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Sample records for electromagnetic radiation detectors

  1. Electromagnetic radiation detector

    DOEpatents

    Benson, Jay L.; Hansen, Gordon J.

    1976-01-01

    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.

  2. Optical electromagnetic radiation detector

    NASA Astrophysics Data System (ADS)

    Miceli, W. J.; Ludman, J. E.

    1985-08-01

    An optical electromagnetic radiation detector is invented having a probe for receiving nearby electromagnetic radiation. The probe includes a loop antenna connected to a pair of transparent electrodes deposited on the end surfaces of an electro-optic Fabry-Perot interferometer. When the loop antenna picks up the presence of electromagnetic radiation, a voltage will be developed across the crystal of the electro-optic Fabry-Perot interferometer thereby changing the optical length of the interferometer. A beam of light from a remote location is transmitted through an optical fiber onto the Fabry-Perot interferometer. The change in optical length of the Fabry-Perot interferometer alters the intensity of the beam of light as its is reflected from the Fabry-Perot interferometer back through the optical fiber to the remote location. A beamsplitter directs this reflected beam of light onto an intensity detector in order to provide an output indicative of the variations in intensity. The variations in intensity are directly related to the strength of the electromagnetic radiation received by the loop antenna.

  3. Simple dynamic electromagnetic radiation detector

    NASA Technical Reports Server (NTRS)

    Been, J. F.

    1972-01-01

    Detector monitors gamma dose rate at particular position in a radiation facility where a mixed neutron-gamma environment exists, thus determining reactor power level changes. Device also maps gamma intensity profile across a neutron-gamma beam.

  4. Resonant tuning fork detector for electromagnetic radiation.

    PubMed

    Pohlkötter, Andreas; Willer, Ulrike; Bauer, Christoph; Schade, Wolfgang

    2009-02-01

    A mechanical quartz microresonator (tuning fork) is used to detect electromagnetic radiation. The detection scheme is based on forces created due to the incident electromagnetic radiation on the piezoelectric tuning fork. A force can be created due to the transfer of the photon momentum of the incident electromagnetic radiation. If the surfaces of the tuning fork are nonuniformly heated, a second force acts on it, the so-called photophoretic force. These processes occur for all wavelengths of the incident radiation, making the detector suitable for sensing of ultraviolet, visible, and mid-infrared light, even THz-radiation. Here the detector is characterized in the visible range; noise analysis is performed for 650 nm and 5.26 microm. A linear power characteristic and the dependence on pulse lengths of the incoming light are shown. Examples for applications for the visible and mid-infrared spectral region are given by 2f and absorption spectroscopy of oxygen and nitric oxide, respectively.

  5. Scintillation Detectors for Radiation-Hard Electromagnetic Calorimeters

    NASA Astrophysics Data System (ADS)

    Löhner, H.

    2005-02-01

    For the application in the compact and radiation hard electromagnetic (EM) calorimeter in the PANDA detection system at the new GSI facility, we have started to advance scintillation crystals and the light detection technique. PANDA is the universal internal-target detection system for charmonium spectroscopy and the search for glue-balls and hybrid states in antiproton annihilations. In particular, the large dynamic range from several GeV down to a detection threshold of some MeV for EM radiation and the expected high background rate of neutrons and ions will impose severe requirements on crystals and light sensors. In the magnetic environment of tracking devices the use of Avalanche Photodiodes (APD's) is preferred. In order to achieve suitable resolution for low energy hadrons and photons, the light output of crystals will have to be improved by special production techniques, activation and doping. These procedures might have implications for the radiation hardness. We report on measurements of signal response and radiation damage in crystals of PbWO4 and BGO both from the BTCP (Russia) and SICCAS (China) production sites. Beams of protons, electrons and photons have been applied while detectors with either phototube or APD readout were operated in the range from room temperature to -20°C. Results on light yield and energy resolution are presented. We report on the reduction of light transmission after proton irradiation and results from electron-spin resonance studies on irradiated crystals to analyse the cause of radiation damage.

  6. Electromagnetic and nuclear radiation detector using micromechanical sensors

    DOEpatents

    Thundat, Thomas G.; Warmack, Robert J.; Wachter, Eric A.

    2000-01-01

    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.

  7. RADIATION DETECTOR

    DOEpatents

    Wilson, H.N.; Glass, F.M.

    1960-05-10

    A radiation detector of the type is described wherein a condenser is directly connected to the electrodes for the purpose of performing the dual function of a guard ring and to provide capacitance coupling for resetting the detector system.

  8. COHERENCE PROPERTIES OF ELECTROMAGNETIC RADIATION,

    DTIC Science & Technology

    ELECTROMAGNETIC RADIATION , COHERENT SCATTERING), (*COHERENT SCATTERING, ELECTROMAGNETIC RADIATION ), LIGHT, INTERFERENCE, INTENSITY, STATISTICAL FUNCTIONS, QUANTUM THEORY, BOSONS, INTERFEROMETERS, CHINA

  9. Electromagnetic Radiation Analysis

    DTIC Science & Technology

    1978-04-10

    A methodology is given for determining whether electromagnetic radiation of sufficient strength to cause performance degradation to the test item...exists at the test item location. The results of an electromagnetic radiation effects test are used to identify the radio frequencies and electromagnetic ... radiation levels to which the test item is susceptible. Further, using a test bed, comparisons are made with the representative signal levels to

  10. Semiconductor radiation detector

    DOEpatents

    Bell, Zane W.; Burger, Arnold

    2010-03-30

    A semiconductor detector for ionizing electromagnetic radiation, neutrons, and energetic charged particles. The detecting element is comprised of a compound having the composition I-III-VI.sub.2 or II-IV-V.sub.2 where the "I" component is from column 1A or 1B of the periodic table, the "II" component is from column 2B, the "III" component is from column 3A, the "IV" component is from column 4A, the "V" component is from column 5A, and the "VI" component is from column 6A. The detecting element detects ionizing radiation by generating a signal proportional to the energy deposited in the element, and detects neutrons by virtue of the ionizing radiation emitted by one or more of the constituent materials subsequent to capture. The detector may contain more than one neutron-sensitive component.

  11. Electromagnetic Radiation System (EMRS) for Susceptibility Testing.

    DTIC Science & Technology

    ELECTROMAGNETIC COMPATIBILITY, *ELECTROMAGNETIC SUSCEPTIBILITY, COMMUNICATION EQUIPMENT, ELECTRONIC EQUIPMENT, ELECTROMAGNETIC RADIATION , ANTENNAS, ELECTROMAGNETIC INTERFERENCE, RADAR SIGNALS, RADIO SIGNALS, FIELD INTENSITY.

  12. Radiation detector

    DOEpatents

    Fultz, Brent T.

    1983-01-01

    Apparatus is provided for detecting radiation such as gamma rays and X-rays generated in backscatter Mossbauer effect spectroscopy and X-ray spectrometry, which has a large "window" for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  13. Radiation detector

    DOEpatents

    Fultz, B.T.

    1980-12-05

    Apparatus is provided for detecting radiation such as gamma rays and x-rays generated in backscatter Moessbauer effect spectroscopy and x-ray spectrometry, which has a large window for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  14. Directional radiation detectors

    DOEpatents

    Dowell, Jonathan L.

    2017-09-12

    Directional radiation detectors and systems, methods, and computer-readable media for using directional radiation detectors to locate a radiation source are provided herein. A directional radiation detector includes a radiation sensor. A radiation attenuator partially surrounds the radiation sensor and defines an aperture through which incident radiation is received by the radiation sensor. The aperture is positioned such that when incident radiation is received directly through the aperture and by the radiation sensor, a source of the incident radiation is located within a solid angle defined by the aperture. The radiation sensor senses at least one of alpha particles, beta particles, gamma particles, or neutrons.

  15. Adaptors for radiation detectors

    DOEpatents

    Livesay, Ronald Jason

    2015-07-28

    Described herein are adaptors and other devices for radiation detectors that can be used to make accurate spectral measurements of both small and large bulk sources of radioactivity, such as building structures, soils, vessels, large equipment, and liquid bodies. Some exemplary devices comprise an adaptor for a radiation detector, wherein the adaptor can be configured to collimate radiation passing through the adapter from an external radiation source to the radiation detector and the adaptor can be configured to enclose a radiation source within the adapter to allow the radiation detector to measure radiation emitted from the enclosed radiation source.

  16. Adaptors for radiation detectors

    DOEpatents

    Livesay, Ronald Jason

    2014-04-22

    Described herein are adaptors and other devices for radiation detectors that can be used to make accurate spectral measurements of both small and large bulk sources of radioactivity, such as building structures, soils, vessels, large equipment, and liquid bodies. Some exemplary devices comprise an adaptor for a radiation detector, wherein the adaptor can be configured to collimate radiation passing through the adapter from an external radiation source to the radiation detector and the adaptor can be configured to enclose a radiation source within the adapter to allow the radiation detector to measure radiation emitted from the enclosed radiation source.

  17. Radiation detector

    DOEpatents

    Taleyarkhan, Rusi P.

    2017-06-27

    Alpha particle detecting devices are disclosed that have a chamber that can hold a fluid in a tensioned metastable state. The chamber is tuned with a suitable fluid and tension such that alpha emitting materials such as radon and one or more of its decay products can be detected. The devices can be portable and can be placed in areas, such as rooms in dwellings or laboratories and used to measure radon in these areas, in situ and in real time. The disclosed detectors can detect radon at and below 4 pCi/L in air; also, at and below 4,000 pCi/L or 300 pCi/L in water.

  18. Tin Can Radiation Detector.

    ERIC Educational Resources Information Center

    Crull, John L.

    1986-01-01

    Provides instructions for making tin can radiation detectors from empty aluminum cans, aluminum foil, clear plastic, copper wire, silica gel, and fine, unwaxed dental floss put together with tape or glue. Also provides suggestions for activities using the detectors. (JN)

  19. Tin Can Radiation Detector.

    ERIC Educational Resources Information Center

    Crull, John L.

    1986-01-01

    Provides instructions for making tin can radiation detectors from empty aluminum cans, aluminum foil, clear plastic, copper wire, silica gel, and fine, unwaxed dental floss put together with tape or glue. Also provides suggestions for activities using the detectors. (JN)

  20. Time domain electromagnetic metal detectors

    SciTech Connect

    Hoekstra, P.

    1996-04-01

    This presentation focuses on illustrating by case histories the range of applications and limitations of time domain electromagnetic (TDEM) systems for buried metal detection. Advantages claimed for TDEM metal detectors are: independent of instrument response (Geonics EM61) to surrounding soil and rock type; simple anomaly shape; mitigation of interference by ambient electromagnetic noise; and responsive to both ferrous and non-ferrous metallic targets. The data in all case histories to be presented were acquired with the Geonics EM61 TDEM system. Case histories are a test bed site on Molokai, Hawaii; Fort Monroe, Virginia; and USDOE, Rocky Flats Plant. The present limitations of this technology are: discrimination capabilities in terms of type of ordnance, and depth of burial is limited, and ability of resolving targets with small metallic ambient needs to be improved.

  1. RADIATION WAVE DETECTOR

    DOEpatents

    Wouters, L.F.

    1958-10-28

    The detection of the shape and amplitude of a radiation wave is discussed, particularly an apparatus for automatically indicating at spaced lntervals of time the radiation intensity at a flxed point as a measure of a radiation wave passing the point. The apparatus utilizes a number of photomultiplier tubes surrounding a scintillation type detector, For obtainlng time spaced signals proportional to radiation at predetermined intervals the photolnultiplier tubes are actuated ln sequence following detector incidence of a predetermined radiation level by electronic means. The time spaced signals so produced are then separately amplified and relayed to recording means.

  2. Absolute radiation detector

    NASA Astrophysics Data System (ADS)

    Martin, John E.

    1996-11-01

    An absolute radiation detector (a cryogenic radiometer) is being developed to replace the existing UK primary national standard cryogenic radiometer with an improved uncertainty. The cryogenic radiometer will be capable of measuring black body radiation and laser radiation with an uncertainty approaching 10 ppm. From these measurements it will be possible to determine the fundamental constant, the Stefan Boltzmann constant, confirming the radiometer as an absolute detector, and link this determination to the SI unit of luminous intensity, the candela. Thus detector and source based scales/standards will be tied to an invariant physical quantity ensuring their long-term stability.

  3. Gravitational scattering of electromagnetic radiation

    NASA Technical Reports Server (NTRS)

    Brooker, J. T.; Janis, A. I.

    1980-01-01

    The scattering of electromagnetic radiation by linearized gravitational fields is studied to second order in a perturbation expansion. The incoming electromagnetic radiation can be of arbitrary multipole structure, and the gravitational fields are also taken to be advanced fields of arbitrary multipole structure. All electromagnetic multipole radiation is found to be scattered by gravitational monopole and time-varying dipole fields. No case has been found, however, in which any electromagnetic multipole radiation is scattered by gravitational fields of quadrupole or higher-order multipole structure. This lack of scattering is established for infinite classes of special cases, and is conjectured to hold in general. The results of the scattering analysis are applied to the case of electromagnetic radiation scattered by a moving mass. It is shown how the mass and velocity may be determined by a knowledge of the incident and scattered radiation.

  4. Gravitational scattering of electromagnetic radiation

    NASA Technical Reports Server (NTRS)

    Brooker, J. T.; Janis, A. I.

    1980-01-01

    The scattering of electromagnetic radiation by linearized gravitational fields is studied to second order in a perturbation expansion. The incoming electromagnetic radiation can be of arbitrary multipole structure, and the gravitational fields are also taken to be advanced fields of arbitrary multipole structure. All electromagnetic multipole radiation is found to be scattered by gravitational monopole and time-varying dipole fields. No case has been found, however, in which any electromagnetic multipole radiation is scattered by gravitational fields of quadrupole or higher-order multipole structure. This lack of scattering is established for infinite classes of special cases, and is conjectured to hold in general. The results of the scattering analysis are applied to the case of electromagnetic radiation scattered by a moving mass. It is shown how the mass and velocity may be determined by a knowledge of the incident and scattered radiation.

  5. Conical electromagnetic radiation flux concentrator

    NASA Technical Reports Server (NTRS)

    Miller, E. R.

    1972-01-01

    Concentrator provides method of concentrating a beam of electromagnetic radiation into a smaller beam, presenting a higher flux density. Smaller beam may be made larger by sending radiation through the device in the reverse direction.

  6. STRUCTURAL RESPONSE TO INTENSE ELECTROMAGNETIC RADIATION.

    DTIC Science & Technology

    EXPLODING WIRES, *GLASS, *DAMAGE, ELECTROMAGNETIC RADIATION , ENERGY CONVERSION, ENERGY CONVERSION, ELECTROMAGNETIC RADIATION , ELECTROMAGNETIC ... RADIATION , PLASTICS, PLASMAS(PHYSICS), STRESSES, THERMAL STRESSES, INSTRUMENTATION, ELECTRICAL RESISTANCE, ELECTRIC DISCHARGES, THERMOCOUPLES, MATHEMATICAL ANALYSIS, MATHEMATICAL ANALYSIS.

  7. Underwater radiation detector

    DOEpatents

    Kruse, Lyle W.; McKnight, Richard P.

    1986-01-01

    A detector apparatus for differentiating between gamma and neutron radiation is provided. The detector includes a pair of differentially shielded Geiger-Mueller tubes. The first tube is wrapped in silver foil and the second tube is wrapped in lead foil. Both the silver and lead foils allow the passage of gamma rays at a constant rate in a gamma ray only field. When neutrons are present, however, the silver activates and emits beta radiation that is also detected by the silver wrapped Geiger-Mueller tube while the radiation detected by the lead wrapped Geiger-Mueller tube remains constant. The amount of radiation impinging on the separate Geiger-Mueller tubes is then correlated in order to distinguish between the neutron and gamma radiations.

  8. Radiation Detectors and Art

    NASA Astrophysics Data System (ADS)

    Denker, Andrea

    The use of radiation detectors in the analysis of art objects represents a very special application in a true interdisciplinary field. Radiation detectors employed in this field detect, e.g., x-rays, γ-rays, β particles, and protons. Analyzed materials range from stones, metals, over porcelain to paintings. The available nondestructive and noninvasive analytical methods cover a broad range of techniques. Hence, for the sake of brevity, this chapter will concentrate on few techniques: Proton Induced X-ray Emission (PIXE) and Proton Induced γ-ray Emission (PIGE).

  9. Ionizing radiation detector

    DOEpatents

    Thacker, Louis H.

    1990-01-01

    An ionizing radiation detector is provided which is based on the principle of analog electronic integration of radiation sensor currents in the sub-pico to nano ampere range between fixed voltage switching thresholds with automatic voltage reversal each time the appropriate threshold is reached. The thresholds are provided by a first NAND gate Schmitt trigger which is coupled with a second NAND gate Schmitt trigger operating in an alternate switching state from the first gate to turn either a visible or audible indicating device on and off in response to the gate switching rate which is indicative of the level of radiation being sensed. The detector can be configured as a small, personal radiation dosimeter which is simple to operate and responsive over a dynamic range of at least 0.01 to 1000 R/hr.

  10. Amorphous silicon radiation detectors

    DOEpatents

    Street, Robert A.; Perez-Mendez, Victor; Kaplan, Selig N.

    1992-01-01

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification.

  11. Amorphous silicon radiation detectors

    DOEpatents

    Street, R.A.; Perez-Mendez, V.; Kaplan, S.N.

    1992-11-17

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification. 13 figs.

  12. Photovoltaic radiation detector element

    DOEpatents

    Agouridis, Dimitrios C.

    1983-01-01

    A radiation detector element is formed of a body of semiconductor material, a coating on the body which forms a photovoltaic junction therewith, and a current collector consisting of narrow metallic strips, the aforesaid coating having an opening therein the edge of which closely approaches but is spaced from the current collector strips.

  13. Semiconductor radiation detector

    DOEpatents

    Patt, Bradley E.; Iwanczyk, Jan S.; Tull, Carolyn R.; Vilkelis, Gintas

    2002-01-01

    A semiconductor radiation detector is provided to detect x-ray and light photons. The entrance electrode is segmented by using variable doping concentrations. Further, the entrance electrode is physically segmented by inserting n+ regions between p+ regions. The p+ regions and the n+ regions are individually biased. The detector elements can be used in an array, and the p+ regions and the n+ regions can be biased by applying potential at a single point. The back side of the semiconductor radiation detector has an n+ anode for collecting created charges and a number of p+ cathodes. Biased n+ inserts can be placed between the p+ cathodes, and an internal resistor divider can be used to bias the n+ inserts as well as the p+ cathodes. A polysilicon spiral guard can be implemented surrounding the active area of the entrance electrode or surrounding an array of entrance electrodes.

  14. Handheld CZT radiation detector

    DOEpatents

    Murray, William S.; Butterfield, Kenneth B.; Baird, William

    2004-08-24

    A handheld CZT radiation detector having a CZT gamma-ray sensor, a multichannel analyzer, a fuzzy-logic component, and a display component is disclosed. The CZT gamma-ray sensor may be a coplanar grid CZT gamma-ray sensor, which provides high-quality gamma-ray analysis at a wide range of operating temperatures. The multichannel analyzer categorizes pulses produce by the CZT gamma-ray sensor into channels (discrete energy levels), resulting in pulse height data. The fuzzy-logic component analyzes the pulse height data and produces a ranked listing of radioisotopes. The fuzzy-logic component is flexible and well-suited to in-field analysis of radioisotopes. The display component may be a personal data assistant, which provides a user-friendly method of interacting with the detector. In addition, the radiation detector may be equipped with a neutron sensor to provide an enhanced mechanism of sensing radioactive materials.

  15. Nanocomposites for electromagnetic radiation protection

    SciTech Connect

    Petrunin, V. F.

    2016-12-15

    Specific features that characterize nanoparticles and which are due to their small size and allow one to enhance the interaction between the electromagnetic radiation and nanostructured materials and to develop the effective protection of man and equipment against harmful uncontrolled radiation are reported. Examples of the development of nanocomposite radar absorbing materials that can be used for protection of man and equipment are presented.

  16. Heat Radiators for Electromagnetic Pumps

    NASA Technical Reports Server (NTRS)

    Campana, R. J.

    1986-01-01

    Report proposes use of carbon/carbon composite radiators in electromagnetic coolant pumps of nuclear reactors on spacecraft. Carbon/carbon composite materials function well at temperatures in excess of 2,200 K. Aluminum has melting temperature of only 880 K.

  17. Heat Radiators for Electromagnetic Pumps

    NASA Technical Reports Server (NTRS)

    Campana, R. J.

    1986-01-01

    Report proposes use of carbon/carbon composite radiators in electromagnetic coolant pumps of nuclear reactors on spacecraft. Carbon/carbon composite materials function well at temperatures in excess of 2,200 K. Aluminum has melting temperature of only 880 K.

  18. Microstructured silicon radiation detector

    DOEpatents

    Okandan, Murat; Derzon, Mark S.; Draper, Bruce L.

    2017-03-14

    A radiation detector comprises a silicon body in which are defined vertical pores filled with a converter material and situated within silicon depletion regions. One or more charge-collection electrodes are arranged to collect current generated when secondary particles enter the silicon body through walls of the pores. The pores are disposed in low-density clusters, have a majority pore thickness of 5 .mu.m or less, and have a majority aspect ratio, defined as the ratio of pore depth to pore thickness, of at least 10.

  19. Electromagnetic interactions in the MINOS detectors

    SciTech Connect

    Vahle, Patricia LaVern

    2004-08-01

    MINoS is a long-baseline neutrino experiment designed to observe the oscillation of neutrinos traveling between two detectors, a Near Detector at Fermi National Accelerator Laboratory and a Far Detector at the Soudan Underground Laboratory in northern Minnesota. Precision measurement of the oscillation parameters requires a better than 5% absolute energy calibration with is derived using a dedicated calibration detector, called CalDet. A smaller version of the MINOS detectors, the CalDet was exposed to particular beams in the CERN PS East Area test beams in 2001-2003. This document describes the conditions under which the CalDet beam data were taken, establishes selection criteria to identify a sample of electrons, and discusses the characteristics of electromagnetic interactions in the CalDet.

  20. Radiation Hazard Detector

    NASA Technical Reports Server (NTRS)

    1978-01-01

    NASA technology has made commercially available a new, inexpensive, conveniently-carried device for protection, of people exposed to potentially dangerous levels of microwave radiation. Microwaves are radio emissions of extremely high frequency. They can be hazardous but the degree of hazard is not yet well understood. Generally, it is believed that low intensity radiation of short duration is not harmful but that exposure to high levels can induce deep internal burns, affecting the circulatory and nervous systems, and particularly the eyes. The Department of Labor's Occupational Safety and Health Administration (OSHA) has established an allowable safe threshold of exposure. However, people working near high intensity sources of microwave energy-for example, radar antennas and television transmitters-may be unknowingly exposed to radiation levels beyond the safe limit. This poses not only a personal safety problem but also a problem for employers in terms of productivity loss, workman's compensation claims and possible liability litigation. Earlier-developed monitoring devices which warn personnel of dangerous radiation levels have their shortcomings. They can be cumbersome and awkward to use while working. They also require continual visual monitoring to determine if a person is in a dangerous area of radiation, and they are relatively expensive, another deterrent to their widespread adoption. In response to the need for a cheaper and more effective warning system, Jet Propulsion Laboratory developed, under NASA auspices, a new, battery-powered Microwave Radiation Hazard Detector. To bring the product to the commercial market, California Institute Research Foundation, the patent holder, granted an exclusive license to Cicoil Corporation, Chatsworth, California, an electronic components manufacturer.

  1. Foam radiators for transition radiation detectors

    NASA Astrophysics Data System (ADS)

    Chernyatin, V.; Dolgoshein, B.; Gavrilenko, I.; Potekhin, M.; Romaniouk, A.; Sosnovtsev, V.

    1993-02-01

    A wide variety of foam radiators, potentially useful in the design of a transition radiation detector, the possible particle identification tool in collider experiments, have been tested in the beam. Various characteristics of these radiators are compared, and the conclusion is reached that certain brands of polyethylene foam are best suited for use in the detector. Comparison is made with a "traditional" radiator, which is a periodic structure of plastic foils.

  2. Compton Sources of Electromagnetic Radiation

    SciTech Connect

    Geoffrey Krafft,Gerd Priebe

    2011-01-01

    When a relativistic electron beam interacts with a high-field laser beam, intense and highly collimated electromagnetic radiation will be generated through Compton scattering. Through relativistic upshifting and the relativistic Doppler effect, highly energetic polarized photons are radiated along the electron beam motion when the electrons interact with the laser light. For example, X-ray radiation can be obtained when optical lasers are scattered from electrons of tens-of-MeV beam energy. Because of the desirable properties of the radiation produced, many groups around the world have been designing, building, and utilizing Compton sources for a wide variety of purposes. In this review article, we discuss the generation and properties of the scattered radiation, the types of Compton source devices that have been constructed to date, and the prospects of radiation sources of this general type. Due to the possibilities of producing hard electromagnetic radiation in a device that is small compared to the alternative storage ring sources, it is foreseen that large numbers of such sources may be constructed in the future.

  3. Nano structural anodes for radiation detectors

    DOEpatents

    Cordaro, Joseph V.; Serkiz, Steven M.; McWhorter, Christopher S.; Sexton, Lindsay T.; Retterer, Scott T.

    2015-07-07

    Anodes for proportional radiation counters and a process of making the anodes is provided. The nano-sized anodes when present within an anode array provide: significantly higher detection efficiencies due to the inherently higher electric field, are amenable to miniaturization, have low power requirements, and exhibit a small electromagnetic field signal. The nano-sized anodes with the incorporation of neutron absorbing elements (e.g., .sup.10B) allow the use of neutron detectors that do not use .sup.3He.

  4. THE GENERATION OF THERMOELASTIC STRESS WAVES BY IMPULSIVE ELECTROMAGNETIC RADIATION.

    DTIC Science & Technology

    ELECTROMAGNETIC RADIATION , ABSORPTION), (*STRESSES, ELECTROMAGNETIC RADIATION ), SURFACE PROPERTIES, INTERACTIONS, HEAT TRANSFER, ELASTIC PROPERTIES, ELECTROMAGNETIC PULSES, LASERS, MATHEMATICAL ANALYSIS, BOUNDARY VALUE PROBLEMS, SOLIDS

  5. Anisotropic conducting films for electromagnetic radiation applications

    SciTech Connect

    Cavallo, Francesca; Lagally, Max G.; Rojas-Delgado, Richard

    2015-06-16

    Electronic devices for the generation of electromagnetic radiation are provided. Also provided are methods for using the devices to generate electromagnetic radiation. The radiation sources include an anisotropic electrically conducting thin film that is characterized by a periodically varying charge carrier mobility in the plane of the film. The periodic variation in carrier mobility gives rise to a spatially varying electric field, which produces electromagnetic radiation as charged particles pass through the film.

  6. Accurate electromagnetic modeling of terahertz detectors

    NASA Technical Reports Server (NTRS)

    Focardi, Paolo; McGrath, William R.

    2004-01-01

    Twin slot antennas coupled to superconducting devices have been developed over the years as single pixel detectors in the terahertz (THz) frequency range for space-based and astronomy applications. Used either for mixing or direct detection, they have been object of several investigations, and are currently being developed for several missions funded or co-funded by NASA. Although they have shown promising performance in terms of noise and sensitivity, so far they have usually also shown a considerable disagreement in terms of performance between calculations and measurements, especially when considering center frequency and bandwidth. In this paper we present a thorough and accurate electromagnetic model of complete detector and we compare the results of calculations with measurements. Starting from a model of the embedding circuit, the effect of all the other elements in the detector in the coupled power have been analyzed. An extensive variety of measured and calculated data, as presented in this paper, demonstrates the effectiveness and reliability of the electromagnetic model at frequencies between 600 GHz and 2.5THz.

  7. Radiation detectors in nuclear medicine.

    PubMed

    Ranger, N T

    1999-01-01

    Single-photon-emitting or positron-emitting radionuclides employed in nuclear medicine are detected by using sophisticated imaging devices, whereas simpler detection devices are used to quantify activity for the following applications: measuring doses of radiopharmaceuticals, performing radiotracer bioassays, and monitoring and controlling radiation risk in the clinical environment. Detectors are categorized in terms of function, the physical state of the transducer, or the mode of operation. The performance of a detector is described by the parameters efficiency, energy resolution and discrimination, and dead time. A detector may be used to detect single events (pulse mode) or to measure the rate of energy deposition (current mode). Some detectors are operated as simple counting systems by using a single-channel pulse height analyzer to discriminate against background or other extraneous events. Other detectors are operated as spectrometers and use a multichannel analyzer to form an energy spectrum. The types of detectors encountered in nuclear medicine are gas-filled detectors, scintillation detectors, and semiconductor detectors. The ionization detector, Geiger-Müller detector, extremity and area monitor, dose calibrator, well counter, thyroid uptake probe, Anger scintillation camera, positron emission tomographic scanner, solid-state personnel dosimeter, and intraoperative probe are examples of detectors used in clinical nuclear medicine practice.

  8. ORDNANCE CORPS VIEWS ELECTROMAGNETIC RADIATION HAZARDS TO WEAPONS SYSTEMS,

    DTIC Science & Technology

    EXPLOSIVES INITIATORS, * ELECTROMAGNETIC RADIATION ), HAZARDS, ELECTROMAGNETIC SHIELDING, RADIOFREQUENCY POWER, ANTENNAS, ATTENUATORS, IMPEDANCE MATCHING, SENSITIVITY, WEAPON SYSTEMS, MODULATION, CIRCUITS, BROADBAND

  9. Method and apparatus for measuring electromagnetic radiation

    NASA Technical Reports Server (NTRS)

    Been, J. F. (Inventor)

    1973-01-01

    An apparatus and method are described in which the capacitance of a semiconductor junction subjected to an electromagnetic radiation field is utilized to indicate the intensity or strength of the radiation.

  10. [Mechanisms of electromagnetic radiation damaging male reproduction].

    PubMed

    Xue, Lei; Chen, Hao-Yu; Wang, Shui-Ming

    2012-08-01

    More and more evidence from over 50 years of researches on the effects of electromagnetic radiation on male reproduction show that a certain dose of electromagnetic radiation obviously damages male reproduction, particularly the structure and function of spermatogenic cells. The mechanisms of the injury may be associated with energy dysmetabolism, lipid peroxidation, abnormal expressions of apoptosis-related genes and proteins, and DNA damage.

  11. Electromagnetic modeling and resonant detectors and arrays

    NASA Astrophysics Data System (ADS)

    Choi, K. K.; Sun, J.; DeCuir, E. A.; Olver, K. A.; Wijewarnasuriya, P.

    2015-05-01

    We recently developed a finite element three-dimensional electromagnetic model for quantum efficiency (QE) computation. It is applicable to any arbitrary detector geometry and materials. Using this model, we can accurately account for the open literature experimental results that we have investigated, which include those from GaAs solar cells, GaSb type-II superlattices, and GaAs quantum wells. We applied the model to design a photon trap to increase detector QE. By accumulating and storing incident light in the resonator-QWIP structure, we observed experimental QE as high as 71%. This improvement shows that we are now able to fully determine the optical properties of QWIPs. For example, we can design QWIPs to detect at certain wavelengths with certain bandwidths. To illustrate this capability, we designed QWIPs with its QE spectrum matching well with the transmission spectrum of a medium. We subsequently produced several focal plane arrays according to these designs with 640 × 512 and 1 K × 1 K formats. In this paper, we will compare the modeled QE and the experimental results obtained from single detectors as well as FPAs.

  12. Apparatus for processing electromagnetic radiation and method

    NASA Technical Reports Server (NTRS)

    Gatewood, George D. (Inventor)

    1983-01-01

    Measuring apparatus including a ruled member having alternate transparent and opaque zones. An optical coupler connecting the ruled member with electromagnetic radiation-conversion apparatus. The conversion apparatus may include a photomultiplier and a discriminator. Radiation impinging on the ruled member will, in part, be converted to electrical pulses which correspond to the intensity of the radiation. A method of processing electromagnetic radiation includes providing a member having alternating dark and light zones, establishing movement of the member through the beam of electromagnetic radiation with the dark zones interrupting passage of radiation through the rule, providing an optical coupler to connect a portion of the radiation with a conversion station where the radiation portion is converted into an electrical pulse which is related to the intensity of the radiation received at the conversion station. The electrical pulses may be counted and the digitized signals stored or permanently recorded to produce positional information.

  13. Cadmium telluride photovoltaic radiation detector

    DOEpatents

    Agouridis, Dimitrios C.; Fox, Richard J.

    1981-01-01

    A dosimetry-type radiation detector is provided which employs a polycrystalline, chlorine-compensated cadmium telluride wafer fabricated to operate as a photovoltaic current generator used as the basic detecting element. A photovoltaic junction is formed in the wafer by painting one face of the cadmium telluride wafer with an n-type semiconductive material. The opposite face of the wafer is painted with an electrically conductive material to serve as a current collector. The detector is mounted in a hermetically sealed vacuum containment. The detector is operated in a photovoltaic mode (zero bias) while DC coupled to a symmetrical differential current amplifier having a very low input impedance. The amplifier converts the current signal generated by radiation impinging upon the barrier surface face of the wafer to a voltage which is supplied to a voltmeter calibrated to read quantitatively the level of radiation incident upon the detecting wafer.

  14. Cadmium telluride photovoltaic radiation detector

    DOEpatents

    Agouridis, D.C.; Fox, R.J.

    A dosimetry-type radiation detector is provided which employs a polycrystalline, chlorine-compensated cadmium telluride wafer fabricated to operate as a photovoltaic current generator used as the basic detecting element. A photovoltaic junction is formed in the wafer by painting one face of the cadmium telluride wafer with an n-type semi-conductive material. The opposite face of the wafer is painted with an electrically conductive material to serve as a current collector. The detector is mounted in a hermetically sealed vacuum containment. The detector is operated in a photovoltaic mode (zero bias) while DC coupled to a symmetrical differential current amplifier having a very low input impedance. The amplifier converts the current signal generated by radiation impinging upon the barrier surface face of the wafer to a voltage which is supplied to a voltmeter calibrated to read quantitatively the level of radiation incident upon the detecting wafer.

  15. Portable Radiation Detectors

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Through a Small Business Innovation Research (SBIR) contract from Kennedy Space Center, General Pneumatics Corporation's Western Research Center satisfied a NASA need for a non-clogging Joule-Thomson cryostat to provide very low temperature cooling for various sensors. This NASA-supported cryostat development played a key part in the development of more portable high-purity geranium gamma-ray detectors. Such are necessary to discern between the radionuclides in medical, fuel, weapon, and waste materials. The outcome of the SBIR project is a cryostat that can cool gamma-ray detectors, without vibration, using compressed gas that can be stored compactly and indefinitely in a standby mode. General Pneumatics also produces custom J-T cryostats for other government, commercial and medical applications.

  16. Advanced Space Radiation Detector Technology Development

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D.; Wrbanek, Susan Y.; Fralick, Gustave C.

    2013-01-01

    The advanced space radiation detector development team at NASA Glenn Research Center (GRC) has the goal of developing unique, more compact radiation detectors that provide improved real-time data on space radiation. The team has performed studies of different detector designs using a variety of combinations of solid-state detectors, which allow higher sensitivity to radiation in a smaller package and operate at lower voltage than traditional detectors. Integration of multiple solid-state detectors will result in an improved detector system in comparison to existing state-of-the-art (SOA) instruments for the detection and monitoring of the space radiation field for deep space and aerospace applications.

  17. Advanced Space Radiation Detector Technology Development

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D.; Wrbanek, Susan Y.; Fralick, Gustave C.

    2013-01-01

    The advanced space radiation detector development team at NASA Glenn Research Center (GRC) has the goal of developing unique, more compact radiation detectors that provide improved real-time data on space radiation. The team has performed studies of different detector designs using a variety of combinations of solid-state detectors, which allow higher sensitivity to radiation in a smaller package and operate at lower voltage than traditional detectors. Integration of multiple solid-state detectors will result in an improved detector system in comparison to existing state-of-the-art instruments for the detection and monitoring of the space radiation field for deep space and aerospace applications.

  18. Advanced Space Radiation Detector Technology Development

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D.; Wrbanek, Susan Y.; Fralick, Gustave C.

    2013-01-01

    The advanced space radiation detector development team at the NASA Glenn Research Center (GRC) has the goal of developing unique, more compact radiation detectors that provide improved real-time data on space radiation. The team has performed studies of different detector designs using a variety of combinations of solid-state detectors, which allow higher sensitivity to radiation in a smaller package and operate at lower voltage than traditional detectors. Integration of multiple solid-state detectors will result in an improved detector system in comparison to existing state-of-the-art instruments for the detection and monitoring of the space radiation field for deep space and aerospace applications.

  19. Flexible composite radiation detector

    DOEpatents

    Cooke, D. Wayne; Bennett, Bryan L.; Muenchausen, Ross E.; Wrobleski, Debra A.; Orler, Edward B.

    2006-12-05

    A flexible composite scintillator was prepared by mixing fast, bright, dense rare-earth doped powdered oxyorthosilicate (such as LSO:Ce, LSO:Sm, and GSO:Ce) scintillator with a polymer binder. The binder is transparent to the scintillator emission. The composite is seamless and can be made large and in a wide variety of shapes. Importantly, the composite can be tailored to emit light in a spectral region that matches the optimum response of photomultipliers (about 400 nanometers) or photodiodes (about 600 nanometers), which maximizes the overall detector efficiency.

  20. Ionizing Radiation Detector

    DOEpatents

    Wright, Gomez W.; James, Ralph B.; Burger, Arnold; Chinn, Douglas A.

    2003-11-18

    A CdZnTe (CZT) crystal provided with a native CdO dielectric coating to reduce surface leakage currents and thereby, improve the resolution of instruments incorporating detectors using CZT crystals is disclosed. A two step process is provided for forming the dielectric coating which includes etching the surface of a CZT crystal with a solution of the conventional bromine/methanol etch treatment, and passivating the CZT crystal surface with a solution of 10 w/o NH.sub.4 F and 10 w/o H.sub.2 O.sub.2 in water after attaching electrical contacts to the crystal surface.

  1. Radiation detector spectrum simulator

    DOEpatents

    Wolf, M.A.; Crowell, J.M.

    1985-04-09

    A small battery operated nuclear spectrum simulator having a noise source generates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith to generate several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

  2. Radiation detector spectrum simulator

    DOEpatents

    Wolf, Michael A.; Crowell, John M.

    1987-01-01

    A small battery operated nuclear spectrum simulator having a noise source nerates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith generates several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

  3. Advanced Radiation Detector Development

    SciTech Connect

    The University of Michigan

    1998-07-01

    Since our last progress report, the project at The University of Michigan has continued to concentrate on the development of gamma ray spectrometers fabricated from cadmium zinc telluride (CZT). This material is capable of providing energy resolution that is superior to that of scintillation detectors, while avoiding the necessity for cooling associated with germanium systems. In our past reports, we have described one approach (the coplanar grid electrode) that we have used to partially overcome some of the major limitations on charge collection that is found in samples of CZT. This approach largely eliminates the effect of hole motion in the formation of the output signal, and therefore leads to pulses that depend only on the motion of a single carrier (electrons). Since electrons move much more readily through CZT than do holes, much better energy resolution can be achieved under these conditions. In our past reports, we have described a 1 cm cube CZT spectrometer fitted with coplanar grids that achieved an energy resolution of 1.8% from the entire volume of the crystal. This still represents, to our knowledge, the best energy resolution ever demonstrated in a CZT detector of this size.

  4. Detection of electromagnetic radiation using nonlinear materials

    DOEpatents

    Hwang, Harold Y.; Liu, Mengkun; Averitt, Richard D.; Nelson, Keith A.; Sternbach, Aaron; Fan, Kebin

    2016-06-14

    An apparatus for detecting electromagnetic radiation within a target frequency range is provided. The apparatus includes a substrate and one or more resonator structures disposed on the substrate. The substrate can be a dielectric or semiconductor material. Each of the one or more resonator structures has at least one dimension that is less than the wavelength of target electromagnetic radiation within the target frequency range, and each of the resonator structures includes at least two conductive structures separated by a spacing. Charge carriers are induced in the substrate near the spacing when the resonator structures are exposed to the target electromagnetic radiation. A measure of the change in conductivity of the substrate due to the induced charge carriers provides an indication of the presence of the target electromagnetic radiation.

  5. Updating Plasma Scattering of Electromagnetic Radiation

    NASA Astrophysics Data System (ADS)

    Sheffield, J.

    2010-05-01

    The monograph Plasma Scattering of Electromagnetic Radiation was published by Academic Press in 1975. A Russian edition, Atomidzat, came out in 1978. An updated version is being prepared by D. Froula, S. Glenzer. N Luhmann, and J. Sheffield for publication in 2010 by Elsevier. The new version will discuss the broader applications of Thomson scattering, which include the full range of plasmas used in research and industry. The expansion of the field has been made possible by the growing number of powerful radiation sources (from X-rays to microwaves), detectors, and innovative techniques. When the book was published, the highest temperatures in laboratory plasmas were around 2 keV for the electrons. Compare this to today's 25 keV where the relativistic effects are dramatic. The application to low temperature plasmas with Te in the range of 1 - 30+ eV, important in industry, has grown. Important capabilities have been developed in the areas of energetic particle, micro-instability, and high energy density plasma measurements. For the future, we look forward to the use of scattering as a diagnostic on the large new fusion facilities-NIF, LMJ, and ITER.

  6. Thermopile detector radiation hard readout

    NASA Astrophysics Data System (ADS)

    Gaalema, Stephen; Van Duyne, Stephen; Gates, James L.; Foote, Marc C.

    2010-08-01

    The NASA Jupiter Europa Orbiter (JEO) conceptual payload contains a thermal instrument with six different spectral bands ranging from 8μm to 100μm. The thermal instrument is based on multiple linear arrays of thermopile detectors that are intrinsically radiation hard; however, the thermopile CMOS readout needs to be hardened to tolerate the radiation sources of the JEO mission. Black Forest Engineering is developing a thermopile readout to tolerate the JEO mission radiation sources. The thermal instrument and ROIC process/design techniques are described to meet the JEO mission requirements.

  7. Porous material for protection from electromagnetic radiation

    SciTech Connect

    Kazmina, Olga E-mail: bdushkina89@mail.ru; Dushkina, Maria E-mail: bdushkina89@mail.ru; Suslyaev, Valentin; Semukhin, Boris

    2014-11-14

    It is shown that the porous glass crystalline material obtained by a low temperature technology can be used not only for thermal insulation, but also for lining of rooms as protective screens decreasing harmful effect of electromagnetic radiation as well as to establish acoustic chambers and rooms with a low level of electromagnetic background. The material interacts with electromagnetic radiation by the most effective way in a high frequency field (above 100 GHz). At the frequency of 260 GHz the value of the transmission coefficient decreases approximately in a factor times in comparison with foam glass.

  8. Direct detector for terahertz radiation

    DOEpatents

    Wanke, Michael C.; Lee, Mark; Shaner, Eric A.; Allen, S. James

    2008-09-02

    A direct detector for terahertz radiation comprises a grating-gated field-effect transistor with one or more quantum wells that provide a two-dimensional electron gas in the channel region. The grating gate can be a split-grating gate having at least one finger that can be individually biased. Biasing an individual finger of the split-grating gate to near pinch-off greatly increases the detector's resonant response magnitude over prior QW FET detectors while maintaining frequency selectivity. The split-grating-gated QW FET shows a tunable resonant plasmon response to FIR radiation that makes possible an electrically sweepable spectrometer-on-a-chip with no moving mechanical optical parts. Further, the narrow spectral response and signal-to-noise are adequate for use of the split-grating-gated QW FET in a passive, multispectral terahertz imaging system. The detector can be operated in a photoconductive or a photovoltaic mode. Other embodiments include uniform front and back gates to independently vary the carrier densities in the channel region, a thinned substrate to increase bolometric responsivity, and a resistive shunt to connect the fingers of the grating gate in parallel and provide a uniform gate-channel voltage along the length of the channel to increase the responsivity and improve the spectral resolution.

  9. Electromagnetic radiation under explicit symmetry breaking.

    PubMed

    Sinha, Dhiraj; Amaratunga, Gehan A J

    2015-04-10

    We report our observation that radiation from a system of accelerating charges is possible only when there is explicit breaking of symmetry in the electric field in space within the spatial configuration of the radiating system. Under symmetry breaking, current within an enclosed area around the radiating structure is not conserved at a certain instant of time resulting in radiation in free space. Electromagnetic radiation from dielectric and piezoelectric material based resonators are discussed in this context. Finally, it is argued that symmetry of a resonator of any form can be explicitly broken to create a radiating antenna.

  10. Electromagnetic radiation from beam-plasma instabilities

    NASA Technical Reports Server (NTRS)

    Pritchett, P. L.; Dawson, J. M.

    1983-01-01

    A computer simulation is developed for the generation of electromagnetic radiation in an electron beam-plasma interaction. The plasma is treated as a two-dimensional finite system, and effects of a continuous nonrelativistic beam input are accounted for. Three momentum and three field components are included in the simulation, and an external magnetic field is excluded. EM radiation generation is possible through interaction among Langmuir oscillations, ion-acoustic waves, and the electromagnetic wave, producing radiation perpendicular to the beam. The radiation is located near the plasma frequency, and polarized with the E component parallel to the beam. The scattering of Langmuir waves caused by ion-acoustic fluctuations generates the radiation. Comparison with laboratory data for the three-wave interactions shows good agreement in terms of the radiation levels produced, which are small relative to the plasma thermal energy.

  11. Relativistically strong electromagnetic radiation in a plasma

    SciTech Connect

    Bulanov, S. V. E-mail: bulanov.sergei@jaea.go.jp; Esirkepov, T. Zh.; Kando, M.; Kiriyama, H.; Kondo, K.

    2016-03-15

    Physical processes in a plasma under the action of relativistically strong electromagnetic waves generated by high-power lasers have been briefly reviewed. These processes are of interest in view of the development of new methods for acceleration of charged particles, creation of sources of bright hard electromagnetic radiation, and investigation of macroscopic quantum-electrodynamical processes. Attention is focused on nonlinear waves in a laser plasma for the creation of compact electron accelerators. The acceleration of plasma bunches by the radiation pressure of light is the most efficient regime of ion acceleration. Coherent hard electromagnetic radiation in the relativistic plasma is generated in the form of higher harmonics and/or electromagnetic pulses, which are compressed and intensified after reflection from relativistic mirrors created by nonlinear waves. In the limit of extremely strong electromagnetic waves, radiation friction, which accompanies the conversion of radiation from the optical range to the gamma range, fundamentally changes the behavior of the plasma. This process is accompanied by the production of electron–positron pairs, which is described within quantum electrodynamics theory.

  12. Electromagnetic radiation from beam-plasma instabilities

    NASA Technical Reports Server (NTRS)

    Stenzel, R. L.; Whelan, D. A.

    1982-01-01

    The mechanism by which unstable electrostatic waves of an electron-beam plasma system are converted into observed electromagnetic waves is of great current interest in space plasma physics. Electromagnetic radiation arises from both natural beam-plasma systems, e.g., type III solar bursts and kilometric radiation, and from man-made electron beams injected from rockets and spacecraft. In the present investigation the diagnostic difficulties encountered in space plasmas are overcome by using a large laboratory plasma. A finite diameter (d approximately equal to 0.8 cm) electron beam is injected into a uniform quiescent magnetized afterglow plasma of dimensions large compared with electromagnetic wavelength. Electrostatic waves grow, saturate and decay within the uniform central region of the plasma volume so that linear mode conversion on density gradients can be excluded as a possible generation mechanism for electromagnetic waves.

  13. Stochastic electromagnetic radiation of complex sources.

    PubMed

    Naus, H W L

    2007-08-01

    The emission of electromagnetic radiation by localized complex electric charge and current distributions is studied. A statistical formalism in terms of general dynamical multipole fields is developed. The appearing coefficients are treated as stochastic variables. Hereby as much as possible a priori physical knowledge is exploited. First results of simulated statistical electromagnetic fields as a function of position are presented. Sampling this field at one point approximates its resulting probability density.

  14. The Electromagnetic Calorimetry of the PANDA Detector at FAIR

    NASA Astrophysics Data System (ADS)

    Novotny, R. W.; PANDA Collaboration

    2012-12-01

    The PANDA collaboration at FAIR, Germany, will focus on undiscovered charm-meson states and glueballs in antiproton annihilations to study QCD phenomena in the non-perturbative regime. For fixed target experiments at the storage ring HESR a 4π-detector for tracking, particle ID and calorimetry is under development and construction to operate at high annihilation rates up to 20 MHz. The electromagnetic calorimeters are composed of a target spectrometer (EMC) based on PbWO4 crystals and a shashlyk-type sampling calorimeter at the most forward region. The EMC, comprising more than 15,000 crystals, is operated at a temperature of -25°C and read-out via large-area avalanche photo-diodes or vacuum phototriodes/tetrodes. The photo sensor signals are continuously digitized by sampling ADCs. More than 50% of the high quality PWO-II crystals are delivered and tested. The excellent performance with respect to energy, time and position information was determined over a shower energy range from 10 MeV up to 15 GeV by operating several prototype detectors. In addition, the concept of stimulated recovery has been investigated to recover radiation damage on- and off-line during the calorimeter operation. Besides the overall concept of the target spectrometer the response function of the shashlyk spectrometer down to photon energies even below 100 MeV is presented.

  15. Cellular Effects of Electromagnetic Radiation.

    DTIC Science & Technology

    2014-09-26

    cells of characean algae were examined for electrophysiological sequelae to acute electromagnetic field irradiation at 10 mW/cm Carrier frequencies...the low frequency excess noise in single cells of characean algae . J. Microwave Power _Z, 43-46 (1985). E63 A. V. Gokhale and W. F. Pickard, Extremely...A giant cell of a characean alga (normally about 15 mm long and 300 .um in diameter) would be placed in the channel downsteam from the strip, impaled

  16. Majorana fermions coupled to electromagnetic radiation

    NASA Astrophysics Data System (ADS)

    Ohm, Christoph; Hassler, Fabian

    2014-01-01

    We consider a voltage-biased Josephson junction between two nanowires hosting Majorana zero modes which occur as topological protected zero-energy excitations at the junction. We show that two Majorana fermions localized at the junction, despite being neutral particles, interact with the electromagnetic field and generate coherent radiation similar to the conventional Josephson radiation. Within a semiclassical analysis of the radiation field, we find that the phase of the radiation gets locked to the superconducting phase difference and that the radiation is emitted at half the Josephson frequency. In order to confirm the coherence of the radiation, we study correlations of the radiation emitted by two spatially separated junctions in a dc-SQUID geometry taking into account decoherence due to spontaneous state-switches as well as due to quasi-particle poisoning.

  17. Electricity generation using electromagnetic radiation

    DOEpatents

    Halas, Nancy J.; Nordlander, Peter; Neumann, Oara

    2017-08-22

    In general, in one aspect, the invention relates to a system to create vapor for generating electric power. The system includes a vessel comprising a fluid and a complex and a turbine. The vessel of the system is configured to concentrate EM radiation received from an EM radiation source. The vessel of the system is further configured to apply the EM radiation to the complex, where the complex absorbs the EM radiation to generate heat. The vessel of the system is also configured to transform, using the heat generated by the complex, the fluid to vapor. The vessel of the system is further configured to sending the vapor to a turbine. The turbine of the system is configured to receive, from the vessel, the vapor used to generate the electric power.

  18. Radiation Assessment Detector for Mars Science Laboratory

    NASA Image and Video Library

    2010-11-09

    The Radiation Assessment Detector, shown prior to its September 2010 installation onto NASA Mars rover Curiosity, will aid future human missions to Mars by providing information about the radiation environment on Mars and on the way to Mars.

  19. Radiated fields from an electromagnetic pulse simulator

    NASA Astrophysics Data System (ADS)

    Pelletier, M.; Delisle, G. Y.; Kashyap, S.

    Simulators of electromagnetic pulses allow generation within a limited time of very high-intensity fields such as those produced in a nuclear explosion. These fields can be radiated out of the test zone at a lower but nevertheless significant level; if the intensity of these fields is sufficiently high, damage to humans and electronic equipment can result. An evaluation of the potential danger of these simulator emissions requires knowledge of the amplitude, duration, and the energy of the radiated impulses. A technique is presented for calculating the fields radiated by a parallel-plane electromagnetic pulse simulator. The same method can also be applied to a rhombic type simulator. Sample numerical results are presented along with the calculations of the energy and power density and a discussion of the formation of the field in the frequency domain.

  20. Hawking radiation in an electromagnetic waveguide?

    PubMed

    Schützhold, Ralf; Unruh, William G

    2005-07-15

    It is demonstrated that the propagation of electromagnetic waves in an appropriately designed waveguide is (for large wavelengths) analogous to that within a curved space-time--such as around a black hole. As electromagnetic radiation (e.g., microwaves) can be controlled, amplified, and detected (with present-day technology) much easier than sound, for example, we propose a setup for the experimental verification of the Hawking effect. Apart from experimentally testing this striking prediction, this would facilitate the investigation of the trans-Planckian problem.

  1. Hybrid anode for semiconductor radiation detectors

    DOEpatents

    Yang, Ge; Bolotnikov, Aleksey E; Camarda, Guiseppe; Cui, Yonggang; Hossain, Anwar; Kim, Ki Hyun; James, Ralph B

    2013-11-19

    The present invention relates to a novel hybrid anode configuration for a radiation detector that effectively reduces the edge effect of surface defects on the internal electric field in compound semiconductor detectors by focusing the internal electric field of the detector and redirecting drifting carriers away from the side surfaces of the semiconductor toward the collection electrode(s).

  2. Pocket-size microwave radiation hazard detector

    NASA Technical Reports Server (NTRS)

    Kolbly, R. B.

    1974-01-01

    Inexpensive lightweight unit is easily carried in coat pocket or attached to belt, detector sounds alarm in presence of dangerous microwave radiation levels. Unit consists of antenna, detector, level sensor, keyed oscillator, and speaker. Antenna may be single equiangular spiral or set of orthogonal slot dipoles. Signal detector is simple diode in small package.

  3. [Applications of electromagnetic radiation in medicine].

    PubMed

    Miłowska, Katarzyna; Grabowska, Katarzyna; Gabryelak, Teresa

    2014-05-08

    Recent decades have been devoted to the intense search for the response to questions related to the impact of radiation on the human body. Due to the growing fashion for a healthy lifestyle, increasing numbers of works about the alleged dangers of electromagnetic waves and diseases that they cause appeared. However, the discoveries of 20th century, and knowledge of the properties of electromagnetic radiation have allowed to broaden the horizons of the use of artificial sources of radiation in many fields of science and especially in medicine. The aim of this paper is to show that although excessive radiation or high doses are dangerous to the human body, its careful and controlled use, does not pose a threat, and it is often necessary in therapy. The possibility of using ionizing radiation in radiotherapy, isotope diagnostics or medical imaging, and non-ionizing radiation in the treatment for dermatological disorders and cancers will be presented. The unique properties of synchrotron radiation result in using it on a large scale in the diagnosis of pathological states by imaging methods.

  4. Radiation experience with the CDF silicon detectors

    SciTech Connect

    Husemann, Ulrich; /Rochester U.

    2005-11-01

    The silicon detectors of the CDF experiment at the Tevatron collider are operated in a harsh radiation environment. The lifetime of the silicon detectors is limited by radiation damage, and beam-related incidents are an additional risk. This article describes the impact of beam-related incidents on detector operation and the effects of radiation damage on electronics noise and the silicon sensors. From measurements of the depletion voltage as a function of the integrated luminosity, estimates of the silicon detector lifetime are derived.

  5. Electromagnetic radiation--parameters for risk assessment.

    PubMed

    Israel, M S

    1994-01-01

    The assessment of human exposure to electromagnetic radiation (EMR) under occupational and environmental conditions is one of the most complicated problems of public health science and practice. The problems arise from the very essence of EMR, the conflicting requirements of the measuring instruments, the complexity of electromagnetic waves in the working environment, and the still unknown mechanisms of their biological effects. One of the best ways to develop methods and criteria for exposure assessment of EMR is to determine the electromagnetic field parameters as well as those related to the quantity of energy absorbed by the organism. Definitions have been given mainly regarding tissues' electric and magnetic characteristics, and regarding the energetic parameters of EMR, without description of concrete methods of exposure assessment in different complicated cases of wide-ranging impulsive, non-homogeneous radiation. The best parameters for exposure assessment are the Specific Absorption Rate (SAR), the energetic loading of the human body (the electromagnetic dose W), the time-weighted average (TWA), using time-dependent hygienic norms and standards.

  6. Does electromagnetic radiation accelerate galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Eichler, D.

    1977-01-01

    The 'reactor' theories of Tsytovich and collaborators (1973) of cosmic-ray acceleration by electromagnetic radiation are examined in the context of galactic cosmic rays. It is shown that any isotropic synchrotron or Compton reactors with reasonable astrophysical parameters can yield particles with a maximum relativistic factor of only about 10,000. If they are to produce particles with higher relativistic factors, the losses due to inverse Compton scattering of the electromagnetic radiation in them outweigh the acceleration, and this violates the assumptions of the theory. This is a critical restriction in the context of galactic cosmic rays, which have a power-law spectrum extending up to a relativistic factor of 1 million.

  7. Does electromagnetic radiation accelerate galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Eichler, D.

    1977-01-01

    The 'reactor' theories of Tsytovich and collaborators (1973) of cosmic-ray acceleration by electromagnetic radiation are examined in the context of galactic cosmic rays. It is shown that any isotropic synchrotron or Compton reactors with reasonable astrophysical parameters can yield particles with a maximum relativistic factor of only about 10,000. If they are to produce particles with higher relativistic factors, the losses due to inverse Compton scattering of the electromagnetic radiation in them outweigh the acceleration, and this violates the assumptions of the theory. This is a critical restriction in the context of galactic cosmic rays, which have a power-law spectrum extending up to a relativistic factor of 1 million.

  8. Classical electromagnetic radiation of the Dirac electron

    NASA Technical Reports Server (NTRS)

    Lanyi, G.

    1973-01-01

    A wave-function-dependent four-vector potential is added to the Dirac equation in order to achieve conservation of energy and momentum for a Dirac electron and its emitted electromagnetic field. The resultant equation contains solutions which describe transitions between different energy states of the electron. As a consequence it is possible to follow the space-time evolution of such a process. This evolution is shown in the case of the spontaneous emission of an electromagnetic field by an electron bound in a hydrogen-like atom. The intensity of the radiation and the spectral distribution are calculated for transitions between two eigenstates. The theory gives a self-consistent deterministic description of some simple radiation processes without using quantum electrodynamics or the correspondence principle.

  9. Electromagnetic radiation absorbers and modulators comprising polyaniline

    DOEpatents

    Epstein, Arthur J.; Ginder, John M.; Roe, Mitchell G.; Hajiseyedjavadi, Hamid

    1992-01-01

    A composition for absorbing electromagnetic radiation, wherein said electromagnetic radiation possesses a wavelength generally in the range of from about 1000 Angstroms to about 50 meters, wherein said composition comprises a polyaniline composition of the formula ##STR1## where y can be equal to or greater than zero, and R.sup.1 and R.sup.2 are independently selected from the group containing of H, --OCH.sub.3, --CH.sub.3, --F, --Cl, --Br, --I, NR.sup.3 .sub.2, --NHCOR.sup.3, --OH, --O.sup.-, SR.sup.3, --OCOR.sup.3, --NO.sub.2, --COOH, --COOR.sup.3, --COR.sup.3, --CHO, and --CN, where R.sup.3 is a C.sub.1 to C.sub.8 alkyl, aryl or aralkyl group.

  10. Classical electromagnetic radiation of the Dirac electron

    NASA Technical Reports Server (NTRS)

    Lanyi, G.

    1973-01-01

    A wave-function-dependent four-vector potential is added to the Dirac equation in order to achieve conservation of energy and momentum for a Dirac electron and its emitted electromagnetic field. The resultant equation contains solutions which describe transitions between different energy states of the electron. As a consequence it is possible to follow the space-time evolution of such a process. This evolution is shown in the case of the spontaneous emission of an electromagnetic field by an electron bound in a hydrogen-like atom. The intensity of the radiation and the spectral distribution are calculated for transitions between two eigenstates. The theory gives a self-consistent deterministic description of some simple radiation processes without using quantum electrodynamics or the correspondence principle.

  11. Radiation damage effects on solid state detectors

    NASA Technical Reports Server (NTRS)

    Trainor, J. H.

    1972-01-01

    Totally depleted silicon diodes are discussed which are used as nuclear particle detectors in investigations of galactic and solar cosmic radiation and trapped radiation. A study of radiation and chemical effects on the diodes was conducted. Work on electron and proton irradiation of surface barrier detectors with thicknesses up to 1 mm was completed, and work on lithium-drifted silicon devices with thicknesses of several millimeters was begun.

  12. Propagation of electromagnetic radiation in mitochondria?

    PubMed

    Thar, Roland; Kühl, Michael

    2004-09-21

    Mitochondria are the main source of ultra-weak chemiluminescence generated by reactive oxygen species, which are continuously formed during the mitochondrial oxidative metabolism. Vertebrate cells show typically filamentous mitochondria associated with the microtubules of the cytoskeleton, forming together a continuous network (mitochondrial reticulum). The refractive index of both mitochondria and microtubules is higher than the surrounding cytoplasm, which results that the mitochondrial reticulum can act as an optical waveguide, i.e. electromagnetic radiation can propagate within the network. A detailed analysis of the inner structure of mitochondria shows, that they can be optically modelled as a multi-layer system with alternating indices of refraction. The parameters of this multi-layer system are dependent on the physiologic state of the mitochondria. The effect of the multi-layer system on electromagnetic radiation propagating along the mitochondrial reticulum is analysed by the transfer-matrix method. If induced light emission could take place in mitochondria, the multi-layer system could lead to lasing action like it has been realized in technical distributed feedback laser. Based on former reports about the influence of external illumination on the physiology of mitochondria it is speculated whether there exists some kind of long-range interaction between individual mitochondria mediated by electromagnetic radiation.

  13. Ultra-thin plasma radiation detector

    DOEpatents

    Friedman, Peter S.

    2017-01-24

    A position-sensitive ionizing-radiation counting detector includes a radiation detector gas chamber having at least one ultra-thin chamber window and an ultra-thin first substrate contained within the gas chamber. The detector further includes a second substrate generally parallel to and coupled to the first substrate and defining a gas gap between the first substrate and the second substrate. The detector further includes a discharge gas between the substrates and contained within the gas chamber, where the discharge gas is free to circulate within the gas chamber and between the first and second substrates at a given gas pressure. The detector further includes a first electrode coupled to one of the substrates and a second electrode electrically coupled to the first electrode. The detector further includes a first discharge event detector coupled to at least one of the electrodes for detecting a gas discharge counting event in the electrode.

  14. 49 CFR 173.310 - Exceptions for radiation detectors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Exceptions for radiation detectors. 173.310... for radiation detectors. Radiation detectors, radiation sensors, electron tube devices, or ionization chambers, herein referred to as “radiation detectors,” that contain only Division 2.2 gases, are...

  15. 49 CFR 173.310 - Exceptions for radiation detectors.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Exceptions for radiation detectors. 173.310... for radiation detectors. Radiation detectors, radiation sensors, electron tube devices, or ionization chambers, herein referred to as “radiation detectors,” that contain only Division 2.2 gases, are excepted...

  16. 49 CFR 173.310 - Exceptions for radiation detectors.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Exceptions for radiation detectors. 173.310... for radiation detectors. Radiation detectors, radiation sensors, electron tube devices, or ionization chambers, herein referred to as “radiation detectors,” that contain only Division 2.2 gases, are excepted...

  17. 49 CFR 173.310 - Exceptions for radiation detectors.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Exceptions for radiation detectors. 173.310... for radiation detectors. Radiation detectors, radiation sensors, electron tube devices, or ionization chambers, herein referred to as “radiation detectors,” that contain only Division 2.2 gases, are excepted...

  18. 49 CFR 173.310 - Exceptions for radiation detectors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Exceptions for radiation detectors. 173.310... for radiation detectors. Radiation detectors, radiation sensors, electron tube devices, or ionization chambers, herein referred to as “radiation detectors,” that contain only Division 2.2 gases, are excepted...

  19. Radiation force and balance of electromagnetic momentum

    NASA Astrophysics Data System (ADS)

    Campos, I.; Jiménez, J. L.; Roa-Neri, J. A. E.

    2016-07-01

    Some force densities can be expressed as a divergence of a stress tensor, as is the case with the electromagnetic force density. We have shown elsewhere that from the Maxwell equations several balance equations of electromagnetic momentum can be derived, depending on the form these equations are expressed in terms of fields E, D, B, H, and polarisations P and M. These balance equations imply different force densities and different stress tensors, providing a great flexibility to solve particular problems. Among these force densities we have found some proposed in the past with plausibility arguments, like the Einstein-Laub force density, while other proposed force densities appear as particular or limit cases of these general force densities, like the Helmholtz force density. We calculate the radiation force of an electromagnetic wave incident on a semi-infinite negligibly absorbing material using these balance equations, corroborating in this way that the surface integration of the stress tensor gives the same result that the calculation made through a volume integration of the force density, as done by Bohren. As is usual in applications of Gauss’s theorem, the surface on which the surface integral is to be performed must be chosen judiciously, and due care of discontinuities on the boundary conditions must be taken. Advanced undergraduates and graduate students will find a different approach to new aspects of the interaction of radiation with matter.

  20. Electron gas grid semiconductor radiation detectors

    DOEpatents

    Lee, Edwin Y.; James, Ralph B.

    2002-01-01

    An electron gas grid semiconductor radiation detector (EGGSRAD) useful for gamma-ray and x-ray spectrometers and imaging systems is described. The radiation detector employs doping of the semiconductor and variation of the semiconductor detector material to form a two-dimensional electron gas, and to allow transistor action within the detector. This radiation detector provides superior energy resolution and radiation detection sensitivity over the conventional semiconductor radiation detector and the "electron-only" semiconductor radiation detectors which utilize a grid electrode near the anode. In a first embodiment, the EGGSRAD incorporates delta-doped layers adjacent the anode which produce an internal free electron grid well to which an external grid electrode can be attached. In a second embodiment, a quantum well is formed between two of the delta-doped layers, and the quantum well forms the internal free electron gas grid to which an external grid electrode can be attached. Two other embodiments which are similar to the first and second embodiment involve a graded bandgap formed by changing the composition of the semiconductor material near the first and last of the delta-doped layers to increase or decrease the conduction band energy adjacent to the delta-doped layers.

  1. Electro-magnetic radiation reflective concentrator

    SciTech Connect

    Johnson, A.L.

    1982-01-26

    A system for concentrating electro-magnetic radiation, such as solar radiation, includes a plurality of reflectors mounted on a common frame and aimed at a radiation absorber that is rigidly coupled to the frame by an intermediate support. The combined frame, reflectors, absorber and intermediate support are coupled to a cantilever beam by means of a suspension assembly located between the absorber and the reflectors. This suspension is at the center of gravity of the combined frame, reflectors, absorber and intermediate support. The cantilever beam is coupled at one end to a main support and at the other to the suspension assembly. This suspension assembly allows the combined frame, reflectors, absorber and intermediate support to pivot relative to the beam about two perpendicular axes.

  2. Electromagnetic field radiation model for lightning strokes to tall structures

    SciTech Connect

    Motoyama, H.; Janischewskyj, W.; Hussein, A.M.; Chisholm, W.A.; Chang, J.S.; Rusan, R.

    1996-07-01

    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.

  3. Bubble detector characterization for space radiation.

    PubMed

    Green, A R; Andrews, H R; Bennett, L G I; Clifford, E T H; Ing, H; Jonkmans, G; Lewis, B J; Noulty, R A; Ough, E A

    2005-01-01

    In light of the importance of the neutron contribution to the dose equivalent received by space workers in the near-Earth radiation environment, there is an increasing need for a personal dosimeter that is passive in nature and able to respond to this neutron field in real time. Recent Canadian technology has led to the development of a bubble detector, which is sensitive to neutrons, but insensitive to low linear energy transfer (LET) radiation. By changing the composition of the bubble detector fluid (or "superheat"), the detectors can be fabricated to respond to different types of radiation. This paper describes a preliminary ground-based research effort to better characterize the bubble detectors of different compositions at various charged-particle accelerator facilities, which are capable of simulating the space radiation field. c2005 Elsevier Ltd. All rights reserved.

  4. Resonant-mass detectors of gravitational radiation

    NASA Astrophysics Data System (ADS)

    Michelson, Peter F.; Price, John C.; Taber, Robert C.

    1987-07-01

    A network of second-generation low-temperature gravitational radiation detectors is nearing completion. These detectors, sensitive to mechanical strains of order 10 to the -18th, are possible because of a variety of technical innovations that have been made in cryogenics, low-noise superconducting instrumentation, and vibration isolation techniques. Another five orders of magnitude improvement in energy sensitivity of resonant-mass detectors is possible before the linear amplifier quantum limit is encountered.

  5. Metamaterials for Cherenkov Radiation Based Particle Detectors

    SciTech Connect

    Tyukhtin, A. V.; Schoessow, P.; Kanareykin, A.; Antipov, S.

    2009-01-22

    Measurement of Cherenkov radiation (CR) has long been a useful technique for charged particle detection and beam diagnostics. We are investigating metamaterials engineered to have refractive indices tailored to enhance properties of CR that are useful for particle detectors and that cannot be obtained using conventional media. Cherenkov radiation in dispersive media with a large refractive index differs significantly from the same effect in conventional detector media, like gases or aerogel. The radiation pattern of CR in dispersive metamaterials presents lobes at very large angles with respect to particle motion. Moreover, the frequency and particle velocity dependence of the radiated energy can differ significantly from CR in a conventional dielectric medium.

  6. Testing black hole candidates with electromagnetic radiation

    NASA Astrophysics Data System (ADS)

    Bambi, Cosimo

    2017-04-01

    Astrophysical black hole candidates are thought to be the Kerr black holes of general relativity, but there is not yet direct observational evidence that the spacetime geometry around these objects is described by the Kerr solution. The study of the properties of the electromagnetic radiation emitted by gas or stars orbiting these objects can potentially test the Kerr black hole hypothesis. This paper reviews the state of the art of this research field, describing the possible approaches to test the Kerr metric with current and future observational facilities and discussing current constraints.

  7. Radiation damage in semiconductor detectors

    SciTech Connect

    Kraner, H.W.

    1981-12-01

    A survey is presented of the important damage-producing interactions in semiconductor detectors and estimates of defect numbers are made for MeV protons, neutrons and electrons. Damage effects of fast neutrons in germanium gamma ray spectrometers are given in some detail. General effects in silicon detectors are discussed and damage constants and their relationship to leakage current is introduced.

  8. New radiation dosimeter using a pyroelectric detector

    SciTech Connect

    de Paula, M.H.; Carvalho, A.A.; Mascarenhas, S.; Zimmerman, R.L.

    1984-11-01

    We describe a new type of radiation dosimeter, for the diagnostic x-ray region, using a pyroelectric detector. It consists of a PZT ceramic crystal thick enough to absorb all the incident radiation at 33 keV. This pyroelectric radiation dosimeter (PERD) produces an electrical signal when exposed to a chopped beam of x-ray photons. The PERD is basically a microcalorimeter. It has the following characteristics: (1) it responds linearly to the energy fluence rate of the radiation; (2) it responds linearly to the radiation intensity for a given radiation spectrum; (3) it has excellent stability; (4) it is simple to construct and inexpensive; and (5) it is rugged.

  9. Enhanced radiation detectors using luminescent materials

    DOEpatents

    Vardeny, Zeev V.; Jeglinski, Stefan A.; Lane, Paul A.

    2001-01-01

    A radiation detecting device comprising a radiation sensing element, and a layer of luminescent material to expand the range of wavelengths over which the sensing element can efficiently detect radiation. The luminescent material being selected to absorb radiation at selected wavelengths, causing the luminescent material to luminesce, and the luminescent radiation being detected by the sensing element. Radiation sensing elements include photodiodes (singly and in arrays), CCD arrays, IR detectors and photomultiplier tubes. Luminescent materials include polymers, oligomers, copolymers and porphyrines, Luminescent layers include thin films, thicker layers, and liquid polymers.

  10. Three-dimensional architecture for solid state radiation detectors

    DOEpatents

    Parker, S.

    1999-03-30

    A radiation-damage resistant radiation detector is formed on a substrate formed of a material doped with a first conductivity type dopant. The detector includes at least one first electrode formed of first conductivity type dopant, and at least one second electrode that is spaced-apart from the first electrode and formed of a second conductivity type dopant. Each first and second electrode penetrates into the substrate from a substrate surface, and one or more electrodes may penetrate entirely through the substrate, that is traversing from one surface to the other surface. Particulate and/or electromagnetic radiation penetrating at least a surface of the substrate releases electrons and holes in substrate regions. Because the electrodes may be formed entirely through the substrate thickness, the released charges will be a relatively small distance from at least a portion of such an electrode, e.g., a distance less than the substrate thickness. The electrons and/or holes traverse the small distance and are collected by said electrodes, thus promoting rapid detection of the radiation. By providing one or more electrodes with a dopant profile radially graded in a direction parallel to a substrate surface, an electric field results that promotes rapid collection of released electrons and said holes. Monolithic combinations of such detectors may be fabricated including CMOS electronics to process radiation signals. 45 figs.

  11. Three-dimensional architecture for solid state radiation detectors

    DOEpatents

    Parker, Sherwood

    1999-01-01

    A radiation-damage resistant radiation detector is formed on a substrate formed of a material doped with a first conductivity type dopant. The detector includes at least one first electrode formed of first conductivity type dopant, and at least one second electrode that is spaced-apart from the first electrode and formed of a second conductivity type dopant. Each first and second electrode penetrates into the substrate from a substrate surface, and one or more electrodes may penetrate entirely through the substrate, that is traversing from one surface to the other surface. Particulate and/or electromagnetic radiation penetrating at least a surface of the substrate releases electrons and holes in substrate regions. Because the electrodes may be formed entirely through the substrate thickness, the released charges will be a relatively small distance from at least a portion of such an electrode, e.g., a distance less than the substrate thickness. The electrons and/or holes traverse the small distance and are collected by said electrodes, thus promoting rapid detection of the radiation. By providing one or more electrodes with a dopant profile radially graded in a direction parallel to a substrate surface, an electric field results that promotes rapid collection of released electrons and said holes. Monolithic combinations of such detectors may be fabricated including CMOS electronics to process radiation signals.

  12. Wafer-fused semiconductor radiation detector

    DOEpatents

    Lee, Edwin Y.; James, Ralph B.

    2002-01-01

    Wafer-fused semiconductor radiation detector useful for gamma-ray and x-ray spectrometers and imaging systems. The detector is fabricated using wafer fusion to insert an electrically conductive grid, typically comprising a metal, between two solid semiconductor pieces, one having a cathode (negative electrode) and the other having an anode (positive electrode). The wafer fused semiconductor radiation detector functions like the commonly used Frisch grid radiation detector, in which an electrically conductive grid is inserted in high vacuum between the cathode and the anode. The wafer-fused semiconductor radiation detector can be fabricated using the same or two different semiconductor materials of different sizes and of the same or different thicknesses; and it may utilize a wide range of metals, or other electrically conducting materials, to form the grid, to optimize the detector performance, without being constrained by structural dissimilarity of the individual parts. The wafer-fused detector is basically formed, for example, by etching spaced grooves across one end of one of two pieces of semiconductor materials, partially filling the grooves with a selected electrical conductor which forms a grid electrode, and then fusing the grooved end of the one semiconductor piece to an end of the other semiconductor piece with a cathode and an anode being formed on opposite ends of the semiconductor pieces.

  13. Processing circuitry for single channel radiation detector

    NASA Technical Reports Server (NTRS)

    Holland, Samuel D. (Inventor); Delaune, Paul B. (Inventor); Turner, Kathryn M. (Inventor)

    2009-01-01

    Processing circuitry is provided for a high voltage operated radiation detector. An event detector utilizes a comparator configured to produce an event signal based on a leading edge threshold value. A preferred event detector does not produce another event signal until a trailing edge threshold value is satisfied. The event signal can be utilized for counting the number of particle hits and also for controlling data collection operation for a peak detect circuit and timer. The leading edge threshold value is programmable such that it can be reprogrammed by a remote computer. A digital high voltage control is preferably operable to monitor and adjust high voltage for the detector.

  14. Large numbers hypothesis. II - Electromagnetic radiation

    NASA Technical Reports Server (NTRS)

    Adams, P. J.

    1983-01-01

    This paper develops the theory of electromagnetic radiation in the units covariant formalism incorporating Dirac's large numbers hypothesis (LNH). A direct field-to-particle technique is used to obtain the photon propagation equation which explicitly involves the photon replication rate. This replication rate is fixed uniquely by requiring that the form of a free-photon distribution function be preserved, as required by the 2.7 K cosmic radiation. One finds that with this particular photon replication rate the units covariant formalism developed in Paper I actually predicts that the ratio of photon number to proton number in the universe varies as t to the 1/4, precisely in accord with LNH. The cosmological red-shift law is also derived and it is shown to differ considerably from the standard form of (nu)(R) - const.

  15. Radiation damage due to electromagnetic showers

    SciTech Connect

    Rakhno, Igor; Mokhov, Nikolai; Striganov, Sergei; /Fermilab

    2008-05-01

    Radiation-induced damage due to atomic displacements is essential to correctly predict the behavior of materials in nuclear reactors and at charged-particle accelerators. Traditionally the damage due to hadrons was of major interest. The recent increased interest in high-energy lepton colliders gave rise to the problem of prediction of radiation damage due to electromagnetic showers in a wide energy range--from a few hundred keV and up to a few hundred GeV. The report describes results of an electron- and positron-induced displacement cross section evaluation. It is based on detailed lepton-nucleus cross sections, realistic nuclear form-factors and a modified Kinchin-Pease damage model. Numerical data on displacement cross sections for various target nuclei is presented.

  16. PAMELA Space Mission: The Transition Radiation Detector

    NASA Astrophysics Data System (ADS)

    Ambriola, M.; Bellotti, R.; Cafagna, F.; Circella, M.; De Marzo, C.; Giglietto, N.; Marangelli, B.; Mirizzi, N.; Romita, M.; Spinelli, P.

    2003-07-01

    PAMELA telescope is a satellite-b orne magnetic spectrometer built to fulfill the primary scientific objectives of detecting antiparticles (antiprotons and positrons) in the cosmic rays, and to measure spectra of particles in cosmic rays. The PAMELA telescope is currently under integration and is composed of: a silicon tracker housed in a permanent magnet, a time of flight and an anticoincidence system both made of plastic scintillators, a silicon imaging calorimeter, a neutron detector and a Transition Radiation Detector (TRD). The TRD detector is composed of 9 sensitive layers of straw tubes working in proportional mode for a total of 1024 channels. Each layer is interleaved with a radiator plane made of carbon fibers. The TRD detector characteristics will be described along with its performance studied exposing the detector to particle beams of electrons, pions, muons and protons of different momenta at both CERN-PS and CERN-SPS facilities.

  17. Imaging Using Energy Discriminating Radiation Detector Array

    SciTech Connect

    Willson, Paul D.; Clajus, Martin; Tuemer, Tuemay O.; Visser, Gerard; Cajipe, Victoria

    2003-08-26

    Industrial X-ray radiography is often done using a broad band energy source and always a broad band energy detector. There exist several major advantages in the use of narrow band sources and or detectors, one of which is the separation of scattered radiation from primary radiation. ARDEC has developed a large detector array system in which every detector element acts like a multi-channel analyzer. A radiographic image is created from the number of photons detected in each detector element, rather than from the total energy absorbed in the elements. For high energies, 25 KeV to 4 MeV, used in radiography, energy discriminating detectors have been limited to less than 20,000 photons per second per detector element. This rate is much too slow for practical radiography. Our detector system processes over two million events per second per detector pixel, making radiographic imaging practical. This paper expounds on the advantages of the ARDEC radiographic imaging process.

  18. Space radiation dosimetry using bubble detectors.

    PubMed

    Ing, H; Mortimer, A

    1994-10-01

    Bubble detectors--a new development in radiation detection--has only recently been used for radiation measurements in space. One important characteristic of the bubble detector is that it operates on a phenomenon which bears considerable resemblance to biological response. Recent experimental results from irradiating bubble detectors with high-energy heavy ions point to the need to re-examine the methodology used for assessing space radiation and the relevance of conventional quantities such as dose equivalent for space dosimetry. It may be that biological hazard associated with the intensely ionizing events--associated with nuclear fragmentation but delivering relatively small dose equivalent--may be much more important than that associated with lightly ionizing events which comprise the bulk of the conventional radiation dose equivalent.

  19. The potential carcinogenic hazards of electromagnetic radiation: a review.

    PubMed

    Horn, Y

    1995-01-01

    The purpose of this review is to summarize the experience gained thus far on the potential health hazards of electromagnetic radiation. Far less information is available in the medical literature on this kind of radiation than on ionizing radiation, which has been recognized as a health hazard long ago. Increased rates of cancer morbidity and mortality have been noted in populations exposed to ionizing radiation, and international quantitative safety criteria have been established. Electromagnetic radiation (radiofrequency levels between several hundred kilohertz and 300 GHz) is not an infrequent phenomenon. The literature consists mainly of epidemiological studies out of which grew the assumption that this kind of radiation may be carcinogenic. However, only limited data are available on electromagnetic radiation as a potential cancer inducer. A review of the literature does not demonstrate a direct and clear linkage between electromagnetic radiation and the occurrence of malignant tumors, but much more research and clarification are necessary before reaching any conclusions.

  20. New radiation dosimeter using a pyroelectric detector

    SciTech Connect

    de Paula, M.H.; Carvalho, A.A.; Mascarenhas, S.; Zimmerman, R.L.

    1984-11-01

    We describe a new type of radiation dosimeter, for the diagnostic x-ray region, using a pyroelectric detector. It consists of a PZT ceramic crystal thick enough to absorb all the incident radiation at 33 keV. This pyroelectric radiation dosimeter (PERD) produces an electrical signal when exposed to a chopped beam of x-ray photons. The PERD is basically a microcalorimeter. It has the following characteristics: (1) it responds linearly to the energy fluence rate of the radiation; (2) it responds linearly to the radiation inten

  1. Societal Impacts of Solar Electromagnetic Radiation

    NASA Astrophysics Data System (ADS)

    Lean, J. L.

    2000-05-01

    Changes in solar electromagnetic radiation, which occur continuously and at all wavelengths of the spectrum, can have significant societal impacts on a wide range of time scales. Detection of climate change and ozone depletion requires reliable specification of solar-induced processes that mask or exacerbate anthropogenic effects. Living with, and mitigating, climate change and ozone depletion has significant economic, habitat and political impacts of international extent. As an example, taxes to restrict carbon emission may cause undue economic stress if the role of greenhouse gases in global warming is incorrectly diagnosed. Ignoring solar-induced ozone changes in the next century may lead to incorrect assessment of the success of the Montreal Protocol in protecting the ozone layer by limiting the use of ozone-destroying chlorofluorocarbons. Societal infrastructure depends in many ways on space-based technological assets. Communications and navigation for commerce, industry, science and defense rely on satellite signals transmitted through, and reflected by, electrons in the ionosphere. Electron densities change in response to solar flares, and by orders of magnitude in response to EUV and X-ray flux variations during the Sun's 11-year activity cycle. Spacecraft and space debris experience enhanced drag on their orbits when changing EUV radiation causes upper atmosphere densities to increase. Especially affected are spacecraft and debris in lower altitude orbits, such as Iridium-type communication satellites, and the International Space Station (ISS). Proper specification of solar-induced fluctuations in the neutral upper atmosphere can, for example, aid in tracking the ISS and surrounding space debris, reducing the chance of ISS damage from collisions, and maximizing its operations. Aspects of solar electromagnetic radiation variability will be briefly illustrated on a range of time scales, with specific identification of the societal impacts of different

  2. Device for calibrating a radiation detector system

    DOEpatents

    McFee, M.C.; Kirkham, T.J.; Johnson, T.H.

    1994-12-27

    A device is disclosed for testing a radiation detector system that includes at least two arrays of radiation detectors that are movable with respect to each other. The device includes a ''shield plate'' or shell, and an opposing ''source plate'' containing a source of ionizing radiation. Guides are attached to the outer surface of the shell for engaging the forward ends of the detectors, thereby reproducibly positioning the detectors with respect to the source and with respect to each other, thereby ensuring that a predetermined portion of the radiation emitted by the source passes through the shell and reaches the detectors. The shell is made of an hydrogenous material having approximately the same radiological attenuation characteristics as composite human tissue. The source represents a human organ such as the lungs, heart, kidneys, liver, spleen, pancreas, thyroid, testes, prostate, or ovaries. The source includes a source of ionizing radiation having a long half-life and an activity that is within the range typically searched for in human subjects. 3 figures.

  3. Device for calibrating a radiation detector system

    DOEpatents

    Mc Fee, Matthew C.; Kirkham, Tim J.; Johnson, Tippi H.

    1994-01-01

    A device for testing a radiation detector system that includes at least two arrays of radiation detectors that are movable with respect to each other. The device includes a "shield plate" or shell, and an opposing "source plate" containing a source of ionizing radiation. Guides are attached to the outer surface of the shell for engaging the forward ends of the detectors, thereby reproducibly positioning the detectors with respect to the source and with respect to each other, thereby ensuring that a predetermined portion of the radiation emitted by the source passes through the shell and reaches the detectors. The shell is made of an hydrogenous material having approximately the same radiological attenuation characteristics as composite human tissue. The source represents a human organ such as the lungs, heart, kidneys, heart, liver, spleen, pancreas, thyroid, testes, prostate, or ovaries. The source includes a source of ionizing radiation having a long half-life and an activity that is within the range typically searched for in human subjects.

  4. Electromagnetic Compatibility Testing of Implantable Neurostimulators Exposed to Metal Detectors

    PubMed Central

    Seidman, Seth J; Kainz, Wolfgang; Casamento, Jon; Witters, Donald

    2010-01-01

    This paper presents results of electromagnetic compatibility (EMC) testing of three implantable neurostimulators exposed to the magnetic fields emitted from several walk-through and hand-held metal detectors. The motivation behind this testing comes from numerous adverse event reports involving active implantable medical devices (AIMDs) and security systems that have been received by the Food and Drug Administration (FDA). EMC testing was performed using three neurostimulators exposed to the emissions from 12 walk-through metal detectors (WTMDs) and 32 hand-held metal detectors (HHMDs). Emission measurements were performed on all HHMDs and WTMDs and summary data is presented. Results from the EMC testing indicate possible electromagnetic interference (EMI) between one of the neurostimulators and one WTMD and indicate that EMI between the three neurostimulators and HHMDs is unlikely. The results suggest that worst case situations for EMC testing are hard to predict and testing all major medical device modes and setting parameters are necessary to understand and characterize the EMC of AIMDs. PMID:20448818

  5. Discriminating electromagnetic radiation based on angle of incidence

    DOEpatents

    Hamam, Rafif E.; Bermel, Peter; Celanovic, Ivan; Soljacic, Marin; Yeng, Adrian Y. X.; Ghebrebrhan, Michael; Joannopoulos, John D.

    2015-06-16

    The present invention provides systems, articles, and methods for discriminating electromagnetic radiation based upon the angle of incidence of the electromagnetic radiation. In some cases, the materials and systems described herein can be capable of inhibiting reflection of electromagnetic radiation (e.g., the materials and systems can be capable of transmitting and/or absorbing electromagnetic radiation) within a given range of angles of incidence at a first incident surface, while substantially reflecting electromagnetic radiation outside the range of angles of incidence at a second incident surface (which can be the same as or different from the first incident surface). A photonic material comprising a plurality of periodically occurring separate domains can be used, in some cases, to selectively transmit and/or selectively absorb one portion of incoming electromagnetic radiation while reflecting another portion of incoming electromagnetic radiation, based upon the angle of incidence. In some embodiments, one domain of the photonic material can include an isotropic dielectric function, while another domain of the photonic material can include an anisotropic dielectric function. In some instances, one domain of the photonic material can include an isotropic magnetic permeability, while another domain of the photonic material can include an anisotropic magnetic permeability. In some embodiments, non-photonic materials (e.g., materials with relatively large scale features) can be used to selectively absorb incoming electromagnetic radiation based on angle of incidence.

  6. Estimation of radiation effects in the front-end electronics of an ILC electromagnetic calorimeter

    NASA Astrophysics Data System (ADS)

    Bartsch, V.; Postranecky, M.; Targett-Adams, C.; Warren, M.; Wing, M.

    2008-08-01

    The front-end electronics of the electromagnetic calorimeter of an International Linear Collider detector are situated in a radiation environment. This requires the effect of the radiation on the performance of the electronics, specifically FPGAs, to be examined. In this paper we study the flux, particle spectra and deposited doses at the front-end electronics of the electromagnetic calorimeter of a detector at the ILC. We also study the occupancy of the electromagnetic calorimeter. These estimates are compared with measurements, e.g. of the radiation damage of FPGAs, done elsewhere. The outcome of the study shows that the radiation doses and the annual flux is low enough to allow today's FPGAs to operate. The Single Event Upset rate, however, lies between 14 min and 12 h depending on the FPGA used and therefore needs to be considered in the design of the data acquisition system of the electromagnetic calorimeter. The occupancy is about 0.002 per bunch train not taking into account the effect of noise which depends on the choice of the detector.

  7. Synchronization behaviors of coupled neurons under electromagnetic radiation

    NASA Astrophysics Data System (ADS)

    Ma, Jun; Wu, Fuqiang; Wang, Chunni

    2017-01-01

    Based on an improved neuronal model, in which the effect of magnetic flux is considered during the fluctuation and change of ion concentration in cells, the transition of synchronization is investigated by imposing external electromagnetic radiation on the coupled neurons, and networks, respectively. It is found that the synchronization degree depends on the coupling intensity and the intensity of external electromagnetic radiation. Indeed, appropriate intensity of electromagnetic radiation could be effective to realize intermittent synchronization, while stronger intensity of electromagnetic radiation can induce disorder of coupled neurons and network. Neurons show rhythm synchronization in the electrical activities by increasing the coupling intensity under electromagnetic radiation, and spatial patterns can be formed in the network under smaller factor of synchronization.

  8. Radiation and particle detector and amplifier

    NASA Technical Reports Server (NTRS)

    Schmidt, K. C. (Inventor)

    1973-01-01

    A radiation or charged particle detector is described which incorporates a channel multiplier structure to amplify the detected rays or particles. The channel multiplier structure has a support multiplying element with a longitudinal slot along one side. The element supports a pair of plates positioned contiguous with the slot. The plates funnel the particles or rays to be detected into the slotted aperture and the element, thus creating an effectively wide aperture detector of the windowless type.

  9. Collectivity and electromagnetic radiation in small systems

    NASA Astrophysics Data System (ADS)

    Shen, Chun; Paquet, Jean-François; Denicol, Gabriel S.; Jeon, Sangyong; Gale, Charles

    2017-01-01

    Collective behavior has been observed in hadronic measurements of high multiplicity proton+lead collisions at the Large Hadron Collider, as well as in (proton, deuteron, helium-3) + gold collisions at the Relativistic Heavy Ion Collider. To better understand the evolution dynamics and the properties of the matter created in these small systems, a systematic study of the soft hadronic observables together with electromagnetic radiation from these collisions is performed by using a hydrodynamic framework. Quantitative agreement is found between theoretical calculations and existing experimental hadronic observables. The validity of the fluid-dynamical description is estimated by calculating Knudsen and inverse Reynolds numbers. Sizeable thermal yields are predicted for low-pT photons. Further predictions of higher-order charged hadron anisotropic flow coefficients and of thermal photon enhancement are proposed.

  10. The Electromagnetic Calorimeter of the future PANDA Detector

    SciTech Connect

    Novotny, Rainer

    2006-10-27

    Experiments with a cooled antiproton beam at the future accelerator facility FAIR at GSI, Darmstadt, will be performed with the 4{pi} detector PANDA comprising a high resolution, compact and fast homogeneous electromagnetic calorimeter to detect photons between 10MeV and 10GeV energy inside a superconducting solenoid (2T). The target calorimeter comprises more than 20,000 PbWO4 crystals of significantly enhanced quality read-out with large area avalanche photodiodes at an operating temperature of -25 degree sign C. The paper describes the quality of PWO-II and illustrates the future performance based on response measurements with high-energy photons.

  11. Electromagnetic Shower Reconstruction for theSilicon Detector

    SciTech Connect

    Meyer, N.

    2005-12-08

    This report presents a two-pass reconstruction algorithm for electromagnetic showers, based on studies with simulated photons in the highly segmented Silicon Tungsten calorimeter of the Silicon Detector concept for the International Linear Collider. It is shown that the initial reconstruction and identification of the dense shower cores allows shower separation down to 3 cm distance between two photons on the calorimeter surface. First results are shown for the subsequent collection of unassociated hits around the shower cores necessary to reconstruct complete energy deposits by individual particles.

  12. Multiple-mode radiation detector

    DOEpatents

    Claus, Liam D.; Derzon, Mark S.; Kay, Randolph R.; Bauer, Todd; Trotter, Douglas Chandler; Henry, Michael David

    2015-08-25

    An apparatus for detecting radiation is provided. In embodiments, at least one sensor medium is provided, of a kind that interacts with radiation to generate photons and/or charge carriers. The apparatus also includes at least one electrode arrangement configured to collect radiation-generated charge from a sensor medium that has been provided. The apparatus also includes at least one photodetector configured to produce an electrical output in response to photons generated by radiation in such a sensor medium, and an electronic circuit configured to produce an output that is jointly responsive to the collected charge and to the photodetector output. At least one such electrode arrangement, at least one such photodetector, and at least one such sensor medium are combined to form an integral unit.

  13. The High Energy Particle Detector on Board of the China Seismo-Electromagnetic Satellite

    NASA Astrophysics Data System (ADS)

    Sparvoli, Roberta; Palma, Francesco; Panico, Beatrice; Sotgiu, Alessandro; Vitale, Vincenzo

    2016-08-01

    The study of the Van Allen belts temporal stability is among the main objectives of the China Seismo- Electromagnetic Satellite (CSES) space mission, as well as the study of other electromagnetic disturbances with possible seismic origin. In parallel to this, the CSES mission will address issues of heliospheric and magnetospheric physics, by measuring the cosmic radiation around the Earth.The CSES satellite, developed by a Chinese-Italian collaboration, will be launched in the first half of 2017 and inserted into a circular Sun-synchronous orbit with 98° inclination and 500 km altitude. The expected lifetime is 5 years. CSES hosts several instruments on board: 2 magnetometers, an electric field detector, a plasma analyser, a Langmuir probe and a High-Energy Particle Detector (HEPD). The HEPD detector, responsibility of the Italian side of the CSES collaboration, will measure electrons (3 - 100 MeV) and protons (30 - 300 MeV) along CSES orbit. It consists of a segmented layer of plastic scintillators for the trigger and a calorimeter constituted by a tower of plastic scintillator counters and a LYSO plane. The direction of the incident particle is provided by two planes of double-side silicon micro-strip detectors placed in front of the trigger. Topic of this talk is the technical description of the HEPD and its main characteristics.

  14. Low-Power Multi-Aspect Space Radiation Detector System

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D.; Wrbanek, Susan Y.; Fralick, Gustave; Freeman, Jon C.; Burkebile, Stephen P.

    2012-01-01

    The advanced space radiation detector development team at NASA Glenn Research Center (GRC) has the goal of developing unique, more compact radiation detectors that provide improved real-time data on space radiation. The team has performed studies of different detector designs using a variety of combinations of solid-state detectors, which allow higher sensitivity to radiation in a smaller package and operate at lower voltage than traditional detectors. Integration of all of these detector technologies will result in an improved detector system in comparison to existing state-of-the-art (SOA) instruments for the detection and monitoring of the deep space radiation field.

  15. Electromagnetic radiation accompanying gravitational waves from black hole binaries

    NASA Astrophysics Data System (ADS)

    Dolgov, A.; Postnov, K.

    2017-09-01

    The transition of powerful gravitational waves, created by the coalescence of massive black hole binaries, into electromagnetic radiation in external magnetic fields is considered. In contrast to the previous calculations of the similar effect we study the realistic case of the gravitational radiation frequency below the plasma frequency of the surrounding medium. The gravitational waves propagating in the plasma constantly create electromagnetic radiation dragging it with them, despite the low frequency. The plasma heating by the unattenuated electromagnetic wave may be significant in hot rarefied plasma with strong magnetic field and can lead to a noticeable burst of electromagnetic radiation with higher frequency. The graviton-to-photon conversion effect in plasma is discussed in the context of possible electromagnetic counterparts of GW150914 and GW170104.

  16. Imaging radiation detector with gain

    DOEpatents

    Morris, C.L.; Idzorek, G.C.; Atencio, L.G.

    1982-07-21

    A radiation imaging device which has application in x-ray imaging. The device can be utilized in CAT scanners and other devices which require high sensitivity and low x-ray fluxes. The device utilizes cumulative multiplication of charge carriers on the anode plane and the collection of positive ion charges to image the radiation intensity on the cathode plane. Parallel and orthogonal cathode wire arrays are disclosed as well as a two-dimensional grid pattern for collecting the positive ions on the cathode.

  17. Imaging radiation detector with gain

    DOEpatents

    Morris, Christopher L.; Idzorek, George C.; Atencio, Leroy G.

    1984-01-01

    A radiation imaging device which has application in x-ray imaging. The device can be utilized in CAT scanners and other devices which require high sensitivity and low x-ray fluxes. The device utilizes cumulative multiplication of charge carriers on the anode plane and the collection of positive ion charges to image the radiation intensity on the cathode plane. Parallel and orthogonal cathode wire arrays are disclosed as well as a two-dimensional grid pattern for collecting the positive ions on the cathode.

  18. Detectivity of gas leakage based on electromagnetic radiation transfer

    NASA Astrophysics Data System (ADS)

    Long, Yunting; Wang, Lingxue; Li, Jiakun; Zhang, Changxing; Zhang, Bei

    2011-05-01

    Standoff detection of gas leakage is a fundamental need in petrochemical and power industries. The passive gas imaging system using thermal imager has been proven to be efficient to visualize leaking gas which is not visible to the naked eye. The detection probability of gas leakage is the basis for designing a gas imaging system. Supposing the performance parameters of the thermal imager are known, the detectivity based on electromagnetic radiation transfer model to image gas leakage is analyzed. This model takes into consideration a physical analysis of the gas plume spread in the atmosphere-the interaction processes between the gas and its surrounding environment, the temperature of the gas and the background, the background surface emissivity, and also gas concentration, etc. Under a certain environmental conditions, through calculating the radiation reaching to the detector from the camera's optical field of view, we obtain an entity "Gas Equivalent Blackbody Temperature Difference (GEBTD)" which is the radiation difference between the on-plume and off-plume regions. Comparing the GEBTD with the Noise Equivalent Temperature Difference (NETD) of the thermal imager, we can know whether the system can image the gas leakage. At last, an example of detecting CO2 gas by JADE MWIR thermal imager with a narrow band-pass filter is presented.

  19. Apparatus and method for the simultaneous detection of neutrons and ionizing electromagnetic radiation

    DOEpatents

    Bell, Zane W.

    2000-01-01

    A sensor for simultaneously detecting neutrons and ionizing electromagnetic radiation comprising: a sensor for the detection of gamma radiation, the sensor defining a sensing head; the sensor further defining an output end in communication with the sensing head; and an exterior neutron-sensitive material configured to form around the sensing head; wherein the neutron-sensitive material, subsequent to the capture of the neutron, fissions into an alpha-particle and a .sup.7 Li ion that is in a first excited state in a majority of the fissions, the first excited state decaying via the emission of a single gamma ray at 478 keV which can in turn be detected by the sensing head; and wherein the sensing head can also detect the ionizing electromagnetic radiation from an incident radiation field without significant interference from the neutron-sensitive material. A method for simultaneously detecting neutrons and ionizing electromagnetic radiation comprising the steps of: providing a gamma ray sensitive detector comprising a sensing head and an output end; conforming an exterior neutron-sensitive material configured to form around the sensing head of the detector; capturing neutrons by the sensing head causing the neutron-sensitive material to fission into an alpha-particle and a .sup.7 Li ion that is in a first excited state in a majority of the fissions, the state decaying via the emission of a single gamma ray at 478 keV; sensing gamma rays entering the detector through the neutron-sensitive material; and producing an output through a readout device coupled to the output end; wherein the detector provides an output which is proportional to the energy of the absorbed ionizing electromagnetic radiation.

  20. Radiation damage in barium fluoride detector materials

    SciTech Connect

    Levey, P.W.; Kierstead, J.A.; Woody, C.L.

    1988-01-01

    To develop radiation hard detectors, particularly for high energy physics studies, radiation damage is being studied in BaF/sub 2/, both undoped and doped with La, Ce, Nd, Eu, Gd and Tm. Some dopants reduce radiation damage. In La doped BaF/sub 2/ they reduce the unwanted long lifetime luminescence which interferes with the short-lived fluorescence used to detect particles. Radiation induced coloring is being studied with facilities for making optical measurements before, during and after irradiation with /sup 60/C0 gamma rays. Doses of 10/sup 6/ rad, or less, create only ionization induced charge transfer effects since lattice atom displacement damage is negligible at these doses. All crystals studied exhibit color center formation, between approximately 200 and 800 nm, during irradiation and color center decay after irradiation. Thus only measurements made during irradiation show the total absorption present in a radiation field. Both undoped and La doped BaF/sub 2/ develop damage at minimum detectable levels in the UV---which is important for particle detectors. For particle detector applications these studies must be extended to high dose irradiations with particles energetic enough to cause lattice atom displacement damage. In principle, the reduction in damage provided by dopants could apply to other applications requiring radiation damage resistant materials.

  1. Neutron responsive self-powered radiation detector

    DOEpatents

    Brown, Donald P.; Cannon, Collins P.

    1978-01-01

    An improved neutron responsive self-powered radiation detector is disclosed in which the neutron absorptive central emitter has a substantially neutron transmissive conductor collector sheath spaced about the emitter and the space between the emitter and collector sheath is evacuated.

  2. Integrator Circuitry for Single Channel Radiation Detector

    NASA Technical Reports Server (NTRS)

    Holland, Samuel D. (Inventor); Delaune, Paul B. (Inventor); Turner, Kathryn M. (Inventor)

    2008-01-01

    Input circuitry is provided for a high voltage operated radiation detector to receive pulses from the detector having a rise time in the range of from about one nanosecond to about ten nanoseconds. An integrator circuit, which utilizes current feedback, receives the incoming charge from the radiation detector and creates voltage by integrating across a small capacitor. The integrator utilizes an amplifier which closely follows the voltage across the capacitor to produce an integrator output pulse with a peak value which may be used to determine the energy which produced the pulse. The pulse width of the output is stretched to approximately 50 to 300 nanoseconds for use by subsequent circuits which may then use amplifiers with lower slew rates.

  3. Photon: the minimum dose of electromagnetic radiation

    NASA Astrophysics Data System (ADS)

    Suntola, Tuomo

    2005-08-01

    A radio engineer can hardly think about smaller amount of electromagnetic radiation than given by a single oscillation cycle of a unit charge in a dipole. When solved from Maxwell's equations for a dipole of one wavelength, the energy of the emitted radiation cycle obtains the form Eλ = 2/3 hf, where the Planck constant h can be expressed in terms of the unit charge, e, the vacuum permeability, μ0, the velocity of light, c, and a numerical factor as h = 1.1049*2π3e2μ0c=6.62607*10-34 [kgm2/s]. A point emitter like an atom can be regarded as a dipole in the fourth dimension. The length of such dipole is measured in the direction of the line element cdt, which in one oscillation cycle means the length of one wavelength. For a dipole in the fourth dimension, three space directions are in the normal plane which eliminates the factor 2/3 from the energy expression thus leading to Planck's equation Eλ = hf for the radiation emitted by a single electron transition in an atom. The expression of the Planck constant obtained from Maxwell's equations leads to a purely numerical expression of the fine structure constant α=1/(1.1049*4π3) = 1/137 and shows that the Planck constant is directly proportional to the velocity of light. When applied to Balmer's formula, the linkage of the Planck constant to the velocity of light shows, that the frequency of an atomic oscillator is directly proportional to the velocity of light. This implies that the velocity of light is observed as constant in local measurements. Such an interpretation makes it possible to convert relativistic spacetime with variable time coordinates into space with variable clock frequencies in universal time, and thus include relativistic phenomena in the framework of quantum mechanics.

  4. Electromagnetic Compatibility Assessment of CCD Detector Acquisition Chains not Synchronized

    NASA Astrophysics Data System (ADS)

    Nicoletto, M.; Boschetti, D.; Ciancetta, E.; Maiorano, E.; Stagnaro, L.

    2016-05-01

    Euclid is a space observatory managed by the European Space Agency; it is the second medium class mission (see Figure 1) in the frame of Cosmic Vision 2015-2025 program.In the frame of this project, the electromagnetic interference between two different and not synchronized Charge Coupled Device (CCD) (see Figure 2) acquisition chains has been evaluated. The key parameter used for this assessment is the electromagnetic noise induced on each other. Taking into account the specificity of the issue, radiation coupling at relative low frequency and in near field conditions, classical approach based on simulations and testing on qualification model cannot be directly applied. Based on that, it has been decided to investigate the issue by test in an incremental way.

  5. Workshop on detectors for synchrotron radiation

    SciTech Connect

    Robinson, Arthur L.

    2000-11-22

    Forefront experiments in many scientific areas for which synchrotron sources provide sufficient flux are nonetheless hindered because detectors cannot collect data fast enough, do not cover sufficiently solid angle, or do no have adequate resolution. Overall, the synchrotron facilities, each of which represents collective investments from funding agencies and user institutions ranging from many hundreds of millions to more than a billion dollars, are effectively significantly underutilized. While this chronic and growing problem plagues facilities around the world, it is particularly acute in the United States, where detector research often has to ride on the coat tails of explicitly science-oriented projects. As a first step toward moving out of this predicament, scientists from the U.S. synchrotron facilities held a national workshop in Washington, DC, on October 30-31, 2000. The Workshop on Detectors for Synchrotron Research aimed to create a national ''roadmap'' for development of synchrotron-radiation detectors.

  6. Silicon radiation detectors: materials and applications

    SciTech Connect

    Walton, J.T.; Haller, E.E.

    1982-10-01

    Silicon nuclear radiation detectors are available today in a large variety of sizes and types. This profusion has been made possible by the ever increasing quality and diameter silicon single crystals, new processing technologies and techniques, and innovative detector design. The salient characteristics of the four basic detector groups, diffused junction, ion implanted, surface barrier, and lithium drift are reviewed along with the silicon crystal requirements. Results of crystal imperfections detected by lithium ion compensation are presented. Processing technologies and techniques are described. Two recent novel position-sensitive detector designs are discussed - one in high-energy particle track reconstruction and the other in x-ray angiography. The unique experimental results obtained with these devices are presented.

  7. A semiconductor radiation imaging pixel detector for space radiation dosimetry.

    PubMed

    Kroupa, Martin; Bahadori, Amir; Campbell-Ricketts, Thomas; Empl, Anton; Hoang, Son Minh; Idarraga-Munoz, John; Rios, Ryan; Semones, Edward; Stoffle, Nicholas; Tlustos, Lukas; Turecek, Daniel; Pinsky, Lawrence

    2015-07-01

    Progress in the development of high-performance semiconductor radiation imaging pixel detectors based on technologies developed for use in high-energy physics applications has enabled the development of a completely new generation of compact low-power active dosimeters and area monitors for use in space radiation environments. Such detectors can provide real-time information concerning radiation exposure, along with detailed analysis of the individual particles incident on the active medium. Recent results from the deployment of detectors based on the Timepix from the CERN-based Medipix2 Collaboration on the International Space Station (ISS) are reviewed, along with a glimpse of developments to come. Preliminary results from Orion MPCV Exploration Flight Test 1 are also presented. Copyright © 2015 The Committee on Space Research (COSPAR). All rights reserved.

  8. Radiation detectors: needs and prospects

    SciTech Connect

    Armantrout, G.A.

    1981-01-01

    Important applications for x- and ..gamma..-ray spectroscopy are found in prospecting, materials characterization, environmental monitoring, the life sciences, and nuclear physics. The specific requirements vary for each application with varying degrees of emphasis on either spectrometer resolution, detection efficiency, or both. Since no one spectrometer is ideally suited to this wide range of needs, compromises are usually required. Gas and scintillation spectrometers have reached a level of maturity, and recent interest has concentrated on semiconductor spectrometers. Germanium detectors are showing continuing refinement and are the spectrometers of choice for high resolution applications. The new high-Z semiconductors, such as CdTe and HgI/sub 2/, have shown steady improvement but are limited in both resolution and size and will likely be used only in applications which require their unique properties.

  9. High resolution amorphous silicon radiation detectors

    DOEpatents

    Street, R.A.; Kaplan, S.N.; Perez-Mendez, V.

    1992-05-26

    A radiation detector employing amorphous Si:H cells in an array with each detector cell having at least three contiguous layers (n-type, intrinsic, p-type), positioned between two electrodes to which a bias voltage is applied. An energy conversion layer atop the silicon cells intercepts incident radiation and converts radiation energy to light energy of a wavelength to which the silicon cells are responsive. A read-out device, positioned proximate to each detector element in an array allows each such element to be interrogated independently to determine whether radiation has been detected in that cell. The energy conversion material may be a layer of luminescent material having a columnar structure. In one embodiment a column of luminescent material detects the passage therethrough of radiation to be detected and directs a light beam signal to an adjacent a-Si:H film so that detection may be confined to one or more such cells in the array. One or both electrodes may have a comb structure, and the teeth of each electrode comb may be interdigitated for capacitance reduction. The amorphous Si:H film may be replaced by an amorphous Si:Ge:H film in which up to 40 percent of the amorphous material is Ge. Two dimensional arrays may be used in X-ray imaging, CT scanning, crystallography, high energy physics beam tracking, nuclear medicine cameras and autoradiography. 18 figs.

  10. High resolution amorphous silicon radiation detectors

    DOEpatents

    Street, Robert A.; Kaplan, Selig N.; Perez-Mendez, Victor

    1992-01-01

    A radiation detector employing amorphous Si:H cells in an array with each detector cell having at least three contiguous layers (n type, intrinsic, p type), positioned between two electrodes to which a bias voltage is applied. An energy conversion layer atop the silicon cells intercepts incident radiation and converts radiation energy to light energy of a wavelength to which the silicon cells are responsive. A read-out device, positioned proximate to each detector element in an array allows each such element to be interrogated independently to determine whether radiation has been detected in that cell. The energy conversion material may be a layer of luminescent material having a columnar structure. In one embodiment a column of luminescent material detects the passage therethrough of radiation to be detected and directs a light beam signal to an adjacent a-Si:H film so that detection may be confined to one or more such cells in the array. One or both electrodes may have a comb structure, and the teeth of each electrode comb may be interdigitated for capacitance reduction. The amorphous Si:H film may be replaced by an amorphous Si:Ge:H film in which up to 40 percent of the amorphous material is Ge. Two dimensional arrays may be used in X-ray imaging, CT scanning, crystallography, high energy physics beam tracking, nuclear medicine cameras and autoradiography.

  11. Radiation detectors for occupational safety measurements

    NASA Astrophysics Data System (ADS)

    Kaase, Heinrich; Chen, Mai; Grothmann, Knut

    1995-09-01

    The effective radiant exposures for artificial and natural UV-sources are determined by temporal integration over an 8 h working day. Therefore the spectrally weighted integration of the spectral irradiance from the radiation source in the plane of the exposure is to measure. Such measaurements are made with two different detector systems: measurements of UV radiation according to the integral method should be possible according to a quasi partial filtering method using different individually filtered photodiodes. A spectroradiometer for UV radiation analysis was tested due to its application in field measurements for meteorology, medicin, and occupational safety. The optical part of this compact instrument consists of a cosentrance optic, a monochromator and detector system. A comparison with commercial instruments is described.

  12. Amorphous silicon based radiation detectors

    SciTech Connect

    Perez-Mendez, V.; Cho, G.; Drewery, J.; Jing, T.; Kaplan, S.N.; Qureshi, S.; Wildermuth, D. ); Fujieda, I.; Street, R.A. )

    1991-07-01

    We describe the characteristics of thin(1 {mu}m) and thick (>30{mu}m) hydrogenated amorphous silicon p-i-n diodes which are optimized for detecting and recording the spatial distribution of charged particles, x-rays and {gamma} rays. For x-ray, {gamma} ray, and charged particle detection we can use thin p-i-n photosensitive diode arrays coupled to evaporated layers of suitable scintillators. For direct detection of charged particles with high resistance to radiation damage, we use the thick p-i-n diode arrays. 13 refs., 7 figs.

  13. The Radiation Assessment Detector (RAD) Investigation

    NASA Astrophysics Data System (ADS)

    Hassler, D. M.; Zeitlin, C.; Wimmer-Schweingruber, R. F.; Böttcher, S.; Martin, C.; Andrews, J.; Böhm, E.; Brinza, D. E.; Bullock, M. A.; Burmeister, S.; Ehresmann, B.; Epperly, M.; Grinspoon, D.; Köhler, J.; Kortmann, O.; Neal, K.; Peterson, J.; Posner, A.; Rafkin, S.; Seimetz, L.; Smith, K. D.; Tyler, Y.; Weigle, G.; Reitz, G.; Cucinotta, F. A.

    2012-09-01

    The Radiation Assessment Detector (RAD) on the Mars Science Laboratory (MSL) is an energetic particle detector designed to measure a broad spectrum of energetic particle radiation. It will make the first-ever direct radiation measurements on the surface of Mars, detecting galactic cosmic rays, solar energetic particles, secondary neutrons, and other secondary particles created both in the atmosphere and in the Martian regolith. The radiation environment on Mars, both past and present, may have implications for habitability and the ability to sustain life. Radiation exposure is also a major concern for future human missions. The RAD instrument combines charged- and neutral-particle detection capability over a wide dynamic range in a compact, low-mass, low-power instrument. These capabilities are required in order to measure all the important components of the radiation environment. RAD consists of the RAD Sensor Head (RSH) and the RAD Electronics Box (REB) integrated together in a small, compact volume. The RSH contains a solid-state detector telescope with three silicon PIN diodes for charged particle detection, a thallium doped Cesium Iodide scintillator, plastic scintillators for neutron detection and anti-coincidence shielding, and the front-end electronics. The REB contains three circuit boards, one with a novel mixed-signal ASIC for processing analog signals and an associated control FPGA, another with a second FPGA to communicate with the rover and perform onboard analysis of science data, and a third board with power supplies and power cycling or "sleep"-control electronics. The latter enables autonomous operation, independent of commands from the rover. RAD is a highly capable and highly configurable instrument that paves the way for future compact energetic particle detectors in space.

  14. Electromechanically cooled germanium radiation detector system

    NASA Astrophysics Data System (ADS)

    Lavietes, Anthony D.; Joseph Mauger, G.; Anderson, Eric H.

    1999-02-01

    We have successfully developed and fielded an electromechanically cooled germanium radiation detector (EMC-HPGe) at Lawrence Livermore National Laboratory (LLNL). This detector system was designed to provide optimum energy resolution, long lifetime, and extremely reliable operation for unattended and portable applications. For most analytical applications, high purity germanium (HPGe) detectors are the standard detectors of choice, providing an unsurpassed combination of high energy resolution performance and exceptional detection efficiency. Logistical difficulties associated with providing the required liquid nitrogen (LN) for cooling is the primary reason that these systems are found mainly in laboratories. The EMC-HPGe detector system described in this paper successfully provides HPGe detector performance in a portable instrument that allows for isotopic analysis in the field. It incorporates a unique active vibration control system that allows the use of a Sunpower Stirling cycle cryocooler unit without significant spectral degradation from microphonics. All standard isotopic analysis codes, including MGA and MGA++ [1], GAMANL [2], GRPANL [3]and MGAU [4], typically used with HPGe detectors can be used with this system with excellent results. Several national and international Safeguards organisations including the International Atomic Energy Agency (IAEA) and U.S. Department of Energy (DOE) have expressed interest in this system. The detector was combined with custom software and demonstrated as a rapid Field Radiometric Identification System (FRIS) for the U.S. Customs Service [5]. The European Communities' Safeguards Directorate (EURATOM) is field-testing the first Safeguards prototype in their applications. The EMC-HPGe detector system design, recent applications, and results will be highlighted.

  15. Electromechanically-cooled germanium radiation detector system

    SciTech Connect

    Lavietes, A. D., LLNL.

    1998-05-01

    We have successfully developed and fielded an electromechanically cooled germanium radiation detector (EMC-HPGe) at Lawrence Livermore National Laboratory (LLNL). This detector system was designed to provide optimum energy resolution, long lifetime, and extremely reliable operation for unattended and portable applications. For most analytical applications, high-purity germanium (HPGe) detectors are the standard detectors of choice, providing an unsurpassed combination of high energy resolution performance and exceptional detection efficiency. Logistical difficulties associated with providing the required liquid nitrogen (LN) for cooling is the primary reason that these systems are found mainly in laboratories. The EMC-HPGe detector system described in this paper successfully provides HPGe detector performance in a portable instrument that allows for isotopic analysis in the field. It incorporates a unique active vibration control system that allows the use of a Sunpower Stirling cycle cryocooler unit without significant spectral degradation from microphonics. All standard isotopic analysis codes, including MGA and MGA++[1], GAMANL[2], GRPANL[3] and MGAU[4], typically used with HPGe detectors can be used with this system with excellent results. Several national and international Safeguards organizations including the International Atomic Energy Agency (IAEA) and U.S. Department of Energy (DOE) have expressed interest in this system. The detector was combined with custom software and demonstrated as a rapid Field Radiometric Identification System (FRIS) for the U.S. Customs Service[5]. The European Communities' Safeguards Directorate (EURATOM) is field-testing the first Safeguards prototype in their applications. The EMC-HPGe detector system design, recent applications, and results will be highlighted.

  16. [Dynamics of biomacromolecules in coherent electromagnetic radiation field].

    PubMed

    Leshcheniuk, N S; Apanasevich, E E; Tereshenkov, V I

    2014-01-01

    It is shown that induced oscillations and periodic displacements of the equilibrium positions occur in biomacromolecules in the absence of electromagnetic radiation absorption, due to modulation of interaction potential between atoms and groups of atoms forming the non-valence bonds in macromolecules by the external electromagnetic field. Such "hyperoscillation" state causes inevitably the changes in biochemical properties of macromolecules and conformational transformation times.

  17. [Instrumental radiofrequency electromagnetic radiation dosimetry: general principals and modern methodology].

    PubMed

    Perov, S Iu; Kudriashov, Iu B; Rubtsova, N B

    2012-01-01

    The modern experimental radiofrequency electromagnetic field dosimetry approach has been considered. The main principles of specific absorbed rate measurement are analyzed for electromagnetic field biological effect assessment. The general methodology of specific absorbed rate automated dosimetry system applied to establish the compliance of radiation sources with the safety standard requirements (maximum permissible levels and base restrictions) is described.

  18. [Mechanism of radiobiological effects of low intensity nonionizing electromagnetic radiation].

    PubMed

    Kudriashov, Iu B; Perov, Iu F; Golenitskaia, I A

    1999-01-01

    The results of the research of the biological effects of the non-ionizing electromagnetic radiation were studied from the position of "thermal" and "unthermal" mechanisms. The special attention was spared to analysing the information characterising the high sensitiveness of the human and animals organism to the very-low intensity electromagnetic fields.

  19. Alpha-beta radiation detector

    DOEpatents

    Fleming, D.M.; Simmons, K.L.; Froelich, T.J.; Carter, G.L.

    1998-08-18

    The invention is based in part on the discovery that a plastic housing that is lightweight is surprisingly efficient inasmuch as background signals from any gamma radiation are significantly reduced by using a plastic housing instead of a metal housing. A further aspect of the present invention is the profile of the housing as a bi-linear approximation to a parabola resulting in full optical response from any location on the scintillation material to the photomultiplier tube. A yet further aspect of the present invention is that the survey probe is resistant to magnetic fields. A yet further aspect of the present invention is the use of a snap-fit retaining bracket that overcomes the need for multiple screws. 16 figs.

  20. Alpha-beta radiation detector

    DOEpatents

    Fleming, Dale M.; Simmons, Kevin L.; Froelich, Thomas J.; Carter, Gregory L.

    1998-01-01

    The invention is based in part on the discovery that a plastic housing that is lightweight is surprisingly efficient inasmuch as background signals from any gamma radiation are significantly reduced by using a plastic housing instead of a metal housing. A further aspect of the present invention is the profile of the housing as a bi-linear approximation to a parabola resulting in full optical response from any location on the scintillation material to the photomultiplier tube. A yet further aspect of the present invention is that the survey probe is resistant to magnetic fields. A yet further aspect of the present invention is the use of a snap-fit retaining bracket that overcomes the need for multiple screws.

  1. Adverse reproductive events and electromagnetic radiation

    SciTech Connect

    Stewart, W.; Ouellet-Hellstrom, R.

    1991-07-31

    In 1989 approximately 42,000 questionnaires were mailed to female physical therapists to assess the risk of adverse reproductive effects among those exposed to electromagnetic radiation at radiofrequencies. From the resulting data, the risk of early recognized fetal loss was assessed using a nested case-control design. The cases (1753 miscarriages) were matched to controls (1753 other pregnancies except ectopics) on mothers age at conception and the number of years elapsed between conception and interview. The results of the study indicate that female physical therapists who work with microwave diathermy 6 months prior to the pregnancy and/or during the first trimester were at increased risk of experiencing a recognized early fetal loss, but female physical therapists who work with shortwave diathermy were not at an increased risk. This association was shown to hold even when the mother's age at conception, the number of years elapsed between conception and interview, the number of prior early fetal losses, mother's conditions ever diagnosed, and use of other modalities were controlled. The data also suggest a possible association between exposure to transcutaneous electrical nerve stimulation with an elevated risk of early recognized fetal loss.

  2. Development of a plasma panel radiation detector

    SciTech Connect

    Ball, Robert; Beene, James R; Ben Moshe, M.; Benhammou, Yan; Bensimon, B; Chapman, J. Wehrley; Etzion, E; Ferretti, Claudio; Friedman, Dr. Peter S.; Levin, Daniel S.; Silver, Yiftah; Weaverdyck, Curtis; Wetzel, R.; Zhou, Bing; Anderson, T; McKinny, K; Bentefour, E

    2014-11-01

    This article reports on the development and experimental results of commercial plasma display panels adapted for their potential use as micropattern gas radiation detectors. The plasma panel sensor (PPS) design and materials include glass substrates, metal electrodes and inert gas mixtures which provide a physically robust, hermetically sealed device. Plasma display panels used as detectors were tested with cosmic ray muons, beta rays and gamma rays, protons, and thermal neutrons. The results demonstrated rise times and time resolution of a few nanoseconds, as well as sub-millimeter spatial resolution compatible with the pixel pitch.

  3. Development of a plasma panel radiation detector

    NASA Astrophysics Data System (ADS)

    Ball, R.; Beene, J. R.; Ben-Moshe, M.; Benhammou, Y.; Bensimon, B.; Chapman, J. W.; Etzion, E.; Ferretti, C.; Friedman, P. S.; Levin, D. S.; Silver, Y.; Varner, R. L.; Weaverdyck, C.; Wetzel, R.; Zhou, B.; Anderson, T.; McKinny, K.; Bentefour, E. H.

    2014-11-01

    This article reports on the development and experimental results of commercial plasma display panels adapted for their potential use as micropattern gas radiation detectors. The plasma panel sensor (PPS) design and materials include glass substrates, metal electrodes and inert gas mixtures which provide a physically robust, hermetically sealed device. Plasma display panels used as detectors were tested with cosmic ray muons, beta rays and gamma rays, protons, and thermal neutrons. The results demonstrated rise times and time resolution of a few nanoseconds, as well as sub-millimeter spatial resolution compatible with the pixel pitch.

  4. Quadrupole electromagnetic radiation of an oscillating charged droplet

    NASA Astrophysics Data System (ADS)

    Grigor'ev, A. I.; Kolbneva, N. Yu.; Shiryaeva, S. O.

    2017-06-01

    Analytical calculations using the first order of smallness with respect to dimensionless amplitude of oscillations show that the intensity of electromagnetic radiation of a charged droplet is determined by time-dependent quadrupole moment.

  5. Geometric calibration of the SND detector electromagnetic calorimeter

    NASA Astrophysics Data System (ADS)

    Korol, A. A.; Melnikova, N. A.

    2017-03-01

    This paper presents the design, implementation and validation of the software alignment procedure used to perform geometric calibration of the electromagnetic calorimeter with respect to the tracking system of the SND detector which is taking data at the VEPP-2000 e+e- collider (BINP, Novosibirsk). This procedure is based on the mathematical model describing the relative calorimeter position. The parameter values are determined by minimizing a χ2 function using the difference between particle directions reconstructed in these two subdetectors for e+e- →e+e- scattering events. The results of the calibration applied to data and MC simulation fit the model well and give an improvement in particle reconstruction. They are used in data reconstruction and MC simulation.

  6. First experience of vectorizing electromagnetic physics models for detector simulation

    NASA Astrophysics Data System (ADS)

    Amadio, G.; Apostolakis, J.; Bandieramonte, M.; Bianchini, C.; Bitzes, G.; Brun, R.; Canal, P.; Carminati, F.; de Fine Licht, J.; Duhem, L.; Elvira, D.; Gheata, A.; Jun, S. Y.; Lima, G.; Novak, M.; Presbyterian, M.; Shadura, O.; Seghal, R.; Wenzel, S.

    2015-12-01

    The recent emergence of hardware architectures characterized by many-core or accelerated processors has opened new opportunities for concurrent programming models taking advantage of both SIMD and SIMT architectures. The GeantV vector prototype for detector simulations has been designed to exploit both the vector capability of mainstream CPUs and multi-threading capabilities of coprocessors including NVidia GPUs and Intel Xeon Phi. The characteristics of these architectures are very different in terms of the vectorization depth, parallelization needed to achieve optimal performance or memory access latency and speed. An additional challenge is to avoid the code duplication often inherent to supporting heterogeneous platforms. In this paper we present the first experience of vectorizing electromagnetic physics models developed for the GeantV project.

  7. First experience of vectorizing electromagnetic physics models for detector simulation

    SciTech Connect

    Amadio, G.; Apostolakis, J.; Bandieramonte, M.; Bianchini, C.; Bitzes, G.; Brun, R.; Canal, P.; Carminati, F.; Licht, J.de Fine; Duhem, L.; Elvira, D.; Gheata, A.; Jun, S. Y.; Lima, G.; Novak, M.; Presbyterian, M.; Shadura, O.; Seghal, R.; Wenzel, S.

    2015-12-23

    The recent emergence of hardware architectures characterized by many-core or accelerated processors has opened new opportunities for concurrent programming models taking advantage of both SIMD and SIMT architectures. The GeantV vector prototype for detector simulations has been designed to exploit both the vector capability of mainstream CPUs and multi-threading capabilities of coprocessors including NVidia GPUs and Intel Xeon Phi. The characteristics of these architectures are very different in terms of the vectorization depth, parallelization needed to achieve optimal performance or memory access latency and speed. An additional challenge is to avoid the code duplication often inherent to supporting heterogeneous platforms. In this paper we present the first experience of vectorizing electromagnetic physics models developed for the GeantV project.

  8. Gravitational Stokes parameters. [for electromagnetic and gravitational radiation in relativity

    NASA Technical Reports Server (NTRS)

    Anile, A. M.; Breuer, R. A.

    1974-01-01

    The electromagnetic and gravitational Stokes parameters are defined in the general theory of relativity. The general-relativistic equation of radiative transfer for polarized radiation is then derived in terms of the Stokes parameters for both high-frequency electromagnetic and gravitational waves. The concept of Stokes parameters is generalized for the most general class of metric theories of gravity, where six (instead of two) independent states of polarization are present.

  9. Detailed observations of the source of terrestrial narrowband electromagnetic radiation

    NASA Technical Reports Server (NTRS)

    Kurth, W. S.

    1982-01-01

    Detailed observations are presented of a region near the terrestrial plasmapause where narrowband electromagnetic radiation (previously called escaping nonthermal continuum radiation) is being generated. These observations show a direct correspondence between the narrowband radio emissions and electron cyclotron harmonic waves near the upper hybrid resonance frequency. In addition, electromagnetic radiation propagating in the Z-mode is observed in the source region which provides an extremely accurate determination of the electron plasma frequency and, hence, density profile of the source region. The data strongly suggest that electrostatic waves and not Cerenkov radiation are the source of the banded radio emissions and define the coupling which must be described by any viable theory.

  10. Summary of the SWS Detector Radiation Effects

    NASA Astrophysics Data System (ADS)

    Heras, A. M.; Wieprecht, E.; Nieminen, P.; Feuchtgruber, H.; Lahuis, F.; Leech, K.; Lorente, R.; Morris, P. W.; Salama, A.; Vandenbussche, B.

    We present a study of the space radiation effects on the ISO SWS detectors. Radiation effects were mainly recognised by the presence of glitches in the science data, although in some cases they were also associated with changes in detector responsivity, dark current levels and noise. The glitch rates observed in the science observation window were from 2 to 4 times higher than the value predicted by the CREME96 model for the cosmic ray flux in the period considered. A comparison of the glitch derived energy deposited distributions with the results of ray-tracing simulations (which model primary cosmic ray-induced glitches) showed a good agreement at high energies, but the peak of the observed distributions at the lower deposited energies was not reproduced. Furthermore we found a good correlation between the electron fluxes detected by the GOES-9 spacecraft and the glitch rates in the first measurements after perigee passage. These facts lead us to the conclusion that the contribution to the glitch rates from γ-rays and secondary particles produced by cosmic rays and electrons in the detectors and the shield were as important, at least, as the contribution from primary cosmic rays. The effects of the only intense solar proton event during the ISO mission, on 6 November 1997, on dark currents, dark current noise, responsivity and glitch rates were such that all observations in the revolution were declared failed. The space radiation environment affected the long term behaviour of band 3 Si:As detectors, causing their dark current levels, and in some cases their dark current noise, to increase during the mission. The other SWS detector bands were stable and did not show long-term trends.

  11. Surface wave chemical detector using optical radiation

    DOEpatents

    Thundat, Thomas G.; Warmack, Robert J.

    2007-07-17

    A surface wave chemical detector comprising at least one surface wave substrate, each of said substrates having a surface wave and at least one measurable surface wave parameter; means for exposing said surface wave substrate to an unknown sample of at least one chemical to be analyzed, said substrate adsorbing said at least one chemical to be sensed if present in said sample; a source of radiation for radiating said surface wave substrate with different wavelengths of said radiation, said surface wave parameter being changed by said adsorbing; and means for recording signals representative of said surface wave parameter of each of said surface wave substrates responsive to said radiation of said different wavelengths, measurable changes of said parameter due to adsorbing said chemical defining a unique signature of a detected chemical.

  12. Window for radiation detectors and the like

    DOEpatents

    Sparks, C.J. Jr.; Ogle, J.C.

    1975-10-28

    An improved x- and gamma-radiation and particle transparent window for the environment-controlling enclosure of various types of radiation and particle detectors is provided by a special graphite foil of a thickness of from about 0.1 to 1 mil. The graphite must have very parallel hexagonal planes with a mosaic spread no greater than 5$sup 0$ to have the necessary strength in thin sections to support one atmosphere or more of pressure. Such graphite is formed by hot- pressing and annealing pyrolytically deposited graphite and thereafter stripping off layers of sufficient thickness to form the window.

  13. Radiation response issues for infrared detectors

    NASA Technical Reports Server (NTRS)

    Kalma, Arne H.

    1990-01-01

    Researchers describe the most important radiation response issues for infrared detectors. In general, the two key degradation mechanisms in infrared detectors are the noise produced by exposure to a flux of ionizing particles (e.g.; trapped electronics and protons, debris gammas and electrons, radioactive decay of neutron-activated materials) and permanent damage produced by exposure to total dose. Total-dose-induced damage is most often the result of charge trapping in insulators or at interfaces. Exposure to short pulses of ionization (e.g.; prompt x rays or gammas, delayed gammas) will cause detector upset. However, this upset is not important to a sensor unless the recovery time is too long. A few detector technologies are vulnerable to neutron-induced displacement damage, but fortunately most are not. Researchers compare the responses of the new technologies with those of the mainstream technologies of PV HgCdTe and IBC Si:As. One important reason for this comparison is to note where some of the newer technologies have the potential to provide significantly improved radiation hardness compared with that of the mainstream technologies, and thus to provide greater motivation for the pursuit of these technologies.

  14. [Features of control of electromagnetic radiation emitted by personal computers].

    PubMed

    Pal'tsev, Iu P; Buzov, A L; Kol'chugin, Iu I

    1996-01-01

    Measurements of PC electromagnetic irradiation show that the main sources are PC blocks emitting the waves of certain frequencies. Use of wide-range detectors measuring field intensity in assessment of PC electromagnetic irradiation gives unreliable results. More precise measurements by selective devices are required. Thus, it is expedient to introduce a term "spectral density of field intensity" and its maximal allowable level. In this case a frequency spectrum of PC electromagnetic irradiation is divided into 4 ranges, one of which is subjected to calculation of field intensity for each harmonic frequency, and others undergo assessment of spectral density of field intensity.

  15. Effects of electromagnetic radiation on the hemorheology of rats

    NASA Astrophysics Data System (ADS)

    Huang, Zhiwei; Tian, Tian; Xiao, Bo; Li, Wen

    2017-01-01

    The current work examines the effects of electromagnetic radiation on the hemorheology to provide an experimental basis for radiation protection. Electromagnetic radiation was generated by a Helmholtz coil constructed from copper wire. There were six rats altogether: three rats in the experimental group, and three rats in the control group. The rats in the experimental group were continuously exposed to radiation for 10 hours every day, and rats in the control group remained in a normal environment. After 30 days, the characteristics of hemorheology of the two groups were compared. The average plasma viscosity, whole blood high shear velocity, and whole blood low shear viscosity were lower in rats in the experimental group than in rats in the control group, while the whole blood shear viscosity was higher in the experimental group than in the control group. Results suggest that long term exposure to electromagnetic radiation does have certain impacts on the cardiovascular system, deeming it necessary to take preventative measures.

  16. Radiation simulations of the CMS detector

    NASA Astrophysics Data System (ADS)

    Stoddard, Graham J.

    This thesis presents results of recent radiation simulations for the Compact Muon Solenoid detector at the Large Hadron Collider at CERN performed using the Monte Carlo simulation package FLUKA. High statistics simulations with a fine granularity in the detector were carried out using the Condor batch system at the Fermilab LHC Physics Center. In addition, an existing web tool for accessing and displaying simulation data was upgraded. The FLUKA data and previously generated MARS Monte Carlo data can be plotted using 1-D or 2-D plotting functionalities along R and Z, the transverse distance from the beamline and the distance along the beamline, respectively. Comparisons between the data sets have been carried out; the effect of particle transport thresholds in both packages was explored, comparisons with zero magnetic field in the CMS solenoid and full field are made, a model of non-ionizing energy losses is examined, and sensitive areas of interest within the simulation are identified.

  17. [Adaptive changes in the body upon exposure to electromagnetic radiation].

    PubMed

    Zubkova, S M

    1996-01-01

    The chance to use electromagnetic exposures as active adaptogen and the detecting of adaptive changes following them were objects of our studies. The data of experimental and clinical studies significative the dependence of changes on the functional state of organism were seen. Particular attention is paid to the site of exposure and to the advantages in the action of electromagnetic exposures on areas overlaying the endocrine glands and control centers of central nerve system. In these conditions electromagnetic exposures play a part of trigger initiated natural processes of homeostatic regulation in the organism functional systems. It is shown that the course of electromagnetic exposures in wide frequency range until laser radiation (infrared and red) arises adaptive changes of the regulator systems, of the bioenergetic and the biosynthetic processes in myocardium, liver, brain, thymus and other tissues predetermined genetically and secured the power of the adaptive systems. The cross-adaptation effects underlie the electromagnetic exposures medical action.

  18. [Organization of monitoring of electromagnetic radiation in the urban environment].

    PubMed

    Savel'ev, S I; Dvoeglazova, S V; Koz'min, V A; Kochkin, D E; Begishev, M R

    2008-01-01

    The authors describe new current approaches to monitoring the environment, including the sources of electromagnetic radiation and noise. Electronic maps of the area under study are shown to be made, by constructing the isolines or distributing the actual levels of controlled factors. These current approaches to electromagnetic and acoustic monitoring make it possible to automate a process of measurements, to analyze the established situation, and to simplify the risk controlling methodology.

  19. Electromagnetic THz Radiation Modeling by DPSM

    NASA Astrophysics Data System (ADS)

    Rahani, Ehsan Kabiri; Kundu, Tribikram

    2012-03-01

    THz or T-ray imaging and spectroscopy are becoming increasingly popular nondestructive evaluation techniques for damage detection and characterization of materials. In order to understand the interaction between the T-ray electromagnetic waves and dielectric media a reliable model of electromagnetic wave propagation through dielectric materials must be developed. A recently developed semi-analytical method called the distributed point source method (DPSM) is extended to model electromagnetic wave propagation in THz range. Since T-ray signals generated by emitters or sources are close to Gaussian beams, the DPSM modeling is carried out for Gaussian beams generated by finite sized emitters. The DPSM generated results are compared with the analytical and experimental results. T-ray propagation in layered structures in absence of any anomaly and the interaction between the Gaussian beam and the spherical scatterer are also investigated.

  20. Low frequency electromagnetic radiation and hearing.

    PubMed

    Morales, J; Garcia, M; Perez, C; Valverde, J V; Lopez-Sanchez, C; Garcia-Martinez, V; Quesada, J L

    2009-11-01

    To analyse the possible impact of low and extremely low frequency electromagnetic fields on the outer hairs cells of the organ of Corti, in a guinea pig model. Electromagnetic fields of 50, 500, 1000, 2000, 4000 and 5000 Hz frequencies and 1.5 microT intensity were generated using a transverse electromagnetic wave guide. Guinea pigs of both sexes, weighing 100-150 g, were used, with no abnormalities on general and otic examination. Total exposure times were: 360 hours for 50, 500 and 1000 Hz; 3300 hours for 2000 Hz; 4820 hours for 4000 Hz; and 6420 hours for 5000 Hz. One control animal was used in each frequency group. The parameters measured by electric response audiometer included: hearing level; waves I-IV latencies; wave I-III interpeak latency; and percentage appearance of waves I-III at 90 and 50 dB sound pressure level intensity. Values for the above parameters did not differ significantly, comparing the control animal and the rest of each group. In addition, no significant differences were found between our findings and those of previous studies of normal guinea pigs. Prolonged exposure to electromagnetic fields of 50 Hz to 5 KHz frequencies and 1.5 microT intensity, produced no functional or morphological alteration in the outer hair cells of the guinea pig organ of Corti.

  1. Radiation detector having a multiplicity of individual detecting elements

    DOEpatents

    Whetten, Nathan R.; Kelley, John E.

    1985-01-01

    A radiation detector has a plurality of detector collection element arrays immersed in a radiation-to-electron conversion medium. Each array contains a multiplicity of coplanar detector elements radially disposed with respect to one of a plurality of positions which at least one radiation source can assume. Each detector collector array is utilized only when a source is operative at the associated source position, negating the necessity for a multi-element detector to be moved with respect to an object to be examined. A novel housing provides the required containment of a high-pressure gas conversion medium.

  2. Study of electromagnetic radiation pollution in Jalandhar city, India

    NASA Astrophysics Data System (ADS)

    Basandrai, D.; Dhami, A. K.; Bedi, R. K.; Khan, S. A.

    2017-07-01

    Environment pollution from electromagnetic radiations emitted from cell phone towers is a new kind of health hazard, which has increase the public concern regarding the health implications of electromagnetic radiations on humans and animals. Long term consequences of these radiations are still unknown. So it become important to measure and maps the electromagnetic radiation level to analyze potential risk. The present study has been taken to estimate the RF pollution by measuring radiation power densities level near school, hospitals and old age home of Jalandhar City, India. The radiation exposure was measured using a handheld portable electrosmog meter. Results were compared with the safety guidelines issued by ICNIRP (International commission on non ionizing radiation protection) and Bio-initiative report, 2012. It has been found that the radiation exposure level in terms of power densities and corresponding specific absorption rate (SAR) are much below than ICNIRP guidelines for all schools, hospitals and old age home. But in the case of 3 schools, the results are quite alarming where the power density and SAR was found to be 79.6% and 4%, respectively higher in comparisons with safe biological limit.

  3. Portable radiation detector and mapping system

    SciTech Connect

    Hofstetter, K.J.; Hayes, D.W.; Eakle, R.F.

    1995-12-31

    A portable radiation detector and mapping system (RADMAPS) has been developed to detect, locate, and plot nuclear radiation intensities on commercially available digital maps and other images. The field unit records gamma-ray spectra or neutron signals together with positions from a global positioning system (GPS) on flash memory cards. The recorded information is then transferred to a laptop computer for spectral data analyses and then georegistered graphically on maps, photographs, etc. RADMAPS integrates several existing technologies to produce a preprogrammable field unit uniquely suited for each survey, as required. The system records spectra from a NaI(Tl) gamma-ray detector or an enriched {sup 6}Li doped glass neutron scintillator. Standard Geographic Information System (GIS) software installed in a lap-top, complete with CD-ROM supporting digitally imaged maps, permits the characterization of nuclear material in the field when the presence of such material is not otherwise documented. This paper gives the results of a typical site survey of the Savannah River site (SRS) using RADMAPS. The ability to provide rapid field data should be of use in treaty verification, safeguards, decontamination, and nuclear weapons dismantlement.

  4. Biological Effects of Electromagnetic Radiation. Volume II, Number 4.

    DTIC Science & Technology

    1975-12-01

    Electromagnetic Radiation # - A digest of current erature and a forum of communication 1~ ~~~~~~;:~~~~~~Iein:ejnI(T t...unclassified ~ .~~~I4 I~~I~O Security CIas,iac.tioft A - 1140S BiOLOGiCA L. EFFECTS OF ELECTROMAGNETIC RADIATION A Digest of Current Lite rature and a...Forum of Com munication Preparation of This Digest Supported by.~U.S. Army Research Office — Durham ~/ D D C Under Grant No. DAHCO4-74-G-0132 L

  5. Influence of gravitation on the propagation of electromagnetic radiation

    NASA Technical Reports Server (NTRS)

    Mashhoon, B.

    1975-01-01

    The existence of a general helicity-rotation coupling is demonstrated for electromagnetic waves propagating in the field of a slowly rotating body and in the Goedel universe. This coupling leads to differential focusing of circularly polarized radiation by a gravitational field which is detectable for a rapidly rotating collapsed body. The electromagnetic perturbations and their frequency spectrum are given for the Goedel universe. The spectrum of frequencies is bounded from below by the characteristic rotation frequency of the Goedel universe. If the universe were rotating, the differential focusing effect would be extremely small due to the present upper limit on the anisotropy of the microwave background radiation.

  6. Influence of gravitation on the propagation of electromagnetic radiation

    NASA Technical Reports Server (NTRS)

    Mashhoon, B.

    1975-01-01

    The existence of a general helicity-rotation coupling is demonstrated for electromagnetic waves propagating in the field of a slowly rotating body and in the Goedel universe. This coupling leads to differential focusing of circularly polarized radiation by a gravitational field which is detectable for a rapidly rotating collapsed body. The electromagnetic perturbations and their frequency spectrum are given for the Goedel universe. The spectrum of frequencies is bounded from below by the characteristic rotation frequency of the Goedel universe. If the universe were rotating, the differential focusing effect would be extremely small due to the present upper limit on the anisotropy of the microwave background radiation.

  7. Radiation detector system having heat pipe based cooling

    DOEpatents

    Iwanczyk, Jan S.; Saveliev, Valeri D.; Barkan, Shaul

    2006-10-31

    A radiation detector system having a heat pipe based cooling. The radiation detector system includes a radiation detector thermally coupled to a thermo electric cooler (TEC). The TEC cools down the radiation detector, whereby heat is generated by the TEC. A heat removal device dissipates the heat generated by the TEC to surrounding environment. A heat pipe has a first end thermally coupled to the TEC to receive the heat generated by the TEC, and a second end thermally coupled to the heat removal device. The heat pipe transfers the heat generated by the TEC from the first end to the second end to be removed by the heat removal device.

  8. Non-Thermal Electromagnetic Radiation Damage to Lens Epithelium

    PubMed Central

    Bormusov, Elvira; P.Andley, Usha; Sharon, Naomi; Schächter, Levi; Lahav, Assaf; Dovrat, Ahuva

    2008-01-01

    High frequency microwave electromagnetic radiation from mobile phones and other modern devices has the potential to damage eye tissues, but its effect on the lens epithelium is unknown at present. The objective of this study was to investigate the non-thermal effects of high frequency microwave electromagnetic radiation (1.1GHz, 2.22 mW) on the eye lens epithelium in situ. Bovine lenses were incubated in organ culture at 35°C for 10-15 days. A novel computer-controlled microwave source was used to investigate the effects of microwave radiation on the lenses. 58 lenses were used in this study. The lenses were divided into four groups: (1) Control lenses incubated in organ culture for 10 to15 days. (2) Electromagnetic radiation exposure group treated with 1.1 GHz, 2.22 mW microwave radiation for 90 cycles of 50 minutes irradiation followed by 10 minutes pause and cultured up to 10 days. (3) Electromagnetic radiation exposure group treated as group 2 with 192 cycles of radiation and cultured for 15 days. (4) Lenses exposed to 39.5ºC for 2 hours 3 times with 24 hours interval after each treatment beginning on the second day of the culture and cultured for 11 days. During the culture period, lens optical quality was followed daily by a computer-operated scanning laser beam. At the end of the culture period, control and treated lenses were analyzed morphologically and by assessment of the lens epithelial ATPase activity. Exposure to 1.1 GHz, 2.22 mW microwaves caused a reversible decrease in lens optical quality accompanied by irreversible morphological and biochemical damage to the lens epithelial cell layer. The effect of the electromagnetic radiation on the lens epithelium was remarkably different from those of conductive heat. The results of this investigation showed that electromagnetic fields from microwave radiation have a negative impact on the eye lens. The lens damage by electromagnetic fields was distinctly different from that caused by conductive heat. PMID

  9. Non-thermal electromagnetic radiation damage to lens epithelium.

    PubMed

    Bormusov, Elvira; P Andley, Usha; Sharon, Naomi; Schächter, Levi; Lahav, Assaf; Dovrat, Ahuva

    2008-05-21

    High frequency microwave electromagnetic radiation from mobile phones and other modern devices has the potential to damage eye tissues, but its effect on the lens epithelium is unknown at present. The objective of this study was to investigate the non-thermal effects of high frequency microwave electromagnetic radiation (1.1GHz, 2.22 mW) on the eye lens epithelium in situ. Bovine lenses were incubated in organ culture at 35°C for 10-15 days. A novel computer-controlled microwave source was used to investigate the effects of microwave radiation on the lenses. 58 lenses were used in this study. The lenses were divided into four groups: (1) Control lenses incubated in organ culture for 10 to15 days. (2) Electromagnetic radiation exposure group treated with 1.1 GHz, 2.22 mW microwave radiation for 90 cycles of 50 minutes irradiation followed by 10 minutes pause and cultured up to 10 days. (3) Electromagnetic radiation exposure group treated as group 2 with 192 cycles of radiation and cultured for 15 days. (4) Lenses exposed to 39.5°C for 2 hours 3 times with 24 hours interval after each treatment beginning on the second day of the culture and cultured for 11 days. During the culture period, lens optical quality was followed daily by a computer-operated scanning laser beam. At the end of the culture period, control and treated lenses were analyzed morphologically and by assessment of the lens epithelial ATPase activity. Exposure to 1.1 GHz, 2.22 mW microwaves caused a reversible decrease in lens optical quality accompanied by irreversible morphological and biochemical damage to the lens epithelial cell layer. The effect of the electromagnetic radiation on the lens epithelium was remarkably different from those of conductive heat. The results of this investigation showed that electromagnetic fields from microwave radiation have a negative impact on the eye lens. The lens damage by electromagnetic fields was distinctly different from that caused by conductive heat.

  10. Dynamics of Cometary Dust Particles in Electromagnetic Radiation Fields

    NASA Astrophysics Data System (ADS)

    Herranen, Joonas; Markkanen, Johannes; Penttilä, Antti; Muinonen, Karri

    2016-10-01

    The formation of cometary dust tails and comae is based on solar radiation pressure. The pressure effects of electromagnetic radiation were originally conceptualized in Kepler's observations of the tails of comets and formulated mathematically by Maxwell in 1873. Today, the dynamics of cometary dust are known to be governed by gravity, electromagnetic forces, drag, solar wind, and solar radiation pressure.Solar radiation pressure has its roots in absorption, emission, and scattering of electromagnetic radiation. Due to modern advances in so-called integral equation methods in electromagnetics, a new approach of studying the effect of radiation pressure on cometary dust dynamics can be constructed. We solve the forces and torques due to radiation pressure for an arbitrarily shaped dust particle using volume integral equation methods.We then present a framework for solving the equations of motion of cometary dust particles due to radiative interactions. The solution is studied in a simplified cometary environment, where the radiative effects are studied at different orbits. The rotational and translational equations of motion are solved directly using a quaternion-based integrator. The rotational and translational equations of motion affect dust particle alignment and concentration. This is seen in the polarization of the coma. Thus, our direct dynamical approach can be used in modelling the observed imaging photo-polarimetry of the coma.In future studies, the integrator can be further extended to an exemplary comet environment, taking into account the drag, and the electric and magnetic fields. This enables us to study the dynamics of a single cometary dust particle based on fundamental physics.Acknowledgments. Research supported, in part, bythe European Research Council (ERC, grant Nr. 320773).

  11. Radiation measurements inside the CDF detector

    SciTech Connect

    Yarema, R.J.

    1989-07-20

    During the last CDF experimental period from 6/88 to 6/1/89, radiation measurements were made inside the detector on or near the beampipe using various types of monitors. The purpose of the tests was to help predict the radiation levels for future electronics which must be located close to the interaction area. The results from two different types of monitors, PIN diodes and TLD's are reported in this paper. The TLD's (Harshaw/Filtrol type 700) are sensitive to x-rays, gammas, alphas, electrons, and protons. They are calibrated against a cesium source and corrected for nonlinear effects at higher radiation levels. The PIN diodes (Harshaw/Filtrol type DN-156) are sensitive only to neutrons. The devices are calibrated for 1 MeV neutrons and require correction factors for neutrons at other energy levels. All of the monitors were placed just outside of the VTPC, but still inside the CDF magnetic field. The monitors were located 68 inches from the center of the interaction region. The beam pipe is 2 inches in diameter. Therefore the closest monitoring points were on the beampipe or 1 inch from the beam. 5 figs., 2 tabs.

  12. Characterisation of bubble detectors for aircrew and space radiation exposure.

    PubMed

    Green, A R; Bennett, L G I; Lewis, B J; Tume, P; Andrews, H R; Noulty, R A; Ing, H

    2006-01-01

    The Earth's atmosphere acts as a natural radiation shield which protects terrestrial dwellers from the radiation environment encountered in space. In general, the intensity of this radiation field increases with distance from the ground owing to a decrease in the amount of atmospheric shielding. Neutrons form an important component of the radiation field to which the aircrew and spacecrew are exposed. In light of this, the neutron-sensitive bubble detector may be ideal as a portable personal dosemeter at jet altitudes and in space. This paper describes the ground-based characterisation of the bubble detector and the application of the bubble detector for the measurement of aircrew and spacecrew radiation exposure.

  13. Electromagnetic Radiation in the Atmosphere Generated by Excess Negative Charge in a Nuclear-Electromagnetic Cascade

    NASA Astrophysics Data System (ADS)

    Malyshevsky, V. S.; Fomin, G. V.

    2017-01-01

    On the basis of the analytical model "PARMA" (PHITS-based Analytical Radiation Model in the Atmosphere), developed to model particle fluxes of secondary cosmic radiation in the Earth's atmosphere, we have calculated the characteristics of radio waves emitted by excess negative charge in an electromagnetic cascade. The results may be of use in an analysis of experimental data on radio emission of electron-photon showers in the atmosphere.

  14. Probing Bose-Einstein condensation of excitons with electromagnetic radiation.

    PubMed

    Johnsen, K; Kavoulakis, G M

    2001-01-29

    We examine the absorption spectrum of electromagnetic radiation from excitons, where an exciton in the 1s state absorbs a photon and makes a transition to the 2p state. We demonstrate that the absorption spectrum depends strongly on the quantum degeneracy of the exciton gas, and that it will generally manifest many-body effects. Based on our results we propose that absorption of infrared radiation could resolve recent contradictory experimental results on excitons in Cu(2)O.

  15. Electromagnetic radiation of superconducting cosmic strings

    NASA Astrophysics Data System (ADS)

    Rogozin, D. A.; Zadorozhna, L. V.

    2013-12-01

    Cosmic strings are relics of the early Universe which can be formed during the phase transitions of fields with spontaneously broken symmetry in the early Universe. Their existence finds support in modern superstrings theories, both in compactification models and in theories with extended additional dimensions. Strings can hold currents, effectively become electrically superconducting wires of astrophysical dimensions. Superconducting cosmic strings can serve as powerful sources of non-thermal radiation in wide energy range. Mechanisms of radiation are synchrotron, synchrotron self-Compton and inverse-Compton on CMB photons radiation of electrons accelerated by bow shock wave, created by magnetosphere of relativistically moving string in intergalactic medium (IGM). Expected fluxes of radiation from the shocked plasma around superconducting cosmic strings are calculated for strings with various tensions and for different cases of their location. Possibilities of strings detection by existing facilities are estimated.

  16. Self-powered radiation detector with conductive emitter support

    SciTech Connect

    Bauer, R.F.; Goldstein, N.P.; Playfoot, K.C.

    1981-05-12

    A more reliable self-powered radiation detector structure and method of manufacture is provided by a detector structure in which a relatively ductile centrally disposed conductive emitter wire supports and is in electrical contact with a generally tubular emitter electrode. The detector is fabricated by swaging and the ductile center wire insures that electrical discontinuities of the emitter are minimized.

  17. The HERMES dual-radiator RICH detector

    NASA Astrophysics Data System (ADS)

    Jackson, H. E.

    2003-04-01

    The HERMES experiment emphasizes measurements of semi-inclusive deep-inelastic scattering. Most of the hadrons produced lie between 2 and 10 GeV, a region in which it had not previously been feasible to separate pions, kaons, and protons with standard particle identification (PID) techniques. The recent development of new clear, large, homogeneous and hydrophobic silica aerogel material with a low index of refraction offered the means to apply RICH PID techniques to this difficult momentum region. The HERMES instrument uses two radiators, C 4F 10, a heavy fluorocarbon gas, and a wall of silica aerogel tiles. A lightweight spherical mirror constructed using a newly perfected technique to make resin-coated carbon-fiber surfaces of optical quality provides optical focusing on a photon detector consisting of 1934 photomultiplier tubes (PMT) for each detector half. The PMT array is held in a soft steel matrix to provide shielding against the residual field of the main spectrometer magnet. Ring reconstruction is accomplished with pattern recognition techniques based on a combination of inverse and direct ray tracing.

  18. Space Radiation Detector with Spherical Geometry

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D. (Inventor); Fralick, Gustave C. (Inventor); Wrbanek, Susan Y. (Inventor)

    2011-01-01

    A particle detector is provided, the particle detector including a spherical Cherenkov detector, and at least one pair of detector stacks. In an embodiment of the invention, the Cherenkov detector includes a sphere of ultraviolet transparent material, coated by an ultraviolet reflecting material that has at least one open port. The Cherenkov detector further includes at least one photodetector configured to detect ultraviolet light emitted from a particle within the sphere. In an embodiment of the invention, each detector stack includes one or more detectors configured to detect a particle traversing the sphere.

  19. Space Radiation Detector with Spherical Geometry

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D. (Inventor); Fralick, Gustave C. (Inventor); Wrbanek, Susan Y. (Inventor)

    2012-01-01

    A particle detector is provided, the particle detector including a spherical Cherenkov detector, and at least one pair of detector stacks. In an embodiment of the invention, the Cherenkov detector includes a sphere of ultraviolet transparent material, coated by an ultraviolet reflecting material that has at least one open port. The Cherenkov detector further includes at least one photodetector configured to detect ultraviolet light emitted from a particle within the sphere. In an embodiment of the invention, each detector stack includes one or more detectors configured to detect a particle traversing the sphere.

  20. Ruggedization of CdZnTe detectors and detector assemblies for radiation detection applications

    NASA Astrophysics Data System (ADS)

    Lu, P. H.; Gomolchuk, P.; Chen, H.; Beitz, D.; Grosser, A. W.

    2015-06-01

    This paper described improvements in the ruggedization of CdZnTe detectors and detector assemblies for use in radiation detection applications. Research included experimenting with various conductive and underfill adhesive material systems suitable for CZT substrates. A detector design with encapsulation patterning was developed to protect detector surfaces and to control spacing between CZT anode and PCB carrier. Robustness of bare detectors was evaluated through temperature cycling and metallization shear testing. Attachment processes using well-chosen adhesives and PCB carrier materials were optimized to improve reliability of detector assemblies, resulted in Improved Attachment Detector Assembly. These detector assemblies were subjected to aggressive temperature cycling, and varying levels of drop/shock and vibration, in accordance with modified JEDEC, ANSI and FedEx testing standards, to assess their ruggedness. Further enhanced detector assembly ruggedization methods were investigated involving adhesive conformal coating, potting and dam filling on detector assemblies, which resulted in the Enhanced Ruggedization Detector Assembly. Large numbers of CZT detectors and detector assemblies with 5 mm and 15 mm thick, over 200 in total, were tested. Their performance was evaluated by exposure to various radioactive sources using comprehensive predefined detector specifications and testing protocols. Detector assemblies from improved attachment and enhanced ruggedization showed stable performances during the harsh environmental condition tests. In conclusion, significant progress has been made in improving the reliability and enhancing the ruggedness of CZT detector assemblies for radiation detection applications deployed in operational environments.

  1. Simulation of radiation environment for the LHeC detector

    NASA Astrophysics Data System (ADS)

    Nayaz, Abdullah; Piliçer, Ercan; Joya, Musa

    2017-02-01

    The detector response and simulation of radiation environment for the Large Hadron electron Collider (LHeC) baseline detector is estimated to predict its performance over the lifetime of the project. In this work, the geometry of the LHeC detector, as reported in LHeC Conceptual Design Report (CDR), built in FLUKA Monte Carlo tool in order to simulate the detector response and radiation environment. For this purpose, events of electrons and protons with high enough energy were sent isotropically from interaction point of the detector. As a result, the detector response and radiation background for the LHeC detector, with different USRBIN code (ENERGY, HADGT20M, ALL-CHAR, ALL-PAR) in FLUKA, are presented.

  2. Characteristics of detectors for prevention of nuclear radiation terrorism

    NASA Astrophysics Data System (ADS)

    Kolesnikov, S. V.; Ryabeva, E. V.; Samosadny, V. T.

    2017-01-01

    There is description of one type of detectors in use for the task of nuclear terrorism cases prevention to determine the direction to the radioactive source and geometrical structure of radiation field. This type is a modular detector with anisotropic sensitivity. The principle of work of a modular detecting device is the simultaneous operation of several detecting modules with anisotropic sensitivity to gamma radiation.

  3. Real-time self-networking radiation detector apparatus

    DOEpatents

    Kaplan, Edward; Lemley, James; Tsang, Thomas Y.; Milian, Laurence W.

    2007-06-12

    The present invention is for a radiation detector apparatus for detecting radiation sources present in cargo shipments. The invention includes the features of integrating a bubble detector sensitive to neutrons and a GPS system into a miniaturized package that can wirelessly signal the presence of radioactive material in shipping containers. The bubble density would be read out if such indicated a harmful source.

  4. Pyroelectric detector development for the Radiation Measurement system

    NASA Technical Reports Server (NTRS)

    Hubbard, G. S.; Mcmurray, Robert E., Jr.; Hanel, R. P.; Dominguez, D. E.; Valero, F. P. J.; Baumann, Hilary; Hansen, W. L.; Haller, E. E.

    1993-01-01

    A new class of high detectivity pyroelectric detectors developed for optimization of the radiation measurement system within the framework of the Atmospheric Radiation Measurement program is described. These devices are intended to provide detectivities of up to about 10 exp 11 cm Hz exp 0.5/W with cooling to about 100 K required for the detector focal plane.

  5. Pyroelectric detector development for the Radiation Measurement system

    NASA Technical Reports Server (NTRS)

    Hubbard, G. S.; Mcmurray, Robert E., Jr.; Hanel, R. P.; Dominguez, D. E.; Valero, F. P. J.; Baumann, Hilary; Hansen, W. L.; Haller, E. E.

    1993-01-01

    A new class of high detectivity pyroelectric detectors developed for optimization of the radiation measurement system within the framework of the Atmospheric Radiation Measurement program is described. These devices are intended to provide detectivities of up to about 10 exp 11 cm Hz exp 0.5/W with cooling to about 100 K required for the detector focal plane.

  6. Adverse cutaneous effects of ionizing and non-ionizing electromagnetic radiation.

    PubMed

    Testa, E R; Cooper, J S

    1980-03-01

    Modern man is constantly exposed to many forms of electromagnetic radiation, both ionizing and non-ionizing. Although many uses of electromagnetic radiation artfully administered serve man well, injudicious exposure carries a potential for harm. Various types of electromagnetic radiation and possible hazards from them are discussed.

  7. A large area transition radiation detector for the NOMAD experiment

    NASA Astrophysics Data System (ADS)

    Bassompierre, G.; Bermond, M.; Berthet, M.; Bertozzi, T.; Détraz, C.; Dubois, J.-M.; Dumps, L.; Engster, C.; Fazio, T.; Gaillard, G.; Gaillard, J.-M.; Gouanère, M.; Manola-Poggioli, E.; Mossuz, L.; Mendiburu, J.-P.; Nédélec, P.; Palazzini, E.; Pessard, H.; Petit, P.; Petitpas, P.; Placci, A.; Sillou, D.; Sottile, R.; Valuev, V.; Verkindt, D.; Vey, H.; Wachnik, M.

    1998-02-01

    A transition radiation detector to identify electrons at 90% efficiency with a rejection factor against pions of 10 3 on an area of 2.85 × 2.85 m 2 has been constructed for the NOMAD experiment. Each of its 9 modules includes a 315 plastic foil radiator and a detector plane of 176 vertical straw tubes filled with a xenon-methane gas mixture. Details of the design, construction and operation of the detector are given.

  8. Wire chamber radiation detector with discharge control

    DOEpatents

    Perez-Mendez, Victor; Mulera, Terrence A.

    1984-01-01

    A wire chamber radiation detector (11) has spaced apart parallel electrodes (16) and grids (17, 18, 19) defining an ignition region (21) in which charged particles (12) or other ionizing radiations initiate brief localized avalanche discharges (93) and defining an adjacent memory region (22) in which sustained glow discharges (94) are initiated by the primary discharges (93). Conductors (29, 32) of the grids (18, 19) at each side of the memory section (22) extend in orthogonal directions enabling readout of the X-Y coordinates of locations at which charged particles (12) were detected by sequentially transmitting pulses to the conductors (29) of one grid (18) while detecting transmissions of the pulses to the orthogonal conductors (36) of the other grid (19) through glow discharges (94). One of the grids (19) bounding the memory region (22) is defined by an array of conductive elements (32) each of which is connected to the associated readout conductor (36) through a separate resistance (37). The wire chamber (11) avoids ambiguities and imprecisions in the readout of coordinates when large numbers of simultaneous or near simultaneous charged particles (12) have been detected. Down time between detection periods and the generation of radio frequency noise are also reduced.

  9. Electromagnetic radiation due to nonlinear oscillations of a charged drop

    NASA Astrophysics Data System (ADS)

    Shiryaeva, S. O.; Grigor'ev, A. N.; Kolbneva, N. Yu.

    2016-03-01

    The nonlinear oscillations of a spherical charged drop are asymptotically analyzed under the conditions of a multimode initial deformation of its equilibrium shape. It is found that if the spectrum of initially excited modes contains two adjacent modes, the translation mode of oscillations is excited among others. In this case, the center of the drop's charge oscillates about the equilibrium position, generating a dipole electromagnetic radiation. It is shown that the intensity of this radiation is many orders of magnitude higher than the intensity of the drop's radiation, which arises in calculations of the first order of smallness and is related to the drop's charged surface oscillations.

  10. Electromagnetic radiation screening of semiconductor devices for long life applications

    NASA Technical Reports Server (NTRS)

    Hall, T. C.; Brammer, W. G.

    1972-01-01

    A review is presented of the mechanism of interaction of electromagnetic radiation in various spectral ranges, with various semiconductor device defects. Previous work conducted in this area was analyzed as to its pertinence to the current problem. The task was studied of implementing electromagnetic screening methods in the wavelength region determined to be most effective. Both scanning and flooding type stimulation techniques are discussed. While the scanning technique offers a considerably higher yield of useful information, a preliminary investigation utilizing the flooding approach is first recommended because of the ease of implementation, lower cost and ability to provide go-no-go information in semiconductor screening.

  11. [Biological effects of non-ionizing electromagnetic radiation].

    PubMed

    Fedorowski, A; Steciwko, A

    1998-01-01

    Since the mid 1970's, when Adey discovered that extremely-low-frequency electromagnetic field (ELF EMF) may affect the calcium ions efflux from various cells, bioeffects of non-ionizing radiation (NIR) have become the subject of growing interest and numerous research projects. At present, the fact that NIR exerts both stimulatory and inhibitory effects on different physiological cellular parameters is rather unquestionable. At the same time, some epidemiological studies suggest that exposure to EMF is potentially harmful even if its intensity is very low. It has been proved that thermal factors are not responsible for these effects, therefore nowadays, they are called 'non-thermal effects'. Our paper deals with three different aspects of biological effects of non-ionizing radiation, bioelectromagnetism, electromagnetobiology and electromagnetic bioinformation. Firstly, we describe how EMF and photons can be produced within a living cell, how biological cycles are controlled, and what are the features of endogenous electromagnetic radiation. Secondly, we discuss various facets of external EMF interactions with living matter, focusing on extremely-low-frequencies, radio- and microwaves. Possible mechanisms of these interactions are also mentioned. Finally, we present a short overview of current theories which explain how electromagnetic couplings may control an open and dissipative structure, namely the living organism. The theory of electromagnetic bioinformation seems to explain how different physiological processes are triggered and controlled, as well as how long-range interactions may possibly occur within the complex biological system. The review points out that the presented research data must be assessed very carefully since its evaluation is crucial to set the proper limits of EMF exposure, both occupational and environmental. The study of biological effects of non-ioinizing radiation may also contribute to the development of new diagnostic and therapeutic

  12. Dichroic filters to protect milliwatt far-infrared detectors from megawatt ECRH radiation.

    PubMed

    Bertschinger, G; Endres, C P; Lewen, F; Oosterbeek, J W

    2008-10-01

    Dichroic filters have been used to shield effectively the far infrared (FIR) detectors at the interferometer/polarimeter on TEXTOR. The filters consist of metal foils with regular holes, the hole diameter, the mutual spacing and the thickness of the foils are chosen to transmit radiation at the design frequency with transmission >90%. The attenuation at the low frequency end of the bandpass filter is about 30 dB per octave, the high frequency transmission is between 20% and 40%. The filters have been used to block the stray radiation from the megawatt microwave heating beam to the detectors of the FIR interferometer, operating with power on the detector in the milliwatt range. If required, the low frequency attenuation can be still enhanced, without compromising the transmission in the passband. The FIR interferometer used for plasma density and position control is no longer disturbed by electromagnetic waves used for plasma heating.

  13. Dichroic filters to protect milliwatt far-infrared detectors from megawatt ECRH radiation

    SciTech Connect

    Bertschinger, G.; Oosterbeek, J. W.; Endres, C. P.; Lewen, F.

    2008-10-15

    Dichroic filters have been used to shield effectively the far infrared (FIR) detectors at the interferometer/polarimeter on TEXTOR. The filters consist of metal foils with regular holes, the hole diameter, the mutual spacing and the thickness of the foils are chosen to transmit radiation at the design frequency with transmission >90%. The attenuation at the low frequency end of the bandpass filter is about 30 dB per octave, the high frequency transmission is between 20% and 40%. The filters have been used to block the stray radiation from the megawatt microwave heating beam to the detectors of the FIR interferometer, operating with power on the detector in the milliwatt range. If required, the low frequency attenuation can be still enhanced, without compromising the transmission in the passband. The FIR interferometer used for plasma density and position control is no longer disturbed by electromagnetic waves used for plasma heating.

  14. Study on the electromagnetic radiation characteristics of discharging excimer laser system

    NASA Astrophysics Data System (ADS)

    Zhao, Duliang; Liang, Xu; Fang, Xiaodong; Wang, Qingsheng

    2016-10-01

    Excimer laser in condition of high voltage, large current and fast discharge will produce strong electromagnetic pulse radiation and electromagnetic interference on the around electrical equipment. The research on characteristics and distribution of excimer laser electromagnetic radiation could provide important basis for electromagnetic shielding and suppressing electromagnetic interference, and further improving the electromagnetic compatibility of system. Firstly, electromagnetic radiation source is analyzed according to the working principle of excimer laser. The key test points of the electromagnetic radiation, hydrogen thyratron, main discharge circuit and laser outlet, are determined by the mechanical structure and the theory of electromagnetic radiation. Secondly, characteristics of electromagnetic field were tested using a near field probe on the key positions of the vertical direction at 20, 50, and 80 cm, respectively. The main radiation frequencies and the radiation field characteristics in the near field are obtained. The experimental results show that the main radiation frequencies distribute in 47, 65, and 130 MHz for electric field and the main radiation frequencies distribute in 34, 100, and 165 MHz for magnetic field. The intensity of electromagnetic field decreases rapidly with the increase of test distance. The higher the frequency increases, the faster the amplitude attenuate. Finally, several electromagnetic interference suppression measurement methods are proposed from the perspective of electromagnetic compatibility according to the test results.

  15. Feed network and electromagnetic radiation source

    DOEpatents

    Ardavan, Arzhang; Singleton, John; Linehan, Kevin E.; Ardavan, Houshang; Schmidt-Zwiefel, Andrea Caroline

    2017-01-17

    An antenna may include a volume polarization current radiator and a feed network. The volume polarization current radiator, includes a dielectric solid (such as a dielectric strip), and a plurality of closely-spaced excitation elements (24), each excitation element (24) being configured to induce a volume polarization current distribution in the dielectric solid proximate to the excitation element when a voltage is applied to the excitation element. The feed network is coupled to the volume polarization current radiator. The feed network also includes a plurality of passive power divider elements (32) and a plurality of passive delay elements (d1-d6) coupling the first port (30) and the plurality of second ports (108, 109, 164), the plurality of power divider elements (32) and the plurality of phase delay elements (d1-d6) being configured such that a radio-frequency signal that is applied to the first port (30) experiences a progressive change of phase as it is coupled to the plurality of second ports (108, 109, 164) so as to cause the volume polarization current distribution to propagate along the dielectric solid.

  16. Electromagnetic crystal based terahertz thermal radiators and components

    NASA Astrophysics Data System (ADS)

    Wu, Ziran

    This dissertation presents the investigation of thermal radiation from three-dimensional electromagnetic crystals (EMXT), as well as the development of a THz rapid prototyping fabrication technique and its application in THz EMXT components and micro-system fabrication and integration. First, it is proposed that thermal radiation from a 3-D EMXT would be greatly enhanced at the band gap edge frequency due to the redistribution of photon density of states (DOS) within the crystal. A THz thermal radiator could thus be built upon a THz EMXT by utilizing the exceptional emission peak(s) around its band gap frequency. The thermal radiation enhancement effects of various THz EMXT including both silicon and tungsten woodpile structures (WPS) and cubic photonic cavity (CPC) array are explored. The DOS of all three structures are calculated, and their thermal radiation intensities are predicted using Planck's Equation. These calculations show that the DOS of the silicon and tungsten WPS can be enhanced by a factor of 11.8 around 364 GHz and 2.6 around 406 GHz respectively, in comparison to the normal blackbody radiation at same frequencies. An enhancement factor of more than 100 is obtained in calculation from the CPC array. A silicon WPS with a band gap around 200 GHz has been designed and fabricated. Thermal emissivity of the silicon WPS sample is measured with a control blackbody as reference. And enhancements of the emission from the WPS over the control blackbody are observed at several frequencies quite consistent with the theoretical predictions. Second, the practical challenge of THz EMXT component and system fabrication is met by a THz rapid prototyping technique developed by us. Using this technique, the fabrications of several EMXTs with 3D electromagnetic band gaps in the 100-400 GHz range are demonstrated. Characterization of the samples via THz Time-domain Spectroscopy (THz-TDS) shows very good agreement with simulation, confirming the build accuracy of this

  17. Radiation damage studies for the D0 silicon detector

    SciTech Connect

    Lehner, F.; /Zurich U.

    2004-01-01

    We report on irradiation studies performed on spare production silicon detector modules for the current D0 silicon detector. The lifetime expectations due to radiation damage effects of the existing silicon detector are reviewed. A new upgrade project was started with the goal of a complete replacement of the existing silicon detector. In that context, several investigations on the radiation hardness of new prototype silicon microstrip detectors were carried out. The irradiation on different detector types was performed with 10 MeV protons up to fluences of 10{sup 14} p/cm{sup 2} at the J.R. Mcdonald Laboratory at Kansas State University. The flux calibration was carefully checked using different normalization techniques. As a result, we observe roughly 40-50% less radiation damage in silicon for 10 MeV p exposure than it is expected by the predicted NIEL scaling.

  18. Radiation-electromagnetic effect in germanium single crystals

    SciTech Connect

    Kikoin, I.K.; Kikoin, L.I.; Lazarev, S.D.

    1980-10-01

    An experimental study was made of the radiation-electromagnetic effect in germanium single crystals when excess carriers were generated by bombardment with ..cap alpha.. particles, protons, or x rays in magnetic fields up to 8 kOe. The source of ..cap alpha.. particles and protons was a cyclotron and x rays were provided by a tube with a copper anode. The radiation-electromagnetic emf increased linearly on increase in the magnetic field and was directly proportional to the flux of charged particles at low values of the flux, reaching saturation at high values of the flux (approx.5 x 10/sup 11/ particles .cm/sup -2/ .sec/sup -1/). In the energy range 4--40 MeV the emf was practically independent of the ..cap alpha..-particle energy. The sign of the emf was reversed when samples with a ground front surface were irradiated. Measurements of the photoelectromagnetic and Hall effects in the ..cap alpha..-particle-irradiated samples showed that a p-n junction was produced by these particles and its presence should be allowed for in investigations of the radiation-electromagnetic effect. The measured even radiation-electromagnetic emf increased quadratically on increase in the magnetic field. An investigation was made of the barrier radiation-voltaic effect (when the emf was measured between the irradiated and unirradiated surfaces). Special masks were used to produce a set of consecutive p-n junctions in germanium crystals irradiated with ..cap alpha.. particles. A study of the photovoltaic and photoelectromagnetic effects in such samples showed that the method could be used to increase the efficiency of devices utilizing the photoelectromagnetic effect.

  19. Generation of radiation by intense plasma and electromagnetic undulators

    SciTech Connect

    Joshi, C.

    1991-10-01

    We examine the characteristics of the classical radiation emission resulting from the interaction of a relativistic electron beam that propagates perpendicularly through a large amplitude relativistic plasma wave. Such a study is useful for evaluating the feasibility of using relativistic plasma waves as extremely short wavelength undulators for generating short wavelength radiation. The electron trajectories in a plasma wave undulator and in an ac FEL undulator are obtained using perturbation techniques. The spontaneous radiation frequency spectrum and angular distribution emitted by a single electron oscillating in these two undulators are then calculated. The radiation gain of a copropagating electromagnetic wave is calculated. The approximate analytic results for the trajectories, spontaneous radiation and gain are compared with 3-D simulation results. The characteristics of the plasma wave undulator are compared with the ac FEL undulator and linearly polarized magnetic undulator. 50 refs., 26 figs., 3 tabs.

  20. Electromagnetic radiation from linearly and nonlinearly oscillating charge drops

    NASA Astrophysics Data System (ADS)

    Grigor'ev, A. I.; Shiryaeva, S. O.

    2016-12-01

    It has been shown that analytic calculations of the intensity of electromagnetic radiation from an oscillating charged drop in the approximation linear in the oscillation amplitude (small parameter is on the order of 0.1) give only the quadrupole component of the total radiation. The dipole component can only be obtained in calculations using higher-order approximations. Nevertheless, the intensity of the dipole radiation turns out to be substantially higher (by 14-15 orders of magnitude). This is because the decomposition of radiation from a system of charges into multipole components (differing even in the rates of decrease in the potential with the distance) is carried out using the expansion in a substantially smaller parameter, viz., the ratio of the size of the emitting system (in our case, a drop of radius 10 μm) to the distance to the point of observation in the wave zone of the emission of radiation (emitted wavelength) of 100-1000 m. As a result, this second small parameter is on the order of 10-7 to 10-8. On the other hand, in accordance with the field theory, the ratio of intensities of quadrupole and dipole radiations is proportional to the squared ratio of the hydrodynamic velocity of the oscillating surface of a charged drop to the velocity of propagation of an electromagnetic signal in vacuum (velocity of light), which yields a ratio of 10-14 to 10-15.

  1. Tinnitus and cell phones: the role of electromagnetic radiofrequency radiation.

    PubMed

    Medeiros, Luisa Nascimento; Sanchez, Tanit Ganz

    2016-01-01

    Tinnitus is a multifactorial condition and its prevalence has increased on the past decades. The worldwide progressive increase of the use of cell phones has exposed the peripheral auditory pathways to a higher dose of electromagnetic radiofrequency radiation (EMRFR). Some tinnitus patients report that the abusive use of mobiles, especially when repeated in the same ear, might worsen ipsilateral tinnitus. The aim of this study was to evaluate the available evidence about the possible causal association between tinnitus and exposure to electromagnetic waves. A literature review was performed searching for the following keywords: tinnitus, electromagnetic field, mobile phones, radio frequency, and electromagnetic hypersensitivity. We selected 165 articles that were considered clinically relevant in at least one of the subjects. EMRFR can penetrate exposed tissues and safety exposure levels have been established. These waves provoke proved thermogenic effects and potential biological and genotoxic effects. Some individuals are more sensitive to electromagnetic exposure (electrosensitivity), and thus, present earlier symptoms. There may be a common pathophysiology between this electrosensitivity and tinnitus. There are already reasonable evidences to suggest caution for using mobile phones to prevent auditory damage and the onset or worsening of tinnitus. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  2. Large dynamic range radiation detector and methods thereof

    DOEpatents

    Marrs, Roscoe E [Livermore, CA; Madden, Norman W [Sparks, NV

    2012-02-14

    According to one embodiment, a radiation detector comprises a scintillator and a photodiode optically coupled to the scintillator. The radiation detector also includes a bias voltage source electrically coupled to the photodiode, a first detector operatively electrically coupled to the photodiode for generating a signal indicative of a level of a charge at an output of the photodiode, and a second detector operatively electrically coupled to the bias voltage source for generating a signal indicative of an amount of current flowing through the photodiode.

  3. Energy harvesting devices for harvesting energy from terahertz electromagnetic radiation

    DOEpatents

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

    2012-10-09

    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.

  4. Multipole charge conservation and implications on electromagnetic radiation

    NASA Astrophysics Data System (ADS)

    Seraj, Ali

    2017-06-01

    It is shown that conserved charges associated with a specific subclass of gauge symmetries of Maxwell electrodynamics are proportional to the well known electric mul-tipole moments. The symmetries are residual gauge transformations surviving the Lorenz gauge, with nontrivial conserved charge at spatial infinity. These "Multipole charges" receive contributions both from the charged matter and electromagnetic fields. The former is nothing but the electric multipole moment of the source. In a stationary configuration, there is a novel equipartition relation between the two contributions. The multipole charge, while conserved, can freely interpolate between the source and the electromagnetic field, and therefore can be propagated with the radiation. Using the multipole charge conservation, we obtain infinite number of constraints over the radiation produced by the dynamics of charged matter.

  5. Structures, systems and methods for harvesting energy from electromagnetic radiation

    DOEpatents

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

    2011-12-06

    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.

  6. Calcium protects differentiating neuroblastoma cells during 50 Hz electromagnetic radiation.

    PubMed

    Tonini, R; Baroni, M D; Masala, E; Micheletti, M; Ferroni, A; Mazzanti, M

    2001-11-01

    Despite growing concern about electromagnetic radiation, the interaction between 50- to 60-Hz fields and biological structures remains obscure. Epidemiological studies have failed to prove a significantly correlation between exposure to radiation fields and particular pathologies. We demonstrate that a 50- to 60-Hz magnetic field interacts with cell differentiation through two opposing mechanisms: it antagonizes the shift in cell membrane surface charges that occur during the early phases of differentiation and it modulates hyperpolarizing K channels by increasing intracellular Ca. The simultaneous onset of both mechanisms prevents alterations in cell differentiation. We propose that cells are normally protected against electromagnetic insult. Pathologies may arise, however, if intracellular Ca regulation or K channel activation malfunctions.

  7. Energy harvesting devices for harvesting energy from terahertz electromagnetic radiation

    DOEpatents

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

    2012-10-09

    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.

  8. Radiation damage measurements in room temperature semiconductor radiation detectors

    SciTech Connect

    Franks, L.A.; Olsen, R.W.; James, R.B.; Brunett, B.A. |; Walsh, D.S.; Doyle, B.L.; Vizkelethy, G. |; Trombka, J.I.

    1998-12-01

    The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide (HgI{sub 2}) is reviewed and in the case of CZT supplemented by new alpha particle data. CZT strip detectors exposed to intermediate energy (1.3 MeV) proton fluences exhibit increased interstrip leakage after 10{sup 10} p/cm{sup 2} and significant bulk leakage after 10{sup 12} p/cm{sup 2}. CZT exposed to 200 MeV protons shows a two-fold loss in energy resolution after a fluence of 5 {times} 10{sup 9} p/cm{sup 2} in thick (3 mm) planar devices but little effect in 2 mm devices. No energy resolution effects were noted from moderated fission spectrum of neutrons after fluences up to 10{sup 10} n/cm{sup 2}, although activation was evident. Exposures of CZT to 5 MeV alpha particle at fluences up to 1.5 {times} 10{sup 10} {alpha}/cm{sup 2} produced a near linear decrease in peak position with fluence and increases in FWHM beginning at about 7.5 {times} 10{sup 9} {alpha}/cm{sup 2}. CT detectors show resolution losses after fluences of 3 {times} 10{sup 9} p/cm{sup 2} at 33 MeV for chlorine-doped detectors. Indium doped material may be more resistant. Neutron exposures (8 MeV) caused resolution losses after fluences of 2 {times} 10{sup 10} n/cm{sup 2}. Mercuric iodide has been studied with intermediate energy protons (10 to 33 MeV) at fluences up to 10{sup 12} p/cm{sup 2} and with 1.5 GeV protons at fluences up to 1.2 {times} 10{sup 8} p/cm{sup 2}. Neutron exposures at 8 MeV have been reported at fluences up to 10{sup 15} n/cm{sup 2}. No radiation damage was reported under these irradiation conditions.

  9. Electromagnetic Radiation: Final Range Environmental Assessment, Revision 1

    DTIC Science & Technology

    2009-12-03

    predation by feral cats and loss of dune habitat from recreational foot traffic and storms. American Alligator (Alligator mississippiensis) The...by ANSI Std Z39-18 FINDING OF NO SIGNIFICANT IMPACT FOR ELECTROMAGNETIC RADIATION RANGE ENVIRONMENTAL ASSESSMENT ON EGLIN AIR FORCE BASE, FLORIDA...regulations as promulgated at 40 Code of Federal Regulations (CFR) Part 1500 (40 CFR 1500-1508) plus: • U.S. Air Force Environmental Impact Analysis

  10. Heat Transfer Issues in Thin-Film Thermal Radiation Detectors

    NASA Technical Reports Server (NTRS)

    Barry, Mamadou Y.

    1999-01-01

    The Thermal Radiation Group at Virginia Polytechnic Institute and State University has been working closely with scientists and engineers at NASA's Langley Research Center to develop accurate analytical and numerical models suitable for designing next generation thin-film thermal radiation detectors for earth radiation budget measurement applications. The current study provides an analytical model of the notional thermal radiation detector that takes into account thermal transport phenomena, such as the contact resistance between the layers of the detector, and is suitable for use in parameter estimation. It was found that the responsivity of the detector can increase significantly due to the presence of contact resistance between the layers of the detector. Also presented is the effect of doping the thermal impedance layer of the detector with conducting particles in order to electrically link the two junctions of the detector. It was found that the responsivity and the time response of the doped detector decrease significantly in this case. The corresponding decrease of the electrical resistance of the doped thermal impedance layer is not sufficient to significantly improve the electrical performance of the detector. Finally, the "roughness effect" is shown to be unable to explain the decrease in the thermal conductivity often reported for thin-film layers.

  11. Alpha particle response study of polycrstalline diamond radiation detector

    SciTech Connect

    Kumar, Amit; Topkar, Anita

    2016-05-23

    Chemical vapor deposition has opened the possibility to grow high purity synthetic diamond at relatively low cost. This has opened up uses of diamond based detectors for wide range of applications. These detectors are most suitable for harsh environments where standard semiconductor detectors cannot work. In this paper, we present the fabrication details and performance study of polycrystalline diamond based radiation detector. Effect of different operating parameters such as bias voltage and shaping time for charge collection on the performance of detector has been studied.

  12. Study of electromagnetic radiation pollution in an Indian city.

    PubMed

    Dhami, A K

    2012-11-01

    Electromagnetic radiation emitted by cell phone towers is a form of environmental pollution and is a new health hazard, especially to children and patients. The present studies were taken to estimate the microwave/RF pollution by measuring radiation power densities near schools and hospitals of Chandigarh city in India. The cell phone radiations were measured using a handheld portable power density meter TES 593 and specific absorption rates were estimated from the measured values. These values of electromagnetic radiation in the environment were compared with the levels at which biological system of humans and animals starts getting affected. The values were also compared with the international exposure limits set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The highest measured power density was 11.48 mW/m(2) which is 1,148% of the biological limit. The results indicated that the exposure levels in the city were below the ICNIRP limit, but much above the biological limit.

  13. The dielectric response to the magnetic field of electromagnetic radiation

    NASA Astrophysics Data System (ADS)

    Mukherjee, Shouvik; Mukhopadhyay, Sourabh; Datta, Prasanta Kumar

    2017-04-01

    Light-matter interaction in transparent dielectrics is revisited, including the magnetic force on bound charges in the Lorentz oscillator model. The parameter ranges of incident radiation and the medium on which the magnetic field of the electromagnetic radiation will have a significant effect are traced using Floquet theory. The analysis reveals that the threshold intensity for a significant response of the magnetic field of the radiation at the second harmonic of the incident radiation can be reduced to {10}12 {{W}}{{cm}}-2 for off resonant and even lower for resonant interaction. This phenomenon has already been observed indirectly in experiments [1, 2]. Induced magnetizing current due to the magnetic force is shown to originate from a modified dielectric response, which may be useful in future magneto-optic devices, solar energy harvesting, and studying the ultrafast dynamics in doped dielectrics.

  14. Spontaneous emission of electromagnetic radiation in turbulent plasmas

    SciTech Connect

    Ziebell, L. F.; Yoon, P. H.; Simões, F. J. R.; Pavan, J.; Gaelzer, R.

    2014-01-15

    Known radiation emission mechanisms in plasmas include bremmstrahlung (or free-free emission), gyro- and synchrotron radiation, cyclotron maser, and plasma emission. For unmagnetized plasmas, only bremmstrahlung and plasma emissions are viable. Of these, bremmstrahlung becomes inoperative in the absence of collisions, and the plasma emission requires the presence of electron beam, followed by various scattering and conversion processes. The present Letter proposes a new type of radiation emission process for plasmas in a state of thermodynamic quasi-equilibrium between particles and enhanced Langmuir turbulence. The radiation emission mechanism proposed in the present Letter is not predicted by the linear theory of thermal plasmas, but it relies on nonlinear wave-particle resonance processes. The electromagnetic particle-in-cell numerical simulation supports the new mechanism.

  15. [Emission of electromagnetic radiation from selected computer monitors].

    PubMed

    Zyss, T

    1995-01-01

    The emission of electromagnetic fields from computer monitors was analysed. The data were compared with the permissible exposure level. EM radiation of chromatic monitors is higher than that of monochromatic ones. The radiation of magnetic fraction is insignificant. Both electric and magnetic fractions of EM radiation, 50 cm away from the monitor, are very low and do not exceed permissible values. It was observed that screen filters were effective in suppressing EM emission only at a short (up to 30 cm) distance from the monitor. At a distance of 50 cm they proved to be ineffective. Metallic-net filters were more effective than glass filters in suppressing EM radiation. It seems that EM fields generated by computer monitors are not harmful to computer operators if the distance is kept in safe limits.

  16. The peak electromagnetic power radiated by lightning return strokes

    NASA Technical Reports Server (NTRS)

    Krider, E. P.; Guo, C.

    1983-01-01

    Estimates of the peak electromagnetic (EM) power radiated by return strokes have been made by integrating the Poynting vector of measured fields over an imaginary hemispherical surface that is centered on the lightning source, assuming that ground losses are negligible. Values of the peak EM power from first and subsequent strokes have means and standard deviations of 2 + or - 2 x 10 to the 10th and 3 + or - 4 x 10 to the 9th W, respectively. The average EM power that is radiated by subsequent strokes, at the time of the field peak, is about 2 orders of magnitude larger than the optical power that is radiated by these strokes in the wavelength interval from 0.4 to 1.1 micron; hence an upper limit to the radiative efficiency of a subsequent stroke is of the order of 1 percent or less at this time.

  17. The peak electromagnetic power radiated by lightning return strokes

    NASA Technical Reports Server (NTRS)

    Krider, E. P.; Guo, C.

    1983-01-01

    Estimates of the peak electromagnetic (EM) power radiated by return strokes have been made by integrating the Poynting vector of measured fields over an imaginary hemispherical surface that is centered on the lightning source, assuming that ground losses are negligible. Values of the peak EM power from first and subsequent strokes have means and standard deviations of 2 + or - 2 x 10 to the 10th and 3 + or - 4 x 10 to the 9th W, respectively. The average EM power that is radiated by subsequent strokes, at the time of the field peak, is about 2 orders of magnitude larger than the optical power that is radiated by these strokes in the wavelength interval from 0.4 to 1.1 micron; hence an upper limit to the radiative efficiency of a subsequent stroke is of the order of 1 percent or less at this time.

  18. A fast and compact electromagnetic calorimeter for the PANDA detector at FAIR

    SciTech Connect

    Wilms, Andrea

    2005-10-26

    In this presentation we report on the electromagnetic calorimeter of the 4{pi} detector PANDA to be installed at the antiproton storage ring of the proposed Facility for Antiproton and Ion Research (FAIR). We present details of the R and D work with two scintillator materials, PbWO4 (PWO) and BGO, and the new developed large area avalanche photodiodes (LAAPDs) as detector readout.

  19. EFFECT OF VISIBLE RANGE ELECTROMAGNETIC RADIATIONS ON ESCHERICHIA COLI.

    PubMed

    Azeemi, Samina T Yousuf; Shaukat, Saleem Farooq; Azeemi, Khawaja Shamsuddin; Khan, Idrees; Mahmood, Khalid; Naz, Farah

    2017-01-01

    Escherichia coli is the agent responsible for a range of clinical diseases. With emerging antimicrobial resistance, other treatment options including solar/photo-therapy are becoming increasingly common. Visible Range Radiation Therapy/Colour Therapy is an emerging technique in the field of energy/vibrational medicine that uses visible spectrum of Electromagnetic Radiations to cure different diseases. In this study, our goal was to understand the effect of Visible Range Electromagnetic Radiations on E. coli (in vitro) and therefore find out the most appropriate visible range radiation for the treatment of diseases caused by E. coli. A total of 6 non-repetitive E. coli isolates were obtained from urine samples obtained from hospitalized patients with UTI. Single colony of E. coli was inoculated in 3 ml of Lysogeny Broth (LB) and 40 μl of this E. coli suspension was poured into each of the plastic tubes which were then irradiated with six different wavelengths in the visible region (Table. 1) after 18 hours with one acting as a control. The Optical Densities of these irradiated samples were then measured. Furthermore, scanning electron microscopy (TEFCAN ZEGA3) was carried out. The analysis of the microscopic and SEM images of irradiated E. coli samples with six different visible range radiations is representative of The fact that E. coli responded differently to every applied radiation in the visible region and the most profound inhibitory effects were that of 538nm Visible Range Radiation (Green) which proved to be bactericidal and 590nm Visible Range Radiation (yellow) which was bacteriostatic. The enhanced growth of E. coli with varying degrees was clearly observed in 610nm (orange), 644nm (red), 464nm (Purple) and 453nm (blue). It can be concluded that 538nm (Green) and 590nm (Yellow) can effectively be used for treating E. coli borne diseases.

  20. Electromagnetic radiation generated by arcing in low density plasma

    NASA Technical Reports Server (NTRS)

    Vayner, Boris V.; Ferguson, Dale C.; Snyder, David B.; Doreswamy, C. V.

    1996-01-01

    An unavoidable step in the process of space exploration is to use high-power, very large spacecraft launched into Earth orbit. Obviously, the spacecraft will need powerful energy sources. Previous experience has shown that electrical discharges occur on the surfaces of a high-voltage array, and these discharges (arcs) are undesirable in many respects. Moreover, any high voltage conductor will interact with the surrounding plasma, and that interaction may result in electrical discharges between the conductor and plasma (or between two conductors with different potentials, for example, during docking and extravehicular activity). One very important aspect is the generation of electromagnetic radiation by arcing. To prevent the negative influence of electromagnetic noise on the operation of spacecraft systems, it seems necessary to determine the spectra and absolute levels of the radiation, and to determine limitations on the solar array bias voltage that depend on the parameters of LEO plasma and the technical requirements of the spacecraft equipment. This report describes the results of an experimental study and computer simulation of the electromagnetic radiation generated by arcing on spacecraft surfaces. A large set of high quality data was obtained during the Solar Array Module Plasma Interaction Experiment (SAMPIE, flight STS-62) and ground test. These data include the amplitudes of current, pulse forms, duration of each arc, and spectra of plasma waves. A theoretical explanation of the observed features is presented in this report too. The elaborated model allows us to determine the parameters of the electromagnetic noise for different frequency ranges, distances from the arcing site, and distinct kinds of plasma waves.

  1. [Influence of electromagnetic radiation on toxicity of Vipera lebetina obtusa venom].

    PubMed

    Abiev, G A; Babaev, E I; Topchieva, Sh A; Chumburidze, T B; Nemsitsveridze, N G

    2009-11-01

    The aim of the article was to study the effect of electromagnetic radiation on toxicity of Vipera lebetina obtusa venom. It was found that mice intoxicated with snake venom, with moderate to high exposure to electromagnetic radiation and mice intoxicated with venom, which had not been exposed to the radiation showed the same symptoms of intoxication and death. At the same time, the longevity of mice intoxicated with venom exposed to electromagnetic radiation was higher. The longevity of mice in control group was 25+/-5 min. The longevity of mice intoxicated with exposed to electromagnetic radiation snake venom was from 29 to 60 min. The research showed that the longevity of mice intoxicated with snake venom rose with the level of electromagnetic radiation intensity the snake was exposed to. Accordingly, snake venom, with exposure to high intensity electromagnetic radiation is less toxic.

  2. Theory of electromagnetic insertion devices and the corresponding synchrotron radiation

    DOE PAGES

    Shumail, Muhammad; Tantawi, Sami G.

    2016-07-27

    Permanent magnet insertion devices (IDs), which are the main radiation generating devices in synchrotron light sources and free-electron lasers, use a time-invariant but space-periodic magnetic field to wiggle relativistic electrons for short-wavelength radiation generation. Recently, a high power microwave based undulator has also been successfully demonstrated at SLAC which promises the advantage of dynamic tunability of radiation spectrum and polarization. Such IDs employ transverse elecromagnetic fields which are periodic in both space and time to undulate the electrons. In this paper we develop a detailed theory of the principle of electromagnetic IDs from first principles for both linear and circularmore » polarization modes. The electromagnetic equivalent definitions of undulator period (λu) and undulator deflection parameter (K) are derived. In the inertial frame where the average momentum of the electron is zero, we obtain the figure-8-like trajectory for the linear polarization mode and the circular trajectory for the circular polarization mode. As a result, the corresponding radiation spectra and the intensity of harmonics is also calculated.« less

  3. Diamond radiation detectors I. Detector properties for IIa diamond

    SciTech Connect

    Kania, D.R.

    1997-05-16

    The detector properties and carrier dynamics of type IIa diamonds are reasonably well understood. The trends in the electron and hole mobilities have been characterized as a function of temperature, impurity content, electric field and carrier density. The carrier lifetimes are coupled through the nitrogen impurity. This leaves us with typical samples with collection distances of 20 to 50 micrometers. The detailed dynamics of the carriers can be modeled using a rate equation analysis. Much progress has been made in understanding the detector properties of diamond, but continued progress has been limited by the geologic processes used to make the material, for example sample size and no synthesis control. CVD diamond promises to eliminate these restrictions.

  4. A method for detection of muon induced electromagnetic showers with the ANTARES detector

    NASA Astrophysics Data System (ADS)

    Aguilar, J. A.; Al Samarai, I.; Albert, A.; André, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Assis Jesus, A. C.; Astraatmadja, T.; Aubert, J. J.; Baret, B.; Basa, S.; Bertin, V.; Biagi, S.; Bigi, A.; Bigongiari, C.; Bogazzi, C.; Bou-Cabo, M.; Bouhou, B.; Bouwhuis, M. C.; Brunner, J.; Busto, J.; Camarena, F.; Capone, A.; Cârloganu, C.; Carminati, G.; Carr, J.; Cecchini, S.; Charif, Z.; Charvis, P.; Chiarusi, T.; Circella, M.; Coniglione, R.; Costantini, H.; Coyle, P.; Curtil, C.; Decowski, M. P.; Dekeyser, I.; Deschamps, A.; Distefano, C.; Donzaud, C.; Dornic, D.; Dorosti, Q.; Drouhin, D.; Eberl, T.; Emanuele, U.; Enzenhöfer, A.; Ernenwein, J. P.; Escoffier, S.; Fermani, P.; Ferri, M.; Flaminio, V.; Folger, F.; Fritsch, U.; Fuda, J. L.; Galatà, S.; Gay, P.; Giacomelli, G.; Giordano, V.; Gómez-González, J. P.; Graf, K.; Guillard, G.; Halladjian, G.; Hallewell, G.; van Haren, H.; Hartman, J.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Herold, B.; Hößl, J.; Hsu, C. C.; de Jong, M.; Kadler, M.; Kalekin, O.; Kappes, A.; Katz, U.; Kavatsyuk, O.; Kooijman, P.; Kopper, C.; Kouchner, A.; Kreykenbohm, I.; Kulikovskiy, V.; Lahmann, R.; Lamare, P.; Larosa, G.; Lattuada, D.; Lefèvre, D.; Lim, G.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Mangano, S.; Marcelin, M.; Margiotta, A.; Martinez-Mora, J. A.; Meli, A.; Montaruli, T.; Moscoso, L.; Motz, H.; Neff, M.; Nezri, E.; Palioselitis, D.; Păvălaş, G. E.; Payet, K.; Payre, P.; Petrovic, J.; Piattelli, P.; Picot-Clemente, N.; Popa, V.; Pradier, T.; Presani, E.; Racca, C.; Reed, C.; Richardt, C.; Richter, R.; Rivière, C.; Robert, A.; Roensch, K.; Rostovtsev, A.; Ruiz-Rivas, J.; Rujoiu, M.; Russo, G. V.; Salesa, F.; Sapienza, P.; Schöck, F.; Schuller, J. P.; Schüssler, F.; Shanidze, R.; Simeone, F.; Spies, A.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, T.; Sánchez-Losa, A.; Taiuti, M.; Tamburini, C.; Toscano, S.; Vallage, B.; Van Elewyck, V.; Vannoni, G.; Vecchi, M.; Vernin, P.; Wijnker, G.; Wilms, J.; de Wolf, E.; Yepes, H.; Zaborov, D.; Zornoza, J. D.; Zúñiga, J.

    2012-05-01

    The primary aim of ANTARES is neutrino astronomy with upward going muons created in charged current muon neutrino interactions in the detector and its surroundings. Downward going muons are background for neutrino searches. These muons are the decay products of cosmic-ray collisions in the Earth's atmosphere far above the detector. This paper presents a method to identify and count electromagnetic showers induced along atmospheric muon tracks with the ANTARES detector. The method is applied to both cosmic muon data and simulations and its applicability to the reconstruction of muon event energies is demonstrated.

  5. Radiation and scattering from imperfect cylindrical electromagnetic cloaks.

    PubMed

    Isic, G; Gajic, R; Novakovic, B; Popovic, Z V; Hingerl, K

    2008-02-04

    The design of electromagnetic invisibility cloaks is based on singular mappings prescribing zero or infinite values for material parameters on the inner surface of the cloak. Since this is only approximately feasible, an asymptotic analysis is necessary for a sound description of cloaks. We adopt a simple and effective approach for analyzing electromagnetic cloaks - instead of the originally proposed singular mapping, nonsingular mappings asymptotically approaching the ideal one are considered. Scattering and radiation from this type of imperfect cylindrical cloaks is solved analytically and the results are confirmed by full-wave finite element simulations. Our analysis sheds more light on the influence of this kind of imperfection on the cloaking performance and further explores the physics of cloaking devices.

  6. GSM base station electromagnetic radiation and oxidative stress in rats.

    PubMed

    Yurekli, Ali Ihsan; Ozkan, Mehmed; Kalkan, Tunaya; Saybasili, Hale; Tuncel, Handan; Atukeren, Pinar; Gumustas, Koray; Seker, Selim

    2006-01-01

    The ever increasing use of cellular phones and the increasing number of associated base stations are becoming a widespread source of nonionizing electromagnetic radiation. Some biological effects are likely to occur even at low-level EM fields. In this study, a gigahertz transverse electromagnetic (GTEM) cell was used as an exposure environment for plane wave conditions of far-field free space EM field propagation at the GSM base transceiver station (BTS) frequency of 945 MHz, and effects on oxidative stress in rats were investigated. When EM fields at a power density of 3.67 W/m2 (specific absorption rate = 11.3 mW/kg), which is well below current exposure limits, were applied, MDA (malondialdehyde) level was found to increase and GSH (reduced glutathione) concentration was found to decrease significantly (p < 0.0001). Additionally, there was a less significant (p = 0.0190) increase in SOD (superoxide dismutase) activity under EM exposure.

  7. Purely radiating and nonradiating scalar, electromagnetic and weak gravitational sources

    NASA Astrophysics Data System (ADS)

    Marengo, Edwin A.; Ziolkowski, Richard W.

    2000-03-01

    It has been known for some time that localized sources to the scalar wave equation and Maxwell's equations exist which do not radiate. Such sources, referred to as non-radiating (NR) sources, generate vanishing fields outside their spatial support which prevents them from interacting with nearby objects by means of their fields. Work on NR sources dates back to Sommerfeld, Herglotz, Hertz, Ehrenfest and Schott who studied these objects in connection with electron and atom models. NR sources have also appeared extensively in inverse source/scattering theories as members of the null space of the source-to-field mapping. In this presentation, we provide a new description of scalar, vector or tensor NR sources and of a complementary class of sources, namely, sources that lack a NR part, i.e., `purely radiating' sources. We show that the class of square-integrable localized purely radiating scalar, electromagnetic or weak gravitational sources is exactly the class of solutions - within the source's support - of the homogeneous form of the associated partial differential equation relating the sources to their fields, i.e., purely radiating sources are themselves fields. As a consequence of this result, NR sources are shown to be inseparable components of a broad class of physically relevant sources, thereby having a physical significance that transcends their use in wave-theoretic inversion models. Localized NR sources are characterized in connection with the concept of reciprocity as non-interactors. The role of NR sources in absorption of radiation and energy storage is addressed. The general theoretical results are illustrated with the aid of a one-dimensional (1D) electromagnetic example corresponding to a transmission line system (equivalently, a 1D plane wave system) with uniformly distributed sources/loads.

  8. Organic Scintillation Detectors for Spectroscopic Radiation Portal Monitors

    NASA Astrophysics Data System (ADS)

    Paff, Marc Gerrit

    Thousands of radiation portal monitors have been deployed worldwide to detect and deter the smuggling of nuclear and radiological materials that could be used in nefarious acts. Radiation portal monitors are often installed at bottlenecks where large amounts of people or goods must traverse. Examples of use include scanning cargo containers at shipping ports, vehicles at border crossings, and people at high profile functions and events. Traditional radiation portal monitors contain separate detectors for passively measuring neutron and gamma ray count rates. 3He tubes embedded in polyethylene and slabs of plastic scintillators are the most common detector materials used in radiation portal monitors. The radiation portal monitor alarm mechanism relies on measuring radiation count rates above user defined alarm thresholds. These alarm thresholds are set above natural background count rates. Minimizing false alarms caused by natural background and maximizing sensitivity to weakly emitting threat sources must be balanced when setting these alarm thresholds. Current radiation portal monitor designs suffer from frequent nuisance radiation alarms. These radiation nuisance alarms are most frequently caused by shipments of large quantities of naturally occurring radioactive material containing cargo, like kitty litter, as well as by humans who have recently undergone a nuclear medicine procedure, particularly 99mTc treatments. Current radiation portal monitors typically lack spectroscopic capabilities, so nuisance alarms must be screened out in time-intensive secondary inspections with handheld radiation detectors. Radiation portal monitors using organic liquid scintillation detectors were designed, built, and tested. A number of algorithms were developed to perform on-the-fly radionuclide identification of single and combination radiation sources moving past the portal monitor at speeds up to 2.2 m/s. The portal monitor designs were tested extensively with a variety of

  9. Sky Localization and Electromagnetic Follow-up with Third-Generation Detectors

    NASA Astrophysics Data System (ADS)

    Anand, Shreya; Singer, Leo; Miller, Cole

    2017-01-01

    We present a preliminary investigation of the potential of third-generation gravitational-wave (GW) detectors for multi-messenger astronomy, from the standpoint of electromagnetic follow-up and identification of host galaxies. Using approximate sky localization inferred from GW observations, we intend to plan their electromagnetic follow-up in order to pinpoint the host galaxies. This involves simulating GW data, matching it with electromagnetic observations, and converting it into a sky-map used to chart locations of host galaxies of known sources. We aim to understand whether there are identifiable trends for host galaxies of transients in order to address whether a strategy that focuses on individual host galaxies is more optimal than one that locates them based on a statistical trend. Our project also concerns the configuration and calibration of a next generation detector network. Questions we focus on include: at what redshift will sky localization accuracy be limited by detector calibration? Using different combinations of detectors, what sky localization can be achieved? Our research motivates why third generation GW detector networks are crucial in enhancing signals detected and in providing insight into the sources and their physical environments. University of Maryland-College Park.

  10. A high-efficiency focusing Cherenkov radiation detector

    NASA Astrophysics Data System (ADS)

    Lewis, Katina-Pilar; Moran, Michael J.; Hall, James; Graser, Michael

    1992-03-01

    A new design uses advanced technology to produce an efficient, high-bandwidth Cherenkov detector for relativistic charged particles. The detector consists of a diamond-lathe machined ultraviolet-grade Lucite radiator, a parabolic focusing mirror, and a photodiode with an S-20 cathode. This article discusses some details of the detector design and describes preliminary measurements of its response characteristics. The data show the detector to have an overall gain of ≊76 signal electrons per incident electron and a photodiode-limited response time of ≊450 ps.

  11. Development of bulk GaAs room temperature radiation detectors

    SciTech Connect

    McGregor, D.S.; Knoll, G.F. . Dept. of Nuclear Engineering); Eisen, Y. . Soreq Nuclear Research Center); Brake, R. )

    1992-10-01

    This paper reports on GaAs, a wide band gap semiconductor with potential use as a room temperature radiation detector. Various configurations of Schottky diode detectors were fabricated with bulk crystals of liquid encapsulated Czochralski (LEC) semi-insulating undoped GaAs material. Basic detector construction utilized one Ti/Au Schottky contact and one Au/Ge/Ni alloyed ohmic contact. Pulsed X-ray analysis indicated pulse decay times dependent on bias voltage. Pulse height analysis disclosed non-uniform electric field distributions across the detectors tentatively explained as a consequence of native deep level donors (EL2) in the crystal.

  12. Proton-induced radiation damage in germanium detectors

    NASA Technical Reports Server (NTRS)

    Brueckner, J.; Koerfer, M.; Waenke, H.; Schroeder, A. N. F.; Filges, D.; Dragovitsch, P.; Englert, P. A. J.; Starr, R.; Trombka, J. I.

    1991-01-01

    High-purity germanium (HPGe) detectors will be used in future space missions for gamma-ray measurements and will be subject to interactions with energetic particles. To simulate this process, several large-volume n-type HPGe detectors were incrementally exposed to a particle fluence of up to 10 to the 8th protons/sq cm (proton energy: 1.5 GeV) at different operating temperatures (90 to 120 K) to induce radiation damage. Basic scientific and engineering data on detector performance were collected. During the incremental irradiation, the peak shape produced by the detectors showed a significant change from a Gaussian shape to a broad complex structure. After the irradiation, all detectors were thoroughly characterized by measuring many parameters. To remove the accumulated radiation damage, the detectors were stepwise-annealed at temperatures below 110 C, while kept in their specially designed cryostats. This study shows that n-type HPGe detectors can be used in charged-particle environments as high-energy resolution devices until a certain level of radiation damage is accumulated and that the damage can be removed at moderate annealing temperatures and the detector returned to operating condition.

  13. Proton-induced radiation damage in germanium detectors

    SciTech Connect

    Bruckner, J.; Korfer, M.; Wanke, H. , Mainz ); Schroeder, A.N.F. ); Figes, D.; Dragovitsch, P. ); Englert, P.A.J. ); Starr, R.; Trombka, J.I. . Goddard Space Flight Center); Taylor, I. ); Drake, D.M.; Shunk, E.R. )

    1991-04-01

    High-purity germanium (HPGe) detectors will be used in future space missions for gamma-ray measurements and will be subject to interactions with energetic particles. To simulate this process several large-volume n-type HPGe detectors were incrementally exposed to a particle fluence of up to 10{sub 8} protons cm{sup {minus}2} (proton energy: 1.5 GeV) at different operating temperatures (90 to 120 K) to induce radiation damage. Basic scientific as well as engineering data on detector performance were collected. During the incremental irradiation, the peak shape produced by the detectors showed a significant change from a Gaussian shape to a broad complex structure. After the irradiation all detectors were thoroughly characterized by measuring many parameters. To remove the accumulated radiation damage the detectors were stepwise annealed at temperatures T {le} 110{degrees}C while staying specially designed cryostats. This paper shows that n-type HPGe detectors can be used in charged particles environments as high-energy resolution devices until a certain level of radiation damage is accumulated and that the damage can be removed at moderate annealing temperatures and the detector returned to operating condition.

  14. Monolithic active pixel radiation detector with shielding techniques

    DOEpatents

    Deptuch, Grzegorz W.

    2016-09-06

    A monolithic active pixel radiation detector including a method of fabricating thereof. The disclosed radiation detector can include a substrate comprising a silicon layer upon which electronics are configured. A plurality of channels can be formed on the silicon layer, wherein the plurality of channels are connected to sources of signals located in a bulk part of the substrate, and wherein the signals flow through electrically conducting vias established in an isolation oxide on the substrate. One or more nested wells can be configured from the substrate, wherein the nested wells assist in collecting charge carriers released in interaction with radiation and wherein the nested wells further separate the electronics from the sensing portion of the detector substrate. The detector can also be configured according to a thick SOA method of fabrication.

  15. Apparatus and Methods for Locating Source of and Analyzing Electromagnetic Radiation

    DTIC Science & Technology

    2015-11-19

    Filed: November 3, 2014 For: APPARATUS AND METHODS FOR LOCATING SOURCE OF AND ANALYZING ELECTROMAGNETIC RADIATION Group Art Unit: 2878 Examiner...OF INVENTION) Apparatus and Methods for Locating Source of and Analyzing Electromagnetic Radiation INVENTORS(S) Byron G. Zollars, Steve M. Savoy...ANALYZING ELECTROMAGNETIC RADIATION (71) Applicant: Nanohmics, Inc., Austin, TX (US) (72) Inventors: Byron G. Zollars, Georgetown, TX (US); Steve M

  16. Detection of electromagnetic radiation using micromechanical multiple quantum wells structures

    DOEpatents

    Datskos, Panagiotis G [Knoxville, TN; Rajic, Slobodan [Knoxville, TN; Datskou, Irene [Knoxville, TN

    2007-07-17

    An apparatus and method for detecting electromagnetic radiation employs a deflectable micromechanical apparatus incorporating multiple quantum wells structures. When photons strike the quantum-well structure, physical stresses are created within the sensor, similar to a "bimetallic effect." The stresses cause the sensor to bend. The extent of deflection of the sensor can be measured through any of a variety of conventional means to provide a measurement of the photons striking the sensor. A large number of such sensors can be arranged in a two-dimensional array to provide imaging capability.

  17. Scattering of electromagnetic radiation by a metal nanoparticle

    NASA Astrophysics Data System (ADS)

    Kuznetsova, I. A.; Lebedev, M. E.; Yushkanov, A. A.

    2014-04-01

    The scattering cross section of electromagnetic radiation by a small spherical metal particle has been calculated in the framework of the standard kinetic theory in a dipole approximation. The calculation has been performed for relatively small (˜10 nm) particles, which allows the skin effect to be ignored. A mechanism of mixed specular-diffuse reflection of conduction electrons from the particle surface is considered. It is established that, at certain angles of scattering, the mechanism of magnetic-dipole scattering becomes dominating. The influence of kinetic effects on the differential scattering cross section is analyzed.

  18. Nuclear radiation-warning detector that measures impedance

    DOEpatents

    Savignac, Noel Felix; Gomez, Leo S; Yelton, William Graham; Robinson, Alex; Limmer, Steven

    2013-06-04

    This invention is a nuclear radiation-warning detector that measures impedance of silver-silver halide on an interdigitated electrode to detect light or radiation comprised of alpha particles, beta particles, gamma rays, X rays, and/or neutrons. The detector is comprised of an interdigitated electrode covered by a layer of silver halide. After exposure to alpha particles, beta particles, X rays, gamma rays, neutron radiation, or light, the silver halide is reduced to silver in the presence of a reducing solution. The change from the high electrical resistance (impedance) of silver halide to the low resistance of silver provides the radiation warning that detected radiation levels exceed a predetermined radiation dose threshold.

  19. Detecting excess ionizing radiation by electromagnetic breakdown of air

    SciTech Connect

    Granatstein, Victor L.; Nusinovich, Gregory S.

    2010-09-15

    A scheme is proposed for detecting a concealed source of ionizing radiation by observing the occurrence of breakdown in atmospheric air by an electromagnetic wave whose electric field surpasses the breakdown field in a limited volume. The volume is chosen to be smaller than the reciprocal of the naturally occurring concentration of free electrons. The pulse duration of the electromagnetic wave must exceed the avalanche breakdown time (10-200 ns) and could profitably be as long as the statistical lag time in ambient air (typically, microseconds). Candidate pulsed electromagnetic sources over a wavelength range, 3 mm>{lambda}>10.6 {mu}m, are evaluated. Suitable candidate sources are found to be a 670 GHz gyrotron oscillator with 200 kW, 10 {mu}s output pulses and a Transversely Excited Atmospheric-Pressure (TEA) CO{sub 2} laser with 30 MW, 100 ns output pulses. A system based on 670 GHz gyrotron would have superior sensitivity. A system based on the TEA CO{sub 2} laser could have a longer range >100 m.

  20. Recent progress in the development of transition radiation detectors

    NASA Technical Reports Server (NTRS)

    Cherry, M. L.; Hartmann, G.; Prince, T.; Mueller, D.

    1978-01-01

    Transition-radiation detectors have been used in several recent cosmic-ray experiments for particle identification at energies E/mc-squared of at least about 1000. In order to optimize the design of such detectors and to use them for energy measurements over a broad energy range, it is necessary to study the details of the transition-radiation process. Experimental results are presented which test the theoretical predictions more precisely and at higher energies than in previous experiments. The dependence of the interference pattern in the frequency spectrum on the radiator dimensions is studied, and the total transition-radiation yield generated by electrons in various radiators is measured over a very wide energy range, from 5 to 300 GeV. The significance of the individual experimental parameters in the design of transition radiation detectors is reviewed, and the characteristics of transition-radiation detectors capable of measuring particle energies over the range E/mc-squared from about 300 to 100,000 are discussed.

  1. Use of a superconductive gradiometer in an ultrasensitive electromagnetic metal detector

    SciTech Connect

    Czipott, P.V.; Podney, W.N.

    1989-03-01

    The authors present a new instrument that we call an electromagnetic gradiometer. It uses a SQUID sensor as the receiver in an active, electromagnetic detector of nonferrous as well as ferrous objects. The gradiometer pickup loops sit in the center of magnet coils that generate a time-varying magnetic field inducing eddy currents in conductive bodies. The gradiometer measures the secondary magnetic field of the eddy currents. The SQUID's sensitivity at frequencies below 1 kHz makes electromagnetic metal detectors practical in the marine environment, where the electrical conductivity of seawater precludes conventional systems. The authors describe a prototype system that attains a detection range of 10 m in seawater for targets 50 cm in diameter. It operates at frequencies from 1 Hz to a few hundred Hz. Uses of the electromagnetic gradiometer include locating naval mines and undersea treasure. The system's response to seawater enables application to airborne electromagnetic bathymetry. On land, its sensitivity to crustal conductivity contrasts suits it to mineral exploration.

  2. Incident position detector for radiation beam

    SciTech Connect

    Koumura, N.; Niwa, Y.; Ogino, Y.; Ohwada, M.; Tanaka, K.

    1983-05-17

    Disclosed is a device for detecting an incident position of radiation beam, particularly, its center or center of gravity. The detecting device is provided with a scanning type radiation beam sensing device having a plurality of radiation sensing elements in a linear arrangement, and the sensing device is disposed in such a manner that its radiation receiving surface may be substantially coincided with an incident surface of the radiation beam to be detected. When reading an output from the sensing device, the time sequential output signals from the sensing device are split into predetermined sections, and the signal quantities among the sections are compared. In this way, the position of the center or the center of gravity of the radiation beam on the incident surface is detected with the position corresponding to a split point of the signals as the reference.

  3. Radiation Bandwidth Improvement of Electromagnetic Band Gap Cavity Antenna

    NASA Astrophysics Data System (ADS)

    Chaabane, Abdelhalim; Djahli, Farid; Attia, Hussein; Denidni, Tayeb. A.

    2017-09-01

    In this paper, an electromagnetic band gap cavity antenna with improved radiation and impedance bandwidths is presented. The proposed antenna is constructed by placing a triple-layer heterogeneous printed-unprinted partially reflective surface (PRS) above a primary aperture-coupled patch antenna. The PRS unit-cell provides a positive gradient reflection phase behavior over the desired frequency range. A prototype antenna is fabricated and measured that highlighted its ability to achieve 3-dB gain bandwidth of about 35.9 %, from 7.93 GHz to 11.4 GHz, with a peak gain of 14.25 dBi at 8.5 GHz. In addition, the impedance bandwidth is 40.32 %, from 7.9 GHz to 11.89 GHz. Thus, the designed antenna outperforms many other competitors for improving the radiation bandwidth of planar antennas with the same presented concept.

  4. Geometrical Effects on the Electromagnetic Radiation from Lightning Return Strokes

    NASA Technical Reports Server (NTRS)

    Willett, J. C.; Smith, D. A.; LeVine, D. M.; Zukor, Dorothy J. (Technical Monitor)

    2001-01-01

    The morphological difference between the electromagnetic radiation-field waveforms of "first" and "subsequent" return strokes in cloud-to-ground lightning flashes is well known and can be used to identify the formation of new channels to ground. This difference is generally believed due to the existence of branches on first-stroke channels, whereas subsequent strokes re-illuminate only the main channel of a previous stroke; but experimental evidence for this hypothesis is relatively weak. It has been argued for the influence of channel geometry on the fine structure of radiation from subsequent return strokes by comparing the field-change waveforms recorded at the same station from strokes within the same flash and between different flashes of both natural and triggered lightning. The present paper introduces new evidence for both of these hypotheses from a comparison of waveforms between sensors in different directions from the same stroke.

  5. Electromagnetic radiation from a kicked sheet of charge

    NASA Astrophysics Data System (ADS)

    Peters, P. C.

    1986-03-01

    The plane-wave electromagnetic fields for a kicked sheet of charge are found and then compared with the fields obtained by superimposing the radiation fields of the individual charges in the plane. Unlike the case of the oscillating sheet of charge discussed in The Feynman Lectures on Physics, Vol. I [R. P. Feynman et al. (Addison-Wesley, Reading, MA, 1963)], the plane-wave fields of the kicked sheet differ from the fields obtained by superposition of the individual radiation fields. The resolution of this problem requires consideration of relativistic effects even though the velocity of the sheet after the kick may be as small as desired. The relation between the solution for the kicked sheet and solution for the oscillating sheet is discussed, and it is shown how the two solutions are consistent if all contributions to the fields are taken into account.

  6. Modernization of radiation detectors thickness gauge

    NASA Astrophysics Data System (ADS)

    Artemyev, I. B.; Artemiev, B. V.; Vladimirov, Yu L.; Vladimirov, L. V.

    2017-02-01

    Currently, there is a tendency in the industry by refusing isotopic radiation sources in favor of the X-ray machines. This is due to several factors, main among them radiation safety and maintenance problems, movement and disposal of gamma-ray sources. Compared to the gamma ray-source these devices have a number of disadvantages. The spectral energy distribution and therefore change in the spectrum as the radiation passes through the controlled material. Instability of radiation compared with gamma sources. All this complicates the use of X-ray sources for the materials thickness measurement with different chemical compositions.

  7. The HERMES dual-radiator ring imaging Cherenkov detector

    NASA Astrophysics Data System (ADS)

    Akopov, N.; Aschenauer, E. C.; Bailey, K.; Bernreuther, S.; Bianchi, N.; Capitani, G. P.; Carter, P.; Cisbani, E.; De Leo, R.; De Sanctis, E.; De Schepper, D.; Djordjadze, V.; Filippone, B. W.; Frullani, S.; Garibaldi, F.; Hansen, J.-O.; Hommez, B.; Iodice, M.; Jackson, H. E.; Jung, P.; Kaiser, R.; Kanesaka, J.; Kowalczyk, R.; Lagamba, L.; Maas, A.; Muccifora, V.; Nappi, E.; Negodaeva, K.; Nowak, W.-D.; O'Connor, T.; O'Neill, T. G.; Potterveld, D. H.; Ryckbosch, D.; Sakemi, Y.; Sato, F.; Schwind, A.; Shibata, T.-A.; Suetsugu, K.; Thomas, E.; Tytgat, M.; Urciuoli, G. M.; Van de Kerckhove, K.; Van de Vyver, R.; Yoneyama, S.; Zohrabian, H.; Zhang, L. F.

    2002-03-01

    The construction and use of a dual radiator Ring Imaging Cherenkov (RICH) detector is described. This instrument was developed for the HERMES experiment at DESY which emphasises measurements of semi-inclusive deep-inelastic scattering. It provides particle identification for pions, kaons, and protons in the momentum range from 2 to 15 GeV, which is essential to these studies. The instrument uses two radiators, C 4F 10, a heavy fluorocarbon gas, and a wall of silica aerogel tiles. The use of aerogel in a RICH detector has only recently become possible with the development of clear, large, homogeneous and hydrophobic aerogel. A lightweight mirror was constructed using a newly perfected technique to make resin-coated carbon-fiber surfaces of optical quality. The photon detector consists of 1934 photomultiplier tubes (PMT) for each detector half, held in a soft steel matrix to provide shielding against the residual field of the main spectrometer magnet.

  8. Flat detectors and new aspects of radiation safety.

    PubMed

    Gurley, John C

    2009-08-01

    Flat detectors are the heart of high-performance imaging systems that provide new capabilities as well as new hazards. The superior image quality enables operators to work with heavier patients and steeper projections. Under these conditions, exposure control computers automatically increase the production of x-rays to compensate for absorption by body tissues. Image quality is preserved, and operators may not be aware of the very high skin doses delivered during prolonged procedures. Although it is assumed that flat detector systems are safe, the potential for radiation overexposure and skin injury is real. This article examines the unique radiation hazards of flat detector fluoroscopy and suggests practical steps that clinicians can take to protect themselves and their patients from radiation injury.

  9. Radiation hardness of three-dimensional polycrystalline diamond detectors

    SciTech Connect

    Lagomarsino, Stefano Sciortino, Silvio; Bellini, Marco; Corsi, Chiara; Cindro, Vladimir; Kanxheri, Keida; Servoli, Leonello; Morozzi, Arianna; Passeri, Daniele; Schmidt, Christian J.

    2015-05-11

    The three-dimensional concept in particle detection is based on the fabrication of columnar electrodes perpendicular to the surface of a solid state radiation sensor. It permits to improve the radiation resistance characteristics of a material by lowering the necessary bias voltage and shortening the charge carrier path inside the material. If applied to a long-recognized exceptionally radiation-hard material like diamond, this concept promises to pave the way to the realization of detectors of unprecedented performances. We fabricated conventional and three-dimensional polycrystalline diamond detectors, and tested them before and after neutron damage up to 1.2 ×10{sup 16 }cm{sup −2}, 1 MeV-equivalent neutron fluence. We found that the signal collected by the three-dimensional detectors is up to three times higher than that of the conventional planar ones, at the highest neutron damage ever experimented.

  10. Design of compact electromagnetic impulse radiating antenna for melanoma treatment.

    PubMed

    Arockiasamy, Petrishia; Mohan, Sasikala

    2016-01-01

    Cancer therapy is one of the several new applications which use nanosecond and subnanosecond high voltage pulses. New treatment based on electromagnetic (EM) fields have been developed as non-surgical and minimally invasive treatments of tumors. In particular, subnanosecond pulses can introduce important non-thermal changes in cell biology, especially the permeabilization of the cell membrane. The motivation behind this work is to launch intense subnanosecond pulses to the target (tumors) non-invasively. This works focuses on the design of a compact intense pulsed EM radiating antenna. In tense EM waves radiated at the first focal point of the Prolate Spheroidal Reflector (PSR) are focused at the second focal point where the target (tumor) is present. Two antennas with PSR but fed with different compact wave radiator are designed to focus pulsed field at the second focal point. The PSR with modified bicone antenna feed and PSR with elliptically tapered horn antenna feed are designed. The design parameters and radiation performance are discussed.

  11. Three-axis asymmetric radiation detector system

    DOEpatents

    Martini, Mario Pierangelo; Gedcke, Dale A.; Raudorf, Thomas W.; Sangsingkeow, Pat

    2000-01-01

    A three-axis radiation detection system whose inner and outer electrodes are shaped and positioned so that the shortest path between any point on the inner electrode and the outer electrode is a different length whereby the rise time of a pulse derived from a detected radiation event can uniquely define the azimuthal and radial position of that event, and the outer electrode is divided into a plurality of segments in the longitudinal axial direction for locating the axial location of a radiation detection event occurring in the diode.

  12. Silicon carbide detector for laser-generated plasma radiation

    NASA Astrophysics Data System (ADS)

    Bertuccio, Giuseppe; Puglisi, Donatella; Torrisi, Lorenzo; Lanzieri, Claudio

    2013-05-01

    We present the performance of a Silicon Carbide (SiC) detector in the acquisition of the radiation emitted by laser generated plasmas. The detector has been employed in time of flight (TOF) configuration within an experiment performed at the Prague Asterix Laser System (PALS). The detector is a 5 mm2 area 100 nm thick circular Nisbnd SiC Schottky junction on a high purity 4Hsbnd SiC epitaxial layer 115 μm thick. Current signals from the detector with amplitudes up to 1.6 A have been measured, achieving voltage signals over 80 V on a 50 Ω load resistance with excellent signal to noise ratios. Resolution of few nanoseconds has been experimentally demonstrated in TOF measurements. The detector has operated at 250 V DC bias under extreme operating conditions with no observable performance degradation.

  13. Low dose radiation damage effects in silicon strip detectors

    NASA Astrophysics Data System (ADS)

    Wiącek, P.; Dąbrowski, W.

    2016-11-01

    The radiation damage effects in silicon segmented detectors caused by X-rays have become recently an important research topic driven mainly by development of new detectors for applications at the European X-ray Free Electron Laser (E-XFEL). However, radiation damage in silicon strip is observed not only after extreme doses up to 1 GGy expected at E-XFEL, but also at doses in the range of tens of Gy, to which the detectors in laboratory instruments like X-ray diffractometers or X-ray spectrometers can be exposed. In this paper we report on investigation of radiation damage effects in a custom developed silicon strip detector used in laboratory diffractometers equipped with X-ray tubes. Our results show that significant degradation of detector performance occurs at low doses, well below 200 Gy, which can be reached during normal operation of laboratory instruments. Degradation of the detector energy resolution can be explained by increasing leakage current and increasing interstrip capacitance of the sensor. Another observed effect caused by accumulation of charge trapped in the surface oxide layer is change of charge division between adjacent strips. In addition, we have observed unexpected anomalies in the annealing process.

  14. Radiation detectors as surveillance monitors for IAEA safeguards

    SciTech Connect

    Fehlau, P.E.; Dowdy, E.J.

    1980-10-01

    Radiation detectors used for personnel dosimetry are examined for use under IAEA Safeguards as monitors to confirm the passage or nonpassage (YES/NO) of plutonium-bearing nuclear material at barrier penetrations declared closed. In this application where backgrounds are ill defined, no advantage is found for a particular detector type because of intrinsic efficiency. Secondary considerations such as complexity, ease of tamper-proofing, and ease of readout are used to recommend specific detector types for routine monitoring and for data-base measurements. Recommendations are made for applications, data acquisition, and instrument development.

  15. R&D for Better Nuclear Security: Radiation Detector Materials

    SciTech Connect

    Kammeraad, J E

    2009-04-02

    I am going to talk about the need for better materials for radiation detectors. I believe that government investment in this area can enable transformational technology change that could impact domestic nuclear security and also national nuclear security in some very positive and powerful ways. I'm not going to give you a lecture on how radiation detectors work, but I am going to tell you a bit about today's off-the-shelf technology and why it is not sufficient, what we need, and what security benefit you could get from improvements. I think we're at a critical point in time for some very impactful investments. In particular I'm going to focus on the use of gamma-ray radiation detectors at ports of entry. Not long before DHS was formed, Congress decreed that counter measures against the delivery of radiological and nuclear threats would be put in place at US ports of entry, under the authority of US Customs (later Customs and Border Protection in DHS). This included the screening of all cars and trucks passing through a port of entry. Existing off-the-shelf radiation detectors had to be selected for this purpose. Plans were made to make the most of the available technologies, but there are some inherent limitations of these detectors, plus the operational setting can bring out other limitations.

  16. Risks of carcinogenesis from electromagnetic radiation of mobile telephony devices.

    PubMed

    Yakymenko, I; Sidorik, E

    2010-07-01

    Intensive implementation of mobile telephony technology in everyday human life during last two decades has given a possibility for epidemiological estimation of long-term effects of chronic exposure of human organism to low-intensive microwave (MW) radiation. Latest epidemiological data reveal a significant increase in risk of development of some types of tumors in chronic (over 10 years) users of mobile phone. It was detected a significant increase in incidence of brain tumors (glioma, acoustic neuroma, meningioma), parotid gland tumor, seminoma in long-term users of mobile phone, especially in cases of ipsilateral use (case-control odds ratios from 1.3 up to 6.1). Two epidemiological studies have indicated a significant increase of cancer incidence in people living close to the mobile telephony base station as compared with the population from distant area. These data raise a question of adequacy of modern safety limits of electromagnetic radiation (EMR) exposure for humans. For today the limits were based solely on the conception of thermal mechanism of biological effects of RF/MW radiation. Meantime the latest experimental data indicate the significant metabolic changes in living cell under the low-intensive (non-thermal) EMR exposure. Among reproducible biological effects of low-intensive MWs are reactive oxygen species overproduction, heat shock proteins expression, DNA damages, apoptosis. The lack of generally accepted mechanism of biological effects of low-intensive non-ionizing radiation doesn't permit to disregard the obvious epidemiological and experimental data of its biological activity. Practical steps must be done for reasonable limitation of excessive EMR exposure, along with the implementation of new safety limits of mobile telephony devices radiation, and new technological decisions, which would take out the source of radiation from human brain.

  17. [Recent data from the literature on the biological and pathologic effects of electromagnetic radiation, radio waves and stray currents].

    PubMed

    Orbach-Arbouys, S; Abgrall, S; Bravo-Cuellar, A

    1999-12-01

    Electromagnetic radiation is present in increasing amounts in our environment, and its potential effects on human (and animal) health has been investigated. It remains unclear whether the risk of acute childhood leukemia is associated with cumulative exposure to magnetic fields. An association with brain cancer and colon cancer has been suggested in electrical company workers. The radars used by police departments may increase the incidence of cancer. Electromagnetic radiation may play a role in a number of disorders such as depression and memory loss. It has been established that cell phones interfere with pacemakers only if direct contact occurs and have no effect if held in their normal position. Interferences have been reported between pacemakers and shop-lifting detectors.

  18. Effect of temperature on silicon PIN photodiode radiation detectors

    NASA Astrophysics Data System (ADS)

    Kim, Han Soo; Jeong, Manhee; Kim, Young Soo; Ha, Jang Ho; Cho, Seong Yeon

    2014-03-01

    One of the noise sources of a semiconductor radiation detector is thermal noise, which degrades the performance, such as the energy resolution and unexpected random pulse signals. In this study, PIN photodiode radiation detectors, with different active areas were designed and fabricated for an experimental comparison of the energy resolutions for different temperatures and capacitances by using a Ba-133 calibration gamma-ray source. The experimental temperature was approximately in the range from -7 to 24 °C and was controlled by using a peltier device. The design considerations and the electrical characteristics, such as the I-V and the C-V characteristics, are also addressed.

  19. Scattering of Electromagnetic Radiation by Apertures: II. Oblique Incidence on the Slotted Plane for Parallel Polarization,

    DTIC Science & Technology

    The report is the second in a series of investigations into the diffraction of electromagnetic radiation by apertures in conducting screens. Herein...is presented a technique for obtaining the fields everywhere for plane electromagnetic radiation incident obliquely on a slotted conducting plane. The

  20. Computational Electromagnetic Studies for Low-Frequency Compensation of the Reflector Impulse-radiating Antenna

    DTIC Science & Technology

    2015-03-26

    COMPUTATIONAL ELECTROMAGNETIC STUDIES FOR LOW-FREQUENCY COMPENSATION OF THE REFLECTOR IMPULSE-RADIATING ANTENNA THESIS Casey E. Fillmore, Capt, USAF... ELECTROMAGNETIC STUDIES FOR LOW-FREQUENCY COMPENSATION OF THE REFLECTOR IMPULSE-RADIATING ANTENNA THESIS Presented to the Faculty Department of Electrical and...2015 DISTRIBUTION STATEMENT A APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. AFIT-ENG-MS-15-M-011 COMPUTATIONAL ELECTROMAGNETIC STUDIES FOR LOW

  1. Applications of a-Si:H radiation detectors

    SciTech Connect

    Fujieda, I.; Cho, G.; Conti, M.; Drewery, J.; Kaplan, S.N.; Perez-Mendez, V.; Qureshi, S.; Street, R.A.

    1989-07-01

    Device structures and operation principles are described for detecting various kinds of radiation with hydrogenated amorphous silicon (a-Si:H) layers. With some new configurations such as the buried p-i-n structure and the use of interdigitated electrodes, the a-Si:H radiation detectors will find their applications in many fields of science. Some applications in high energy physics, medical imaging, materials sciences and life sciences are discussed in this paper. 41 refs., 7 figs., 1 tab.

  2. Recent progress in the transition radiation detector techniques

    NASA Technical Reports Server (NTRS)

    Yuan, L. C. L.

    1973-01-01

    A list of some of the major experimental achievements involving charged particles in the relativistic region are presented. With the emphasis mainly directed to the X-ray region, certain modes of application of the transition radiation for the identification and separation of relativistic charged particles are discussed. Some recent developments in detection techniques and improvements in detector performances are presented. Experiments were also carried out to detect the dynamic radiation, but no evidence of such an effect was observed.

  3. Semiconductor radiation detector with internal gain

    DOEpatents

    Iwanczyk, Jan; Patt, Bradley E.; Vilkelis, Gintas

    2003-04-01

    An avalanche drift photodetector (ADP) incorporates extremely low capacitance of a silicon drift photodetector (SDP) and internal gain that mitigates the surface leakage current noise of an avalanche photodetector (APD). The ADP can be coupled with scintillators such as CsI(Tl), NaI(Tl), LSO or others to form large volume scintillation type gamma ray detectors for gamma ray spectroscopy, photon counting, gamma ray counting, etc. Arrays of the ADPs can be used to replace the photomultiplier tubes (PMTs) used in conjunction with scintillation crystals in conventional gamma cameras for nuclear medical imaging.

  4. Thermal electromagnetic radiation in heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Rapp, R.; van Hees, H.

    2016-08-01

    We review the potential of precise measurements of electromagnetic probes in relativistic heavy-ion collisions for the theoretical understanding of strongly interacting matter. The penetrating nature of photons and dileptons implies that they can carry undistorted information about the hot and dense regions of the fireballs formed in these reactions and thus provide a unique opportunity to measure the electromagnetic spectral function of QCD matter as a function of both invariant mass and momentum. In particular we report on recent progress on how the medium modifications of the (dominant) isovector part of the vector current correlator ( ρ channel) can shed light on the mechanism of chiral symmetry restoration in the hot and/or dense environment. In addition, thermal dilepton radiation enables novel access to a) the fireball lifetime through the dilepton yield in the low invariant-mass window 0.3 GeV ≤ M ≤ 0.7 GeV, and b) the early temperatures of the fireball through the slope of the invariant-mass spectrum in the intermediate-mass region (1.5 GeV < M < 2.5 GeV). The investigation of the pertinent excitation function suggests that the beam energies provided by the NICA and FAIR projects are in a promising range for a potential discovery of the onset of a first-order phase transition, as signaled by a non-monotonous behavior of both low-mass yields and temperature slopes.

  5. Radiation hardness study of Silicon Detectors for the CMS High Granularity Calorimeter (HGCAL)

    NASA Astrophysics Data System (ADS)

    Currás, E.; Mannelli, M.; Moll, M.; Nourbakhsh, S.; Steinbrueck, G.; Vila, I.

    2017-02-01

    The high luminosity LHC (HL-LHC or Phase-II) is expected to increase the instantaneous luminosity of the LHC by a factor of about five, delivering 0~25 fb ‑1 per year between 2025 and 2035. Under these conditions the performance degradation of detectors due to integrated radiation dose/fluence will need to be addressed. The CMS collaboration is planning to upgrade many detector components, including the forward calorimeters. The replacement for the existing endcap preshower, electromagnetic and hadronic calorimeters is called the High Granularity Calorimeter (HGCAL) and it will be realized as a sampling calorimeter, including 40 layers of silicon detectors totalling 600 m2. The sensors will be realized as pad detectors with cell size between 0.5 and 1.0 cm2 and an active thickness between 100 μm and 300 μm depending on their location in the endcaps. The thinner sensors will be used in the highest radiation environment. For an integrated luminosity of 3000 fb ‑1, the electromagnetic calorimeter will have to sustain a maximum integrated dose of 1.5 MGy and neutron fluences of 1.0×1016 neq/cm2. A tolerance study after neutron irradiation of 300 μm, 200 μm, 100 μm and 50 μm n-on-p and p-on-n silicon pads irradiated to fluences up to 1.6×1016 neq/cm2 is presented. The main properties of these diodes have been studied before and after irradiation: leakage current, capacitance, charge collection efficiency with laser and sensitivity to minimum ionizing particles with radioactive source (90Sr). The results show a good performance even after the most extreme irradiation.

  6. Electromagnetic radiation trapped in the magnetosphere above the plasma frequency

    NASA Technical Reports Server (NTRS)

    Gurnett, D. A.; Shaw, R. R.

    1973-01-01

    An electromagnetic noise band is frequently observed in the outer magnetosphere by the Imp 6 spacecraft at frequencies from about 5 to 20 kHz. This noise band generally extends throughout the region from near the plasmapause boundary to near the magnetopause boundary. The noise typically has a broadband field strength of about 5 microvolts/meter. The noise band often has a sharp lower cutoff frequency at about 5 to 10 kHz, and this cutoff has been identified as the local electron plasma frequency. Since the plasma frequency in the plasmasphere and solar wind is usually above 20 kHz, it is concluded that this noise must be trapped in the low-density region between the plasmapause and magnetopause boundaries. The noise bands often contain a harmonic frequency structure which suggests that the radiation is associated with harmonics of the electron cyclotron frequency.

  7. A metasurface for conversion of electromagnetic radiation to DC

    NASA Astrophysics Data System (ADS)

    El Badawe, Mohamed; Almoneef, Thamer S.; Ramahi, Omar M.

    2017-03-01

    We present a metasurface electromagnetic energy harvester based on electrically small resonators. An array of 8 × 8 cross resonators was designed to operate at 3GHz. Unlike earlier designs of metasurface harvesters where each resonator was connected to a single rectifier or load, in this work the received power by all resonators is channeled to a single rectifier which in turn channels the DC energy to a single 50 Ω resistive load. The critical advantage of the proposed structure is maximizing power density per diode which maximizes the diode turn-on time. We show through simulation and measurements that the proposed metasurface harvester provides Radiation to DC conversion efficiency of more than 40%.

  8. Research on radiation detectors, boiling transients, and organic lubricants

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The accomplishments of a space projects research facility are presented. The subjects discussed are: (1) a study of radiation resistant semiconductor devices, (2) synthesis of high temperature organic lubricants, (3) departure from phase equilibrium during boiling transients, (4) effects of neutron irradiation on defect state in tungsten, and (5) determination of photon response function of NE-213 liquid scintillation detectors.

  9. Radiation Response of Emerging High Gain, Low Noise Detectors

    NASA Technical Reports Server (NTRS)

    Becker, Heidi N.; Farr, William H; Zhu, David Q.

    2007-01-01

    Data illustrating the radiation response of emerging high gain, low noise detectors are presented. Ionizing dose testing of silicon internal discrete avalanche photodiodes, and 51-MeV proton testing of InGaAs/InAlAs avalanche photodiodes operated in Geiger mode are discussed.

  10. Mercuric iodide single crystals for nuclear radiation detectors

    SciTech Connect

    Li, W.; Li, Z.; Zhu, S.; Yin, S.; Zhao, B.; Chen, G.; Yin, S.; Yuan, H.; Xu, H.

    1996-06-01

    Large size HgI{sub 2} single crystals were grown using the Modified Temperature Oscillation Method (MTOM) with low dislocation densities in a relatively stable temperature environment. Radiation detectors were fabricated from the single crystals which showed good energy resolution with small polarization. Applications have been found in geological explorations, marine mineral analysis, environment pollution monitoring, industrial material quality assurance, and space explorations.

  11. Radiation Response of Emerging High Gain, Low Noise Detectors

    NASA Technical Reports Server (NTRS)

    Becker, Heidi N.; Farr, William H; Zhu, David Q.

    2007-01-01

    Data illustrating the radiation response of emerging high gain, low noise detectors are presented. Ionizing dose testing of silicon internal discrete avalanche photodiodes, and 51-MeV proton testing of InGaAs/InAlAs avalanche photodiodes operated in Geiger mode are discussed.

  12. On Linsley Effect and Electromagnetic Radiation from Large EAS

    NASA Astrophysics Data System (ADS)

    Deb, Manab Jyoti

    The aim of the present work was to study the following aspects of EAS : i) Detection and determination of air showers parameters by measuring the particle densities. ii) Measurement of inclination of shower axis by recording arrival time distribution of shower front particles. iii) Measurement of FWHM of pulses photographed and study of Linsley effect. iv) Characteristics of Cherenkov radiation from air showers. v) Characteristics of low frequency (120 KHz) radio signal from showers. The experiments based on the above investigations were carried out at the Cosmic Ray Research Laboratory, Gauhati University, India, since September 91 to March, 1994. Electromagnetic radiation both optical Cherenkov radiation and radio frequency (120 KHz) as well as pulses associated with extensive air showers (EAS) of energy ranging from 1.5 X 1015ev to 2.1 X 10 18ev and zenith angles 15° < 0 < 60° were selected for the present analysis. The lateral distribution of Cherenkov pulses were assumed to have an exponential form fitted with an exponential law with an exponent reflecting the depth of shower maxima (Xm). The variation of rise time (FWHM) with core distance (R) was studied from pulses photographed. The high field associated with low frequency radio signal (120KHz) and its variation with primary energy (Ep), core distance and zenith angle (0) were observed. The thesis consists of the following five chapters: 1. INTRODUCTION - This chapter contains a brief history of cosmic rays, its composition, development of EAS, emission of electromagnetic radiation from EAS, a brief introduction to the present work including review of the earlier works and aim of the experiment. 2. THEORY - This chapter mainly reviews the theories and numerical calculations. 3. EXPERIMENTAL SET-UP - This chapter describes in detail the instrumentation developed, working principle, calibration etc. 4. DATA COLLECTION AND ANALYSIS - This chapter includes data collection, selection of data for required

  13. Study on the performance of electromagnetic particle detectors of LHAASO-KM2A

    NASA Astrophysics Data System (ADS)

    Zhang, Zhongquan; Hou, Chao; Cao, Zhen; Chang, Jingfan; Feng, Cunfeng; Hanapia, Erlan; Gong, Guanghua; Liu, Jia; Lv, Hongkui; Sheng, Xiangdong; Zhang, Shaoru; Zhu, Chengguang

    2017-02-01

    The electromagnetic particle detectors (EDs) for one square kilometer detector array (KM2A) of large high altitude air shower observation (LHAASO) are designed to measure the densities and arrival times of secondary particles in extensive air showers (EASs). ED is a type of plastic scintillator detector with an active area of 1 m2. This study investigates the design and performance of prototype ED. Approximately 20 photoelectrons are collected by the 1st dynode of a photomultiplier tube (PMT). The prototype ED exhibited good detection efficiency and time resolution. The detection for the wide dynamic particle density varying from 1 to 10 000 particles/m2 is realized with the design of the PMT divider for the readout of both the anode and 6th dynode.

  14. [Experimental research on the electromagnetic radiation immunity of a kind of portable monitor].

    PubMed

    Yuan, Jun; Xiao, Dongping; Jian, Xin

    2010-11-01

    The paper is focused on a kind of portable monitor that is widely used in military hospitals. In order to study the electromagnetic radiation immunity of the monitor, the experiments of electromagnetic radiation caused by radio frequency continuous wave in reverberation chamber and by ultra wide band (UWB) electromagnetic pulse have been done. The study results show that UWB electromagnetic pulse interferes observably the operating state of the monitor. It should be paid high attention to take protective measures. The monitor tested has some electromagnetic immunity ability for radio frequency continuous wave radiation. The frequent abnormal phenomena are baseline drift and waveform distortion. The electromagnetic sensitivity of the monitor is related to the frequency of interference source. The monitor tested is most sensitive to the frequency of 390 MHz.

  15. Electromagnetic induction detector for capillary electrophoresis and its application in pharmaceutical analysis.

    PubMed

    Yang, Xiu-Juan; Chen, Zuan-Guang; Liu, Cui; Li, Ou-Lian

    2010-10-15

    A new electromagnetic induction detector for capillary electrophoresis and its application are described. The detector is consisted of an inductor, a resistor, a high-frequency signal generator and a high-frequency millivoltmeter. The conditions affecting the response of the detector, including dimension of the magnetic ring, position of the capillary, number of coil turns, frequency, excitation voltage and value of the resistor were examined and optimized. The feasibility of the proposed detector was evaluated by detection of inorganic ions and separation of amino aids. Its quantification applicability was investigated by determination of aspirin and paracetamol in pharmaceutical preparation (Akafen powder). The primary factors affecting separation efficiency, which include variety of buffer, buffer concentration, injection time and injection height and separation voltage, were researched. Experimental results demonstrated that this new detector showed a well-defined correlation between sample concentrations and responses (r=0.997-0.999), with detection limits of 30 μmol L(-1) for aspirin and 10 μmol L(-1) for paracetamol, as well as good reproducibility and stability. Compared with currently available detection techniques, this new detector has several advantages, such as simple construction, no complicated elements, ease of assembly and operation, and potential for universal applications. It can be an alternative to the traditional methods in the quality control of the pharmaceutical preparations.

  16. Two-dimensional position sensitive radiation detectors

    DOEpatents

    Mihalczo, J.T.

    1994-02-22

    Nuclear reaction detectors capable of position sensitivity with submillimeter resolution in two dimensions are each provided by placing arrays of scintillation or wavelength shifting optical fibers formed of a plurality of such optical fibers in a side-by-side relationship in X and Y directions with a layer of nuclear reactive material operatively associated with surface regions of the optical fiber arrays. Each nuclear reaction occurring in the layer of nuclear reactive material produces energetic particles for simultaneously providing a light pulse in a single optical fiber in the X oriented array and in a single optical fiber in the Y oriented array. These pulses of light are transmitted to a signal producing circuit for providing signals indicative of the X-Y coordinates of each nuclear event. 6 figures.

  17. Two-dimensional position sensitive radiation detectors

    DOEpatents

    Mihalczo, John T.

    1994-01-01

    Nuclear reaction detectors capable of position sensitivity with submillimeter resolution in two dimensions are each provided by placing arrays of scintillation or wave length shifting optical fibers formed of a plurality of such optical fibers in a side-by-side relationship in X and Y directions with a layer of nuclear reactive material operatively associated with surface regions of the optical fiber arrays. Each nuclear reaction occurring in the layer of nuclear reactive material produces energetic particles for simultaneously providing a light pulse in a single optical fiber in the X oriented array and in a single optical fiber in the Y oriented array. These pulses of light are transmitted to a signal producing circuit for providing signals indicative of the X-Y coordinates of each nuclear event.

  18. Examination results of the Three Mile Island radiation detector HP-R-212

    SciTech Connect

    Mueller, G.M.

    1983-12-01

    Area radiation detector HP-R-212 was removed from the Three Mile Island containment building on November 13, 1981. The detector apparently started to fail during November 1979 and by the first part of December 1979 the detector readings had degraded from 1 R/hr to 20 mR/hr. This report discusses the cause of failure, detector radiation measurement characteristics, and our estimates of the total gamma radiation dose received by the detector electronics.

  19. Examination results of the Three Mile Island radiation detector HP-R-212

    SciTech Connect

    Mueller, G M

    1984-01-01

    Area radiation detector HP-R-212 was removed from the Three Mile Island containment building on November 13, 1981. The detector apparently started to fail during November 1979 and by the first part of December 1979 the detector readings had degraded from 1 R/h to 20 mR/h. This report discusses the cause of ailure, detector radiation measurement characteristics, and our estimates of the total gamma radiation dose received by the detector electronics.

  20. Multi-directional radiation detector using photographic film

    NASA Astrophysics Data System (ADS)

    Junet, L. K.; Majid, Z. A. Abdul; Sapuan, A. H.; Sayed, I. S.; Pauzi, N. F.

    2014-11-01

    Ionising radiation has always been part of our surrounding and people are continuously exposed to it. Ionising radiation is harmful to human health, thus it is vital to monitor the radiation. To monitor radiation, there are three main points that should be observed cautiously, which are energy, quantity, and direction of the radiation sources. A three dimensional (3D) dosimeter is an example of a radiation detector that provide these three main points. This dosimeter is able to record the radiation dose distribution in 3D. Applying the concept of dose detection distribution, study has been done to design a multi-directional radiation detector of different filter thicknesses. This is obtained by designing a cylinder shaped aluminum filter with several layers of different thickness. Black and white photographic material is used as a radiation-sensitive material and a PVC material has been used as the enclosure. The device is then exposed to a radiation source with different exposure factors. For exposure factor 70 kVp, 16 mAs; the results have shown that optical density (OD) value at 135° is 1.86 higher compared with an OD value at 315° which is 0.71 as the 135° area received more radiation compare to 315° region. Furthermore, with an evidence of different angle of film give different value of OD shows that this device has a multidirectional ability. Materials used to develop this device are widely available in the market, thus reducing the cost of development and making it suitable for commercialisation.

  1. Radiation damage effects in Si materials and detectors and rad-hard Si detectors for SLHC

    NASA Astrophysics Data System (ADS)

    Li, Z.

    2009-03-01

    Silicon sensors, widely used in high energy and nuclear physics experiments, suffer severe radiation damage that leads to degradations in sensor performance. These degradations include significant increases in leakage current, bulk resistivity, space charge concentration, and free carrier trapping. For LHC applications, where the total fluence is in the order of 1 × 1015 neq/cm2 for 10 years, the increase in space charge concentration has been the main problem since it can significantly increase the sensor full depletion voltage, causing either breakdown if operated at high biases or charge collection loss if operated at lower biases than full depletion. For LHC Upgrade, or the SLHC, however, whit an increased total fluence up to 1 × 1016 neq/cm2, the main limiting factor for Si detector operation is the severe trapping of free carriers by radiation-induced defect levels. Several new approaches have been developed to make Si detector more radiation hard/tolerant to such ultra-high radiation, including 3D Si detectors, Current-Injected-Diodes (CID) detectors, and Elevated temperature annealing.

  2. Controlling Energy Radiations of Electromagnetic Waves via Frequency Coding Metamaterials

    PubMed Central

    Wu, Haotian; Liu, Shuo; Wan, Xiang; Zhang, Lei; Wang, Dan; Li, Lianlin

    2017-01-01

    Metamaterials are artificial structures composed of subwavelength unit cells to control electromagnetic (EM) waves. The spatial coding representation of metamaterial has the ability to describe the material in a digital way. The spatial coding metamaterials are typically constructed by unit cells that have similar shapes with fixed functionality. Here, the concept of frequency coding metamaterial is proposed, which achieves different controls of EM energy radiations with a fixed spatial coding pattern when the frequency changes. In this case, not only different phase responses of the unit cells are considered, but also different phase sensitivities are also required. Due to different frequency sensitivities of unit cells, two units with the same phase response at the initial frequency may have different phase responses at higher frequency. To describe the frequency coding property of unit cell, digitalized frequency sensitivity is proposed, in which the units are encoded with digits “0” and “1” to represent the low and high phase sensitivities, respectively. By this merit, two degrees of freedom, spatial coding and frequency coding, are obtained to control the EM energy radiations by a new class of frequency‐spatial coding metamaterials. The above concepts and physical phenomena are confirmed by numerical simulations and experiments. PMID:28932671

  3. Controlling Energy Radiations of Electromagnetic Waves via Frequency Coding Metamaterials.

    PubMed

    Wu, Haotian; Liu, Shuo; Wan, Xiang; Zhang, Lei; Wang, Dan; Li, Lianlin; Cui, Tie Jun

    2017-09-01

    Metamaterials are artificial structures composed of subwavelength unit cells to control electromagnetic (EM) waves. The spatial coding representation of metamaterial has the ability to describe the material in a digital way. The spatial coding metamaterials are typically constructed by unit cells that have similar shapes with fixed functionality. Here, the concept of frequency coding metamaterial is proposed, which achieves different controls of EM energy radiations with a fixed spatial coding pattern when the frequency changes. In this case, not only different phase responses of the unit cells are considered, but also different phase sensitivities are also required. Due to different frequency sensitivities of unit cells, two units with the same phase response at the initial frequency may have different phase responses at higher frequency. To describe the frequency coding property of unit cell, digitalized frequency sensitivity is proposed, in which the units are encoded with digits "0" and "1" to represent the low and high phase sensitivities, respectively. By this merit, two degrees of freedom, spatial coding and frequency coding, are obtained to control the EM energy radiations by a new class of frequency-spatial coding metamaterials. The above concepts and physical phenomena are confirmed by numerical simulations and experiments.

  4. Polarization of low-frequency electromagnetic radiation in the lobes of Jupiter's magnetotail

    NASA Technical Reports Server (NTRS)

    Moses, S. L.; Kennel, C. F.; Coroniti, F. V.; Scarf, F. L.; Kurth, W. S.

    1987-01-01

    The plasma wave instruments on the Voyager spacecraft have detected intense electromagnetic radiation within the lobes of Jupiter's magnetic tail down to the lowest frequency of the detector (10 Hz). During a yaw maneuver performed by Voyager 1 in the lobe of the Jovian magnetotail, a modulation appeared in the amplitudes of waves detected in the 10-, 17.8- and 31.1-Hz channels of the plasma wave analyzer, well below the local electron cyclotron frequency of 260 Hz. The lowest amplitudes occurred when the antenna axis was most nearly parallel to the magnetic field. Wave amplitudes in the 56.2-Hz and higher frequency channels remained nearly constant during the maneuver. From the cold-plasma theory of electromagnetic waves, it is concluded that the plasma frequency was between the 56.2- and 31.1-Hz channels where the parallel-polarized component of the spectrum cuts off. This implies a tail-lobe density between 0.000032 and 0.000015/cu cm. The left-hand cutoff frequency would then be below 10 Hz, consistent with either the Z-mode (L, X) or whistlers (R-mode) in the modulated channels.

  5. Polarization of low-frequency electromagnetic radiation in the lobes of Jupiter's magnetotail

    NASA Technical Reports Server (NTRS)

    Moses, S. L.; Kennel, C. F.; Coroniti, F. V.; Scarf, F. L.; Kurth, W. S.

    1987-01-01

    The plasma wave instruments on the Voyager spacecraft have detected intense electromagnetic radiation within the lobes of Jupiter's magnetic tail down to the lowest frequency of the detector (10 Hz). During a yaw maneuver performed by Voyager 1 in the lobe of the Jovian magnetotail, a modulation appeared in the amplitudes of waves detected in the 10-, 17.8- and 31.1-Hz channels of the plasma wave analyzer, well below the local electron cyclotron frequency of 260 Hz. The lowest amplitudes occurred when the antenna axis was most nearly parallel to the magnetic field. Wave amplitudes in the 56.2-Hz and higher frequency channels remained nearly constant during the maneuver. From the cold-plasma theory of electromagnetic waves, it is concluded that the plasma frequency was between the 56.2- and 31.1-Hz channels where the parallel-polarized component of the spectrum cuts off. This implies a tail-lobe density between 0.000032 and 0.000015/cu cm. The left-hand cutoff frequency would then be below 10 Hz, consistent with either the Z-mode (L, X) or whistlers (R-mode) in the modulated channels.

  6. Test of radiation detectors used in homeland security applications.

    PubMed

    Pibida, L; Minniti, R; O'Brien, M; Unterweger, M

    2005-05-01

    This work was performed as part of the National Institute of Standards and Technology (NIST) program to support the development of the new American National Standards Institute (ANSI) standards N42.32-2003 and N42.33-2003 for hand-held detectors, and personal electronic dosimeters, as well as to support the Office of Law Enforcement Standards (OLES) and the Department of Homeland Security (DHS) in testing these types of detectors for their use by first responders. These instruments are required to operate over a photon energy range of 60 keV to 1.33 MeV and over a wide range of air-kerma rates. The performance and response of various radiation detectors, purchased by the NIST, was recorded when placed in 60Co, 137Cs, and x-ray beams at different air-kerma rates. The measurements described in this report were performed at the NIST x-ray and gamma-ray radiation calibration facilities. The instruments' response (exposure or dose rate readings) shows strong energy dependence but almost no dependence to different air-kerma rates. The data here reported provide a benchmark in support of current protocols that are being developed for radiation detection instrumentation used in homeland security applications. A future plan is to test these devices, plus other commercially available detectors, against ANSI standards N42.32-2003 and N42.33-2003.

  7. Device for detachably securing a collimator to a radiation detector

    SciTech Connect

    Hanz, G.J.; Jung, G.; Pflaum, M.

    1986-12-16

    A device is described for detachably securing a collimator to a radiation detector, comprising: (a) a first annular groove means secured to the radiation detector; (b) a second annular groove means secured to the collimator; (c) a split ring having a first and second ring ends, the ring being received in the first annular groove means; and (d) a ring diameter control system, including (d1) a first lever system having two ends; (d2) a second lever system having two ends; and (d3) a rotating hub being rotatably secured to the detector head; wherein the first lever system is rotatably mounted with one end linked to the first ring end and with the other end linked to the rotating hub. The second lever system is rotatably mounted with one end linked to the second ring end and with the other end linked to the rotating hub, such that rotation of the rotating hub moves the first and second lever systems in opposite directions thereby moving the first and second ring ends between a first position, in which the split ring is positioned only in the first annular groove means, and a second position, in which the split ring is located in both the first annular groove means and the second annular groove means, thus attaching the collimator to the radiation detector.

  8. Diamond based detectors for high temperature, high radiation environments

    NASA Astrophysics Data System (ADS)

    Metcalfe, A.; Fern, G. R.; Hobson, P. R.; Smith, D. R.; Lefeuvre, G.; Saenger, R.

    2017-01-01

    Single crystal CVD diamond has many desirable properties as a radiation detector; exceptional radiation hardness and physical hardness, chemical inertness, low Z (close to human tissue, good for dosimetry and transmission mode applications), wide bandgap (high temperature operation with low noise and solar blind), an intrinsic pathway to fast neutron detection through the 12C(n,α)9Be reaction. This combination of radiation hardness, temperature tolerance and ability to detect mixed radiation types with a single sensor makes diamond particularly attractive as a detector material for harsh environments such as nuclear power station monitoring (fission and fusion) and oil well logging. Effective exploitation of these properties requires the development of a metallisation scheme to give contacts that remain stable over extended periods at elevated temperatures (up to 250°C in this instance). Due to the cost of the primary detector material, computational modelling is essential to best utilise the available processing methods for optimising sensor response through geometry and conversion media configurations and to fully interpret experimental data. Monte Carlo simulations of our diamond based sensor have been developed, using MCNP6 and FLUKA2011, assessing the sensor performance in terms of spectral response and overall efficiency as a function of the detector and converter geometry. Sensors with varying metallisation schemes for high temperature operation have been fabricated at Brunel University London and by Micron Semiconductor Limited. These sensors have been tested under a varied set of conditions including irradiation with fast neutrons and alpha particles at high temperatures. The presented study indicates that viable metallisation schemes for high temperature contacts have been successfully developed and the modelling results, supported by preliminary experimental data from partners, indicate that the simulations provide a reasonable representation of

  9. Living Organisms Coupling to Electromagnetic Radiation Below Thermal Noise

    NASA Astrophysics Data System (ADS)

    Stolc, Viktor; Freund, Friedemann

    2013-04-01

    Ultralow frequency (ULF) and extremely low frequency (ELF) electromagnetic (EM) radiation is part of the natural environment. Prior to major earthquakes the local ULF and global ELF radiation field is often markedly perturbed. This has detrimental effects on living organisms. We are studying the mechanism of these effects on the biochemical, cellular and organismal levels. The transfer of electrons along the Electron Transfer Chain (ETC) controls the universal reduction-oxidation reactions that are essential for fundamental biochemical processes in living cells. In order for these processes to work properly, the ETC has to maintain some form of synchronization, or coherence with all biochemical reactions in the living cells, including energy production, RNA transcription, and DNA replication. As a consequence of this synchronization, harmful chemical conflict between the reductive and the oxidative partial reactions can be minimized or avoided. At the same time we note that the synchronization allows for a transfer of energy, coherent or interfering, via coupling to the natural ambient EM field. Extremely weak high frequency EM fields, well below the thermal noise level, tuned in frequency to the electron spins of certain steps in the ETC, have already been shown to cause aberrant cell growth and disorientation among plants and animals with respect to the magnetic and gravity vectors. We investigate EM fields over a much wider frequency range, including ULF known to be generated deep in the Earth prior to major earthquakes locally, and ELF known to be fed by lightning discharges, traveling around the globe in the cavity formed between the Earth's surface and the ionosphere. This ULF/ELF radiation can control the timing of the biochemical redox cycle and thereby have a universal effect on physiology of organisms. The timing can even have a detrimental influence, via increased oxidative damage, on the DNA replication, which controls heredity.

  10. Specific Electromagnetic Effects of Microwave Radiation on Escherichia coli▿

    PubMed Central

    Shamis, Yury; Taube, Alex; Mitik-Dineva, Natasa; Croft, Rodney; Crawford, Russell J.; Ivanova, Elena P.

    2011-01-01

    The present study investigated the effects of microwave (MW) radiation applied under a sublethal temperature on Escherichia coli. The experiments were conducted at a frequency of 18 GHz and at a temperature below 40°C to avoid the thermal degradation of bacterial cells during exposure. The absorbed power was calculated to be 1,500 kW/m3, and the electric field was determined to be 300 V/m. Both values were theoretically confirmed using CST Microwave Studio 3D Electromagnetic Simulation Software. As a negative control, E. coli cells were also thermally heated to temperatures up to 40°C using Peltier plate heating. Scanning electron microscopy (SEM) analysis performed immediately after MW exposure revealed that the E. coli cells exhibited a cell morphology significantly different from that of the negative controls. This MW effect, however, appeared to be temporary, as following a further 10-min elapsed period, the cell morphology appeared to revert to a state that was identical to that of the untreated controls. Confocal laser scanning microscopy (CLSM) revealed that fluorescein isothiocyanate (FITC)-conjugated dextran (150 kDa) was taken up by the MW-treated cells, suggesting that pores had formed within the cell membrane. Cell viability experiments revealed that the MW treatment was not bactericidal, since 88% of the cells were recovered after radiation. It is proposed that one of the effects of exposing E. coli cells to MW radiation under sublethal temperature conditions is that the cell surface undergoes a modification that is electrokinetic in nature, resulting in a reversible MW-induced poration of the cell membrane. PMID:21378041

  11. [Effect of decimeter polarized electromagnetic radiation on germinating capacity of seeds].

    PubMed

    Polevik, N D

    2013-01-01

    The effect of a polarization structure of electromagnetic radiation on the germinating capacity of seeds of such weeds as Green foxtail (Setaria viridis) and Green amaranth (Amaranthus retroflexus) has been studied. Seeds have been exposed to impulse electromagnetic radiation in a frequency of 896 MHz with linear, elliptical right-handed and elliptical left-handed polarizations at different power flux density levels. It is determined that the effect of the right-handed polarized electromagnetic radiation increases and the influence of the left-handed polarized one reduces the germinating capacity of seeds compared to the effect of the linearly polarized electromagnetic radiation. It is shown that the seeds have an amplitude polarization selectivity as evinced by the major effect of the right-handed polarized radiation on seeds. An electrodynamic model as the right-handed elliptically polarized antenna with the given quantity of the ellipticity of polarization is suggested to use in description of this selectivity.

  12. THz electromagnetic radiation driven by intense relativistic electron beam based on ion focus regime

    SciTech Connect

    Zhou, Qing; Xu, Jin; Zhang, Wenchao; Duan, Zhaoyun; Gong, Yubin; Yang, Shengpeng; Tang, Changjian

    2016-06-15

    The simulation study finds that the relativistic electron beam propagating through the plasma background can produce electromagnetic (EM) radiation. With the propagation of the electron beam, the oscillations of the beam electrons in transverse and longitudinal directions have been observed simultaneously, which provides the basis for the electromagnetic radiation. The simulation results clearly show that the electromagnetic radiation frequency can reach up to terahertz (THz) wave band which may result from the filter-like property of plasma background, and the electromagnetic radiation frequency closely depends on the plasma density. To understand the above simulation results physically, the dispersion relation of the beam-plasma system has been derived using the field-matching method, and the dispersion curves show that the slow wave modes can couple with the electron beam effectively in THz wave band, which is an important theoretical evidence of the EM radiation.

  13. Studies of high temperature superconductors as radiation detectors

    NASA Astrophysics Data System (ADS)

    Qiu, A.; Bhattarai, A. R.; Dahlberg, E. D.; Khan, M. Asif; Moloni, K.; van Hove, James M.

    1992-12-01

    Both DyBaCuO (DBCO) and YBaCuO (YBCO) films deposited on a variety of substrates have been investigated for their applicability as detectors of high frequency radiation. Both 10 GHz and infrared radiation (IR) were used as the high frequency radiation source. The measurements consisted of monitoring the temperature dependent resistance of superconducting films both in the presence and absence of radiation. This investigation shows that because the superconducting transition temperature is sensitive to the magnitude of the current in the film, the temperature dependence of the bolometric response is slightly tunable. In addition, effects of radiation on the current voltage characteristics below T superconducting were studied. This study found that films in this regime could also serve as radiation detectors. The substrates used included MgO, SiO, LaAlO(subscript 3), and SrTiO(subscript 3). The results obtained were independent of the substrate except for the width of the resistive transition. Disorder in the films as characterized by the resistive transition, affected the microwave more than the IR response.

  14. SU-E-T-12: Radiation Detector Responses to Applied Homogeneous Transverse and Parallel Magnetic Fields.

    PubMed

    Reynolds, M; Rathee, S; Vidakovic, S; Fallone, B

    2012-06-01

    To determine the relative dose response of a diamond detector and a ion chamber in a clinical photon beam within uniform magnetic fields, endeavoring to evaluate and refine reference dosimetry techniques for use in integrated MR-linac systems. The Monte Carlo code PENELOPE was used to model the structure and materials of the PTW60003 diamond detector and PR06 ion chamber in a 6MV beam in the presence of a homogeneous magnetic field. The magnetic field strength was varied from 0 to 1.5T, and both the parallel and transverse magnetic field orientations with respect to the beam central axis were simulated. The long axes of the detectors were oriented both perpendicular and parallel to the radiation beam direction for each magnetic field orientation. All simulations determined the detectors' signal in air. A small electromagnet was used to experimentally determine the detectors' response in transverse magnetic fields up to 0.2T to validate the simulations. The simulated response of both detectors matched to the experimental data within the estimation error. The relative response of PR06 and diamond detector varied up to ±8.5% (depending on chamber orientation) and >9% respectively with increasing transverse magnetic field strength. In contrast, both detectors were found to be relatively insensitive to the increasing magnetic fields irrespective of the detector orientation in parallel magnetic field. A maximum change of 2% in PR06 response was observed at 1.5T parallel magnetic field and in the parallel orientation of chamber. This work has significant impact on dosimetry protocols for integrated MR-linac systems, where detector response may be altered by the presence of a magnetic field. The need for a magnetic field dependent correction factor is strongly indicated for the transverse magnetic field cases, while such changes in detector response can be largely ignored in parallel magnetic fields < 1T. CIHR (Canadian Institutes of Health Research) - funding support

  15. Novel detector for portal imaging in radiation therapy

    NASA Astrophysics Data System (ADS)

    Ostling, Janina; Wallmark, M.; Brahme, Anders; Danielsson, Mats; Iacobaeus, Christian; Fonte, P.; Peskov, Vladimir N.

    2000-04-01

    We are developing a novel concept for portal imaging that would allow for on-line control and verification of the radiation treatment of cancer patients both at diagnostic and therapeutic energies. This device will consist of two consecutive detectors confided in one gas chamber: a KeV- photon detector, which can visualize the internal soft tissue of the patient, and an MeV-photon detector, which will measure the absolute intensity of the therapeutic beam and its position with respect to the tumor and normal tissues. Both detectors are based on gas and solid photon to electron converters combined with recently invented gas electron multipliers. The device will have a common charge collecting pad-type readout plate equipped with ASIC-based electronics for both detectors. A first simplified prototype device has recently been built and extensively tested. Special efforts were made to find conditions for a safe and reliable operation of the readout electronics that can be damaged by plasma-type discharge effects induced specially at high dose rates. Results obtained so far indicate that our new detector concept may satisfy all requirements on advanced therapy beam monitoring systems.

  16. Influence of electromagnetic radiation produced by mobile phone on some biophysical blood properties in rats.

    PubMed

    El-Bediwi, Abu Bakr; Saad, Mohamed; El-kott, Attall F; Eid, Eman

    2013-04-01

    Effects of electromagnetic radiation produced by mobile phone on blood viscosity, plasma viscosity, hemolysis, Osmotic fragility, and blood components of rats have been investigated. Experimental results show that there are significant change on blood components and its viscosity which affects on a blood circulation due to many body problems. Red blood cells, White blood cells, and Platelets are broken after exposure to electromagnetic radiation produced by mobile phone. Also blood viscosity and plasma viscosity values are increased but Osmotic fragility value decreased after exposure to electromagnetic radiation produced by mobile phone.

  17. Variable-Temperature Cryostat For Radiation-Damage Testing Of Germanium Detectors

    NASA Technical Reports Server (NTRS)

    Floyd, Samuel R.; Puc, Bernard P.

    1992-01-01

    Variable-temperature cryostats developed to study radiation damage to, and annealing of, germanium gamma-ray detectors. Two styles: one accommodates large single detector and one accommodates two medium-sized detectors. New cryostats allow complete testing of large-volume germanium gamma-ray detectors without breaking cryostat vacuum and removing detectors for annealing.

  18. Spin-down of Pulsars, and Their Electromagnetic and Gravitational Wave Radiations

    NASA Astrophysics Data System (ADS)

    Yue-zhu, Zhang; Yan-yan, Fu; Yi-huan, Wei; Cheng-min, Zhang; Shao-hua, Yu; Yuan-yue, Pan; Yuan-qi, Guo; De-hua, Wang

    2016-04-01

    Pulsars posses extremely strong magnetic fields, and their magnetic axis does not coincide with their rotation axis, this causes the pulsars to emit electromagnetic radiations. Pulsars rely on their rotational energy to compensate for the energy loss caused by the electromagnetic radiation, which leads to the gradually decelerated spin of pulsars. According to the theoretical deduction, we have calculated the initial period of the Crab Nebula pulsar, and derived the period evolution of the pulsar at any time in the future under the effect of the electromagnetic radiation. Considered the possible existence of quadrupole moment in the mass distribution of a pulsar, the gravitational wave radiation will also make the pulsar spin down, hence the variation of spin period of the Crab pulsar under the effect of gravitational wave radiation is further analyzed. Finally, combining the two kinds of radiation mechanisms, the evolution of spin period of the Crab pulsar under the joint action of these two kinds of radiation mechanisms is analyzed.

  19. Multipurpose High Sensitivity Radiation Detector: Terradex

    NASA Astrophysics Data System (ADS)

    Alpat, Behcet; Aisa, Damiano; Bizzarri, Marco; Blasko, Sandor; Esposito, Gennaro; Farnesini, Lucio; Fiori, Emmanuel; Papi, Andrea; Postolache, Vasile; Renzi, Francesca; Ionica, Romeo; Manolescu, Florentina; Ozkorucuklu, Suat; Denizli, Haluk; Tapan, Ilhan; Pilicer, Ercan; Egidi, Felice; Moretti, Cesare; Dicola, Luca

    2007-05-01

    Terradex project aims to realise an accurate and programmable multiparametric tool which will measure relevant physical quantities such as observation time, energy and type of all decay products of three naturally occurring decay chains of uranium and thorium series present in nature as well as the decay products of man-made radioactivity. The measurements described in this work are based on the performance tests of the first version of an instrument that is designed to provide high counting accuracy, by introducing self-triggering, delayed time-coincidence technique, of products of a given decay chain. In order to qualify the technique and to calibrate the Terradex, a 222Rn source is used. The continuous and accurate monitoring of radon concentration in air is realised by observing the alpha and beta particles produced by the decay of 222Rn and its daughters and tag each of them with a precise occurrence time. The validity of delayed coincident technique by using the state of the art electronics with application of novel data sampling and analysis methods are discussed. The flexibility of sampling protocols and the advantages of online calibration capability to achieve the highest level of precision in natural and man-made radiation measurements are also described.

  20. Scattering of electromagnetic radiation by a multilayered sphere

    NASA Astrophysics Data System (ADS)

    Peña, O.; Pal, U.

    2009-11-01

    The computer implementation of the algorithm for the calculation of electromagnetic radiation scattering by a multilayered sphere developed by Yang, is presented. It has been shown that the program is effective, resulting in very accurate values of scattering efficiencies for a wide range of size parameters, which is a considerable improvement over previous implementations of similar algorithms. The program, named scattnlay, would be the first of its kind to be publicly available. Catalogue identifier: AEEY_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEY_1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Gnu General Public License (GPL) No. of lines in distributed program, including test data, etc.: 8932 No. of bytes in distributed program, including test data, etc.: 175 276 Distribution format: tar.gz Programming language: ANSI C Computer: Any with a C compiler Operating system: Linux (any), Windows, Solaris RAM: ∼1-100 MB Classification: 1.3 Nature of problem: The scattering of electromagnetic (EM) radiation by a multilayered sphere is an interesting phenomenon to study for the application of such materials in several fields. Just to mention two examples, metal nanoshells (a dielectric core surrounded by a metallic shell) are a class of nanoparticles with tunable optical resonances that can be used, among others, in medicine for optical imaging and photothermal cancer therapy; while in the field of atmospheric sciences, light absorption by aerosols has a heating effect in the atmosphere that is of great interest to study several climatic effects. Although at first glance the expressions of the scattering coefficients seem simple and straightforward to implement, they involve several numerical difficulties which make most of

  1. Radiation hardness and precision timing study of silicon detectors for the CMS High Granularity Calorimeter (HGC)

    NASA Astrophysics Data System (ADS)

    Currás, Esteban; Fernández, Marcos; Gallrapp, Christian; Gray, Lindsey; Mannelli, Marcello; Meridiani, Paolo; Moll, Michael; Nourbakhsh, Shervin; Scharf, Christian; Silva, Pedro; Steinbrueck, Georg; Fatis, Tommaso Tabarelli de; Vila, Iván

    2017-02-01

    The high luminosity upgraded LHC or Phase-II is expected to increase the instantaneous luminosity by a factor of 10 beyond the LHC's design value, expecting to deliver 250 fb-1 per year for a further 10 years of operation. Under these conditions the performance degradation due to integrated radiation dose will need to be addressed. The CMS collaboration is planning to upgrade the forward calorimeters. The replacement is called the High Granularity Calorimeter (HGC) and it will be realized as a sampling calorimeter with layers of silicon detectors interleaved. The sensors will be realized as pad detectors with sizes of less that ∼1.0 cm2 and an active thickness between 100 and 300 μm depending on the position, respectively, the expected radiation levels. For an integrated luminosity of 3000 fb-1, the electromagnetic calorimetry will sustain integrated doses of 1.5 MGy (150 Mrads) and neutron fluences up to 1016 neq/cm2. A radiation tolerance study after neutron irradiation of 300, 200, and 100 μm n-on-p and p-on-n silicon pads irradiated to fluences up to 1.6×1016 neq/cm2 is presented. The properties of these diodes studied before and after irradiation were leakage current, capacitance, charge collection efficiency, annealing effects and timing capability. The results of these measurements validate these sensors as candidates for the HGC system.

  2. Time and energy reconstruction at the electromagnetic calorimeter of the Belle-II detector

    NASA Astrophysics Data System (ADS)

    Aulchenko, V.; Bobrov, A.; Ferber, T.; Kuzmin, A.; Miyabayshi, K.; de Nardo, G.; Shebalin, V.; Sibidanov, A.; Usov, Yu.; Zhulanov, V.

    2017-08-01

    The Belle-II electromagnetic calorimeter inherited crystals and front-end electronics from the Belle detector, however the readout electronics was essentially modified. New electronics provides continuous digitization of the shaped signal followed by the signal wave form analysis with the further reconstruction of both, amplitude and time of the signal. The time information allows one to suppress background essentially. The algorithm, which is implemented in FPGA, is properly simulated. We implemented this algorithm to the simulation software and studied it with the MC background data. The procedure for the calibration of the response function has been developed and tested with the barrel counters using cosmic-ray data.

  3. Charge transport properties of CdMnTe radiation detectors

    SciTech Connect

    Kim K.; Rafiel, R.; Boardman, M.; Reinhard, I.; Sarbutt, A.; Watt, G.; Watt, C.; Uxa, S.; Prokopovich, D.A.; Belas, E.; Bolotnikov, A.E.; James, R.B.

    2012-04-11

    Growth, fabrication and characterization of indium-doped cadmium manganese telluride (CdMnTe)radiation detectors have been described. Alpha-particle spectroscopy measurements and time resolved current transient measurements have yielded an average charge collection efficiency approaching 100 %. Spatially resolved charge collection efficiency maps have been produced for a range of detector bias voltages. Inhomogeneities in the charge transport of the CdMnTe crystals have been associated with chains of tellurium inclusions within the detector bulk. Further, it has been shown that the role of tellurium inclusions in degrading chargecollection is reduced with increasing values of bias voltage. The electron transit time was determined from time of flight measurements. From the dependence of drift velocity on applied electric field the electron mobility was found to be n = (718 55) cm2/Vs at room temperature.

  4. Super-thin single crystal diamond membrane radiation detectors

    SciTech Connect

    Pomorski, Michal; Caylar, Benoit; Bergonzo, Philippe

    2013-09-09

    We propose to use the non-electronic grade (nitrogen content 5 ppb < [N] < 5 ppm) single crystal (sc) chemical vapour deposited (CVD) diamond as a thin-membrane radiation detector. Using deep Ar/O{sub 2} plasma etching it is possible to produce self-supported few micrometres thick scCVD membranes of a size approaching 7 mm × 7 mm, with a very good surface quality. After metallization and contacting, electrical properties of diamond membrane detectors were probed with 5.486 MeV α-particles as an ionization source. Despite nitrogen impurity, scCVD membrane detectors exhibit stable operation, charge collection efficiency close to 100%, with homogenous response, and extraordinary dielectric strength up to 30 V/μm.

  5. Cadmium selenide: a promising novel room temperature radiation detector

    SciTech Connect

    Burger, A.; Schieber, M.; Shilo, I.

    1983-02-01

    Large single crystals of CdSe weighing about 30g were grown by the vertical unseeded vapor growth technique at a linear growth rate of 5mm/day and a temperature gradient of 10/sup 0/C/cm. Crystal perfection and homogeneity were evaluated by Laue X-ray diffraction, etch pit density, SEM and microprobe analysis methods. The dark resistivity of the as-grown and the heat treated crystal was about 1..cap omega..cm and 10/sup 12/..cap omega..cm respectively. Slices were used to fabricate room temperature detectors for nuclear radiation energy. The detectors showed high efficiency and stability as a function of time for radiation sources from 10KeV to 660KeV.

  6. Modeling radiation loads to detectors in a SNAP mission

    SciTech Connect

    Nikolai V. Mokhov et al.

    2004-05-12

    In order to investigate degradation of optical detectors of the Supernova Acceleration Project (SNAP) space mission due to irradiation, a three-dimensional model of the satellite has been developed. Realistic radiation environment at the satellite orbit, including both galactic and trapped in radiation belts cosmic rays, has been taken into account. The modeling has been performed with the MARS14 Monte Carlo code. In a current design, the main contribution to dose accumulated in the photodetectors is shown to be due to trapped protons. A contribution of primary {alpha}-particles is estimated. Predicted performance degradation for the photo-detector for a 4-year space mission is 40% and can be reduced further by means of shielding optimization.

  7. The transition radiation detector of the PAMELA space mission

    NASA Astrophysics Data System (ADS)

    Ambriola, M.; Bellotti, R.; Cafagna, F.; Circella, M.; de Marzo, C.; Giglietto, N.; Marangelli, B.; Mirizzi, N.; Romita, M.; Spinelli, P.

    2004-04-01

    PAMELA space mission objective is to flight a satellite-borne magnetic spectrometer built to fulfill the primary scientific goals of detecting antiparticles (antiprotons and positrons) and to measure spectra of particles in cosmic rays. The PAMELA telescope is composed of: a silicon tracker housed in a permanent magnet, a time-of-flight and an anticoincidence system both made of plastic scintillators, a silicon imaging calorimeter, a neutron detector and a Transition Radiation Detector (TRD). The TRD is composed of nine sensitive layers of straw tubes working in proportional mode for a total of 1024 channels. Each layer is interleaved with a radiator plane made of carbon fibers. The TRD characteristics will be described along with its performances studied at both CERN-PS and CERN-SPS facilities, using electrons, pions, muons and protons of different momenta.

  8. Synchrotron radiation computed laminography using an inclined detector.

    PubMed

    Zhang, Jie; Li, Gang; Yi, Qiru; Chen, Yu; Gao, Zhenhua; Jiang, Xiaoming

    2015-01-01

    Synchrotron radiation computed laminography (SR-CL) has been in use in three-dimensional non-destructive imaging of flat objects for several years. A new set-up is proposed based on the traditional SR-CL method but with the detector inclined at the same angle as the sample inclination to collect projections. The results of computer simulations and real-sample experiments demonstrate that reconstructions acquired using an inclined detector are of better quality compared with those acquired using ordinary detecting methods, especially for the situation of few projections and small difference of attenuation ratio of the sample. This method could be applied to obtain high-quality images of weak-contrast samples with short measurement time and mild radiation damage.

  9. Modelling radiation loads to detectors in a SNAP mission.

    PubMed

    Mokhov, N V; Rakhno, I L; Striganov, S I; Peterson, T J

    2005-01-01

    In order to investigate the degradation of optical detectors of the Supernova Acceleration Project (SNAP) space mission because of irradiation, a three-dimensional model of the satellite has been developed. A realistic radiation environment at the satellite orbit, including both galactic cosmic rays and cosmic ray trapped in radiation belts, has been taken into account. The modelling has been performed with the MARS14 Monte Carlo code. In a current design, the main contribution to dose accumulated in the photo-detectors is shown to be due to trapped protons. The contribution of primary alpha particles is estimated. Predicted performance degradation for the photodetector for a four-year space mission is 40% and this can be reduced further by means of shielding optimisation.

  10. Radiation Tolerance of Aluminum Microwave Kinetic Inductance Detector

    NASA Astrophysics Data System (ADS)

    Karatsu, K.; Dominjon, A.; Fujino, T.; Funaki, T.; Hazumi, M.; Irie, F.; Ishino, H.; Kida, Y.; Matsumura, T.; Mizukami, K.; Naruse, M.; Nitta, T.; Noguchi, T.; Oka, N.; Sekiguchi, S.; Sekimoto, Y.; Sekine, M.; Shu, S.; Yamada, Y.; Yamashita, T.

    2016-08-01

    Microwave kinetic inductance detector (MKID) is one of the candidates of focal plane detector for future satellite missions such as LiteBIRD. For the space use of MKIDs, the radiation tolerance is one of the challenges to be characterized prior to the launch. Aluminum (Al) MKIDs with 50 nm thickness on silicon substrate and on sapphire substrate were irradiated with a proton beam of 160 MeV at the heavy ion medical accelerator in Chiba. The total water-equivalent absorbed dose was ˜ 10 krad which should simulate the worst radiation absorption of 5 years observation at the Lagrange point L2. We measured characteristics of these MKIDs before and after the irradiation. We found no significant changes on resonator quality factor, responsivity, and recombination time of quasi-particles. The change on electrical noise equivalent power was also evaluated, and no significant increase was found at the noise level of O(10^{-18}) W/√{ Hz }.

  11. Experiences with radiation portal detectors for international rail transport

    SciTech Connect

    Stromswold, David C.; McCormick, Kathleen R.; Todd, Lindsay C.; Ashbaker, Eric D.; Evans, J. C.

    2006-08-30

    Radiation detectors monitored trains at two international borders to evaluate the performance of NaI(Tl) and plastic (polyvinyltoluene: PVT) gamma-ray detectors to characterize rail cargo. The detectors included a prototype NaI(Tl) radiation-portal-monitor panel having four large detectors (10-cm × 10-cm × 41-cm) and a PVT panel with a 41 cm × 173 cm × 3.8-cm detector. Spectral data from the NaI(Tl) and PVT detectors were recorded. Of particular emphasis was the identification of naturally occurring radioactive material (NORM) and the resultant frequency of nuisance alarms. For rail monitoring, the difficulty in stopping trains to perform secondary inspection on alarming cars creates a need for reliable identification of NORM during initial screening. Approximately 30 trains were monitored, and the commodities in individual railcars were ascertained from manifest information. At one test site the trains carried inter-modal containers that had been unloaded from ships, and at the other site the trains contained bulk cargo or individual items in boxcars or flatbeds. NORM encountered included potash, liquefied petroleum gas, fireworks, televisions, and clay-based products (e.g., pottery). Analysis of the spectral data included the use of the template-fitting program GADRAS/FitToDB from Sandia National Laboratories. For much of the NORM the NaI(Tl) data produced a correct identification of the radionuclides present in the railcars. The same analysis was also used for PVT data in which the spectral information (no peaks but only gradual spectral changes including Compton edges) was limited. However, the PVT analysis provided correct identification of 40K and 226Ra in many cases.

  12. Experiences with radiation portal detectors for international rail transport

    NASA Astrophysics Data System (ADS)

    Stromswold, D. C.; McCormick, K.; Todd, L.; Ashbaker, E. D.; Evans, J. C.

    2006-08-01

    Radiation detectors monitored trains at two international borders to evaluate the performance of NaI(Tl) and plastic (polyvinyltoluene: PVT) gamma-ray detectors to characterize rail cargo. The detectors included a prototype NaI(Tl) radiation-portal-monitor panel having four large detectors (10-cm × 10-cm × 41-cm) and a PVT panel with a 41 cm × 173 cm × 3.8-cm detector. Spectral data from the NaI(Tl) and PVT detectors were recorded. Of particular emphasis was the identification of naturally occurring radioactive material (NORM) and the resultant frequency of nuisance alarms. For rail monitoring, the difficulty in stopping trains to perform secondary inspection on alarming cars creates a need for reliable identification of NORM during initial screening. Approximately 30 trains were monitored, and the commodities in individual railcars were ascertained from manifest information. At one test site, the trains carried inter-modal containers that had been unloaded from ships, and at the other site, the trains contained bulk cargo in tanker cars and hopper cars or individual items in boxcars or flatbeds. NORM encountered included potash, liquefied petroleum gas, fireworks, televisions, and clay-based products (e.g., pottery). Analysis of the spectral data included the use of the template-fitting portion of the program GADRAS developed at Sandia National Laboratories. For most of the NORM, the NaI(Tl) data produced a correct identification of the radionuclides present in the railcars. The same analysis was also used for PVT data in which the spectral information (no peaks but only gradual spectral changes including Compton edges) was limited. However, the PVT analysis provided correct identification of 40K and 226Ra in many cases.

  13. New electronics of the spectrometric channel for the SND detector electromagnetic calorimeter

    NASA Astrophysics Data System (ADS)

    Achasov, M. N.; Aulchenko, V. M.; Bogdanchikov, A. G.; Druzhinin, V. P.; Golubev, V. B.; Korol, A. A.; Koshuba, S. V.; Kovrizhin, D. P.; Serednyakov, S. I.; Surin, I. K.; Tekut`ev, A. I.; Usov, Yu. V.

    2016-07-01

    The Spherical Neutral Detector (SND) is intended for study of electron-positron annihilation at the VEPP-2000 e+e- collider (BINP, Novosibirsk) in the center-of-mass energy region below 2 GeV. The main part of the detector is a three-layer electromagnetic calorimeter based on NaI(Tl) crystals. The physics program of the SND experiment includes a high statistics study of neutron-antineutron production near threshold, for which time measurements in the calorimeter are required. In this paper we describe new shaping and digitizing calorimeter electronics, which allow to reach a time resolution of about 1 ns for 100 MeV signal and an amplitude resolution of about 250 keV.

  14. Study of Electromagnetic Interactions with the MicroBooNE Detector

    NASA Astrophysics Data System (ADS)

    Caratelli, David; MicroBooNE Collaboration

    2017-01-01

    MicroBooNE is an experiment which employs the Liquid Argon Time Projection Chamber (LArTPC) detector technology to study neutrinos produced with the Fermilab Booster Neutrino Beam. As for any accelerator-based detector interested in studying neutrino oscillations, it is essential to be able to identify and reconstruct the kinematic properties of electrons and photons produced in μν and νe interactions. We report current progress in reconstructing electron and photon electromagnetic (EM) showers using data from the MicroBooNE LArTPC. These studies cover EM showers in the tens to hundreds of MeV energy range; they lay the foundation for MicroBooNE's investigation of the excess of low-energy EM events reported by MiniBooNE, and are of interest to the wider LArTPC neutrino community.

  15. A precision synchrotron radiation detector using phosphorescent screens

    SciTech Connect

    Jung, C.K.; Lateur, M.; Nash, J.; Tinsman, J. ); Butler, J. ); Wormser, G. . Lab. de l'Accelerateur Lineaire); Levi, M.; Rouse, F. )

    1990-01-01

    A precision detector to measure synchrotron radiation beam positions has been designed and installed as part of beam energy spectrometers at the Stanford Linear Collider (SLC). The distance between pairs of synchrotron radiation beams is measured absolutely to better than 28 {mu}m on a pulse-to-pulse basis. This contributes less than 5 MeV to the error in the measurement of SLC beam energies (approximately 50 GeV). A system of high-resolution video cameras viewing precisely aligned fiducial wire arrays overlaying phosphorescent screens has achieved this accuracy. 3 refs., 5 figs., 1 tab.

  16. Calibration of the active radiation detector for Spacelab-One

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The flight models of the active radiation detector (ARD) for the ENV-01 environmental monitor were calibrated using gamma radiation. Measured sensitivities of the ion chambers were 6.1 + or - 0.3 micron rad per count for ARD S/N1, and 10.4 + or - 0.5 micron rad per count for ARD S/N2. Both were linear over the measured range 0.10 to 500 m/rad hour. The particle counters (proportional counters) were set to respond to approximately 85% of minimum ionizing particles of unit charge passing through them. These counters were also calibrated in the gamma field.

  17. The electromagnetic radiation from semiconductor minerals in orebody

    NASA Astrophysics Data System (ADS)

    Ozawa, M.; Nagahama, H.; Muto, J.; Nagase, T.

    2013-12-01

    In complex ore deposits composing semiconductor minerals, electromagnetic radiation in the radio frequency (30 kHz ~ 3 MHz) is induced by propagation of elastic waves [1]. Semiconductor minerals are divided into n- or p-type. When each p-type and n-type is joined, the resulting junction (p-n junction) has the rectifying property. Many natural orebodies show this property, but it has not been evaluated qualitatively. A lot of p-n junctions exist as which connect in parallel and in series in the orebody [2]. They can be regarded as a single p-n junction at large scale. Hence elucidating the electric property of micro p-n junction is required to understand the semiconductor properties of orebody. To discuss the electromagnetic emission from semiconductor minerals in the orebody associated with tectonic process, we measure the electric property of the semiconductor pyrite. Composition and electric properties of natural semiconductor minerals are heterogeneous due to the presence of impurities and defects. Therefore, it is needed to clarify the properties at each microscopic region. In this research, we apply electroetching method and SEM analysis to acquire composition characteristics and use an indentation probe to reveal microscopic electric properties. Sample of pyrite is from Waga-Sennin mine, Akita prefecture, Japan. The area of cross section is 1.4 cm2 with thickness of 0.38 mm2. In the electrolytic etching, the surface of samples showed etching figures and zonal structures with widths of about 10 -100 μm. According to the SEM analysis, Pb inclusions were observed to be precipitated parallel to crystallographic planes. The heterogeneous change in electric properties of each area was observed to be as etching figure. Thermal probing method clarified that the regions of n-p type differences were also coincidence well to etching figure patterns. P-type regions showed a higher solubility than n-type regions. At p-n junction regions, rectifying property was observed

  18. The effects of radiofrequency electromagnetic radiation on sperm function.

    PubMed

    Houston, B J; Nixon, B; King, B V; De Iuliis, G N; Aitken, R J

    2016-12-01

    Mobile phone usage has become an integral part of our lives. However, the effects of the radiofrequency electromagnetic radiation (RF-EMR) emitted by these devices on biological systems and specifically the reproductive systems are currently under active debate. A fundamental hindrance to the current debate is that there is no clear mechanism of how such non-ionising radiation influences biological systems. Therefore, we explored the documented impacts of RF-EMR on the male reproductive system and considered any common observations that could provide insights on a potential mechanism. Among a total of 27 studies investigating the effects of RF-EMR on the male reproductive system, negative consequences of exposure were reported in 21. Within these 21 studies, 11 of the 15 that investigated sperm motility reported significant declines, 7 of 7 that measured the production of reactive oxygen species (ROS) documented elevated levels and 4 of 5 studies that probed for DNA damage highlighted increased damage due to RF-EMR exposure. Associated with this, RF-EMR treatment reduced the antioxidant levels in 6 of 6 studies that discussed this phenomenon, whereas consequences of RF-EMR were successfully ameliorated with the supplementation of antioxidants in all 3 studies that carried out these experiments. In light of this, we envisage a two-step mechanism whereby RF-EMR is able to induce mitochondrial dysfunction leading to elevated ROS production. A continued focus on research, which aims to shed light on the biological effects of RF-EMR will allow us to test and assess this proposed mechanism in a variety of cell types.

  19. Channeling and electromagnetic radiation of relativistic charged particles in metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Zhevago, N. K.; Glebov, V. I.

    2017-06-01

    We have developed the theory of electromagnetic interaction of relativistic charged particles with metal-organic frameworks (MOFs). The electrostatic potential and electron number density distribution in MOFs were calculated using the most accurate data for the atomic form factors. Peculiarities of axial channeling of fast charged particles and various types of electromagnetic radiation from relativistic particles has been discussed.

  20. Electromagnetic noise studies in a silicon strip detector, used as part of a luminosity monitor at LEP

    NASA Astrophysics Data System (ADS)

    Ødegaard, Trygve; Tafjord, Harald; Buran, Torleiv

    1995-02-01

    As part of the luminosity monitor, SAT, in the DELPHI [1] experiment at CERN's Large Electron Positron collider, a tracking detector constructed from silicon strip detector elements was installed in front of an electromagnetic calorimeter. The luminosity was measured by counting the number of Bhabha events at the interaction point of the electron and the positron beans. The tracking detector reconstructs from the interaction point and the calorimeter measures the corresponding particles' energies. The SAT Tracker [2] consists of 504 silicon strip detectors. The strips are DC-coupled to CMOS VLSI-chips, baptized Balder [3,4]. The chip performs amplification, zero-suppression, digitalisation, and multiplexing. The requirements of good space resolution and high efficiency put strong requirements on noise control. A short description of the geometry and the relevant circuit layout is given. We describe the efforts made to minimise the electromagnetic noise in the detector and present some numbers of the noise level using various techniques.

  1. Proposal to reduce the carcinogenic character of electromagnetic radiation (EMR)

    NASA Astrophysics Data System (ADS)

    Lundquist, Marjorie

    2011-03-01

    Non-ionizing electromagnetic radiation (NIEMR) interacts with matter in 3 ways: it can transfer energy, linear momentum, and angular momentum to matter. At high frequencies (e.g., microwaves), evidence exists of a carcinogenic effect on living creatures irradiated with NIEMR. Which effect is carcinogenic? NIEMR heats matter by transfer of energy; this effect is used to kill established cancers. Transfer of linear momentum to matter merely alters the local pressure; cancer has never been associated with pressure changes. So the transfer of non-zero angular momentum to matter is the interaction most likely to be carcinogenic. EMR polarization can be circular, elliptical, or plane. Only plane-polarized EMR possesses zero angular momentum and therefore cannot transfer any angular momentum to matter. Everything that is true of NIEMR is also true of ionizing EMR, so it seems likely that the carcinogenic potential of all EMR (whether ionizing or non-ionizing) will be minimized by filtering it or taking other steps to make it plane-polarized before using it to irradiate a person or animal. Obvious applications are medical/dental X-rays and the full body scanners used on travelers at airports. M. Lundquist, BAPS 51(1):518 (2006).

  2. Cardiovascular risk in operators under radiofrequency electromagnetic radiation.

    PubMed

    Vangelova, Katia; Deyanov, Christo; Israel, Mishel

    2006-03-01

    The aim of the study was to assess the long-term effects of radiofrequency electromagnetic radiation (EMR) on the cardiovascular system. Two groups of exposed operators (49 broadcasting (BC) station and 61 TV station operators) and a control group of 110 radiorelay station operators, matched by sex and age, with similar job characteristics except for the radiofrequency EMR were studied. The EMR exposure was assessed and the time-weighted average (TWA) was calculated. The cardiovascular risk factors arterial pressure, lipid profile, body mass index, waist/hip ratio, smoking, and family history of cardiovascular disease were followed. The systolic and diastolic blood pressure (SBP and DBP), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were significantly higher in the two exposed groups. It was found that the radiofrequency EMR exposure was associated with greater chance of becoming hypertensive and dyslipidemic. The stepwise multiple regression equations showed that the SBP and TWA predicted the high TC and high LDL-C, while the TC, age and abdominal obesity were predictors for high SBP and DBP. In conclusion, our data show that the radiofrequency EMR contributes to adverse effects on the cardiovascular system.

  3. Rock Burst Monitoring by Integrated Microseismic and Electromagnetic Radiation Methods

    NASA Astrophysics Data System (ADS)

    Li, Xuelong; Wang, Enyuan; Li, Zhonghui; Liu, Zhentang; Song, Dazhao; Qiu, Liming

    2016-11-01

    For this study, microseismic (MS) and electromagnetic radiation (EMR) monitoring systems were installed in a coal mine to monitor rock bursts. The MS system monitors coal or rock mass ruptures in the whole mine, whereas the EMR equipment monitors the coal or rock stress in a small area. By analysing the MS energy, number of MS events, and EMR intensity with respect to rock bursts, it has been shown that the energy and number of MS events present a "quiet period" 1-3 days before the rock burst. The data also show that the EMR intensity reaches a peak before the rock burst and this EMR intensity peak generally corresponds to the MS "quiet period". There is a positive correlation between stress and EMR intensity. Buckling failure of coal or rock depends on the rheological properties and occurs after the peak stress in the high-stress concentration areas in deep mines. The MS "quiet period" before the rock burst is caused by the heterogeneity of the coal and rock structures, the transfer of high stress into internal areas, locked patches, and self-organized criticality near the stress peak. This study increases our understanding of coal and rock instability in deep mines. Combining MS and EMR to monitor rock burst could improve prediction accuracy.

  4. Simple classical model for Fano statistics in radiation detectors

    NASA Astrophysics Data System (ADS)

    Jordan, David V.; Renholds, Andrea S.; Jaffe, John E.; Anderson, Kevin K.; René Corrales, L.; Peurrung, Anthony J.

    2008-02-01

    A simple classical model that captures the essential statistics of energy partitioning processes involved in the creation of information carriers (ICs) in radiation detectors is presented. The model pictures IC formation from a fixed amount of deposited energy in terms of the statistically analogous process of successively sampling water from a large, finite-volume container ("bathtub") with a small dipping implement ("shot or whiskey glass"). The model exhibits sub-Poisson variance in the distribution of the number of ICs generated (the "Fano effect"). Elementary statistical analysis of the model clarifies the role of energy conservation in producing the Fano effect and yields Fano's prescription for computing the relative variance of the IC number distribution in terms of the mean and variance of the underlying, single-IC energy distribution. The partitioning model is applied to the development of the impact ionization cascade in semiconductor radiation detectors. It is shown that, in tandem with simple assumptions regarding the distribution of energies required to create an (electron, hole) pair, the model yields an energy-independent Fano factor of 0.083, in accord with the lower end of the range of literature values reported for silicon and high-purity germanium. The utility of this simple picture as a diagnostic tool for guiding or constraining more detailed, "microscopic" physical models of detector material response to ionizing radiation is discussed.

  5. Radiation monitoring of the GEM muon detectors at CMS

    NASA Astrophysics Data System (ADS)

    Dimitrov, L.; Iaydjiev, P.; Mitev, G.; Vankov, I.

    2016-09-01

    The higher energy and luminosity of future High Luminosity (HL) LHC, determines a significant increasing of the radiation background around the CMS subdetectors, and especially in the higher pseudorapidity region. Under such heavy conditions, the RPC (used in muon trigger) most probably could not operate effectively. GEM (Gas Electron Multiplier) detectors have been identified as a suitable technology to operate in the high radiation environment in that region and test at CMS will start in 2016. A monitoring system to control the absorbed radiation dose by the GEM under test is developed. Two types of sensors are used in it: RadFETs for total absorbed dose and p-i-n diodes for particle (proton and neutron) detection. The basic detector unit, called RADMON, contains two sensors of each type and can be installed at each GEM detector. The system has a modular structure, permitting to increase easily the number of controlled RADMONs: one module controls up to 12 RADMONs, organized in three group of four and communicates outside by RS 485 and CANBUS interfaces.

  6. Gauge Invariant Formulation of the Interaction of Electromagnetic Radiation and Matter

    ERIC Educational Resources Information Center

    Kobe, Donald H.; Smirl, Arthur L.

    1978-01-01

    Presents a discussion in Perturbation theory in quantum mechanics for the interaction of electromagnetic radiation with matter. Advocates the use of electric dipole interaction whenever it can be used as compared to the vector potential interaction. (GA)

  7. Gauge Invariant Formulation of the Interaction of Electromagnetic Radiation and Matter

    ERIC Educational Resources Information Center

    Kobe, Donald H.; Smirl, Arthur L.

    1978-01-01

    Presents a discussion in Perturbation theory in quantum mechanics for the interaction of electromagnetic radiation with matter. Advocates the use of electric dipole interaction whenever it can be used as compared to the vector potential interaction. (GA)

  8. Features of electromagnetic radiation time-and-frequency fluctuation intensity distributions from human brain structures.

    PubMed

    Kublanov, V S; Gasilov, V L; Kazakov, Y E

    2000-01-01

    Time-and-frequency fluctuation intensity distributions' analysis is made of the electromagnetic radiation obtained from deep human brain structures. The role of monitoring the distribution changes due to various cerebral circulation disorders is explained.

  9. Radiation Testing of IR Detectors for WFC3

    NASA Astrophysics Data System (ADS)

    Hill, R. J.; Waczynski, A.; Johnson, S. D.; Marshall, P.; Marshall, C.; Foltz, R.; Kimble, R. A.

    2005-12-01

    The near-IR channel of Wide Field Camera 3, an instrument being developed for installation onto the Hubble Space Telescope, employs a Rockwell Scientific Company 1K x 1K HgCdTe detector array hybridized to a Hawaii-1R multiplexer. Radiation testing of test detectors showed that the WFC3 detectors do not exhibit a post-SAA glow of the sort seen in the NICMOS detectors. However, an anomalously high background was observed during the irradiation in the proton beam. This background goes away promptly when the beam is turned off. Subsequent testing and analysis revealed that the background arises due to emission of photons from within the CdZnTe detector substrate at the blue transmission edge of the substrate material. Further testing of devices with the substrate removed show no excess background signal. These results lead to a recommendation that the CdZnTe substrate material should be removed for space applications which require the ability to detect faint objects.

  10. Generation of high-power electromagnetic radiation by a beam-driven plasma antenna

    NASA Astrophysics Data System (ADS)

    Annenkov, V. V.; Volchok, E. P.; Timofeev, I. V.

    2016-04-01

    In this paper we study how efficiently electromagnetic radiation can be generated by a relativistic electron beam with a gigawatt power level during its injection into a thin magnetized plasma. It is shown that, if the transverse beam and plasma size is compared with the radiation wavelength and the plasma density is modulated along the magnetic field, such a beam-plasma system can radiate electromagnetic waves via the antenna mechanism. We propose a theoretical model describing generation of electromagnetic waves by this plasma antenna and calculate its main radiation characteristics. In the two-dimensional case theoretical predictions on the radiation efficiency are shown to be confirmed by the results of particle-in-cell simulations, and the three-dimensional variant of this theory is used to estimate the peak power of sub-terahertz radiation that can be achieved in beam-plasma experiments in mirror traps.

  11. [Effect of electromagnetic radiation on discharge activity of neurons in the hippocampus CA1 in rats].

    PubMed

    Tong, Jun; Chen, Su; Liu, Xiang-Ming; Hao, Dong-Mei

    2013-09-01

    In order to explore effect of electromagnetic radiation on learning and memory ability of hippocampus neuron in rats, the changes in discharge patterns and overall electrical activity of hippocampus neuron after electromagnetic radiation were observed. Rat neurons discharge was recorded with glass electrode extracellular recording technology and a polygraph respectively. Radiation frequency of electromagnetic wave was 900 MHZ and the power was 10 W/m2. In glass electrode extracellular recording, the rats were separately irradiated for 10, 20, 30, 40, 50 and 60 min, every points repeated 10 times and updated interval of 1h, observing the changes in neuron discharge and spontaneous discharge patterns after electromagnetic radiation. In polygraph recording experiments, irradiation group rats for five days a week, 6 hours per day, repeatedly for 10 weeks, memory electrical changes in control group and irradiation group rats when they were feeding were repeatedly monitored by the implanted electrodes, observing the changes in peak electric digits and the largest amplitude in hippocampal CA1 area, and taking some electromagnetic radiation sampling sequence for correlation analysis. (1) Electromagnetic radiation had an inhibitory role on discharge frequency of the hippocampus CA1 region neurons. After electromagnetic radiation, discharge frequency of the hippocampus CA1 region neurons was reduced, but the changes in scale was not obvious. (2) Electromagnetic radiation might change the spontaneous discharge patterns of hippocampus CA1 region neurons, which made the explosive discharge pattern increased obviously. (3) Peak potential total number within 5 min in irradiation group was significantly reduced, the largest amplitude was less than that of control group. (4) Using mathematical method to make the correlation analysis of the electromagnetic radiation sampling sequence, that of irradiation group was less than that of control group, indicating that there was a tending

  12. Effects of low-intensity ultrahigh frequency electromagnetic radiation on inflammatory processes.

    PubMed

    Lushnikov, K V; Shumilina, Yu V; Yakushina, V S; Gapeev, A B; Sadovnikov, V B; Chemeris, N K

    2004-04-01

    Low-intensity ultrahigh frequency electromagnetic radiation (42 GHz, 100 microW/cm(2)) reduces the severity of inflammation and inhibits production of active oxygen forms by inflammatory exudate neutrophils only in mice with inflammatory process. These data suggest that some therapeutic effects of electromagnetic radiation can be explained by its antiinflammatory effect which is realized via modulation of functional activity of neutrophils in the focus of inflammation.

  13. Study on electromagnetic radiation and mechanical characteristics of coal during an SHPB test

    NASA Astrophysics Data System (ADS)

    Chengwu, Li; Qifei, Wang; Pingyang, Lyu

    2016-06-01

    Dynamic loads provided by a Split Hopkinson pressure bar are applied in the impact failure experiment on coal with an impact velocity of 4.174-17.652 m s-1. The mechanical property characteristics of coal and an electromagnetic radiation signal can be detected and measured during the experiment. The variation of coal stress, strain, incident energy, dissipated energy and other mechanical parameters are analyzed by the unidimensional stress wave theory. It suggests that with an increase of the impact velocity, the mechanical parameters and electromagnetic radiation increased significantly and the dissipated energy of the coal sample has a high discrete growing trend during the failure process of coal impact. Combined with the received energy of the electromagnetic radiation signal, the relationship between these mechanical parameters and electromagnetic radiation during the failure process of coal burst could be analyzed by the grey correlation model. The results show that the descending order of the gray correlation degree between the mechanical characteristics and electromagnetic radiation energy are impact velocity, maximum stress, the average stress, incident energy, the average strain, maximum strain, the average strain rate and dissipation energy. Due to the correlation degree, the impact velocity and incident energy are relatively large, and the main factor affecting the electromagnetic radiation energy of coal is the energy magnitude. While the relationship between extreme stress and the radiation energy change trend is closed, the stress state of coal has a greater impact on electromagnetic radiation than the strain and destruction which can deepen the research of the coal-rock dynamic disaster electromagnetic monitoring technique.

  14. Degradation of silicon ac-coupled microstrip detectors induced by radiation

    SciTech Connect

    Bacchetta, N.; Gotra, Yu.; Bisello, D. |; Canali, C.; Fuochi, P.G.; Paccagnella, A.; Verzellesi, G. |

    1993-12-01

    Results are presented showing the radiation response of ac-coupled FOXFET biased microstrip detectors and related test patterns to be used in the microvertex detector of the CDF experiment at Fermi National Laboratory. Radiation tolerance of detectors to gamma and proton irradiation has been tested and the radiation induced variations of the dc electrical parameters have been analyzed. Long term post-irradiation behavior of detector characteristics have been studied, and the relevant room temperature annealing phenomena have been discussed.

  15. On the radiation tolerance of SU-8, a new material for gaseous microstructure radiation detector fabrication

    NASA Astrophysics Data System (ADS)

    Key, M. J.; Cindro, V.; Lozano, M.

    2004-12-01

    SU-8 photosensitive epoxy resin was developed for the fabrication of high-aspect ratio microstructures in MEMS and microengineering applications, and has potential for use in the construction of novel gaseous micropattern radiation detectors. However, little is known of the behaviour of the cured material under irradiation. Mechanical properties of SU-8 film have been measured as a function of neutron exposure and compared with Kapton ® polyimide and Mylar ® PET polyester films, materials routinely used in gaseous radiation detectors, to asses the suitability of SU-8 based microstructures for gaseous detector applications. After exposure to a reactor core neutron fluence of 7.5×10 18 n cm -2, the new material showed a high level of resistance to radiation damage, comparable to Kapton film.

  16. Performance prospects for the CMS electromagnetic calorimeter barrel avalanche photodiodes for LHC phase I and phase II: Radiation hardness and longevity

    NASA Astrophysics Data System (ADS)

    Addesa, F.; Cavallari, F.

    2015-07-01

    The electromagnetic calorimeter of the Compact Muon Solenoid (CMS) experiment at the LHC is a hermetic, fine-grained, homogeneous calorimeter, comprising 75,848 lead tungstate scintillating crystals. Avalanche photodiodes produced by Hamamatsu are used as sensors for the electromagnetic barrel calorimeter. These devices were tested for radiation hardness assuming an integrated luminosity of 500 fb-1, which corresponds to a neutron fluence of 2- 4 ×1013 n /cm2, depending on the detector location. Beginning in 2022, a new phase of the LHC is foreseen to exploit the full potential of the accelerator, which will deliver 3000 fb-1 of integrated luminosity. Irradiation studies up to a fluence of 1.5 ×1014 n /cm2 have been performed to qualify the avalanche photodiodes for radiation hardness. We present measurements of gain, quantum efficiency and noise, and discuss the implications for the CMS electromagnetic barrel calorimeter performance.

  17. [Influence of Detector Radiation Damage on CR Mammography Quality Control].

    PubMed

    Moriwaki, Atsumi; Ishii, Mie; Terazono, Shiho; Arao, Keiko; Ishii, Rie; Sanada, Taizo; Yoshida, Akira

    2016-05-01

    Recently, radiation damage to the detector apparatus employed in computed radiography (CR) mammography has become problematic. The CR system and the imaging plate (IP) applied to quality control (QC) program were also used in clinical mammography in our hospital, and the IP to which radiation damage has occurred was used for approximately 5 years (approximately 13,000 exposures). We considered using previously acquired QC image data, which is stored in a server, to investigate the influence of radiation damage to an IP. The mammography unit employed in this study was a phase contrast mammography (PCM) Mermaid (KONICA MINOLTA) system. The QC image was made newly, and it was output in the film, and thereafter the optical density of the step-phantom image was measured. An input (digital value)-output (optical density) conversion curve was plotted using the obtained data. The digital values were then converted to optical density values using a reference optical density vs. digital value curve. When a high radiation dose was applied directly, radiation damage occurred at a position on the IP where no object was present. Daily QC for mammography is conducted using an American College of Radiology (ACR) accreditation phantom and acrylic disc, and an environmental background density measurement is performed as one of the management indexes. In this study, the radiation damage sustained by the acrylic disc was shown to differ from that of the background. Thus, it was revealed that QC results are influenced by radiation damage.

  18. System for determining the type of nuclear radiation from detector output pulse shape

    DOEpatents

    Miller, William H.; Berliner, Ronald R.

    1994-01-01

    A radiation detection system determines the type of nuclear radiation received in a detector by producing a correlation value representative of the statistical cross correlation between the shape of the detector signal and pulse shape data previously stored in memory and characteristic of respective types of radiation. The correlation value is indicative of the type of radiation. The energy of the radiation is determined from the detector signal and is used to produce a spectrum of radiation energies according to radiation type for indicating the nature of the material producing the radiation.

  19. System for determining the type of nuclear radiation from detector output pulse shape

    DOEpatents

    Miller, W.H.; Berliner, R.R.

    1994-09-13

    A radiation detection system determines the type of nuclear radiation received in a detector by producing a correlation value representative of the statistical cross correlation between the shape of the detector signal and pulse shape data previously stored in memory and characteristic of respective types of radiation. The correlation value is indicative of the type of radiation. The energy of the radiation is determined from the detector signal and is used to produce a spectrum of radiation energies according to radiation type for indicating the nature of the material producing the radiation. 2 figs.

  20. Expanding the use of real-time electromagnetic tracking in radiation oncology.

    PubMed

    Shah, Amish P; Kupelian, Patrick A; Willoughby, Twyla R; Meeks, Sanford L

    2011-11-15

    In the past 10 years, techniques to improve radiotherapy delivery, such as intensity-modulated radiation therapy (IMRT), image-guided radiation therapy (IGRT) for both inter- and intrafraction tumor localization, and hypofractionated delivery techniques such as stereotactic body radiation therapy (SBRT), have evolved tremendously. This review article focuses on only one part of that evolution, electromagnetic tracking in radiation therapy. Electromagnetic tracking is still a growing technology in radiation oncology and, as such, the clinical applications are limited, the expense is high, and the reimbursement is insufficient to cover these costs. At the same time, current experience with electromagnetic tracking applied to various clinical tumor sites indicates that the potential benefits of electromagnetic tracking could be significant for patients receiving radiation therapy. Daily use of these tracking systems is minimally invasive and delivers no additional ionizing radiation to the patient, and these systems can provide explicit tumor motion data. Although there are a number of technical and fiscal issues that need to be addressed, electromagnetic tracking systems are expected to play a continued role in improving the precision of radiation delivery.

  1. [Adaptation reactions of rat blood exposed to low intensity electromagnetic radiation].

    PubMed

    Krylov, V N; Deriugina, A V

    2010-06-01

    It is carried out research of action low-intensive electromagnetic radiations--low-intensive laser radiation and radiations of the highest frequency on normal animals and at modelling the stress-reaction, caused by introduction of adrenaline. Absence of effects of system of blood is noted at action low-intensive electromagnetic radiations on normal an organism and them correction action on alteration an organism, shown in restoration of the broken parameters--leukocyte the blood count, electrophoretic mobility of erythrocytes and phospholipide's structure of their membranes.

  2. Field Testing of a Portable Radiation Detector and Mapping System

    SciTech Connect

    Hofstetter, K.J.; Hayes, D.W.; Eakle, R.F.

    1998-03-01

    Researchers at the Savannah River Site (SRS) have developed a man- portable radiation detector and mapping system (RADMAPS) which integrates the accumulation of radiation information with precise ground locations. RADMAPS provides field personnel with the ability to detect, locate, and characterize nuclear material at a site or facility by analyzing the gamma or neutron spectra and correlating them with position. the man-portable field unit records gamma or neutron count rate information and its location, along with date and time, using an embedded Global Positioning System (GPS). RADMAPS is an advancement in data fusion, integrating several off-the-shelf technologies with new computer software resulting in a system that is simple to deploy and provides information useful to field personnel in an easily understandable form. Decisions on subsequent actions can be made in the field to efficiently use available field resources. The technologies employed in this system include: recording GPS, radiation detection (typically scintillation detectors), pulse height analysis, analog-to-digital converters, removable solid-state (Flash or SRAM) memory cards, Geographic Information System (GIS) software and personal computers with CD-ROM supporting digital base maps. RADMAPS includes several field deployable data acquisition systems designed to simultaneously record radiation and geographic positions. This paper summarizes the capabilities of RADMAPS and some of the results of field tests performed with the system.

  3. Automated data collection and analysis system for MOSFET radiation detectors.

    PubMed

    Gladstone, D J; Chin, L M

    1991-01-01

    Metal oxide semiconductor field effect transistors (MOSFET) have been used as radiation dosimeters. Because of their small detector size, minimal power requirements, and signal integration characteristics, they offer unique possibilities as real-time dose monitors in radiotherapy. An automated data collection and analysis system for use with MOSFET radiation dosimeters has been designed and built. The objective was to design a system which can acquire and process the MOSFET signals in real time, in any radiation field encountered in radiotherapy. In particular, major problems have been solved arising from the intrinsic drifts of the MOSFET signal during low dose rate measurements. These signal drifts are significant when the MOSFET detector is used in applications such as on-line monitoring of radiation dose delivery in brachytherapy or radioimmunotherapy. The data collection and analysis system includes a portable IBM-compatible personal computer fitted with digital-to-analog and analog-to-digital converter boards. A single-chip programmable current supply is used to power the MOSFET dosimeters. Intrinsic and extrinsic drifts in signal due to ion diffusion and electron tunneling are corrected by deconvolution of the collected data in real time or after data collection. The data acquisition system and signal-processing methodologies are described.

  4. Investigation of radiation doses in open space using TLD detectors.

    PubMed

    Reitz, G; Facius, R; Bilski, P; Olko, P

    2002-01-01

    The low energy component of the cosmic radiation field is strongly modified by the shielding of the spacecraft and it is time and location dependent. Thermoluminescent lithium fluoride detectors have been applied to determine the radiation doses inside the ESA-Facility BIOPAN. The BIOPAN facility was mounted outside and launched on a Foton spacecraft and opened to space to allow exposure of several experiments to open space. Standard TLD-600. TLD-700 chips, two layers MTS-Ns sintered pellets with different effective thickness of the sensitive layer and MTS-N of different thickness have been exposed with different shielding thicknesses in front of them. The measured TL signal in the 0.1 mm thick detector just shielded by an aluminised Kapton foil of 25 microm thickness in front yielded a dose of 29.8 Gy (calibrated with 137Cs gamma rays) for an exposure time of 12.7 days: after 2.5 g.cm(-2) shielding the doses dropped to 3 mGy. The monitoring of radiation doses and its depth dose distribution outside the spacecraft are of great interest for radiation protection of astronauts working in open space. The knowledge of depth-dose distribution is a prerequisite to determine the organ doses an astronaut will receive during an extravehicular activity (EVA). The BIOPAN experiments are to be continued in the future.

  5. Novel semiconductor radiation detector based on mercurous halides

    NASA Astrophysics Data System (ADS)

    Chen, Henry; Kim, Joo-Soo; Amarasinghe, Proyanthi; Palosz, Withold; Jin, Feng; Trivedi, Sudhir; Burger, Arnold; Marsh, Jarrod C.; Litz, Marc S.; Wiejewarnasuriya, Priyalal S.; Gupta, Neelam; Jensen, Janet; Jensen, James

    2015-08-01

    The three most important desirable features in the search for room temperature semiconductor detector (RTSD) candidate as an alternative material to current commercially off-the-shelf (COTS) material for gamma and/or thermal neutron detection are: low cost, high performance and long term stability. This is especially important for pager form application in homeland security. Despite years of research, no RTSD candidate so far can satisfy the above 3 features simultaneously. In this work, we show that mercurous halide materials Hg2X2 (X= I, Cl, Br) is a new class of innovative compound semiconductors that is capable of delivering breakthrough advances to COTS radiation detector materials. These materials are much easier to grow thicker and larger volume crystals. They can detect gamma and potentially neutron radiation making it possible to detect two types of radiation with just one crystal material. The materials have wider bandgaps (compared to COTS) meaning higher resistivity and lower leakage current, making this new technology more compatible with available microelectronics. The materials also have higher atomic number and density leading to higher stopping power and better detector sensitivity/efficiency. They are not hazardous so there are no environmental and health concerns during manufacturing and are more stable making them more practical for commercial deployment. Focus will be on Hg2I2. Material characterization and detector performance will be presented and discussed. Initial results show that an energy resolution better than 2% @ 59.6 keV gamma from Am-241 and near 1% @ 662 keV from Cs-137 source can be achieved at room temperature.

  6. [Effects of electromagnetic radiation on RAF/MEK/ERK signaling pathway in rats hippocampus].

    PubMed

    Zuo, Hong-yan; Wang, De-wen; Peng, Rui-yun; Wang, Shui-ming; Gao, Ya-bing; Xu, Xin-ping; Ma, Jun-Jie

    2009-05-01

    To study the development of changes for signaling molecules related to Raf/MEK/ERK pathway in hippocampus of rats after electromagnetic radiation, and investigate the mechanisms of radiation injury. Rats were exposed to X-HPM, S-HPM and EMP radiation source respectively, and animal model of electromagnetic radiation was established. Western blot was used to detect the expression of Raf-1, phosphorylated Raf-1 and phospholylated ERK. The expression of Raf-1 down-regulated during 6 h-14 d after radiation, most significantly at 7 d, and recovered at 28 d. There was no significant difference between the radiation groups. The expression of phosphorylated Raf-1 and phosphorylated ERK both up-regulated at 6 h and 7 d after radiation, more significantly at 6 h, and the two microwave groups were more serious for phosphorylated ERK. During 6 h-14 d after S-HPM radiation, the expression of phosphorylated Raf-1 increased continuously, but phosphorylated ERK changed wavily, 6 h and 7 d were expression peak. Raf/MEK/ERK signaling pathway participates in the hippocampus injury induced by electromagnetic radiation. The excessive activation of ERK pathway may result in the apoptosis and death of neurons, which is the important mechanism of recognition disfunction caused by electromagnetic radiation.

  7. [The role of RKIP mediated ERK pathway in hippocampus neurons injured by electromagnetic radiation].

    PubMed

    Zuo, Hong-Yan; Wang, De-Wen; Peng, Rui-Yun; Wang, Shui-Ming; Gao, Ya-Bing; Zhang, Zhi-Yi; Xiao, Feng-Jun

    2008-07-01

    To study the effects of electromagnetic radiation on RKIP and phosphorylated ERK in primary cultured hippocampus neurons. The inhibitor of MEK U0126 was applied to investigate the role of RKIP mediated ERK pathway in radiation injury. Primary hippocampus neurons were cultured in vitro. X-HPM, S-HPM and EMP were taken as radiation source respectively to establish three cell models exposed to electromagnetic radiation. RKIP and phosphorylated ERK were measured by immunofluorescent labelling and laser scanning confocal microscope. Apoptosis and death fraction of the cells were detected by Annexin V-PI double labelling and flow cytometry. After three kinds of electromagnetic radiation, the expression of RKIP in hippocampus neurons decreased but the expression of phosphorylated ERK increased, and its nuclear translocation occurred. No significant differences were seen between radiation groups. Apoptosis and death fraction of the neurons in U0126 pretreatment groups was significantly lower than that in radiation groups but they were still higher than those in sham-radiation group. The excessive activation of RKIP mediated ERK pathway is one of the important mechanisms for the apoptosis and death of hippocampus neurons induced by electromagnetic radiation. U0126 have some protective effects on radiation injury.

  8. [Role of modulation in biological effects of electromagnetic radiation].

    PubMed

    Grigor'ev, Iu G

    1996-01-01

    Data, describing a role of modulation of electromagnetic fields in development of biological effect, are considered. Outcomes of researches, indicating the dependence of a response of nervous and immune systems on a kind of modulation at low levels of effect, are represented. The necessity of the account of a role of modulation in an evaluation of electromagnetic danger is formulated.

  9. [Effect of extremely low frequency electromagnetic radiation and ultra-violet radiation on aggregation of thymocytes and erythrocytes].

    PubMed

    Roshchupkin, D I; Kramarenko, G G; Anosov, A K

    1996-01-01

    Electromagnetic radiation of superhigh frequencies (46.12 and 46.19 GHz, 0.3-1 mV/cm2) at an incident dose of about 12 kJ/m2 enhances the ability of isolated rabbit thymocytes for aggregation interaction with homologous erythrocytes. In the case of 46.19 GHz frequency, the stimulatory effect disappears as radiation dose in increased. A radiation of 46.12 GHz stimulates thymocytes also at high radiation doses. Superhigh-frequency radiation enhances the sensitivity of thymocytes to the damaging effect of UV radiation.

  10. The electromagnetic calorimeter for the T2K near detector ND280

    NASA Astrophysics Data System (ADS)

    Allan, D.; Andreopoulos, C.; Angelsen, C.; Barker, G. J.; Barr, G.; Bentham, S.; Bertram, I.; Boyd, S.; Briggs, K.; Calland, R. G.; Carroll, J.; Cartwright, S. L.; Carver, A.; Chavez, C.; Christodoulou, G.; Coleman, J.; Cooke, P.; Davies, G.; Densham, C.; Di Lodovico, F.; Dobson, J.; Duboyski, T.; Durkin, T.; Evans, D. L.; Finch, A.; Fitton, M.; Gannaway, F. C.; Grant, A.; Grant, N.; Grenwood, S.; Guzowski, P.; Hadley, D.; Haigh, M.; Harrison, P. F.; Hatzikoutelis, A.; Haycock, T. D. J.; Hyndman, A.; Ilic, J.; Ives, S.; Kaboth, A. C.; Kasey, V.; Kellet, L.; Khaleeq, M.; Kogan, G.; Kormos, L. L.; Lawe, M.; Lawson, T. B.; Lister, C.; Litchfield, R. P.; Lockwood, M.; Malek, M.; Maryon, T.; Masliah, P.; Mavrokoridis, K.; McCauley, N.; Mercer, I.; Metelko, C.; Morgan, B.; Morris, J.; Muir, A.; Murdoch, M.; Nicholls, T.; Noy, M.; O'Keeffe, H. M.; Owen, R. A.; Payne, D.; Pearce, G. F.; Perkin, J. D.; Poplawska, E.; Preece, R.; Qian, W.; Ratoff, P.; Raufer, T.; Raymond, M.; Reeves, M.; Richards, D.; Rooney, M.; Sacco, R.; Sadler, S.; Schaack, P.; Scott, M.; Scully, D. I.; Short, S.; Siyad, M.; Smith, R.; Still, B.; Sutcliffe, P.; Taylor, I. J.; Terri, R.; Thompson, L. F.; Thorley, A.; Thorpe, M.; Timis, C.; Touramanis, C.; Uchida, M. A.; Uchida, Y.; Vacheret, A.; Van Schalkwyk, J. F.; Veledar, O.; Waldron, A. V.; Ward, M. A.; Ward, G. P.; Wark, D.; Wascko, M. O.; Weber, A.; West, N.; Whitehead, L. H.; Wilkinson, C.; Wilson, J. R.

    2013-10-01

    The T2K experiment studies oscillations of an off-axis muon neutrino beam between the J-PARC accelerator complex and the Super-Kamiokande detector. Special emphasis is placed on measuring the mixing angle θ13 by observing νe appearance via the sub-dominant νμ → νe oscillation and searching for CP violation in the lepton sector. The experiment includes a sophisticated, off-axis, near detector, the ND280, situated 280 m downstream of the neutrino production target in order to measure the properties of the neutrino beam and to understand better neutrino interactions at the energy scale below a few GeV. The data collected with the ND280 are used to study charged- and neutral-current neutrino interaction rates and kinematics prior to oscillation, in order to reduce uncertainties in the oscillation measurements by the far detector. A key element of the near detector is the ND280 electromagnetic calorimeter (ECal), consisting of active scintillator bars sandwiched between lead sheets and read out with multi-pixel photon counters (MPPCs). The ECal is vital to the reconstruction of neutral particles, and the identification of charged particle species. The ECal surrounds the Pi-0 detector (PØD) and the tracking region of the ND280, and is enclosed in the former UA1/NOMAD dipole magnet. This paper describes the design, construction and assembly of the ECal, as well as the materials from which it is composed. The electronic and data acquisition (DAQ) systems are discussed, and performance of the ECal modules, as deduced from measurements with particle beams, cosmic rays, the calibration system, and T2K data, is described.

  11. A Micro-Cantilever Based Photoacoustic Detector of Terahertz Radiation for Chemical Sensing

    NASA Astrophysics Data System (ADS)

    Glauvitz, Nathan E.; Coutu, Ronald A. Coutu, Jr.; Kistler, Michael N.; Hamilton, Ryan F.; Petkie, Douglas T.; Medvedev, Ivan R.

    2013-06-01

    In this paper we describe a novel photoacoustic detector that can detect radiation in the Terahertz/sub-millimeter (THz/smm) spectral range, is immune to the effect of standing waves, and potentially can have spectral response that is independent of the absorption path length, thus offering crucial advantages for acquisition of THz/smm molecular spectra. The photoacoustic effect occurs when the energy from electromagnetic waves is absorbed by molecules and collisionally transferred into translational energy, thus resulting in local heating induced by the radiation. If radiation produced by the source is modulated, an acoustic wave results which can be detected by a pressure sensitive device such as a microphone or a cantilever. This transduction of the THz signal into a photoacoustic wave is what makes this approach insensitive to the detrimental standing waves associated with traditional THz sensors and allows for a significant reduction in the size of the absorption cell. A Microelectromechanical system (MEMS) cantilever pressure sensor was designed, modeled, fabricated, and tested for sensing the photoacoustic response of gases to THz/smm radiation. Here we present our manufacturing, experimental set-up and most recent spectroscopic results, which demonstrate the capabilities of this spectroscopic technique.

  12. Applications of Noble Gas Radiation Detectors to Counter-terrorism

    NASA Astrophysics Data System (ADS)

    Vanier, Peter E.; Forman, Leon

    2002-10-01

    Radiation detectors are essential tools in the detection, analysis and disposition of potential terrorist devices containing hazardous radioactive and/or fissionable materials. For applications where stand-off distance and source shielding are limiting factors, large detectors have advantages over small ones. The ability to distinguish between Special Nuclear Materials and false-positive signals from natural or man-made benign sources is also important. Ionization chambers containing compressed noble gases, notably xenon and helium-3, can be scaled up to very large sizes, improving the solid angle for acceptance of radiation from a distant source. Gamma spectrometers using Xe have a factor of three better energy resolution than NaI scintillators, allowing better discrimination between radioisotopes. Xenon detectors can be constructed so as to have extremely low leakage currents, enabling them to operate for long periods of time on batteries or solar cells. They are not sensitive to fluctuations in ambient temperature, and are therefore suitable for deployment in outdoor locations. Position-sensitive 3He chambers have been built as large as 3000 cm2, and with spatial resolution of less than 1 mm. Combined with coded apertures made of cadmium, they can be used to create images of thermal neutron sources. The natural background of spallation neutrons from cosmic rays generates a very low count rate, so this instrument could be quite effective at identifying a man-made source, such as a spontaneous fission source (Pu) in contact with a moderator (high explosive).

  13. [The assessment of modulated radiofrequence electromagnetic radiation on cognitive function in rats of different ages].

    PubMed

    Priakhin, E A; Triapitsyna, G A; Andreev, S S; Kolomiets, I A; Polevik, N D; Akleev, A V

    2007-01-01

    The modulated radiofrequence electromagnetic radiation influence on cognitive function of male uninbred Wister rat exposed at the age of sexual maturation (2 months) and at the age of morphofunctional maturity (3.5 months) was examined. Animals were subjected to pulse electromagnetic radiation (925 MHz) modulated as a GSM standard with the power density 1.2 mW/cm2 for 10 minutes every day for 12 days. At day 8 of exposure the cognitive function were examined with the Morris water maze. In the result of investigation it was determines that modulated radiofrequence electromagnetic radiation at the sexual maturation age did not affect the spatial learning and improve the visual orientation performance. Modulated radiofrequence electromagnetic exposure of animals at the sex maturity age did not affect the visual performance and improve the spatial performance of male rats.

  14. Electromagnetic radiation and nonlinear energy flow in an electron beam-plasma system

    NASA Technical Reports Server (NTRS)

    Whelan, D. A.; Stenzel, R. L.

    1985-01-01

    It is shown that the unstable electron-plasma waves of a beam-plasma system can generate electromagnetic radiation in a uniform plasma. The generation mechanism is a scattering of the unstable electron plasma waves off ion-acoustic waves, producing electromagnetic waves whose frequency is near the local plasma frequency. The wave vector and frequency matching conditions of the three-wave mode coupling are experimentally verified. The electromagnetic radiation is observed to be polarized with the electric field parallel to the beam direction, and its source region is shown to be localized to the unstable plasma wave region. The frequency spectrum shows negligible intensity near the second harmonic of the plasma frequency. These results suggest that the observed electromagnetic radiation of type III solar bursts may be generated near the local plasma frequency and observed downstream where the wave frequency is near the harmonic of the plasma frequency.

  15. Electromagnetic radiation and nonlinear energy flow in an electron beam-plasma system

    NASA Technical Reports Server (NTRS)

    Whelan, D. A.; Stenzel, R. L.

    1985-01-01

    It is shown that the unstable electron-plasma waves of a beam-plasma system can generate electromagnetic radiation in a uniform plasma. The generation mechanism is a scattering of the unstable electron plasma waves off ion-acoustic waves, producing electromagnetic waves whose frequency is near the local plasma frequency. The wave vector and frequency matching conditions of the three-wave mode coupling are experimentally verified. The electromagnetic radiation is observed to be polarized with the electric field parallel to the beam direction, and its source region is shown to be localized to the unstable plasma wave region. The frequency spectrum shows negligible intensity near the second harmonic of the plasma frequency. These results suggest that the observed electromagnetic radiation of type III solar bursts may be generated near the local plasma frequency and observed downstream where the wave frequency is near the harmonic of the plasma frequency.

  16. PERDaix -Proton Electron Radiation Detector Aix-la-Chapelle

    NASA Astrophysics Data System (ADS)

    Schug, David; Schael, Stefan; Yearwood Roper, Gregorio; Bachlechner, Andreas; Beischer, Bastian; Deckenhoff, Mirco; Greim, Roman; Jenniches, Laura; Kucirek, Philipp; Lewke, Ronja; Mai, Carsten; Schug, David; Shchutska, Lesya; Tholen, Heiner; Ulrich, Jascha; Wienkenhoever, Jens; Zimmermann, Nikolas

    For the purpose of understanding recent cosmic ray measurements in the energy region below 10 GeV it is important to obtain good knowledge of the charge-sign dependent modulation caused by interplanetary magnetic fields. Existing three-dimensional time-dependent models of the heliosphere can be constrained further using series of measurements of the low-energy cosmic ray fluxes over the course of a solar cycle. Following the measurements of the positron fraction from AESOP in 2006 and 2009, we present a new light-weighted spectrometer which is under construction in Aachen for measuring helium, proton, positron and electron fluxes. The detector is designed to measure in the energy range between 0.5 GeV and 5 GeV and identify helium, protons, electrons and positrons. The detector consists of a spectrometer made up of a permanent magnet and a scintillating fiber tracking detector, a transition radiation detector and a time of flight system with a total weight of approximately 30kg. We applied successfully for a flight on a stratosphere balloon in late 2010 as part of the German-Swedish Balloon-Borne Experiments for University Students (BEXUS) Program.

  17. SENTIRAD—An innovative personal radiation detector based on a scintillation detector and a silicon photomultiplier

    NASA Astrophysics Data System (ADS)

    Osovizky, A.; Ginzburg, D.; Manor, A.; Seif, R.; Ghelman, M.; Cohen-Zada, I.; Ellenbogen, M.; Bronfenmakher, V.; Pushkarsky, V.; Gonen, E.; Mazor, T.; Cohen, Y.

    2011-10-01

    The alarming personal radiation detector (PRD) is a device intended for Homeland Security (HLS) applications. This portable device is designed to be worn or carried by security personnel to detect photon-emitting radioactive materials for the purpose of crime prevention. PRD is required to meet the scope of specifications defined by various HLS standards for radiation detection. It is mandatory that the device be sensitive and simultaneously small, pocket-sized, of robust mechanical design and carriable on the user's body. To serve these specialized purposes and requirements, we developed the SENTIRAD, a new radiation detector designed to meet the performance criteria established for counterterrorist applications. SENTIRAD is the first commercially available PRD based on a CsI(Tl) scintillation crystal that is optically coupled with a silicon photomultiplier (SiPM) serving as a light sensor. The rapidly developing technology of SiPM, a multipixel semiconductor photodiode that operates in Geiger mode, has been thoroughly investigated in previous studies. This paper presents the design considerations, constraints and radiological performance relating to the SENTIRAD radiation sensor.

  18. [Influence of electromagnetic radiation on raf kinase inhibitor protein and its related proteins of hippocampus].

    PubMed

    Zuo, Hong-yan; Wang, De-wen; Peng, Rui-yun; Wang, Shui-ming; Gao, Ya-bing; Xu, Xin-ping; Ma, Jun-jie

    2008-09-01

    To study the development of changes for Raf kinase inhibitor protein (RKIP) and its mRNA in rats hippocampus after electromagnetic radiation. Rats were exposed to X-band high power microwave (X-HPM), S-band high power microwave (S-HPM) and electromagnetic pulse (EMP) radiation source respectively. The animal model of electromagnetic radiation was established. Western blot was used to detect the expression of RKIP, and RT-PCR was applied to detect the expression of RKIP mRNA. The interaction of RKIP and Raf-1 was measured with co-immunoprecipitation method, and the expression of cerebral choline acetyltransferase (CHAT) was measured by immunohistochemistry. The expression of RKIP significantly down-regulated at 6 h after radiation, and recovered at 1 d in group EMP, but the down-regulation continued during 1 approximately 7 d after radiation in the two microwave groups. The expression of RKIP mRNA changed wavily during 6 h approximately 7 d after radiation, which showed down-regulation at 6 h, and up-regulation at 3 d. The interaction of RKIP and Raf-1 decreased during 6 h approximately 7 d after radiation, most significantly at 7 d, and the two microwave groups were more significant. The expression of CHAT decreased continuously during 6 h approximately 7 d after radiation, and generally recovered on 14 d. The down-regulation of RKIP and its related proteins of hippocampus is induced by electromagnetic radiation.

  19. Prototype of readout electronics for the LHAASO KM2A electromagnetic particle detectors

    NASA Astrophysics Data System (ADS)

    Liu, Xiang; Chang, Jing-Fan; Wang, Zheng; Fan, Lei

    2016-07-01

    The KM2A (one kilometer square extensive air shower array) is the largest detector array in the LHAASO (Large High Altitude Air Shower Observatory) project. The KM2A consists of 5242 EDs (Electromagnetic particle Detectors) and 1221 MDs (Muon Detectors). The EDs are distributed and exposed in the wild. Two channels, anode and dynode, are employed for the PMT (photomultiplier tube) signal readout. The readout electronics designed in this paper aims at accurate charge and arrival time measurement of the PMT signals, which cover a large amplitude range from 20 P.E. (photoelectrons) to 2 × 105 P.E. By using a “trigger-less” architecture, we digitize signals close to the PMTs. All digitized data is transmitted to DAQ (Data Acquisition) via a simplified White Rabbit protocol. Compared with traditional high energy experiments, high precision of time measurement over such a large area and suppression of temperature effects in the wild become the key techniques. Experiments show that the design has fulfilled the requirements in this project. Supported by National Natural Science Foundation of China (11375210) and the Knowledge Innovation Fund of IHEP, Beijing

  20. The Forward Endcap of the Electromagnetic Calorimeter for the PANDA Detector at FAIR

    NASA Astrophysics Data System (ADS)

    Albrecht, Malte; PANDA Collaboration

    2015-02-01

    The versatile 4π-detector PANDA will be built at the Facility for Antiproton and Ion Research (FAIR), an accelerator complex, currently under construction near Darmstadt, Germany. A cooled antiproton beam in a momentum range of 1.5 - 15GeV/c will be provided by the High Energy Storage Ring (HESR). All measurements at PANDA rely on an excellent performance of the detector with respect to tracking, particle identification and energy measurement. The electromagnetic calorimeter (EMC) of the PANDA detector will be equipped with 15744 PbWO4 crystals (PWO-II), which will be operated at a temperature of - 25° C in order to increase the light output. The design of the forward endcap of the EMC has been finalized. The crystals will be read out with Large Area Avalanche Photo Diodes (LAAPDs) in the outer regions and with Vacuum Photo Tetrodes (VPTTs) in the innermost part. Production of photosensor units utilizing charge integrating preamplifiers has begun. A prototype comprised of 216 PbWO4 crystals has been built and tested at various accelerators (CERN SPS, ELSA/Bonn, MAMI/Mainz), where the crystals have been exposed to electron and photon beams of 25MeV up to 15GeV. The results of these test measurements regarding the energy and position resolution are presented.

  1. Porous Silicon-Based Quantum Dot Broad Spectrum Radiation Detector

    PubMed Central

    Urdaneta, M.; Stepanov, P.; Weinberg, I. N.; Pala, I. R.; Brock, S.

    2013-01-01

    Silicon is a convenient and inexpensive platform for radiation detection, but has low stopping power for x-rays and gamma-rays with high energy (e.g., 100 keV, as used in computed tomography and digital radiography, or 1 MeV, as desired for detection of nuclear materials). We have effectively increased the stopping power of silicon detectors by producing a layer of porous or micro-machined silicon, and infusing this layer with semiconductor quantum dots made of electron-dense materials. Results of prototype detectors show sensitivity to infrared, visible light, and x-rays, with dark current of less than 1 nA/mm2. PMID:24432047

  2. The correlated characteristics of micro-seismic and electromagnetic radiation signals on a deep blasting workface

    NASA Astrophysics Data System (ADS)

    Li, Chengwu; Sun, Xiaoyuan; Wang, Chuan; Xu, Xiaomeng; Xie, Beijing; Li, Jing

    2016-12-01

    To date, both micro-seismic (MS) and electromagnetic radiation (EMR) techniques are used as normal, daily safety monitoring tools for coal or rock dynamic disasters in China. In previous studies, these two non-destructive techniques are usually analyzed independently; few works have been done to characterize the correlation or difference between them. This paper aims to analyze the correlated features of the MS and EMR signals obtained from a field site test on a deep blasting workface in Pingdingshan 10# coal colliery. The de-noised signals are firstly compared for their associated features, both in time synchronization and energy correlation, and then the mechanism for the correlated response is also investigated. The results show that: (1) MS and EMR signals have a higher time-synchronization and energy correlation. (2) The EMR signal in a blasting operation is a local signal, near to the location of the detectors. (3) The two orthogonal layout magnetic antennas (along the roadway and vertical to the coal wall) can detect a single pulse signal and group-occurring cluster signals. These two kinds of EMR signals result from coal crack evolution and resistance-capacitance (RC) oscillation circuits respectively, which are triggered by seismic longitudinal waves. (4) The seismic transverse wave, especially for the low frequency component of it, makes a rubbing friction effect on coal, producing a low-frequency electromagnetic oscillation signal. Affected by the power and propagation direction of the energy, the signal can only be captured by the antenna in the vertical direction of the coal wall.

  3. Scalable, Finite Element Analysis of Electromagnetic Scattering and Radiation

    NASA Technical Reports Server (NTRS)

    Cwik, T.; Lou, J.; Katz, D.

    1997-01-01

    In this paper a method for simulating electromagnetic fields scattered from complex objects is reviewed; namely, an unstructured finite element code that does not use traditional mesh partitioning algorithms.

  4. Scalable, Finite Element Analysis of Electromagnetic Scattering and Radiation

    NASA Technical Reports Server (NTRS)

    Cwik, T.; Lou, J.; Katz, D.

    1997-01-01

    In this paper a method for simulating electromagnetic fields scattered from complex objects is reviewed; namely, an unstructured finite element code that does not use traditional mesh partitioning algorithms.

  5. IceCube: A Cubic Kilometer Radiation Detector

    SciTech Connect

    IceCube Collaboration; Klein, Spencer R; Klein, S.R.

    2008-06-01

    IceCube is a 1 km{sup 3} neutrino detector now being built at the Amudsen-Scott South Pole Station. It consists of 4800 Digital Optical Modules (DOMs) which detect Cherenkov radiation from the charged particles produced in neutrino interactions. IceCube will observe astrophysical neutrinos with energies above about 100 GeV. IceCube will be able to separate {nu}{sub {mu}}, {nu}{sub t}, and {nu}{sub {tau}} interactions because of their different topologies. IceCube construction is currently 50% complete.

  6. Effects of Electromagnetic Radiation from Smartphones on Learning Ability and Hippocampal Progenitor Cell Proliferation in Mice.

    PubMed

    Choi, Yu-Jin; Choi, Yun-Sik

    2016-02-01

    Nonionizing radiation is emitted from electronic devices, such as smartphones. In this study, we intended to elucidate the effect of electromagnetic radiation from smartphones on spatial working memory and progenitor cell proliferation in the hippocampus. Both male and female mice were randomly separated into two groups (radiated and control) and the radiated group was exposed to electromagnetic radiation for 9 weeks and 11 weeks for male and female mice, respectively. Spatial working memory was examined with a Y maze, and proliferation of hippocampal progenitor cells were examined by 5-bromo-2'-deoxyuridine administration and immunohistochemical detection. When spatial working memory on a Y maze was examined in the 9(th) week, there was no significant difference in the spontaneous alternation score on the Y maze between the two groups. In addition, there was no significant difference in hippocampal progenitor cell proliferation. However, immunoreactivity to glial fibrillary acidic protein was increased in exposed animals. Next, to test the effect of recovery following chronic radiation exposure, the remaining female mice were further exposed to electromagnetic radiation for 2 more weeks (total 11 weeks), and spontaneous alternation was tested 4 weeks later. In this experiment, although there was no significant difference in the spontaneous alternation scores, the number of arm entry was significantly increased. These data indicate that although chronic electromagnetic radiation does not affect spatial working memory and hippocampal progenitor cell proliferation it can mediate astrocyte activation in the hippocampus and delayed hyperactivity-like behavior.

  7. Stimulated quantum phase slips from weak electromagnetic radiations in superconducting nanowires

    SciTech Connect

    Jafari-Salim, Amir; Eftekharian, Amin; Majedi, A. Hamed; Ansari, Mohammad H.

    2016-03-15

    We study the rate of quantum phase slips in an ultranarrow superconducting nanowire exposed to weak electromagnetic radiations. The superconductor is in the dirty limit close to the superconducting-insulating transition, where fluxoids move in strong dissipation. We use a semiclassical approach and show that external radiation stimulates a significant enhancement in the probability of quantum phase slips.

  8. Generation of ordinary mode electromagnetic radiation near the upper hybrid frequency in the magnetosphere

    NASA Technical Reports Server (NTRS)

    Ashour-Abdalla, M.; Okuda, H.

    1984-01-01

    It is shown by means of plasma numerical simulations that long-wavelength ordinary mode electromagnetic radiation can be generated from short-wavelength electrostatic waves near the upper hybrid resonance frequency in an inhomogeneous plasma. A possible relation of this process to nonthermal continuum radiation in the magnetosphere is discussed.

  9. Localization of non-stationary sources of electromagnetic radiation with the aid of phasometry

    NASA Technical Reports Server (NTRS)

    Mersov, G. A.

    1978-01-01

    The possibility of localizing sources of electromagnetic radiation by measurement of the time of passage of the radiation or the measurement of its phase at various points of cosmic space, at which are located satellite observatories is examined. Algorithms are proposed for localization using two, three, and four astronomical observatories. The precision of the localization and several partial results of practical significance are deduced.

  10. [Effect of impulse extrabroad-band electromagnetic radiation on electroencephalogram and sleep in laboratory animals].

    PubMed

    Petrova, E V; Guliaeva, N V; Titarov, S I; Rozhnov, Iu V; Koval'zon, V M

    2003-07-01

    1-hour exposure to ultra-short impulse low-frequency (6 Hz) superbroad band electromagnetic radiation altered cortical EEG in rats just after the exposure and increased the paradoxical sleep in rabbits within 16-22 hours following the radiation.

  11. Radiation characteristics of electromagnetic eigenmodes at the corrugated interface of a left-handed material.

    PubMed

    Cuevas, Mauro; Depine, Ricardo A

    2009-08-28

    We study the radiation characteristics of electromagnetic surface waves at a periodically corrugated interface between a conventional and a negatively refracting (or left-handed) material. In this case, and contrary to the surface plasmon polariton in a metallic grating, surface plasmon polaritons may radiate on both sides of the rough interface along which they propagate. We find novel radiation regimes which provide an indirect demonstration of other unusual phenomena characteristic of electromagnetic wave propagation in left-handed materials, such as negative refraction or backward wave propagation.

  12. Measurement of the radiation field surrounding the Collider Detector at Fermilab

    SciTech Connect

    K. Kordas et al.

    2004-01-28

    We present here the first direct and detailed measurements of the spatial distribution of the ionizing radiation surrounding a hadron collider experiment. Using data from two different exposures we measure the effect of additional shielding on the radiation field around the Collider Detector at Fermilab (CDF). Employing a simple model we parameterize the ionizing radiation field surrounding the detector.

  13. Centrifugal Tensioned Metastable Fluid Detectors for Trace Radiation Sources: Experimental Verification and Military Employment

    DTIC Science & Technology

    2016-06-01

    TENSIONED METASTABLE FLUID DETECTORS FOR TRACE RADIATION SOURCES: EXPERIMENTAL VERIFICATION AND MILITARY EMPLOYMENT by Dominic J. Chiaverotti...DETECTORS FOR TRACE RADIATION SOURCES: EXPERIMENTAL VERIFICATION AND MILITARY EMPLOYMENT 5. FUNDING NUMBERS 6. AUTHOR(S) Dominic J. Chiaverotti 7...the detection of fast neutrons or alpha particles that are telltale signs of nuclear material, while remaining blind to gamma radiation that could

  14. [Effect of weak electromagnetic radiation on larva development and metamorphosis of grain beetle Tenebrio molitor].

    PubMed

    Sheĭman, I M; Shkutin, M F

    2003-01-01

    The effect of weak electromagnetic radiation (36 GHz, 100 mu W/cm2) on the development of the grain beetle Tenebrio molitor was studied. Insects were irradiated in different larval instars and at the pupal stage. It was found that weak electromagnetic radiation stimulated the molting and pupation of larvae and the metamorphosis of pupae. The stimulating effect of radiation was weak when animals were exposed in the initial period of the instar and the pupal stage and was more pronounced if the irradiation was carried out in the second half of the current instar and the pupil stage. The effect of weak electromagnetic radiation on the development of beetle can be related to the function of the hormones of metamorphosis.

  15. GEM detectors development for radiation environment: neutron tests and simulations

    NASA Astrophysics Data System (ADS)

    Chernyshova, Maryna; Jednoróg, Sławomir; Malinowski, Karol; Czarski, Tomasz; Ziółkowski, Adam; Bieńkowska, Barbara; Prokopowicz, Rafał; Łaszyńska, Ewa; Kowalska-Strzeciwilk, Ewa; Poźniak, Krzysztof T.; Kasprowicz, Grzegorz; Zabołotny, Wojciech; Wojeński, Andrzej; Krawczyk, Rafał D.; Linczuk, Paweł; Potrykus, Paweł; Bajdel, Barcel

    2016-09-01

    One of the requests from the ongoing ITER-Like Wall Project is to have diagnostics for Soft X-Ray (SXR) monitoring in tokamak. Such diagnostics should be focused on tungsten emission measurements, as an increased attention is currently paid to tungsten due to a fact that it became a main candidate for the plasma facing material in ITER and future fusion reactor. In addition, such diagnostics should be able to withstand harsh radiation environment at tokamak during its operation. The presented work is related to the development of such diagnostics based on Gas Electron Multiplier (GEM) technology. More specifically, an influence of neutron radiation on performance of the GEM detectors is studied both experimentally and through computer simulations. The neutron induced radioactivity (after neutron source exposure) was found to be not pronounced comparing to an impact of other secondary neutron reaction products (during the exposure).

  16. High field CdS detector for infrared radiation

    NASA Technical Reports Server (NTRS)

    Tyagi, R. C.; Robertson, J. B.; Boer, K. W.; Hadley, H. C., Jr. (Inventor)

    1974-01-01

    An infrared radiation detector including a cadmium sulfide platelet having a cathode formed on one of its ends and an anode formed on its other end is presented. The platelet is suitably doped such that stationary high-field domains are formed adjacent the cathode when based in the negative differential conductivity region. A negative potential is applied to the cathode such that a high-field domain is formed adjacent to the cathode. A potential measuring probe is located between the cathode and the anode at the edge of the high-field domain and means are provided for measuring the potential at the probe whereby this measurement is indicative of the infrared radiation striking the platelet.

  17. Low Energy Electron Detector for Space Radiation Measurements

    NASA Astrophysics Data System (ADS)

    Hajdas, Wojtek

    Low Energy Electron Detector LEED is a miniature particle monitor for measurements in space. It is based on the MYTHEN Si-microstrip system made at Paul Scherrer Institut PSI for X-ray detection at the Synchrotron Light Source SLS. It was designed in collaboration with the European Space Agency ESA in order to provide a new instrument covering an unexplored energy range of space electrons below few tens of keV. A lack of measurements and realtime data both at low and high energies of particle as well as difficulties in radiation belts modeling are still persisting even after 40 years from their discovery. In particular the low energy electrons, up to few hundred keV are particularly poorly studied. Such electrons can shed a new light on the acceleration and trapping processes and on the dynamics of radiation belts. Measurements of electrons in wide range of energies can provide a link between hot plasma and trapped higher energy particles. The long term observations can probe and verify a coupling between Sun and Earth magnetosphere. On the spacecraft environment side, the electrons with energies of tens of keV can create radiation hazard for on-board instruments, induce spacecraft charging and increase the background in precise X-ray observations. Therefore the requirements put on monitors devoted for above studies are very demanding and often opposing. A special care in construction of LEED - the space version of MYTHEN was optimizing it for very high fluxes and harsh radiation environment. The device aims to monitor Space Weather, map planetary Radiation Belts and study hot plasmas and particle acceleration. It will detect electrons with energies from few up to few hundred keV with energy resolution of several keV. The detector is characterized by ability to deal with very high counting rate of up to 1.4 million counts per second per strip. Its core is a PSI developed radiation hard ASIC read-out chip serving for 128 detection channels. The main design features

  18. [Cellphone electromagnetic radiation damages the testicular ultrastructure of male rats].

    PubMed

    Gao, Xiao-Hui; Hu, Hui-Rong; Ma, Xue-Lian; Chen, Jie; Zhang, Guo-Hong

    2016-06-01

    To investigate the influence of cellphone electromagnetic radiation (CER) on the testicular ultrastructure and the apoptosis of spermatogenic cells in male rats.atability, feasibility, applicability, and controllability in the construction of experimental animal models, we compared the major anatomic features of the penis of 20 adult beagle dogs with those of 10 adult men. Using microsurgical techniques, we performed cross-transplantation of the penis in the 20 (10 pairs) beagle dogs and observed the survival rate of the transplanted penises by FK506+MMF+MP immune induction. We compared the relevant indexes with those of the 10 cases of microsurgical replantation of the amputated penis. Thirty adult male SD rats were equally randomized into a 2 h CER, a 4 h CER, and a normal control group, the former two groups exposed to 30 days of 900 MHz CER for 2 and 4 hours a day, respectively, while the latter left untreated. Then the changes in the ultrastructure of the testis tissue were observed under the transmission electron microscope and the apoptosis of the spermatogenic cells was determined by TUNEL. Compared with the normal controls, the rats of the 2 h CER group showed swollen basement membrane of seminiferous tubules, separated tight junction of Sertoli cells, increased cell intervals, apparent vacuoles and medullization in some mitochondria, and increased apoptosis of spermatogenic cells, mainly the apoptosis of primary spermatocytes (P<0.05 ). In comparison with the 2 h CER group, the animals of the 4 h CER group exhibited swollen basement membrane of seminiferous tubules, more separated tight junction of Sertoli cells, wider cell intervals, incomplete membrane of spermatogonial cells, fragments of cytoplasm, nuclear pyknosis and notch, slight dilation of perinuclear space, abnormalities of intracellular mitochondria with vacuoles, fuzzy structure, and fusion or disappearance of some cristae, and increased damage of mitochondria and apoptosis of spermatogenic

  19. Gravitational wave radiation by LIGO-type detectors and its reciprocity relation with the detector's fundamental quantum limited sensitivity

    NASA Astrophysics Data System (ADS)

    Pang, Belinda; Ma, Yiqiu; Miao, Haixing; Chen, Yanbei

    2017-01-01

    We relate the radiation of gravitational waves (GW) by a light interferometer with cavity arms (such as LIGO) to its quantum limited sensitivity as a detector of GW's, thereby demonstrating a reciprocity relation between the interferometer's function as a detector and emitter. We derive the pairwise interactions among the cavity optical field, the cavity end mirror, and the gravitational perturbation from the action principle. We quantize these degrees of freedom to calculate the GW's generated by a quantum object. We find that the rate of gravitational wave generation is related to the so-called quantum Cramer Rao bound of the detector, which is a general result from linear measurement theory that gives the fundamental limit to a detector's sensitivity. We show that increasing the maximal sensitivity for the interferometer also increases its GW radiation. This finding may point towards a new paradigm for improving detector sensitivity by maximizing GW radiator.

  20. [Fluorescence used to investigate the sensitivity of spinach chloroplast membrane to low intensity electromagnetic radiation].

    PubMed

    Xi, Gang; Yang, Yun-Jing; Lu, Hong

    2009-07-01

    A system for studying biological effect of radio frequency electromagnetic field was developed. The system can form an area where electromagnetic wave with large frequency range is well distributed. The strength of electromagnetic wave was measured easily. Electromagnetic wave in the system did not have effect on environment. The sensitivity of spinach chloroplast membrane to low intensity electromagnetic radiation of 300 MHz under power density of 5 mW x cm(-2) was studied by the spectral analysis method of fluorescence of 8-anilino-1-naphthalene-sulfonic acid (ANS) and the changes in chlorophyll a (Chla) fluorescence parameters of spinach chloroplast membrane. The result showed that the position of spectrum of ANS fluorescence of spinach chloroplast membrane did not change, but the intensity of ANS fluorescence was obviously increased under the action of electromagnetic radiation with power density of 1-5 mW x cm(-2). There was an increase in the intensity of ANS fluorescence with the increase in electromagnetic radiation. The increase of ANS fluorescence of spinach chloroplast membrane showed that low level electromagnetic field induced the decrease in fluidity of chloroplast membrane compared with control experiment. The cause of the change in the fluidity could be related to the polarization of chloroplast membrane under the electromagnetic field. The analysis of Chla fluorescence parameters of spinach chloroplast membrane indicated that low level electromagnetic field of 300 MHz made the fluorescence parameters F0 and F(VI/)F(V) decrease, and F(V)/Fo, Fv/F(m) and deltaF(V)/T increase. It was showed that low level electromagnetic field caused the change of non-active center of photosystem II of spinach chloroplast membrane to active center and the increase in potential active and photochemical efficiency of PSII, and promoted the transmit process of electron in photosynthesis of chloroplast membrane of photosynthesis cell in spinach leaf. The study confirmed

  1. Ambient temperature cadmium zinc telluride radiation detector and amplifier circuit

    DOEpatents

    McQuaid, James H.; Lavietes, Anthony D.

    1998-05-29

    A low noise, low power consumption, compact, ambient temperature signal amplifier for a Cadmium Zinc Telluride (CZT) radiation detector. The amplifier can be used within a larger system (e.g., including a multi-channel analyzer) to allow isotopic analysis of radionuclides in the field. In one embodiment, the circuit stages of the low power, low noise amplifier are constructed using integrated circuit (IC) amplifiers , rather than discrete components, and include a very low noise, high gain, high bandwidth dual part preamplification stage, an amplification stage, and an filter stage. The low noise, low power consumption, compact, ambient temperature amplifier enables the CZT detector to achieve both the efficiency required to determine the presence of radio nuclides and the resolution necessary to perform isotopic analysis to perform nuclear material identification. The present low noise, low power, compact, ambient temperature amplifier enables a CZT detector to achieve resolution of less than 3% full width at half maximum at 122 keV for a Cobalt-57 isotope source. By using IC circuits and using only a single 12 volt supply and ground, the novel amplifier provides significant power savings and is well suited for prolonged portable in-field use and does not require heavy, bulky power supply components.

  2. Ambient temperature cadmium zinc telluride radiation detector and amplifier circuit

    DOEpatents

    McQuaid, J.H.; Lavietes, A.D.

    1998-05-26

    A low noise, low power consumption, compact, ambient temperature signal amplifier for a Cadmium Zinc Telluride (CZT) radiation detector is disclosed. The amplifier can be used within a larger system (e.g., including a multi-channel analyzer) to allow isotopic analysis of radionuclides in the field. In one embodiment, the circuit stages of the low power, low noise amplifier are constructed using integrated circuit (IC) amplifiers , rather than discrete components, and include a very low noise, high gain, high bandwidth dual part preamplification stage, an amplification stage, and an filter stage. The low noise, low power consumption, compact, ambient temperature amplifier enables the CZT detector to achieve both the efficiency required to determine the presence of radionuclides and the resolution necessary to perform isotopic analysis to perform nuclear material identification. The present low noise, low power, compact, ambient temperature amplifier enables a CZT detector to achieve resolution of less than 3% full width at half maximum at 122 keV for a Cobalt-57 isotope source. By using IC circuits and using only a single 12 volt supply and ground, the novel amplifier provides significant power savings and is well suited for prolonged portable in-field use and does not require heavy, bulky power supply components. 9 figs.

  3. Experiences in flip chip production of radiation detectors

    NASA Astrophysics Data System (ADS)

    Savolainen-Pulli, Satu; Salonen, Jaakko; Salmi, Jorma; Vähänen, Sami

    2006-09-01

    Modern imaging devices often require heterogeneous integration of different materials and technologies. Because of yield considerations, material availability, and various technological limitations, an extremely fine pitch is necessary to realize high-resolution images. Thus, there is a need for a hybridization technology that is able to join together readout amplifiers and pixel detectors at a very fine pitch. This paper describes radiation detector flip chip production at VTT. Our flip chip technology utilizes 25-μm diameter tin-lead solder bumps at a 50-μm pitch and is based on flux-free bonding. When preprocessed wafers are used, as is the case here, the total yield is defined only partly by the flip chip process. Wafer preprocessing done by a third-party silicon foundry and the flip chip process create different process defects. Wafer-level yield maps (based on probing) provided by the customer are used to select good readout chips for assembly. Wafer probing is often done outside of a real clean room environment, resulting in particle contamination and/or scratches on the wafers. Factors affecting the total yield of flip chip bonded detectors are discussed, and some yield numbers of the process are given. Ways to improve yield are considered, and finally guidelines for process planning and device design with respect to yield optimization are given.

  4. Electromagnetic diffraction radiation of a subwavelength-hole array excited by an electron beam.

    PubMed

    Liu, Shenggang; Hu, Min; Zhang, Yaxin; Li, Yuebao; Zhong, Renbin

    2009-09-01

    This paper explores the physics of the electromagnetic diffraction radiation of a subwavelength holes array excited by a set of evanescent waves generated by a line charge of electron beam moving parallel to the array. Activated by a uniformly moving line charge, numerous physical phenomena occur such as the diffraction radiation on both sides of the array as well as the electromagnetic penetration or transmission below or above the cut-off through the holes. As a result the subwavelength holes array becomes a radiation array. Making use of the integral equation with relevant Green's functions, an analytical theory for such a radiation system is built up. The results of the numerical calculations based on the theory agree well with that obtained by the computer simulation. The relation among the effective surface plasmon wave, the electromagnetic penetration or transmission of the holes and the diffraction radiation is revealed. The energy dependence of and the influence of the hole thickness on the diffraction radiation and the electromagnetic penetration or transmission are investigated in detail. Therefore, a distinct diffraction radiation phenomenon is discovered.

  5. Lévy noise improves the electrical activity in a neuron under electromagnetic radiation

    PubMed Central

    Wu, Juan; Ma, Jun

    2017-01-01

    As the fluctuations of the internal bioelectricity of nervous system is various and complex, the external electromagnetic radiation induced by magnet flux on membrane can be described by the non-Gaussian type distribution of Lévy noise. Thus, the electrical activities in an improved Hindmarsh-Rose model excited by the external electromagnetic radiation of Lévy noise are investigated and some interesting modes of the electrical activities are exhibited. The external electromagnetic radiation of Lévy noise leads to the mode transition of the electrical activities and spatial phase, such as from the rest state to the firing state, from the spiking state to the spiking state with more spikes, and from the spiking state to the bursting state. Then the time points of the firing state versus Lévy noise intensity are depicted. The increasing of Lévy noise intensity heightens the neuron firing. Also the stationary probability distribution functions of the membrane potential of the neuron induced by the external electromagnetic radiation of Lévy noise with different intensity, stability index and skewness papremeters are analyzed. Moreover, through the positive largest Lyapunov exponent, the parameter regions of chaotic electrical mode of the neuron induced by the external electromagnetic radiation of Lévy noise distribution are detected. PMID:28358824

  6. Lévy noise improves the electrical activity in a neuron under electromagnetic radiation.

    PubMed

    Wu, Juan; Xu, Yong; Ma, Jun

    2017-01-01

    As the fluctuations of the internal bioelectricity of nervous system is various and complex, the external electromagnetic radiation induced by magnet flux on membrane can be described by the non-Gaussian type distribution of Lévy noise. Thus, the electrical activities in an improved Hindmarsh-Rose model excited by the external electromagnetic radiation of Lévy noise are investigated and some interesting modes of the electrical activities are exhibited. The external electromagnetic radiation of Lévy noise leads to the mode transition of the electrical activities and spatial phase, such as from the rest state to the firing state, from the spiking state to the spiking state with more spikes, and from the spiking state to the bursting state. Then the time points of the firing state versus Lévy noise intensity are depicted. The increasing of Lévy noise intensity heightens the neuron firing. Also the stationary probability distribution functions of the membrane potential of the neuron induced by the external electromagnetic radiation of Lévy noise with different intensity, stability index and skewness papremeters are analyzed. Moreover, through the positive largest Lyapunov exponent, the parameter regions of chaotic electrical mode of the neuron induced by the external electromagnetic radiation of Lévy noise distribution are detected.

  7. On board electronic devices safety subject to high frequency electromagnetic radiation effects

    NASA Astrophysics Data System (ADS)

    Nikitin, V. F.; Smirnov, N. N.; Smirnova, M. N.; Tyurenkova, V. V.

    2017-06-01

    Spacecraft on board electronic devices are subjected to the effects of Space environment, in particular, electromagnetic radiation. The weight limitations for spacecraft pose an important material and structures problem: developing effective protection for on board electronic devices from high frequency electromagnetic radiation. In the present paper the problem of the effect of external high frequency electromagnetic field on electronic devices shielding located on orbital platforms is investigated theoretically. It is demonstrated that the characteristic time for the unsteady stage of the process is negligibly small as compared with characteristic time of electromagnetic field diffusion into a conductor for the studied range of governing parameters. A system of governing material parameters is distinguished, which contribute to protecting electronic devices from induced electrical currents.

  8. Transition radiation detectors: state of art and new developments

    NASA Astrophysics Data System (ADS)

    Mazziotta, M. N.; Brigida, M.; Favuzzi, C.; Fusco, P.; Gargano, F.; Giglietto, N.; Giordano, F.; Loparco, F.; Marangelli, B.; Mirizzi, N.; Rainò, S.; Spinelli, P.

    2005-08-01

    Transition radiation (TR) is emitted whenever a fast particle (γ > 1000) crosses the boundaries of a periodic structure. Since the prediction of this effect, many studies and tests have been accomplished to understand both the features of this radiation and the eventual practical applications. Nowadays. the main application of TR is particle identification in accelerator physics and astrophysics. Particle identification is one of the most challenging aspect of the experiments performed in these fields. In fact the experimental problems arisen in the recent accelerator physics pose stringent constraints on the detectors due to the high rates, severe background conditions, event final state complexity. On the other hand, the cosmic ray physics requires in some cases simple but refined and reliable devices to be used in outer space or otherwise huge and stable apparata for surface and underground laboratories. After a brief presentation of the TR phenomenon produced by ultrarelativistic particles and relative detectors, the state of the art of this particle identification technique relative to the more recent TRDs will be discussed.

  9. Laser system for testing radiation imaging detector circuits

    NASA Astrophysics Data System (ADS)

    Zubrzycka, Weronika; Kasinski, Krzysztof

    2015-09-01

    Performance and functionality of radiation imaging detector circuits in charge and position measurement systems need to meet tight requirements. It is therefore necessary to thoroughly test sensors as well as read-out electronics. The major disadvantages of using radioactive sources or particle beams for testing are high financial expenses and limited accessibility. As an alternative short pulses of well-focused laser beam are often used for preliminary tests. There are number of laser-based devices available on the market, but very often their applicability in this field is limited. This paper describes concept, design and validation of laser system for testing silicon sensor based radiation imaging detector circuits. The emphasis is put on keeping overall costs low while achieving all required goals: mobility, flexible parameters, remote control and possibility of carrying out automated tests. The main part of the developed device is an optical pick-up unit (OPU) used in optical disc drives. The hardware includes FPGA-controlled circuits for laser positioning in 2 dimensions (horizontal and vertical), precision timing (frequency and number) and amplitude (diode current) of short ns-scale (3.2 ns) light pulses. The system is controlled via USB interface by a dedicated LabVIEW-based application enabling full manual or semi-automated test procedures.

  10. Room temperature aluminum antimonide radiation detector and methods thereof

    DOEpatents

    Lordi, Vincenzo; Wu, Kuang Jen J.; Aberg, Daniel; Erhart, Paul; Coombs, III, Arthur W; Sturm, Benjamin W

    2015-03-03

    In one embodiment, a method for producing a high-purity single crystal of aluminum antimonide (AlSb) includes providing a growing environment with which to grow a crystal, growing a single crystal of AlSb in the growing environment which comprises hydrogen (H.sub.2) gas to reduce oxide formation and subsequent incorporation of oxygen impurities in the crystal, and adding a controlled amount of at least one impurity to the growing environment to effectively incorporate at least one dopant into the crystal. In another embodiment, a high energy radiation detector includes a single high-purity crystal of AlSb, a supporting structure for the crystal, and logic for interpreting signals obtained from the crystal which is operable as a radiation detector at a temperature of about 25.degree. C. In one embodiment, a high-purity single crystal of AlSb includes AlSb and at least one dopant selected from a group consisting of selenium (Se), tellurium (Te), and tin (Sn).

  11. Methodology for Assessing Radiation Detectors Used by Emergency Responders

    SciTech Connect

    Piotr Wasiolek; April Simpson

    2008-03-01

    The threat of weapons of mass destruction terrorism resulted in the U.S. Department of Homeland Security deploying large quantities of radiation detectors throughout the emergency responder community. However, emergency responders specific needs were not always met by standard health physics instrumentation used in radiation facilities. Several American National Standards Institute standards were developed and approved to evaluate the technical capabilities of detection equipment. Establishing technical capability is a critical step, but it is equally important to emergency responders that the instruments are easy to operate and can withstand the rugged situations they encounter. The System Assessment and Validation for Emergency Responders (SAVER) Program (managed by the U.S. Department of Homeland Security, Office of Grants and Training, Systems Support Division) focuses predominantly on the usability, ergonomics, readability, and other features of the detectors, rather than performance controlled by industry standards and the manufacturers. National Security Technologies, LLC, as a SAVER Technical Agent, conducts equipment evaluations using active emergency responders who are familiar with the detection equipment and knowledgeable of situations encountered in the field, which provides more relevant data to emergency responders.

  12. On the continuous spectrum electromagnetic radiation in electron-fullerene collision

    SciTech Connect

    Amusia, M.Y.

    1995-08-01

    It is demonstrated that the electromagnetic radiation spectrum in electron-fullerene collisions is dominated by a huge maximum of multielectron nature, similar to that already predicted and observed in photoabsorption. Due to coherence, the intensity of this radiation is much stronger than the sum of the intensities of isolated atoms. Experimental detection of such radiation would be of great importance for understanding the mechanism of its formation and for investigating fullerene structures. A paper describing these results was published.

  13. Long-distance transmission of light in a scintillator-based radiation detector

    DOEpatents

    Dowell, Jonathan L.; Talbott, Dale V.; Hehlen, Markus P.

    2017-07-11

    Scintillator-based radiation detectors capable of transmitting light indicating the presence of radiation for long distances are disclosed herein. A radiation detector can include a scintillator layer and a light-guide layer. The scintillator layer is configured to produce light upon receiving incident radiation. The light-guide layer is configured to receive light produced by the scintillator layer and either propagate the received light through the radiation detector or absorb the received light and emit light, through fluorescence, that is propagated through the radiation detector. A radiation detector can also include an outer layer partially surrounding the scintillator layer and light-guide layer. The index of refraction of the light-guide layer can be greater than the index of refraction of adjacent layers.

  14. Metronidazole as a protector of cells from electromagnetic radiation of extremely high frequencies

    NASA Astrophysics Data System (ADS)

    Kuznetsov, Pavel E.; Malinina, Ulia A.; Popyhova, Era B.; Rogacheva, Svetlana M.; Somov, Alexander U.

    2006-08-01

    It is well known that weak electromagnetic fields of extremely high frequencies cause significant modification of the functional status of biological objects of different levels of organization. The aim of the work was to study the combinatory effect of metronidazole - the drug form of 1-(2'hydroxiethil)-2-methil-5-nitroimidazole - and electromagnetic radiation of extremely high frequencies (52...75 GHz) on the hemolytic stability of erythrocytes and hemotaxis activity of Infusoria Paramecium caudatum.

  15. Radiation of electromagnetic waves by a dipole in an external uniform electrostatic field

    NASA Astrophysics Data System (ADS)

    Manaenkov, S. I.

    2017-01-01

    Exact solution for the electromagnetic field densities E and H of a dipole of uniformly accelerated point-charges with identical masses is discussed. It is shown that, for any fixed time t and a large distance R between the center of the dipole and the fieldpoint, | E| R -4, | H| R -5, while for large c| t| R, | E| | H| 1/ R as in spherical electromagnetic waves. Nevertheless, any irreversible radiation of electromagnetic waves is absent since the wave zone does not exist.

  16. Stored electromagnetic energy and quality factor of radiating structures

    PubMed Central

    Jelinek, Lukas; Vandenbosch, Guy A. E.

    2016-01-01

    This paper deals with the old yet unsolved problem of defining and evaluating the stored electromagnetic energy—a quantity essential for calculating the quality factor, which reflects the intrinsic bandwidth of the considered electromagnetic system. A novel paradigm is proposed to determine the stored energy in the time domain leading to the method, which exhibits positive semi-definiteness and coordinate independence, i.e. two key properties actually not met by the contemporary approaches. The proposed technique is compared with an up-to-date frequency domain method that is extensively used in practice. Both concepts are discussed and compared on the basis of examples of varying complexity. PMID:27274693

  17. Effects of Millimeter-Wave Electromagnetic Radiation on the Experimental Model of Migraine.

    PubMed

    Sivachenko, I B; Medvedev, D S; Molodtsova, I D; Panteleev, S S; Sokolov, A Yu; Lyubashina, O A

    2016-02-01

    Effects of millimeter-wave electromagnetic radiation (40 GHz frequency, 0.01 mW power) on the spontaneous fi ring of convergent neurons of the spinal trigeminal nucleus and their responses to electrical stimulation of the dura mater were studied in neurophysiological experiments on rats. Irradiation of the area of cutaneous receptive fields of spinal trigeminal nucleus reversibly inhibited both spontaneous discharges and activity induced by electrical stimulation of the dura mater. The second and third exposures to electromagnetic radiation with an interval of 10 min were ineffective. These results suggest that suppression of neuronal excitability in the spinal trigeminal ganglion can be a mechanism of the anti-migraine effects of electromagnetic radiation observed in clinical practice.

  18. Polarization of Electromagnetic Radiation a Resource for Predicting Soil Moisture

    DTIC Science & Technology

    2005-07-25

    7]. Hayt, W. (1958). Engineering electromagnetics. Mcgraw-Hill Book Company,INC, London. [8]. Musil , J . & Zacek, F. (1986). Studies...standards for landscape architecture. McGraw-Hill Publishing Company, Washington D. C. [2]. McKelvey, J . & Grotch, H. (1978). Physics for science and...6]. Thuery, J . (1992). Microwaves: Industrial, scientific and medical applications. Artech House, Inc. Norwood, Massachusetts

  19. Field Deployable Gamma Radiation Detectors for DHS Use

    SciTech Connect

    Sanjoy Mukhopadhyay

    2007-08-01

    Recently, the Department of Homeland Security (DHS) has integrated all nuclear detection research, development, testing, evaluation, acquisition, and operational support into a single office: the Domestic Nuclear Detection Office (DNDO). The DNDO has specific requirements set for all commercial off-the-shelf and government off-the-shelf radiation detection equipment and data acquisition systems. This article would investigate several recent developments in field deployable gamma radiation detectors that are attempting to meet the DNDO specifications. Commercially available, transportable, handheld radio isotope identification devices (RIID) are inadequate for DHS requirements in terms of sensitivity, resolution, response time, and reach-back capability. The leading commercial vendor manufacturing handheld gamma spectrometer in the United States is Thermo Electron Corporation. Thermo Electron's identiFINDER{trademark}, which primarily uses sodium iodide crystals (3.18 x 2.54cm cylinders) as gamma detectors, has a Full-Width-at-Half-Maximum energy resolution of 7 percent at 662 keV. Thermo Electron has just recently come up with a reach-back capability patented as RadReachBack{trademark} that enables emergency personnel to obtain real-time technical analysis of radiation samples they find in the field. The current project has the goal to build a prototype handheld gamma spectrometer, equipped with a digital camera and an embedded cell phone to be used as an RIID with higher sensitivity, better resolution, and faster response time (able to detect the presence of gamma-emitting radio isotopes within 5 seconds of approach), which will make it useful as a field deployable tool. The handheld equipment continuously monitors the ambient gamma radiation, and, if it comes across any radiation anomalies with higher than normal gamma gross counts, it sets an alarm condition. When a substantial alarm level is reached, the system automatically triggers the saving of relevant

  20. Field Deployable Gamma Radiation Detectors for DHS Use

    SciTech Connect

    Sanjoy Mukhopadhyay

    2007-08-31

    Recently, the U.S. Department of Homeland Security (DHS) has integrated all nuclear detection research, development, testing, evaluation, acquisition, and operational support into a single office: the Domestic Nuclear Detection Office (DNDO). The DNDO has specific requirements set for all commercial and government off-the-shelf radiation detection equipment and data acquisition systems. This article would investigate several recent developments in field deployable gamma radiation detectors that are attempting to meet the DNDO specifications. Commercially available, transportable, handheld radio isotope identification devices (RIID) are inadequate for DHS’s requirements in terms of sensitivity, resolution, response time and reach back capability. The leading commercial vendor manufacturing handheld gamma spectrometer in the United States is Thermo Electron Corporation. Thermo Electron’s identiFINDER™, which primarily uses sodium iodide crystals (3.18-cm x 2.54-cm cylinders) as gamma detector, has a Full-Width-at-Half-Maximum energy resolution of 7 percent at 662 keV. Thermo Electron has just recently come up with a reach-back capability patented as RadReachBack™ that enables emergency personnel to obtain real-time technical analysis of radiation samples they find in the field. The current project has the goal to build a prototype handheld gamma spectrometer, equipped with a digital camera and an embedded cell phone to be used as an RIID with higher sensitivity (comparable to that of a 7.62-cm x 7.62-cm sodium iodide crystal at low gamma energy ranging from 30 keV to 3,000 keV), better resolution (< 3.0 percent at 662 keV), faster response time (able to detect the presence of gamma-emitting radio isotopes within 5 seconds of approach), which will make it useful as a field deployable tool. The handheld equipment continuously monitors the ambient gamma radiation and, if it comes across any radiation anomalies with higher than normal gamma gross counts, it sets

  1. Field-deployable gamma-radiation detectors for DHS use

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Sanjoy

    2007-09-01

    Recently, the Department of Homeland Security (DHS) has integrated all nuclear detection research, development, testing, evaluation, acquisition, and operational support into a single office: the Domestic Nuclear Detection Office (DNDO). The DNDO has specific requirements set for all commercial off-the-shelf and government off-the-shelf radiation detection equipment and data acquisition systems. This article would investigate several recent developments in field deployable gamma radiation detectors that are attempting to meet the DNDO specifications. Commercially available, transportable, handheld radio isotope identification devices (RIID) are inadequate for DHS' requirements in terms of sensitivity, resolution, response time, and reach-back capability. The leading commercial vendor manufacturing handheld gamma spectrometer in the United States is Thermo Electron Corporation. Thermo Electron's identiFINDER TM, which primarily uses sodium iodide crystals (3.18 x 2.54cm cylinders) as gamma detectors, has a Full-Width-at-Half-Maximum energy resolution of 7 percent at 662 keV. Thermo Electron has just recently come up with a reach-back capability patented as RadReachBack TM that enables emergency personnel to obtain real-time technical analysis of radiation samples they find in the field1. The current project has the goal to build a prototype handheld gamma spectrometer, equipped with a digital camera and an embedded cell phone to be used as an RIID with higher sensitivity, better resolution, and faster response time (able to detect the presence of gamma-emitting radio isotopes within 5 seconds of approach), which will make it useful as a field deployable tool. The handheld equipment continuously monitors the ambient gamma radiation, and, if it comes across any radiation anomalies with higher than normal gamma gross counts, it sets an alarm condition. When a substantial alarm level is reached, the system automatically triggers the saving of relevant spectral data and

  2. Improved detector for the measurement of gamma radiation

    NASA Astrophysics Data System (ADS)

    Zelt, F. B.

    1985-07-01

    The present invention lies in the field of gamma ray spectrometry of geologic deposits and other materials, such as building materials (cement, asphalt, etc.) More specifically, the invention is an improved device for the gamma ray spetcrometery of gelogical deposits as a tool for petroleum exploration, geologic research and monitoring of radio-active materials such as in uranium mill tailings and the like. Improvement consists in enlarging the area of the receptor face and without any necessarily substantial increase in the volume of the receptor crystal over the current cylindrical shapes. The invention also provides, as a corollary of the increase in area receptor crystal face, a reduction in the weight of the amount of material necessary to provide effective shielding of the crystal from atmospheric radiation and radiation from deposits not under examination. The area of the receptor crystal face is increased by forming the crystal as a truncated cone with the shielding shaped as a hollow frustrum of a cone. A photomultiplier device is secured to the smaller face of the crystal. The improved detector shape can also be used in scintillometers which measure total gamma radiation.

  3. EFFECTS OF LASER RADIATION ON MATTER. LASER PLASMA: Radiation emitted by a beam of particles crossing an inhomogeneous electromagnetic wave

    NASA Astrophysics Data System (ADS)

    Kol'tsov, A. V.; Serov, Alexander V.

    1995-03-01

    A theoretical investigation is made of the time dependence of the spatial distribution of particles injected perpendicular to the direction of propagation of a linearly polarised inhomogeneous electromagnetic wave and reflected by this wave. It is shown that such reflection modulates the particle density in a beam which is homogeneous at injection. Stimulated emission of radiation from a ribbon electron beam reflected by a wave is considered. The spectral—angular and polarisation characteristics of such radiation are investigated.

  4. Electromagnetic processes in nucleus-nucleus collisions relating to space radiation research

    NASA Technical Reports Server (NTRS)

    Norbury, John W.

    1992-01-01

    Most of the papers within this report deal with electromagnetic processes in nucleus-nucleus collisions which are of concern in the space radiation program. In particular, the removal of one and two nucleons via both electromagnetic and strong interaction processes has been extensively investigated. The theory of relativistic Coulomb fission has also been developed. Several papers on quark models also appear. Finally, note that the theoretical methods developed in this work have been directly applied to the task of radiation protection of astronauts. This has been done by parameterizing the theoretical formalism in such a fashion that it can be used in cosmic ray transport codes.

  5. Modeling of the propagation of low-frequency electromagnetic radiation in the Earth’s magnetosphere

    SciTech Connect

    Lebedev, N. V. Rudenko, V. V.

    2015-06-15

    A numerical algorithm for solving the set of differential equations describing the propagation of low-frequency electromagnetic radiation in the magnetospheric plasma, including in the presence of geomagnetic waveguides in the form of large-scale plasma density inhomogeneities stretched along the Earth’s magnetic field, has been developed. Calculations of three-dimensional ray trajectories in the magnetosphere and geomagnetic waveguide with allowance for radiation polarization have revealed characteristic tendencies in the behavior of electromagnetic parameters along the ray trajectory. The results of calculations can be used for magnetospheric plasma diagnostics.

  6. Radiation reaction from electromagnetic fields in the neighborhood of a point charge

    NASA Astrophysics Data System (ADS)

    Singal, Ashok K.

    2017-03-01

    From the expression for the electromagnetic field in the neighborhood of a point charge, we determine the rate of electromagnetic momentum flow, calculated using the Maxwell stress tensor, across a surface surrounding the charge. From that we derive for a "point" charge the radiation reaction formula, which turns out to be proportional to the first time-derivative of the acceleration of the charge, identical to the expression for the self-force, hitherto obtained in the literature from the detailed mutual interaction between constituents of a small charged sphere. We then use relativistic transformations to arrive at a generalized formula for radiation reaction for a point charge undergoing relativistic motion.

  7. [Application of low-intensity and ultrahigh frequency electromagnetic radiation in modern pediatric practice].

    PubMed

    Azov, N A; Azova, E A

    2009-01-01

    The use of an Amfit-0,2/10-01 apparatus generating low-intensity ultrahigh frequency (UHF) electromagnetic radiation improved efficiency of therapy of sick children. This treatment allowed to reduce the frequency of intake of anesthetics in the post-operative period, correct metabolic disorders in children with type 1 diabetes mellitus, reduce severity of diabetic nephropathy and polyneuropathy, prevent formation of fresh foci of lipoid necrobiosis. The results of the study indicate that the use of low-intensity UHF electromagnetic radiation may be recommended for more extensive introduction into practical clinical work of pediatric endocrinologists and surgeons.

  8. Communications system using a mirror kept in outer space by electromagnetic radiation pressure

    DOEpatents

    Csonka, Paul L.

    1981-01-01

    A method and system are described for transmitting electromagnetic radiation by using a communications mirror located between about 100 kilometers and about 200 kilometers above ground. The communications mirror is kept aloft above the atmosphere by the pressure of the electromagnetic radiation which it reflects, and which is beamed at the communications mirror by a suitably constructed transmitting antenna on the ground. The communications mirror will reflect communications, such as radio, radar, or television waves up to about 1,100 kilometers away when the communications mirror is located at a height of about 100 kilometers.

  9. Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe

    DOEpatents

    Majewski, Stanislaw; Kross, Brian J.; Zorn, Carl J.; Majewski, Lukasz A.

    1996-01-01

    An optimized examination system and method based on the Reverse Geometry X-Ray.RTM. (RGX.RTM.) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first end optically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging.

  10. Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe

    SciTech Connect

    Majewski, S.; Kross, B.J.; Zorn, C.J.; Majewski, L.A.

    1996-10-22

    An optimized examination system and method based on the Reverse Geometry X-Ray{trademark} (RGX{trademark}) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first end optically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging. 5 figs.

  11. Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe

    DOEpatents

    Majewski, S.; Kross, B.J.; Zorn, C.J.; Majewski, L.A.

    1996-10-22

    An optimized examination system and method based on the Reverse Geometry X-Ray{trademark} (RGX{trademark}) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first end optically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging. 5 figs.

  12. The effect of electromagnetic radiation (550-850 nm) on 1-lactate dehydrogenase kinetics.

    PubMed

    Vojisavljevic, Vuk; Pirogova, Elena; Cosic, Irena

    2007-04-01

    This work is based on our earlier research of the Resonant Recognition Model (RRM), where we have proposed that protein activation is electromagnetic in its nature. In this study we investigated experimentally the possibility of modulating the protein activity by the electromagnetic radiation of the specific frequency. The concept is studied here by applying a visible light radiation to example of 1-Lactate Dehydrogenase enzyme (LDH). The selected LDH example is radiated by monochromatic visible light in a frequency range predicted computationally by the RRM. The kinetics of the irradiated LDH is measured by continuous monitoring of the NADH absorption at 340 nm. A comparative analysis of the LDH enzyme activity before and after the electromagnetic field (EMF) exposures is performed. It was found that the LDH activity is selectively increased only by the radiation at the particular wavelengths of 595 nm and 828 nm. These experimentally determined wavelengths of the applied EMF are within the range predicted by the RRM. Results reveal the LDH activity was modulated by the EMF exposures at the computationally predicted frequencies. The RRM concept presented provides new insights into proteins susceptibility to perturbation by electromagnetic radiation and possibility to program, predict, design and modify proteins and their bioactivity.

  13. A Study of Electromagnetic Radiation of Corona Discharge Near 500-Kv Electric Installations

    SciTech Connect

    Korzhov, A. V.; Okrainskaya, I. S.; Sidorov, A. I.; Kufel'd, V. D.

    2004-01-15

    Data on the spectral composition and intensity of electromagnetic radiation of corona discharge are obtained in an experimental study performed on the outdoor switchgear of the Shagol 500-kV substation of the Chelyabinsk Enterprise of Trunk Transmission Grids and under a 500-kV Shagol - Kozyrevo overhead transmission line. The electromagnetic environment on the territory of the 500-kV outdoor switchgear is shown to be determined by narrow-band radiations (harmonics of the frequency of electric supply) and wide-band radiations due to corona discharges of high-voltage sources. This means that the personnel experience the action of a commercial-frequency electric field and electromagnetic radiation of a quite wide range, which is not allowed for by the existing guidelines. It is recommended to continue the study in cooperation with medical institutions in order to create guidelines that would allow for the joint action of commercial-frequency electric field and electromagnetic radiation and for the voltage in the line, the current load, the meteorological situation, and other factors.

  14. BOBCAT Personal Radiation Detector Field Test and Evaluation Campaign

    SciTech Connect

    Chris Hodge

    2008-03-01

    Following the success of the Anole test of portable detection system, the U.S. Department of Homeland Security (DHS) Domestic Nuclear Detection Office organized a test and evaluation campaign for personal radiation detectors (PRDs), also known as “Pagers.” This test, “Bobcat,” was conducted from July 17 to August 8, 2006, at the Nevada Test Site. The Bobcat test was designed to evaluate the performance of PRDs under various operational scenarios, such as pedestrian surveying, mobile surveying, cargo container screening, and pedestrian chokepoint monitoring. Under these testing scenarios, many operational characteristics of the PRDs, such as gamma and neutron sensitivities, positive detection and false alarm rates, response delay times, minimum detectable activities, and source localization errors, were analyzed. This paper will present the design, execution, and methodologies used to test this equipment for the DHS.

  15. Personal Radiation Detector Field Test and Evaluation Campaign

    SciTech Connect

    Chris A. Hodge, Ding Yuan, Raymond P. Keegan, Michael A. Krstich

    2007-07-09

    Following the success of the Anole test of portable detection system, the U.S. Department of Homeland Security (DHS) Domestic Nuclear Detection Office organized a test and evaluation campaign for personal radiation detectors (PRDs), also known as 'Pagers'. This test, 'Bobcat', was conducted from July 17 to August 8, 2006, at the Nevada Test Site. The Bobcat test was designed to evaluate the performance of PRDs under various operational scenarios, such as pedestrian surveying, mobile surveying, cargo container screening, and pedestrian chokepoint monitoring. Under these testing scenarios, many operational characteristics of the PRDs, such as gamma and neutron sensitivities, positive detection and false alarm rates, response delay times, minimum detectable activities, and source localization errors, were analyzed. This paper will present the design, execution, and methodologies used to test this equipment for the DHS.

  16. Multiple cell radiation detector system, and method, and submersible sonde

    DOEpatents

    Johnson, Larry O.; McIsaac, Charles V.; Lawrence, Robert S.; Grafwallner, Ervin G.

    2002-01-01

    A multiple cell radiation detector includes a central cell having a first cylindrical wall providing a stopping power less than an upper threshold; an anode wire suspended along a cylindrical axis of the central cell; a second cell having a second cylindrical wall providing a stopping power greater than a lower threshold, the second cylindrical wall being mounted coaxially outside of the first cylindrical wall; a first end cap forming a gas-tight seal at first ends of the first and second cylindrical walls; a second end cap forming a gas-tight seal at second ends of the first and second cylindrical walls; and a first group of anode wires suspended between the first and second cylindrical walls.

  17. Electrical delay line multiplexing for pulsed mode radiation detectors

    PubMed Central

    Vinke, Ruud; Yeom, Jung Yeol; Levin, Craig S.

    2015-01-01

    Medical imaging systems are composed of a large number of position sensitive radiation detectors to provide high resolution imaging. For example, whole-body Positron Emission Tomography (PET) systems are typically composed of thousands of scintillation crystal elements, which are coupled to photosensors. Thus, PET systems greatly benefit from methods to reduce the number of data acquisition channels, in order to reduce the system development cost and complexity. In this paper we present an electrical delay line multiplexing scheme that can significantly reduce the number of readout channels, while preserving the signal integrity required for good time resolution performance. We experimented with two 4 × 4 LYSO crystal arrays, with crystal elements having 3 mm × 3 mm × 5 mm and 3 mm × 3 mm × 20 mm dimensions, coupled to 16 Hamamatsu MPPC S10931-050P SiPM elements. Results show that each crystal could be accurately identified, even in the presence of scintillation light sharing and inter-crystal Compton scatter among neighboring crystal elements. The multiplexing configuration degraded the coincidence timing resolution from ~ 243 ps FWHM to ~272 ps FWHM when 16 SiPM signals were combined into a single channel for the 4 × 4 LYSO crystal array with 3 mm × 3 mm × 20 mm crystal element dimensions, in coincidence with a 3 mm × 3 mm × 5 mm LYSO crystal pixel. The method is exible to allow multiplexing configurations across different block detectors, and is scalable to an entire ring of detectors. PMID:25768002

  18. Comparative Response of Microchannel Plate and Channel Electron Multiplier Detectors to Penetrating Radiation in Space

    SciTech Connect

    Funsten, Herbert O.; Harper, Ronnie W.; Dors, Eric E.; Janzen, Paul A.; Larsen, Brian A.; MacDonald, Elizabeth A.; Poston, David I.; Ritzau, Stephen M.; Skoug, Ruth M.; Zurbuchen, Thomas H.

    2015-10-02

    Channel electron multiplier (CEM) and microchannel plate (MCP) detectors are routinely used in space instrumentation for measurement of space plasmas. Here, our goal is to understand the relative sensitivities of these detectors to penetrating radiation in space, which can generate background counts and shorten detector lifetime. We use 662 keV γ-rays as a proxy for penetrating radiation such as γ-rays, cosmic rays, and high-energy electrons and protons that are ubiquitous in the space environment. We find that MCP detectors are ~20 times more sensitive to 662 keV γ-rays than CEM detectors. This is attributed to the larger total area of multiplication channels in an MCP detector that is sensitive to electronic excitation and ionization resulting from the interaction of penetrating radiation with the detector material. In contrast to the CEM detector, whose quantum efficiency εγ for 662 keVγ -rays is found to be 0.00175 and largely independent of detector bias, the quantum efficiency of the MCP detector is strongly dependent on the detector bias, with a power law index of 5.5. Lastly, background counts in MCP detectors from penetrating radiation can be reduced using MCP geometries with higher pitch and smaller channel diameter.

  19. Comparative Response of Microchannel Plate and Channel Electron Multiplier Detectors to Penetrating Radiation in Space

    DOE PAGES

    Funsten, Herbert O.; Harper, Ronnie W.; Dors, Eric E.; ...

    2015-10-02

    Channel electron multiplier (CEM) and microchannel plate (MCP) detectors are routinely used in space instrumentation for measurement of space plasmas. Here, our goal is to understand the relative sensitivities of these detectors to penetrating radiation in space, which can generate background counts and shorten detector lifetime. We use 662 keV γ-rays as a proxy for penetrating radiation such as γ-rays, cosmic rays, and high-energy electrons and protons that are ubiquitous in the space environment. We find that MCP detectors are ~20 times more sensitive to 662 keV γ-rays than CEM detectors. This is attributed to the larger total area ofmore » multiplication channels in an MCP detector that is sensitive to electronic excitation and ionization resulting from the interaction of penetrating radiation with the detector material. In contrast to the CEM detector, whose quantum efficiency εγ for 662 keVγ -rays is found to be 0.00175 and largely independent of detector bias, the quantum efficiency of the MCP detector is strongly dependent on the detector bias, with a power law index of 5.5. Lastly, background counts in MCP detectors from penetrating radiation can be reduced using MCP geometries with higher pitch and smaller channel diameter.« less

  20. Development of high temperature, radiation hard detectors based on diamond

    NASA Astrophysics Data System (ADS)

    Metcalfe, Alex; Fern, George R.; Hobson, Peter R.; Ireland, Terry; Salimian, Ali; Silver, Jack; Smith, David R.; Lefeuvre, Gwenaelle; Saenger, Richard

    2017-02-01

    Single crystal CVD diamond has many desirable properties compared to current, well developed, detector materials; exceptional radiation, chemical and physical hardness, chemical inertness, low Z (close to human tissue, good for dosimetry), wide bandgap and an intrinsic pathway to fast neutron detection through the 12C(n,α)9Be reaction. However effective exploitation of these properties requires development of a suitable metallisation scheme to give stable contacts for high temperature applications. To best utilise available processing techniques to optimise sensor response through geometry and conversion media configurations, a reliable model is required. This must assess the performance in terms of spectral response and overall efficiency as a function of detector and converter geometry. The same is also required for proper interpretation of experimental data. Sensors have been fabricated with varying metallisation schemes indented to permit high temperature operation; Present test results indicate that viable fabrication schemes for high temperature contacts have been developed and present modelling results, supported by preliminary data from partners indicate simulations provide a useful representation of response.

  1. Improved gas mixtures for gas-filled radiation detectors

    DOEpatents

    Christophorou, L.G.; McCorkle, D.L.; Maxey, D.V.; Carter, J.G.

    1980-03-28

    Improved binary and ternary gas mixtures for gas-filled radiation detectors are provided. The components are chosen on the basis of the principle that the first component is one molecular gas or mixture of two molecular gases having a large electron scattering cross section at energies of about 0.5 eV and higher, and the second component is a noble gas having a very small cross section at and below about 1.0 eV, whereby fast electrons in the gaseous mixture are slowed into the energy range of about 0.5 eV where the cross section for the mixture is small and hence the electron mean free path is large. The reduction in both the cross section and the electron energy results in an increase in the drift velocity of the electrons in the gas mixtures over that for the separate components for a range of E/P (pressure-reduced electric field) values. Several gas mixtures are provided that provide faster response in gas-filled detectors for convenient E/P ranges as compared with conventional gas mixtures.

  2. Gas mixtures for gas-filled radiation detectors

    DOEpatents

    Christophorou, Loucas G.; McCorkle, Dennis L.; Maxey, David V.; Carter, James G.

    1982-01-05

    Improved binary and ternary gas mixtures for gas-filled radiation detectors are provided. The components are chosen on the basis of the principle that the first component is one molecular gas or mixture of two molecular gases having a large electron scattering cross section at energies of about 0.5 eV and higher, and the second component is a noble gas having a very small cross section at and below about 1.0 eV, whereby fast electrons in the gaseous mixture are slowed into the energy range of about 0.5 eV where the cross section for the mixture is small and hence the electron mean free path is large. The reduction in both the cross section and the electron energy results in an increase in the drift velocity of the electrons in the gas mixtures over that for the separate components for a range of E/P (pressure-reduced electric field) values. Several gas mixtures are provided that provide faster response in gas-filled detectors for convenient E/P ranges as compared with conventional gas mixtures.

  3. Compensation for radiation damage of SOI pixel detector via tunneling

    NASA Astrophysics Data System (ADS)

    Yamada, M.; Arai, Y.; Fujita, Y.; Hamasaki, R.; Ikegami, Y.; Kurachi, I.; Miyoshi, T.; Nishimura, R.; Tauchi, K.; Tsuboyama, T.

    2016-09-01

    We are developing a method for removing holes trapped in the oxide layer of a silicon-on-insulator (SOI) monolithic pixel detector after irradiation. Radiation that passes through the detector generates positive charge by trapped holes in the buried oxide layer (BOX) underneath the MOSFET. The positive potential caused by these trapped holes modifies the characteristics of the MOSFET of the signal readout circuit. In order to compensate for the effect of the positive potential, we tried to recombine the trapped holes with electrons via Fowler-Nordheim (FN) tunneling. By applying high voltage to the buried p-well (BPW) under the oxide layer with the MOSFET fixed at 0 V, electrons are injected into the BOX by FN tunneling. X-rays cause a negative shift in the threshold voltage Vth of the MOSFET. We can successfully recover Vth close to its pre-irradiation level after applying VBPW ≥ 120 V. However, the drain leakage current increased after applying VBPW; we find that this can be suppressed by applying a negative voltage to the BPW.

  4. Device for conversion of electromagnetic radiation into electrical current

    DOEpatents

    Blakeslee, A. Eugene; Mitchell, Kim W.

    1981-01-01

    Electromagnetic energy may be converted directly into electrical energy by a device comprising a sandwich of at least two semiconductor portions, each portion having a p-n junction with a characteristic energy gap, and the portions lattice matched to one another by an intervening superlattice structure. This superlattice acts to block propagation into the next deposited portion of those dislocation defects which can form due to lattice mismatch between adjacent portions.

  5. Device for conversion of electromagnetic radiation into electrical current

    DOEpatents

    Blakeslee, A.E.; Mitchell, K.W.

    1980-03-25

    Electromagnetic energy may be converted directly into electrical energy by a device comprising a sandwich of at least two semiconductor portions, each portion having a p-n junction with a characteristic energy gap, and the portions lattice matched to one another by an intervening superlattice structure. This superlattice acts to block propagation into the next deposited portion of those dislocation defects which can form due to lattice mismatch between adjacent portions.

  6. Personal medical electronic devices and walk-through metal detector security systems: assessing electromagnetic interference effects.

    PubMed

    Guag, Joshua; Addissie, Bisrat; Witters, Donald

    2017-03-20

    There have been concerns that Electromagnetic security systems such as walk-through metal detectors (WTMDs) can potentially cause electromagnetic interference (EMI) in certain active medical devices including implantable cardiac pacemakers and implantable neurostimulators. Incidents of EMI between WTMDs and active medical devices also known as personal medical electronic devices (PMED) continue to be reported. This paper reports on emission measurements of sample WTMDs and testing of 20 PMEDs in a WTMD simulation system. Magnetic fields from sample WTMD systems were characterized for emissions and exposure of certain PMEDs. A WTMD simulator system designed and evaluated by FDA in previous studies was used to mimic the PMED exposures to the waveform from sample WTMDs. The simulation system allows for controlled PMED exposure enabling careful study with adjustable magnetic field strengths and exposure duration, and provides flexibility for PMED exposure at elevated levels in order to study EMI effects on the PMED. The PMED samples consisted of six implantable cardiac pacemakers, six implantable cardioverter defibrillators (ICD), five implantable neurostimulators, and three insulin pumps. Each PMED was exposed in the simulator to the sample WTMD waveforms using methods based on appropriate consensus test standards for each of the device type. Testing the sample PMEDs using the WTMD simulator revealed EMI effects on two implantable pacemakers and one implantable neurostimulator for exposure field strength comparable to actual WTMD field strength. The observed effects were transient and the PMEDs returned to pre-exposure operation within a few seconds after removal from the simulated WTMD exposure fields. No EMI was observed for the sample ICDs or insulin pumps. The findings are consistent with earlier studies where certain sample PMEDs exhibited EMI effects. Clinical implications were not addressed in this study. Additional studies are needed to evaluate potential PMED

  7. [Impact of various millimeter-range electromagnetic radiation schedules on immunological parameters in patients with respiratory sarcoidosis].

    PubMed

    Borisov, S B; Shpykov, A S; Terent'eva, N A

    2007-01-01

    The paper analyzes the impact of various millimeter-range electromagnetic radiation schedules on immunological parameters in 152 patients with new-onset respiratory sarcoidosis. It shows that the immunomodulatory effect of millimeter-range therapy depends on the treatment regimen chosen. There is evidence for the advantages of millimeter-range noise electromagnetic radiation.

  8. Radiation detector device for rejecting and excluding incomplete charge collection events

    DOEpatents

    Bolotnikov, Aleksey E.; De Geronimo, Gianluigi; Vernon, Emerson; Yang, Ge; Camarda, Giuseppe; Cui, Yonggang; Hossain, Anwar; Kim, Ki Hyun; James, Ralph B.

    2016-05-10

    A radiation detector device is provided that is capable of distinguishing between full charge collection (FCC) events and incomplete charge collection (ICC) events based upon a correlation value comparison algorithm that compares correlation values calculated for individually sensed radiation detection events with a calibrated FCC event correlation function. The calibrated FCC event correlation function serves as a reference curve utilized by a correlation value comparison algorithm to determine whether a sensed radiation detection event fits the profile of the FCC event correlation function within the noise tolerances of the radiation detector device. If the radiation detection event is determined to be an ICC event, then the spectrum for the ICC event is rejected and excluded from inclusion in the radiation detector device spectral analyses. The radiation detector device also can calculate a performance factor to determine the efficacy of distinguishing between FCC and ICC events.

  9. [Study on effects of bioelectric parameters of rats in electromagnetic radiation of HV transmission line].

    PubMed

    Zhang, Anying; Pang, Xiaofeng; Yuan, Ping

    2007-02-01

    With the development of economy and coming of information era, the chance of exposure to electromagnetic fields with various frequencies has been increased for every human. The effects of electromagnetic radiattion on human being's health are versatile. To study the effects of bioelctronic parameters of rats in the electromagnetic radiations of HV transmission line, EEG, ECG and CMAP were measured in rats exposed to simulating high-voltage transmission line electromagnetic radiation for over one year. Brain tissues were studied by Fourier transform infrared spectroscopy. The results showed that no significant difference between exposed group and control group in EEG; however the FT-infrared spectra of brain tissues were different; the ECG of the exposed animals was considerably altered. Significant slowing of heart rate was observed in those rates exposed to EMFs; the latent period of CMAP in exposed group were not different compared with those of control group however there was a significant difference in wave amplitude of CMAP between the exposed group and control group. All results indicated that there must be some effects on bioelectric parameters of rats exposed to electromagnetic radiation of high-voltage transmission line for a long time.

  10. Derivation of the blackbody radiation spectrum from the equivalence principle in classical physics with classical electromagnetic zero-point radiation

    SciTech Connect

    Boyer, T.H.

    1984-03-15

    A derivation of Planck's spectrum including zero-point radiation is given within classical physics from recent results involving the thermal effects of acceleration through classical electromagnetic zero-point radiation. A harmonic electric-dipole oscillator undergoing a uniform acceleration a through classical electromagnetic zero-point radiation responds as would the same oscillator in an inertial frame when not in zero-point radiation but in a different spectrum of random classical radiation. Since the equivalence principle tells us that the oscillator supported in a gravitational field g = -a will respond in the same way, we see that in a gravitational field we can construct a perpetual-motion machine based on this different spectrum unless the different spectrum corresponds to that of thermal equilibrium at a finite temperature. Therefore, assuming the absence of perpetual-motion machines of the first kind in a gravitational field, we conclude that the response of an oscillator accelerating through classical zero-point radiation must be that of a thermal system. This then determines the blackbody radiation spectrum in an inertial frame which turns out to be exactly Planck's spectrum including zero-point radiation.

  11. Food collection and response to pheromones in an ant species exposed to electromagnetic radiation.

    PubMed

    Cammaerts, Marie-Claire; Rachidi, Zoheir; Bellens, François; De Doncker, Philippe

    2013-09-01

    We used the ant species Myrmica sabuleti as a model to study the impact of electromagnetic waves on social insects' response to their pheromones and their food collection. We quantified M. sabuleti workers' response to their trail, area marking and alarm pheromone under normal conditions. Then, we quantified the same responses while under the influence of electromagnetic waves. Under such an influence, ants followed trails for only short distances, no longer arrived at marked areas and no longer orientated themselves to a source of alarm pheromone. Also when exposed to electromagnetic waves, ants became unable to return to their nest and recruit congeners; therefore, the number of ants collecting food increases only slightly and slowly. After 180 h of exposure, their colonies deteriorated. Electromagnetic radiation obviously affects social insects' behavior and physiology.

  12. The Electromagnetic Dipole Radiation Field through the Hamiltonian Approach

    ERIC Educational Resources Information Center

    Likar, A.; Razpet, N.

    2009-01-01

    The dipole radiation from an oscillating charge is treated using the Hamiltonian approach to electrodynamics where the concept of cavity modes plays a central role. We show that the calculation of the radiation field can be obtained in a closed form within this approach by emphasizing the role of coherence between the cavity modes, which is…

  13. The Electromagnetic Dipole Radiation Field through the Hamiltonian Approach

    ERIC Educational Resources Information Center

    Likar, A.; Razpet, N.

    2009-01-01

    The dipole radiation from an oscillating charge is treated using the Hamiltonian approach to electrodynamics where the concept of cavity modes plays a central role. We show that the calculation of the radiation field can be obtained in a closed form within this approach by emphasizing the role of coherence between the cavity modes, which is…

  14. [Effect of radiofrequency of electromagnetic radiation on yeast sensitivity to fungicide antibiotics].

    PubMed

    Voĭchuk, S I; Gromozova, E N

    2004-01-01

    Saccharomyces cerevisiae UCM Y-517, Candida utilis UCM Y-961 and Schizosaccharomyces pombe UCM Y-94T have been studied for their sensitivity to fungicide antibiotics under the effect of electromagnetic radiation (40.68 MHz, 15 and 30 W). Yeast sensitivity to nystatin, amphotericin B, klotrimazol, itrakonazol, flukonazol as well as the effects arising as a result of the effect of radiofrequency radiation are characterized by species specificity. Irradiation did not exert statistically reliable effect on S. cerevisiae and S. pombe sensitivity to fungicide antibiotics. The increase of resistance of C. utilis to antibiotics (growth delay zones were absent in 70-90% of experiments) in the case of preliminary irradiation of this strain was stated. Separate preliminary irradiation of antibiotics did not result in the change of their antifungal activity. The arising effects were noticed to depend on the radiation power. Possible reasons of species specificity in sensing electromagnetic radiation are considered.

  15. ON DISCOVERING ELECTROMAGNETIC EMISSION FROM NEUTRON STAR MERGERS: THE EARLY YEARS OF TWO GRAVITATIONAL WAVE DETECTORS

    SciTech Connect

    Kasliwal, Mansi M.; Nissanke, Samaya

    2014-07-01

    We present the first simulation addressing the prospects of finding an electromagnetic (EM) counterpart to gravitational wave (GW) detections during the early years of only two advanced detectors. The perils of such a search may have appeared insurmountable when considering the coarse ring-shaped GW localizations spanning thousands of square degrees using time-of-arrival information alone. Leveraging the amplitude and phase information of the predicted GW signal narrows the localization to arcs with a median area of only a few hundred square degrees, thereby making an EM search tractable. Based on the locations and orientations of the two LIGO detectors, we find that the GW sensitivity is limited to only two of the four sky quadrants. Thus, the rates of GW events with two interferometers is only ≈40% of the rate with three interferometers of similar sensitivity. Another important implication of the sky quadrant bias is that EM observatories in North America and Southern Africa would be able to systematically respond to GW triggers several hours sooner than Russia and Chile. Given the larger sky areas and the relative proximity of detected mergers, 1 m class telescopes with very wide-field cameras are well-positioned for the challenge of finding an EM counterpart. Identification of the EM counterpart amidst the larger numbers of false positives further underscores the importance of building a comprehensive catalog of foreground stellar sources, background active galactic nucleus and potential host galaxies in the local universe. This initial study is based on a small sample of 17 detected mergers; future works will expand this sample.

  16. Review of studies on modulating enzyme activity by low intensity electromagnetic radiation.

    PubMed

    Vojisavljevic, Vuk; Pirogova, Elena; Cosic, Irena

    2010-01-01

    This paper is a compilation of our findings on non-thermal effects of electromagnetic radiation (EMR) at the molecular level. The outcomes of our studies revealed that that enzymes' activity can be modulated by external electromagnetic fields (EMFs) of selected frequencies. Here, we discuss the possibility of modulating protein activity using visible and infrared light based on the concepts of protein activation outlined in the resonant recognition model (RRM), and by low intensity microwaves. The theoretical basis behind the RRM model expounds a potential interaction mechanism between electromagnetic radiation and proteins as well as protein-protein interactions. Possibility of modulating protein activity by external EMR is experimentally validated by irradiation of the L-lactate Dehydrogenase enzyme.

  17. Wire-chamber radiation detector with discharge control

    DOEpatents

    Perez-Mendez, V.; Mulera, T.A.

    1982-03-29

    A wire chamber; radiation detector has spaced apart parallel electrodes and grids defining an ignition region in which charged particles or other ionizing radiations initiate brief localized avalanche discharges and defining an adjacent memory region in which sustained glow discharges are initiated by the primary discharges. Conductors of the grids at each side of the memory section extend in orthogonal directions enabling readout of the X-Y coordinates of locations at which charged particles were detected by sequentially transmitting pulses to the conductors of one grid while detecting transmissions of the pulses to the orthogonal conductors of the other grid through glow discharges. One of the grids bounding the memory region is defined by an array of conductive elements each of which is connected to the associated readout conductor through a separate resistance. The wire chamber avoids ambiguities and imprecisions in the readout of coordinates when large numbers of simultaneous or; near simultaneous charged particles have been detected. Down time between detection periods and the generation of radio frequency noise are also reduced.

  18. Grad-Level Radiation Damage of SIO2 Detectors

    SciTech Connect

    Simos, N.; Atoian, G.; Ludewig, H; White, S; O'Conor, J; Mokhov, N.V.

    2009-05-04

    Radiation effects and levels to detectors. SiO{sub 2} quartz fibers of the LHC ATLAS Zero-degree Calorimeter (ZDC) anticipated to experience integrated doses of a few Grad at their closest position were exposed to 200 MeV protons and neutrons at the Brookhaven National Laboratory (BNL) Linac. Specifically, 1 mm- and 2mm-diameter quartz (GE 124) rods were exposed to direct 200 MeV protons during the first phase of exposure leading to peak integrated dose of {approx}28 Grad. Exposure to a primarily neutron flux of 1mm-diameter SiO{sub 2} fibers was also achieved with a special neutron source arrangement. In a post-irradiation analysis the quartz fiber transmittance was evaluated as a function of the absorbed dose. Dramatic degradation of the transmittance property was observed with increased radiation damage. In addition, detailed evaluation of the fibers under the microscope revealed interesting micro-structural damage features and irradiation-induced defects.

  19. Effect of electromagnetic microwave radiation on the growth of Ehrlich ascites carcinoma.

    PubMed

    Kryukova, O V; Pyankov, V F; Kopylov, A F; Khlebopros, R G

    2016-09-01

    Daily exposure of mouse recipients of Ehrlich ascites carcinoma to electromagnetic radiation of the microwave range leads to a change in the dynamics of tumor growth by decreasing the total number of cells. The number of tumor cells with blebbing morphological signs after microwave radiation increases gradually with tumor growth. The maximum content of tumor cells in the state of blebbing is observed during active proliferation in tumor-recipient mice of the control group (without irradiation).

  20. Magnetic field instability of a plasma in a beam of electromagnetic radiation

    NASA Astrophysics Data System (ADS)

    Gradov, O. M.; Stenflo, L.

    1980-04-01

    A beam of electromagnetic radiation can generate magnetic fields in plasmas. It is shown that those fields grow significantly when the incident radiation is sufficiently strong. We obtain expressions for the characteristic time of the growth of the fields as well as for their spatial distribution and point out a possible mechanism, which can lead to the formation of a quasi-stationary state. The maximum value of the magnetic field strength is estimated.

  1. Effects of Electromagnetic Radiation from Smartphones on Learning Ability and Hippocampal Progenitor Cell Proliferation in Mice

    PubMed Central

    Choi, Yu-Jin; Choi, Yun-Sik

    2015-01-01

    Objectives Nonionizing radiation is emitted from electronic devices, such as smartphones. In this study, we intended to elucidate the effect of electromagnetic radiation from smartphones on spatial working memory and progenitor cell proliferation in the hippocampus. Methods Both male and female mice were randomly separated into two groups (radiated and control) and the radiated group was exposed to electromagnetic radiation for 9 weeks and 11 weeks for male and female mice, respectively. Spatial working memory was examined with a Y maze, and proliferation of hippocampal progenitor cells were examined by 5-bromo-2′-deoxyuridine administration and immunohistochemical detection. Results When spatial working memory on a Y maze was examined in the 9th week, there was no significant difference in the spontaneous alternation score on the Y maze between the two groups. In addition, there was no significant difference in hippocampal progenitor cell proliferation. However, immunoreactivity to glial fibrillary acidic protein was increased in exposed animals. Next, to test the effect of recovery following chronic radiation exposure, the remaining female mice were further exposed to electromagnetic radiation for 2 more weeks (total 11 weeks), and spontaneous alternation was tested 4 weeks later. In this experiment, although there was no significant difference in the spontaneous alternation scores, the number of arm entry was significantly increased. Conclusion These data indicate that although chronic electromagnetic radiation does not affect spatial working memory and hippocampal progenitor cell proliferation it can mediate astrocyte activation in the hippocampus and delayed hyperactivity-like behavior. PMID:26981337

  2. Method and system for determining depth distribution of radiation-emitting material located in a source medium and radiation detector system for use therein

    DOEpatents

    Benke, Roland R.; Kearfott, Kimberlee J.; McGregor, Douglas S.

    2004-04-27

    A radiation detector system includes detectors having different properties (sensitivity, energy resolution) which are combined so that excellent spectral information may be obtained along with good determinations of the radiation field as a function of position.

  3. Non-thermal continuous and modulated electromagnetic radiation fields effects on sleep EEG of rats☆

    PubMed Central

    Mohammed, Haitham S.; Fahmy, Heba M.; Radwan, Nasr M.; Elsayed, Anwar A.

    2012-01-01

    In the present study, the alteration in the sleep EEG in rats due to chronic exposure to low-level non-thermal electromagnetic radiation was investigated. Two types of radiation fields were used; 900 MHz unmodulated wave and 900 MHz modulated at 8 and 16 Hz waves. Animals has exposed to radiation fields for 1 month (1 h/day). EEG power spectral analyses of exposed and control animals during slow wave sleep (SWS) and rapid eye movement sleep (REM sleep) revealed that the REM sleep is more susceptible to modulated radiofrequency radiation fields (RFR) than the SWS. The latency of REM sleep increased due to radiation exposure indicating a change in the ultradian rhythm of normal sleep cycles. The cumulative and irreversible effect of radiation exposure was proposed and the interaction of the extremely low frequency radiation with the similar EEG frequencies was suggested. PMID:25685416

  4. Quantum radiation of Maxwell’s electromagnetic field in nonstationary Kerr-de Sitter black hole

    NASA Astrophysics Data System (ADS)

    Ibungochouba Singh, T.; Ablu Meitei, I.; Yugindro Singh, K.

    2016-03-01

    Quantum radiation properties of nonstationary Kerr-de Sitter (KdS) black hole is investigated using the method of generalized tortoise coordinate transformation. The locations of horizons and the temperature of the thermal radiation as well as the maximum energy of the nonthermal radiation are derived. It is found that the surface gravity and the Hawking temperature depend on both time and different angles. An extra coupling effect is obtained in the thermal radiation spectrum of Maxwell’s electromagnetic field equations which is absent in the thermal radiation spectrum of scalar particles. Further, the chemical potential derived from the thermal radiation spectrum of scalar particle has been found to be equal to the highest energy of the negative energy state of the scalar particle in the nonthermal radiation for KdS black hole. It is also shown that the generalized tortoise coordinate transformation produces a constant term in the expression of the surface gravity and Hawking temperature.

  5. Non-thermal continuous and modulated electromagnetic radiation fields effects on sleep EEG of rats.

    PubMed

    Mohammed, Haitham S; Fahmy, Heba M; Radwan, Nasr M; Elsayed, Anwar A

    2013-03-01

    In the present study, the alteration in the sleep EEG in rats due to chronic exposure to low-level non-thermal electromagnetic radiation was investigated. Two types of radiation fields were used; 900 MHz unmodulated wave and 900 MHz modulated at 8 and 16 Hz waves. Animals has exposed to radiation fields for 1 month (1 h/day). EEG power spectral analyses of exposed and control animals during slow wave sleep (SWS) and rapid eye movement sleep (REM sleep) revealed that the REM sleep is more susceptible to modulated radiofrequency radiation fields (RFR) than the SWS. The latency of REM sleep increased due to radiation exposure indicating a change in the ultradian rhythm of normal sleep cycles. The cumulative and irreversible effect of radiation exposure was proposed and the interaction of the extremely low frequency radiation with the similar EEG frequencies was suggested.

  6. [Paternal exposure to occupational electromagnetic radiation and sex ratio of the offspring: a meta-analysis].

    PubMed

    Tong, Shu-Hui; Liu, Yi-Ting; Liu, Yang

    2013-02-01

    To investigate the association between paternal exposure to occupational electromagnetic radiation and the sex ratio of the offspring. We searched various databases, including PubMed, Embase, Cochrane Library, OVID, Bioscience Information Service (BIOSIS), China National Knowledge Infrastructure, VIP Database for Chinese Technical Periodicals and Wanfang Database, for the literature relevant to the association of paternal exposure to occupational electromagnetic radiation with the sex ratio of the offspring. We conducted a meta-analysis on their correlation using Stata 11.0. There was no statistically significant difference in the sex ratio between the offspring with paternal exposure to occupational electromagnetic radiation and those without (pooled OR = 1.00 [95% CI: 0.95 -1.05], P = 0.875). Subgroup analysis of both case-control and cohort studies revealed no significant difference (pooled OR = 1.03 [95% CI: 0.99 -1.08], P = 0.104 and pooled OR = 0.98 [95% CI: 0.99 -1.08], P = 0.186, respectively). Paternal exposure to occupational electromagnetic radiation is not correlated with the sex ratio of the offspring.

  7. [Reparative Osteogenesis and Angiogenesis in Low Intensity Electromagnetic Radiation of Ultra-High Frequency].

    PubMed

    Iryanov, Y M; Kiryanov, N A

    2015-01-01

    Non-drug correction of reparative bone tissue regeneration in different pathological states - one of the most actual problems of modern medicine. Our aim was to conduct morphological analysis of the influence of electromagnetic radiation of ultra-high frequency and low intensity on reparative osteogenesis and angiogenesis in fracture treatment under transosseous osteosynthesis. A controlled nonrandomized study was carried out. In the experiment conducted on rats we modeled tibial fracture with reposition and fixation of the bone fragments both in control and experimental groups. In the animals of the experimental group the fracture zone was exposed to low intensity electromagnetic radiation of ultra-high frequency. Exposure simulation was performed in the control group. The operated bones were examined using radiography, light and electronic microscopy, X-ray electronic probe microanalysis. It has been established that electromagnetic radiation of ultra-high frequency sessions in fracture treatment stimulate secretory activity and degranulation of mast cells, produce microcirculatory bed vascular permeability increase, endotheliocyte migration phenotype expression, provide endovascular endothelial outgrowth formation, activate reparative osteogenesis and angiogenesis while fracture reparation becomes the one of the primary type. The full periosteal, intermediary and intraosteal bone union was defined in 28 days. Among the therapeutic benefits of electromagnetic radiation of ultra-high frequency in fracture treatment we can detect mast cell secretorv activity stimulation and endovascular anziozenesis activation.

  8. Electromagnetic Radiation Hazards Testing for Non-Ionizing Radio Frequency Transmitting Equipment

    DTIC Science & Technology

    2012-12-19

    Ordnance (HERO), Personnel ( HERP ), and Fuel (HERF) protection guidance for intentional non-ionizing Radio Frequency (RF) transmitting equipment as...Effects HERO RADHAZ HERF HERP RF 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18. NUMBER OF...Hazards of Electromagnetic Radiation to Ordnance (HERO), Personnel ( HERP ), and Fuel (HERF) protection guidance for intentional non-ionizing Radio

  9. [Interaction of oxytocin, laser and electromagnetic radiation on the persistence properties of Staphylococcus aureus].

    PubMed

    Kurlaev, P P; Chernova, O L; Kirgizova, S B

    2000-01-01

    The suppressive action of oxytocin, heliumneon radiation and ultrahigh-frequency electromagnetic waves (UHF-therapy) on the persistence properties of S. aureus has been experimentally established. The effectiveness of the therapeutic actions under study in the treatment of patients with the prognosticated unfavorable course of purulent inflammatory diseases of soft tissues has been shown.

  10. Electromagnetic Radiation from Vortex Flow in Type-II Superconductors

    SciTech Connect

    Bulaevskii, L. N.; Chudnovsky, E. M.

    2006-11-10

    We show that a moving vortex lattice, as it comes to a crystal edge, radiates into a free space the harmonics of the washboard frequency, {omega}{sub 0}=2{pi}v/a, up to a superconducting gap, {delta}/({Dirac_h}/2{pi}). Here v is the velocity of the vortex lattice and a is the intervortex spacing. We compute radiation power and show that this effect can be used for the generation of terahertz radiation and for characterization of moving vortex lattices.

  11. Electromagnetic radiation from vortex flow in Type-II superconductors.

    PubMed

    Bulaevskii, L N; Chudnovsky, E M

    2006-11-10

    We show that a moving vortex lattice, as it comes to a crystal edge, radiates into a free space the harmonics of the washboard frequency, omega(0)=2pi v/a, up to a superconducting gap, Delta/variant Planck's over 2pi. Here v is the velocity of the vortex lattice and a is the intervortex spacing. We compute radiation power and show that this effect can be used for the generation of terahertz radiation and for characterization of moving vortex lattices.

  12. On the possibility to use semiconductive hybrid pixel detectors for study of radiation belt of the Earth.

    NASA Astrophysics Data System (ADS)

    Guskov, A.; Shelkov, G.; Smolyanskiy, P.; Zhemchugov, A.

    2016-02-01

    The scientific apparatus GAMMA-400 designed for study of electromagnetic and hadron components of cosmic rays will be launched to an elliptic orbit with the apogee of about 300 000 km and the perigee of about 500 km. Such a configuration of the orbit allows it to cross periodically the radiation belt and the outer part of magnetosphere. We discuss the possibility to use hybrid pixel detecters based on the Timepix chip and semiconductive sensors on board the GAMMA-400 apparatus. Due to high granularity of the sensor (pixel size is 55 mum) and possibility to measure independently an energy deposition in each pixel, such compact and lightweight detector could be a unique instrument for study of spatial, energy and time structure of electron and proton components of the radiation belt.

  13. [Effects of electromagnetic radiation on health and immune function of operators].

    PubMed

    Li, Yan-zhong; Chen, Shao-hua; Zhao, Ke-fu; Gui, Yun; Fang, Si-xin; Xu, Ying; Ma, Zi-jian

    2013-08-01

    To investigate the effects of electromagnetic radiation on the physiological indices and immune function of operators. The general conditions and electromagnetic radiation awareness rate of 205 operators under electromagnetic radiation were evaluated using a self-designed questionnaire. Physical examination, electrocardiography, and routine urine test were performed in these operators. Peripheral blood was collected from the operators under electromagnetic radiation for blood cell counting and biochemical testing, and their peripheral blood lymphocytes were cultured for determination of chromosomal aberrant frequency and micronucleus frequency. The data from these operators (exposure group) were compared with those of 95 ordinary individuals (control group). The chief complaint of giddiness, tiredness, dizziness, and amnesia showed significant differences between the exposure group and control group (P < 0.01), and the difference in headache became larger with an increase in working years. The awareness rate of electromagnetic radiation damage was significantly higher in the exposure group than in the control group. The difference in bradycardia was significant between the two groups (P <0.01), and the incidence was higher with longer working years. Significant differences between the two groups were also found in the numbers of individuals with elevated alanine aminotransferase, total bilirubin, and direct bilirubin (P < 0.01), populations with increased lymphocyte ratio and decreased neutrophil ratio (P < 0.01), populations with positive occult blood, urobilinogen, and bilirubin tests, and the number of individuals with increased micronucleus frequency of cultured peripheral blood lymphocytes (P < 0.01). In addition, the exposure group had significantly increased complement C3 and C4 (P < 0.01), significantly increased IgG (P < 0.05), and significantly decreased IgM (P < 0.01), as compared with the control group. Electromagnetic radiation may lead to the changes

  14. On the Transport and Radiative Properties of Plasmas with Small-Scale Electromagnetic Fluctuations

    NASA Astrophysics Data System (ADS)

    Keenan, Brett D.

    Plasmas with sub-Larmor-scale ("small-scale") electromagnetic fluctuations are a feature of a wide variety of high-energy-density environments, and are essential to the description of many astrophysical/laboratory plasma phenomena. Radiation from particles, whether they be relativistic or non-relativistic, moving through small-scale electromagnetic turbulence has spectral characteristics distinct from both synchrotron and cyclotron radiation. The radiation, carrying information on the statistical properties of the turbulence, is also intimately related to the particle diffusive transport. We investigate, both theoretically and numerically, the transport of non-relativistic and transrelativistic particles in plasmas with high-amplitude isotropic sub-Larmor-scale magnetic turbulence---both with and without a mean field component---and its relation to the spectra of radiation simultaneously produced by these particles. Furthermore, the transport of particles through small-scale electromagnetic turbulence---under certain conditions---resembles the random transport of particles---via Coulomb collisions---in collisional plasmas. The pitch-angle diffusion coefficient, which acts as an effective "collision" frequency, may be substantial in these, otherwise, collisionless environments. We show that this effect, colloquially referred to as the plasma "quasi-collisionality", may radically alter the expected radiative transport properties of candidate plasmas. We argue that the modified magneto-optic effects in these plasmas provide an attractive, novel, diagnostic tool for the exploration and characterization of small-scale electromagnetic turbulence. Lastly, we speculate upon the manner in which quasi-collisions may affect inertial confinement fusion (ICF), and other laser-plasma experiments. Finally, we show that mildly relativistic jitter radiation, from laser-produced plasmas, may offer insight into the underlying electromagnetic turbulence. Here we investigate the

  15. [Effects of extremely low frequency electromagnetic radiation on cardiovascular system of workers].

    PubMed

    Zhao, Long-yu; Song, Chun-xiao; Yu, Duo; Liu, Xiao-liang; Guo, Jian-qiu; Wang, Chuan; Ding, Yuan-wei; Zhou, Hong-xia; Ma, Shu-mei; Liu, Xiao-dong; Liu, Xin

    2012-03-01

    To observe the exposure levels of extremely low frequency electromagnetic fields in workplaces and to analyze the effects of extremely low frequency electromagnetic radiation on cardiovascular system of occupationally exposed people. Intensity of electromagnetic fields in two workplaces (control and exposure groups) was detected with EFA-300 frequency electromagnetic field strength tester, and intensity of the noise was detected with AWA5610D integral sound level. The information of health physical indicators of 188 controls and 642 occupationally exposed workers was collected. Data were analyzed by SPSS17.0 statistic software. The intensity of electric fields and the magnetic fields in exposure groups was significantly higher than that in control group (P < 0.05), but there was no significant difference of noise between two workplaces (P > 0.05). The results of physical examination showed that the abnormal rates of HCY, ALT, AST, GGT, ECG in the exposure group were significantly higher than those in control group (P < 0.05). There were no differences of sex, age, height, weight between two groups (P > 0.05). Exposure to extremely low frequency electromagnetic radiation may have some effects on the cardiovascular system of workers.

  16. Study Regarding Electromagnetic Radiation Exposure Generated By Mobile Phone

    SciTech Connect

    Marica, Lucia; Moraru, Luminita

    2011-12-26

    Number of mobile phone users reached to 5 billion subscribers in 2010 [ABI Research, 2010]. A large number of studies illustrated the public concern about adverse effects of mobile phone radiation and possible health hazards. Position of mobile phone use in close proximity to the head leads the main radiation between the hand and the head. Many investigations studying the possible effects of mobile phone exposure, founded no measurable effects of short-term mobile phone radiation, and there was no evidence for the ability to perceive mobile phone EMF in the general population. In this study, field radiation measurements were performed on different brand and different models of mobile phones in active mode, using an EMF RF Radiation Field Strength Power Meter 1 MHz-8 GHz. The study was effectuated on both the 2G and 3G generations phones connected to the providers operating in the frequency range 450 MHz-1800 MHz. There were recorded values in outgoing call and SMS mode, incoming call and SMS mode. Results were compared with ICNIRP guidelines for exposure to general public.

  17. Study Regarding Electromagnetic Radiation Exposure Generated By Mobile Phone

    NASA Astrophysics Data System (ADS)

    Marica, Lucia; Moraru, Luminita

    2011-12-01

    Number of mobile phone users reached to 5 billion subscribers in 2010 [ABI Research, 2010]. A large number of studies illustrated the public concern about adverse effects of mobile phone radiation and possible health hazards. Position of mobile phone use in close proximity to the head leads the main radiation between the hand and the head. Many investigations studying the possible effects of mobile phone exposure, founded no measurable effects of short-term mobile phone radiation, and there was no evidence for the ability to perceive mobile phone EMF in the general population. In this study, field radiation measurements were performed on different brand and different models of mobile phones in active mode, using an EMF RF Radiation Field Strength Power Meter 1 MHz-8 GHz. The study was effectuated on both the 2G and 3G generations phones connected to the providers operating in the frequency range 450 MHz-1800 MHz. There were recorded values in outgoing call and SMS mode, incoming call and SMS mode. Results were compared with ICNIRP guidelines for exposure to general public.

  18. Plural-wavelength flame detector that discriminates between direct and reflected radiation

    NASA Technical Reports Server (NTRS)

    Hall, Gregory H. (Inventor); Barnes, Heidi L. (Inventor); Medelius, Pedro J. (Inventor); Simpson, Howard J. (Inventor); Smith, Harvey S. (Inventor)

    1997-01-01

    A flame detector employs a plurality of wavelength selective radiation detectors and a digital signal processor programmed to analyze each of the detector signals, and determine whether radiation is received directly from a small flame source that warrants generation of an alarm. The processor's algorithm employs a normalized cross-correlation analysis of the detector signals to discriminate between radiation received directly from a flame and radiation received from a reflection of a flame to insure that reflections will not trigger an alarm. In addition, the algorithm employs a Fast Fourier Transform (FFT) frequency spectrum analysis of one of the detector signals to discriminate between flames of different sizes. In a specific application, the detector incorporates two infrared (IR) detectors and one ultraviolet (UV) detector for discriminating between a directly sensed small hydrogen flame, and reflections from a large hydrogen flame. The signals generated by each of the detectors are sampled and digitized for analysis by the digital signal processor, preferably 250 times a second. A sliding time window of approximately 30 seconds of detector data is created using FIFO memories.

  19. Plant sensitivity to low intensity 105 GHz electromagnetic radiation.

    PubMed

    Tafforeau, Marc; Verdus, Marie-Claire; Norris, Vic; White, Glenn J; Cole, Mike; Demarty, Maurice; Thellier, Michel; Ripoll, Camille

    2004-09-01

    Exposing seedlings of the flax, Linum usitatissimum L., to a variety of weak environmental stresses followed by a 2 day calcium deprivation, triggers the common response of production of epidermal meristems (actively dividing groups of cells) in the hypocotyl, which is the part of the stem between the root and the cotyledons (the pre-existing leaves in the embryo). This production reaches a plateau of 10-20 meristems after a month in the case of mechanical stimulation and cold shock. Recently, we have shown that radiation from a global system for mobile communication (GSM) telephone also triggers production of meristems with a plateau of around six meristems. Here, we show that a single 2 h exposure to radiation emitted at 105 GHz at non-thermal levels by a Gunn oscillator induces meristem production with kinetics similar to that induced by weak environmental stimuli and radiation from GSM telephone.

  20. Radiation Protection of New Lightweight Electromagnetic Interference Shielding Materials Determined

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Weight savings as high as 80 percent could be achieved by simply switching from aluminum electromagnetic interference (EMI) shielding covers for spacecraft power systems to EMI covers made from intercalated graphite fiber composites. Because EMI covers typically make up about one-fifth of the power system mass, this change would decrease the mass of a spacecraft power system by more than 15 percent. Intercalated graphite fibers are made by diffusing guest atoms or molecules, such as bromine, between the carbon planes of the graphite fibers. The resulting bromine-intercalated fibers have mechanical and thermal properties nearly identical to pristine graphite fibers, but their resistivity is lower by a factor of 5, giving them better electrical conductivity than stainless steel and making these composites suitable for EMI shielding.

  1. Immunologic and hematopoietic alterations by 2,450-MHz electromagnetic radiation.

    PubMed

    Huang, A T; Mold, N G

    1980-01-01

    A biphasic modulation of responsiveness of spleen lymphocytes to mitogens was observed in mice exposed to 2,450-MHz radiation at power densities of 5-15 mW/cm2 over various periods ranging between one and 17 days. This modulated phenomenon may be explained on the basis of 1) suppression of lymphocyte response to microwave-activated macrophages which persists throughout the entire course of radiation, and 2) concurrent progressive direct stimulation of lymphocytes which culminates around day 9 of exposure. Tumor cytotoxicity of killer lymphocytes from mice exposed to five or nine days of radiation did not appear different from sham controls. The highly proliferative hematopoietic marrow cells were sensitive to microwave radiation. Nine days of exposure to radiation (15 mW/cm2) reduced the colony-forming units of myeloid and erythroid series by 50%. This observation may offer a new and more sensitive assay for studying biological effects of electromagnetic radiation.

  2. Electromagnetic fields radiated from a lightning return stroke - Application of an exact solution to Maxwell's equations

    NASA Technical Reports Server (NTRS)

    Le Vine, D. M.; Meneghini, R.

    1978-01-01

    A solution is presented for the electromagnetic fields radiated by an arbitrarily oriented current filament over a conducting ground plane in the case where the current propagates along the filament at the speed of light, and this solution is interpreted in terms of radiation from lightning return strokes. The solution is exact in the fullest sense; no mathematical approximations are made, and the governing differential equations and boundary conditions are satisfied. The solution has the additional attribute of being specified in closed form in terms of elementary functions. This solution is discussed from the point of view of deducing lightning current wave forms from measurements of the electromagnetic fields and understanding the effects of channel tortuosity on the radiated fields. In addition, it is compared with two approximate solutions, the traditional moment approximation and the Fraunhofer approximation, and a set of criteria describing their applicability are presented and interpreted.

  3. Effects of GSM-Frequency Electromagnetic Radiation on Some Physiological and Biochemical Parameters in Rats.

    PubMed

    Khirazova, E E; Baizhumanov, A A; Trofimova, L K; Deev, L I; Maslova, M V; Sokolova, N A; Kudryashova, N Yu

    2012-10-01

    Single exposure of white outbred rats to electromagnetic radiation with a frequency 905 MHz (GSM frequency) for 2 h increased anxiety, reduced locomotor, orientation, and exploration activities in females and orientation and exploration activities in males. Glucocorticoid levels and antioxidant system activity increased in both males and females. In addition to acute effects, delayed effects of radiation were observed in both males and females 1 day after the exposure. These results demonstrated significant effect of GSM-range radiation on the behavior and activity of stress-realizing and stress-limiting systems of the body.

  4. Electromagnetic radiation from a plasma slab during the development of Weibel instability

    SciTech Connect

    Vagin, K. Yu.; Romanov, A. Yu.; Uryupin, S. A.

    2012-01-15

    Electromagnetic radiation from an anisotropic plasma slab formed by ionization of matter in the field of a high-power femtosecond pulse is studied. It is shown that the growth of initial field perturbations in the course of Weibel instability is accompanied by the generation of nonmonochromatic radiation with a characteristic frequency on the order of the instability growth rate. It is found that perturbations with characteristic scale lengths less than or on the order of the ratio of the speed of light to the Langmuir frequency are excited and radiated most efficiently, provided that the slab is thicker than this ratio.

  5. Soft-photon emission effects and radiative corrections for electromagnetic processes at very high energies

    NASA Technical Reports Server (NTRS)

    Gould, R. J.

    1979-01-01

    Higher-order electromagnetic processes involving particles at ultrahigh energies are discussed, with particular attention given to Compton scattering with the emission of an additional photon (double Compton scattering). Double Compton scattering may have significance in the interaction of a high-energy electron with the cosmic blackbody photon gas. At high energies the cross section for double Compton scattering is large, though this effect is largely canceled by the effects of radiative corrections to ordinary Compton scattering. A similar cancellation takes place for radiative pair production and the associated radiative corrections to the radiationless process. This cancellation is related to the well-known cancellation of the infrared divergence in electrodynamics.

  6. On the Long-Range Detection of Radioactivity Using Electromagnetic Radiation

    SciTech Connect

    Peurrung, Anthony J. )

    2001-12-01

    A series of recent publications (1-9) has provided experimental evidence that radiation fields can be detected well beyond the 10-100 meter limit that holds for conventional (direct) approaches to radiation detection. The techniques that are claimed to provide this capability rely upon the alteration of atmospheric electrostatic parameters, and measurement of these changes using remote electromagnetic interrogation. This paper examines the physics that underlies these proposed new approaches to radiation detection. If found to be viable for applications, the proposed techniques would be highly significant as they directly address a variety of problems in national security and environmental monitoring.

  7. Effect of electromagnetic radiation on the coils used in aneurysm embolization.

    PubMed

    Lv, Xianli; Wu, Zhongxue; Li, Youxiang

    2014-06-01

    This study evaluated the effects of electromagnetic radiation in our daily lives on the coils used in aneurysm embolization. Faraday's electromagnetic induction principle was applied to analyze the effects of electromagnetic radiation on the coils used in aneurysm embolization. To induce a current of 0.5mA in less than 5 mm platinum coils required to stimulate peripheral nerves, the minimum magnetic field will be 0.86 μT. To induce a current of 0.5 mA in platinum coils by a hair dryer, the minimum aneurysm radius is 2.5 mm (5 mm aneurysm). To induce a current of 0.5 mA in platinum coils by a computer or TV, the minimum aneurysm radius is 8.6 mm (approximate 17 mm aneurysm). The minimum magnetic field is much larger than the flux densities produced by computer and TV, while the minimum aneurysm radius is much larger than most aneurysm sizes to levels produced by computer and TV. At present, the effects of electromagnetic radiation in our daily lives on intracranial coils do not produce a harmful reaction. Patients with coiled aneurysm are advised to avoid using hair dryers. This theory needs to be proved by further detailed complex investigations. Doctors should give patients additional instructions before the procedure, depending on this study.

  8. Effect of Electromagnetic Radiation on the Coils Used in Aneurysm Embolization

    PubMed Central

    Lv, Xianli; Wu, Zhongxue; Li, Youxiang

    2014-01-01

    Summary This study evaluated the effects of electromagnetic radiation in our daily lives on the coils used in aneurysm embolization. Faraday’s electromagnetic induction principle was applied to analyze the effects of electromagnetic radiation on the coils used in aneurysm embolization. To induce a current of 0.5mA in less than 5 mm platinum coils required to stimulate peripheral nerves, the minimum magnetic field will be 0.86 μT. To induce a current of 0.5 mA in platinum coils by a hair dryer, the minimum aneurysm radius is 2.5 mm (5 mm aneurysm). To induce a current of 0.5 mA in platinum coils by a computer or TV, the minimum aneurysm radius is 8.6 mm (approximate 17 mm aneurysm). The minimum magnetic field is much larger than the flux densities produced by computer and TV, while the minimum aneurysm radius is much larger than most aneurysm sizes to levels produced by computer and TV. At present, the effects of electromagnetic radiation in our daily lives on intracranial coils do not produce a harmful reaction. Patients with coiled aneurysm are advised to avoid using hair dryers. This theory needs to be proved by further detailed complex investigations. Doctors should give patients additional instructions before the procedure, depending on this study. PMID:24976203

  9. Mobile phone electromagnetic radiation activates MAPK signaling and regulates viability in Drosophila.

    PubMed

    Lee, Kyu-Sun; Choi, Jong-Soon; Hong, Sae-Yong; Son, Tae-Ho; Yu, Kweon

    2008-07-01

    Mobile phones are widely used in the modern world. However, biological effects of electromagnetic radiation produced by mobile phones are largely unknown. In this report, we show biological effects of the mobile phone 835 MHz electromagnetic field (EMF) in the Drosophila model system. When flies were exposed to the specific absorption rate (SAR) 1.6 W/kg, which is the proposed exposure limit by the American National Standards Institute (ANSI), more than 90% of the flies were viable even after the 30 h exposure. However, in the SAR 4.0 W/kg strong EMF exposure, viability dropped from the 12 h exposure. These EMF exposures triggered stress response and increased the production of reactive oxygen species. The EMF exposures also activated extracellular signal regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) signaling, but not p38 kinase signaling. Interestingly, SAR 1.6 W/kg activated mainly ERK signaling and expression of an anti-apoptotic gene, whereas SAR 4.0 W/kg strongly activated JNK signaling and expression of apoptotic genes. In addition, SAR 4.0 W/kg amplified the number of apoptotic cells in the fly brain. These findings demonstrate that the exposure limit on electromagnetic radiation proposed by ANSI triggered ERK-survival signaling but the strong electromagnetic radiation activated JNK-apoptotic signaling in Drosophila.

  10. CONCORD: comparison of cosmic radiation detectors in the radiation field at aviation altitudes

    NASA Astrophysics Data System (ADS)

    Meier, Matthias M.; Trompier, François; Ambrozova, Iva; Kubancak, Jan; Matthiä, Daniel; Ploc, Ondrej; Santen, Nicole; Wirtz, Michael

    2016-05-01

    Space weather can strongly affect the complex radiation field at aviation altitudes. The assessment of the corresponding radiation exposure of aircrew and passengers has been a challenging task as well as a legal obligation in the European Union for many years. The response of several radiation measuring instruments operated by different European research groups during joint measuring flights was investigated in the framework of the CONCORD (COmparisoN of COsmic Radiation Detectors) campaign in the radiation field at aviation altitudes. This cooperation offered the opportunity to measure under the same space weather conditions and contributed to an independent quality control among the participating groups. The CONCORD flight campaign was performed with the twin-jet research aircraft Dassault Falcon 20E operated by the flight facility Oberpfaffenhofen of the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt, DLR). Dose rates were measured at four positions in the atmosphere in European airspace for about one hour at each position in order to obtain acceptable counting statistics. The analysis of the space weather situation during the measuring flights demonstrates that short-term solar activity did not affect the results which show a very good agreement between the readings of the instruments of the different institutes.

  11. Response of two-phase droplets to intense electromagnetic radiation

    NASA Technical Reports Server (NTRS)

    Spann, James F.; Maloney, Daniel J.; Lawson, William F.; Casleton, Kent H.

    1993-01-01

    The behavior of two-phase droplets subjected to high intensity radiation pulses is studied. Droplets are highly absorbing solids in weakly absorbing liquid medium. The objective of the study was to define heating thresholds required for causing explosive boiling and secondary atomization of the fuel droplet. The results point to mechanisms for energy storage and transport in two-phase systems.

  12. Response of two-phase droplets to intense electromagnetic radiation

    NASA Astrophysics Data System (ADS)

    Spann, James F.; Maloney, Daniel J.; Lawson, William F.; Casleton, Kent H.

    1993-04-01

    The behavior of two-phase droplets subjected to high intensity radiation pulses is studied. Droplets are highly absorbing solids in weakly absorbing liquid medium. The objective of the study was to define heating thresholds required for causing explosive boiling and secondary atomization of the fuel droplet. The results point to mechanisms for energy storage and transport in two-phase systems.

  13. The impact of electromagnetic radiation of different parameters on platelet oxygen metabolism - in vitro studies.

    PubMed

    Lewicka, Małgorzata; Henrykowska, Gabriela A; Pacholski, Krzysztof; Szczęsny, Artur; Dziedziczak-Buczyńska, Maria; Buczyński, Andrzej

    2015-01-01

    Electromagnetic radiation emitted by a variety of devices, e.g. cell phones, computers and microwaves, interacts with the human body in many ways. Research studies carried out in the last few decades have not yet resolved the issue of the effect of this factor on the human body and many questions are left without an unequivocal answer. Various biological and health-related effects have not been fully recognized. Thus further studies in this area are justified. A comparison of changes within catalase enzymatic activity and malondialdehyde concentration arising under the influence of the electromagnetic radiation emitted by car electronics, equipment used in physiotherapy and LCD monitors. The suspension of human blood platelets at a concentration of 1 × 109/0.001 dm 3, obtained from whole blood by manual apheresis, was the study material. Blood platelets were exposed to an electromagnetic field for 30 min in a laboratory stand designed for the reconstruction of the electromagnetic radiation generated by car electronics, physiotherapy equipment and LCD monitors. The changes in catalase activity and malondialdehyde concentration were investigated after the exposure and compared to the control values (unexposed material). An increase in catalase activity and malondialdehyde concentration was observed after 30 min exposure of platelets to EMF regardless of the radiation source. The most significant changes determining the degree of oxidative stress were observed after exposure to the EMF generated by car electronics. The low frequency electromagnetic fields generated by car electronics, physiotherapy equipment and LCD monitors may be a cause of oxidative stress in the human body and may lead to free radical diseases.

  14. Electromagnetic Radiofrequency Radiation Emitted from GSM Mobile Phones Decreases the Accuracy of Home Blood Glucose Monitors.

    PubMed

    Mortazavi, Smj; Gholampour, M; Haghani, M; Mortazavi, G; Mortazavi, Ar

    2014-09-01

    Mobile phones are two-way radios that emit electromagnetic radiation in microwave range. As the number of mobile phone users has reached 6 billion, the bioeffects of exposure to mobile phone radiation and mobile phone electromagnetic interference with electronic equipment have received more attention, globally. As self-monitoring of blood glucose can be a beneficial part of diabetes control, home blood glucose testing kits are very popular. The main goal of this study was to investigate if radiofrequency radiation emitted from a common GSM mobile phone can alter the accuracy of home blood glucose monitors. Forty five female nondiabetic students aged 17-20 years old participated in this study. For Control-EMF group (30 students), blood glucose concentration for each individual was measured in presence and absence of radiofrequency radiation emitted by a common GSM mobile phone (HTC touch, Diamond 2) while the phone was ringing. For Control- Repeat group (15 students), two repeated measurements were performed for each participant in the absence of electromagnetic fields. The magnitude of the changes between glucose levels in two repeated measurements (|ΔC|) in Control-Repeat group was 1.07 ± 0.88 mg/dl while this magnitude for Control-EMF group was 7.53 ± 4.76 mg/dl (P < 0.001, two-tailed test). To the best of our knowledge, this is the first study to assess the electromagnetic interference in home blood glucose monitors. It can be concluded that electromagnetic interference from mobile phones has an adverse effect on the accuracy of home blood glucose monitors. We suggest that mobile phones should be used at least 50 cm away from home blood glucose monitors.

  15. Electromagnetic Radiofrequency Radiation Emitted from GSM Mobile Phones Decreases the Accuracy of Home Blood Glucose Monitors

    PubMed Central

    Mortazavi, SMJ; Gholampour, M; Haghani, M; Mortazavi, G; Mortazavi, AR

    2014-01-01

    Mobile phones are two-way radios that emit electromagnetic radiation in microwave range. As the number of mobile phone users has reached 6 billion, the bioeffects of exposure to mobile phone radiation and mobile phone electromagnetic interference with electronic equipment have received more attention, globally. As self-monitoring of blood glucose can be a beneficial part of diabetes control, home blood glucose testing kits are very popular. The main goal of this study was to investigate if radiofrequency radiation emitted from a common GSM mobile phone can alter the accuracy of home blood glucose monitors. Forty five female nondiabetic students aged 17-20 years old participated in this study. For Control-EMF group (30 students), blood glucose concentration for each individual was measured in presence and absence of radiofrequency radiation emitted by a common GSM mobile phone (HTC touch, Diamond 2) while the phone was ringing. For Control- Repeat group (15 students), two repeated measurements were performed for each participant in the absence of electromagnetic fields. The magnitude of the changes between glucose levels in two repeated measurements (|ΔC|) in Control-Repeat group was 1.07 ± 0.88 mg/dl while this magnitude for Control-EMF group was 7.53 ± 4.76 mg/dl (P < 0.001, two-tailed test). To the best of our knowledge, this is the first study to assess the electromagnetic interference in home blood glucose monitors. It can be concluded that electromagnetic interference from mobile phones has an adverse effect on the accuracy of home blood glucose monitors. We suggest that mobile phones should be used at least 50 cm away from home blood glucose monitors. PMID:25505778

  16. Experimental investigation of the radiation shielding of a MCP detector in the radiation environment near Europa

    NASA Astrophysics Data System (ADS)

    Tulej, Marek; Wurz, Peter; Meyer, Stefan; Lasi, Davide; Lüthi, Matthias; Galli, André; Piazza, Daniele; Desorgher, Laurent; Hajdas, Wojciech; Reggiani, Davide; Karlsson, Stefan; Kalla, Leif

    2016-04-01

    The Neutral Ion Mass spectrometer (NIM) is one of the six instruments in the Particle Environmental Package (PEP) designed for the JUICE mission of ESA to the Jupiter system. NIM will conduct detailed measurements of chemical composition of Jovian moon exospheres and is equipped with a sensitive MCP ion detector. To maintain high sensitivity of the NIM instrument, background signals arising from the presence of a large background of penetrating radiation (mostly high-energy electrons and protons) in Jupiter's magnetosphere have to be minimised. We investigate the performance of a layered-Z radiation shield, an Al-Ta-Al sandwich, as a potential shielding against high-energy electrons. The experimental investigations were performed at the PiM1 beam line of the High Intensity Proton Accelerator Facilities located at the Paul Scherrer Institute (PSI), Villigen, Switzerland. The facility delivers a particle beam containing e,  and  with an adjustable momentum ranging from 17.5 to 345 MeV/c. The measurements of the induced radiation background generated during the interaction of primary particles with Al-Ta-Al sandwich were conducted by beam diagnostic methods and a MCP detector. Diagnostic methods provided for the characterisation of the beam parameters (beam geometry, flux and intensity) and identification of individual particles in the primary beam and in the flux of secondary particles. The MCP detector measurements provided information on the effects of radiation and the results of these measurements define the performance of the shielding material in reducing the background arising from penetrating radiation. In parallel, we performed modelling studies using GEANT 4 and GRASS methods to identify products of the interaction and predict their fluxes and particle rates at the MCP detector. Combination of the experiment and modelling studies yields detailed characterisation of the radiation effects produced by the interaction of the incident e- in the

  17. Some results of test beam studies of Transition Radiation Detector prototypes at CERN

    NASA Astrophysics Data System (ADS)

    Tikhomirov, V. O.; Brooks, T.; Joos, M.; Rembser, C.; Celebi, E.; Gurbuz, S.; Cetin, S. A.; Konovalov, S. P.; Zhukov, K.; Fillipov, K. A.; Romaniouk, A.; Smirnov, S. Yu; Teterin, P. E.; Vorobev, K. A.; Boldyrev, A. S.; Maevsky, A.; Derendarz, D.

    2017-01-01

    Operating conditions and challenging demands of present and future accelerator experiments result in new requirements on detector systems. There are many ongoing activities aimed to develop new technologies and to improve the properties of detectors based on existing technologies. Our work is dedicated to development of Transition Radiation Detectors (TRD) suitable for different applications. In this paper results obtained in beam tests at SPS accelerator at CERN with the TRD prototype based on straw technology are presented. TRD performance was studied as a function of thickness of the transition radiation radiator and working gas mixture pressure.

  18. Apparatuses and method for converting electromagnetic radiation to direct current

    DOEpatents

    Kotter, Dale K; Novack, Steven D

    2014-09-30

    An energy conversion device may include a first antenna and a second antenna configured to generate an AC current responsive to incident radiation, at least one stripline, and a rectifier coupled with the at least one stripline along a length of the at least one stripline. An energy conversion device may also include an array of nanoantennas configured to generate an AC current in response to receiving incident radiation. Each nanoantenna of the array includes a pair of resonant elements, and a shared rectifier operably coupled to the pair of resonant elements, the shared rectifier configured to convert the AC current to a DC current. The energy conversion device may further include a bus structure operably coupled with the array of nanoantennas and configured to receive the DC current from the array of nanoantennas and transmit the DC current away from the array of nanoantennas.

  19. Biological Effects of Nonionizing Electromagnetic Radiation. Volume IV. Number 3.

    DTIC Science & Technology

    1980-03-01

    vertically and ± 0.05 C horizontally. Thus, heating through a triple -stub tuner to coaxial Transco uniformity to within 0.1 C may be achieved when...significant discomfort. The use of decimeter-wave therapy in combination The antitumor effects of a triple combination of with radiation therapy is currently...applied with cancer. an inductive Eddy current applicator (3.8-cm di- ameter) at 461 MHz with a Siemens generator. Mice receiving the triple combination

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

    SciTech Connect

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

    2009-11-30

    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.