A global modeling approach of the leakage phenomena in dielectrics

Thanks to its low noise level, the LSBB environment provides particular environment to carry out high quality electrical characterizations. In this paper, we propose a complete modeling approach of the experimental results from our experimental microelectronic setup. The tested device is a Metal Oxide Semiconductor (MOS) floating gate capacitor which can be found in electrostatic non volatile memories such as Flash. The main idea is to characterize and model the leakage current through the tunnel oxide. We proposed, in a previous work, a model for charge loss considering a fractional Poisson process, involving only two parameters, expressed as a Mittag-Leffler (ML) function. Here, we also propose a combo of Fowler-Nordheim (FN) and Poole-Frenkel (PF) models for leakage currents, based on tunnel effect transport through the oxide. It gives the leakage current on a medium-to-long scale of time while the ML model can possibly take into account a shorter time step. The perspective is to find a relationship between these different models, used in various fields, to propose a generic model of phenomena involving leakage in complex and porous materials at different scales of time and space

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 obtaining of the

The Low-Noise Underground Research Laboratory (LSBB URL) in Rustrel (near Avignon, Southern France) is born from the reconversion of a command firing post of nuclear rocket. Since 1996, the site has been transformed in an international scientific facility for interdisciplinary research. Scientists working on different fields and from different countries are supervised by the engineer team of the LSBB. The LSBB URL wanted to point the competences of the lab and prove that their measures could be trusted. The accreditation according to the ISO 17025 didn’t appear suitable. Indeed, this well-known standard is not really suited to the needs of research lab and the work to set up for a first accreditation is consistent and costly. Working with partners in the field of public and private research, the CT2M has developed a new quality system fully compatible with the ISO 17025 but more suitable to establish with the concerned academic labs and private companies: The “Label Fiabilité Mesure”. The LSBB URL has obtained the graduation for the Label for its activity of measurement of gravity

The obtaining of the Label Reliability Measure for gravity measurement by the LSBB underground lab

International audienceThe Low-Noise Underground Research Laboratory (LSBB URL) in Rustrel (near Avignon, Southern France) is born from the reconversion of a command firing post of nuclear rocket. Since 1996, the site has been transformed in an international scientific facility for interdisciplinary research. Scientists working on different fields and from different countries are supervised by the engineer team of the LSBB. The LSBB URL wanted to point the competences of the lab and prove that their measures could be trusted. The accreditation according to the ISO 17025 didn’t appear suitable. Indeed, this well-known standard is not really suited to the needs of research lab and the work to set up for a first accreditation is consistent and costly. Working with partners in the field of public and private research, the CT2M has developed a new quality system fully compatible with the ISO 17025 but more suitable to establish with the concerned academic labs and private companies: The “Label Fiabilité Mesure”. The LSBB URL has obtained the graduation for the Label for its activity of measurement of gravity

A global modeling approach of the leakage phenomena in dielectrics

International audienceThanks to its low noise level, the LSBB environment provides particular environment to carry out high quality electrical characterizations. In this paper, we propose a complete modeling approach of the experimental results from our experimental microelectronic setup. The tested device is a Metal Oxide Semiconductor (MOS) floating gate capacitor which can be found in electrostatic non volatile memories such as Flash. The main idea is to characterize and model the leakage current through the tunnel oxide. We proposed, in a previous work, a model for charge loss considering a fractional Poisson process, involving only two parameters, expressed as a Mittag-Leffler (ML) function. Here, we also propose a combo of Fowler-Nordheim (FN) and Poole-Frenkel (PF) models for leakage currents, based on tunnel effect transport through the oxide. It gives the leakage current on a medium-to-long scale of time while the ML model can possibly take into account a shorter time step. The perspective is to find a relationship between these different models, used in various fields, to propose a generic model of phenomena involving leakage in complex and porous materials at different scales of time and space

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

Seismic wavefield polarization – Part II: Definition of a parameter system in three-dimensional (3D) space, example case review using LSBB seismic station data

A full polarization parameter system in 3D space is presented to characterize the state of polarization of a seismic wavefield and to parametrize any type of elliptical polarized seismic wave including extreme linear and circular polarizations. This parameter system does not require the a-priori knowledge of the orientation of the polarization plane and provides access to all parameters required in most polarization studies. Two groups of angular and vectorial parameters are defined, which can be easily related to one another. The knowledge of particle motion polarization opens the field of applications for 3-component seismic records contributing to improvements in phase identification. An example of a time-frequency visualization of the polarization parameters on a teleseimic earthquake recorded at a seismic station of LSBB is presented

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

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Simulations of the muon flux sensitivity to rock perturbation associated to hydrogeological processes

Muon tomography is a method to investigate the in-situ rock density. It is based on the absorption of cosmic-ray muons according to the quantity of matter (thickness and density). Numerical simulations are performed in order to estimate the expected muon flux in LSBB Underground Research Laboratory (URL) (Rustrel, France). The aim of the muon measurements in the underground galleries of this laboratory is to characterize the spatial and temporal density variations caused by water transfer in the unsaturated zone of the Fontaine-de-Vaucluse karstic aquifer

Seismic wavefield polarization – Part II: Definition of a parameter system in three-dimensional (3D) space, example case review using LSBB seismic station data

International audienceA full polarization parameter system in 3D space is presented to characterize the state of polarization of a seismic wavefield and to parametrize any type of elliptical polarized seismic wave including extreme linear and circular polarizations. This parameter system does not require the a-priori knowledge of the orientation of the polarization plane and provides access to all parameters required in most polarization studies. Two groups of angular and vectorial parameters are defined, which can be easily related to one another. The knowledge of particle motion polarization opens the field of applications for 3-component seismic records contributing to improvements in phase identification. An example of a time-frequency visualization of the polarization parameters on a teleseimic earthquake recorded at a seismic station of LSBB is presented