Two-center interference in electron-impact ionization of molecular hydrogen

Li, Xingyu; Ren, Xueguang; Hossen, Khokon; Wang, Enliang; Chen, Xiangjun; Dorn, Alexander

doi:10.1103/physreva.97.022706

Cited by 20 publications

(14 citation statements)

References 23 publications

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“…In our previous studies for lower ejected electron energies of E 2 = 10 eV [36] and 18 eV [18] we observed significant higher cross section if the molecular axis was parallel to the emission direction φ m = φ 2 as compared to perpendicular alignment. This was interpreted as deflection of the emitted electron in the anisotropic potential of the molecular ion and preferred emission along the molecular axis.…”

Section: Resultsmentioning

confidence: 68%

“…Using the coincident detection of protons from molecular hydrogen dissociation, we were able to obtain molecular frame (e, 2e) data [31]. In a recent study for E 0 = 520 eV, we found strong molecular alignment dependent cross sections for lowenergy electron emission of E 2 = 10 eV [36]. Since the electron emission pattern was in strong disagreement with the predictions of the interference model, we concluded that the underlying approximations are not applicable at low energy.…”

Section: Introductionmentioning

confidence: 84%

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Molecular-frame (e, 2e) ionization dynamics of H2 at high impact-energy

Wang

Ali

et al. 2020

Eur. Phys. J. D

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We report a combined experimental and theoretical study on the electron-impact ionization dynamics of H2 at an impact-energy of 520 eV. The molecular-frame fivefold-differential cross sections were measured for electron emission in the plane perpendicular to the incoming projectile beam. An (e, 2e + ion) triple coincidence method was used covering projectile scattering angles of 6.5 • , 10.0 • and 20.0 • and ejected energies of 20 eV and 30 eV. The experimental cross sections are compared with results from the multicenter distorted-wave (MCDW) as well as the molecular three-body distorted wave (M3DW) approaches. M3DW is in overall better agreement with the measured data in the binary lobes than MCDW, while the intensity of recoil lobes are underestimated by both theories. Furthermore, we examine the presence of two-center interference patterns by comparing the experimental cross section ratios between mutually perpendicular alignment angles of the molecular axis with that predicated by the interference model. Agreement with the interference model is found only for Bethe ridge kinematics, i.e. in the binary peak region and with the ejected electron momentum being roughly equal to the momentum transfer. Finally, we suggest a modified interference formula for the recoil peak which takes into account the backscattering of the ejected electron in the ionic potential.

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Section: Resultsmentioning

confidence: 68%

Section: Introductionmentioning

confidence: 84%

Molecular-frame (e, 2e) ionization dynamics of H2 at high impact-energy

Wang

Ali

et al. 2020

Eur. Phys. J. D

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“…This is likely due to the spreading of the dominant lobe as the uncertainty in the momentum transfer increases, making the interference structures more visible. Unlike the s-state targets, the 2p target is not spherically symmetric and can serve as an analogue for diatomic molecule targets, where nuclear alignment effects are known to be important [31,32]. As seen from Fig.…”

Section: Resultsmentioning

confidence: 99%

Projectile transverse momentum controls emission in electron vortex ionization collisions

Plumadore

Harris

2020

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

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The realization of electron vortex beams in the past decade has led to numerous proposed applications in fields from electron microscopy to control and manipulation of individual molecules. Yet despite the many unique characteristics and promising advantages of electron vortex beams, such as transverse momentum and quantized orbital angular momentum, there remains a limited understanding of their fundamental interactions with matter at the atomic scale.Collisions between electron vortex projectiles and atomic targets can provide some insight into these interactions and we present here fully differential cross sections for ionization of excited state atomic hydrogen targets using electron vortex projectiles. We show that the projectile's transverse momentum causes the ionized electron angular distributions to be altered compared to non-vortex projectiles and that the ionized electron's ejection angle can be controlled by adjustment of the vortex opening angle, a feature unique to vortex projectiles. Additionally, an inherent uncertainty in the projectile's momentum transfer leads to a broadening of the classical binary peak, making signatures of the target electron density more readily observable. Fully differential cross sections for aligned 2p targets exhibit structures that can be used to determine the alignment.

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“…In literature, more sophisticated models exist (like, two-effective center (TEC), molecular threebody distorted wave (M3DW), multicenter molecular three-body distorted-wave (MCM3DW), multicenter distorted-wave (MCDW) etc.) for the plane wave (e,2e) processes on H 2 molecule [35,[60][61][62]. We hope that one can also explore the twisted (e,2e) process with a more sophisticated model for further grinding of our results in the future.…”

Section: Angular Profiles Of the Tdcs For Plane Wavementioning

confidence: 98%

“…The interference effect was also observed for electron emission on H 2 by fast ion impact [28,29]. Different groups have studied this aspect, both at the theoretical and experimental level, by studying the ejected electron's angular distribution [30][31][32][33][34][35]. To the best of our knowledge, almost all of the (e,2e) collision studies on molecular targets have been done for the plane wave electron beam (not possessing any orbital angular momentum).…”

Section: Introductionmentioning

confidence: 99%

Electron impact single ionization of hydrogen molecule by twisted electron beam

Dhankhar,

Choubisa

2020

Preprint

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In this communication, we present the results of the Five-fold Differential Cross Section (5DCS) and Triple Differential Cross Section (TDCS) for the (e,2e) process on molecular hydrogen (H 2 ) by the plane wave and the twisted electron beam impact. The formalism is developed within the first Born approximation using the plane wave and the twisted wave for the incident electron beam. We describe the plane wave, Heitler-London type wave function and Coulomb wave for the scattered electron, H 2 molecular state, and the ejected electron respectively. We compare the angular profiles of the 5DCS and TDCS for the different values of Orbital Angular Momentum (OAM) number m of the twisted electron beam with that of the plane wave beam. We also present the 5DCS for different molecular orientations and study the effect of m on the 5DCS. We further investigate the influence of the twisted electron beam on the (e,2e) process on the H 2 molecule from the perspective of the "Young-type" interference of the scattered waves, emanating from the two atomic centers of the H 2 molecule. We also study the TDCS for macroscopic H 2 target to explore the effect of opening angle (θp) of the twisted electron beam on the TDCS. Our results clearly show the effect of the twisted electron's OAM number (m) and the opening angle (θp) on the 5DCS and TDCS of the molecular hydrogen.

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Two-center interference in electron-impact ionization of molecular hydrogen

Cited by 20 publications

References 23 publications

Molecular-frame (e, 2e) ionization dynamics of H2 at high impact-energy

Molecular-frame (e, 2e) ionization dynamics of H2 at high impact-energy

Projectile transverse momentum controls emission in electron vortex ionization collisions

Electron impact single ionization of hydrogen molecule by twisted electron beam

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