W. H. Trzaska
A5091644253- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Nuclear physics research studies
- Nuclear Physics and Applications
- Neutrino Physics Research
- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Atomic and Molecular Physics
- Nuclear reactor physics and engineering
- Astronomical and nuclear sciences
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Quantum, superfluid, helium dynamics
- Advanced Chemical Physics Studies
- Particle accelerators and beam dynamics
- Radiation Therapy and Dosimetry
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced NMR Techniques and Applications
- Cold Fusion and Nuclear Reactions
- Superconducting Materials and Applications
- Astro and Planetary Science
- Radioactive Decay and Measurement Techniques
- Nuclear Materials and Properties
University of Jyväskylä
2016-2025
A. Alikhanyan National Laboratory
2015-2024
Helsinki Institute of Physics
2008-2024
University of Helsinki
2001-2024
Université Libre de Bruxelles
2022-2024
Pontifical Catholic University of Rio de Janeiro
2022-2024
Universidade Estadual de Londrina
2022-2024
Beijing Normal University
2022-2024
China Institute of Atomic Energy
2024
China Academy of Space Technology
2024
Reaction products from the system ${}^{136}\mathrm{Xe}+{}^{208}$Pb at ${}^{136}$Xe ions laboratory energies of 700, 870, and 1020 MeV were studied by two-body kinematics a catcher-foil activity analysis to explore theoretically proposed suitability such reaction as means produce neutron-rich nuclei in neutron shell closure $N=126$. Cross sections for heavier than ${}^{208}$Pb measured found sensibly larger new theoretical predictions. Transfers up 16 nucleons Xe Pb observed.
Abstract New developments in liquid scintillators, high-efficiency, fast photon detectors, and chromatic sorting have opened up the possibility for building a large-scale detector that can discriminate between Cherenkov scintillation signals. Such could reconstruct particle direction species using light while also having excellent energy resolution low threshold of scintillator detector. Situated deep underground, utilizing new techniques computing reconstruction, this achieve unprecedented...
This document reports on a series of experimental and theoretical studies conducted to assess the astro-particle physics potential three future large-scale particle detectors proposed in Europe as next generation underground observatories. The apparatus employ different and, some extent, complementary detection techniques: GLACIER (liquid Argon TPC), LENA scintillator) MEMPHYS (\WC), based use large mass liquids active media. results these are presented along with critical discussion...
Background: Suppression of compound nucleus formation in the reactions with heavy ions by a quasifission process dependence on reaction entrance channel.Purpose: Investigation fission and processes $^{36}\mathrm{S},^{48}\mathrm{Ca},^{48}\mathrm{Ti}$, $^{64}\mathrm{Ni}+\phantom{\rule{0.16em}{0ex}}^{238}\mathrm{U}$ at energies around Coulomb barrier.Methods: Mass-energy distributions fissionlike fragments formed $^{48}\mathrm{Ti}+\phantom{\rule{0.16em}{0ex}}^{238}\mathrm{U}$ 247, 258, 271 MeV...
An in-beam study of excited states in the transfermium nucleus 252No has been performed using recoil separator RITU together with JUROSPHERE II array at University Jyväskylä. This is second studied an experiment. Levels up to spin 20 were populated and compared levels 254No. upbend seen a frequency 200 keV/ħ corresponding 16. We also use improved systematics connect energy lowest 2+ state its half-life find that deformation both 252,254No slightly larger than previously assumed.Received July...
The 18O(p, α)15N reaction is of primary importance to pin down the uncertainties, due nuclear physics input, affecting present-day models asymptotic giant branch stars. Its rate can modify both fluorine nucleosynthesis inside such stars and oxygen nitrogen isotopic ratios, which allow one constrain proposed astrophysical scenarios. Thus, an indirect measurement low-energy region has been performed access, for first time, range relevance application. In particular, a full, high-accuracy...
This study is concerned with the search for entrance channels suitable to synthesize elements Z>118. Mass–energy distributions as well capture cross-sections of fission-like fragments have been measured reactions 64Ni + 238U → 302120 and 48Ca 286112 at energies near Coulomb barrier. Compound nucleus fission were estimated from analysis mass total kinetic energy distributions. The cross-section drops three orders magnitude formation compound Z=120 obtained in reaction compared Z=112 an...
Background: In heavy-ion-induced reactions the mechanism leading to formation of compound nucleus and role quasifission is still not clear.Purpose: Investigation process superheavy composite systems with $Z=110\text{\ensuremath{-}}116$ comparison properties fusion-fission lighter systems.Method: Mass energy distributions fissionlike fragments formed in $^{48}\mathrm{Ca}+^{232}\mathrm{Th}$, ${}^{238}\mathrm{U}$, ${}^{244}\mathrm{Pu}$, ${}^{248}\mathrm{Cm}$ at energies near Coulomb barrier...
This work is a study of the influence shell effects on formation binary fragments in damped collision. We have investigated reaction channels composite system with $Z=108$ produced $^{88}\mathrm{Sr}$${+}^{176}$Yb at an energy slightly above Bass barrier (${E}_{\text{c.m.}}/{E}_{\text{Bass}}=1.03$). Reaction products were detected by using two-arm time-of-flight spectrometer CORSET K130 cyclotron Department Physics, University Jyv\"askyl\"a. The mass-energy distribution primary has been...
A significant fraction of stars between 7 and 11 solar masses are thought to become supernovae, but the explosion mechanism is unclear. The answer depends critically on rate electron capture Ne20 in degenerate oxygen-neon stellar core. However, because unknown strength transition ground states F20, it has not previously been possible fully constrain rate. By measuring transition, we establish that its exceptionally large enhances by several orders magnitude. This a decisive impact evolution...
EOS is a technology demonstrator, designed to explore the capabilities of hybrid event detection technology, leveraging both Cherenkov and scintillation light simultaneously. With fiducial mass four tons, operate in high-precision regime, with sufficient size utilize time-of-flight information for full reconstruction, flexibility demonstrate range cutting edge technologies, simplicity design facilitate potential future deployment at alternative sites. Results from can inform neutrino...
For the first time, differential cross section of ${}^{16}\mathrm{O}{+}^{12}\mathrm{C}$ elastic scattering at ${E}_{\mathrm{lab}}=170,$ 200, 230, and 260 MeV has been measured over a wide angular range which covers both diffractive refractive regions. In addition, recent data 132 for this system have remeasured with much better statistics. A well developed rainbow structure observed, where up to three Airy minima could be identified in each distribution. The optical model analysis these was...
Low-lying low-spin collective states in even $^{106\mathrm{\ensuremath{-}}112}\mathrm{Cd}$ and $^{116}\mathrm{Cd}$ were investigated using in-beam off-beam \ensuremath{\gamma}-ray conversion-electron spectroscopy. New spin assignments decay branching ratios for the levels $^{106}\mathrm{Cd}$, $^{108}\mathrm{Cd}$, $^{110}\mathrm{Cd}$, $^{112}\mathrm{Cd}$ obtained. The present results essentially complement level systematics from $^{106}\mathrm{Cd}$ to $^{120}\mathrm{Cd}$. From new data, it is...
The $^{18}\mathrm{O}(p,\ensuremath{\alpha})^{15}\mathrm{N}$ reaction is of primary importance in several astrophysical scenarios, including fluorine nucleosynthesis inside asymptotic giant branch stars as well oxygen and nitrogen isotopic ratios meteorite grains. Thus the indirect measurement low energy region has been performed to reduce nuclear uncertainty on theoretical predictions. In particular strength 20 90 keV resonances deduced change rate evaluated.
Background: Observation of asymmetric fission $^{180}\mathrm{Hg}$ has led to intensive theoretical and experimental studies neutron-deficient nuclei in the lead region.Purpose: The study symmetric modes $^{180,190}\mathrm{Hg}$ $^{184,192,202}\mathrm{Pb}$ nuclei.Methods: Mass-energy distributions fragments $^{184}\mathrm{Pb}$ formed $^{36}\mathrm{Ar}+^{144,154}\mathrm{Sm}$ $^{40}\mathrm{Ca}+^{144}\mathrm{Sm}$ reactions, respectively, at energies near Coulomb barrier have been measured using...
Background: The nature of asymmetric fission preactinides is not yet understood in detail, despite intense experimental and theoretical studies carried out at present.Purpose: study symmetric $^{180,182,183}\mathrm{Hg}$ $^{178}\mathrm{Pt}$ nuclei as a function their excitation energy isospin.Methods: Mass-energy distributions fragments $^{180}\mathrm{Hg}, ^{178}\mathrm{Pt}$ (two protons less than $^{180}\mathrm{Hg}$), $^{182}\mathrm{Hg}$ neutrons more $^{180}\mathrm{Hg}$) formed the...
The ${}^{33}\mathrm{Na}$ \ensuremath{\beta} decay was studied online using mass separation techniques and a first description of the level structure neutron-rich isotope ${}^{33}\mathrm{Mg},$ with $N=21,$ has been obtained. experiment involved measurement \ensuremath{\beta}-\ensuremath{\gamma}, \ensuremath{\beta}-\ensuremath{\gamma}-\ensuremath{\gamma}, $\ensuremath{\beta}\ensuremath{-}n\ensuremath{-}\ensuremath{\gamma}$ coincidences as well neutron spectra by time-of-flight technique. low...
States in $^{154}\mathrm{Dy}$ have been located up to ${I}^{\ensuremath{\pi}}={48}^{+}$ and their lifetimes measured. Marked structural changes occur along the yrast line with a transition from prolate oblate shape, followed by an unexpected return moderate collectivity at highest spins. Structural increasing energy above are also observed.