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Wyszukujesz frazę "Strzelecki, S." wg kryterium: Autor


Wyświetlanie 1-6 z 6
Tytuł:
Application of the compress sensing theory for improvement of the TOF resolution in a novel J-PET instrument
Autorzy:
Raczyński, L.
Moskal, P.
Kowalski, P.
Wiślicki, W.
Bednarski, T.
Białas, P.
Czerwiński, E.
Gajos, A.
Kapłon, Ł.
Kochanowski, A.
Korcyl, G.
Kowal, J.
Kozik, T.
Krzemień, W.
Kubicz, E.
Niedźwiecki, S.
Pałka, M.
Rudy, Z.
Salabura, P.
Gupta-Sharma, N.
Silarski, M.
Słomski, A.
Smyrski, J.
Strzelecki, A.
Wieczorek, A.
Zieliński, M.
Zoń, N.
Powiązania:
https://bibliotekanauki.pl/articles/146280.pdf
Data publikacji:
2016
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
compressed sensing
positron emission tomography
time-of-flight
Opis:
Nowadays, in positron emission tomography (PET) systems, a time of fl ight (TOF) information is used to improve the image reconstruction process. In TOF-PET, fast detectors are able to measure the difference in the arrival time of the two gamma rays, with the precision enabling to shorten signifi cantly a range along the line-of-response (LOR) where the annihilation occurred. In the new concept, called J-PET scanner, gamma rays are detected in plastic scintillators. In a single strip of J-PET system, time values are obtained by probing signals in the amplitude domain. Owing to compressive sensing (CS) theory, information about the shape and amplitude of the signals is recovered. In this paper, we demonstrate that based on the acquired signals parameters, a better signal normalization may be provided in order to improve the TOF resolution. The procedure was tested using large sample of data registered by a dedicated detection setup enabling sampling of signals with 50-ps intervals. Experimental setup provided irradiation of a chosen position in the plastic scintillator strip with annihilation gamma quanta.
Źródło:
Nukleonika; 2016, 61, 1; 35-39
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reconstruction of hit time and hit position of annihilation quanta in the J-PET detector using the Mahalanobis distance
Autorzy:
Sharma, N. G.
Silarski, M.
Bednarski, T.
Białas, P.
Czerwiński, E.
Gajos, A.
Gorgol, M.
Jasińska, B.
Kamińska, D.
Kapłon, Ł.
Korcyl, G.
Kowalski, P.
Kozik, T.
Krzemień, W.
Kubicz, E.
Niedźwiecki, S.
Pałka, M.
Raczyński, L.
Rudy, Z.
Rundel, O.
Słomski, A.
Strzelecki, A.
Wieczorek, A.
Wiślicki, W.
Zieliński, M.
Zgardzińska, B.
Moskal, P.
Powiązania:
https://bibliotekanauki.pl/articles/146937.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
J-PET detector
Mahalanobis distance
time resolution
threshold levels
Opis:
The J-PET detector being developed at the Jagiellonian University is a positron emission tomograph composed of the long strips of polymer scintillators. At the same time, it is a detector system that will be used for studies of the decays of positronium atoms. The shape of photomultiplier signals depends on the hit time and hit position of the gamma quantum. In order to take advantage of this fact, a dedicated sampling front-end electronics that enables to sample signals in voltage domain with the time precision of about 20 ps and novel reconstruction method based on the comparison of examined signal with the model signals stored in the library has been developed. As a measure of the similarity, we use the Mahalanobis distance. The achievable position and time resolution depend on the number and values of the threshold levels at which the signal is sampled. A reconstruction method as well as preliminary results are presented and discussed.
Źródło:
Nukleonika; 2015, 60, No. 4, part 1; 765-769
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Searches for discrete symmetries violation in ortho-positronium decay using the J-PET detector
Autorzy:
Kamińska, D.
Gajos, A.
Czerwiński, E.
Bednarski, T.
Białas, P.
Gorgol, M.
Jasińska, B.
Kapłon, Ł.
Korcyl, G.
Kowalski, P.
Kozik, T.
Krzemień, W.
Kubicz, E.
Niedźwiecki, S.
Pałka, M.
Raczyński, L.
Rudy, Z.
Rundel, O.
Sharma, N. G.
Silarski, M.
Słomski, A.
Strzelecki, A.
Wieczorek, A.
Wiślicki, W.
Zieliński, M.
Zgardzińska, B.
Moskal, P.
Powiązania:
https://bibliotekanauki.pl/articles/147408.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
discrete symmetries
J-PET
ortho-positronium
Opis:
In this paper, we present prospects for using the Jagiellonian positron emission tomograph (J-PET) detector to search for discrete symmetries violations in a purely leptonic system of the positronium atom. We discuss tests of CP and CPT symmetries by means of ortho-positronium decays into three photons. No zero expectation values for chosen correlations between ortho-positronium spin and momentum vectors of photons would imply the existence of physics phenomena beyond the standard model. Previous measurements resulted in violation amplitude parameters for CP and CPT symmetries consistent with zero, with an uncertainty of about 10−3. The J-PET detector allows to determine those values with better precision, thanks to the unique time and angular resolution combined with a high geometrical acceptance. Achieving the aforementioned is possible because of the application of polymer scintillators instead of crystals as detectors of annihilation quanta.
Źródło:
Nukleonika; 2015, 60, No. 4, part 1; 729-732
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies of unicellular microorganisms Saccharomyces cerevisiae by means of positron annihilation lifetime spectroscopy
Autorzy:
Kubicz, E.
Jasińska, B.
Zgardzińska, B.
Bednarski, T.
Białas, P.
Czerwiński, E.
Gajos, A.
Gorgol, M.
Kamińska, D.
Kapłon, Ł.
Kochanowski, A.
Korcyl, G.
Kowalski, P.
Kozik, T.
Krzemień, W.
Niedźwiecki, S.
Pałka, M.
Raczyński, L.
Rajfur, Z.
Rudy, Z.
Rundel, O.
Sharma, N. G.
Silarski, M.
Słomski, A.
Strzelecki, A.
Wieczorek, A.
Wiślicki, W.
Zieliński, M.
Moskal, P.
Powiązania:
https://bibliotekanauki.pl/articles/147902.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
environmental scanning electron microscopy (ESEM)
free volume
inverted microscopy
positron annihilation
positronium
yeasts
Opis:
Results of positron annihilation lifetime spectroscopy (PALS) and microscopic studies on simple microorganisms, brewing yeasts, are presented. Lifetime of ortho-positronium (o-Ps) were found to change from 2.4 to 2.9 ns (longer-lived component) for lyophilized and aqueous yeasts, respectively. Also hygroscopicity of yeasts in time was examined, allowing to check how water – the main component of the cell – affects PALS parameters, thus lifetime of o-Ps were found to change from 1.2 to 1.4 ns (shorter-lived component) for the dried yeasts. The time sufficient to hydrate the cells was found below 10 hours. In the presence of liquid water, an indication of reorganization of yeast in the molecular scale was observed. Microscopic images of the lyophilized, dried, and wet yeasts with best possible resolution were obtained using inverted microscopy (IM) and environmental scanning electron microscopy (ESEM) methods. As a result, visible changes to the surface of the cell me mbrane were observed in ESEM images.
Źródło:
Nukleonika; 2015, 60, No. 4, part 1; 749-753
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
PALS investigations of free volumes thermal expansion of J-PET plastic scintillator synthesized in polystyrene matrix
Autorzy:
Wieczorek, A.
Zgardzińska, B.
Jasińska, B.
Gorgol, M.
Bednarski, T.
Białas, P.
Czerwiński, E.
Gajos, A.
Kamińska, D.
Kapłon, Ł.
Kochanowski, A.
Korcyl, G.
Kowalski, P.
Kozik, T.
Krzemień, W.
Kubicz, E.
Niedźwiecki, S.
Pałka, M.
Raczyński, L.
Rudy, Z.
Rundel, O.
Sharma, N. G.
Silarski, M.
Silarski, A.
Strzelecki, A.
Wiślicki, W.
Zieliński, M.
Moskal, P.
Powiązania:
https://bibliotekanauki.pl/articles/147132.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
free volume
positron annihilation
polystyrene
positronium
scintillator
Opis:
The polystyrene doped with 2,5-diphenyloxazole as a primary fluor and 2-(4-styrylphenyl)benzoxazole as a wavelength shifter prepared as a plastic scintillator was investigated using positronium probe in wide range of temperatures from 123 to 423 K. Three structural transitions at 260, 283, and 370 K were found in the material. In the o-Ps intensity dependence on temperature, the significant hysteresis is observed. Heated to 370 K, the material exhibits the o-Ps intensity variations in time.
Źródło:
Nukleonika; 2015, 60, No. 4, part 1; 777-781
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Processing optimization with parallel computing for the J-PET scanner
Autorzy:
Krzemień, W.
Bała, M.
Bednarski, T.
Białas, P.
Czerwiński, E.
Gajos, A.
Gorgol, M.
Jasińska, B.
Kamińska, D.
Kapłon, Ł.
Korcyl, G.
Kowalski, P.
Kozik, T.
Kubicz, E.
Niedźwiecki, S.
Pałka, M.
Raczyński, L.
Rudy, Z.
Rundel, O.
Sharma, N. G.
Silarski, M.
Słomski, A.
Stola, K.
Strzelecki, A.
Trybek, D.
Wieczorek, A.
Wiślicki, W.
Zieliński, M.
Zgardzińska, B.
Moskal, P.
Powiązania:
https://bibliotekanauki.pl/articles/148285.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
data aquisition system (DAQ)
parallel computing
TOF-PET
Opis:
The Jagiellonian Positron Emission Tomograph (J-PET) collaboration is developing a prototype time of flight (TOF)-positron emission tomograph (PET) detector based on long polymer scintillators. This novel approach exploits the excellent time properties of the plastic scintillators, which permit very precise time measurements. The very fast fi eld programmable gate array (FPGA)-based front-end electronics and the data acquisition system, as well as low- and high-level reconstruction algorithms were specially developed to be used with the J-PET scanner. The TOF-PET data processing and reconstruction are time and resource demanding operations, especially in the case of a large acceptance detector that works in triggerless data acquisition mode. In this article, we discuss the parallel computing methods applied to optimize the data processing for the J-PET detector. We begin with general concepts of parallel computing and then we discuss several applications of those techniques in the J-PET data processing.
Źródło:
Nukleonika; 2015, 60, No. 4, part 1; 745-748
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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