Development of new Time Projection Chambers for societal and academic applications: muon tomography in confined environment and T2K upgrade of the near detector

Muon tomography is an example of how fundamental research in particle physics can benefit society. Micromegas-based telescopes were developed and successfully detected unknown cavities in Khufu's pyramid. With this first success came the possibilities for novel underground applications requiring the development of a new instrument capable of performing 3D track reconstruction in a confined environment. The design of D3DT (Detector 3D for muon Tomography) is discussed and the first prototypes are developed and characterized. The performances of a new reconstruction algorithm are also tested on simulated data. D3DT first prototypes are successfully operated and the reconstruction algorithm is applied on the acquired data. At the same time the T2K experiment, which probes the mass differences and mixing of neutrinos by measuring neutrino oscillations, is being upgraded. In particular, new Time Projection Chambers (TPCs) have to be installed on the near detector to ensure a better efficiency of the high angle tracks reconstruction. A test beam is conducted in order to fix the prototype design before production and a validation of performances is achieved. Potential improvements of the analysis are also investigated. (author)