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[{"key": "dc.contributor.advisor", "value": "Ihantola, Sakari", "language": "", "element": "contributor", "qualifier": "advisor", "schema": "dc"}, {"key": "dc.contributor.advisor", "value": "Greenlees, Paul", "language": "", "element": "contributor", "qualifier": "advisor", "schema": "dc"}, {"key": "dc.contributor.author", "value": "Bogdanoff, Ville", "language": "", "element": "contributor", "qualifier": "author", "schema": "dc"}, {"key": "dc.date.accessioned", "value": "2020-11-10T07:09:28Z", "language": null, "element": "date", "qualifier": "accessioned", "schema": "dc"}, {"key": "dc.date.available", "value": "2020-11-10T07:09:28Z", "language": null, "element": "date", "qualifier": "available", "schema": "dc"}, {"key": "dc.date.issued", "value": "2020", "language": "", "element": "date", "qualifier": "issued", "schema": "dc"}, {"key": "dc.identifier.uri", "value": "https://jyx.jyu.fi/handle/123456789/72545", "language": null, "element": "identifier", "qualifier": "uri", "schema": "dc"}, {"key": "dc.description.abstract", "value": "T\u00e4ss\u00e4 pro gradu -tutkielmassa kehitettiin ilmaisimen pinnan kontaminaation mittausj\u00e4rjestelm\u00e4\u00e4 Suomen ulkoisen s\u00e4teilyn valvontaverkon uuden sukupolven s\u00e4teilymittausaseman gammailmaisimeen. Ydinvoimalaonnettomuuksissa ja ydinr\u00e4j\u00e4hdyksiss\u00e4 ilmakeh\u00e4\u00e4n voi vapautua suuria m\u00e4\u00e4ri\u00e4 radioaktiivisia aineita, jotka voivat kiinnitty\u00e4 gammailmaisimen ulkopinnalle. Pinnalle kiinnittyneet radioaktiiviset aineet voivat aiheuttaa virheellisi\u00e4 mittaustuloksia. Pintakontaminaation mittausj\u00e4rjestelm\u00e4 toteutettiin ohuella muovituikeaineella, jonka avulla ilmaisimen ulkopuolelle kiinnittyneiden radioaktiivisten aineiden l\u00e4hett\u00e4m\u00e4\u00e4 beetas\u00e4teily\u00e4 mitattiin ja n\u00e4in ilmaisimen kontaminaatiotasoa voitiin arvioida. T\u00e4ss\u00e4 tutkielmassa kontaminaatiomittausj\u00e4rjestelm\u00e4st\u00e4 kehitettiin kaksi konfiguraatiota ja tutkimuksissa m\u00e4\u00e4ritettiin kunkin konfiguraation beetas\u00e4teilyn havaitsemistehokkuus sek\u00e4 tutkittiin muovituikesignaalin vaimenemisesta johtuvaa valonker\u00e4ystehokkuuden heikentymist\u00e4. Lis\u00e4ksi tutkielmassa demonstroitiin pulssimuotoanalyysitekniikoiden k\u00e4ytt\u00f6\u00e4 tuikesignaalien erottelemiseksi phoswich-tyyppisiss\u00e4 monituikekidej\u00e4rjestelmiss\u00e4.\n\nTutkielmassa ohuella muovituikeaineella havaittiin olevan eritt\u00e4in hyv\u00e4 beetas\u00e4teilyn havaitsemistehokkuus. Kuitenkin tutkituissa konfiguraatiossa valonker\u00e4ys muovituikemateriaalista j\u00e4i todella heikoksi, mik\u00e4 heikensi muovituikesignaalin n\u00e4kymist\u00e4 valomonistinputkella. Jatkotutkimuksissa valonker\u00e4ystehokkuutta muovituikeaineesta tulisi parantaa, mik\u00e4li kontaminaatiomittausj\u00e4rjestelm\u00e4 otettaisiin k\u00e4ytt\u00f6\u00f6n Suomen s\u00e4teilyvalvontaverkossa.", "language": "fi", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.abstract", "value": "This MSc thesis demonstrated a contamination monitoring system to be installed in the detector of the next generation radiation monitoring stations planned for the Finnish radiation early warning network. Severe nuclear incidents can result in a large-scale release of airborne radioactive contamination, which can be deposited on the outer surfaces of the detector and could falsify the data collected with the gamma-ray detector. The contamination monitoring system was based on using a thin plastic scintillator to measure the beta radiation emitted by the deposited radionuclides. In this thesis, two viable configurations were developed to demonstrate the contamination monitoring system. Experiments were done to determine the beta counting efficiency and light collection of each configuration. As the detector will contain a novel phoswich based gamma-ray detector, pulse shape discrimination techniques were investigated for the separation of scintillation signals.\n\nThe thin plastic scintillator was found to be very efficient for detecting beta radiation. Moreover, the demonstrated configurations suffered a tremendous loss of scintillation light and resulted in a weak signal to be measured. A means to improve the light collection efficiency should be researched if the system is incorporated into the detector in the future.", "language": "en", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Submitted by Paivi Vuorio (paelvuor@jyu.fi) on 2020-11-10T07:09:28Z\nNo. of bitstreams: 0", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Made available in DSpace on 2020-11-10T07:09:28Z (GMT). No. of bitstreams: 0\n Previous issue date: 2020", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.format.extent", "value": "103", "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": "plastic scintillator", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "radiation early warning network", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "radioactive contamination", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "phoswich", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.title", "value": "Detector contamination monitoring system for Finnish radiation early warning network", "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-202011106585", "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": "Soveltava fysiikka", "language": "fi", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Applied Physics", "language": "en", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "yvv.contractresearch.collaborator", "value": "public", "language": "", "element": "contractresearch", "qualifier": "collaborator", "schema": "yvv"}, {"key": "yvv.contractresearch.funding", "value": "14200", "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": 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