G. Veres

7004536635

Publications - 8

Lithium beam diagnostic system on the COMPASS tokamak

M. Berta G. Anda S. Bató D. Dunai T. Krizsanóczi T. Ilkei P. Hacek D. Réfy J. Krbec I. G. Kiss G. Veres S. Zoletnik A. Bencze

Publication Name: Fusion Engineering and Design

Publication Date: 2016-10-01

Volume: 108

Issue: Unknown

Page Range: 1-6

Description:

An improved lithium beam based beam emission spectroscopy system - installed on COMPASS tokamak - is described. The beam energy enhanced up to 120 keV for Atomic Beam Probe measurement. The size of the ion source is doubled, using a newly developed thermionic heater instead of the conventionally used heating (tungsten or molybdenum) filament. The neutralizer is also improved. It produces the same sodium vapor in a cell but minimize the loss condensing the vapor on a cold surface which is led back (in fluid state) into the sodium oven. This way we call it recirculating neutralizer. The observation system consists of a CCD camera and an avalanche photodiode array.

Open Access: Yes

DOI: 10.1016/j.fusengdes.2016.04.022

Li-BES detection system for plasma turbulence measurements on the COMPASS tokamak

M. Berta G. Anda D. Dunai P. Hacek D. Réfy A. Kovácsik J. Krbec M. Hron G. Veres R. Pánek S. Zoletnik A. Bencze V. Weinzettl

Publication Name: Fusion Engineering and Design

Publication Date: 2015-10-01

Volume: 96-97

Issue: Unknown

Page Range: 795-798

Description:

A new Li beam emission spectroscopy (Li-BES) diagnostic system with a ∼ cm spatial resolution, and with beam energy ranging from 10 keV up to 120 keV and a 18 channel Avalanche photo diode (APD) detector system sampled at 2 MHz has been recently installed and tested on the COMPASS tokamak. This diagnostic allows to reconstruct density profile based on directly measured light profiles, and to follow turbulent behaviour of the edge plasma. The paper reports technical capabilities of this new system designed for fine spatio-temporal measurements of plasma electron density. Focusing on turbulence-induced fluctuation measurements, we demonstrate how physically relevant information can be extracted using the COMPASS Li-BES system.

Open Access: Yes

DOI: 10.1016/j.fusengdes.2015.06.030

Development of atomic beam probe for tokamaks

M. Berta G. Anda I. G. Kiss J. Havlicek S. Tulipán P. Hacek M. Aradi Cs Buday G. Veres S. Zoletnik A. Bencze

Publication Name: Fusion Engineering and Design

Publication Date: 2013-11-01

Volume: 88

Issue: 11

Page Range: 2875-2880

Description:

The concept and development of a new detection method for light alkali ions stemming from diagnostic beams installed on medium size tokamak is described. The method allows us the simultaneous measurement of plasma density fluctuations and fast variations in poloidal magnetic field, therefore one can infer the fast changes in edge plasma current. The concept has been worked out and the whole design process has been done at Wigner RCP. The test detector with appropriate mechanics and electronics is already installed on COMPASS tokamak. General ion trajectory calculation code (ABPIons) has also been developed. Detailed calculations show the possibility of reconstruction of edge plasma current density profile changes with high temporal resolution, and the possibility of density profile reconstruction with better spatial resolution compared to standard Li-BES measurement, this is important for pedestal studies. © 2013 Elsevier B.V.

Open Access: Yes

DOI: 10.1016/j.fusengdes.2013.05.064

Overview of the COMPASS diagnostics

P. Bilkova P. Bohm D. I. Naydenkova J. Adámek J. Horacek R. Dejarnac M. Hron R. Pánek I. Ďuran G. Anda J. Stockel J. Mlynar D. Sestak M. Aftanas G. Veres F. Janky J. Brotankova R. Melich P. Hacek R. Gomes M. Berta J. Havlicek V. Weinzettl F. Zacek A. Szappanos J. Zajac D. Jares J. Ghosh V. F. Shevchenko R. Scannell M. Walsh H. W. Müller V. Igochine A. Silva M. Manso S. Zoletnik Tsv Popov D. Sarychev V. K. Kiselov S. Nanobashvili

Publication Name: Fusion Engineering and Design

Publication Date: 2011-10-01

Volume: 86

Issue: 6-8

Page Range: 1227-1231

Description:

The COMPASS tokamak, a divertor device with clear H-mode and ITER-relevant geometry, has been re-installed in IPP Prague after its transport from CCFE in UK. The first plasma was achieved in December 2008. Many new diagnostic tools with both high temporal and spatial resolutions have been developed to address the scientific programme of COMPASS focused on H-mode physics and pedestal investigations. In the paper, an overview of existing and in near future planned diagnostics (magnetic, spectroscopy, microwave, probe and beam/particle) on COMPASS is given including their basic technical specifications and achievements. © 2011 EURATOM. Published by Elsevier B.V. All rights reserved.

Open Access: Yes

DOI: 10.1016/j.fusengdes.2010.12.024

Fast tomographic reconstruction on parallel hardware

Gábor Takács G. Veres Zoltán Horváth

Publication Name: Aip Conference Proceedings

Publication Date: 2010-12-01

Volume: 1281

Issue: Unknown

Page Range: 1793-1796

Description:

Tomographic reconstruction is the mathematical procedure of approximating a function f, based on the integrals of f along a set of line sections. The need for fast tomographic reconstruction arises for example in the challenging problem of real time control of some plasma parameters in a fusion reactor. In this paper, we present a fast algorithm for tomographic reconstruction. A good property of our approach is that it fits well to hardware with two levels of parallelism (e.g. a GPU cluster). We also propose an objective evaluation method for measuring the quality of reconstruction on real datasets where f is unknown. We will demonstrate that our algorithm is able to perform more than 50 000 reconstructions per second at reasonably good quality, running on a relatively cheap hardware. © 2010 American Institute of Physics.

Open Access: Yes

DOI: 10.1063/1.3498232

EDICAM fast video diagnostic installation on the COMPASS tokamak

M. Berta S. Tulipán A. Szappanos M. Hron G. Veres R. Pánek S. Zoletnik V. Weinzettl J. Stockel

Publication Name: Fusion Engineering and Design

Publication Date: 2010-01-01

Volume: 85

Issue: 3-4

Page Range: 370-373

Description:

A new camera system event detection intelligent camera (EDICAM) is being developed by the Hungarian Association and has been installed on the COMPASS tokamak in the Institute of Plasma Physics AS CR in Prague, during February 2009. The standalone system contains a data acquisition PC and a prototype sensor module of EDICAM. Appropriate optical system have been designed and adjusted for the local requirements, and a mechanical holder keeps the camera out of the magnetic field. The fast camera contains a monochrome CMOS sensor with advanced control features and spectral sensitivity in the visible range. A special web based control interface has been implemented using Java spring framework to provide the control features in a graphical user environment. Java native interface (JNI) is used to reach the driver functions and to collect the data stored by direct memory access (DMA). Using a built in real-time streaming server one can see the live video from the camera through any web browser in the intranet. The live video is distributed in a Motion Jpeg format using real-time streaming protocol (RTSP) and a Java applet have been written to show the movie on the client side. The control system contains basic image processing features and the 3D wireframe of the tokamak can be projected to the selected frames. A MatLab interface is also presented with advanced post processing and analysis features to make the raw data available for high level computing programs. In this contribution all the concepts of EDICAM control center and the functions of the distinct software modules are described. © 2009 Elsevier B.V. All rights reserved.

Open Access: Yes

DOI: 10.1016/j.fusengdes.2009.11.001

Concept of an atomic beam probe diagnostic on COMPASS tokamak

M. Berta G. Anda D. Dunai M. Aradi G. Veres S. Zoletnik A. Bencze

Publication Name: 36th Eps Conference on Plasma Physics 2009 Eps 2009 Europhysics Conference Abstracts

Publication Date: 2009-12-01

Volume: 33 E2

Issue: Unknown

Page Range: 1399-1402

Description:

No description provided

Open Access: Yes

DOI: DOI not available

On the statistics of ELM filaments measured by fast low field side wall Langmuir probes on TCV

M. Berta G. Veres R. A. Pitts O. E. Garcia A. Bencze

Publication Name: 34th Eps Conference on Plasma Physics 2007 Eps 2007 Europhysics Conference Abstracts

Publication Date: 2007-12-01

Volume: 31

Issue: 2

Page Range: 820-823

Description:

No description provided

Open Access: Yes

DOI: DOI not available