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In anticipation of a possible future breakthrough in developing metamaterials with at least a factor of 10 lower losses we analyze in this paper different resonant and nonresonant structures and the achievable performance. One example is waveguides made from arrays of near resonantly operated near-field coupled metal nanoparticles in the shape of e.g. spheres, which have attracted some attention....
To reduce the variance of color temperature among packages and the spatial color temperature variance in the package, we adopted a unique phosphor conformal coating technique in the packaging process, thereby fabricating the self-positioned phosphor layer. Additionally, to acquire the spatial color uniformity without considerable shrinkage of luminous efficacy, we applied sub-micrometer scale titanium...
The following topics are dealt with: microelectronic materials; optoelectronic materials; optoelectronic devices; microelectronic devices; solar cells; photodetectors; nanowires; wide band gap materials; and photonics.
A nuclear material detection system based on neutron/gamma-ray hybrid approach has been proposed for the container inspection at the sea port. The neutron from the inertial electrostatic confinement fusion source will be used for a fast pre-screening process. The quasi-monochromatic gamma-ray beam from the laser Compton Backscattering source will be used for an isotope identification for the precise...
The importance of the development of high-end computers (HEC) lies in their ability to solve complex problems in many areas of science and engineering. In order to develop the next generation of HEC faster buses are required. However, faster buses cannot be achieved in a cost-effective way by means of further scaling of today's electrical technology. Some of the parameters that prevent this further...
Photofission is the process in which a nucleus disintegrates into two daughter products after absorbing a photon. Photofission near threshold in actinides is very similar to spontaneous fission in terms of the number of emitted decay neutrons and their energy distribution. Most of the neutrons are in the ~2 MeV energy range, and can be efficiently detected with liquid scintillator detectors. Thus,...
Photonic crystals, in which the refractive index changes periodically, provide an exciting tool for the manipulation of photons and have made substantial progresses in recent years. In this presentation, I will discuss recent progresses in photonic-crystal researches including (i) two-dimensional photonic-crystal cavities and waveguides, (ii) three-dimensional photonic crystals, and (iii) two-dimensional...
The measured value of the 2.176 MeV 238U Nuclear Resonance Fluorescence (NRF) peak count rate were compared with simulation results. The simulation methods studied include GEANT4, MCNP5 and MCNPX. The simulation results were found out to be consistent but one order of magnitude higher than the measured value. The possible reasons for this discrepancy were discussed.
We present a method for producing flexible and high precision solutions applicable to detector shielding and pinhole apertures using a fusible metal called Rose's metal. Custom Rose's metal parts have been manufactured to both shield detectors as well as incorporate platinum pinholes in a small animal imaging system based on BazookaSPECT technology dubbed InSPECT.
In geology the simulation of the sedimention process deposition is very used on different kind of studies. However a great problem is to get the information without destroy the architecture of the deposited material (since now named testimonial). Usually they do slice the real sample and they take pictures of it. However this technique is too aggressive (invasive) and usually cause damage to the testimonial...
Development at LETI of X-ray photon counting detectors based on CdTe/CZT architecture has shown many improvements in counting abilities and in energy resolution for fast digital imaging modalities. In this context, this study aims at quantifying contribution of these technologies associated to new data processing methods for radiographic material recognition in homeland security. An ideal spectrometric...
These instructions provide guidelines for preparing manuscripts for submission to the Conference Record (CR) of the 2010 IEEE Nuclear Science Symposium and Medical Imaging Conference. If you are using Microsoft Word 6.0 or later to prepare your manuscript, you should use this document as a template. Define all symbols used in the abstract. Do not cite references in the abstract.
The photon counting detectors such as cadmium zinc telluride (CZT) and cadmium telluride (CdTe) have powerful advantages compared to energy integrating detectors. CZT or CdTe can detect individual gamma-ray or x-ray photon with energy discrimination. In recent years, energy-resolving and material decomposition x-ray imaging based on photon counting detectors has attracted attention from biomedical...
This paper analyzes the Intense Pulsed Active Detection (IPAD) approach for active detection of fissile material, highlights some of its merits, and compares it to the multiple-pulse-train LINAC approach. In both cases, bremsstrahlung photons are used to induce fissions. IPAD's single, 100-ns bremsstrahlung pulse offers the possibility to utilize prompt as well as delayed neutrons emitted during the...
A photo-neutron source has been realized at the DaΦne Beam Test Facility: neutrons are produced by sending high energy electrons (510 MeV) to impinge on an optimized target. Neutron flux and spectra have been measured along well designed extraction lines. The experimental data have been compared with Monte Carlo predictions performed with FLUKA and MCNPX, respectively. The comparison between measured...
We report on Monte Carlo studies of the hard X-ray polarimeter X-Calibur. The polarimeter will be used in the focal plane of a grazing incidence hard X-ray telescope. It combines a low-Z Compton scatterer with a high-Z Cadmium Zinc Telluride (CZT) detector assembly to measure the polarization of 10 keV - 80 keV X-rays. X-Calibur makes use of the fact that polarized photons Compton scatter preferentially...
We have devised a standardization method for a sealed point source that can be applied to nuclides such as 22Na that emit a positron and at least one gamma ray. This method is based on coincidence counting of annihilation radiation and gamma rays using a scintillation detector array. In the present study, we performed Monte Carlo simulations to examine this method for various measurement conditions...
A prototype CdTe pixel detector system with 19 pixels arranged in a 200um pitch hexagonal format is being developed for energy resolved medical X-ray imaging applications; this device should be capable of detecting input photon rates of up to 2*108 counts per mm2 and energy resolution of approximately 5% at 122keV. This paper presents a description of this system along with the initial spectral and...
Compound semiconductors detectors, such as Cadmium Telluride (CdTe) and Cadmium Zinc Telluride (CdZnTe), have demonstrated spectroscopic performances for X- and Gamma-ray detection at room temperature operation. Several groups are working on using these detector materials for use in high rate photon counting / energy resolving pixelated detector systems. This paper is focused on the modelling from...
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