UKAEA Journals

Showing 1 - 10 of 22 Journals Results
2019
UKAEA-CCFE-PR(19)50

A model for a beam-driven plasma neutraliser for a 1MeV, 40A beam of D- ions is presented and is based on the dimensions of the ITER gas neutraliser. For the beam-driven plasma neutraliser there is no need for an external power source for producing and sustaining the plasma. Instead the use of high magnetic fields is employed for plasma confinement…

Preprint Published
2018
UKAEA-CCFE-PR(19)48

A 1D model of an RF driven ion source is presented and is based on the ionisation of thermal electrons. The RF source differs from traditional filament and arc ion sources because there are no primary electrons present, and is simply composed of an antenna region (driver) and a main plasma discharge region. However the model does still make use …

Preprint Published
2016
CCFE-PR(16)46

A summary of negative ion development work being presently undertaken at the Culham Centre for Fusion Energy (CCFE) is given. The Small Negative Ion Facility (SNIF) has an RF driven volume ion source with beam extraction at energies up to 30keV. The extracted beam of Hions has an associated co-extracted electron beam with an electron to ion ratio o…

Preprint Published
2015
CCFE-PR(15)35

A one dimensional model of the magnetic multipole volume plasma source has been developed for application to intense ion/neutral atom beam injectors. The model uses plasma transport coefficients for particle and energy flow to create a detailed description of the plasma parameters along an axis parallel to that of the extracted beam. In this paper …

Preprint Published
2015
CCFE-PR(15)34

A one dimensional model of the magnetic multipole volume plasma source has been developed for use in intense ion/neutral atom beam injectors. The model uses plasma transport coefficients for particle and energy flow to create a detailed description of the plasma parameters along an axis parallel to that of the extracted beam. Primarily constructed …

Preprint Published
2013

The improvement of the efficiency of neutral beam systems to be compatible with the economic requirements of fusion power plants is a key theme in the European research programme. A novel plasma neutralizer, in which the negative ion beam itself is the source of the plasma, is described. Its success depends on the confinement of the free electrons …

Published
2013

A one dimensional model of the sheath between the plasma and the wall in a negative ion source has been expanded to include the effects of a variable wall surface work function and fast positive ion species. The plasma consists of positive ions, electrons and negative ions. The model also includes the emission of negative ions from the wall into th…

Published
2012

In fusion negative ion sources, the negative ions are formed on the caesiated plasma grid predominantly by hydrogen atoms from the plasma. The space charge of the negative ions leaving the wall is not fully compensated by incoming positive ions and at high enough emission a virtual cathode is formed. This virtual cathode limits the flux of negative…

Published