Speaker
Description
Stellar helium burning results in the formation of carbon and oxygen [1]. However, the carbon-to-oxygen ratio at the end of helium burning is not well known, despite its importance in stellar evolution theory. Furthermore, alpha particle clustering in 12C remains somewhat mysterious, with the structure of the first excited 0+ Hoyle state still under question [2].
The gamma-ray beam facility at HIgS (Duke University, USA) coupled with active target detectors, present an ideal opportunity for solving these problems, by allowing precise measurements of the 16O(γ,α) and 12O(γ,α) cross sections.
This talk will discuss the Optical Readout Time Projection Chamber (O-TPC) at HIgS [3] and the experiments that were performed to measure the photo-disassociation of 16O and 12C. The experimental analyses so far will be discussed with a focus on the unique opportunity that this detector provides to precisely measure detailed angular distributions.
[1] W. A. Fowler, Rev. Mod. Phys. 56, (1984)
[2] M. Freer and H. O. U. Fynbo, Prog. Part. Nucl. Phys. 78, (2014)
[3] M. Gai, et al., JINST 5 (2010)
