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Monte Carlo simulations of neutron and photon radiation fields at the PF-24 plasma focus device at IFJ PAN in Krakow
No full textThe medium scale PF‐24 facility was installed at the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN), Poland. The MCNP model of the PF ‐ 24 device in the main hall of the laboratory was elaborated. Two variants of the plasma source emitting particles were considered: a point neutron source and a volume source with photon and neutron emission. Based on presented calculations the influence of the laboratory construction (the walls, the ceiling and the floor) on neutron and photon space distributions in the main hall were assessed. A study of fast uncolided and collided neutrons contributions to the total field of neutrons was performed. The contribution of photons emitted directly from the source and created as the result of neutron scattering was established. Neutron spectra at selected points were calculated
Search for baryon and lepton number violation in heavy baryon decays and the background studies for exotic searches
No full textThe thesis describes searches for baryon and lepton number violation in X b → K−µ + (X b = Λ b , Ξ 0 b ) decays. The study is performed in the LHCb experiment using data sample corresponding to an integrated luminosity of 3.0 fb− 1 of proton-proton collisions at the centre-of-mass energy of 7 TeV (8 TeV), collected in 2011 (2012), respectively. No statistically significant signal of the decays in question has been found. As a result, the upper limits have been set: B (Λ b → K−µ + ) < 3.6 × 10− 9 and B (Ξ 0 b → K−µ + ) < 1.8 × 10− 8 at the 95% confidence level. The second part of the thesis presents the background studies for exotic searches. The measurement of σ(bb) and σ(cc) production cross-sections with b − (c − ) hadron inclusive final states has been performed with data collected by the LHCb experiment in 2010 in proton-proton collisions at the centre-of-
mass energy of 7 TeV. The author of this thesis has prepared the interface to the Next-To-Leading-Order POWHEG simulation framework into the LHCb software chain. All the kinematic characteristics of the hadron production in proton-proton collisions have been studied. The resulting angular and momentum correlations indicate a possible contribution from other mechanisms
of bb production than the flavour creation, mainly the gluon splitting.13
Neutrino beam simulations and background studies for the SUNLAB location in Poland
No full textThe main purpose of this thesis is to explore the opportunities which would
be provided by the Sieroszowice Underground Laboratory SUNLAB, located in the
Polkowice-Sieroszowice mine in the Lower Silesia province in Poland, to discover
the CP violation in the neutrino sector. This discovery would be a milestone on the
road to understanding the observed dominance of matter over antimatter in the
Universe, which is one of the fundamental questions of contemporary science.The
motivation for the presented study is the current very exciting situation in neutrino
physics. According to many physicists, the discovery of neutrino oscillations in the
years 1998-2002 and their interpretation within the framework of three neutrino
flavour mixing, awarded the 2015 Nobel Prize in physics, provides firm evidence for
new physics beyond the Standard Model. Recently, the θ13 mixing angle has been
determined to be moderately large. This makes it possible to use conventional
high power neutrino beams in accelerator long baseline experiments to answer the
remaining questions in neutrino oscillations, which are the neutrino mass hierarchy
and the measurement of the CP-violating phase
Chromatografia cieczowa z tandemową spektrometrią mas (LC-MS/MS), jako przykład techniki łączonej - podstawy teoretyczne i przykłady zastosowań
No full textW technikach sprzężonych wykorzystana zostaje zdolność rozdzielcza metody analitycznej oraz zdolność spektrometrii mas do identyfikacji rozdzielonych składników. Jedną z technik analitycznych cieszącą się coraz większym zainteresowaniem laboratoriów środowiskowych, przyrodniczych czy diagnostyki medycznej, jest chromatografia cieczowa sprzężona ze spektrometrią mas. Najważniejszą zaletą tej techniki jest możliwość oznaczania związków polarnych i wielkocząsteczkowych, dlatego znajduje szerokie zastosowanie w analizie próbek biologicznych. W odróżnieniu od chromatografii gazowej chromatografia cieczowa pozwala na analizę związków nielotnych, o masie atomowej do kilku tysięcy Da1. Jest techniką o potencjalnie większych możliwościach aplikacyjnych niż chromatografia gazowa. Stosując chromatografię cieczową, można analizować znacznie większą grupę substancji (ok. 80% znanych związków chemicznych). Mogą to być ciecze i ciała stałe, w tym związki łatwo ulegające rozkładowi termicznemu, polimery i związki nieorganiczne. Warunkiem koniecznym zastosowania chromatografii cieczowej jest rozpuszczalność analitów [1-6]. W pracy zebrano podstawowe informacje o chromatografii cieczowej, omówiono rozwiązania pozwalające na połączenie analizy chromatograficznej ze spektrometrem masowym wykorzystanym, jako detektor. Szczególną uwagę zwrócono na możliwości aplikacyjne chromatografii cieczowej połączonej z tandemową spektrometrią mas (LC/MS/MS). W tej technice możliwa jest identyfikacja analitów na podstawie widma masowego, co zapewnia wysoką specyficzność i umożliwia ilościowe oznaczanie badanej substancji w złożonych mieszaninach nawet, jeżeli nie są w pełni rozdzielone chromatograficznie [1-7]
Efekty systematyczne w obserwacjach promieni kosmicznych najwyższych energii – wielokrotne rozpraszanie światła
No full textOd chwili odkrycia podczas lotu balonowego przez Victora Hessa, promienie kosmiczne nieustanie są przedmiotem badań. Liczne eksperymenty zostały przeprowadzone dla zbadania tych cząstek przybywających do Ziemi z głębi kosmosu. Eksperymenty te z jednej strony poszerzały wiedzę o promieniach kosmicznych, z drugiej zaś, odkrywając część tajemnicy, otwierały pole do dalszych badań. Dziś, po ponad stuleciu od odkrycia, pochodzenie i własności promieni kosmicznych, szczególnie najwyższych energii, ciągle stanowią jedną z największych zagadek astrofizyki. Zakres energii cząstek promieniowania kosmicznego docierającego do Ziemi obejmuje wiele rzędów wielkości: od najniższych energii, rzędu 10 7 eV, aż do najwyższych dotychczas zaobserwowanych, przekraczających 10 20 eV. Ze wzrostem energii cząstek obserwujemy potęgowy spadek ich strumienia (rys. 1), co czyni obserwacje promieniowania kosmicznego o najwyższych energiach szczególnie trudnym. Dzięki atmosferze powierzchnia Ziemi jest chroniona przed ciągłym bombardowaniem wysokoenergetycznymi cząstkami - oznacza to jednak, że bezpośrednia obserwacja promieniowania kosmicznego wymaga wyniesienia detektorów ponad gęste warstwy atmosfery, przy użyciu balonów lub satelitów. Dzięki takim właśnie eksperymentom własności promieniowania kosmicznego, takie jak skład i wielkość strumienia, zostały określone z dużą dokładnością przy niższych energiach. Jednak ograniczone rozmiary i czas działania detektorów jakie mogą być wyniesione ponad atmosferę, w połączeniu z malejącym strumieniem cząstek, narzucają granice możliwości badań takimi metodami do energii poniżej ∼ 10 15 eV. Detekcja promieniowania kosmicznego o wyższych energiach możliwa jest natomiast pośrednio, poprzez obserwacje kaskad cząstek wtórnych, czyli tak zwanych wielkich pęków atmosferycznych, wywoływanych przez cząstki pierwotne
Calculations of neutron and gamma energy spectra in surroundings of the HRNS for ITER
No full textAn optimisation of the High Resolution Neutron Spectrometer HRNS) shield was performed. Concrete and polyethylene shields of different thicknesses were considered. Two boxes for two sets of detectors are to be built of polyethylene though the underside is planned to be made of concrete. The final external dimensions of the first box are to be 175 cm (length), 150 cm (width) and 170 cm (height) while the second box is to be 215 cm long, 150 cm wide and 200cm high. All the shield elements are to be 10 cm thick including a wall between the boxes.
Next, photons and scattered neutrons spectra in the first box detectors were calculated. The results will be used as a source to estimate the background contribution on the different detectors. Finally, the neutron and photon spectra through the inner and outer surfaces of the first box were computed. The results are to be used as gamma and neutron sources in subsequent evaluations of shut-down dose rates in the port cell. A detailed MCNP input file was elaborated, based on a CAD model, which geometric part contains over 600 cells of HRNS, not counting void.F4E-GRT-403, entitled “Conceptual Design and Interface Specifications of High Resolution Neutron Spectrometer
Characterization of cell surface structure and its relation to cytoskeleton elasticity in cancer cells
No full textThe alterations observed in tumour cells include the number of processes introducing
abnormalities in cellular morphology, structure and growth profiles. Despite continuous efforts, the molecular mechanism of the metastasis is still not understood completely. That is the reason why there is an urgent need for the search of new scientific approaches in the cancer progression investigations. The development of various biochemical and biological methods increases the chance to detect cancer, however, in past decades, single cell biomechanics has gained large significance since certain diseases are known to manifest in altered biomechanical properties. Stiffness of single cells is one of the major properties that changes during cancerous progression. Studies have demonstrated that biomechanics can bring both data describing mechanisms underlying cancer progression and tools for its detection and diagnosis at the single cell level. However, one of the emerging directions is to correlate cellular biomechanics with biochemical and biophysical properties of single cells.The main objective of the presented thesis is to study how single cell deformability is linked with cellular surface properties, and how these changes correlate with cancer progression. Thus, the elasticity of melanoma cells was measured by means of atomic force microscopy (AFM). Measurements were carried out for three groups of cells encompassing cells originating from primary tumour sites i.e. from radial and vertical growth phases (RGP and VGP, respectively), and those derived from skin and lung metastasis. The results were compared with properties of melanocytes (cells from which melanoma originates). The surface properties were determined using time of flight secondary ions mass spectrometry(ToF SIMS). The use of ToF SIMS has required to develop a dedicated sample preparation protocol enablingmeasurements of biological material in the high vacuum environment. The final results show the correlation between single cell deformability and surface biochemical properties of melanoma cells. They confirm the hypothesis that cancer progression causes alterations in the morphological and mechanical properties of cancerous cells and these differences are connected with changes in the cellular surface composition.This work was partially supported by National Science Centre (NCN) Project Number DEC-2013/11/N/ST4/01860
Plasma-Focus and controlled nuclear fusion
No full textThe dependence of the binding energy per nucleon on the nucleus mass number known in nuclear physics shows that nuclear energy can be produced (emitted) not only in the fission reactions of heavy nuclei, but also in the fusion reactions of light nuclei. In both cases, the production (emission) of energy is equal to the increment of the total binding energy. Thus nuclear fusion reactions, in addition to fission reactions, may be the second major source of energy production on Earth
Projekt źródła prądowego, do testów sterowania systemu produkcji wiązki cyklotronu C230, pod kątem pomiarów energii metodą TOF
No full textThe project involved creation of the control system for the beam production system in order to allow measurements of the proton energy using TOF method. Two conceptual solutions were considered. Triggering system based on the existing power supply was rejected at the stage of testing due to excessive delays present in the system. Therefore new source control system (power supply) was made in order to regulate the BCREU (Beam Control Regulation Electronic Unit). Main features of this system include generating pulses of variable duration, adjusting the time between pulses and creating dedicated control interface. The control system was based on the ATmega328 microcontroller (located on the Arduino Uno board) and the adjusting system was realized using the embedded system based on Linux. Performed tests of the pulsing source revealed limitations of the Beam Control Regulation Electronic Unit (BCREU) which resulted in necessity to set duration of the pulse greater than 25 μs
Symulacja Monte-Carlo odpowiedzi spektrometrycznej sondy geofizyki otworowej sPNG w ośrodku modelowym stanowiska kalibracyjnego w Zielonej Górze
No full textThe MCNP model of the spectrometric well-loging tool, sPNG, was designed and coded. Responses of the sPNG probe were simulated,and obtained gamma spectra compared with measurements performed at Zielona Góra calibration facility. Good agreement of the calculated and measured spectra seams to confirm correctness of the modelling