Speaker
Jeremias Garcia Duarte
(INFN Napoli)
Description
Stellar model calculations are extremely sensitive to the rate of 12C(alpha,gamma)16O. Although great efforts were devoted to decrease the uncertainty in the extrapolations, more precise data are needed to provide a good input to the stellar models. The available data indicate that its cross section at E0 = 300 keV is dominated by E1 and E2 radiative capture processes into the 16O ground state, where the main contribution to the capture cross section is given by two subthreshold states with Jpi = 1- and 2+ at Elevel = 7.12 and 6.92 MeV, respectively. Since the measurement of Dyer and Barnes in 1974 [1], the E1 and E2 contributions have been determined by measuring the gamma-rays in coincidence with 16O-recoils to reduce background. In one case [2] it was possible to measure the total cross section by the detection of recoils using the RMS (Recoil Mass Separator) ERNA (European Recoil mass separator for Nuclear Astrophysics). In the case of a RMS, an additional constrain to the gamma-ray data can be the measurement of the angular distribution of the recoils. Monte Carlo simulations together with the simulation of the beam transport through ERNA have shown that it could be possible to determine the E1 and E2 contributions by the analyses of the angular and time of flight distributions of the recoils at the end of the RMS. In order to achieve that, a two stage tracking detector is being developed. The first stage is a modification of the existing mirror detector [3]. The second stage is a parallel grid position sensitive detector that will be placed inside of the existing Ionization Chamber Telescope [4]. The detector development will be described and the expected physics outcome presented.
[1] P. Dyer et al., Nuc. Phys. A 233(1974)495520.
[2] D. Schrmann et al., Eur. Phys. J. A 26(2005)301.
[3] A. Di Leva et al., NIM A 595(2008)381390.
[4] D. Rogalla et al., NIM A 437(1999)266.
Primary author
Jeremias Garcia Duarte
(INFN Napoli)
Co-authors
Antonino Di Leva
(NA)
Antonio D'Onofrio
(NA)
David Rapagnani
(PG)
Elia Lizeth Morales Gallegos
(NA)
Giuseppe Porzio
(AC)
Leandro Romero Gasques
(N)
Lucio Gialanella
(NA)
Mauro Romoli
(NA)
Raffaele Buompane
(NA)
