BATMAN beam properties characterization by the beam emission spectroscopy diagnostic

Journal Article · Wed Apr 08 00:00:00 EDT 2015 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4916478· OSTI ID:22391458

Ruf, B.; Schiesko, L.; Fantz, U.; Franzen, P.; Riedl, R.; Wünderlich, D. ^[1]; Barbisan, M.; Pasqualotto, R.; Serianni, G. ^[2]; Cristofaro, S. ^[3]

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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. Universitá degli Studi di Padova, Via 8 Febbraio 2, 35122 Padova (Italy)

The ITER neutral beam heating systems are based on the production and acceleration of negative ions (H/D) up to 1 MV. The requirements for the beam properties are strict: a low core beam divergence (< 0.4 °) together with a low source pressure (≤ 0.3 Pa) would permit to reduce the ion losses along the beamline, keeping the stripping particle losses below 30%. However, the attainment of such beam properties is not straightforward. At IPP, the negative ion source testbed BATMAN (BAvarian Test MAchine for Negative ions) allows for deepening the knowledge of the determination of the beam properties. One of the diagnostics routinely used to this purpose is the Beam Emission Spectroscopy (BES): the H{sub α} light emitted in the beam is detected and the corresponding spectra are evaluated to estimate the beam divergence and the stripping losses. The BES number of lines of sight in BATMAN has been recently increased: five horizontal lines of sight providing a vertical profile of the beam permit to characterize the negative ion beam properties in relation to the source parameters. Different methods of H{sub α} spectra analysis are here taken into account and compared for the estimation of the beam divergence and the amount of stripping. In particular, to thoroughly study the effect of the space charge compensation on the beam divergence, an additional hydrogen injection line has been added in the tank, which allows for setting different background pressure values (one order of magnitude, from about 0.04 Pa up to the source pressure) in the beam drift region.

• OSTI ID: 22391458
• Journal Information: AIP Conference Proceedings, Vol. 1655, 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); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ACCELERATION
ANIONS
BEAM INJECTION HEATING
COMPARATIVE EVALUATIONS
EMISSION SPECTROSCOPY
HEATING SYSTEMS
HYDROGEN
ION BEAMS
ITER TOKAMAK
NEUTRAL ATOM BEAM INJECTION
PARTICLE LOSSES
PHOTON EMISSION
SPACE CHARGE
STRIPPING
VISIBLE RADIATION