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Title: 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 beginning of 2013 at the Max-Planck-Institut für Plasmaphysik (IPP) in Garching bei München. The large radio frequency driven ion source of ELISE is about 1×1 m{sup 2} in size (1/2 the ITER source) 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{sup 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 diagnostic calorimeter has been installed in the test facility at the end of 2013, starting operation in January 2014. The diagnostic calorimeter is split into 4 copper plates with separate water calorimetry for each of the plates. Each calorimeter plate is made of 15×15 copper blocks, which act as many separate inertial calorimeters and are attached to a coppermore » 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. The surface of the blocks is covered with a black coating that allows infrared (IR) thermography which provides a 2D profile of the beam power density. In order to calibrate the IR thermography, 48 thermocouples are installed in as many blocks, arranged in two vertical and two horizontal rows. The paper describes the beam calorimetry in ELISE, including the methods used for the IR thermography, the water calorimetry and the analytical methods for beam profile evaluation. It is shown how the maximum beam inhomogeneity amounts to 13% in average. The beam divergence derived by IR thermography ranges between 1° and 4° and correlates relatively well with the values measured by beam emission spectroscopy with up to 30% difference. It has also been observed that the beam inhomogeneity decreases with lower beam divergence.« less
Authors:
; ; ; ; ; ; ;  [1] ;  [2] ;  [3] ;  [4] ;  [2]
  1. Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany)
  2. Consorzio RFX(CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy)
  3. (Italy)
  4. Università degli Studi di Padova, Via 8 Febbraio 2, 35122 Padova (Italy)
Publication Date:
OSTI Identifier:
22391455
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1655; Journal Issue: 1; Conference: NIBS 2014: 4. International Symposium on Negative Ions, Beams and Sources, Garching (Germany), 6-10 Oct 2014; Other Information: (c) 2015 U.S. Government; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 43 PARTICLE ACCELERATORS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BEAM INJECTION HEATING; BEAM PROFILES; CALORIMETRY; COPPER; ELECTRIC POTENTIAL; EMISSION SPECTROSCOPY; ION BEAMS; ITER TOKAMAK; NEUTRAL ATOM BEAM INJECTION; PLASMA; PLASMA DIAGNOSTICS; PLATES; POWER DENSITY; RADIOWAVE RADIATION; TEST FACILITIES; THERMOCOUPLES; THERMOGRAPHY