The ITER neutral bea
m syste
m is using inductively coupled radio frequency (RF) ion sources, that have de
monstrated the required ITER para
meters on (s
mall) sources with extraction areas up to 200 c
mmlns="""">2. As a next step towards the full size ITER source IPP is presently constructing the test facility ELISE (¡°Extraction fro
m a Large Ion Source Experi
ment? operating with a ¡°half-size?source which has approxi
mately the width but only half the height of the ITER source. The
modular driver concept is expected to allow a further extrapolation to the full size in one direction to be
made. The
main ai
m of this experi
ment is to de
monstrate the production of a large unifor
m negative ion bea
m with ITER relevant para
meters in stable conditions up to one hour.
Plasma operation of the source is foreseen to be performed continuously for 1 h; extraction and acceleration of negative ions up to 60 kV is only possible in pulsed mode (10 s every 180 s) due to limitations of the existing IPP HV system. The design of the source and extraction system implements a high experimental flexibility and a good diagnostic access while still staying as close as possible to the ITER design. The main differences are the source operating in air and the use of a large gate valve between the source and the target chamber.
ELISE is expected to start operation at the end of 2011 and is an important step for the development of the ITER NBI system; the experience gained early will support the design as well as the commissioning and operating phases of the PRIMA NBI test facilities and the ITER neutral beam system.