T-15MD Tokamak Research Articles

Simulation of an ohmic regime in the T-15MD tokamak based on the canonical profile transport model

mail: nrcki@nrcki.ru The canonical profiles transport model (CPTM), whose coefficients were determined from the T-10 tokamak database with a standard magnetic field BT = 2.3—2.5 T, has shown its robustness in ohmic regimes with a reduced magnetic field BT = 1.55—2.1 T. We used the CPTM for predictions of radial profiles and dependences of the electron and ion temperatures and the energy confinement time on the average plasma density for the T-15MD tokamak at the initial stage of its operation: the ohmic regime in a circular limiter configuration with BT = 1.0—2.0 T and plasma current Ip 1 MA.

Development of a Complex for Materials Science Studies on the T-15MD Tokamak

Development of a Complex for Materials Science Studies on the T-15MD Tokamak

T-15MD Tokamak Microwave Interferometer for Measuring the Average Electron Density of Plasma

T-15MD Tokamak Microwave Interferometer for Measuring the Average Electron Density of Plasma

Simulation of an Ohmic Regime in the T-15MD Tokamak Based on the Canonical Profile Transport Model

Simulation of an Ohmic Regime in the T-15MD Tokamak Based on the Canonical Profile Transport Model

Development of a Software Module for Synthetic Optical Diagnostics of Plasmas in the T-15MD Tokamak and Calculation of Passive Spectroscopy Signals

Development of a Software Module for Synthetic Optical Diagnostics of Plasmas in the T-15MD Tokamak and Calculation of Passive Spectroscopy Signals

Measurement of the Characteristics of Fine-Grained Graphite Used as a Material for the First Wall of the T-15MD Tokamak

Measurement of the Characteristics of Fine-Grained Graphite Used as a Material for the First Wall of the T-15MD Tokamak

Verification of the 3D CAD Model of the T-15MD Tokamak

Verification of the 3D CAD Model of the T-15MD Tokamak

Measurements of the Characteristics of Fine Grain Graphite Used as a First Wall Material for the T-15MD TOKAMAK

Measurements of the Characteristics of Fine Grain Graphite Used as a First Wall Material for the T-15MD TOKAMAK

Assessment of the Effect of Plasma Density Evolution of the T-15MD Tokamak on the Phase and Frequency Shift of the Signals of the Vertical Channel of the Microwave Interferometer

Assessment of the Effect of Plasma Density Evolution of the T-15MD Tokamak on the Phase and Frequency Shift of the Signals of the Vertical Channel of the Microwave Interferometer

Development of a System for Materials Science Studies on the T-15MD Tokamak

One of the main objectives pursued in carrying out materials science studies on the T-15MD tokamak is to insert samples, including large-scale ones, both for their long-term life cycle tests in the near-wall plasma areas and for studying the effect of impulse loads in the divertor section. A conceptual design of a system for carrying out materials science studies on the T-15MD tokamak has been developed at the Department of General Physics and Nuclear Fusion of the National Research University Moscow Power Engineering Institute. The system will open the possibility to carry out unique experiments on studying the state and composition of the divertor and first wall surfaces without the need to disturb the tokamak chamber vacuum and dismantle the components. It will be possible to perform such studies in the time intervals between tokamak pulses, which will make it possible to reveal changes on the divertor surface after each pulse and estimate correlations between the plasma parameters and changes on the first wall surface. In the attachment assembly, means are provided for cooling the mockups with both water flow and dispersed water-air flow. In addition, various diagnostic devices for monitoring the first wall and divertor surfaces can be installed on the attachment assembly.

Simulation of Magnetic Measurements on the T-15MD Tokamak Taking into Account Eddy Currents in the Vacuum Chamber

Simulation of Magnetic Measurements on the T-15MD Tokamak Taking into Account Eddy Currents in the Vacuum Chamber

Possibility of Using the 140 GHz Frequency for ECR Plasma Heating in the T-15MD Tokamak

Possibility of Using the 140 GHz Frequency for ECR Plasma Heating in the T-15MD Tokamak

Optimization of Robust LMI-Control Systems for Unstable Vertical Plasma Position in D-Shaped Tokamak

The paper is devoted to the synthesis, comparison, and optimization of robust LMI-control systems for the vertical plasma position in a D-shaped tokamak, specifically the T-15MD tokamak (Kurchatov Institute, Moscow, Russia). The novelty of this work is to find out the possibilities of LMI robust control systems, according to the criteria of the robust stability radius and control power peak at the rejection of a minor disruption type disturbance and a reference step signal using a unique unstable first-order plasma model. The plant under control consists of the connected in series plasma model with additive disturbance containing plant uncertainties, horizontal field coil (HFC), and actuator model as a multiphase rectifier. A set of robust controllers was designed by Linear Matrix Inequalities (LMI) method with pole placement in the LMI regions, state H2/H∞ performance, and output signal performance. The LMI theorems of the paper are directed to design the robust controllers and study the systems with the aim of eliminating the gap between theory and practice. The main achievement of this work consists in the optimization of robust control systems of the unstable plant with uncertain disturbance on the set of LMI synthesis approaches. The control systems have original quality criteria, such as control power and robust stability radius. The best control system on the basis of two criteria, namely, Dα,r,ϑ control system provides stabilization of the vertical plasma position on the real-time digital control testbed.

Simulation of lithium flow, redeposition, and vapor shielding in liquid lithium divertor of T-15MD tokamak with SOLPS 4.3 code

The erosion module of the SOLPS 4.3 code package for the liquid Li divertor target is developed to include the thermal sputtering, evaporation, and prompt redeposition effects. Eroded Li atoms are treated within a fully kinetic approach. Simulations for the T-15MD tokamak with liquid Li divertor targets are performed for various operational regimes. The main parameters characterizing the divertor operation are identified. The Li shielding effect is found significant at the input power P SOL > 15 MW. The target conditions remain reasonable in terms of both the erosion rate and target temperature but core plasma dilution with Li remains a problem. The Li flow patterns in the scrape-of-layer (SOL) are analyzed in detail. About 80% of eroded Li is redeposited back on the target. The energy dissipated per an eroded Li particle, E sh, is calculated and its values are in the range of 100–200 eV. These values are 2–4 times lower than those obtained from a simple 0D estimation of E sh. Therefore, relying on simple 0D models for the analysis of Li divertor performance may cause an overestimation of the shielding efficiency.

On the Issue of the Possibility of Studying Anomalous Scattering of Microwave Beams of Ordinary Polarization in Plasma of Edge Transport Barrier in the T-15MD Tokamak

On the Issue of the Possibility of Studying Anomalous Scattering of Microwave Beams of Ordinary Polarization in Plasma of Edge Transport Barrier in the T-15MD Tokamak

Design of a phasemeter for real-time measurements of the average plasma density with the microwave interferometer of the tokamak T-15MD

Interferometry is one of the key diagnostics for fusion research. This diagnostic measures electron plasma density. Interferometers that work on an intermediate frequency are widespread nowadays. The phase shift between interferometer signals has to be measured. The use of a microwave interferometer on machines, such as a tokamak, leads to challenging requirements for the phasemeter operation. We present a method to provide real-time measurements of phase shifts with values much higher than 2π. The phasemeter has been designed for the microwave interferometer of the T-15MD tokamak. It is based on microcircuits AD8302. Two signals with frequencies of 5 and 10MHz are used as interferometer outputs. The phasemeter output will be used to create a feedback loop for the working gas injection into the tokamak chamber to control the plasma density. The phasemeter has been successfully tested. The typical phase error and non-linearity of the device are 1° and 5 × 10-4, respectively.

HF-launcher system of the gyrotron set-up of the T-15MD tokamak
 on the first stage operation

HF-launcher system of the gyrotron set-up of the T-15MD tokamak
 on the first stage operation

Comparison Study of Power Supplies in Real-Time Robust Control Systems of Vertical Plasma Position in Tokamak

The article is devoted to a comparative study of VIs (Voltage Inverters) in the RAO (Relay Auto-Oscillatory) mode and in the multilevel PWM (Pulse Width Modulation) mode as actuators in closed-loop control systems of vertical plasma motion in the T-15MD tokamak. The new digital multilevel PWM controller was developed. Both systems were put under equivalent conditions in terms of the same response to external signals. The discrete robust controller is single for both control systems and has been designed by LMI (Linear Matrix Inequalities) approach using the LPV (Linear Parameter Varying) plant model. The main criteria for comparison are the control power and signal spectrum on the HFC (Horizontal Field Coil). The simulations were performed on the real-time test bed consisting of two real-time target machines connected in a feedback loop “Plant Model – Controller”, to basically bring the system as close to reality as possible. The comparison results have showed the significant superiority of the 9-level PWM VI over the VI in RAO mode according to the selected criteria.

Calculations of Settings in the Protection and Blocking Circuits of the Power Supply System of Electromagnetic Windings and the Duration of Plasma Discharges in T-15MD Tokamak

Calculations of Settings in the Protection and Blocking Circuits of the Power Supply System of Electromagnetic Windings and the Duration of Plasma Discharges in T-15MD Tokamak

Analysis of the Possibility of Measuring the Electron Plasma Density of the T-15MD Tokamak by Probing with Electromagnetic Waves of the Submillimeter Range

Analysis of the Possibility of Measuring the Electron Plasma Density of the T-15MD Tokamak by Probing with Electromagnetic Waves of the Submillimeter Range