Angular distribution of Auger-electron emission following double-electron capture inC6++He collisions

Abstract

Angular distributions of Auger electrons ejected in 60-keV C ++He collisions were measured. This study extends previous work where cross sections for the production of the configuration 2lnl' (n~3) have been determined from measurements at the observation angle of 0' only. For n =3 and 4, the present angular distributions were measured to be anisotropic, whereas for n = 5 and 6 the electron emissions were found to be isotropic within the experimental uncertainties. The integration over the observation angle yields total production cross sections 0. 2I"I that were found to follow an n law, in agreement with previous calculations. The observed angular distributions are discussed in terms of different capture mechanisms.PACS number(s): 32.80.Hd, 34.50.Fa

Auger electron emission following double electron capture in 150-keVNe10++He collisions

“…nd that Auger-electron emission cross sections for the 3lnl' configurations follow a n law. This finding agrees with the cross-section data obtained for configurations 2lnl' in the collision system 90-keV C ++He [7,11].…”

“…Since the Auger yield is rather constant, the double capture cross section for producing the con5gurations 31n1' also follow the n law. It was noted [6,7,11] that the n law may be a signature for the dielectronic processes, as discussed in the following section. and Niehaus [13].…”

Electron Capture in Collisions of Slow Highly Charged Ions with an Atom and a Molecule: Processes and Fragmentation Dynamics

“…Hence, the DEC process may occur by two independent one-electron transitions (denoted monoelectronic in the following), due to the nucleus electron interaction. Then, configurations of quasi equivalent electrons 2l3l' and 3l3l' are produced [22,23]. Furthermore, as shown in Figure 1, resonance conditions are created at ∼ 3 a.u.…”

“…While DEC can be rather well described using independent electron models, it has been shown that dynamic correlation effects due to the electronelectron interaction which is not incorporated in these models may play a decisive role during the collision [22,23]. The importance of these processes depends strongly onto the collision systems involved [24], and the projectile velocity [15,18].…”

“…Since the doubly excited states involved during the collision decay mainly via Auger electron emission, the experiments were performed using the method of Auger electron spectroscopy [13,18,[22][23][24]. Recently, more detailed information was obtained using imaging techniques and Recoil Ion Momentum Spectroscopy (RIMS) [6,32].…”