Yrast Brands In I-117 And Xe-116-118 - Anomalous Quasi-Particle Alignment Frequencies And Band Termination

The yrast bands of neutron-deficient $^{117}\\mathrm{I}$ and $^{116}\\mathrm{Xe}$ have been extended to I\\ensuremath{\\sim}34\\ensuremath{\\Elzxh}, and $^{117,118}\\mathrm{Xe}$ to I\\ensuremath{\\sim}46\\ensuremath{\\Elzxh}, using highfold \\ensuremath{\\gamma}-ray coincidence data collected with the Eurogam II spectrometer. Systematic quasiparticle alignment frequencies are discussed and compared to theoretical cranked Woods-Saxon calculations. The first pair alignment is attributed to ${\\mathit{h}}_{11/2}$ protons despite theoretical expectations for ${\\mathit{h}}_{11/2}$ neutron alignment; the neutron alignment appears significantly delayed. At higher spins, the $^{117}\\mathrm{I}$ and $^{117}\\mathrm{Xe}$ isobars exhibit contrasting forms of band termination.