Monte Carlo simulation of electron emission from solids

Kuhr, Jan-Christian; Fitting, H.‐J.

doi:10.1016/s0368-2048(99)00082-1

Cited by 121 publications

(84 citation statements)

References 40 publications

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“…The plots show the characteristic and well-known shape of the secondary electron (hole) distributions [55,56]: the distribution rapidly increases at very low energies, reaching a peak value at a few electron volts, and then smoothly decreases, forming a long tail extending to high energies. The position of the peak moves towards lower energies, as the number of secondary electrons increases.…”

Section: Evolutionmentioning

confidence: 85%

Modelling ultrafast transitions within laser-irradiated solids

Ziaja

Medvedev

2012

High Energy Density Physics

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Section: Evolutionmentioning

confidence: 85%

Modelling ultrafast transitions within laser-irradiated solids

Ziaja

Medvedev

2012

High Energy Density Physics

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“…A major issue is the utilization of the large inelastic mean free path (IMFP) of the photoelectrons, i.e., the distance until the electron undergoes an inelastic scattering event and loses energy. For the classical region of photoelectron spectroscopy up to 2 keV a host of measured and calculated data exists due to its intensive application over many years, of which we give here only a few references [2][3][4][5][6][7][8][9]. However, there are relatively few measurements of IMFPs at higher energies, up to 10 keV and above.…”

Section: Introductionmentioning

confidence: 99%

“…This allows performing the analysis analytically, without specific Monte Carlo calculations that are often applied at lower energies where large-angle scattering is of importance (see e.g. [6][7][8]). The photoelectrons are released by the hard Xray beam in the carbon samples uniformly over a large depth (>1 m).…”

Section: Introductionmentioning

confidence: 99%

Relative electron inelastic mean free paths for diamond and graphite at 8keV and intrinsic contributions to the energy-loss

Kunz¹,

Cowie

Drube

et al. 2009

Journal of Electron Spectroscopy and Related Phenomena

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a b s t r a c tWe used hard X-ray photoelectron spectroscopy (HAXPES) with 8 keV X-rays to investigate the 1s emission of carbon. We recorded spectra extending from the peak of the C 1s electrons ("elastic" line) to electrons with up to 110 eV energy-loss. Using two samples side by side, we could compare the inelastic mean free paths (IMFPs) of the electrons of almost 8 keV in diamond and graphite and find them to be practically identical despite about 50% difference in densities. Published extrapolations of their IMFP calculations at lower energies are in good agreement with this result. We show that information from the almost structureless region of overlapping multiple extrinsic energy-losses can be used to quantify the fraction of photoelectrons experiencing intrinsic energy-losses (those due to the sudden creation of the hole). We find that this fraction is 58% of the primary excited C 1s electrons for diamond and is practically the same for graphite. This is at first sight an unexpected result since hole-screening should differ in a semimetal from that in an insulator. The observation can be accounted for by dynamic screening in contrast to static screening.

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“…Calculations of elastic scattering amplitudes can be done reasonably well in the muffin-tin potential approximation [3][4][5]. In contrast, a fully rigorous method for including inelastic scattering has not yet been published.The main aim of this paper is to provide a more accurate description of secondary electron emission rates in solids than the currently existing models [6][7][8][9][10][11][12]. This is important for a better understanding of radiation damage.…”

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confidence: 99%

“…Due to the low impact energy of primary electrons (E ∼ 250 eV), we neglect interactions of the electrons with inner shells of the atoms (cf. [6][7][8][9][10][11][12]). The interactions with valence electrons are modelled as interactions with the band in the solid.…”

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confidence: 99%

Space-time evolution of electron cascades in diamond

et al. 2002

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Abstract:The impact of a primary electron initiates a cascade of secondary electrons in solids, and these cascades play a significant role in the dynamics of ionization. Here we describe model calculations to follow the spatiotemporal evolution of secondary electron cascades in diamond. The band structure of the insulator has been explicitly incorporated into the calculations as it affects ionizations from the valence band. A Monte-Carlo model was constructed to describe the path of electrons following the impact of a single electron of energy E ∼ 250 eV. This energy is similar to the energy of an Auger electron from carbon. Two limiting cases were considered: the case in which electrons transmit energy to the lattice, and the case where no such energy transfer is permitted. The results show the evolution of the secondary electron cascades in terms of the number of electrons liberated, the spatial distribution of these electrons, and the energy distribution among the electrons as a function of time. The predicted ionization rates (∼ 5-13 electrons in 100 fs) lie within the limits given by experiments and phenomenological models. Calculation of the local electron density and the correspond-1 e-mail:ziaja@tsl.uu.se, szoke1@llnl.gov, spoel@xray.bmc.uu.se, hajdu@xray.bmc.uu.se ing Debye length shows that the latter is systematically larger than the radius of the electron cloud, and it increases exponentially with the radial size of the cascade. This means that the long-range Coulomb field is not shielded within this cloud, and the electron gas generated does not represent a plasma in a single impact cascade triggered by an electron of E ∼ 250 eV energy. This is important as it justifies the independent-electron approximation used in the model. At 1 fs, the (average) spatial distribution of secondary electrons is anisotropic with the electron cloud elongated in the direction of the primary impact. The maximal radius of the cascade is about 50Å at this time. At 10 fs the cascade has a maximal radius of ∼ 70Å, and is already dominated by low energy electrons (> 50%, E < 10 eV). These electrons do not contribute to ionization but exchange energies with the lattice. As the system cools, energy is distributed more equally, and the spatial distribution of the electron cloud becomes isotropic. At 90 fs, the maximal radius is about 150Å. An analysis of the ionization fraction shows that ionization level needed to create an Auger electron plasma in diamond will be reached with a dose of ∼ 2 × 10 5 impact X-ray photons perÅ 2 if these photons arrive before the cascade electrons recombine. The Monte-Carlo model described here could be adopted for the investigation of radiation damage in other insulators and has implications for planned experiments with intense femtosecond X-ray sources.The treatment of electron cascades in this paper is restricted to low energy electrons (E impact = 250 eV) and weakly ionized samples where only a few interatomic bonds are perturbed. We chose diamond as a model compound because of its significan...

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Monte Carlo simulation of electron emission from solids

Cited by 121 publications

References 40 publications

Modelling ultrafast transitions within laser-irradiated solids

Modelling ultrafast transitions within laser-irradiated solids

Relative electron inelastic mean free paths for diamond and graphite at 8keV and intrinsic contributions to the energy-loss

Space-time evolution of electron cascades in diamond

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