An alternative ion source for the SINGAP development

It is crucial that the ion source produces > 200 A/m2 to demonstrate the correct performance of the Singap concept for ITER. It is considered prudent to have a second ion source in case the source does not deliver the required current density or is broken in use. An alternative, back-up, source for use with the ITER-like Singap accelerator has been designed. The starting point was to use permanent magnets for electron confinement, and the design were constrained to use the existing power supplies and to fit into a space envelope defined for the source on the ITER-like accelerator. A large variety of possible magnet configurations were studied using a code to calculate primary electron trajectories (no collisions) and to calculate an electron ''confinement time'' and the fraction of electrons capable of reaching the plasma grid. The chosen design has reasonable ''confinement'', no electrons reach the plasma grid and a simple magnet configuration. The main part of the engineering design has been completed by the Cadarache drawing office and a call for tender is expected in June