ADITYA TOKAMAK



Aditya being upgraded to include divertors


  INTRODUCTION


ADITYA is the first indigenously designed and built tokamak of the country. It was commissioned in 1989. ADITYA, a medium size Tokamak, is being operated for over a decade. It has a major radius of 0.75m and minor radius of the plasma is 0.25 m. A maximum of 1.2 T toroidal magnetic field is generated with the help of 20 toroidal field coils spaced symmetrically in the toroidal direction. The major subsystems and parameters of the machine have been described elsewhere.

ADITYA is regularly being operated with the transformer-converter power system. ~100 msec 80 - 100 kA plasma discharges at toroidal field of 8.0 kG are being regularly studied. During this period experiments on edge plasma fluctuations, turbulence and other related works have been conducted. Standard diagnostics have been employed during these measurements. Figure below gives a view of ADITYA with the auxiliary heating systems attached to it.



ADITYA has been upgraded. Upgradation has been in different fronts. Vacuum system has been upgraded interms of more cleaning facilities. As found earlier, successful breakdown and startup require compensation of the error magnetic fields in the first few milliseconds. This is accomplished using the four fast feedback coils connected to give a radial magnetic field. Recent measurements of the magnetic fields due to the TR coils and BV coils also indicate the need for compensation of the error fields. The compensation also helped in improving the operating pressure range, which has the beneficial effect of reducing hard x-rays during the discharge. Plasma current feedback on the loop voltage and vertical field also is implemented.

Some more diagnostics have been integrated and made on-line. Some are in the design/fabrication phase. To increase the plasma energy content during the discharge, auxiliary heating systems have been integrated. A 20 - 40 MHz, 200 KW Ion Cyclotron Resonance Heating (ICRH) system has been integrated to ADITYA vacuum vessel and successfully operated in the last campaign. A 28 GHz, 200 KW gyrotron based electron cyclotron resonance heating (ECRH) system has also been successfully commissioned on ADITYA tokamak. Some neural network analysis to predict disruptions and density limit on ADITYA have also been performed.

 


                                                            Parameters of ADITYA                                                           TOP

TOP

  Main sytems of ADITYA


  • Data Acquisition and Control system.


  • Pulsed Power System


  • Fast Feedback Position Control System


  • Magnetic Field Coils System


  • Vacuum system


  • Fuelling (gas pre-fill and gas-puff system)


  • Discharge Cleaning Systems


  • Electron Cyclotron Resonance


  • Ion Cyclotron Resonance


  • Lower Hybride Current Drive



                                                                 DIAGNOSTICS                                                               TOP

1. MAGNETIC DIAGNOSTICS


  • Rogowski Coils

  • Magnetic Probes

  • Loop Volatge

  • Diamagnetic Loop


2. MICROWAVE DIGNOSTICS


  • Inerferometry
  • Reflectometry
  • Electron Cyclotron Emission

3. SPECTROSCOPY


  • UV(NIM, GIM)
  • Visible(Photo Diode Array,Multi-track spectrometer filters)

4. X-RAY DIAGNOSTICS


  • Hard X-Ray
  • Soft X-Ray Tomography

5. LASER DIAGNOSTICS


  • Thomson Scattering
  • Laser Blow-Off
  • Lithium beam oven

6. ELECTRICAL PROBES


  • Langmuir Probes
  • Mach Probes

7. OTHER DIAGNOSTIC SYSTEMS