The full energy peak efficiencies and covariances of a high purity germanium (HPGe) detector studied by the regression method and Monte Carlo method were compared. The impact of the obtained results ...on the neutron activation cross-sections measured relative to monitor cross-sections was studied. In the regression method, the efficiencies measured for a set of calibration point sources were analysed by the least-squares analysis. In the Monte Carlo method, the efficiencies for the calibration point sources were calculated by MCNP. The covariances of the efficiencies determined by the regression method were calculated analytically. Perturbation analysis was performed to estimate the covariances of the efficiencies calculated by the Monte Carlo method. Positive correlations higher than 0.8 were found in the uncertainties of the MCNP data for point-like sources. In the case of the regression method, the correlation coefficient contains both positive and negative terms. The efficiencies and their covariances for finite sample geometry were also estimated by both methods to take into account sample effects such as geometrical effect, and gamma-ray self-absorption, and found considerable differences in the cross-sections and their uncertainties for reaction products quantified with low energy gammas. The efficiencies and covariances were clearly affected by the properties of the sample.
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We studied the role of the recently identified CALR mutations in 141 patients with Budd-Chiari Syndrome (BCS) or portal vein thrombosis (PVT) in a large multinational cohort. A CALR ...mutation was present in one of the 141 patients (0.7%). This patient was previously diagnosed with primary myelofibrosis. This results in CALR positivity in one out of 44 (2.3%) patients with myeloproliferative neoplasm (MPN), and in one of 11 (9.1%) JAK2V617F negative patients diagnosed with MPN. We suggest that analysis of CALR mutations should be performed in JAK2V617F negative BCS and PVT patients...
Activation method was employed to measure the cross section for the 58Ni(n,pα)54Mn and 63Cu(n,pα)59Fe reactions in the energy range from the threshold up to 21 MeV. The quasi-monoenergetic neutrons ...in the energy range from 14 to 21 MeV were produced via the 3H(d,n)4He reaction at 1, 2, 3 and 4 MeV incident deuteron energies. High purity Ni and Cu samples with natural isotopic composition and dimensions of ϕ12x5 mm and ϕ20x5 mm respectively were utilized. The gamma-ray spectrometry using HPGe detector was utilized to measure the activity induced in the sample. The cross sections were determined relative to the standard cross section the 27Al(n,α)24Na reaction. The results for the 63Cu(n,pα)59Fe reaction cross section were obtained for the first time.
ARIEL & SANDA nuclear data activities Franzen, Carola; Junghans, Arnd R.; Gonzalez, Enrique M. ...
EPJ Nuclear sciences & technologies,
2022, Letnik:
8
Journal Article
Recenzirano
Odprti dostop
Nuclear data are fundamental quantities for developing nuclear energy concepts and research. They are essential for the simulation of nuclear systems, safety and performance calculations, and reactor ...instrumentation. Nuclear data improvement requires a combination of many different know-hows that are distributed over many institutions along Europe. In the EURATOM call for Nuclear Fission and Radiation Protection NFRP-2018, two nuclear data projects were started in September 2019: the Coordination and Support Action ARIEL (Accelerator and Research reactor Infrastructures for Education and Learning) and the Research and Innovation Action SANDA (Solving Challenges in Nuclear Data for the Safety of European Nuclear facilities). The ARIEL project integrates education and training of young scientists and technicians with access to neutron beam research infrastructures and supports scientific visits to conduct short-term research projects relevant to thesis works. The SANDA project is focuses on research innovation actions, including detector and nuclear target development, important nuclear data measurements, nuclear data evaluation, and validation. A description of these ongoing projects, including the first results, is the subject of this article.
A comprehensive set of Monte Carlo simulations was performed with the MCNP5 code to provide a generic characterisation of the neutron and photon fluxes for time-of-flight measurements at all flight ...paths of the GELINA facility. Simulations were performed for the direct flux configuration (DFC, 10
keV–20
MeV) and the moderated flux configuration (MFC, 10
meV–1
MeV). Fluxes and flux energy spectra were obtained for both neutrons and photons. For neutrons, additionally, detailed resolution functions and figures of merit were obtained. The validity of the approach for the photon spectra is shown by comparison with a dedicated measurement. Also, a verification is presented of the validity of the neutron resolution function by comparison with measured capture and transmission data for
103Rh and
56Fe in the incident neutron energy range from 70
eV to 50
keV. This comprehensive overview will facilitate the planning and analysis of measurements at the GELINA facility with an improved knowledge of its physical characteristics.
A single crystal diamond detector was exposed to quasi mono-energetic neutron fields in the energy range from 5 to 20.5
MeV. Response functions of such a detector were measured for the first time for ...neutron energies above 14
MeV. The pulse height spectra showed sharp peaks at specific energies. These peaks result from neutron induced charged particle reactions occurring in carbon at different neutron energies. The centroid of the peaks due to the
12C(n,α)
9Be reaction permitted, by means of the reaction
Q-values, to point out a good linearity of the detector response versus neutron energy and a good intrinsic energy resolution of about 56
keV at full width at half maximum. The results reveal that single crystal diamond detectors are good candidates as high resolution fast neutron spectrometers for nuclear fusion applications and for systematic studies of beam and target characteristics for neutron-producing reactions.
Uncertainty propagation to the
γ
-
γ
coincidence-summing correction factor from the covariances of the nuclear data and detection efficiencies have been formulated. The method was applied in the ...uncertainty analysis of the coincidence-summing correction factors in the
γ
-ray spectrometry of the
134
Cs point source using a p-type coaxial HPGe detector.
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