The thermonuclear reaction rate of $^{17}$O($p$,$\gamma$)$^{18}$F---a low-energy, high beam current study at LENA

ORAL

Abstract

Classical novae are thought to be the dominant source of $^{17}$O in our Galaxy. These energetic events produce $^{18}$F that, as it decays to $^{18}$O, drives the ejection of nuclear ``ash'' into the interstellar medium. The importance of the non-resonant component of the $^{17}$O($p$,$\gamma$)$^{18}$F reaction is well established, and numerous studies have been performed to analyze this reaction. However, the temperature regime relevant to explosive hydrogen burning during classical novae corresponds to very low proton bombarding energies. At these low energies, the Coulomb barrier suppresses the reaction yield in the laboratory, and environmental backgrounds dominate the detected signal making it difficult to differentiate the direct capture $\gamma$-cascade from background. At the Laboratory for Experimental Nuclear Astrophysics (LENA), our electron cyclotron resonance (ECR) ion source produces intense, low-energy protons ($\approx$ 2.0 mA at the target), and these high currents boost the thermonuclear reaction yield. The LENA facility also has a coincidence detector setup that reduces environmental background contributions. Improved $^{17}$O($p$,$\gamma$)$^{18}$F direct capture reaction rates are currently being determined, and our progress will be reported.

Authors

  • Matthew Buckner

    The University of North Carolina at Chapel Hill, Triangle Universities Nuclear Laboratory

  • Christian Iliadis

    The University of North Carolina at Chapel Hill, Triangle Universities Nuclear Laboratory

  • Keegan Kelly

    The University of North Carolina at Chapel Hill, Triangle Universities Nuclear Laboratory

  • Lori Downen

    University of North Carolina at Chapel Hill and Triangle Universities Nuclear Laboratory, The University of North Carolina at Chapel Hill, Triangle Universities Nuclear Laboratory

  • Arthur Champagne

    University of North Carolina at Chapel Hill and Triangle Universities Nuclear Laboratory, The University of North Carolina at Chapel Hill, Triangle Universities Nuclear Laboratory

  • John Cesaratto

    The University of North Carolina at Chapel Hill, Triangle Universities Nuclear Laboratory

  • Richard Longland

    The University of North Carolina at Chapel Hill, Triangle Universities Nuclear Laboratory