Status of the START neutral beam project
- Association EURATOM-CCFE, Abingdon, UK
- ORNL
A major advantage of spherical tokamaks is their potential for achieving high beta and high plasma density in modest sized plasmas using low magntic field. Given this combination of low field and high density, neutral beam injection can provide effective auxiliary heating for the next generation of spherical tokamaks. A neutral beam injector, shipped recently from Oak Ridge National Laboratory as part of an ongoing collaboration on spherical tokamak research, has now been installed onto the START (Small Tight Aspect Ratio Tokamak) experiment at Culham Laboratory. This should provide the first experimental test of neutral injectino into spherical tokamak plasmas, and allow the effects of neutral beam heating on energy confinement and beta values to be assessed at low aspect ratios. This experiment also extends the data base of confinement scaling for tokamaks in general. Modifications to START have included in-situ machining of a new 31 cm diameter port for NBI, plus the installation of a new graphite neutral beam stop equipped with thermocouples to provide beam profile and shinethrough diagnosis. The major modification to the NBI beamline has been the installation of an optical fiber coupled control and instrumentation system. The injector will be operated without cryopumps in a 'volume pumped' configuration, and should provide 0.5 MW of injected hydrogen neutral power at a beam energy of 40 keV for 20 ms pulses. The status of the installation and commissioning program is reported.
- Research Organization:
- Oak Ridge National Laboratory (ORNL)
- Sponsoring Organization:
- SC USDOE - Office of Science (SC)
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1024736
- Country of Publication:
- United States
- Language:
- English
Similar Records
High {beta} produced by neutral beam injection in the START (Small Tight Aspect Ratio Tokamak) spherical tokamak
New applications of ORNL neutral beam injectors