J. Phys. IV France 03 (1993) C4-105-C4-111
Positronium chemical reactions in solutions : magnetic quenching of ortho-positronium in solutions of nitrobenzene in n- and iso-octaneQ. ZHANG1, Y. KOBAYASHI2, E.W. HELLMUTH1 and Y.C. JEAN1
1 Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, U.S.A.
2 National Institute of Materials and Chemical Research, Tsukuba, Ibaraki 305, Japan.
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°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°C. A small deviation appears at 24°C and 50°C but disappears at 77°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.
© EDP Sciences 1993