Analytical ionization cross sections for atomic collisions

Kunc, Joseph A.; Soon, Willie

doi:10.1063/1.461622

Cited by 27 publications

(29 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This change is characterized by change of one, or more, parameters of the set C. Subsequently, the cross section q& with respect to a parameter g is defined as [12] q&(w, g, . .…”

Section: The Approachmentioning

confidence: 99%

“…In the approximation, the target atom interacting with the incident electron is considered a group of localized particles (called hereafter "components" of the target atom) which are either electrons (in the case of ordinary atom) or muons (((, (in the case of muonic atom) orbiting the nucleus in the field of a central force. Dynamic properties of the collision system (the incident electron plus the target atom} before the collision are defined [11,12] by a set C of n parameters (C&, Cz, . .…”

mentioning

confidence: 99%

See 1 more Smart Citation

Ionization of muonic atoms by nonrelativistic electrons

Kunc

1994

Phys. Rev. A

Self Cite

View full text Add to dashboard Cite

show abstract

“…This change is characterized by change of one, or more, parameters of the set C. Subsequently, the cross section q& with respect to a parameter g is defined as [12] q&(w, g, . .…”

Section: The Approachmentioning

confidence: 99%

mentioning

confidence: 99%

Ionization of muonic atoms by nonrelativistic electrons

Kunc

1994

Phys. Rev. A

Self Cite

View full text Add to dashboard Cite

show abstract

“…(24). It was concluded by Kunc and Soon [23] that Eq. (24) is a good representation of the atom-impact sodium-ionization cross section.…”

Section: Contribution Of Potential Sodium-ionization Processesmentioning

confidence: 91%

“…(22)(23)(24) that the atom-atom-ionization activation energy is two times greater than the electron-impactionization activation energy. Therefore, the atom-impact sodiumionization activation energy is about 10 eV.…”

Section: Contribution Of Potential Sodium-ionization Processesmentioning

confidence: 96%

Modeling of Sodium Radiation from Reentry Flows at High Altitudes

Zhong

Levin

2010

Journal of Spacecraft and Rockets

View full text Add to dashboard Cite

A kinetic-based quasi-steady-state model is developed to study sodium radiation intensity for reentry high-altitude flows of the blunt-body Stardust and a slender body. The sodium detected in the high-speed Stardust-reentry flow was from an impurity of the ablative thermal protection material. In this work, the particle-based direct simulation Monte Carlo method is used to obtain flow solutions, and a quasi-steady-state model is used to derive the sodium number-density distributions in the ground and excited electronic states. The sodium radiation intensity is calculated based on the sodium number-density distributions in the excited states and agrees reasonably well with the observation data for the Stardust reentry at 81 km. It was also found that sodium radiation in the slender-body reentry flow will be orders of magnitude less than the value observed for the blunt body.electron h = Planck constant I = radiation intensity k = reaction rate, Boltzmann's constant M = neutral species m = molecular mass N = number density Na = sodium atom T = temperature t = time x = distance along a line of sight = wave length = cross section = lifetime of excited state Subscripts a = atomic species e = electron species g = ground state i = atomic ground or excited state 1 = first excited state 2 = second excited state

show abstract

“…In this approach we neglect the possible inelastic collisions between ions or fast neutral atoms and thermal atoms. 19,20 We use the DSMC method to simulate the collisional transport of ions, fast neutrals, and thermal neutrals coming from the evaporation of the electrodes. The difficulty in the context of postarc problem is that the thermal neutral density is typically two or three orders of magnitude larger than the ion density.…”

Section: Collision Cross Sections and Dsmc Procedures For Atoms And Ionsmentioning

confidence: 99%

Sheath expansion and plasma dynamics in the presence of electrode evaporation: Application to a vacuum circuit breaker

Sarrailh

Garrigues

Hagelaar

et al. 2009

Journal of Applied Physics

View full text Add to dashboard Cite

During the postarc dielectric recovery phase in a vacuum circuit breaker, a cathode sheath forms and expels the plasma from the electrode gap. The success or failure of current breaking depends on how efficiently the plasma is expelled from the electrode gap. The sheath expansion in the postarc phase can be compared to sheath expansion in plasma immersion ion implantation except that collisions between charged particles and atoms generated by electrode evaporation may become important in a vacuum circuit breaker. In this paper, we show that electrode evaporation plays a significant role in the dynamics of the sheath expansion in this context not only because charged particle transport is no longer collisionless but also because the neutral flow due to evaporation and temperature gradients may push the plasma toward one of the electrodes. Using a hybrid model of the nonequilibrium postarc plasma and cathode sheath coupled with a direct simulation Monte Carlo method to describe collisions between heavy species, we present a parametric study of the sheath and plasma dynamics and of the time needed for the sheath to expel the plasma from the gap for different values of plasma density and electrode temperatures at the beginning of the postarc phase. This work constitutes a preliminary step toward understanding and quantifying the risk of current breaking failure of a vacuum arc.

show abstract

Analytical ionization cross sections for atomic collisions

Cited by 27 publications

References 49 publications

Ionization of muonic atoms by nonrelativistic electrons

Ionization of muonic atoms by nonrelativistic electrons

Modeling of Sodium Radiation from Reentry Flows at High Altitudes

Sheath expansion and plasma dynamics in the presence of electrode evaporation: Application to a vacuum circuit breaker

Contact Info

Product

Resources

About