The objectives of the ELISe proposal are to explore the physics opportunities offered by the scattering off electrons of energetic secondary beams of exotic nuclei in a storage ring, and to develop the technical design needed to realize this very sophisticated experiment. Electron scattering has contributed significantly to reveal the structure of stable nuclei. With the advent of intense secondary radioactive beams in conjunction with improved experience in the operation of storage rings it seems now possible for the first time to explore the nuclear landscape using a clean electromagnetic probe, the electron. The electron scattering setup will be one of the experiments accepted at the New Experimental Storage Ring (NESR) within the SuperFRS project of the International Accelerator Facility of Ions and Antiprotons planned at GSI. The project as proposed here will include the conceptual exploration of new methods, such as novel approaches to storage ring and collider techniques involving electron beams; the design and development of the appropriate instrumentation; and the carrying out of selected pilot experiments. An essential component of the experiments is the electron spectrometer of large acceptance and high resolution needed to analyze the momenta and scattering angles of the scattered electrons. From the point of view of the laws of ion optics, large acceptance and high momentum resolution are contradictory, and the combination of the two criteria indeed represents a technological challenge. A technical design study will be performed using theory assisted simulation calculations. The electron spectrometer cannot be seen without a appropriate detector system for both heavy ions in the storage rings and electrons in its focal plane. the development and testing of prototypes for both detection systems together with a luminosity monitor will be addressed in this proposal. The scientific program is motivated both by nuclear structure and nuclear astrophysics interests. Here, the precise information on charge density distributions and excitation modes is of vital interest. Electron scattering can be related to neutrino induced processes via the SU(4) symmetry of electroweak interaction. Furthermore, electron scattering off exotic nuclei will provide a novel tool, and many applications also in other scientific fields can be expected.
Dubna, Moscow Region