Control and data acquisition system for SCR-1 Stellarator

Transcription

1 Control and data acquisition system for SCR-1 Stellarator J. Asenjo 1, V.I. Vargas 1 and J. Mora 1, 1 Instituto Tecnológico de Costa Rica, Cartago, 30101, Costa Rica May 8, 2017

2 Agenda SCR-1 Overview SCR-1 Subsystems Platform for Tests, Measurement, and Control Development stages Subsystems validation Application development First SCR-1 plasma Discharge Conclusions

3 SCR-1 Overview Costa Rica A small modular Stellarator was designed, constructed and implemented at the Instituto Tecnolo gico de Costa Rica with the main goal of providing a tool to carry out engineering and physics research of small size confinement magnetic devices

4 SCR-1 Overview Main parameters and other characteristics: Stellarator of Costa Rica 1 2-field period modular stellarator Major radius R= mm Aspect ratio = 6.2 Low shear configuration ι o =0.312 and ι a = T6 aluminium vacuum vessel ECH power 5 kw (2.45 GHz), second harmonic (B = 43.8 mt), B = mt 12 modular coils with 6 turns each 725 A per turn, providing a total toroidal field (TF) current of 4.35 ka-turn per coil The coils will be supplied by a bank of cell batteries of 120 V Plasma pulse between 4 s to 10 s

5 SCR-1 Overview 3D model of the Stellarator of Costa Rica 1 with all the subsystems

6 SCR-1 Subsystems Vacuum Baking bomb Turbo bomb Pressure sensors Vent valve Gate valve 1. Vacuum 2. Gas injection 3. ECHR 4. Confinement 5. Diagnostics SCR-1 Gas Injection ECHR Confinement MFC MFC controller Gas line Solenoid valve Magnetrons Insulators Directional coupling Chiller Current regulator Temperature sensors in coils Relay switch Current sensor Diagnostics Optical spectrometer Langmuir's probe Heterodyne interferometer High speed camera

7 Platform for TMC Vacuum Gas Injection Confinement ECHR Diagnostics

8 Platform for TMC National Instruments PXIe platform NI_PXIe GHz Quad-Core PXI Express Controller NI-PXI Sourse Bank-Isolated PXI Digital I/O ModuleNI-PXI-8430 NI-PXIe AI (16-Bit, 2 MS/s), 4 AO, 48 DIO, PXI Multifunction I/O Module NI-PXI-8430 High-performance interface for highspeed communication with RS232 devices SCR-1 control station

9 Development stages Assembly & Manual testing 1. Assembly of subsystems 2. Manual testing 3. Development of operation protocols Validation Application development 1. Connection to control modules 2. Automatic testing 3. Validation of subsystems 4. Development of control algorithms 1. Integration of all subsystems and control algorithms 2. GUI development 3. Data acquisition and control tests First SCR-1 Plasma

10 Subsystems validation: Vacuum SCR-1 Vacuum diagram Vacuum start sequence Vacuum stop sequence

11 Subsystems validation: Vacuum Pressure at SCR-1

12 Subsystems validation: Gas injection Gas injection sequence SCR-1 Gas injection diagram MFC PR9000B MFC Controller

13 Flow/Setpoint [SCCM Ar ] Presure [Torr] Subsystems validation: Gas injection Set-Point Flow Pressure Time [s] 1.40E E E E E E E E+00 Set-Point, flow and pressure signal during gas pulse at SCR-1

14 Subsystems validation: Gas injection ( 1.2s) G(s) = e s Experimental model for gas injection at SCR-1

15 Subsystems validation: ECRH SCR-1 ECRH diagram ECRH sequence

16 Power [W] Subsystems validation: ECRH Power ECHR P.Forward P.Reflected Potencia P.Absorbed Time [s] ECR Microwave Power at 2.45 GHz ECR Microwave Signals

17 Subsystems validation: Confinement Alternative electric current regulator for the SCR-1 Confinement sequence

18 Current [A] Subsystems validation: Confinement 1000 Current at the coils of SCR Electric current curve on SCR-1 modular coils Time [s]

19 Application Development Signal hierarchy for trigger sequence Process Variables to Control Vacuum generation Base Pressure [Torr] Gas injection Flow [SCCM] Connection time Disconnection time Confinement Connection time Disconnection time Current Set-Point ECRH Power [W] Connection time Disconnection time Diagnostics Trigger Signal Signal hierarchy

20 Several units and scales Activation signals of the Dìwö control system GAS ECRH CONFINEMENT DIAGNOSTICS Time [ms] Figure. Activation signals hierarchy for the SCR-1 operation subprocesses

21 Sequence for plasma generation at SCR -1

22 Application Development Vacuum generation Start Driver verification Status reading Acquisition Execute Start/Stop Plasma discharge sequence

23 Application Development Programming Structure Data flow Timing Execution management

24 Application Development Test: Sequence for plasma generation Thread Execution time [ms] Average iteration time[ms] Security Data acquisition Gas injection CHD

25 Application Development: GUI Graphic interface examples

26 Application Development: GUI Graphic interface examples

27 First SCR-1 plasma Discharge First Plasma

28 Several units and scales Plasma discharge #2 1.4 ECRH CONFINEMENT GAS DIAGNOSTICS Time [ms] Experimental signals at SCR-1 operation

29 Conclusions Verification and tuning of all subsystems Automation of the SCR-1 startup stage and plasma trigger sequence Development of the operational protocol Acquisition of signals First approach for a control an data acquisition system for SCR-1 Generation of the first discharge and subsequent tests

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32 Diagnostics, optical spectrometer