THE CAPTURE RATE OF AN ION BY A SYMMETRICAL-TOP QUADRUPOLE

The rate constant for the ion-symmetrical top quadrupole capture is es timated using a classical variant of the microcanonical version of the transition state theory. The symmetrical top quadrupole reacts faster at all energies than the corresponding linear quadrupole. The depende nce of the capture rate on the dimensionless energy parameter B-3, whi ch determines the effect of energy on the capture rate, deviates much from linearity even at the lowest energies. Another dimensionless para meter, the molecular parameter zeta, determines the contributions of t he orbital and rotational components to the total rotational momentum of the system. The temperature dependence of the capture rate constant is estimated for both the extreme regions of zeta: the region of orbi tal momentum preponderance and the region of rotational momentum prepo nderance. In the first region the capture rate for the symmetrical top quadrupole is slightly faster than for the linear quadrupole. This di fference practically vanishes in the second region.