Table Of Content

Springer Theses Recognizing Outstanding Ph.D. Research Nicholas R. Lewkow Scattering of Particles and Radiation in Astrophysical Environments Springer Theses Recognizing Outstanding Ph.D. Research Moreinformationaboutthisseriesathttp://www.springer.com/series/8790 AimsandScope The series “Springer Theses” brings together a selection of the very best Ph.D. theses from around the world and across the physical sciences. Nominated and endorsed by two recognized specialists, each published volume has been selected for its scientific excellence and the high impact of its contents for the pertinent fieldofresearch.Forgreateraccessibilitytonon-specialists,thepublishedversions includeanextendedintroduction,aswellasaforewordbythestudent’ssupervisor explainingthespecialrelevanceoftheworkforthefield.Asawhole,theserieswill provideavaluableresourcebothfornewcomerstotheresearchfieldsdescribed,and for other scientists seeking detailed background information on special questions. Finally,itprovidesanaccrediteddocumentationofthevaluablecontributionsmade bytoday’syoungergenerationofscientists. Theses are accepted into the series by invited nomination only andmustfulfillallofthefollowingcriteria (cid:129) TheymustbewritteningoodEnglish. (cid:129) ThetopicshouldfallwithintheconfinesofChemistry,Physics,EarthSciences, EngineeringandrelatedinterdisciplinaryfieldssuchasMaterials,Nanoscience, ChemicalEngineering,ComplexSystemsandBiophysics. (cid:129) Theworkreportedinthethesismustrepresentasignificantscientificadvance. (cid:129) Ifthethesisincludespreviouslypublishedmaterial,permissiontoreproducethis mustbegainedfromtherespectivecopyrightholder. (cid:129) They must have been examined and passed during the 12 months prior to nomination. (cid:129) Eachthesisshouldincludeaforewordbythesupervisoroutliningthesignificance ofitscontent. (cid:129) The theses should have a clearly defined structure including an introduction accessibletoscientistsnotexpertinthatparticularfield. Nicholas R. Lewkow Scattering of Particles and Radiation in Astrophysical Environments Doctoral Thesis accepted by the University of Connecticut, Storrs, Connecticut, USA 123 NicholasR.Lewkow UniversityofConnecticut Storrs,Connecticut,USA ISSN2190-5053 ISSN2190-5061 (electronic) SpringerTheses ISBN978-3-319-25077-9 ISBN978-3-319-25079-3 (eBook) DOI10.1007/978-3-319-25079-3 LibraryofCongressControlNumber:2015954636 SpringerChamHeidelbergNewYorkDordrechtLondon ©SpringerInternationalPublishingSwitzerland2016 Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpartof thematerialisconcerned,specificallytherightsoftranslation,reprinting,reuseofillustrations,recitation, broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionorinformation storageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilarmethodology nowknownorhereafterdeveloped. Theuseofgeneraldescriptivenames,registerednames,trademarks,servicemarks,etc.inthispublication doesnotimply,evenintheabsenceofaspecificstatement,thatsuchnamesareexemptfromtherelevant protectivelawsandregulationsandthereforefreeforgeneraluse. Thepublisher,theauthorsandtheeditorsaresafetoassumethattheadviceandinformationinthisbook arebelievedtobetrueandaccurateatthedateofpublication.Neitherthepublishernortheauthorsor theeditorsgiveawarranty,expressorimplied,withrespecttothematerialcontainedhereinorforany errorsoromissionsthatmayhavebeenmade. Printedonacid-freepaper SpringerInternationalPublishingAGSwitzerlandispartofSpringerScience+BusinessMedia(www. springer.com) IdedicatethisworktomymomMerryLee Lewkowforalwaysbelievinginmeand pushingmetorealizemypotential. Supervisor’s Foreword FrontierresearchinAstrophysicsandPlanetaryScienceisfocusedontheevolution of matter and radiation. The scale of the investigated systems is vastly different, ranging from the cosmological scale of the global evolution of the universe, including the formation of galaxies, stars, planets, exoplanets, and comets, to the localevolutionscalesofplanetaryandexoplanetaryatmospheres,interstellargas,or nanometer-scaleevolutionofinterstellarandcometarydustparticles.Theunifying features for this wide variety of evolutionary processes are the momentum-energy transfer and energy relaxation at local and global scales. The momentum-energy exchange and relaxation are required to establish a new stable state of any astrophysicalobjectanddetermineacharacteristictimenecessaryfortheformation of this state. The PhD Thesis written by Nicholas Lewkow considers essentially nonequilibrium processes, involved in the evolution of astrophysical gases and plasmas. Momentum-energy transfer in collisions of atoms, molecules, and ions governstherelaxationofinteractingastrophysicalgasandplasmas.Thesecollisions require an accurate quantum mechanical description, and Nicholas has developed in his thesis a unified kinetic and quantum mechanical model of plasma and gas relaxation processes. It is shown that the simplified classical description of the momentum-energy transfer, commonly used in astrophysics to describe particle collisions, leads to discrepancies of several orders of magnitude in modeling such nonequilibriumprocessesastheescapeofplanetaryandexoplanetaryatmospheres. The multi-scale computational approach, implemented in Nicholas’ Thesis, takes into account nonthermal distributions of atomic particles and clarifies their role in the evolution of interstellar gas and planetary atmospheres. As it is shown in the thesis, physical parameters of nonthermal distributions strongly depend on the differential cross sections of atomic, molecular, and ion collisions. In Nicholas’ Thesis,readerscanfindadetaileddescriptionoftheenergyrelaxationofenergetic atoms, produced in the interstellar gas by the solar and stellar wind plasmas. The firstcomputation of thenonthermal diffusebackground of energetic helium atoms in the interstellar gas and heliosphere, determines contributions from local and cosmicsources.Computeddistributionsofenergeticheliumatomsareusedforan analysisofrecentsatelliteobservations.Modelingoftheprecipitationofenergetic vii viii Supervisor’sForeword particles into planetary atmospheres and formation of planetary and exoplanetary escapefluxeshasbeenperformedinthisthesiswithveryaccuratedifferentialcross sections, describing momentum-energy transfer processes. A high computational precision allows for calculation of nonequilbrium distributions of different atomic andmolecularisotopesandprovidesphysicalparametersrequiredfortheanalysisof theatmosphericescapeandevolution.MonteCarlosimulations,carriedoutinthis thesis work for the Mars atmosphere at different solar conditions, are an excellent example of application of the developed theoretical methods, and new theoretical dataobtainedinsimulationsarecriticalfortheanalysisofMarsatmosphericescape andinvestigationsofthehistoryofMartianwater. Storrs,USA Dr.VasiliKharchenko May2015 Acknowledgments Itisalong,hardroadtocompleteaPhDanditcannotbedonealone.Iwouldlike to thank my advisor Dr. Vasili Kharchenko for all his help and guidance through thepastyears.Fromdiscussingplanetaryatmospheresandquantumphenomenato teaching me how to play tennis, Vasili has been not only a great mentor but also a great friend. Additionally, I would like to thank my co-advisors, Dr. Thomas Blum and Dr. Robin Cote. Their help and guidance throughout my dissertation writingandeditinghavebeeninvaluable.Myfamilyhasalsobeenagreatsourceof support throughout graduate school. Specifically, I would like to thank my father Kenneth Lewkow for installing an excellent work ethic in me as a young child and always helping me when school was difficult and enthusiasm was low. My brother Timothy Lewkow has also been a great source of support as well as a great friend who may easily discuss complex math concepts and data structures over late night conversations. Additionally, Dr. Elizabeth Sather and Genny Ray have been extremely supportive through the years, helping me keep tabs on my familyinColoradowhilestudyingontheeastcoast.Dr.JoshuaLaddhasalsobeen an amazing mentor throughout both undergraduate and graduate school, helping me realize my passion for high-performance computing and in turn directing my love of physics toward the framework of computational science. I would also like to thank all my fellow graduate and postdoctoral students at both the University of Connecticut and the Harvard-Smithsonian Center for Astrophysics for all the support and friendships throughout the years. Lastly, I would like to thank my friends from Bay State for being awesome roommates during the thesis writing process. ix