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The National Spherical Torus Experiment-Upgrade (NSTX-U) is the most powerful spherical torus facility at PPPL, Princeton USA. The major mission of NSTX-U is to develop the physics basis for an ST-based Fusion Nuclear Science Facility (FNSF). The ST-based FNSF has the promise of achieving the high neutron fluence needed for reactor component testing with relatively modest tritium consumption. At the same time, the unique operating regimes of NSTX-U can contribute to several important issues in the physics of burning plasmas to optimize the performance of ITER. NSTX-U further aims to determine the attractiveness of the compact ST for addressing key research needs on the path toward a fusion demonstration power plant (DEMO). The upgrade will nearly double the toroidal magnetic field BT to 1 T at a major radius of R0 = 0.93 m, plasma current Ip to 2 MA and neutral beam injection (NBI) heating power to 14 MW. The anticipated plasma performance enhancement is a quadrupling of the plasma stored energy and near doubling of the plasma confinement time, which would result in a 5–10 fold increase in the fusion performance parameter nτ T. A much more tangential 2nd NBI system, with 2–3 times higher current drive efficiency compared to the 1st NBI system, is installed to attain the 100% non-inductive operation needed for a compact FNSF design. With higher fields and heating powers, the NSTX-U plasma collisionality will be reduced by a factor of 3–6 to help explore the favourable trend in transport towards the low collisionality FNSF regime. The NSTX-U first plasma is planned for the Summer of 2015, at which time the transition to plasma operations will occur.

____ The NSTX-U requirements will double the Toroidal Field (TF), Plasma Current (Ip), Beam Injection Power, and extend pulse length. The larger centerstack requires re-aiming of the Multi Pulse Thomson Scattering (MPTS) lasers and Vacuum Vessel (VV) modifications at Bay L. The second neutral beam requirements include larger tangency radii and thus a VV modification at Bay K and Bay J. A cap design for a new weldment was developed to achieve these larger beam trajectories without losing the utility of the Bay J port for diagnostics. Analyses of loads indicated the need for reinforcements of the vessel at the midplane. NSTX has 6 picture frame type Resistive Wall Mode (RWM) coils around the exterior circumference of the vacuum vessel; each coil surrounds pairs of ports. The modifications needed for the upgrade were intended to minimize the impact to the RWM fields at the plasma. A Pro E global model segment was used to model the vacuum vessel. ANSYS was used to apply loads and investigate reinforcement configurations. A focused effort and analysis produced a design capable of achieving the desired performance of the upgrade while maintaining utility and continuity of RWM coil physics pre-and post-upgrade physics performance. The installation of the Bay J-K and Bay L Port Caps was completed and the reinforcing weldments have been partially installed.

Dispersed nanoparticles of solid lubricants in sheet metal forming fluids are studied for enhanced lubrication that can lead to improved product surface quality and reduced tool wear. Molybdenum disulfide (MoS2) and hexagonal boron nitride (hBN) nanoparticles of varying size and concentrations have shown marked reduction in wear of steel counterfaces representing the tool and in scoring of titanium sheet surfaces. The most effective particle concentration and size ranges were 0.25–4% and 70–100 nm. The counterface wear was reduced by 50–75% while the friction coefficient only marginally improved.

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