Positron annihilation studies on Amberlite XAD-4 adsorbed with nitrobenzene

XAD-4 resin was loaded with various amounts of nitrobenzene which is known to be a strong chemical quencher of positronium. The positron annihilation lifetime studies showed a continuous decrease in the o-Ps intensity with increasing nitrobenzene loading. No appreciable change in the o-Ps lifetime was observed. This suggests that the nitrobenzene acts as inhibitor rather than quencher in the current case. Possible reasons for the manifestations of such powerful quencher as an inhibitor are discussed.