0000000000073257
AUTHOR
O. Lielausis
Interaction of a Liquid Gallium Jet with ISTTOK Edge Plasmas
The use of liquid metals as plasma facing components in tokamaks has recently experienced a renewed interest stimulated by their advantages in the development of a fusion reactor. Liquid metals have been proposed to solve problems related to the erosion and neutronic activation of solid walls submitted to high power loads allowing an efficient heat exhaust from fusion devices. Presently the most promising candidate materials are lithium and gallium. However, lithium has a short liquid state range when compared, for example, with gallium that has essentially better thermal properties and lower vapor pressure. To explore further these properties, ISTTOK tokamak is being used to test the inter…
A comparison between the chemical behaviour of lead-gold and lead-bismuth eutectics towards 316L stainless steel
Radiochimica acta, 101 (10)
Internal geometry and coolant choices for solid high power neutron spallation targets
Abstract The next generation of neutron spallation sources envisages high power proton beam interaction with a heavy metal target. Solid targets have potentially higher spallation efficiency due to the possibility to use metals with higher density than used in liquid metal targets, but to realize this potential the solid fraction must be high enough. As the power released in the form of heat can reach several MW in the target volume of typically 10 l, target cooling can be a serious challenge. Heat evacuation efficiency for different solid fraction geometries at high power is analyzed for different coolant options (helium, water and gallium) using empirical correlations for friction factors…
Interaction of a liquid gallium jet with the tokamak ISTTOK edge plasma
Abstract The interaction of a liquid gallium jet with plasma has been investigated in the tokamak ISTTOK. This paper presents a description of the conceived experimental setup, a detailed characterization of the produced jets and the first experimental results related to the gallium–plasma interaction. A stable jet has been obtained, which was not noticeably affected by magnetic field transients. ISTTOK has been successfully operated with the gallium jet without degradation of the discharge or a significant plasma contamination by liquid metal. This observation is supported by spectroscopic measurements showing that gallium radiation is limited to the region around the jet. Furthermore, the…
Riga experience in spallation neutron target related investigations
Abstract Mercury has awakened interest as a potential material for spallation neutron source targets. Institute of Physics, University of Latvia has a 30 years experience of investigations in mercury. As specially projected building includes a 350 m2 experimental hall. The largest loop, containing 5×103 kg of Hg, can be transferred for solution of different tasks. As the first example results are presented when integral developed pressure and local (distribution of void fraction) characteristics of a two-phase mercury/gas riser were investigated. Second example – investigation of velocity fields and heat transfer conditions close to the beam entrance window in the SINQ target thermohydrauli…
ISTTOK tokamak plasmas influence on a liquid gallium jet dynamic behavior
Abstract The main concern in using free flowing liquid metals in fusion devices is related to their interaction with magnetic fields. On ISTTOK tokamak, liquid gallium jets are injected deep into the plasma along a vertical direction. The influence of the plasma interaction on the jet has been investigated monitoring the liquid metal behavior using a fast frame camera. A radial shift on its trajectory has been detected and found to depend on the toroidal magnetic field magnitude and principally on the plasma position within the chamber. The analysis performed to understand the dynamics of the jet perturbation by the plasma is presented in this paper. The jet surface temperature increase dur…
First Results of the Testing of the Liquid Gallium Jet Limiter Concept for ISTTOK
The use of liquid metals as plasma facing components in tokamaks has recently experienced a renewed interest stimulated by their advantages to the development of a fusion reactor. Liquid metals have been proposed to solve problems related to the erosion and neutronic activation of solid walls submitted to high power loads allowing an efficient heat exhaustion from fusion devices. Presently the most promising materials are Lithium and Gallium. ISTTOK, a small size tokamak, will be used to test the behavior of a liquid Gallium jet in the vacuum chamber and its influence on the plasma. This paper presents a description of the conceived setup as well as experimental results. The liquid Gallium …
Liquid gallium jet–plasma interaction studies in ISTTOK tokamak
Abstract Liquid metals have been pointed out as a suitable solution to solve problems related to the use of solid walls submitted to high power loads allowing, simultaneously, an efficient heat exhaustion process from fusion devices. The most promising candidate materials are lithium and gallium. However, lithium has a short liquid state temperature range when compared with gallium. To explore further this property, ISTTOK tokamak is being used to test the interaction of a free flying liquid gallium jet with the plasma. ISTTOK has been successfully operated with this jet without noticeable discharge degradation and no severe effect on the main plasma parameters or a significant plasma conta…
Experimental setup for analysis of sorption and desorption of tritium in liquid lithium under different external conditions
An original complex device has been designed and created specially for this research. Some of tritium sorption and thermal desorption in liquid lithium experiments has been successfully done already. First experiment series were carried out under reduced pressure (vacuum) to rule out other operating gases (like Ar) that may squeeze out tritium from lithium. Experiments showed good tritium desorption from lithium which highly depends on the temperature. A proportional gas counter tritium monitor was used to collect data from tritium thermal desorption experiments.