«Association EURATOM / IPP.CR I N S T I T U T E O F P L A S M A P H Y S I C S, v.v. i. ACADEMY OF SCIENCES OF THE CZECH REPUBLIC ANNUAL REPORT ...»
Task: IPP-CR_ TW6-TTMS-003, D5 Field: Tritium Breeding and Materials, Area: Breeding Blanket Collaborative staff:: L. Kosek, J. Berka, M. Ruzickova, M. Zmitko, K. Splichal This task will be focused on development and testing of key components for the Pb-Li liquid metal loop of the design of Helium Cooled Lithium Lead (HCLL) Test Blanket Module (TBM). Based on the previous design studies of Pb-Li auxiliary system the following components are to be developed, in particular cold traps, high temperature flanges and a circulation pump. Development of these components has to be performed by their testing in Pb-Li liquid metals. The aim is to verify their feasibility and operation performance in terms of cold traps purification efficiency, flanges reliability and manipulation and mechanical pump feasibility.
During the TBM operation corrosion products of structure materials and different impurities will be formed and accumulated in the Pb-Li auxiliary circuit, and the necessity of their removal will arise. For this reason, an appropriate Pb-Li purification system needs to be proposed and designed. Also, special high temperature flanges for liquid metal pipelines allowing connection and disconnection in an inert gas need to be developed and their operational performance tested in relevant Pb-Li auxiliary system conditions. In addition, a suitable liquid metal circulation pump needs to be developed and its performance tested.
Testing of the developed components is to be performed in Pb-Li liquid metal with flow rate of 5-30 mm/s at the temperature of 260-500°C.
Part III - TECHNOLOGY Manipulation involves assessments of disassembly, dismantling of bellows systems, testing of displacement mechanisms, evaluation of sealing surface conditions and handling. A mechanical type circulation pump will be designed and verified under testing conditions. The characteristic parameters will be evaluated.
Two testing cycles were performed in the last year. During the first cycle a leak in the weld joint of the cold trap vessel was proved. In the second cycle a small defect in the area of lower part of the mechanical pump was indicated. The corrective actions were performed and tightness of metal loop was proved. Verifications of operational parameters continue after assembling of the Pb-Li loop.
 J. Hájek, V Richter, M Zmitko, Pb-17Li Auxiliary and purification systems: Design of the auxiliary Pb-Li loop for Helium, NRI 12096, 2004
Task: IPP-CR_ TW6-TTMS-003, D5 Field: Tritium Breeding and Materials, Area: Materials Development Collaborative staff: L. Kosek, J. Berka, M. Zmitko Under Test Blanket Module operation conditions sufficient corrosion resistance and limitation of tritium penetration through EUROFER steel are required. Several types of anticorrosion and/or tritium anti-permeation coatings on EUROFER steel were selected. The main objective of experimental works is investigation of the coatings compatibility with Pb-Li liquid metal and their corrosion resistance. The investigation will evaluate kinetics of the coating thickness, mechanism of interaction of eutectic melt with coating layers, microstructure and chemical composition of layers and characterization coating - base metal bonding.
Task: IPP-CR_ TW2-TTMS-003b, D4 Field: Tritium Breeding and Materials, Area: Materials Development Collaborative staff: J. Berka, M. Zmitko, Vl. Masarik, Z. Lahodová, L. Viererbl Compatibility of martensitic steel EUROFER 97 was investigated with Pb-Li eutectic melt under at temperature 500°C under irradiation condition. Effect of irradiation on Pb-Li melts properties was investigated regarding microstructure, chemical composition and radioactivity. The irradiation of eutectic melts results in the production of tritium and polonium owing to transmutation reaction and bismuth from induced reaction. The post irradiation examinations did not show any noticeable attack of martensitic steel.
The aim of the task was to perform compatibility tests of EUROFER weld material with PbLi liquid metal under neutron irradiation at 500°C. In-pile corrosion testing of TBM weld metal was situated in molten Pb-Li and located in the active channel of a reactor LVR 15.
The weld specimens were irradiated for 6,630 hr up to the level of 1.45 dpa. After dismantling the irradiation rig post-irradiation examinations of the specimens are continuing in the hot cell at the present time.
Corresponding temperature gradient is in the range of 100-150° C. Flow of the molten PbLi eutectic was driven by natural convention.
Overflowing generated heat is dissipated by reactor basin water and can be controlled in a certain range. The irradiation rig was dismounted in hot cells and the internals were prepared for specimen holder disassembly.
Gamma-spectrometric analyses of eutectic specimens proved tritium (H3) and polonium Po as a result of transmutation reaction, bismuth Bi as a result of induced reaction. The comparison of gamma analyses and calculation results (Tab.) show that the measured H3 content is about two orders lower than the calculated one and the content of Po is similar for both values. Structure of Pb-17Li melt did not show eutectic structure as results of Li segregation. No increase of Cr, Fe, Mn, Ni contents in Pb-17Li melt was observed as a results of interaction of EUROFER weld metal with in pile environments.
 M. Zmitko, Y. Poitevin, R.Lässer: The European Concepts of the Blanket Module Development, EFDA, Garching, 2005  H. Moryyma at all: Tritium recovery from liquid metals, Fus. Engin. And Design 28 (1995), 226
Task : TW7-8_TTMN_002B_D6 Collaborative staff: V. Burjan, M. Götz, M. Honusek, V. Kroha, J. Novák and E. Šimečková In collaboration with: U. Fischer and S.P. Simakov, Association EURATOM-FZK, Karlsruhe, Germany
 S.P. Simakov, P. Bém, V. Burjan, U. Fischer, M. Götz, M. Honusek, V. Kroha, J.
Novák and E. Šimečková, Development of activation foils method for the IFMIF neutron flux characterization, Fus. Eng. and Design, 82(15-24) 2007. pp.2510-2517  P. Bém, V. Burjan, M. Götz, M. Honusek, U. Fischer, V. Kroha, J. Novák, S.P.
Simakov and E. Šimečková, The NPI Cyclotron-based Fast neutron Facility ND-2007, Proceedings of the International Conference on Nuclear Data for Science and technology, Nice, April 2007
KEEP-IN-TOUCH ACTIVITY ONKeep-in-Touch Activities IV on Inertial Confinement Fusion Activities of the Prague Asterix Laser System (PALS) in the field of inertial confinement fusion have been carried out in close collaboration with Institute of Plasma Physics and Laser Micro-fusion, Warsaw, Poland, with participation of scientists from France. In 2007 the experimental work was focused on investigation of production of plasma jets.
Interaction of laser-produced plasma jets with ambient gas J. Ullschmied, Eduard Krouský, Karel Mašek, Jiří Skála
In collaboration with:
A. Kasperczuk, T. Pisarczyk, D. Baran, Association EURATOM-IPPPM, Warsaw, Poland Ph. Nicolai, V. T. Tikhonchuk, C. Stenz, CELIA, Université Bordeaux 1, Talence, France J. Kravárik, D. Klír, FEE Czech Technical University in Prague, Prague, CR The origin, propagation, and stability of plasma jets are fundamental issues in both laboratory astrophysics and inertial confinement fusion (ICF) research. In the ICF context, the material mixing and jet formation could perturb the performance of high-yield laser targets. For that reason the formation of plasma jets and their interaction with ambient media are important issues for the ICF community. The jet production by laser beams depends strongly on the target irradiation geometry and on the properties of materials composing the target. Recent experiments carried out at the Prague Asterix Laser System (PALS) iodine laser facility have demonstrated that well-formed plasma jets can be produced in a simple way by using a single laser beam and a planar target.
When choosing properly the laser intensity, focal spot radius, and target atomic number a radiative plasma jet can be launched from a metallic planar target. Remarkably stable dense plasma jets were created by focusing the PALS third-harmonic beam on the massive targets made of high-Z metals, like copper, tantalum or lead. Our experiments have shown that wellformed plasma jets can be created at a modest laser energy not exceeding 100 J. Thus, laser experiments of that type ceased to be a privilege of multi-beam super lasers like NOVA or Fig. 1. Scheme of the experiment on interaction of plasma jet with a gas target (a) and the electrondensity profile of the interacting jet obtained by laser interferometry (b).
A shock wave generated in the gas is well seen at the penetrating jet tip.
Part IV – Keep-in-touch on Inertial Fusion GEKKO XII. The jets produced at PALS have a diameter of typically just a fraction of millimeter, they are several millimeters long, and last longer than 15 ns. The jet velocity exceeds 500 km/s, its Mach number is greater than 10, and the density higher than 1018 cm-3.
For measurements of the development of the jet density, temperature and velocity in the time interval 0-18 ns a three-frame laser interferometer/shadowgraph, a framing x-ray pinhole camera, and an x-ray streak camera were used. The optimum conditions for jet formation (in dependence on the laser energy, colour, and focused intensity) have been found for several target materials (Cu, Ag, Ta, Pb), for both the perpendicular and oblique incidences of the laser beam. The optimised Cu plasma jets produced at the oblique incidence of laser beam were used in experiments on jet interaction with ambient gas (Fig.1).
The interaction of laser-produced plasma jets with a gas target was systematically studied during the IPPLM mission to PALS in April 2007. A high-pressure (2-20 bars) supersonic gas nozzle created a cylindrical column of argon (Z=18) or helium (Z=2). Variations of the gas atomic number and pressure made it possible to control the jet to ambient gas density ratio in Fig. 2. Development of the transverse plasma density profiles of Cu-jet penetrating He-gas target. Pressure at the gas nozzle 20 bar (pictures by T. Pisarczyk, IPPLM Warsaw).
the range of 0.1 – 10. The oblique incidence of the laser beam of 30o with respect to the target normal avoids gas preionisation in the jet formation area. The time development of transverse electron density profiles of the Cu-plasma jet interacting with a He-target is shown in Fig. 2.
The shock waves created in ambient gas by the penetrating plasma jet are well seen in several series of unique pictures obtained by a 4-frame pinhole x-ray CCD camera, an example of which is shown in Fig. 3. The camera detected soft x-rays in the energy range 10 - 1000 eV.
The following three stages can be distinguished in the interaction process: (i) ablative plasma generation and preliminary ionization of the ambient gas, (ii) creation of the primary shock wave in, (iii) plasma jet forming and generation of a secondary shock wave. Processing of the experimental results and their theoretical interpretation is in progress now. The experiments with plasma jet will continue also in 2008.
 Kasperczuk, et al., Physics of Plasmas 14 (2007) Art. No. 102706  Kasperczuk, et al., Physics of Plasmas 14 (2007) Art. No. 032701  Kasperczuk, et al., Laser and Particle Beams 25 (2007) 425-433  Kasperczuk, et al., Optica Applicata 37 (2007) 73-82  T. Pisarczyk, et al. Plasma Phys. Control. Fusion 49 (2007) B611-B619  P. Nicolai, et al., Astrophysics and Space Science 307 (2007) 87-91  T. Pisarczyk et al, PLASMA 2007, October 16-19, 2007 Greifswald, Germany, paper WeP44.
IV Training, Education, Outreach KEEP-IN-TOUCH ACTIVITYActivities and Public Information ON
In collaboration with:
G. Veres, M. Berta, A. Bencze, Association EURATOM-HAS, Hungary R Miklaszevski, A. Szydlowski, J. Rzadkiewicz, I. Ksiazek, L. Ryc, Association EURATOM/IPPLM, Poland G. van Oost, Association EURATOM/Etat Belge, Belgium Training and education effort was focused on-co organization of the Summer Training Course (SUMTRAIC) together with the Association EURATOM/HAS, the organization of semester course Physics and Technology of Thermonuclear Fusion for master and PhD students of the Faculty of Nuclear Science and Physical Engineering (FNSPE) of the Czech Technical University. In addition, a new full BSc and MSc Curriculum with the same title continued for the second year at FNSPE.
The SUMTRAIC 2007 was organized by the KFKI-Research Institute for Particle and Nuclear Physics in Budapest in the period 10-18 July 2007. Such arrangement was agreed because of shut-down of the CASTOR tokamak. The Association EURATOM IPP.CR was represented by three supervisors of experiments (J. Stockel, M. Hron and R. Dejarnac). The summer school was attended by nine students from four countries. The elevent lectures was presented to students during first three days of the school. Two of them were given by our
R. Dejarnac: Langmuir probe theory and applications J. Stockel: Langmuir probe measurements on CASTOR and other tokamaks The remaining time was devoted to laboratory experiments: There were three types of measurements performed with equipment provided by HAS with some contribution from IPP
1) Langmuir probe measurements to determine the electron density and temperature in a glow discharge tube at atmospheric pressure
2) Electron density fluctuation measurements
3) Spectroscopy measurements to determine plasma composition
4) Processing of probe data from the CASTOR tokamak The IPP supervisors assist in the items 1,2, and 4. We also provided some equipment for these experiments (power supplies and circuits for probe measurements).