MAST
MAST Upgrade
The Mega Amp Spherical Tokamak (MAST) facility at Culham Centre for Fusion Energy is undergoing a major upgrade that will enhance its role in international fusion research.
MAST Upgrade will enable scientists to:
- Make the case for a fusion Component Test Facility (CTF). A CTF would test reactor systems for the DEMO prototype fusion power plant, and a spherical tokamak is seen as an ideal design for the facility;
- Add to the knowledge base for ITER and help resolve key plasma physics issues to ensure its success;
- Test reactor systems. MAST Upgrade will be the first tokamak to trial the innovative Super-X divertor – a high-power exhaust system that reduces power loads from particles leaving the plasma. If successful, Super-X could be used in DEMO and other future fusion devices.
The diagram below shows MAST Upgrade's relevance in the fusion R&D programme.
The upgrade is planned in two stages. Funding for Stage 1 has been agreed with the Engineering and Physical Sciences Research Council and this phase will be completed in 2015. Main features of the Stage 1 upgrade:
- New centre column, divertor coils, cryopump and power supplies – providing pulse lengths up to ten times that of the existing machine;
- More powerful and flexible heating – an upgrade of the neutral beam power to 7.5 megawatts and an off-axis beam system to allow different heating configurations;
- Super-X divertor – plasma escaping from the core will be guided along a longer exhaust path, cooling the particles and spreading them over a larger area so that the impact on the wall of the machine is reduced;
- Improved machine parameters (see table below) enabling study of steady-state plasmas at near-fusion conditions.
A second stage is planned two to three years later, subject to funding. This would see neutral beam power further increased to 12.5 megawatts and add new features to improve profile control and study of plasma instabilities.
| Parameter | Before upgrade | Stage 1 upgrade | Stage 2 upgrade |
|
Peak power injected |
up to 5,000,000 watts |
up to 7,500,000 watts |
up to 12,500,000 watts |
|
Toroidal magnetic field |
0.55 Tesla |
0.84 Tesla | 0.84 Tesla |
|
Energy deposited in plasma at high current |
5-10 megajoules |
up to 30 megajoules | up to 30 megajoules |
|
Pulse length at high current/field |
up to 0.5 seconds |
4 seconds |
5 seconds |
|
Profile control |
none |
moderate |
extensive |
|
Particle control |
none |
active |
active |
|
Plasma current |
1,300,000 amps |
2,000,000 amps |
2,000,000 amps |
Opportunities for collaboration
MAST Upgrade will offer excellent possibilities for scientific collaborators from the UK and overseas. Research partners can advance their own physics and engineering studies by developing systems for the upgrade. Once the new MAST is online, it will be operated as a 'user facility' to allow scientists from other fusion laboratories and from universities to exploit its capabilities. Contact CCFE to discuss the possibilities for MAST Upgrade collaborations.
MAST Upgrade resources
Video: Introduction to MAST Upgrade
Video: Animation of Super-X divertor
Interactive model of MAST Upgrade's main features
Brochure: MAST Upgrade – Advancing compact fusion sources – PDF file (1244kbs)
MAST Upgrade poster – PDF file (286kbs)
News item: Announcement of MAST Upgrade project – March 2010
