Neon Shells Research Articles

3D simulations of magnetoconvection in a rapidly rotating supernova progenitor

ABSTRACT We present a first 3D magnetohydrodynamic (MHD) simulation of oxygen, neon, and carbon shell burning in a rapidly rotating $16\hbox{-}\mathrm{M}_\odot$ core-collapse supernova progenitor. We also run a purely hydrodynamic simulation for comparison. After $\mathord \approx 180\mathrm{s}$ ($\mathord \approx$ 15 and 7 convective turnovers, respectively), the magnetic fields in the oxygen and neon shells achieve saturation at 1011 and 5 × 1010 G. The strong Maxwell stresses become comparable to the radial Reynolds stresses and eventually suppress convection. The suppression of mixing by convection and shear instabilities results in the depletion of fuel at the base of the burning regions, so that the burning shell eventually move outward to cooler regions, thus reducing the energy generation rate. The strong magnetic fields efficiently transport angular momentum outwards, quickly spinning down the rapidly rotating convective oxygen and neon shells and forcing them into rigid rotation. The hydrodynamic model shows complicated redistribution of angular momentum and develops regions of retrograde rotation at the base of the convective shells. We discuss implications of our results for stellar evolution and for the subsequent core-collapse supernova. The rapid redistribution of angular momentum in the MHD model casts some doubt on the possibility of retaining significant core angular momentum for explosions driven by millisecond magnetars. However, findings from multidimensional models remain tentative until stellar evolution calculations can provide more consistent rotation profiles and estimates of magnetic field strengths to initialize multidimensional simulations without substantial numerical transients. We also stress the need for longer simulations, resolution studies, and an investigation of non-ideal effects.

Self-consistent 3D Supernova Models From −7 Minutes to +7 s: A 1-bethe Explosion of a ∼19 M ⊙ Progenitor

Abstract To date, modern three-dimensional (3D) supernova (SN) simulations have not demonstrated that explosion energies of 1051 erg (=1 bethe=1 B) or more are possible for neutrino-driven SNe of non/slow-rotating M < 20 M ⊙ progenitors. We present the first such model, considering a nonrotating, solar-metallicity 18.88 M ⊙ progenitor, whose final 7 minutes of convective oxygen-shell burning were simulated in 3D and showed a violent oxygen–neon shell merger prior to collapse. A large set of 3D SN models was computed with the Prometheus-Vertex code, whose improved convergence of the two-moment equations with Boltzmann closure allows now to fully exploit the implicit neutrino-transport treatment. Nuclear burning is treated with a 23-species network. We vary the angular grid resolution and consider different nuclear equations of state and muon formation in the proto-neutron star (PNS), which requires six-species transport with coupling of all neutrino flavors across all energy–momentum groups. Elaborate neutrino transport was applied until ∼2 s after bounce. In one case, the simulation was continued to >7 s with an approximate treatment of neutrino effects that allows for seamless continuation without transients. A spherically symmetric neutrino-driven wind does not develop. Instead, accretion downflows to the PNS and outflows of neutrino-heated matter establish a monotonic rise of the explosion energy until ∼7 s post-bounce, when the outgoing shock reaches ∼50,000 km and enters the He layer. The converged value of the explosion energy at infinity (with overburden subtracted) is ∼1 B and the ejected 56Ni mass ≲0.087 M ⊙, both within a few 10% of the SN 1987A values. The final NS mass and kick are ∼1.65 M ⊙ and >450 km s−1, respectively.

3D simulations of oxygen shell burning with and without magnetic fields.

We present a first 3D magnetohydrodynamic (MHD) simulation of convective oxygen and neon shell burning in a non-rotating [Formula: see text] star shortly before core collapse to study the generation of magnetic fields in supernova progenitors. We also run a purely hydrodynamic control simulation to gauge the impact of the magnetic fields on the convective flow and on convective boundary mixing. After about 17 convective turnover times, the magnetic field is approaching saturation levels in the oxygen shell with an average field strength of [Formula: see text], and does not reach kinetic equipartition. The field remains dominated by small-to-medium scales, and the dipole field strength at the base of the oxygen shell is only [Formula: see text]. The angle-averaged diagonal components of the Maxwell stress tensor mirror those of the Reynolds stress tensor, but are about one order of magnitude smaller. The shear flow at the oxygen-neon shell interface creates relatively strong fields parallel to the convective boundary, which noticeably inhibit the turbulent entrainment of neon into the oxygen shell. The reduced ingestion of neon lowers the nuclear energy generation rate in the oxygen shell and thereby slightly slows down the convective flow. Aside from this indirect effect, we find that magnetic fields do not appreciably alter the flow inside the oxygen shell. We discuss the implications of our results for the subsequent core-collapse supernova and stress the need for longer simulations, resolution studies, and an investigation of non-ideal effects for a better understanding of magnetic fields in supernova progenitors.

Discovery of Four Space Dimensions in a Sphere for Electronic Orbitals in a Neon Shell

For the first time we discover four space dimensions in a sphere, namely two periphery points, two semicircular arcs, two hemispherical surfaces, and two spherical solids. When these four geometric elements are compared with electronic orbitals in a neon shell, we draw a conclusion that while 2s orbitals are spherical, three types of 2p orbitals in the X, Y, and Z directions are different in the number of space dimensions. These anisotropic 2p orbitals prompt us to modify Schrödinger’s equation to reflect these fine space gradients. Within the atomic sphere, electrons are transforming from one dimension to another following the rule of calculus implemented by circular functions rather than position movement. An electron may exist in the physical shape of a point, an arc, a surface, or a solid. Eight electrons in the neon shell are undergoing various harmonic oscillations that form a continuous octet cycle. This motion feature is derived from a four-dimensional space harmonic oscillation equation coupled with a one-dimensional time harmonic oscillation equation in synthesis of the modified Schrödinger’s equation. Substantial amount of evidence can be found in organic chemistry where a carbon atom has an anisotropic electron configuration of 2s2px2py2pz. By furnishing a fresh and fundamental spacetime worldview, the quaternity theory may change the direction of quantum mechanics from discrete linear algebra toward continuous dynamic calculus in the future.

Forecast & Vigil

57 KYLE MARBUT Forecast & Vigil  Forecast My superpower is feeling sad about things before they happen: my first kiss, winter sunsets, sunrise in general, telling you I’m scared of who I’ve been, running out of laundry detergent, birthdays, a summer spent in bed, two degrees Celsius, the day my cat dies and I bury him without flowers, the sea returning to its bed—the valley where I live, primordial ocean floor. The creek meets its banks, ponds bloom in the sandlot—speechless birds crowd black cherry trees, ruffling 58 feathers between strokes of lightning and the answering crash. I count four silent miles on my fingers. Somewhere a patch of grass smolders—somewhere a sycamore splits and flames, fountaining blackbirds. A puddle swallows my ankles, the storm drains can’t keep up with all this sky—passing cars arc gutter water into my eyes waves lap my thighs rainwater rises slow as cooling glass islands disappear I hold the sky -blue umbrella like a bowl overflowing raised to my brimming lips I cannot contain everything I am myself alone a child floats by on an oak door translating Hamlet into water into Ophelia words pour off clean pages my dress 59 a raft water-laden and drifting my dress a mermaid tail emerald-scaled inlaid with pearls a willow grows aslant the new seafloor branches sprawling underwater my brothers crowd the crown dueling for their castaway birthright ramshackle driftwood barge fistfight over gyres of jetsam and uprooted picnic tables white-water storm surge claims the coastline the eastern seaboard becomes open water landlocked corn country becomes beachfront property becomes open water I always wanted to live in a beach house my father is the ocean my mother is the sea I am tide-borne I am sinking Hurricane-force, black sky—when will the weather learn to behave itself? I’m not calling this an apocalypse, an ending, though the flood drowns two of each species and then some, and the richest bastards cry out to breaking skies for an island timeshare in high-and-dry Colorado, and the clouds 60 do not answer. In my dreams, the new world -ocean is not barren. All the arks are empty or unbuilt—the water teems with golden mer-cheetahs and jewel-toned hermit crab-rabbits with neon shells and moray ferrets tucked into crags—and the birds are mostly the same, except they wing saltwater and sing like little whales, crowing with humpbacks at dawn, when godbeams slice the epipelagic over our submerged street, our town below sea level, block after block of houseboat shipwrecks—open doors and windows, waterlogged, all our glasses are always full of the world, no room for pessimistic air, and we never have to wash our hair again. The body is governed by water. Can you swim? The water is governed by water. Come again? I can’t hear over all this storm, this icemelt—Antarctica cracking into continents, the planet jingling like a glass of coke. The icebergs are just icebergs. The water is just the world, now. I hope you said yes about the swimming— remember, I carried you to the deep end once by your armpits, and let go, and you flailed, gasped, learned: 61 You don’t have to hold yourself. Don’t worry—the water will catch you. Don’t worry—the water won’t come here anyway. 62 Vigil Meet me in the garden so I can weave us crowns from grass and clover, a stem twisted over a blade around tiny blossoms till the ends disappear . This is how I claim my kingdom, in the sunroom at moonrise, rain painting half-shadows on the thin glass walls. No one does what I ask, so I tell my subjects to pile pale white doll shoes and the black paper wings of ladybugs at the foot of this slow-rocking swing-bench, my throne. They come to me from far reaches, bearing slivers of dusty lace from an old maid’s wedding dress, panes of glass from rose windows in churches at the bottoms of lakes, boats of broken porcelain glazed with desert rain. All this they bring in through...

Large-scale Mixing in a Violent Oxygen–Neon Shell Merger Prior to a Core-collapse Supernova

Abstract We present a 7 minute long 4π-3D simulation of a shell merger event in a nonrotating 18.88 M ⊙ supernova progenitor before the onset of gravitational collapse. The key motivation is to capture the large-scale mixing and asymmetries in the wake of the shell merger before collapse using a self-consistent approach. The 4π geometry is crucial, as it allows us to follow the growth and evolution of convective modes on the largest possible scales. We find significant differences between the kinematic, thermodynamic, and chemical evolution of the 3D and 1D models. The 3D model shows vigorous convection leading to more efficient mixing of nuclear species. In the 3D case, the entire oxygen shell attains convective Mach numbers of ≈0.1, whereas in the 1D model, the convective velocities are much lower, and there is negligible overshooting across convective boundaries. In the 3D case, the convective eddies entrain nuclear species from the neon (and carbon) layers into the deeper part of the oxygen-burning shell, where they burn and power a violent convection phase with outflows. This is a prototypical model of a convective–reactive system. Due to the strong convection and resulting efficient mixing, the interface between the neon layer and the silicon-enriched oxygen layer disappears during the evolution, and silicon is mixed far out into the merged oxygen/neon shell. Neon entrained inward by convective downdrafts burns, resulting in lower neon mass in the 3D model compared to the 1D model at the time of collapse. In addition, the 3D model develops remarkable large-scale, large-amplitude asymmetries, which may have important implications for the impending gravitational collapse and subsequent explosion.

Forecast & Vigil

57 KYLE MARBUT Forecast & Vigil  Forecast My superpower is feeling sad about things before they happen: my first kiss, winter sunsets, sunrise in general, telling you I’m scared of who I’ve been, running out of laundry detergent, birthdays, a summer spent in bed, two degrees Celsius, the day my cat dies and I bury him without flowers, the sea returning to its bed—the valley where I live, primordial ocean floor. The creek meets its banks, ponds bloom in the sandlot—speechless birds crowd black cherry trees, ruffling 58 feathers between strokes of lightning and the answering crash. I count four silent miles on my fingers. Somewhere a patch of grass smolders—somewhere a sycamore splits and flames, fountaining blackbirds. A puddle swallows my ankles, the storm drains can’t keep up with all this sky—passing cars arc gutter water into my eyes waves lap my thighs rainwater rises slow as cooling glass islands disappear I hold the sky -blue umbrella like a bowl overflowing raised to my brimming lips I cannot contain everything I am myself alone a child floats by on an oak door translating Hamlet into water into Ophelia words pour off clean pages my dress 59 a raft water-laden and drifting my dress a mermaid tail emerald-scaled inlaid with pearls a willow grows aslant the new seafloor branches sprawling underwater my brothers crowd the crown dueling for their castaway birthright ramshackle driftwood barge fistfight over gyres of jetsam and uprooted picnic tables white-water storm surge claims the coastline the eastern seaboard becomes open water landlocked corn country becomes beachfront property becomes open water I always wanted to live in a beach house my father is the ocean my mother is the sea I am tide-borne I am sinking Hurricane-force, black sky—when will the weather learn to behave itself? I’m not calling this an apocalypse, an ending, though the flood drowns two of each species and then some, and the richest bastards cry out to breaking skies for an island timeshare in high-and-dry Colorado, and the clouds 60 do not answer. In my dreams, the new world -ocean is not barren. All the arks are empty or unbuilt—the water teems with golden mer-cheetahs and jewel-toned hermit crab-rabbits with neon shells and moray ferrets tucked into crags—and the birds are mostly the same, except they wing saltwater and sing like little whales, crowing with humpbacks at dawn, when godbeams slice the epipelagic over our submerged street, our town below sea level, block after block of houseboat shipwrecks—open doors and windows, waterlogged, all our glasses are always full of the world, no room for pessimistic air, and we never have to wash our hair again. The body is governed by water. Can you swim? The water is governed by water. Come again? I can’t hear over all this storm, this icemelt—Antarctica cracking into continents, the planet jingling like a glass of coke. The icebergs are just icebergs. The water is just the world, now. I hope you said yes about the swimming— remember, I carried you to the deep end once by your armpits, and let go, and you flailed, gasped, learned: 61 You don’t have to hold yourself. Don’t worry—the water will catch you. Don’t worry—the water won’t come here anyway. 62 Vigil Meet me in the garden so I can weave us crowns from grass and clover, a stem twisted over a blade around tiny blossoms till the ends disappear . This is how I claim my kingdom, in the sunroom at moonrise, rain painting half-shadows on the thin glass walls. No one does what I ask, so I tell my subjects to pile pale white doll shoes and the black paper wings of ladybugs at the foot of this slow-rocking swing-bench, my throne. They come to me from far reaches, bearing slivers of dusty lace from an old maid’s wedding dress, panes of glass from rose windows in churches at the bottoms of lakes, boats of broken porcelain glazed with desert rain. All this they bring in through...

Influence of eikonal-initial-state on ionization of atom by proton

Apart from its fundamental importance, ionization phenomenon of atoms by impact of energetic charged particles has practical applications in various kinds of plasmas, in radiation physics and in the study of penetration of charged particles through matter. Compared with other processes, this particular reaction helps to reveal many details about the dynamical process and the level population, and, in fact, can provide a new insight into and a promising route to studying the e-p interactions in the presence of Coulomb field. The development of ion sources producing multiply charged ions and of antiproton beams allow us to change the potentials and hence the whole final momentum distribution. A great variety of experimental conditions allowed by changing the projectile charge and velocity constitute a stringent test for theory. The continuum-distorted-wave eikonal-initial-state (CDW-EIS) approximation model has emerged as a reliable method to compute cross sections for different projectile/target combinations from intermediate to high non-relativistic impact energies. This model is of the first order in a distorted-wave series. It takes into account the long-range behaviour of the Coulomb potential and includes the distortion of the target states in both the initial and final channels. In the present work, the single different cross sections (SDCS), double different cross sections (DDCS), and total cross sections for single ionization of 1s, 2s and 2p shell of Ne atom by impact of proton are calculated in the framework of continuum-distorted-wave (CDW) method and the CDW-EIS approximation model, respectively. The influence of the eikonal-initial-state on the cross section, and the mechanism of the proton-atom collision ionization are discussed in detail. Moreover, the structures of the SDCS and DDCS of each shell are studied and the ionization mechanism of soft collision, electron capture to the continuum state, binary encounter collision are demonstrated. Our results show that for the 2p shell of Neon, as the incident proton energy increases, the region of the SDCS becomes larger and the soft ionization turns dominant in the low energy region. The eikonal-initial-state effect on the cross section is obvious in the lower energy region, yet smaller as the incident energy increases. These effects on the DDCS are greater than on the SDCS. The present CDW-EIS and CDW results are compared with the experimental data available in the energy range of 1-5000 keV/u for H+ on Ne in the literature, showing that they are quantitatively in good agreement. In general, the CDW-EIS describes well the multiple ionization above 50 keV/u, showing a clear tendency to coalesce with the CDW at high energies.

Adaptation as critique: Gender and politics in the plays of Effat Yehia and Amel Fadgy, Caridad Svich and Christine Evans

Abstract This article explores three adaptations of classical Greek stories/myths: Kan Ya Ma Kan/Once Upon a Time (2000), Iphigenia Crash Land Falls On The Neon Shell That Was Once Her Heart (a rave fable) (2004) and Trojan Barbie: A Car Crash Encounter with Euripides’ Trojan Women (2007). These adaptations seek to deconstruct ‘source’ texts by presenting new readings that challenge the dominant patriarchal and political discourses embedded in these myths. Even though the plays offer examples of different modes of adaptation, they all use myth as a catalyst to explore issues of gender and politics. The article examines these three feministoriented adaptations in order to explore the ways in which their theatrical practices illuminate and critique contemporary social and political issues.

The theory and application of anisotropic geometries of 2p electronic orbitals within a neon shell

The theory and application of anisotropic geometries of 2p electronic orbitals within a neon shell

Using ICD for structural analysis of clusters: a case study on NeAr clusters

We present a method to utilize interatomic Coulombic decay (ICD) to retrieve information about the mean geometric structures of heteronuclear clusters. It is based on observation and modelling of competing ICD channels, which involve the same initial vacancy, but energetically different final states with vacancies in different components of the cluster. Using binary rare gas clusters of Ne and Ar as an example, we measure the relative intensity of ICD into (Ne+)2 and Ne+Ar+ final states with spectroscopically well separated ICD peaks. We compare in detail the experimental ratios of the Ne–Ne and Ne–Ar ICD contributions and their positions and widths to values calculated for a diverse set of possible structures. We conclude that NeAr clusters exhibit a core–shell structure with an argon core surrounded by complete neon shells and, possibly, further an incomplete shell of neon atoms for the experimental conditions investigated. Our analysis allows one to differentiate between clusters of similar size and stochiometric Ar content, but different internal structure. We find evidence for ICD of Ne 2s−1, producing Ar+ vacancies in the second coordination shell of the initial site.

Non-dipole effects in the angular distribution of photoelectrons in sequential two-photon double ionization: argon and neon

As an extension to recent developments in the theory of non-dipole effects in nonlinear photoprocesses in the XUV/x-ray wavelength regime, the sequential two-photon double ionization of the 3p shell in atomic argon is studied theoretically and compared to similar processes in the 2p shell of neon. The calculations predict distinct non-dipole effects in the region of the Cooper minimum in argon at photon energies around 50 eV, where they are of similar importance as at photon energies of more than 500 eV. The non-dipole effects should therefore be clearly observable in experiments performed at the present x-ray free electron lasers.

Low energy (e,2e) studies from CH4: Results from symmetric coplanar experiments and molecular three-body distorted wave theory

Low energy experimental and theoretical triply differential cross sections are presented for electron impact ionization of methane (CH(4)) for both the highest occupied molecular orbital (HOMO) and next highest occupied molecular orbital (NHOMO). The HOMO is a predominantly p-type orbital which is labeled 1t(2) and the NHOMO is predominantly s-type labeled 2a(1). Coplanar symmetric (symmetric both in final state electron energies and observation angles) are presented for final state electron energies ranging from 2.5 to 20 eV. The theoretical M3DW (molecular three-body distorted wave) results are in surprisingly good agreement with experiment for the HOMO state and less satisfactory agreement for the NHOMO state. The molecular NHOMO results are also compared with the ionization of the 2s shell of neon which is the isoelectronic atom.

Soft X-ray emissions from neon gas-puff Z-pinch powered by Qiang Guang-I accelerator

AbstractThe X-ray emission, especially the K-shell emission, from a neon gas-puff Z-pinch powered by the Qiang Guang-I accelerator, about 1.5 MA in amplitude and 100 ns in rise time, were calculated based on the two-level model and measured with X-ray diodes and an eight-frame X-ray pinhole camera. The simulation results showed that the K-shell yield is highly sensitive to the peak current. The experimental results confirmed that the matching of the Z-pinch load (mass and initial radius) to the current is crucial for getting a higher X-ray yield. Being determined by the imploding time, the pinch current plays a more important role than the current amplitude in K-shell emission. It seems that the preferable imploding time is about 110 ns. The K-shell radiation power with double shells, as a whole, is higher than that using single neon shell. While an implosion of a light (32 µg/cm) and small (20 mm in diameter) neon shell evolves with rather twist and asymmetries, a heavier (41 µg/cm) and bigger (25 mm in diameter) neon shell implodes more symmetrically. The double neon shells, 30 mm and 30 µg/cm for the outer shell, and 15-mm and 10 µg/cm for the inner shell, create almost “perfect” implosions evidenced by the early-time plasma shells with little perturbation and late stagnated pinch liners with a good axial uniformity. It was found that the “Zippering” effect leads to an earlier K-shell emission in the cathode region than that in the anode region, which extends the pulse width of K-shell emission.

Doubly differential cross sections for single and multiple ionization of Ne by electron impact

We present doubly differential cross sections for single and multiple ionization of the outer shell of neon by $750\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ electron impact. The distinction between single and multiple ionization was achieved by performing a charge state analysis of the recoil ions in coincidence with forward scattered, energy analyzed electrons. By a comparison to photon impact data, the contribution of the second-order double ionization mechanism is estimated and found to be neglible at this impact energy. Following a similar procedure adopted by J. A. R. Samson [Phys. Rev. Lett. 65, 2861 (1990)], the importance of the first-order TS-1 double ionization mechanism is also estimated. As a result it is found that for large energy losses shakeoff is the dominant double ionization mechanism.

Electron impact double ionization of neon

Electron-impact double ionization from the valence shell of neon has been measured at an incident electron energy of 3662.5 eV. Double-coincidence (e,(3-1)e) measurements have been made between the scattered electron and each of the ejected electrons in turn, ejected energies were 10 eV and 90 eV, respectively, at ejection angles of 45, 60, 90, 120 and 135 degrees with respect to the incident electron beam. Absolute four-fold-differential cross-sections have been derived from the measured data and can be interpreted in terms of a fast, single-step, shake-off process

Introduction of short-range interactions in continuum distorted-wave theory of electron capture for ion-atom collisions

The authors show that the representation of continuum functions by an expansion on Slater orbitals allows them to account for the short-range part of the interaction between the active electron and the cores in the CDW theory of capture reactions. The method is applied to capture from the L shell of neon by 100-300 keV protons.

The cross section for ionisation of the 2s subshell of neon by electron impact

An analysis is made of the existing data of Luyken et al. (1972) for the cross section for 2s subshell ionisation of neon by electron impact. These cross sections were obtained by detection of 2s2p6 to 2s22p5 transitions in Ne+(2s2p6) at 46.1-46.2 nm as a function of electron impact energy. Their relative data have been normalised to the absolute cross section of van Raan et al. (1971) given at 300 eV impact energy. In the present article this absolute scale is compared with that derived by the application of the Bethe formula. In this formula the quantity Mi2 for the 2s shell of neon is evaluated using existing experimental photoionisation data. The analysis shows that the absolute value of van Raan has to be reduced by a factor of 3.7-0.8+1.3.

Inner-shell excitation in heteronuclear collisions II. Differential and total cross sections for K-shell excitation

For pt.I, see ibid., vol.8, no.11 (1975). The differential and total cross sections for ionization of the K shells of neon and oxygen atoms in close collisions are calculated. The time-dependent electronic wavefunction is expanded in terms of the four lowest diabatic one-electron MO(1s sigma , 2p sigma , 2s sigma and 2p pi ) of the neon-oxygen molecule. These MO are derived from adiabatic Hartree-Fock orbitals. Vacancies are created in the K shell of oxygen, predominantly by the rotational 2p pi -2p sigma coupling at small distances of approach. The ionization of the K shell of neon is due largely to the subsequent transfer of these vacancies into the 1s sigma orbital by the 2p sigma -1s sigma radial coupling. It is shown that coupling to the 2s sigma orbital has little influence of the K-shell cross sections. The calculated total cross sections are compared with existing experimental results.

Inner-shell excitation in heteronuclear collisions. II. Differential and total cross sections for K-shell excitation

For pt.I, see ibid., vol.8, no.11 (1975). The differential and total cross sections for ionization of the K shells of neon and oxygen atoms in close collisions are calculated. The time-dependent electronic wavefunction is expanded in terms of the four lowest diabatic one-electron MO(1s sigma , 2p sigma , 2s sigma and 2p pi ) of the neon-oxygen molecule. These MO are derived from adiabatic Hartree-Fock orbitals. Vacancies are created in the K shell of oxygen, predominantly by the rotational 2p pi -2p sigma coupling at small distances of approach. The ionization of the K shell of neon is due largely to the subsequent transfer of these vacancies into the 1s sigma orbital by the 2p sigma -1s sigma radial coupling. It is shown that coupling to the 2s sigma orbital has little influence of the K-shell cross sections. The calculated total cross sections are compared with existing experimental results.