Investigation of plasma start-up at Golem
Supervisor
- Name: Jan Stockel
- Contact: stockel@ipp.cas.cz
Introduction
Optimization of the start-up phase of the discharge is an essential issue for any tokamak including ITER. The GOLEM tokamak is very suitable experiment to study underlying physics of plasma formations, because of its flexibility, sufficient amount of required diagnostics, and relatively high cadency of discharges. This makes possible to perform a systematic scan of discharge parameters and get enough data in a relatively short time available during GOMTRAIC.
Task description
Our plan is as follows:
We fix the pressure of the working gas (hydrogen) in the tokamak vessel to p = 6-10 mPa, which is according our previous experience the optimum value for an efficient plasma breakdown.
We fix the value of the toroidal magnetic field at the moment when the toroidal electric field (the loop voltage) is applied.
We perform the scan of the charging voltage of the condenser bank for powering of primary winding of the GOLEM transformer in the range U CD = 300 – 800 V, with the step 50 V.
In total, 11 discharges will be executed, which can be done during one afternoon session. The remaining time, data analysis will be performed and impact of the UCD scan on plasma performance will be studied. We will focus on resulting discharge duration, maximum plasma current achieved, the breakdown voltage, the amount of runaway electron generation, e.c.t.
Requirements
Experimental data will be processed by software available on PCs of GOMTRAIC participants, such as Python, or Origin.
