Properties of the first $1/2+$ state in $9Be$ from electron scattering and astrophysical implications

Spectra of the $9Be(e,e′)$ reaction have been measured at the S‐DALINAC at an electron energy $E0 = 73 MeV$ and scattering angles of 93° and 141° with high energy resolution up to excitation energies $Ex = 8 MeV.$ The astrophysically relevant $9Be(γ,n)$ cross sections have been extracted from the $(e,e′)$ data. The resonance parameters of the first $1/2+$ state in $9Be$ have been derived in a one‐level R‐matrix approximation resulting in a resonance energy $ER = 1.748(6) MeV$ and a resonance width $ΓR = 274(8) keV$ These parameters are in mutual agreement with those obtained from the latest real photon experiments but with improved uncertainties.