Highspeed correction factor to the O(+)O resonance charge exchange collision frequency
Abstract
The highspeed correction factor to the O+O collision frequency, resulting from drift velocities between ions and neutrals, is calculated by solving the integral expression in this factor both numerically and analytically. Although the analytic solution is valid for either small or large drift velocities between ions and neutrals, for temperatures of interest and all drift velocities considered, agreement is found between analytic and detailed numerical integration results within less than 1% error. Let Tr designate the average of the ion and neutral temperatures in K, and u=vd/<alpha>, where vd is the relative drift velocity in cm s1, and <alpha>=4.56×10^{3}sqrtT_{r} cm s^{1} is the thermal velocity of the O^{+}O system. Then, as u ranges from 0 to 2, the correction factor multiplying the collision frequency increases monotonically from 1 to about 1.5. An interesting result emerging from this calculation is that the correction factor for temperatures of aeronomical interest is to a good approximation independent of the temperature, depending only on the scaled velocity u.
 Publication:

Annales Geophysicae
 Pub Date:
 March 1995
 DOI:
 10.1007/s0058599502532
 Bibcode:
 1995AnGeo..13..253O
 Keywords:

 Atomic Collisions;
 Collision Rates;
 Earth Ionosphere;
 Oxygen Atoms;
 Oxygen Ions;
 Resonance Charge Exchange;
 Thermosphere;
 Drift Rate;
 Kinetic Energy;
 Momentum Transfer;
 Temperature;
 Velocity;
 Geophysics