You will investigate possible interactions between VUV radiation and the detector materials as well as delve into the physics solar neutrinos and neutrino interactions. This multi-disciplinary project is a joint effort between the Dark Matter and the Optics of Quantum Materials groups. The XENONnT detector, located in the Italian Gran Sasso mountain range, is one of the best Dark Matter detectors in the world. The XENON collaboration operates the detector and consists of approximately 200 physicists from 29 different institutions. Besides looking for Dark Matter, the collaboration pursues a diverse physics programme focused on rare interactions, such as coherent elastic neutrino-nucleus scattering (CEνNS) of solar neutrinos. The detector has been taking data for nearly 4 years.

This PhD project will be about measuring the boron-8 neutrino flux in the running XENONnT and the future XLZD detector. This is an interesting measurement because a) deviations from theoretical prediction may indicate 'new physics' beyond the standard model (BSM) of particle physics, for example neutrino oscillation into a sterile neutrino state, or challenge the standard solar model, and b) boron-8 CEνNS events are themselves also a background to the Dark Matter search and must therefore be characterised well. The main challenge in this measurement is understanding detector backgrounds.

You will work with experts on the XENONnT detector to learn how to analyze detector data and how to identify signatures of rare neutrino (and other) interactions, as well as understand the phenomenology of detector backgrounds. You will then work with experts in the optical spectroscopy group to develop and test (through lab experiments) hypotheses as to the origin of the background relevant to the neutrino signal. Finally, you will determine the flux of boron-8 neutrinos, as well as make recommendations as to the design of the new XLZD detector.

After gathering data for the past 4 years, the XENONnT detector will be turned off this summer for upgrades. Your PhD program starts on-site at the Gran Sasso National Laboratory (LNGS) in Italy where you will contribute to the upgrade of the XENONnT detector, providing you with a unique opportunity to get introduced to the XENON collaboration and to gain hands-on experience.

You should hold an MSc degree in physics (or equivalent) by the time you start this position.

Your experience and profile :

• As you will work with both the Dark Matter and the Optics of Quantum Materials groups, you should be comfortable translating between these different disciplines
• you are able to conduct research in the context of a large international collaboration, which includes
  • communicating well with collaborators of differing educational levels and cultural backgrounds,
  • seeking consensus,
  • graciously accepting and offering feedback,
  • following a professional code of conduct,
  • participating in weekly (online) meetings to stay up to date on the status of the project, to align your work with wider collaboration, and to present your own work
• you are creative in developing hypotheses to explain phenomena, and in designing and running lab experiments to test them
• you are comfortable using (or willing to learn) a variety of experimental techniques related to particle detection, Fourier transform spectroscopy and near-field microscopy.
• you are willing to spend 3-4 weeks a year in Italy to participate in detector upgrades and detector operation, and to travel to international collaboration meetings and conferences
• you have excellent command of the English language

The following skills or experiences are an advantage: International experience, programming skills (C++/Python), experience with particle detection techniques, experience with techniques of studying surface material properties, VUV optics techniques.

A temporary contract for 38 hours per week for the duration of 4 years (the initial contract will be for a period of 18 months and after satisfactory evaluation it will be extended for a total duration of 4 years). The preferred starting date is as soon as possible. This should lead to a dissertation (PhD thesis). We will draft an educational plan that includes attendance of courses and (international) meetings. We also expect you to assist in teaching undergraduates and master students.

The gross monthly salary, based on 38 hours per week and dependent on relevant experience, ranges between €2.901 to €3,707 This does not include 8% holiday allowance and 8,3% year-end allowance. The UFO profile PhD is applicable. A favourable tax agreement, the ‘30% ruling’, may apply to non-Dutch applicants. The Collective Labour Agreement of Universities of the Netherlands is applicable. Are you curious to read more about our extensive package of secondary employment benefits, take a look here.