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[{"key": "dc.contributor.author", "value": "Monto, Tiia", "language": null, "element": "contributor", "qualifier": "author", "schema": "dc"}, {"key": "dc.date.accessioned", "value": "2013-09-27T10:03:41Z", "language": "", "element": "date", "qualifier": "accessioned", "schema": "dc"}, {"key": "dc.date.available", "value": "2013-09-27T10:03:41Z", "language": "", "element": "date", "qualifier": "available", "schema": "dc"}, {"key": "dc.date.issued", "value": "2013", "language": null, "element": "date", "qualifier": "issued", "schema": "dc"}, {"key": "dc.identifier.other", "value": "oai:jykdok.linneanet.fi:1281113", "language": null, "element": "identifier", "qualifier": "other", "schema": "dc"}, {"key": "dc.identifier.uri", "value": "https://jyx.jyu.fi/handle/123456789/42235", "language": "", "element": "identifier", "qualifier": "uri", "schema": "dc"}, {"key": "dc.description.abstract", "value": "Cosmic rays are high-energy subatomic particles which travel almost at the speed of light all over the space. The shape of the cosmic ray energy spectrum is measured experimentally, but it is not perfectly understood. The slope of the spectrum at high energies is constant up to the knee energy (about 10^15 eV) where the slope steepens. The knee has been tried to be explained by several models which aim to describe the origin and the acceleration mechanisms of the cosmic ray. The stars and the shockwaves from supernova explosions are believed to be at least a part of cosmic ray evolution. \r\n\r\nThe cosmic rays were found in the early 20th century and they have been studied with several methods. When a primary cosmic particle collides with Earth atmosphere, different reactions create a cascade of secondary particles (air shower) which may be detected on Earth. The EMMA experiment studies the cosmic ray with the knee energy by detecting the muons of air shower. EMMA is operating underground at the depth of 75 meters in Pyh\u00e4salmi mine. The measurement stations are reached only by the muons with 50 GeV thresold energy. The stations are consisted of drift chambers, scintillation detectors and limited streamer tubes. The gas-\ufb01lled drift chambers form the basis of the experiment. Their operation is based on the gas ionization which causes signals on the electrical wires. One plank is formed of seven drift chambers attached together.\r\n\r\nIn this work I study the ef\ufb01ciencies of the drift chambers of EMMA. My C++ program evaluates the ef\ufb01ciencies as a function of time and as a function of position by using data measured in calibration runs in the surface laboratory. According to my results the average \u201dmean top ef\ufb01ciency\u201d (excluding the largest ef\ufb01ciency peaks) of the drift chambers is 76.5 %. The ef\ufb01ciency of the worst plank is 65.4 % and the best 88.1 %. The results\u2019 systematical inaccuracy may be from the method of determining the ef\ufb01ciency and possible fault in data. The random inaccuracy may be from the problems of the measurement system and the method of calculating the mean top ef\ufb01ciency by excluding the ef\ufb01ciency peaks. My results seem to be slightly lower than the others\u2019 results, thus my method of determining the ef\ufb01ciency may be stricter. Actually some ef\ufb01ciency peaks may be explained by the external factors like pressure changes and problems in electronics. The differencies of left and right part of a chamber may be due to the possible problems in grading lines.", "language": "en", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.abstract", "value": "Kosminen s\u00e4teily koostuu korkeaenergisist\u00e4 subatomisista hiukkasista, jotka liikkuvat avaruudessa l\u00e4hes valonnopeudella. Kosmisen s\u00e4teilyn energiaspektrin muoto on mitattu kokeellisesti, mutta sit\u00e4 ei t\u00e4ysin ymm\u00e4rret\u00e4. Energiaspektrin kulmakerroin on vakio polvienergiaan (n. 10^15 eV) saakka, t\u00e4ss\u00e4 kohdassa spektrin derivaatta pienenee. Spektrin polvea on yritetty selitt\u00e4\u00e4 useilla malleilla, jotka pyrkiv\u00e4t kuvaamaan kosmisen s\u00e4teilyn alkuper\u00e4\u00e4 ja kiihdytysmekanismeja. T\u00e4htien ja supernovien shokkiaaltojen uskotaan liittyv\u00e4n ainakin osittain kosmisen s\u00e4teily evoluutioon.\r\n\r\nKosminen s\u00e4teily l\u00f6ydettiin 1900-luvun alussa ja sit\u00e4 on tutkittu useilla menetelmill\u00e4. Primaarisen kosmisen hiukkasen t\u00f6rm\u00e4tess\u00e4 ilmakeh\u00e4\u00e4n syntyy erilaisten reaktioiden kautta sekundaarihiukkasten kaskadi eli ilmakuuro, josta voidaan tehd\u00e4 havaintoja Maapallolla. EMMA-koe tutkii polvienergian kosmista s\u00e4teily\u00e4 havaitsemalla ilmakuuron myoneita. EMMA:n koeasema sijaitsee Pyh\u00e4salmen kaivoksella noin 75 metrin syvyydess\u00e4. Kalliokerroksen l\u00e4pi koeasemalle p\u00e4\u00e4sev\u00e4t vain sellaiset myonit, joiden energia on v\u00e4hint\u00e4\u00e4n noin 50 GeV. Koeasema koostuu ajautumiskammioista, tuikeilmaisimista ja limited streamer tube -tyyppisist\u00e4 ilmaisimista. Kokeen rungon muodostavat ajautumiskammiot, jotka ovat kaasut\u00e4ytteisi\u00e4 lankailmaisimia. Niiden toiminta perustuu kaasussa tapahtuvaan ionisaatioon, joka aiheuttaa signaalin s\u00e4hk\u00f6lankoihin. Yksi plankki koostuu seitsem\u00e4st\u00e4 yhteen liitetyst\u00e4 kammiosta.\r\n\r\nTy\u00f6ss\u00e4ni tutkin ajautumiskammioiden tehokkuuksia. C++-ohjelmani laskee tehokkuudet sek\u00e4 ajan ett\u00e4 paikan funktiona k\u00e4ytt\u00e4en mittausdataa, joka on saatu maanp\u00e4\u00e4llisist\u00e4 kalibraatiomittauksista. Tulosteni mukaan kammioiden keskiteho on 76,5 % (keskiarvon laskemisessa suurimmat tehopiikit on j\u00e4tetty huomioimatta). Huonoimman plankin tehokkuus on 65,4 % ja parhaan 88,1 %. Tulosteni systemaattinen virhe voi aiheutua tavasta m\u00e4\u00e4ritell\u00e4 tehokkuus ja mahdollisesta mittausdatan virheest\u00e4. Satunnaisvirheet voivat johtua hetkellisist\u00e4 ongelmista mittausj\u00e4rjestelm\u00e4ss\u00e4 sek\u00e4 tavasta laskea keskiteho j\u00e4tt\u00e4m\u00e4ll\u00e4 huomiotta suurimmat tehopiikit. Tulosteni tehokkuudet ovat hieman pienemm\u00e4t verrattuna muiden tuloksiin, joten tehokkuuden m\u00e4\u00e4ritt\u00e4mistapani lienee vaativampi. Osa hetkellisist\u00e4 tehokkuuden alentumista voidaan selitt\u00e4\u00e4 mittausj\u00e4rjestelm\u00e4\u00e4n vaikuttaneilla ulkoisilla tekij\u00f6ill\u00e4, kuten paineen vaihteluilla ja s\u00e4hk\u00f6laitteiden ongelmilla. Kammion vasemman ja oikean puolisen tehokkuuden eroavaisuudet saattavat johtua ongelmista gradinglangoissa.", "language": "fi", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Submitted using Plone Publishing form by Tiia Monto (timajomo) on 2013-09-27 10:03:38.315119. Form: Pro gradu -lomake (1 tekij\u00e4) (https://kirjasto.jyu.fi/julkaisut/julkaisulomakkeet/pro-gradu-lomake-1-tekijae). JyX data:", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Submitted by jyx lomake-julkaisija (jyx-julkaisija@noreply.fi) on 2013-09-27T10:03:41Z\r\nNo. of bitstreams: 2\r\nURN:NBN:fi:jyu-201309272366.pdf: 8362057 bytes, checksum: 7a58841d291ace003191fba60979f983 (MD5)\r\nlicense.html: 107 bytes, checksum: a7d86e598caa500b1b433bbb9dc8ef1c (MD5)", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Made available in DSpace on 2013-09-27T10:03:41Z (GMT). No. of bitstreams: 2\r\nURN:NBN:fi:jyu-201309272366.pdf: 8362057 bytes, checksum: 7a58841d291ace003191fba60979f983 (MD5)\r\nlicense.html: 107 bytes, checksum: a7d86e598caa500b1b433bbb9dc8ef1c (MD5)\r\n Previous issue date: 2013", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.format.extent", "value": "139 sivua", "language": null, "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": "ajautumiskammiot", "language": null, "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "cosmic ray", "language": null, "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "drift chamber", "language": null, "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.title", "value": "Efficiencies of the drift chambers in the EMMA experiment", "language": null, "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-201309272366", "language": null, "element": "identifier", "qualifier": "urn", "schema": "dc"}, {"key": "dc.type.dcmitype", "value": "Text", "language": "en", "element": "type", "qualifier": "dcmitype", "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": "University of Jyv\u00e4skyl\u00e4", "language": "en", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "Jyv\u00e4skyl\u00e4n yliopisto", "language": "fi", "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": "dc.date.updated", "value": "2013-09-27T10:03:41Z", "language": "", "element": "date", "qualifier": "updated", "schema": "dc"}, {"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": "fi", "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": null, "element": "subject", "qualifier": "oppiainekoodi", "schema": "dc"}, {"key": "dc.subject.yso", "value": "kosminen s\u00e4teily", "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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