07 Dec 2021



Observation of the Migdal effect in the atoms of noble gases


Co-supervisors: PPD - P. Majewski, University of Birmingham - K. Nikolopoulous

The Migdal In Galactic Dark Matter expLoration (MIGDAL) collaboration was formed 2 years ago and now comprises 40 participants from 11 institutions (including PPD and ISIS at RAL, the University of Birmingham and the GDD group at CERN); it is co-led by Dr P. Majewski and Prof. H. Araujo from Imperial College. The project was set up as a work package of the STFC-funded Xenon Futures R&D programme towards a next-generation dark matter experiment, and aims to observe and measure the Migdal effect for the first time in nuclear scattering. The experiment will use a low-pressure Optical Time Projection Chamber filled with CF4 as a base gas mixed with noble gases, which are key target elements in the lading dark matter search technologies.  The signal will be recorded by a fast CMOS camera and fast digitizers connected to ITO anode strips for charge readout. The experiment will exploit high-flux D-D and D-T neutron generators recently installed at the NILE facility at ISIS (RAL).  Observation and detailed measurement of the Migdal effect in key elements will have high visibility and impact on present and future dark matter experiments.

The studentship will focus on the calibration of the detector, data taking using D-D and D-T neutrons generators at NILE, and data analysis – in order to probe the effect in different energy regimes. This will require advanced image processing techniques including machine learning algorithms.  Apart from the data analysis, the studentship will also include simulations of the nuclear recoils in low-pressure gases and end-to-end modelling of the experiment.
There are natural synergies with the work being conducted at Birmingham on gaseous detectors, including on spherical TPC dark matter experiments, which we wish to exploit. The student will be a member of the local MIGDAL team at RAL and at the University of Birmingham, and through frequent meetings will be interacting with the whole collaboration including international partners from CERN, US and Portugal.  

The work will take place mainly at the Rutherford Appleton Laboratory.

Dr Pawel Majewski is the Dark Matter group leader in the Particle Physics Department at the Rutherford Appleton Laboratory.   
Prof. Konstantinos Nikolopoulos from the University of Birmingham​

Contact: Majewski, Pawel (STFC,RAL,PPD)