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D. F. 7. C. 8. U. 6. 1 : Source and simple lens doublet (“Einzellens") 2,5,9,10 : Deflection plates 3,6,8 : Simple lenses. 10. 4. 5. 12. Detector. 2. 14 : Laser 15 : Column of constant F 16 : MCP 17 : Phosphor screen 18 : CCD. 4 : Wien filter 7 : Deflection
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D F 7 C 8 U 6 1 : Source and simple lens doublet (“Einzellens") 2,5,9,10 : Deflection plates 3,6,8 : Simple lenses 10 4 5 12 Detector 2 14 : Laser 15 : Column of constant F 16 : MCP 17 : Phosphor screen 18 : CCD 4 : Wien filter 7 : Deflection 11 : Focalisation quadrupole 12 : Deceleration plates 13 : Interection zone 9 1 11 13 3 ion Main proprieties z0 Tunable single longitudinal mode. Dual polarization stabilized He-Ne Sigmameter QCW Long & short time stabilization Pumped QCW 20 Hz, 515 nm Ti:Sa QCW, 150 µs Lambdameter WSU uncertain. +/- 0.041 m-1 L. Cabaret, Appl. Phys.B 94, 71 (2009) Nanosecond pulse Energy ≈ 400mJ Frequency doubled Nd:YAG 25 mJ @ 532 nm Pulsed Ti:Sa ~ 10 mJ @ 810 nm BBO Uncertainty ≈0.8 m-1 ~ 1 mJ @ 405 nm 15 ns L. Cabaret and C. Drag, Eur. Phys. J. Appl. Phys.37, 65 (2006) l0 = 0.045 mm a = 0.35 mm F = 427 Vm-1 j e = 0,926 ± 0,002 cm-1 Ai R Rmax 2P3/2 F2 = 4 14.097 m-1 F2 = 3 6.5575 m-1 F2 = 2 2.46 m-1 F2 = 1 I [F2]=2 F2 +1 eA=2467287(3) m-1 1S0 F1 = 5/2 Electron affinity (m-1) e neutral atom hn eA Laser pulse energy (µJ) negative ion Photodetachment microscopy with a pulsed laser R. J. Peláez, C. Blondel, C. Delsart and C. Drag Laboratoire Aimé-Cotton, Centre national de la recherche scientifique, batiment 505, Univ. Paris-sud, F-91405 Orsay cedex, France Photodetachment microscopy Pulsed laser Classical parameters Highest height Maximum radius Quantum parameters : Number of rings Interfranges distance Radial current density Principle: Y.N. Demkov et al., JETP Lett.34, 403 (1981) Photodetachment microscopy: C. Blondel et al., Phys. Rev . Lett.77, 3755 (1996) Photoionization microscopy: C. Nicole et al., Phys. Rev . Lett.88, 133001 (2002) Molecular photodetachment microscopy : C. Delsart et al., Phys. Rev . Lett.89, 183002 (2002) Results : electron affinity of 127I Electron Count Experiment set-up Barycenter Accumulation Radius (mm) Ponderomotive effect : electron oscillations in electromagnetic waves. 18 17 • Ponderomotive effect has been negligible, for two reasons: • i) Blue wavelength (405 nm for I-) • ii) Low energy ≈ 400µJ 16 15 Electron Affinity (eV) 14 Electron Affinity (eV) eA(127I) = 24672.867 (28) cm-1 = 3.0590453 (36) eV XXVI International Conference on Photonic, Electronic, and Atomic Collisions.Kalamazoo, Michigan 22 - 28 July 2009 R. J. Peláez et al.J. Phys. B. 42, 125001 (2009)