Ion–Molecule Reactions in a 50‐MHz Discharge

Extensive investigations of the dependence of the relative ionic composition of a high‐frequency plasma on the discharge conditions (particularly the pressure) and of the relative ionic composition of the plasma as a function of the translational energy of the ions issuing from the orifice of the sampling probe at constant pressure were made by the use of a quadrupole mass spectrometer employing a retarding‐potential grid system. The results indicate that the ions collected and observed are formed in a narrow region in the plasma (approximately 1 mm in depth) in front of the probe orifice and that these ions gain most of their energy from the electric field of the sheath in a distance that is much less than a reaction mean‐free path (∼0.01 mm). The average time available for reaction (reaction time) was a few tenths of a microsecond and independent of the vessel geometry and dimensions. The reaction time was relatively insensitive to changes in pressure and was reasonably constant for ions in several diff...

[1]  P. K. Ghosh,et al.  TRANSLATIONAL ENERGY DISTRIBUTION OF ELECTRONS AND POSITIVE IONS IN THE PLASMA OF MICROWAVE AND HIGH-FREQUENCY DISCHARGES OF He, Ne, AND Ar. , 1968 .

[2]  D. Bohme,et al.  Ion Sampling Considerations for a Discharge Plasma of Nitrogen , 1966 .

[3]  D. Bohme,et al.  Mass Spectrometric Sampling Probe for Discharge Plasmas , 1966 .

[4]  M. Bachynski,et al.  The Particle Kinetics of Plasmas , 1966 .

[5]  P. Dawson,et al.  Mass Spectrometry of Ions in Glow Discharges: Application to H2—D2 Exchange Reactions , 1966 .

[6]  M. M. Shahin.  ION-MOLECULE INTERACTION IN THE CATHODE REGION OF A GLOW DISCHARGE , 1965 .

[7]  F. H. Field,et al.  Project SQUID. Reactions of Gaseous Ions. XIV. Mass Spectrometric Studies of Methane at Pressures to 2 Torr. , 1965 .

[8]  P. Dawson,et al.  Ion Clusters in the Ammonia Glow Discharge , 1964 .

[9]  S. Rice,et al.  Mass Spectrometry of Organic Ions , 1964 .

[10]  G. Volpi,et al.  Ion—Molecule Reactions in Methane and in Ethane , 1964 .

[11]  E. W. McDaniel,et al.  Collision phenomena in ionized gases , 1964 .

[12]  H. P. Broida,et al.  Microwave Discharge Cavities Operating at 2450 MHz , 1964 .

[13]  F. H. Field,et al.  Project SQUID: Reactions of Gaseous Ions. XII. High Pressure Mass Spectrometric Study of Methane. , 1963 .

[14]  P. F. Knewstubb,et al.  Mass Spectrometry of Ions in Glow Discharges. IV. Water Vapor , 1963 .

[15]  P. F. Knewstubb,et al.  Mass Spectrometry of Ions in Glow Discharges. III. Nitrogen and Its Mixtures with Hydrogen and Oxygen , 1962 .

[16]  S. Wexler,et al.  CONSECUTIVE ION-MOLECULE REACTIONS IN METHANE , 1962 .

[17]  I. Ortenburger,et al.  Secondary Reactions in a Gas Discharge , 1960 .

[18]  T. Shaw.  Dissociation of Hydrogen in a Microwave Discharge , 1959 .

[19]  W. Paul,et al.  Das elektrische Massenfilter als Massenspektrometer und Isotopentrenner , 1958 .

[20]  F. W. Lampe,et al.  Reactions of Gaseous Ions. I. Methane and Ethylene , 1957 .

[21]  David J. Rose,et al.  Basic Processes of Gaseous Electronics , 1956 .

[22]  D. Stevenson,et al.  Rate of the Gaseous Reactions, X++YH=XH++Y , 1955 .

[23]  H. G. Poole.  Atomic Hydrogen. I. The Calorimetry of Hydrogen Atoms , 1937 .

[24]  Joseph John Thomson,et al.  Rays of positive electricity and their application to chemical analyses , 1913 .