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MAST-Upgrade (MAST-U) is undergoing several enhancements to deliver increased performance and functionality. One such enhancement is the design, development, and implementation of an Electron Bernstein Wave (EBW) Heating and Current Drive (HCD) System. The MAST-U EBW System aims to provide experimental data for model validation, and to provide a greater understanding of EBW physics and its capabilities. The MAST-U EBW System provides up to 1.8 MW of microwave power into the plasma, through a system comprising: high voltage power supplies; two gyrotrons; evacuated transmission lines; a steerable in-vessel launching system; and associated control and ancillary systems. The gyrotrons from Kyoto Fusioneering have a 0.9 MW output power capability at the dual frequencies of 28GHz and 34.8GHz, allowing start-up and current drive studies to be carried out at their respective optimum frequencies. Additional diagnostics, termed interceptor plates, are proposed to sit in the path of the first reflection. These will measure the reflected power from the plasma, to both act as an interlock if the reflected power is too high, and provide key information on the coupling efficiency.

The UK’s Spherical Tokamak for Energy Production (STEP) reactor design program has recently taken the decision to use exclusively microwave-based heating and current drive (HCD) actuators for its reactor concepts. This is based on a detailed assessment considering all viable HCD concepts, covering the grid to plasma efficiency, physics applications, technology maturity, integration, maintenance, and costs. Of the two microwave techniques: Electron Cyclotron (EC) and Electron Bernstein Wave (EBW), EC was deemed the lowest risk and EBW is retained as a potential path to a more efficient, higher performing device. To assess the ECCD efficiency, the GRAY beam tracing code was employed to perform detailed scans of the launcher position, toroidal and poloidal launch angle, and frequency over the first 3 cyclotron harmonics. For EBW, GENRAY/CQL3D were used to estimate the CD efficiency, demonstrating promising results. To reduce the physics uncertainties in present models for EBW coupling and current drive, MAST Upgrade will install two dual frequency (28, 34.8 GHz), 900kW, 5s gyrotrons from Kyoto Fusioneering, as part of the MAST Upgrade enhancements package. This will be accompanied by a flexible 2D steering launcher system to allow midplane coand counter-CD and above midplane launch for co-direction off-axis CD. Coupling efficiency is quantified by measuring the heating induced by reflected (i.e. non-coupled) power to a plate inserted in the reflected beam path. The experiments will also include EBW driven solenoid-free start-up, increasing power and pulse length by a factor of 10 compared to previous MAST experiments. This presentation will discuss the STEP microwave studies and the MAST Upgrade physics design and capabilities.

Dr. Russell Davies is a largely forgotten pioneer of both post-operative theatre recovery but also a key figure in the establishment of anaesthetics services in Yugoslavia in the late 1940s. Davies spent the majority of his career working as an anaesthetist at Queen Victoria Hospital, East Grinstead, Sussex, England, later being promoted to the head anaesthetist role. Davies set up one of the first recovery wards in the United Kingdom at Queen Victoria Hospital, the ward being named after him in 1989. Here he became a founding member of the Guinea Pig Club, alongside Dr. Archibald McIndoe. The Guinea Pig Club was founded in 1941 to support airmen in the Second World War undergoing plastic surgery at Queen Victoria Hospital. Davies was crucial to the pastoral care of the Club, providing clinical care and guiding members over access to pensions they would have previously been denied. Little is recognised of Davies's achievement of establishing anaesthetics services in Yugoslavia. Davies and his contributions have been largely overlooked. Davies should be considered one of the foremost British anaesthetists of the 20th century., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Balloon pulmonary valvotomy was attempted in eight children with cyanotic congenital heart disease and pulmonic stenosis who were scheduled for a palliative procedure (shunt). In seven patients the balloon could be positioned across the pulmonary anulus, and valvotomy was performed. Five of the patients had tetralogy of Fallot with multiple levels of pulmonary outflow obstruction. For all patients in whom the balloon could be properly positioned the valvotomy was successful, as judged by arterial hemoglobin saturation, which increased from 72% +/- 5% to 83% +/- 5% (p less than .005). Valvotomy was followed by an immediate rise in mean pulmonary artery pressure (12.6 +/- 2.8 to 18.3 +/- 4.8 mm Hg, p less than 0.05) and a decline in hematocrit level at 2 months (54% +/- 5% to 47% +/- 4%, p less than 0.05). There was no mortality or complication from the valvotomy, and the need for a systemic to pulmonary artery shunt was eliminated in six of eight patients. Follow-up has ranged from 0.5 to 2.8 years. This trial indicates that balloon pulmonary valvotomy can be safely performed and is effective palliation in selected patients with cyanotic heart disease that is not suitable for primary repair. The increased pulmonary flow may improve oxygenation and growth of the pulmonary arteries without the need of a systemic to pulmonary artery shunt.