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Demokritos March 11, 2009 1 High resolution Auger projectile e - spectroscopy : A state-selective tool to study highly charged ion - atom collisions Theo.

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Presentation on theme: "Demokritos March 11, 2009 1 High resolution Auger projectile e - spectroscopy : A state-selective tool to study highly charged ion - atom collisions Theo."— Presentation transcript:

1 Demokritos March 11, High resolution Auger projectile e - spectroscopy : A state-selective tool to study highly charged ion - atom collisions Theo J.M. Zouros Department of Physics University of Crete - Heraklion LIBRA kick-off meeting

2 Ion – Atom/electron Collisions Ion beam Z ~ 1-12 I ~ nA q ~ 1-12 E ~ MeV/u V ~ 3-6 a.u. gs or metastable t = -∞ ∆t = s Preparation Ionization Excitation Transfer combinations Relaxation e-e- e-e- e- γ γ Black box?! Non radiative: Auger electrons Radiative: Photon decay Atom/Molecule Target q = 0 (neutral) Gas/Solid gs or excited state n ~ #/cm 3 Interaction Detectors projectile, recoil, photon, electron coincidences ΔΩ – solid angle ε - efficiency e- beam Target q = -1 I ~ 1-50 μA n ~ #/cm 3

3 UoC HEMISPHERICAL ANALYZER WITH 2-D PSD 0 o ELECTRON SPECTROMETER UoC HEMISPHERICAL ANALYZER WITH 2-D PSD 0 o ELECTRON SPECTROMETER Ion Beam Gas in Pressure Gauge Gas Cell PSD X-Position Y- Position Timing 4-element lens Faraday Cup Inner hemisphere electrons Outer hemisphere θ e-e- Ion Resolution ~ 0.1% ΔΩ = 1.8 x sr 0 0 dgrs

4 Experimental Setup at the 7MV tandem of J R Macdonald Laboratory – Kansas State university Dedicated experimental setup 1990 – 2007 Now have moved all to Demokritos Tandem

5 Demokritos 13, 20035

6 High resolution ion Auger electron spectra E.P. Benis – PhD thesis, UoC 2001

7 Elastic Scattering of Quasi-free Electrons on B 4+ Ions Doubly Excited states Zouros, Benis, Gorczyca, PRA68, (R) (2003)

8 Elastic Scattering of Quasi-free Electrons on B 3+ Ions Doubly Excited states s2p 3 P s2p 1 P Zouros, Benis, Gorczyca, PRA68, (R) (2003)

9 Ion-atom/electron interactions: Investigation of the Coulomb force Force is Coulomb: Force is Coulomb: Potential usually known - can write down a Hamiltonian Potential usually known - can write down a Hamiltonian Calculate emission or interaction cross sections Calculate emission or interaction cross sections Difficulties: many particles, long range force, correlation effects Difficulties: many particles, long range force, correlation effects Model calculations Model calculations Develop theoretical and experimental techniques Develop theoretical and experimental techniques Test approximations Test approximations

10 Interest in ion-electron/atom collisions Applications Tokomak and Astrophysical Plasmas Tokomak and Astrophysical Plasmas Accelerator technology - Storage rings Accelerator technology - Storage rings Radiation damage – cancer therapy Radiation damage – cancer therapy Basic atomic collisions Basic atomic collisions Use HCI and simple targets – few-electron systems Study ion excitation rather than target excitation:   Control charge state q of ion – N number of electrons   Isoelectronic sequence study – same N different Z In preparation for PHYSICS REPORTS Zero-degree Auger spectroscopy of Projectile Ions in atomic collisions in collaboration with N. Stolterfoht (HMI-Berlin)

11 Dept. of Physics, University of Crete-Heraklion, Crete Theo J.M. Zouros (Θεόδωρος Τζούρος - Project: Investigation of one- and two-electron processes in energetic ion-atom collisions using high resolution Auger projectile electron spectroscopy Goal: State-selective cross section measurements of basic atomic collision processes and the investigation of their collisional energy dependence. Processes include capture, excitation, ionization and combinations such as transfer- excitation, transfer-loss, double-electron capture etc. Investigation of dynamic electron correlation effects. Scientific domain: Atomic collision physics (Basic Research) Beams: p, Li, B, Be, C, N, O, F and possibly higher Z Charge-states: bare, one-, two-, three- and four electron ions, i.e. F 6-9+ etc. Intensities:  10 nA Setup: installed at INP permanently, modifications necessary. Spectrometer: Electrostatic energy analyzer in magnetically shielded chamber. Detectors: MCP or channeltron Targets: differential pumped gas target using H 2, He, Ne, Ar etc. Personnel: 1 Senior scientist, ideally 1 post-doc and or 1 or 2 students Man-power support by INP (Yes/No – No. of scientists – Mech. Workshop etc.) : Other details: Will need basic NIM electronic support, kV power supplies, 2-3 turbo pumps and data acquisition and control programs – possibility of collision chamber and spectrometer exists Is the project part of an international collaboration ? : Yes (Kansas State U., ATOMKI, ITS-LEIF EU network) Is the project a preparatory work for expmts. abroad ? : Not necessarily but could be 1 st TANDEM users meeting, Feb. 3, 2006, INP/Demokritos, Athens

12 Looking forward to a mutually profitable collaboration/use of the facility Thank the LIBRA organizers and the DEMOKRITOS tandem staff for their help so far And in the future to come Will need help setting up and running experiments all interested parties (particularly students) all interested parties (particularly students) are invited to join


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