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Home page > PhD fellowships > Proposed PhD subjects 2016-2019 > MIMAC : Directional Direct Dark Matter Detection with MIMAC and non-directional with NEWS

MIMAC : Directional Direct Dark Matter Detection with MIMAC and non-directional with NEWS

by Luc Frappat - 17 December 2015

Topics:  Dark Matter detection

Proponents:  Daniel Santos

Address:  LPSC Grenoble - 53, rue des Martyrs - 38026 GRENOBLE CEDEX

Phone:  + 33 (0)476 28 40 21

Contact Email:

The hypothesis of the existence of non-baryonic dark matter in our galactic halo is supported by all astrophysical observations performed from cosmological to local scales. The measurement of one clear experimental signal of this matter represents one of the most important challenges for physics today. The direct detection of an elastic collision with a target nucleus of a weakly interacting massive particle (WIMP), the most accepted candidate for such a matter, has to be discriminated from those produced by neutrons, which produce the same expected signal. The only non-ambiguous signature to be able to discriminate the WIMP events from neutrons-induced events is to correlate these elastic collisions in the detector with the relative motion of our Solar system with respect to the galactic halo. The measurement of the direction of the nuclear recoil track of a few tens of keV is called “directional detection”. The directional detection opens a new field in cosmology: it brings the possibility to build a map of nuclear recoils exploring the galactic halo and gives access to a particle characterization of dark matter. The MIMAC (MIcro-tpc MAtrix of Chambers) collaboration has developed in the last years an original prototype detector based on the direct coupling of a pixelized Micromegas with a special developed fast self-triggered electronics showing the feasibility of a new generation of directional detectors. The flexibility of the MIMAC detector to change the nucleus target, changing its mass and spin, makes possible to adapt the search of candidates proposed by the large mass direct detection projects as LUX, Xenon1T, SCDMS, Edelweiss. In the next years, these large mass detectors will either detect some candidates or the neutrino background floor will limit them. In both cases a directional detector will be needed to confirm the galactic halo origin of such candidates or to go further the neutrino background.

In parallel, in order to explore the WIMP low masses , we participate in NEWS (New Experiment for Wimps detection with a Sphere), a project funded by ANR-2015, complementary to MIMAC, without directionality, but having a very low energy threshold with a spherical detector.

The main objective of NEWS is the direct search for very-low mass Dark Matter particles, from 0.1 to 10 GeV. The gas detector mainly benefits from the following advantages: light target and hence higher momentum transfer from light WIMPs scattering. Lighter atoms have also lower quenching (part of the energy loss ionizing the medium) and combining the low energy threshold (thanks to the multiplication process) thus allowing for better sensitivity to light WIMPs.
The NEWS collaboration will develop, build and operate a gaseous spherical detector able to detect extremely tiny impacts from very-light Dark Matter particles, thereby opening new windows of exploration, at SNOLAB, which is 2 km underground in the Vale Creighton Mine near Sudbury Ontario/Canada.

The PhD thesis proposed will cover the following points:
- Participation in the development, simulation and commissioning of the new MIMAC- 1 m3 matrix detector and in the data analysis of the present MIMAC prototype installed at the underground Modane laboratory (LSM).
- Participation in the NEWS experiment measuring the ionization quenching factors for the different targets (H, He, Ne) with COMIMAC facility.
- Phenomenology studies covering the WIMP low masses candidates.