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Initiative Physique des Infinis


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Accueil > Thèses, Stages, Formation et Enseignement > Propositions de thèses 2024 > Measurement of solar pp neutrinos flux in XENONnT and development of new electrodes for DARWIN

Measurement of solar pp neutrinos flux in XENONnT and development of new electrodes for DARWIN

par Tristan Beau - 6 décembre 2023

Titre : Measurement of solar pp neutrinos flux in XENONnT and development of new electrodes for DARWIN

Directrice/directeur de thèse : Luca Scotto Lavina

Co-encadrant.e : Bernard Andrieu

Groupe d’accueil :XENON

Webpage du projet :

Collaboration : XENONnT and XeLab

Description :

Astronomical and cosmological observations reveal that the vast majority of the matter content of our universe is invisible – or dark – and interacts neither strongly nor electromagnetically with ordinary matter. One of the leading technologies today to detect eventual Dark Matter (DM) particles is dual-phase liquid xenon (LXe) Time Projection Chambers (TPCs). The simultaneous detection of both ionization and scintillation signals down to a few keV enables dual-phase TPCs to be sensitive to low-energy depositions, the likely signature of a DM particle scattering off a xenon atom. Thanks to an incredibly low radioactive background and an unprecedented detector size (10 tons of LXe), the XENONnT experiment, located at Gran Sasso National Laboratory (LNGS), an underground laboratory built below the Apennine Mountains in Italy, is world-leading for this research, but offers also a unique opportunity to explore extremely rare processes, such as the detection of solar neutrinos. The solar pp neutrinos (electron neutrinos produced by proton fusion reaction in the center of the Sun) are the most abundant and can be detected in XENONnT via Electron Recoil (ER) with an unprecedented low energy threshold, which will help to constrain solar models. However this detection is a real challenge for present detectors, such as XENONnT, and even more for the next generation DARWIN detector, due to an experimental background composed of isolated electrons or small electron clusters, whose origin remains largely unclear. It is the aim of the Xelab R&D project, based on a small-scale dual-phase TPC installed at LPNHE, to characterize this background source and test new concept of electrodes, less sensitive to it, for DARWIN. The candidate will have therefore the chance to work on the data analysis of XENONnT and at the same time to operate a local Liquid Xenon TPC.

The candidate is encouraged to start an M2 internship in our group. The activities we propose in 2024 for the internship are dual as well. From one side, he/she will contribute to the improvement of the analysis of so-called « S2 » (ionization) signals in XENONnT, by including a more detailed description of a not-yet covered part of the electrodes in the simulation, then certifying this new simulation via comparison with data. From the other side, we will start the commissioning of XeLab, which is a great occasion to see a TPC starting detecting its first light.

Lieu(x) de travail : LPNHE

Déplacements éventuels : LNGS Underground Laboratory, Italy

Stage proposé avant la thèse : Oui

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