Analysis of autoionization resonances in the Hg 6s 2-photoionization by measurements of photoelectron polarization

Abstract

Measurements of the spin polarization of photoelectrons in the autoionization region of the Hg 6sZ-subshell using circularly polarized synchrotron radiation and using unpolarized light from rare gas discharge lamps are reported. The results obtained show a pronounced structure across the resonances. Together with data of the cross section and its angular distribution these data from a complete parameter set for the determination of the transition matrix elements and the phase difference of the continuum wavefunctions. Evidences for strong configuration interaction and channel mixing between the open and closed channels were found. The matrix elements and their ratio vary strongly across the resonances and the relative phase shows some changes of sign. A change of the relative phase by rc across an autoionization resonance, predicted by Fano, has been verified experimentally for the triplet resonance.

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

“…In the last weeks, a high-temperature atomic beam oven went into operation, and first spin-polarization measurements on indium atoms were performed. With this atomic beam source, open-shell systems can be investigated, where theoretical methods beyond the RRPA are expected to be necessary, as is already the case in Hg 6s-ionization [17,22].…”

“…Spinorbit interaction again is the reason for the spinpolarization, which is caused by interference between different continuum wavefunctions. Since then experiments have been performed at various targets, where the spin-polarization transfer with circularly polarized radiation [11][12][13][14][15][16][17][18][19][20][21][22], as well as the photoelectron spin-polarization with unpolarized and linearly polarized light [17,18,21,[23][24][25][26][27] have been investigated.…”

Measurements of photoionization of mercury atoms into the 6s2S1/2, 5d96s2 2D5/2and 5d96s2 2D3/2ionic states over the energy range from 10.5 eV to 18.7 eV

“…Baig (2008) reported high resolution (≈0.05 cm −1 ) absorption spectra obtained in selected but narrow energy ranges and analysed the line shapes of the observed autoionizing resonances using the multichannel quantum defect theory. The structures of the autoionizing resonances were also recorded in photoelectron spectra, in the 2 S 1/2 near-threshold region by Brehm and Hoefler (1978) and Schaefers et al (1982) and for the individual 2 S 1/2 , 2 D 5/2 and 2 D 3/2 ionic channels by Blake (1971). The resonance structures were also observed in the ionization efficiency curves using the mass spectrometric techniques by Brehm (1966), Berkowitz and Lifshitz (1968) and Cairns et al (1970).…”

Two‐Photon Resonant Third Harmonic Generation IN Hg

“…have calculated a value of f 0.53, using the equation f (mc/2e2)trar (q2_ 1), where f is the oscillator strength, O'a is the photoionization cross-section for the prt of the continuum that interacts with that state, r is the autoionization linewidth in cm-, and q is the corresponding Fano parameter. The values of the q and r parameters of the 6p' 3D state of Hg have been reported by Schafer et al 26 For the states 7p' P, 8p' P we estimated the oscillator strengths by fitting the function (q+e)2/l+e (where e 2[E-Er]/F, E being the energy of the state) to the photoionization data reported by Brehm 2 and by using the cross-section values reported by Berkowitz. TM The results together with the already reported information are presented in Table 2, where trmax is the maximum absorption cross section and Orb is the photoionization cross-section for the part of the continuum that does not interact with the state and all the other parameters have been defined above.…”