Wyniki wyszukiwania - BazTech

1

Evaluation of Modular J-PET sensitivity

Tayefi Ardebili Faranak, Niedźwiecki Szymon, Moskal Paweł

Bio-Algorithms and Med-Systems

|

2023

|

Vol. 19, no. 1

132--138

EN

The Modular J-PET represents the latest advancement in the Jagiellonian-PET series, utilizing extended plastic scintillator strips. This prototype's modular design enables cost-effective imaging of multi-photon annihilation and positronium, allowing for easy assembly, portability, and versatility. Additionally, its lightweight construction facilitates static bed examinations with a mobile detection system that can be positioned conveniently alongside the patient, negating the requirement for spacious clinical settings. Comprising 24 modules arranged in regular 24-sided polygons circumscribing a 73.9 cm diameter circle, each module integrates 13 scintillator strips, measuring 50 cm in length and 6 mm × 24 mm in cross-section. Scintillation light is captured at both ends through analog Silicon Photomultipliers (SiPMs). This research presents Sensitivity of the Modular J-PET tomograph, adhering to the NEMA_NU 2-2018 standards. Sensitivity measurement was performed with 68Ge line source inside the 5 sleeves aluminium phantom placed at center of the detector`s field-of-view (FOV) and 10 cm offset from the center of detector. Analyzing the gathered data involved employing the specialized J-PET Framework software, developed within the C++ architecture. To validate the experimental findings, comparisons were made with GATE simulations, wherein the source and phantom were emulated in the same configuration as employed in the actual experiment. The system sensitivity of the Modular J-PET was assessed to be 1.03 ± 0.02 cps/kBq in the center of the detector`s FOV with the peak sensitivity of 2.1 cps/kBq. However, the simulations indicate that at the center of the detector's FOV, the Modular J-PET achieves a system sensitivity of 1.32 ± 0.03 cps/kBq, with a peak sensitivity of 2.9 cps/kBq.

2

Blue-emitting polystyrene scintillators for plastic scintillation dosimetry

Kapłon Łukasz, Moskal Gabriel

Bio-Algorithms and Med-Systems

|

2021

|

Vol. 17, no. 3

191--197

EN

Objectives: Purpose of this research was to find the best blue-emitting fluorescent substance for plastic scintillator used for gamma radiation dosimetry. Scintillator should convert gamma radiation into blue light with high efficiency. Methods: Plastic scintillators with fixed concentration of various fluorescent additives, called wavelength shifters, absorbing ultraviolet light and emitting blue light were manufactured by radical bulk polymerization of styrene. Light output were measured and compared to the light output of commercial plastic scintillator. Results: Performed measurements of charge Compton spectra confirmed usefulness of majority of researched substances as wavelength shifters in plastic scintillators with emission maximum at blue range of visible light. Conclusions: Plastic scintillation dosimeter may be constructed from manufactured polystyrene-based scintillators. Performance of synthesized scintillators is close to commercial polystyrene scintillators.

3

Plastic scintillators for positron emission tomography obtained by the bulk polymerization method

Kapłon Ł., Kochanowski A., Molenda M., Moskal P., Wieczorek A., Bednarski T., Białas P., Czerwiński E., Korcyl G., Kowal J., Kowalski P., Kozik T., Krzemień W., Niedźwiecki S., Pałka M., Pawlik M., Raczyński L., Rudy Z., Salabura P., Gupta-Sharma N., Silarski M., Słomski A., Smyrski J., Strzelecki A., Wiślicki W., Zieliński M., Zoń N.

Bio-Algorithms and Med-Systems

|

2014

|

Vol. 10, no. 1

27--31

EN

This paper describes three methods regarding the production of plastic scintillators. One method appears to be suitable for the manufacturing of plastic scintillators, revealing properties which fulfill the requirements of novel positron emission tomography scanners based on plastic scintillators. The key parameters of the manufacturing process are determined and discussed.

4

Performance of a plastic scintillator and GM pancake tubes as alpha and beta contamination detectors in dosimetric stand

Machaj B., Mirowicz J., Kowalska E.

Nukleonika

|

2011

|

Vol. 56, No. 1

53-56

EN

A model of detection probe with a plastic scintillator (230 × 105 × 1 mm3) with a ZnS(Ag) layer at the top, and a model with six pancake Geiger-Müller (GM) counters were investigated as alpha particles (Am-241) and beta radiation (Sr-90) contamination detection probes at a dosimetric stand. A detection probe, 166 × 104 mm2 of active area, with a proportional counter was also investigated for comparison. The scintillation probe showed a higher alpha detection efficiency and a comparable beta detection efficiency with respect to the probe containing the proportional counter. The GM probe shoved a higher alpha detection efficiency, and a lower beta detection efficiency than the proportional counter probe. Detection efficiency of the scintillation probe strongly depends on the distance from the photomultiplier tube (PMT) photocathode. Active area of the GM probe of all counters constitutes approximately 50% of its measuring area.