Computer Simulation of Electronic Excitation in Atomic Collision Cascades
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Energy Spectra of Primary Knock-On Atoms Under Neutron Irradiation
UCLA UCLA Previously Published Works Title Energy spectra of primary knock-on atoms under neutron irradiation Permalink https://escholarship.org/uc/item/4110q0xk Authors Gilbert, MR Marian, J Sublet, JC Publication Date 2015-12-01 DOI 10.1016/j.jnucmat.2015.09.023 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Journal of Nuclear Materials 467 (2015) 121e134 Contents lists available at ScienceDirect Journal of Nuclear Materials journal homepage: www.elsevier.com/locate/jnucmat Energy spectra of primary knock-on atoms under neutron irradiation * M.R. Gilbert a, , J. Marian b, J.-Ch. Sublet a a Culham Centre of Fusion Energy, Culham Science Centre, Abingdon, OX14 3DB, UK b Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, CA, 90095, USA article info abstract Article history: Materials subjected to neutron irradiation will suffer from a build-up of damage caused by the Received 2 July 2015 displacement cascades initiated by nuclear reactions. Previously, the main “measure” of this damage Received in revised form accumulation has been through the displacements per atom (dpa) index, which has known limitations. 11 September 2015 This paper describes a rigorous methodology to calculate the primary atomic recoil events (often called Accepted 14 September 2015 the primary knock-on atoms or PKAs) that lead to cascade damage events as a function of energy and Available online 16 September 2015 recoiling species. A new processing code SPECTRA-PKA combines a neutron irradiation spectrum with nuclear recoil data obtained from the latest nuclear data libraries to produce PKA spectra for any material Keywords: Radiation damage quantification composition. -
1 Simulation of Ion Irradiation of Nuclear Materials and Comparison
Simulation of Ion Irradiation of Nuclear Materials and Comparison with Experiment Z. Insepov a , A. Kuksin *, J. Rest a, S. Starikov a, b, A. Yanilkin a, b, A. M. Yacout a, B. Ye a, c, D. Yun a, c, a Argonne National Laboratory, 9700 S. Cass Ave, Lemont, IL, 60439 b Joint Institute for High Temperatures RAS, 13 Izhorskaya , Moscow, 125412 c University of Illinois at Urbana-Champaign, 104 S. Wright Street, Urbana, IL 61801 Abstract: Radiation defects generated in various nuclear materials such as Mo and CeO2, used as a surrogate material for UO2, formed by sub-MeV Xe and Kr ion implantations were studied via TRIM and MD codes. Calculated results were compared with defect distributions in CeO2 crystals obtained from experiments by implantation of these ions at the doses of 11017 ions/cm2 at several temperatures. A combination of in situ TEM (Transmission Electron Microscopy) and ex situ TEM experiments on Mo were used to study the evolution of defect clusters during implantation of Xe and Kr ions at energies of 150-700 keV, depending on the experimental conditions. The simulation and irradiation were performed on thin film single crystal materials. The formation of defects, dislocations, and solid-state precipitates were studied by simulation and compared to experiment. Void and bubble formation rates are estimated based on a new mesoscale approach that combines experiment with the kinetic models validated by atomistic and Ab-initio simulations. Various sets of quantitative experimental results were obtained to characterize the dose and temperature effects of irradiation. These experimental results include size distributions of dislocation loops, voids and gas bubble structures created by irradiation. -
"Normal-Metal Quasiparticle Traps for Superconducting Qubits"
Normal-Metal Quasiparticle Traps For Superconducting Qubits: Modeling, Optimization, and Proximity Effect Von der Fakultät für Mathematik, Informatik und Naturwissenschaften der RWTH Aachen University zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften genehmigte Dissertation vorgelegt von Amin Hosseinkhani, M.Sc. Berichter: Universitätsprofessor Dr. David DiVincenzo, Universitätsprofessorin Dr. Kristel Michielsen Tag der mündlichen Prüfung: March 01, 2018 Diese Dissertation ist auf den Internetseiten der Universitätsbibliothek online verfügbar. Metallische Quasiteilchenfallen für supraleitende Qubits: Modellierung, Optimisierung, und Proximity-Effekt Kurzfassung: Bogoliubov Quasiteilchen stören viele Abläufe in supraleitenden Elementen. In supraleitenden Qubits wechselwirken diese Quasiteilchen beim Tunneln durch den Josephson- Kontakt mit dem Phasenfreiheitsgrad, was zu einer Relaxation des Qubits führt. Für Tempera- turen im Millikelvinbereich gibt es substantielle Hinweise für die Präsenz von Nichtgleichgewicht- squasiteilchen. Während deren Entstehung noch nicht einstimmig geklärt ist, besteht dennoch die Möglichkeit die von Quasiteilchen induzierte Relaxation einzudämmen indem man die Qu- asiteilchen von den aktiven Bereichen des Qubits fernhält. In dieser Doktorarbeit studieren wir Quasiteilchenfallen, welche durch einen Kontakt eines normalen Metalls (N) mit der supraleit- enden Elektrode (S) eines Qubits definiert sind. Wir entwickeln ein Modell, das den Einfluss der Falle auf die Quasiteilchendynamik beschreibt, -
Physical Modeling of Photoelectrochemical Hydrogen Production Devices
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Aaltodoc Publication Archive This is an electronic reprint of the original article. This reprint may differ from the original in pagination and typographic detail. Author(s): Kemppainen, Erno & Halme, Janne & Lund, Peter Title: Physical Modeling of Photoelectrochemical Hydrogen Production Devices Year: 2015 Version: Post print Please cite the original version: Kemppainen, Erno & Halme, Janne & Lund, Peter. 2015. Physical Modeling of Photoelectrochemical Hydrogen Production Devices. The Journal of Physical Chemistry C. Volume 119, Issue 38. 21747-21766. DOI: 10.1021/acs.jpcc.5b04764. Rights: © 2015 American Chemical Society (ACS). http://pubs.acs.org/page/policy/articlesonrequest/index.html. This document is the unedited author's version of a Submitted Work that was subsequently accepted for publication in The Journal of Physical Chemistry C, copyright © American Chemical Society after peer review. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/acs.jpcc.5b04764. All material supplied via Aaltodoc is protected by copyright and other intellectual property rights, and duplication or sale of all or part of any of the repository collections is not permitted, except that material may be duplicated by you for your research use or educational purposes in electronic or print form. You must obtain permission for any other use. Electronic or print copies may not be offered, whether for sale or otherwise to anyone who is not an authorised user. Powered by TCPDF (www.tcpdf.org) Physical Modeling of Photoelectrochemical Hydrogen Production Devices Erno Kemppainen, Janne Halme*, Peter Lund Aalto University School of Science, Department of Applied Physics, P.O.Box 15100, FI-00076 Aalto, Finland. -
G Ni Re En Ig N E Fo Eg Ell O C .S. E. P S CI S Y H P F O T N E M T R a P
PHYSICS, Un ti – IV : La es rs and Optical Fi sreb , PES EC .P E.S. oC ll ege fo Engi reen ing, Mandya – 571 04 1, Karna at ka (An A ut ono mous Instituti no af ilif ated to VTU, Belaga iv ) DEP RA TMENT OF PHYSICS Unit - IV Las re s and Op it ac l rebiF s Notes Laser Dr. T. S. Shashikumar, Department of Physics, PESCE, Mandya LASERS INTRODUCTION: LASER is an optical device that amplifies light. LASER is the acronym of Light Amplification by Stimulated Emission of Radiation. Laser device is a source of highly intense and highly parallel coherent beam of light produced by stimulated emission. Laser action is achieved by creating population inversion between a pair of energy levels. Production of laser light is a particular consequence of interaction of radiation with matter. Basic Principle and Production of LASERS: The working principle of laser is based on the phenomenon of interaction of radiation with matter. A material medium is composed of identical atoms or molecules each of which is characterized by a set of discrete allowed energy states E1 and E2 as shown in figure (1). An atom can move from one energy state to another when it receives or releases an amount of ∆Ε E − E energyγ = ⇒ γ = 2 1 ⇒ γh = E − E equal to the energy to the energy difference h h 2 1 between those two states (∆E = E2 − E1 ). There are three possible ways through which interaction of radiation with matter can take place. They are, (1) Induced Absorption, (2) Spontaneous Emission, and (3) Stimulated Emission. -
Exciton Polaritons Confined in a Zno Nanowire Cavity
PHYSICAL REVIEW LETTERS week ending PRL 97, 147401 (2006) 6 OCTOBER 2006 Exciton Polaritons Confined in a ZnO Nanowire Cavity Lambert K. van Vugt,1 Sven Ru¨hle,1 Prasanth Ravindran,2 Hans C. Gerritsen,2 Laurens Kuipers,3 and Danie¨l Vanmaekelbergh1 1Condensed Matter and Interfaces, Debye Institute, Utrecht University, Post Office Box 80 000, 3508 TA Utrecht, The Netherlands 2Molecular Biophysics, Debye Institute, Utrecht University, Post Office Box 80 000, 3508 TA Utrecht, The Netherlands 3Center for Nanophotonics, FOM Institute for Atomic and Molecular Physics (AMOLF), Kruislaan 407, 1098 SJ Amsterdam, The Netherlands (Received 10 May 2006; published 5 October 2006) Semiconductor nanowires of high purity and crystallinity hold promise as building blocks for miniaturized optoelectrical devices. Using scanning-excitation single-wire emission spectroscopy, with either a laser or an electron beam as a spatially resolved excitation source, we observe standing-wave exciton polaritons in ZnO nanowires at room temperature. The Rabi splitting between the polariton branches is more than 100 meV. The dispersion curve of the modes in the nanowire is substantially modified due to light-matter interaction. This finding forms a key aspect in understanding subwavelength guiding in these nanowires. DOI: 10.1103/PhysRevLett.97.147401 PACS numbers: 78.67.Pt, 71.36.+c, 71.55.Gs, 78.66.Hf Chemically prepared semiconductor nanowires form a In this Letter we report extremely strong exciton-photon class of very promising building blocks for miniaturized coupling in ZnO nanowires at room temperature. We col- optical and electrical devices [1]. They possess a high lect emission spectra of single wires upon scanning a degree of crystallinity and the lattice orientation is often focused laser or electron excitation spot along the wire. -
Comparison of Molecular Dynamics and Binary Collision Approximation Simulations for Atom Displacement Analysis ⇑ L
Nuclear Instruments and Methods in Physics Research B 297 (2013) 23–28 Contents lists available at SciVerse ScienceDirect Nuclear Instruments and Methods in Physics Research B journal homepage: www.elsevier.com/locate/nimb Comparison of molecular dynamics and binary collision approximation simulations for atom displacement analysis ⇑ L. Bukonte a, F. Djurabekova a, , J. Samela a, K. Nordlund b, S.A. Norris b, M.J. Aziz c a Helsinki Institute of Physics and Department of Physics, P.O. Box 43, FI-00014 University of Helsinki, Finland b Department of Mathematics, Southern Methodist University, Dallas, TX 75205, USA c Harvard School of Engineering and Applied Sciences, Cambridge, MA 02138, USA article info abstract Article history: Molecular dynamics (MD) and binary collision approximation (BCA) computer simulations are employed Received 26 November 2012 to study surface damage by single ion impacts. The predictions of BCA and MD simulations of displace- Received in revised form 14 December 2012 ment cascades in amorphous and crystalline silicon and BCC tungsten by 1 keV Arþ ion bombardment are Available online 4 January 2013 compared. Single ion impacts are studied at angles of 50°,60° and 80° from normal incidence. Four parameters for BCA simulations have been optimized to obtain the best agreement of the results with Keywords: MD. For the conditions reported here, BCA agrees with MD simulation results at displacements larger Molecular dynamics than 5 Å for amorphous Si, whereas at small displacements a difference between BCA and MD arises Binary collision approximation due to a material flow component observed in MD simulations but absent from a regular BCA approach Ion irradiation Atomic displacement due to the algorithm limitations. -
Effect of Collision Cascades on Dislocations in Tungsten: a Molecular Dynamics Study
This is a repository copy of Effect of collision cascades on dislocations in tungsten: A molecular dynamics study. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/107153/ Version: Accepted Version Article: Fu, BQ, Fitzgerald, SP orcid.org/0000-0003-2865-3057, Hou, Q et al. (2 more authors) (2017) Effect of collision cascades on dislocations in tungsten: A molecular dynamics study. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 393. pp. 169-173. ISSN 0168-583X https://doi.org/10.1016/j.nimb.2016.10.028 © 2016, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/. Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version - refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher’s website. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. -
Crack Healing Induced by Collision Cascades in Nickel
Crack healing induced by collision cascades in Nickel Peng Chen, Michael J. Demkowicz Texas A&M University, College Station, TX, USA Advika Chesetti University of North Texas, Denton, TX email: [email protected] Motivation ❖ Nanoscale cracks could be inadvertently ❖ Metallic structural components in nuclear introduced into materials during processing reactors are exposed to radiation damage. or in service. Atomistic simulation of radiation-induced defect creation Gao et al. / Computational Materials Science, 2017 Nordlund et al. / Nature Communications, 2018 For the structural metallic material in nuclear power engineering, such as nickel, the interaction between nanoscale crack and collision cascade is inevitable. Questions: 1. How collision cascades and the generated damage affect structure of nanoscale cracks? 2. How crack influences the collision cascade and the formation of radiation damage? Peng Chen/Crack healing induced by collision cascades in Nickel 2 Simulation methodology • HPRC cluster: Ada • LAMMPS for MD simulation • Ovito for visualization Configuration of simulation cell—Ni single crystal with a nanoscale crack Simulation setup: 1) A nanoscale crack (휙 =50 Å) is introduced at the center of simulation cell, crack surface ∥ 111 plane. 2) The collision cascade is initiated by imparting a kinetic energy to a primary knock-on atom (PKA). Four scenarios: different distances of PKA above the crack—10, 40, 70 and 100 Å; for each scenario three different PKA directions —0°, 45°and 90°are further considered. As such, the interaction between collision cascade and crack can be investigated, the effect of PKA positions and velocity directions can also be studied. Peng Chen/Crack healing induced by collision cascades in Nickel 3 Results: collision cascade induced-crack healing Collision cascade: ➢ PKA distance=10 Å; kinetic energy=10 keV 1. -
Collaborative Studies of Proton Induced Multiple Ionization and Electron Emission Resulting from Dressed Ion Impact
Abstract Number: D1/1-01 COLLABORATIVE STUDIES OF PROTON INDUCED MULTIPLE IONIZATION AND ELECTRON EMISSION RESULTING FROM DRESSED ION IMPACT Robert Dubois Missouri University of Science and Technology, Rolla, USA [email protected] During a several decade collaboration between S.T. Manson and R.D. DuBois and coworkers, a series of papers concerned with multiple ionization mechanisms in proton-atom collisions and with electron emission resulting from dressed ion impact were published. This talk will briefly discuss the major findings of these studies. Abstract Number: D1/2-02 SPECTROSCOPY AND DYNAMICS OF RARE-GAS ATOMS IN THE HARD X-RAY DOMAIN Maria Piancastelli Uppsala University, Uppsala, Sweden [email protected] Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, Paris, France and Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden The possibility of conducting hard x-ray photoexcitation and photoionization experiments under state-of-the art conditions in terms of photon and electron kinetic energy resolution has become available only in the last few years at selected synchrotron radiation facilities, in particular at the GALAXIES beam line operational at the French synchrotron SOLEIL. Some significant examples of recent developments in spectroscopy and dynamics of isolated atoms in the hard x-ray regime will be presented, including recoil phenomena, post-collision interaction effects, double-core-hole formation, and nonstatistical ratio of spin-orbit split components (the latter in collaboration with S.T.Manson). Abstract Number: D1/3-03 A STUDY OF THE NEAR THRESHOLD REGION FOR DOUBLE PHOTOIONIZATION OF ATOMIC OXYGEN Wayne Stolte Lawrence Berkeley National Laboratory, USA [email protected] A joint experimental and theoretical investigation on oxygen double photoionization — the emission of two electrons from atomic oxygen following single photon absorption. -
Collision Cascade and Spike Effects of X-Ray Irradiation On
Vol. 130 (2016) ACTA PHYSICA POLONICA A No. 1 Special issue of the 2nd International Conference on Computational and Experimental Science and Engineering (ICCESEN 2015) Collision Cascade and Spike Effects of X-ray Irradiation on Optoelectronic Devices S. Salleha, H.F. Abdul Amirb, A. Kumar Tiwaria and F. Pien Cheea;∗ aPhysics and Electronics Department, Faculty of Science and Natural Resources, University of Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia bSchool of Physics and Materials, Faculty of Applied Science, University Teknologi Mara, Shah Alam, Selangor, Malaysia Bombardment with high energy particles and photons can cause potential hazards to the electronic systems. These effects range from degradation of performance to functional failure, which can affect the operation of a system. Such failures become increasingly likely as electronic components are getting more sophisticated, while decreasing in size and tending to a larger integration. In this paper, the effects of X-ray irradiation on a plastic encapsulated infrared light emitting diode, coupled to a plastic encapsulated silicon infrared phototransistor, with both of them being electrically isolated at ON and OFF modes, are investigated. All the devices are exposed to a total dose of up to 1000 mAs. The electrical parameters of the optoelectronic devices during the radiation exposure and at post-irradiation are compared to the pre-irradiation readings. The findings show that the highest degradation occurs at low dose of exposure; beyond 100 mAs the relative decrease in collector current of the phototransistor is gradually reduced. The most remarkable feature found, is the operational dependence of the bias collector current, indicating a higher degradation for low bias forward current of the light emitting diode. -
Ion Implantation Phenomena by Binary Collision Approximation Collision
Ion implantation phenomena by binary collision approximation Masahiko Aoki In the November 2020 issue of Applied Physics, an article entitled "Analyzing Ion Implantation Phenomena with Old and New MARLOWE" was published, which introduced a brief explanation of the MARLOWE code and examples of its application to compound semiconductors (1). The physical background in that article was not treated in detail. So, this article will show what the MARLOWE code analyses ion implantation phenomena based on collision theory. This article will guide to better understanding the phenomenon of ion implantation and to consider implantation in new materials. Collision cascade At first, what kind of collision phenomenon occurs when an ion hits the target is explained. Let the energy of the incident ion be E0 and the atomic number be Z1. Let the atomic number of the target be Z2. When the incident ion collides with the target atom, the target atom is ejected from the lattice site when the energy is higher than the displacement energy Ed. Assuming that the energy of the incident ion after collision is E1 and the energy of the ejected atom is E2, the following cases can be classified. E1>Ed E2>Ed :vacancy production E1<Ed E2>Ed Z1=Z2:replacement E1<Ed E2<Ed Z1≠Z2:Interstitial atom Z1 The incident particle loses the energy and change direction as a result of collision with the nucleus. Until the next collision, the incident particle loses the energy through the collision with electrons. It will stop when the energy finally falls below the rest energy. The maximum energy received by the target atom is as follows.