| Popis: |
On the TdeV tokamak, a microwave probe diagnostic enables direct electromagnetic field measurements at the grill mouth of the LHCD multijunction antenna. On the upper row, 10 reduced waveguides out of 32 are instrumented to measure the amplitude and phase of the incident and reflected fields. These measurements have been compared to the predictions of the antenna coupling code SWAN, over a wide range of operating conditions. At low LH power (⩽10 MW/m2) the agreement between the code predictions and the measurements is good, confirming that a high quality spectrum is launched by the antenna as predicted by the code. In the power regime of interest for LHCD experiments (⩾25 MW/m2) systematic discrepancies between measured and calculated fields are observed. However, Fourier analysis indicates that the field spectrum at the antenna mouth is not significantly degraded. |
