Report from A+M Data Centre, RRC Kurchatov Institute

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1 Report from A+M Data Centre, RRC Kurchatov Institute Yu.V.Martynenko 20th Meeting of the Atomic and Molecular Data Centers and ALADDIN Network Vienna, September 2009

2 The main activities on A+M/PSI DATA: 1. New Data generation. (Experiment, theory, codes). 2. Computer code for tokamak plasma processes. 3. Data Acquisition System + (DAS+). System for operation with experimental data of various devices of controlled nuclear fusion (storage, transmission, processing and results representation). The software allows to create Data warehouse for experimental data and possibility for multi-installations fusion researches.

3 Data related to neutral beam heating V. A. Belyaev, M. M. Dubrovin, D. A. Kozlov, A. A. Terentiev, A. Ye. Trenin, and G. V. Sholin) [Plasma Phys. Rep.2009]. D - ion source Preacceleration, kev Binary collisions, neutralization D - acceleration, MeV Neutralization Neutral beam Object: D - + D - D 0, E rel < E excit ~ 11 ev 3

4 Data related to neutral beam heating D - Spectra of Detached Electrons Produced in Collisions D - Ions V. A. Belyaev, M. M. Dubrovin, D. A. Kozlov, A. A. Terentiev, A. Ye. Trenin, and G. V. Sholin) [Plasma Phys. Rep. August. 2009]. + Split beam E relat = ev + + e - I, отн. ед. 1,0 0,8 0,6 0,4 0,2 0, T, эв 3 (в) E relat = 6.1 эв (1) (2) (3) (4) D + D D + D + e 0.75eV 0 0 D + D D + D + 2e 1.51eV D + D D D + 2e 2 2 D + D D D + e D 2 molecules and D 2- molecular ions in the ground electronic state revealed. Lifetime longer than the period of molecular oscillations. 0 I, отн. ед. I, отн. ед. 1,0 0,8 0,6 0,4 0,2 0,0 1,0 0,8 0,6 0,4 0,2 0, T, эв T, эв (б) (а) E relat = 2.4 эв E relat = 1.8 эв 4

5 PLASMA RADIATION Ultra fast method of calculating the ion s dynamic contribution to spectral line shapes. (A. Calisti,, C. Mossey,, F. Rosmej, B. Talin France. L.A. Bureyeva,, V.S. Lisitsa -Russia. Phys. Rev. E to be published) The method gives the intensity in dynamic Stark spectral line shape as a functional from static Stark lines shape. New method is faster than the standard Frequency Fluctuation Model (FFM( B.Talin et al. PRA 1995) ) by nearly two orders of magnitude. Method significantly simplifies the radiation transport modeling, opens new possibilities for integrated modeling of the edge and divertor plasma in tokamaks. 5

6 PLASMA RADIATION Fast code nl-kinryd (collisional-radiative kinetics of Rydberg atomic states) M.B. Kadomtsev, M.G. Levashova, V.S. Lisitsa: Calculation of two-dimensional (i.e., n & l ) collisional-radiative steady-state kinetics of Rydberg atomic states and of line intensities The Coulomb collisions of atomic electron with plasma electrons and ions are treated classically. Radiative cascade is treated either with quantum cascade matrix, generalized to the case of collisions or in its quasi-classical version with k-step radiative transitions (for k>k*). The code is applicable to a wide range of fusion and astrophysical plasmas and is especially important for selective sources of external population in multilevel atom/ion (n>>1). 6

7 PLASMA RADIATION Fast code: ESMEABRR (Electron + Static Many-Electron Atom) (Bremsstrahlung + Radiative Recombination) V.I. Kogan, A.B. Kukushkin kuka@nfi.kiae.ru Semi-analytic description of Bremsstrahlung and radiative recombination cross sections for collisions of quasiclassical electrons with a static many electron atoms and ions. The code has ~30% agreement with quantum mechanical numerical modeling by R.H. Pratt et al. for all frequencies and any stripping atom in the range 0.1 ~< ε ~< 1 (ε = Ea TF /Ze 2 = 32.6 E(keV)/Z 4/3, E is electron energy, Z is nucleus electric charge, a TF is Thomas-Fermi raduis). The code is applicable to a wide range of fusion plasmas including hot plasmas with multi charged ions for inertial confinement fusion. Electron + Static Many-Electron Atom) (Bremsstrahlung + 7 Radiative Recombination

8 CRP "Data for surface Composition Dynamics Relevant to Erosion Processes TUNGSTEN AND CARBON SURFACE CHANGE UNDER HIGH DOSE PLASMA EXPOSURE. Contract 14073, Yu. Martynenko, B. Khripunov, V. Petrov. Submitted to PDO. MATERIALS CHOISE Tungsten WL-10 PLANSEE, W+1weight % La 2 O 3, good working Graphite RGT (Russian grade) up to 7% Ti (in the TiC form) improved heat conduction INVESTIGATION Surface morphology, Surface element content, Erosion yield Y, 8

9 LENTA linear plasma facility Beam collector Optical monochromator МДР-6 Gas feeding (gas target) Probes Electron beam Anode Gas inlet Cathode Interaction zone Discharge zone Plasma stream Probes To mass-spectrometer Beam-plasma discharge in crossed electric and magnetic fields E B is realized to produce plasma in steady state Axial magnetic field 0,15 Т Total energy in plasma 10 квт Plasma density cm -3 Electron temperature ev Ion flux density ion cm -2 s -1 D plasma density cm -3, T e = 6 ev, U bias = 0 E i = 20 ev, U bias = 200eV E i = 200eV Ion current density j = 0.15 A/cm 2 T= 340K N plasma density cm -3, T e = 8 ev, U bias = 100eV E i = 100eV j = 66 ma/cm 2, fluence ion/cm 2 T= 1050 K 9

10 W surface composition dynamic W at the initial state W after D plasma exposition at 20 ev. W, La, O, C W after D plasma exposition at 200 ev W after N plasma exposition E ion = 100eV La 2 O 3 includes appear on the surface as result of surface etching. They occur even at D + energy 20 ev (!?), Initially La 2 O 3 includes were removed from the surface by working; Includes appearance increases with energy and mass of ions. 10

11 RGT graphite composition dynamic in D plasma Electron beam Beam collector Gas feeding (gas Anode Optical target) Gas inlet monochromator Cathode МДР-6 Probes Interaction zone Discharge zone Plasma stream Plasma density N e =(2-4) cm -3, T e = 2 ev, U bias = 0 E i < 10 ev T=1400K Probes Sample To mass-spectrometer Element Weight % C Ti 4.04 Total Element Weight % C Total Erosion, fine elongated elements. Ti disappearance on the surface. Y = at/ion 11

12 TUNGSTEN AND CARBON SURFACE CHANGE UNDER HIGH DOSE PLASMA EXPOSURE. CONCLUSION Performed experiments together with previous investigations show: Surface composition dynamic in W+1%La 2 O 3 is result of etching, No real element redistribution was observed. Surface etching is possible even at 20 ev D + ion irradiation, and increases with ion energy and mass. Surface composition dynamic in RGT graphite is result of Ti migration and evaporation from the surface. Ti redistribution in RGT graphite is strongly target temperature dependent. 12

13 Nanostructured deposited films and dust in tokamaks Nanostructured films Dust 120 Particle number ¹ nm 20 Globular film 2 µm T-10 Film from dust Particle size, µm T nm 5 µm Tore Supra Lamellar film. T-10 13

14 Problems connected with nanostructured films and dust 1. Erosion lifetime material redeposition alloys formation, tiles joining 2. Reactor economy and safety tritium retention in films and dust, chemical activity of large surface specific area structures (H 2 O H 2 + O) dust radioactivity 3. Dust influence on discharge parameters dust in core plasma radiation losses discharge stabilization by dust injection 4. Fuel input by dust and cluster jet. 14

15 Nanostructured films box counting method : globul number - N i globul size - r i N i (r) ~ r i -D, fractal dimension - D = log N i / log r i N i (r) N i (r) D=2.2 ± SSA = S 0 ρ V 0,1 1 r, µm α 2 D = Ar 4πa0 ( ) dr ρ a 0 r Ar α 4 πa ( r a 0 D 3 ) dr = ρa SSA area per gram, a 0 minimal cluster size, ρ -density. 0 15

16 Main results Nanostructured films 1. a 0 ~ 15 nm, SSA 170 m 2 /g for C ~ 16 m 2 /g for W (experiment L. Kimchenko, S. Kamneva) a 0 = 2σ Ω/T ~ nm, (theory Yu. Martynenko, M. Nagel) (σ - surface tension, T surface temperature, Ω atomic volume). 2. Theory of fractal film formation Initial stage - film growth from single atoms diffusing on the surface. Stable clusters nucleation determines film structure: smooth or fractal. (Yu. Martynenko, M. Nagel) Late stage - diffusion-limited aggregation DLA of deposited atoms. (V. Budaev) 3. Tritium content in the films Fractal film D/C < 10%. Smooth dark film D/C = Smooth gold-colored film D/C = Smooth СН x films are amorphous, but contain clusters 0.28nm, 0.7nm, 4nm и 12 nm. (synchrotron radiation, V.Stankevich et al) 16

17 DUST Previous investigation: T-10, plasma accelerators: 1. Size distribution N(r) ~r α, α = 2 2.4, r min ~ 10 nm. 2. Source: Divertor. ELMs, Disruptions. 3. Mechanism: graphite brittle distraction, metal droplet erosion. Resent results: 1. Dust particle charge and T in plasma 2. Discharge stabilization by dust injection into plasma Project (ITER Task): - Be dust-explosion characterization - T desorption in from Be-co-deposited layers 17

18 Dust particle charge and T in plasma (Theory Yu.Martynenko, M. Nagel, M. Orlov. Phys. Plasmy. 2009) Particle charge in plasma can change sign from - to +. Main cause -- thermo electron emission. Electron emission 0, , ,00030 T e =5eV Addition electron flow from plasma = addition energy flow from plasma α 0, , , , ,00005 T e =10eV T part & Electron emission growth, U>0 Particle overheating at U > 0 T part > T atoms, ions 0, E17 1E18 1E19 1E20 1E21 1E22 1E23 1E24 n a [1/m 3 ] Critical ionization degree α cr as function of plasma density. At α > α cr U >0. Selfconsistent solution New data for particle in periphery plasma Particle lifetime. Dust formation due to condensation is impossible 18

19 DUST. Discharge stabilization by dust injection into plasma Ne Discharge in installation «Plasma Focus PF-3» 30 ns 150 ns 500 ns Discharge in Ne with dust: Al 2 O 3 (1 100 µm) 500 ns 650 ns 950 ns Dust injection increases discharge lifetime more than an order of magnitude. Nagdis II experiment with С x Н y dust (d<5 µm) confirms discharge stabilization V.E. Fortov, V.I. Kraus, V.P. Smirnov et al 19

20 DUST. Projected works. ITER Task The capability of the new licensed QSPA-Be facility in Bochvar Institute with respect to dust safety issues in general and with specific attention on: - Be dust-explosion characterization -T retention in Be-co-deposited layers as function of the temperature L.Khimchenko & Bochvar/TRINITY teem 20

21 Conclusions New data and codes 1. Data related to neutral beam heating. D 2 2- molecular ions. 2. Plasma radiation. Ultra fast method of calculating the dynamic spectral line shapes. Fast codes: (i) n,l collisional-radiative kinetics of Rydberg atomic states, (ii) Bremsstrahlung + Radiative Recombination. Electron + Static Many- Electron Atom. 3. Data for surface Composition Dynamics Relevant to Erosion Processes. Tungsten and carbon surface change under high dose plasma exposure. 4. Nanostructured deposited films in tokamaks Data about deposited film structure. Minimal globular size of fractal films Surface Specific Area. Hydrogen contents in different kind of films. 5. Dust in tokamaks. Dust particle charge and T in plasma. Overheating regime condition. Discharge stabilization by dust injection into plasma. Data Acquisition System updated 21

22 Thank you 22