GAMMASPHERE+FMA: A journey beyond the proton drip-line

The majority of experiments performed during the 2-year long stay of GAMMAS PHERE at the Argonne National Laboratory aimed to study proton-rich nuclei far from the line of stability at and beyond the proton drip-line. A high r eaction channel selectivity was required to assign in-beam gamma -ray trans itions to weakly populated exotic nuclei in the presence of background from strong reaction channels. In many of the experiments this was achieved by using the Argonne fragment mass analyzer to separate heavy-ion fusion-evapo ration reaction products from scattered beam and disperse them according to their mass-over-charge-state ratio. For medium mass and heavy ct and proto n emitters the Recoil-Decay Tagging method was implemented. In-beam gamma - ray transitions were observed in several proton emitters between Z=50 and Z =82. Among others, rotational bands were assigned to Ho-141 and Eu-131. A q uadrupole deformation of beta = 0.25(4) was deduced for the ground state in Ho-141 from the extracted dynamic moment of inertia. Based on observed ban d crossings and signature splittings the 7/2(-)[523] and 1/2(+)[411] config urations were proposed for the ground state and the isomeric state, respect ively. A comparison with particle-rotor calculations indicates, however, th at Ho-141 may have significant hexadecapole deformation and could be triaxi al.