Generation of quasi-Fano profiles in the low field stark spectrum of caesium

Chardonnet, Christian; Delande, Dominique

doi:10.1016/0030-4018(84)90052-x

Cited by 13 publications

(4 citation statements)

References 11 publications

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“…The coupling to the continuum for one of the eigenstates will vanish and the coupling for the other eigenstate will be enhanced due to the interference between the coupling amplitudes that govern their ionization. Such observations have been made previously in sodium [24,29], rubidium [33,34], and in cesium [35,36].…”

Section: Selective Field Ionizationsupporting

confidence: 71%

Field ionization of Rydberg atoms for high-brightness electron and ion beams

et al. 2017

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We present an ionization mechanism for use in a cold atom electron source with the goal of producing highly monochromatic electron beams. We experimentally produce a map of the Stark states of 85 Rb below the ionization threshold and identify states that undergo selective field ionization. The properties of an electron beam produced by field-assisted ionization of such states are quantified. A theoretical framework is established to predict the improvement to beam quality when ionization is conducted above the ionization threshold, where ionization conditions are typically more favorable than below the threshold. Calculations suggest that selective ionization of Rydberg states may offer a pathway to the production of high-brightness, highly monochromatic ion and electron beams.

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Section: Selective Field Ionizationsupporting

confidence: 71%

Field ionization of Rydberg atoms for high-brightness electron and ion beams

et al. 2017

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“…In the case of cesium such interference effects have been reported in Ref. [46,51] but due to interaction with a quasicontinuum formed by a Stark manifold. If this is the first observation of an interference narrowing effect in cesium this is only because of lack of research and not because this effect is rare.…”

Section: B Interference Narrowingmentioning

confidence: 69%

“…A second example of stable Rydberg states becoming unstable can be seen in Fig. 6 where the standard Fano profile line shapes appears [45,46].…”

Section: B Interference Narrowingmentioning

confidence: 93%

Forced field ionization of Rydberg states for the production of monochromatic beams

et al. 2017

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We study Rydberg ionization in an electric field in order to produce monochromatic ion and electron beams. We present an experimental study of the photoexcitation and ionization of high quantum defect states, using excitation from the 7s state in cesium to Rydberg states in the presence of a uniform electric field. Such states can exhibit complex ionization behavior, for instance, highly localized growth in the ionization rate due to interference effects. The data are well reproduced by WKB quantum-defect and frame transformation methods with no adjustable parameters. This indicates that large changes in the Rydberg ionization rate from small changes in electric field are possible when a nearly stable state crosses a more unstable state. A fast variation of the ionization rate with electric field allows for the production of beams with very low energy dispersion. We develop a simple two-level model to predict the voltage and spatial resolution that would occur when atoms are prepared in a state with such sharp ionization in electric field. This confirms that Rydberg forced ionization in an electric field presents a pathway for the production of highbrightness, highly monochromatic ion and electron beams.

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“…Photoabsorption spectra in electric fields (Stark spectra) have been obtained on Rb [1,2], Na [3,4], He [5][6][7], or Ba [8], featuring observations of unstable levels crossings and interference narrowing effects. However, almost no study on Cs exist [9][10][11][12]. This is unfortunate because Cs atoms, being the heaviest (stable) alkali-metal atoms, have the strongest relativistic (such as spin-orbit) couplings, resulting in exaggerated behavior compared with other alkali-metal atoms.…”

Section: Introductionmentioning

confidence: 99%

Cesium Rydberg-state ionization study by three-dimensional ion-electron correlation: Toward a monochromatic electron source

et al. 2021

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We study the excitation and ionization of cesium Rydberg states in an electric field (≈ 2200 V/cm) near the classical field-ionization threshold (≈ − 280 cm −1 binding energy) by three-dimensional (3D) ion-electron coincidence spectroscopy. Cesium atoms are produced by an effusive oven and excited with lasers to Starkshifted Rydberg states or directly ionized. Using a double time-of-flight setup we record 3D (X , Y , time of flight) coincidence imaging of electrons and ions. Above-threshold photoionization creates broad images with poor electron-ion spatial correlation. Fast ionizing states produce very good correlations and the images reveal the electric-field map of the ionization region. Slow ionizing states show that the relatively high atomic velocity is detrimental to the correlations. Experimental data are accurately reproduced by detailed Monte Carlo excitation and ionization simulations based on Stark maps obtained with local-frame transformation (LFT) theory. Agreement between our spectroscopic experiment and LFT theory is very good, with better that hundreds of megahertz accuracy. But, on rare particular states, several gigahertz discrepancy is found. This study can be used to select appropriate states for the creation of ion and electron beams with high brightness, good correlation, and low energy dispersion.

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Generation of quasi-Fano profiles in the low field stark spectrum of caesium

Cited by 13 publications

References 11 publications

Field ionization of Rydberg atoms for high-brightness electron and ion beams

Field ionization of Rydberg atoms for high-brightness electron and ion beams

Forced field ionization of Rydberg states for the production of monochromatic beams

Cesium Rydberg-state ionization study by three-dimensional ion-electron correlation: Toward a monochromatic electron source

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