Narrow-band pulsed electron source based on near-threshold photoionization of Cs in a magneto-optical trap

  title={Narrow-band pulsed electron source based on near-threshold photoionization of Cs in a magneto-optical trap},
  author={Olena Fedchenko and S. V. Chernov and Gerd Schǒnhense and Rapha{\"e}l Hahn and Daniel Comparat},
  journal={Physical Review A},
The newly developed method of time-of-flight (ToF) momentum microscopy was used to analyse the cold electron emission from a Cs 3D magneto-optical trap (MOT). Three-step resonant photoionization was implemented via two intermediate states (6P3/2 pumped with 852 nm laser and 7S1/2 with 1470 nm) and a tuneable femtosecond Ti:sapphire laser for the final ionization step. The magnetic field of the MOT is switched off during the photoionization step. The natural bandwidth of the fs-laser is reduced… 

Figures from this paper



Extraction dynamics of electrons from magneto-optically trapped atoms

Pulsed photoionization of laser-cooled atoms in a magneto-optical trap (MOT) has the potential to create cold electron beams of few meV bandwidths and few ps pulse lengths. Such a source would be

Pulse length of ultracold electron bunches extracted from a laser cooled gas

Measurements of the pulse length of ultracold electron bunches generated by near-threshold two-photon photoionization of a laser-cooled gas are presented and Rydberg states which slowly ionize on microsecond time scales are produced.

High-coherence electron bunches produced by femtosecond photoionization.

It is shown that high coherence electron pulses can be produced by femtosecond photoionization, opening up a new regime of ultrafast structural dynamics experiments and the transverse coherence turns out to be much better than expected on the basis of the large bandwidth of the femtosescond ionization laser pulses.

Ultracold Electron Source for Single-Shot, Ultrafast Electron Diffraction

Correlations in transverse phase-space indicate that the transverse emittance can be improved even further, enabling single-shot studies of biomolecular samples, and proposes a new type of electron source, based on near-threshold photoionization of a laser-cooled and trapped atomic gas.

Identification of competing ionization processes in the generation of ultrafast electron bunches from cold-atom electron sources

We make direct measurements of the duration of ultrafast cold-electron bunches produced by photoionization of laser-cooled atoms. We show that the bunch duration can vary by up to six orders of

Ultracold electron source for single-shot diffraction studies

Ultracold electron sources, which are based on near-threshold photo- and field-ionization of a cloud of laser-cooled atoms, offer the unique combination of low emittance and extended size that is

Rydberg-state ionization dynamics and tunnel ionization rates in strong electric fields

Tunnel ionization rates of triplet Rydberg states in helium with principal quantum numbers close to 37 have been measured in electric fields at the classical ionization threshold of $\sim197$ V/cm.

Stimulated Raman Adiabatic Passage for Improved Performance of a Cold Atom Electron and Ion Source

We implement high-efficiency coherent excitation to a Rydberg state using stimulated Raman adiabatic passage in a cold atom electron and ion source. We achieve an efficiency of 60% averaged over the

Optimization of the current extracted from an ultracold ion source

Photoionization of trapped atoms is a recent technique for creating ion beams with low transverse temperature. The temporal behavior of the current that can be extracted from such an ultracold ion