EXCITED-STATES OF I-111 AND THE OBSERVATION OF A 21-NS ISOMER

Proton rich nuclei close to Sn-100 have been investigated an-beam usin g the NORDBALL detector array. A beam of 270 MeV Ni-58 was used to bom bard a Fe-54 target. Reaction channel separation was achieved with a 4 pi charged particle multi-detector set-up together with a 1 pi neutro n detector wall placed in the forward direction. Gamma-ray transitions belonging do the I-111 nucleus were identified for the first time. A level scheme constructed from gamma-gamma-perticle-coincidence analysi s is proposed. The level structure is discussed within the framework o f the shell model and the systematics of the heavier odd iodine nuclei .