Hybrid recoil mass analyzer (HYRA) is a unique, dual-mode spectrometer designed to carry out nuclear reaction and structure studies in heavy and medium-mass nuclei using gas-filled and vacuum modes, respectively and has the potential to address newer domains in nuclear physics accessible using high energy, heavy-ion beams from superconducting LINAC accelerator (being commissioned) and ECR-based high current injector system (planned) at IUAC. The first stage of HYRA is operational and initial experiments have been carried out using gas-filled mode for the detection of heavy evaporation residues and heavy quasielastic recoils in the direction of primary beam. Excellent primary beam rejection and transmission efficiency (comparable with other gas-filled separators) have been achieved using a smaller focal plane detection system. There are plans to couple HYRA to other detector arrays such as Indian national gamma array (INGA) and 4π spin spectrometer for ER tagged spectroscopic/spin distribution studies and for focal plane decay measurements.

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A superconducting linear accelerator based on niobium quarter wave resonators has recently become operational to boost the energy of the heavy ion beams available from the existing 15 UD (unit doubled) Pelletron accelerator. The niobium resonators typically performed at an accelerating field of 3-6 MV=m at 6 watts of input power in the test cryostat. When they were tested in the linac cryostat, the accelerating fields were drastically reduced and a number of other problems were also encountered. At present, all the problems have been diagnosed and solved. Many design modifications, e.g., in power coupler, mechanical tuner, helium cooling system, etc. were incorporated to solve the problems. A novel method of vibration damping was also implemented to reduce the effect of microphonics on the resonators. Finally, the accelerated beam through linac was delivered to conduct experiments.

The high pressure and low temperature environment in deep water creates tremendous flow assurance challenges for subsea tiebacks, which are frequently used in offshore oil and gas development. During extended production shutdown, gas hydrates can form and block the flowline unless necessary time consuming and/or complex prevention measures are taken. For passively insulated flowlines, these measures include hydrate inhibitor injection and dead oil displacement of produced fluids. In an emergency shutdown, the flowline is only protected by the cooldown time of the insulation since the prevention measures usually are not possible in the emergency shutdown situation. For production start-up or restart, hydrate inhibitor injection and/or other procedures such as hot oil circulation are necessary. Heated flowline systems can significantly reduce the complexity of shutdown and start-up operations, and provide better overall flow assurance. Heating methods developed by the industry include hot water/liquid heating, electrical trace heating, and direct electrical heating. This paper discusses the issues in the design of hot water heated production flowline bundles using two typical offshore West Africa developments as case studies. Two design options, direct and indirect heating, are analyzed and compared. Factors affecting the warm-up time, such as water flowrate and temperature, pressure limitations, and topsides heating capabilities are analyzed and compared. Determining the warm-up time of the heated bundle with good accuracy is one of the most challenging tasks for the design of water/liquid heated flowline bundles. A thermal analysis method was developed and implemented in an inhouse computer program. The paper describes the method and discusses its validation by comparing the results with those from three-dimensional transient finite element analyses. Introduction Advancement of technology and the discoveries of abundant petroleum reserves have produced a rapid growth of deepwater offshore development activities in recent years. This trend is expected to continue in the foreseeable future in areas such as the Gulf of Mexico, West Africa, and offshore Brazil. One of the frequently used development concepts is subsea tieback, either for producing satellite fields to a production platform, or for total field production to a floating production, storage and offloading vessel (FPSO). The term "deepwater" evolves quickly and at present generally refers to water depth over 1000 m. In this environment, the pressure is generally high and the ambient temperature is low (about 4°C), a combination that creates tremendous flow assurance challenges for the production system. The most challenging problem is gas hydrate formation. At typical deepwater flowline pressures, gas hydrates can form at 10-20°C above the ambient water temperature at seabed. During extended production shutdown, gas hydrates can form and block the flowline unless necessary prevention measures are taken. These measures typically are very time consuming. Some are also quite complex.

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