Academic literature on the topic '3 photon'

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Journal articles on the topic "3 photon"

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FA, OU, HE MINGGAO, and WU FUGEN. "OPTICAL NONLINEARITY VIA PHONONS AS AN INTERMEDIARY." Journal of Nonlinear Optical Physics & Materials 10, no. 01 (March 2001): 65–77. http://dx.doi.org/10.1142/s0218863501000449.

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A new model to describe the origin of optical nonlinearity is presented. In this model, the interaction between light and medium is reduced to the coupling of photons with phonons, which occurs in the crystal lattice vibrating anharmonically. Then the optical nonlinearity originates from the nonlinear photon–phonon coupling or the interaction among phonons themselves. In this paper, more attention is drawn to the latter. By the given model, (1) degenerate and (2) nondegenerate parametric oscillations, (3) Stokes and (4) anti-Stokes Raman scattering, (5) sum-frequency and (6) second harmonic generation and (7) two-photon absorption are dealt with systematically and quantum-mechanically. The results of theoretical analysis show that the effects (1)–(4) are associated with threshold phenomenon, whereas the effects (5)–(7) with the saturation phenomenon.
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Tavares-Velasco, G., and J. J. Toscano. "Photon-photon scattering in a 3-3-1 model." Europhysics Letters (EPL) 53, no. 4 (February 2001): 465–70. http://dx.doi.org/10.1209/epl/i2001-00175-8.

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Chef, Samuel, Chung Tah Chua, and Chee Lip Gan. "Machine Learning for Time-Resolved Emission: Image Resolution Enhancement." EDFA Technical Articles 23, no. 3 (August 1, 2021): 24–31. http://dx.doi.org/10.31399/asm.edfa.2021-3.p024.

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Abstract This article describes a novel method for improving image resolution achieved using time-resolved photon emission techniques. Instead of directly generating images from photon counting, all detected photons are displayed as a point cloud in 3D space and a new higher-resolution image is generated based on probability density functions associated with photon distributions. Unsupervised learning algorithms identify photon distribution patterns as well as fainter emission sources.
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U'Ren, A. B., K. Banaszek, and I. A. Walmsley. "Photon engineering for quantum information processing." Quantum Information and Computation 3, special (October 2003): 480–502. http://dx.doi.org/10.26421/qic3.s-3.

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We study distinguishing information in the context of quantum interference involving more than one parametric downconversion (PDC) source and in the context of generating polarization-entangled photon pairs based on PDC. We arrive at specific design criteria for two-photon sources so that when used as part of complex optical systems, such as photon-based quantum information processing schemes, distinguishing information between the photons is eliminated guaranteeing high visibility interference. We propose practical techniques which lead to suitably engineered two-photon states that can be realistically implemented with available technology. Finally, we study an implementation of the nonlinear-sign shift (NS) logic gate with PDC sources and show the effect of distinguishing information on the performance of the gate.
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Hu, Huiqin, Xinyi Ren, Zhaoyang Wen, Xingtong Li, Yan Liang, Ming Yan, and E. Wu. "Single-Pixel Photon-Counting Imaging Based on Dual-Comb Interferometry." Nanomaterials 11, no. 6 (May 24, 2021): 1379. http://dx.doi.org/10.3390/nano11061379.

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We propose and experimentally demonstrate single-pixel photon counting imaging based on dual-comb interferometry at 1550 nm. Different from traditional dual-comb imaging, this approach enables imaging at the photon-counting regime by using single-photon detectors combined with a time-correlated single-photon counter to record the returning photons. The illumination power is as low as 14 pW, corresponding to 2.2 × 10−3 photons/pulse. The lateral resolution is about 50 μm. This technique paves the way for applying dual-comb in remote sensing and imaging.
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White, John, Victoria Centonze, David Wokosin, and William Mohler. "Using Multiphoton Microscopy for the Study of Embryogenesis." Microscopy and Microanalysis 3, S2 (August 1997): 307–8. http://dx.doi.org/10.1017/s1431927600008424.

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Multiphoton fluorescence excitation imaging is an optical sectioning technique for fluorescence microscopy. At very high photon densities, two or more photons may coordinately excite an energy transition in a fluorophore that corresponds to the sum of the energies of the individual photons. by this means, a fluorophore may be excited by a wavelength that is considerably longer than its single photon excitation wavelength. Ultra-fast pulsed (femtosecond) lasers can produce the peak power densities in the focal volume of an objective lens needed to provide sufficient 2- or 3- photon excitation events for imaging. The use of short-pulse lasers provides the high peak powers necessary for imaging yet with modest mean power levels that do not thermally damage biological specimens. Production of multiphoton events depends on the square of photon density for 2-photon excitation and the cube of photon density for 3-photon excitation. The power density therefore rapidly falls off away from the focal volume of an objective lens, thereby confining fluorescence excitation to the focal volume.
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Xiu, Xiao-Ming, Li Dong, Hong-Zhi Shen, Ya-Jun Gao, and X. X. Yi. "Two-party QPC with polarization-entangled Bell states and the coherent states." Quantum Information and Computation 14, no. 3&4 (March 2014): 236–54. http://dx.doi.org/10.26421/qic14.3-4-3.

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We propose a protocol of quantum privacy comparison with polarization-entangled Einstein-Podolsky-Rosen (Bell) states and the coherent states. One of two legitimate participants, Alice, prepares polarization-entangled Bell states and keeps one photon of each photon pair and sends the other photons to the third party, Charlie. Receiving the photons, Charlie performs single-photon transformation operations on them and then sends them to the other legitimate participant, Bob. Three participants adopt parity analysis method to check the distribution security of Bell states. Exploiting polarization beam splitters and nonlinear interactions mediated by the probe coherent states in Kerr media, Alice and Bob check the parities of their photons using the bases of $\{\ket H, \ket V\}$ or $\{\ket +, \ket -\}$. On the basis of the parity analysis outcomes and Charlie's publicized information, they can analyze the security of the distributed quantum channel. Confirming secure distribution of the shared Bell states, two participants perform respective parity measurements on the privacy photons and own photons of Bell states, and then send the results to Charlie. According to information provided by two legitimate participants and his single-qubit transformation operations, Charlie compares the privacy information of Alice and Bob and publicizes the conclusion.
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Dhobi, Saddam Husain, Kishori Yadav, and Bhishma Karki. "Variation of Energy Density and Mass Density of Photon with Wavelength." Indian Journal of Advanced Physics 1, no. 2 (October 10, 2021): 1–5. http://dx.doi.org/10.54105/ijap.b1003.101221.

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The mass density and energy density of visible photon is calculated as 10-8 Kgm-3 and 109jm3 respectively. Moreover it is also observed that mass density and energy density of photon depend upon photons mass, wavelength, volume and energy. This is clear from figure 1, figure 2 and literatures. Therefore the mass density and energy density of photon varies with masses of photon, wavelength, volume, etc.
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Chandra, N., and R. Ghosh. "Generation of entanglement between spin of an electron and polarization of a photon." Quantum Information and Computation 9, no. 1&2 (January 2009): 36–61. http://dx.doi.org/10.26421/qic9.1-2-3.

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This paper shows an electron and a photon, emitted in two consecutive steps from an atom following the absorption of a single photon, may be entangled in the presence of the spin-orbit interaction only. This entanglement strongly depends upon the polarization of the absorbed and of the radiated photons, kinematics of two emitted particles, and dynamics of photoionization; however, the photoemission dynamics plays no role in this entanglement. This hybrid entanglement can be used in teleporting a quantum state encoded in a flying/stationary material particle onto a light pulse, or vice versa. Such an electron-photon entanglement, in addition, will make it possible to learn about the polarization of a single photon or spin-polarization of a free electron without making any measurements on the corresponding particle itself.
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Peresunko, D. "Direct photon production in pp, p–Pb and Pb–Pb collisions measured with the ALICE experiment." EPJ Web of Conferences 191 (2018): 05001. http://dx.doi.org/10.1051/epjconf/201819105001.

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We review recent ALICE results on direct photon production in pp, p–Pb and Pb–Pb collisions at LHC energies. In light systems, pp and p–Pb, no signal of direct photons at low pT < 3-5 GeV/c is observed within uncertainties, while at high pT our measurements are consistent with NLO pQCD calculations. In central and mid-central Pb–Pb collisions a thermal photon contribution is observed at low pT < 3 - 4 GeV/c with slopes Teff = (304 ± 11stat ± 40syst) MeV and (407 ± 61stat ± 96syst) MeV respectively. A collective elliptic flow of direct photons is measured and appeared to be close to the decay photon flow.
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Dissertations / Theses on the topic "3 photon"

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Sunter, Kristen Ann. "Optical Modeling of Superconducting Nanowire Single Photon Detectors." Thesis, Harvard University, 2014. http://nrs.harvard.edu/urn-3:HUL.InstRepos:13106421.

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Superconducting nanowire single photon detectors (SNSPDs) can detect single photons or low levels of infrared light in applications that require high speed and low timing jitter, such as integrated circuit analysis. Most applications also require a high device detection efficiency (DDE), but the DDE of SNSPDs is limited by many factors. A good optical design with an integrated optical cavity and dielectric layers can increase the absorptance of 1550-nm light in the active area to over 90%. Therefore, optical modeling using the transfer matrix method was used to guide the design and fabrication of high-efficiency detectors with a measured DDE of over 70%. In addition, finite element analysis was used to simulate the effect of adding different types of optical antennas to SNSPD designs to increase their active area without compromising their speed, and the fabrication of antennas integrated with nanowires achieved sub-10 nm gaps between features. Thin films of niobium nitride, the starting material of the SNSPDs, were investigated using several techniques for thin film characterization, including x-ray diffraction, Auger electron spectroscopy and x-ray photoelectron spectroscopy. Optical setups based on reflectometry and transmittometry were built to determine the film thickness more accurately than deposition time for optical modeling and to provide feedback on the deposition conditions. The optical setups are able to provide reproducible and precise thickness measurements to within 0.1 nm.
Engineering and Applied Sciences
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Romijn, Elisabeth Inge. "Development of 3-D Quantitative Analysis of Multi-Photon Microscopy Images." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for fysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18425.

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Motivation: Cartilage is a robust but flexible connective tissue found in most joints of the body. The collagen fibres present in the extracellular matrix of cartilage contribute to its tensile strength and stiffness. The purpose of this study is to develop and implement methods to determine the orientation and anisotropy of collagen fibres in 3-D images gen- erated with multi-photon microscopy. The motivation behind developing these techniques is to improve the foundation for further studies on understanding the characteristics of the cartilage matrix. This in turn would give a better foundation for developing artificial matrices and mechanical models, as well as improve diagnostics.Material and methods: The two methods developed in this study are based on analysing the frequency domain. One is an expansion of a previous developed method by Chaudhuri et al. [1]. This method is based on evaluating the average intensity at different directions in the frequency domain. The direction with the least average intensity is equivalent to the direction of the fibres. The other method is based on thresholding the frequency domain according to intensity followed by fitting an ellipsoid to the remaining data set. The direction of the collagen fibres is equivalent to the direction of the shortest axis of the ellipsoid. These methods are called the sector and ellipsoid method, respectively. To determine how robust these methods are a series of tests were developed. The focus of these tests was to determine if the methods are rotational invariant and if the results are influences by different preprocessing techniques. These preprocessing techniques are: median filtering, deconvolution and skeletonization of the original image containing the collagen fibres. It is also important to determine the sensitivity of the ellipsoid method according to the chosen threshold value. In addition data generated fibres and frequency domains were made to determine the accuracy of the methods.Results and conclusion: The sector method was not very robust. For most cases there is not one specific direction that has the least average intensity in the frequency domain. Instead there is a quite large minimum area. The ellipsoid method shows promising results. It managed to find the correct direction both for the data generated data sets, but also for the real images. It seems like no preprocessing nor frequency filtering, except for thresholding, is needed to still find the correct direction and its anisotropy. The only remark is that the automatically chosen threshold value was to low for one of the samples. This can probably be improved by making a slight change in the process for choosing a threshold value.
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Sun, Chengwei. "First measurement of the reaction helium-3(photon,proton -proton)neutron." W&M ScholarWorks, 1990. https://scholarworks.wm.edu/etd/1539623791.

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Differential cross sections for the {dollar}\sp3{dollar}He({dollar}\gamma{dollar},pp)n reaction were measured with a bremsstrahlung beam for kinematics selected in the quasi-free two-nucleon region with neutron recoil q{dollar}\sb{lcub}\rm n{rcub}\approx{dollar} 0. Five photon energy points were taken between 200 and 440 MeV. The two proton detectors were positioned in such a way that the angle of one proton, in the CM of the pp pair, relative to the photon direction is 75{dollar}\sp\circ{dollar}. The data confirm the predicted quenching of the cross section. In the photon energy region from 310 to 440 MeV the data are in agreement with a theoretical prediction based on a diagrammatic description of the process. at lower energies (200 to 310 MeV) the data are about 40% to 70% higher than the predictions. However the shape of the proton momentum spectrum is reproduced when three body mechanisms are included.
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Telliez, Cécile. "Advanced optical microscopy for spatially and temporally precise deep brain interrogation." Electronic Thesis or Diss., Sorbonne université, 2024. http://www.theses.fr/2024SORUS041.

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Dans le domaine des neurosciences, l'avènement des outils optogénétiques sensibles à la lumière a ouvert de nouvelles opportunités pour contrôler précisément l'activité neuronale et étudier le fonctionnement cérébral optiquement. En optique, cela a motivé le développement de diverses stratégies d'illumination et de collecte de la lumière pour imager l'activité neuronale et la manipuler avec une précision spatiotemporelle élevée. En particulier, les approches de mise en forme de la lumière, telles que l'holographie générée par ordinateur combinée à la focalisation temporelle, ont permis de cibler des neurones individuels ou des groupes de neurones avec une grande précision temporelle et une précision spatiale proche de la cellule unique, dans des espaces volumétriques de centaines de microns. Cette précision est cruciale pour obtenir des informations critiques sur le code neuronal et établir des connexions entre l'activité neuronale, le comportement et la perception à une échelle fine. Malgré ces avancées, des défis persistent pour permettre des investigations cérébrales complexes, notamment en ce qui concerne le contrôle de vastes populations de cellules avec une précision spatiotemporelle élevée en profondeur. Pendant ma thèse, j'ai particulièrement concentré mes efforts sur ces défis et développé de nouvelles stratégies optiques de mise en forme de la lumière visant à (i) étendre le nombre de neurones excitables, (ii) améliorer la résolution temporelle et (iii) augmenter la profondeur de pénétration de l'investigation optogénétique multi-photonique ciblée et basée sur la modulation de phase de la lumière.Initialement, j'ai concentré mes efforts sur le développement d'un système optique ultra-rapide à deux photons (2P) (FLiT), où un modulateur spatial de lumière et un miroir galvanométrique sont couplés pour permettre la commutation à un taux de kHz de motifs d'illumination précis spatialement sur l'échantillon. Cela sert deux objectifs principaux. Premièrement, cela permet d'ajuster optiquement le temps d'excitation relatif de cellules distinctes avec une résolution temporelle d'environ un ordre de grandeur supérieur par rapport aux méthodes précédentes. Deuxièmement, FLiT permet de cibler un ensemble donné de cellules en réduisant le budget de puissance d'excitation d'un facteur 4-5, tout en minimisant l'élévation thermique induite par la lumière. Pour pousser cette approche encore plus loin, j'ai ensuite modifié la conception optique originale en incluant une unité de de-scan (deFLiT), ce qui a permis d'élargir le nombre d'hologrammes utilisables et d'augmenter encore davantage le gain de puissance et la précision temporelle du FLiT conventionnel.Dans la deuxième phase de la thèse, je me suis concentré sur un système holographique à trois photons (3P) pour mener des expériences d'optogénétique plus profondément à l'intérieur du cerveau. J'ai conçu et construit le système, puis je l'ai validé en photo-activant diverses opsines et en induisant leur activation à haute fréquence dans les neurones ciblés sous un régime d'excitation à 3P que j'ai également vérifié. Par rapport aux systèmes holographiques à deux photons précédents, cette approche permettra d'étendre les investigations entièrement optiques à des régions plus profondes du cerveau.Ces nouvelles stratégies seront importantes pour étudier les circuits neuronaux avec une stimulation optogénétique rapide et précise à travers de vastes ensembles neuronaux en profondeur
In the field of neuroscience, the advent of light-sensitive optogenetic tools has opened new opportunities for precisely controlling neuronal activity and study brain functioning optically. In optics, this has motivated the development of various light-delivery and collection strategies to functionally image and manipulate neural activity with high spatiotemporal precision. Particularly, light-shaping approaches, such as Computer-Generated Holography combined with Temporal Focusing, have enabled temporally precise targeting of individual neurons or clusters with near single-cell accuracy within volumetric spaces of hundreds of microns. This precision is crucial to get critical insights into the neural code and establishing connections between neural activity with behavior and perception at fine scale. Despite these advancements, challenges persist in enabling complex brain investigations, especially when it comes to control vast populations of cells with high spatiotemporal precision in depth. During my thesis, I particularly focused on those challenges and developed new light-shaping optical strategies aiming at (i) expanding the number of excitable neurons, (ii) improving temporal resolution and (iii) increasing the penetration depth of cell-targeted multiphoton optogenetic investigation based on phase-modulation light-targeting.Initially, I concentrated on developing an ultra-fast two-photon (2P) optical system (FLiT), where a multiplexing LC-SLM and a galvanometric mirror are coupled to allow kHz-rate switching of spatially precise illumination patterns on the sample. This serves two primary purposes. Firstly, it enables to optically tune the relative spiking time of distinct cells with a temporal resolution of about one order of magnitude higher compared to previous methods. Secondly, FLiT allows targeting a given ensemble of cells by reducing the excitation power budget by a 4-5 factor, while minimizing light-induced thermal rise. To push forward this approach, I further modified the original optical design by including a de-scan unit (deFLiT) which enabled to enlarge the number of usable holograms and increase even further the power gain and temporal precision of conventional FLiT .In the second phase of the thesis, I focused on a three-photon (3P) holographic system to conduct optogenetics experiments deeper inside the brain. I designed and built the system and I then validated it by photo-activating various opsins and driving high-rate firing in targeted neurons under a verified 3PE regime. Compared to previous holographic 2P-photon systems, this approach will enable the extension of all-optical investigations to deeper brain regions.These new strategies will be important for studying neuronal circuits with rapid and precise optogenetic stimulation across large neuronal ensembles in depth
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Yilmaz, Ercan. "Characteristic X-ray, Photoelectron And Compton-scattered Photon Escape From A Hpge Detector." Phd thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/3/1210061/index.pdf.

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Escape of photoelectrons, Compton-scattered photons and Ge X-rays from a HPGe detector was studied as a function of energy in the range 8-52 keV. A variable-energy source producing Cu, Rb, Mo, Ag, Ba, and Tb X-rays was used. All three mechanisms for energy loss were observed in the same experiment for Ba and Tb, while only X-ray and photoelectron escapes were evident in the spectra for Ag, Mo, Rb, and Cu. Spectral features and possible mechanisms for partial energy deposition were investigated. A Monte Carlo program was used to simulate the relevant interactions and to estimate the escape probabilities.
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Damon, Vianney. "Filtrage programmable et mémoire quantique dans Er 3+ YSO." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00877060.

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Les ions de terres rares en matrice cristalline, refroidis à très basse température, offrent des propriétés remarquables pour le traitement analogique du signal sur porteuse optique. L'élargissement inhomogène du spectre d'absorption peut en effet atteindre plusieurs centaines de gigahertz alors que la largeur homogène des raies d'absorption des ions individuels ne dépasse pas quelques kilohertz. Par pompage optique il est alors possible de modifier à volonté le profil du spectre d'absorption. On dispose ainsi d'un filtre programmable présentant à la fois une très grande bande passante, donnée par la largeur inhomogène, et une excellente résolution, fixée par la largeur homogène. Une raie d'absorption étroite correspond à un état de superposition quantique de longue durée de vie. C'est sous cet angle, celui des transitoires cohérents, et spécifiquement celui des échos de photons que nous abordons les propriétés du filtre programmable. Dans la première partie de la thèse, le filtre est programmé comme un élément dispersif. Il permet d'atteindre des taux de dispersion inaccessibles aux dispositifs optiques conventionnels, tels que les fibres optiques. Nous l'utilisons comme un composant de lentille temporelle, en vue de produire des signaux de forme arbitraire. Par rapport à des dispositifs d'optique conventionnels, on gagne plusieurs ordres de grandeurs en termes de produit temps x bande passante. Après avoir exploité l'écho de photon dans un contexte de filtrage linéaire, nous tirons parti de ses propriétés de très forte non-linéarité dans la seconde partie de la thèse. Cette fois nous cherchons à capturer un signal lumineux de très faible intensité, à le convertir en état de superposition atomique, puis à le restituer dans son état lumineux initial. Cela suppose en particulier d'empêcher les effets d'émission spontanée ou stimulé qui nuisent à la fidélité de la restitution. Pour ce faire, nous proposons un nouveau protocole que nous avons appelé " Revival Of Silenced Echo " (ROSE)
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Aldousari, Hanan. "Study of 2-to-3 photon annihilation using hydrophilic material as hypoxic tumour phantom." Thesis, University of Surrey, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.616952.

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The use of three gamma annihilation as a new PET molecular imaging modality which can predict tumour hypoxia was proposed by Kacperski and Spyrou in 2004. The positronium and its annihilation, could then serve as an oxygen-sensitive marker. The relative magnitude of three photon annihilation is increased in an oxygen deficient environment. The main questions addressed in this thesis are the potential use of the lanthanum bromide LaBr3: Ce (5%) scintillator detector for three-photon positron annihilation measurements. Also, the optimum source-to-detector distance that achieves good efficiency and sensitivity of the measurements. The other question is finding the best method to prepare in vitro three types of hypoxic samples (mineral water, defibrinated horse blood and semm). In addition, the suitability of the hydrophilic material is examined in terms of hydration behaviour, radiation and physical properties, for use as a phantom that represents the hypoxic tumour in the three-photon positron annihilation measurements. The main critical question is which the best method that could be used to measure the three-photon positron annihilation yields. Also, how does the 3y/2y ratio vary with different oxygen concentrations in different hydrophilic materials? Lanthanum bromide LaBr3: Ce (5%) scintillator detectors have good fast timing resolution, good stopping power and large light output. The LaBr3:Ce (5%) has very good scintillator characteristics, combining high effective Z and density, fast decay time, light emission wavelengths matching that of commonly available photon detectors and excellent energy resolution (~3% at 662 keY). However, it is highly hygroscopic in nature, making it difficult to produce, but its commercial availability has been gradually increasing in recent times. LaBr3: Ce (5%) has come to be accepted for the superior energy resolution it offers. Therefore, LaBr3: Ce (5%) detectors can be considered as the scintillators of choice for determining the yield of 2-and3-y positron annihilation. The characterisation of the detector used was can-ied out in terms of energy resolution and efficiency. The effect of amplifier parameters on the energy resolution was also studied. The 'geometrical solid angles subtended by the source-to-detector distances play an important role in the sensitivity and accuracy of the detector efficiency measurements. Therefore, the efficiency measurements were investigated at various distances to optimise the geometrical solid angle for the LaBr3: Ce (5%) detector for the three photon annihilation measurements. The experimental data were compared with the GATE simulated results obtained. The objective to study the factors that affect dissolved oxygen (DO) in three types of samples (mineral water, defibrinated horse blood and semm) was to investigate the 3y/2y ratio in hypoxic, nOlIDoxic and hyperoxic conditions of tissues for future application in oncology in the detection and quantification of tumour hypoxia. This was achieved by measuring the DO, pH and temperature before, during and after treating the samples with nitrogen, carbon dioxide and ascorbic acid (AnaeroGen). Two methods for the preparation of the in vitro hypoxic samples were investigated and evaluated. Carbon dioxide proved to be most effective for the reduction of DO in the samples. Blood tended to resist DO reduction since it decreased at a much slower rate than in water and semm. Together with the fact that the oxygen level in blood remained low after the end of exposure to the gases and ascorbic acid suggests that the solubility of oxygen in blood depends upon the concentration of haemoglobin as well as upon ligands such as CO2 • CO2 combines with haemoglobin affecting oxygen binding and fonns bicarbonate which further decreases the affinity of haemoglobin to oxygen Hydrophilic materials.
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Nunes, Luiz Antonio de Oliveira. "Espectroscopia de dois fotons do ion Gd+3 em estruturas perovskitas." Universidade de São Paulo, 1988. http://www.teses.usp.br/teses/disponiveis/54/54132/tde-10032008-113404/.

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Através da absorção de um e de dois fótons estudamos as diferentes transições do íon \'Gd POT.+3\' e GGG. Utilizando técnicas espectroscópicas com laser pulsado e laser contínuo, analisamos a influência do campo cristalino sobre o íon. Estes resultados estão em concordância com as previsões advindas da teoria de grupo. A partir da análise dos espectros de luminescência das amostras de GdAl\'O IND.3\', conseguimos detectar pequenos traços de impurezas nas mesmas. Não conseguimos detectar nenhuma anomalia nos espectros obtidos, de modo a não acreditarmos na existência de alguma interação Gadolínio - Galdoíno, acima da temperatura de transição de fase. Laser de corante contínuo de alta resolução, laser de corante pulsado foram construídos para a realização dos experimentos. Também desenvolvemos os equipamentos eletrônicos envolvidos.
The different transitions of \'Gd POT.3+\' ion in samples of GdAl\'O IND.3\' and GGG were studied by means of the absorption of one and two photons. The crystalline field influence an the ion was studied by using spectroscopic techniques with pulsed laser as well as continuous laser. These results are in agreement with the group theory prediction. From the luminescence spectrum of this sample little impurities aspects in the GdA1\'O IND.3\' sample were detected. No anomaly was detected in the spectra obtained so that we believed there is no \'Gd POT.3+\'-\'Gd POT.3+\' interaction above the phase transition temperature. High resolution continuous dye laser and pulsed die laser were built up to carry out the experiments. The electronic equipment used in the experiment was developed by us.
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Makgopa, Bessie Mmakgoto. "Simulation of the irradiation behaviour of the PBMR fuel in the SAFARI-1 reactor / B.M. Makgopa." Thesis, North-West University, 2009. http://hdl.handle.net/10394/4030.

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Irradiation experiments for the pebble bed modular reactor PBMR fuel (coated fuel particles and pebble fuel) are planned at the South African First Atomic Reactor Installation (SAFARI-1). The experiments are conducted to investigate the behavior of the fuel under normal operating and accelerated/accident simulating conditions because the safe operation of the reactor relies on the integrity of the fuel for retention of radioactivity. For fuel irradiation experiments, the accurate knowledge and analysis of the neutron spectrum of the irradiation facility is required. In addition to knowledge of the neutron spectrum in the irradiation facility, power distributions and knowledge of nuclear heating values has to be acquired. The SAFARI-1 reactor boosts operating fluid temperatures of about 300 K. On the contrary, the PBMR can reach temperatures in up to about 1370 K under normal operating conditions. This calls for design of high temperature irradiation rigs for irradiation of the PBMR fuel in the SAFARI-1 reactor. The design of this instrument (rig) should be such that to create an isolated high temperature environment in the SAFARI-1 reactor, to achieve the requirements of the PBMR fuel irradiation program. The design of the irradiation rig is planned such that the rig should fit in the existing irradiation channels of the SAFARI-1 reactor, a time and cost saving from the licensing perspective. This study aims to establish the know-how of coated particle and pebble modeling in using the Monte Carlo N-Particle code (MCNP5). The study also aims to establish the know-how of rig design. In this study, the Necsa in-house code Overall System for the Calculation of Reactors (OSCAR-3), a software known as OScar 3-Mcnp INTerface (OSMINT) linking OSCAR-3 and MCNP5, also developed at Necsa, as well as MCNP5 code developed and maintained by the Los Alamos team, are used to calculate neutronic and power distribution parameters that are important for fuel irradiations and for rig design. This study presents results and data that can be used to make improvements in the design of the rig or to confirm if the required operational conditions can be met with the current preliminary rig design. Result of the neutronic analysis are presented for the SAFARI-1 core, core irradiation channel B6 (where the PBMR fuel irradiation rig is loaded for the purpose of this study), the rig structure and the pebble fuel are presented. Furthermore results of the power distribution and nuclear heating values in the reactor core, the irradiation channel B6, the rig structures and the pebble fuel is also presented. The loading of the PBMR fuel irradiation rig in core position B6 reduces the core reactivity due to the fact that the loading of the rig displaces the water moderator in channel B6 introducing vast amounts of helium. This impacts on the keff value because there will be less neutron thermalization and reproduction due to the decreased population of thermal neutrons. The rig is found to introduce a negative reactivity insertion of 46 pcm. The loading of this rig in the core leads to no significant perturbations on the core power distribution. The core hottest channel is still localized in core channel C6 both with RIG IN and RIG OUT cases. A power tilt is observed, with the south side of the core experiencing reduced assembly averaged fission power, with correspondingly small compensations from the assemblies on the north side of the core. The perturbations on the core assembly averaged fluxes are more pronounced in the eight assemblies surrounding B6. Core position B6 suffers an 18% neutron flux depression with the loading of the rig. The fluxes in core positions A5, A6, A7, B5, B7 and C7 are increased when the rig is loading. The largest increases are noted as 12% in A7, 9% in A6 and 6% in A5 and B7. All the eight core positions surrounding B6 experience reduced photon fluxes with the loading of the rig. Core position B6 shows a flux depression of up to 20%, with 10% reduction in core position A6. The remainder seven positions surrounding B6 shows flux depressions of no more than 5%. Further on, due to decreased moderation effects, the axial neutron flux in core position B6 is reduced by 20% when the rig is loaded. The energy dependent neutron flux in B6 decreases by 50% in the thermal energy range with corresponding increases of up to 50% in the resonance and fast energy regions. The axial and the energy dependent photon flux in core position B6 decreases by up to 20% when the rig is loaded. The magnitude of the neutron and photon fluxes is found to have a direct proportion on the neutron and photon heating values. While the amount of neutron heating in core position B6 increases by one order of magnitude, when the rig is loaded, the photon heating values increases by up to 60% in the region spanning ±10cm about the core centerline. The amount of photon heating in the rig structural materials dominates neutron heating, except in the helium regions of the rig, where neutron heating dominates photon heating. In the fuel region of the pebble, fission heating (3803W) largely dominates photon heating (119W).
Thesis (M.Sc. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2009
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Paulik, Julia [Verfasser]. "[123I]-3-Iodcytisin als möglicher Radiotracer für die Darstellung der nikotinergen Acetylcholinrezeptoren mittels Single-Photon-Emissions-Tomographie / Julia Paulik." Bonn : Universitäts- und Landesbibliothek Bonn, 2015. http://d-nb.info/1077271263/34.

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Books on the topic "3 photon"

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1950-, Becker W., Society of Photo-optical Instrumentation Engineers., Boston Electronics Corporation, and Becker & Hickl., eds. Advanced photon counting techniques: 1-3 October, 2006, Boston, Massachusetts, USA. Bellingham, Wash: SPIE, 2006.

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J, Schanda, Lippényi T, International Measurement Confederation, Society of Photo-optical Instrumentation Engineers. Hungarian Chapter., and Méréstechnikai és Automatizálási Tudományos Egyesület (Hungary), eds. 14th Symposium on Photonic Measurements: 1-3 June 1992, Sopron, Hungary. Bellingham, Wash., USA: SPIE, 1993.

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Myneni, Ranga B., and Juhan Ross, eds. Photon-Vegetation Interactions. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-75389-3.

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Yamanouchi, Kaoru, Sergey Tunik, and Vladimir Makarov, eds. Progress in Photon Science. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-05974-3.

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Yamanouchi, Kaoru, ed. Progress in Photon Science. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-52431-3.

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Zhang, Fan. Photon Upconversion Nanomaterials. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-45597-5.

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Evans, Myron W., Jean-Pierre Vigier, Sisir Roy, and Stanley Jeffers. The Enigmatic Photon. Dordrecht: Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-010-9840-3.

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Seitz, Peter, and Albert JP Theuwissen, eds. Single-Photon Imaging. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-18443-7.

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Kapusta, Peter, Michael Wahl, and Rainer Erdmann, eds. Advanced Photon Counting. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-15636-1.

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Chang, You-Hao. Study of Double Parton Scattering in Photon + 3 Jets Final State. Singapore: Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-3824-2.

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Book chapters on the topic "3 photon"

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Böer, Karl W., and Udo W. Pohl. "Photon–Phonon Interaction." In Semiconductor Physics, 1–36. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-319-06540-3_11-3.

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Böer, Karl W., and Udo W. Pohl. "Photon–Phonon Interaction." In Semiconductor Physics, 389–424. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-69150-3_11.

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Böer, Karl W., and Udo W. Pohl. "Photon–Phonon Interaction." In Semiconductor Physics, 429–66. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-18286-0_11.

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Böer, Karl W., and Udo W. Pohl. "Photon-Phonon Interaction." In Semiconductor Physics, 1–36. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-06540-3_11-1.

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Böer, Karl W., and Udo W. Pohl. "Photon–Phonon Interaction." In Semiconductor Physics, 1–36. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-06540-3_11-2.

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Böer, Karl W., and Udo W. Pohl. "Photon–Phonon Interaction." In Semiconductor Physics, 1–38. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-319-06540-3_11-4.

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Sudhir, Vivishek. "Photon-Phonon Coupling: Cavity Optomechanics." In Springer Theses, 83–101. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-69431-3_4.

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Evans, Myron W. "B (3) Echoes." In The Enigmatic Photon, 285–93. Dordrecht: Springer Netherlands, 1999. http://dx.doi.org/10.1007/978-94-010-9044-5_19.

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Rouan, Daniel. "Photon." In Encyclopedia of Astrobiology, 1244. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-11274-4_1201.

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Rouan, Daniel. "Photon." In Encyclopedia of Astrobiology, 1877. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-44185-5_1201.

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Conference papers on the topic "3 photon"

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Hunter, Geoffrey. "Einstein’s Photon Concept Quantified by the Bohr Model of the Photon." In QUANTUM THEORY: Reconsideration of Foundations - 3. AIP, 2006. http://dx.doi.org/10.1063/1.2158738.

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Braverman, Boris, Nicholas M. Sullivan, and Robert W. Boyd. "Photon Counting with an Adaptive Storage Loop." In Frontiers in Optics. Washington, D.C.: Optica Publishing Group, 2023. http://dx.doi.org/10.1364/fio.2023.fth3b.3.

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Single-photon detectors can be used to resolve photon number by storing the photons in a delay loop. We consider a loop with adaptive, detection-record dependent out-coupling, finding that the dynamic range and effective speed of the detector can be enhanced compared to a purely passive setup.
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Zhao, Haoqi, Yichen Ma, Zihe Gao, Na Liu, Tianwei Wu, Shuang Wu, Xilin Feng, James Hone, Stefan Strauf, and Liang Feng. "Integrated tunable twisted single photon source." In CLEO: Science and Innovations. Washington, D.C.: Optica Publishing Group, 2023. http://dx.doi.org/10.1364/cleo_si.2023.stu4j.3.

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Twisted single photons, carrying orbital angular momentum (OAM) as an unbounded dimension, could address the growing demand for high-dimensional quantum information encoding and transmission. By hybrid integration of two-dimensional semiconductor WSe2 with a spin-orbit-coupled microring resonator, we demonstrate an integrated tunable twisted single photon source with the ability to precisely define and switch between highly pure spin-OAM states.
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Huang, Jiahui, Wei Liu, Alessio Miranda, Benjamin Dwir, Alok Rudra, Eli Kapon, and Chee Wei Wong. "Site-controlled QD embedded coupled photonic crystal cavity waveguides for on-chip photon routing." In CLEO: Fundamental Science. Washington, D.C.: Optica Publishing Group, 2023. http://dx.doi.org/10.1364/cleo_fs.2023.fth4j.3.

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We demonstrate the on-chip photon routing on a site-controlled quantum dots embedded W1 photonic crystal waveguides side coupled to a L3 cavity. Observed photon propagation through the device indicates the connectivity of all photonic elements.
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Esener, Sadik, and P. M. Rentzepis. "Two-photon 3-D optical memories." In Optical Data Storage. Washington, D.C.: Optica Publishing Group, 1991. http://dx.doi.org/10.1364/ods.1991.mf1.

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Esener, Sadik C., and Peter M. Rentzepis. "Two-photon 3-D optical memories." In Optical Data Storage, edited by James J. Burke, Thomas A. Shull, and Nobutake Imamura. SPIE, 1991. http://dx.doi.org/10.1117/12.45953.

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Lipson, M., J. Michel, K. Wada, and L. C. Kimerling. "Strong Er/sup 3+/-photon coupling." In Conference on Lasers and Electro-Optics (CLEO 2000). Technical Digest. Postconference Edition. TOPS Vol.39. IEEE, 2000. http://dx.doi.org/10.1109/cleo.2000.906892.

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McCormick, F. B., I. Cokgor, A. S. Dvornikov, M. Wang, N. Kim, K. Coblentz, S. E. Esener, and P. M. Rentzepis. "3-D Data Storage in Two-Photon Photochromic Optical Memories." In Symposium on Optical Memory. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/isom.1996.owb.1.

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Rapid increases in the computer processing power available per unit cost, as well as a growing hunger for multimedia (text, audio, and image) entertainment and processing has led to heightened interest in multilayer and other volume optical storage technologies.1 One such technology is 2-photon absorption-based storage.2,3,4 In this approach, writing or erasure takes place only at the intersection of 2 beams of different wavelengths, thus allowing independent addressing of any point within a 3-dimensional volume. As a bit oriented (rather than holographic) memory, a unique physical location is allocated for each data bit. If individual bits are stored, volumetric densities on the order of terabits/cm3 may be achievable, and parallel reading of the bits (e.g.-in planes or pages) can enable 100 Gb/s data transfer rates. The key principle behind 2-photon memories is the creation of a molecular change in the media by the simultaneous absorption of 2 photons from 2 different beams by the dopant molecule, as shown in Fig. 1(a). The localized change can store bits by changing the index of refraction, absorption, fluorescence, or the material’s electrical properties. In our system experiments so far we have utilized materials in which 2-photon excitation creates a new absorption peak and subsequent 1 or 2-photon illumination results in efficient fluorescence for readout. The broad readout absorption profile, and the high fluorescence efficiency enable the use of inexpensive, low power replay sources, including LEDs and filtered lamps. In addition to non-destructive memory recall, we have also demonstrated optically induced erasure, thus enabling random accessibility and erasure of bits. These two-photon 3-D memories are similar to the multilayer optical disk systems with the potential for simple media fabrication, many layers, parallel access for high data transfer rates, and low raw bit error rates (BER). As shown in Fig. 1(b), orthogonal intersection of the writing beams may be used, or if ultra-short (e.g.-<100 femtosecond) pulses are used, a counter-propagating arrangement10,5 is feasible. While single bits may be stored and recalled, parallel access of lines or planes of data is naturally accommodated in two-photon 3-D memories, to provide increased data transfer rates. Due to diffraction of the addressing beam as it propagates across the data image, there exists a tradeoff between the volumetric density of the memory and the parallelism, or data transfer rate.9
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Benić, Sanjin, Kenji Fukushima, Oscar Garcia-Montero, and Raju Venugopalan. "CGC Photon Production at NLO in pA Collisions." In INT Program INT-18-3. WORLD SCIENTIFIC, 2020. http://dx.doi.org/10.1142/9789811214950_0060.

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Zhang, Guiyin, Mengjun Li, and Yidong Jin. "Photo-ionization probability of 3+1 resonance enhanced multi-photon process." In Photonics Asia, edited by Qihuang Gong, Guang-Can Guo, and Yuen-Ron Shen. SPIE, 2012. http://dx.doi.org/10.1117/12.981861.

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Reports on the topic "3 photon"

1

Cullen, D. E. TART96: a coupled neutron-photon 3-D, combinatorial geometry Monte Carlo transport code. Office of Scientific and Technical Information (OSTI), November 1996. http://dx.doi.org/10.2172/461393.

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Cullen, D. E. TART97 a coupled neutron-photon 3-D, combinatorial geometry Monte Carlo transport code. Office of Scientific and Technical Information (OSTI), November 1997. http://dx.doi.org/10.2172/572762.

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Rhoades, W. A., and D. B. Simpson. The TORT three-dimensional discrete ordinates neutron/photon transport code (TORT version 3). Office of Scientific and Technical Information (OSTI), October 1997. http://dx.doi.org/10.2172/582265.

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Cullen, D. E. TART98 a coupled neutron-photon 3-D, combinatorial geometry time dependent Monte Carlo Transport code. Office of Scientific and Technical Information (OSTI), November 1998. http://dx.doi.org/10.2172/8435.

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Cullen, D. E. TART 2000: A Coupled Neutron-Photon, 3-D, Combinatorial Geometry, Time Dependent, Monte Carlo Transport Code. Office of Scientific and Technical Information (OSTI), November 2000. http://dx.doi.org/10.2172/802092.

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Cristy, M., and K. F. Eckerman. Specific absorbed fractions of energy at various ages from internal photon sources: 3, Five-year-old. Office of Scientific and Technical Information (OSTI), April 1987. http://dx.doi.org/10.2172/6263443.

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Bruinvis, I. A. D., R. B. Keus, W. J. M. Lenglet, G. J. Meijer, B. J. Mijnheer, A. A. Van 't Veld, J. L. M. Venselaar, J. Welleweerd, and E. Woudstra. NCS Report 15: Quality assurance of 3-D treatment planning systems for external photon and electron beams. Delft: NCS, March 2005. http://dx.doi.org/10.25030/ncs-015.

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Cullen, D. TART2012 An Overview of A Coupled Neutron Photon 3-D, Combinatorial Geometry Time Dependent Monte Carlo Transport Code. Office of Scientific and Technical Information (OSTI), July 2012. http://dx.doi.org/10.2172/1056631.

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Cullen, D. E. Users Manual for TART 2002: A Coupled Neutron-Photon 3-D, Combinatorial Geometry Time Dependent Monte Carlo Transport Code. Office of Scientific and Technical Information (OSTI), June 2003. http://dx.doi.org/10.2172/15004094.

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Prasad, Paras N. Development of Bottom-Up Chemical Approaches to 3-D Negative Index Meta-Materials: Two Photon Lithographic Approach-Chiral Chemical Synthesis Approach. Fort Belvoir, VA: Defense Technical Information Center, June 2014. http://dx.doi.org/10.21236/ad1013206.

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