�ber die Energieabh�ngigkeit von Ionen-Molek�l-Reaktionen mit negativen Ionen

Abstract

Some ion-molecule reactions with negative ions (OH− and NH 2 − ) have been studied using a primary ion source, in which the negative ions were produced by electron impacts with electron resonance capture, and a secondary ion source, in which the primary negative ions produced ion-molecule reactions with formation of secondary negative ions. The secondary ions were magnetically analyzed and registered by a multiplier. Cross sections of the reactions in function of the energy of the primary ions were measured in the region of low energies up to about 20 eV. In the low energy region the cross sections rapidly decrease with increasing energy ∼E −1/2 as it has been the case with the energy dependence of the cross section of charge transfer reactions with negative ions at the same energies.