T. Krizsanóczi
36677460200
Publications - 3
Advanced neutral alkali beam diagnostics for applications in fusion research (invited)
Publication Name: Review of Scientific Instruments
Publication Date: 2018-10-01
Volume: 89
Issue: 10
Page Range: Unknown
Description:
Diagnosing the density profile at the edge of high temperature fusion plasmas by an accelerated lithium beam is a known technique since decades. By knowledge of the relevant atomic physics rate coefficients, the plasma electron density profile can be calculated from the relatively calibrated light profile along the beam. Several additional possibilities have already been demonstrated: Charge Exchange Resonance Spectroscopy (CXRS) for ion temperature/flow and Zeeman polarimetry for edge plasma current; therefore the Li-beam diagnostic offers a wealth of information at the plasma edge. The weaknesses of the method are the relatively faint light signal, background light, and technical difficulties of the beam injector which usually seriously limit the applicability. In this talk, we present systematic developments in alkali-beam diagnostics (Li, Na) for the injector and the observation system and detectors which resulted in strongly increased capabilities. Advanced systems have been built, and microsecond scale density profile, turbulence, and zonal flow measurement have been demonstrated. A novel edge current measurement technique has also been designed, and components have been tested with potential microsecond-scale time resolution. Additional possibilities of these advanced systems for spectral measurements (CXRS and various Zeeman schemes) are also discussed.
Open Access: Yes
DOI: 10.1063/1.5039309
Progress in diagnostics of the COMPASS tokamak
P. Bilkova
P. Bohm
O. Bogár
E. Gauthier
K. Kovarik
J. P. Gunn
D. I. Naydenkova
A. Podolnik
D. Réfy
N. Vianello
J. Adámek
J. Horacek
O. Grover
R. Dejarnac
J. Cavalier
O. Ficker
M. Hron
M. Komm
E. Matveeva
R. Pánek
M. Peterka
J. Seidl
M. Dimitrova
D. Fridrich
A. Devitre
T. Markovic
G. Anda
D. Dunai
M. Rabinski
J. Stockel
J. Mlynar
R. Paprok
K. Mitošinková
M. Sos
J. Varju
M. Tomes
M. Varavin
P. Hacek
J. Krbec
R. Gomes
M. Berta
J. Havlicek
A. Havranek
T. Krizsanóczi
V. Weinzettl
P. Vondráček
F. Zacek
M. Vlainic
M. Stano
T. Pereira
G. P. Ermak
J. Zebrowski
M. Jakubowski
K. Malinowski
M. Spolaore
J. Zajac
A. Silva
S. Zoletnik
Tsv Popov
D. Sarychev
M. Imrišek
S. Nanobashvili
Publication Name: Journal of Instrumentation
Publication Date: 2017-12-07
Volume: 12
Issue: 12
Page Range: Unknown
Description:
The COMPASS tokamak at IPP Prague is a small-size device with an ITER-relevant plasma geometry and operating in both the Ohmic as well as neutral beam assisted H-modes since 2012. A basic set of diagnostics installed at the beginning of the COMPASS operation has been gradually broadened in type of diagnostics, extended in number of detectors and collected channels and improved by an increased data acquisition speed. In recent years, a significant progress in diagnostic development has been motivated by the improved COMPASS plasma performance and broadening of its scientific programme (L-H transition and pedestal scaling studies, magnetic perturbations, runaway electron control and mitigation, plasma-surface interaction and corresponding heat fluxes, Alfvenic and edge localized mode observations, disruptions, etc.). In this contribution, we describe major upgrades of a broad spectrum of the COMPASS diagnostics and discuss their potential for physical studies. In particular, scrape-off layer plasma diagnostics will be represented by a new concept for microsecond electron temperature and heat flux measurements - we introduce a new set of divertor Langmuir and ball-pen probe arrays, newly constructed probe heads for reciprocating manipulators as well as several types of standalone probes. Among optical tools, an upgraded high-resolution edge Thomson scattering diagnostic for pedestal studies and a set of new visible light and infrared (plasma-surface interaction investigations) cameras will be described. Particle and beam diagnostics will be covered by a neutral particle analyzer, diagnostics on a lithium beam, Cherenkov detectors (for a direct detection of runaway electrons) and neutron detectors. We also present new modifications of the microwave reflectometer for fast edge density profile measurements.
Open Access: Yes
Lithium beam diagnostic system on the COMPASS tokamak
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
