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[{"key": "dc.contributor.advisor", "value": "Siljam\u00e4ki, Sami", "language": "", "element": "contributor", "qualifier": "advisor", "schema": "dc"}, {"key": "dc.contributor.advisor", "value": "Apaja, Vesa", "language": "", "element": "contributor", "qualifier": "advisor", "schema": "dc"}, {"key": "dc.contributor.author", "value": "Laakkonen, Linda", "language": "", "element": "contributor", "qualifier": "author", "schema": "dc"}, {"key": "dc.date.accessioned", "value": "2019-11-18T05:55:23Z", "language": null, "element": "date", "qualifier": "accessioned", "schema": "dc"}, {"key": "dc.date.available", "value": "2019-11-18T05:55:23Z", "language": null, "element": "date", "qualifier": "available", "schema": "dc"}, {"key": "dc.date.issued", "value": "2019", "language": "", "element": "date", "qualifier": "issued", "schema": "dc"}, {"key": "dc.identifier.uri", "value": "https://jyx.jyu.fi/handle/123456789/66408", "language": null, "element": "identifier", "qualifier": "uri", "schema": "dc"}, {"key": "dc.description.abstract", "value": "Tutkielma tehtiin yhteisty\u00f6ss\u00e4 Varian Medical Systems Finland -yrityksen kanssa. Tutkielmassa keskityttiin ulkoiseen alle 15 MeV energian s\u00e4teilyl\u00e4hteseen, jolla tarkoitetaan yleens\u00e4 sit\u00e4, ett\u00e4 s\u00e4teilykeila on tuotettu lineaarikiihdyttimell\u00e4. Tutkielman tavoitteena oli tutkia fotonil\u00e4hteen puolivarjoa vesifantomissa ja kohtion avulla synnytetty\u00e4 fotonikeilaa sek\u00e4 sen spektri\u00e4. Simulaatiot pyrkiv\u00e4t kuvaamaan fysikaalista tilannetta todenmukaisesti ja niist\u00e4 saatava tieto on k\u00e4yt\u00e4nn\u00f6ss\u00e4 hyvin vaikea saada kliinisen ymp\u00e4rist\u00f6n ja ilmaisimien rajoitteissa. Informaatio on t\u00e4rke\u00e4\u00e4 s\u00e4dehoidon laadunvalvonnalle ja sen suunnittelun kehitykselle.\n \tTutkielmassa k\u00e4ytettiin apuna Monte Carlo -menetelm\u00e4\u00e4n perustuvaa Geant4 simulaatio- ja ohjelmointikirjastoa. Geant4-applikaation eri parametrej\u00e4 tutkittiin ulkoisen fotonil\u00e4hteen puolivarjon m\u00e4\u00e4ritelm\u00e4n avulla. Kolmea eri fysiikkakirjastoa verrattiin ja tulokset olivat samankaltaiset, mutta niiss\u00e4 n\u00e4kyi my\u00f6s eroja.\n \tParametrien validoinnin j\u00e4lkeen tutkittiin kolmen eri kohtiomateriaalin (volframi, lyijy sek\u00e4 n\u00e4iden yhdistelm\u00e4) hiukkas- ja energiaspektrej\u00e4. Spektreiss\u00e4 n\u00e4kyi alkuaineille ominaiset karakteristisen s\u00e4teilyn piikit sek\u00e4 voimakas annihilaatiopiikki. Tulokset olivat samankaltaiset Varian Medical System -yrityksen tarjoaman datan kanssa. Energiaspektrien kulmariippuvuus havaittiin volframi ja lyijy kohtioille selke\u00e4sti kolmella eri kulmalla 0\u00b0, 5.7\u00b0 ja 11.3\u00b0. Kulman kasvaessa muutos spektriss\u00e4 n\u00e4kyi huipun siirtymisen\u00e4 matalemmille energioille ja h\u00e4nn\u00e4n kurvikkuuden pienentymisen\u00e4. Kyseiset tulokset vaativat lis\u00e4tutkimuksia.", "language": "fi", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.abstract", "value": "This Master's Thesis was made in cooperation with Varian Medical Systems Finland. The main focus of the thesis is on the external photon beam with energy below 15 MeV. The aim of this thesis is to obtain information about the beam edge and the spectrum of the photon beam, which are difficult to measure in practice because of the clinical limitations. \n \tThe information was obtained by Monte Carlo simulations with a Geant4 application. The effects of user-editable parameters of Geant4 were studied by looking at the behavior of the penumbra region of an external beam. There were three physics lists compared and calculated results showed similarity but rather big differences.\n \tAfter the validation of parameters, particle and energy spectra with three different targets (tungsten, lead, and a combination of these two) at the isocenter plane were studied. There were the characteristic peaks of the corresponding element and the annihilation peak shown in the spectra. These results were consistent with the older data provided by Varian Medical Systems. The angle dependence of spectra with tungsten and lead targets was shown to be significant with different angles 0\u00b0, 5.7\u00b0 and 11.3\u00b0. The shape of the spectra detected to shift and curvaceousness of the tail decrease with an increasing angle. Further studies are needed to evaluate these results.", "language": "en", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Submitted by Miia Hakanen (mihakane@jyu.fi) on 2019-11-18T05:55:23Z\nNo. of bitstreams: 0", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Made available in DSpace on 2019-11-18T05:55:23Z (GMT). No. of bitstreams: 0\n Previous issue date: 2019", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.format.extent", "value": "78", "language": "", "element": "format", "qualifier": "extent", "schema": "dc"}, {"key": "dc.format.mimetype", "value": "application/pdf", "language": null, "element": "format", "qualifier": "mimetype", "schema": "dc"}, {"key": "dc.language.iso", "value": "eng", "language": null, "element": "language", "qualifier": "iso", "schema": "dc"}, {"key": "dc.rights", "value": "In Copyright", "language": "en", "element": "rights", "qualifier": null, "schema": "dc"}, {"key": "dc.subject.other", "value": "Geant4", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "photon beam", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "penumbra", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "spectrum", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.title", "value": "Monte Carlo simulations of spectral properties of clinical photon beams with Geant4", "language": "", "element": "title", "qualifier": null, "schema": "dc"}, {"key": "dc.type", "value": "master thesis", "language": null, "element": "type", "qualifier": null, "schema": "dc"}, {"key": "dc.identifier.urn", "value": "URN:NBN:fi:jyu-201911184912", "language": "", "element": "identifier", "qualifier": "urn", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Pro gradu -tutkielma", "language": "fi", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Master\u2019s thesis", "language": "en", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Matemaattis-luonnontieteellinen tiedekunta", "language": "fi", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Faculty of Sciences", "language": "en", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Fysiikan laitos", "language": "fi", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Department of Physics", "language": "en", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "Jyv\u00e4skyl\u00e4n yliopisto", "language": "fi", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "University of Jyv\u00e4skyl\u00e4", "language": "en", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Fysiikka", "language": "fi", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Physics", "language": "en", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "yvv.contractresearch.collaborator", "value": "business", "language": "", "element": "contractresearch", "qualifier": "collaborator", "schema": "yvv"}, {"key": "yvv.contractresearch.funding", "value": "0", "language": "", "element": "contractresearch", "qualifier": "funding", "schema": "yvv"}, {"key": "yvv.contractresearch.initiative", "value": "student", "language": "", "element": "contractresearch", "qualifier": "initiative", "schema": "yvv"}, {"key": "dc.type.coar", "value": "http://purl.org/coar/resource_type/c_bdcc", "language": null, "element": "type", "qualifier": "coar", "schema": "dc"}, {"key": "dc.rights.accesslevel", "value": "openAccess", "language": null, "element": "rights", "qualifier": "accesslevel", "schema": "dc"}, {"key": "dc.type.publication", "value": "masterThesis", "language": null, "element": "type", "qualifier": "publication", "schema": "dc"}, {"key": "dc.subject.oppiainekoodi", "value": "4021", "language": "", "element": "subject", "qualifier": "oppiainekoodi", "schema": "dc"}, {"key": "dc.subject.yso", "value": "Monte Carlo -menetelm\u00e4t", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "fotonit", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "s\u00e4dehoito", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "Monte Carlo methods", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "photons", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "radiotherapy", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.format.content", "value": "fulltext", "language": null, "element": "format", "qualifier": "content", "schema": "dc"}, {"key": "dc.rights.url", "value": "https://rightsstatements.org/page/InC/1.0/", "language": null, "element": "rights", "qualifier": "url", "schema": "dc"}, {"key": "dc.type.okm", "value": "G2", "language": null, "element": "type", "qualifier": "okm", "schema": "dc"}]
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