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Results for “ELECTROMAGNETIC RADIATION”

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At least 343 records · Page 19

Numerical Investigation of a Cascaded Longitudinal Space-Charge Amplifier at the Fermilab's Advanced Superconducting Test Accelerator

In a cascaded longitudinal space-charge amplifier (LSCA), initial density noise in a relativistic e-beam is amplified via the interplay of longitudinal space charge forces and properly located dispersive sections. This type of amplification process was shown to potentially result in large final density modulations [1] compatible with the production of broadband electromagnetic radiation. The technique was recently demonstrated in the optical domain [2]. In this paper we investigate, via numerical simulations, the performances of a cascaded LSCA beamline at the Fermilab’s Advanced Superconducting Test Accelerator (ASTA). We especially explore the properties of the produced broadband radiation. Our studies have been conducted with a grid-less three-dimensional space-charge algorithm.

43 PARTICLE ACCELERATORS↗

Energy harvesting devices, systems, and related methods

Energy harvesting devices include a substrate and a plurality of resonance elements coupled to the substrate. Each resonance element is configured to collect energy in the visible and infrared light spectra and to reradiate energy having a wavelength in the range of about 0.8 .mu.m to about 0.9 .mu.m. The resonance elements are arranged in groups of two or more resonance elements. Systems for harvesting electromagnetic radiation include a substrate, a plurality of resonance elements including a conductive material carried by the substrate, and a photovoltaic material coupled to the substrate and to at least one resonance element. The resonance elements are arranged in groups, such as in a dipole, a tripole, or a bowtie configuration. Methods for forming an energy harvesting device include forming groups of two or more discrete resonance elements in a substrate and coupling a photovoltaic material to the groups of discrete resonance elements.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Types of Nuclear Radiation

Radiation is one of those words that frightens many people. In this video, Fermilab’s Dr. Don Lincoln explains the known kinds of nuclear radiation and their different properties.

61 RADIATION PROTECTION AND DOSIMETRY↗

Devices and methods for photoelectrochemical water splitting

The present disclosure relates to photoelectrochemical devices and systems for capturing the energy of electromagnetic radiation and utilizing the captured energy for electrolysis to produce hydrogen gas and oxygen gas.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

System and method for the direct calorimetric measurement of laser absorptivity of materials

A method and system for calorimetrically measuring the temperature-dependent absorptivity of a homogeneous material dimensioned to be thin and flat with a predetermined uniform thickness and a predetermined porosity. The system includes a material holder adapted to support and thermally isolate the material to be measured, an irradiation source adapted to uniformly irradiate the material with a beam of electromagnetic radiation, and an irradiation source controller adapted to control the irradiation source to uniformly heat the material during a heating period, followed by a cooling period when the material is not irradiated. A thermal sensor measures temperature of the material during the heating and cooling periods, and a computing system first calculates temperature-dependent convective and radiative thermal losses of the material based on the measured temperature of the material during the cooling period when beam intensity is zero, followed by calculation of the temperature-dependent absorptivity of the material based on the temperature-dependent convective and radiative thermal losses determined from the cooling period.

Rubenchik, Alexander↗

Detection of acetone via nanostructure sensors

A method of detecting at least one of analyte in an environment (such as in breath) includes providing a structure including nanostructures in contact with titanium dioxide, applying electromagnetic radiation to the structure for a period of time, measuring at least one response and using the measured response to determine the presence of the analyte in the environment.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Methods for producing hydrogen using nanoparticle-catalyst mixtures

Provided are compositions for and methods of producing hydrogen. For example, the compositions comprise nanocrystals, a catalyst, a source of electrons, and an aqueous medium. The nanocrystals, catalyst, aqueous medium, and, optionally, the source of electrons are present as a mixture. The methods produce hydrogen by exposing the compositions to electromagnetic radiation (e.g., solar flux).

08 HYDROGEN↗

Sagnac fourier spectrometer (SAFOS)

A technique and device to determine the spectrum of electromagnetic radiation in a certain range of wavelengths comprising: splitting said radiation into more than one beam; let these beams counter-propagate in a Sagnac-type ring interferometer; and imprinting a wavelength-dependent angular tilt onto the wavefront of each beam by at least one dispersive element which preferably is a transmission grating or grism; and re-combining the multiple beams on a detector that exhibits spatial resolution and can therefore resolve the fringes formed by interference; and perform the mathematical operations to determine the spectrum of said radiation from the obtained interferogram, wherein the dispersive element is mounted on a stage providing linear and/or rotational movement.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Organic-semiconducting hybrid solar cell

The embodiment of this invention lies on experimental evidence of photoconductivity activity of a hybrid solar cell, organic/chalcogenide. The device is made of thin layers of conductive indium-tin-oxide (ITO) on glass with a 100 nm layer of chalcogenide molybdenum di-sulfide (MoS 2 ) and a thin layer of about ˜50 nm of complex organic compound assembled at room temperature. The device was tested to conventional electrical transport measurements in the regime of −1V to 1V under electromagnetic radiation simulator at 100 mW/cm 2 . Results indicate solar conversion efficiency of 2.48% and current density of 6.35 mA/cm 2 .

14 SOLAR ENERGY↗

Plasma field faraday cage system

A system for creating a plasma field Faraday cage around a structure, the system comprising a plurality of lasers spaced apart from each other, each laser being configured to transmit an electromagnetic energy beam to a focal point of an atmosphere region, each electromagnetic energy beam having an amount of energy less than an amount of energy required to ionize air, the electromagnetic energy beams intersecting at the focal point such that the electromagnetic energy beams cooperatively ionize the air at the focal point to block electromagnetic radiation from passing through the focal point.

Timpson, Erik Joseph↗

Metallo-graphene nanocomposites and methods for using metallo-graphene nanocomposites for electromagnetic energy conversion

Nanocomposites in accordance with many embodiments of the invention can be capable of converting electromagnetic radiation to an electric signal, such as signals in the form of current or voltage. In some embodiments, metallic nanostructures are integrated with graphene material to form a metallo-graphene nanocomposite. Graphene is a material that has been explored for broadband and ultrafast photodetection applications because of its distinct optical and electronic characteristics. However, the low optical absorption and the short carrier lifetime of graphene can limit its use in many applications. Nanocomposites in accordance with various embodiments of the invention integrates metallic nanostructures, such as (but not limited to) plasmonic nanoantennas and metallic nanoparticles, with a graphene-based material to form metallo-graphene nanostructures that can offer high responsivity, ultrafast temporal responses, and broadband operation in a variety of optoelectronic applications.

Jarrahi, Mona↗

Method and apparatus for real time, in situ sensing and characterization of roughness, geometrical shapes, geometrical structures, composition, defects, and temperature in three-dimensional manufacturing systems

Methods and apparatuses for manufacturing are disclosed, including (a) providing an apparatus having: a laser; scanner; powder injection system; powder spreading system; dichroic filter; imager-and-processor; and computer; (b) programming the computer with specifications of a sample; (c) using the computer to set initial parameters based on the sample specifications; (d) adjusting a stage to position the sample; (e) focusing and scanning electromagnetic radiation onto the sample while powder is concurrently injected onto the sample in order to deposit a layer; (f) capturing two-dimensional images of the sample and probing the sample to determine whether the deposited layer was manufactured per the specifications; (g) use the computer to adjust the three-dimensional manufacturing parameters based on the determination made in step (f) prior to additively manufacturing a subsequent layer or making repairs; and (h) repeating steps (d), (e), (f), and (g) until the manufacture is complete. Other embodiments are described and claimed.

Liu, Jian↗

Plasma field faraday cage system

A system for creating a plasma field Faraday cage around a structure, the system comprising a plurality of lasers spaced apart from each other, each laser being configured to transmit an electromagnetic energy beam to a focal point of an atmosphere region, each electromagnetic energy beam having an amount of energy less than an amount of energy required to ionize air, the electromagnetic energy beams intersecting at the focal point such that the electromagnetic energy beams cooperatively ionize the air at the focal point to block electromagnetic radiation from passing through the focal point.

Timpson, Erik Joseph↗

Remote Gamma Ray Spectrum Acquisition

An approach is presented that utilizes networking, hardware, and software components to allow data acquisition from Canberra's Osprey multi-channel analyzer (MCA) detector. The research has allowed researchers to remotely connect to Canberra's ProSpect gamma spectroscopy software and the detector by making use of Windows Server 2012 and a network connection. Gamma rays are ionizing, electromagnetic radiation of high energy and short wavelength. They are produced primarily by radioactive decay. Several undergraduate courses at Texas A and M University-Kingsville focus on teaching students to measure and research gamma rays while in the laboratory. Recent needs have motivated efforts to develop a network solution that allows authorized students and researchers to access the ProSpect software and Osprey MCA detectors remotely from multiple computers connected to the campus network. (authors)

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

System and method for high power diode based additive manufacturing

The present disclosure relates to a system for performing an Additive Manufacturing (AM) fabrication process on a powdered material, deposited as a powder bed and forming a substrate. The system makes use of a laser for generating a laser beam, and an optical subsystem. The optical subsystem is configured to receive the laser beam and to generate an optical signal comprised of electromagnetic radiation sufficient to melt or sinter the powdered material. The optical subsystem uses a digitally controlled mask configured to pattern the optical signal as needed to melt select portions of a layer of the powdered material to form a layer of a 3D part. A power supply and at least one processor are also included for generating a plurality of different power density levels selectable based on a specific material composition, absorptivity and diameter of the powder particles, and a known thickness of the powder bed. The powdered material is used to form the 3D part in a sequential layer-by-layer process.

El-Dasher, Bassem S.↗

(Poster) TRIPWIRE: Multi-modal Distributed Sensing For Repository Verification

Poster submission. This project is developing and demonstrating a multi-modal sensor system, TRIPWIRE, for containment verification in inaccessible radiological and nuclear waste repositories. The TRIPWIRE system will continuously monitor ionizing radiation, electromagnetic fields and vibration in the vicinity of emplaced nuclear materials buried in a repository, reporting on disturbances with a real-time alarm control station.

98 - NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL↗

Characterization and Evaluation of Scintillating Fiber System Components

Idaho National Laboratory is studying long scintillation fibers (SF) in a project called “TRIPWIRE” which aims to verify containment in inaccessible nuclear waste repositories. This system will continuously monitor ionizing radiation, electromagnetic fields, and seismic activity in the vicinity of nuclear waste. Previous experiments have determined a better alternative to long SF is to couple shorter SF to kilometer scale optical fiber (OF) to reach electronics far outside of the repository. Minor signal attenuation from coupling these fibers has been observed using optical spectrometry. This experiment characterized two photomultiplier tubes (PMT) to reduce this loss by matching their spectral response characteristics to the SF’s emission spectrum. The experiment created a comparison between the two PMTs showing results that suggest other characteristics are playing a major role in improving signal attenuation when the SF is coupled to OF.

98 - NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL↗

Nonlinear quantum theory of stimulated Cherenkov radiation of transverse electromagnetic waves from a low-density relativistic electron beam in a dielectric medium

A nonlinear quantum theory of stimulated Cherenkov radiation of transverse electromagnetic waves from a low-density relativistic electron beam in an isotropic dielectric medium is presented. A quantum model based on the Klein-Gordon equation is used. The growth rates of beam instabilities caused by the effect of stimulated Cherenkov radiation have been determined in the linear approximation. Mechanisms of the nonlinear saturation of relativistic quantum Cherenkov beam instabilities have been analyzed and the corresponding analytical solutions have been obtained.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗