arXiv subjects

Tomasz Matulewicz

Publications and source records attributed to Tomasz Matulewicz.

5 recordsLinked to original sources

arXiv2025

Influence of $^{13}$C on proton-induced $^{13}$N production from natural carbon target

Two recent measurements of $^{12}$C(p,$γ$)$^{13}$N reaction on natural carbon were performed by detecting $β^+$ decay of $^{13}$N residue. It is argued that the measurements at energies above the $^{13}$C(p,n)$^{13}$N reaction threshold of 3.24 MeV proton kinetic energy can be interpreted as a consequence of 1.06\% admixture of $^{13}$C isotope in natural carbon, as the cross section for $^{13}$N production raised by 3 orders of magnitude with respect to the measurements of $^{12}$C(p,$γ$)$^{13}$N at lower energies.

nucl-ex↗

arXiv2025

$β^+$ radioactive nuclei created during proton therapy

During proton therapy, the beam flux decreases due to inelastic interactions with nuclei. At the highest energies used in proton therapy around 25\% protons initiate nuclear reactions. This report presents the cross section measurements of proton-induced production of three $β^+$ emitters -- $^{11}$C, $^{13}$N, $^{15}$O -- with half-lives between 2 and 20 minutes, using solid C, BN and SiO$_2$ targets. Stacks of up to 15 targets were irradiated simultaneously with proton beams of kinetic energy below 58 MeV at the AIC-144 cyclotron of the Institute of Nuclear Physics, Polish Academy of Sciences. The measured cross sections follow the excitation function obtained in the previous experiments, with uncertainty of a few percent.

nucl-ex↗

arXiv2025

Enhanced production of charged over neutral kaons in Ar+Sc collisions measured by NA61/SHINE at CERN SPS

The isospin symmetry, originating from similar masses of $u$ and $d$ quarks, if exact would result in equal numbers of charged ($K^+$ and $K^{-}$) and neutral ($K^0$ and $\overline{K}^0$) mesons produced in collisions of isospin-symmetric atomic nuclei. The charged and neutral $K$ meson production in Ar+Sc collisions at a center-of-mass energy of 11.9 GeV per nucleon pair was measured by the NA61/SHINE Collaboration. The production of charged $K$ mesons at mid-rapidity is (18.4$\pm$6.1)\% higher than that of the neutral $K$ mesons.The models of hadron production, including known isospin-symmetry breaking effects, cannot explain the measurements.

nucl-ex↗

arXiv2021

Radioactive nuclei for $β^+γ$ PET and theranostics: selected candidates

PET is an established medical diagnostic imaging method. Continuous improvements are aimed at refining image reconstruction, reducing the amount of radioactive tracer and combining with targeted therapy. TOF-PET provides the localization of the tracer through improved time resolution, nuclear physics may contribute to this goal via selection of radioactive nuclei emitting additional $γ$-rays. This additional radiation, when properly detected, localizes the decay of the tracer at the line of response determined by two detected 511 keV quanta. Selected candidates are presented. Some are particularly interesting, as they are strong candidates for theranostic applications.

physics.med-ph↗

arXiv2018

Measurement of proton-induced radiation in animal tissue

Hadron therapy, because of the dosimetric and radiobiological advantages, is more and more often used in tumour treatment. This treatment method leads also to the radioactive effects induced by energetic protons on nuclei. Nuclear reactions may lead to the production of radioactive isotopes. In the present experiment, two animal (human-like) tissue samples were irradiated with 60 MeV protons. Gamma-ray spectroscopy and lifetime measurements allowed identifying isotopes produced during the irradiation, e.g. $^{18}$F and $^{34m}$Cl.

physics.med-ph↗