X-ray burst studies with the JENSA gas jet target

¹ National Superconducting Cyclotron Laboratory, East Lansing, MI, USA
² JINA Center for the Evolution of the Elements, East Lansing, MI, USA
³ Oak Ridge National Laboratory, Oak Ridge, TN, USA
⁴ University of Notre Dame, Notre Dame, IN, USA
⁵ Michigan State University, East Lansing, MI, USA
⁶ Louisiana State University, Baton Rouge, LA, USA
⁷ Sungkyunkwan University, Suwon, South Korea
⁸ Rutgers University, Piscataway, NJ, USA
⁹ Florida International University, Miami, FL, USA
¹⁰ Colorado School of Mines, Golden, CO, USA
¹¹ University of Tennessee, Knoxville, TN, USA
¹² Massachusetts Institute of Technology, Cambridge, MA, USA
¹³ Tennessee Technological University, Cookeville, TN, USA
¹⁴ International Atomic Energy Agency, Vienna, Austria
¹⁵ Ohio University, Athens, OH, USA
¹⁶ Federal Center for Technological Education of Minas Gerais, Brazil
¹⁷ University of Surrey, Guildford, England, UK

^* e-mail: schmidtk@nscl.msu.edu

Published online: 30 December 2017

Abstract

When a neutron star accretes hydrogen and helium from the outer layers of its companion star, thermonuclear burning enables the αp-process as a break out mechanism from the hot CNO cycle. Model calculations predict (α, p) reaction rates significantly affect both the light curves and elemental abundances in the burst ashes. The Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas jet target enables the direct measurement of previously inaccessible (α,p) reactions with radioactive beams provided by the rare isotope re-accelerator ReA3 at the National Superconducting Cyclotron Laboratory (NSCL), USA. JENSA is going to be the main target for the Recoil Separator for Capture Reactions (SECAR) at the Facility for Rare Isotope Beams (FRIB). Commissioning of JENSA and first experiments at Oak Ridge National Laboratory (ORNL) showed a highly localized, pure gas target with a density of ∼10¹⁹ atoms per square centimeter. Preliminary results are presented from the first direct cross section measurement of the ³⁴Ar(α, p)³⁷ K reaction at NSCL.