1 / 14

Rapporteur: M. Hanada (JAEA)

EFDA. NEUTRAL BEAM R&D toward ITER. Rapporteur: M. Hanada (JAEA).

apowell
Download Presentation

Rapporteur: M. Hanada (JAEA)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EFDA NEUTRAL BEAM R&D toward ITER Rapporteur: M. Hanada (JAEA) IT/2-3RaProduction of High Power and Large-Area Negative Ion Beams for ITERHanada M., JAEAIT/2-3RbTechnological aspects of the different schemes for accelerator and ion source of the ITER Neutral Beam InjectorAntoni V., Consorzio RFXIT/2-3RcProgress of the development of the IPP RF Negative Ion Source for the ITER Neutral Beam SystemFranzen P., IPP GarchingIT/2-3RdReview of the EU Activities in Preparation of ITER in the Field of EC Power Sources and NB systemBonicelli T., EFDA

  2. Overview of ITER NB system IT/2-3Rb ITER requirement 16.5 MW, 1 MeV D0 NBI 40 A,1 MeV D- ion beam ITER plan view NB injector module 2 (+1) NBI = 33 (50) MW HV bushing Two design options MAMuG + Arc ion source(JA team) SINGAP + RF ion source (EU team) ion source & accelerator

  3. Progress in key component R&D • Large negative ion source : 40 A (200A/m2) from 0.6 x1.5 m2 • Arc ion source and RF ion source • Long pulse operation :21 s, 3.2 MW D0 injection in JT-60U • 600 s H- ion beam in RF ion source • Beam uniformity :±4% in arc ion source • 2. 1 MeV negative ion accelerator: D- ion beam of 200A/m2 • Beamlet divergence < 7 mrad • MAMuG and SINGAP • Beamlet divergence : 5 mrad in both accelerators • 3. High voltage bushing: Large insulator ring of 1.56 m dia. • The full-size ITER insulator is fabricated.

  4. Design of ITER ion source IT/2-3Rb ITER target: 40 A (200 A/m2) D- ion beam from an extraction area of 0.6 x1.5 m2. Two design options: Arc or RF ion sources. Reference design Arc ion source (JAEA) Alternative design RF ion source (IPP) • KAMABOKO source • Filaments: 72 pcs. • Replacement: • regular maintenance • 8 RF drivers • Possibly • less frequent • Maintenance

  5. Arc ion source development 17s 80 JT-60U N-NB 40 3.6 MW DT of water (0C) 3.2 MW 60 20 Grid power 500 kW 0 40 Injection energy (MJ) 20 1.5 MW Iacc ~1 MW 10 Current(A) 20 0 0 5 10 15 20 25 30 2 ion sources Time (sec) 1 ion source 0 0 10 20 30 Beam pulse length (s) IT/2-3Ra Achievement of arc sources (short pulses) Long pulse operation of large negative ion sources in JT-60 N-NB system. Pulse length was in the order of ~1 s. 20A, 320 keV D- beams ( 2 ion sources) Water temperature rise The cooling capability of the acceleration grids was verified to sustain the long pulse beam of the present power level. 3.2 MW, 21 s D0 injection

  6. Beam uniformity Tent shaped filter IT/2-3Ra • It is essential to reduce the grid power loading for the longer pulse of higher power beams. • The grid power loading is caused by non-uniformity of the negative ions, which is due to plasma localization by a drift of primary electrons. External filter Beam uniformity : ± 4% (ITER:< ± 10% ) Schematic of electron motion in tent filter Estimation area of deviation ± 4% The primary electrons ideally rotate around the tent filter. JAEA proposes a tent-shaped filter for the arc ion source in ITER NB system.

  7. RF ion source development ~0.85m ～0.9m EFDA IT/2-3Rd IT/2-3Rc Full width and half height of ITER ion source RF ion source at IPP (BATMAN) RF Antenna Plasma chamber Faraday shield Achievement of RF ion sources • Modular concept : 4 RF drivers for a half height of the ITER source. • The ion source under commissioning • plasma uniformity • negative ion uniformity Long pulse operation is significantly in progress.

  8. Design of ITER Accelerator IT/2-3Rb IT/2-3Ra ITER target: acceleration of 40 A (200 A/m2) D- ion beam up to 1 MeV. Two design options: MAMuG or SINGAP accelerators. MAMuG (Multi-Aperture Multi-Grid at JAEA) 5 acceleration grids with multi-apertures Ion source e D- ion beam Plasma grid Extraction grid Suppression of electron acceleration by multi-grids SINGAP (Single GAP at Cadarache) Pre-acceleration grid (～60keV) Electrode (grounded grid) Ion source e D- ion beam One single acceleration gap Plasma grid Extraction grid Simple structure

  9. MAMuG Accelerator Development 750 keV, 134 A/m2 (186 mA) H- ion beam 100 mm IT/2-3Ra Beamlet divergence:7 mrad （ITER design) MAMuG accelerator in JAEA Target: 1 MeV 200 A/m2 (0.5 A) H- 3x3 beamlets at optimum perveance Light intensity profile by CCD 836 keV, 146 A/m2 (0.2 A) H- ion for 0.2 s beamlet divergence: 5 mrad

  10. SINGAP Accelerator Development EFDA IT/2-3Rd • SINGAP accelerator is developed at CEA Cadarache. • D- ions are accelerated to 1 MeV in one single gap with a single aperture electrode. Preaccel. Grid (～60keV) Test of “ITER-like” SINGAP H- beamlets SINGAP electrode at 1 MV • 727 keV, 120 A/m2 (0.02 A) D- achieved. • The beamlet divergence was ~ 5 mrad. • Suppression of electron acceleration in the single acceleration gap is studied. • To be tested at JAEA Naka, for feasibility test of SINGAP in high current operation of ~0.5 A ( Issues: beam optics and suppression of electron acceleration).

  11. High Voltage Bushing Design flange Kovar IT/2-3Ra IT/2-3Rb High voltage insulation of 1 MV and vacuum boundary ITER HV bushing Detail of vacuum boundary To power supply FRP 1 MPa Air (guard gas) High voltage feeder SF6gas Vacuum FRP SF6 Vacuum ~2 m Alumina ceramic ring 1.56 m in dia. 0.29 m in height ~1.8 m Metalizing/ brazing of alumina with a thin Kovar plate of ~2.5mm thick. To vacuum insulated ion source and accelerator

  12. Development of ITER insulator OD:1.56 m IT/2-3Ra To fabricate the full-size ITER insulator, new cold iso-static press was developed. Full-size ITER insulator was successfully fabricated. Cold iso-static press (CIP) is processed in the largest existing water pressure vessel Conventional New 0.29 m Max. outer diameter 1.56 m Max. outer diameter < 1 m • - Metalizing / Blazing test of the full-size ITER insulator. • Voltage holding and mechanical test. • After test, to be assembled in the ITER HV bushing.

  13. NB test facility for ITER EFDA IT/2-3Rb IT/2-3Rd • The R&D status is reaching close to the envelope of the existing facilities. • Ion source R&D: ≤ 20 A, 500 keV, • Accelerator R&D: ≤ 1 A, 1 MeV. • However, integration test at 40 A, 1 MeV would be necessary for ITER before installation. • Full scale “Test Facility” (TF) is planned to be built at RFX Padova. Progress of negative ion source and accelerator R&D for ITER

  14. Conclusion • A 3.2 MW D0 beam has been successfully injected for 21 s from the JT-60U negative ion source that has the relevant size to the ITER source. A tent filter is proposed to improve the beam uniformity in large arc ion sources. • A long pulse beam production for 600 s was demonstrated at the H- ion current density of 160 A/m2in RF ion source. A half size of the ITER source is under commissioning. • For 1 MeV, 200 A/m2 accelerator for ITER, 146 A/m2, 836 keV H-ion beam produced in MAMuG accelerator and 120 A/m2, 727 keV D- ion beam produced in SINGAP accelerator. • A full-size ceramic insulator (1.56 m dia.) for ITER has been successfully fabricated. • Full scale “Test Facility” (TF) is planned to be built at RFX Padova.

More Related