Analytical models of radiobiological response in ion beams are used in studies on improving treatment planning in proton therapy. The best known models are Carabe [1], Wedenberg [2] and McNamara [3]. They relate response of the system (i.e. cell survival) with beam characterication (kinetic energy, linear energy transfer, ion type) and tissue radiosensitivity expressed by parameters of linear...
The intrinsic spatial resolution of clinical positron emission tomography (PET) detectors is ~ 3 - 4 mm. A further improvement of the resolution using pixelated detectors will not only result in a prohibitive cost, but is also inevitably accompanied by a strong degradation of important performance parameters like timing, energy resolution and sensitivity. Therefore, it is likely that future...
Violation of the combination of two discrete symmetries C (charge conjugation) and P (parity) is a very important mechanism in the Standard Model. It is, for example, one of the conditions for existance of asymmetry between matter and antimatter in the Universe. One of the purely CP-violating process, which is still not discovered is the $K_S \rightarrow 3\pi^0$ decay.
The best upper limit on...
Nowadays Silicon photomultipliers (SiPM) becomes a reasonable choice for time of flights Positron emission tomography( TOF-PET). To achieve the best performance of SiPMs, it is necessary to adjust a suitable voltage bias; this means that SiPMs are very sensitive to voltage fluctuations [1]. One of the most significant issues in electronic circuits related to medical imaging equipments is...
One of the challenge for the total and large PET tomographs is the efficient selection of the true coincidence photon pairs and reduction of the background consisting of events with the photons scattered in the patient body, multiple scattered in the detector or coming from different annihilations (random coincidences). The J-PET scanner is the multi-layer, large field-of-view,...
The success or failure of radiotherapy largely depends on the accuracy with which the dose will be delivered to a specific volume in the patient's body. In many cases, a change in dose by 3-4% may cause failure of the treatment. Both national and international guidelines on coherence and accuracy in ionizing radiation dosimetry are focused on homogeneous media (i.e. water), however, the human...
The JISP16 nucleon-nucleon potential [1] is applied to investigate the nucleon induced deuteron breakup reaction at energies E=13 and 65 MeV. We use the formalism of Faddeev equation [2] and proceed like in the case of the application of the JISP16 potential to the elastic scattering process [3].
Our study reveals that this force delivers, in general, qualitatively a similar description of the...
The ab-initio theoretical study of the three-nucleon (3N) observables for the nucleon elastic and inelastic scattering on the deuteron is possible using realistic models of nuclear forces. Such models contain a number of free parameters whose values are typically fixed using the two-nucleon data. In case of few models, as the One-Pion-Exchange-Gaussian (OPE-Gaussian) force [1] or the chiral...
Initial tests of a new measuring probe for use in PALS spectrometry were designed and carried out. Unlike commercial measuring probes, SiPM’s were used as scintillation light detectors. Tests were carried out with various types of scintillation materials, e.g. NaI (Tl), BaF2 & BC412. Three types of SiPM’s (KETEK & SensL) were also tested.
Main adventages of this project are: mobilty of new...
The proposed studies focus on a performing the comprehensive analysis of the optimal conditions for a detailed knowledge of the nuclear excitation by electron capture (NEEC) process for selected nuclear isomers (i.e. metastable exited states of atomic nuclei) of a few elements. The part of these research focuses on the especially interesting and important case of NEEC process for the...
The work is dedicated to the development of the new free RTPS (the Radiation Therapy Planning System), the using GPU hardware and Artificial Intelligence algorithms for dose calculation. The semi-empirical algorithms and Monte Carlo methods are applied to obtain balance between of speed and precision of work. Free RTPS systems are effective not only for training students and medical...
The purpose of the presented investigations is to design, construct and to establish the characteristic performance of the J-PEM (Jagiellonian Positron Emission Mammography), which is imaging modality for the detection and diagnosis of breast cancer, based on a novel idea with plastic scintillator [1,2] and wavelength shifter (WLS) [3]. Out of all imaging modalities, J-PEM is a type of...
Vacuum chambers are necessary for the physics experiments, planned to be carried out with the use the J-PET detector. Several chambers, with particular purposes listed below, were manufactured and tested at various stages of development of the detector.
The chambers used for particular runs of J-PET experiments had generally cylindrical shapes, while the radioactive source was placed in the...
The existence of CP violation in the decays of strange and beauty mesons is very well established experimentally. On the contrary, CP violation in the decays of charmed particles has never been observed before (2018). During the LHC Run I and Run II the LHCb collaboration has collected a huge sample of charmed hadrons. This sample enables some of the most sensitive searches for CP violation...
A novel Positron Emission Tomography (PET) detector consisting of strips of polymer scintillators is being developed in J-PET Collaboration. Despite other commercial PET scanners which are based on crystal scintillators, 24 modular J-PET is the latest prototype of the J-PET collaboration using Silicon photomultipliers. Each module in this prototype contains 13 strips of EJ-230 with 50 cm long...
The electron-electron interaction is a crucial aspect of atomic reactions involving electron-ion collisions. An effective way to investigate electron-electron interaction is to study the higher-order recombination processes. The most basic of those recombination processes is dielectronic recombination. DR is the time reversal to the Auger process and thus is well-known and investigated in many...
The work is devoted to the development of inexpensive scintillation spectrometer systems on the base SiPM light detectors for various radiation applications (compact cheap mobile spectrometers of gamma, beta and alpha particles, monitoring of accelerator beams - Beam Loss Monitors). CsI(Tl) was used as scintillation crystals. Hulls was built using 3D printing. Detector electronics (with 512...
The Belle II detector, dedicated to investigation of B mesons properties, started data acquisition on SuperKEKB e+e- collider this year. Precise measurement of particle momentum in 1.5T magnetic field is crucial for the success of physics program. The measurement of the field inside tracking detector volume was performed in collaboration between CERN, DESY, IFJ PAN and KEK labs. Field itself...
In the last decades hadron therapy has become an important cancer treatment modality. Therefore, research towards improvement of quality assurance and new online treatment monitoring methods has intensified. Prompt gamma imaging (PGI) is one of the most promising techniques for real time monitoring of deposited dose distribution. Recent development in production of inorganic scintillators...
Laser shock peening (LSP) is a proven surface modification process designed to improve the mechanical properties of materials. LSP is mainly applied on surfaces of metallic components [1]. It consists in irradiating a metallic target surface with a high power density laser beam pulses. The beam heats and ionizes the sample surface, turning it into rapidly expanding plasma which generates a...
Using 1.63 fb$^{-1}$ of integrated luminosity collected by the KLOE experiment about $7 \times 10^4$ $K_S \rightarrow \pi e \nu$ decays have been reconstructed. The measured value of the charge asymmetry for this decay is $A_S = (−4.9 \pm 5.7_{stat} \pm 2.6_{syst}) \times 10^{-3}$, which is almost twice more precise than the previous KLOE result. The combination of these two measurements gives...
One of the great mysteries in the natural sciences is why matter dominates over antimatter in the visible universe. The breaking of the combined charge conjugation and parity symmetries in the Standard Model of particle physics is insufficient to explain this. Therefore, other sources of CP-violations are sought, and these could manifest in the Electric Dipole Moments (EDM) of fundamental...
Proton therapy is a method of radiotherapy allowing the delivery of a high radiation dose to the target volume in a conformal way. This is possible thanks to the very beneficial shape of the depth dose distribution of proton beam, called the Bragg peak.
However, the steep distal fall-off of the beam can result in over- or under-dosage in critical regions. Therefore the monitoring of the beam...
Proton computed tomography (pCT) is an imaging modality for generation of accurate relative-stopping-power images. Such images are used in the context of particle therapy for treatment-planning and dose-recalculation according to the anatomy-of-the-day. A recently proposed method for fluence-modulated pCT (FMpCT) imaging may further reduce imaging dose while maintaining image quality within a...
In 2014 NuPECC listed online monitoring of the beam range in hadron therapy as one of the most important challenges in hadron therapy. Monitoring systems based on the detection of prompt gamma radiation are considered as one of the most promising options. Different detector setups are developed and tested around the world. A Compton camera, yielding the full three-dimensional dose...
The search for non-strange $B=2$ (dibaryon) bound/resonance states has a long history. The dibaryon state is of interest, which can be a molecule consisting of two baryons or a spatially compact hexaquark object. The $\gamma d\to \pi^0\pi^0 d$ reaction has been experimentally investigated at incident energies ranging from 0.58 to 1.2 GeV to study non-strange dibaryons. The angular...
The significantly large mass of the $\eta(958)$ ($\eta'$) meson within the other light pseudoscalar mesons is understood to be generated by the $\rm U_{A}(1)$ anomaly and the chiral symmetry breaking. In the nuclear medium, the $\eta'$ mass is considered to be reduced due to a partial restoration of chiral symmetry [1]. The reduction of the $\eta'$ mass leads to an attractive $\eta'$-nucleus...
The experimental total production cross sections of intermediate mass fragments (isotopes of Li, Be, B, C, N, O, F, Ne, Na, and Mg) were extracted by the integration of dsigma/dOmega dE data measured at several angles for p+Ag collisions at proton beam energy of 480 MeV. The total cross sections show typical odd-even staggering (OES) when presented as a function of the atomic number Z of...
Purpose
In spatially fractionated proton therapy (SFTP) the arrays of parallel and narrow proton beams are applied to reduce the impact of irradiation on healthy tissue. At the beam entrance the locally irradiated skin benefits from faster recovery than that observed for the uniform exposure. In the same time, due to the multiple Coulomb scattering of the proton beam, the target volume can be...
Breast cancer (BC), a most common women malignancy, is often screened by mammography and ultrasound exams. Mammography provides early micro-calcification recognition, that is important for further cancer diagnosis. The imaging method-of-choice in the case of BC is an X-ray mammography (MG), also with the use of high-resolution digital modality. However, a planar MG has some limitations in...
The CKM angle γ is the least precise measured parameter of the Unitary Triangle. Discrepancies between precise measurements of the CKM angle γ in the tree-level and loop dominated processes might provide evidence of New Physics - beyond the Standard Model. The value can be well determined by exploiting the interference between favored 𝑏→𝑐 and suppressed 𝑏→ 𝑢 transition amplitudes (e.g. 𝐵→𝐷𝐾...
Current total-body PET scans are time consuming, expensive, and require high-activity radiopharmaceuticals. In available clinical PET scanners, the cost of detectors introduces restrictions to the field of view. The J-PET project of a total-body scanner based on polymer detectors is expected to increase geometric efficiency without increasing the production costs. The results of reconstruction...
Neutrino scattering on nuclei has been investigated for several decades. It played an important role in establishing fundamentals of the theory of weak interactions and electroweak unification. Later it became a tool to study the much more subtle properties of neutrinos, such as masses and oscillations.
Most of the calculations for neutrino scattering on light nuclei were performed in...
The negatively charged pions and kaons can be trapped in the Coulomb potential of atomic nucleus forming so called mesonic atoms. It is also conceivable that a neutral meson could be bound to a nucleus. In this case the binding is exclusively due to the strong interaction and hence such object can be referred to as a mesic nucleus.
The most promising candidate for such state is the...
Discrete symmetries ( reflection in space (P), reversal in time (T) and charge conjugation (C)) are violated in weak interactions only. Charge conjugation transforms a particle into antiparticle and vice versa by changing its internal quantum numbers. Positronium atom (Ps) which is the meta-stable bound system of particle (e-) and its antiparticle (e+) can be an excellent tool for studying...
The Standard Model (SM) of Particle Physics fails to explain the reason for our very existence since it is not capable to account for the apparent matter-antimatter asymmetry of our Universe. Permanent EDMs of particles violate both time reversal and parity invariance, therefore via CPT theorem CP is violated. Finding an EDM value larger than predicted by SM would be a strong indication for...
Since 2010 the nuclear medicine community has been expressing global concern for the shortage of 99mTc supply based on fission production of 99Mo from highly enriched uranium to produce 99Mo/99mTc generators. As an alternative to reactor based 99Mo/99mTc generator technology, many research groups have suggested the direct production of 99mTc through accelerators. There are many production...
The test of the three discrete symmetries of quantum mechanics under the chargeconjugation (C), parity transformation (P), and time reversal (T) is one of the most important issues in nuclear and elementary particle physics. All of three discrete symmetries are violated, singly or in pairs with different orders. The CPT combination of these three symmetries seems to be conserved in nature so...
Thermal evaporation or magnetron sputtering of metals in carefully adjusted low pressure (~100 Pa) of nitrogen gas enables deposition of peculiar porous structures known as black metals. Because of their unique morphology black metals highly absorb light in the visible to infrared spectral region. The surface of black metals appears dark since light incident on the surface is completely...
The aim of the project is the development of a method for on-line monitoring of dose distribution in proton therapy based on detection of prompt gamma (PG) radiation emitted from a patient during irradiation. During this project, an imaging prototype of Compton Camera (CC) based on heavy scintillating fibers together with the corresponding data handling and an image reconstruction framework...
The improved chiral nucleon-nucleon (NN) interaction with the semi-local regularization in the momentum space was derived recently [1] up to the fifth order of the chiral expansion (N4LO) and even some contributions from the next order have been tested in so-called N4LO+ model. In comparison to the first generation of the chiral potential [2] the regularization of the potential is now...
Following the first experimental observation of $^{93m}$Mo isomer depletion via nuclear excitation by electron capture (NEEC), we have made theoretical investigation related to the $^{242m}$Am isomer ($T_{1/2}$ ~ 141 y). It is worth to underline that for $^{242m}$Am isomer the probability of the NEEC process can be even higher than for the $^{93m}$Mo isomer [1-3].
We have performed here the...
Heavy-ion induced reactions offer unique opportunities to probe nuclear properties far from the ground state. The isospin flow during heavy-ion collisions is a subject of current investigation due to its link with the nuclear symmetry energy ($E_{sym}$) which is only partly known far from stability and ground-state conditions. More specifically, at incident energies between 10 and 100 AMeV, it...
Kaonic atoms provide a perfect testing ground for studying the low-energetic, non-perturbative regime of quantum chromodynamics. Since kaons are the lightest mesons carrying strangeness, they allow for a direct observation of the influence of the strong interaction on the kaonic atom ground state in the form of an induced energy shift and broadened width. The SIDDHARTA-2 experiment, located at...
Living systems exhibit complex response to radiation during and after radiotherapy with protons beams. The response, measured usually by cell survival is mostly affected by the quantity of absorbed radiation. Many other factors, including cell type, dose rate and beam energy have also non-negligible effect on cell-survival.
In proton radiotherapy constant value of the relative biological...
Recently, the developments on digital time of flight are made for the pair of fast scintillator detectors ; BaF2-LaBr3, BaF2-BC501A, and LaBr3-BC501A using CAEN 250 mega samples per second (MSPS), model V1720, and 500 MSPS, model DT5730 digitizers [1,2]. Study reveals the improvement in the TOF resolution from 12%-17% while digitizing the signal from 250 MSPS to 500 MSPS rate. To investigate...
The work is devoted to using MicroPattern Gas Detectors with modern imaging CMOS sensors for obtaining inexpensive radiation imaging detectors. Last years there is fast progress of new cheap CMOS sensors. It is allows to obtain new quality of radiation image detector systems on the base of "MPGD - CMOS sensor" electronics.
In modern radiotherapy of cancer using charged particles, the Monte Carlo (MC) methods are exploited for reliable dose recalculation. Unlike analytical dose calculation methods employed in commercially available Treatment Planning Systems (TPS), the MC tools explicitly take into account many details of particle interactions with target athoms, such as multiple coulomb scattering or nuclear...
Purpose
Knowledge of stopping power in various materials used in the proton therapy is essential for the correct estimation of dose distribution in the patient. Differences between materials result from different cross –sections for interaction of primary protons and production of secondary particles from non-elastic nuclear reactions. One of the most commonly used parameters for...
