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The PAMELA satellite experiment will soon be launched and during its 3 year mission perform measurement of charged particle fluxes in the cosmic radiation. PAMELA is specifically designed to identify antiprotons and positrons in the vast background of other charged particles. These antiparticle measurements will be performed using: a permanent magnet spectrometer, a scintillator based time of flight system, an electromagnetic imaging calorimeter, a transition radiation detector and a scintillator triggered neutron detector. There is also a scintillator based anticoincidence system to reject spurious triggers from out of acceptance events (developed and built at KTH). These detectors will allow the background in the antiproton and positron measurements to be significantly reduced, and PAMELA will thus be able to perform high precision measurements with unprecedented statistics and over a wide energy range, far surpassing any previous experiment. To determine the antiparticle identification and background rejection capability of the experiment, studies have been performed using simulations and data collected at particle beams. These studies have focused on: the proton rejection in positron measurements (using the calorimeter), contamination by locally produced pions in antiproton measurements and estimations of the expected statistics due to the energy dependence (caused by e.g. the geomagnetic field and the magnetic field in the spectrometer) of the gathering power. This work significantly extends previous studies of the PAMELA performance in antiparticle identification.

<p>The PAMELA satellite experiment will soon be launched and during its 3 year mission perform measurement of charged particle fluxes in the cosmic radiation. PAMELA is specifically designed to identify antiprotons and positrons in the vast background of other charged particles. These antiparticle measurements will be performed using: a permanent magnet spectrometer, a scintillator based time of flight system, an electromagnetic imaging calorimeter, a transition radiation detector and a scintillator triggered neutron detector. There is also a scintillator based anticoincidence system to reject spurious triggers from out of acceptance events (developed and built at KTH). These detectors will allow the background in the antiproton and positron measurements to be significantly reduced, and PAMELA will thus be able to perform high precision measurements with unprecedented statistics and over a wide energy range, far surpassing any previous experiment. To determine the antiparticle identification and background rejection capability of the experiment, studies have been performed using simulations and data collected at particle beams. These studies have focused on: the proton rejection in positron measurements (using the calorimeter), contamination by locally produced pions in antiproton measurements and estimations of the expected statistics due to the energy dependence (caused by e.g. the geomagnetic field and the magnetic field in the spectrometer) of the gathering power. This work significantly extends previous studies of the PAMELA performance in antiparticle identification.</p>

Made available in DSpace on 2016-04-28T14:16:32Z (GMT). No. of bitstreams: 1 Mauro Sebastiao Martins.pdf: 805307 bytes, checksum: bf96e1e0d841ef228e79449796e6fd6b (MD5) Previous issue date: 2008-05-13 / This Work, a thesis in history of subatomic particles, is an historic and epistemological development study of the theoretical and experimental subatomic particles and antiparticles from the early Dirac s quantum theory of the electron, published in a year of 1928, until the publications of the theories of the quarks in a decade of the sixths, the Gell Mann theory of quarks include. That research studies was made in primaries and secondary bibliographies, didactic manuals, articles of scientific journals and scientific magazines, history and philosophy of science books and history of particles books. This studies show that in the delimitated period of study, the paradigmatic theories and experiments appear in the period call of common science, in suite the scientific period is the crisis, so, have a concurrency theories and experimental models period, finally appear a paradigmatic theory and experimental model, like the Khun historical analyses. The paradigmatic particles theories and experimental models, appear a manner of broke up whit of old scientific know, like understood of Bachelard analysis. In the daily period the candidate of paradigmatic theory of particles is the supercordas theory. However, ours studies are conclusive that it have a periodic cycle, into theirs, appear the paradigmatic theoretical and experimental models and had surpassed in the suite period by others paradigmatic theoretical and experimental models, and other periodic cycle occur when of paradigmatic theories and experimental models appear, and so on / Este trabalho, uma tese em história das partículas subatômicas, é um estudo da evolução histórica e epistemológica das teorias e experimentos em partículas e antipartículas, desde o advento da teoria quântica do elétron de Dirac, no ano de 1928, até as publicações das teorias sobre os quarks da década de sessenta, incluindo, nestas, a teoria dos quarks de Gell Mann. Os estudos foram embasados nos levantamentos de bibliografias primárias e secundárias: manuais didáticos, artigos de revistas e jornais científicos, obras em história e filosofia da ciência e em história das partículas. Ele demonstra que o período delimitado para o estudo revela que as teorias e experimentos paradigmáticos surgem após um período de ciência normal, seguido de crise e concorrência entre as teorias e modelos experimentais, como compreendido pela análise histórica de Thomas Khun. As teorias e experimentos paradigmáticos, em partículas, surgem de rupturas com o velho conhecimento estabelecido, como entendido pela análise epistemológica de Bachelard, do desenvolvimento do conhecimento científico. No período atual a candidata à teoria paradigmática em partículas, segundo a manifestação da comunidade científica dos pesquisadores em física de partículas, é a teoria das supercordas. Entretanto, os estudos são conclusivos, quanto à existência de ciclos periódicos, nos quais, as teorias e modelos paradigmáticos aparecem e são superados por outras teorias e modelos paradigmáticos emergentes