Explosive desorption of solid methane particles induced by an electron beam

Khizhny, I. V.; Uyutnov, S. A.; Bludov, M. A.; Savchenko, and E. V.

doi:10.1063/1.5062166

Cited by 6 publications

(10 citation statements)

References 17 publications

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“…We will present the solutions describing oscillations with a large period and a sharp maximum in the temperature dependence of oscillations on time and oscillations having a short period and located in the vicinity of the maximum oscillations with a long period. This type of dynamics was observed experimentally in [29,30].…”

Section: Calculations and Discussionsupporting

confidence: 70%

“…It should be noted that in the results obtained, the self-oscillations occur at much lower values of the incident flux density than those observed in experiments [29,30]. In our opinion, this is because of significantly smaller sizes of the irradiated region in the task being solved in comparison with the dimensions of the sample.…”

Section: Calculations and Discussionmentioning

confidence: 50%

“…We investigate temperature fluctuations associated with the accumulation of defects. At the electron energies used in the experiments [29,30], of the order of 1 keV, the energy transfer to the hydrogen atom is small (less than the hydrogen binding energy in the molecule) and therefore its direct knocking from the molecule is unlikely. Methane dissociation occurs as a result of subthreshold processes, for example, during energy transfer from excited states, in particular, from the long-lived triplet states [31].…”

Section: Model and Investigation Methodsmentioning

confidence: 99%

“…A key feature of the experiments [29,30] is the fact that the electron range (that is, the region in which defects are created by irradiation) at an electron energy of 1 keV is of the order of 0.1 µm that is much less than the thickness of the sample. In this case, the temperature distribution in the sample will be heterogeneous and the study of selfoscillations is a difficult task.…”

Section: Model and Investigation Methodsmentioning

confidence: 99%

“…In experiments [29,30], when solid methane was irradiated with electrons at helium temperature, explosive delayed desorption of particles was detected. In contrast to the case of ion bombardment [27,28] with high energy during the bursts stimulated by electron beam, the periodic oscillations of the desorption yield were also observed.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Self-oscillations in solid methane irradiated by electrons

Bludov¹,

Khyzhniy²,

Savchenko³

et al. 2020

Nucl. Phys. At. Energy

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The formation of self-oscillations of temperature and concentration of radicals in an electron-irradiated methane film at low temperatures has been investigated experimentally and theoretically. Self-oscillations arise due to the activation nature of diffusion and radical recombination processes. Self-oscillations were studied experimentally by measuring the desorption of particles from an irradiated sample and theoretically by solving the kinetic equations for defects in a methane sample. Concentration self-oscillations of two types of particles have been found and investigated; namely, hydrogen atoms and CH3 radicals formed during the irradiation of methane by electrons. It is shown that with an increase in the irradiation intensity, the oscillation periods decrease, and the calculation value are of the order of magnitude observed in the experiment. A model of a manifestation of the self-oscillation of hydrogen molecule concentration during desorption is presented.

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Section: Calculations and Discussionsupporting

confidence: 70%

Section: Calculations and Discussionmentioning

confidence: 50%

Section: Model and Investigation Methodsmentioning

confidence: 99%

Section: Model and Investigation Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Self-oscillations in solid methane irradiated by electrons

Bludov¹,

Khyzhniy²,

Savchenko³

et al. 2020

Nucl. Phys. At. Energy

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Electron-induced delayed desorption of solid argon doped with methane

Khyzhniy

Uyutnov

Bludov

et al. 2019

Low Temperature Physics

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The total yield of particles desorption from solid Ar doped with CH4 under irradiation with an electron beam was studied at 5 K. The measurements were carried out at a CH4 concentration of 1 and 5%. The effect of explosive delayed desorption from the surface of argon matrix was discovered in both mixtures. With a higher concentration of CH4, it appeared at lower doses and was more pronounced. Two types of self-oscillations were observed: long-period bursts (on a time scale of about 25 min) and short-period oscillations (of about 10 s). In pure solid Ar delayed desorption was not observed despite the accumulation of a significant number of excess electrons, exceeding their number in mixtures of Ar and CH4 as it was found by measurements of thermally stimulated exoelectron emission. This finding discards the model of Coulomb explosion for the phenomenon detected. In this paper we focused on the role of hydrogen (one of the radiolysis products) in delayed desorption. The formation of atomic hydrogen in the matrix was traced via cathodoluminescence by the emission band of the excimer Ar2H* at 166 nm. Desorption of excited hydrogen atoms in the excited state was detected by the Ly-α emission line. A decrease of the Ar2H* band intensity at higher concentration of CH4 was found evidencing bleaching these centers likely due to recombination of H atoms with energy release and formation of molecular hydrogen. The data obtained give additional evidence in favor of the hypothesis that the exothermic reactions of radiolysis products serve as a stimulating factor for delayed desorption.

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Desorption of excited H* atoms from free clusters Ar/CH4 and solid Ar doped with CH4

Doronin

Vakula

Kamarchuk

et al. 2021

Low Temperature Physics

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Desorption of excited hydrogen atoms was detected from both solid Ar doped with CH4 and free nanoclusters Ar/CH4 at irradiation with an electron beam. It was monitored by an emission of the Lyman-a line. Measurements of cathodoluminescence (CL) spectra in the VUV range were performed within the CH4 concentration limits 0.1–10% in the solid matrix. The CL of free clusters with an average size of 1200 atoms per cluster was detected from pure Ar cluster jet and from Ar clusters doped with 0.1% CH4. The mechanisms of desorption of electronically excited H* atoms from solids and clusters are proposed on the basis of an analysis of energy transfer pathways with the final stage of relaxation — population of the n = 3 state of hydrogen atoms.

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Explosive desorption of solid methane particles induced by an electron beam

Cited by 6 publications

References 17 publications

Self-oscillations in solid methane irradiated by electrons

Self-oscillations in solid methane irradiated by electrons

Electron-induced delayed desorption of solid argon doped with methane

Desorption of excited H* atoms from free clusters Ar/CH4 and solid Ar doped with CH4

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