scientific activities of the ipplm in the area of pwi selected research jerzy wołowski paweł...

Scientific activities of the IPPLM Scientific activities of the IPPLM in the area of PWIin the area of PWI

Selected researchSelected research

Jerzy WołowskiPaweł Gąsior

Monika Kubkowska

Institute of Plasma Physics and Laser Microfusion (IPPLM)Institute of Plasma Physics and Laser Microfusion (IPPLM)Association EURATOM – IPPLM, Warsaw, PolandAssociation EURATOM – IPPLM, Warsaw, Poland

Laser Plasma Division (LPD).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

ContentsContents



1.1. INTRODUCTIONINTRODUCTION



The LPD employs 14 researchers (including 4 PhD students), 2 engineers and 10 technicians.

A many years' research programme accomplished at the Institute of

Plasma Physics and Laser Microfusion by the LaserLaser PlasmaPlasma Division Division

(LPD)(LPD) in collaboration with foreign teams includes:

► ► study of laser-matter interaction and development of laser study of laser-matter interaction and development of laser

techniques for various applications, including PWI technologies,techniques for various applications, including PWI technologies,

► ► study of study of laser-generatedlaser-generated plasmasplasmas,, including processes related including processes related

to laser-fusion. to laser-fusion.


Introduction.Introduction.The Laser Plasma Division in IPPLM.The Laser Plasma Division in IPPLM.


To develop methods of laser-induced removal of co-

deposit layers from the surface of in-vessel components supported

by different diagnostics.

To analyse the elemental content of the ionized material

removed from the in-vessel samples with the use of ion

diagnostics and optical spectroscopy.

To develop methods of collection and characterisation

of laser-produced co-deposit dust.

To characterise the properties of surface of in-vessel

components after laser treatment using different methods

of material research in collaborating laboratories.

Introduction.Introduction.PWI research - motivation.PWI research - motivation.



■■ FZJ, Jülich GMBh, GermanFZJ, Jülich GMBh, German

■■ VR, Alfven Lab., (KTH), Stockholm, VR, Alfven Lab., (KTH), Stockholm, SwedenSweden

■■ 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.Introduction.Lollaborating Laboratories.Lollaborating Laboratories.



2.2. EQUIPMENT USED FOR PWI STUDIES IN LPD_IPPLM.EQUIPMENT USED FOR PWI STUDIES IN LPD_IPPLM.



Laser beam:• beam diameter: 3-10 mm• laser pulse energy: up to 0.8J• repetition rate: up to 10 Hz.

Set of ion collectorsfront 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)Scheme of the experimental set-up (I)

An ion energyanalyser (IAE)

IEA

Sample signal for tungsten



Electrostatic ion energy analyser (IEA)

Photo of the experimental arrangement IPhoto of the experimental arrangement I

Repetative Nd:YAG laser system

Chamber for laser-induced removal of codeposit layer from graphite tokamak tiles



PC controlledmotion system

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)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.



Spectrometer Mechelle5000

Wavelength range 200 – 975 nm

Focal length 195 mm

Dispersion / 213.2 [nm/ mm]

/ 16400 [nm/ pixel]

Active pixels in

iCCD 1024 1024

Photo of the experimental set-up (II)Photo of the experimental set-up (II)



Vacuum chamberNd:YAG laser

Me5000 spectrometer

Fiber laser YLP-1-120-100-100

Pulse repetition rate: 20 - 100 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.


A new pulsed Yb:fiber laser system A new pulsed Yb:fiber laser system for technological applicationsfor technological applications


3. STUDY OF LASER-INDUCED CO-DEPOSIT REMOVAL

FROM GRAPHITE ALT LIMITER TILE RETRIEVED

FROM THE TEXTOR TOKAMAK.



Conclusion:

The IEA delivers information about chemical composition including

the amount of deuterium and impurities on surface of graphite tile.

58Ni

+152Cr

+1

H+1

D+1

10B+1

11B+1

12C+2

13C

+1

12C

+1

56Fe+1

28Si

+2 28Si

+1

16O+1

E/z = 0.15 keV

ampl

itude

, V

time of flight, µs

The IAE spectra of laser-produced codeposit plasma The IAE spectra of laser-produced codeposit plasma produced by laser interacting with graphite tile retrived from produced by laser interacting with graphite tile retrived from the TEXTOR tokamak.the TEXTOR tokamak.

0 5 10 15 20 25

-0,002

0,000

184W+1

96Mo+1

93Nb+1

56Fe+1 58Ni+1

E/z = 4.00 keV

#05040715(16) Target Lim E

L = 21.6*27 = 583 mJ

= 3 ns, = 2.3 mm, I = 4.8109 W/cm2, f = 39 cm, LLT

= 54.5 cm, LCT

= 72.6 cm

ampl

itude

, V

time of flight, µs

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)



0 60 120

-0,04

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 Efficiency of codeposit removal estimated on the basis of IEA spectra.on the basis of IEA spectra.



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 30-40 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 sampleOptical spectrum evolution from TEXTOR sample

Laser Plasma Div.IPP&LM8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

650 655 660

0

50

100

signal in preliminary stage

approximation

Rel

ativ

e in

tens

ity [

AU

] D CII

Wavelength [nm]

648 650 652 654 656 658 660 662 664

0

20

40

60

80

100

signal after 50 shots approximation

of deuteriu peak

Rel

ativ

e in

tens

ity [

AU

]

D CII

Wavelength [nm]

0 10 20 30 40 50 60

-20

-15

-10

-5

0

Inve

ntor

y le

vel

[dB

]

Number of shots

spot diameter 4.5 mm spot diameter 3.5 mm

Conclusion:The relative deuterium content in the plasma surface near the target decreases during subsequent laser shots.

650 655 660

0

50

100

spectrum after20 laser shots

approximation of D line

Rel

ativ

e in

tens

ity [A

U]

D CII

Wavelength [nm]

Application of optical spectroscopy for characterisation Application of optical spectroscopy for characterisation of laser-induced co-deposit removal fro the TEXTOR sample.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.



1- 5 laser shotsv

after 20 laser shots after 50

laser shots

Mass of the particles

H2D2

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 Investigation of results of laser-nduced codeposite removal using profilometry, SEM and QMS methods in FZJ.using profilometry, SEM and QMS methods in FZJ.



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.



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 measurementsMotivation of dust measurements



Vacuum chamber

Laser beam

Lens

Focusing lens

Diffractive optical system

CCD

Computer A&CU

Spectroscopy stage

Spectrometer

Irradiated

AL

Ttile

Laser light

Cylindricaldust catcher

44mm

22mm

B)

A)

Experimental arrangements with dust collectin devices Experimental arrangements with dust collectin devices

Image taken by a standard

camera for co-deposite

on carbon based material.



Glass plates for dust collection

Laser beam

Focusing lens

Target

Vacuum chamber

Dust collector for SEM measurements

Al. platesNet for dustcollection

Cylindrical dust catcher Net and glass or metal plates for dust collection

Laser Plasma Div.

IPP&LM8th Annual Meeting of the EU- PWI Task Force, Warsaw, 4-6. November 2009.

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 (3He, 2 MeV) and microscopy at Alfven Lab.

Amount of Deuterium in dust collected on metal: CDeuterium = 3.9 x1017 cm2

Amount of Deuterium in codeposit on a surface of TEXTOR tile: CDeuterium = up to 1019 cm2

Characterisation of laser- produced codeposit dust Characterisation of laser- produced codeposit dust particles collected on surface of metallic substrate 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.Dust analysis – TEM investigation performed in FZJ.



4. STUDY OF LASER ABLATION OF SURFACE LAYER

FROM ASDEX UPGRADE SAMPLES.



Spectrum collected for first 2 laser shots.

Spectrum collected for shots 3-4.



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.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.



424 426 428 430 432

3

6

9

Inte

nsi

ty x

104

[a.u

.]

Wavelength [nm]

1

424 426 428 430 432

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104

[a.u

.]

Wavelength [nm]

2

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[a.u

.]

Wavelength [nm]

3

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[a.u

.]

Wavelength [nm]

4

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[a.u

.]

Wavelength [nm]

5

424 426 428 430 432

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[a.u

.]

Wavelength [nm]

6

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nsi

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104

[a.u

.]

Wavelength [nm]

7

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[a.u

.]

Wavelength [nm]

8

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nsi

ty x

104

[a.u

.]

Wavelength [nm]

9

424 426 428 430 432

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9

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nsi

ty x

104

[a.u

.]

Wavelength [nm]

10

424 426 428 430 432

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9

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nsi

ty x

104

[a.u

.]

Wavelength [nm]

11

424 426 428 430 432

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9

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nsi

ty x

104

[a.u

.]

Wavelength [nm]

12

424 426 428 430 432

3

6

9

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nsi

ty x

104

[a.u

.]

Wavelength [nm]

13

424 426 428 430 432

3

6

9

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nsi

ty x

104

[a.u

.]

Wavelength [nm]

14

424 426 428 430 432

3

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9

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nsi

ty x

104

[a.u

.]

Wavelength [nm]

15

424 426 428 430 432

3

6

9

Inte

nsi

ty x

104

[a.u

.]

Wavelength [nm]

16

Spectra measured for ASDEX sample 041 Spectra measured for ASDEX sample 041 (graphite covered with 4mm layer of tungsten)(graphite covered with 4mm layer of tungsten)

Nd:YAG laser: 1.063m, 3.5 ns, 300 mJ, 13 GW/cm2

Delay time: = 100 ns, time of exposition: = 500 nsEeach spectrum is a sum of 5 spectra recorded for 5 consecutive laser shots.



CII

426

.73

WI

429

.46

Spectra measured for ASDEX sample 041 Spectra measured for ASDEX sample 041

(graphite covered with 4 (graphite covered with 4 m layer of tungsten)m layer of tungsten)

CII

4

26.7

3

0 10 20 30 40 50 60 70 80

0.0

0.5

1.0

WI 429.46 nm CII 426.73 nm

no

rmal

ize

d li

ne

inte

nsi

ty [

a.u

.]

number of laser pulse

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.



Evolution of the ion spectrum evolution taken Evolution of the ion spectrum evolution taken

for Asdex Upgrade 04/1 samplefor 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)



A)

D)C)

B)

5.5. SummarySummary



The diagnostics equipment at IPPLM (ion diagnostics and optical

spectroscopy) allows measuring wide spectrum of parameters of laser-

ionised co-deposit.

SEM and QMS measurements performed at collaborating

laboratories have shown absence of the co-deposited layers on

the scanned tracks of investigated samples.

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.Summary.



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 m3 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

Year Budget of the project [PLN]

2009 157 000

2010 2 678 000

2011 13 878 000

2012 11 228 000

Sum 27 941 000

(Euro: ~6 500 000)

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!Thank you for your attention!



scientific activities of the ipplm in the area of pwi selected research jerzy wołowski paweł...

Documents

laser beam

characterisation of

methods of laser

introduction laser plasma

laser treatment

tungsten laser plasma

laser pulse energy

fiber laser system