arXiv subjects
Publications and source records attributed to H. Godfrin.
MACHe3 (MAtrix of Cells of superfluid He3) is a project of a new detector for direct Dark Matter search, using superfluid He3 as a sensitive medium. This paper presents a phenomenological study done with the DarkSUSY code, in order to investigate the discovery potential of this project of detector, as well as its complementarity with existing and planned devices.
MACHe3 (MAtrix of Cells of superfluid He3) is a project of a new detector for direct Dark Matter Search. The idea is to use superfluid He3 as a sensitive medium. The existing device, the superfluid He3 cell, will be briefly introduced. Then a description of the MACHe3 project will be presented, in particular the background rejection and the neutralino event rate that may be achieved with such a device.
MACHe3 (MAtrix of Cells of superfluid He3) is a project of a new detector for direct Dark Matter (DM) search. A cell of superfluid He3 has been developed and the idea of using a large number of such cells in a high granularity detector is proposed.This contribution presents, after a brief description of the superfluid He3 cell, the simulation of the response of different matrix configurations allowing to define an optimum design as a function of the number of cells and the volume of each cell. The exclusion plot and the predicted interaction cross-section for the neutralino as a photino are presented.
MACHe3 (MAtrix of Cells of superfluid He3) is a project of a new detector for direct Dark Matter (DM) search. A cell of superfluid He3 has been developed and the idea of using a large number of such cells in a high granularity detector is proposed. This paper presents, after a brief description of the superfluid He3 cell, the simulation of the response of different matrix configurations allowing to define an optimum design as a function of the number of cells and the volume of each cell. The background rejection, for several configurations, is presented both for neutrons and gamma-rays of various kinetic energies.
Due to its broken spin and orbit rotation symmetries, superfluid $^3$He plays a unique role for testing rotational quantum properties on a macroscopic scale. In this system the orbital momentum forms textures that provide an effective potential well for the creation of stationary spin waves. In the limit of the lowest temperatures presently attainable, we observe by NMR techniques a profound change in the spin dynamics. The NMR line shape becomes asymmetric, strongly hysteretic and displays substantial frequency shifts. This behavior, quantitatively described by an anharmonic oscillator model, indicates that the parameters of the potential well depend on the spin waves amplitude, and therefore that the orbital motion is not damped in this new regime, not considered by the standard Leggett-Takagi theory. This regime of non-linear stationary spin waves is shown to give rise to the pulsed NMR "Persistent Signals" reported recently.