ah 0v
Detector
Fion
z0
R. J. Peláez, C. Blondel, C. Delsart and C. DragLaboratoire Aimé-Cotton, Centre national de la recherche
scientifique, batiment 505,Univ. Paris-sud, F-91405 Orsay cedex, France
Photodetachment microscopy with a pulsed laser
Experiment set-up
qFa
0max 2 azR
23
032
aN
Interfrangesdistance
a
z
NR
i3
00max 3
Pulsed laser
7
6
5 4
3
2
1
8
9
10
11
12
13
1 : Source and simple lens doublet (“Einzellens") 2,5,9,10 : Deflection plates3,6,8 : Simple lenses
4 : Wien filter7 : Deflection 11 : Focalisation quadrupole 12 : Deceleration plates13 : Interection zone
C
D
F
U
Pumped QCW20 Hz, 515 nm
Ti:SaQCW, 150 µs
Dual polarizationstabilized He-Ne
Sigmameter QCW
Lambdameter WSUuncertain. +/- 0.041 m-1
Frequency doubled Nd:YAG 25 mJ @ 532 nm
Pulsed Ti:Sa~ 10 mJ @ 810 nm
BBO
~ 1 mJ @ 405 nm 15 ns
L. Cabaret and C. Drag, Eur. Phys. J. Appl. Phys. 37, 65 (2006)
L. Cabaret, Appl. Phys. B 94, 71 (2009)
1S0
2P3/2
F1 = 5/2
F2 = 1F2 = 2F2 = 3
F2 = 4
I [F2]=2 F2 +1
14.097 m-1
6.5575 m-1
2.46 m-1
eA=2467287(3) m-1
Ele
ctro
n C
oun
t
Radius (mm)
2467275
2467280
2467285
2467290
2467295
0 100 200 300 400Laser pulse energy (microJ)
Ele
ctr
on
aff
init
y (
m-1
)Ele
ctro
n a
ffinit
y (
m-1)
Laser pulse energy (µJ)
Quantum parameters :
Number of rings
Classical parameters
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)
Highest height
Maximum radius
32
0 2mqF
0 = 0.045 ma = 0.35 m
R
F = 427 Vm-1
= 0,926 ± 0,002 cm-1
Rmax
j
14
15
14 : Laser 15 : Column of constant F16 : MCP17 : Phosphor screen18 : CCD
negative
ion
neutral atom
h
eA
18
16
17
Accumulation Barycenter
Photodetachment microscopy
Results : electron affinity of 127I
2
'
2
1
21
U
F
C
DhA
Tunable single longitudinal mode.Long & short time stabilization
Nanosecond pulse
Uncertainty ≈0.8 m-1
Energy ≈ 400J
Main proprieties
1980 1990 2000 2010Year
Ele
ctro
n A
fin
ity
(eV
)
3.05899
3.05904
3.05909
3.05914
3.05919
Experiment
2467275
2467280
2467285
2467290
2467295
0 20 40 60 80 100
Photoelectron average energy (m-1)
Ele
ctro
n afi
nity
(m
-1)
2.7
2.8
2.9
3.0
3.1
3.2
1980 1990 2000 2010
Year
Ele
ctro
n A
fin
ity
Theory
Experiment
Ele
ctro
n A
ffinit
y (
eV
)
Ele
ctron A
ffinity
(eV
)
Ponderomotive effect : electron oscillations in electromagnetic waves.
2
22
P4 m
EqU
R. J. Peláez et al. J. Phys. B. 42, 125001 (2009)
eA(127I) = 24672.867 (28) cm-1
= 3.0590453 (36) eV
Ponderomotive effect has been negligible, for two reasons:i) Blue wavelength (405 nm
for I-)ii) Low energy ≈ 400µJ
XXVI International Conference on Photonic, Electronic, and Atomic Collisions.Kalamazoo, Michigan 22 - 28 July 2009
a
z
RRj
0
2
0
2
4
1)(
Ai
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