R. Dressler
A5021147135- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Nuclear physics research studies
- Radiation Detection and Scintillator Technologies
- Nuclear Materials and Properties
- Radioactive element chemistry and processing
- Particle physics theoretical and experimental studies
- Radiation Therapy and Dosimetry
- Astronomical and nuclear sciences
- Atomic and Subatomic Physics Research
- Astro and Planetary Science
- Atomic and Molecular Physics
- Particle Detector Development and Performance
- Quantum Chromodynamics and Particle Interactions
- Radiopharmaceutical Chemistry and Applications
- Advanced Chemical Physics Studies
- Chemical Thermodynamics and Molecular Structure
- Fusion materials and technologies
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Chemical Synthesis and Characterization
- Radioactive Decay and Measurement Techniques
- Radioactive contamination and transfer
- X-ray Spectroscopy and Fluorescence Analysis
- Ion-surface interactions and analysis
Paul Scherrer Institute
2015-2024
University of Pavia
2024
Istituto Nazionale di Fisica Nucleare, Sezione di Pavia
2024
Istituto Nazionale di Fisica Nucleare, Sezione di Bari
2019-2023
Dalhousie University
2022
Japan Atomic Energy Agency
2021
Advanced Science Research Center
2021
Ibaraki University
2021
Niigata University
2021
University of Tsukuba
2021
The neutron time-of-flight facility n_TOF features a white source produced by spallation through 20GeV/c protons impinging on lead target. facility, aiming primarily at the measurement of neutron-induced reaction cross sections, was operating CERN between 2001 and 2004, then underwent major upgrade in 2008. This paper presents detail all characteristics new beam currently available configurations, which correspond to two different collimation systems choices moderator. discussed include...
We have analyzed data of the DISTO experiment on exclusive pp -> p Lambda K+ reaction at 2.85 GeV to search for a strongly bound compact K-pp (= X) state be formed in + X reaction. The observed spectra missing-mass and invariant-mass with high transverse momenta revealed broad distinct peak mass M_X = 2265 +- 2 (stat) 5 (syst) MeV/c2 width Gamma_X 118 8 10 MeV.
Theoretical calculations predict 270Hs (Z=108, N=162) to be a doubly magic deformed nucleus, decaying mainly by alpha-particle emission. In this work, based on rapid chemical isolation of Hs isotopes produced in the 26Mg+248Cm reaction, we observed 15 genetically linked nuclear decay chains. Four chains were attributed new nuclide 270Hs, which decays emission with Qalpha=9.02+/-0.03 MeV 266Sg undergoes spontaneous fission half-life 444(-148)(+444) ms. A production cross section about 3 pb...
Recently, the chemical investigation of element 112 revealed a highly volatile, noble metallic behaviour, as expected for last group 12 member periodic table. The observed volatility and inertness were ascribed to growing influence relativistic effects on properties heaviest elements with increasing nuclear charge. Here, we report first time gas phase experiments aiming at determination 114 properties. This was investigated using its isotopes 287114 288114 produced in fusion reactions 48Ca...
The energy-dependent cross section of the ^{7}Be(n,α)^{4}He reaction, interest for so-called cosmological lithium problem in big bang nucleosynthesis, has been measured first time from 10 meV to keV neutron energy. challenges posed by short half-life ^{7}Be and low reaction have overcome at n_TOF thanks an unprecedented combination extremely high luminosity good resolution beam new experimental area (EAR2) facility CERN, availability a sufficient amount chemically pure ^{7}Be, specifically...
At the neutron time-of-flight facility n_TOF at CERN a new vertical beam line was constructed in 2014, order to extend experimental possibilities this an even wider range of challenging cross-section measurements interest astrophysics, nuclear technology and medical physics. The design hall based on FLUKA Monte Carlo simulations, aiming maximizing flux, reducing halo minimizing background from neutrons interacting with collimator or back-scattered dump. present paper gives overview relevant...
Every atom counts: New data for the adsorption chromatographic behavior of single atoms element 112 confirm a metallic character involved in their interaction with gold surface, similar to lighter homologues Zn, Cd, and Hg. The elemental volatility is much higher than that Group 12 periodic table, as empirically deduced from experimental results.
Radiotheragnostics makes use of the same molecular targeting vectors, labeled either with a diagnostic or therapeutic radionuclide, ideally chemical element. The matched pair scandium radionuclides, 44Sc and 47Sc, satisfies desired physical aspects for PET imaging radionuclide therapy, respectively. While production application was extensively studied, 47Sc is still in its infancy. aim present study was, therefore, to investigate compare two different methods production, based on neutron...
In order to resolve a recent discrepancy in the half-life of 60Fe, we performed an independent measurement with new method that determines 60Fe content material relative 55Fe (t1/2=2.744 yr) accelerator mass spectrometry. Our result (2.50±0.12)×10(6) yr clearly favors recently reported value (2.62±0.04)×10(6) yr, and rules out older (1.49±0.27)×10(6) yr. The present weighted mean (2.60±0.05)×10(6) substantially improves reliability as important chronometer for astrophysical applications...
The exclusive production cross sections for ω and φ mesons have been measured in proton-proton reactions at plab=3.67 GeV/c. observed φ/ω section ratio is (3.8±0.2−0.9+1.2)×10−3. After phase space corrections, this enhanced by about an order of magnitude relative to naive predictions based upon the Okubo-Zweig-Iizuka (OZI) rule, comparison enhancement a factor ∼3 previously higher beam momenta. modest increase near threshold compared much larger specific channels p¯p annihilation...
Abstract. Ambient concentrations of trace elements with 2 h time resolution were measured in PM10–2.5, PM2.5–1.0 and PM1.0–0.3 size ranges at kerbside, urban background rural sites London during winter 2012. Samples collected using rotating drum impactors (RDIs) subsequently analysed synchrotron radiation-induced X-ray fluorescence spectrometry (SR-XRF). Quantification kerb increments (defined as kerb-to-urban urban-to-rural concentration ratios, respectively), assessment diurnal weekly...
This work examined the impact of depth discharge (DOD), C-rate, upper cut-off voltage (UCV), and temperature on lifetime single-crystal NMC811/Artificial Graphite (AG) cells. Cells were cycled at C/50, C/10, C/5, or C/3, 25, 50, 75, 100% DOD room (RT, 20 ± 2 °C) 40.0 0.1 °C. The UCVs 4.06 4.20 V. After 12000 hr cycling, experiments such as electrochemical impedance spectroscopy (EIS), Li-ion differential thermal analysis (DTA), ultrasonic mapping, X-ray fluorescence (XRF), capacity analysis,...
The $^{63}$Ni($n, \gamma$) cross section has been measured for the first time at neutron time-of-flight facility n\_TOF CERN from thermal energies up to 200 keV. In total, capture kernels of 12 (new) resonances were determined. Maxwellian Averaged Cross Sections calculated kT = 5 keV 100 with uncertainties around 20%. Stellar model calculations a 25 M$_\odot$ star show that new data have significant effect on $s$-process production $^{63}$Cu, $^{64}$Ni, and $^{64}$Zn in massive stars,...
Abstract This article presents a few selected developments and future ideas related to the measurement of $$(n,\gamma )$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>n</mml:mi> <mml:mo>,</mml:mo> <mml:mi>γ</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> data astrophysical interest at CERN n_TOF. The MC-aided analysis methodology for use low-efficiency radiation detectors in time-of-flight neutron-capture measurements is discussed, with...
^{140}Ce(n,γ) is a key reaction for slow neutron-capture (s-process) nucleosynthesis due to being bottleneck in the flow. For this reason, it was measured with high accuracy (uncertainty ≈5%) at n_TOF facility, an unprecedented combination of purity sample and low neutron-sensitivity detectors. The Maxwellian averaged cross section up 40% higher than previously accepted values. Stellar model calculations indicate reduction around 20% s-process contribution Galactic cerium abundance smaller...
The presently known most neutron-rich isotopes of element 106 (seaborgium, Sg), ${}^{265}$Sg and ${}^{266}$Sg, were produced in the fusion reaction ${}^{22}$Ne+${}^{248}$Cm at beam energies 121 123 MeV. Using On-Line Gas chemistry Apparatus OLGA, a continuous separation Sg was achieved within few seconds. Final products assayed by $\ensuremath{\alpha}$-particle spontaneous fission (SF) spectrometry. ${}^{266}$Sg identified observing time correlated...
Abstract In preparation for the experimental investigation of chemical properties element 112 model studies were conducted based on assumed similarity to either noble gas Rn or transition metal Hg, its supposed lighter homologue in group 12. The adsorption behavior elemental Hg metals Ag, Au, Ni, Pd, and Pt investigated experimentally by off-line thermochromatography. deduced data compared with new values calculated using Eichler–Miedema model. observed sequence increasing...
This work reports on accurate, high-resolution measurements of the $^{25}$Mg($n, \gamma$)$^{26}$Mg and tot$) cross sections in neutron energy range from thermal to about 300 keV, leading a significantly improved parametrization. The relevant resonances for $n+^{25}$Mg were characterized combined R-matrix analysis experimental data. resulted an unambiguous spin/parity assignment corresponding excited states $^{26}$Mg. With this information upper limits reaction rates $^{22}$Ne($\alpha,...