Neutron capture cross section measurements of 238U, 241Am and 243Am at n_TOF

Proposal: Neutron capture cross section measurements of 238U, 241Am and 243Am at n_TOFThe increase of the world energy demand and the need of low carbon energy sources have triggered the renaissance and/or enhancement of nuclear energy in many countries. Fundamental nuclear physics can contribute in a practical way to the sustainability and safety of the nuclear energy production and the management of the nuclear waste. There exists a series of recent studies which address the most relevant isotopes, decay data, nuclear reaction channels and energy ranges which have to be investigated in more detail for improving the design of different advanced nuclear systems [1] and nuclear fuel cycles [2]. In this proposal, we aim at the measurement of the neutron capture cross sections of 238U, 241Am and 243Am. All three isotopes are listed in the NEA High Priority Request List [37], are recommended for measurements [1] and play an important role in the nuclear energy production and fuel cycle scenarios. The measurements will provide as well valuable nuclear structure data necessary for the improvement of nuclear models and the statistical interpretation of the nuclear propertiesPostprint (author's final draft

Men’s and women’s migration in coastal Ghana

This article uses life history calendar (LHC) data from coastal Ghana and event history statistical methods to examine inter-regional migration for men and women, focusing on four specific migration types: rural-urban, rural-rural, urban-urban, and urban-rural. Our analysis is unique because it examines how key determinants of migration—including education, employment, marital status, and childbearing—differ by sex for these four types of migration. We find that women are significantly less mobile than men overall, but that more educated women are more likely to move (particularly to urban areas) than their male counterparts. Moreover, employment in the prior year is less of a deterrent to migration among women. While childbearing has a negative effect on migration, this impact is surprisingly stronger for men than for women, perhaps because women’s search for assistance in childcare promotes migration. Meanwhile, being married or in union appears to have little effect on migration probabilities for either men or women. These results demonstrate the benefits of a LHC approach and suggest that migration research should further examine men’s and women’s mobility as it relates to both human capital and household and family dynamics, particularly in developing settings.event history analysis, Ghana, life history, migration, Sub-Saharan Africa, urbanization

Electrodynamics of the vortex lattice in untwinned YBaCuO by complex impedance measurements

We report complex impedance measurements in an untwinned YBaCuO crystal. Our broad frequency range covers both the quasi static response and the resistive response of the vortex lattice. It allow us to characterize the irreversibility line without the need of any frequency dependent pinning parameters. We confirm the validity of the two modes model of vortex dynamic, and extract both the surface critical current and the flux flow resistivity around the first order transition $T_{m}$. This latter is identified by the abrupt loss of pinning and by an unexpected step of $\rho_{ff}(T)$ at $T_{m}$.Comment: accepted for publication in EPJ

The neutron time-of-flight facility n-TOF at CERN: Phase II

Neutron-induced reactions are studied at the neutron time-of-flight facility n-TOF at CERN. The facility uses 6∼ns wide pulses of 20 GeV/c protons impinging on a lead spallation target. The large neutron energy range and the high instantaneous neutron flux combined with high resolution are among the key characteristics of the facility. After a first phase of data taking during the period 2001-2004, the facility has been refurbished with an upgraded spallation target and cooling system for a second phase of data taking which started in 2009. Since 2010, the experimental area at 185 m where the neutron beam arrives, has been modified into a worksector of type A, allowing the extension of the physics program to include neutron-induced reactions on radioactive isotopes

Adequacy of Maternal Iron Status Protects against Behavioral, Neuroanatomical, and Growth Deficits in Fetal Alcohol Spectrum Disorders

Fetal alcohol spectrum disorders (FASD) are the leading non-genetic cause of neurodevelopmental disability in children. Although alcohol is clearly teratogenic, environmental factors such as gravidity and socioeconomic status significantly modify individual FASD risk despite equivalent alcohol intake. An explanation for this variability could inform FASD prevention. Here we show that the most common nutritional deficiency of pregnancy, iron deficiency without anemia (ID), is a potent and synergistic modifier of FASD risk. Using an established rat model of third trimester-equivalent binge drinking, we show that ID significantly interacts with alcohol to impair postnatal somatic growth, associative learning, and white matter formation, as compared with either insult separately. For the associative learning and myelination deficits, the ID-alcohol interaction was synergistic and the deficits persisted even after the offsprings’ iron status had normalized. Importantly, the observed deficits in the ID-alcohol animals comprise key diagnostic criteria of FASD. Other neurobehaviors were normal, showing the ID-alcohol interaction was selective and did not reflect a generalized malnutrition. Importantly ID worsened FASD outcome even though the mothers lacked overt anemia; thus diagnostics that emphasize hematological markers will not identify pregnancies at-risk. This is the first direct demonstration that, as suggested by clinical studies, maternal iron status has a unique influence upon FASD outcome. While alcohol is unquestionably teratogenic, this ID-alcohol interaction likely represents a significant portion of FASD diagnoses because ID is more common in alcohol-abusing pregnancies than generally appreciated. Iron status may also underlie the associations between FASD and parity or socioeconomic status. We propose that increased attention to normalizing maternal iron status will substantially improve FASD outcome, even if maternal alcohol abuse continues. These findings offer novel insights into how alcohol damages the developing brain

Quantum noise and mixedness of a pumped dissipative non-linear oscillator

Evolutions of quantum noise, characterized by quadrature squeezing parameter and Fano factor, and of mixedness, quantified by quantum von Neumann and linear entropies, of a pumped dissipative non-linear oscillator are studied. The model can describe a signal mode interacting with a thermal reservoir in a parametrically pumped cavity with a Kerr non-linearity. It is discussed that the initial pure states, including coherent states, Fock states, and finite superpositions of coherent states evolve into the same steady mixed state as verified by the quantum relative entropy and the Bures metric. It is shown analytically and verified numerically that the steady state can be well approximated by a nonclassical Gaussian state exhibiting quadrature squeezing and sub-Poissonian statistics for the cold thermal reservoir. A rapid increase is found in the mixedness, especially for the initial Fock states and superpositions of coherent states, during a very short time interval, and then for longer evolution times a decrease in the mixedness to the same, for all the initial states, and relatively low value of the nonclassical Gaussian state.Comment: 10 pages, 12 figure

Measurement of the 70Ge(n,γ) cross section up to 300 keV at the CERN n_TOF facility

Neutron capture data on intermediate mass nuclei are of key importance to nucleosynthesis in the weak component of the slow neutron capture processes, which occurs in massive stars. The (n,γ) cross section on 70Ge, which is mainly produced in the s process, was measured at the neutron time-of-flight facility n_TOF at CERN. Resonance capture kernels were determined up to 40 keV neutron energy and average cross sections up to 300 keV. Stellar cross sections were calculated from kT =5 keV tokT =100 keV and are in very good agreement with a previous measurement by Walter and Beer (1985) and recent evaluations. Average cross sectionsareinagreementwithWalterandBeer(1985)overmostoftheneutronenergyrangecovered,whilethey aresystematicallysmallerforneutronenergiesabove150keV.Wehavecalculatedisotopicabundancesproduced in s-process environments in a 25 solar mass star for two initial metallicities (below solar and close to solar). While the low metallicity model reproduces best the solar system germanium isotopic abundances, the close to solar model shows a good global match to solar system abundances in the range of mass numbers A=60–80.Austrian Science Fund J3503Adolf Messer Foundation ST/M006085/1European Research Council ERC2015-StGCroatian Science Foundation IP-2018-01-857

Fm receiver, re test console, appendix i final report

Input bandpass filter, limiter, conventional and phase lock FM detector, output low pass filter, and offset frequency for FM receive