POSITRONIUM CHEMICAL-REACTIONS IN SOLUTIONS - MAGNETIC QUENCHING OF ORTHO-POSITRONIUM IN SOLUTIONS OF NITROBENZENE IN N-OCTANE AND ISOOCTANE

The magnetic quenching of ortho-positronium (o-Ps) has been studied for the solutions of nitrobenzene in n- and iso-octane (2, 2, 4-trimethylpentane). Static magnetic fields up to 20 kG were applied to the solutions and the lifetime of the m = 0 state of o-Ps was determined as a function of the field strength at 24, 50, and 77-degrees-C. The observed lifetime of o-Ps substantially deviates from the quadratic Zeeman effect in iso-octane solutions (0.1 and 0.2 M) in the range of several kG at 24 and 50-degrees-C. A small deviation appears at 24-degrees-C and 50-degrees-C but disappears at 77-degrees-C in n-octane solution (0.3 M). It is suggested that particular bound states formed during the attachment-detachment of o-Ps on nitrobenzene in a solution with a certain range of surface tension may be responsible for the deviation from the quadratic Zeeman effect.