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Showing 1 to 20 of 38 for “"stopping power"”.
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A Theoretical Model for Calculation of Molecular Stopping Power
… is employed to obtain a formula to evaluate the stopping power of many useful molecular systems. The stopping power of H<sub>2</sub> and He gas was calculated for incident proton energy ranging from 100 KeV to 2.5 MeV. The stopping power of O<sub>2</sub>, N<sub>2</sub> and water vapor was also …
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On the prediction of electronic stopping power from first principles
The prediction of electronic stopping power in materials from first principles using real-time time-dependent density functional theory, as implemented in the SIESTA code, combines classical motion of the nuclei with evolution of the electronic wavefunctions according to the time-dependent …
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Evaluation and Clinical Implementation of a Dual-Energy CT Stopping-Power Ratio Mapping Technique for Proton-Therapy Treatment Planning
… of the Bragg-peak position from predicted stopping-power ratio maps. The method that is most commonly used in today’s clinical practice for predicting stopping-power ratio (SPR) consists of a stoichiometric calibrationtechnique based on single-energy CT (SECT) for direct estimation of …
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Using fusion-product spectroscopy to study inertial fusion implosions, stopping power, and astrophysical nucleosynthesis at OMEGA and the NIF
… fusion implosions, measure charged-particle stopping in dense plasmas to high accuracy, and study reactions relevant to nuclear astrophysics. 'Surrogate' plastic-shell implosions at the National Ignition Facility with D³He fuel produce 14.7-MeV protons. Spectrometry capability developed for …
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Using fusion-product spectroscopy to diagnose inertial confinement fusion implosions and study stopping power on OMEGA, the NIF, and Z
… Confinement Fusion (ICF) implosions or study stopping power to better understand the areal density requirements of said implosions. The first project at the Z Facilty regards spectroscopy of the primary DD neutron spectra from Magnetized Liner Inertial Fusion (MagLIF) implosions enables …
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Sub-10-nm lithography with light-ion beams
… as directly proportional to the so-called stopping power of incident beam particles - i.e. the average energy loss per unit path length, particularly for thin (less than 20 nm thick) resist. Values of stopping power are readily obtained via the popular Stopping and Range of Ions in Matter …
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Muon regeneration in muon catalyzed dt-fusion
… emphasis put on the density dependence of the stopping power in dense hydrogen. The main technical details and improvements in this work are: The (aμ)+ 2s and 2p states are treated independently and are assigned individual reaction rates. The essential muonic excitation rates have been …
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Monte Carlo simulations for heavy ion dosimetry
Water-to-air stopping power ratio ( ) calculations for the ionization chamber dosimetry of clinically relevant ion beams with initial energies from 50 to 450 MeV/u have been performed using the Monte Carlo technique. To simulate the transport of a particle in water the computer code SHIELD-HIT v2 …
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Robust and efficient methods for proton computed tomography.
… goal of generating accurate 3D maps of relative stopping power (RSP) with respect to water. Since the early developments of this imaging technique in 1970's, there have been significant improvements regarding the reconstruction of accurate RSP which makes pCT a reliable alternative to X-ray CT …
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Implementation of An Anthropomorphic Phantom For The Evaluation of Proton Therapy Treatment Procedures
… for use in proton therapy. The relative stopping power (SP) of each phantom material was measured. Hounsfield Units (HU) for each phantom material were measured with a CT scanner and compared to the relative stopping power calibration curve. The tissue equivalency for each material was …
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An AFM study of the surface of a polymer film bombarded by low energy gaseous ions
… ZBL (Ziegler, Biersack and Littmark) theory of stopping power and range. The depth measurements and unique cross-section of the radiation-induced damage clearly support he proposed model for ion induced crater formation on a polymer surface.
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The Development and Implementation of An Anthropomorphic Head Phantom For The Assessment of Proton Therapy Treatment Procedures
… with a reproducibility of ±3%. The relative stopping power (RSP) and Hounsfield Units (HU) were measured for potential phantom materials and a human skull was cast in tissue-equivalent Alderson material (RLSP 1.00, HU 16) with anatomical airways and a cylindrical hole for imaging and …
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Characterization of single-sided cadmium zinc telluride strip detectors for high energy astrophysics applications
… high atomic number, high density and good stopping power in the early 1990s. UNH has focused on developing CZT strip detector designs for astrophysical measurement applications in the 0.05 to 1 MeV photon energy range. This thesis presents characterization efforts of two types of …
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Effects of Proton Irradiation on the Mechanical and Physical Properties of Carbon Nanotube Based Composites
… instrumented nanoindentation tests. The proton stopping power of the epoxy was shown to be unchanged by the addition of CNTs, which is a promising result since the hardness of the samples was shown to be increased by addition of CNTs. Unfortunately, however, the surface of the samples proved to …
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Proton Computed Tomography: a novel calibration approach for proton treatment planning
… validation of phantom-based calibration for stopping power estimation, and an initial exploration of clinical applications for proton therapy planning. Collaborative studies with international research groups further demonstrated the potential of integrating pCT and multi-energy CT data to …
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Ab-initio molecular dynamics studies of laser- and collision-induced processes in multielectron diatomics, organic molecules and fullerenes
… vibrational and electronic energy transfer (\"stopping~power\"). For low energetic (adiabatic) collisions, it is surprisingly found, that a two-dimensional, phenomenological collision model can reproduce (even quantitatively) the basic features of fusion and scattering observed in the fully …
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Molecular dynamic simulation of xenon bubble re-solution in uranium dioxide
… re-dissolved, however, for ions with electronic stopping power lower than 34 keV/nm, bubble re-solution is not observed. Thus, bubble re-solution due to the electronic stopping of fission fragments in UO2 is likely to be insignificant compared to homogeneous re-solution.
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Formation and Rupture of Nanofilaments in Metal/TaOx/Metal Resistive Switches
… of their excellent scaling potential, low power consumption, high switching speed, good retention and endurance properties. Although, various mechanisms have been proposed to explain the switching behavior in CBRAM devices, i.e. metal ion migration and subsequent formation and rupture of …
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Development and Implementation of An Anthropomorphic Pediatric Spine Phantom For The Assessment of Craniospinal Irradiation Procedures In Proton Therapy
… was determined by measuring the relative stopping power and Hounsfield unit of potential phantom materials. The materials selected as bone, tissue, and cartilage substitutes were Techron HPV Bearing Grade (RSP 1.3, HU 595.6), solid water (RSP 1.004, HU 16), and blue water (RSP 1.07, HU …
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