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

Mon., July 21, 2008, at 3:00 p.m. (refreshments at 2:40 p.m.)

Underground Measurements at the LUNA Accelerator Facility at Gran Sasso

Alberto Lemut, Istituto Nazionale di Fisica Nucleare, Genova, Italy
Building 6008 Conference Room

Experimental studies of nuclear reactions of astrophysical interest are hampered by the exponential drop of the cross section with decreasing energy. Generally, the cross section has a very low value at the Gamow peak this preventing direct measurement in a laboratory at the Earth's surface where the signal to background ratio is too small because of the cosmic ray interactions with detectors. Hence, cross sections are measured at high energies and then extrapolated to the Gamow peak region. In the present work, the main advantages of an underground accelerator facility for measuring nuclear reaction cross section of astrophysical interest are presented. Undergoing experiments at the LUNA accelerator facility at Gran Sasso will be described in detail. The main source of background in a typical detector will be shown together with some technical solution that could reduce it. Few selected nuclear reactions who received and could benefit from this approach will be reviewed. Future perspective of the underground nuclear astrophysics will be discussed.