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Auger Electron Spectroscopy of Double and Triple Capture in Flourine on Argon Collisions. Arifa Habib. J. R. Macdonald Laboratory. The Star of this talk, the Tandem Van de Graaf accelerator. The Corona point housing. The Charging belt . The Scenario.
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Auger Electron Spectroscopy of Double and Triple Capture in Flourine on Argon Collisions Arifa Habib J. R. Macdonald Laboratory
The Star of this talk, the Tandem Van de Graaf accelerator
The Corona point housing The Charging belt
The Scenario.... • The 2l2l’2l’’ triply excited states of F9+ had recently been observed in fast energy collisions using the method of triple ion capture to a bare ion using the paracentric HDA [Zamkov. et all, Phys. Rev. A, 67, (050703), 2003] • Since these states are not completely described within the IPM, C.D. Lin et all were working on new ways to describe these states from the correlated motion of the electrons within the state.[Phys.Rev. A, 67, 022511]
The plan....... Take advantage of the better resolution of the tandem parallel plate spectrometer designed by H. Aliabadi to find the absolute SDCS and compare the ratios of the following processes: • triple electron capture & double capture in F9+ at different beam energies • double capture of F8+ to triple capture in F9+ • Excitation + capture in F8+ to double capture in F9+.
The tools.... The electronics set-up The spectrometer
The reason for using this spectrometer..... Spectrometer resolution found using an electron gun[H. Aliabadi, doctoral thesis, (2004)] ΔE = Epass * R E E
What the previous graph means..... Peak designations: 1: 525.4 eV, (1s2s2)2S 2: 529.4 eV, (1s2s2p)4P 3: 539.9 eV, (1s2s2p)2P_ 4: 544.9 eV, (1s2p2)4P 5: 551.0 eV, (1s2p2)2D 6: 561.1 eV, (1s2p2)2S
Yes, but what’s it all about ? Zero degree projectile Auger electron “full spectrum”
What was discovered... at 16 MeV
The only energy dependence of cross sections calculation so far...... Absolute SDCS measurements of triple electron capture to the C3+ KLL states, populated in collisions of bare carbon ions with Ar targets. [Phys. Rev A, 66, 042714 (2002)]
and more ratios ..... F9+ Double capture to F8+ excitation + capture = 5.99 Results of individual lines not plotted yet
So for the future.... • During last summer and this semester the paracentric spectrometer has been improved • It is hoped that the improvements will allow us to operate with higher decel factors and thus obtain higher energy resolustion. • Its therefore to repeat all of this on the paracentric HDA! so that we can further investigate the beam energy dependence of triple to double capture. Thanks for listening !