R. T. Osawa S. L. Newton D. Moulton S. S. Henderson V. Badicel A. Hudoba
In order to achieve a compatible solution between the divertors and the core, SOLPS-ITER simulations were performed on STEP (Spherical Tokamak for Energy Production) connected double-null geometry to investigate the possibility of using deuterium (D) fuelling puff locations as an actuator for divertor argon (Ar) retention. Significant reduction of …
PreprintS. B. L. Chislett-McDonald L. Bullock A. Turner F. Schoofs Y. Dieudonne A. Reilly
Rare-earth-barium-copper-oxide (REBCO) coated conductor tapes within next-generation tokamak pilot and power plant magnets will be exposed to broad-spectrum gamma-ray and neutron irradiation concurrently. It has been known since the 1980s that cumulative neutron fluence affects the superconducting properties of REBCO, but the effects of gamma rays …
Preprint PublishedA.N. Petrov S. Wray K. Zarebski T. Stroud J. Acres T. Owoeye M. Cannon F. Christie T. Jackson V. Laksharam S. Stewart R. Griffiths N. Brewer K. Rochford S. Gribben
The work presented in this paper is an integrated time-dependent model, describing the power demands of the major tokamak components (magnets, cryogenics, heating and current drive, etc.), as well as the power generated. The physics are implemented in OpenModelica and make use of a Python API (Application Programming Interface) to collect inputs, r…
PreprintS. Merriman J. Abraham J. Bailey J. Billingsley B. Edwards J. Hagues D. León Hernández N. Mantel N. Otway A. Saigiridhari S. Sherwood P. Ting J. Fradera P. Andrés A. Bernad D. Catalán S. Haouala S. Sádaba B. Echeveste S. Ha
The UK Spherical Tokamak for Energy Production (STEP) program is currently progressing the conceptual engineering design of a Spherical Tokamak-based fusion reactor. The program includes a project concerned with design of the reactor breeding blanket. The objective of this work was to develop a low fidelity, integrated simulation approach to sup…
PreprintDaniel Kennedy Bhavin S Patel Colin M Roach
Microinstabilities often result in turbulence that influences energy confinement in tokamak discharges. One such microinstability, of particular importance to the design of next-generation spherical tokamaks (STs) such as STEP [1], is the microtearing mode (MTM), a tearing-parity mode centred on high-order rational surfaces. MTMs are short-wavel…
PreprintR. T. Osawa D. Moulton S. L. Newton S. Henderson B. Lipschultz A. Hudoba
To mitigate the issue of plasma exhaust in reactor scale tight aspect ratio tokamaks such as STEP (Spherical Tokamak for Energy Production), a double-null (DN) configuration is thought to be advantageous over a single-null (SN) configuration. However, practical control of the plasma vertical stability will likely lead to an oscillation around th…
PreprintHendrik Meyer the STEP Plasma Control Heating & Current Drive Team
With steady progress on ITER project and the design of DEMO, the international community is now entering an era in which fusion power on the grid could become a reality within the next 20 – 30 years. In this environment the UK has started the ambitious Spherical Tokamak for Energy Production (STEP) programme, aiming to develop a compact protot…
PreprintJ.H.P. Rice J. Geng C.W. Bumby H.W. Weijers S. Wray H. Zhang F. Schoofs D. Moseley R.A. Badcock
High temperature superconducting magnets offer a novel pathway to magnetic confinement fusion energy generation. Reactor-scale fusion devices require tens of kA of current to generate large toroidal fields for magnetic confinement. Operating HTS magnets at kA-current levels is difficult due to unavoidable joint resistances that require active dr…
PreprintJames H.P. Rice Jianzhao Geng Rodney A. Badcock Dominic A. Moseley Steven Wray Heng Zhang
The application of dc magnetic field to a 2G high temperature superconducting (HTS) tape can reduce the critical current Ic of the tape, without driving the material normal. This property can be used in the development of HTS switching elements through so-called Jc(B) switching. The design of a dc magnetic field switch is reported, in both singl…
PreprintB. Din A. I. Blair F. Schoofs D. P. Hampshire
Understanding the properties of grain boundaries in polycrystalline superconductors is essential for optimizing their critical current density. Here, we provide computational simulations of 2D Josephson junctions (JJs) in low magnetic fields using time–dependent Ginzburg–Landau theory, since they can be considered a proxy for a grain boundar…
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