N.A. Kirneva, I.O. Anashkin, E.R. Akhmedov, S.V. Akhtyrskij, V.F. Andreev, I.I. Arkhipov, G.M. Asadulin, A.Yu. Balashov, E.E. Barkalov, K.E. Barkalov, A.M. Belov, E.N. Bondarchuk(a), A.A. Borschegovskij, V.P. Budaev, P.Yu. Chistyakov, A.I. Chudesnov, A.V. Gorbunov, A.V. Gorshkov, S.A. Grashin, A.I. Gubanova, E.D. Dlugach, M.M. Dremin, A.S. Drozd, A.Ph. Dubinitskij, L.G. Eliseev, A.V. Evseev, A.D. Izarova, Yu.V. Kapustin, A.V. Karpov, N.V. Kasyanova, R.R. Khajrutdinov, A.V. Khramenkov, A.P. Khvostenko, P.P. Khvostenko, D.A. Kislov, A.E. Konkov, P.S. Korenev, V.A. Krupin, A.Yu. Kuyanov, I.V. Levin, V.E. Lukash, A.V. Lutchenko, V.V. Lukyanov, A.V. Melnikov, A.B. Mineev(a), D.S. Molchanov, N.A. Mustafin, T.B. Myalton, K.O. Nedbajlov, A.R. Nemets, S.V. Neudatchin, G.E. Notkin, V.N. Novikov, I.S. Obraztsov, A.A. Panasenkov, D.S. Panfilov, I.S. Pimenov, A.S. Rzhevskij, K.A. Rogozin, A.N. Romannikov, I.N. Roy, D.V. Ryzhakov, G.A. Sarancha, D.V. Sarychev, P.V. Savrukhin, D.S. Sergeev, D.A. Shelukhin, E.A. Shestakov, V.V. Smirnov, N.A. Solovjev, A.V. Sushkov, D.Yu. Sychugov, K.N. Tarasyan, V.I. Tepikin, Yu.I. Tolpegina, D.L. Ulasevich, V.A. Vershkov, I.A. Zemtsov NRC “Kurchatov Institute”, Moscow, Russian Federation (a) JSC NIIEFA, St. Petersburg, Russian Federation Contact: [email protected] ID: 3142 Further development of fusion research and fusion energy in the Russian Federation is associated with two areas: the fusion power plant (DEMO) and hybrid fusion-fission systems based on the tokamak as a neutron source (FNS). The goal of the scientific research on the T-15MD tokamak [1] is to establish the scientific basis in support of the creation of steady-state FNS as well as research activity in support of the ITER project. T-15MD research program will be aimed at solving of modern physical and engineering problems of tokamaks [2]: - Noninductive scenario development, transport physics, MHD stability and control, plasma-wall interaction and divertor physics, physics of heating and CD, development of diagnostics etc.; - Design of heating and CD systems, fuelling systems, development of first wall technologies, analysis of safety problem, development of remote handling systems etc. Project Parameters: - Major radius R0 = 1.48 m - Minor radius a = 0.67 m - Aspect ratio A = 2.2 - Elongation k = 1.8 - Triangularity δ = 0.4 - Plasma current Ip = 2 MA - Toroidal field BT = 2 T - Working gas: H - Pulse duration: 10…30 s Milestones: - 31.03.2023: First plasma - Experimental campaigns: 2023 spring & autumn; 2024 autumn; 2025 spring ECRH/ECCD: - Total power 8 MW - 5 MW gyrotrons on site: 3 (82.6 GHz) + 2 (105 GHz) (2 gyrotrons under operation) - 3 MW gyrotrons – development - Individual evacuated waveguides, Steerable mirrors ICRH: - 6 MW, 15-60 MHz (Under development) LHCD: - 4 MW, 2.45 GHz PAM (Under development) NBI: - Total power 6 MW, H beam Eb = 20-60 keV, φT ~ 27°, Rt ~ 1.3 m - 2 ion sources in each injector (Under construction) T-15MD tokamak diagnostics will be represented by more than 50 systems that allow measuring the plasma discharge parameters, as well as monitoring the state of technological systems. The set of diagnostics will include traditional systems and innovative ones designed to ensure plasma discharge control and control of facility state, measurement of basic parameters of plasma and an advanced set of characteristics. In Operation: - Rogowskij coils - Poloidal Flux coils - Two-component magnetic probes - Loop voltage sensors - High-Res Visible Light Diagnostics - Pyroelectric bolometers - AXUV detectors - mm-wave interferometer (1 ch.) - Thomson scattering – tang. view - Multichannel SXR spectrometer - Visible Light Plasma Emission - Bremsstrahlung and linear emission - Diagnostics of plasma line emission spectra - SXR monitor - HXR monitor - HXR spectrometer - n0 emission monitor - Automatic radiation monitoring system - Fast cameras in visible light - Vacuummetry - Vacuum vessel temperature control - Water cooling monitoring system - Fault indication system - Mass-spectrometry Commissioning: - Diamagnetic coils - Mirnov coils - Divertor Langmuir probes - CXRS - Neutral particle analyser Development: - Fiber-optics current sensor - Saddle coils - Heavy Ion Beam Probe - MSE diagnostic - Heterodyne CO2 laser interferometer - Two-color fiber laser interferometer - Sweeping (FMCW) reflectometry - Correlation reflectometry - Doppler reflectometry - Helium beam spectroscopy - Thomson scattering – vert. view - Divertor Thomson Scattering - ECE - Laser induced quenching Planned: - Fast movable magnetic probe - BES - Fast reciprocating Langmuir probe - Diagnostics of ion temperature fluctuations on the heating beam - X-ray crystalline monochromator - Fast Ion diagnostics - Diagnostics of transient SXR disturbances - Suprathermal XR tomography - n0 emission tomography - n0 emission spectrometer - Fast cameras in IR light - Materials Science Station - Diagnostics of vibrations and deformations of tokamak components FIG. 1. Increasing the plasma current in experimental campaigns on the T-15MD tokamak (a); high current discharges on the operational diagram (b). • Plasma current up to 0.6 MA is reached after 2 years of experiments. • Simulations made using SCENPLINT code [3] for T-15MD shot #3089 showed that the current is carried by thermal plasmas. FIG. 2. Shot #3452. Visible light image of the plasma cross section with the formed divertor configuration, t=1293 ms (a), traces of the plasma parameters (b)-(d) and (e) - the radiation loss power measured using AXUV detectors along two observation chords (shown by arrows in Fig. (a)); (f) - plasma equilibrium restored by dBound code [4]. The instant of the divertor configuration formation tdiv is shown by the vertical dotted line. • First discharges with divertor configuration formation were obtained at Ip > 0.38 MA and k > 1.5. Transition to the divertor configuration was registered by visible light imaging, AXUV, bolometers and Langmuir probes and was confirmed by equilibrium codes. FIG. 3. Shot #3452. Electron temperature (a) and density (b) profiles from Thomson scattering. • Density and temperature profiles correspond to L-mode in both limiter and divertor configuration. • Energy confinement time estimated as τE = WEe / (POH + PEC) is in agreement with ITER L-mode scaling ITER-89P. FIG. 4. EC assisted start-up. Left: traces of the Hb (a), Ip (b), current in the CS2 section of solenoid (c) for T-15MD shots #3440 and #3441. Right: vertical component of poloidal magnetic field, BZ (in Gauss) at t = 200 ms: d) – shot #3440; e) – shot #3441. Position of the 2ωce resonance layer is shown by vertical red line (R=1.2 m). • T-15MD discharges were initiated using EC preionization. • Optimization of magnetic configuration made it possible to get EC assisted plasma start-up in a wide range of PEC = 0.47-0.9 MW. The value of initial current depends on the BZ value and was found to be independent on toroidal launch angles (observed in a whole range from φT = 0° to φT = 18°). • Dependence of IBZ on magnetic configuration, pinit, PEC etc. and its effect on discharge development are under investigation. • Plasma discharges with the current up to 0.6 MA have been obtained in T-15MD tokamak with ECR assisted start-up. The first discharges with divertor configuration were produced. • Development of the heating systems and diagnostics continues. • Upcoming work at the T-15MD facility will be focused on developing discharge scenarios with a divertor configuration, ECRH power increase (up to 5 MW), commissioning of the first neutral beam injector, and expanding the range of physical research. The work was supported by the National Research Center “Kurchatov Institute” under the State Assignment. [1] Khvostenko, P.P., Anashkin, I.O., Bondarchuk, E.N., et al., Phys. of Atomic Nucl. 83 7 (2020) 1037-1057. [2] Velikhov, E.P., Kovalchuk, M.V., Anashkin, I.O., et al., Physical research program on the T-15MD tokamak, Prob. of Atomic Science and Techn., ser. «Thermonuclear Fusion» 47 4 (2024) 9-183 (in Russian). [3] de Vries, P.C., Mineev, A.B., et al, Nucl. Fusion 65 5 (2025) 056001. [4] Ulasevich, D., et al, Submitted to Plasma Phys. Reports, 2025.