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Reference : UMR5821-CHRVEL-086
Workplace : GRENOBLE
Date of publication : Friday, May 07, 2021
Scientific Responsible name : Monsieur Jacob LAMBLIN
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 1 October 2021
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
The measurement of the Coherent Elastic Neutrino-Nucleus Scattering (CENNS) has been a challenge in neutrino physics since its prediction almost 40 years ago. In August 2017, the COHERENT experiment located at the Spallation Neutron Source (SNS) in Oak Ridge has reported the first CENNS detection. Even though this first detection has only limited sensitivity to new physics, it has proven the existence of this new neutrino detection channel that opens the door to a myriad of new scientific opportunities. For instance, a non-zero neutrino magnetic moment or the existence of a new massive mediator, such the Z' boson, would induce deviations in the nuclear recoil energy spectrum at very low energy, below 100 eV.
Thanks to its exceptionally rich science program, the precise measurement of CENNS has led to significant worldwide experimental efforts with several ongoing and planned dedicated experiments based on a host of techniques. RICOCHET project is one of them. The principle of the experiment is to place very low energy threshold (~50 eV) detectors, such as Ge-semiconductors and Zn-superconductors, close to a nuclear reactor to deliver a high precision measurement of the CENNS at the percentage level. The first key feature of the RICOCHET program, compared to other planned or ongoing CENNS projects, is to aim for a kg-scale experiment with unparalleled background rejection down to the O(10) eV energy threshold. The second key feature is to combine several targets and cryogenic detector techniques to benefit from target complementarity in the quest of new physics. The Institut Laue Langevin (ILL) with its research nuclear reactor is an excellent site to host the experiment, given the possibility to go very close to the core.
The proposed PhD will be fully devoted to the RICOCHET experiment at ILL. The most crucial point is the background. Indeed, due to neighboring experiments, the gamma and neutron backgrounds are particularly high, especially at low energies. The PhD student will participate to the background studies design using simulations and extrapolation of existing measurements. In particular, he/she will be in charge of the muon veto characterization, used for the cosmic events rejection. Another important aspect will concern the detector performances. The R&D on Ge detectors is made by the IP2I laboratory in Lyon and first results are very encouraging. The PhD student will have the opportunity to contribute to the characterization of detectors. Then, the PhD student will be involved in the installation of the experiment at the ILL foreseen for September 2022 and in the commissioning of the detectors. Finally, he/she will analyze the data to infer the first physics results.
To carry out this project, the candidate has to be graduated in particle physics, giving all necessary theoretical and experimental knowledge.
The candidate must have skills in Monte-Carlo simulations, an experience with the GEANT4 code would be greatly appreciated.
The candidate must have also skills in data analysis in order to interpret the simulation outputs and to analyze the first data of the experiment.
Computing aspects are present in several foreseen activities. A good knowledge of the C++ and/or python computing languages will be valuable.
Finally, the candidate must have a great interest in experimental physics to address all aspects of the project with motivation.
The Laboratoire de Physique Subatomique et Cosmologie de Grenoble (LPSC) (http://lpsc.in2p3.fr) is a Mixed Teaching and Research Unit, affiliated to the National Nuclear and Particle Physics Institute l'IN2P3 from the CNRS, as well as to the UGA and Grenoble-INP universities, with about 230 people. The PhD student will join the Neutrinos team, counting 7 members. The PhD supervisor will be Jacob LAMBLIN.
Constraints and risks
The PhD student will have to work at the ILL with radioactive sources.
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