrared Electro-Magnetic Filters for Thermophotovoltaic Spectral Control  

DOE Green Energy (OSTI)

Frequency selective surfaces (FSS) effectively filter electromagnetic radiation in the microwave band (1mm to 100mm). Interest exists in extending this technology to the near infrared (1 {micro}m to 10 {micro}m) for use as a filter of thermal radiation in thermophotovoltaic (TPV) direct energy conversion. This paper assesses the ability of FSS to meet the strict spectral performance requirements of a TPV system. Inherent parasitic absorption, which is the result of the induced currents in the FSS metallization, is identified as a significant obstacle to achieving high spectral performance.

Ryan T. Kristensen; John F. Beausang; David M. DePoy

2003-12-01T23:59:59.000Z

94

Frequency Selective Surfaces as Near Infrared Electro-Magnetic Filters for Thermophotovoltaic Spectral Control  

DOE Green Energy (OSTI)

Frequency selective surfaces (FSS) effectively filter electromagnetic radiation in the microwave band (1 mm to 100 mm). Interest exists in extending this technology to the near infrared (1 {micro}m to 10 {micro}m) for use as a filter of thermal radiation in thermophotovoltaic (TPV) direct energy conversion. This paper assesses the ability of FSS to meet the strict spectral performance requirements of a TPV system. Inherent parasitic absorption, which is the result of the induced currents in the FSS metallization, is identified as a significant obstacle to achieving high spectral performance.

RF Kristensen; JF Beausang; DM DePoy

2004-06-28T23:59:59.000Z

95

On the application of radio frequency voltages to ion traps via helical resonators  

E-Print Network (OSTI)

Ions confined using a Paul trap require a stable, high voltage and low noise radio frequency (RF) potential. We present a guide for the design and construction of a helical coil resonator for a desired frequency that maximises the quality factor for a set of experimental constraints. We provide an in-depth analysis of the system formed from a shielded helical coil and an ion trap by treating the system as a lumped element model. This allows us to predict the resonant frequency and quality factor in terms of the physical parameters of the resonator and the properties of the ion trap. We also compare theoretical predictions with experimental data for different resonators, and predict the voltage applied to the ion trap as a function of the Q-factor, input power and the properties of the resonant circuit.

Siverns, J D; Weidt, S; Hensinger, W K

2011-01-01T23:59:59.000Z

96

On the application of radio frequency voltages to ion traps via helical resonators  

E-Print Network (OSTI)

Ions confined using a Paul trap require a stable, high voltage and low noise radio frequency (RF) potential. We present a guide for the design and construction of a helical coil resonator for a desired frequency that maximises the quality factor for a set of experimental constraints. We provide an in-depth analysis of the system formed from a shielded helical coil and an ion trap by treating the system as a lumped element model. This allows us to predict the resonant frequency and quality factor in terms of the physical parameters of the resonator and the properties of the ion trap. We also compare theoretical predictions with experimental data for different resonators, and predict the voltage applied to the ion trap as a function of the Q-factor, input power and the properties of the resonant circuit.

J. D. Siverns; L. R. Simkins; S. Weidt; W. K. Hensinger

2011-06-24T23:59:59.000Z

97

THE FERRITE BIASING SYSTEM FOR THE RADIO FREQUENCY CAVITIES OF THE PRINCETON-PENNSYLVANIA 3 Bev PROTON SYNCHROTRON  

SciTech Connect

A description is given of the ferrite biasing system for the four tuned radio frequency cavities of the synchrotron. Each ferrite loaded double cavity has a single turn bias winding which is driven to a peak current of 13,500 amperes by a push-pull transformer arrangement. There is automatic tap changing of the transformer to accommodate the variable impedance load (for power considerations). The programming and frequency response of the system have to be such that each cavity can operate as the reso nant circuit of a self tracking radio frequency amplifier over the frequency range 6.5 to 30 Mc at the 20 cps repetition rate of the synchrotron. Between acceleration cycles it is necessary to program the ferrite to a given magnetic state, near that of maximum radio frequency permeability. (auth)

Rees, G.H.

1962-08-29T23:59:59.000Z

98

Radio-Frequency (RF) Devices for Safeguards: Where We Are and Where We Need to Go  

Science Conference Proceedings (OSTI)

Radio-Frequency (RF) devices have revolutionized many aspects of modern industrial processes. RF technology can enable wireless communication for tag identification, sensor communication, and asset tracking. Radio-frequency identification (RFID) is a technology that utilizes wireless communication to interrogate and identify an electronic tag attached to an item in order to identify the item. The technology can come in many forms: passive or active tags, low to ultra-wideband frequencies, small paper-thin tags to brick-sized units, and simple tags or highly integrated sensor packages. RF technology, and specifically RFID, has been applied widely in commercial markets for inventory, supply chain management, and asset tracking. Several recent studies have demonstrated the safeguards benefits of utilizing RFID versus conventional inventory tagging methods for tracking nuclear material. These studies have indicated that the RF requirements for safeguards functions are more stringent than the RF requirements for other inventory tracking and accounting applications. Additionally, other requirements must be addressed, including environmental and operating conditions, authentication, and tag location and attachment. Facility restrictions on radio spectrum, method of tag attachment, and sensitivity of the data collected impact the tag selection and system design. More important, the intended use of the system must be considered. The requirements for using RF to simply replace or supplement container identifiers such as bar codes that facilitate the inventory function will differ greatly from the requirements for deploying RF for unattended monitoring applications. Several studies have investigated these considerations to advance commercial RF devices for safeguards use, and a number of system concepts have been developed. This paper will provide an overview of past studies and current technologies, and will investigate the requirements, existing gaps, and several potential next steps for advancing RF techniques for safeguards use.

Rowe, Nathan C [ORNL; Younkin, James R [ORNL; Pickett, Chris A [ORNL; Whitaker, J Michael [ORNL

2011-01-01T23:59:59.000Z

99

A prototype system for detecting the radio-frequency pulse associated with cosmic ray air showers  

E-Print Network (OSTI)

The development of a system to detect the radio-frequency (RF) pulse associated with extensive air showers of cosmic rays is described. This work was performed at the CASA/MIA array in Utah, with the intention of designing equipment that can be used in conjunction with the Auger Giant Array. A small subset of data (less than 40 out of a total of 600 hours of running time), taken under low-noise conditions, permitted upper limits to be placed on the rate for pulses accompanying showers of energies around $10^{17}$ eV.

Kevin Green; Jonathan L. Rosner; Denis A. Suprun; J. F. Wilkerson

2002-05-03T23:59:59.000Z

100

Simulation of an RFQ (radio-frequency quadruple) funnel for heavy-ion beams  

Science Conference Proceedings (OSTI)

Use of the magnetic force to focus and deflect heavy-ion beams is marginal at low ion velocities. Low-emittance-growth funnels using discrete magnetic elements are difficult to design for these beams. We show that a new type of radio-frequency quadruple (RFQ) funnel is especially suitable for this application. Simulation procedures, which include space-charge and image effects, have produced a high-quality funnel design for 20-MeV Bi/sup +1/ ions. 4 refs., 4 figs., 2 tabs.

Guy, F.W.; Stokes, R.H.

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

A new Main Injector radio frequency system for 2.3 MW Project X operations  

SciTech Connect

For Project X Fermilab Main Injector will be required to provide up to 2.3 MW to a neutrino production target at energies between 60 and 120 GeV. To accomplish the above power levels 3 times the current beam intensity will need to be accelerated. In addition the injection energy of Main Injector will need to be as low as 6 GeV. The current 30 year old Main Injector radio frequency system will not be able to provide the required power and a new system will be required. The specifications of the new system will be described.

Dey, J.; Kourbanis, I.; /Fermilab

2011-03-01T23:59:59.000Z

102

Vane fabrication for the proof-of-principle radio-frequency quadrupole accelerator  

SciTech Connect

The electrodes for the Proof-of-Principle (POP) Radio-Frequency Quadrupole (RFQ) accelerator were machined on a numerically controlled, three-axis, vertical mill. These pole tips, or vanes, were prepared for, and used, in the successful demonstration of RFQ practicality at Los Alamos National Laboratory in February 1980. The data set that described the vanes contained about 10 million bits of tool position data. The vanes were cut from OFHC copper blanks. The tolerances achieved were approximately +- 0.005 cm. The design and manufacturing procedures are described.

Williams, S.W.; Potter, J.M.

1981-01-01T23:59:59.000Z

103

Determination of High-Frequency Current Distribution Using EMTP-Based Transmission Line Models with Resulting Radiated Electromagnetic Fields  

SciTech Connect

Application of BPL technologies to existing overhead high-voltage power lines would benefit greatly from improved simulation tools capable of predicting performance - such as the electromagnetic fields radiated from such lines. Existing EMTP-based frequency-dependent line models are attractive since their parameters are derived from physical design dimensions which are easily obtained. However, to calculate the radiated electromagnetic fields, detailed current distributions need to be determined. This paper presents a method of using EMTP line models to determine the current distribution on the lines, as well as a technique for using these current distributions to determine the radiated electromagnetic fields.

Mork, B; Nelson, R; Kirkendall, B; Stenvig, N

2009-11-30T23:59:59.000Z

104

Small Satellite Applications of Commercial off the Shelf Radio Frequency Integrated Circuits  

E-Print Network (OSTI)

Within the first decade of the 21st century, the aerospace community has seen many more opportunities to launch small spacecraft in the 10 to 100 kg mass class. Coupled with this has been consistent interest from the government in developing small-spacecraft platforms to expand civil and military mission possibilities. Small spacecraft have also given small organizations such as universities an increased access to space. Because small satellites are limited in size, power, and mass, new and often nontraditional capabilities must be explored and developed to make them viable and attractive when compared with larger and more proven spacecraft. Moreover, small organizations that wish to contribute technically are often limited by the small size of their teams and available resources, and need creative solutions for meeting mission requirements. A key need is in space-to-ground communications. Complex missions typically require large amounts of data transfer to the ground and in a timely fashion. Available options trade hardware cost, available ground stations or networks, available operating-frequency range, data-rate performance, and ease of use. A system for small spacecraft will be presented based upon Radio Frequency Integrated Circuits (RFIC) that minimizes development effort and maximizes interface control to meet typical small-spacecraft communications requirements. RFICs are low-cost components that feature pre-built radio hardware on a chip that can be expanded easily by developers with little or no radio experience. These devices are widespread in domestic applications for short-range connectivity. A preliminary design and prototype is presented that meets basic spaceflight requirements, offers data rates in the 55 to 85 kbps range, and has completed basic proof-of-concept testing. While there are higher-data-rate alternatives in existence, the solution presented here strikes a useful balance among data rate, parts cost, and ease of use for non experts, and gives the user operational control necessary to make air-to-ground communications time effective.

Graves, John

2011-12-01T23:59:59.000Z

105

Radio Frequency Phototube, Optical Clock and Precise Measurements in Nuclear Physics  

E-Print Network (OSTI)

Recently a new experimental program of novel systematic studies of light hypernuclei using pionic decay was established at JLab (Study of Light Hypernuclei by Pionic Decay at JLab, JLab Experiment PR-08-012). The highlights of the proposed program include high precision measurements of binding energies of hypernuclei by using a high resolution pion spectrometer, HpiS. The average values of binding energies will be determined within an accuracy of ~10 keV or better. Therefore, the crucial point of this program is an absolute calibration of the HpiS with accuracy 10E-4 or better. The merging of continuous wave laser-based precision optical-frequency metrology with mode-locked ultrafast lasers has led to precision control of the visible frequency spectrum produced by mode-locked lasers. Such a phase-controlled mode-locked laser forms the foundation of an optical clock or femtosecond optical frequency comb (OFC) generator, with a regular comb of sharp lines with well defined frequencies. Combination of this technique with a recently developed radio frequency (RF) phototube results in a new tool for precision time measurement. We are proposing a new time-of-flight (TOF) system based on an RF phototube and OFC technique. The proposed TOF system achieves 10 fs instability level and opens new possibilities for precise measurements in nuclear physics such as an absolute calibration of magnetic spectrometers within accuracy 10E-4 - 10E-5.

Amur Margaryan

2009-10-16T23:59:59.000Z

106

The Study of Electromagnetic Field Response Using Very Low Frequency Methods in Geothermal Area, Sabang  

SciTech Connect

Electromagnetic field measurements have been performed using the method of Very Low Frequency tilt angle pattern in Jaboi, Sabang. A site survey was conducted and carried out to identify the anomalies of location, depth and geometry of hydrothermal based on tilt angle measurement and ellipse. Objective of this study is to see the response of the magnetic and electric field in relation to location, depth and hydrothermal geometry. The devices of T-VLF-R IRIS was used in this study, while the (NWC) station was selected as main station and (JJF4) station was selected as comparison station. The electromagnetic field survey was recorded for a line spanned as long as 900 meters at the interval of 10 meter depth. The results of this study show the greatest anomaly occurred at line interval between 400-600 meters with a depth of 10-140 meters. Anomaly pattern of each depth shows that the propagation pattern of hydrothermal is in the form of vertical pipe flow.

Isa, M. [Departement of Physics Syiah Kuala University Banda Aceh, 23111 (Indonesia); School of Physics, Universiti Sains Malaysia 11800, Penang (Malaysia); Lim, H. S.; Jafri, M. Z. Mat [School of Physics, Universiti Sains Malaysia 11800, Penang (Malaysia)

2011-03-30T23:59:59.000Z

107

An investigation of the usefulness of extremely low-frequency electromagnetic measurements for treaty verification  

SciTech Connect

From FY 1986 through FY 1988, we monitored extremely low-frequency (ELF) electromagnetic (EM) fields to determine whether these signals could be detected from underground nuclear explosions. Signals clearly related to underground tests were detected only when the ELF field sensors were located within 10 km of surface ground zero. Theoretical analysis, based on the results of these measurements, shows that the ELF impulse signals from underground nuclear tests are of longer duration than those from lightning sources and are, therefore, less efficient in exciting resonances in the earth-ionosphere cavity, even though the source strength for each may be the same. Thus, ELF signals from underground nuclear tests with yields of <150 kT are generally lower than the background signals caused by worldwide lightning activity. Our conclusion is that ELF monitoring probably will not be useful for detecting underground nuclear tests at distances >10 km from the tests. 16 refs., 24 figs., 3 tabs.

Sweeney, J.J.

1989-01-01T23:59:59.000Z

108

An investigation of the usefulness of extremely low-frequency electromagnetic measurements for treaty verification  

Science Conference Proceedings (OSTI)

From FY 1986 through FY 1988, we monitored extremely low-frequency (ELF) electromagnetic (EM) fields to determine whether these signals could be detected from underground nuclear explosions. Signals clearly related to underground tests were detected only when the ELF field sensors were located within 10 km of surface ground zero. Theoretical analysis, based on the results of these measurements, shows that the ELF impulse signals from underground nuclear tests are of longer duration than those from lightning sources and are, therefore, less efficient in exciting resonances in the earth-ionosphere cavity, even though the source strength for each may be the same. Thus, ELF signals from underground nuclear tests with yields of nuclear tests at distances >10 km from the tests. 16 refs., 24 figs., 3 tabs.

Sweeney, J.J.

1989-01-01T23:59:59.000Z

109

Flux pinning characteristics in cylindrical ingot niobium used in superconducting radio frequency cavity fabrication  

Science Conference Proceedings (OSTI)

We present the results of from DC magnetization and penetration depth measurements of cylindrical bulk large-grain (LG) and fine-grain (FG) niobium samples used for the fabrication of superconducting radio frequency (SRF) cavities. The surface treatment consisted of electropolishing and low temperature baking as they are typically applied to SRF cavities. The magnetization data were fitted using a modified critical state model. The critical current density Jc and pinning force Fp are calculated from the magnetization data and their temperature dependence and field dependence are presented. The LG samples have lower critical current density and pinning force density compared to FG samples which implies a lower flux trapping efficiency. This effect may explain the lower values of residual resistance often observed in LG cavities than FG cavities.

Dhavale Ashavai, Pashupati Dhakal, Anatolii A Polyanskii, Gianluigi Ciovati

2012-04-01T23:59:59.000Z

110

Coupled microwave ECR and radio-frequency plasma source for plasma processing  

DOE Patents (OSTI)

In a dual plasma device, the first plasma is a microwave discharge having its own means of plasma initiation and control. The microwave discharge operates at electron cyclotron resonance (ECR), and generates a uniform plasma over a large area of about 1000 cm.sup.2 at low pressures below 0.1 mtorr. The ECR microwave plasma initiates the second plasma, a radio frequency (RF) plasma maintained between parallel plates. The ECR microwave plasma acts as a source of charged particles, supplying copious amounts of a desired charged excited species in uniform manner to the RF plasma. The parallel plate portion of the apparatus includes a magnetic filter with static magnetic field structure that aids the formation of ECR zones in the two plasma regions, and also assists in the RF plasma also operating at electron cyclotron resonance.

Tsai, Chin-Chi (Oak Ridge, TN); Haselton, Halsey H. (Knoxville, TN)

1994-01-01T23:59:59.000Z

111

Development of Equipment to Separate Nonthermal and Thermal Effects of Radio Frequency Energy on Microorganisms  

SciTech Connect

A radio frequency (RF) dielectric heater has been developed for isolating thermal and nonthermal effects of RF energy on microorganisms in liquid foods. The modified heater enables the simultaneous application of RF energy and removal of thermal energy from the liquids. A double-pipe heat exchanger is an integral part of the heater. The outer pipe is made of Teflon. The inner pipe is made of stainless steel that is grounded in the RF circuit. Liquid food flows through the annular region between the two concentric pipes. Cooling water flows through the stainless steel pipe. The food in the annular region absorbs the RF energy. Concurrently, the cooling water flowing in the inner pipe removes the thermal energy from the food, thus controlling the temperature.

D.J. Geveke; M. Kozempel; C. Brunkhorst

1999-11-01T23:59:59.000Z

112

Collisionless electron heating by radio frequency bias in low gas pressure inductive discharge  

SciTech Connect

We show experimental observations of collisionless electron heating by the combinations of the capacitive radio frequency (RF) bias power and the inductive power in low argon gas pressure RF biased inductively coupled plasma (ICP). With small RF bias powers in the ICP, the electron energy distribution (EED) evolved from bi-Maxwellian distribution to Maxwellian distribution by enhanced plasma bulk heating and the collisionless sheath heating was weak. In the capacitive RF bias dominant regime, however, high energy electrons by the RF bias were heated on the EEDs in the presence of the ICP. The collisionless heating mechanism of the high energy electrons transited from collisionless inductive heating to capacitive coupled collisionless heating by the electron bounce resonance in the RF biased ICP.

Lee, Hyo-Chang; Chung, Chin-Wook [Department of Electrical Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

2012-12-10T23:59:59.000Z

113

Low-Level Radio Frequency System Development for the National Synchrotron Light Source II  

SciTech Connect

The National Synchrotron Light Source-II (NSLS-II) is a new ultra-bright 3GeV 3rd generation synchrotron radiation light source. The performance goals require operation with a beam current of 500mA and a bunch current of at least 0.5mA. The position and timing specifications of the ultra-bright photon beam imposes a set of stringent requirements on the performance of radio frequency (RF) control. In addition, commissioning and staged installation of damping wigglers and insertion devices requires the flexibility of handling varying beam conditions. To meet these requirements, a digital implementation of the LLRF is chosen, and digital serial links are planned for the system integration. The first prototype of the controller front-end hardware has been built, and is currently being tested.

Ma,H.; Rose, J.

2009-05-04T23:59:59.000Z

114

Radio Frequency Noise Effects on the CERN Large Hadron Collider Beam Diffusion  

SciTech Connect

Radio frequency (rf) accelerating system noise can have a detrimental impact on the Large Hadron Collider (LHC) performance through longitudinal motion and longitudinal emittance growth. A theoretical formalism has been developed to relate the beam and rf station dynamics with the bunch length growth. Measurements were conducted at LHC to determine the performance limiting rf components and validate the formalism through studies of the beam diffusion dependence on rf noise. As a result, a noise threshold was established for acceptable performance which provides the foundation for beam diffusion estimates for higher energies and intensities. Measurements were also conducted to determine the low level rf noise spectrum and its major contributions, as well as to validate models and simulations of this system.

Mastoridis, T.; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; /CERN; Rivetta, C.; Fox, J.D.; /SLAC

2012-04-30T23:59:59.000Z

115

Supersonic combustion of a transverse injected H sub 2 jet in a radio frequency heated flow  

DOE Green Energy (OSTI)

The combustion of a single hydrogen jet, normally injected into a radio frequency (RF) heated, oxidant-containing, supersonic flow, has been established to characterize the chemical and fluid dynamic phenomena associated with the reaction process and ultimately validate the predictive capability of computational computer dynamic (CFD) codes. The experimental system employed for this study is unique in that it uses an electrodeless, inductively coupled plasma tube to generate the high temperature oxidant-containing gas for subsequent nozzle expansion. Advantages of an RF heated flow system include reduced free-stream chemical contamination, continuous operation, and relative ease of integration into a typical flow laboratory environment. A description of the system utilized for this study is presented including preliminary results of the reactive flow characterization. In addition, the use of the laser-based diagnostic techniques, such as planar laser-induced fluorescence (PLIF), for measuring flow properties is also discussed. 8 refs., 7 figs.

Wantuck, P.J.; Tennant, R.A.; Watanabe, H.H.

1991-01-01T23:59:59.000Z

116

Laser polishing of niobium for application to superconducting radio frequency cavities  

SciTech Connect

Superconducting radio frequency niobium cavities are at the heart of an increasing number of particle accelerators. Their performance is dominated by a several nanometer thick layer at the interior surface. Maximizing the smoothness of this surface is critical, and aggressive chemical treatments are now employed to this end. The authors describe laser-induced surface melting as an alternative “greener” approach. Selection of laser parameters guided by modeling achieved melting that reduced the surface roughness from the fabrication process. The resulting topography was examined by scanning electron microscope and atomic force microscope (AFM). Plots of power spectral density computed from the AFM data give further insight into the effect of laser melting on the topography of the mechanically polished (only) niobium.

Senthil Singaravelu ,John Klopf, Chen Xu, Geoffrey Krafft, Michael Kelley

2012-09-01T23:59:59.000Z

117

Temperature distributions of radio-frequency plasma in water by spectroscopic analysis  

Science Conference Proceedings (OSTI)

Distributions of emission intensity from radicals, electron temperature, and rotational temperature at a radio frequency of 27.12 MHz plasma in water are clarified by detailed spectroscopy measurement. Through this investigation, the following were observed. The points of maximum emission intensity of Halpha, Hbeta, O (777 nm), and O (845 nm) are almost the same, while that of OH shifts upward. The electron temperature decreases, while the rotational temperature increases with pressure. The distribution of the electron temperature changes at a threshold pressure, which is concerned with a change in the electron discharge mechanism. The self-bias of the electrode changes from a negative to positive at a threshold pressure. The point of the maximum rotational temperature of OH radicals shifts to approximately 1 mm above that for the maximum intensity of OH emission.

Mukasa, Shinobu; Nomura, Shinfuku; Toyota, Hiromichi; Maehara, Tsunehiro; Abe, Fumiaki [Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama 790-8577 (Japan); Kawashima, Ayato [Faculty of Agriculture, Ehime University, Matsuyama 790-8566 (Japan)

2009-12-01T23:59:59.000Z

118

Coupled microwave ECR and radio-frequency plasma source for plasma processing  

DOE Patents (OSTI)

In a dual plasma device, the first plasma is a microwave discharge having its own means of plasma initiation and control. The microwave discharge operates at electron cyclotron resonance (ECR), and generates a uniform plasma over a large area of about 1000 cm[sup 2] at low pressures below 0.1 mtorr. The ECR microwave plasma initiates the second plasma, a radio frequency (RF) plasma maintained between parallel plates. The ECR microwave plasma acts as a source of charged particles, supplying copious amounts of a desired charged excited species in uniform manner to the RF plasma. The parallel plate portion of the apparatus includes a magnetic filter with static magnetic field structure that aids the formation of ECR zones in the two plasma regions, and also assists in the RF plasma also operating at electron cyclotron resonance. 4 figures.

Tsai, C.C.; Haselton, H.H.

1994-03-08T23:59:59.000Z

119

Investigation of the State and Uses of Ultra-Wide-Band Radio-Frequency Identification Technology  

SciTech Connect

Radio-frequency identification (RFID) technology has revolutionized the concept of asset tracking. By affixing an RFID tag to a valued asset, one can track the item throughout any facility where RIFD readers are in place, thereby alerting inspectors to theft, misuse, and misplacement of the tracked item. While not yet implemented for tracking very high value assets, RFID technology is already widely used in many industries as the standard for asset tracking. A subset of RFID technology exists called Ultra-Wide-Band (UWB) RFID. While traditional (sometimes called narrow-band) RFID technology transmits a continuous sine-wave signal of a narrow frequency range, UWB technology works by transmitting signals as short pulses of a broad frequency range. This improves performance in several areas, namely, range, precision, and accuracy of motion detection. Because of the nature of the technology, it also performs well in close proximity to metal, which sets it apart from traditional RFID. The purpose of this paper is to investigate the current state of UWB RFID technology and research the areas where it already is being used. This is accomplished through study of publicly known uses of the technology as well as personal exploration of RFID hardware and software. This paper presents the findings in a general manner to facilitate their usefulness for diverse applications.

Hickerson, Jonathan W [ORNL; Younkin, James R [ORNL

2010-01-01T23:59:59.000Z

120

Development of Ultra High Gradient and High Q{sub 0} Superconducting Radio Frequency Cavities  

SciTech Connect

We report on the recent progress at Jefferson Lab in developing ultra high gradient and high Q{sub 0} superconducting radio frequency (SRF) cavities for future SRF based machines. A new 1300 MHz 9-cell prototype cavity is being fabricated. This cavity has an optimized shape in terms of the ratio of the peak surface field (both magnetic and electric) to the acceleration gradient, hence the name low surface field (LSF) shape. The goal of the effort is to demonstrate an acceleration gradient of 50 MV/m with Q{sub 0} of 10{sup 10} at 2 K in a 9-cell SRF cavity. Fine-grain niobium material is used. Conventional forming, machining and electron beam welding method are used for cavity fabrication. New techniques are adopted to ensure repeatable, accurate and inexpensive fabrication of components and the full assembly. The completed cavity is to be first mechanically polished to a mirror-finish, a newly acquired in-house capability at JLab, followed by the proven ILC-style processing recipe established already at JLab. In parallel, new single-cell cavities made from large-grain niobium material are made to further advance the cavity treatment and processing procedures, aiming for the demonstration of an acceleration gradient of 50 MV/m with Q{sub 0} of 2?10{sup 10} at 2K.

Geng, Rongli [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Clemens, William A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Follkie, James E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Harris, Teena M. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Kushnick, Peter W. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Machie, Danny [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Martin, Robert E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Palczewski, Ari D. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Perry, Era A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Slack, Gary L. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Williams, R. S. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Adolphsen, C. [SLAC, Menlo Park, California, (United States); Li, Z. [SLAC, Menlo Park, California, (United States); Hao, J. K. [Peking University, Beijing (China); Li, Y. M. [Peking University, Beijing (China); Liu, K. X. [Peking University, Beijing (China)

2013-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "radio frequency electromagnetic" from the National Library of EnergyBeta (NLEBeta).
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121

In-Born Radio Frequency Identification Devices for Safeguards Use at Gas-Centrifuge Enrichment Plants  

Science Conference Proceedings (OSTI)

Global expansion of nuclear power has made the need for improved safeguards measures at Gas Centrifuge Enrichment Plants (GCEPs) imperative. One technology under consideration for safeguards applications is Radio Frequency Identification Devices (RFIDs). RFIDs have the potential to increase IAEA inspector"s efficiency and effectiveness either by reducing the number of inspection visits necessary or by reducing inspection effort at those visits. This study assesses the use of RFIDs as an integral component of the "Option 4" safeguards approach developed by Bruce Moran, U.S. Nuclear Regulatory Commission (NRC), for a model GCEP [1]. A previous analysis of RFIDs was conducted by Jae Jo, Brookhaven National Laboratory (BNL), which evaluated the effectiveness of an RFID tag applied by the facility operator [2]. This paper presents a similar evaluation carried out in the framework of Jo’s paper, but it is predicated on the assumption that the RFID tag is applied by the manufacturer at the birth of the cylinder, rather than by the operator. Relevant diversion scenarios are examined to determine if RFIDs increase the effectiveness and/ or efficiency of safeguards in these scenarios. Conclusions on the benefits offered to inspectors by using in-born RFID tagging are presented.

Ward,R.; Rosenthal,M.

2009-07-12T23:59:59.000Z

122

Radio frequency pulse compression experiments at SLAC (Stanford Linear Accelerator Center)  

Science Conference Proceedings (OSTI)

Proposed future positron-electron linear colliders would be capable of investigating fundamental processes of interest in the 0.5--5 TeV beam-energy range. At the SLAC Linear Collider (SLC) gradient of about 20 MV/m this would imply prohibitive lengths of about 50--250 kilometers per linac. We can reduce the length by increasing the gradient but this implies high peak power, on the order of 400-- to 1000-MW at X-Band. One possible way to generate high peak power is to generate a relatively long pulse at a relatively low power and compress it into a short pulse with higher peak power. It is possible to compress before DC to RF conversion, as is done using magnetic switching for induction linacs, or after DC to RF conversion, as is done for the SLC. Using RF pulse compression it is possible to boost the 50-- to 100-MW output that has already been obtained from high-power X-Band klystrons the levels required by the linear colliders. In this note only radio frequency pulse compression (RFPC) is considered.

Farkas, Z.D.; Lavine, T.L.; Menegat, A.; Miller, R.H.; Nantista, C.; Spalek, G.; Wilson, P.B.

1991-01-01T23:59:59.000Z

123

Method of making radio frequency ion source antenna and such antenna  

DOE Patents (OSTI)

In the method, the radio frequency (rf) antenna is made by providing a clean coil made of copper tubing or other metal conductor, which is coated with a tacky organic binder, and then with a powdered glass frit, as by sprinkling the frit uniformly over the binder. The coil is then heated internally in an inert gas atmosphere, preferably by passing an electrical heating current along the coil. Initially, the coil is internally heated to about 200/sup 0/C to boil off the water from the binder, and then to about 750 to 850/sup 0/C to melt the glass frit, while also burning off the organic binder. The melted frit forms a molten glass coating on the metal coil, which is then cooled to solidify the glass, so that the metal coil is covered with a thin continuous homogeneous impervious glass coating of substantially uniform thickness. The glass coating affords complete electrical insulation and complete dielectric protection for the metal coil of the rf antenna, to withstand voltage breakdown and to prevent sputtering, while also doubling the plasma generating efficiency of the rf antenna, when energized with RF power in the vacuum chamber of an ion source for a particle accelerator or the like. The glass frit preferably contains approximately 45% lead oxide.

Ehlers, K.W.; Leung, K.N.

1985-05-22T23:59:59.000Z

124

RADIO FREQUENCY IDENTIFICATION DEVICES: EFFECTIVENESS IN IMPROVING SAFEGUARDS AT GAS-CENTRIFUGE URANIUM-ENRICHMENT PLANTS.  

SciTech Connect

Recent advances in radio frequency identification devices (RFIDs) have engendered a growing interest among international safeguards experts. Potentially, RFIDs could reduce inspection work, viz. the number of inspections, number of samples, and duration of the visits, and thus improve the efficiency and effectiveness of international safeguards. This study systematically examined the applications of RFIDs for IAEA safeguards at large gas-centrifuge enrichment plants (GCEPs). These analyses are expected to help identify the requirements and desirable properties for RFIDs, to provide insights into which vulnerabilities matter most, and help formulate the required assurance tests. This work, specifically assesses the application of RFIDs for the ''Option 4'' safeguards approach, proposed by Bruce Moran, U. S. Nuclear Regulatory Commission (NRC), for large gas-centrifuge uranium-enrichment plants. The features of ''Option 4'' safeguards include placing RFIDs on all feed, product and tails (F/P/T) cylinders, along with WID readers in all FP/T stations and accountability scales. Other features of Moran's ''Option 4'' are Mailbox declarations, monitoring of load-cell-based weighing systems at the F/P/T stations and accountability scales, and continuous enrichment monitors. Relevant diversion paths were explored to evaluate how RFIDs improve the efficiency and effectiveness of safeguards. Additionally, the analysis addresses the use of RFIDs in conjunction with video monitoring and neutron detectors in a perimeter-monitoring approach to show that RFIDs can help to detect unidentified cylinders.

JOE,J.

2007-07-08T23:59:59.000Z

125

Characterization of nonthermal Ne-N{sub 2} mixture radio frequency discharge  

Science Conference Proceedings (OSTI)

This paper deals with optical emission spectroscopic studies of low pressure (p=0.1{yields}0.5 mbar) Ne-N{sub 2} capacitively coupled radio frequency (rf) plasma that can be used for plasma nitriding, etc. It reports the methods to calculate the electron temperature (T{sub e}) in nonthermal plasmas. Since, the selected Ne I lines, used to calculate electron temperature, are found in corona balance; therefore, it allows us to use modified Boltzmann technique to calculate electron temperature. Langmuir probe is also used to calculate electron temperature and electron energy distribution functions (EEDFs). The measurements are worked out for different discharge parameters like neon percentage, filling pressure and RF power. It is found that electron temperature increases with the increase in neon percentage and decreases with the increase in pressure, whereas excitation temperature (T{sub exc}) increases with power, neon percentage, and decreases with pressure. It is also observed that electron temperature measured by Langmuir probe technique is slightly greater than the one measured via modified Boltzmann plot method. The tails of the EEDFs gain height and extend toward the higher energy with the increase in neon percentage in the mixture.

Rehman, N. U.; Zakaullah, M. [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Khan, F. U. [Department of Physics, Gomal University, 29050 D.I. Khan (Pakistan); Naseer, S. [Department of Physics, Peshawar University, 25120 Peshawar (Pakistan)

2008-12-15T23:59:59.000Z

126

Influence of the power on the particles generated in a low pressure radio frequency nitrogen-rich methane discharge  

SciTech Connect

Particles are generated in low pressure radio frequency (13.56 MHz) CH{sub 4}/N{sub 2} discharges containing 90% of nitrogen. The influence of the radio frequency power supply on the particle presence within the plasma is studied. Particles are evidenced by laser light scattering. The particle formation leads to modifications in the discharge electrical parameters such as the dc self-bias voltage and the phase angle third harmonic. The plasma is analyzed by optical emission spectroscopy by following the temporal evolution of excited species such as CN, N{sub 2}, N{sub 2}{sup +}, Ar, and He. Finally, the particle morphology and size are analyzed by scanning electron microscopy. The correlation between these results allows a better understanding of the power influence on the particle growth within the plasma.

Massereau-Guilbaud, Veronique; Pereira, Jeremy; Geraud-Grenier, Isabelle; Plain, Andre [GREMI, Groupe de Recherches sur l'Energetique des Milieux Ionises, UMR6606, CNRS/Universite d' Orleans, Site de Bourges, Rue G. Berger, BP 4043, 18028 Bourges Cedex (France)

2009-02-01T23:59:59.000Z

127

Throughput and delay analysis for hybrid radio-frequency and free-space-optical (RF/FSO) networks  

Science Conference Proceedings (OSTI)

In this paper the per-node throughput and end-to-end delay of randomly deployed (i.e. ad-hoc) hybrid radio frequency - free space optics (RF/FSO) networks are studied. The hybrid RF/FSO network consists of an RF ad hoc network of n nodes, f(n) ... Keywords: Ad hoc networks, Delay, Free space optics, Hybrid networks, Throughput capacity

Di Wang; Alhussein A. Abouzeid

2011-05-01T23:59:59.000Z

128

Review of High Frequency Conducted Susceptibility Limits for Electromagnetic Compatibility Testing  

Science Conference Proceedings (OSTI)

To continue meeting safety and reliability requirements while controlling costs, operators of nuclear power plants must be able to replace and upgrade equipment in a cost-effective manner. One issue that has been problematic for new plant equipment and especially for digital instrumentation and control (I&C) systems in recent years is electromagnetic compatibility (EMC). The EMC issue usually involves testing to show that critical equipment will not be adversely affected by electromagnetic interference (...

2007-12-14T23:59:59.000Z

129

H{sup -} radio frequency source development at the Spallation Neutron Source  

Science Conference Proceedings (OSTI)

The Spallation Neutron Source (SNS) now routinely operates nearly 1 MW of beam power on target with a highly persistent {approx}38 mA peak current in the linac and an availability of {approx}90%. H{sup -} beam pulses ({approx}1 ms, 60 Hz) are produced by a Cs-enhanced, multicusp ion source closely coupled with an electrostatic low energy beam transport (LEBT), which focuses the 65 kV beam into a radio frequency quadrupole accelerator. The source plasma is generated by RF excitation (2 MHz, {approx}60 kW) of a copper antenna that has been encased with a thickness of {approx}0.7 mm of porcelain enamel and immersed into the plasma chamber. The ion source and LEBT normally have a combined availability of {approx}99%. Recent increases in duty-factor and RF power have made antenna failures a leading cause of downtime. This report first identifies the physical mechanism of antenna failure from a statistical inspection of {approx}75 antennas which ran at the SNS, scanning electron microscopy studies of antenna surface, and cross sectional cuts and analysis of calorimetric heating measurements. Failure mitigation efforts are then described which include modifying the antenna geometry and our acceptance/installation criteria. Progress and status of the development of the SNS external antenna source, a long-term solution to the internal antenna problem, are then discussed. Currently, this source is capable of delivering comparable beam currents to the baseline source to the SNS and, an earlier version, has briefly demonstrated unanalyzed currents up to {approx}100 mA (1 ms, 60 Hz) on the test stand. In particular, this paper discusses plasma ignition (dc and RF plasma guns), antenna reliability, magnet overheating, and insufficient beam persistence.

Welton, R. F.; Gawne, K. R.; Han, B. X.; Murray, S. N.; Pennisi, T. R.; Roseberry, R. T.; Santana, M.; Stockli, M. P. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471 (United States); Dudnikov, V. G. [Muons, Inc., 552 N. Batavia Avenue, Batavia, Illinois 60510 (United States); Turvey, M. W. [Villanova University, 800E. Lancaster Ave, Villanova, Pennsylvania 19085 (United States)

2012-02-15T23:59:59.000Z

130

H{sup -} beam extraction from a cesium seeded field effect transistor based radio frequency negative hydrogen ion source  

SciTech Connect

H{sup -} beam was successfully extracted from a cesium seeded ion source operated using a field effect transistor inverter power supply as a radio frequency (RF) wave source. High density hydrogen plasma more than 10{sup 19} m{sup -3} was obtained using an external type antenna with RF frequency of lower than 0.5 MHz. The source was isolated by an isolation transformer and H{sup -} ion beam was extracted from a single aperture. Acceleration current and extraction current increased with the increase of extraction voltage. Addition of a small amount of cesium vapor into the source enhanced the currents.

Ando, A.; Matsuno, T.; Funaoi, T.; Tanaka, N. [School of Engineering, Tohoku University, Sendai 980-8579 (Japan); Tsumori, K.; Takeiri, Y. [National Institute for Fusion Science, Toki 509-5292 (Japan)

2012-02-15T23:59:59.000Z

131

Tailoring electron energy distribution functions through energy confinement in dual radio-frequency driven atmospheric pressure plasmas  

SciTech Connect

A multi-scale numerical model based on hydrodynamic equations with semi-kinetic treatment of electrons is used to investigate the influence of dual frequency excitation on the effective electron energy distribution function (EEDF) in a radio-frequency driven atmospheric pressure plasma. It is found that variations of power density, voltage ratio, and phase relationship provide separate control over the electron density and the mean electron energy. This is exploited to directly influence both the phase dependent and time averaged effective EEDF. This enables tailoring the EEDF for enhanced control of non-equilibrium plasma chemical kinetics at ambient pressure and temperature.

O'Neill, C.; Waskoenig, J. [Centre for Plasma Physics, School of Maths and Physics, Queen's University Belfast, Belfast BT7 1NN (United Kingdom); Gans, T. [Centre for Plasma Physics, School of Maths and Physics, Queen's University Belfast, Belfast BT7 1NN (United Kingdom); York Plasma Institute, Department of Physics, University of York, York YO10 5DD (United Kingdom)

2012-10-08T23:59:59.000Z

132

Faraday Acceleration with Radio-frequency Assisted Discharge Edgar Y. Choueiri and Kurt A. Polzin  

E-Print Network (OSTI)

, CA, July 10-12, 1989. AIAA 89-2266. 18 T.E. Markusic. Current sheet canting in pulsed electromagnetic accelerators. PhD thesis, Dept. of Mechanical and 27 #12;CHOUEIRI AND POLZIN FARAD Concept Aerospace

Choueiri, Edgar

133

Slow Radio-Frequency Processing of Large Oil Shale Volumes to Produce Petroleum-Like Shale Oil  

Science Conference Proceedings (OSTI)

A process is proposed to convert oil shale by radio frequency heating over a period of months to years to create a product similar to natural petroleum. Electrodes would be placed in drill holes, either vertical or horizontal, and a radio frequency chosen so that the penetration depth of the radio waves is of the order of tens to hundreds of meters. A combination of excess volume production and overburden compaction drives the oil and gas from the shale into the drill holes, where it is pumped to the surface. Electrical energy for the process could be provided initially by excess regional capacity, especially off-peak power, which would generate {approx}3 x 10{sup 5} bbl/day of synthetic crude oil, depending on shale grade. The electricity cost, using conservative efficiency assumptions, is $4.70 to $6.30/bbl, depending on grade and heating rate. At steady state, co-produced gas can generate more than half the electric power needed for the process, with the fraction depending on oil shale grade. This would increase production to 7.3 x 10{sup 5} bbl/day for 104 l/Mg shale and 1.6 x 10{sup 6} bbl/day for 146 l/Mg shale using a combination of off-peak power and power from co-produced gas.

Burnham, A K

2003-08-20T23:59:59.000Z

134

Harmonic filters influences regarding the power quality on high frequency electrothermal installation with electromagnetic induction  

Science Conference Proceedings (OSTI)

This paper presents a study regarding the functioning of a melting/hardening electrothermal installation with electromagnetic induction from the point of view of generated harmonics in the power distribution. The authors made simulations in scope of ... Keywords: electrothermal installation, harmonic, passive filters, static converter

Raluca Rob; Ioan Sora; Caius Panoiu; Manuela Panoiu

2010-01-01T23:59:59.000Z

135

Coupled Deconvolution for Frequency Extrapolation of Electromagnetic Solutions with Matrix Pencil Method  

E-Print Network (OSTI)

of electromagnetic solutions," 2005 IEEE AP-S International Symposium, Washington, DC, July 2005. [2] Alan V extrapolation results to achieve a lower error level. We first define two window functions in the solution in the interval (fL, fmax). Fig. 1 shows two Chebyshev windows that are constructed in this manner. Forward MPM

Gürel, Levent

136

Medical Devices: Electromagnetic Interference Status and the Role of Standards  

Science Conference Proceedings (OSTI)

This technical update discusses the role of voluntary and regulatory standards in determining the risks of interference from electric and magnetic fields (EMF) with the functioning of implantable and wearable medical devices. The update covers frequencies from the extremely low frequency (ELF) range through the radio-frequency (RF) range. It augments a 2008 EPRI technical update on electromagnetic interference (EMI) with newer types of implanted medical devices (1016815) and previous EPRI publications th...

2009-12-22T23:59:59.000Z

137

Through-Barrier Electromagnetic Communication and Sensing: Advances in  

NLE Websites -- All DOE Office Websites (Extended Search)

Through-Barrier Electromagnetic Communication and Sensing: Advances in Through-Barrier Electromagnetic Communication and Sensing: Advances in Wideband Radio-Wave Communications and ..... Speaker(s): Farid Dowla Date: June 1, 2007 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Mary Ann Piette (Complete seminar title is: Through-Barrier Electromagnetic Communication and Sensing: Advances in Wideband Radio-Wave Communications and Radar Imaging, Radio-Frequency (RF) Tags and Tera-Hertz (THz) Standoff Detection Spectroscopy) In many remote sensing problems there is a critical need to detect and image objects through barriers, such as buildings, with high reliability and resolution and at long ranges. A related problem is the wireless communication and geolocation of transceivers in harsh RF environments, such as in urban areas and underground caves, where

138

Radio frequency dc-dc converters : device characterization, topology evaluation, and design  

E-Print Network (OSTI)

High frequency power conversion is attractive for the opportunities it affords for improved performance. Dc-dc converters operating at high frequencies use smaller-valued energy storage elements, which tend to be physically ...

Leitermann, Olivia

2008-01-01T23:59:59.000Z

139

Radio-frequency measurements of UNiX compounds (X= Al, Ga, Ge) in high magnetic fields  

SciTech Connect

We performed radio-frequency (RF) skin-depth measurements of antiferromagnetic UNiX compounds (X=Al, Ga, Ge) in magnetic fields up to 60 T and at temperatures between 1.4 to {approx}60 K. Magnetic fields are applied along different crystallographic directions and RF penetration-depth was measured using a tunnel-diode oscillator (TDO) circuit. The sample is coupled to the inductive element of a TDO resonant tank circuit, and the shift in the resonant frequency {Delta}f of the circuit is measured. The UNiX compounds exhibit field-induced magnetic transitions at low temperatures, and those transitions are accompanied by a drastic change in {Delta}f. The results of our skin-depth measurements were compared with previously published B-T phase diagrams for these three compounds.

Mielke, Charles H [Los Alamos National Laboratory; Mcdonald, David R [Los Alamos National Laboratory; Zapf, Vivien [Los Alamos National Laboratory; Altarawneh, Moaz M [Los Alamos National Laboratory; Lacerda, Alex H [Los Alamos National Laboratory; Adak, Sourav [Los Alamos National Laboratory; Karunakar, Kothapalli [Los Alamos National Laboratory; Nakotte, Heinrich [Los Alamos National Laboratory; Chang, S [NIST; Alsmadi, A M [HASHEMITE UNIV; Alyones, S [HASHEMIT UNIV

2009-01-01T23:59:59.000Z

140

Low frequency electrostatic and electromagnetic modes of ultracold magnetized nonuniform dense plasmas  

SciTech Connect

A coupled linear dispersion relation for the basic electrostatic and electromagnetic waves in the ultracold nonuniform magnetized dense plasmas has been obtained which interestingly is analogous to the classical case. The scales of macroscopic phenomena and the interparticle quantum interactions are discussed. It is important to point out that hydrodynamic models cannot take into account strong quantum effects and they are not applicable to very dense plasmas. The analysis is presented with applications to dense plasmas which are relevant to both laboratory and astrophysical environments.

Saleem, H. [National Centre for Physics (NCP), Quaid-i-Azam University Campus, Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Ahmad, Ali [Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Theoretical Plasma Physics Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), Islamabad (Pakistan); Khan, S. A. [National Centre for Physics (NCP), Quaid-i-Azam University Campus, Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Department of Physics, Government College Bagh AJK (Pakistan)

2008-09-15T23:59:59.000Z

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

The magnetic field along the jets of NGC 4258 as deduced from high frequency radio observations  

E-Print Network (OSTI)

We present 2.4" resolution, high sensitivity radio continuum observations of the nearby spiral galaxy NGC 4258 in total intensity and linear polarization obtained with the Very Large Array at 3.6 cm (8.44 GHz). The radio emission along the northern jet and the center of the galaxy is polarized and allows investigation of the magnetic field. Assuming energy-equipartition between the magnetic field and the relativistic particles and distinguishing between (1) a relativistic electron-proton jet and (2) a relativistic electron-positron jet, we obtain average magnetic field strengths of about (1) 310\\muG and (2) 90\\muG. The rotation measure is determined to range from -400 to -800 rad/m^2 in the northern jet. Correcting the observed E-vectors of polarized intensity for Faraday rotation, the magnetic field along the jet turns out to be orientated mainly along the jet axis. An observed tilt with respect to the jet axis may indicate also a toroidal magnetic field component or a slightly helical magnetic field around the northern jet.

M. Krause; A. L"ohr

2004-03-05T23:59:59.000Z

142

Utilization of electromagnetic detector for selection and detection of high-frequency relic gravitational waves  

E-Print Network (OSTI)

It is shown that coupling system between fractal membranes and a Gaussian beam passing through a static magnetic field has strong selection capability for the stochastic relic gravitational wave background. The relic GW components propagating along the positive direction of the symmetrical axis of the Gaussian beam might generate an optimal electromagnetic perturbation while the perturbation produced by the relic GW components propagating along the negative and perpendicular directions to the symmetrical axis will be much less than the former.The influence of the random fluctuation of the relic GWs to such effect can be neglected and the influence of the random fluctuation of the relic GWs to such effect can be neglected.

Fangyu Li; Zhenya Chen; Ying Yi

2005-11-03T23:59:59.000Z

143

Lossless multi-way power combining and outphasing for radio frequency power amplifiers  

E-Print Network (OSTI)

For applications requiring the use of power amplifiers (PAs) operating at high frequencies and power levels, it is often preferable to construct multiple low power PAs and combine their output powers to form a high-power ...

Jurkov, Alexander S

2013-01-01T23:59:59.000Z

144

Probing the Climatological Impact of a Cosmic Ray-Cloud Connection through Low-Frequency Radio Observations  

E-Print Network (OSTI)

It has been proposed that cosmic ray events could have a causal relationship with cloud formation rates. Given the weak constraints on the role that cloud formation plays in climate forcing it is essential to understand the role such a relationship could have in shaping the Earth's climate. This issue has been previously investigated in the context of the long-term effect of cosmic ray events on climate. However, in order to establish whether or not such a relationship exists, measurements of short-timescale solar events, individual cosmic ray events, and spatially correlated cloud parameters could be of great significance. Here we propose such a comparison using observations from a pair of radio telescopes arrays, the Long Wavelength Array (LWA) and the Eight-meter-wavelength Transient Array (ETA). These low-frequency radio arrays have a unique ability to simultaneously conduct solar, ionospheric and cosmic rays observations and are thus ideal for such a comparison. We will outline plans for a comparison usi...

Magee, Nathan

2011-01-01T23:59:59.000Z

145

CRC handbook of biological effects of electromagnetic fields  

Science Conference Proceedings (OSTI)

This book presents the current knowledge about the effects of electromagnetic fields on living matter. The three-part format covers dielectric permittivity and electrical conductivity of biological materials; effects of direct current and low frequency fields; and effects of radio frequency (including microwave) fields. The parts are designed to be consulted independently or in sequence, depending upon the needs of the reader. Useful appendixes on measurement units and safety standards are also included.

Polk, C.; Postow, E.

1986-01-01T23:59:59.000Z

146

CRC handbook of biological effects of electromagnetic fields  

Science Conference Proceedings (OSTI)

This book presents current knowledge about the effects of electromagnetic fields on living matter. The three-part format covers: dielectric permittivity and electrical conductivity of biological materials; effects of direct current and low frequency fields; and effects of radio frequency (including microwave) fields. The parts are designed to be consulted independently or in sequence, depending upon the needs of the reader. Useful appendixes on measurement units and safety standards are also included.

Polk, C. (Rhode Island Univ., Kingston, RI (United States). Dept. of Electrical Engineering); Postow, E. (National Naval Medical Center, Bethesda, MD (United States))

1986-01-01T23:59:59.000Z

147

Energetic electron avalanches and mode transitions in planar inductively coupled radio-frequency driven plasmas operated in oxygen  

Science Conference Proceedings (OSTI)

Space and phase resolved optical emission spectroscopic measurements reveal that in certain parameter regimes, inductively coupled radio-frequency driven plasmas exhibit three distinct operation modes. At low powers, the plasma operates as an alpha-mode capacitively coupled plasma driven through the dynamics of the plasma boundary sheath potential in front of the antenna. At high powers, the plasma operates in inductive mode sustained through induced electric fields due to the time varying currents and associated magnetic fields from the antenna. At intermediate powers, close to the often observed capacitive to inductive (E-H) transition regime, energetic electron avalanches are identified to play a significant role in plasma sustainment, similar to gamma-mode capacitively coupled plasmas. These energetic electrons traverse the whole plasma gap, potentially influencing plasma surface interactions as exploited in technological applications.

Zaka-ul-Islam, M.; Niemi, K. [Centre for Plasma Physics, School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN, Northern Ireland (United Kingdom); Gans, T.; O'Connell, D. [Centre for Plasma Physics, School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN, Northern Ireland (United Kingdom); York Plasma Institute, Department of Physics, University of York, Innovation Way, Heslington York YO10 5DQ (United Kingdom)

2011-07-25T23:59:59.000Z

148

Experimental measurements in a radio frequency discharge heated supersonic flow: Evaluation of a potential electric propulsion thruster  

DOE Green Energy (OSTI)

An operational radio frequency discharge-driven supersonic flow system, which utilizes an inductively and capacitively coupled plasma (ICCP) tube to produce high enthalpy source gas, is described. The ICCP coupled to a properly designed nozzle represents a potential electric propulsion device. The high gas temperatures achieved in the plasma discharge (> 5000 K) and the electrodeless nature of the tube's operation offers potentially high thruster performance coupled and long operational lifetime. A preliminary characterization of the current system was established using emission and probe-based measurements. A nominal peak specific impulse of 155 s was estimated for operation with argon. The calculated thrust based upon the peak velocity and mass flow through the device is 1.1 N. 14 refs., 10 figs.

Wantuck, P.J.; Hull, D.E.

1991-01-01T23:59:59.000Z

149

Reduced leakage in epitaxial BiFeO{sub 3} films following oxygen radio frequency plasma treatment  

SciTech Connect

Epitaxial BiFeO{sub 3} (BFO) films were deposited using pulsed laser deposition method. The prepared films were characterized using x-ray diffraction, x-ray reflectivity, ferroelectric loop tracer, and leakage current measurements before and after oxygen plasma treatment. The leakage current of the films, a crucial parameter in device applications, is observed to be reduced by two orders of magnitude with oxygen plasma treatment at room temperature. P-E hysteresis loops were observed in oxygen plasma treated BFO films. The observed results indicate the usefulness of oxygen radio frequency plasma treatment (RF 13.56 MHz), which is an effective and low temperature processing technique, in such lossy ferroelectric thin films.

Kothari, Deepti [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India) [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India); UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452 017 (India); Upadhyay, Sanjay K.; Raghavendra Reddy, V. [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452 017 (India)] [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452 017 (India); Jariwala, C.; Raole, P. M. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)] [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

2013-06-07T23:59:59.000Z

150

Implementation of a Dual Containment/Surveillance System utilizing scene-change detection and radio frequency technology  

SciTech Connect

This paper will examine the implementation of scene-change detection and radio frequency technology within a Dual Containment/Surveillance (C/S) System. Additionally, this paper will examine the human performance factors in the operation of these systems. Currently, Westinghouse Savannah River Company utilizes the Continuous Item Monitoring and Surveillance System (CIMS) in the performance of Dual C/S to monitor special nuclear materials within International Atomic Energy Agency (IAEA) Safeguards and Domestic Safeguards. CIMS is comprised of the Material Monitoring System (MMS) (R), a multi-media electronic surveillance system developed by Sandia National Laboratory which incorporates the use of active seals commonly called Radio Frequency Tamper Indicating Devices (RFTIDs), NT Vision (R) as developed by Los Alamos National Laboratory, a Microsoft Windows NT (R) based operating system providing for domestic scene-change detection and the Digital Multi-Camera Optical Surveillance System (DMOS) (R) which provides scene-change detection for IAEA. Although this paper will focus on the implementation of Dual C/S utilizing the Continuous Item Monitoring and Surveillance System, the necessity for a thorough review of Safeguards and Security requirements with organizations and personnel having minimal to no prior MPC&A training will also be covered. Successful Dual C/S implementation plans must consider not only system design and failure modes, but must also be accompanied with the appropriate ''mind shift'' within operations and technical personnel. This is required to ensure completion of both physical and electronic activities, and system design changes are performed conscientiously and with full awareness of MPC&A requirements.

FITZGERALD, ERIC; KOENIG, RICHARD

2005-06-27T23:59:59.000Z

151

Efficient Inversion of Multi-frequency and Multi-source Electromagnetic Data: Final report  

Science Conference Proceedings (OSTI)

BES grant DE-FG02-06ER15819 supported efforts at Oregon State University (OSU) to develop improved inversion methods for 3D subsurface electromagnetic (EM) imaging. Three interrelated activities have been supported by this grant, and its predecessor (DE-FG02-06ER15818): (1) collaboration with a former student of the PI, Dr. Weerachai Siripunvaraporn (now Professor at Mahidol University in Bangkok, Thailand) on developing and refining inversion methods for 3D Magnetotelluric (MT) data . (2) Development at Oregon State University of a new modular system of computer codes for EM inversion, and initial testing and application of this inversion on several large field data sets. (3) Research on more efficient approaches to multi-transmitter EM inverse problems, to optimize use of expensive data sensitivity calculations needed for gradient based inversion schemes. The last of these activities was the main motivation for this research project, but the first two activities were important enabling steps that produced useful products and results in their own right, including freely avaialable software for 3D inversion of EM geophysical data.

Gary D. Egbert

2013-04-10T23:59:59.000Z

152

CMOS injection locked oscillators for quadrature generation at radio-frequency  

Science Conference Proceedings (OSTI)

The design of quadrature local oscillators for CMOS wireless transceivers is still one of the most challenging issues. This paper focuses the advantages of injection locking techniques to achieve high-performance quadrature generators. A synchronizing ... Keywords: CMOS RF integrated circuits, Frequency dividers, Injection locking, Phase noise, Quadrature local oscillators, VCO

Andrea Mazzanti; Francesco Svelto

2006-11-01T23:59:59.000Z

153

Method and apparatus for powering an electrodeless lamp with reduced radio frequency interference  

DOE Patents (OSTI)

An electrodeless lamp waveguide structure includes tuned absorbers for spurious RF signals. A lamp waveguide with an integral frequency selective attenuation includes resonant absorbers positioned within the waveguide to absorb spurious out-of-band RF energy. The absorbers have a negligible effect on energy at the selected frequency used to excite plasma in the lamp. In a first embodiment, one or more thin slabs of lossy magnetic material are affixed to the sidewalls of the waveguide at approximately one quarter wavelength of the spurious signal from an end wall of the waveguide. The positioning of the lossy material optimizes absorption of power from the spurious signal. In a second embodiment, one or more thin slabs of lossy magnetic material are used in conjunction with band rejection waveguide filter elements. In a third embodiment, one or more microstrip filter elements are tuned to the frequency of the spurious signal and positioned within the waveguide to couple and absorb the spurious signal's energy. All three embodiments absorb negligible energy at the selected frequency and so do not significantly diminish the energy efficiency of the lamp.

Simpson, James E. (Gaithersburg, MD)

1999-01-01T23:59:59.000Z

154

Method and apparatus for powering an electrodeless lamp with reduced radio frequency interference  

DOE Patents (OSTI)

An electrodeless lamp waveguide structure includes tuned absorbers for spurious RF signals. A lamp waveguide with an integral frequency selective attenuation includes resonant absorbers positioned within the waveguide to absorb spurious out-of-band RF energy. The absorbers have a negligible effect on energy at the selected frequency used to excite plasma in the lamp. In a first embodiment, one or more thin slabs of lossy magnetic material are affixed to the sidewalls of the waveguide at approximately one quarter wavelength of the spurious signal from an end wall of the waveguide. The positioning of the lossy material optimizes absorption of power from the spurious signal. In a second embodiment, one or more thin slabs of lossy magnetic material are used in conjunction with band rejection waveguide filter elements. In a third embodiment, one or more microstrip filter elements are tuned to the frequency of the spurious signal and positioned within the waveguide to couple and absorb the spurious signal's energy. All three embodiments absorb negligible energy at the selected frequency and so do not significantly diminish the energy efficiency of the lamp. 18 figs.

Simpson, J.E.

1999-06-08T23:59:59.000Z

155

PARMTEQ (Phase And Radial Motion in Transverse Electric Quadrupole linacs): A beam dynamics code for the RFQ (radio-frequency quadrupole)  

SciTech Connect

The PARMTEQ code is used for generating the complete cell design of a radio-frequency quadrupole linear accelerator and for multiparticle simulation of the beam dynamics. We present a review of the code, with an emphasis on the physics used to describe the particle motion and the cell generation. 9 refs., 1 fig.

Crandall, K.R.; Wangler, T.P.

1987-01-01T23:59:59.000Z

156

Demonstration (DEMO) of Radio Frequency Identification (RFID) system for tracking and monitoring of nuclear materials.  

Science Conference Proceedings (OSTI)

The US Department of Energy (DOE) [Environmental Management (EM), Office of Packaging and Transportation (EM-45)] Packaging Certification Program (PCP) has developed a radiofrequency identification (RFID) tracking and monitoring system for the management of nuclear materials packages during storage and transportation. The system, developed by the PCP team at Argonne National Laboratory, involves hardware modification, application software development, secured database and web server development, and irradiation experiments. In April 2008, Argonne tested key features of the RFID tracking and monitoring system in a weeklong, 1700 mile (2736 km) demonstration employing 14 empty type B fissile material drums of three designs (models 9975, 9977 and ES-3100) that have been certified for shipment by the DOE and the US Nuclear Regulatory Commission. The demonstration successfully integrated global positioning system (GPS) technology for vehicle tracking, satellite/cellular (general packet radio service, or GPRS) technologies for wireless communication, and active RFID tags with multiple sensors (seal integrity, shock, temperature, humidity and battery status) on drums. In addition, the demonstration integrated geographic information system (GIS) technology with automatic alarm notifications of incidents and generated buffer zone reports for emergency response and management of staged incidents. The demonstration was sponsored by EM and the US National Nuclear Security Administration, with the participation of Argonne, Savannah River and Oak Ridge National Laboratories. Over 50 authorised stakeholders across the country observed the demonstration via secured Internet access. The DOE PCP and national laboratories are working on several RFID system implementation projects at selected DOE sites, as well as continuing device and systems development and widening applications beyond DOE sites and possibly beyond nuclear materials to include other radioactive materials.

Tsai, H. C.; Chen, K.; Liu, Y. Y.; Shuler, J. (Decision and Information Sciences); (USDOE)

2010-01-01T23:59:59.000Z

157

Dust removal in radio-frequency plasmas by a traveling potential modulation  

Science Conference Proceedings (OSTI)

The dust contamination in plasma deposition processes plays a crucial role in the quality and the yield of the products. To improve the quality and the yield of plasma processing, a favorable way is to remove the dust particles actively from the plasma reactors.Our recent experiments in the striped electrode device show that a traveling plasma modulation allows for a systematic particle removal independent of the reactor size. Besides the rf powered electrode, the striped electrode device includes a segmented electrode that consists of 100 electrically insulated narrow stripes. A traveling potential profile is produced by the modulation of the voltage signals applied on the stripes. The dust particles are trapped in the potential wells and transported with the traveling of the potential profile.The particle-in-cell (PIC) simulation on the potential above the segmented electrode indicates that the traveling potential profile can be realized either by applying low-frequency (0.1-10 Hz) voltage signals with a fixed phase shift between adjacent stripes or high-frequency (10 kHz a circumflex AS 100 MHz) signals with the amplitudes modulated by a low-frequency envelope. The transportation of the dust particles is simulated with a two-dimensional molecular dynamics (MD) code with the potential profile obtained from the PIC simulation. The MD results reproduce the experimental observations successfully.This technology allows for an active removal of the contaminating particles in processing plasmas and it is independent of the reactor size. The removal velocity is controllable by adjusting the parameters for the modulation.

Li Yangfang; Jiang Ke; Thomas, Hubertus M.; Morfill, Gregor E. [Max-Planck-Institute for Extraterrestrial Physics, 85748 Garching (Germany)

2010-06-16T23:59:59.000Z

158

Radio frequency plasma heating in large tokamak systems near the lower hybrid resonance  

SciTech Connect

The frequency range, power, efficiency, and pulse length of a high power rf system are discussed as they might be applied to the TFTR Tokamak facility as well as on a full scale reactor. Comparisons are made of the size, power output, and costs to obtain microwave power sufficient to satisfy the physics requirements. A new microwave feed concept is discussed which will improve the coupling of the microwave energy into the plasma. The unique advantages of waveguide feed systems is apparent when one considers the practical problems associated with coupling supplementary heating energy into a reactor. (auth)

Deitz, A.; Hooke, W.M.

1975-01-01T23:59:59.000Z

159

Parallel radio-wave propagation modeling with image-based ray tracing techniques  

Science Conference Proceedings (OSTI)

Ray tracing is a technique based on the numerical simulation of geometrical optics and the uniform theory of diffraction, two well-known approximate methods for estimating a high-frequency electromagnetic field, based on the ray theory of field propagation. ... Keywords: Load balancing, Message passing interface, Performance evaluation, Radio-wave propagation, Ray tracing, Wireless communications

T. E. Athanaileas; G. E. Athanasiadou; G. V. Tsoulos; D. I. Kaklamani

2010-12-01T23:59:59.000Z

160

Experiment for transient effects of sudden catastrophic loss of vacuum on a scaled superconducting radio frequency cryomodule  

SciTech Connect

Safe operation of superconducting radio frequency (SRF) cavities require design consideration of a sudden catastrophic loss of vacuum (SCLV) adjacent with liquid helium (LHe) vessels and subsequent dangers. An experiment is discussed to test the longitudinal effects of SCLV along the beam line of a string of scaled SRF cavities. Each scaled cavity includes one segment of beam tube within a LHe vessel containing 2 K saturated LHe, and a riser pipe connecting the LHe vessel to a common gas header. At the beam tube inlet is a fast acting solenoid valve to simulate SCLV and a high/low range orifice plate flow-meter to measure air influx to the cavity. The gas header exit also has an orifice plate flow-meter to measure helium venting the system at the relief pressure of 0.4 MPa. Each cavity is instrumented with Validyne pressure transducers and Cernox thermometers. The purpose of this experiment is to quantify the time required to spoil the beam vacuum and the effects of transient heat and mass transfer on the helium system. Heat transfer data is expected to reveal a longitudinal effect due to the geometry of the experiment. Details of the experimental design criteria and objectives are presented.

Dalesandro, A.; Theilacker, J.; /Fermilab; Van Sciver, S.W.; /Natl. High Mag. Field Lab.

2011-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

Radio-frequency integrated-circuit design for CMOS single-chip UWB systems  

E-Print Network (OSTI)

Low cost, a high-integrated capability, and low-power consumption are the basic requirements for ultra wide band (UWB) system design in order for the system to be adopted in various commercial electronic devices in the near future. Thus, the highly integrated transceiver is trended to be manufactured by companies using the latest silicon based complimentary metal-oxide-silicon (CMOS) processes. In this dissertation, several new structural designs are proposed, which provide solutions for some crucial RF blocks in CMOS for UWB for commercial applications. In this dissertation, there is a discussion of the development, as well as an illustration, of a fully-integrated ultra-broadband transmit/receive (T/R) switch which uses nMOS transistors with deep n-well in a standard 0.18-?m CMOS process. The new CMOS T/R switch exploits patterned-ground-shield on-chip inductors together with MOSFET’s parasitic capacitances in order to synthesize artificial transmission lines which result in low insertion loss over an extremely wide bandwidth. Within DC-10 GHz, 10-18 GHz, and 18-20 GHz, the developed CMOS T/R switch exhibits insertion loss of less than 0.7, 1.0 and 2.5 dB and isolation between 32-60 dB, 25-32 dB, and 25-27 dB, respectively. The measured 1-dB power compression point and input third-order intercept point reach as high as 26.2 and 41 dBm, respectively. Further, there is a discussion and demonstration of a tunable Carrier-based Time-gated UWB transmitter in this dissertation which uses a broadband multiplier, a novel fully integrated single pole single throw (SPST) switch designed by the CMOS process, where a tunable instantaneous bandwidth from 500 MHz to 4 GHz is exhibited by adjusting the width of the base band impulses in time domain. The SPST switch utilizes the synthetic transmission line concept and multiple reflections technique in order to realize a flat insertion loss less than 1.5 dB from 3.1 GHz to 10.6 GHz and an extremely high isolation of more than 45 dB within this frequency range. A fully integrated complementary LC voltage control oscillator (VCO), designed with a tunable buffer, operates from 4.6 GHz to 5.9 GHz. The measurement results demonstrate that the integrated VCO has a very low phase noise of –117 dBc/ Hz at 1 MHz offset. The fully integrated VCO achieves a very high figure of merit (FOM) of 183.5 using standard CMOS process while consuming 4 mA DC current.

Jin, Yalin

2008-05-01T23:59:59.000Z

162

Electromagnetic Interference with Implanted Medical Devices: An Update  

Science Conference Proceedings (OSTI)

Electric and magnetic fields (EMF) and contact currents at both power and radio frequencies can interfere with the functioning of implanted medical electronic devices. In both public and occupational environments, electromagnetic interference issues are now exacerbated by the exponential increase in sources of interference over the last decade, an increasing variety of types of susceptible devices, and greater potential for unintended consequences that can be serious. This technical update discusses pote...

2008-09-18T23:59:59.000Z

163

Radio frequency phototube  

SciTech Connect

A method and apparatus of obtaining a record of repetitive optical or other phenomena having durations in the picosecond range, comprising a circular scan electron tube to receive light pulses and convert them to electron images consisting with fast nanosecond electronic signals, a continuous wave light or other particle pulses, e.g. electron picosecond pulses, and a synchronizing mechanism arranged to synchronize the deflection of the electron image (images) in the tube (tubes) with the repetition rate of the incident pulse train. There is also provided a method and apparatus for digitization of a repetitive and random optical waveform with a bandwidth higher than 10 GHz.

Margaryan, Amur (Yerevan, AM); Gynashyan, Karlen (Yerevan, AM); Hashimoto, Osamu (Sendai, JP); Majewski, Stanislaw (Morgantown, WV); Tang, Linguang (Yorktown, VA); Marikyan, Gagik (Yerevan, AM); Marikyan, legal representative, Lia (Yerevan, AM)

2012-03-20T23:59:59.000Z

164

Apparatus and method for enhanced chemical processing in high pressure and atmospheric plasmas produced by high frequency electromagnetic waves  

DOE Patents (OSTI)

An apparatus and method for creating high temperature plasmas for enhanced chemical processing of gaseous fluids, toxic chemicals, and the like, at a wide range of pressures, especially at atmospheric and high pressures includes an electro-magnetic resonator cavity, preferably a reentrant cavity, and a wave guiding structure which connects an electro-magnetic source to the cavity. The cavity includes an intake port and an exhaust port, each having apertures in the conductive walls of the cavity sufficient for the intake of the gaseous fluids and for the discharge of the processed gaseous fluids. The apertures are sufficiently small to prevent the leakage of the electro-magnetic radiation from the cavity. Gaseous fluid flowing from the direction of the electro-magnetic source through the guiding wave structure and into the cavity acts on the plasma to push it away from the guiding wave structure and the electro-magnetic source. The gaseous fluid flow confines the high temperature plasma inside the cavity and allows complete chemical processing of the gaseous fluids at a wide range of pressures.

Efthimion, Philip C. (Bedminister, NJ); Helfritch, Dennis J. (Flemington, NJ)

1989-11-28T23:59:59.000Z

165

Cognitive radio: an enabling technology for the green radio communications concept  

Science Conference Proceedings (OSTI)

In this paper, Cognitive Radio (CR) is proposed as an efficient technology to meet the Green communications concept. First of all, the concept of "green communications" is extended to the radio communications world. The main topics, described for example ... Keywords: cognitive radio, consumption, electromagnetic pollution, green communications, health, peak-to-average power ratio (PAPR), radio communications, sustainable development

Jacques Palicot

2009-06-01T23:59:59.000Z

166

Report on a 2009 mini-demonstration of the ARG-US Radio Frequency Identification (RFID) system in transportation.  

SciTech Connect

The Packaging Certification Program (PCP) of the U.S. Department of Energy (DOE) Environmental Management (EM), Office of Packaging and Transportation (EM-14), has developed a radio frequency identification (RFID) tracking and monitoring system for the management of nuclear materials during storage and transportation. The system, developed by the PCP team at Argonne National Laboratory, consists of hardware (Mk-series sensor tags, fixed and handheld readers, form factor for multiple drum types, seal integrity sensors, and enhanced battery management), software (application programming interface, ARG-US software for local and remote/web applications, secure server and database management), and cellular/satellite communication interfaces for vehicle tracking and item monitoring during transport. The ability of the above system to provide accurate, real-time tracking and monitoring of the status of multiple, certified containers of nuclear materials has been successfully demonstrated in a week-long, 1,700-mile DEMO performed in April 2008. While the feedback from the approximately fifty (50) stakeholders who participated in and/or observed the DEMO progression were very positive and encouraging, two major areas of further improvements - system integration and web application enhancement - were identified in the post-DEMO evaluation. The principal purpose of the MiniDemo described in this report was to verify these two specific improvements. The MiniDemo was conducted on August 28, 2009. In terms of system integration, a hybrid communication interface - combining the RFID item-monitoring features and a commercial vehicle tracking system by Qualcomm - was developed and implemented. In the MiniDemo, the new integrated system worked well in reporting tag status and vehicle location accurately and promptly. There was no incompatibility of components. The robust commercial communication gear, as expected, helped improve system reliability. The MiniDemo confirmed that system integration is technically feasible and reliable with the existing RFID and Qualcomm satellite equipment. In terms of web application, improvements in mapping, tracking, data presentation, and post-incident spatial query reporting were implemented in ARG-US, the application software that manages the dataflow among the RFID tags, readers, and servers. These features were tested in the MiniDemo and found to be satisfactory. The resulting web application is both informative and user-friendly. A joint developmental project is being planned between the PCP and the DOE TRANSCOM that uses the Qualcomm gear in vehicles for tracking and communication of radioactive material shipments across the country. Adding an RFID interface to TRANSCOM is a significant enhancement to the DOE infrastructure for tracking and monitoring shipments of radioactive materials.

Tsai, H.; Chen, K.; Jusko, M.; Craig, B.; Liu, Y.; Decision and Information Sciences

2009-11-23T23:59:59.000Z

167

On The Behaviour of Linear Dipole Antennas with Application to Passive Radio Frequency Identification Tags Operating at 869 MHz  

E-Print Network (OSTI)

energy launched by the reader. Data for the study are calculated using CST microwave studio which applies and controllers, and the software platform made up of the middleware and the enabled applications. The transponder to attract rectifiable electromagnetic energy from the interrogating field of the reader which is used

Haddadi, Hamed

168

SOLAR NANTENNA ELECTROMAGNETIC COLLECTORS  

DOE Green Energy (OSTI)

This research explores a new efficient approach for producing electricity from the abundant energy of the sun. A nanoantenna electromagnetic collector (NEC) has been designed, prototyped, and tested. Proof of concept has been validated. The device targets mid-infrared wavelengths where conventional photovoltaic (PV) solar cells do not respond but is abundant in solar energy. The initial concept of designing NEC antennas was based on scaling of radio frequency antenna theory. This approach has proven unsuccessful by many due to not fully understanding and accounting for the optical behavior of materials in the THz region. Also until recent years the nanofabrication methods were not available to fabricate the optical antenna elements. We have addressed and overcome both technology barriers. Several factors were critical in successful implementation of NEC including: 1) frequency-dependent modeling of antenna elements, 2) selection of materials with proper THz properties and 3) novel manufacturing methods that enable economical large-scale manufacturing. The work represents an important step toward the ultimate realization of a low-cost device that will collect as well as convert this radiation into electricity, which will lead to a wide spectrum, high conversion efficiency, and low cost solution to complement conventional PVs.

Steven D. Novack; Dale K. Kotter; Dennis Slafer; Patrick Pinhero

2008-08-01T23:59:59.000Z

169

Influence of the Particle Formation and Behavior on the Electrical Parameters in Low Pressure Radio-Frequency CH{sub 4}/N{sub 2} Discharges  

Science Conference Proceedings (OSTI)

The particle formation in low pressure radio-frequency (13.56 MHz) CH{sub 4}/N{sub 2} discharges results from the gas decomposition and from the sputtering of the powered electrode. The particle formation and behavior are strongly modified with the nitrogen amount increase in the mixture. The observation of the particles in the CH{sub 4}/N{sub 2} mixture containing 70% of N{sub 2} reveals a particular particle behavior. The particle behavior is correlated with the electrical parameters of the discharge.

Pereira, J.; Massereau-Guilbaud, V.; Geraud-Grenier, I.; Plain, A. [LASEP, Faculte des Sciences, Universite d'Orleans, Site de Bourges, rue G. Berger, BP 4043, 18028 BOURGES CEDEX (France)

2008-03-19T23:59:59.000Z

170

Nitrogen effect on the dust presence and behavior in a radio frequency CH{sub 4}/N{sub 2} discharge  

Science Conference Proceedings (OSTI)

In this paper, we have studied the effects of the nitrogen percentage on particles generated in low pressure radio frequency CH{sub 4}/N{sub 2} discharges. The particle behavior has been analyzed by laser beam extinction and scattering. The nitrogen percentage in the mixture influences the particle presence, behavior, and size in the discharge. For nitrogen percentages greater than 50%, we have evidenced a particle multigeneration and oscillations in particle clouds. These oscillations have been correlated with the discharge electrical parameters.

Pereira, Jeremy; Massereau-Guilbaud, Veronique; Geraud-Grenier, Isabelle; Plain, Andre [LASEP, Faculte des Sciences, Universite d'Orleans, Site de Bourges, rue G. Berger, BP 4043, 18028 Bourges Cedex (France)

2008-02-01T23:59:59.000Z

171

NONLINEAR WAVE INTERACTIONS AS EMISSION PROCESS OF TYPE II RADIO BURSTS  

SciTech Connect

The emission of fundamental and harmonic frequency radio waves of type II radio bursts are assumed to be products of three-wave interaction processes of beam-excited Langmuir waves. Using a particle-in-cell code, we have performed simulations of the assumed emission region, a coronal mass ejection foreshock with two counterstreaming electron beams. Analysis of wavemodes within the simulation shows self-consistent excitation of beam-driven modes, which yield interaction products at both fundamental and harmonic emission frequencies. Through variation of the beam strength, we have investigated the dependence of energy transfer into electrostatic and electromagnetic modes, confirming the quadratic dependence of electromagnetic emission on electron beam strength.

Ganse, Urs; Kilian, Patrick; Spanier, Felix [Lehrstuhl fuer Astronomie, Universitaet Wuerzburg, Wuerzburg (Germany); Vainio, Rami, E-mail: uganse@astro.uni-wuerzburg.de [Department of Physics, University of Helsinki, Helsinki (Finland)

2012-06-01T23:59:59.000Z

172

Poynting-vector based method for determining the bearing and location of electromagnetic sources  

DOE Patents (OSTI)

A method and apparatus is utilized to determine the bearing and/or location of sources, such as, alternating current (A.C.) generators and loads, power lines, transformers and/or radio-frequency (RF) transmitters, emitting electromagnetic-wave energy for which a Poynting-Vector can be defined. When both a source and field sensors (electric and magnetic) are static, a bearing to the electromagnetic source can be obtained. If a single set of electric (E) and magnetic (B) sensors are in motion, multiple measurements permit location of the source. The method can be extended to networks of sensors allowing determination of the location of both stationary and moving sources.

Simons, David J. (Modesto, CA); Carrigan, Charles R. (Tracy, CA); Harben, Philip E. (Livermore, CA); Kirkendall, Barry A. (Golden, CO); Schultz, Craig A. (Danville, CA)

2008-10-21T23:59:59.000Z

173

Absolute atomic oxygen and nitrogen densities in radio-frequency driven atmospheric pressure cold plasmas: Synchrotron vacuum ultra-violet high-resolution Fourier-transform absorption measurements  

SciTech Connect

Reactive atomic species play a key role in emerging cold atmospheric pressure plasma applications, in particular, in plasma medicine. Absolute densities of atomic oxygen and atomic nitrogen were measured in a radio-frequency driven non-equilibrium plasma operated at atmospheric pressure using vacuum ultra-violet (VUV) absorption spectroscopy. The experiment was conducted on the DESIRS synchrotron beamline using a unique VUV Fourier-transform spectrometer. Measurements were carried out in plasmas operated in helium with air-like N{sub 2}/O{sub 2} (4:1) admixtures. A maximum in the O-atom concentration of (9.1 {+-} 0.7) Multiplication-Sign 10{sup 20} m{sup -3} was found at admixtures of 0.35 vol. %, while the N-atom concentration exhibits a maximum of (5.7 {+-} 0.4) Multiplication-Sign 10{sup 19} m{sup -3} at 0.1 vol. %.

Niemi, K.; O'Connell, D.; Gans, T. [York Plasma Institute, Department of Physics, University of York, York YO10 5DD (United Kingdom); Oliveira, N. de; Joyeux, D.; Nahon, L. [Synchrotron Soleil, l'Orme des Merisiers, St. Aubin BP 48, 91192 Gif sur Yvette Cedex (France); Booth, J. P. [Laboratoire de Physique des Plasmas-CNRS, Ecole Polytechnique, 91128 Palaiseau (France)

2013-07-15T23:59:59.000Z

174

Electromagnetic Compatibility & Telecommunications  

Science Conference Proceedings (OSTI)

Directory of Accredited Laboratories. Electromagnetic Compatibility & Telecommunications. The Electromagnetic Compatability ...

2013-11-08T23:59:59.000Z

175

Electromagnetic Compatibility in Nuclear Power Plants  

SciTech Connect

Electromagnetic compatibility (EMC) has long been a key element of qualification for mission critical instrumentation and control (I&C) systems used by the U.S. military. The potential for disruption of safety-related I&C systems by electromagnetic interference (EMI), radio-frequency interference (RFI), or power surges is also an issue of concern for the nuclear industry. Experimental investigations of the potential vulnerability of advanced safety systems to EMI/RFI, coupled with studies of reported events at nuclear power plants (NPPs) that are attributed to EMI/RFI, confirm the safety significance of EMC for both analog and digital technology. As a result, Oak Ridge National Laboratory has been engaged in the development of the technical basis for guidance that addresses EMC for safety-related I&C systems in NPPs. This research has involved the identification of engineering practices to minimize the potential impact of EMI/RFI and power surges and an evaluation of the ambient electromagnetic environment at NPPs to tailor those practices for use by the nuclear industry. Recommendations for EMC guidance have been derived from these research findings and are summarized in this paper.

Ewing, P.D.; Kercel, S.W.; Korsah, K.; Wood, R.T.

1999-08-29T23:59:59.000Z

176

Radio Remote Sensing of the Corona and the Solar Wind  

E-Print Network (OSTI)

Modern radio telescopes are extremely sensitive to plasma on the line of sight from a radio source to the antenna. Plasmas in the corona and solar wind produce measurable changes in the radio wave amplitude and phase, and the phase difference between wave fields of opposite circular polarization. Such measurements can be made of radio waves from spacecraft transmitters and extragalactic radio sources, using radio telescopes and spacecraft tracking antennas. Data have been taken at frequencies from about 80 MHz to 8000 MHz. Lower frequencies probe plasma at greater heliocentric distances. Analysis of these data yields information on the plasma density, density fluctuations, and plasma flow speeds in the corona and solar wind, and on the magnetic field in the solar corona. This paper will concentrate on the information that can be obtained from measurements of Faraday rotation through the corona and inner solar wind. The magnitude of Faraday rotation is proportional to the line of sight integral of the plasma density and the line-of-sight component of the magnetic field. Faraday rotation provides an almost unique means of estimating the magnetic field in this part of space. This technique has contributed to measurement of the large scale coronal magnetic field, the properties of electromagnetic turbulence in the corona, possible detection of electrical currents in the corona, and probing of the internal structure of coronal mass ejections (CMEs). This paper concentrates on the search for small-scale coronal turbulence and remote sensing of the structure of CMEs. Future investigations with the Expanded Very Large Array (EVLA) or Murchison Widefield Array (MWA) could provide unique observational input on the astrophysics of CMEs.

Steven R. Spangler; Catherine A. Whiting

2008-09-26T23:59:59.000Z

177

Are Cluster Radio Relics Revived Fossil Radio Cocoons?  

E-Print Network (OSTI)

A new model for the, so called, `cluster radio relics' is presented (Ensslin & Gopal-Krishna 2000). Fossil radio cocoons, resulting from the former activity of radio galaxies, should contain a low energy relativistic electron population and magnetic fields. Electrons with an age of even up to 2 Gyr can be re-accelerated adiabatically to radio emitting energies, if the fossil radio plasma gets compressed in an environmental shock wave. Such a wave can be caused by a merging event of galaxy clusters, or by the accretion onto galaxy clusters. An implication of this model is the existence of a population of diffuse, ultra-steep spectrum, very low-frequency radio sources located inside and possibly outside of clusters of galaxies, tracing the revival of aged fossil radio plasma by the shock waves associated with large-scale structure formation.

Torsten A. Ensslin; Gopal-Krishna

2000-10-30T23:59:59.000Z

178

Acceleration of ordering transformation of a new Fe{sub 2}(Mn,Cr)Si Heusler-alloy film by very high frequency plasma irradiation process during radio frequency sputter deposition  

Science Conference Proceedings (OSTI)

A new Heusler alloy, Fe{sub 2}(Mn,Cr)Si, that is likely to have high spin polarization (P) and high damping constant ({alpha}) was proposed to obtain high magneto-resistance ratio and low spin torque noise in a magnetic read head with a current-perpendicular-to-plane (CPP) giant magneto-resistance (GMR) multilayer. A very high frequency (VHF) plasma irradiation process during radio frequency (RF) sputter deposition was investigated to form the highly ordered structure of the Heusler alloy film with low thermal treatment temperature. The main results are as follows: (1) P and magnetic moment of Fe{sub 2}(Mn{sub 0.5}Cr{sub 0.5})Si with an L2{sub 1} structure were estimated at 0.99 and 2.49 {mu}{sub B}/f.u., respectively, and {alpha} was also estimated to be larger compared with the case of Co{sub 2}MnSi, according to density of states (DOS) calculations. (2) The ordering (at least B2 structure) temperature of Fe{sub 2}(Mn{sub 0.6}Cr{sub 0.4})Si film decreased from 500 to 300 deg. C by using the VHF plasma irradiation process with optimized condition. (3) The surface roughness of Fe{sub 2}(Mn{sub 0.6}Cr{sub 0.4})Si film also reduced from 1.7 to 0.5 nm by using the VHF plasma irradiation process. It is found that the Fe{sub 2}(Mn,Cr)Si Heusler alloy and the VHF plasma irradiation process with optimized condition seems to be applicable for fabrication of high-performance magnetic read head with CPP-GMR device.

Yoshimura, S.; Kobayashi, H.; Egawa, G.; Saito, H. [Center for Geo-environmental Science, Graduate School of Engineering and Resource Science, Akita University, Akita, 010-8502 (Japan); Ishida, S. [Department of Physics, Graduate School of Science and Engineering, Kagoshima University, Kagoshima, 890-8580 (Japan)

2011-04-01T23:59:59.000Z

179

Electromagnetics - DC/Low Frequency  

Science Conference Proceedings (OSTI)

... GA [200403- 0] ID. Idaho National Laboratory -Calibration Services Dept., Idaho Falls, ID [200115- 0] IL. S. Himmelstein ...

2013-07-26T23:59:59.000Z

180

Electromagnetics - DC/Low Frequency  

Science Conference Proceedings (OSTI)

... TN. Oak Ridge Metrology Center, Oak Ridge, TN [105000- 0] Oak Ridge National Laboratory - Metrology, Oak Ridge, TN [200659- 0] Transcat ...

2013-07-19T23:59:59.000Z

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

Nonlocal theory of electromagnetic wave decay into two electromagnetic waves in a rippled density plasma channel  

SciTech Connect

Parametric decay of a large amplitude electromagnetic wave into two electromagnetic modes in a rippled density plasma channel is investigated. The channel is taken to possess step density profile besides a density ripple of axial wave vector. The density ripple accounts for the momentum mismatch between the interacting waves and facilitates nonlinear coupling. For a given pump wave frequency, the requisite ripple wave number varies only a little w.r.t. the frequency of the low frequency decay wave. The radial localization of electromagnetic wave reduces the growth rate of the parametric instability. The growth rate decreases with the frequency of low frequency electromagnetic wave.

Sati, Priti; Tripathi, V. K. [Indian Institute of Technology, Hauz Khas, Delhi 110054 (India)

2012-12-15T23:59:59.000Z

182

ELECTROMAGNETIC PUMP  

DOE Patents (OSTI)

This patent reiates to electromagnetic pumps for electricity-conducting fluids and, in particular, describes several modifications for a linear conduction type electromagnetic interaction pump. The invention resides in passing the return conductor for the current traversing the fiuid in the duct back through the gap in the iron circuit of the pump. Both the maximum allowable pressure and the efficiency of a linear conduction electromagnetic pump are increased by incorporation of the present invention.

Pulley, O.O.

1954-08-17T23:59:59.000Z

183

Collaborative spectrum sensing in cognitive radio networks.  

E-Print Network (OSTI)

??The radio frequency (RF) spectrum is a scarce natural resource, currently regulated by government agencies. With the explosive emergence of wireless applications, the demands for… (more)

Sun, Hongjian

2011-01-01T23:59:59.000Z

184

Modeling Electromagnetic Reflectivity of Agbabu Oil Sand from Hyperspectral Infrared Reflectance Spectra and Dielectric Properties at L-, C- and X-Band Frequencies  

Science Conference Proceedings (OSTI)

In this paper remote identification of oil sand reservoirs from synthetic aperture radar (SAR) is enhanced by accurate modeling of the electromagnetic (EM) reflectivity of Agbabu oil sands. This is demonstrated using a novel combination of hyperspectral ... Keywords: EM Reflectivity, Computer Simulation, Agbabu Oil Sand, Dielectric property, Petroleum Exploration

Maurice Ezeoke, Kenneth Tong

2013-06-01T23:59:59.000Z

185

Reversible Parallel Discrete Event Formulation of a TLM-Based Radio Signal Propagation Model  

Science Conference Proceedings (OSTI)

Radio signal strength estimation is essential in many applications, including the design of military radio communications and industrial wireless installations. For scenarios with large or richly featured geographical volumes, parallel processing is ... Keywords: Parallel simulation, electromagnetic wave propagation, radio signal, reverse computation, time warp, transmission line matrix

Sudip K. Seal; Kalyan S. Perumalla

2011-12-01T23:59:59.000Z

186

1814 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 44, NO. 6, JUNE 2009 A Bio-Inspired Active Radio-Frequency  

E-Print Network (OSTI)

: analysis time, power and hardware usage all scale linearly with , the number of output frequency bins cochlea designs with sharper rolloff slopes and lower group delay than prior all-pole versions. Index with position: The membrane gradually becomes wider and less stiff, and resonates at lower frequencies. Thus

Sarpeshkar, Rahul

187

High quality ultrathin Bi{sub 2}Se{sub 3} films on CaF{sub 2} and CaF{sub 2}/Si by molecular beam epitaxy with a radio frequency cracker cell  

Science Conference Proceedings (OSTI)

We report a method to fabricate high quality Bi{sub 2}Se{sub 3} thin films using molecular beam epitaxy with a radio frequency cracker cell as an atomic selenium source. With Se-to-Bi ratios close to exact stoichiometry, optimal layer-by-layer growth of high quality Bi{sub 2}Se{sub 3} thin films with smooth surfaces has been achieved on CaF{sub 2}(111) substrates and Si(111) substrates with a thin epitaxial CaF{sub 2} buffer layer (CaF{sub 2}/Si). Transport measurements show a characteristic weak-antilocalization magnetoresistance in all the films, with the emergence of a weak-localization contribution in the ultrathin film limit. Quantum oscillations, attributed to the topological surface states have been observed, including in films grown on CaF{sub 2}/Si.

Zhang Li; Dolev, Merav [Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305 (United States); Hammond, Robert [Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305 (United States); Liu Min [Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305 (United States); Department of Physics, Stanford University, Stanford, California 94305 (United States); Palevski, Alexander [School of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv (Israel); Kapitulnik, Aharon [Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305 (United States); Department of Physics, Stanford University, Stanford, California 94305 (United States)

2012-10-08T23:59:59.000Z

188

Generation of electro-magnetic oscillation in surface multijunction MOMOM  

Science Conference Proceedings (OSTI)

An intergrated surface multijunction MOMOM (metal-oxide-metal-oxide-metal) is reported and coherent electromagnetic oscillation is observed in the low frequency range.

Liao Shiqiang; Wang Yuzhu

1986-04-01T23:59:59.000Z

189

Experimental methodology for non-thermal effects of electromagnetic radiation on biologics  

E-Print Network (OSTI)

Appropriate equipment is needed for research on the effects of radio-frequency radiation from radio-frequency identification (RF-ID) systems on biological materials. In the present study, a complete test system comprising ...

Cox, Felicia C. A. I

2006-01-01T23:59:59.000Z

190

Detection of electromagnetic waves using MEMS antennas  

SciTech Connect

We describe the design, fabrication and characterization of simple micromechanical structures that are capable of sensing static electric time varying electromagnetic fields. Time varying electric field sensing is usually achieved using an electromagnetic antenna and a receiver. However, these antenna-based approaches do not exhibit high sensitivity over a broad frequency (or wavelength) range. An important aspect of the present work is that, in contrast to traditional antennas, the dimensions of these micromechanical oscillators can be much smaller than the wavelength of the electromagnetic wave. We characterized the fabricated micromechanical oscillators by measuring their responses to time varying electric and electromagnetic fields.

Lavrik, Nickolay V [ORNL; Tobin, [Oak Ridge National Laboratory (ORNL); Bowland, Landon T [ORNL

2011-01-01T23:59:59.000Z

191

Phenomenological Model of Current Sheet Canting in Pulsed Electromagnetic Accelerators  

E-Print Network (OSTI)

Phenomenological Model of Current Sheet Canting in Pulsed Electromagnetic Accelerators T of current sheet canting in pulsed electromagnetic accelerators is the departure of the plasma sheet (that - canting angle [degrees] 5 - plasma frequency [rad/s] 1 Introduction Pulsed electromagnetic accelerators

Choueiri, Edgar

192

Electromagnetic Leptogenesis  

E-Print Network (OSTI)

We present a new leptogenesis scenario, where the lepton asymmetry is generated by CP violating decays of heavy electroweak singlet neutrinos via electromagnetic dipole moment couplings to the ordinary light neutrinos. Akin to the usual scenario where the decays are mediated through Yukawa interactions, we have shown, by explicit calculations, that the desired asymmetry can be produced through the interference of the corresponding tree-level and one-loop decay amplitudes involving the effective dipole moment operators. We also find that the relationship of the leptogenesis scale to the light neutrino masses is similar to that for the standard Yukawa-mediated mechanism.

Bell, Nicole F; Law, Sandy S C

2008-01-01T23:59:59.000Z

193

Electromagnetic Leptogenesis  

E-Print Network (OSTI)

We present a new leptogenesis scenario, where the lepton asymmetry is generated by CP violating decays of heavy electroweak singlet neutrinos via electromagnetic dipole moment couplings to the ordinary light neutrinos. Akin to the usual scenario where the decays are mediated through Yukawa interactions, we have shown, by explicit calculations, that the desired asymmetry can be produced through the interference of the corresponding tree-level and one-loop decay amplitudes involving the effective dipole moment operators. We also find that the relationship of the leptogenesis scale to the light neutrino masses is similar to that for the standard Yukawa-mediated mechanism.

Nicole F. Bell; Boris J. Kayser; Sandy S. C. Law

2008-06-20T23:59:59.000Z

194

The environments of radio-loud quasars  

E-Print Network (OSTI)

We have obtained multi-colour imaging of a representative, statistically complete sample of low-frequency selected (S_408MHz > 0.95Jy) radio loud quasars at intermediate (0.6 environmental richness, based upon single-band observations are inadequate at these redshifts for a variety of reasons. Environmental richness seems correlated with the size and morphology of the radio source, as expected if the energy density in the radio lobes is approximately the equipartition value and the lobes are in pressure equilbrium with a surrounding intragroup/cluster medium. Selecting on radio size therefore efficiently selects dense galactic sytems at these redshifts.

J. M. Barr; M. N. Bremer; J. C. Baker

2001-04-18T23:59:59.000Z

195

Synchronization and Characterization of an Ultra-Short Laser for Photoemission and Electron-Beam Diagnostics Studies at a Radio Frequency Photoinjector  

SciTech Connect

A commercially-available titanium-sapphire laser system has recently been installed at the Fermilab A0 photoinjector laboratory in support of photoemission and electron beam diagnostics studies. The laser system is synchronized to both the 1.3-GHz master oscillator and a 1-Hz signal use to trigger the radiofrequency system and instrumentation acquisition. The synchronization scheme and performance are detailed. Long-term temporal and intensity drifts are identified and actively suppressed to within 1 ps and 1.5%, respectively. Measurement and optimization of the laser's temporal profile are accomplished using frequency-resolved optical gating.

Maxwell, Timothy; Ruan, Jinhao; Piot, Philippe; Lumpkin, Alex

2012-03-01T23:59:59.000Z

196

Robust Low-Frequency Spread-Spectrum Navigation System ...  

•Military, emergency, and law-enforcement safety applications •Radio-frequency communications, wireless security, and intermodal logistics

197

radioCherenkov.dvi  

NLE Websites -- All DOE Office Websites (Extended Search)

. . Coherent radio Cherenkov radiation detectors: Revised February 2013 by S.R. Klein (LBNL/UC Berkeley) 100 10 10 -4 10 -3 10 -5 1.0 0.1 0.01 E 2 I(E ν ) [GeV m -2 s -1 sr -1 ] E ν [GeV] ν NuMoon 10 9 10 10 10 11 10 12 10 13 10 14 10 15 ATCA (no SSR) ATCA (SSR incl.) RICE ANITA Central GZK ν flux predictions Central GZK ν flux predictions Figure 1: Representative ν flux limits from radio-detection experiments, illustrating the energy ranges for different techniques. Shown are limits from the Rice, ANITA, NuMoon and Lunaska (ATCA) collaborations. NuMoon and Lunaska are low and high frequency lunar scans respectively, showing the strengths of the two different frequency bands. The two limits for ATCA are for different models of the lunar regolith; their separation is a measure of the resultant uncertainty. Also shown, for comparison is the mid-range of flux predictions

198

Category:Electromagnetic Profiling Techniques | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Category Edit History Facebook icon Twitter icon » Category:Electromagnetic Profiling Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Electromagnetic Profiling Techniques page? For detailed information on Electromagnetic Profiling Techniques, click here. Category:Electromagnetic Profiling Techniques Add.png Add a new Electromagnetic Profiling Techniques Technique Pages in category "Electromagnetic Profiling Techniques" This category contains only the following page. F Frequency-Domain Electromagnetic Survey Retrieved from "http://en.openei.org/w/index.php?title=Category:Electromagnetic_Profiling_Techniques&oldid=689835"

199

NVLAP Electromagnetic Compatibility & Telecommunications ...  

Science Conference Proceedings (OSTI)

Electromagnetic Compatibility & Telecommunications LAP. Welcome. This site has been established for new applicants ...

2013-07-30T23:59:59.000Z

200

Dangerous electromagnetic fields?  

NLE Websites -- All DOE Office Websites (Extended Search)

Dangerous electromagnetic fields? Dangerous electromagnetic fields? Name: Tommy T Joseph Location: N/A Country: N/A Date: N/A Question: Why are electromagnetic fields supposedly dangerous? Replies: I assume you are asking about power line frequency (60 Hz) fields, since they have been in the news lately. No one knows for sure that they are dangerous. There have been a few studies which seem to show an association between how close homes are to power lines, and the incidence of childhood cancer (mostly leukemia) in children living (or who have lived) in those homes. Other similar studies have not found such an association. In all the studies which have found an association, none has actually measured the fields. Studies which actually have measured the fields find no association. There is no known mechanism for 60 Hz fields to cause cancer. Furthermore, the classic "dose-response relationship," that is, the greater the dose, the greater the response, does not seem to work here. Many laboratory studies have found that 60 Hz fields have an effect on organisms under certain conditions, but none of the observed effects can be convincingly related to a hazard. The bottom line is, no one knows for sure. It is important to realize that it is impossible to prove that anything is completely safe. My personal opinion is that, if there is a risk, it must be very small, or it wouldn't be so hard to prove. I can supply some good unbiased references if you are interested.

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

Recommended electromagnetic operating envelopes for safety-related I and C systems in nuclear power plants: Draft report for comment  

Science Conference Proceedings (OSTI)

This document presents recommendations for electromagnetic operating envelopes to augment test criteria and test methods addressing electromagnetic interference (EMI), radio-frequency interference (RFI), and power surges that are applicable to safety-related instrumentation and control (I and C) systems in nuclear power plants. The Oak Ridge National Laboratory (ORNL) was engaged by the US Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research to assist in developing the technical basis for regulatory guidance on EMI/RFI immunity and power surge withstand capability (SWC). Previous research has provided recommendations on electromagnetic compatibility (EMC) design and installation practices, endorsement of EMI/RFI immunity and SWC test criteria and test methods, and determination of ambient electromagnetic conditions at nuclear power plants. The present research involves development of recommended electromagnetic envelopes that are applicable to nuclear power plant locations where safety-related I and C systems either are or may be installed. These recommended envelopes establish both emissions criteria and the levels of radiated and conducted interference that I and C systems should be able to withstand without upset or malfunction. The EMI/RFI operating envelopes are derived from conditions in comparable military environments and are confirmed by comparison with the nuclear power plant electromagnetic environment based on measured plant emissions profiles. Detailed information on specific power surge conditions in nuclear power plants is not available, so industrial guidance on representative surge characteristics for susceptibility testing is adopted. An engineering assessment of the power surge environment in nuclear power plants leads to the recommendation of operating envelopes based on location categories and exposure levels defined in IEEE Std C62.41-1991, IEEE Recommended Practice on Surge Voltages in Low-Voltage AC Power Circuits.

Ewing, P.D.; Wood, R.T. [Oak Ridge National Lab., TN (United States)

1997-12-01T23:59:59.000Z

202

Narrow field electromagnetic sensor system and method  

DOE Patents (OSTI)

A narrow field electromagnetic sensor system and method of sensing a characteristic of an object provide the capability to realize a characteristic of an object such as density, thickness, or presence, for any desired coordinate position on the object. One application is imaging. The sensor can also be used as an obstruction detector or an electronic trip wire with a narrow field without the disadvantages of impaired performance when exposed to dirt, snow, rain, or sunlight. The sensor employs a transmitter for transmitting a sequence of electromagnetic signals in response to a transmit timing signal, a receiver for sampling only the initial direct RF path of the electromagnetic signal while excluding all other electromagnetic signals in response to a receive timing signal, and a signal processor for processing the sampled direct RF path electromagnetic signal and providing an indication of the characteristic of an object. Usually, the electromagnetic signal is a short RF burst and the obstruction must provide a substantially complete eclipse of the direct RF path. By employing time-of-flight techniques, a timing circuit controls the receiver to sample only the initial direct RF path of the electromagnetic signal while not sampling indirect path electromagnetic signals. The sensor system also incorporates circuitry for ultra-wideband spread spectrum operation that reduces interference to and from other RF services while allowing co-location of multiple electronic sensors without the need for frequency assignments. 12 figs.

McEwan, T.E.

1996-11-19T23:59:59.000Z

203

Customer Electromagnetic Compatibility: A Study on Interference Issues  

Science Conference Proceedings (OSTI)

Electromagnetic compatibility (EMC) has been a problem since before the invention of radio. The proliferation of ever-more sensitive electronic devices has made EMC and RFI into quite pervasive problems. When confronted with an interference problem, it is easy and tempting to automatically blame the electric power company or the radio amateur next door, but in fact the source may be right in the interference recipient's own home. Or, because of the long-distance propagation of radio waves, it may turn ou...

2004-12-20T23:59:59.000Z

204

Auction-Based Throughput Maximization in Cognitive Radio Networks Under Interference Constraint  

Science Conference Proceedings (OSTI)

Cognitive radio is an emerging technique to improve the utilization of radio frequency spectrum in wireless communication networks. That is, spectrum efficiency can be increased significantly by giving opportunistic access of the frequency bands to a ... Keywords: Auction, Channel assignment, Cognitive radio, Graph theory, Interference constraint, OSI cross layer applications

Hakan Murat Karaca, Tolga Kurt, Salih Zafer Dicle, Emin Anarim

2013-09-01T23:59:59.000Z

205

Non-contact biopotential sensing  

E-Print Network (OSTI)

reduces electromagnetic interference from outside sources.interference. Portable sensors must be robust against radio- frequency and other electromagnetic

Chi, Yu Mike

2011-01-01T23:59:59.000Z

206

Analysis Of Factors Affecting Natural Source Slf Electromagnetic  

Open Energy Info (EERE)

Factors Affecting Natural Source Slf Electromagnetic Factors Affecting Natural Source Slf Electromagnetic Exploration At Geothermal Wells Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Analysis Of Factors Affecting Natural Source Slf Electromagnetic Exploration At Geothermal Wells Details Activities (0) Areas (0) Regions (0) Abstract: The Super Low Frequency (SLF) electromagnetic exploration was performed by using a nature source SLF electromagnetic detector at two geothermal wells in Peking University. The data of the SLF electromagnetic exploration at well JR-119 and JR-168 were obtained with the observation of continued five days and four times per day at well JR-119 and of one day at well JR-168. Based on these data, the influencing factors of the SI-F electromagnetic exploration were analyzed, which included the relationship

207

Dielectric supported radio-frequency cavities  

DOE Patents (OSTI)

A device which improves the electrical and thermomechanical performance of an RF cavity, for example, in a disk-loaded accelerating structure. A washer made of polycrystalline diamond is brazed in the middle to a copper disk washer and at the outer edge to the plane wave transformer tank wall, thus dissipating heat from the copper disk to the outer tank wall while at the same time providing strong mechanical support to the metal disk. The washer structure eliminates the longitudinal connecting rods and cooling channels used in the currently available cavities, and as a result minimizes problems such as shunt impedance degradation and field distortion in the plane wave transformer, and mechanical deflection and uneven cooling of the disk assembly.

Yu, David U. L. (Rancho Palos Verdes, CA); Lee, Terry G. (Cupertino, CA)

2000-01-01T23:59:59.000Z

208

Radio-Frequency Electronics Group Homepage  

Science Conference Proceedings (OSTI)

... High Speed Electronics—This project supports the microwave, telecommunications ... this project we measure the fundamental electrical ...

2010-12-22T23:59:59.000Z

209

Radio frequency digital to analog converter  

E-Print Network (OSTI)

Dynamic performance of high speed, high resolution digital-to-analog converters (DACs) is limited by distortion at the data switching instants. Inter-symbol interference (ISI), imperfect timing synchronization and clock ...

Luschas, Susan, 1975-

2003-01-01T23:59:59.000Z

210

Radio Frequency Identification Tags - Semi Passive (Battery ...  

PNNL developed this semi-passive RF Tag for the Army to detect and locate nightvision goggles in a cluttered ... and boxes it is easier to track and ...

211

Radio Frequency Lamination for Photovoltaic Panels  

Science Conference Proceedings (OSTI)

Strategies for overcoming residual stress in interlayers surrounding embedded PV cells will be discussed. Working prototypes of RF laminated solar panels will ...

212

Light modulated switches and radio frequency emitters  

DOE Patents (OSTI)

The disclosure relates to a light modulated electron beam driven radiofrequency emitter. Pulses of light impinge on a photoemissive device which generates an electron beam having the pulse characteristics of the light. The electron beam is accelerated through a radiofrequency resonator which produces radiofrequency emission in accordance with the electron, hence, the light pulses.

Wilson, Mahlon T. (Los Alamos, NM); Tallerico, Paul J. (Los Alamos, NM)

1982-01-01T23:59:59.000Z

213

Radio Frequency Identification Tags - Passive Tags ...  

Computers & Electronics; Consumer Products; Energy & Utilities; Entertainment & Recreation; Fabric & Apparel; Food, Beverage & ...

214

Phase manipulation for efficient radio frequency transmission  

E-Print Network (OSTI)

Power amplifiers (PAs) for microwave communications are generally the most power-hungry element of a transmitter. High linearity is required for modern digital communications standards, and often is achieved at the expense ...

Barton, Taylor Wallis

2012-01-01T23:59:59.000Z

215

Investigation of electromagnetic welding  

E-Print Network (OSTI)

We propose several methodologies to study and optimize the electromagnetic process for Electromagnetic Forming (EMF) and Welding (EMW), thereby lowering the necessary process energy up to a factor of three and lengthening ...

Pressl, Daniel G. (Daniel Gerd)

2009-01-01T23:59:59.000Z

216

Electromagnetic torque analysis of a DFIG for wind turbines  

Science Conference Proceedings (OSTI)

Electromagnetic torque of doubly fed induction generator (DFIG) is a consequence of the rotor and stator supply. The stator voltage has a fixed amount and frequency. The rotor voltage of the DFIG as a part of a wind turbine has a variable amount and ... Keywords: DFIG, electromagnetic torque, renewable energy, wind turbine

Jurica Smajo; Dinko Vukadinovic

2008-05-01T23:59:59.000Z

217

Radio Channel Simulator  

Radio Channel Simulator (RCSim) is a simulation package for making site-specific predictions of radio signal strength. The software computes received power atdiscrete grid points as a function of the transmitter location and propagation environment. ...

218

Effect of O{sub 2} gas partial pressure on mechanical properties of Al{sub 2}O{sub 3} films deposited by inductively coupled plasma-assisted radio frequency magnetron sputtering  

SciTech Connect

The effect of O{sub 2} partial pressure on the mechanical properties of Al{sub 2}O{sub 3} films is studied. Using films prepared by inductively coupled plasma-assisted radio frequency magnetron sputtering, the deposition rate of Al{sub 2}O{sub 3} decreases rapidly when oxygen is added to the argon sputtering gas. The internal stresses in the films are compressive, with magnitude decreasing steeply from 1.6 GPa for films sputtered in pure argon gas to 0.5 GPa for films sputtered in argon gas at an O{sub 2} partial pressure of 0.89 Multiplication-Sign 10{sup -2} Pa. Stress increases gradually with increasing O{sub 2} partial pressure. Using a nanoindentation tester with a Berkovich indenter, film hardness was measured to be about 14 GPa for films sputtered in pure argon gas. Hardness decreases rapidly on the addition of O{sub 2} gas, but increases when the O{sub 2} partial pressure is increased. Adhesion, measured using a Vickers microhardness tester, increases with increasing O{sub 2} partial pressure. Electron probe microanalyzer measurements reveal that the argon content of films decreases with increasing O{sub 2} partial pressure, whereas the O to Al composition ratio increases from 1.15 for films sputtered in pure argon gas to 1.5 for films sputtered in argon gas at O{sub 2} partial pressures over 2.4 Multiplication-Sign 10{sup -2} Pa. X-ray diffraction measurements reveal that films sputtered in pure argon gas have an amorphous crystal structure, whereas {gamma}-Al{sub 2}O{sub 3} is produced for films sputtered in argon gas with added O{sub 2} gas. Atomic force microscopy observations reveal that the surface topography of sputtered Al{sub 2}O{sub 3} films changes from spherical to needlelike as O{sub 2} partial pressure is increased. Fracture cross sections of the films observed by scanning electron microscopy reveal that the film morphology exhibits no discernible features at all O{sub 2} partial pressures.

Fujiyama, Hirokazu; Sumomogi, Tsunetaka; Nakamura, Masayoshi [Faculty of Engineering, Fukuoka Institute of Technology, 3-30-1 Wajirohigashi, Higashi-ku, Fukuoka 811-0295 (Japan); Faculty of Engineering, Hiroshima Kokusai Gakuin University, 6-20-1 Nakano, Aki-ku, Hiroshima 739-0321 (Japan)

2012-09-15T23:59:59.000Z

219

Electromagnetic Transients in Substations, Volumes 5: Test Data Tapes  

Science Conference Proceedings (OSTI)

EPRI has investigated high-frequency electromagnetic interference (EMI) resulting from high-voltage switching, lightning, and faults in substations. This report provides information about EMI levels to which equipment is exposed.

1993-08-19T23:59:59.000Z

220

A Simple Method for Generating Electromagnetic Oscillations  

E-Print Network (OSTI)

We propose a novel approach to the generation of electromagnetic oscillations by means of a low-frequency pumping of two coupled linear oscillators. A theory of such generation mechanism is proposed, and its feasibility is demonstrated by using coupled RLC oscillators. A comparison of the theoretical results and the experimental data is presented.

Vyacheslav Buts; Dmitriy Vavriv; Oleg Nechayev; Dmitriy Tarasov

2013-08-23T23:59:59.000Z

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

An electromagnetic measurement tool for UHS RFID diagnostics  

E-Print Network (OSTI)

This thesis presents the design and analysis of a radio frequency identification (RFID) passive UHF emulation tag designed to be used as an environment evaluation tool. The tag implements the Auto-ID Center/EPCglobal ...

Redemske, Richard Michael

2005-01-01T23:59:59.000Z

222

Vital Alert's C1000 mine and tunnel radios use magnetic induction...  

NLE Websites -- All DOE Office Websites (Extended Search)

Vital Alert's C1000 mine and tunnel radios use magnetic induction, advanced digital communications techniques and ultra-low frequency transmission to wirelessly provide...

223

Detection of electromagnetic waves using charged MEMS structures  

SciTech Connect

We describe micromechanical structures that are capable of sensing both electrostatic fields and electromagnetic fields over a wide frequency range. Typically, sensing of electromagnetic waves is achieved with electrically conducting antennas, which despite the many advantages do not exhibit high sensitivity over a broad frequency range. An important aspect of our present work is that, in contrast to traditional antennas, the dimensions of micromechanical oscillators sensitive to electromagnetic waves can be much smaller than the wavelength. We characterized the micromechanical oscillators and measured responses to electric fields and estimated the performance limits by evaluating the signal-to-noise ratio theoretically and experimentally.

Datskos, Panos G [ORNL; Lavrik, Nickolay V [ORNL; Tobin, Jacob D [ORNL; Bowland, Landon T [ORNL

2012-01-01T23:59:59.000Z

224

EIA Radio test  

U.S. Energy Information Administration (EIA) Indexed Site

September 10, 2012 September 10, 2012 Test of Energy News Radio Service This is a test audio file of the U.S. Energy Information Administration's energy news radio service to be launched on Tuesday, September 11 th with the release of EIA's monthly Short-Term Energy Outlook. EIA's radio service will provide free short broadcast stories on EIA energy data reports and analysis to radio stations nationwide. The stories will be recorded in MP3 format and can be downloaded from EIA's radio service webpage at www.eia.gov/radio. The first broadcast stories will be posted around noon Eastern Time on Sept. 11 after the release of EIA's monthly Short Term Energy Outlook forecast. These initial stories will focus on the outlook for U.S. gasoline prices, crude oil production and natural gas production.

225

A superconducting bandpass delta-sigma modulator for direct analog-to-digital conversion of microwave radio  

E-Print Network (OSTI)

Direct analog-to-digital conversion of multi-GHz radio frequency (RF) signals is the ultimate goal in software radio receiver design but remains a daunting challenge for any technology. This thesis examines the potential ...

Bulzacchelli, John F. (John Francis)

2003-01-01T23:59:59.000Z

226

Tunability enhanced electromagnetic wiggler  

DOE Patents (OSTI)

The invention discloses a wiggler used in synchrotron radiation sources and free electron lasers, where each pole is surrounded by at least two electromagnetic coils. The electromagnetic coils are energized with different amounts of current to provide a wide tunable range of the on-axis magnetic flux density, while preventing magnetic saturation of the poles. 14 figs.

Schlueter, R.D.; Deis, G.A.

1992-03-24T23:59:59.000Z

227

Underground radio technology saves miners and emergency response personnel  

NLE Websites -- All DOE Office Websites (Extended Search)

Underground radio technology saves miners and emergency response Underground radio technology saves miners and emergency response personnel Underground radio technology saves miners and emergency response personnel Founded through LANL, Vital Alert Technologies, Inc. (Vital Alert) has launched a wireless, two-way real-time voice communication system that is effective through 1,000+ feet of solid rock. April 3, 2012 Vital Alert's C1000 mine and tunnel radios use magnetic induction, advanced digital communications techniques and ultra-low frequency transmission to wirelessly provide reliable 2-way voice, text, or data links through rock strata and other solid media. Vital Alert's C1000 mine and tunnel radios use magnetic induction, advanced digital communications techniques and ultra-low frequency transmission to wirelessly provide reliable 2-way voice, text, or data links through rock

228

Smart Radio Spectrum Management for Cognitive Radio  

E-Print Network (OSTI)

Today's wireless networks are characterized by fixed spectrum assignment policy. The limited available spectrum and the inefficiency in the spectrum usage necessitate a new communication paradigm to exploit the existing wireless spectrum opportunistically. Cognitive radio is a paradigm for wireless communication in which either a network or a wireless node changes its transmission or reception parameters to communicate efficiently avoiding interference with licensed or unlicensed users. In this work, a fuzzy logic based system for spectrum management is proposed where the radio can share unused spectrum depending on some parameters like distance, signal strength, node velocity and availability of unused spectrum. The system is simulated and is found to give satisfactory results.

Bhattacharya, Partha Pratim; Gera, Rishita; Agarwal, Anjali

2011-01-01T23:59:59.000Z

229

Microslots : scalable electromagnetic instrumentation  

E-Print Network (OSTI)

This thesis explores spin manipulation, fabrication techniques and boundary conditions of electromagnetism to bridge the macroscopic and microscopic worlds of biology, chemistry and electronics. This work is centered around ...

Maguire, Yael G., 1975-

2004-01-01T23:59:59.000Z

230

Electromagnetic Soundings At Raft River Geothermal Area (1977) | Open  

Open Energy Info (EERE)

Electromagnetic Soundings At Raft River Geothermal Area (1977) Electromagnetic Soundings At Raft River Geothermal Area (1977) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Electromagnetic Soundings At Raft River Geothermal Area (1977) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Electromagnetic Sounding Techniques Activity Date 1977 Usefulness not indicated DOE-funding Unknown Exploration Basis The purpose of the survey was: (1) to field test U.S. Geological Survey extra-low-frequency (ELF) equipment using a grounded wire source and receiver loop configuration (which is designed to measure the vertical magnetic field (Hz) at the loop center for various frequencies); (2) to present an example of the EM sounding data and interpretations using a

231

Interpretation of electromagnetic soundings in the Raft River geothermal  

Open Energy Info (EERE)

Interpretation of electromagnetic soundings in the Raft River geothermal Interpretation of electromagnetic soundings in the Raft River geothermal area, Idaho Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Interpretation of electromagnetic soundings in the Raft River geothermal area, Idaho Details Activities (1) Areas (1) Regions (0) Abstract: An electromagnetic (EM) controlled source survey was conducted in the Raft River Valley, near Malta, Idaho. The purpose of the survey was: to field test U.S. Geological Survey extra-low-frequency (ELF) equipment using a grounded wire source and receiver loop configuration (which is designed to measure the vertical magnetic field (Hz) at the loop center for various frequencies); to present an example of the EM sounding data and interpretations using a previously developed inversion program; and (3) to

232

The Covariant Electromagnetic Casimir Effect for Real Conducting Cylindrical Shells  

E-Print Network (OSTI)

Using covariant quantization of the electromagnetic field, the Casimir force per unit area experienced by a long conducting cylindrical shell, under both Dirichlet and Neumann boundary conditions, is calculated. The renormalization procedure is based on the plasma cut-off frequency for real conductors. The real case of a gold (silver) cylindrical shell is considered and the corresponding electromagnetic Casimir pressure is computed. It is discussed that the Dirichlet and Neumann problems should be considered separately without adding their corresponding results.

H. Razmi; N. Fadaei

2013-07-31T23:59:59.000Z

233

Nonlinear Landau damping of transverse electromagnetic waves in dusty plasmas  

SciTech Connect

High-frequency transverse electromagnetic waves in a collisionless isotropic dusty plasma damp via nonlinear Landau damping. Taking into account the latter we have obtained a generalized set of Zakharov equations with local and nonlocal terms. Then from this coupled set of Zakharov equations a kinetic nonlinear Schroedinger equation with local and nonlocal nonlinearities is derived for special cases. It is shown that the modulation of the amplitude of the electromagnetic waves leads to the modulation instability through the nonlinear Landau damping term. The maximum growth rate is obtained for the special case when the group velocity of electromagnetic waves is close to the dust acoustic velocity.

Tsintsadze, N. L. [E. Andronikashvili Institute of Physics, Tbilisi 0171 (Georgia); Department of Physics, Government College University, Lahore 54000 (Pakistan); Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan); Chaudhary, Rozina [Department of Physics, Government College University, Lahore 54000 (Pakistan); Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan); Shah, H. A. [Department of Physics, Government College University, Lahore 54000 (Pakistan); Murtaza, G. [Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan)

2009-04-15T23:59:59.000Z

234

Theory and Manufacturing Processes of Solar NanoAntenna Electromagnetic Collectors  

DOE Green Energy (OSTI)

DRAFT For Submittal to Journal of Solar Energy - Rev 10.1 ---SOL-08-1091 SOLAR Nantenna Electromagnetic Collectors Dale K. Kotter Idaho National Laboratory Steven D. Novack Idaho National Laboratory W. Dennis Slafer MicroContinuum, Inc. Patrick Pinhero University of Missouri ABSTRACT The research described in this paper explores a new and efficient approach for producing electricity from the abundant energy of the sun, using nanoantenna (nantenna) electromagnetic collectors (NECs). NEC devices target mid-infrared wavelengths, where conventional photovoltaic (PV) solar cells are inefficient and where there is an abundance of solar energy. The initial concept of designing NECs was based on scaling of radio frequency antenna theory to the infrared and visible regions. This approach initially proved unsuccessful because the optical behavior of materials in the terahertz (THz) region was overlooked and, in addition, economical nanofabrication methods were not previously available to produce the optical antenna elements. This paper demonstrates progress in addressing significant technological barriers, including: 1) development of frequency-dependent modeling of double-feedpoint square spiral nantenna elements; 2) selection of materials with proper THz properties; and 3) development of novel manufacturing methods that could potentially enable economical large-scale manufacturing. We have shown that nantennas can collect infrared energy and induce THz currents, and we have also developed cost-effective proof-of-concept fabrication techniques for the large-scale manufacture of simple square loop nantenna arrays. Future work is planned to embed rectifiers into the double-feedpoint antenna structures. This work represents an important first step toward the ultimate realization of a low-cost device that will collect as well as convert this radiation into electricity. This could lead to a broadband, high conversion efficiency low-cost solution to complement conventional PV devices.

Dale K. Kotter; Steven D. Novack

2010-02-01T23:59:59.000Z

235

Automatic calibration of modulated fractional-N frequency synthesizers  

E-Print Network (OSTI)

The focus of this research has been the development of a low power, radio frequency transmitter architecture. Specifically, a technique for in service automatic calibration of a modulated phase locked loop (PLL) frequency ...

McMahill, Dan

2001-01-01T23:59:59.000Z

236

Enhanced Interpretation of Electromagnetic Signature Analysis for Large Machines  

Science Conference Proceedings (OSTI)

This project developed and applied frequency domain models to enhance interpretation of electromagnetic signature analysis (EMSA) for large electrical generators. The project's rationale was to provide a prediction of the native frequency response of the winding calculated from machine dimensions and design data so that the positions of the resonances would be known a priore. This procedure allowed augmentation of an EMSA spectrum at the characteristic resonant frequencies of the machine in the interpret...

2010-11-16T23:59:59.000Z

237

Gradient instabilities of electromagnetic waves in Hall thruster plasma  

SciTech Connect

This paper presents a linear analysis of gradient plasma instabilities in Hall thrusters. The study obtains and analyzes the dispersion equation of high-frequency electromagnetic waves based on the two-fluid model of a cold plasma. The regions of parameters corresponding to unstable high frequency modes are determined and the dependence of the increments and intrinsic frequencies on plasma parameters is obtained. The obtained results agree with those of previously published studies.

Tomilin, Dmitry [Department of Electrophysics, Keldysh Research Centre, Moscow 125438 (Russian Federation)

2013-04-15T23:59:59.000Z

238

MEASURING THE JET POWER OF FLAT-SPECTRUM RADIO QUASARS  

SciTech Connect

We use frequency-dependent position shifts of flat-spectrum radio cores to estimate the kinetic power of active galactic nucleus (AGN) jets. We find a correlation between the derived jet powers and AGN narrow-line luminosity, consistent with the well-known relation for radio galaxies and steep spectrum quasars. This technique can be applied to intrinsically weak jets even at high redshift.

Shabala, S. S.; Santoso, J. S. [School of Mathematics and Physics, University of Tasmania, Private Bag 37, Hobart, TAS 7001 (Australia); Godfrey, L. E. H. [International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth, Western Australia 6845 (Australia)

2012-09-10T23:59:59.000Z

239

Interaction Between AM Radio Broadcast Antennas and Overhead Power Lines  

Science Conference Proceedings (OSTI)

Metallic structures, power lines or otherwise, can affect the operation of AM radio broadcast station antennas if the dimensions of those structures are related to the wavelength of the radio signal at the station's operating frequency. For power lines, the dimensions of interest can be either the height of the support structures themselves or the length of a loop formed by adjacent structures, the shield wires connecting them, and the return path in the earth. When resonance occurs between the power lin...

2012-05-10T23:59:59.000Z

240

Superconducting dipole electromagnet  

DOE Patents (OSTI)

A dipole electromagnet of especial use for bending beams in particle accelerators is wound to have high uniformity of magnetic field across a cross section and to decrease evenly to zero as the ends of the electromagnet are approached by disposing the superconducting filaments of the coil in the crescent-shaped nonoverlapping portions of two intersecting circles. Uniform decrease at the ends is achieved by causing the circles to overlap increasingly in the direction of the ends of the coil until the overlap is complete and the coil is terminated.

Purcell, John R. (San Diego, CA)

1977-07-26T23:59:59.000Z

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

eRadio : empowerment through community Web radio  

E-Print Network (OSTI)

The eRadio project proposes to be an effective aid to increase interaction and reduce alienation among the members of dispersed communities by using a holistic approach to participatory and interactive web radio-production, ...

Gomez-Monroy, Carla, 1977-

2004-01-01T23:59:59.000Z

242

Electromagnetic radiation detector  

DOE Patents (OSTI)

An electromagnetic radiation detector including a collimating window, a cathode member having a photoelectric emissive material surface angularly disposed to said window whereby radiation is impinged thereon at acute angles, an anode, separated from the cathode member by an evacuated space, for collecting photoelectrons emitted from the emissive cathode surface, and a negatively biased, high transmissive grid disposed between the cathode member and anode.

Benson, Jay L. (Albuquerque, NM); Hansen, Gordon J. (Albuquerque, NM)

1976-01-01T23:59:59.000Z

243

Electromagnetically induced interference at superconducting qubits  

E-Print Network (OSTI)

We study electromagnetically induced interference at superconducting qubits. The interaction between qubits and electromagnetic fields can provide additional coupling channels to qubit states, leading to quantum interference in a microwave driven qubit. In particular, the interwell relaxation or Rabi oscillation, resulting respectively from the multi- or single-mode interaction, can induce effective crossovers. The environment is modeled by a multi-mode thermal bath, generating the interwell relaxation. Relaxation induced interference, independent of the tunnel coupling, provides deeper understanding to the interaction between the qubits and their environment. It also supplies a useful tool to characterize the relaxation strength as well as the characteristic frequency of the bath. In addition, we demonstrate the relaxation can generate population inversion in a strongly driving two-level system. On the other hand, different from Rabi oscillation, Rabi oscillation induced interference involves more complicate...

Du, Lingjie

2010-01-01T23:59:59.000Z

244

Satellite Radio: Its Global Impact  

E-Print Network (OSTI)

Geo-Stationary High-powered Satellites · Processed and Transparent Payloads · Solar-Powered Provides A is the satellite transmit characteristics, determined by state-of art satellite power, coverage area; B is Receive WorldSpace XM Sirius MBSAT #12;8 Satellite Radio: A Confluence of Technologies Radio Radio Internet

Udgaonkar, Jayant B.

245

RADIO RANGING DEVICE  

DOE Patents (OSTI)

A radio ranging device is described. It utilizes a super regenerative detector-oscillator in which echoes of transmitted pulses are received in proper phase to reduce noise energy at a selected range and also at multiples of the selected range.

Nieset, R.T.

1961-05-16T23:59:59.000Z

246

ELECTROMAGNETIC PROPERTIES OF SUPERCONDUCTORS  

SciTech Connect

A method of calculating the response of superconductors to weak electromagnetic fields is formulated. The response is generated from a single- particle Green's function, defined in the presence of an electromagnetic perturbation, that satisfies the conditions imposed by guauge invariance and charge conservation. The response function is thus itself explicitly gauge invariant and charge conserving. The single-particle Green-s function is obtained by making Gorkov's factorizatation of the tiio-partiele Green's funetion in the presence oi the external field. The sy'mmetry' properties of the approximation are used to simplify the calculatioa. This is trivially' carried out in the London limit. An economieal derivation is thus obtaiaed of Anderson's result thai the Bardeen, Cooper, and Sehrieffer quasi particle excitations must be supplemented by collective excitation in order to satisfy the conservation laws. (auth)

Ambegaokar, V.; Kadanoff, L.P.

1961-12-01T23:59:59.000Z

247

Banded electromagnetic stator core  

DOE Patents (OSTI)

A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figures.

Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

1994-04-05T23:59:59.000Z

248

Special Presentation: Key Findings from the Barrier Immune Radio  

NLE Websites -- All DOE Office Websites (Extended Search)

Special Presentation: Key Findings from the Barrier Immune Radio Special Presentation: Key Findings from the Barrier Immune Radio Communications Project Speaker(s): Francis Rubinstein Girish Ghatikar Peter Haugen Date: November 29, 2007 - 12:00pm Location: 90-3122 The Barrier Immune Radio Communications (BIRC) Project was established in January 2007 by the Demand Response Emerging Technologies Program (DRETD) to identify radio frequency technologies that could enable the widespread deployment of Demand Response strategies in buildings. Researchers from Lawrence Berkeley National Laboratory and Lawrence Livermore National Laboratory will present the key findings from this project in a one-hour presentation. Researchers found that several of the RF technologies tested at LBNL's Molecular Foundry building were able to provide sufficiently

249

Radio emissions from terrestrial gamma-ray flashes Joseph R. Dwyer1  

E-Print Network (OSTI)

. Introduction 1.1. TGF Theory Overview [2] Terrestrial gamma-ray flashes (TGFs) are bright bursts of gamma raysRadio emissions from terrestrial gamma-ray flashes Joseph R. Dwyer1 and Steven A. Cummer2 Received frequency (RF) emissions by terrestrial gamma-ray flashes (TGFs) is developed. These radio emissions, which

Cummer, Steven A.

250

Electromagnetic interferences from plasmas generated in meteoroids impacts  

E-Print Network (OSTI)

Submitted to Europhysics Letters. It is shown that the plasma, generated during an impact of a meteoroid with an artificial satellite, can produce electromagnetic radiations below the microwave frequency range. These interferences can disturb the regular satellite operations. Pacs 96.50.Kr: Meteors and meteoroids. Pacs 52.50.Lp: Plasma production and heating by shock waves and compression.

Luigi Foschini

1998-01-01T23:59:59.000Z

251

Electromagnetic interferences from plasmas generated in meteoroids impacts  

E-Print Network (OSTI)

It is shown that the plasma, generated during an impact of a meteoroid with an artificial satellite, can produce electromagnetic radiation below the microwave frequency range. This interference is shown to exceed local noise sources and might disturb regular satellite operations.

Luigi Foschini

1998-04-23T23:59:59.000Z

252

Electromagnetic Transients Program (EMTP) Workbook  

Science Conference Proceedings (OSTI)

High-speed electromagnetic transients are often the controlling factor in transmission system design and operation. This workbook provides case studies for introducing the basics of electromagnetic transient analysis. Sample problems demonstrate analyses of such transients with the EMTP computer code.BackgroundThe electromagnetic transients program (EMTP) is a versatile and efficient computer program that utilities worldwide use for analyzing high-speed power ...

1986-09-30T23:59:59.000Z

253

Physics Out Loud - Electromagnetic Force  

NLE Websites -- All DOE Office Websites (Extended Search)

Detector Previous Video (Detector) Physics Out Loud Main Index Next Video (Electron Scattering) Electron Scattering Electromagnetic Force Cynthia Keppel, a nuclear physicist,...

254

Electromagnetic fields in cased borehole  

DOE Green Energy (OSTI)

Borehole electromagnetic (EM) measurements, using fiberglass-cased boreholes, have proven useful in oil field reservoir characterization and process monitoring (Wilt et al., 1995). It has been presumed that these measurements would be impossible in steel-cased wells due to the very large EM attenuation and phase shifts. Recent laboratory and field studies have indicated that detection of EM signals through steel casing should be possible at low frequencies, and that these data provide a reasonable conductivity image at a useful scale. Thus, we see an increased application of this technique to mature oilfields, and an immediate extension to geothermal industry as well. Along with the field experiments numerical model studies have been carried out for analyzing the effect of steel casing to the EM fields. The model used to be an infinitely long uniform casing embedded in a homogeneous whole space. Nevertheless, the results indicated that the formation signal could be accurately recovered if the casing characteristics were independently known (Becker et al., 1998; Lee el al., 1998). Real steel-cased wells are much more complex than the simple laboratory models used in work to date. The purpose of this study is to develop efficient numerical methods for analyzing EM fields in realistic settings, and to evaluate the potential application of EM technologies to cross-borehole and single-hole environment for reservoir characterization and monitoring.

Lee, Ki Ha; Kim, Hee Joon; Uchida, Toshihiro

2001-07-20T23:59:59.000Z

255

Excitation and conversion of electromagnetic waves in pulsar magnetospheres  

E-Print Network (OSTI)

We demonstrate that nonlinear decay of obliquely propagating Langmuir waves into Langmuir and Alfven waves (L --> L'+A) is possible in a one-dimensional, highly relativistic, streaming, pair plasma. Such a plasma may be in the magnetospheres of pulsars. It is shown that the characteristic frequency of generated Alfven waves is much less than the frequency of Langmuir waves and may be consistent with the observational data on the radio emission of pulsars.

G. Gogoberidze; G. Z. Machabeli; V. V. Usov

2007-02-07T23:59:59.000Z

256

Mode Conversion of Langmuir to Electromagnetic Waves with Parallel Inhomogeneity in the Solar Wind and the Corona  

SciTech Connect

Linear mode conversion of Langmuir waves to radiation near the plasma frequency at density gradients is potentially relevant to multiple solar radio emissions, ionospheric radar experiments, laboratory plasma devices, and pulsars. Here we study mode conversion in warm magnetized plasmas using a numerical electron fluid simulation code with the density gradient parallel to the ambient magnetic field B0 for a range of incident Langmuir wavevectors. Our results include: (1) Both o- and x-mode waves are produced for ? ? (?L)1/3(?c/?) somewhat less than 1, contrary to previous ideas. Only o mode is produced for ? and somewhat greater than 1.5. Here ?c is the (angular) electron cyclotron frequency, ? the angular wave frequency, and L the length scale of the (linear) density gradient. (2) In the unmagnetized limit, equal amounts of o- and x-mode radiation are produced. (3) The mode conversion window narrows as ? increases. (4) As ? increases the total electromagnetic field changes from linear to circular polarization, with the o- and x- mode signals remaining circularly polarized. (5) The conversion efficiency to the x mode decreases monotonically as ? increases while the o-mode conversion efficiency oscillates due to an interference phenomenon between incoming and reflected Langmuir/z modes. (6) The total conversion efficiency for wave energy from the Langmuir/z mode to radiation is typically less than 10%, but the corresponding power efficiencies differ by the ratio of the group speeds for each mode and are of order 50 ? 70%. (7) The interference effect and the disappearance of the x mode at ? somewhat greater than 1 can be accounted for semiquantitatively using a WKB-like analysis. (8) Constraints on density turbulence are developed for the x mode to be generated and be able to propagate from the source. (9) Standard parameters for the corona and the solar wind near 1 AU suggest that linear mode conversion should produce both o- and x- mode radiation for solar and interplanetary radio bursts. It is therefore possible that linear mode conversion under these conditions might explain the weak total circular polarizations of type II and III solar radio bursts.

Eun-Hwa Kim, Iver H. Cairns, and Peter A. Robinson

2008-06-09T23:59:59.000Z

257

Nonlinear fan instability of electromagnetic waves  

Science Conference Proceedings (OSTI)

This paper studies the linear and nonlinear stages of the fan instability, considering electromagnetic waves of the whistler frequency range interacting resonantly with energetic electron fluxes in magnetized plasmas. The main attention is paid to determine the wave-particle interaction processes that can lead to the excitation of intense electromagnetic waves by nonequilibrium particle distributions involving suprathermal tails, and to explain under what conditions and through what mechanisms they can occur, develop, and saturate. This paper presents and discusses two main processes: (i) the linear fan instability and (ii) the nonlinear process of dynamical resonance merging, which can significantly amplify the energy carried by linearly destabilized waves after they saturate due to particle trapping. This study consists of (i) determining analytically and numerically, for parameters typical of space and laboratory plasmas, the linear growth rates of whistlers excited by suprathermal particle fluxes through the fan instability, as well as the corresponding thresholds and the physical conditions at which the instability can appear, (ii) building a theoretical self-consistent 3D model and a related numerical code for describing the nonlinear evolution of the wave-particle system, and (iii) performing numerical simulations to reveal and characterize the nonlinear amplification process at work, its conditions of development, and its consequences, notably in terms of electromagnetic wave radiation. The simulations show that when the waves have reached sufficient energy levels owing to the linear fan instability, they saturate by trapping particles and due to the complex dynamics of these particles in the electromagnetic fields, the resonant velocities' domains of the waves overlap and merge, meanwhile a strong increase of the wave energy occurs.

Krafft, C. [Laboratoire de Physique des Plasmas, Ecole Polytechnique, 91128 Palaiseau Cedex (France) and University Paris Sud, 91405 Orsay Cedex (France); Volokitin, A. [Space Research Institute (IKI), 117997, 84/32 Profsoyuznaya Str., Moscow (Russian Federation)

2010-10-15T23:59:59.000Z

258

Measurement Innovations Add Up to Big Savings for ...  

Science Conference Proceedings (OSTI)

Measurement Innovations Add Up to Big Savings for Semiconductors. ... techniques for controlling radio-frequency electromagnetic energy and high ...

2012-03-19T23:59:59.000Z

259

Higher layer issues in cognitive radio network  

Science Conference Proceedings (OSTI)

Cognitive radio networks are smart networks that automatically sense the channel and adjust the network parameters accordingly. Cognitive radio is an emerging technology that enables the dynamic deployment of highly adaptive radios that are built upon ... Keywords: cognitive radio network (CRN), issues, routing issues, security issues, software defined radio

Saed Alrabaee; Anjali Agarwal; Nishith Goel; Marzia Zaman; Mahmoud Khasawneh

2012-08-01T23:59:59.000Z

260

Sandia National Laboratories: Electromagnetics: Main Page  

NLE Websites -- All DOE Office Websites (Extended Search)

Brochure Adobe Logo Related Links Pulsed Power ELECTROMAGNETIC TECHNOLOGY AT SANDIA NATIONAL LABORATORIES Electromagnetics (EM) is the study of the nature and interaction of...

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

RASDR: Benchtop Demonstration of SDR for Radio Astronomy  

SciTech Connect

The Society of Amateur Radio Astronomers (SARA) members present the benchtop version of RASDR, a Software Defined Radio (SDR) that is optimized for Radio Astronomy. RASDR has the potential to be a common digital receiver interface useful to many SARA members. This document describes the RASDR 0.0 , which provides digitized radio data to a backend computer through a USB 2.0 interface. A primary component of RASDR is the Lime Microsystems Femtocell chip which tunes from a 0.4-4 GHz center frequency with several selectable bandwidths from 0.75 MHz to 14 MHz. A second component is a board with a Complex Programmable Logic Device (CPLD) chip that connects to the Femtocell and provides two USB connections to the backend computer. A third component is an analog balanced mixer up conversion section. Together these three components enable RASDR to tune from 0.015 MHz thru 3.8GHz of the radio frequency (RF) spectrum. We will demonstrate and discuss capabilities of the breadboard system and SARA members will be able to operate the unit hands-on throughout the workshop.

Vacaliuc, Bogdan [ORNL; Oxley, Paul [Retired; Fields, David [ORNL; Kurtz, Dr. Stan [Universidad Nacional Autonoma de Mexico (UNAM); Leech, Marcus [Shirleys Bay Radio Astronomy Consortium

2012-01-01T23:59:59.000Z

262

Applications and noise properties of high repetition rate : TiSapphire frequency combs  

E-Print Network (OSTI)

Femtosecond mode-locked lasers are a unique laser technology due to their broad optical bandwidth and potential for linking the optical and radio frequency domains when these lasers are configured as frequency combs. ...

Benedick, Andrew John

2011-01-01T23:59:59.000Z

263

Waveform Distortion on a 7-Channel Heart Monitor Produced by a Worn Cable Connector & 60-Hertz Electromagnetic Fields  

Science Conference Proceedings (OSTI)

This case study describes an equipment-to-electromagnetic environment incompatibility that occurred in a training laboratory that is part of a large teaching hospital. Specifically, it discusses the causes of low-frequency electromagnetic fields that led to the malfunction of a 7-channel heart monitor used in cardiovascular surgical training to monitor, record, and display small electrical impulses associated with the heart.

2003-12-31T23:59:59.000Z

264

Superconductors Programs/Projects in Electromagnetics  

Science Conference Proceedings (OSTI)

Superconductors Programs/Projects in Electromagnetics. Superconductor Electromechanics. Contact. General Information ...

2010-10-05T23:59:59.000Z

265

Ion cyclotron range of frequencies heating of plasma with small impurity production  

SciTech Connect

Plasma including plasma ions is magnetically confined by a magnetic field. The plasma has a defined outer surface and is intersected by resonance surfaces of respective common ion cyclotron frequency of a predetermined species of plasma ions moving in the magnetic field. A radio frequency source provides radio frequency power at a radio frequency corresponding to the ion cyclotron frequency of the predetermined species of plasma ions moving in the field at a respective said resonance surface. RF launchers coupled to the radio frequency source radiate radio frequency energy at the resonance frequency onto the respective resonance surface within the plasma from a plurality of locations located outside the plasma at such respective distances from the intersections of the respective resonance surface and the defined outer surface and at such relative phases that the resulting interference pattern provides substantially null net radio frequency energy over regions near and including substantial portions of the intersections relative to the radio frequency energy provided thereby at other portions of the respective resonance surface within the plasma.

Ohkawa, Tihiro (La Jolla, CA)

1987-01-01T23:59:59.000Z

266

Three-dimensional transient electromagnetic modeling in the Laplace Domain  

Science Conference Proceedings (OSTI)

In modeling electromagnetic responses, Maxwell's equations in the frequency domain are popular and have been widely used (Nabighian, 1994; Newman and Alumbaugh, 1995; Smith, 1996, to list a few). Recently, electromagnetic modeling in the time domain using the finite difference (FDTD) method (Wang and Hohmann, 1993) has also been used to study transient electromagnetic interactions in the conductive medium. This paper presents a new technique to compute the electromagnetic response of three-dimensional (3-D) structures. The proposed new method is based on transforming Maxwell's equations to the Laplace domain. For each discrete Laplace variable, Maxwell's equations are discretized in 3-D using the staggered grid and the finite difference method (FDM). The resulting system of equations is then solved for the fields using the incomplete Cholesky conjugate gradient (ICCG) method. The new method is particularly effective in saving computer memory since all the operations are carried out in real numbers. For the same reason, the computing speed is faster than frequency domain modeling. The proposed approach can be an extremely useful tool in developing an inversion algorithm using the time domain data.

Mizunaga, H.; Lee, Ki Ha; Kim, H.J.

1998-09-01T23:59:59.000Z

267

Guidelines for Electromagnetic Interference Testing  

Science Conference Proceedings (OSTI)

One issue that has been problematic for new plant equipment and especially for digital instrumentation and control (I&C) systems in recent years is electromagnetic compatibility (EMC). Guidance from the Nuclear Regulatory Commission (NRC), EPRI, and various standards organizations has been evolving for many years and generally converging. However, the NRC's most recent guidance, Regulatory Guide 1.180 Revision 1, and EPRI's most recent EMI Guideline (Guidelines for Electromagnetic Interference Testing in...

2008-02-21T23:59:59.000Z

268

Black Hole Thermodynamics and Electromagnetism  

E-Print Network (OSTI)

We show a strong parallel between the Hawking, Beckenstein black hole Thermodynamics and electromagnetism: When the gravitational coupling constant transform into the electromagnetic coupling constant, the Schwarzchild radius, the Beckenstein temperature, the Beckenstein decay time and the Planck mass transform to respectively the Compton wavelength, the Hagedorn temperature, the Compton time and a typical elementary particle mass. The reasons underlying this parallalism are then discussed in detail.

Burra G. Sidharth

2005-07-15T23:59:59.000Z

269

A bio-inspired active radio-frequency silicon cochlea  

E-Print Network (OSTI)

Fast wideband spectrum analysis is expensive in power and hardware resources. We show that the spectrum-analysis architecture used by the biological cochlea is extremely efficient: analysis time, power and hardware usage ...

Sarpeshkar, Rahul

270

Current Challenges and Physics of Superconducting Radio-Frequency...  

NLE Websites -- All DOE Office Websites (Extended Search)

Recent performance advances in superconducting RF (SRF) cavities have made RF superconductivity a vital technology for accelerators which serve a variety of experimental...

271

UTags-Long Range Ultra Wideband Passive Radio Frequency ...  

Giving animals in need a HOME. November 14, 2013. LLNL, Intel, Cray produce big data machine. ... for the Department of Energy's National Nuclear Security Administration

272

Quantum dots and radio-frequency electrometry in silicon.  

E-Print Network (OSTI)

??This thesis describes the development and demonstration of a new technique for the fabrication of well-defined quantum dots in a bulk silicon substrate, for potential… (more)

Angus, Susan J.

2008-01-01T23:59:59.000Z

273

NIST SP 800-98, Guidelines for Securing Radio Frequency ...  

Science Conference Proceedings (OSTI)

... business risks associated with implementing RFID technology. ... GUIDELINES FOR SECURING RFID SYSTEMS ... to understand later material in the ...

2012-02-09T23:59:59.000Z

274

Electronic and Embedded Systems Low-frequency radio identification  

E-Print Network (OSTI)

-cost hardware and easy installation. Users: Stewards of high-valued assets, protective forces, DOE, NNSA, DOD

275

Compact, low power radio frequency cavity for femtosecond electron microscopy  

Science Conference Proceedings (OSTI)

Reported here is the design, construction, and characterization of a small, power efficient, tunable dielectric filled cavity for the creation of femtosecond electron bunches in an existing electron microscope without the mandatory use of femtosecond lasers. A 3 GHz pillbox cavity operating in the TM{sub 110} mode was specially designed for chopping the beam of a 30 keV scanning electron microscope. The dielectric material used is ZrTiO{sub 4}, chosen for the high relative permittivity ({epsilon}{sub r}= 37 at 10 GHz) and low loss tangent (tan {delta}= 2 x 10{sup -4}). This allows the cavity radius to be reduced by a factor of six, while the power consumption is reduced by an order of magnitude compared to a vacuum pillbox cavity. These features make this cavity ideal as a module for existing electron microscopes, and an alternative to femtosecond laser systems integrated with electron microscopes.

Lassise, A.; Mutsaers, P. H. A.; Luiten, O. J. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

2012-04-15T23:59:59.000Z

276

Radio frequency discharge with control of plasma potential distribution  

Science Conference Proceedings (OSTI)

A RF discharge plasma generator with additional electrodes for independent control of plasma potential distribution is proposed. With positive biasing of this ring electrode relative end flanges and longitudinal magnetic field a confinement of fast electrons in the discharge will be improved for reliable triggering of pulsed RF discharge at low gas density and rate of ion generation will be enhanced. In the proposed discharge combination, the electron energy is enhanced by RF field and the fast electron confinement is improved by enhanced positive plasma potential which improves the efficiency of plasma generation significantly. This combination creates a synergetic effect with a significantly improving the plasma generation performance at low gas density. The discharge parameters can be optimized for enhance plasma generation with acceptable electrode sputtering.

Dudnikov, Vadim [Muons, Inc., Batavia, Illinois 60510 (United States); Dudnikov, A. [BINP, Novosibirsk 63090 (Russian Federation)

2012-02-15T23:59:59.000Z

277

Surface plasma source with saddle antenna radio frequency plasma generator  

Science Conference Proceedings (OSTI)

A prototype RF H{sup -} surface plasma source (SPS) with saddle (SA) RF antenna is developed which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability. Several versions of new plasma generators with small AlN discharge chambers and different antennas and magnetic field configurations were tested in the plasma source test stand. A prototype SA SPS was installed in the Spallation Neutron Source (SNS) ion source test stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency up to 1.6 mA/kW. Control experiments with H{sup -} beam produced by SNS SPS with internal and external antennas were conducted. A new version of the RF triggering plasma gun has been designed. A saddle antenna SPS with water cooling is fabricated for high duty factor testing.

Dudnikov, V.; Johnson, R. P. [Muons, Inc., Batavia, Illinios 60510 (United States); Murray, S.; Pennisi, T.; Piller, C.; Santana, M.; Stockli, M.; Welton, R. [ORNL, Oak Ridge, Tennessee 37831 (United States)

2012-02-15T23:59:59.000Z

278

Radio-frequency quadrupole resonator for linear accelerator  

DOE Patents (OSTI)

An RFQ resonator for a linear accelerator having a reduced level of interfering modes and producing a quadrupole mode for focusing, bunching and accelerating beams of heavy charged particles, with the construction being characterized by four elongated resonating rods within a cylinder with the rods being alternately shorted and open electrically to the shell at common ends of the rods to provide an LC parallel resonant circuit when activated by a magnetic field transverse to the longitudinal axis.

Moretti, A.

1982-10-19T23:59:59.000Z

279

NIST Time and Frequency Radio Stations: WWV, WWVH, and ...  

Science Conference Proceedings (OSTI)

... that would later also become the home of WWV. ... They include heating coils and run year round. ... company provides power through an oil-filled, 500 ...

2012-10-30T23:59:59.000Z

280

19th Topical Conference on Radio Frequency Power in Plasmas ...  

NLE Websites -- All DOE Office Websites (Extended Search)

Join Our Mailing List A Collaborative National Center for Fusion & Plasma Research Search form Search Search Home About Overview Learn More Visiting PPPL History...

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


281

Bootstrap currents in radio-frequency-driven tokamak equilibria  

SciTech Connect

Interest in the bootstrap current arising from neoclassical transport in tokamaks has increased recently in view of certain experimental observations. In this study, the bootstrap current is calculated for a number of rf current-driven tokamaks. Two-dimensional, self-consistent, steady-state tokamak MHD equilibria are obtained by including both the transport-driven bootstrap current and the externally driven rf current. The self-consistency is acomplished by iterating between two-dimensional MHD equilibrium calculations and the current calculations (including bootstrap and rf ray-tracing). Calculations for other reactor parameters of interest are also carried out. It is found that for reactor-grade plasmas, the bootstrap current contribution to the toroidal current is, in general, important. An approxiamte scaling law for GAMMA, based on parametric survey performed, is also obtained. 16 refs., 8 figs., 1 tab.

Hsiao, Ming-Yuan; Ehst, D.A.; Evans, K. Jr.

1988-05-01T23:59:59.000Z

282

NIST Time and Frequency Radio Stations: WWV, WWVH, and ...  

Science Conference Proceedings (OSTI)

... year, depending on weather conditions and irrigation ... The air conditioning units currently in operation ... kVA, Y-connected three-phase transformer. ...

2011-11-16T23:59:59.000Z

283

PREDICTION OF TYPE II SOLAR RADIO BURSTS BY THREE-DIMENSIONAL MHD CORONAL MASS EJECTION AND KINETIC RADIO EMISSION SIMULATIONS  

Science Conference Proceedings (OSTI)

Type II solar radio bursts are the primary radio emissions generated by shocks and they are linked with impending space weather events at Earth. We simulate type II bursts by combining elaborate three-dimensional MHD simulations of realistic coronal mass ejections (CMEs) at the Sun with an analytic kinetic radiation theory developed recently. The modeling includes initialization with solar magnetic and active region fields reconstructed from magnetograms of the Sun, a flux rope of the initial CME dimensioned with STEREO spacecraft observations, and a solar wind driven with averaged empirical data. We demonstrate impressive accuracy in time, frequency, and intensity for the CME and type II burst observed on 2011 February 15. This implies real understanding of the physical processes involved regarding the radio emission excitation by shocks and supports the near-term development of a capability to predict and track these events for space weather prediction.

Schmidt, J. M.; Cairns, Iver H. [School of Physics, University of Sydney, NSW 2006 (Australia); Hillan, D. S., E-mail: jschmidt@physics.usyd.edu.au [CSIRO Earth Science and Resource Engineering, North Ryde, NSW 2113 (Australia)

2013-08-20T23:59:59.000Z

284

Reading Comprehension - Magnets and Electromagnets  

NLE Websites -- All DOE Office Websites (Extended Search)

and electricity When the light television radio electricity is on, you have a magnet, but turn the power off, and you just have a hunk of metal and some wire. Unlike...

285

Structures, systems and methods for harvesting energy from electromagnetic radiation  

DOE Patents (OSTI)

Methods, devices and systems for harvesting energy from electromagnetic radiation are provided including harvesting energy from electromagnetic radiation. In one embodiment, a device includes a substrate and one or more resonance elements disposed in or on the substrate. The resonance elements are configured to have a resonant frequency, for example, in at least one of the infrared, near-infrared and visible light spectra. A layer of conductive material may be disposed over a portion of the substrate to form a ground plane. An optical resonance gap or stand-off layer may be formed between the resonance elements and the ground plane. The optical resonance gap extends a distance between the resonance elements and the layer of conductive material approximately one-quarter wavelength of a wavelength of the at least one resonance element's resonant frequency. At least one energy transfer element may be associated with the at least one resonance element.

Novack, Steven D. (Idaho Falls, ID); Kotter, Dale K. (Shelley, ID); Pinhero, Patrick J. (Columbia, MO)

2011-12-06T23:59:59.000Z

286

Energy harvesting devices for harvesting energy from terahertz electromagnetic radiation  

DOE Patents (OSTI)

Methods, devices and systems for harvesting energy from electromagnetic radiation are provided including harvesting energy from electromagnetic radiation. In one embodiment, a device includes a substrate and one or more resonance elements disposed in or on the substrate. The resonance elements are configured to have a resonant frequency, for example, in at least one of the infrared, near-infrared and visible light spectra. A layer of conductive material may be disposed over a portion of the substrate to form a ground plane. An optical resonance gap or stand-off layer may be formed between the resonance elements and the ground plane. The optical resonance gap extends a distance between the resonance elements and the layer of conductive material approximately one-quarter wavelength of a wavelength of the at least one resonance element's resonant frequency. At least one energy transfer element may be associated with the at least one resonance element.

Novack, Steven D.; Kotter, Dale K.; Pinhero, Patrick J.

2012-10-09T23:59:59.000Z

287

Structures, systems and methods for harvesting energy from electromagnetic radiation  

Science Conference Proceedings (OSTI)

Methods, devices and systems for harvesting energy from electromagnetic radiation are provided including harvesting energy from electromagnetic radiation. In one embodiment, a device includes a substrate and one or more resonance elements disposed in or on the substrate. The resonance elements are configured to have a resonant frequency, for example, in at least one of the infrared, near-infrared and visible light spectra. A layer of conductive material may be disposed over a portion of the substrate to form a ground plane. An optical resonance gap or stand-off layer may be formed between the resonance elements and the ground plane. The optical resonance gap extends a distance between the resonance elements and the layer of conductive material approximately one-quarter wavelength of a wavelength of the at least one resonance element's resonant frequency. At least one energy transfer element may be associated with the at least one resonance element.

Novack, Steven D. (Idaho Falls, ID); Kotter, Dale K. (Shelley, ID); Pinhero, Patrick J. (Columbia, MO)

2011-12-06T23:59:59.000Z

288

THE NEXT GENERATION ATLAS OF QUASAR SPECTRAL ENERGY DISTRIBUTIONS FROM RADIO TO X-RAYS  

SciTech Connect

We have produced the next generation of quasar spectral energy distributions (SEDs), essentially updating the work of Elvis et al. by using high-quality data obtained with several space- and ground-based telescopes, including NASA's Great Observatories. We present an atlas of SEDs of 85 optically bright, non-blazar quasars over the electromagnetic spectrum from radio to X-rays. The heterogeneous sample includes 27 radio-quiet and 58 radio-loud quasars. Most objects have quasi-simultaneous ultraviolet-optical spectroscopic data, supplemented with some far-ultraviolet spectra, and more than half also have Spitzer mid-infrared Infrared Spectrograph spectra. The X-ray spectral parameters are collected from the literature where available. The radio, far-infrared, and near-infrared photometric data are also obtained from either the literature or new observations. We construct composite SEDs for radio-loud and radio-quiet objects and compare these to those of Elvis et al., finding that ours have similar overall shapes, but our improved spectral resolution reveals more detailed features, especially in the mid- and near-infrared.

Shang Zhaohui; Li Jun; Xie Yanxia [Department of Physics, Tianjin Normal University, Tianjin 300387 (China); Brotherton, Michael S.; Cales, Sabrina L.; Dale, Daniel A.; Runnoe, Jessie C.; Kelly, Benjamin J. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Wills, Beverley J.; Wills, D. [Department of Astronomy, University of Texas at Austin, 1 University Station, C1400 Austin, TX 78712 (United States); Green, Richard F. [Large Binocular Telescope Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Nemmen, Rodrigo S. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Gallagher, Sarah C. [Department of Physics and Astronomy, University of Western Ontario, London, ON N6A 3K7 (Canada); Ganguly, Rajib [Department of Computer Science, Engineering, and Physics, University of Michigan-Flint, 213 Murchie Science Building, 303 Kearsley Street, Flint, MI 48502 (United States); Hines, Dean C. [Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 (United States); Kriss, Gerard A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Tang, Baitian, E-mail: zshang@gmail.com [Department of Physics, 1245 Webster Hall, Washington State University, Pullman, WA 99164-2814 (United States)

2011-09-01T23:59:59.000Z

289

Interplanetary Radio Transmission Through Serial Ionospheric and Material Barriers  

Science Conference Proceedings (OSTI)

A usual first principle in planning radio astronomy observations from the earth is that monitoring must be carried out well above the ionospheric plasma cutoff frequency (~5 MHz). Before space probes existed, radio astronomy was almost entirely done above 6 MHz, and this value is considered a practical lower limit by most radio astronomers. Furthermore, daytime ionization (especially D-layer formation) places additional constraints on wave propagation, and waves of frequency below 10-20 MHz suffer significant attenuation. More careful calculations of wave propagation through the earth s ionosphere suggest that for certain conditions (primarily the presence of a magnetic field) there may be a transmission window well below this assumed limit. Indeed, for receiving extraterrestrial radiation below the ionospheric plasma cutoff frequency, a choice of VLF frequency appears optimal to minimize loss. The calculation, experimental validation, and conclusions are presented here. This work demonstrates the possibility of VLF transmission through the ionosphere and various subsequent material barriers. Implications include development of a new robust communications channel, communications with submerged or subterranean receivers / instruments on or offworld, and a new approach to SETI.

Fields, David [ORNL; Kennedy, Robert G [ORNL; Roy, Kenneth I [ORNL; Vacaliuc, Bogdan [ORNL

2013-01-01T23:59:59.000Z

290

V-FASTR: THE VLBA FAST RADIO TRANSIENTS EXPERIMENT  

Science Conference Proceedings (OSTI)

Recent discoveries of dispersed, non-periodic impulsive radio signals with single-dish radio telescopes have sparked significant interest in exploring the relatively uncharted space of fast transient radio signals. Here we describe V-FASTR, an experiment to perform a blind search for fast transient radio signals using the Very Long Baseline Array (VLBA). The experiment runs entirely in a commensal mode, alongside normal VLBA observations and operations. It is made possible by the features and flexibility of the DiFX software correlator that is used to process VLBA data. Using the VLBA for this type of experiment offers significant advantages over single-dish experiments, including a larger field of view, the ability to easily distinguish local radio-frequency interference from real signals, and the possibility to localize detected events on the sky to milliarcsecond accuracy. We describe our software pipeline, which accepts short integration ({approx} ms) spectrometer data from each antenna in real time during correlation and performs an incoherent dedispersion separately for each antenna, over a range of trial dispersion measures. The dedispersed data are processed by a sophisticated detector and candidate events are recorded. At the end of the correlation, small snippets of the raw data at the time of the events are stored for further analysis. We present the results of our event detection pipeline from some test observations of the pulsars B0329+54 and B0531+21 (the Crab pulsar).

Wayth, Randall B.; Tingay, Steven J. [International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth, WA 6845 (Australia); Brisken, Walter F.; Deller, Adam T. [NRAO, P.O. Box O, Socorro, NM 87801 (United States); Majid, Walid A.; Thompson, David R.; Wagstaff, Kiri L., E-mail: randall.wayth@icrar.org [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

2011-07-10T23:59:59.000Z

291

Electromagnetically induced interference at superconducting qubits  

E-Print Network (OSTI)

We study electromagnetically induced interference at superconducting qubits. The interaction between qubits and electromagnetic fields can provide additional coupling channels to qubit states, leading to quantum interference in a microwave driven qubit. In particular, the interwell relaxation or Rabi oscillation, resulting respectively from the multi- or single-mode interaction, can induce effective crossovers. The environment is modeled by a multi-mode thermal bath, generating the interwell relaxation. Relaxation induced interference, independent of the tunnel coupling, provides deeper understanding to the interaction between the qubits and their environment. It also supplies a useful tool to characterize the relaxation strength as well as the characteristic frequency of the bath. In addition, we demonstrate the relaxation can generate population inversion in a strongly driving two-level system. On the other hand, different from Rabi oscillation, Rabi oscillation induced interference involves more complicated and modulated photon exchange thus offers an alternative means to manipulate the qubit, with more controllable parameters including the strength and position of the tunnel coupling. It also provides a testing ground for exploring nonlinear quantum phenomena and quantum state manipulation, in not only the flux qubit but also the systems with no crossover structure, e.g. phase qubits.

Lingjie Du; Yang Yu

2010-12-14T23:59:59.000Z

292

Wavelet-like bases for thin-wire integral equations in electromagnetics  

Science Conference Proceedings (OSTI)

In this paper, wavelets are used in solving, by the method of moments, a modified version of the thin-wire electric field integral equation, in frequency domain. The time domain electromagnetic quantities, are obtained by using the inverse discrete fast ... Keywords: 02.30.Rz, 02.60.Cb, 02.70.-c, 41.20.-q, 41.20.Jb, M-band wavelet transform, Method of moments, Preconditioning, Thin-wire integral equations in electromagnetics

E. Francomano; A. Tortorici; E. Toscano; G. Ala; F. Viola

2005-03-01T23:59:59.000Z

293

Effects of Detuning on Control of Intersubband Quantum Well Transitions with Chirped Electromagnetic Pulses  

Science Conference Proceedings (OSTI)

We study the interaction of a chirped electromagnetic pulse with intersubband transitions of a double semiconductor quantum well. We specifically consider the interaction of the ground and first excited subbands with the electromagnetic field and use the nonlinear density matrix equations for the description of the system dynamics. These equations are solved numerically for various values of the electron sheet density for a realistic double GaAs/AlGaAs quantum well, and the efficiency of population transfer is discussed with emphasis given to the effects of the detuning of the central frequency of the electromagnetic field from resonance.

Blekos, Konstantinos; Terzis, Andreas F. [Physics Department, School of Natural Sciences, University of Patras, Patras 265 04 (Greece); Simserides, Constantinos [Institute of Materials Science, National Center of Scientific Research Demokritos, 153 10 Athens (Greece); Paspalakis, Emmanuel [Materials Science Department, School of Natural Sciences, University of Patras, Patras 265 04 (Greece)

2010-11-10T23:59:59.000Z

294

A Trusted Hybrid Software Radio  

frequencies and communications standards. It would be capable of global interoperability across a variety of frequencies and communications standards.

295

Broadcasting in unreliable radio networks  

E-Print Network (OSTI)

Practitioners agree that unreliable links, which sometimes deliver messages and sometime do not, are an important characteristic of wireless networks. In contrast, most theoretical models of radio networks fix a static set ...

Kuhn, Fabian

296

Broadcasting in Unreliable Radio Networks  

E-Print Network (OSTI)

Practitioners agree that unreliable links, which fluctuate between working and not working, are an important characteristic of wireless networks. In contrast, most theoretical models of radio networks fix a static set of ...

Oshman, Rotem

2010-06-08T23:59:59.000Z

297

Definition: Ground Electromagnetic Techniques | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Ground Electromagnetic Techniques Jump to: navigation, search Dictionary.png Ground Electromagnetic Techniques Ground electromagnetic techniques measure electromagnetic fields in order to determine subsurface electrical resistivity with the earth surface as the observation point.[1] View on Wikipedia Wikipedia Definition The electromagnetic force is one of the four fundamental interactions in nature, the other three being the strong interaction, the weak interaction, and gravitation. This force is described by electromagnetic fields, and has innumerable physical instances including the interaction of electrically charged particles and the interaction of uncharged magnetic force fields with electrical conductors. The word

298

Amplitude calibration of a digital radio antenna array for measuring cosmic ray air showers  

E-Print Network (OSTI)

Radio pulses are emitted during the development of air showers, where air showers are generated by ultra-high energy cosmic rays entering the Earth's atmosphere. These nanosecond short pulses are presently investigated by various experiments for the purpose of using them as a new detection technique for cosmic particles. For an array of 30 digital radio antennas (LOPES experiment) an absolute amplitude calibration of the radio antennas including the full electronic chain of the data acquisition system is performed, in order to estimate absolute values of the electric field strength for these short radio pulses. This is mandatory, because the measured radio signals in the MHz frequency range have to be compared with theoretical estimates and with predictions from Monte Carlo simulations to reconstruct features of the primary cosmic particle. A commercial reference radio emitter is used to estimate frequency dependent correction factors for each single antenna of the radio antenna array. The expected received power is related to the power recorded by the full electronic chain. Systematic uncertainties due to different environmental conditions and the described calibration procedure are of order 20%.

S. Nehls; A. Hakenjos; M. J. Arts; J. Bluemer; H. Bozdog; W. A. van Cappellen; H. Falcke; A. Haungs; A. Horneffer; T. Huege; P. G. Isar; O. Kroemer

2008-02-28T23:59:59.000Z

299

Software-Defined Ultra-wideband Radio Communications: A New RF Technology for Emergency Response Applications  

SciTech Connect

Reliable wireless communication links for local-area (short-range) and regional (long-range) reach capabilities are crucial for emergency response to disasters. Lack of a dependable communication system can result in disruptions in the situational awareness between the local responders in the field and the emergency command and control centers. To date, all wireless communications systems such as cell phones and walkie-talkies use narrowband radio frequency (RF) signaling for data communication. However, the hostile radio propagation environment caused by collapsed structures and rubble in various disaster sites results in significant degradation and attenuation of narrowband RF signals, which ends up in frequent communication breakdowns. To address the challenges of reliable radio communication in disaster fields, we propose an approach to use ultra-wideband (UWB) or wideband RF waveforms for implementation on Software Defined Radio (SDR) platforms. Ultra-wideband communications has been proven by many research groups to be effective in addressing many of the limitations faced by conventional narrowband radio technologies. In addition, LLNL's radio and wireless team have shown significant success in field deployment of various UWB communications system for harsh environments based on LLNL's patented UWB modulation and equalization techniques. Furthermore, using software defined radio platform for UWB communications offers a great deal of flexibility in operational parameters and helps the radio system to dynamically adapt itself to its environment for optimal performance.

Nekoogar, F; Dowla, F

2009-10-19T23:59:59.000Z

300

Reviving Fossil Radio Plasma in Clusters of Galaxies by Adiabatic Compression in Environmental Shock Waves  

E-Print Network (OSTI)

We give for a plasma with a history of several expansion and contraction phases an analytical model of the evolution of a contained relativistic electron population under synchrotron, inverse Compton and adiabatic energy losses or gains. This is applied to different scenarios for evolution of radio plasma inside the cocoons of radio galaxies, after the activity of the central engine has ceased. It is demonstrated that fossil radio plasma with an age of even up to 2 Gyr can be revived by compression in a shock wave of large-scale structure formation, caused during the merging events of galaxy clusters, or by the accretion onto galaxy clusters. We argue, that this is a highly plausible explanation for the observed cluster radio relics, which are the regions of diffuse radio emission found in clusters of galaxies, without any likely parent radio galaxy seen nearby. An implication of this model is the existence of a population of diffuse, ultra-steep spectrum, very low frequency radio sources located inside and possibly outside of clusters of galaxies, tracing the revival of aged fossil radio plasma by the shock waves associated with large-scale structure formation.

Torsten A. Ensslin; Gopal-Krishna

2000-11-06T23:59:59.000Z

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

Measurement and characterization of substation electromagnetic transients. Final report  

SciTech Connect

Little quantitative data exists on radiated electromagnetic interference in substations arising from substation transients. The electromagnetic transient noise produced by normal substation activity such as opening switches and breakers can be significant. Additionally, abnormal events such as faults cause similar electromagnetic noise. The lack of data is in part because suitable measurement equipment techniques have not been generally available to utilities. A new approach to the measurement and characterization of electromagnetic interference caused by substation transients has been developed. A data acquisition system for measurements has been designed and constructed for field use with a bandwidth capability exceeding 100 MHz. Measurements have been taken from staged operations in substations and the resulting data analyzed using specialized computer programs developed for this project. The measurement techniques are presented and the analysis procedures explained in detail. The transients caused by equipment operations in several substations have been studied resulting in an understanding of the expected or typical amplitudes and frequencies of the resulting noise. Suggestions as to equipment tests and withstand levels have been made. An appendix includes raw and analyzed data for research use.

Russell, B.D.

1983-03-01T23:59:59.000Z

302

The ??? Amplitude in an External Homogeneous Electromagnetic  

E-Print Network (OSTI)

Neutrino-photon interactions in the presence of an external homogeneous constant electromagnetic field are studied. The ??? amplitude is calculated in an electromagnetic field of the general type, when the two field invariants are nonzero.

R. Shaisultanov

2000-01-01T23:59:59.000Z

303

Sympathetic Electromagnetically-Induced-Transparency Laser ...  

Science Conference Proceedings (OSTI)

Page 1. Sympathetic Electromagnetically-Induced-Transparency Laser Cooling of Motional Modes in an Ion Chain Y. Lin ...

2013-04-22T23:59:59.000Z

304

Unification of Gravity and Electromagnetism Revisited  

E-Print Network (OSTI)

Unification of gravity and electromagnetism based on a theory with an affine non-symmetric connection $\\Gamma^\\lambda_{\\mu\

Partha Ghose

2013-02-14T23:59:59.000Z

305

Airborne electromagnetic surveys as a reconnaissance technique...  

Open Energy Info (EERE)

electromagnetic surveys as a reconnaissance technique for geothermal exploration Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Airborne...

306

Searching for electromagnetic counterparts of gravitational wave transients  

E-Print Network (OSTI)

A pioneering electromagnetic (EM) observation follow-up program of candidate gravitational wave (GW) triggers has been performed, Dec 17 2009 to Jan 8 2010 and Sep 4 to Oct 20 2010, during the recent LIGO/Virgo run. The follow-up program involved ground-based and space EM facilities observing the sky at optical, X-ray and radio wavelengths. The joint GW/EM observation study requires the development of specific image analysis procedures able to discriminate the possible EM counterpart of GW trigger from background events. The paper shows an overview of the EM follow-up program and the developing image analysis procedures as they are applied to data collected with TAROT and Zadko.

M. Branchesi; on behalf of the LIGO Scientific Collaboration; the Virgo Collaboration; A. Klotz; M. Laas-Bourez

2011-10-14T23:59:59.000Z

307

Electromagnetic SCRF Cavity Tuner  

SciTech Connect

A novel prototype of SCRF cavity tuner is being designed and tested at Fermilab. This is a superconducting C-type iron dominated magnet having a 10 mm gap, axial symmetry, and a 1 Tesla field. Inside the gap is mounted a superconducting coil capable of moving {+-} 1 mm and producing a longitudinal force up to {+-} 1.5 kN. The static force applied to the RF cavity flanges provides a long-term cavity geometry tuning to a nominal frequency. The same coil powered by fast AC current pulse delivers mechanical perturbation for fast cavity tuning. This fast mechanical perturbation could be used to compensate a dynamic RF cavity detuning caused by cavity Lorentz forces and microphonics. A special configuration of magnet system was designed and tested.

Kashikhin, V.; Borissov, E.; Foster, G.W.; Makulski, A.; Pischalnikov, Y.; Khabiboulline, T.; /Fermilab

2009-05-01T23:59:59.000Z

308

Current Sheet Canting in Pulsed Electromagnetic Accelerators  

E-Print Network (OSTI)

Current Sheet Canting in Pulsed Electromagnetic Accelerators Thomas Edward Markusic A DISSERTATION #12;Current Sheet Canting in Pulsed Electromagnetic Accelerators Prepared by: Thomas Edward Markusic of current sheet canting in pulsed electromagnetic accelerators is the de- parture of the plasma sheet

Choueiri, Edgar

309

The courts and electromagnetic fields  

Science Conference Proceedings (OSTI)

This article examines the recent development in eminent domain cases involving power transmission line rights of way, the issue of fear of the mythical buyer. The author feels that the fear of electrocution or of the possible cancer-inducing effects of electromagnetic fields is greatly influencing court decisions in these cases. The results could be more expensive rights of way acquisition by utilities.

Freeman, M. (Univ. of Pennsylvania, Philadelphia (United States))

1990-07-19T23:59:59.000Z

310

A current concern. [Electromagnetic fields  

SciTech Connect

This article examines the risk to homeowners of exposure to electromagnetic fields (EMF). Studies that link EMF to cancer are described and recommendations are given for prudent avoidance. Appliance manufacturers claim to have found no economically feasible way to shield emissions. Meanwhile the EPA's health effects research in this area has been suspended because of budgetary constraints.

Brinckerhoff, S.

1990-09-01T23:59:59.000Z

311

Deep electromagnetic sounding in central Nevada  

DOE Green Energy (OSTI)

Sixteen shallow and deep controlled source electromagnetic soundings were performed in Buena Vista Valley, near Winnemucca, Nevada, to investigate an intra-basement conductor previously detected with magnetotellurics. The survey was carried out with the LBL EM-60 system using a remote magnetic reference for low-frequency geomagnetic noise cancellation, 100-m- and 2.8-km-diameter transmitter loops, and a minicomputer for in-field processing. EM soundings were made at distances from 0.5 to 30 km from three loops over the frequency range 0.02 to 500 Hz. Data were interpreted by means of 1-D inversions and the resulting layered models were pieced together to yield an approximate 2-D geoelectric model along the N-S axis of the valley. The EM soundings and one MT sounding show a 3 to 7 ohm-m zone at a depth of four to seven km. The conductor appears to be deepest at the northern end of the valley and shallowest beneath a basement ridge that seems to divide Buena Vista Valley into two basinal structures. Similar intra-basement conductors are also reported 50 to 75 miles south in the Carson Sink-Fallon areas, suggesting a common source, probably related to an anomalously hot, thin crust.

Wilt, M.; Goldstein, N.E.; Haught, J.R.; Morrison, H.F.

1982-04-01T23:59:59.000Z

312

RapidRadio: Signal Classification and Radio Deployment Framework  

Science Conference Proceedings (OSTI)

In this article, the RapidRadio framework for signal classification and receiver deployment is discussed. The framework is a productivity-enhancing tool that reduces the required knowledge base for implementing a receiver on an FPGA-based SDR platform. ... Keywords: FPGA, signal classification, system synthesis

Jorge A. Surís; Adolfo Recio; Peter Athanas

2012-08-01T23:59:59.000Z

313

Vlf Electromagnetic Investigations Of The Crater And Central Dome Of Mount  

Open Energy Info (EERE)

Vlf Electromagnetic Investigations Of The Crater And Central Dome Of Mount Vlf Electromagnetic Investigations Of The Crater And Central Dome Of Mount St Helens, Washington Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Vlf Electromagnetic Investigations Of The Crater And Central Dome Of Mount St Helens, Washington Details Activities (1) Areas (1) Regions (0) Abstract: A very low frequency (VLF) electromagnetic induction survey in the crater of Mount St. Helens has identified several electrically conductive structures that appear to be associated with thermal anomalies and ground water within the crater. The most interesting of these conductive structures lies beneath the central dome. It is probably a partial melt of dacite similar to that comprising the June 1981 lobe of the central dome. Author(s): James N. Towle

314

Definition: Electromagnetic Profiling Techniques | Open Energy Information  

Open Energy Info (EERE)

Electromagnetic Profiling Techniques Electromagnetic Profiling Techniques Jump to: navigation, search Dictionary.png Electromagnetic Profiling Techniques Electromagnetic profiling techniques map lateral variations in subsurface resistivity.[1] View on Wikipedia Wikipedia Definition Exploration geophysics is the applied branch of geophysics which uses surface methods to measure the physical properties of the subsurface Earth, along with the anomalies in these properties, in order to detect or infer the presence and position of ore minerals, hydrocarbons, geothermal reservoirs, groundwater reservoirs, and other geological structures. Exploration geophysics is the practical application of physical methods (such as seismic, gravitational, magnetic, electrical and electromagnetic) to measure the physical properties of rocks, and in particular, to detect

315

Electromagnetic Sounding Techniques | Open Energy Information  

Open Energy Info (EERE)

Electromagnetic Sounding Techniques Electromagnetic Sounding Techniques (Redirected from Electromagnetic Sounding Methods) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Electromagnetic Sounding Techniques Details Activities (1) Areas (1) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Ground Electromagnetic Techniques Information Provided by Technique Lithology: Rock composition, mineral and clay content Stratigraphic/Structural: Detection of permeable pathways, fracture zones, faults Hydrological: Resistivity influenced by porosity, grain size distribution, permeability, fluid saturation, fluid type and phase state of the pore water

316

Ground Electromagnetic Techniques | Open Energy Information  

Open Energy Info (EERE)

Ground Electromagnetic Techniques Ground Electromagnetic Techniques (Redirected from Ground Electromagnetic Methods) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Ground Electromagnetic Techniques Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Electromagnetic Techniques Information Provided by Technique Lithology: Rock composition, mineral and clay content Stratigraphic/Structural: Detection of permeable pathways, fracture zones, faults Hydrological: Resistivity influenced by porosity, grain size distribution, permeability, fluid saturation, fluid type and phase state of the pore water Thermal: Resistivity influenced by temperature

317

Geometric and Electromagnetic Aspects of Fusion Pore Making  

E-Print Network (OSTI)

For regulated exocytosis, we model the morphology and dynamics of the making of the fusion pore or porosome as a cup-shaped lipoprotein structure (a dimple or pit) on the cytosol side of the plasma membrane. We describe the forming of the dimple by a free boundary problem. We discuss the various forces acting and analyze the magnetic character of the wandering electromagnetic field wave produced by intracellular spatially distributed pulsating (and well observed) release and binding of calcium ions anteceding the bilayer membrane vesicle fusion of exocytosis. Our approach explains the energy efficiency of the observed dimple forming prior to hemifusion and fusion pore, and the observed flickering in secretion. It provides a frame to relate characteristic time length of exocytosis to the frequency, amplitude and direction of propagation of the underlying electromagnetic field wave.

Darya Apushkinskaya; Evgeny Apushkinsky; Bernhelm Booss-Bavnbek; Martin Koch

2009-12-18T23:59:59.000Z

318

Electromagnetic and nuclear radiation detector using micromechanical sensors  

DOE Patents (OSTI)

Electromagnetic and nuclear radiation is detected by micromechanical sensors that can be coated with various interactive materials. As the micromechanical sensors absorb radiation, the sensors bend and/or undergo a shift in resonance characteristics. The bending and resonance changes are detected with high sensitivity by any of several detection methods including optical, capacitive, and piezoresistive methods. Wide bands of the electromagnetic spectrum can be imaged with picoJoule sensitivity, and specific absorptive coatings can be used for selective sensitivity in specific wavelength bands. Microcantilevers coated with optical cross-linking polymers are useful as integrating optical radiation dosimeters. Nuclear radiation dosimetry is possible by fabricating cantilevers from materials that are sensitive to various nuclear particles or radiation. Upon exposure to radiation, the cantilever bends due to stress and its resonance frequency shifts due to changes in elastic properties, based on cantilever shape and properties of the coating.

Thundat, Thomas G. (Knoxville, TN); Warmack, Robert J. (Knoxville, TN); Wachter, Eric A. (Oak Ridge, TN)

2000-01-01T23:59:59.000Z

319

Radio access network power management considering radio over fiber technique for 4G mobile system  

Science Conference Proceedings (OSTI)

Radio over fiber technique was suggested as excelent candidates for 4G radio access network considering large number mobile users. With higher number of base stations, a microwave link presents more disadvantages across base stations in relation to power ... Keywords: 4G mobile system, fiber dispersion, power manaegment, radio access network, radio over fiber

Jalal J. Hamad Ameen; Widad Ismail; Sevia M. Idrus

2011-03-01T23:59:59.000Z

320

Definition: Electromagnetic Techniques | Open Energy Information  

Open Energy Info (EERE)

Electromagnetic Techniques Electromagnetic Techniques The objective of electromagnetic (EM) techniques is to image the electrical resistivity structure of the subsurface through the measurement of naturally- or artificially-generated electromagnetic fields.[1] View on Wikipedia Wikipedia Definition The electromagnetic force is one of the four fundamental interactions in nature, the other three being the strong interaction, the weak interaction, and gravitation. This force is described by electromagnetic fields, and has innumerable physical instances including the interaction of electrically charged particles and the interaction of uncharged magnetic force fields with electrical conductors. The word electromagnetism is a compound form of two Greek terms, ἢλεκτρον, ēlektron, "amber", and μαγνήτης, magnētēs, "magnet". The science

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

Questions and Answers - Which jobs use electromagnets?  

NLE Websites -- All DOE Office Websites (Extended Search)

does adding coils to anelectromagnet make it stronger? does adding coils to an<br>electromagnet make it stronger? Previous Question (Why does adding coils to an electromagnet make it stronger?) Questions and Answers Main Index Next Question (Why is a non-permanent, but long lasting, magnet called a permanent magnet?) Why is a non-permanent, but long lasting,magnet called a permanent magnet? Which jobs use electromagnets? In today's world almost all jobs other than a goat herder use some type of electromagnet. They are everywhere. Electric motors are a type of electromagnet. Cars have dozens of electromagnets that move things or generate electricity. There are all sorts of interesting applications for larger electromagnets. The most obvious and biggest example is electricity. There are some interesting applications like dumping shredded garbage

322

GALAXY CLUSTER ENVIRONMENTS OF RADIO SOURCES  

SciTech Connect

Using the Sloan Digital Sky Survey (SDSS) and the Faint Images of the Radio Sky at Twenty Centimeters (FIRST) catalogs, we examined the optical environments around double-lobed radio sources. Previous studies have shown that multi-component radio sources exhibiting some degree of bending between components are likely to be found in galaxy clusters. Often this radio emission is associated with a cD-type galaxy at the center of a cluster. We cross-correlated the SDSS and FIRST catalogs and measured the richness of the cluster environments surrounding both bent and straight multi-component radio sources. This led to the discovery and classification of a large number of galaxy clusters out to a redshift of z {approx} 0.5. We divided our sample into smaller subgroups based on their optical and radio properties. We find that FR I radio sources are more likely to be found in galaxy clusters than FR II sources. Further, we find that bent radio sources are more often found in galaxy clusters than non-bent radio sources. We also examined the environments around single-component radio sources and find that single-component radio sources are less likely to be associated with galaxy clusters than extended, multi-component radio sources. Bent, visually selected sources are found in clusters or rich groups {approx}78% of the time. Those without optical hosts in SDSS are likely associated with clusters at even higher redshifts, most with redshifts of z>0.7.

Wing, Joshua D.; Blanton, Elizabeth L., E-mail: jwing@bu.edu [Astronomy Department and Institute for Astrophysical Research, Boston University, Boston, MA 02215 (United States)

2011-03-15T23:59:59.000Z

323

'Pirate' radio, convergence and reception in Zimbabwe  

Science Conference Proceedings (OSTI)

Using a qualitative research approach, this study examines the appropriation of digital technologies and their implications for the reception of the so-called 'pirate' radio in Zimbabwe. It specifically explores how the use of the Internet (and its associated ... Keywords: Convergence, Internet, Mobile phone, Oral tradition, Pirate radio, Reception, SMS, SW Radio Africa, Studio 7, Zimbabwe

Hayes Mawindi Mabweazara

2013-08-01T23:59:59.000Z

324

MODELING OF GYROSYNCHROTRON RADIO EMISSION PULSATIONS PRODUCED BY MAGNETOHYDRODYNAMIC LOOP OSCILLATIONS IN SOLAR FLARES  

Science Conference Proceedings (OSTI)

A quantitative study of the observable radio signatures of the sausage, kink, and torsional magnetohydrodynamic (MHD) oscillation modes in flaring coronal loops is performed. Considering first non-zero order effect of these various MHD oscillation modes on the radio source parameters such as magnetic field, line of sight, plasma density and temperature, electron distribution function, and the source dimensions, we compute time-dependent radio emission (spectra and light curves). The radio light curves (of both flux density and degree of polarization) at all considered radio frequencies are then quantified in both time domain (via computation of the full modulation amplitude as a function of frequency) and in Fourier domain (oscillation spectra, phases, and partial modulation amplitude) to form the signatures specific to a particular oscillation mode and/or source parameter regime. We found that the parameter regime and the involved MHD mode can indeed be distinguished using the quantitative measures derived in the modeling. We apply the developed approach to analyze radio burst recorded by Owens Valley Solar Array and report possible detection of the sausage mode oscillation in one (partly occulted) flare and kink or torsional oscillations in another flare.

Mossessian, George; Fleishman, Gregory D. [Center For Solar-Terrestrial Research, New Jersey Institute of Technology, Newark, NJ 07102 (United States)

2012-04-01T23:59:59.000Z

325

Radio detection of high-energy cosmic rays at the Pierre Auger Observatory  

E-Print Network (OSTI)

The southern Auger Observatory provides an excellent test bed to study the radio detection of extensive air showers as an alternative, cost-effective, and accurate tool for cosmic-ray physics. The data from the radio setup can be correlated with those from the well-calibrated baseline detectors of the Pierre Auger Observatory. Furthermore, human-induced radio noise levels at the southern Auger site are relatively low. We have started an R&D program to test various radio-detection concepts. Our studies will reveal Radio Frequency Interferences (RFI) caused by natural effects such as day-night variations, thunderstorms, and by human-made disturbances. These RFI studies are conducted to optimise detection parameters such as antenna design, frequency interval, antenna spacing and signal processing. The data from our initial setups, which presently consist of typically 3 - 4 antennas, will be used to characterise the shower from radio signals and to optimise the initial concepts. Furthermore, the operation of a large detection array requires autonomous detector stations. The current design is aiming at stations with antennas for two polarisations, solar power, wireless communication, and local trigger logic. The results of this initial phase will provide an important stepping stone for the design of a few tens kilometers square engineering array

A. M. van den Berg; for the Pierre Auger Collaboration

2007-08-13T23:59:59.000Z

326

Electromagnetic Interference and the Pacemaker Patient T1-Electromagnetic Interference and the Pacemaker Patient 10/03/03  

E-Print Network (OSTI)

While clinically significant problems with electromagnetic interference (EMI) are rare, a pacemaker’s response to EMI becomes more diverse as technology advances. Pacemaker manufacturers continue to develop interference protection circuitry to keep up with these vast sources of EMI. The pacemaker’s response to EMI is dependent on the characteristics of the EMI, proximity to the interference, available shielding, and the sensing characteristics and polarity of the pacemaker. The pacemaker circuitry is designed to attenuate any interference outside the normal intracardiac range (10 Hz – 100 Hz). This is achieved by using bandpass filters. EMI sources can be broadly classified as galvanic, electromagnetic or magnetic. • Galvanic interference requires direct contact with electrical current. This is most often seen in defibrillation/cardioversion, cautery, TENS units and diathermy. • Electromagnetic or electrically coupled interference does not require direct body contact. This interference is most often seen with arc welders, ham radios, electrical appliances, metal detectors, therapeutic ultrasound and high voltage power lines. • Magnetic interference occurs when a patient comes in close proximity with an intense magnetic field. This is often seen in nuclear magnetic resonance imaging (NMR/MRI) and steel mill induction furnaces. EMI with signal modulation can mimic normal intracardiac signals. When detected, the response to EMI may present itself as a single beat inhibition, total inhibition, noise reversion/asynchronous pacing, rate increase, erratic pacing, or no output. These responses are usually temporary, but can be permanent if the pulse generator circuitry is damaged. A pacemaker’s response to EMI is highly dependent on the specific EMI source, the pacemaker’s mode, and sensing polarity. Included is a list that details the interaction of commonly encountered pacemaker EMI sources. Accompanying this list is a summary table of these sources and reported associated pacemaker responses.

Rev A

1998-01-01T23:59:59.000Z

327

TYPE III RADIO BURSTS PERTURBED BY WEAK CORONAL SHOCKS  

Science Conference Proceedings (OSTI)

Some type III bursts are observed to undergo sudden flux modifications, e.g., reductions and intensifications, when type III beams cross shocks in the upper corona or solar wind. First simulations are presented for type III bursts perturbed by weak coronal shocks, which type III beams traverse. The simulations incorporate spatially localized jumps in plasma density and electron and ion temperatures downstream of a shock. A shock is predicted to produce significant modulations to a type III burst: (1) a broadband flux reduction or frequency gap caused by the shock's density jump, (2) a narrowband flux intensification originating from where the downstream plasma density locally has a small gradient, (3) a possible intensification from the shock front or just upstream, and (4) changes in the frequency drift rate profile and the temporal evolution of radiation flux at frequencies corresponding to the shocked plasma. The modulations are caused primarily by fundamental modifications to the radiation processes in response to the shocked density and temperatures. The predicted intensifications and reductions appear qualitatively consistent with the available small number of reported observations, although it is unclear how representative these observations are. It is demonstrated that a weak shock can cause an otherwise radio-quiet type III beam to produce observable levels of narrowband radio emission. The simulations suggest that type III bursts with frequency-time fine structures may provide a tool to probe shocks in the corona and solar wind, especially for weak shocks that do not radiate by themselves.

Li, B.; Cairns, Iver H. [School of Physics, University of Sydney, New South Wales 2006 (Australia)

2012-07-10T23:59:59.000Z

328

Gene Frequency  

NLE Websites -- All DOE Office Websites (Extended Search)

Gene Frequency Gene Frequency Name: donna Location: N/A Country: N/A Date: N/A Question: If six fingers is a dominant human trait why do we have only five? Replies: This is simple. There are just not many genes in the human population for six fingers. Steve Sample Look in any high school biology book for what is known as Hardy-Weinberg equilibrium. These two scientists (separately) said that gene frequencies do not change much unless something in the environment selects them over other genes. In other words, unless 6 fingers somehow becomes an advantage, and five-fingered people have less of an advantage, the frequency of six fingered people in the population will not necessarily increase. This is the same reason that recessive traits don't disappear from the population. Also, six fingers is not considered attractive and they may not get as many mates. Also, more people are born with six fingers than you might imagine but just have them amputated shortly after birth.

329

Electromagnetic Techniques | Open Energy Information  

Open Energy Info (EERE)

form form View source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit with form History Facebook icon Twitter icon » Electromagnetic Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Electromagnetic Techniques Details Activities (0) Areas (0) Regions (0) NEPA(5) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Electrical Techniques Information Provided by Technique Lithology: Rock composition, mineral and clay content Stratigraphic/Structural: Detection of permeable pathways, fracture zones, faults Hydrological: Resistivity influenced by porosity, grain size distribution, permeability, fluid saturation, fluid type and phase state of the pore water

330

INITIATION AND DEVELOPMENT OF THE WHITE-LIGHT AND RADIO CORONAL MASS EJECTION ON 2001 APRIL 15  

SciTech Connect

The 2001 April 15 event was one of the largest of the last solar cycle. A former study established that this event was associated with a coronal mass ejection (CME) observed both at white light and radio frequencies. This radio CME is illuminated by synchrotron emission from relativistic electrons. In this paper, we investigate the relation of the radio CME to its extreme-ultraviolet (EUV) and white-light counterpart and reach four main conclusions. (1) The radio CME corresponds to the white-light flux rope cavity. (2) The presence of a reconnecting current sheet behind the erupting flux rope is framed, both from below and above, by bursty radio sources. This reconnection is the source of relativistic radiating electrons which are injected down along the reconnected coronal arches and up along the flux rope border forming the radio CME. (3) Radio imaging reveals an important lateral overexpansion in the low corona; this overexpansion is at the origin of compression regions where type II and III bursts are imaged. (4) Already in the initiation phase, radio images reveal large-scale interactions of the source active region (AR) with its surroundings, including another AR and open magnetic fields. Thus, these complementary radio, EUV, and white-light data validate the flux rope eruption model of CMEs.

Demoulin, P.; Pick, M.; Bouteille, A. [LESIA, UMR 8109 CNRS, UPMC, Universite Paris-Diderot, Observatoire de Paris-Meudon, Meudon 92195 (France); Vourlidas, A., E-mail: Pascal.Demoulin@obspm.fr [Space Sciences Division, Naval Research Laboratory, Washington, DC 20375 (United States)

2012-05-10T23:59:59.000Z

331

Comparison between Poissonian and Markovian Primary Traffics in Cognitive Radio Networks  

E-Print Network (OSTI)

Cognitive Radio generates a big interest as a key cost-effective solution for the underutilization of frequency spectrum in legacy communication networks. The objective of this work lies in conducting a performance evaluation of the end-to-end message delivery under both Markovian and Poissonian primary traffics in lossy Cognitive Radio networks. We aim at inferring the most appropriate conditions for an efficient secondary service provision according to the Cognitive Radio network characteristics. Meanwhile, we have performed a general analysis for many still open issues in Cognitive Radio, but at the end only two critical aspects have been considered, namely, the unforeseen primary reclaims in addition to the collided cognitive transmissions due to the Opportunistic Spectrum Sharing. Some graphs, in view of the average Spectral Efficiency, have been computed and plotted to report some comparative results for a given video transmission under the Markovian and the Poissonian primary interruptions.

Chaoub, Abdelaali

2012-01-01T23:59:59.000Z

332

Shear driven electromagnetic drift-waves in a nonuniform dense magnetoplasma  

SciTech Connect

Linear characteristic properties of high- and low-frequency (in comparison with the cyclotron frequency) electromagnetic drift-waves are studied in a nonuniform, dense magnetoplasma (composed of electrons and ions), in the presence of parallel (magnetic field-aligned) velocity shear, by using quantum magnetohydrodynamic model. By applying the drift-approximation (viz., |{partial_derivative} {sub t}|<<{omega}{sub ci}<<{omega}{sub ce}) to the quantum momentum equations, together with the continuity equations and the Poisson equation, we derive the governing equations for electromagnetic drift-waves with the shear flow. These linear equations are then Fourier transformed to obtain the dispersion relation in both high-frequency and low-frequency regimes. The dispersion relations are then discussed under various limiting cases.

Tariq, Sabeen; Mirza, Arshad M. [Theoretical Plasma Physics Group, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Masood, Waqas [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad 44000 (Pakistan); National Center for Physics (NCP), Islamabad 44000 (Pakistan)

2011-08-15T23:59:59.000Z

333

Radio astronomical imaging in the presence of strong radio interference  

E-Print Network (OSTI)

Abstract—Radio-astronomical observations are increasingly contaminated by interference, and suppression techniques become essential. A powerful candidate for interference mitigation is adaptive spatial filtering. We study the effect of spatial filtering techniques on radio-astronomical imaging. Current deconvolution procedures, such as CLEAN, are shown to be unsuitable for spatially filtered data, and the necessary corrections are derived. To that end, we reformulate the imaging (deconvolution/calibration) process as a sequential estimation of the locations of astronomical sources. This not only leads to an extended CLEAN algorithm, but also the formulation allows the insertion of other array signal processing techniques for direction finding and gives estimates of the expected image quality and the amount of interference suppression that can be achieved. Finally, a maximum-likelihood (ML) procedure for the imaging is derived, and an approximate ML image formation technique is proposed to overcome the computational burden involved. Some of the effects of the new algorithms are shown in simulated images. Index Terms—CLEAN, interference mitigation, maximum likelihood, minimum variance, parametric imaging, radio astronomy, spatial filtering, synthesis imaging. I.

Amir Leshem; Alle-jan Van Der Veen

2000-01-01T23:59:59.000Z

334

Problem of the decay instability of electromagnetic waves in a magnetoactive plasma  

SciTech Connect

The processes of decay of transverse electromagnetic waves propagating across a constant magnetic field are considered. The possibility of using these decays for tuning the frequency of the stimulated radiation in the magnetoactive plasma of semiconductors, as well as for the diagnostics of the magnetic fields that spontaneously develop in a laser plasma is discussed.

Roslyakov, V.A.; Starostin, A.N.

1977-11-01T23:59:59.000Z

335

A RADIO-SELECTED SAMPLE OF GAMMA-RAY BURST AFTERGLOWS  

SciTech Connect

We present a catalog of radio afterglow observations of gamma-ray bursts (GRBs) over a 14 year period from 1997 to 2011. Our sample of 304 afterglows consists of 2995 flux density measurements (including upper limits) at frequencies between 0.6 GHz and 660 GHz, with the majority of data taken at 8.5 GHz frequency band (1539 measurements). We use this data set to carry out a statistical analysis of the radio-selected sample. The detection rate of radio afterglows has stayed unchanged almost at 31% before and after the launch of the Swift satellite. The canonical long-duration GRB radio light curve at 8.5 GHz peaks at three to six days in the source rest frame, with a median peak luminosity of 10{sup 31} erg s{sup -1} Hz{sup -1}. The peak radio luminosities for short-hard bursts, X-ray flashes, and the supernova-GRB classes are an order of magnitude or more fainter than this value. There are clear relationships between the detectability of a radio afterglow and the fluence or energy of a GRB, and the X-ray or optical brightness of the afterglow. However, we find few significant correlations between these same GRB and afterglow properties and the peak radio flux density. We also produce synthetic light curves at centimeter and millimeter bands using a range of blast wave and microphysics parameters derived from multiwavelength afterglow modeling, and we use them to compare to the radio sample. Finding agreement, we extrapolate this behavior to predict the centimeter and millimeter behavior of GRBs observed by the Expanded Very Large Array and the Atacama Large Millimeter Array.

Chandra, Poonam [Department of Physics, Royal Military College of Canada, Kingston, ON K7M3C9 (Canada); Frail, Dale A., E-mail: Poonam.Chandra@rmc.ca [National Radio Astronomy Observatory, Socorro, NM 87801 (United States)

2012-02-20T23:59:59.000Z

336

Molecular based magnets comprising vanadium tetracyanoethylene complexes for shielding electromagnetic fields  

DOE Patents (OSTI)

The invention presents a vanadium tetracyanoethylene solvent complex for electromagnetic field shielding, and a method for blocking low frequency and magnetic fields using these vanadium tetracyanoethylene compositions. The compositions of the invention can be produced at ambient temperature and are light weight, low density and flexible. The materials of the present invention are useful as magnetic shields to block low frequency fields and static fields, and for use in cores in transformers and motors.

Epstein, Arthur J. (Columbus, OH); Morin, Brian G. (Columbus, OH)

1998-01-01T23:59:59.000Z

337

Molecular based magnets comprising vanadium tetracyanoethylene complexes for shielding electromagnetic fields  

DOE Patents (OSTI)

The invention presents a vanadium tetracyanoethylene solvent complex for electromagnetic field shielding, and a method for blocking low frequency and magnetic fields using these vanadium tetracyanoethylene compositions. The compositions of the invention can be produced at ambient temperature and are light weight, low density and flexible. The materials of the present invention are useful as magnetic shields to block low frequency fields and static fields, and for use in cores in transformers and motors. 21 figs.

Epstein, A.J.; Morin, B.G.

1998-10-13T23:59:59.000Z

338

Generator On-Line Monitoring and Condition Assessment, Partial Discharge and Electromagnetic Interference  

Science Conference Proceedings (OSTI)

On-line partial discharge (PD) and electromagnetic interference (EMI) analysis systems have been promoted as a means to assess the condition of turbine-driven generator stator winding insulation systems. Although PD is a time-domain measurement and EMI measures activity with a frequency scan, both techniques still evaluate the same phenomenon -- high-frequency currents that flow as a result of electrical (partial) discharges occurring within the structure. This report documents EPRI's ongoing initiative ...

2004-09-10T23:59:59.000Z

339

Category:Electromagnetic Sounding Techniques | Open Energy Information  

Open Energy Info (EERE)

Electromagnetic Sounding Techniques Electromagnetic Sounding Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Electromagnetic Sounding Techniques page? For detailed information on Electromagnetic Sounding Techniques, click here. Category:Electromagnetic Sounding Techniques Add.png Add a new Electromagnetic Sounding Techniques Technique Subcategories This category has only the following subcategory. M [×] Magnetotelluric Techniques‎ 1 pages Pages in category "Electromagnetic Sounding Techniques" The following 2 pages are in this category, out of 2 total. M Magnetotelluric Techniques T Time-Domain Electromagnetics Retrieved from "http://en.openei.org/w/index.php?title=Category:Electromagnetic_Sounding_Techniques&oldid=689837"

340

DO RADIO MAGNETARS PSR J1550-5418 AND J1622-4950 HAVE GIGAHERTZ-PEAKED SPECTRA?  

Science Conference Proceedings (OSTI)

We study the radio spectra of two magnetars, PSR J1550-5418 and J1622-4950. We argue that they are good candidates for pulsars with gigahertz-peaked spectra (GPS), as their observed flux density decreases at frequencies below 7 GHz. We suggest that this behavior is due to the influence of the pulsars' environments on radio waves. Both of the magnetars are associated with supernova remnants and thus are surrounded by hot, ionized gas, which can be responsible for the free-free absorption of radio waves. We conclude that the GPS feature of both magnetars and typical pulsars are formed by similar processes in the surrounding media rather than by different radio-emission mechanisms. Thus, the radio magnetars PSR J1550-5418 and J1622-4950 can be included in the class of GPS pulsars.

Kijak, J.; Tarczewski, L.; Lewandowski, W. [Kepler Institute of Astronomy, University of Zielona Gora, Lubuska 2, 65-265 Zielona Gora (Poland); Melikidze, G., E-mail: jkijak@astro.ia.uz.zgora.pl [Also at Abastumani Astrophysical Observatory, Ilia State University, 3-5 Cholokashvili Avenue, Tbilisi 0160, Georgia. (Georgia)

2013-07-20T23:59:59.000Z

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

Electromagnetic Transients Program (EMTP) Application Guide  

Science Conference Proceedings (OSTI)

The electromagnetic transients program is a versatile computer program that utilities worldwide use to analyze high-speed power system transients. This application guide provides procedures and data to assist engineers experienced in electromagnetic transient analysis based on EMTP.BackgroundThe electromagnetic transients program (EMTP), developed in the early 1970s by the Bonneville Power Administration (BPA), has been widely used for transient analysis. To ...

1986-12-08T23:59:59.000Z

342

Electromagnetic Profiling Techniques | Open Energy Information  

Open Energy Info (EERE)

Electromagnetic Profiling Techniques Electromagnetic Profiling Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Electromagnetic Profiling Techniques Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Ground Electromagnetic Techniques Information Provided by Technique Lithology: Rock composition, mineral and clay content Stratigraphic/Structural: Detection of permeable pathways, fracture zones, faults Hydrological: Resistivity influenced by porosity, grain size distribution, permeability, fluid saturation, fluid type and phase state of the pore water Thermal: Resistivity influenced by temperature

343

Ground Electromagnetic Techniques | Open Energy Information  

Open Energy Info (EERE)

Ground Electromagnetic Techniques Ground Electromagnetic Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Ground Electromagnetic Techniques Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Electromagnetic Techniques Information Provided by Technique Lithology: Rock composition, mineral and clay content Stratigraphic/Structural: Detection of permeable pathways, fracture zones, faults Hydrological: Resistivity influenced by porosity, grain size distribution, permeability, fluid saturation, fluid type and phase state of the pore water Thermal: Resistivity influenced by temperature Dictionary.png

344

Crosswell Electromagnetic Resistivity Imaging: Illuminating the Reservior |  

Open Energy Info (EERE)

Page Page Edit with form History Facebook icon Twitter icon » Crosswell Electromagnetic Resistivity Imaging: Illuminating the Reservior Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Crosswell Electromagnetic Resistivity Imaging: Illuminating the Reservior Published Middle East Asia Reservior Reviiew, 2006 DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for Crosswell Electromagnetic Resistivity Imaging: Illuminating the Reservior Citation Crosswell Electromagnetic Resistivity Imaging: Illuminating the Reservior [Internet]. 2006. Middle East Asia Reservior Reviiew. [cited 2013/10/22]. Available from: http://www.slb.com/~/media/Files/resources/mearr/num7/illuminating_reservoir.pdf Retrieved from

345

Electromagnetic Sounding Techniques | Open Energy Information  

Open Energy Info (EERE)

Electromagnetic Sounding Techniques Electromagnetic Sounding Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Electromagnetic Sounding Techniques Details Activities (1) Areas (1) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Ground Electromagnetic Techniques Information Provided by Technique Lithology: Rock composition, mineral and clay content Stratigraphic/Structural: Detection of permeable pathways, fracture zones, faults Hydrological: Resistivity influenced by porosity, grain size distribution, permeability, fluid saturation, fluid type and phase state of the pore water Thermal: Resistivity influenced by temperature

346

Time-Domain Electromagnetics | Open Energy Information  

Open Energy Info (EERE)

Time-Domain Electromagnetics Time-Domain Electromagnetics Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Time-Domain Electromagnetics Details Activities (10) Areas (10) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Electromagnetic Sounding Techniques Information Provided by Technique Lithology: Detection of rock units or geological features with contrasting apparent resistivity. Stratigraphic/Structural: Structural information may be inferred from TDEM data. Hydrological: Hydrological information such as depth to groundwater table may be determined. Thermal: Extent of hydrothermal alteration mineralogy may be inferred. Cost Information

347

Definition: Electromagnetic Sounding Techniques | Open Energy...  

Open Energy Info (EERE)

Sounding Techniques Electromagnetic soundings aim to map the distribution of electrical resistivity as a function of depth.1 References http:www.amazon.com...

348

22.105 Electromagnetic Interactions, Fall 1998  

E-Print Network (OSTI)

Principles and applications of electromagnetism, starting from Maxwell's equations, with emphasis on phenomena important to nuclear engineering and radiation sciences. Solution methods for electrostatic and magnetostatic ...

Hutchinson, I. H. (Ian H.)

349

Algebraic sub-structuring for electromagnetic applications  

E-Print Network (OSTI)

Li, I. Malik, W. M i , C. Ng, and M . Wolf. ElectromagneticP. Husbands, and E. G. Ng. An Alge- braic Sub-structuring

2004-01-01T23:59:59.000Z

350

The Triggering and Bias of Radio Galaxies  

E-Print Network (OSTI)

We present new results on the clustering and three-dimensional distribution of radio galaxies from the Texas-Oxford NVSS Structure (TONS) survey. The TONS survey was constructed to look at the distribution of radio galaxies in a region of moderate (0 3 mJy) radio galaxies over large areas on the sky. We find that redshift spikes, which represent large concentrations of radio galaxies which trace (~ 100 Mpc^3) super-structures are a common phenomena in these surveys. Under the assumption of quasi-linear structure formation theory and a canonical radio galaxy bias, the structures represent ~ 4-5 sigma peaks in the primordial density field and their expected number is low. The most plausible explanation for these low probabilities is an increase in the radio galaxy bias with redshift. To investigate potential mechanisms which have triggered the radio activity in these galaxies - and hence may account for an increase in the bias of this population, we performed imaging studies of the cluster environment of the radio galaxies in super-structure regions. Preliminary results show that these radio galaxies may reside preferentially at the edges of rich clusters. If radio galaxies are preferentially triggered as they fall towards rich clusters then they would effectively adopt the cluster bias.

Kate Brand; Steve Rawlings; Joe Tufts; Gary Hill

2004-03-16T23:59:59.000Z

351

Measurements of ion cyclotron range of frequencies mode converted wave intensity with phase contrast imaging in Alcator C-Mod and comparison with full-wave simulations  

E-Print Network (OSTI)

Radio frequency waves in the ion cyclotron range of frequencies (ICRF) are widely used to heat tokamak plasmas. In ICRF heating schemes involving multiple ion species, the launched fast waves convert to ion cyclotron waves ...

Jaeger, E. F.

352

ISM band to U-NII band frequency transverter and method of frequency transversion  

DOE Patents (OSTI)

A frequency transverter (10) and method for enabling bi-frequency dual-directional transfer of digitally encoded data on an RF carrier by translating between a crowded or otherwise undesirable first frequency band, such as the 2.4 GHz ISM band, and a less-crowded or otherwise desirable second frequency band, such as the 5.0 GHz 6.0 GHz U-NII band. In a preferred embodiment, the transverter (10) connects between an existing data radio (11) and its existing antenna (30), and comprises a bandswitch (12); an input RF isolating device (14); a transmuter (16); a converter (18); a dual output local oscillator (20); an output RF isolating device (22); and an antenna (24) tuned to the second frequency band. The bandswitch (12) allows for bypassing the transverter (10), thereby facilitating its use with legacy systems. The transmuter (14) and converter (16) are adapted to convert to and from, respectively, the second frequency band.

Stepp, Jeffrey David (Grandview, MO); Hensley, Dale (Grandview, MO)

2006-09-12T23:59:59.000Z

353

ISM band to U-NII band frequency transverter and method of frequency transversion  

DOE Patents (OSTI)

A frequency transverter (10) and method for enabling bi-frequency dual-directional transfer of digitally encoded data on an RF carrier by translating between a crowded or otherwise undesirable first frequency band, such as the 2.4 GHz ISM band, and a less-crowded or otherwise desirable second frequency band, such as the 5.0 GHz-6.0 GHz U-NII band. In a preferred embodiment, the transverter (10) connects between an existing data radio (11) and its existing antenna (30), and comprises a bandswitch (12); an input RF isolating device (14); a transmuter (16); a converter (18); a dual output local oscillator (20); an output RF isolating device (22); and an antenna (24) tuned to the second frequency band. The bandswitch (12) allows for bypassing the transverter (10), thereby facilitating its use with legacy systems. The transmuter (14) and converter (16) are adapted to convert to and from, respectively, the second frequency band.

Stepp, Jeffrey David (Grandview, MO); Hensley, Dale (Grandview, MO)

2006-04-04T23:59:59.000Z

354

Concerning mechanisms for the zebra pattern formation in the solar radio emission  

SciTech Connect

The nature of the zebra patterns in continuous type-IV solar radio bursts is discussed. The most comprehensively developed models of such patterns involve mechanisms based on the double plasma resonance and plasma wave-whistler interaction. Over the last five years, there have appeared a dozen papers concerning the refinement of the mechanism based on the double plasma resonance, because, in its initial formulation, this mechanism failed to describe many features of the zebra pattern. It is shown that the improved model of this mechanism with a power-law distribution function of hot electrons within the loss cone is inapplicable to the coronal plasma. In recent papers, the formation of the zebra pattern in the course of electromagnetic wave propagation through the solar corona was considered. In the present paper, all these models are estimated comparatively. An analysis of recent theories shows that any types of zebra patterns can form in the course of radio wave propagation in the corona, provided that there are plasma inhomogeneities of different scales on the wave path. The superfine structure of zebra stripes in the form of millisecond spikes with a strict period of {approx}30 ms can be attributed to the generation of continuous radio emission in the radio source itself, assuming that plasma inhomogeneities are formed by a finite-amplitude wave with the same period.

Laptukhov, A. I.; Chernov, G. P. [Russian Academy of Sciences, Pushkov Institute of Terrestrial Magnetism, Ionosphere, and Radio-Wave Propagation (Russian Federation)

2009-02-15T23:59:59.000Z

355

Optimal monitoring in multi-channel multi-radio wireless mesh networks  

Science Conference Proceedings (OSTI)

Wireless mesh networks (WMN) are finding increasing usage in city-wide deployments for providing network connectivity. Mesh routers in WMNs typically use multiple wireless channels to enhance the spatial-reuse of frequency bands, often with multiple ... Keywords: approximation algorithm, lp rounding, multi-channel multi-radio wireless networks, security monitoring, wireless mesh networks

Dong-Hoon Shin; Saurabh Bagchi

2009-05-01T23:59:59.000Z

356

A 610-MHz Galactic Plane Pulsar Search with the Giant Meterwave Radio Telescope  

E-Print Network (OSTI)

We report on the discovery of three new pulsars in the first blind survey of the north Galactic plane (45 < l < 135 ; |b| < 1) with the Giant Meterwave Radio telescope (GMRT) at an intermediate frequency of 610 MHz. The timing parameters, obtained in follow up observations with the Lovell Telescope at Jodrell Bank Observatory and the GMRT, are presented.

B. C. Joshi; M. A. McLaughlin; M. Kramer; A. G. Lyne; D. R. Lorimer; D. A. Ludovici; M. Davies; A. J. Faulkner

2007-10-16T23:59:59.000Z

357

Electromagnetic weak turbulence theory revisited  

SciTech Connect

The statistical mechanical reformulation of weak turbulence theory for unmagnetized plasmas including fully electromagnetic effects was carried out by Yoon [Phys. Plasmas 13, 022302 (2006)]. However, the wave kinetic equation for the transverse wave ignores the nonlinear three-wave interaction that involves two transverse waves and a Langmuir wave, the incoherent analogue of the so-called Raman scattering process, which may account for the third and higher-harmonic plasma emissions. The present paper extends the previous formalism by including such a term.

Yoon, P. H. [IPST, University of Maryland, College Park, Maryland 20742 (United States); Ziebell, L. F. [Instituto de Fisica, UFRGS, Porto Alegre, RS (Brazil); Gaelzer, R.; Pavan, J. [Instituto de Fisica e Matematica, UFPel, Pelotas, RS (Brazil)

2012-10-15T23:59:59.000Z

358

Category:Ground Electromagnetic Techniques | Open Energy Information  

Open Energy Info (EERE)

Ground Electromagnetic Techniques Ground Electromagnetic Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Ground Electromagnetic Techniques page? For detailed information on Ground Electromagnetic Techniques, click here. Category:Ground Electromagnetic Techniques Add.png Add a new Ground Electromagnetic Techniques Technique Subcategories This category has the following 2 subcategories, out of 2 total. E [×] Electromagnetic Profiling Techniques‎ 1 pages [+] Electromagnetic Sounding Techniques‎ (1 categories) 2 pages Pages in category "Ground Electromagnetic Techniques" The following 2 pages are in this category, out of 2 total. E Electromagnetic Profiling Techniques Electromagnetic Sounding Techniques Retrieved from "http://en.openei.org/w/index.php?title=Category:Ground_Electromagnetic_Techniques&oldid=689834"

359

Magnetic field effect on stimulated Raman scattering of electromagnetic waves from nanoparticle lattice  

Science Conference Proceedings (OSTI)

The influence of a static magnetic field on the Raman scattering of a millimeter pump wave propagating through periodic nanoparticles is studied. Formulas for the growth rate of the scattered electromagnetic wave and the electrostatic wave are derived and analyzed. It is found that the growth rate for the backscattering case is larger than that of forward scattering and the growth rate is increased by the static magnetic field. A resonance in the dispersion relation of the electromagnetic wave is found as a combination of the cyclotron and plasma frequency. However, no instability was found for this lower branch of the dispersion curve.

Chakhmachi, A. [Plasma Physics and Nuclear Fusion Research School, Nuclear Science and Technology Research Institute, P.O. Box 14155-1339, Tehran (Iran, Islamic Republic of); Maraghechi, B. [Department of Physics, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran, Islamic Republic of)

2011-02-15T23:59:59.000Z

360

Electromagnetic energy within magnetic spheres  

E-Print Network (OSTI)

Consider that an incident plane wave is scattered by a homogeneous and isotropic magnetic sphere of finite radius. We determine, by means of the rigorous Mie theory, an exact expression for the time-averaged electromagnetic energy within this particle. For magnetic scatterers, we find that the value of the average internal energy in the resonance picks is much larger than the one associated with a scatterer with the same nonmagnetic medium properties. This result is valid even, and specially, for low size parameter values. Expressions for the contributions of the radial and angular field components to the internal energy are determined. For the analytical study of the weak absorption regime, we derive an exact expression for the absorption cross section in terms of the magnetic Mie internal coefficients. We stress that although the electromagnetic scattering by particles is a well-documented topic, almost no attention has been devoted to magnetic scatterers. Our aim is to provide some new analytical results, which can be used for magnetic particles, and empha- size the unusual properties of the magnetic scatters, which could be important in some applications.

Tiago Jose Arruda; Alexandre Souto Martinez

2010-10-14T23:59:59.000Z

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

Electromagnetic form factors of hadrons  

SciTech Connect

A vector meson dominance model of the electromagnetic form factors of hadrons is developed which is based on the use of unstable particle propagators. Least-square fits are made to the proton, neutron, pion and kaon form factor data in both the space and time-like regions. A good fit to the low-energy nucleon form factor data is obtained using only rho, $omega$, and phi dominance, and leads to a determination of the vector meson resonance parameters in good agreement with experiment. The nucleon-vector meson coupling constants obey simple sum rules indicating that there exists no hard core contribution to the form factors within theoretical uncertainties. The prediction for the electromagnetic radii of the proton is in reasonable agreement with recent experiments. The pion and kaon charge form factors as deduced from the nucleon form factors assuming vector meson universality are compared to the data. The pion form factor agrees with the data in both the space and time-like regions. The pion charge radius is in agreement with the recent Dubna result, but the isovector P-wave pion-pion phase shift calculated from the theory disagrees with experiment. A possible contribution to the form factors from a heavy rho meson is also evaluated. (auth)

Zidell, V.S.

1976-01-01T23:59:59.000Z

362

Available Technologies: Nanotube Radio for Communications and ...  

APPLICATIONS OF TECHNOLOGY: All-in-one radio receiver for cell phones/wireless networks/GPS and other electronic devices

363

NIST Radio Station WWV Broadcast Format  

Science Conference Proceedings (OSTI)

... 2, Space Weather for the past 24 hours has been severe. Solar radiation storm(s) reaching the S4 level is in progress. Radio ...

2011-12-22T23:59:59.000Z

364

NIST Radio Stations WWV/WWVH  

Science Conference Proceedings (OSTI)

... 2, Space Weather for the past 24 hours has been severe. Solar radiation storm(s) reaching the S4 level is in progress. Radio ...

2010-10-05T23:59:59.000Z

365

Electromagnetic Transients Program (EMTP) Workbook II  

Science Conference Proceedings (OSTI)

The complex and versatile EMTP computer program can help utilities analyze electromagnetic transients, which affect the design and operation of power systems. A workbook published in 1986 introduced basic EMTP concepts.To guide advanced users, EPRI and the EMTP Development Coordination Group cosponsored the preparation of three workbooks on complicated program applications.BackgroundStudies of electromagnetic transients were traditionally performed with special ...

1989-07-18T23:59:59.000Z

366

Electromagnetic Transients Program (EMTP) Workbook IV  

Science Conference Proceedings (OSTI)

The complex and versatile EMTP computer program can help utilities analyze electromagnetic transients, which affect the design and operation of power systems. A workbook published in 1986 introduced basic EMTP concepts. To guide advanced users, EPRI and the EMTP Development Coordination Group cosponsored the preparation of three workbooks on complicated program applications.BackgroundStudies of electromagnetic transients were traditionally performed with special ...

1989-07-18T23:59:59.000Z

367

Electromagnetic Transients Program (EMTP) Workbook III  

Science Conference Proceedings (OSTI)

The complex and versatile EMTP computer program can help utilities analyze electromagnetic transients, which affect the design and operation of power systems. A workbook published in 1986 introduced basic EMTP concepts.To guide advanced users, EPRI and the EMTP Development Coordination Group cosponsored the preparation of three workbooks on complicated program applications.BackgroundStudies of electromagnetic transients were traditionally performed with special ...

1989-07-06T23:59:59.000Z

368

Survey on solar X-ray flares and associated coherent radio emissions  

E-Print Network (OSTI)

The radio emission during 201 X-ray selected solar flares was surveyed from 100 MHz to 4 GHz with the Phoenix-2 spectrometer of ETH Zurich. The selection includes all RHESSI flares larger than C5.0 jointly observed from launch until June 30, 2003. Detailed association rates of radio emission during X-ray flares are reported. In the decimeter wavelength range, type III bursts and the genuinely decimetric emissions (pulsations, continua, and narrowband spikes) were found equally frequently. Both occur predominantly in the peak phase of hard X-ray (HXR) emission, but are less in tune with HXRs than the high-frequency continuum exceeding 4 GHz, attributed to gyrosynchrotron radiation. In 10% of the HXR flares, an intense radiation of the above genuine decimetric types followed in the decay phase or later. Classic meter-wave type III bursts are associated in 33% of all HXR flares, but only in 4% they are the exclusive radio emission. Noise storms were the only radio emission in 5% of the HXR flares, some of them with extended duration. Despite the spatial association (same active region), the noise storm variations are found to be only loosely correlated in time with the X-ray flux. In a surprising 17% of the HXR flares, no coherent radio emission was found in the extremely broad band surveyed. The association but loose correlation between HXR and coherent radio emission is interpreted by multiple reconnection sites connected by common field lines.

Arnold O. Benz; Paolo Grigis; Andre Csillagy; Pascal Saint-Hilaire

2004-10-19T23:59:59.000Z

369

A Search for the Radio Counterpart to the March 1, 1994 Gamma Ray Burst  

E-Print Network (OSTI)

We report on the results of a search for the radio counterpart to the bright gamma-ray burst of March 1, 1994. Using the Dominion Radio Astrophysical Observatory Synthesis Telescope sensitive, wide-field radio images at 1.4 GHz and 0.4 GHz were made of a region around GRB940301. A total of 15 separate radio images were obtained at each frequency, sampling a near-continuous range of post-burst timescales between 3 and 15 days, as well as 26, 47 and 99 days. We place an upper limit of 3.5 mJy on a fading/flaring radio counterpart at 1.4 GHz and 55 mJy at 0.4 GHz. Previous searches have concentrated on searching for a counterpart at only one epoch following the outburst. In contrast, the present search maintains high sensitivity over two decades of post-burst time durations. Time-variable radio emission after the initial gamma-ray burst is a prediction of all fireball models, currently the most popular model for gamma-ray bursts. Our observations allow us to put significant constraints on the fireball parameters for cosmological models of gamma-ray bursts.

Frail; Kulkarni; Hurley; Fishman; Kouveliotou; Meegan; Sommer; Boer; Niel; Cline

1994-09-12T23:59:59.000Z

370

Revised equipartition & minimum energy formula for magnetic field strength estimates from radio synchrotron observations  

E-Print Network (OSTI)

The commonly used classical equipartition or minimum-energy estimate of total magnetic fields strengths from radio synchrotron intensities is of limited practical use because it is based on the hardly known ratio K of the total energies of cosmic ray protons and electrons and also has inherent problems. We present a revised formula, using the number density ratio K for which we give estimates. For particle acceleration in strong shocks K is about 40 and increases with decreasing shock strength. Our revised estimate for the field strength gives larger values than the classical estimate for flat radio spectra with spectral indices of about 0.5-0.6, but smaller values for steep spectra and total fields stronger than about 10 muG. In very young supernova remnants, for example, the classical estimate may be too large by up to 10x. On the other hand, if energy losses of cosmic ray electrons are important, K increases with particle energy and the equipartition field may be underestimated significantly. Our revised larger equipartition estimates in galaxy clusters and radio lobes are consistent with independent estimates from Faraday rotation measures, while estimates from the ratio between radio synchrotron and X-ray inverse Compton intensities generally give much weaker fields. This may be explained e.g. by a concentration of the field in filaments. Our revised field strengths may also lead to major revisions of electron lifetimes in jets and radio lobes estimated from the synchrotron break frequency in the radio spectrum.

Rainer Beck; Marita Krause

2005-07-15T23:59:59.000Z

371

Mathematical model of the seismic electromagnetic signals (SEMS) in non crystalline substances  

Science Conference Proceedings (OSTI)

The mathematical model of seismic electromagnetic waves in non crystalline substances is developed and the solutions are discussed to show the possibility of improving the electromagnetic waves especially the electric field. The shear stress of the medium in fourth order tensor gives the equation of motion. Analytic methods are selected for the solutions written in Hansen vector form. From the simulated SEMS, the frequency of seismic waves has significant effects to the SEMS propagating characteristics. EM waves transform into SEMS or energized seismic waves. Traveling distance increases once the frequency of the seismic waves increases from 100% to 1000%. SEMS with greater seismic frequency will give seismic alike waves but greater energy is embedded by EM waves and hence further distance the waves travel.

Dennis, L. C. C.; Yahya, N.; Daud, H.; Shafie, A. [Electromagnetic cluster, Universiti Teknologi Petronas, 31750 Tronoh, Perak (Malaysia)

2012-09-26T23:59:59.000Z

372

Noninvasive valve monitor using alternating electromagnetic field  

SciTech Connect

One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.

Eissenberg, David M. (Oak Ridge, TN); Haynes, Howard D. (Knoxville, TN); Casada, Donald A. (Knoxville, TN)

1993-01-01T23:59:59.000Z

373

High-resolution radio observations of submillimetre galaxies  

E-Print Network (OSTI)

We have produced sensitive, high-resolution radio maps of 12 SMGs in the Lockman Hole using combined MERLIN and VLA data at a frequency of 1.4 GHz. Integrating for 350hr yielded an r.m.s. noise of 6.0 uJy/beam and a resolution of 0.2-0.5". For the first time, wide-field data from the two arrays have been combined in the (u,v) plane and the bandwidth smearing response of the VLA data has been removed. All of the SMGs are detected in our maps as well as sources comprising a non-submm luminous control sample. We find evidence that SMGs are more extended than the general uJy radio population and that therefore, unlike in local ULIRGs, the starburst component of the radio emission is extended and not confined to the galactic nucleus. For the eight sources with redshifts we measure linear sizes between 1 and 8 kpc with a median of 5 kpc. Therefore, they are in general larger than local ULIRGs which may support an early-stage merger scenario for the starburst trigger. X-rays betray AGN in six of the 33 sources in the combined sample. All but one of these are in the control sample, suggesting a lower incidence of AGN amongst the submm-luminous galaxies which is, in turn, consistent with increased X-ray absorption in these dust-obscured starbursts. Only one of our sources is resolved into multiple, distinct components with our high-resolution data. Finally, compared to a previous study of faint radio sources in the GOODS-N field we find systematically smaller source sizes and no evidence for a tail extending to ~4". Possible reasons for this are discussed.

A. D. Biggs; R. J. Ivison

2007-12-18T23:59:59.000Z

374

Plasma Frequency Shift Due to a Slowly Rotating Compact Star  

E-Print Network (OSTI)

We investigate the effects of a slowly rotating compact gravitational source on plasma oscillations using the gravitoelectromagnetic approximation to General Relativity. It is shown that there is a shift in the plasma frequency and hence in the refractive index of the plasma due to the gravitomagnetic force. Estimates for the difference in frequency of radially transmitted electromagnetic signals are given for typical compact star candidates. 1

Babur M. Mirza; Hamid Saleem

2005-01-01T23:59:59.000Z

375

Post-outburst radio observation of the region around McNeil's nebula (V1647 Ori)  

E-Print Network (OSTI)

We present post-outburst (~ 100 days after outburst) radio continuum observation of the region (~ 30' x 30') around McNeil's nebula (V1647 Orionis). The observations were carried out using the Giant Metrewave Radio Telescope (GMRT), India, at 1272 MHz on 2004 Feb 14.5 UT. Although 8 sources have been detected within a circular diameter of 25' centred on V1647 Ori, we did not detect any radio continuum emission from McNeil's nebula. We assign a 5-sigma upper limit of 0.15 mJy/beam for V1647 Ori where the beam size is 5.6" x 2.7". Even at higher frequencies of 4.9 and 8.5 GHz (VLA archival data), no radio emission has been detected from this region. Three scenarios namely, emission from homogeneous HII region, ionised stellar wind and shock ionised gas, are explored in the light of our GMRT upper-limit. For the case of homogeneous HII region, the radius of the emitting region is constrained to be ~ 2,500 K, which is consistent with the reported radio and H-alpha emission. In the ionised stellar wind picture, our upper limit of radio emission translates to the ratio of mass loss rate and terminal velocity, (M_dot/v_infinity) wind shocks the dense neutral (molecular) cloud, the radio upper limit implies that the fraction of the wind encountering the dense obstacle is ~ 7.2 x 10^7 cm^(-3) of the radio emitting plasma have been constrained using a two phase medium in pressure equilibrium for a volume filling factor of 0.9.

S. Vig; S. K. Ghosh; V. K. Kulkarni; D. K. Ojha

2005-10-15T23:59:59.000Z

376

The depolarisation properties of powerful extragalactic radio sources as a function of cosmic epoch  

E-Print Network (OSTI)

We use the observed polarisation properties of a sample of 26 powerful radio galaxies and radio-loud quasars to constrain the conditions in the Faraday screens local to the sources. We adopt the cosmological redshift, low-frequency radio luminosity and physical size of the large-scale radio structures as our `fundamental' parameters. We find no correlation of the radio spectral index with any of the fundamental parameters. The observed rotation measure is also independent of these parameters. The difference between the rotation measures of the two lobes of an individual source as well as the dispersion of the rotation measure show significant correlations with the source redshift, but not with the radio luminosity or source size. Thus the small-scale structure observed in the rotation measure is caused by a Faraday screen local to the sources. The observed asymmetries between the lobes of our sources show no significant trends with each other or other source properties. Finally, we show that the commonly used model for the depolarisation of synchrotron radio emission by foreground Faraday screens is inconsistent with our observations. We apply alternative models to our data and show that they require a strong increase of the dispersion of the rotation measure inside the Faraday screens with cosmological redshift. Correcting our observations with these models for redshift effects, we find a strong correlation of the depolarisation measure with redshift and a significantly weaker correlation with radio luminosity. All our results are consistent with a decrease in the order of the magnetic field structure of the Faraday screen local to the sources for increasing cosmological redshift. (abridged)

J. A. Goodlet; C. R. Kaiser

2005-03-08T23:59:59.000Z

377

Electromagnetic Imaging of CO2 Sequestration at an Enhanced Oil Recovery Site  

NLE Websites -- All DOE Office Websites (Extended Search)

Electromagnetic Imaging of CO Electromagnetic Imaging of CO 2 Sequestration at an Enhanced Oil Recovery Site Barry Kirkendall (Kirkendall1@llnl.gov ; 925-423-1513) Jeff Roberts (Roberts17@llnl.gov ; 925-422-7108) Lawrence Livermore National Laboratory 7000 East Avenue Livermore, CA 94550 1.1 Introduction Lawrence Livermore National Laboratory (LLNL) is currently involved in a long term study using time-lapse multiple frequency electromagnetic (EM) characterization at a waterflood enhanced oil recovery (EOR) site in California operated by Chevron Heavy Oil Division in Lost Hills, California (Figure 1). The petroleum industry's interest and the successful imaging results from this project suggest that this technique be extended to monitor CO 2 sequestration at an EOR site also operated by Chevron. The impetus for this study is

378

New radio observations of QSO 0957+561 confirm optical-to radio time delay  

E-Print Network (OSTI)

In our previous publications have been reported about possible time delay between optical and radio (6 cm) variations in QSO 0957+561 and noted that the result can be tested with new radio observations. Here we have made this test using new published (Haarasma et al., 1999) radio observations of the object in 6 cm and 4 cm. We have found that the new observations confirm optical-to-radio time delay. Additionally we have found that radio 6 cm variations followed 4 cm ones with time delay about 230 days. Obtained results imply existence of the variable beamed hard radiation in the nucleus of the QSO.

V. L. Oknyanskij

2005-02-02T23:59:59.000Z

379

CONSTRAINING THE VELA PULSAR'S RADIO EMISSION REGION USING NYQUIST-LIMITED SCINTILLATION STATISTICS  

SciTech Connect

Using a novel technique, we achieve {approx}100 picoarcsec resolution and set an upper bound of less than 4 km for the characteristic size of the Vela pulsar's emission region. Specifically, we analyze flux-density statistics of the Vela pulsar at 760 MHz. Because the pulsar exhibits strong diffractive scintillation, these statistics convey information about the spatial extent of the radio emission region. We measure both a characteristic size of the emission region and the emission sizes for individual pulses. Our results imply that the radio emission altitude for the Vela pulsar at this frequency is less than 340 km.

Johnson, M. D.; Gwinn, C. R. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Demorest, P., E-mail: michaeltdh@physics.ucsb.edu, E-mail: cgwinn@physics.ucsb.edu, E-mail: pdemores@nrao.edu [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22093 (United States)

2012-10-10T23:59:59.000Z

380

The new amateur radio university network: AMUNET  

Science Conference Proceedings (OSTI)

The intention of this paper is to give the readers an opportunity to become familiar with nonofficial and often ad-hoc constructed, computerized amateur radio networks, that might be easily used as AMUNETs - the digital links between university centers, ... Keywords: ADL, AMUNET, amateur radio, communication, computer, education, rural area, university

Miroslav Skoric

2005-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

Review: Cognitive radio network security: A survey  

Science Conference Proceedings (OSTI)

Recent advancements in wireless communication are creating a spectrum shortage problem on a daily basis. Recently, Cognitive Radio (CR), a novel technology, has attempted to minimize this problem by dynamically using the free spectrum in wireless communications ... Keywords: Attacks, Primary users, Radio, Secondary users, Security, Trust

Sazia Parvin; Farookh Khadeer Hussain; Omar Khadeer Hussain; Song Han; Biming Tian; Elizabeth Chang

2012-11-01T23:59:59.000Z

382

Radio channel modeling for mobile ad hoc wireless networks .  

E-Print Network (OSTI)

??The radio channel places fundamental limitations on the performance of mobile ad hoc wireless networks. In the mobile radio environment, fading due to multipath delay… (more)

Sng, Sin Hie

2004-01-01T23:59:59.000Z

383

Underground radio technology saves miners and emergency response...  

NLE Websites -- All DOE Office Websites (Extended Search)

Underground radio technology saves miners and emergency response personnel Underground radio technology saves miners and emergency response personnel Founded through LANL, Vital...

384

The crosswell electromagnetic response of layered media  

SciTech Connect

Crosswell electromagnetic measurements are a promising new geophysical technique for mapping subsurface electrical conductivity which can provide information about the subsurface distribution of water, oil or steam. In this work the fields from a low frequency vertical magnetic dipole have been examined from the specific point of view of their application to the determination of the conductivity of a layered medium. The source and the receiver were placed inside two separate boreholes. The range of penetration of such a crosswell system for typical earth resistivities and for currently available transmitter and receiver technologies was found to be up to 1,000 meters so problems in ground water and petroleum reservoir characteristics can be practically examined. An analysis of the behavior of the magnetic fields at the boundary between two half-spaces showed that the horizontal magnetic field component, H{rho}, and the vertical derivative of a vertical component, {delta}H{sub z}/{delta}z, are more sensitive to conductivity variations than H{sub z}. The analysis of derivatives led to the concept of measuring the conductivity directly using a second vertical derivative of H{sub z}. Conductivity profiles interpreted from field data using this technique reproduced accurately the electrical logs for a test site near Devine, Texas. It was found in this study that the inversion techniques are more stable when the first vertical derivative of H{sub z} is used rather than H{sub z} itself. Using data from a salt water injection experiment at the Richmond Field test site in Berkeley it was also found that these robust layer inversions were successful in identifying the preferential flow direction of the injected brine to four boreholes surrounding the injection well.

Deszcz-Pan, M. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering]|[Lawrence Berkeley Lab., CA (United States). Earth Sciences Div.

1994-04-01T23:59:59.000Z

385

Cold atmospheric pressure plasma jets: Interaction with plasmid DNA and tailored electron heating using dual-frequency excitation  

SciTech Connect

Recent progress in plasma science and technology has enabled the development of a new generation of stable cold non-equilibrium plasmas operating at ambient atmospheric pressure. This opens horizons for new plasma technologies, in particular in the emerging field of plasma medicine. These non-equilibrium plasmas are very efficient sources for energy transport through reactive neutral particles (radicals and metastables), charged particles (ions and electrons), UV radiation, and electro-magnetic fields. The effect of a cold radio frequency-driven atmospheric pressure plasma jet on plasmid DNA has been investigated. The formation of double strand breaks correlates well with the atomic oxygen density. Taken with other measurements, this indicates that neutral components in the jet are effective in inducing double strand breaks. Plasma manipulation techniques for controlled energy delivery are highly desirable. Numerical simulations are employed for detailed investigations of the electron dynamics, which determines the generation of reactive species. New concepts based on nonlinear power dissipation promise superior strategies to control energy transport for tailored technological exploitations.

Niemi, K.; O'Neill, C.; Cox, L. J.; Waskoenig, J.; Hyland, W. B.; McMahon, S. J.; Reuter, S.; Currell, F. J.; Graham, W. G.; O'Connell, D.; Gans, T. [Centre for Plasma Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland (United Kingdom)

2012-05-25T23:59:59.000Z

386

Synchronizing carrier frequencies of co-channel amplitude-modulated broadcast  

DOE Patents (OSTI)

Systems and methods are described for carrier-frequency synchronization for improved AM and TV broadcast reception. A method includes synchronizing a carrier frequency of a broadcast signal with a remote reference frequency. An apparatus includes a reference signal receiver; a phase comparator coupled to the reference signal receiver; a voltage controlled oscillator coupled to the phase comparator; and a radio frequency output coupled to the voltage controlled oscillator.

Smith, Stephen F. (London, TN); Moore, James A. (Powell, TN)

2007-05-15T23:59:59.000Z

387

Low frequency indoor radiolocation  

E-Print Network (OSTI)

This thesis concerns the application of electromagnetic wave propagation to the problem of indoor radiolocation. Determining the location of people and objects relative to their environment is crucial for asset tracking, ...

Reynolds, Matthew S. (Matthew Stephen), 1975-

2003-01-01T23:59:59.000Z

388

System analysis of a negative impedance converter receiver for ultra low frequencies  

Science Conference Proceedings (OSTI)

Monitoring electromagnetic waves in the Ultra Low Frequency (ULF) range between 1 mHz and 1 Hz is essential for an understanding of the processes in the earths magnetosphere. Also earthquake prone areas are under suspect to emit precursor ULF signals. ... Keywords: magnetosphere, negative impedance convert, system analysis, ultra low frequency

Ernst D. Schmitter

2008-07-01T23:59:59.000Z

389

Reinforcement learning based sensing policy optimization for energy efficient cognitive radio networks  

E-Print Network (OSTI)

This paper introduces a machine learning based collaborative multi band spectrum sensing policy for cognitive radios. The proposed sensing policy guides secondary users to focus the search of unused radio spectrum to those frequencies that persistently provide them high data rate. The proposed policy is based on machine learning, which makes it adaptive with the temporally and spatially varying radio spectrum. Furthermore, there is no need for dynamic modeling of the primary activity since it is implicitly learned over time. Energy efficiency is achieved by minimizing the number of assigned sensors per each subband under a constraint on miss detection probability. It is important to control the missed detections because they cause collisions with primary transmissions and lead to retransmissions at both the primary and secondary user. The minimization of the number of active sensors is formulated as a binary integer programming problem. Simulations show that the proposed machine learning based sensing policy ...

Oksanen, Jan; Koivunen, Visa

2011-01-01T23:59:59.000Z

390

Airborne Electromagnetic Survey | Open Energy Information  

Open Energy Info (EERE)

Airborne Electromagnetic Survey Airborne Electromagnetic Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Airborne Electromagnetic Survey Details Activities (2) Areas (2) Regions (0) NEPA(1) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Electromagnetic Techniques Information Provided by Technique Lithology: provide data on rock type and mineral content Stratigraphic/Structural: Hydrological: can be used to detect changes in density of fluids and indicate if there is salt water intrusion Thermal: Cost Information Low-End Estimate (USD): 48.274,827 centUSD 0.0483 kUSD 4.827e-5 MUSD 4.827e-8 TUSD / mile Median Estimate (USD): 317.3831,738 centUSD 0.317 kUSD

391

Magnesium Metal Matrix Nanocomposites By Electromagnetic ...  

Science Conference Proceedings (OSTI)

EMAT transforms electromagnetic energy into high intensity sonication to induce ... In the current work, the physics of acoustic production, the initial conditions of ... Department of Energy's Energy Efficiency and Renewable Energy Industrial ...

392

Electrical, electromagnetic, and magnetotelluric methods | Open Energy  

Open Energy Info (EERE)

Electrical, electromagnetic, and magnetotelluric methods Electrical, electromagnetic, and magnetotelluric methods Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Electrical, electromagnetic, and magnetotelluric methods Abstract Application of electrical methods began with Robert W. Fox's 1830 observation of self potentials associated with copper vein deposits in Cornwall. Conrad Schlumberger introduced the direct current equal potential line resistivity method in 1912. Harry W. Conklin received the first patents on the electromagnetic (EM) method in 1917. From these beginnings, the history of the development of the resistivity induced-polarization (IP), magnetotelluric and EM methods are traced to the present time. It is of interest to note that application of electrical methods flourished from

393

Do you know what an electromagnet is?  

NLE Websites -- All DOE Office Websites (Extended Search)

Do you know what an electromagnet is? Boy did you come to the right place and ask the right question. Jefferson Lab is magnet central to the world. Several of the world's most...

394

An Acoustic Doppler and Electromagnetic Velocity Profiler  

Science Conference Proceedings (OSTI)

A freely failing current meter called the Absolute Velocity Profiler (AVP) is described. This profiler is an expansion of a previously developed instrument, the Electro-Magnetic Velocity Profiler (EMVP), with the additional capability of acoustic ...

Thomas B. Sanford; Robert G. Driver; John H. Dunlap

1985-06-01T23:59:59.000Z

395

SP-100 thermoelectric-electromagnetic pump review  

DOE Green Energy (OSTI)

This report contains vugraphs of a presentation on thermoelectric-electromagnetic pumps. It contains: engineering drawings; summary of rectangular TEMP results and comparison with GE predictions; and results of optimization study.

NONE

1988-12-31T23:59:59.000Z

396

Advances in non-planar electromagnetic prototyping  

E-Print Network (OSTI)

The advent of metamaterials has introduced new ways to manipulate how electromagnetic waves reflect, refract and radiate in systems where the range of available material properties now includes negative permittivity, ...

Ehrenberg, Isaac M

2013-01-01T23:59:59.000Z

397

Electromagnetic Pulse (EMP) and the Power Grid  

Science Conference Proceedings (OSTI)

This document provides background and an introduction to the topic of electromagnetic pulse (EMP, including high-altitude EMP or HEMP) for stakeholders concerned about potential damage to power grid infrastructures.

2013-08-21T23:59:59.000Z

398

Dynamic programming applied to electromagnetic satellite actuation  

E-Print Network (OSTI)

Electromagnetic formation flight (EMFF) is an enabling technology for a number of space mission architectures. While much work has been done for EMFF control for large separation distances, little work has been done for ...

Eslinger, Gregory John

2013-01-01T23:59:59.000Z

399

Electrical wire insulation and electromagnetic coil  

DOE Patents (OSTI)

An electromagnetic coil for high temperature and high radiation application in which glass is used to insulate the electrical wire. A process for applying the insulation to the wire is disclosed which results in improved insulation properties.

Bich, George J. (Penn Hills, PA); Gupta, Tapan K. (Monroeville, PA)

1984-01-01T23:59:59.000Z

400

Time and Frequency Portal  

Science Conference Proceedings (OSTI)

NIST Home > Time and Frequency Portal. Time and Frequency Portal. Programs and Projects. CODATA values of the fundamental constants ...

2013-06-27T23:59:59.000Z

Note: This page contains sample records for the topic "radio frequency electromagnetic" 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

DIFFUSIVE SHOCK ACCELERATION SIMULATIONS OF RADIO RELICS  

Science Conference Proceedings (OSTI)

Recent radio observations have identified a class of structures, so-called radio relics, in clusters of galaxies. The radio emission from these sources is interpreted as synchrotron radiation from GeV electrons gyrating in {mu}G-level magnetic fields. Radio relics, located mostly in the outskirts of clusters, seem to associate with shock waves, especially those developed during mergers. In fact, they seem to be good structures to identify and probe such shocks in intracluster media (ICMs), provided we understand the electron acceleration and re-acceleration at those shocks. In this paper, we describe time-dependent simulations for diffusive shock acceleration at weak shocks that are expected to be found in ICMs. Freshly injected as well as pre-existing populations of cosmic-ray (CR) electrons are considered, and energy losses via synchrotron and inverse Compton are included. We then compare the synchrotron flux and spectral distributions estimated from the simulations with those in two well-observed radio relics in CIZA J2242.8+5301 and ZwCl0008.8+5215. Considering that CR electron injection is expected to be rather inefficient at weak shocks with Mach number M {approx}< a few, the existence of radio relics could indicate the pre-existing population of low-energy CR electrons in ICMs. The implication of our results on the merger shock scenario of radio relics is discussed.

Kang, Hyesung [Department of Earth Sciences, Pusan National University, Pusan 609-735 (Korea, Republic of); Ryu, Dongsu [Department of Astronomy and Space Science, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Jones, T. W., E-mail: kang@uju.es.pusan.ac.kr, E-mail: ryu@canopus.cnu.ac.kr, E-mail: twj@msi.umn.edu [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

2012-09-01T23:59:59.000Z

402

Generating highly uniform electromagnetic field characteristics  

DOE Patents (OSTI)

An apparatus and method for generating homogenous electromagnetic fields within a volume. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially canceling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set.

Crow, James T. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

403

Generating highly uniform electromagnetic field characteristics  

DOE Patents (OSTI)

An apparatus and method for generating homogenous electromagnetic fields within a volume. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented mirror symmetrically about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially canceling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set.

Crow, James Terry (Albuquerque, NM)

1998-01-01T23:59:59.000Z

404

Generating highly uniform electromagnetic field characteristics  

DOE Patents (OSTI)

An apparatus and method for generating homogenous electromagnetic fields within a volume. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented mirror symmetrically about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially cancelling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set.

Crow, James T. (Albuquerque, NM)

1997-01-01T23:59:59.000Z

405

Generating highly uniform electromagnetic field characteristics  

DOE Patents (OSTI)

An apparatus and method are disclosed for generating homogeneous electromagnetic fields within a volume. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented mirror symmetrically about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially canceling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set. 26 figs.

Crow, J.T.

1997-06-24T23:59:59.000Z

406

Generating highly uniform electromagnetic field characteristics  

DOE Patents (OSTI)

An apparatus and method for generating homogeneous electromagnetic fields within a volume is disclosed. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented mirror symmetrically about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially canceling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set. 39 figs.

Crow, J.T.

1998-02-10T23:59:59.000Z

407

Generating highly uniform electromagnetic field characteristics  

DOE Patents (OSTI)

An apparatus and method are disclosed for generating homogeneous electromagnetic fields within a volume. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially canceling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set. 55 figs.

Crow, J.T.

1998-05-05T23:59:59.000Z

408

Composite materials for electromagnetic shielding  

Science Conference Proceedings (OSTI)

The paper shows up the research results on processing and characterization of composite materials with polymeric matrix (silicone rubber). The materials obtained in laboratory contain metallized nettling like reinforcement material and powdery graphite ... Keywords: attenuation, filling additions, frequency, plated nettling, polymeric composite on de basis of silicone rubber, shielding effectiveness

Stoian Elena Valentina; Rizescu Cristiana; Iordache Iulian; Ionita Gheorghe; Bacinschi Zorica

2010-07-01T23:59:59.000Z

409

An Integrated Risk Management Strategy for High-Impact, Low-Frequency (HILF) Events  

Science Conference Proceedings (OSTI)

Although the American electric system is one of the most reliable power systems in the world, it is vulnerable to events that rarely occur, but could have devastating impact. Collectively called high-impact, low-frequency (HILF) events, these include coordinated attacks, pandemics, severe geomagnetic disturbances (GMDs), electromagnetic pulse weapons (EMPs), and high-altitude electromagnetic pulse weapons (HEMPs). Industry has little experience in dealing with these events and lacks an integrated ...

2012-10-31T23:59:59.000Z

410

A self-calibration scheme for extended frequency-band-decomposition sigma-delta ADC  

Science Conference Proceedings (OSTI)

Frequency-band-decomposition (FBD) is a good candidate to be used to increase the bandwidths of ADC converters based on sigma-delta modulators for software and cognitive radio applications where we need to convert wide bandwidths. Each modulator processes ... Keywords: Analog-to-digital conversion, Bandpass, Filter bank, Frequency-band-decomposition, Self-calibration, Sigma-delta

Philippe Benabes; Ali Beydoun

2010-03-01T23:59:59.000Z

411

'Radio Wave Cooling' Offers New Twist on Laser Cooling  

Science Conference Proceedings (OSTI)

'Radio Wave Cooling' Offers New Twist on Laser Cooling. From NIST Tech Beat: September 13, 2007. ...

2013-07-08T23:59:59.000Z

412

Electromagnetic Transient-Type Transformer Models for Geomagnetically-Induced Current (GIC) Studies  

Science Conference Proceedings (OSTI)

The simulation of geomagnetically-induced currents (GICs) requires adequate low-frequency transformer models. This report discusses models used for electromagnetic transient (EMT) studies in EMT-type simulation tools. Because transformers may saturate in the presence of GICs, the proper representation of transformer nonlinear behavior is important for understanding the impact of GIC on power system reliability. Other parameters, such as winding losses and core losses, will change the dc current flow ...

2013-11-20T23:59:59.000Z

413

LIMITS ON PROMPT, DISPERSED RADIO PULSES FROM GAMMA-RAY BURSTS  

Science Conference Proceedings (OSTI)

We have searched for prompt radio emission from nine gamma-ray bursts (GRBs) with a 12 m telescope at 1.4 GHz, with a time resolution of 64 {mu}s to 1 s. We detected single dispersed radio pulses with significances >6{sigma} in the few minutes following two GRBs. The dispersion measures of both pulses are well in excess of the expected Galactic values, and the implied rate is incompatible with known sources of single dispersed pulses. The arrival times of both pulses also coincide with breaks in the GRB X-ray light curves. A null trial and statistical arguments rule out random fluctuations as the origin of these pulses with >95% and {approx}97% confidence, respectively, although a simple population argument supports a GRB origin with confidence of only 2%. We caution that we cannot rule out radio frequency interference (RFI) as the origin of these pulses. If the single pulses are not related to the GRBs, we set an upper limit on the flux density of radio pulses emitted between 200 and 1800 s after a GRB of 1.27w {sup -1/2} Jy, where 6.4 Multiplication-Sign 10{sup -5} s 1 s) variations. These limits are some of the most constraining at high time resolution and GHz frequencies in the early stages of the GRB phenomenon.

Bannister, K. W.; Murphy, T.; Gaensler, B. M. [Sydney Institute for Astronomy (SIfA), School of Physics A29, University of Sydney, NSW 2006 (Australia); Reynolds, J. E., E-mail: keith.bannister@csiro.au [CSIRO Astronomy and Space Science, P.O. Box 76, Epping, NSW 1710 (Australia)

2012-09-20T23:59:59.000Z

414

External control of ion waves in a plasma by high frequency fields  

DOE Patents (OSTI)

An apparatus and method are described for stabilizing plasma instabilities, in a magnetically confined plasma column by transmitting into the plasma high frequency electromagnetic waves at a frequency close to the electron plasma frequency. The said frequencies, e.g., are between the plasma frequency and 1.5 times the plasma frequency at a power level below the level for producing parametric instabilities in a plasma having temperatures from below 10 eV to about 10 keV or more, at densities from below 10/sup 13/ to above 10/sup 18/ particles/cm/sup 3/. (Official Gazette)

Kaw, P.K.; Dawson, J.M.

1973-12-18T23:59:59.000Z

415

GNSS radio occultation constellation observing system experiments  

Science Conference Proceedings (OSTI)

Observing system experiments within the operational ECMWF data assimilation framework have been performed for summer 2008 when the largest recorded number of GNSS radio occultation observations from both operational and experimental satellites ...

Peter Bauer; Gábor Radnóti; Sean Healy; Carla Cardinali

416

Errors in Radio Acoustic Sounding of Temperature  

Science Conference Proceedings (OSTI)

With the use of simultaneous correction for radial wind, the accuracy of radio acoustic sounding systems for the measurement of temperature has been substantially improved. The temperature accuracy can now be affected by a number of factors that ...

Wayne M. Angevine; W. L. Ecklund

1994-06-01T23:59:59.000Z

417

Electrical, electromagnetic and structural characteristics of carbon nanotube-polymer nanocomposites  

E-Print Network (OSTI)

Composites for Electromagnetic Interference Shielding. NanoY. Ma, et al. Electromagnetic Interference (EMI) Shieldingof Bonn). Chung DDL. Electromagnetic interference shielding

Park, Sung-Hoon

2009-01-01T23:59:59.000Z

418

Kinetically Dominated FRII Radio Sources  

E-Print Network (OSTI)

The existence of FR II objects that are kinetically dominated, the jet kinetic luminosity, $Q$, is larger than the total thermal luminosity (IR to X-ray) of the accretion flow, $L_{bol}$, is of profound theoretical interest. Such objects are not expected in most theoretical models of the central engine of radio loud AGN. Thus, establishing such a class of objects is an important diagnostic for filtering through the myriad of theoretical possibilities. This paper attempts to establish a class of quasars that have existed in a state of kinetic dominance, $R(t)\\equiv Q(t)/L_{bol}(t)>1$, at some epoch, $t$. It is argued that the 10 quasars in this article with a long term time average $Q(t)$, $\\bar{Q}$, that exceed $L_{Edd}$ are likely to have satisfied the condition $R(t)>1$ either presently or in the past based on the rarity of $L_{bol}>L_{Edd}$ quasars. Finally, the existence of these sources is discussed in the context of the theory of the central engine.

Brian Punsly

2006-10-02T23:59:59.000Z

419

Extremely high frequency RF effects on electronics.  

SciTech Connect

The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.

Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale; Williams, Jeffery Thomas; Wouters, Gregg A.; Bacon, Larry Donald; Mar, Alan

2012-01-01T23:59:59.000Z

420

Strong-field spatial interference in a tailored electromagnetic bath  

E-Print Network (OSTI)

Light scattered by a regular structure of atoms can exhibit interference signatures, similar to the classical double-slit. These first-order interferences, however, vanish for strong light intensities, restricting potential applications. Here, we show how to overcome these limitations to quantum interference in strong fields. First, we recover the first-order interference in strong fields via a tailored electromagnetic bath with a suitable frequency dependence. At strong driving, the optical properties for different spectral bands are distinct, thus extending the set of observables. We further show that for a two-photon detector as, e.g., in lithography, increasing the field intensity leads to twice the spatial resolution of the second-order interference pattern compared to the weak-field case.

M. Macovei; J. Evers; G. -x. Li; C. H. Keitel

2006-06-19T23:59:59.000Z

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421

Evaluation of borehole electromagnetic and seismic detection of fractures  

DOE Green Energy (OSTI)

Experiments were conducted to establish the feasibility of downhole high-frequency techniques for location of fractures in the vicinity of boreholes. An existing flame-cut slot in granite was filled with salt water to simulate a brine-filled fracture. The first method used an electromagnetic wave at 30 to 300 MHz, vhf frequencies. A transmitter consisting of a phased dual-dipole array arranged to provide a directional signal toward the fracture was installed in a borehole opposite the fracture. A receiver was also located in the same borehole. The radar returns from the simulated fracture were detectable in boreholes located at distances of up to 12 meters from the fracture. These results indicate for the first time the feasibility of a downhole vhf radar for use in a single borehole for detection of fractures located away from the borehole. Similar experiments were also conducted using seismic waves at 4.5 to 6 KHz. The transmitter and the receiver in this case were located in separate boreholes. During this experiment, reflections from the slot were obtained only with the transducers oriented for shear wave illumination and detection. These results suggest that a high-frequency shear wave can also be used to detect fractures away from a borehole.

Chang, H.T.; Suhler, S.A.; Owen, T.E.

1984-02-01T23:59:59.000Z

422

GMRT study of X-shaped radio sources  

E-Print Network (OSTI)

Context. The nature of X-shaped sources is a matter of considerable debate in the literature: it has even been proposed that they provide evidence for black-hole-mergers/spin-reorientation, and therefore constrain the rate of strong gravitational wave events. Aim. To explore the nature of these X-shaped radio galaxies. Method. We conduct a systematic study of a large sample of known and newly discovered X-shaped sources along with a comparison sample. We used the Giant Metrewave Radio Telescope with resolution of $\\sim6^{\\prime\\prime}$ to $\\sim15^{\\prime\\prime}$ at 610 MHz and 240 MHz in the dual-frequency mode. Preliminary Result. Based on our careful analysis and estimation of the possible systematic errors, the known X-shaped sources divide into the following three categories: (i) the wings have flatter spectral indices than the active lobes, (ii) the wings and the active lobes have comparable spectral indices, and (iii) the wings have steeper spectral indices than the active lobes. In addition, based on our preliminary analysis, one sample source from our comparison sample shows a spectral index result belonging to category (i). Future. Milliarcsecond scale imaging will be conducted on some of these X-shaped sources to investigate if they are examples of binary AGN systems and thereby understand the nature of these sources.

Dharam Vir Lal; A. Pramesh Rao; Martin J. Hardcastle; C. C. Cheung; Sanjay Bhatnagar; Ralph P. Kraft; Andrei P. Lobanov; Anton J. Zensus

2008-10-06T23:59:59.000Z

423

LOW-FREQUENCY OBSERVATIONS OF THE MOON WITH THE MURCHISON WIDEFIELD ARRAY  

SciTech Connect

A new generation of low-frequency radio telescopes is seeking to observe the redshifted 21 cm signal from the epoch of reionization (EoR), requiring innovative methods of calibration and imaging to overcome the difficulties of wide-field low-frequency radio interferometry. Precise calibration will be required to separate the expected small EoR signal from the strong foreground emission at the frequencies of interest between 80 and 300 MHz. The Moon may be useful as a calibration source for detection of the EoR signature, as it should have a smooth and predictable thermal spectrum across the frequency band of interest. Initial observations of the Moon with the Murchison Widefield Array 32 tile prototype show that the Moon does exhibit a similar trend to that expected for a cool thermally emitting body in the observed frequency range, but that the spectrum is corrupted by reflected radio emission from Earth. In particular, there is an abrupt increase in the observed flux density of the Moon within the internationally recognized frequency modulated (FM) radio band. The observations have implications for future low-frequency surveys and EoR detection experiments that will need to take this reflected emission from the Moon into account. The results also allow us to estimate the equivalent isotropic power emitted by the Earth in the FM band and to determine how bright the Earth might appear at meter wavelengths to an observer beyond our own solar system.

McKinley, B.; Briggs, F. [Research School of Astronomy and Astrophysics, Australian National University, Canberra (Australia); Kaplan, D. L. [Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI (United States); Greenhill, L. J.; Bernardi, G.; De Oliveira-Costa, A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Bowman, J. D. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ (United States); Tingay, S. J.; Gaensler, B. M. [ARC Centre of Excellence for All-Sky Astrophysics (CAASTRO), School of Physics, The University of Sydney, Sydney, NSW (Australia); Oberoi, D. [National Centre for Radio Astrophysics, Tata Institute for Fundamental Research, Pune (India); Johnston-Hollitt, M. [School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington (New Zealand); Arcus, W.; Emrich, D. [International Centre for Radio Astronomy Research, Curtin University, Perth (Australia); Barnes, D. [Center for Astrophysics and Supercomputing, Swinburne University of Technology, Melbourne (Australia); Bunton, J. D. [CSIRO Astronomy and Space Science, Canberra (Australia); Cappallo, R. J.; Corey, B. E. [MIT Haystack Observatory, Westford, MA (United States); Deshpande, A. [Raman Research Institute, Bangalore (India); DeSouza, L. [Sydney Institute for Astronomy, School of Physics, University of Sydney, Sydney (Australia); Goeke, R. [MIT Kavli Institute for Astrophysics and Space Research, Cambridge, MA (United States); and others

2013-01-01T23:59:59.000Z

424

Electromagnetic Isotope Separation Lab (EMIS) | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Electromagnetic Isotope Separation Lab Electromagnetic Isotope Separation Lab May 30, 2013 ORNL established the Stable Isotope Enrichment Laboratory (SIEL) as part of a project funded by the DOE Office of Science, Nuclear Physics Program to develop a modernized electromagnetic isotope separator (EMIS), optimized for separation of a wide range of stable isotopes. The SIEL is located in the Building 6010 Shield Test Station, space formerly allocated to the Oak Ridge Electron Linear Accelerator, on the main campus of ORNL. ORNL staff have designed and built a nominal 10 mA ion current EMIS (sum of all isotopes at the collector) in the SIEL. This EMIS is currently being tested to determine basic performance metrics such as throughput and enrichment factor per pass. This EMIS unit and space will be used to

425

Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy gamma-rays  

E-Print Network (OSTI)

The radio galaxy NGC 1275, recently identified as a very high energy (VHE, >100 GeV) gamma-ray emitter by MAGIC, is one of the few non-blazar AGN detected in the VHE regime. In order to better understand the origin of the gamma-ray emission and locate it within the galaxy, we study contemporaneous multi-frequency observations of NGC 1275 and model the overall spectral energy distribution (SED). We analyze unpublished MAGIC observations carried out between Oct. 2009 and Feb. 2010, and the already published ones taken between Aug. 2010 and Feb. 2011. We study the multi-band variability and correlations analyzing data of Fermi-LAT (0.1 - 100 GeV), Chandra (X-ray), KVA (optical) and MOJAVE (radio) taken during the same period. Using custom Monte Carlo simulations corresponding to early MAGIC stereo data, we detect NGC 1275 also in the earlier MAGIC campaign. The flux level and energy spectra are similar to the results of the second campaign. The monthly light curve above 100 GeV shows a hint of variability at the...

Aleksi?, J; Antonelli, L A; Antoranz, P; Babic, A; Bangale, P; de Almeida, U Barres; Barrio, J A; González, J Becerra; Bednarek, W; Berger, K; Bernardini, E; Biland, A; Blanch, O; Bock, R K; Bonnefoy, S; Bonnoli, G; Borracci, F; Bretz, T; Carmona, E; Carosi, A; Fidalgo, D Carreto; Colin, P; Colombo, E; Contreras, J L; Cortina, J; Covino, S; Da Vela, P; Dazzi, F; De Angelis, A; De Caneva, G; De Lotto, B; Mendez, C Delgado; Doert, M; Domínguez, A; Prester, D Dominis; Dorner, D; Doro, M; Einecke, S; Eisenacher, D; Elsaesser, D; Farina, E; Ferenc, D; Fonseca, M V; Font, L; Frantzen, K; Fruck, C; López, R J García; Garczarczyk, M; Terrats, D Garrido; Gaug, M; Giavitto, G; Godinovi?, N; Muñoz, A González; Gozzini, S R; Hadamek, A; Hadasch, D; Herrero, A; Hildebrand, D; Hose, J; Hrupec, D; Idec, W; Kadenius, V; Kellermann, H; Knoetig, M L; Krause, J; Kushida, J; La Barbera, A; Lelas, D; Lewandowska, N; Lindfors, E; Lombardi, S; López, M; López-Coto, R; López-Oramas, A; Lorenz, E; Lozano, I; Makariev, M; Mallot, K; Maneva, G; Mankuzhiyil, N; Mannheim, K; Maraschi, L; Marcote, B; Mariotti, M; Martínez, M; Mazin, D; Menzel, U; Meucci, M; Miranda, J M; Mirzoyan, R; Moralejo, A; Munar-Adrover, P; Nakajima, D; Niedzwiecki, A; Nilsson, K; Nowak, N; Orito, R; Overkemping, A; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, J M; Paredes-Fortuny, X; Partini, S; Persic, M; Prada, F; Moroni, P G Prada; Prandini, E; Preziuso, S; Puljak, I; Reinthal, R; Rhode, W; Ribó, M; Rico, J; Garcia, J Rodriguez; Rügamer, S; Saggion, A; Saito, K; Salvati, M; Satalecka, K; Scalzotto, V; Scapin, V; Schultz, C; Schweizer, T; Shore, S N; Sillanpää, A; Sitarek, J; Snidaric, I; Sobczynska, D; Spanier, F; Stamatescu, V; Stamerra, A; Steinbring, T; Storz, J; Sun, S; Suri?, T; Takalo, L; Tavecchio, F; Temnikov, P; Terzi?, T; Tescaro, D; Teshima, M; Thaele, J; Tibolla, O; Torres, D F; Toyama, T; Treves, A; Uellenbeck, M; Vogler, P; Wagner, R M; Zandanel, F; Zanin, R; Balmaverde, B; Kataoka, J; Rekola, R; Takahashi, Y; .,

2013-01-01T23:59:59.000Z

426

Imprint of Intergalactic Shocks on the Radio Sky  

E-Print Network (OSTI)

Strong intergalactic shocks are a natural consequence of structure formation in the universe. They are expected to deposit large fractions of their energy in relativistic electrons (xi_e~0.05 according to SNR observations) and magnetic fields (xi_B~0.01 according to cluster halo observations). We calculate the synchrotron emission from such shocks using an analytical model, calibrated with a hydrodynamical LCDM simulation. The resulting signal composes a large fraction of the extragalactic radio background (ERB) below 500 MHz. The associated angular fluctuations dominate the sky for frequencies nu3*10^-4. The fluctuating signal is most pronounced for nugas and magnetic fields. Space missions such as ALFA will thus provide important insight into the structure and composition of our Galaxy (abridged).

Uri Keshet; Eli Waxman; Abraham Loeb

2004-02-12T23:59:59.000Z

427

Time-of-flight radio location system  

DOE Patents (OSTI)

A bi-static radar configuration measures the direct time-of-flight of a transmitted RF pulse and is capable of measuring this time-of-flight with a jitter on the order of about one pico-second, or about 0.01 inch of free space distance for an electromagnetic pulse over a range of about one to ten feet. A transmitter transmits a sequence of electromagnetic pulses in response to a transmit timing signal, and a receiver samples the sequence of electromagnetic pulses with controlled timing in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the sequence of electromagnetic pulses such that the time between transmission of pulses in the sequence and sampling by the receiver sweeps over a range of delays. The receive timing signal sweeps over the range of delays in a sweep cycle such that pulses in the sequence are sampled at the pulse repetition rate, and with different delays in the range of delays to produce a sample signal representing magnitude of a received pulse in equivalent time. Automatic gain control circuitry in the receiver controls the magnitude of the equivalent time sample signal. A signal processor analyzes the sample signal to indicate the time-of-flight of the electromagnetic pulses in the sequence.

McEwan, Thomas E. (Livermore, CA)

1996-01-01T23:59:59.000Z

428

Time-of-flight radio location system  

DOE Patents (OSTI)

A bi-static radar configuration measures the direct time-of-flight of a transmitted RF pulse and is capable of measuring this time-of-flight with a jitter on the order of about one pico-second, or about 0.01 inch of free space distance for an electromagnetic pulse over a range of about one to ten feet. A transmitter transmits a sequence of electromagnetic pulses in response to a transmit timing signal, and a receiver samples the sequence of electromagnetic pulses with controlled timing in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the sequence of electromagnetic pulses such that the time between transmission of pulses in the sequence and sampling by the receiver sweeps over a range of delays. The receive timing signal sweeps over the range of delays in a sweep cycle such that pulses in the sequence are sampled at the pulse repetition rate, and with different delays in the range of delays to produce a sample signal representing magnitude of a received pulse in equivalent time. Automatic gain control circuitry in the receiver controls the magnitude of the equivalent time sample signal. A signal processor analyzes the sample signal to indicate the time-of-flight of the electromagnetic pulses in the sequence. 7 figs.

McEwan, T.E.

1996-04-23T23:59:59.000Z

429

Acousto-optical correlation spectrometer for radio astronomy  

Science Conference Proceedings (OSTI)

The objective of this thesis is to develop and construct a wide-band, high-resolution, two-channel prototype acousto-optic correlation spectrometer (AOCS) to analyze signals received by the three-element millimeter-wave interferometer at Caltech's Owens Valley Radio Observatory (OVRO), which may be used to study the distribution of carbon monoxide and other molecules in galaxies. The proposed correlation spectrometer has the main advantage of large time-bandwidth products and hence of low cost per frequency channel. Thus, it is suitable for many scientific objectives that require both large bandwidth and high resolution, such as mapping the distribution and temperature of the interstellar gases of galactic sources and extragalactic sources or studying the atmospheric conditions of planets in the solar system. Phase switching has been used to reduce the zero level variation of this instrument, and is found to be more effective than other schemes used by the single dish acousto-optical spectrometers. Both the frequency resolution and the frequency coverage of this instrument can be changed easily, and give it a flexibility not attainable by the filter-bank spectrometers.

Cheung, K.

1987-01-01T23:59:59.000Z

430

Topology optimization for the design of periodic microstructures composed of electromagnetic materials  

Science Conference Proceedings (OSTI)

Electromagnetic structures that incorporate certain structural periodicities are known to display special behavior when subjected to electromagnetic waves, and can be designed to have specific functions such as inhibiting the intrusion of electromagnetic ... Keywords: Electromagnetic field, Periodic boundary, Topology optimization

Tsuyoshi Nomura; Shinji Nishiwaki; Kazuo Sato; Koichi Hirayama

2009-02-01T23:59:59.000Z

431

Comparing LOPES measurements of air-shower radio emission with REAS 3.11 and CoREAS simulations  

E-Print Network (OSTI)

Cosmic ray air showers emit radio pulses at MHz frequencies, which can be measured with radio antenna arrays - like LOPES at the Karlsruhe Institute of Technology in Germany. To improve the understanding of the radio emission, we test theoretical descriptions with measured data. The observables used for these tests are the absolute amplitude of the radio signal, and the shape of the radio lateral distribution. We compare lateral distributions of more than 500 LOPES events with two recent and public Monte Carlo simulation codes, REAS 3.11 and CoREAS (v 1.0). The absolute radio amplitudes predicted by REAS 3.11 are in good agreement with the LOPES measurements. The amplitudes predicted by CoREAS are lower by a factor of two, and marginally compatible with the LOPES measurements within the systematic scale uncertainties. In contrast to any previous versions of REAS, REAS 3.11 and CoREAS now reproduce the shape of the measured lateral distributions correctly. This reflects a remarkable progress compared to the si...

Apel, W D; Bähren, L; Bekk, K; Bertaina, M; Biermann, P L; Blümer, J; Bozdog, H; Brancus, I M; Chiavassa, A; Daumiller, K; de Souza, V; Di Pierro, F; Doll, P; Engel, R; Falcke, H; Fuchs, B; Fuhrmann, D; Gemmeke, H; Grupen, C; Haungs, A; Heck, D; Hörandel, J R; Horneffer, A; Huber, D; Huege, T; Isar, P G; Kampert, K -H; Kang, D; Krömer, O; Kuijpers, J; Link, K; Luczak, P; Ludwig, M; Mathes, H J; Melissas, M; Morello, C; Oehlschläger, J; Palmieri, N; Pierog, T; Rautenberg, J; Rebel, H; Roth, M; Rühle, C; Saftoiu, A; Schieler, H; Schmidt, A; Schröder, F G; Sima, O; Toma, G; Trinchero, G C; Weindl, A; Wochele, J; Zabierowski, J; Zensus, J A

2013-01-01T23:59:59.000Z

432

Java-Applet For Radio Spectra Analysis  

E-Print Network (OSTI)

New services for Clusters of Galaxies Database created in the Astronomical Institute of SPbU have been constructed. The detailed description of database and its content is available at http://www.astro.spbu.ru/CLUSTERS/. The information contained in the database can be used for solution of the specific astronomical problems. One of these problems is the researches of radio emission spectra of clusters' objects. The researches can give help in solution of the problems of origin and evolution of extragalactic radio sources. Spectra of radio galaxies contain important information about radio power in the processes responsible for their activity. This report presents the software for the database that provides work with radio spectra of extragalactic sources. This client-application has been released as the Java-applet and thus provides a Web based interface that is supported on many operating systems. The facilities of the applet such as approximations of spectra measurement points and calculation of spectral parameters are illustrated in the report. Also we demonstrate new version of the application that realized on Java2 and gave access to additional functions such as printing.

A. S. Trushkina; A. G. Gubanov

2000-12-29T23:59:59.000Z

433

Interplanetary shocks lacking type II radio bursts  

E-Print Network (OSTI)

We report on the radio-emission characteristics of 222 interplanetary (IP) shocks. A surprisingly large fraction of the IP shocks (~34%) is radio quiet (i.e., the shocks lacked type II radio bursts). The CMEs associated with the RQ shocks are generally slow (average speed ~535 km/s) and only ~40% of the CMEs were halos. The corresponding numbers for CMEs associated with radio loud (RL) shocks are 1237 km/s and 72%, respectively. The RQ shocks are also accompanied by lower peak soft X-ray flux. CMEs associated with RQ (RL) shocks are generally accelerating (decelerating). The kinematics of CMEs associated with the km type II bursts is similar to those of RQ shocks, except that the former are slightly more energetic. Comparison of the shock The RQ shocks seem to be mostly subcritical and quasi-perpendicular. The radio-quietness is predominant in the rise phase and decreases through the maximum and declining phases of solar cycle 23. The solar sources of the shock-driving CMEs follow the sunspot butterfly diagra...

Gopalswamy, N; Makela, P; Akiyama, S; Yashiro, S; Kaiser, M L; Howard, R A; Bougeret, J -L

2009-01-01T23:59:59.000Z

434

Kinetics of density striations excited by powerful electromagnetic waves in the ionosphere  

Science Conference Proceedings (OSTI)

One of the most important effects observed when pumping ionospheric plasma by powerful radio waves from the ground is the excitation of filamentary density striations that are stretched along the ambient geomagnetic field. The kinetics of the striations present in the pump electromagnetic field is studied theoretically. The density irregularities cause inhomogeneities in the pump field, which result in a ponderomotive force acting on the striations that makes the density depressions move perpendicular to the geomagnetic field. Striations moving with different velocities can collide, thereby merging to produce larger scale striations. The merging of striations constitutes a cascade process that distributes the energy over the spatial spectrum of the striations. The resulting inhomogeneity spectrum as well as the obtained outward radial drift of a few meters per second is consistent with experimental results.

Istomin, Ya. N. [P. N. Lebedev Physical Institute, Leninsky Prospect 53, 117924 Moscow (Russian Federation); Leyser, T. B. [Swedish Institute of Space Physics, Box 537, SE-751 21 Uppsala (Sweden)

2010-03-15T23:59:59.000Z

435

Measurements of current sheet canting in a pulsed electromagnetic accelerator  

E-Print Network (OSTI)

Measurements of current sheet canting in a pulsed electromagnetic accelerator T. E. Markusic, E. Y canting in pulsed electromagnetic accelerators is the departure of the plasma sheet (that carries in an experimental pulsed electromagnetic accelerator, using a variety of propellants and pressure levels

Choueiri, Edgar

436

Information Leakage via Electromagnetic Emanation and Effectiveness of Averaging Technique  

Science Conference Proceedings (OSTI)

It is well known that there is relationship between electromagnetic emanation and processing information in IT devices such as personal computers and smart cards. In this paper, we show how to estimate amount of information that is leaked as electromagnetic ... Keywords: Tempest, Channel capacity, electromagnetic emanation, averaging technique

Hidema Tanaka

2008-04-01T23:59:59.000Z

437

Radio Towers Geothermal Area | Open Energy Information  

Open Energy Info (EERE)

Radio Towers Geothermal Area Radio Towers Geothermal Area Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermal Resource Area: Radio Towers Geothermal Area Contents 1 Area Overview 2 History and Infrastructure 3 Regulatory and Environmental Issues 4 Exploration History 5 Well Field Description 6 Geology of the Area 7 Geofluid Geochemistry 8 NEPA-Related Analyses (0) 9 Exploration Activities (0) 10 References Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"TERRAIN","zoom":6,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"500px","height":"300px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":43.03666667,"lon":-115.4566667,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

438

Measurement of radio wave reflection due to temperature rising from rock salt and ice irradiated by an electron beam for an ultra-high-energy neutrino detector  

Science Conference Proceedings (OSTI)

An ultra-high-energy neutrino (UHE{nu}) gives temperature rise along the hadronic and electromagnetic shower when it enters into rock salt or ice. Permittivities of them arise with respect the temperatures at ionization processes of the UHE{nu} shower. It is expected by Fresnel's formula that radio wave reflects at the irregularity of the permittivity in the medium. We had found the radio wave reflection effect in rock salt. The reflection effect and long attenuation length of radio wave in rock salt and ice would yield a new UHE{nu} detection method. An experiment for ice was performed to study the reflection effect. A coaxial tube was filled with rock salt powder or ice. Open end of the coaxial tube was irradiated by a 2 MeV electron beam. Radio wave of 435 MHz was introduced to the coaxial tube. We measured the reflection wave from the open end. We found the radio wave reflection effect due to electron beam irradiation in ice as well as in rock salt.

Tanikawa, Takahiro; Chiba, Masami; Kamijo, Toshio; Yabuki, Fumiaki; Yasuda, Osamu; Akiyama, Hidetoshi; Chikashige, Yuichi; Kon, Tadashi; Shimizu, Yutaka; Utsumi, Michiaki; Fujii, Masatoshi [Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Ohsawa, Hachioji-shi, Tokyo 192-0397 (Japan); Faculty of Science and Technology, Seikei University, Musashino-shi, Tokyo 180-8633 (Japan); Department of Applied Science and Energy Engineering, School of Engineering, Tokai University, Hiratsuka-shi, Kanagawa 259-1292 (Japan); School of Medicine, Shimane University, Izumo-shi, Shimane 693-8501 (Japan)

2012-11-12T23:59:59.000Z

439

CHAPTER 10 10.3.1. Radio Propagation Factors ....................... ...  

Science Conference Proceedings (OSTI)

... entails propagation of electromagnetic radiation through some ... degrees by extraneous radiations in the ... path inter- ference, nuclear blast effects ...

2002-08-23T23:59:59.000Z

440

Electromagnetic Wellbore Heating Ibrahim Agyemang1  

E-Print Network (OSTI)

. temperature from the heat sources in any EMIT regions. Parts i) and ii) result in a second order ODE is inversely proportional to the velocity. Fluid that moves slowly past an EMIT region will absorb more heatChapter 5 Electromagnetic Wellbore Heating Ibrahim Agyemang1 , Matthew Bolton2 , Lloyd Bridge2

Bohun, C. Sean

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441

Electromagnetic Composites at the Compton Scale  

E-Print Network (OSTI)

A new class of electromagnetic composite particles is proposed. The composites are very small (the Compton scale), potentially long-lived, would have unique interactions with atomic and nuclear systems, and, if they exist, could explain a number of otherwise anomalous and conflicting observations in diverse research areas.

Frederick J. Mayer; John R. Reitz

2011-09-10T23:59:59.000Z

442

Build A Stronger Electromagnet Project Overview  

E-Print Network (OSTI)

this activity? 5. How did various sub-populations of students perform? Consider factors such as gender, race Electromagnet Sunshine State Standards Middle School: · The student recognizes that energy may be changed: · The student recognizes that energy may be changed in form with varying efficiency. (SC.B.1.4) · The student

Weston, Ken

443

Problems in electromagnetic mass-difference calculations  

SciTech Connect

A brief discussion is given on the progress made thus far in calculating the electromagnetic mass differences of elementary particles. Some of the methods discussed include Feynman's method, Cottinghams method, the methods involving Bjorken scaling iunctions, and the formalism of Dashen and Frautschi. (LBS)

Majumdar, D.P.

1972-01-01T23:59:59.000Z

444

Televisions, video privacy, and powerline electromagnetic interference  

Science Conference Proceedings (OSTI)

We conduct an extensive study of information leakage over the powerline infrastructure from eight televisions (TVs) spanning multiple makes, models, and underlying technologies. In addition to being of scientific interest, our findings contribute to ... Keywords: electromagnetic interference, information leakage, powerline security

Miro Enev; Sidhant Gupta; Tadayoshi Kohno; Shwetak N. Patel

2011-10-01T23:59:59.000Z

445

SURVEYING THE DYNAMIC RADIO SKY WITH THE LONG WAVELENGTH DEMONSTRATOR ARRAY  

Science Conference Proceedings (OSTI)

This paper presents a search for radio transients at a frequency of 73.8 MHz (4 m wavelength) using the all-sky imaging capabilities of the Long Wavelength Demonstrator Array (LWDA). The LWDA was a 16-dipole phased array telescope, located on the site of the Very Large Array in New Mexico. The field of view of the individual dipoles was essentially the entire sky, and the number of dipoles was sufficiently small that a simple software correlator could be used to make all-sky images. From 2006 October to 2007 February, we conducted an all-sky transient search program, acquiring a total of 106 hr of data; the time sampling varied, being 5 minutes at the start of the program and improving to 2 minutes by the end of the program. We were able to detect solar flares, and in a special-purpose mode, radio reflections from ionized meteor trails during the 2006 Leonid meteor shower. We detected no transients originating outside of the solar system above a flux density limit of 500 Jy, equivalent to a limit of no more than about 10{sup -2} events yr{sup -1} deg{sup -2}, having a pulse energy density {approx}>1.5 x 10{sup -20} J m{sup -2} Hz{sup -1} at 73.8 MHz for pulse widths of about 300 s. This event rate is comparable to that determined from previous all-sky transient searches, but at a lower frequency than most previous all-sky searches. We believe that the LWDA illustrates how an all-sky imaging mode could be a useful operational model for low-frequency instruments such as the Low Frequency Array, the Long Wavelength Array station, the low-frequency component of the Square Kilometre Array, and potentially the Lunar Radio Array.

Lazio, T. Joseph W.; Clarke, Tracy E.; Lane, W. M.; Gross, C.; Kassim, N. E.; Hicks, B.; Polisensky, E.; Stewart, K. [Remote Sensing Division, Naval Research Laboratory, 4555 Overlook Ave., SW, Washington, DC 20375 (United States); Ray, P. S. [Space Science Division, Naval Research Laboratory, 4555 Overlook Ave., SW, Washington, DC 20375-5382 (United States); Wood, D. [Praxis, Inc., 5845 Richmond Highway, Suite 700, Alexandria, VA 22303 (United States); York, J. A.; Kerkhoff, A. [Applied Research Laboratories, University of Texas at Austin, P.O. Box 8029, Austin, TX 78713-8029 (United States); Dalal, N. Paravastu [American Society for Engineering Education, Washington, DC 20036 (United States); Cohen, A. S. [Johns Hopkins University, Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Erickson, W. C., E-mail: Joseph.Lazio@jpl.nasa.go [School of Mathematics and Science, University of Tasmania, Churchill Ave., Sandy Bay, Tasmania 7005 (Australia)

2010-12-15T23:59:59.000Z

446

A GMRT multifrequency radio study of the isothermal core of the poor galaxy cluster AWM 4  

E-Print Network (OSTI)

We present a detailed radio morphological study and spectral analysis of the wide-angle-tail radio source 4C +24.36 associated with the dominant galaxy in the relaxed galaxy cluster AWM 4. Our study is based on new high sensitivity GMRT observations at 235 MHz, 327 MHz and 610 MHz, and on literature and archival data at other frequencies. We find that the source major axis is likely oriented at a small angle with respect to the plane of the sky. The wide-angle-tail morphology can be reasonably explained by adopting a simple hydrodynamical model in which both ram pressure (driven by the motion of the host galaxy) and buoyancy forces contribute to bend the radio structure. The spectral index progressively steepens along the source major axis from $\\alpha \\sim$0.3 in the region close to the radio nucleus to beyond 1.5 in the lobes. The results of the analysis of the spectral index image allow us to derive an estimate of the radiative age of the source of $\\sim$ 160 Myr. The cluster X-ray emitting gas has a relax...

Giacintucci, S; Murgia, M; Raychaudhuri, S; O'Sullivan, E J; Venturi, T; David, L P; Mazzotta, P; Clarke, T E; Athreya, R M

2008-01-01T23:59:59.000Z

447

Survey on solar X-ray flares and associated coherent radio emissions  

E-Print Network (OSTI)

The radio emission during 201 X-ray selected solar flares was surveyed from 100 MHz to 4 GHz with the Phoenix-2 spectrometer of ETH Zurich. The selection includes all RHESSI flares larger than C5.0 jointly observed from launch until June 30, 2003. Detailed association rates of radio emission during X-ray flares are reported. In the decimeter wavelength range, type III bursts and the genuinely decimetric emissions (pulsations, continua, and narrowband spikes) were found equally frequently. Both occur predominantly in the peak phase of hard X-ray (HXR) emission, but are less in tune with HXRs than the high-frequency continuum exceeding 4 GHz, attributed to gyrosynchrotron radiation. In 10% of the HXR flares, an intense radiation of the above genuine decimetric types followed in the decay phase or later. Classic meter-wave type III bursts are associated in 33% of all HXR flares, but only in 4% they are the exclusive radio emission. Noise storms were the only radio emission in 5% of the HXR flares, some of them w...

Benz, A O; Csillagy, A; Saint-Hilaire, P; Benz, Arnold O.; Grigis, Paolo; Csillagy, Andre; Saint-Hilaire, Pascal

2004-01-01T23:59:59.000Z

448

DIAGNOSTICS ON THE SOURCE PROPERTIES OF A TYPE II RADIO BURST WITH SPECTRAL BUMPS  

SciTech Connect

In recent studies, we proposed that source properties of type II radio bursts can be inferred through a causal relationship between the special shape of the type II dynamic spectrum (e.g., bump or break) and simultaneous extreme ultraviolet (EUV)/white light imaging observations (e.g., CME-shock crossing streamer structures). As a further extension of these studies, in this paper we examine the coronal mass ejection (CME) event on 2007 December 31 associated with a multiple type II radio burst. We identify the presence of two spectral bump features on the observed dynamic spectrum. By combining observational analyses of the radio spectral observations and the EUV-white light imaging data, we conclude that the two spectral bumps result from a CME-shock propagating across dense streamers on the southern and northern sides of the CME. It is inferred that the corresponding two type II emissions originate separately from the two CME-shock flanks where the shock geometries are likely quasi-perpendicular or oblique. Since the emission lanes are bumped as a whole within a relatively short time, it suggests that the type II radio bursts with bumps of this study are emitted from spatially confined sources (with a projected lateral dimension smaller than 0.05-0.1 R{sub Sun} at a fundamental frequency level of 20-30 MHz).

Feng, S. W.; Chen, Y.; Kong, X. L.; Li, G.; Song, H. Q. [Institute of Space Sciences and School of Space Science and Physics, Shandong University, Weihai 264209 (China)] [Institute of Space Sciences and School of Space Science and Physics, Shandong University, Weihai 264209 (China); Feng, X. S. [SIGMA Weather Group, State Key laboratory for Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China)] [SIGMA Weather Group, State Key laboratory for Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China); Guo, Fan, E-mail: yaochen@sdu.edu.cn [Department of Planetary Sciences and Lunar and Planetary laboratory, University of Arizona, Tucson, AZ 85721 (United States)] [Department of Planetary Sciences and Lunar and Planetary laboratory, University of Arizona, Tucson, AZ 85721 (United States)

2013-04-10T23:59:59.000Z

449

Definition: Time-Domain Electromagnetics | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Time-Domain Electromagnetics Jump to: navigation, search Dictionary.png Time-Domain Electromagnetics Time-domain electromagnetic (TDEM) surveys are active-source soundings which provide information about the electrical structure of the shallow subsurface.[1] View on Wikipedia Wikipedia Definition Transient electromagnetics, (also time-domain electromagnetics / TDEM), is a geophysical exploration technique in which electric and magnetic fields are induced by transient pulses of electric current and the subsequent decay response measured. TEM / TDEM methods are generally able to determine subsurface electrical properties, but are also sensitive to subsurface magnetic properties in applications like UXO detection and

450

Electromagnetic field radiation model for lightning strokes to tall structures  

SciTech Connect

This paper describes observation and analysis of electromagnetic field radiation from lightning strokes to tall structures. Electromagnetic field waveforms and current waveforms of lightning strokes to the CN Tower have been simultaneously measured since 1991. A new calculation model of electromagnetic field radiation is proposed. The proposed model consists of the lightning current propagation and distribution model and the electromagnetic field radiation model. Electromagnetic fields calculated by the proposed model, based on the observed lightning current at the CN Tower, agree well with the observed fields at 2km north of the tower.

Motoyama, H. [CRIEPI, Tokyo (Japan); Janischewskyj, W.; Hussein, A.M. [Univ. of Toronto, Ontario (Canada); Chisholm, W.A. [Ontario Hydro Technologies, Toronto, Ontario (Canada); Chang, J.S. [McMaster Univ., Hamilton, Ontario (Canada); Rusan, R.

1996-07-01T23:59:59.000Z

451

Electromagnetic compatibility, tropospheric and ionospheric aspects of SPS MPTS operations  

DOE Green Energy (OSTI)

The results of a preliminary study of the effects of operation of a Solar Power Satellite (SPS) on the general performance of terrestrial and space based electromagnetic systems are given. In addition, the effects of a passing high energy Microwave Power Transmission System (MPTS) through the troposphere and through the ionosphere are also considered. The SPS as envisioned will be a satellite system in geosynchronous orbit with a solar array of about 144 square kilometers. The purpose of the SPS is to capture solar energy, convert the radiant energy to microwave energy and transmit it to the earth as a beam by means of a phased array antenna one kilometer in diameter at a frequency of 2.45 GHz. At the surface of the earth, the energy beam will be captured by an antenna about 100 square kilometers which will convert the microwave energy to high voltage ac power for injection into an electrical power network. The impact of SPS operation on the lower atmosphere, the ionosphere, and on operational telecommunication systems, is addressed in a preliminary manner. Topics include (a) further study on the susceptibility of electronic equipment to SPS emissions; (b) further study on the interference potential of SPS emissions and harmonics to electromagnetic systems; (c) study of the impact of tropospheric attenuation and scattering associated with SPS operation on microwave terrestrial, air/ground and satellite/ground telecommunication systems; (d) further theoretical study on the production of ionospheric irregularities resulting from microwave heating; and (e) further experimental evidence of the impact of SPS operation on the telecommunication system performance collected in conjunction with a Platteville microwave heating experiment.

Not Available

1978-03-01T23:59:59.000Z

452

Electromagnetic field of a charge intersecting a cold plasma boundary in a waveguide  

SciTech Connect

We analyze the electromagnetic field of a charge crossing a boundary between a vacuum and cold plasma in a waveguide. We obtain exact expressions for the field components and the spectral density of the transition radiation. With the steepest descent technique, we investigate the field components. We show that the electromagnetic field has a different structure in a vacuum than in cold plasma. We also develop an algorithm for the computation of the field based on a certain transformation of the integration path. The behavior of the field depending on distance and time and the spectral density depending on frequency are explored for different charge velocities. Some important physical effects are noted. A considerable increase and concentration of the field near the wave front in the plasma is observed for the case of ultrarelativistic particles. In the plasma, the mode envelopes and spectral density show zero points when the charge velocity is within certain limits.

Alekhina, Tatiana Yu.; Tyukhtin, Andrey V. [Radiophysics Department of St. Petersburg University, 1 Ulyanovskaya, St. Petersburg 198504 (Russian Federation)

2011-06-15T23:59:59.000Z

453

Plasma Frequency Shift Due to a Slowly Rotating Compact Star  

E-Print Network (OSTI)

We investigate the effects of a slowly rotating compact gravitational source on electron oscillations in a homogeneous electrically neutral plasma in the absence of an external electric or magnetic field. Neglecting the random thermal motion of the electrons we assume the gravitoelectromagnetic approximation to the general theory of relativity for the gravitational field. It is shown that there is a shift in the plasma frequency and hence in the dielectric constant of the plasma due to the gravitomagnetic force. We also give estimates for the difference in the frequency of radially transmitted electromagnetic signals for typical compact star candidates.

Babur M. Mirza; Hamid Saleem

2005-01-01T23:59:59.000Z

454

Time-of-flight radio location system  

DOE Patents (OSTI)

A bi-static radar configuration measures the direct time-of-flight of a transmitted RF pulse and is capable of measuring this time-of-flight with a jitter on the order of about one pico-second, or about 0.01 inch of free space distance for an electromagnetic pulse over a range of about one to ten feet. A transmitter transmits a sequence of electromagnetic pulses in response to a transmit timing signal, and a receiver samples the sequence of electromagnetic pulses with controlled timing in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the sequence of electromagnetic pulses such that the time between transmission of pulses in the sequence and sampling by the receiver sweeps over a range of delays. The receive timing signal sweeps over the range of delays in a sweep cycle such that pulses in the sequence are sampled at the pulse repetition rate, and with different delays in the range of delays to produce a sample signal representing magnitude of a received pulse in equivalent time. Automatic gain control circuitry in the receiver controls the magnitude of the equivalent time sample signal. A signal processor analyzes the sample signal to indicate the time-of-flight of the electromagnetic pulses in the sequence. The sample signal in equivalent time is passed through an envelope detection circuit, formed of an absolute value circuit followed by a low pass filter, to convert the sample signal to a unipolar signal to eliminate effects of antenna misorientation.

McEwan, Thomas E. (Livermore, CA)

1997-01-01T23:59:59.000Z

455

Time-of-flight radio location system  

DOE Patents (OSTI)

A bi-static radar configuration measures the direct time-of-flight of a transmitted RF pulse and is capable of measuring this time-of-flight with a jitter on the order of about one pico-second, or about 0.01 inch of free space distance for an electromagnetic pulse over a range of about one to ten feet. A transmitter transmits a sequence of electromagnetic pulses in response to a transmit timing signal, and a receiver samples the sequence of electromagnetic pulses with controlled timing in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the sequence of electromagnetic pulses such that the time between transmission of pulses in the sequence and sampling by the receiver sweeps over a range of delays. The receive timing signal sweeps over the range of delays in a sweep cycle such that pulses in the sequence are sampled at the pulse repetition rate, and with different delays in the range of delays to produce a sample signal representing magnitude of a received pulse in equivalent time. Automatic gain control circuitry in the receiver controls the magnitude of the equivalent time sample signal. A signal processor analyzes the sample signal to indicate the time-of-flight of the electromagnetic pulses in the sequence. The sample signal in equivalent time is passed through an envelope detection circuit, formed of an absolute value circuit followed by a low pass filter, to convert the sample signal to a unipolar signal to eliminate effects of antenna misorientation. 8 figs.

McEwan, T.E.

1997-08-26T23:59:59.000Z

456

Environmental assessment for the satellite power system concept development and evaluation program-electromagnetic systems compatibility  

SciTech Connect

The EMC analysis addressed only the direct effects of electromagnetic emissions from the SPS on other technological systems. Emissions were defined quite broadly, including not only those from the microwave system, but also thermal blackbody emission and scattered sunlight from the satellite. The analysis is based on the design for an SPS as described in the Reference System Report and some quantitative conclusions, e.g., ranges from rectenna sites at which effects are expected are specific to that design. The methodology and qualitative conclusions, however, apply to an SPS concept using microwave power transmission. Quantitative conclusions have been obtained parametrically and can be adjusted as SPS designs change. The electromagnetic environment that the Reference System would produce, and in which other systems would have to function, is described. As an early part of the EMC Assessment, the problems expected for a hypothetical rectenna site, in the Mojave Desert of southern California, were analyzed in detail. This effort provided an initial quantitative indication of the scope of potential EMC problems and indicated the importance of EMC considerations in rectenna site selection. The results of this analysis are presented. The effects of SPS microwave emissions on important categories of electronic systems and equipment are summarized, with many examples of test results and demonstrated techniques for mitigation of problems encountered. SPS effects on other satellite systems are presented. Astronomical research frequently involves measurement of extremely low levels of electromagnetic radiation and is thus very susceptible to interference. The concerns of both radio astronomy with microwave emissions from SPS and optical astronomy with sunlight scattered from SPS spacecraft are discussed. Summaries of mitigation techniques, cost estimates, and conclusions are presented. (WHK)

Davis, K.A.; Grant, W.B.; Morrison, E.L.; Juroshek, J.R.

1981-01-01T23:59:59.000Z

457

Large Radio Astronomy: next 70 Years Step  

E-Print Network (OSTI)

Some attempts to predict the very distant future of Radio Astronomy are given. It is not easy to predict a list of the first priority problems which may appear, but the facilities potential is more predictable. It is suggested, that in addition to the "dedicated for Radio Astronomy", facilities may be extended greatly by integration with the next generation living standards facilities, connected with People-to-People communications through the global networks and by incorporating of the "Natural facilities", such as grav. lensing, maser amplification in the ISM etc. As an examples of the extreme cases of the $10^9 m^2$ class of the new generation Radio Telescopes, utilization of the personal dipole size communication facilities by SKA type instrument, and array from the asteroids first "Frehnel zones" will be mentioned. Radio Astronomy from the secondary to optical facilities tool will be the only tool in the exploration of the $z>10$ Universe. The reality of all predictions depend mostly on the way, the Civilization will prefer : "Ahead, to HOMO SAPIENCE" or "BACK TO PRIMATES".

Yu. N. Parijskij

2003-11-15T23:59:59.000Z

458

Molecular gas in nearby elliptical radio galaxies  

E-Print Network (OSTI)

Powerful radio-AGN are hosted by massive elliptical galaxies which are usually very poor in molecular gas. Nevertheless the central Black Hole (BH) needs molecular gas for the nuclear activity. Thus it is important to study the origin, the distribution and the kinematics of the molecular gas in such objects. We have performed at the IRAM-30m telescope a survey of the CO(1-0) and CO(2-1) emission in the most powerful radio galaxies of the Local Universe, selected only on the basis of their radio continuum fluxes. The main result of that survey is the low content in molecular gas of such galaxies compared to Seyfert galaxies. The median value of the molecular gas mass is 4x10^8 Msun. Moreover, the CO spectra indicate the presence of a central molecular gas disk in some of these radio galaxies. We complemented this survey with photometric data of SPITZER and IRAS fluxes with the purpose to study the dust and its relation with the molecular gas and AGN.

B. Ocana-Flaquer; S. Leon; J. Lim; F. Combes; Dinh-V-Trung

2008-03-31T23:59:59.000Z

459

Molecular gas in nearby elliptical radio galaxies  

E-Print Network (OSTI)

Powerful radio-AGN are hosted by massive elliptical galaxies which are usually very poor in molecular gas. Nevertheless the central Black Hole (BH) needs molecular gas for the nuclear activity. Thus it is important to study the origin, the distribution and the kinematics of the molecular gas in such objects. We have performed at the IRAM-30m telescope a survey of the CO(1-0) and CO(2-1) emission in the most powerful radio galaxies of the Local Universe, selected only on the basis of their radio continuum fluxes. The main result of that survey is the low content in molecular gas of such galaxies compared to Seyfert galaxies. The median value of the molecular gas mass is 4x10^8 Msun. Moreover, the CO spectra indicate the presence of a central molecular gas disk in some of these radio galaxies. We complemented this survey with photometric data of SPITZER and IRAS fluxes with the purpose to study the dust and its relation with the molecular gas and AGN.

Ocana-Flaquer, B; Lim, J; Combes, F; Dinh-V-Trung,

2008-01-01T23:59:59.000Z

460

FM radio: family interplay with sonic mementos  

Science Conference Proceedings (OSTI)

Digital mementos are increasingly problematic, as people acquire large amounts of digital belongings that are hard to access and often forgotten. Based on fieldwork with 10 families, we designed a new type of embodied digital memento, the FM Radio. It ... Keywords: audio, mementos, memorie