Fusion Programme - ENEA - Fusione

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Fusion ProgrammeMinority ions, accelerated by rf waves in the range of MeV energies, predominantly transferMinority ion their energy to plasma electrons via collisional slowing down. The use of ICRH in theacceleration minority scheme (H or 3 He) in D plasmas can indeed produce fast particles that, with anby ICRH appropriate choice of the minority concentration, rf power, plasma density andtemperature, can reproduce the dimensionless parameters ρ* fast and β fast characterisingthe alpha-particles in ITER. Thus, a device operating with deuterium plasmas in a dimensionless parameterrange as close as possible to that of ITER and equipped with ICRH as the main heating scheme wouldmake it possible to address a number of burning plasma physics issues, e.g., fast–ion transport due tocollective mode excitations and cross-scale couplings of micro-turbulence with meso-scale fluctuationsdue to the energetic particles themselves.A detailed study with reference to the FAST conceptual design was performed to determine thecharacteristic fast-ion parameters necessary for addressing the above-mentioned burning plasma physicsissues and to present a stability analysis of collective modes excited by the ICRH-induced energetic iontail. The 2D full-wave code TORIC was used, coupled to the SSQLFP code, which solves the quasi-linearFokker-Planck equation in 2D velocity space. The HMGC hybrid code was also used to investigate thedestabilisation and saturation of fast-ion-driven Alfvénic modes below and above the EPM stabilitythreshold, applying as initial velocity space distribution function a bi-Maxwellian distribution for energeticparticles, which takes into account the anisotropy in the velocity space (T ⊥ >T ) due to ICRH. A parametricstudy based on density and temperatures profiles given by the TORIC code was also carried out.Among the R&D missions for possible new European plasma fusion devices, the FASTEdge plasma project will address the issue of “First wall materials & compatibility with ITER/DEMOrelevantplasmas”. FAST can operate with ITER-relevant values of P/R (up to 22 MW/m,issuesagainst the 24 MW/m of ITER, inclusive of the alpha-particle power), thanks to itscompactness; thus it will be possible to investigate the physics of large heat loads on the divertor plates.The FAST divertor will be made of bulk tungsten (W) tiles, for basic operations, but also fully toroidal divertortargets made of L-Li are foreseen. Viability tests of such a solution for the DEMO divertor will be carriedout as final step of an extended programme started on the FTU with the L-Li limiter.To have reliable predictions of the thermal loads on the divertor plates and of the core plasma purity, anumber of numerical self-consistent simulations has been performed for the H-mode and steady-statescenarios by using the code COREDIV. This code, already validated in the past on experimental data(namely JET, FTU, TEXTOR), is able to describe self-consistently the core and edge plasma in a tokamakdevice by imposing the continuity of energy and particle fluxes and of particle densities and temperaturesat the separatrix.2007 Progress ReportThe overall picture shows that at the low plasma densities typical of steady-state regimes, W is effective indissipating input power by radiative losses, while Li needs additional impurities (Ar, Ne). In the intermediateand, mainly, in the high-density H-mode scenarios, impurity seeding is needed with either Li or W as targetmaterial, but a small (0.08% atomic concentration) amount of Ar, not affecting the core purity, is sufficientto maintain the divertor peak loads below 18 MW/m 2 , which represents the safety limit for the Wmonoblock technology presently accepted for the ITER divertor tiles. The impact of ELMs on the divertorin the case of a good H-mode with low pedestal dimensionless collisionality has also been considered, andit has been shown that FAST will reproduce quite closely the ITER edge conditions, so it will be possibleto study and optimise them in order to minimise the ELM perturbation.DiagnosticsOne of the key missions of FAST is the study of fast-particle dynamics in H-mode plasmasat high magnetic field (B T ). Diagnosing fast particles is not easy due to the high spatial and36[2.5] F.P. Orsitto et al., Nucl. Fusion 47, 1 (2007)
2. Fusion Advanced Studies Torus2007 Progress Reporttemporal resolution needed [2.5]: the minimum relevant spatial scale (δR/a, a=minor radius) formeasurements has to be of the order of δR/a~1/20-1/30, close to the fast particle Larmor radius, and theminimum time scale (τ/τ A ,τ A =R 0 /V A =Alfvén time ~0.2 μs, R 0 =major radius, V A =Alfvén velocity) is of theorder of τ/τ A ~300, close to the relevant time scales for the interaction of Alfvén modes with fast particles[2.5]. The study of the H-mode needs high-resolution kinetic measurements of the pedestal, edge currentprofile and fine divertor diagnostic systems. At lower B T values, FAST allows investigation of AT regimeswith ITBs: these scenarios require diagnostic systems for the measurement of current profile, plasmaturbulence, MHD fluctuations and plasma rotation (toroidal and poloidal) and a very flexible real-time controlsystem.The diagnostics foreseen for FAST can be subdivided in five groups: 1) burning plasma; 2) kineticparameters and current profile; 3) magnetics; 4) SOL and divertor; 5) turbulence and emission of radiation.Group 1 (neutron monitors, neutron/gamma camera, neutron spectroscopy, collective Thomsonscattering, escaping and confined fast-ion probes) is essential to the mission of FAST and enables thestudy of burning plasma, fast particles and MHD-related parameters. Group 2 (motional Stark effect andcharge exchange recombination spectroscopy, electron cyclotron emission, Thomson scattering, CO 2interferometry, Bremsstrahlung, spectroscopy and polarimetry) is used for the physics evaluation ofplasmas. Group 3 (magnetic sensors) is used for the equilibrium and measurement of MHD activity and forreal-time control of the machine (safe operation and scenario realisation). Group 4 (divertor spectroscopy,main chamber reciprocating probes, infrared thermography) is dedicated to determining SOL kinetics,thermal loads on the wall and divertor, erosion, deposition and plasma fluxes. Group 5 (Langmuir probes,reflectometry, bolometry, tomographic gas puff imaging, microwave Thomson scattering) should provide acomplete picture of the temporal evolution of electrostatic instabilities (fluctuations in plasma density)related to the ion temperature gradient (ITG) and possibly to the electron temperature gradient (ETG), withreasonable space resolution inside and at the plasma edge.FAST can be a test bed for the development of the ITER diagnostics that require consistent R&D activity,particularly those for measuring the energy and density distribution of confined and escaping fast particles,for the following reasons: plasma conditions similar to those of ITER (production and confinement ofenergetic ions accelerated by ICRH delivering a high fraction [40-90%] of their energy to electrons; fastion-inducedfluctuation spectrum, power load and fast particles); reduced costs and development time ofthe diagnostics (as FAST works in DD with a tungsten wall, problems and cost related to the use of tritiumand beryllium are avoided); flexibility of the device in terms of testing different technical solutions to optimisediagnostic performance; reduced optimisation time due to fewer operational constraints, e.g., inscheduling diagnostic system commissioning.2.3 Design DescriptionLoadassemblyThe FAST load assembly (fig. 2.2) consists of 18 toroidal field coils (TFCs), 6 centralsolenoid (CS) coils, 6 external poloidal field coils (PFCs), the vacuum vessel (VV) and itsinternal components and mechanical structure. Resistive coils, maintained at cryogenictemperatures, are adiabatically heated during the plasma pulse.FAST is a flexible device capable of operating in several scenarios with I p from 2 MA (around 3-min-longpulse advanced scenario ) up to 7.5 MA (H-mode scenario). Since the FAST magnet has to sustain theduration of a long pulse, helium gas at 30 K has been chosen for cooling the oxygen-free copper magnet,as the ratio of copper resistivity to specific heat is minimum at this temperature.The load assembly is kept under vacuum inside a stainless steel cryostat to provide the thermal insulationof the machine. Several feedthroughs allow the penetrations of bus bars, fluidic pipes and support legs.37
Page 1 and 2: PROGRESS REPORT2007Nuclear Fusion a
Page 3 and 4: ContentsPART I - FUSION PROGRAMME 7
Page 5 and 6: 2007PART IV - MISCELLANEOUS 18314.
Page 7: 2007analyses of the missions to be
Page 10 and 11: Fusion Programme2007 Progress Repor
Page 12 and 13: Fusion ProgrammeTable 1.I - Summary
Page 14 and 15: Fusion ProgrammeFollowing a Europea
Page 16 and 17: Fusion Programmen e (10 20 m -3 )3.
Page 20 and 21: Fusion Programmewas not affected by
Page 22 and 23: Fusion ProgrammeShear Alfvén wavec
Page 24 and 25: Fusion Programmen H (10 20 /m 3 )0.
Page 26 and 27: Fusion Programmei.e., typically, ra
Page 28 and 29: Fusion ProgrammeENEA has provided t
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Page 34 and 35: Fusion Programmedifference between
Page 36 and 37: Fusion ProgrammeIntroductionThe suc
Page 40 and 41: Fusion ProgrammeThe cryostat overal
Page 42 and 43: Fusion ProgrammeIntroductionThe tec
Page 44 and 45: Fusion ProgrammeThe main results so
Page 46 and 47: Fusion ProgrammeInfrared absorption
Page 48 and 49: Fusion ProgrammeFig. 3.8 - Frascati
Page 50 and 51: Fusion ProgrammeThe second year of
Page 52 and 53: 250Fusion Programmeflow-rate in the
Page 54 and 55: Fusion ProgrammeThe aim of the work
Page 56 and 57: Fusion ProgrammeFig. 3.21 - X-ray s
Page 58 and 59: Fusion ProgrammeRange (mm)593583573
Page 60 and 61: Fusion ProgrammeZ (m)6420-2-4-6sour
Page 62 and 63: Fusion Programmea) b)c)Fig. 3.31 -
Page 64 and 65: Fusion Programmeactivation. Eight r
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Page 72 and 73: Fusion ProgrammeTritium roomTritium
Page 74 and 75: Fusion ProgrammeImplications for PS
Page 76 and 77: Fusion ProgrammeThe development and
Page 78 and 79: Fusion ProgrammeIntroductionDuring
Page 80 and 81: Fusion Programme19.5Section view B-
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Fusion ProgrammeMagnetic moment (em
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Fusion ProgrammeCeO 2YSZCeO 2YBCOMa
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Fusion Programme0 1 10 0 1 100 1 10
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Fusion ProgrammeLoad (mN)0.80.60.40
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Fusion Programme5.1 Outline and Ove
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Fusion Programme(λ D /Δ 0 ) 2Δ 0
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5. Inertial Fusion2007 Progress Rep
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6. Communication and Relationswith
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7. Publications and Events - Fusion
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Fission Technology8.1 Advanced and
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Fission TechnologyAcceleration m/s
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Fission Technology232.73 mm (17 pin
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Fission TechnologyThe Very High Tem
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Fission Technology500Thermocouple t
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Fission Technology0.16 mm 0.16 mm0.
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Fission Technology-4800-85000.00SGU
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Fission Technologythrough calculati
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Fission Technology1.23 e+001.17 e+0
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Fission TechnologyPressure (bar)642
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Fission TechnologyFig. 8.37 - Creep
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Fission TechnologyENEA organised th
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Fission TechnologyTemperature600400
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Fission TechnologyZ(m)1.00.80.60.40
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Fission Technologythat a system is
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Fission TechnologyMaxwellian-averag
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Fission TechnologyBOT3P has large w
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Fission Technology9.1 Boron Neutron
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Fission TechnologyIn collaboration
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Fission Technologyvolume. Thus the
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Fission TechnologyFig. 9.9 - Logger
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Fission TechnologyIn relation to EN
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Fission TechnologyArticles11.1 Publ
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Fission TechnologyArticles incourse
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Fission TechnologyF. ROELOFS, B. DE
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Fission TechnologyE. BERTHOUMIEUX e
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Fission TechnologyInternal reportsR
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Fission TechnologyRTI FPN-P815-008
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PART IIINUCLEAR PROTECTION171
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12. Radioactive Waste Management an
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13. Publications - Nuclear Protecti
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Miscellaneous14.1 Advances in the I
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Miscellaneoususing a full wave code
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MiscellaneousAt present the effect
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MiscellaneousSuperAGILE view of the
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Abbreviations and AcronymsAacACPADS
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Abbreviations and AcronymsEFITEHRSE
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Abbreviations and AcronymsITERITGIT
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Abbreviations and AcronymsPFWPGAPHY
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Abbreviations and AcronymsVVDEVELLA
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