Revealing the non- s ² contributions in the momentum wave function of ground-state He

Abstract

(received ; accepted ) PACS. 34.70.+e -Charge transfer. PACS. 34.50.Fa -Electronic excitation and ionization of atoms. PACS. 39.90.+d-Other instrumentation and techniques for atomic and molecular physics (restricted to new topics in section 39).Abstract. -The correlated Tunneling Transfer Ionization (TuTI) channel in fast 4-body processes p + He → H 0 + He 2+ + e is utilized to probe the highly correlated asymptotic parts of the He ground state momentum space wave function. In this reaction, predominantly at large nuclear impact parameters, one electron in the He ground state is captured by the proton by tunneling through the two-center barrier when electron and proton velocity vectors resonantly match. The measured 3-particle final-state momentum distributions show characteristic features that we trace back to the highly correlated non-s 2 components of the He ground state momentum wave function. This conclusion is supported by a simple heuristic model.In atomic physics, the ground state of He provides an ideal test case for studying the correlated motion of electrons in a bound few-electron system [1]. In this paper we reveal new information on the electron correlation in He by employing a novel high resolution momentum imaging technique. A very small fraction of the He ground state occupation probability is projected onto the continuum by an electron capture reaction in which one electron is picked up by a fast proton and the second electron is left in the continuum. The correlation can be seen directly in the momentum distribution of the continuum electron rather than having to

Recoil-ion and electron momentum spectroscopy: reaction-microscopes

“…In order to boost the resolution for high-energy electron imaging ( eV 100 > ) Weber et al (2003) (Matthäus et al (1991(Matthäus et al ( , 1993) and was recently used by Schmidt-Böcking et al 2003(see also Jalowy et al (20022002a,b;). …”

“…In a later publication Mergel et al (2001) and Schmidt-Böcking et al (2002; analyzed the electron emission characteristics for the same collision system at small scattering angles. In this case, transfer ionisation is expected to be well described as a two-step process.…”

Transfer excitation reactions in fast proton-helium collisions

“…Transfer ionization, where one electron is captured into a bound state of the projectile and a second one is released into the continuum, have been studied in great detail [2][3][4][5][6][7][8][9][10][11][12][13][14] and have led to a better understanding of initial and final state correlation [15][16][17]. Instead of being lifted to the continuum, the second target electron can also be promoted to a bound but excited state.…”

Dynamics of transfer ionization in fast ion-atom collisions

“…Such a process, which becomes possible if the atomic target has at least two electrons, is called transfer ionization. During the last decade transfer ionization in collisions of protons with helium atoms has attracted much attention [1][2][3][4][5][6].…”