PSI-2 - the pilot experiment of the JULE-PSI project

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PSI-2 - the pilot experiment of the JULE-PSI project

Arkadi Kreter on behalf of FZJ PWI team

Institute for Energy and Climate Research - Plasma Physics, Forschungszentrum Jülich, Association EURATOM-FZJ, Trilateral Euregio Cluster, Germany

2nd International Workshop on Plasma Material Interaction Facilities

for Fusion Research (PMIF)

Jülich, Germany, 19 September 2011

Arkadi Kreter “PSI-2 - the pilot experiment of the JULE-PSI project" PMIF, Jülich, 19 Sep 2011 2

JULE-PSI: Jülich Linear Experiment for PSI studies in a Hot Cell

Based on PSI-2 / PISCES type deviceInstallation in a Hot Cell for handling of radioactive and toxic materials

Talk by B. Unterberg

Schematic viewPlasma source Target chamber Surface analysis Linear manipulator

PMI studies with• Neutron irradiated materials• All wall materials incl. Beryllium• Low quantities of Tritium

PSI-2 is the pilot experiment of the JULE-PSI project


PSI-1/2: 17 years of operation in Berlin

PSI-2 installation in Berlin

Formerly operated by IPP-Garching at Humboldt Univ., Berlin¨ PSI-1 was first operated in 1992¨ Upgrade to PSI-2 in 1998: extended target chamber with 2 additional coils¨ Transfer to FZJ in October 2009

1 m


PSI-2: new life in Jülich

¨ Transferred from Berlin to Jülich in October 2009

¨ First plasma in Jülich in January 2011

¨ Idea: Existing PSI-2 as the pilot experiment of the JULE-PSI project, outside of hot cell

¨ Name: PSI-2 (Jülich)

¨ Goals: Gain experience operating linear plasma device Test of components for JULE-PSI

• Prototype of target station• Plasma source optimization• Diagnostics• Other peripheral components

Contribute to current PMI research topics


Current installation of PSI-2

Current status corresponds to the installation in Berlin before transport


First plasma of PSI-2 in Jülich

Text from IEK-4 news web site of 7/Jan/2011

First plasma in PSI-2 JülichToday, Friday 7th of January 2011, 6.30 pm, the very first Argon discharge has been produced in the PSI-2 Jülich device. This achievement constitutes a major milestone for our PSI programme on linear devices, which aims at the investigation of PSI processes with neutron activated fusion materials with the linear plasma device JULE-PSI in the Hot Material Laboratory (HML) of FZJ. PSI-2 Jülich will serve as a pilot experiment for this development and supplement our portfolio of facilities for the joint TEC programme on plasma-surface interactions.Many thanks to the whole PSI-2 team, in particular to our colleagues from Berlin, Werner Bohmeyer and Achim Mans.

Since August 2011 routine operation in deuterium


Typical plasma parameters in PSI-2

Example of Ar plasma profile at target position

ne [m-3] Te [eV] Flux [m-2 s-1] Ei [eV]

< 1019 < 20 < 1023 10 – 300 (bias)

For deuterium plasma


PSI-2: plasma generator with cylindrical cathode

• Arc discharge up to 1000 A and 150 V• Typical regime of operation:

• Heating up and cooling down ~60 min• Steady-state plasma of several hours per day• Change of discharge parameters (incl.

working gas) on one day possible• Exchange of the cathode every 12 – 18 months• Advantages:

• Larger emitter area more efficient plasma production

• Less prone to break due to thermal stresses• Observation through the aperture

• Drawback (decisive):• Hollow plasma profile

Cylindrical cathode assembly

Cylindrical cathode w/o heat shield


PSI-2: new disc-shaped cathode

• Originally designed by H. Greuner• Partially constructed and tested in Berlin, but never in plasma operation• Currently: optimization of design and testing• Installation on PSI-2 is planned for Dec. 2011

Disc-shaped cathode assemblyHeater of disc-shaped cathode


Plasma source options for JULE-PSI

¨ Options to optimize arc source performance / reliability are analysed in collaboration with the Budker Institute talk by A. Ivanov (for V. Davydenko)

¨ Alternatively, helicon-type plasma source is considered, also in collaboration with the Budker Institute

• Synergy from the helicon source development at ORNL?


Target manipulators

• First stage: side-fed manipulator from Berlin• Currently being refurbished

and adapted for our purposes

• To be installed in Oct 2011

• Second stage: new target station

Side-fed manipulator support structure

Layout of sample holder in plasma

PSI-2 current installation


Target station

Target manipulator

Exchange and Analysis chamber

Plasmasource Typical target position

• Serves as prototype of JULE-PSI target station talk by B. Unterberg

• Currently being manufactured• Installation by the end of 2011


Diagnostics on PSI-2

Plasma diagnostics (characterization of background plasma)

In-vacuo sample analysis

• Optical spectroscopy• Langmuir probe• Thomson scattering being considered as substitute of Langmuir probe

Target station: linear manipulator and surface analysis station with • Laser-aided analysis methods (LID, LIBS) talk by B. Unterberg• Glow discharge spectroscopy talk by C. Klepper

In-situ PMI diagnostics• Optical spectroscopy• IR thermography• Quartz microbalance (QMB)

PSI-2 serves as test-bed for diagnostic development for JULE-PSI Focus on reliability and easy maintenance


Spectroscopy

Spectrometer systems available:

i) Direct imaging spectrometer at the target Spectrometer Acton 0.75m (SP2750 UV-VIS-NIR) with detector 2D EMCCD Andor NEWTON DU971 1600 x 400

ii) Fibre-coupled spectrometer in Littrow arrangement (10 nm coverage @ R=20000) Spectrometer 0.75 m Echelle optimised for VIS with detector 2D EMCCD Andor IXON DU888 EC 1024 x 1024

iii) Fibre-coupled spectrometer in Littrow arrangement (2 nm coverage @ R=100000) Spectrometer 1.25 m Echelle optimised for VIS with detector 2D EMCCD Andor IXON DU888 EC 1024 x 1024

iv) 2 sets of 4 channel compact spectrometers (300-858 nm @ R= 7500) Avantes set (JET KT1-type with 1800 l/mm and 10 m slit): Ch.1 300-455 nm, ch.2 450-577 nm, ch.3 575-681 nm, ch.4 658-858 nm

v) Overview compact spectrometer Avantes 300 -1100 nm with 300 l/mm and 10 m slit

vi) Spectrelle and deep UV compact spectrometer to be shared with TEXTOR


Ex-situ surface analysis available in FZJ

• High-precision balance (0.1 g) Weight loss measurements

• Thermal desorption spectrometry (TDS) Retention with temperature resolution

• SEM / EDX Morphology / Elemental composition

• Ion beam analyses: NRA, RBS,.. Absolute amounts of surface materials, limited depth resolution

• Secondary Ion Mass Spectrometry (SIMS) Depth distribution of elements

• X-ray Photoelectron Spectrometry (XPS) Chemical composition and state (e.g. carbidization)


Physics programme on PSI-2

• Plasma characterization• Hydrogen and impurity spectroscopy• Fuel retention in tungsten and graphite under

the influence of impurities• Erosion of tungsten and tungsten

spectroscopy• Simulation of transient heat loads by laser

(collaboration with Budker Institute) Talks by A. Burdakov and A. Shoshin

• EUROFER as first wall material

Recombining deuterium plasma

Neutralizer plate


Summary

¨ PSI-2 to serve as pilot experiment for JULE-PSI ¨ Transferred from Berlin to Jülich and successfully taken into operation¨ New components (cathode, target station, laser, diagnostics) purchased

and partially delivered and commissioned¨ Physics programme started with plasma characterization and

spectroscopic studies¨ PMI programme to start from October 2011

Documents

PSI-2 - the pilot experiment of the JULE-PSI project