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BAPGEAPSI; Only a few studies on pea (Pisum sativum) investigated the association of single nucleotide polymorphisms (SNP) markers with key agronomic traits. This study aimed to explore the association of a standard set of 384 SNP with grain yield, seed protein content, seed weight, onset of flowering, plant height and lodging susceptibility, in three connected bi-parental recombinant inbred line (RIL) populations including 90 lines each. These RIL originated from crosses between three cultivars that displayed high and stable grain yield across Italian environments, namely, Attika (A), Isard (I), and Kaspa (K). The 270 lines were phenotyped in a spring-sown environment of Lodi (northern Italy; 45°19'N, 9°30'E). Variation among lines within the populations was significant (P < 0.01) in all cases except lodging susceptibility in one cross and, when expressed in terms of the genetic coefficient of variation, proved moderately large for most traits (including grain yield and seed protein content). Overall, we detected six quantitative trait loci (QTL) in the A × I linkage map, eight QTL in K × A, and nine QTL in K × I. Among them, there were three QTL in K × A and two QTL in K × I for grain yield, and one QTL in A × I and two QTL in both K × A and K × I for seed protein content. The consensus map, which included 130 markers (covering about 1094 cM), retained one QTL for grain yield and one for flowering time that co-located on LGII, and three for seed weight on LGIII, LGVI and LGVII. The QTL co-locating for yield and flowering time explained 8% and 31% of the overall phenotypic variation, respectively, for the two traits, and could be exploited in marker-assisted selection for adaptation to the target region.

The ohmic heating system and the poloidal field coils of ASDEX upgrade are supplied by 15 thyristor converter units with an installed apparent power of 600 MVA. To protect the thyristor converters against dc overvoltage arising from abnormal operations and resulting damages caused by the large energy stored in the AUG magnet coils an overvoltage protection system was required. The paper describes the motivation for—and the design and testing of the thyristor crowbar system representing the thyristor converter overvoltage protection system. It will present the layout, analyse the results of measurements obtained during commissioning, compare them to the calculated (design) values and report on the first experience of operation on the AUG coils improving the safety of the equipment.

The power supply of the ASDEX Upgrade (AUG) tokamak consists of 11 thyristor converter modules which feed the poloidal field coils. All converters installed are powered by 10.5 kV flywheel generators starting at a frequency of 110 Hz, running down to 85 Hz during a pulse. For quasi-stationary advanced tokamak experiments with enlarged flat-top phase, the power supply system must be extended. The variable frequency of the pulsed network, fast load changes, together with the different parameters of the load coils require a very sophisticated converter design with reduced reactive power consumption. The paper describes the design and testing of the modular Thyristor Converter Group 6 with neutral control and four quadrant possibilities. It presents the various configurations available for operation on AUG magnetic coils, analyses the results of measurements obtained during commissioning, compares them to the calculated (design) values and reports on the performance achieved in fast four quadrant operation, improving the possibilities of the AUG feedback control of plasma shape and position.

The power supply of the ASDEX Upgrade (AUG) tokamak consists of three pulsed distribution systems (110–85 Hz), each supplied by a dedicated flywheel generator: EZ2 (1.45 GJ/167 MVA) which solely feeds the toroidal field coils, EZ3 (500 MJ/144 MVA) and EZ4 (650 MJ/220 MVA). For quasi-stationary advanced tokamak experiments with extended flat-top phase, the power systems of EZ3 and EZ4 must be connected in parallel, so that full advantage of the installed generator power and flywheel energy can be realised. The variable frequency of the pulsed network, fast load changes (up to 1000 MW/s), together with the different parameters of the generators and saturation effects during pulsed operation, require detailed numerical models for an investigation of the stability limits of a parallel operation of the two machines on one common 10.5 kV busbar. The paper describes the dynamic load requirements of a feedback controlled plasma experiment, the controller development for paralleling two large flywheel generators, the results of system studies with optimised power supply and implications of these results on the technical realisation.

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

The authors report on the improvement of the radial field amplifier (RFA) and on its subsequent positive effect on the plasma vertical stabilization. It is noted that the work carried out on the RFA has enabled an increase in reliability and performance. Full output voltage swings no longer lead to large circulating current excursions and subsequently to trips of the amplifier with loss of plasma vertical control. For small output voltage variations (amplitude >

Mechanical by-pass switches rated for a continuous current of 60 kA and provided with some arc commutation capability are required in the ITER discharging networks to be connected in parallel to the main vacuum circuit breakers. The development work was carried out on a suitable industrial switch and was aimed at increasing substantially its voltage rating and at improving its speed of operation. A fully rated commutating unit was built and subjected to an extensive test program aimed at its full characterisation.

An overview of the present design of the ITER coil power supply system is presented, along with brief descriptions of the main components including the AC/DC converters, switching networks, and discharge circuits.

The interleaved structure of the TF coils allows to obtain a programmable TF ripple field by feeding the two sub-sets of the TF coils with different currents. This would allow to vary the ripple field within one JET pulse and allow a direct assessment of the increased ripple on confinement time, fast particle losses, plasma rotation and H-mode. The TF ripple experiment (RIPPLE 2) was carried out in the pumped divertor configuration in conditions relevant to ITER. In this configuration, the normal field ripple at the plasma edge is about 0.1%. In the experiment, the ripple field was varied up to 2% at the plasma edge, the plasma current was typically 2-3 MA and the TF field 2-2.5 T.

Two large vertical shaft flywheel generators each provides the JET (Joint European Torus) device with peak power up to 400 MW and energy up to 2600 MJ per pulse to induce and confine the multi-mega-ampère plasma current. The integrated rotor flywheel consists of a 650 tonne/10 m diameter rim carrying the poles of the machine. The energy is stored kinetically during a 9 min interval of acceleration from half-speed to full-speed and then released during a 20 s long deceleration. A design life of 100 000 cycles at full energy rating was specified. Following a review of the mechanical design and construction of the generators, the paper will concentrate on the assessment of the stresses and fatigue life of the rotor system, its dynamic behaviour (rim movement, critical speed and balancing) and on the performance in operation of the large thrust bearing.

After a review of the results obtained and of the modifications performed, on the poloidal field system, during the first three years of operation, the paper describes the progress development, on the power supplies, to reach the nominal flux swing capability of JET.

Two large vertical shaft generators with integrated flywheel energy storage and output diode rectifiers will deliver DC pulses of current up to lOOkA and energy up to 2600 MJ to the toroidal and poloidal field coils of the JET Tokamak.

The JET Magnet Power Supply Scheme includes a combination of flywheel generator-diode rectifiers and mains driven transformer-thyristor rectifiers for the supply of energy to the coils and a switching network with air blast circuit breakers and commutating resistors for inducing the high voltage required for the plasma initiation.

The Poloidal Vertical Field Boost Amplifier (PVFB) is designed solely to assist the plasma start-up phase in JET (1–2s)). Its rating of 11kV no load, 6.0kA DC is obtained from four identical modules each consisting of dry-type transformer and air-cooled thyristor rectifiers mounted in high voltage decks. The paper will review the system design of the power supply, the layout of control and protection, the firing generation and monitoring as well as the thyristor failure detection. Finally, the paper will review the factory tests performed on the equipment.