Radiative electron capture to the continuum in U89++N2 collisions: Experiment and theory

For U89+ projectiles colliding at a beam energy of 75.91 MeV/u with a N-2 target, we present a coincidence measurement between the cusp electrons emitted under an angle of 0. with respect to the projectile beam and the photons emitted under a polar angle of 90 degrees. This radiative-electron-capture-to-continuum cusp directly probes the theory of electron-nucleus bremsstrahlung up to the high-energy endpoint in inverse kinematics. In the present study, significant improvement with respect to the experimental accuracy has been achieved, resulting in a finer agreement between experimental and theoretical results.