NSTX began operation in September 1999. As described below, the NSTX research team has made excellent progress in exploring the characteristics and effectiveness of the ST configuration and also in resolving scientific issues relevant for ITER and future fusion devices. In the process, the team has implemented numerous improvements in measurement and operational capabilities thereby opening the door to future progress in ST research.
2014 Two models for fast ion transport due to Alfven Eigenmodes were developed and are being implemented in TRANSP. Real-time algorithms for rotation and current profile control were developed and tested in TRANSP simulations. These algorithms use NBI and NTV as actuators for rotation profile control and NBI and plasma position as actuators for current profile control.
2013 A multi-signal disruption warning algorithm was developed and shown to predict disruptions to over a 96% accuracy. Designs of the high-k scattering diagnostic, Material Analysis Particle Probe, and the physics design of the ECH/EBW system for NSTX-U were completed.
2012 Advances in Neoclassical Toroidal Viscosity and associated magnetic braking physics were made using the Particle Orbit Code for Anisotropic pressure (POCA) code, which was developed to compute the perturbed particle distribution function on perturbed field lines. Co-axial Helicity Injection plasma current ramp-up and flux closure physics was studied using the TSC and NIMROD codes respectively.
2011 Non-linear gyro-kinetic simulations indicate that small-scale overlapping magnetic islands may contribute significantly to the anomalous electron energy transport observed in high-beta ST plasmas.
In addition, approval to begin construction of the NSTX Upgrade Project is granted by DOE.
2010 A new divertor configuration - the "snowflake" divertor - achieves very high flux expansion and substantially reduces the peak divertor heat flux and carbon impurity content in the plasma core.
2009 The role of kinetic resonance effects, including both thermal and energetic particles, is shown to be important in the stability of the Resistive Wall Mode. This knowledge, combined with optimization of plasma shaping and control produces ST plasmas with durations limited only by magnet heating limits.
2008 First-of-a-kind high spatial resolution measurements on NSTX confirm the existence of a long-theorized form of plasma turbulence driven by variation of the electron temperature across the plasma. These tiny swirls of turbulence in the plasma may be one cause of the long standing mystery of electron heat loss.
2007 The evaporation of lithium coatings on plasma facing components in NSTX is shown to improve plasma confinement and to prevent instabilities called Edge-Localized Modes.
2006 A 160-thousand-ampere plasma current is initiated in NSTX without induction from its central solenoid. This world records is attained using a technique known as Coaxial Helicity Injection.
2005 NSTX researchers develop methods to sustain high beta by employing a set of small magnetic coils, controlled by feedback, to counteract the growth of certain instabilities.
2004 NSTX achieves a record toroidal beta of 40%, three times the best values achieved in conventional tokamaks. Beta relates to the economics of fusion power production.
2002 A combination of neutral-beam-driven and self-generated “bootstrap current” in NSTX provides about 60% of the total plasma current, thereby relaxing the need for induction to sustain the current.