Measurements of the elastic scattering cross section of 3He and 4He are important in order to improve constraints on theoretical models of 4He (3He ,𝛾) 7Be, a key reaction in Big Bang nucleosynthesis and solar neutrino production. The astrophysical 𝑆 factor for this reaction is a significant source of uncertainty in the standard-solar-model prediction of the 7Be and 8B solar neutrino fluxes. The elastic scattering measurements reported in the literature do not extend to low energies and lack proper uncertainty quantification. A new measurement of the 4He (3He, 3He) 4He reaction has been made at center-of-mass energies 𝐸c.m.=0.38−3.13 MeV using the Scattering of Nuclei in Inverse Kinematics (SONIK) scattering chamber: a windowless, extended gas target surrounded by an array of 30 collimated silicon charged particle detectors situated at TRIUMF. This is the first elastic scattering measurement of 3He + 4He made below 500 keV and it has greater angular range and better precision than previous measurements. The elastic scattering data were analyzed using both 𝑅-matrix and halo effective field theory frameworks, and values of the 𝑠-wave scattering length and effective range were extracted. Here, the resulting improvement in knowledge of the 𝑠-wave effective-range function at low energies reduces the overall uncertainty in 𝑆34 at solar energies.
Paneru, S. N., et al. "Elastic scattering of <sup>3</sup>He +<sup>4</sup>He with the SONIK scattering chamber." Physical Review. C, vol. 109, no. 1, Jan. 2024. https://doi.org/10.1103/PhysRevC.109.015802
Paneru, S. N., Brune, C. R., Connolly, D., Odell, D., Poudel, M., Phillips, D. R., Karpesky, J., Davids, B., Ruiz, C., Lennarz, A., Greife, U., Alcorta, M., Giri, R., Lovely, M., Bowry, M., Delgado, M., Esker, N. E., Garnsworthy, A. B., ... Weinerman, C. (2024). Elastic scattering of <sup>3</sup>He +<sup>4</sup>He with the SONIK scattering chamber. Physical Review. C, 109(1). https://doi.org/10.1103/PhysRevC.109.015802
Paneru, S. N., Brune, C. R., Connolly, D., et al., "Elastic scattering of <sup>3</sup>He +<sup>4</sup>He with the SONIK scattering chamber," Physical Review. C 109, no. 1 (2024), https://doi.org/10.1103/PhysRevC.109.015802
@article{osti_2916434,
author = {Paneru, S. N. and Brune, C. R. and Connolly, D. and Odell, D. and Poudel, M. and Phillips, D. R. and Karpesky, J. and Davids, B. and Ruiz, C. and Lennarz, A. and others},
title = {Elastic scattering of <sup>3</sup>He +<sup>4</sup>He with the SONIK scattering chamber},
annote = {Measurements of the elastic scattering cross section of 3He and 4He are important in order to improve constraints on theoretical models of 4He (3He ,𝛾) 7Be, a key reaction in Big Bang nucleosynthesis and solar neutrino production. The astrophysical 𝑆 factor for this reaction is a significant source of uncertainty in the standard-solar-model prediction of the 7Be and 8B solar neutrino fluxes. The elastic scattering measurements reported in the literature do not extend to low energies and lack proper uncertainty quantification. A new measurement of the 4He (3He, 3He) 4He reaction has been made at center-of-mass energies 𝐸c.m.=0.38−3.13 MeV using the Scattering of Nuclei in Inverse Kinematics (SONIK) scattering chamber: a windowless, extended gas target surrounded by an array of 30 collimated silicon charged particle detectors situated at TRIUMF. This is the first elastic scattering measurement of 3He + 4He made below 500 keV and it has greater angular range and better precision than previous measurements. The elastic scattering data were analyzed using both 𝑅-matrix and halo effective field theory frameworks, and values of the 𝑠-wave scattering length and effective range were extracted. Here, the resulting improvement in knowledge of the 𝑠-wave effective-range function at low energies reduces the overall uncertainty in 𝑆34 at solar energies.},
doi = {10.1103/PhysRevC.109.015802},
url = {https://www.osti.gov/biblio/2916434},
journal = {Physical Review. C},
issn = {ISSN 2469-9993},
number = {1},
volume = {109},
place = {United States},
publisher = {American Physical Society (APS)},
year = {2024},
month = {01}}
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