Wyniki wyszukiwania - Biblioteka Nauki

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A Method to Produce Linearly Polarized Positrons and Positronium Atoms with the J-PET Detector

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Mohammed M. , Białas P. , Curceanu C. , Czerwiński E. , Dulski K. , Gajos A. , Głowacz B. , Gorgol M. , Hiesmayr B. , Jasińska B. , Kisielewska D. , Korcyl G. , Kowalski P. , Kozik T. , Krawczyk N. , Krzemień W. , Kubicz E. , Pawlik-Niedźwiecka M. , Niedźwiecki S. , Pałka M. , Raczyński L. , Raj J. , Rudy Z. , Sharma N. , Sharma S. , Shivani , Skurzok M. , Silarski M. , Wieczorek A. , Wiślicki W. , Zgardzińska B. , Zieliński M. , Moskal P.

Acta Physica Polonica A

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2017

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tom 132

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nr 5

1486-1489

EN

A method for creating linearly polarized positrons and ortho-positronium (o-Ps) atoms with the J-PET detector is presented. The unique geometry and properties of the J-PET tomography enable one to design a positron source such that the quantization axis for the estimation of the linear polarization of produced o-Ps can be determined on the event by event basis in a direction of the positron motion. We intend to use ²²Na or other β⁺ decay isotopes as a source of polarized positrons. Due to the parity violation in the beta decay, the emitted positrons are longitudinally polarized. The choice of the quantization axis is based on the known position of the positron emitter and the reconstructed position of the positronium annihilation. We show that the J-PET tomography is equipped with all needed components.

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Time Calibration of the J-PET Detector

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Skurzok M. , Silarski M. , Alfs D. , Białas P. , Shivani , Curceanu C. , Czerwiński E. , Dulski K. , Gajos A. , Głowacz B. , Gorgol M. , Hiesmayr B. , Jasińska B. , Kisielewska-Kamińska D. , Korcyl G. , Kowalski P. , Kozik T. , Krawczyk N. , Krzemień W. , Kubicz E. , Mohammed M. , Pawlik-Niedźwiecka M. , Niedźwiecki S. , Pałka M. , Raczyński L. , Raj J. , Rudy Z. , Sharma N. , Sharma S. , Shopa R. , Wieczorek A. , Wiślicki W. , Zgardzińska B. , Zieliński M. , Moskal P.

Acta Physica Polonica A

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2017

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tom 132

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nr 5

1641-1644

EN

The Jagiellonian positron emission tomograph project carried out in the Institute of Physics of the Jagiellonian University is focused on construction and tests of the first prototype of PET scanner for medical diagnostic which allows for the simultaneous 3D imaging of the whole human body using organic scintillators. The J-PET prototype consists of 192 scintillator strips forming three cylindrical layers which are optimized for the detection of photons from the electron-positron annihilation with high time-and high angular resolutions. In this article we present time calibration and synchronization of the whole J-PET detection system by irradiating each single detection module with a ²²Na source and a small detector providing common reference time for synchronization of all the modules.

3

Analysis Procedure of the Positronium Lifetime Spectra for the J-PET Detector

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Dulski K. , Zgardzińska B. , Białas P. , Curceanu C. , Czerwiński E. , Gajos A. , Głowacz B. , Gorgol M. , Hiesmayr B. , Jasińska B. , Kisielewska-Kamińska D. , Korcyl G. , Kowalski P. , Kozik T. , Krawczyk N. , Krzemień W. , Kubicz E. , Mohammed M. , Pawlik-Niedźwiecka M. , Niedźwiecki S. , Pałka M. , Raczyński L. , Raj J. , Rudy Z. , Sharma N. , Sharma S. , Shivani S. , Shopa R. , Silarski M. , Skurzok M. , Wieczorek A. , Wiślicki W. , Zieliński M. , Moskal P.

Acta Physica Polonica A

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2017

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tom 132

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nr 5

1637-1640

EN

Positron annihilation lifetime spectroscopy has shown to be a powerful tool to study the nanostructures of porous materials. Positron emission tomograph is a device allowing imaging of metabolic processes e.g. in human bodies. A newly developed device, the Jagiellonian PET will allow positron annihilation lifetime spectroscopy in addition to imaging, thus combining both analyses providing new methods for physics and medicine. In this contribution we present a computer program that is compatible with the Jagiellonian PET software. We compare its performance with the standard program LT 9.0 by using positron annihilation lifetime spectroscopy data from hexane measurements at different temperatures. Our program is based on an iterative procedure, and our fits prove that it performs as good as LT 9.0.

4

Preliminary Studies of J-PET Detector Spatial Resolution

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Pawlik-Niedźwiecka M. , Niedźwiecki S. , Alfs D. , Białas P. , Curceanu C. , Czerwiński E. , Dulski K. , Gajos A. , Głowacz B. , Gorgol M. , Hiesmayr B. , Jasińska B. , Kisielewska D. , Korcyl G. , Kowalski P. , Kozik T. , Krawczyk N. , Krzemień W. , Kubicz E. , Mohammed M. , Pałka M. , Raczyński L. , Raj J. , Rudy Z. , Shivani , Silarski M. , Skurzok M. , Sharma N. , Sharma S. , Shopa R. , Strzelecki A. , Wieczorek A. , Wiślicki W. , Zgardzińska B. , Zieliński M. , Moskal P.

Acta Physica Polonica A

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2017

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tom 132

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nr 5

1645-1648

EN

The J-PET detector, based on long plastic scintillator strips, was recently constructed at the Jagiellonian University. It consists of 192 modules axially arranged into three layers, read out from both sides by digital constant-threshold front-end electronics. This work presents preliminary results of measurements of the spatial resolution of the J-PET tomograph performed with ²²Na source placed at selected position inside the detector chamber.