Nuclear Seminar

A New Measurement of the E1 Component of the ¹²C(a,g)¹⁶O Reaction

Dr. Xiaodong Tang
Argonne National Laboratory

Monday, February 20, 2006   4:00 p.m.   NSH 124
(Refreshments served prior to seminar in NSH 124)

 

The radiative capture reaction ¹²C(a,g)¹⁶O is an important process in nuclear astrophysics. Since the cross sections at helium burning temperatures are extremely small (~10^-17b) indirect techniques have to be used to determine its astrophysical reaction rate. The E1 component of this rate is best determined through a measurement of the beta-delayed alpha decay of ¹⁶N. For a measurement of this decay we have built a system of high-acceptance gas-ionization detectors, which are insensitive to beta particles that limited earlier measurements. Beam impurities that affected one of the earlier experiments were eliminated through the choice of the ¹⁶N production technique. New results from this experiment and comparisons with earlier data will be presented. This work was supported by the US Department of Energy, Nuclear Physics Division, under contract No. W-31-109-ENG and by the NSF Grant No. PHY-02-16783 (Joint Institute for Nuclear Astrophysics).