Rydberg state ionization by half-cycle-pulse excitation: strong kicks create slow electrons.
The asymptotic velocity distribution of electrons ionized in half-cycle-pulse excitation of high Rydberg states (n=34), placed in a static electric field, is studied using electron velocity-map imaging. At weak half-cycle pulse strengths, the electrons escape over the saddle point in the potential. For strong half-cycle pulses, the electrons are emitted in the direction of the field kick. The much slower and less intense half cycle of opposite polarity, which necessarily follows the main half-cycle pulse, strongly affects the momentum distribution and reduces the excess energy of the electrons significantly.
Wetzels
A
A
Fom Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.
Gürtler
A
A
Noordam
L D
LD
Robicheaux
F
F
Dinu
C
C
Muller
H G
HG
Vrakking
M J J
MJ
van der Zande
W J
WJ