Electron-capture-to-continuum cusp in U88+ + N2 collisions

HILLENBRAND, PIERRE-MICHEL; HAGMANN, SIEGBERT; JAKUBASSA-AMUNDSEN, DORIS; MONTI, JUAN MANUEL; BANAS, D; BLUMENHAGEN, K-H; BRANDAU, C; CHEN, W; FAINSTEIN, PABLO DANIEL; DE FILIPPO, E; GUMBERIDZE, A; GUO, D L; LESTINSKY M; LITVINOV, YU A; MÜLLER, A; RIVAROLA, ROBERTO DANIEL; ROTHARD, H; SCHIPPERS, S; SCHÖFFLER, M S; SPILLMAN, U; TROTSENKO, S; ZHU, X L; STÖHLKER, TH

PHYSICAL REVIEW A - ATOMIC, MOLECULAR AND OPTICAL PHYSICS

AMER PHYSICAL SOC

Lugar: New York; Año: 2015 vol. 91 p. 27051 - 270510

1050-2947

For the collision system U8+ + N2 a collision energy of 90 MeV/u, the energy distribution of electrons being nonradiatively captured from the target into the projectile continuum has been measured under an angle of 0º with respect to the projectile beam axis. This measurement of the electron-capture-to-continuum cusp with the highest effective projectile charge Zpeff=88 at a near-relativistic collision velocity of β≈0.41 is shown to be characterized by a strong asymmetry in the cusp shape. By comparing the data to measurements of the radiative-electron-capture-to-continuum cusp for the same collision system, the opposite asymmetry of the cusp is traced back to the varying underlying mechanisms. The experimental results are compared with the two theoretical calculations available for this process, one of them in the semirelativistic impulse approximation and the other in the nonrelativistic continuum-distorted-wave approach. A corresponding fully relativistic treatment may be motivated by the presented experimental data.