R Mcadams A J T Holmes D B King E Surrey
A 1d analytical model of the sheath in a negative ion source, such as those proposed for heating and diagnostic beams on present and future fusion devices, has been developed. The model describes the transport of surface produced negative ions from a cathode, across the sheath to a plasma containing electrons, positive ions and negative ions. It ac…
PublishedE. Surrey D. Ciric S. J. Cox L. Hackett D. Homfray I. Jenkins T. T. C. Jones D. Keeling R. King A. Whitehead D. Young
Operation of the JET Neutral Beam Injectors with tritium is described. Supplying the tritium feed via the special electrically grounded gas feed compromised the performance of the up-graded high current triode Positive Ion Neutral Injectors (PINI) due to gas starvation of the source and the methods adopted to ameliorate this effect are described. A…
PublishedRJH Pearce AC Bell D Brennan H Boyer J Bruce T Budd PR Butcher N Davies T Edlington R Felton J Harling T Hartrampf M Hitchin S Hotchin TTC Jones R King G Lawrence R Lobel P Morgan SR Shaw M Stamp E Surrey D Wilson L Worth K Zastrow
‘Trace Tritium Experiments’ (TTE) were successfully performed on JET in 2003. The Campaign marked the first use of tritium in JET plasmas since the Deuterium- Tritium Experiment (DTE1) Campaign in 1997, and was the first use of tritium in experiments under the EFDA organisation with the UKAEA as JET Operator. The safety and regulatory preparati…
PublishedD.B. King V.M. Nakariakov E.E. Deluca L. Golub K.G. McClements
Quasi-periodic EUV disturbances simultaneously observed in 171 Å and 195 Å TRACE bandpasses propagating outwardly in a fan-like magnetic structure of a coronal active region are analysed. Time series of disturbances observed in the different bandpasses have a relatively high correlation coefficient (up to about 0.7). The correlation has a tendenc…
PublishedR. Mcadams R. F. King A. F. Newman
Two designs of electron suppressor have been tested in a volume negative ion source operating dc with a large extraction aperture diameter (16 mm). Both suppressors employ magnetic fields to divert the electrons near the extraction aperture onto collector electrodes. However, while one suppressor uses a fixed field produced by permanent magnets, th…
PublishedR. Mcadams R. F. King A. F. Newman
This paper reports tests of an electron suppressor, for volume negative ion sources with variable electric and magnetic fields. The experiments have been carried out with a source and accelerator operating d.c. and with an extraction aperture of 16 mm diameter. The results are compared to those obtained with a permanent magnet suppressor and to a t…
Published