A new cryomodule containing seven low-beta superconducting radio frequency (SRF) cavities has been added to the ATLAS heavy ion linac, providing an additional 15 MV accelerating potential to the existing accelerator. We describe the final stages of cryomodule assembly, commissioning, and installation in the ATLAS accelerator. The clean techniques used to achieve low-particulate rf surfaces are presented, as are the module design features which enable clean assembly and reliable high-gradient operation. The thermal performance of the cryomodule is described, along with performance data for the SRF cavities. Details on subsystem performance including helium and nitrogen systems, vacuum systems, thermal and magnetic shields, slow and fast tuners, and survey/alignment systems are given.

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Lifetimes of 30 high-spin levels in 80 Y were measured using the Doppler-shift attenuation method. The high-spin states were populated using the 54 Fe͑ 28 Si, pn͒ reaction at 90 MeV, with a thick 14 mg/ cm 2 54 Fe target used to stop all recoils. Prompt ␥ -␥ coincidences were detected using a Compton-suppressed Ge array consisting of three Clover detectors and seven single-crystal detectors. Lifetimes were determined from experimental line shapes measured at both 35°and 145°whenever possible. Transition quadrupole moments Q t inferred from the lifetimes in the lowest positive-and negative-parity bands are large ͑Ͼ3 eb͒ at low spin, but show a rather abrupt decrease at high spin. Results of calculations using the projected shell and cranked Woods-Saxon models in conjunction with the cranked-shell model suggest that these drops in Q t are due to quasiparticle alignment, which introduce shape changes in each band from nearly prolate below the alignment to triaxial above. Magnetic dipole transition strengths B͑M1͒ in the yrast positive-parity band show a strong alternating pattern with spin, similar to that observed in other neighboring odd-odd nuclei.

High-spin states in 79 Sr were studied using the 54 Fe( 28 Si,2pn) reaction at 90 MeV, with a thick 14 mg/cm 2 54 Fe target used to stop all recoils. Prompt γ − γ coincidences were detected using the FSU Compton-suppressed Ge array consisting of three Clover detectors and seven single-crystal detectors. The most recent 79 Sr level scheme has been confirmed in three separate band structures up to a spin as high as the ( 37 2 + ) yrast state based on γ-ray coincidence relations, intensity and effective lifetime measurements, and directional correlation of oriented nuclei ratios. Lifetimes of 33 excited states were measured using the Doppler-shift attenuation method, with the experimental line shapes obtained at two separate observation angles and by gating from above the transitions of interest whenever possible. Transition quadrupole moments Q t inferred from the lifetimes indicate a high degree of collectivity and deformation over a rather wide range of spins in all three observed bands, with evidence for modest reductions in the values with increasing spin. The changes in Q t are attributed to the onset of quasiproton alignment and are supported qualitatively by the predictions of the projected shell model and cranked Woods-Saxon calculations in conjunction with the cranked shell model. Lifetimes measured in a band based on the [431] 1 2 + intrinsic Nilsson configuration suggest a large quadrupole deformation (β 2 ≈ 0.41) associated with this band, providing another example of the strong deformation-driving properties of the d 5/2 intruder orbital in the mass 80 region.