SHAPE TRANSITION REGION IMPLIED IN THE LIGHT NB ISOTOPES - EXCITED-STATES IN NB-83

Excited states in the very neutron deficient isotope {sup 83}Nb were observed for the first time in the reaction {sup 28}Si({sup 58}Ni,2{ital np}){sup 83}Nb at 195 MeV. Identification was made with a recoil separator and a cross section of {sigma}=180(80) {mu}b estimated. Eight transitions were arranged in a level scheme which resembles the {ital N}=41 isotones {sup 77}Kr and {sup 79}Sr rather than the heavier, weakly deformed Nb isotopes. This suggests that a shape transition to a strong deformation exists in the light Nb isotopes. A ground state spin of 5/2{sup +} is suggested.