Postdoctoral position: "Development of geophysical imaging by joint analysis of muography and associated methods. Applications to near-surface problems and volcanology" - IP2I (UMR5822) et LGL-TPE (UMR5276)

Research project

Muography is an innovative investigation method using cosmic-rays induced atmospheric muons to probe large structures of geological relevance. In the last decades the method has known a fast and important development and has been applied in various fields from geosciences (volcanology, hydro-geology, atmosphere physics etc) to industrial controls and monitoring (civil engineering, tunnel boring machines, nuclear plants etc).

The basic principles of the method are similar to those of medical X-ray imaging where the absorption of the incident particles flux is interpreted in terms of opacity of the target. The main difference relies in the fact that the particles used for the measurement are naturally produced in the atmosphere with a given and limited statistics. This induces severe constrains on the way the inverse problem is thought and applied.

The main objective of the project is to improve present methods to increase the sensitivity of muography in terms of spatial imaging capability and of timing resolution for all monitoring applications (follow-up of the content of a target with time and assessment of the typical time constants). One possible improvement arises from possible coupling of muography measurements with other geophysical measurements like seismic noise recording, electrical resistivity tomography, gravimetry etc. A possible development may be based on recent developments using optical fibers as distributed acoustic or strain sensors monitoring large areas as well as means of implementation of precise timing and synchronization. A coupling between muography and distributed fibers would be a very promising multi-messenger approach. Another improvement relies on the detection technology itself where more informations on the particles may be added wrt the present trackers in use. This important development may be based on the upgrade of a first Cerenkov prototype that requires energy calibration and validation with in situ measurements.

The results obtained may be constrained on different near surface targets : structural imaging of a shallow archaeological site south Lyon, analysis of the hydrothermal system dynamics of a volcanic system, investigation of effect of newtonian noise sources on the sensitivity of gravitational antennas like Virgo close to Pisa. The subject has a lot of potential applications in the industry for the long-term storage problematics or the urban civil engineering for instance.