Isoelectronic study of triply excited Lilike electron scattering resonances

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Isoelectronic study of triply- excited Li-like
electron scattering resonances

• Theo J.M. Zouros
• University of Crete/FORTH Heraklion
• GREECE

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Recent collaborators
J.R. Macdonald Lab Kansas State Univ.
Dr. Manolis Benis PhD 2001 Univ. of Crete JRM
Prof. Tom Gorczyca Western Michigan
Univ. R-matrix calculations
Prof. Pat Richard
Mikhail Zamkov Grad Student
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Production of triply-excited Li-like states
Photoionization ? 1s22p 2P0 ?1s2l 3,1L e-(el)
Resonant Electron Scattering
1s2p 3,1Po
ALS synchrotron G39meV
Foil excitation
1s2 1Se
671 nm cw dye laser
He-like ions Z5-9
1s22s 2Se
Lithium
-like
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Electron - ion collisions Production and decay
of doubly excited states
radiative stabilization recombination DR or RTEX
Aq
capture of a (quasi-) free electron excitation
inverse autoionization
autoionization Resonant electron scattering RES
or RTEA
Ee Bn E1-E0
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UoC HEMISPHERICAL ANALYZER WITH 2-D PSD 0o
ELECTRON SPECTROMETER
Faraday Cup
Ion Beam
4-element lens
Inner hemisphere
Gas Cell
Pressure Gauge
Gas in
electrons
PSD X-Position Y- Position Timing
Outer hemisphere
e-
?
Resolution 0.1 ?O 1.8 x 10-4 sr
00 dgrs
Ion
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Elastic scattering of quasi-free electrons on B3
ions
Triply Excited States !
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Resonant electron scattering R-matrix calculation
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First Z-dependence study of a triply-excited state
Benis et al. submitted PRL June 2003
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Summary and Conclusion

• Isoelectronic investigation of the scattering
  properties of
• the triply-excited 2s2p2 2D state for He-like
  B, C, N, O, F
• in collisions with H2
• Resonant electron scattering R-matrix
  calculations within
• the electron scattering model (impulse
  approximation)
• found to be in good agreement with experiment
• Scattering techniques still the only way to
  obtain
• information about resonances for HCI with Zgt3
• - Free electron laser is expected to change this
  
• but still need about 10 years?!