Long-pulse diagnostic calorimeter for the negative ion source testbed BATMAN upgrade.

The RF-driven negative ion source testbed BATMAN upgrade is being developed at IPP Garching in the framework of the ion source development for ITER and DEMO neutral beam injection systems. The testbed has recently been enhanced to allow for steady state operation with a focus on beam optics studies. The previous titanium sublimation pumps and inertial calorimeter limited the beam pulse length to about 6 s every 3 min.

Beamlet scraping and its influence on the beam divergence at the BATMAN Upgrade test facility.

For the ITER fusion experiment, two neutral beam injectors are required for plasma heating and current drive. Each injector supplies a power of about 17 MW, obtained from neutralization of 40 A (46 A), 1 MeV (0.87 MeV) negative deuterium (hydrogen) ions.