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The division was organized to promote the advancement of knowledge of the use of particle accelerator technologies for nuclear and other applications. It focuses on production of neutrons and other particles, utilization of these particles for scientific or industrial purposes, such as the production or destruction of radionuclides significant to energy, medicine, defense or other endeavors, as well as imaging and diagnostics.
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Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
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Fusion Science and Technology
Latest News
Vogtle-3 shuts down for valve issue
One of the new Vogtle units in Georgia was shut down unexpectedly on Monday last week for a valve issue that has since been investigated and repaired. According to multiple local news outlets, Georgia Power reported on July 17 that Unit 3 was back in service.
Southern Company spokesperson Jacob Hawkins confirmed that Vogtle-3 went off line at 9:25 p.m. local time on July 8 “due to lowering water levels in the steam generators caused by a valve issue on one of the three main feedwater pumps.”
Luigi Scibile, Basil Kouvaritakis
Fusion Science and Technology | Volume 36 | Number 2 | September 1999 | Pages 139-164
Technical Paper | doi.org/10.13182/FST99-A98
Articles are hosted by Taylor and Francis Online.
The plasma vertical position in a tokamak can be open-loop unstable with time-varying dynamics. The limitation in the output power of the control amplifier makes the time-varying unstable system particularly difficult to control. Fixed-coefficient linear controllers usually fail to maintain control in the presence of large disturbances, like edge-localized modes (ELMs), which saturate the amplifier output. During the saturation period, the vertical position of the plasma will grow exponentially with the unstable eigenvalue and may reach values that cannot be controlled by the energy provided by the control amplifier, which is limited by practical constraints. The primary sources of disturbances and measurement noise that effect the vertical position are the ELMs and the 600-Hz noise from the thyristor power supplies. The former are present in the form of pulses and appear during high-energy confinement plasma configurations. A novel nonlinear controller for the vertical position based on a discrete adaptive near-time optimum control algorithm (DANTOC) is used to stabilize the system, to maximize the stability region, and to provide robustness with respect to the aforementioned sources of disturbances and measurement noise. The controller is tested in simulation for the Joint European Torus tokamak, and the results demonstrate its feasibility in controlling the vertical position for different plasma configurations. The controller is also tested on the COMPASS-D tokamak, and the results demonstrate the improvement with respect to a simple linear proportional and derivative controller in the presence of disturbances and measurement noise.