Low- and high-power measurements on a remote steering upper port launcher mockup for ITER

• Published in: 2005 Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics Vol. 2; pp. 425 - 426 vol. 2
• Main Authors: Bongers, W.A., Graswinckel, M.F., Fernandez, A., Bruschi, A., Elzendoorn, B.S.Q., Heidinger, R., Schwoerer, K., Kruyt, O.G., Lamers, B., Lammerts, R., Piosczyk, B., Ronden, D.M.S., Rugebregt, M.R., Verhoeven, A.G.A.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 2005
• Subjects: Antenna measurements; Corrugated surfaces; Manufacturing; Particle beams; Plasma materials processing; Plasma sources; Plasma waves; Plugs; Testing; Vacuum systems
• ISBN: 9780780393486; 0780393481
• ISSN: 2162-2027
• DOI: 10.1109/ICIMW.2005.1572594

The Euratom association FOM-Rijnhuizen is developing a plug-in 170 GHz ECW launcher system for use in the upper-ports of ITER, based on the remote steering (RS) principle, designed to stabilise the neoclassical tearing modes (NTM) at the q=3/2 and q=2/1 surfaces by inducing off-axis current drive. The launching system enables up to eight mm-wave beams per port plug to be directed from the feeding waveguides through corrugated square waveguides (/spl ap/ 44/spl times/44 mm/sup 2/) inside the port plug to the plasma. A mock-up system has been manufactured, capable of vacuum & high-power short-pulse operation. The transmission line consists of a taper, to launch an HE/sub 11/ mode in 63.5 mm circular corrugated waveguide. (The taper will be replaced by a gyrotron source in high power testing). The circular waveguide is used as input for the steering mechanism, housed in a vacuum vessel, which directs the beam under an angle between -12/spl deg/ and 12/spl deg/ through the CVD diamond window into the copper square corrugated waveguide. Antenna patterns from the exit aperture of the square waveguide are scanned using a 3-axis scanner. Low-power measurements (Takahashi et al., 2003) are a preparatory phase for high-power tests, currently prepared in FZK. In the low-power measurements, waveguide performance will be inferred from antenna pattern measurements. Of interest are slight differences in beam parameters (angle, waist etc.) relative to the input beam.