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dc.contributor.advisorMelott, Adrian L
dc.contributor.authorAtri, Dimitra
dc.date.accessioned2011-06-21T19:30:07Z
dc.date.available2011-06-21T19:30:07Z
dc.date.issued2011-04-26
dc.date.submitted2011
dc.identifier.otherhttp://dissertations.umi.com/ku:11432
dc.identifier.urihttp://hdl.handle.net/1808/7671
dc.description.abstractOn geological timescales, the Earth is likely to be exposed to higher than the usual flux of high energy cosmic rays (HECRs) from astrophysical sources such as nearby supernovae, gamma ray bursts or by galactic shocks. These high-energy particles strike the Earth's atmosphere, initiating an extensive air shower. As the air shower propagates deeper, it ionizes the atmosphere by producing charged secondary particles and photons. Increased ionization leads to changes in atmospheric chemistry, resulting in ozone depletion. This increases the flux of solar UVB radiation at the surface, which is potentially harmful to living organisms. Increased ionization affects the global electrical circuit, which could enhance the low-altitude cloud formation rate. Secondary particles such as muons and thermal neutrons produced as a result of hadronic interactions of the primary cosmic rays with the atmosphere are able to reach the ground, enhancing the biological radiation dose. The muon flux dominates the radiation dose from cosmic rays causing damage to DNA and an increase in mutation rates and cancer, which can have serious biological implications for surface and sub-surface life. Using CORSIKA, we perform massive computer simulations and construct lookup tables for 10 GeV - 1 PeV primaries, which can be used to quantify these effects from enhanced cosmic ray exposure to any astrophysical source. These tables are freely available to the community and can be used for other studies. We use these tables to study the terrestrial implications of galactic shock generated by the infall of our galaxy toward the Virgo cluster. Increased radiation dose from muons could be a possible mechanism explaining the observed periodicity in biodiversity in paleobiology databases.
dc.format.extent124 pages
dc.language.isoen
dc.publisherUniversity of Kansas
dc.rightsThis item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
dc.subjectPhysics
dc.subjectAstrobiology
dc.subjectCosmic rays
dc.titleTerrestrial Effects of High Energy Cosmic Rays
dc.typeDissertation
dc.contributor.cmtememberJohnson, Carey K.
dc.contributor.cmtememberMurray, Michael J
dc.contributor.cmtememberThomas, Brian C
dc.contributor.cmtememberWilson, Graham
dc.thesis.degreeDisciplinePhysics & Astronomy
dc.thesis.degreeLevelPh.D.
kusw.oastatusna
kusw.oapolicyThis item does not meet KU Open Access policy criteria.
kusw.bibid7642954
dc.rights.accessrightsopenAccess


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