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In this paper, an overview of kaonic atoms studies from the late 90s to nowadays at the DAΦNE collider at INFN-LNF is presented. Experiments on kaonic atoms are an important tool to test and optimize phenomenological models on the low-energy strong interaction. Since its construction, the DAΦNE collider has represented an ideal machine to perform kaonic atoms measurements, thanks to the unique beam of kaons coming from the øs produced in the collider decays. The DEAR and SIDDHARTA experiments achieved the precise evaluation of the shift and width of the 2p → 1s transition in kaonic hydrogen due to the strong interaction, and thus provided a measurement strictly linked to isospin-dependent antikaon--nucleon scattering lengths. To fully disentangle the iso-scalar and iso-vector scattering lengths, the measurement of kaonic deuterium is necessary as well. The SIDDHARTA-2 experiment is now taking data at the DAΦNE collider with the aim to fulfill the need of this measurement, and therefore provide important information to the various phenomenological models on low-energy strong interactions with strangeness. The SIDDHARTA-2 Collaboration is also exploring the possibility to perform future kaonic atoms experiments, developing X-ray detector systems beyond the current state-of-art. These measurements are crucial for a deeper understanding of the kaon interactions with nuclei and for solving the kaon mass "puzzle". [ABSTRACT FROM AUTHOR]

Positron Annihilation Lifetime Spectroscopy (PALS) is a technique based on the analysis of the lifetime of positronium emitted from implanted or delivered positronium donors. This technique employs the lifetime and intensity dependence on the structure of analyzed material. Due to this specific features, PALS might be used in further research protocols and clinical studies for cancer diagnostic purposes. This article reports the progress in the study design, main objectives of the study, protocols of measurements and data analysis and further perspective of this study. The main goal of this work was to show the effectiveness of this method and progress in its development. For this purpose, colorectal cancer was examined. [ABSTRACT FROM AUTHOR]

A method for the time calibration of the Time-of-Flight Positron Emmission Tomograph (TOF-PET) systems using fixed sources is described. Compared to the commercially used calibration methods, the new method gives a chance to run the calibration during the medical scan. Reduction of the time needed for calibration can increase the number of patients examined by PET. The process of calibration of the Jagiellonian Positron Emission Tomograph (J-PET) detector is shown as an example. [ABSTRACT FROM AUTHOR]

The Jagiellonian Positron Emission Tomograph (J-PET) is a detector for medical imaging of the whole human body as well as for physics studies involving detection of electron-positron annihilation into photons. J-PET has high angular and time resolution, and allows for measurement of spin of the positronium and the momenta and polarization vectors of annihilation quanta. In this article, we present the potential of the J-PET system for the background rejection in the decays of positronium atoms. [ABSTRACT FROM AUTHOR]

We present a method and preliminary results of the image reconstruction in the Jagiellonian PET tomograph. Using GATE (Geant4 Application for Tomographic Emission), interactions of the 511 keV photons with a cylindrical detector were generated. Pairs of such photons, flying backto- back, originate from e+e- annihilations inside a 1 mm spherical source. Spatial and temporal coordinates of hits were smeared using experimental resolutions of the detector. We incorporated the algorithm of the 3D Filtered Back Projection, implemented in the STIR and TomoPy software packages, which differ in approximation methods. Consistent results for the Point Spread Functions of ~ 5÷7 mm and ~ 9÷20 mm were obtained, using STIR, for transverse and longitudinal directions, respectively, with no time-of-flight information included. [ABSTRACT FROM AUTHOR]

Samples of uterine leiomyomatis and normal tissues taken from patients after surgery were investigated using the Positron Annihilation Lifetime Spectroscopy (PALS). Significant differences in all PALS parameters between normal and diseased tissues were observed. For all studied patients, it was found that the values of the free annihilation and orthopositronium lifetime are larger for the tumorous tissues than for the healthy ones. For most of the patients, the intensity of the free annihilation and ortho-positronium annihilation was smaller for the tumorous than for the healthy tissues. For the first time, in this kind of studies, the 3γfraction of positron annihilation was determined to describe changes in the tissue porosity during morphologic alteration. [ABSTRACT FROM AUTHOR]

In this paper, we extend the state-of-the-art filtered backprojection (FBP) method with application of the concept of Total Variation regularization. We compare the performance of the new algorithm with the most common form of regularizing in the FBP image reconstruction via apodizing functions. The methods are validated in terms of cross-correlation coefficient between reconstructed and real image of radioactive tracer distribution using the standard Derenzo-type phantom. We demonstrate that the proposed approach results in higher cross-correlation values with respect to the standard FBP method. [ABSTRACT FROM AUTHOR]

The Jagiellonian Positron Emission Tomograph (J-PET) is the first PET built from plastic scintillators. J-PET prototype consists of 192 detection modules arranged axially in three layers forming a cylindrical diagnostic chamber with the inner diameter of 85 cm and the axial field-of-view of 50 cm. An axial arrangement of long strips of plastic scintillators, their small light attenuation, superior timing properties, and relative ease of the increase of the axial field-of-view opens promising perspectives for the cost effective construction of the whole-body PET scanner, as well as construction of MR and CT compatible PET inserts. Present status of the development of the J-PET tomograph will be presented and discussed. [ABSTRACT FROM AUTHOR]

In this paper, we present a complete Data Acquisition System (DAQ) together with the readout mechanisms for the J-PET tomography scanner. In general, detector readout chain is constructed out of Front-End Electronics (FEE) measurement devices such as Time-to-Digital or Analog-to- Digital Converters (TDCs or ADCs), data collectors and storage. We have developed a system capable for maintaining continuous readout of digitized data without preliminary selection. Such operation mode results in up to 8 Gbps data stream, therefore, it is required to introduce a dedicated module for on-line event building and feature extraction. The Central Controller Module, equipped with Xilinx Zynq SoC and 16 optical transceivers, serves as such true real time computing facility. Our solution for the continuous data recording (trigger-less) is a novel approach in such detector systems and assures that most of the information is preserved on the storage for further, high-level processing. Signal discrimination applies a unique method of using LVDS buffers located in the FPGA fabric. [ABSTRACT FROM AUTHOR]