Oak Ridge National Laboratory

Physics Division

Physics Division Seminars

Physics Division Seminars bring us speakers on a variety of physics related subjects. Usually these are held in the Building 6008 large Conference Room, at 3:00 pm on the chosen day, but times and locations may vary. For more information, contact our seminar chairman,

Alfredo Galindo-Uribarri
Tel (Office): (865) 574-6124  (FAX): (865) 574-1268

Fri., March 09, 2007, at 11:00 a.m. (refreshments at 10:40 a.m.)

Challenges of SPIRAL 2

Marek Lewitowicz, Scientific Co-ordinator of SPIRAL 2, GANIL, Caen, France
Building 6008 Conference Room

The SPIRAL 2 facility, an ambitious extension of the GANIL accelerator complex, has entered in its construction phase in 2005. In the frame of this project a new superconducting linear accelerator (LINAG) delivering high intensity, up to 40 MeV, proton and deuteron beams as well as a large variety of heavy-ion beams with mass over charge ratio equal to 3 and energy up to 14.5 MeV/nucl. will be constructed. Using a carbon converter and the 5 mA deuteron beam, a neutron-induced fission rate is expected to approach 1014 fissions/s for high-density UCx target. The versatility of the SPIRAL 2 driver accelerator will also allow us to use fusion-evaporation, deep-inelastic or direct reactions in order to produce very high intensity RIB and exotic targets. The energies of accelerated RIB will reach up to 7-8 MeV/nucl. for fission fragments and 20 MeV/nucl. for neutron-deficient nuclei.

The physics case of SPIRAL 2 based on the use of high intensity Radioactive Ion Beams and stable light- and heavy-ion beams as well as possibilities to perform several experiments simultaneously will be discussed. In particular, it will be shown that a use of these beams at GANIL at the low-energy ISOL facility (DESIR) and their acceleration to several MeV/nucl. opens new possibilities in nuclear structure physics, nuclear astrophysics, reaction dynamics studies as well as in atomic physics, condensed matter studies, radio-biology and radiochemistry.

Thanks to the high-energy and high-intensity neutron flux available at SPIRAL2, the facility will offer a unique opportunity for material irradiations and cross-section measurements, both for fission-related (notably accelerator driven systems (ADS) and Gen-IV fast reactors) and fusion-related research. In particular, the neutron energy range and other parameters of the SPIRAL 2 time-of-flight facility are complementary to other such facilities in Europe, notably GELINA of the European Commission's Joint Research Centre in Geel and the CERN based n_TOF facility.

Relatively moderate intensities and high cost of radioactive beams impose a use of the most efficient and innovative detection systems as the magnetic spectrometer VAMOS, the 4PI gamma-array EXOGAM and AGATA as well as charged particle detectors like MAYA, MUST 2 and TIARA. Several new concepts of the detection systems (HERMES*, FAZIA, GASPARD) and a new separator/spectrometer S3 located in dedicated experimental halls are currently under design.