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High-spin states in odd-odd 164 Lu have been studied using 19 F and 23 Na induced fusion-evaporation reactions. Three strongly coupled rotational bands have been established and three decoupled bands were tentatively assigned to 164 Lu. The band crossing frequencies, energy sig-nature splittings, and relative transition probabilities were deduced from experimental data and compared with neighboring even-even and odd- A nuclei. An anomalously large band crossing frequency was observed in the excited band, and a pronounced signature inversion was observed in the yrast band of 164 Lu. These anomalies may be associated with residual neutron-proton interactions.

A focal plane detector system has been developed for the Rochester Recoil Mass Spectrometer. It consists of a parallel grid avalanche counter (PGAC) backed by an ionization counter (IC). The PGAC is used to obtain the horizontal and vertical position of the incident particles and also to provide a fast timing signal. The PGAC has an active area of 5.1 cm x 5.1 cm. The IC consists of three charge collecting anodes (2.0 cm, 6.2 cm, 21.6 cm long) and provides nuclear charge identification and a total energy measurement. Both the PGAC and the IC are filled with isobutane as the counter gas. The intrinsic position resolution of the PGAC was determined to be 0.9 mm (FWHM). The IC is able to resolve neighboring nuclear charges for light ions with energies as low as 0.7 MeV/u. The nuclear charge resolution of the IC for heavy ions with IC energies below 0.7 MeV/u was found to be 1.3 e (FWHM).

A segmented focal plane detector for an Enge split-pole spectrograph has been developed for the study of breakup reactions at very low relative energies. It consists of a 61 cm long segmented position-sensitive parallel plate avalanche counter backed by a large Bragg curve detector. A segmented plastic scintillator is mounted behind the anode of the Bragg curve detector and is used for particle identification of low-ionizing particles. The dead space between the two sections of the focal plane detector is 2.5 mm. The intrinsic position resolution of the detector is 1 mm. The intrinsic energy resolution depends on the energy of the incident ion and can be as good as 0.55%. The nuclear charge and mass resolutions are 0.3 e and 0.3 u, respectively.