QUEST is a medium-sized spherical tokamak which has parameters of R~0.64m, a~0.4m, BT<0.25T. The plasma facing walls (PFWs) are made of metals such as tungsten, atmospheric sprayed tungsten (APS-W), stainless steel type 316 (SS 316L) and 316L (SS316). A RF heating source is available for long pulse operation (LPO). A hot wall has been installed to regulate PFWs temperature. Taking advantage of...
Plasma-wall interaction (PWI) plays a crucial role in plasma control in fusion devices. Apart from impurity generation and power exhaust issues, fuel recycling at plasma-facing components (PFCs) introduces additional challenges by affecting plasma density control and fueling efficiency. Hydrogen transport, retention and release from PFCs is influenced by the incoming ion and neutral particle...
Boron, as a low-Z material, is widely employed for wall conditioning to enhance plasma performance in fusion devices. Boron coatings including pre-discharge coating by using carborane (C2B10H12) as the working material assisted by ion cyclotron wall conditioning (ICWC) and real time coating have been successfully performed in EAST machine with full metal first wall [1].
After pre-discharge...
For a successful operation of ITER and of future fusion reactors, several fusion devices are currently being exploited and upgraded. This paper focuses on the technical developments lead in JT-60SA (Japan) and Wendelstein 7-X (W7-X, Germany) fusion devices to provide support on the long pulse operation in metallic environment using operation conditions complementary to the current existing...
In order to operate for long pulses, magnetic confinement fusion (MCF) devices are typically equipped with actively-cooled plasma-facing components (PFCs). These have been installed in several existing long-pulse MCF machines, but are expected to be more widely used in the next generation of high-powered, long-pulse devices (e.g. ITER, DEMO & commercial power plants). The circulation of...
