Improving the rate of the triple alpha process

Document Type

Conference Proceeding

Publication Date



The rate of the triple alpha process, which plays a central role in the production of 12C in stars, is known with an accuracy of about 12%. Variations within the ±12% errors in this rate can cause significant changes in the determination of the mass of the iron core in core-collapse supernovae and the composition of the material later ejected in the interstellar medium, as well as a factor of two change in the surface abundance of 12C. In Light ABG Stars. The Triple Alpha Exp. Presented Here Is A Collab. Effort between TheWestern Michigan Univ. and the Natl. Superconducting Cyclotron Lab. and Aims at Reducing the Uncertainty on the Knowledge of This Rate to about 6% by Measuring More Accurately Than Has Been Done in the Past the Pair Br. for the 7.654 MeV State in 12C. This State Is Excited by Inelastic Proton Scattering , Taking Advantage of A Strong Reson. at A Bombarding Ener. of about 10.6 MeV and A Scattering Angle of 135 Degrees in the Lab.. The Decay Pairs Are Detected in An Almost 4p Scintillator Syst. Surrounding the Target. The Protons Are Produced Using the Tandem Accel. at W. Michigan Univ. and Detected by Silicon Detectors at 135 Degrees in the Lab. The Pair Br. Is Given by the Ratio of the No. of Electron-positron Pairs Detected in the Plast. Scintillators in Coincidence with the Protons in the 7.654 MeV Silicon Spectra to the No. of Those Protons. A Reduction in the Gamma Ray Background, Mainly Due to the Cascade Gamma Decay of the 7.654 MeV State Through the 4.44 MeV 2+ State, Is Achieved by A Coincidence Requirement between A Thin Scintillator Tube and the Large Block of Plast. Scintillator Surrounding It. The Msrmt. Is Expected to Take Pl. in the Summer of 2006. Copyright Owned by the Author.

Publication Source (Journal or Book title)

Proceedings of Science

This document is currently not available here.