A. Turner
As radiation transport models for ITER become increasingly complex, the use of traditional constructive solid geometry (CSG) modelling approaches such as MCNP presents significant disadvantages during model creation and integration. Studies were performed to assess the capabilities of alternative mesh-based neutronics workflows offered by the MCNP …
PreprintR. McAdams A. J. T. Holmes D. B. King E. Surrey I. Turner J. Zacks
A summary of negative ion development work being presently undertaken at the Culham Centre for Fusion Energy (CCFE) is given. The Small Negative Ion Facility (SNIF) has an RF driven volume ion source with beam extraction at energies up to 30keV. The extracted beam of Hions has an associated co-extracted electron beam with an electron to ion ratio o…
Preprint PublishedR. McAdams A. Sparkes A. Ash I. Day D. King M. Kovari A. Shepherd I. Turner J. Zacks D. Ciric JET EFDA Contributors
In normal operation the JET neutral beam injectors have the operating gas supplied to the ion source and the neutraliser. For tritium operation the gas is supplied to both the ion source and neutraliser at a point close to the earth grid (grid gas) due to the difficulty in producing a gas line with a secondary containment and a ceramic break fo…
Preprint PublishedZ. Ghani A. Turner S. Mangham J. Naish M. Lis L. Packer M. Loughlin
Extensive neutronics and 3-D activation simulations were carried out to assess the levels of radiation throughout the ITER tokamak complex. The simulated radiation sources included DT fusion neutrons exiting the cryostat and gamma rays arising from the activation of cooling water, activated pipe chases and cask transfers. Resultant biological dos…
Preprint PublishedF. Dhalla S. Mistry I. Turner T.R. Barrett I. Day R. McAdams
For the initial phase of MAST-U operation the two existing neutral beam injection systems will be used, but must be substantially upgraded to fulfil expected operational requirements. The major elements are the design, manufacture and installation of a bespoke bending magnet and Residual Ion Dump (RID) system. The MAST-design full energy dump is b…
Preprint PublishedA. Turner D. Leichtle P. Lamalle B. Levesy L. Meunier E. Polunovskiy R. Sartori M. Shannon
The Ion Cyclotron Heating and Current Drive (ICH&CD) system will reside in ITER equatorial port plugs 13 and 15. Shutdown dose rates (SDDR) within the port interspace are required to be less than 100 Sv/h at 106 s cooling. A significant contribution to the SDDR results from neutrons streaming down gaps around the port frame, and the mitigation of …
Preprint PublishedB. Colling T. Eade M.J. Joyce R. Pampin F. Seyvet A. Turner V. Udintsev
Shutdown dose rate calculations have been performed on an integrated ITER C-lite neutronics model with equatorial port 10. A fully shielded configuration, optimized for a given diagnostic designs (i.e. shielding in all available space within the port plug drawers), results in a shutdown dose rate in the port interspace, from the activation of mater…
Preprint PublishedT. Eade D. Stonell A. Turner
As nuclear fusion progresses towards a sustainable energy source and the power of tokamak devices increases, a greater understanding of the radiation fields will be required. As well as on-load radiation fields, off-load or shutdown radiation field are an important consideration for the safety and economic viability of a commercial fusion reactor. …
Preprint PublishedJ. Zacks I. Turner I. Day K. Flinders B. Crowley R. McAdams
The Small Negative Ion Facility (SNIF) at CCFE has been undergoing continuous development and enhancement to both improve operational reliability and increase diagnostic capability. SNIF uses a CW 13.56MHz, 5kW RF driven volume source with a 30kV triode accelerator. Improvement and characterisation work includes: • Installation of a new “L” t…
Preprint PublishedD. Taylor S. Lilley A. Turner A. Davis
A significant functional upgrade is planned for the Mega Ampere Spherical Tokamak (MAST) device, located at Culham in the UK, including the implementation of a notably greater neutral beam injection power. This upgrade will cause the emission of a substantially increased intensity of neutron radiation for a substantially increased amount of time up…
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