Estudio de la activación neutrónica del acero inoxidable en un reactor nuclear

Durante la operación de un reactor nuclear, diferentes componentes pueden activarse por reacciones neutrónicas. La actividad así generada produce una dosis que es un riesgo potencial para los trabajadores del entorno. Se ha simulado mediante los códigos MCNP y CINDER’90 dicha activación en una pieza de acero y comparado los valores obtenidos con mediciones experimentales. Se verifica la equivalencia de ambos métodos para los cálculos de activación neutrónica y evolución de la tasa de dosis con el tiempo de enfriamiento.Lázaro Roche, I.; Ródenas Diago, J.; Marques, J. (2013). Estudio de la activación neutrónica del acero inoxidable en un reactor nuclear. Sociedad Nuclear Española. http://hdl.handle.net/10251/71624

Design, Construction and In Situ Testing of a Muon Camera for Earth Science and Civil Engineering Applications

The MUST2 (MUon Survey Tomography based on Micromegas detectors for Unreachable Sites Technology) camera is based on a thin Time Projection Chamber read by a resistive Micromegas. This innovative combination presents interesting distinctive features compared to existing muon detection technologies. It allows a wide angular acceptance of the detector with a low weight and compact volume, well adapted for confined spaces or underground operation. The current work presents the results obtained during the calibration measurements at the reference site, the Low Background Noise Laboratory (LBNL). Preliminary results from field measurement campaign carried out at the dam overlooking the village of Saint-Saturnin-les-Apt (South-East of France) are presented and discussed

The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation

Estudio de la activación neutrónica del acero inoxidable en un reactor nuclear

Proyecto ConfidencialLázaro Roche, I. (2012). Estudio de la activación neutrónica del acero inoxidable en un reactor nuclear. http://hdl.handle.net/10251/28218.Archivo delegad

Latest Developments in Tomographic Research of Underground and Large Structures with Muographic Expertise, TRUST-ME

International audienc

MUon Survey Tomography based on Micromegas detectors for Unreachable Sites Technology (MUST2): overview and outlook.

International audienceThe use of Micro-Pattern Gaseous Detectors in geophysics and civil engineering applications has experienced an increase related to the incorporation of muon tomography in these fields. The Temporal Tomography of Density by the Measurement of Muons project has developed a new direction-sensitive tool for muon flux measurement based on a thin time projection chamber with a bulk-Micromegas readout and SRS electronics. This configuration presents interesting distinctive features, allowing a wide angular acceptance of the detector with a low weight and compact volume. The functioning principle of the device, the results of the characterisation tests, the ongoing work to improve its performance and the next phase to scale up the existing muon camera network at the Low Background Noise Laboratory of Rustrel are presented

MUon Survey Tomography based on Micromegas detectors for Unreachable Sites Technology (MUST 2 ). Principles, experimental results and overlook.

International audienceTransmission muography is an expanding technique based on the attenuation of the natural-occurring cosmic muons' flux due to the opacity of the medium to obtain the distribution of density around the detector. The current work introduces the technology developed by the Temporal Tomography of the Densitometry by the Measurement of Muons (T2DM2) collaboration. The MUST 2 camera leans on a thin time projection chamber read by a resistive Micromegas. This new tool presents interesting distinctive features, allowing a wide angular acceptance of the detector with a low weight and volume, well adapted for confined spaces or underground operation. The results obtained from field measurement campaign carried out at the dam overlooking the village of Saint-Saturnin-les-Apt (South-East of France) are presented. The influences of (i) the host rock body of the barrage and dam's structure, (ii) the temporal water level variations of the reservoir and (iii) the effect of the temperature on the muons flux measurements are discussed The main challenge that faces the project is that the muon trajectory reconstruction algorithm cannot infer the arrival angles for a non-negligible number of detected events, with the subsequent loss of information. The data collected during the campaign of measurements, should help improving the algorithm's robustness and reconstruction efficiency. Field transportability and the capability to perform long-term out-of-lab measurements have been demonstrated. The successful proof-of-concept trial makes the MUST 2 camera a valuable candidate for transmission muography purposes, particularly in challenging available volume scenarios. The next stage of the T2DM2 project aims at imaging and monitoring the hydrodynamics across the unsaturated zone of the Fontaine-de Vaucluse aquifer. To do so, a network of 20 autonomous detectors will be constructed and deployed within the facilities of the Low Background Noise Laboratory of Rustrel (LSBB), France. The privileged emplacement of the LSBB allows the access to both the surface and to a network of 4 km of underground galleries with depths ranging from 0 to 518 m. Submission deadline: 30 Jul

Muography sensitivity to hydrogeological rock density perturbation: roles of the absorption and scattering on the muon flux measurement reliability

International audienc

Design, Construction and In Situ Testing of a Muon Camera for Earth Science and Civil Engineering Applications

The MUST2 (MUon Survey Tomography based on Micromegas detectors for Unreachable Sites Technology) camera is based on a thin Time Projection Chamber read by a resistive Micromegas. This innovative combination presents interesting distinctive features compared to existing muon detection technologies. It allows a wide angular acceptance of the detector with a low weight and compact volume, well adapted for confined spaces or underground operation. The current work presents the results obtained during the calibration measurements at the reference site, the Low Background Noise Laboratory (LBNL). Preliminary results from field measurement campaign carried out at the dam overlooking the village of Saint-Saturnin-les-Apt (South-East of France) are presented and discussed