Primary processes, reactions of positive ions and radiolytic yields

1 Primary processes, reactions of positive ions and radiolytic yields 

The broad peak with a maximum at 7.5 eV in Fig. 4 corresponds to excitation to the 1II state, and probably also the 3II1 and 3no+ states. These are analogous to the lower states of HI (Fig. 1), and will decompose to halogen atoms in the 

Ion Relative abundance at 140 eV (%) Appearance potentials ieV) Probable ionisation process  

Several of the primary ionisation processes listed in Table 4 yield H and Cl atoms as well as ions, and similar processes are observed with HBr and HI. Atoms may also be formed in secondary ion-molecule reactions which are discussed below. As shown in Table 5, the ionisation potentials of the halogen atoms and their hydrides are such that the charge transfer reaction 

Rate coefficient of the reaction (l.mole HX++HX- H2X++X. sec-1) 4xl010e IxlO11  

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