DTT: a Divertor Tokamak Test facility for the study of the power - - PowerPoint PPT Presentation
DTT: a Divertor Tokamak Test facility for the study of the power exhaust issues in view of DEMO R. Albanese, ENEA-CREATE (Italy) on behalf of the WPDTT2 Team & the DTT report contributors (work carried out in tight cooperation with
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http://users.jet.efda.org/iterphysicswiki www.create.unina.it/dtt2 http://fsn-fusphy.frascati.enea.it/DTT
About 60 MEUR not yet allocated (mostly for HW)
See also I-11: H. Reimerdes
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e , *=Ld/λei,
“DTT - An experiment to study the power exhaust in view of DEMO”, Presented at the3rd IAEA DEMO Programme Workshop (DPW-3) , Hefei, China, 11-15 May 2015
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MAIN DTT PARAMETERS FOR THE REFERENCE SINGLE NULL SCENARIO
R (m) 2.15 bN 1.5 a (m) 0,7 tRes (sec) 8 IP (MA) 6 VLoop (V) 0.17 BT (T) 6 Zeff 1.7 V (m3) 33.0 PRad (MW) 13 PADD (MW) 45 PSep (MW) 32 H98 1 TPed (KeV) 3.1 <ne> (1020 m-3) 1.7 nPed (1020 m-3) 1.4 ne/neG 0.45 bp 0.5 <Te> (KeV) 6.2 PDiv (MW/m2) (No Rad) ~ 55 t (sec) 0.47 PSep/R (MW/m) 15 ne(0) (1020 m-3) 2.2 PTotB/R (MW T/m) 125 Te(0) (KeV) 10.2 λq (mm) ~ 2.0
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Table compiled with the info available to us just to provide a comparison at a glance: some figures might be different for other devices in high performance scenarios
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TD03-I: WP DTT2 Progress Report on the preconceptual “baseline “design of DTT EFDA_D_ 2D3KX2 (Apr. 2015) https://idm.euro-fusion.org/?uid=2D3KX2
http://fsn-fusphy.frascati.enea.it/DTT
Nuclear Fusion Infrastructure for Testing Alternative Power Exhaust Systems “, XXII AIV, Genova, Italy, 20-22 May 2015
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Conventional and alternative magnetic configurations that can be obtained using the DTT PF system. CS, PF and TF coils are superconducting: plasma pulse duration ~ 100 s without current drive
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Internal copper coils can be used for plasma control
local modifications of the magnetic configuration in the divertor region
See also P-2: F. Crisanti
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Each of the 18 D-shaped TF coils has78 turns of Nb3Sn/Cu CIC conductor, carrying 46.3kA He cooled (inlet T of 4.5K): max field 11.4 T, max ripple on the plasma 0.8% Graded solution: Cable-In-Conduit (CIC) conductor layouts: 48 LF turns with thicker 316 LN jacket and lower SC strand number, 30 HF turns. section wound in pancakes to reduce the He path NI=65 MAt, Wm=1.96 GJ, Tmarg= 1.2 K von Mises stress OK (<650 Mpa in 3D analyses) Thotspot also OK (104 K all materials, 268 K Cu & SC only) Based on ITER-like strands with slightly optimized performances, only 20% higher, which should be achievable Jmax ~1.8 higher than ITER: possible SULTAN or EDIPO test facility for both HF & LF grade and the test of full-size joints If needed, a small reduction of Bmax by 5% would increase current density limit by 20% in the HF grade and 10% in the LF grade
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DTT CS coil assembly
ITER CS DTT CS Operating current (kA) 45.0 23.0 Peak magnetic field (T) 13 13.2 Cumulative operating load 585 kN/m 288 kN/m Conductor outer dimensions 49.0 mm x 49.0 mm 31.6 mm x 19.8 mm Jacket Thickness 8.2 mm (minimum value) 2.9 mm Cable area (mm2) 771 (excluding central channel) 353 Steel section per turn (jacket) 1566 mm2 242.4 mm2 *900 MPa yield stress
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PF1 PF2 PF3 PF4 PF5 PF6 Bmax (T) 3.70 3.00 2.35 3.36 3.85 4.02 Imax (MAt) 3.277 2.446 2.371 3.454 3.337 6.046 Name Isat (kA) Vsat (V) turns CS3U 23 800 270 CS2U 23 800 420 CS1U 23 800 420 CS1L 23 800 420 CS2L 23 800 420 CS3L 23 800 270 PF1 25.2 800 130 PF2 22.6 800 108 PF3 21.2 1000 112 PF4 24.7 1000 140 PF5 23 800 152 PF6 23.3 800 260 C1 60 50 1 C2 60 50 1 C3 60 50 1 C4 60 50 1 C5 25 200 4 C6 25 200 4 C7 60 50 1 C8 60 50 1 Field and current limits Current and voltage limits (4 quadrants)
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.1 .2 .3 .4 .5 .6 .7 .8 .9 1
Imax, Imin, Break-down and PS voltages, SNU res.
10 20 30 40 50 60 P Q S
Total active, reactive and apparent power for poloidal coils
CS3U CS2U CS1U CS1L CS2L CS3L PF1 PF2 PF3 PF4 PF5 PF6 IC5 IC6 100 200 300 400 500 600 700 800 900 Poloidal coil name PS current and voltage, SNU R and voltage Ipos (kA) Ineg (kA) VPS (V) RSNU (m) VSNU/10
50 100 150 200 50 100 150 200 250 300 350 400 450 500 550 P Q S
200 s
200 s 900 1
60 550 50 Time (s) Time (s)
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Poloidal Toroidal Additional Auxiliary DTT Total +20% P (MW) 20 (positive) 2.2 130 90 270 Q (Mvar) 60 2.7 150 80 350 S (MVA) 60 2.7 200 120 440 Power factor
0.75 0.67 (average) Duty cycle 100s/3600s CW 100s/3600s CW
(except PF3, PF4, IC5 and IC6 PSs that have an output DC voltage ±1 kV). These AC/DC converters are four quadrants, thyristor based 12 pulses with current circulating and sequential control to reduce the reactive power, except IC5 and IC6 PSs that are IGCT based to be fast enough to control the vertical position of plasma The ENEA Research Centre of Frascati is a candidate site for DTT. It has been foreseen an high voltage connection at 400 kV by an intermediate electric substation 400kV/150kV (whose location is not still defined) and two underground electric cables up to the electric substation 150kV/36kV of ENEA Research Centre of Frascati. The electric characteristics of the power grid are not still available because it is ongoing a contract with TERNA for the definition of connection characteristics and costs.
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1 2 4 3 5 1 2 4 3 5
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L/R time constants of DTT VV VS: 2070 s-1, ms 0.40.8 The maximum Von Mises Stress is lower than INCONEL 625 admissible stress limit (Sm =265Mpa) in VV E 42 ms Br 22 ms Bv 16 ms B 22 ms
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Neutronics calculations show that without any additional shield (considering only VV, FW and front casing) the TF coil nuclear heating density on the first inboard turn is 3.77 mW/cm3. With proper shielding design (5 cm inboard), the total nuclear loads
thickness and improving VV design and/or by slighting reducing the operational density, this figure could be reduced to 2-3 kW.
Total neutron flux (n cm-2 s-1) @ inboard midplane 9.1x1011
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The FW consists of a bundle of tubes armored with plasma-sprayed tungsten (W). The plasma facing tungsten is about 5 mm thick (except for the equatorial and upper inboard segments where the tungsten layer is about 10 mm thick), the bundle of stainless steel tubes (coaxial pipes in charge of cooling operation) is 30 mm thick, and the backplate supporting the tubes is 30 mm thick of SS316L(N) Poloidal profile 3D view FW support structure FW layers RH mandatory for the non-negligible neutron flux
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The main objective of the DTT project is to test several divertor design and configurations, so the concept of the machine could change from the standard single null (SN) plasmas to alternative configurations like X Divertor (XD) Snow Flake Divertor (SFD). Furthermore the design of VV, ports and RH devices should take into account application and testing of a Liquid Metal Divertor. A possible divertor compatible with SN & SF RH Liquid Li limiter tested in FTU
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A mix of different heating systems will provide the required 45MW power: ≈15MW ECRH at 170 GHz; ≈15MW ICRH at 60-90 MHz; ≈15MW NBI at 300 keV. During the initial plasma operations 15 MW of ICRH and 10 MW of ECRH will be available.
4 antennas 16 RF generator units 2 auxiliary PS & 1 HVPS (with 8 units) TLs + tuning and matching (16 units) Cooling, control, data acquisition, test bed facility
gyrotrons MHVPS TL
launcher, CODAS)
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Diagnostics Parameters to be measured: Te Plasma Core, Ne Core, Ti, Ion Flow Plasma Core, Plasma Current, Magnetic Field, Plasma position and shape, Plasma Energy, q profile, MHD, Radiation, Zeff, Impurities Core, Impurities SOL/Divertor, ni, Ti, flow, Divertor Te, ne, Divertor Detachment, Neutrals (pressure), Wall Hot Spots, Escaping Fast ion, Wall temperature, q, Runaway electrons, Halo/Hiro Currents, Vessel deformation/displacement, Redeposition layers Real time control (main components) Overview of interferometer- polarimeter 6+5 viewing chords
Diagnostic Actuator Plasma Current Rogowsky Coils Magnetic Flux Axisymmetric equilibrium Magnetic sensors PF coils Electron Density Interferometer Gas valves/ Cryopumps MHD /NTM Pick-up coils/ECE/SXR ECE/Control coils ELM control Da, Stored energy Control Coils, Plasma Shape Control, Vertical kicks, Pellets , RMP’s Power exhaust IR Cameras/thermocouples/ CCD cameras/spectroscopy Divertor and main plasma Gas valves /impurity gas valves
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Other systems*:
Possible future upgrading*:
* details in the proposal
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