Scientific activities of the IPPLM in the area of PWI Selected research Jerzy Wołowski Paweł Gąsior Monika Kubkowska Institute of Plasma Physics and Laser Microfusion (IPPLM) Association EURATOM – IPPLM, Warsaw, Poland Laser Plasma Division (LPD). Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

1.Introduction. 2.Equipment used for PWI studies in LPD_IPPLM. 3.Study of laser-induced co-deposit removal from graphite ALT limiter tile retrieved from the TEXTOR tokamak. 4.Collection and characterisation of co-deposit dust ablated from the TEXTOR samples. 5.Study of laser ablation of surface layer from ASDEX Upgrade samples. 6.Summary. PUMA-pwi Project Contents Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

1.INTRODUCTION Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

The LPD employs 14 researchers (including 4 PhD students), 2 engineers and 10 technicians. Laser Plasma Division (LPD) A many years' research programme accomplished at the Institute of Plasma Physics and Laser Microfusion by the Laser Plasma Division (LPD) in collaboration with foreign teams includes: study of laser-matter interaction and development of laser techniques for various applications, including PWI technologies, study of laser-matter interaction and development of laser techniques for various applications, including PWI technologies, study of laser-generated plasmas, including processes related to laser-fusion. study of laser-generated plasmas, including processes related to laser-fusion. Laser Plasma Div. IPP&LM Introduction. The Laser Plasma Division in IPPLM. 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

4 To develop methods of laser-induced removal of co- deposit layers from the surface of in-vessel components supported by different diagnostics. 4 To analyse the elemental content of the ionized material removed from the in-vessel samples with the use of ion diagnostics and optical spectroscopy. 4 To develop methods of collection and characterisation of laser-produced co-deposit dust. 4 To characterise the properties of surface of in-vessel components after laser treatment using different methods of material research in collaborating laboratories. Introduction. PWI research - motivation. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

FZJ, Jülich GMBh, German FZJ, Jülich GMBh, German VR, Alfven Lab., (KTH), Stockholm, SwedenVR, Alfven Lab., (KTH), Stockholm, Sweden IPP Garching, GermanyIPP Garching, Germany JET, Culham, UKJET, Culham, UK UKAEA, Culham, UKUKAEA, Culham, UK IPP ASCR, Prague, Czech Rep.IPP ASCR, Prague, Czech Rep. Introduction. Lollaborating Laboratories. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

2.EQUIPMENT USED FOR PWI STUDIES IN LPD_IPPLM. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

Laser beam: beam diameter: 3-10 mm laser pulse energy: up to 0.8J repetition rate: up to 10 Hz. Set of ion collectors front view The experimental set-up: vacuum interaction chamber ion diagnostic devices a repetitive pulse laser system a movable target holder. Scheme of the experimental set-up (I) An ion energy analyser (IAE) IEA Sample signal for tungsten Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

Electrostatic ion energy analyser (IEA) Photo of the experimental arrangement I Repetative Nd:YAG laser system Chamber for laser-induced removal of codeposit layer from graphite tokamak tiles Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

Laser beam: beam diameter: 3-10 mm pulse energy: up to 0.8 J repetition rate: up to 10 Hz focus spot: ~ 2.5 mm. Plasma region: observed by the spectrometer: ~1 mm in the front of the target.` Optical spectrometer: Mechelle5000 with ANDOR iCCD DH734 Scheme of the experimental set-up (II) Ion Energy Analyser Characterisation of ablation process and properties of codepesit in this experiment were performed using: ion energy analyser optical spectrometer. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

Spectrometer Mechelle5000 Photo of the experimental set-up (II) Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November Vacuum chamber Nd:YAG laser Me5000 spectrometer

Fiber laser YLP Pulse repetition rate: kHz Average output power:100 W (at 100 kHz) Central emission wavelength:1065 nm Pulse duration: 100 – 150 ns Pulse energy:1 mJ Polarisation state:random. Laser Plasma Div. IPP&LM A new pulsed Yb:fiber laser system for technological applications 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

3.STUDY OF LASER-INDUCED CO-DEPOSIT REMOVAL FROM GRAPHITE ALT LIMITER TILE RETRIEVED FROM THE TEXTOR TOKAMAK. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

Conclusion: The IEA delivers information about chemical composition including the amount of deuterium and impurities on surface of graphite tile. 58 Ni Cr +1 H D 10 B B C C C Fe Si Si O +1 E/z = 0.15 keV amplitude, V time of flight, µs The IAE spectra of laser-produced codeposit plasma produced by laser interacting with graphite tile retrived from the TEXTOR tokamak. The IAE spectrum of low- and midium-Z ions (E/z = 0.15keV) The IAE spectrum of contaminant high-Z ions (E/z = 4.0 keV) Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

,04 0,00 after series of 50 laser shots U [V] T [ s] before series of laser shots E/z=0.15 keV D +1 Si +1 C +1 O +1 (D +1 ) C +1 (O +1 ) Si +1 Decreased number of deuterium ions Efficiency of codeposit removal estimated on the basis of IEA spectra. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

Spectrum taken for a cleaned surface (after series of 40 shots) – no evidence of deuterium Conclusion: Fuel species are present in relatively thick co-deposit layer, which is removed after laser pulses. The spectrum consists of carbon lines and Swan bands. Spectrum taken for a codeposited surface (first series of 5 shots) – deuterium line can be clearly seen. Optical spectrum recorded for TEXTOR limiter sample (deuterized codeposit on graphite). Optical spectrum evolution from TEXTOR sample Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

Conclusion: The relative deuterium content in the plasma surface near the target decreases during subsequent laser shots. Application of optical spectroscopy for characterisation of laser-induced co-deposit removal fro the TEXTOR sample. The emission spectra consisted mainly of Bremsstrahlung and C II, C III and Dα lines. Deuterium (D ) and carbon (CII) spectral lines of codeposit recrded after consecutive numbers of laser shots. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November laser shotsv after 20 laser shots after 50 laser shots

Mass of the particles H2H2 D2D2 HD Hydrocarbons QMS signal of the ablated sample material before and after codeposite removal. Before codeposite removal After codeposite removal Investigation of results of laser-nduced codeposite removal using profilometry, SEM and QMS methods in FZJ. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November Surface profilometry studies have show the removal of the entire co- deposited layer of ~60 m, with the use of series of 200 laser pulses.

3.COLLECTION AND CHARACTERISATION OF CO-DEPOSIT DUST ABLATED FROM TEXTOR SAMPLES. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

To produce dust using laser-interaction with in-vessel components covered with codeposit. To prepare and test the dust collection methods: glass and metallic plates, cooper grids for TEM aluminum cylindrical catcher. To estimate a structure and size distribution of dust particles. To analyse the dust chemical composition. Motivation of dust measurements Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

Experimental arrangements with dust collectin devices Image taken by a standard camera for co-deposite on carbon based material. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November Cylindrical dust catcher Net and glass or metal plates for dust collection

Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November Size distribution of dust particles collected on metal plate after 200 laser shots. Results of measurements performed in FZJ. Characterisation of dust collected on metal plate using NRA ( 3 He, 2 MeV) and microscopy at Alfven Lab. Amount of Deuterium in dust collected on metal: C Deuterium = 3.9 x10 17 cm 2 Amount of Deuterium in codeposit on a surface of TEXTOR tile: C Deuterium = up to cm 2 Characterisation of laser- produced codeposit dust particles collected on surface of metallic substrate

Single dust particle. Magnified image of conglomerate of particles. Diffraction over a sample particle. The pattern shows crystalline parts in the particle or a complete crystalline particle. Conclusion: The dust consists of wide varity of particles – from macroscopic flakes of co-deposit to amorphous and crystaline nanoparticles. Dust analysis – TEM investigation performed in FZJ. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

4.STUDY OF LASER ABLATION OF SURFACE LAYER FROM ASDEX UPGRADE SAMPLES. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

Spectrum collected for first 2 laser shots. Spectrum collected for shots 3-4. Spectrum collected for shots 5-6. Spectrum collected for shots 7-8. Conclusions: Fuel species are present only on the very surface of the sample. The tungsten layer includes significant amounts of carbon. Irradiation conditions: Pulses of Nd-YAG laser (3ns, 0.6 J, 1064 nm) focused on spot of diameter of ~3-4 mm. Optical spectrum evolution from ASDEX Upgrade sample. Samples: Graphite plates covered with tungsten layer (4 or 200 m) containing deuterised codeposit. Sample were taken from Asdex Upgrade upper outer divertor strikepoint region. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

Spectra measured for ASDEX sample 041 (graphite covered with 4mm layer of tungsten) Nd:YAG laser: m, 3.5 ns, 300 mJ, 13 GW/cm 2 Delay time: = 100 ns, time of exposition: = 500 ns Eeach spectrum is a sum of 5 spectra recorded for 5 consecutive laser shots. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November CII WI

Spectra measured for ASDEX sample 041 (graphite covered with 4 m layer of tungsten) CII Line intensity dependence on number of laser pulses After 20 laser pulses Carbon line appears, what suggests that during 1 laser pulse 0.2 m of surface layer is removed, presence of tungsten for number laser pulses >20 (for removed layer >4 m) was observed. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

Evolution of the ion spectrum evolution taken for Asdex Upgrade 04/1 sample A - C - evaluation of the ion spectra recorded for 1st, 2nd and 3rd laser shot, respectively. D - the spectrum taken for 6th laser shot in the whole energy range of ion energy, i.e. with higher deflecting potential. IEA spectra for sample 04/1 taken from AUG - from upper outer divertor strikepoint region (deuterized co-deposit on tungsten covered graphite) Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November A) D)C) B)

5.Summary Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

yThe diagnostics equipment at IPPLM (ion diagnostics and optical spectroscopy) allows measuring wide spectrum of parameters of laser- ionised co-deposit. y SEM and QMS measurements performed at collaborating laboratories have shown absence of the co-deposited layers on the scanned tracks of investigated samples. y Dust generation by laser treatment offers many possibilities for developing dust diagnostics and may be also a source of information on properties of co-deposit dust. Dust investigation confirms that particles of co-deposit dust still contain fuel particles. The optical spectroscopy looks to be especially useful for real time control of laser cleaning of plasma face components. Summary. Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

PUMA-pwi Project Prepared by Marek Scholz IPPLM, Warsaw Magnetized Plasmas Division

PUMA-pwi Project Project in the frame of Strategic National Polish Program Innovatory Economy – Infrastructure R&D Cooperating Institutes: IPPLM, INP, INS, IEA, WUT The project was prepared at the middle of 2008 and was upgreaded at the March of 2009 and it was sent at 30/04/2009 to Ministry of Science and Higher Education in Poland.

PUMA-pwi Project Focused on: 1.Reproduction of plasma heat loads typical for ITER disruptions and Type I ELMs 2.Features of plasma/surface interaction (shielding, melting and evaporation onsets, erosion mechanisms) 3.Testing of divertor materials with repetitive plasma pulses with varying surface heat loads 4.Production of data for validation of numerical models.

Main elements of the set-up 1.Experimental vacuum chamber ~ 20 m 3 with clean vacuum system, target manipulators, cooling, system of working gas filling etc.; 2.System of wheal current generators 5 GJ for external magnetic field, coils with cooling system and pulse forming current lines; 3.Plasma stream generator - condenser bank with short circuit current ~ 10 MA, current collector and system of plasma accelerator electrodes; 4.Diagnostic set-up - plasma, target, magnetic and electric diagnostics 5.Safety 6.Control and data acquisition 7.Diagnostics set-up.

PUMA-pwi – global lay-out The IPPLM main experimental building where the accelerator will be placed

PUMA-pwi – global lay-out

Comparison of plasma gun devices The green colour aims at highlighting the most relevant parameters matching the ITER requirements for disruptions/unmitigated ELMs studies.

Budget of the project YearBudget of the project [PLN] Sum (Euro: ~ )

PUMA Project is recommended to finnacial support for a positive review reason The project did not get a money until now because of limited budget of the Polish Program Innovatory Economy – Infrastructure R&D. BUT

Thank you for your attention! Laser Plasma Div. IPP&LM 8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.