Dynamics and post-collision interaction effects in two electron decay from the Xenon 4d hole

Two Auger electrons, one very slow, one fast, have been detected in coincidence following near threshold 4d photoionization of the Xe atom. The distribution in the energy the two electrons share has been measured for the first time revealing the presence of post-collision interaction effects that provide unique information on the decay dynamics of the 4d hole. Analysis of the distorted line shapes indicates that the dominant process is decay of Xe+(4d(-1)) to Xe3+ through cascade emission of a zero kinetic energy Auger electron followed by a fast Auger electron. The widths of the intermediate Xe2+* states are estimated to be about 60 meV.

Photoelectron-fragment ion correlations and fixed-molecule photoelectron angular distributions from velocity imaging coincidence experiments

A new technique, based on velocity imaging, has been developed to examine correlations in energy and angle between the several particles formed in dissociative single and double photoionisation at VUV wavelengths. Electrons and positive fragment ions are imaged in coincidence at position-sensitive detectors; the resulting multidimensional data sets contain separable energy distributions, angular distributions and correlations in energy and angle between the particles. In some cases internal or external evidence indicates that pure axial recoil occurs, without molecular rotation. In such cases fixed-molecule photoelectron angular distributions can be extracted and parametrised. Results for H2, N2, NO, CO and O2 are presented. Effects of shape resonances in the ionisation channels are apparent in several cases.

Photoelectron angular distributions from O K shell of oriented CO molecules: A critical comparison between theory and experiment

The dynamical information (ten dipole matrix elements and eight phase differences) has been deduced from the measured angular distributions of photoelectrons from O K shell of oriented CO molecules near the ionization threshold in the region of a sigma(*) shape resonance. Light polarization parallel and perpendicular to the molecular axis has been used. An important contribution of six lsigma partial waves with 0</=l</=5 to the sigma(*) shape resonance is demonstrated. A comparison with our calculations in the relaxed core Hartree-Fock approximation reveals only a qualitative agreement, therefore a more advanced theory is needed.

Manifestation of many-electron correlations in photoionization of the K shell of N2

It is demonstrated theoretically in the random phase approximation (RPA) that due to the intershell many-electron correlations the sigma(*) shape resonance in the photoionization of K shells of the N2 molecule appears not only in the 1sigma(g)-->varepsilonsigma(u) channel as it was believed earlier on the basis of single particle calculations, but in both 1sigma(g)-->varepsilonsigma(u) and 1sigma(u)-->varepsilonsigma(g) channels. As a confirmation of this phenomenon we show that the experimental angular distributions of photoelectrons ejected from fixed-in-space N2 molecules can be reproduced theoretically only after taking into account many-electron correlations.

New results on photoion pair formation from application of the velocity imaging photoionisation coincidence technique

The velocity imaging photoionisation coincidence (VIPCO) technique is shown to be a powerful tool for studies of ion pair formation. Sequential mechanisms are demonstrated for some three-body ion pair formation reactions. Observation of a new type of reaction producing one negatively and two positively charged ions plus an electron is reported.

Familial bilateral papillary cystadenoma of the epididymis: report of three cases in siblings

This paper describes an unusual, familial bilateral papillary cystadenoma of the epididymis found in three siblings. The histological characteristics of the tumor were: 1) papillary proliferation of clear cells, consisting of both tall columnar and round ovoid cells, in the efferent duct epithelium; and 2) cystic dilatation of the duct with colloidal material. The present cases were unique in two respects: 1) familial bilateral papillary cystadenomas probably associated with Lindau's disease have not been reported previously: and 2) electron microscopic observations suggested that the tumors originated from the efferent duct.