First results of the140ce(N,ү)141ce cross-section measurement at n_tof

An accurate measurement of the140Ce(n,ү) energy-dependent cross-section was performed at the n_TOF facility at CERN. This cross-section is of great importance because it represents a bottleneck for the s-process nucleosynthesis and determines to a large extent the cerium abundance in stars. The measurement was motivated by the significant difference between the cerium abundance measured in globular clusters and the value predicted by theoretical stellar models. This discrepancy can be ascribed to an overestimation of the140Ce capture cross-section due to a lack of accurate nuclear data. For this measurement, we used a sample of cerium oxide enriched in140Ce to 99.4%. The experimental apparatus consisted of four deuterated benzene liquid scintillator detectors, which allowed us to overcome the difficulties present in the previous measurements, thanks to their very low neutron sensitivity. The accurate analysis of the p-wave resonances and the calculation of their average parameters are fundamental to improve the evaluation of the140Ce Maxwellian-averaged cross-section. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Measurement of the 77Se(n,¿) cross section up to 200 keV at the n_TOF facility at CERN

The 77Se(n,¿) reaction is of importance for 77Se abundance during the slow neutron capture process in massive stars. We have performed a new measurement of the 77Se radiative neutron capture cross section at the Neutron Time-of-Flight facility at CERN. Resonance capture kernels were derived up to 51 keV and cross sections up to 200 keV. Maxwellian-averaged cross sections were calculated for stellar temperatures between kT=5keV and kT=100keV, with uncertainties between 4.2% and 5.7%. Our results lead to substantial decreases of 14% and 19% in 77Se abundances produced through the slow neutron capture process in selected stellar models of 15M¿ and 2M¿, respectively, compared to using previous recommendation of the cross section.This work was supported by the UK Science and Facilities Council (ST/M006085/1), the MSMT of the Czech Republic, the Charles University UNCE/SCI/013 project, the European Research Council ERC-2015-StG No. 677497, and by the funding agencies of the participating institutes. In line with the principles that apply to scientific publishing and the CERN policy in matters of scientific publications, the n_TOF Col- laboration recognizes the work of Y. Kopatch and V. Furman (JINR, Russia), who have contributed to the experiment used to obtain the results described in this paper.Article signat per 131 autors/es: N. V. Sosnin , C. Lederer-Woods, M. Krtiˇcka, R. Garg, M. Dietz, M. Bacak, M. Barbagallo, U. Battino, S. Cristallo, L. A. Damone, M. Diakaki, S. Heinitz, D. Macina, M. Mastromarco, F. Mingrone, A. St. J. Murphy, G. Tagliente, S. Valenta, D. Vescovi, O. Aberle, V. Alcayne, S. Amaducci, J. Andrzejewski, L. Audouin, V. Bécares, V. Babiano-Suarez, F. Beˇcváˇr, G. Bellia, E. Berthoumieux, J. Billowes, D. Bosnar, A. Brown, M. Busso, M. Caamaño, L. Caballero, F. Calviño, M. Calviani, D. Cano-Ott, A. Casanovas, F. Cerutti, Y. H. Chen, E. Chiaveri, N. Colonna, G. Cortés, M. A. Cortés-Giraldo, L. Cosentino, C. Domingo-Pardo, R. Dressler, E. Dupont, I. Durán, Z. Eleme, B. Fernández-Domínguez, A. Ferrari, P. Finocchiaro, K. Göbel, A. Gawlik-Rami˛ega, S. Gilardoni, T. Glodariu, I. F. Gonçalves, E. González-Romero, C. Guerrero, F. Gunsing, H. Harada, J. Heyse, D. G. Jenkins, E. Jericha, F. Käppeler, Y. Kadi, A. Kimura, N. Kivel, M. Kokkoris, D. Kurtulgil, I. Ladarescu, H. Leeb, J. Lerendegui-Marco, S. Lo Meo, S. J. Lonsdale, A. Manna, T. Martínez, A. Masi, C. Massimi, P. Mastinu, F. Matteucci, E. A. Maugeri, A. Mazzone, E. Mendoza, A. Mengoni, V. Michalopoulou, P. M. Milazzo, A. Musumarra, A. Negret, R. Nolte, F. Ogállar, A. Oprea, N. Patronis, A. Pavlik, J. Perkowski, L. Piersanti, I. Porras, J. Praena, J. M. Quesada, D. Radeck, D. Ramos-Doval, T. Rauscher, R. Reifarth, D. Rochman, C. Rubbia, M. Sabaté-Gilarte, A. Saxena, P. Schillebeeckx, D. Schumann, A. G. Smith, A. Stamatopoulos, J. L. Tain, T. Talip, A. Tarifeño-Saldivia, L. Tassan-Got, P. Torres-Sánchez, A. Tsinganis, J. Ulrich, S. Urlass, G. Vannini, V. Variale, P. Vaz, A. Ventura, V. Vlachoudis, R. Vlastou, A. Wallner, P. J. Woods,T. Wright, and P. Žugec.Postprint (published version

Is it really advantageous to operate proximal femoral fractures within 48 h from diagnosis? – A multicentric retrospective study exploiting COVID pandemic-related delays in time to surgery

Objectives: Hip fractures in the elderly are common injuries that need timely surgical management. Since the beginning of the pandemic, patients with a proximal femoral fracture (PFF) experienced a delay in time to surgery. The primary aim of this study was to evaluate a possible variation in mortality in patients with PFF when comparing COVID-19 negative versus positive. Methods: This is a multicentric and retrospective study including 3232 patients with PFF who underwent surgical management. The variables taken into account were age, gender, the time elapsed between arrival at the emergency room and intervention, pre-operative American Society of Anesthesiology score, pre-operative cardiovascular and respiratory disease, and 10-day/1-month/6-month mortality. For 2020, we had an additional column, “COVID-19 swab positivity.” Results: COVID-19 infection represents an independent mortality risk factor in patients with PFFs. Despite the delay in time-to-surgery occurring in 2020, no statistically significant variation in terms of mortality was detected. Within our sample, a statistically significant difference was not detected in terms of mortality at 6 months, in patients operated within and beyond 48 h, as well as no difference between those operated within or after 12/24/72 h. The mortality rate among subjects with PFF who tested positive for COVID-19 was statistically significantly higher than in patients with PFF who tested. COVID-19 positivity resulted in an independent factor for mortality after PFF. Conclusion: Despite the most recent literature recommending operating PFF patients as soon as possible, no significant difference in mortality was found among patients operated before or after 48 h from diagnosis

The nature of the photometric variability of HgMn stars:a test of simulated light curves of phi Phe against the TESS data

The inhomogeneous surface distribution of heavy elements is known to cause periodic light variability of magnetic chemically peculiar stars. It is unclear to what extent the same paradigm applies to mercury-manganese (HgMn) stars. We aim to model the photometric variability of the HgMn star {\phi}Phe using abundance maps obtained from high-resolution spectroscopy and to study how this variability evolves with time. We compute a grid of ATLAS12 model atmospheres and the corresponding SYNSPEC synthetic spectra. Interpolating within this grid and integrating the specific intensity over the visible stellar surface at different rotational phases, we obtain theoretical light curves of the star. We predict the variability of {\phi} Phe in the ultraviolet and in the visible spectral regions with amplitude of the order of millimagnitudes, mainly caused by absorption in lines of yttrium, chromium, and titanium. We also show how this variability is affected by changes of the distribution of the heavy elements over time. The main characteristics of the predicted light variability of {\phi} Phe correspond roughly to the variability of the star observed with the TESS satellite

Updated Photonuclear Data Library and Database for Photon Strength Functions

Photonuclear cross sections and gamma-ray data used to extract Photon Strength Functions are important for a large range of applications including basic sciences. The recommendations of an IAEA Consultant’s Meeting to update the IAEA Photonuclear Data Library and create a Reference Database for Photon Strength Functions are presented