Experimental characterization of the Xe 5p photoionization by angle- and spin-resolved photoelectron spectroscopy

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Abstract. Using circularly polarized synchrotron radiation, the photoionization of HBr molecules was studied by angle-and spin-resolved photoelectron spectroscopy in the photon energy range from ll.7eV to 21eV. For photoelectrons corresponding to the final ionic states HBr + X2H3/2(v = O) and X2//1/2 (v = 0), the energy dependence of the dynamical photoionization parameters was measured and compared with ab initio calculations for HBr + by Raseev et al. and RRPA calculations for Kr ÷ by Huang et al.. This comparison indicates that, for energies above the electronic autoionization region, photoemission from the outer valence orbital exhibits distinct atomic behavior. By combining the experimental data for the cross section a and the spin polarization parameter A, sums of partial cross section contributions to a were determined and analyzed to obtain specific information on the outgoing partial electron waves. Furthermore, the validity of the so-called non-relativistic relationships for the dynamical photoionization parameters was tested as a function of equal photon and kinetic photoelectron energy, respectively.

Section: Methodsmentioning

confidence: 99%

“…[9] and with results for the X2113/z(V = 0) and XZ//1/2(v = 0) final ionic states of HI [5,6]. Similarities dbserved for the outer p-subshell photoionization process in the atomic and molecular cases are described for the rare gases Kr [15,16], Xe [16,17] and the hydrogen halides HBr, HI.…”

Section: Introductionmentioning

confidence: 95%

Angle- and spin-resolved photoelectron spectroscopy of thepπ outer valence shell of HBr molecules

Salzmann

Böwering

Klausing

et al. 1996

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“…The second equation is only valid in the non-relativistic limit, neglecting any differences between the ed~_ and 2 e& continuum waves of photoelectrons [13] due to spin orl~it interaction. In the relativistic case [14] the Auger electron polarization depends upon two ratios of matrix elements whereas the photoelectron polarization depends in addition on a phase shift difference and therefore no linear relation exists between A Auger and A ph°t°.…”

mentioning

confidence: 99%

Spin polarization of Auger- and of photoelectrons from barium atoms exposed to circularly polarized radiation and their cross comparison

Kuntze

Salzmann

Böwering

et al. 1994

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Abstract.New results of spin polarization of both photoelectrons and Auger electrons are reported after 5p photoionization of free Ba atoms with circularly polarized light. A substantial polarization transfer from the spin polarized photons to the spin polarized photoelectrons and via the hole state orientation to the spin polarized Auger-electrons is observed. The cross comparison of the results for photoelectrons and Auger-electrons allows a quantitative test of the assumed two step model where both electron-emission processes occur in sequence. 32.80.Hd Creation of vacancies in inner atomic shells by photon or particle impact often gives rise to subsequent Auger decay. Recently, these Auger electrons have been measured to be strongly spin polarized for the electron spectroscopy studies with free barium atoms [1] and Rb-adsorbates [2], where the primary photoemission process has been performed by means of spin polarized i.e. circularly polarized radiation. In their emission characteristics these Auger electrons reflect a non-statistical population of the magnetic substates of the intermediate ionic state produced by the spin oriented initial impact [3,4]. Consequently, an orientation of the intermediate state can be transferred partially to the Auger electron spin polarization [5,6]. On the other hand the data of spinand angle resolved Auger spectroscopy can be used to determine alignment and orientation of the intermediate photoion state from the experiment [ 1 ]. Cross comparison of these results with the corresponding dynamical parameters characterizing the primary photoelectron emission process, angular distribution and spin polarization parameters which form a "complete experiment", should answer whether photoelectron and Auger electron emission are subsequent processes in a two-step model or whether they have to be seen as a dynamical combi-

“…This component is the only one which does not vanish after integrating over all emission angles [34]. For angle-resolved determination of the spin-polarization component A (0) and the parameter ce, the electron analyzer has to be rotated through the reaction plane and, subsequently, the electrons have to be transported to the space-fixed Mott detector for spin polarization analysis.…”

Section: F(o)mentioning

confidence: 99%

“…The main effect of the weak admixture of linearly polarized light to the VUV radiation is that the influence of the angular distribution of the photoelectron intensity does not completely vanish for detection at the magic angle. In the experiments using synchrotron radiation [ 17,34,35], this could be circumvented by choosing ~o = 45 ° so that $1 = 0 independent of the ellipticity of the radiation. This was not possible in the experiments described here.…”

Section: Photoionization Experimentsmentioning

confidence: 99%

Angle- and spin-resolved photoelectron spectroscopy in rotationally resolved photoionization of HI

Mank

Drescher

Brockhinke

et al. 1994

Self Cite

Abstract. The method of angle-and spin-resolved photoelectron spectroscopy has been used in combination with a laser based source of vacuum ultraviolet (VUV) radiation to study the photoionization dynamics of the HI molecule. The narrow bandwidth (3 v < 1 cm-1) of the ionizing VUV radiation (v = 83 200 cm-1 _ 89 300 cm 1) enables the resolution of the molecular rotation for single-photon excitation to spin-orbit autoionization resonances. The experimental results for the dynamical parameters a, A, fl, %, and ~ are compared to the results of a recent ab-initio calculation (M. Biichner, G. Raseev, and N.A. Cherepkov, J. Chem. Phys. 96, 2696 (1992)) and used to analyze the photoionization process in terms of partial contributions of different values of I and 2 to the outgoing electron waves.