Multiple scattering of channeling ions in crystals-II. Planar channeling

Beloshitsky, V. V.; Kumakhov, M. A.; Muralev, V. A.

doi:10.1080/00337577308232272

Cited by 50 publications

(16 citation statements)

References 14 publications

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“…All the applications of channeling effect are limited by its instability, induced by the dechanneling process. To describe the latter, a concept of particle diffusion in the energy of its transverse motion (transverse energy) was suggested soon after the channeling discovery [8,9,10].…”

Section: Introductionmentioning

confidence: 99%

Quantitative theory of channeling particle diffusion in transverse energy in the presence of nuclear scattering and direct evaluation of dechanneling length

Tikhomirov

2017

Eur. Phys. J. C

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A refined equation for channeling particle diffusion in transverse energy taking into consideration largeangle scattering by nuclei is suggested. This equation is reduced to the Sturm-Liouville problem, allowing one to reveal both the origin and the limitations of the dechanneling length notion. The values of the latter are evaluated for both positively and negatively charged particles of various energies. New features of the dechanneling dynamics of positively charged particles are also revealed. First, it is demonstrated that the dechanneling length notion is completely inapplicable for their nuclear dechanneling process. Second, the effective electron dechanneling length of positively charged particle varies more than twice converging to a constant asymptotic value only at the depth exceeding the latter.

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Section: Introductionmentioning

confidence: 99%

Quantitative theory of channeling particle diffusion in transverse energy in the presence of nuclear scattering and direct evaluation of dechanneling length

Tikhomirov

2017

Eur. Phys. J. C

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“…one may put z = ct after carrying out the differentiation S ′′ , because all the deviations from c of the particle's velocity along the z-axis were taken into account when writing eqs. (7)(8)(9). Solving the equation of motion (12) and, then, using the result, combined with (11), in (7)(8)(9), one obtains the total spectral-angular distribution of the radiation (6).…”

Section: The Air Radiation In Absence Of the Dechannelingmentioning

confidence: 99%

“…(7)(8)(9). Solving the equation of motion (12) and, then, using the result, combined with (11), in (7)(8)(9), one obtains the total spectral-angular distribution of the radiation (6). This scheme was used in our recent papers [8] where the results of the numerical calculations of the spectra were presented for various shapes S(z) and with using different approximations for the interplanar potential U(ρ).…”

Section: The Air Radiation In Absence Of the Dechannelingmentioning

confidence: 99%

“…In our previous papers [2] (see also [7,8]) we have estimated the role of the dechanneling by assuming simple relation L < L d to be valid. The magnitude of L d was estimated on the basis of the diffusion theory (see [9,10,11,12]) with some corrections introduced due to the bending of the crystal [12,13]. On the basis of these estimates we carried out the calculations of the AIR spectra for various energies of the projectile, different types of the crystals and crystallographic plane and for various parameters of the channel bending (these are explained in more detail below).…”

Section: Introductionmentioning

confidence: 99%

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Effect of dechanneling on the photon emission by ultra-relativistic positrons channeling in a periodically bent crystal

Korol¹,

Solov’yov²,

Greiner³

2001

AIP Conference Proceedings

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We investigate, both analytically and numerically, the influence of the dechanneling process on the parameters of undulator radiation generated by ultrarelativistic positron channelling along a crystal plane, which is periodically bent. The bending might be due either to the propagation of a transverse acoustic wave through the crystal, or due to the static strain as it occurs in superlattices. In either case the periodically bent crystal serves as an undulator which allows to generate X-ray and γ-radiation.We propose the scheme for accurate quantitative treatment of the radiation in presence of the dechanneling. The scheme includes (i) the analytic expression for spectral-angular distribution which contains, as a parameter, the dechanneling length, (ii) the simulation procedure of the dechanneling process of a positron in periodically bent crystals. Using these we calculate the dechanneling lengths of 5 GeV positrons channeling in Si, Ge and W crystals, and the spectral-angular and spectral distributions of the undulator over broad ranges of the photons. The calculations are performed for various parameters of the channel bending.

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“…within the Lindhard angle, which decreases with the square root of the particle energy. Another limit of CR is the process of dechanneling [7,8], i.e. the process for which charged particles escape from the channeling condition due to scattering of the particles on nuclei and electrons of the crystal.…”

Section: Introductionmentioning

confidence: 99%

Investigation on radiation generated by Sub-GeV electrons in ultrashort Si and Ge bent crystals

Bandiera,

Sytov,

De Salvador

et al. 2020

Preprint

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We report on the measurements of the spectra of gamma radiation generated by 855 MeV electrons in bent silicon and germanium crystals at MAMI (MAinzer MIkrotron). The crystals were 15 µm thick along the beam direction to ensure high deflection efficiency. Their (111) crystalline planes were bent by means of a piezo-actuated mechanical holder, which allowed to remotely change the crystal curvature. In such a way it was possible to investigate the radiation emitted under planar channeling and volume reflection as a function of the curvature of the crystalline planes. We show that using volume reflection, one can produce intense gamma radiation with comparable intensity but higher angular acceptance than for channeling. We studied the trade-off between radiation intensity and angular acceptance at different values of the crystal curvature. The measurements of radiation spectra have been carried out for the first time in bent Germanium crystals. In particular, the intensity of radiation in the Ge crystal is higher than in the Si one due to the higher atomic number, which is important for the development of the X-ray and gamma radiation sources based on higher-Z deformed crystals, such as crystalline undulator.

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Multiple scattering of channeling ions in crystals-II. Planar channeling

Cited by 50 publications

References 14 publications

Quantitative theory of channeling particle diffusion in transverse energy in the presence of nuclear scattering and direct evaluation of dechanneling length

Quantitative theory of channeling particle diffusion in transverse energy in the presence of nuclear scattering and direct evaluation of dechanneling length

Effect of dechanneling on the photon emission by ultra-relativistic positrons channeling in a periodically bent crystal

Investigation on radiation generated by Sub-GeV electrons in ultrashort Si and Ge bent crystals

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