Separation of single-and two-center interference in ionization of H<sub>2</sub>by proton impact

Arthanayaka, Thusitha; Sharma, Sachin; Lamichhane, Basu; Hasan, A.; Remolina, J.; Gurung, Shekhar; Schulz, Michael

doi:10.1088/0953-4075/48/7/071001

Cited by 24 publications

(45 citation statements)

References 17 publications

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“…[1]). The present work is an attempt to relate the results of Karlovets et al to those obtained in the past five years in the investigations of the projectile beam coherence effects in ion-atom and ion-molecule collisions [4][5][6][7][8][9][10][11][12][13]. It is an interesting question whether the formulas of Karlovets et al predict a similar wave packet effect in scattering of energetic ions as in the case of electron impact.…”

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confidence: 67%

“…This effect may influence the results of FDCS measurements in the field of ion-atom collisions. The dependence of the FDCS on the projectile coherence has already been investigated experimentally [6,8,10,12,13] and theoretically [11,22]. One of the goals of the investigations was to solve the so-called C 6+ puzzle, a discrepancy between the measured and theoretical FDCSs for the single ionization of He by 100 MeV/nucleon C 6+ projectiles [23], which has remained unexplained for more than a decade.…”

Section: (Cm)mentioning

confidence: 99%

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Loss of wave-packet coherence in ion-atom collisions

et al. 2016

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The projectile beam coherence effects occurring in ion-atom collisions are analyzed on the basis of the recent theory of Karlovets et al. [Phys. Rev. A 92, 052703 (2015)] developed for the elastic scattering of wave packets of particles off a potential field. This theory is generalized to estimate the loss of coherence for inelastically scattered projectiles in ionizing collisions. The results obtained by the suggested model are compared with experimental data for the ionization of hydrogen atoms and molecules by 75-keV proton impact. Significantly improved agreement is observed between the theory and experiment. DOI: 10.1103/PhysRevA.93.032702 In a recent work Karlovets et al.[1] investigated theoretically the scattering of wave packets of nonrelativistic particles off a potential field. The authors derived a simple general expression that determines the number of scattering events for the case when the incident particle beam is a wave packet of arbitrary form but with its mean momentum strongly centered at a given value p i . Furthermore, they considered the example when the wave packet is scattered off randomly distributed potential centers. By averaging the number of events over the impact parameter between the potential center and the wave packet axis, they derived a formula for the effective cross section that reproduces the one obtained by previous authors (see, e.g., [2,3]where dσ /d | q i →q f is the differential cross section for the elastic scattering in an angle θ = arccos(q i ·q f ). Furthermore, by writing (k) = ⊥ (k ⊥ ) (k ), with strongly centered on p i , they obtainedKarlovets et al. carried out sample calculations for the case of electron impact, applying the Born approximation. They considered the collisions of a Gaussian wave packeton a Gaussian potential as well as on the hydrogen atom. Here σ ⊥ is the averaged transverse size of the wave packet. As a remarkable result, they found that the angular distributions of the effective cross section broaden with the decrease of σ ⊥ . [4] could control the coherence properties of the ion beam and thereby demonstrate the effect of the projectile coherence on the angular distribution of the scattered protons. The principle of the experiment is based on the van Cittert-Zernike theorem according to which the transverse coherence length r (the diameter of the area of coherence) of a source of waves at a distance L is of the order of λ/kα, where λ is the wavelength, α is the angular diameter of the source, and k is a dimensionless constant.Egodapitiya et al. used a well-collimated nearly monochromatic [< 1 eV full width at half maximum (FWHM)] proton beam that crossed a molecular hydrogen beam. The measured quantity was the doubly differential cross section (DDCS) for the ionization as a function of the scattering angle θ and the energy loss of the protons. The measurements were made at two coherence length values corresponding to two values of the distance between the target and the last aperture of the collimator, L = 6.5 and 50 cm. The diameter of t...

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confidence: 67%

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confidence: 99%

Loss of wave-packet coherence in ion-atom collisions

et al. 2016

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“…In contrast, for η close to unity by now there is an extensive literature on experimental and theoretical studies [e.g. [15][16][17][18]20,26,27] supporting the interpretation that scattering cross sections can be significantly affected by the projectile coherence properties. In this regime, experimental studies now enter a phase in which such coherence effects are used as a tool to sensitively investigate the few-body reaction dynamics.…”

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confidence: 89%

Fully Differential Study of Capture with Vibrational Dissociation in p+H2 Collisions

et al. 2017

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“…An example is molecular two-center interference, which has been observed in numerous experimental studies and predicted by theory for charged particles colliding with diatomic molecules [e.g. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. There, the diffracted projectile waves originating from the two atomic centers interfere with each other.…”

Section: Introductionmentioning

confidence: 99%

“…However, this assertion was rebutted by Sharma et al [22], who demonstrated that there were no noticeable differences in the beam divergence for the two slit distances. Later, resolution-independent coherence effects were reported for various processes and targets for projectiles with relatively small speed and large perturbation parameters η (projectile charge to speed ratio) [19,20,23,24, for a review see 25].…”

Section: Introductionmentioning

confidence: 99%

Fully differential study of dissociative single capture and Coulomb explosion through double capture in p+H2 collisions

et al. 2017

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We have measured fully differential cross sections for dissociative single capture and Coulomb explosion through double capture in 75 keV p + H 2 collisions. Data were analyzed for fixed kinetic energy releases and molecular orientations as a function of scattering angle. Two-center interference was identified for dissociative single capture. The interference pattern is not inconsistent with the symmetry of the dissociative electronic state affecting the phase angle of the interference term. No clear signatures of single-center interference were observed for either process. For double capture at most only a very weak two-center interference structure was found. This very small (or zero) visibility can probably be attributed to a convolution of two independent scatterings of the projectile with the two electrons yielding the measured scattering angle.

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Separation of single-and two-center interference in ionization of H₂by proton impact

Cited by 24 publications

References 17 publications

Loss of wave-packet coherence in ion-atom collisions

Loss of wave-packet coherence in ion-atom collisions

Fully Differential Study of Capture with Vibrational Dissociation in p+H2 Collisions

Fully differential study of dissociative single capture and Coulomb explosion through double capture in p+H2 collisions

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Separation of single-and two-center interference in ionization of H2by proton impact

Cited by 24 publications

References 17 publications

Loss of wave-packet coherence in ion-atom collisions

Loss of wave-packet coherence in ion-atom collisions

Fully Differential Study of Capture with Vibrational Dissociation in p+H2 Collisions

Fully differential study of dissociative single capture and Coulomb explosion through double capture in p+H2 collisions

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Product

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Separation of single-and two-center interference in ionization of H₂by proton impact