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Lithium-ion batteries, which are widely used in consumer electronics, have the potential to serve as neutron detectors after a nuclear detonation. Their small size permits collection of many samples for subsequent investigations. Besides a large cross section in the 6Li(n,α)3H reaction, there are multiple possible neutron threshold detector materials in the battery. Inductively coupled plasma mass...
X-ray scattering in the cone beam computed tomography system can lead to undesirable reduction in contrast and overall image quality of reconstructed images. The scatters inside the object cause a serious problem, especially when the object is large and contains a lot of materials, such as bones and soft tissues. In this paper, the amount of X-ray scattering is numerically estimated using the Monte...
India's second mission to the Moon - Chandrayaan-2, will have a rover for in-situ exploration of lunar surface around the landing site. Alpha Particle X-ray Spectrometer (APXS) is one of the instruments on board Chandrayaan-2 rover, for measuring elemental composition of the lunar surface using state - of - the - art X-ray detector (Silicon Drift Detector - SDD) with higher energy resolution. The...
The development of photon counting detectors enables us to decompose materials in x-ray CT images. The photon counting detection can measure a linear attenuation coefficient of a given energy range, thereby contributing to the material decomposition or identification. In this detection, measured photon counts were affected by statistical noise, making it difficult to obtain accurate measurements of...
Eu2+-doped LiF/CaF2 eutectic scintillators with different Eu concentrations were fabricated by the simple solidification method. Eu concentrations were 0.005, 0.02, 0.05, 0.1, 0.3, 1, 3, and 5%, and they looked visibly semitransparent. In SEM analysis, fine lamellar structure was observed in Eu low concentration samples. Radioluminescence spectra were collected under X-ray exposure and Eu2+ 5d-4f...
The optimum geometric configuration of the detector system for non-destructive assay (NDA) of special nuclear material (SNM) by using nuclear resonance fluorescence (NRF) measurements has been studied. A Monte Carlo radiation transport code, GEANT4, has been developed to calculate NRF interaction, as well the simulation performed for detector array consist of seven LaBr3:Ce (1.5″ × 3″) detectors positioned...
Muon tomography represents a fairly new type of imaging technique that can be used in detecting high-Z materials. Results of Monte Carlo simulations for muon scattering in different types of target materials are presented. The dependence of the detector capability to identify high-Z targets on position resolution has been studied. Muon tracks are reconstructed using a basic point of closest approach...
The ECSIT project analyses how innovative inspection technologies can lead to an enhanced container security and how these technologies can be embedded into a holistic concept. It has the goal to analyze the possibility and feasibility for 100% scanning of all containers which are shipped to US ports and to develop a concept for integrating necessary infrastructure. A key element of the entire concept...
Single Photon Emission Computed Tomography (SPECT) suffers limited efficiency due to the need for collimators. Collimator properties largely decide the data statistics and image quality. Various materials and configurations of collimators have been investigated in many years. The main thrust of our study is to evaluate the design of pixel-geometry-matching collimators to investigate their potential...
In 2012, Wehe D.K. and coauthors proposed a method of light yield amplification in scintillation detectors. A trivalent activator ion RE3+ captures an electron produced by a particle in scintillator and becomes a divalent rare earth ion RE2+. The scintillator is illuminated by laser photons that excite RE2+ ions, which quickly de-excite and generate light photons. By cyclically excitation RE2+ ions,...
At present, Cs-137 is used as a standard in the calibration of radiation detectors or dosimeters because it is a monoenergetic source (662 keV) and has a long half-life of 30.07 years. When radiation detector is calibrated, it is desireable to calibrate for wide energies. For example 200 keV energy region is important because some detector response is too high and scatter photon energy tend to be...
In this paper, a prototype system was designed to efficiently measure the non-proportional electron response of scintillation materials using only angular information. Similar to other measurement systems used in this type of research, our design relies on the fundamental principles of Compton scattering. All current designs measure coincident events that arise when Compton electrons are deposited...
Radiation Portal Monitors (RPMs) are radiation detection devices which provide passive, non-intrusive means for fast screening of transportation of vehicles, baggage and passengers for the presence of nuclear and radiological materials.
The purpose of our research is to measure the amount of contrast agents used in x-ray CT accurately. The use of contrast agents such as gold nano-particles enables molecular imaging with the x-ray CT system. To realize an energy discriminating measurement, we have developed a photon counting detector with a CdTe semiconductor that is able to measure x-rays with the count rate of 107 cps/mm2 with four...
In-beam positron emission tomography (PET) is expected to be suitable as an in situ dose verification technique in particle therapies. We have developed the world's first open-type PET, OpenPET, to monitor radiation field in heavy ion radiation therapy. In using in-beam PET, the number of annihilation radiation particles to be measured is generally low. On the other hand, OpenPET devices can be activated...
Broadband and sensitive Terahertz (THz) emitter and detector material is required to build cost-effective and mobile THz time-domain spectrometer systems (TDS). We present an efficient THz switch optimized for femtosecond lasers operating at the central wavelength of about 1060 nm. Performance is improved by a factor of 20 due to the implementation of mesa structuring and utilization of low temperature...
Terahertz emitters and detectors made from AIIIBV semiconductors were investigated by means of a tunable wavelength laser system. THz excitation spectra of InAs and InSb has been investigated. It was shown that subsidiary valley position can be determined quite accurately. As terahertz detectors, the photoconductors manufactured from GaAs and InGaAs epitaxial layers grown by MBE at low substrate temperatures...
A follow-up alpha emissivity study was conducted to examine the wide variability observed in previous work that was hypothesized to be due to differences in the pulse height discrimination threshold among participant's equipment. Two samples, one mixed energy and one monoenergetic, were prepared and sequentially circulated to all participants for counting. Analysis of the data demonstrates that only...
Detectors that take full advantage of the energy confinement offered by surface waves could have significant performance advantages in dark current and optical functionality. We use a subwavelength patterned metal nanoantenna structure to convert incoming plane waves to these surface waves.
The Integrated Detector Dewar Cryocooler Assembly (IDDCA) is a critical component for advanced infrared systems, and especially in infrared (IR) applications, a high reliability for the IDDCA is required increasingly. In this paper, we systematically analyze the failure modes of IDDCA, such as interconnect failure, diodes degradation, vacuum failure, spring fracture, leakage of working medium, mechanical...
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