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1

A new concept of fusion neutron monitoring for PF-1000 device

Jednorog S., Laszynska E., Bienkowska B., Ziolkowski A., Paduch M., Szewczak K., Mikszuta K., Malinowski K., Bajdel M., Potrykus P.

Nukleonika

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2017

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Vol. 62, No. 1

17--22

EN

The power output of plasma experiments and fusion reactors is a crucial parameter. It is determined by neutron yields that are proportional and directly related to the fusion yield. The number of emitted neutrons should be known for safety reasons and for neutron budget management. The PF-1000 is the large plasma facility based on the plasma focus phenomenon. PF-1000 is operating in the Institute of Plasma Physics and Laser Microfusion in Warsaw. Neutron yield changes during subsequent pulses, which is immanent part of this type device and so it must be monitored in terms of neutron emission. The reference diagnostic intended for this purpose is the silver activation counter (SAC) used for many years. Our previous studies demonstrated the applicability of radio-yttrium for neutron yield measurements during the deuterium campaign on the PF-1000 facility. The obtained results were compared with data from silver activation counter and shown linear dependence but with some protuberances in local scale. Correlation between results for both neutron monitors was maintained. But the yttrium monitor registered the fast energy neutron that reached measurement apparatus directly from the plasma pinch. Based on the preliminary experiences, the yttrium monitor was designed to automatically register neutron-induced yttrium activity. The MCNP geometrical model of PF-1000 and yttrium monitor were both used for calculation of the activation coefficient for yttrium. The yttrium monitor has been established as the permanent diagnostic for monitoring fusion reactions in the PF-1000 device.

2

Study of tungsten surface interaction with plasma streams at DPF-1000U

Ladygina M. S., Skladnik-Sadowska E., Zaloga D. R., Malinowski K., Sadowski M. J., Kubkowska M., Kowalska-Strzeciwilk E., Paduch M., Zielinska E., Miklaszewski R., Garkusha I. E., Gribkov V. A.

Nukleonika

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2015

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Vol. 60, No. 2

293--296

EN

In this note experimental studies of tungsten (W) samples irradiated by intense plasma-ion streams are reported. Measurements were performed using the modified plasma focus device DPF-1000U equipped with an axial gas-puffing system. The main diagnostic tool was a Mechelle®900 optical spectrometer. The electron density of a freely propagating plasma stream (i.e., the plasma stream observed without any target inside the vacuum chamber) was estimated on the basis of the half-width of the Dβ spectral line, taking into account the linear Stark effect. For a freely propagating plasma stream the maximum electron density amounted to about 1.3 × 1017 cm–3 and was reached during the maximum plasma compression. The plasma electron density depends on the initial conditions of the experiments. It was thus important to determine first the plasma flow characteristics before attempting any target irradiation. These data were needed for comparison with plasma characteristics after an irradiation of the investigated target. In fact, spectroscopic measurements performed during interactions of plasma streams with the investigated W samples showed many WI and WII spectral lines. The surface erosion was determined from mass losses of the irradiated samples. Changes on the surfaces of the irradiated samples were also investigated with an optical microscope and some sputtering and melting zones were observed.

3

Comparison of optical spectra recorded during DPF-1000U plasma experiments with gas-puffing

Zaloga D. R., Skladnik-Sadowska E., Kubkowska M., Ladygina M. S., Malinowski K., Kwiatkowski R., Sadowski M. J., Paduch M., Zielinska E., Makhlaj V. A.

Nukleonika

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2015

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Vol. 60, No. 2

309--314

EN

The results are presented of the optical spectra measurements for free plasma streams generated with the use of the modifi ed DPF-1000U machine. This facility was recently equipped with a gas injection system (the so-called gas-puff) placed on the symmetry axis behind the central opening in the inner electrode. The DPF-1000U experimental chamber was fi lled up with pure deuterium at the initial pressure of 1.6 or 2.4 mbar. Additionally, when the use was made of the gas-puff system about 1 cm3 of pure deuterium was injected at the pressure of 2 bars. The gas injection was initiated 1.5 or 2 ms before the triggering of the main discharge. The investigated plasma discharges were powered from a condenser bank charged initially to 23 kV (corresponding to the energy of 352 kJ), and the maximum discharge current amounted to about 1.8 MA. In order to investigate properties of a dense plasma column formed during DPF-1000U discharges the use was made of the optical emission spectroscopy. The optical spectra were recorded along the line of sight perpendicular to the vacuum chamber, using a Mechelle®900 spectrometer. The recent analysis of all the recorded spectra made it possible to compare the temporal changes in the electron density of a freely propagating plasma stream for discharges without and with the gas-puffing. Using this data an appropriate mode of operation of the DPF-1000U facility could be determined.

4

Charged projectile spectrometry using solid-state nuclear track detector of the PM-355 type

Malinowska A., Jaskóła M., Korman A., Szydłowski A., Malinowski K., Kuk K.

Nukleonika

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2015

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Vol. 60, No. 3, part 2

591--596

EN

To use effectively any radiation detector in high-temperature plasma experiments, it must have a lot of benefits and fulfill a number of requirements. The most important are: a high energy resolution, linearity over a wide range of recorded particle energy, high detection efficiency for these particles, a long lifetime and resistance to harsh conditions existing in plasma experiments and so on. Solid-state nuclear track detectors have been used in our laboratory in plasma experiments for many years, but recently we have made an attempt to use these detectors in spectroscopic measurements performed on some plasma facilities. This paper presents a method that we used to elaborate etched track diameters to evaluate the incident projectile energy magnitude. The method is based on the data obtained from a semiautomatic track scanning system that selects tracks according to two parameters, track diameter and its mean gray level.

5

Price-based coordinability in hierarchical systems with information asymmetry: a comparative analysis of Nash equilibrium conditions

Karpowicz M. P., Malinowski K.

Control and Cybernetics

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2013

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Vol. 42, no. 1

85--110

EN

The well-known problem of price-based coordinability is studied for the case of a multi-agent system in which information regarding the goals of the interacting subsystems is asymmetric. The paper illustrates how the uniform-price-based coordination rulet may create incentives to anticipate the values of coordination signals and, thus, why the coordinability condition cannot be satisfied under asymmetric information. For this purpose a comparison is given of Nash equilibrium outcomes that are reachable individually by priceanticipating agents in two noncooperative games. These games are induced by the uniform-price-based coordination mechanism and are referred to as payment-bidding auction and demand-bidding auction. The analysis presented shows that in the games considered some of the agents may improve payoffs and allocations by applying the price-anticipating bidding strategies. However, the payment-bidding auction cannot be strictly dominated by the demand-bidding action with respect to the resource allocation levels individually received by each agent. The derived results of theoretic considerations are illustrated by numerical examples.

6

Econet - energooszczędne techniki dla przewodowych sieci komputerowych

Kamola M., Arabas P., Wiśniewski T., Niewiadomska-Szynkiewicz E., Malinowski K., Karpowicz M., Sikora A., Marks M., Mincer M.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2012

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nr 8-9

650-655

PL

Przedstawiono projekt Econet, opracowujący mechanizmy skoordynowanego oszczędzania energii na wszystkich poziomach funkcjonalnych i we wszystkich obszarach topologicznych sieci. Prace, wykonywane w projekcie przez NASK oraz Instytut Automatyki i Informatyki Stosowanej PW, skupiają się na stworzeniu struktury i algorytmów sterowania siecią. Dokonano analizy zużycia energii we współczesnym sprzede, opisano projekt interfejsu dla energooszczędnych urządzeń, zadania optymalizacji energii w obszarze sieci oraz narzędzia symulacyjnej weryfikacji konstruowanych algorytmów.

EN

Econet, whose goal is to develop energy-efficient network hardware and control logic, is presented. The main contribution of Research and Academic Computer Network and of Inst. of Computation and Control Engineering to the project consists in creation of a network control structure and algorithms. Power consumption analysis for contemporary devices, API design for green networking components, energy optimization problem formulation and tools for verification through simulation, arę presented as the current main project achievements by the authors.

7

Time - and space - resolved measurements of high - energy ion beams emitted from PF - type discharges

Kwiatkowski R., Sadowski M. J., Skladnik-Sadowska E., Zebrowski J., Malinowski K., Czaus K., Garkusha I. E.

Nukleonika

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2012

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Vol. 57, No. 2

211-214

EN

The paper presents experimental studies of the spatial-microstructure and temporal-characteristics of fast ion beams, which are emitted from high-current plasma-focus (PF) discharges performed within the PF-360 facility at National Centre for Nuclear Research (NCBJ) at Otwock/Świerk, Poland. The spatial structure of the ion beams was investigated by means of pinhole cameras equipped with solid-state nuclear track detectors shielded by absorption filters made of Al-foils of different thickness. In order to perform time-resolved measurements there were applied miniature scintillation detectors placed at different points of the ion-image plane.

8

Research on spatial and energetic characteristics of the ion beams emitted in the PF - 360 discharges

Kwiatkowski R., Skladnik-Sadowska E., Malinowski K., Sadowski M. J., Czaus K., Zebrowski J., Garkusha I. E.

Nukleonika

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2012

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Vol. 57, No. 1

67-74

EN

Experimental results are presented on the spatial structure and energetic characteristics of the fast ion beams produced by high-current discharges in a PF-360 device operated at the National Centre for Nuclear Research (NCBJ, Otwock/Świerk, Poland). The 105 kJ discharges were initiated at the initial deuterium pressure around p0 = 6 hPa and were powered from a 234 miF capacitor bank charged up to 30 kV. The spatial structure of the ion beams was recorded using pinhole cameras equipped with the solid-state nuclear track detectors of the PM-355 type, placed at two different angles (0 centigrade, 45 centigrade) relative to the discharge axis. The detectors were shielded by thin absorption filters made of pure Al foils of various thickness, which made it possible to record only ions with energies exceeding a chosen threshold value. Similarly as in other plasma focus (PF) experiments, energies of the emitted ions ranged from about 30 keV to about 3 MeV, i.e. they were much higher than the voltage applied to the electrodes. The recorded ion images showed a complex spatial structure of the fast ion beams, which consisted of many micro-beams of different energies. It is possible that these beams were emitted by various local micro-sources (e.g. plasma micro-diodes) the were formed inside the PF pinch column.

9

Optical emission spectroscopy of plasma produced from tungsten target irradiated within RPI - IBIS facility

Skladnik-Sadowska E., Malinowski K., Sadowski M. J., Nowakowska-Langier K., Ladygina M. S., Garkusha I. E.

Nukleonika

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2012

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Vol. 57, No. 2

193-196

EN

The paper presents recent research on characteristics of deuterium plasma streams generated within an RPI-IBIS (multi-rod plasma injector) facility, and optical spectra of plasma produced during the interaction of these streams with a tungsten target placed at a distance of 20 cm from the electrode outlets. Distinct WI- and WII-lines were recorded and the noticeable erosion of the W-target was observed for shots delivering more than 4 J/cm2 on the target surface.

10

Estimation of ISTTOK runaway - electrons energies by means of a Cherenkov - type probe with modified AlN radiators

Jakubowski L., Plyusnin V. V., Sadowski M. J., Zebrowski J., Malinowski K., Rabiński M., Fernandes H., Silva C., Duarte P., Jakubowski M.

Nukleonika

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2012

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Vol. 57, No. 2

177-181

EN

Measurements of fast electrons, as performed during recent few years in small tokamaks, demonstrated that detectors based on the Cherenkov effect are very useful tools for such studies. The modernized measuring heads, which were equipped with miniature aluminum-nitride (AlN) radiators, enabled to determine locations and instants of the fast electrons emission and to estimate their energy. A comparison of four measuring channels showed that in ISTTOK the most important role was played by electrons of energy less than 90 keV.

11

Optimal Pump Scheduling for Large Scale Water Transmission System by Linear Programming

Błaszczyk J., Karboński A., Krawczyk K., Malinowski K., Allidina A.

Journal of Telecommunications and Information Technology

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2012

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nr 3

91-96

EN

Large scale potable water transmission system considered in this paper is the Toronto Water System, one of the largest potable water supply networks in North America. The main objective of the ongoing Transmission Operations Optimizer project consists in developing an advanced tool for providing such pumping schedules for 153 pumps, that all quantitative requirements with respect to the system operation are met, while the energy costs are minimized. We describe here a linear, so-called SimplifiedModel (SM), based on mass-balance equations, which is solved on week horizon and delivers boundary conditions for so-called Full Model (FM), which is nonlinear and takes into account hydraulic phenomena and water quality.

12

Optical emission spectroscopy of plasma streams in PF-1000 experiments

Jakubowska K., Kubkowska M., Skladnik-Sadowska E., Malinowski K., Marchenko A. K., Paduch M., Sadowski M. J., Scholz M.

Nukleonika

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2011

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Vol. 56, No. 2

125-129

EN

The optical spectroscopy in the visible range was used to determine properties of the dense magnetized plasma generated in the PF-1000, a 1 MJ plasma focus device operating in the Institute of Plasma Physics and Laser Microfusion (IPPLM) in Warsaw, Poland. The experiments were performed in a vacuum chamber pumped out to the basic pressure of 2 x 10.5 hPa. The initial pressure of the pure deuterium filling was 2.9 hPa, while that of the deuterium--argon mixture was 1.07 hPa of D2 and 0.13 hPa of Ar. The deuterium-plasma emission contained the Balmer series (Dalfa, Dbeta and Dgamma) and a few distinct copper (Cu I) lines originating from the inner electrode material. The emission of the deuterium-argon plasma was rich in Ar II lines. The electron density (ne), averaged over line of sight, of order of 1016 cm.3 was calculated on the basis of the Dalfa and Dbeta emission only, because the D�ż line was strongly self-absorbed. A group of the Ar II spectral lines was used to estimate the excitation temperature (Texc = 3 eV) by means of a Boltzmann plot. Additionally, the temporal evolution of the electron density was determined on basis of the Stark broadening of the Dalfa and Dgamma lines.

13

Measurements of electron and ion beams emitted from the PF-1000 device in the upstream and downstream direction

Kwiatkowski R., Skladnik-Sadowska E., Malinowski K., Sadowski M. J., Czaus K., Zebrowski J., Karpinski L., Paduch M., Scholz M., Garkusha I. E., Kubeš P.

Nukleonika

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2011

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Vol. 56, No. 2

119-123

EN

In this paper we report on measurements of the energy spectra and other properties of the electron and fast ion beams emitted in the upstream and downstream direction along the z-axis of a large plasma focus device PF-1000, that was operated at 21-27 kV, delivering 290–480 kJ pulse. Measurements of the electron beam (EB) properties were performed using a magnetic analyzer. Properties of the ion beams were measured by means of pinhole cameras equipped with PM-355 nuclear track detectors and placed at various angles (0, 60 and 180 centigrade) to the discharge axis. Measurements revealed a complex spatial structure of the fast ion beams. The ion measurements behind the PF-1000 collector proved that some fast deuterons are emitted also in the upstream direction. Measurements of the EBs emitted in the upstream and downstream direction revealed electron energies in the range from approximately 40 keV to approximately 800 keV. These spectra confirm that in localized regions within the PF-1000 plasma column there appear strong fields accelerating charged particles in different directions along the discharge axis.

14

A Software Platform for Research on Auction Mechanisms

Kamola M., Niewiadomska-Szynkiewicz E., Malinowski K., Stańczuk W., Pałka P.

Journal of Telecommunications and Information Technology

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2011

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nr 3

38-46

EN

The platform for research on auction mechanisms is a distributed simulation framework providing means to carry out research on resource allocation efficiency mechanisms and user strategies. Both kinds of algorithms examined are completely user-defined. Interaction of algorithms is recorded and pre-defined measures for the final resource allocation are calculated. Underlying database design provides for efficient results lookup and comparison across different experiments, thus enabling research groupwork. A recognised, open and flexible information model is employed for experiment descriptions.

15

Analiza transformacji gospodarstwa ogrodniczego z uwzględnieniem aspektów technicznych

Gaworski M., Malinowski K.

Inżynieria Rolnicza

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2011

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R. 15, nr 9

41-48

PL

Celem pracy było określenie ekonomicznej efektywności przejścia z produkcji zbóż na uprawy sadownicze z uwzględnieniem nakładów związanych z doskonaleniem technicznego wyposażenia rozpatrywanego gospodarstwa. Z analizy wynika, że odejście od uprawy zbóż na rzecz roślin sadowniczych zwiększy dochód w przeliczeniu na jednostkę powierzchni analizowanego gospodarstwa i pozwoli na stosunkowo szybki zwrot nakładów poniesionych na przebudowę, zakupy maszyn i urządzeń do produkcji.

EN

The purpose of the study was to analyse some problems concerning economic efficiency of farm transformation from cereal to fruit production, including inputs on the improvement of the farm technical infrastructure. The analysis proves that transformation from cereal production into orchard production will result in higher farm unit incomes (per hectare). Moreover, it will allow for quite fast return of inputs incurred for reconstruction, purchase of machines and production devices.

16

Price Method and Network Congestion Control

Malinowski K., Niewiadomska-Szynkiewicz E., Jaskóła P.

Journal of Telecommunications and Information Technology

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2010

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nr 2

73-77

EN

Price instruments are useful in achieving market balance conditions in various markets. Those instruments can be also used for control of other composite systems. The formulation and basic properties of the Price Method are reviewed and then the congestion control by price instruments in a computer network is described and tested.

17

Optymalizacja w zastosowaniu do planowania ruchu ściśle współpracujących robotów

Szynkiewicz W., Błaszczyk J., Malinowski K.

Pomiary Automatyka Robotyka

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2009

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R. 13, nr 2

71-89

PL

W artykule omówiono wykorzystanie zaawansowanych technik optymalizacji do rozwiązywania zadań planowania ścieżek ruchu dla ściśle współpracujących robotów. Zadanie planowania ścieżki jest formułowane jako problem minimalizacji warunkowej funkcjonału, a następnie jest sprowadzane do zadania programowania nieliniowego (NLP). Do numerycznego rozwiązania zadania NLP wykorzystuje się solwer IPOPT oparty na prymalno-dualnej metodzie punktu wewnętrznego dla zadań nieliniowych, będącej obecnie jedną z wiodących technik optymalizacji nieliniowej dla zadań wielkiej skali.

EN

Application of advanced optimization techniques to solve the path planning problem for tightly cooperating robots is discussed in this paper. The approach to path planning is formulated as a "quasi-dynamic" nonlinear optimization (NLP) problem with equality and inequality constraints in terms of the joint variables. The essence of the method is to find joint paths which satisfy the given constraints and minimize the proposed performance index. For numerical solution of the NLP problem the IPOPT solver is used, which implements a nonlinear primal-dual interior-point method one of the leading techniques for large-scale nonlinear optimization.

18

Object library of algorithms for dynamic optimization problems; Benchmarking SQP and nonlinear interior point methods

Błaszczyk J., Karbowski A., Malinowski K.

International Journal of Applied Mathematics and Computer Science

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2007

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Vol. 17, no 4

515-537

EN

The main purpose of this paper is to describe the design, implementation and possibilities of our object-oriented library of algorithms for dynamic optimization problems. We briefly present library classes for the formulation and manipulation of dynamic optimization problems, and give a general survey of solver classes for unconstrained and constrained optimization. We also demonstrate methods of derivative evaluation that we used, in particular automatic differentiation. Further, we briefly formulate and characterize the class of problems solved by our optimization classes. The solution of dynamic optimization problems with general constraints is performed by transformation into structured large-scale nonlinear programming problems and applying methods for nonlinear optimization. Two main algorithms of solvers for constrained dynamic optimization are presented in detail: the sequential quadratic programming (SQP) exploring the multistage structure of the dynamic optimization problem during the solution of a sequence of quadratic subproblems, and the nonlinear interior-point method implemented in a general-purpose large-scale optimizer IPOPT. At the end, we include a typical numerical example of the application of the constrained solvers to a large-scale discrete-time optimal control problem and we use the performance profiles methodology to compare the efficiency and robustness of different solvers or different options of the same solver. In conclusions, we summarize our experience gathered during the library development.

19

Obszary badań Instytutu Automatyki i Informatyki Stosowanej

Zieliński C., Malinowski K., Tatjewski P., Ogryczak W., Pacut A., Toczyłowski E., Sacha K., Kasprzak W.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2006

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nr 10

289-292

PL

Przedstawiono w sposób ogólny badania prowadzone w Instytucie Automatyki i Informatyki Stosowanej. Obejmują one zagadnienia związane ze: sterowaniem, symulacją i optymalizacją systemów złożonych, biometrią uczeniem maszynowym, robotyką, rozpoznawaniem obrazów i sygnałów mowy, sterowaniem układów nieliniowych, metodami wytwarzania oprogramowania oraz oceny jego jakości, wspomaganiem decyzji, badaniami operacyjnymi, harmonogramowaniem oraz bazami danych. Przedstawiono zarówno dokonania teoretyczne jak i aplikacyjne w tym zakresie.

EN

The paper presents in generał the research conducted at the Institute of Control and Computation Engineering. This research encompasses: control, simulation and optimization of complex systems, biometrics, machine leaming, robotics, pattern and speech recognition, nonlinear control, methods of software engineering and evaluation of its quality, decision support, operations research, scheduling and data bases. Both the obtained theoretical results and application of those results have been presented.

20

Optimization of performance of queuing systems with long-tailed service times

Kubica B.J., Malinowski K.

Prace Naukowe Politechniki Warszawskiej. Elektronika

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2006

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z. 156

237-245

EN

This paper considers the problem of the performance optimization of a queuing system with long-tailed service time. Due to nonconvexity of the problem global optimization methods have to be used. Interval methods and genetic algorithms are considered. Approximation of the Laplace transform of the probability distribution function of the service time arises as a subproblem. A new method to do it is developed.