Analytical solution of tokamak vibrations during axisymmetric plasma disruptions

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F22%3A00555331" target="_blank" >RIV/61389021:_____/22:00555331 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0920379621007729?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0920379621007729?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.fusengdes.2021.112997" target="_blank" >10.1016/j.fusengdes.2021.112997</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Analytical solution of tokamak vibrations during axisymmetric plasma disruptions

Popis výsledku v původním jazyce

Tokamaks are structures containing a massive supporting structure housing a vacuum vessel with hot plasma. Due to the vacuum vessel heating and temperatures up to 500 ⁰C as for the COMPASS-U, flexible connections need to be used between the main support and the vacuum vessel to accommodate the thermal expansion. Large electromagnetic forces are generated during plasma disruption events, such as Vertical Displacement Events (VDE), inside the vacuum vessel and in the coil system: Central Solenoid (CS), Poloidal Field (PF) coils and Toroidal Field (TF) coils directly attached to the support. In the present paper a parametric analytical model of tokamak vibrations due to axisymmetric plasma disruptions was presented, allowing predictions of the vacuum vessels and the main tokamak structure displacements, velocities and accelerations as well as the dynamic forces transmitted to the foundations. A tokamak was modelled as a 2 DOF dynamic system, including the mass of the main support and the vacuum vessel and the axial stiffnesses and damping values of their supports. A close-form analytical solution was found assuming proportional (Rayleigh) damping for the most general shape of the force functions – described with a series of piecewise linear functions. The electromagnetic forces during axisymmetric VDE were derived from a dedicated 3D model. Detailed solution for the most recent design of the COMPASS-U tokamak was presented, as well as a number of parametric studies checking the sensitivity to the design parameters. The conditions at which large part of the electromagnetic force is transmitted to the concrete foundations were identified. The accuracy of the derived analytical solution was verified with direct numerical integration of the equations of motion.

Název v anglickém jazyce

Analytical solution of tokamak vibrations during axisymmetric plasma disruptions

Popis výsledku anglicky

Tokamaks are structures containing a massive supporting structure housing a vacuum vessel with hot plasma. Due to the vacuum vessel heating and temperatures up to 500 ⁰C as for the COMPASS-U, flexible connections need to be used between the main support and the vacuum vessel to accommodate the thermal expansion. Large electromagnetic forces are generated during plasma disruption events, such as Vertical Displacement Events (VDE), inside the vacuum vessel and in the coil system: Central Solenoid (CS), Poloidal Field (PF) coils and Toroidal Field (TF) coils directly attached to the support. In the present paper a parametric analytical model of tokamak vibrations due to axisymmetric plasma disruptions was presented, allowing predictions of the vacuum vessels and the main tokamak structure displacements, velocities and accelerations as well as the dynamic forces transmitted to the foundations. A tokamak was modelled as a 2 DOF dynamic system, including the mass of the main support and the vacuum vessel and the axial stiffnesses and damping values of their supports. A close-form analytical solution was found assuming proportional (Rayleigh) damping for the most general shape of the force functions – described with a series of piecewise linear functions. The electromagnetic forces during axisymmetric VDE were derived from a dedicated 3D model. Detailed solution for the most recent design of the COMPASS-U tokamak was presented, as well as a number of parametric studies checking the sensitivity to the design parameters. The conditions at which large part of the electromagnetic force is transmitted to the concrete foundations were identified. The accuracy of the derived analytical solution was verified with direct numerical integration of the equations of motion.

Druh

J_SC - Článek v periodiku v databázi SCOPUS

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

<a href="/cs/project/EF16_019%2F0000768" target="_blank" >EF16_019/0000768: COMPASS-U: Tokamak pro špičkový výzkum jaderné fúze</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Fusion Engineering and Design

ISSN

0920-3796

e-ISSN

1873-7196

Svazek periodika

174

Číslo periodika v rámci svazku

January

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

22

Strana od-do

112997

Kód UT WoS článku

—

EID výsledku v databázi Scopus

2-s2.0-85122633313