SPIRAL2 at GANIL: At the Dawn of a New Era

摘要

The exploration of unknown region of the nuclear mass chart, in particular, the neutron rich side, raised new and challenging physics issues in the understanding of nuclei far from stability. The physics of weakly bound systems, the appearance of shell quenching, the interface with. astrophysical problems prompted the study of new generation of "Rad ioactive Beam Facilities" with high luminosity and the development of associated new experimental tools.GANIL presently offers unique opportunities in nuclear physics and many other fields. With the construction of SPIRAL2 over the next few years, GANIL is in a good position to retain its world - leading capability even though it faces strong competition from new and upgraded ISOL and fragmentation facilities. As selected by the ESFRI committee, the next generation of ISOL facility in Europe is represented by the SPIRAL2 project to be built at GANIL (Caen, France). SPIRAL 2 based on a high power, CW, superconducting LINAC, delivering 5 mA of deuteron beams at 40MeV (200KW) directed on a C converter+ Uranium target and producing therefore more 10 13 fissions/s. The expected radioactive beams intensities in the mass range from A=60 to A=140, will surpass by two order of magnitude any existing facilities in the world. These unstable atoms will be available at energies between few KeV/n to 15 MeV/n. The same driver will accelerate high intensity (100~* A to mA), heavier ions (Ar up to Xe) at maximum energy of 14 MeV/n.In applied areas SPIRAL2 is considered as a powerful variable energy neutron source. The Neutrons For Science collaboration (NFS) is proposing a physics program on fission induced by fast neutrons asll well as fusion studies on materials.Under the 7FP program of European Union called*Preparatory phase*, the SPIRAL2 project has been granted a budget of about 4M to build up an international consortium around this new venture Regarding the future physics program a call for Letter of intents has been launched in Oct 2006 and 8 large International collaborations has been built up around new instruments for SPIRAL?. The status of the construction of SPIRAL2 accelerator and technical R&D programs for physics instrumentation (detectors, spectrometers) in collaboration with EU and International partners will be presented.