Commissioning

Interesting data were acquired by osciloscope B.

1. Signla from puff generator
2. amplified signal (voltage on a valve)
3. pressure by vacuum gauge
4. trigger

Firstly, we searched for a suitable tokamak mode. We had problems with U_loop signal mixed in pressure signal. Our prefered mode was with CD delayed.

• U_bt = 1300 V
• U_cd = 600 V, 20 ms delayed

With this delay, the plasma started when the toroidal magnetic field reached its maximum. Plasma instabilities in later phase of a discharge occured, probably due to fading toroidal magnetic field.

Control shot of our configuration: [http://golem.fjfi.cvut.cz/shots/29977//]

For our initial experimints, we used single puff pulse: 5 ms long, amplitude over 70 V triggered at 20 ms.

Shot without the puff http://golem.fjfi.cvut.cz/shots/29984// Shot with the puff [http://golem.fjfi.cvut.cz/shots/29986//]

By optical comparison of these shots we see, that was the plasma was affected by the puff.