D. Kennedy M. Giacomin B. S. Patel W. A. Hornsby D. Dickinson C. M. Roach
We present herein the results of a linear gyrokinetic analysis of electromagnetic microinstabilites in the conceptual high−β, reactor-scale, tight-aspect-ratio tokamak STEP (Spherical Tokamak for Energy Production, https://step.ukaea.uk). We examine a range of flux surfaces between the deep core and the pedestal top for the two candidate flat…
Preprint PublishedM. Giacomin D. Kennedy C. J. Ajay D. Dickinson B. S. Patel C. M. Roach
In this work, we present the results of first-of-their-kind nonlinear local gyrokinetic simulations of electromagnetic turbulence at mid-radius in the burning plasma phase of the conceptual high-β, reactor-scale, tight-aspect-ratio tokamak STEP (Spherical Tokamak for Energy Production). A prior linear analysis in D.Kennedy et al. submitted to Nucl…
PreprintAlexey Mishchenko Daniel Kennedy Per Helander Axel Konies Gabriel Plunk Pavlos Xanthopoulos Alessandro Zocco
In this paper, we summarize our recent work on gyrokinetic applications in electron- positron and non-neutral plasma. The electrostatic stability of electron-positron plasmas was investigated in dipole and slab geometry, with and without ion admixture. The gyrokinetic dispersion relation was derived and, for the slab case, extended to non-neutra…
PreprintM. Giacomin D. Dickinson D. Kennedy B. Patel C. M. Roach
Linear and nonlinear gyrokinetic simulations are performed in experimentally relevant scenarios built from a MAST case where a microtearing mode instability dominates at ion Larmor radius scale. This collisional microtearing mode instability appears only when a vel…
Preprint PublishedA. Withycombe N. Platt D. Kennedy X. Lefebvre
A Tritium fuel cycle must have the capability to import tritium inventory from transport storage containers to enable initial inventory stockpiling and future refresh of the inventory. The Joint European Torus (JET) Active Gas Handling System (AGHS) previously imported tritium inventory from Amersham Uranium beds (U-beds) via a decanting system hou…
PreprintR. W. George D. Kennedy T. Huddleston A. Vittal R. Morris S. Ng X. Lefebvre
The Exhaust Detritiation System (EDS) of the JET Active Gas Handling System (AGHS) removes tritium from exhaust gases and contaminated air prior to discharge to stack. The system was replaced prior to JET’s tritium experimental campaign due to corrosion damage. In this paper, the following topics are presented: System function and de…
Preprint PublishedDaniel 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…
PreprintD. McGarrigle E. Flynn C. Kennedy A. Loving S. Budden
This paper reports on a study of the existing or proposed maintenance arm systems with similar functions and structure to that of the proposed DEMO Multi-Purpose Deployer (MPD).The current MPD design iteration consists of a boom deployment system that is ~30m long and can support a payload of ~1000kg, while still being able to access the DEMO va…
Preprint Published