Resonance and interference phenomena in the photoionization of a hydrogen atom in a uniform electric field. IV. Differential cross sections

Kondratovich, V.; Ostrovsky, V N

doi:10.1088/0953-4075/23/21/015

Cited by 59 publications

(97 citation statements)

References 9 publications

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“…These oscillations are similar as if they are in the presence of a static electric field [5,6,7,8,9,10,11]. Quite recently, Afaq and Du [12] have argued that this oscillatory effect in the photodetachment cross section of H − is because of two-path interference of the detached-electron wave from the negative ion.…”

Section: Introductionmentioning

confidence: 60%

Photodetachment of H ⁻ near a Partially Reflecting Surface—I

Afaq

2008

Chinese Phys. Lett.

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Theoretical and interpretative study on the subject of photodetachment of H − near a partial reflecting surface is presented, and the absorption effect of the surface is investigated on the total and differential cross sections using a theoretical imaging method. To understand the absorption effect, a reflection parameter K is introduced as a multiplicative factor to the outgoing detached-electron wave of H − propagating toward the wall. The reflection parameter measures, how much electron wave would reflect from the surface; K = 0 corresponds to no reflection and K = 1 corresponds to the total reflection.PACS number: 32.80.GcIt has been observed both theoretically as well as experimentally that the photodetachment cross section of H − shows a smooth behavior in the free space [1,2]; while in the presence of a reflecting surface it displays oscillations [3,4]. These oscillations are similar as if they are in the presence of a static electric field [5,6,7,8,9,10,11]. Quite recently, Afaq and Du [12] have argued that this oscillatory effect in the photodetachment cross section of H − is because of two-path interference of the detached-electron wave from the negative ion. To the observation point, one path comes directly from the source H − , while the second path appears to be coming from an image of the source behind the wall. In reference [12], the idea has been discussed without considering the absorption effect of a wall. What would happen on the photodetachment cross section of negative ion when the wall in use will be absorbing? This problem is still interesting and has to be discussed. I use a simple model for H − and provide quantitative answer to the problem.Near an absorbing wall the physical picture of the photodetachment process may be described as: When the detached-electron wave is made incident on the wall, a part of it is absorbed by the wall and the other part is reflected with low intensity. This low intensity electron wave propagates away from the system and appears to be coming from an image behind the wall, and at a very large distance it interferes with the direct outgoing detached-electron wave. Consequently, we obtain an outgoing electron flux interference pattern on the screen. The photodetachment cross section is proportional to the integrated outgoing electron flux across a large enclosure in which the source H − sits.A partial reflecting wall (0 ≤ K ≤ 1) is used for the electron scattering and it is placed from H − at a distance more than 50 Bohr radii, so that the asymptotic approximations can be valid. The assumptions about the partial reflecting wall are the same as in reference [12]. For an observer at large distance from H − , there are two components of detached-electron wave going from H − to the observer. The first component propagates directly from H − to the observer as if there is no wall; the second component first propagates toward the wall, after being partially reflected by the wall, it then propagates from the wall to the observer. In the theoretical imaging

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Section: Introductionmentioning

confidence: 60%

Photodetachment of H ⁻ near a Partially Reflecting Surface—I

Afaq

2008

Chinese Phys. Lett.

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“…Subsequent experimental observations [37] of electric-fieldinduced resonances in the photodetachment spectrum of H − induced a resurgence of activity on primarily single-photon detachment processes in the presence of a weak external electric field [38][39][40][41][42][43][44][45][46]. More recently, theorists have returned to the investigation of static-field effects on single-photon and multiphoton detachment processes (for the case in which the electric field can no longer be regarded as a weak perturbation) in order to provide detailed predictions which experiment may be capable of testing [47][48][49][50][51][52].…”

Section: A Brief Historical Survey Of Static Electric Field Effects Omentioning

confidence: 99%

Interaction of laser radiation with a negative ion in the presence of a strong static electric field

Manakov

Frolov

Starace

et al. 2000

J. Phys. B: At. Mol. Opt. Phys.

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Abstract. This paper provides a general theoretical description of a weakly bound atomic system (a negative ion) interacting simultaneously with two (generally strong) fields, a static electric field and a monochromatic laser field having an arbitrary elliptical polarization. The zerorange δ-potential is used to model the interaction of a bound electron in a negative ion as well as the interaction of a detached electron with the residual atom. Our treatment combines the quasistationary (complex energy) and quasienergy (Floquet) approaches. This quasistationary, quasienergy state (QQES) formalism is the most appropriate one for analysing a decaying quantum system under the influence of a periodic external perturbation. Existing QQES theory is reviewed and some new results are discussed: the Hellmann-Feynman theorem and the normalization procedure for QQES, and the definition of the dipole moment and the dynamic polarizability for a decaying atomic system (in strong static electric and/or laser fields). These results are illustrated using analytical formulae obtained from an exact solution of the QQES problem for a δ-model potential in two strong fields. Finally, from the imaginary part of the dynamic polarizability we obtain analytic results (to first order in the laser-field intensity) for the photodetachment cross section. Our results are then compared with those of previous theoretical studies.

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“…(12) is not valid. The integral can be evaluated by expanding the action in powers of t − t c where t c (r, r , t) is the solution of the equation (16). Introduce again the modified action S(r, t, r , t ) = R(r, t, r , t ) − Et .…”

Section: ∂S ∂Tmentioning

confidence: 99%

“…These studies have developed in a whole field called "photodetachment microscopy". Similar studies with neutral atoms [16][17][18][19][20][21][22] are called "photoionization microscopy". Replacing static electric fields with low-frequency, particular radiofrequency, fields adds new interesting physics [23][24][25][26] which was investigated in several recent theoretical studies [27][28][29][30][31].…”

Section: Introductionmentioning

confidence: 99%

Photodetachment microscopy in time-dependent fields

Ambalampitiya

Fabrikant

2017

Phys. Rev. A

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Photodetachment of negative ions in combined laser and low-frequency fields is investigated. The time-dependent Green's function method is used for calculation of electron flux at a macroscopic distance away from the photodetachment source, typical for a photodetachment microscopy experiment. In calculating the electron flux, we use the stationary phase method for the time integral, equivalent to the semiclassical approximation, to compute the time dependent wavefunction. The stationary points t (i) 1 , i = 1, ..., n correspond to time instances of launching of classical trajectories arriving at the detector at a given space-time point (r, t). The number of trajectories n contributing to the electron flux at any point in the classically allowed space-time domain can be controlled by varying the switching interval of the high frequency laser which initiates the photodetachment process. The divergences inherent in the electron flux in the semiclassical treatment are removed by using the uniform Airy approximation near the caustics.

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Resonance and interference phenomena in the photoionization of a hydrogen atom in a uniform electric field. IV. Differential cross sections

Cited by 59 publications

References 9 publications

Photodetachment of H ⁻ near a Partially Reflecting Surface—I

Photodetachment of H ⁻ near a Partially Reflecting Surface—I

Interaction of laser radiation with a negative ion in the presence of a strong static electric field

Photodetachment microscopy in time-dependent fields

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Resonance and interference phenomena in the photoionization of a hydrogen atom in a uniform electric field. IV. Differential cross sections

Cited by 59 publications

References 9 publications

Photodetachment of H − near a Partially Reflecting Surface—I

Photodetachment of H − near a Partially Reflecting Surface—I

Interaction of laser radiation with a negative ion in the presence of a strong static electric field

Photodetachment microscopy in time-dependent fields

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Photodetachment of H ⁻ near a Partially Reflecting Surface—I

Photodetachment of H ⁻ near a Partially Reflecting Surface—I