Nuclear Seminar

Nuclear Astrophysics at LUNA: recent results and status of the experiment

Dr. Heide Costantini
University of Notre Dame
INFN, Genova, Italy

Monday, February 6, 2006   4:00 p.m.   NSH 124
(Refreshments served prior to seminar in NSH 124)

 

The 400 kV accelerator installed at the Gran Sasso National Laboratory is dedicated to measure charged particle induced nuclear reaction cross sections of astrophysical interest at energies close to the Gamow window.

We have completed the measurement of the ¹⁴N(p,g)¹⁵O reaction, which is the key reaction of the CNO cycle of hydrogen burning in stars, using two different experimental techniques. First we used a high resolution solid target setup to study the single g-transitions down to 140 keV interaction energy. Then, taking full advantage of the low background laboratory, we used a high efficiency gas target setup to study the total cross section down to 70 keV interaction energy.

We have now started the measurement of the ³He(⁴He,g)⁷Be that is the key process for the production of ⁷Be and ⁸B neutrinos in the Sun. We are using both activation method and prompt on-line g detection technique. The aim of the experiment is to reduce the error on the astrophysical S factor to about 4%.