After a long and successful experimental campaign, in which record heating power and plasma current were achieved, the 2007 experiments on MAST were completed as planned on Friday 20th July. The new JET style PINI neutral beam source operated reliably at power levels up to 2MW. Using the new PINI together with one of the original Oak Ridge neutral beam sources, has allowed operation with injected power up to 3.8MW into plasma.
ITER related results
A wide range of experiments has been carried out, exploiting the increased heating power available, and good progress has been made on a number of joint experiments to address important physics issues for ITER. Several of our international collaborators from Europe and the U.S.A. participated in these experiments, in person and using remote participation tools.
Wide range of experiments
Important progress was also made on energy confinement scaling with plasma current and power, neutral beam current drive studies, plasma fuelling by high speed pellet injection, plasma exhaust studies and high beta (plasma pressure) operation. The new TAE (Toroidal Alfven Eigenmode) antenna array has been used to excite TAE instabilities in MAST and first measurements of damping rates have been obtained. Collaborators from Warwick University, York University and Imperial College have been participating in recent studies of fast particle instabilities in MAST.
Diamond testing
During the last week of MAST operation, two diamond coated samples were exposed to plasma and they will now be examined to investigate the impact. This work is part of an EPSRC-funded collaboration with Heriot-Watt University and University College London to investigate the suitability of diamond as a plasma facing material in future fusion devices.
Engineering shutdown
MAST has now entered an engineering break to upgrade the second NBI source to a JET-style PINI and to install an array of coils for control of edge localised modes (ELMs). The engineering break will run until the end of the year. This will be followed by an extended restart period during which the upgraded NBI system will also be commissioned for high power operation. The engineering break is off to a flying start with first manned vessel entry taking place on 9th August as planned. The first in-vessel task involved collection of dust samples by one of our collaborators, Cecile Arnas of the University of Marseille. The distribution and composition of the dust will be analysed. Such measurements are important for assessing the operational performance and safety in future fusion devices. |
