POSITRONIUM FORMATION IN MIXTURES OF COMPETITIVE ELECTRON-ACCEPTORS

The intensity of the long-lived component, I2, has been measured in mixtures of a number of compounds with C6F6 and CS2. The positronium yield for the mixtures of C6H5Cl, o-C6H4Cl2, p-C6H4Cl2 and C6H5Br with C6F6 and CS2 is higher than that for the mixtures of the same compounds with C6H6 over a wide range of compositions. On the contrary, for butyl chloride and acetone the dependences of I2 on the composition of the mixtures with C6H6 and C6F6 are similar. Small additions of various substances to C6F6 have been found to decrease the positronium yield. The result obtained are discussed in terms of the spur reaction model of Ps formation. © 1979.