Tokamaks and pinches (history, tokamak taxonomy) Gergő Pokol BME NTI Fusion devices 9. March 2020 Gergő Pokol: Tokamaks and pinches 1. Take your mobile phone or laptop 2. WiFi password: wigner2/wigner2008 – or mobilnet 3. Browser: Kahoot.it 4. Code on screen 5. Name: Neptun code !!! 6. Evaluation: – Good answer +1 score – Winner of Kahoot +1 score At the end of semester: normalize with number of questions to get %. 2 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches Provisional program Date Lecturer Topic 10. FebruaryPokol Theory review (fuel flow, magnetic confinement, transport, tokamak, stellarator) Technology review (vacuum, magnetic field, plasma heating, current drive, plasma 17. FebruaryPokol diagnostics) 24. FebruaryVeres Stellarators (history, Wendelstein line, stellarator taxonomy) 2. MarchPokol Wendelstein 7-X stellarator 9. MarchPokol Tokamaks and piches (history, tokamak taxonomy) 16. MarchPokol JET (goals, structure, status) 23. MarchPokol ITER (goals, structure, status) 30. MarchPokol DEMO, Fusion Roadmap 6. AprilPokol Mid-term exam 20. AprilPokol Middle-sized tokamak program 27. AprilPokol Spheromaks, spherical tokamaks, US fusion program 4. MayPokol Far East superconducting tokamaks 11. MayPokol Tokamak simulation exercise 18. MayPokol Final exam 3 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches Pinch effect Pinch effect discovered in 1904 in liquid metals: Radial compressing force in a conductor caused by current. The magnetic field strength: The force balance : Sausage instability Kink instability 4 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches Pinch devices - types Toroidal Z-pinch: high current, high pressure plasma stabilized by a toroidal magnetic field. q-pinch: stable configuration, but problems with ends. Racetrack configuration unstable. (reversed field pinch, RFP) High beta, but unstable configurations! 5 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches Early pinch devices - 1947 UK - Sir G.P. Thomson and P. C. Thonemann - toroidal geometry - ~ cm minor radius - glass vacuum chamber - kink instability ZETA pinch (Sceptre) - Zero Energy Toroidal Assembly -1954 – 1957 - UK - stabilized with toroidal magnetic field - neutrons detected – not thermonuclear fusion! - not continued 6 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches Reversed Field Pinch (RFP) http://www.igi.cnr.it/?q=system/files/rfx_en_0.mpg 7 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches Reversed Field Pinch (RFP) - RFX, Italy - reverse Bt on axis Quasi Single Helicity - dynamo - many modes - active stabilitazion - QSH ~ stellarator 8 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches I.E. Tamm, A.D. Sakharov 9 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches 10 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches 11 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches https://www.youtube.com/watch?v=-wJaFAtCKPc 12 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches tE 1 kT t D B B 16 eB British measurements prove Soviet tokamak results in 1969! 13 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches Thomson scattering today Thomson scattering: light scattering on free charged particles (in practice on electrons) Scattered intensity plasma density Spectrum Electron temperature (Doppler) (e-velocity: 107 m/s) Scattering cross-section is extremely small: possible only with pulsed laser: 1-10 J, few ns, 1 GW!!! - 10-20 Hz Local measurement from crossing of laser and observation. 14 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches 15 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches 16 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches 17 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches 18 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches To be re-opened as T-15MD ? 19 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches Limiter Divertor D-T operation Strong shaping Spherical T 8 Superconducting 20 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches Limiter Divertor D-T operation Strong shaping Spherical T 8 Superconducting 21 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches Sources V.P. Smirnov: Tokamak foundation in USSR/Russia 1950–1990, Nuclear Fusion, 50, 014003 (2010) http://www.igi.pd.cnr.it http://www.tokamak.info/ Robert Arnoux: Which was the first "tokamak" — or was it "tokomag"?, ITER NEWSLINE 55 (2008) L. A, Artsirnovich: Research on Controlled Thermonuclear Reactions in the USSR, Atoms for Peace Geneva Conference (1958) 22 Fusion devices, 9. March 2020 Gergő Pokol: Tokamaks and pinches 1. Take your mobile phone or laptop 2. WiFi password: wigner2/wigner2008 – or mobilnet 3. Browser: Kahoot.it 4. Code on screen 5. Name: Neptun code !!! 6. Evaluation: – Good answer +1 score – Winner of Kahoot +1 score At the end of semester: normalize with number of questions to get %. 23 Fusion devices, 9. March 2020.