Advanced ion beam calorimetry for the test facility ELISE

The negative ion source test facility ELISE (Extraction from a Large Ion Source Experiment) is in operation since the beginning of 201 3 at the Max - Planck - Institut für Plasmaphysik (IPP) in Garching bei München [1]. The large radio frequency driven ion source of ELISE is about 1x1 m 2 in size and can produce a plasma for up to 1 h. Negative ions can be extracted and accelerated by an ITER - like extraction system made of 3 grids with an area of 0.1 m 2 , for 10 s every 3 minutes. A total accelerating voltage of up to 60 kV is available, i. e. a maximum ion beam power of about 1.2 MW can be produced. ELISE is equipped with several beam diagnostic tools for the evaluation of the beam characteristics. In order to evaluate the beam properties with a high level of detail, a sophisticated diagnost ic calorimeter has been installed in the test facility at the end of 2013. The diagnostic calorimeter is split into 4 copper plates with separate water calorimetry for each of the plates. Each calorimeter plate is made of 15x15 copper blocks, which act as many separate inertial calorimeters and are attached to a copper plate with an embedded cooling circuit. The block geometry and the connection with the cooling plate are optimized to accurately measure the time - averaged power of the 10 s ion beam. 48 therm ocouples are installed in as many blocks to reconstruct two vertical and two horizontal beam profiles. In addition, the surface of the blocks is covered with a black coating that allows infrared (IR) thermography which provides a 2D profile of the beam pow er density. The paper describes the beam calorimetry in ELISE, including the methods used for the IR thermography and beam profile evaluation. The results obtained for different experimental conditions will be presented and discussed.