1. Photodetachment microscopy to an excited state and accurate electron affinity measurements
C. Blondel, C. Delsart, C. Drag, R. J. Peláez & M. Vandevraye
Laboratoire Aimé-Cotton, bât. 505, CNRS, université Paris-sud, F Orsay cedex, France
Photodetachment microscopy
Photodetachment microscopy to an excited state: 31P- hν a
Level scheme
Classical parameters
Highest height
Maximum radius
z0 =
Quantum parameters :
Wavelength scale
Number of rings
Interfrange
distance
Radial current density
0 = m
a = 0.35 m R
F = 427 Vm-1
 = 0,926
± 0,002 cm-1
Rmax j
Principle:
Y.N. Demkov et al., JETP Lett. 34 (1981) 403
Photodetachment microscopy:
C. Blondel et al., Phys. Rev . Lett. 77 (1996) 3755
Photoionization microscopy:
C. Nicole et al., Phys. Rev . Lett. 88 (2002)
Molecular photodetachment microscopy :
C. Delsart et al., Phys. Rev . Lett. 89 (2002)
Linear regression to zero kinetic energy
Experimental set-up
Measured thresholds
Experimental spots
Deduced intervals C D F U
negative
ion
neutral
atom h  eA
Electron affinity (10), formerly (6) eV
Neutral atom spectroscopy and fine structure 15 7 6 5 4 3 2 1 8 9 10 11 12 13
Photodetachment microscopy of Se- 14
Electron affinity : (8) m-1
formerly (20) m-1
or (1) vs (2) eV
4 : Wien filter
7 : Deflection 
11 : Focalisation quadrupole
12 : Deceleration plates
13 : Interaction zone
14 : Laser
15 : Column of constant F
16 : MCP
17 : Phosphor screen
18 : CCD
 1 : Source and simple lens doublet (“Einzellens")
2,5,9,10 : Deflection plates
3,6,8 : Simple lenses
43rd EGAS, Fribourg, 28 June – 2 July 2011