The total ionization cross sections of He, Ne, Ar, Kr, Xe, H2, D2, N2, O2, CO, NO, CO2, N2O, and CH4 have been measured from threshold to 1000 eV in a total ionization tube. More limited measurements were performed in C2H4 and SF6. Great care was taken to assure complete collection of electron and ion currents, and the absence of spurious instrumental errors. A new method was devised for obtaining absolute cross sections of gases relative to H2, and a McLeod gauge was used to obtain the absolute cross section in H2. The cross sections in NO and O2 could not be obtained by this method, and an approximate correction to direct McLeod‐gauge readings was used for these gases. It is believed that the results are as accurate as is possible with the present method. It is difficult to explain the differences found between cross sections measured by various investigators. McLeod‐gauge errors appear to account for most of the difference in absolute magnitude.

Total Cross Sections for Ionization and Attachment in Gases by Electron Impact. I. Positive Ionization

A kinetic scheme for non-equilibrium discharge in nitrogen-oxygen mixtures is developed, which almost wholly describes chemical transformations of particles in the cold (200 K<or=T<or=500 K) vibrationally unexcited gas. The kinetic scheme includes processes of excitation of electronic states, destruction and ionization of heavy particles by electron impact, associative ionization, electron attachment and detachment, electron-ion and ion-ion recombination, chemical transformations of neutral particles (in ground and excited electronic states) and ion conversion. On the basis of kinetic modelling in the framework of the kinetic scheme proposed, the influence of the electronic excitations of nitrogen molecules and atoms on air composition dynamics is analysed.

https://iopscience.iop.org/article/10.1088/0963-0252/1/3/011/pdf

Kinetic scheme of the non-equilibrium discharge in nitrogen-oxygen mixtures

Note from the Series Editor. Foreword. Preface. Acknowledgments. Chapter 1: Introduction. 1.1 Electric Propulsion Background. 1.2 Electric Thruster Types. 1.3 Ion Thruster Geometry. 1.4 Hall Thruster Geometry. 1.5 Beam/Plume Characteristics. References. Chapter 2: Thruster Principles. 2.1 The Rocket Equation. 2.2 Force Transfer in Ion and Hall Thrusters. 2.3 Thrust. 2.4 Specific Impulse. 2.5 Thruster Efficiency. 2.6 Power Dissipation. 2.7 Neutral Densities and Ingestion in Electric Thrusters. References. Problems. Chapter 3: Basic Plasma Physics. 3.1 Introduction. 3.2 Maxwell's Equations. 3.3 Single Particle Motions. 3.4 particle Energies and Velocities. 3.5 Plasma as a Fluid. 3.6 Diffusion in Partially Ionized Gases. 3.7 Sheaths at the Boundaries of Plasmas. References. Problems. Chapter 4: Ion Thruster Plasma Generators. 4.1 Introduction. 4.2 Idealized Ion Thruster Plasma Generator. 4.3 DC Discharge Ion Thruster. 4.4 Kaufman Ion Thrusters. 4.5 rf Ion Thrusters. 4.6 Microwave Ion Thrusters. 4.7 2-D Computer Models of the Ion Thruster Discharge Chamber. References. Problems. Chapter 5: Ion Thruster Accelerator Grids. 5.1 Grid Configurations. 5.2 Ion Accelerator Basics. 5.3 Ion Optics. 5.4 Electron Backstreaming. 5.5 High-Voltage Considerations. 5.6 Ion Accelerator Grid Life. References. Problems. Chapter 6: Hollow Cathodes. 6.1 Introduction. 6.2 Cathode Configurations. 6.3 Thermionic Electron Emitter Characteristics. 6.4 Insert Region Plasma. 6.5 Orifice Region Plasma. 6.6 Hollow cathode Thermal Models. 6.7 Cathode Plume-Region Plasma. 6.8 Hollow Cathode Life. 6.9 Keeper Wear and Life. 6.10 Hollow Cathode Operation. References. Problems. Chapter 7: Hall Thrusters. 7.1 Introduction. 7.2 Thruster Operating Principles and Scaling. 7.3 Hall Thruster Performance Models. 7.4 Channel Physics and Numerical Modeling. 7.5 Hall Thruster Life. References. Problems. Chapter 8: Ion and Hall Thruster Plumes. 8.1 Introduction. 8.2 Plume Physics. 8.3 Plume Models. 8.4 Spacecraft Interactions. 8.5 Interactions with Payloads. References. Problems. Chapter 9: Flight Ion and Hall Thrusters. 9.1 Introduction. 9.2 Ion Thrusters. 9.3 Hall Thrusters. References. Appendices. A: Nomenclature. B: Gas Flow Unit Conversions and Cathode Pressure Estimates. C: Energy Loss by Electrons. D: Ionization and Excitation Cross Sections for Xenon. E: Ionization and Excitation Reaction Rates for Xenon in Maxwellian Plasmas. F: Electron Relaxation and Thermalization Times. G: Clausing Factor Monte Carlo Calculation. Index..

/pdf/fundamentals-of-electric-propulsion-ion-and-hall-thrusters-4zwus65dx4.pdf

Fundamentals of electric propulsion : ion and Hall thrusters

Since the appearance of the title paper, a number of new developments have occurred which need to be included in that body of material. We present additional remarks and clarifications which supplement and update numerous aspects of the Bethe theory discussed in the earlier paper. We also bring the bibliography up to date. Plasma stopping power, the ${z}^{3}$ effect, and stopping power for particles at extreme relativistic energies are among the new topics included. We make several comments on Fano's earlier review article, Ann. Rev. Nucl. Sci. 13, 1 (1963).

Inelastic Collisions of Fast Charged Particles with Atoms and Molecules-The Bethe Theory Revisited

https://zenodo.org/record/1253854/files/article.pdf

A Monte Carlo collision model for the particle-in-cell method: applications to argon and oxygen discharges

Cross sections for dissociative ionization have been measured as a function of electron energy from threshold to 1000 eV in nine gases (H2, D2, N2, CO, NO, O2, CO2, N2O, and CH4) by collecting those ions reaching the ion collector after passing through a 0.25‐V retarding potential in a total‐ionization tube. Approximate correction is made for the effective solid angle subtended by the ion collector at the electron beam. The results are reported as the fraction of total ionization, and as absolute cross sections for dissociative ionization. At moderately high electron energies (>70 eV), the fraction of total ionization that is dissociated ions with kinetic energy in excess of 0.25 eV, ranges from ∼7% in H2 and D2 to ∼35% in N2O, with other gases intermediate.

Cross Sections for Dissociative Ionization of Molecules by Electron Impact

A semiclassical calculation of the probabilities of resonant and near‐resonant vibrational energy interchange in molecular collisions is accomplished by means of a collision model similar to that used in vibrational—translational energy transfer. The results indicate that transition probabilities are of the order of ½ in resonant and near‐resonant processes at room temperature.

Paula Englander‐Golden

Papers

Total Cross Sections for Ionization and Attachment in Gases by Electron Impact. I. Positive Ionization

Cross Sections for Dissociative Ionization of Molecules by Electron Impact

Resonant and Near‐Resonant Vibrational—Vibrational Energy Transfer between Molecules in Collisions