PhD Ceremony Marlène da Silva e Silva

On 19 February Marlène da Silva e Silva will defend her thesis 'Sensitive polarimetry in a search for the deuteron electric dipole moment'.

Location: Academy Building, Broerstraat 5, Groningen

Time: 13:15 hrs.

Promotor: K. Jungmann
Co Promotor: C.J.G. Onderwater

Sensitive polarimetry in a search for the deuteron electric dipole moment

The quest for new Physics constitutes one of the main endeavors in physics research. Searches for permanent Electric Dipole Moments (EDMs) in fundamental systems have a wide window to discover Physics beyond the Standard Model. A proposal exists that promises a sensitivity to an EDM of the deuteron at a level of 10⁻²⁹ e.cm. The experiment relies on the interaction between the EDM of the deuteron and the radial motional electric field a relativistic particle experiences in the field of a magnetic storage ring, which would cause the spin of the particle to precess. A non-zero EDM manifests itself by a change in the polarization component along the magnetic field. To monitor this signal, a novel highly efficient polarimeter concept has been investigated. In addition, this polarimeter must be robust against systematic errors and able to continuously monitor the beam polarization, guaranteeing optimal sensitivity. Detailed studies on systematic error control were carried out at KVI, in addition to the measurement of cross sections and analyzing powers necessary for precise simulations. Measurements conducted at COSY-Jülich in Germany yielded the predicted high efficiencies. With these efficiencies and the developed understanding of systematic effects it was possible to track changes in polarization at the level of a few hundred parts-per-million. The developed polarimeter concept is appropriate for reaching the aimed sensitivity of a deuteron EDM experiment.

Marlène da Silva (Portugal, 1982) studied astronomy in Porto. The research was financed by the Netherlands Organization for Scientific Research NWO.