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Near K-Edge Photoionization and Photoabsorption of Singly, Doubly, and Triply Charged Silicon Ions
S. Schippers, S. Stock, T. Buhr +5
Experimental and theoretical results are presented for double, triple, and quadruple photoionization of Si and Si ions and for double photoionization of Si ions b…
Near L-Edge Single and Multiple Photoionization of Doubly Charged Iron Ions
Stefan Schippers, Randolf Beerwerth, Sadia Bari +11
Using the photon-ion merged-beams technique at a synchrotron light source, we have measured relative cross sections for single and up to five-fold photoionization of Fe ions…
Multiple photodetachment of atomic anions via single and double core-hole creation
S. Schippers, A. Perry-Sassmannshausen, T. Buhr +3
We review the recent experimental and theoretical progress in -shell detachment studies of atomic anions. On the experimental side, this field has largely benefitted from techni…
Near L-edge photoionization of triply charged iron ions
Randolf Beerwerth, Ticia Buhr, Alexander Perry-Saßmannshausen +12
Relative cross sections for -fold photoionization () of Fe by single photon absorption were measured employing the photon-ion merged-beams setup PIPE at the…
Photoionization of tungsten ions: experiment and theory for W
A Müller, S Schippers, J Hellhund +3
Experimental and theoretical cross sections are reported for single-photon single ionization of W ions. Absolute measurements were conducted employing the photon-ion merged-…
Near--K-edge double and triple detachment of the F- negative ion: observation of direct two-electron ejection by a single photon
A. Müller, A. Borovik, S. Bari +9
Double and triple detachment of the F-(1s2 2s2 2p6) negative ion by a single photon have been investigated in the photon energy range 660 to 1000 eV. The experimental data provide…
Photoionisation of Ca ions in the valence-energy region 20eV~--~56eV : experiment and theory
A Mueller, S Schippers, R A Phaneuf +8
Relative cross sections for the valence shell photoionisation (PI) of ground level and metastable Ca ions were measured with high energy resolution by usi…
Photoionization of tungsten ions: experiment and theory for W
A Müller, S Schippers, J Hellhund +3
Experimental and theoretical results are reported for single-photon single ionization of the tungsten ion W. Absolute cross sections have been measured employing the photon-…
Photoionization of ions with synchrotron radiation: From ions in space to atoms in cages
S. Schippers, A. L. D. Kilcoyne, R. A. Phaneuf +1
The photon-ion merged-beams technique for the photoionization of mass/charge selected ionized atoms, molecules and clusters by x-rays from synchrotron radiation sources is introduc…
PAMOP project: computations in support of experiments and astrophysical applications
B M McLaughlin, C P Ballance, M S Pindzola +3
Our computation effort is primarily concentrated on support of current and future measurements being carried out at various synchrotron radiation facilities around the globe, and p…
Prominent role of multi-electron processes in K-shell double and triple photodetachment of oxygen anions
S. Schippers, R. Beerwerth, L. Abrok +7
The photon-ion merged-beams technique was used at a synchrotron light source for measuring absolute cross sections of double and triple photodetachment of O ions. The experim…
Absolute rate coefficients for photorecombination of berylliumlike and boronlike silicon ions
D. Bernhardt, A. Becker, C. Brandau +11
We report measured rate coefficients for electron-ion recombination for Si10+ forming Si9+ and for Si9+ forming Si8+, respectively. The measurements were performed using the electr…
Single-photon single ionization of W ions: experiment and theory
A. Müller, S. Schippers, J. Hellhund +5
Experimental and theoretical results are reported for photoionization of Ta-like (W) tungsten ions. Absolute cross sections were measured in the energy range 16 to 245 eV emp…
Storage Ring Cross Section Measurements for Electron Impact Ionization of Fe 7+
M. Hahn, A. Becker, D. Bernhardt +10
We have measured electron impact ionization (EII) for Fe 7+ from the ionization threshold up to 1200 eV. The measurements were performed using the TSR heavy ion storage ring. The i…
Experimental investigation of left-right asymmetry in photon-atom interaction
S. Ricz, T. Buhr, Á. Kövér +5
Single ionization of noble gas atoms by linearly polarized synchrotron radiation has been studied by employing angle- and energy-resolved photoelectron spectroscopy. The measuremen…
Stepwise contraction of the nf Rydberg shells in the 3d photoionization of multiply-charged xenon ions
S. Schippers, A. Borovik, T. Buhr +8
Triple photoionization of Xe3+, Xe4+ and Xe5+ ions has been studied in the energy range 670-750 eV, including the 3d ionization threshold. The photon-ion merged-beam technique was…
Recombination of W18+ ions with electrons: Absolute rate coefficients from a storage-ring experiment and from theoretical calculations
K. Spruck, N. R. Badnell, C. Krantz +10
We present new experimentally measured and theoretically calculated rate coefficients for the electron-ion recombination of W([Kr] ) forming W. A…
Absolute rate coefficients for photorecombination and electron-impact ionization of magnesium-like iron ions from measurements at a heavy-ion storage ring
D. Bernhardt, A. Becker, M. Grieser +10
Rate coefficients for photorecombination (PR) and cross sections for electron-impact ionization (EII) of Fe forming Fe and Fe, respectively, have been measu…
Absolute cross sections for photoionization of Xe ions (1 q 5) at the 3d ionization threshold
S. Schippers, S. Ricz, T. Buhr +26
The photon-ion merged-beams technique has been employed at the new Photon-Ion spectrometer at PETRA III (PIPE) for measuring multiple photoionization of Xe (q=1-5) ions. Tot…
X-ray resonant photoexcitation: line widths and energies of Kα transitions in highly charged Fe ions
J. K. Rudolph, S. Bernitt, S. W. Epp +14
Photoabsorption by and fluorescence of the Kα transitions in highly charged iron ions are essential mechanisms for X-ray radiation transfer in astrophysical environments. We study…
Storage Ring Cross Section Measurements for Electron Impact Single and Double Ionization of Fe^13+ and Single Ionization of Fe^16+ and Fe^17+
M. Hahn, A. Becker, D. Bernhardt +10
We report measurements of electron impact ionization (EII) for Fe^13+, Fe^16+, and Fe^17+ over collision energies from below threshold to above 3000 eV. The ions were recirculated…
Storage-ring measurement of the hyperfine-induced 2s 2p 3P0 -> 2s2 1S0 transition rate in beryllium-like sulfur
S. Schippers, D. Bernhardt, A. Müller +8
The hyperfine induced 2s 2p 3P0 -> 2s2 1S0 transition rate in Be-like sulfur was measured by monitoring the decay of isotopically pure beams of 32-S12+ and 33-S12+ ions in a heavy-…
Storage-ring ionization and recombination experiments with multiply charged ions relevant to astrophysical and fusion plasmas
Stefan Schippers
Past and ongoing research activities at the Heidelberg heavy-ion storage-ring TSR are reviewed which aim at providing accurate absolute rate coefficients and cross sections of atom…
Dielectronic recombination of xenonlike tungsten ions
S. Schippers, D. Bernhardt, A. Müller +8
Dielectronic recombination (DR) of xenonlike W20+ forming W19+ has been studied experimentally at a heavy-ion storage-ring. A merged-beams method has been employed for obtaining ab…