M. Dahlfors
A5035849247- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Nuclear physics research studies
- Nuclear Materials and Properties
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Astro and Planetary Science
- Superconducting Materials and Applications
- Particle Detector Development and Performance
- Radiation Therapy and Dosimetry
- X-ray Spectroscopy and Fluorescence Analysis
- Particle Accelerators and Free-Electron Lasers
- Graphite, nuclear technology, radiation studies
- Advanced Frequency and Time Standards
- Gamma-ray bursts and supernovae
- Molten salt chemistry and electrochemical processes
- Dark Matter and Cosmic Phenomena
- Astronomical and nuclear sciences
- Radioactive element chemistry and processing
- Atomic and Molecular Physics
- Radioactive contamination and transfer
- Nanocluster Synthesis and Applications
- Seismic Waves and Analysis
- High-pressure geophysics and materials
- Trace Elements in Health
Bangor University
2021-2023
European Organization for Nuclear Research
2006-2016
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro
2004-2013
Istituto Nazionale di Fisica Nucleare
2010-2013
Centre de Gestion Scientifique
2009
Uppsala University
2002-2007
Swedish Nuclear Fuel and Waste Management (Sweden)
2007
CEA Paris-Saclay
2005-2007
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2005-2007
A high-resolution measurement of the neutron-induced fission cross section $^{234}\mathrm{U}$ and $^{237}\mathrm{Np}$ has been performed at CERN Neutron Time-of-Flight facility. The sections have determined in a wide energy range from 1 eV to GeV using evaluated $^{235}\mathrm{U}$ as reference. In these measurements determination for resonances could be improved, whereas previous discrepancies were confirmed. New cross-section data are provided high neutron energies that go beyond limits...
The cross section of the reaction $^{197}\mathrm{Au}$($n,\ensuremath{\gamma}$) was measured with time-of-flight technique at n_TOF (neutron time-of-flight) facility in unresolved resonance region between 5 and 400 keV using a pair ${\mathrm{C}}_{6}$D${}_{6}$ (where D denotes $^{2}\mathrm{H}$) liquid scintillators for detection prompt capture $\ensuremath{\gamma}$ rays. results total uncertainty $3.9%--6.7$$%$ resolution 20 bins per energy decade show fair agreement Evaluated Nuclear Data...
We have measured the neutron capture cross sections of stable magnesium isotopes ${}^{24,25,26}$Mg in energy range interest to $s$ process using time-of-flight facility n_TOF at CERN. Capture events from a natural metal sample and samples enriched ${}^{25}$Mg ${}^{26}$Mg were recorded total method based on C${}_{6}$${}^{2}$H${}_{6}$ detectors. Neutron resonance parameters extracted by simultaneous shape analysis present data existing transmission isotopic sample. Maxwellian-averaged for...
The ($n,\ensuremath{\gamma}$) cross section of $^{197}\mathrm{Au}$ has been measured at n_TOF in the resolved resonance region, up to 5 keV, with aim improving accuracy an energy range where it is not yet considered standard. measurements were performed two different experimental setup and detection techniques, total method based on ${\mathrm{C}}_{6}$${\mathrm{D}}_{6}$ detectors, absorption calorimetry a 4$\ensuremath{\pi}$ BaF${}_{2}$ array. By comparing data collected accurate sets...
The151Sm(n,gamma)152Sm cross section has been measured at the spallation neutron facility n_TOF CERN in energy range from 1 eV to MeV. The new combines excellent resolution time-of-flight, low repetition rates, and an unsurpassed instantaneous luminosity, resulting rather favorable signal/background ratios. 151Sm is of importance for characterizing capture nucleosynthesis asymptotic giant branch stars. At a thermal kT=30 keV Maxwellian averaged this unstable isotope (t(1/2)=93 yr) was...
The neutron capture cross sections of the Zr isotopes have important implications in nuclear astrophysics and for reactor design. small section magic nucleus $^{90}\mathrm{Zr}$, which accounts more than 50% natural zirconium represents one key stellar $s$-process, because it acts as a bottleneck chain between Fe seed heavier isotopes. same element, Zr, also is an component structural materials used traditional advanced reactors. ($n,\ensuremath{\gamma}$) has been measured at CERN, using...
The ($n,\ensuremath{\gamma}$) reaction of the radioactive isotope ${}^{93}$Zr has been measured at n_TOF high-resolution time-of-flight facility CERN. Resonance parameters have extracted in neutron energy range up to 8 keV, yielding capture widths smaller (14$%$) than reported an earlier experiment. These results are important for detailed nucleosynthesis calculations and refined studies waste transmutation concepts.
The neutron capture cross section of $^{209}\mathrm{Bi}$ has been measured at the CERN n_TOF facility by employing pulse-height-weighting technique. Improvements over previous measurements are mainly because an optimized detection system, which led to a practically negligible sensitivity. Additional experimental sources systematic error, such as electronic threshold in detectors, summing \ensuremath{\gamma}-rays, internal electron conversion, and isomeric state bismuth, have taken into...
Neutron resonance analyses have been performed for the capture cross sections of $^{186}\mathrm{Os}$, $^{187}\mathrm{Os}$, and $^{188}\mathrm{Os}$ measured at n_TOF facility cern. Resonance parameters extracted up to 5, 3, 8 keV, respectively, using sammy code a full $R$-matrix fit yields. From these results average were derived by statistical analysis provide comprehensive experimental basis modeling stellar neutron rates isotopes in terms Hauser-Feshbach model. Consistent calculations...
Because the relatively small neutron capture cross sections of zirconium isotopes are difficult to measure, results previous measurements often not adequate for a number problems in astrophysics and nuclear technology. Therefore, $^{92}\mathrm{Zr}$($n,\ensuremath{\gamma}$) section has been remeasured at CERN n_TOF facility, providing set improved parameters 44 resonances energy range up 40 keV. With this information cross-section uncertainties keV region could be reduced $5%$ as required...
Neutron-induced fission cross sections for ${}^{\text{nat}}$Pb and $^{209}\mathrm{Bi}$ were measured with a white-spectrum neutron source at the CERN Neutron Time-of-Flight (n_TOF) facility. The experiment, using neutrons from threshold up to 1 GeV, provides first results these nuclei above 200 MeV. relative $^{235}\mathrm{U}$ $^{238}\mathrm{U}$ in dedicated chamber parallel plate avalanche counter detectors. Results are compared previous experimental data. Upgraded parametrizations of...
Background:The design of new nuclear reactors and transmutation devices requires to reduce the present neutron cross section uncertainties minor actinides. Purpose: Reduce $^{243}$Am(n,$\gamma$) uncertainty. Method: The has been measured at n_TOF facility CERN with a BaF$_{2}$ Total Absorption Calorimeter, in energy range between 0.7 eV 2.5 keV. Results: successfully mentioned range. resolved resonance region extended from 250 up 400 eV. In unresolved our results are compatible one two...
We have measured the neutron capture reaction yield of $^{232}\mathrm{Th}$ at time-of-flight facility n_TOF CERN in energy range from 1 eV to MeV. The average cross section has been extracted 4 keV up MeV with an overall accuracy better than 4%. An independent IAEA evaluation shows good agreement data. expressed terms resonance parameters using partial waves $\ensuremath{\ell}=0,1,$ and 2.
The $^{151}\mathrm{Sm}$($n,\ensuremath{\gamma})$ cross section was measured with the time-of-flight technique from 0.6 eV up to 1 MeV relative Au standard an overall uncertainty of typically 6%. Neutrons were produced by spallation at innovative n_TOF facility CERN; $\ensuremath{\gamma}$ rays capture events detected organic ${\text{C}}_{6}{D}_{6}$ scintillators. Experimental setup and data analysis procedures are described emphasis on corrections for detection efficiency, background...
The radiative neutron capture cross section of 207Pb has been measured at the CERN time flight installation n_TOF using pulse height weighting technique in resolved energy region. measurement performed with an optimized setup two C6D6 scintillation detectors, which allowed us to reduce scattered backgrounds down a negligible level. Resonance parameters and kernels have determined for 16 resonances by means R-matrix analysis range from 3 keV 320 keV. Good agreement previous measurements was...
The neutron capture cross section of 204Pb has been measured at the CERN n_TOF installation with high resolution in energy range from 1 eV to 440 keV. An R-matrix analysis resolved resonance region, between and 100 keV, was carried out using SAMMY code. In interval keV we report average section. background entire could be reliably determined measurement a 208Pb sample. Other systematic effects this investigated precisely corrected by means detailed Monte Carlo simulations. We obtain...
The neutron capture cross sections of the Zr isotopes are relevant to studies in nuclear structure, astrophysics, and technology. valence $^{91}\mathrm{Zr}$ with respect magic nucleus $^{90}\mathrm{Zr}$ has interesting implications for statistical analysis proximity shell closures. In stellar nucleosynthesis, important $s$-process reaction flow between Fe seeds heavier isotopes. Because its relatively small ($n,\ensuremath{\gamma}$) sections, represents also an structural material reactors....
The (n, gamma) cross section of 206Pb has been measured at the CERN n_TOF facility with high resolution in energy range from 1 eV to 600 keV by using two optimized C6D6 detectors. In investigated interval about 130 resonances could be observed, which 61 had enough statistics reliably analyzed via R-matrix analysis code SAMMY. Experimental uncertainties were minimized, particular respect (i) angular distribution effects prompt capture gamma-rays, and (ii) TOF-dependent background due...
The precise determination of the neutron capture cross sections $^{186}\mathrm{Os}$ and $^{187}\mathrm{Os}$ is important to define $s$-process abundance at formation solar system. This quantity can be used evaluate radiogenic component due decay unstable $^{187}\mathrm{Re}$ (${t}_{1/2}=41.2$ Gyr) from this infer time duration nucleosynthesis in our galaxy (Re/Os cosmochronometer). $^{186}\mathrm{Os}$, $^{187}\mathrm{Os}$, $^{188}\mathrm{Os}$ have been measured CERN n_TOF facility 1 eV MeV,...