TY - GEN
T1 - Calculation and measurement of higher order mode losses in ITER ECH transmission lines
AU - Kowalski, Elizabeth J.
AU - Tax, David S.
AU - Shapiro, Michael A.
AU - Sirigiri, Jagadishwar R.
AU - Temkin, Richard J.
AU - Woskov, Paul P.
AU - Bigelow, Timothy S.
AU - Rasmussen, David A.
PY - 2009
Y1 - 2009
N2 - The ITER transmission lines (TLs) must be designed to deliver 20 MW from a 24 MW, 170 GHz gyrotron system. Miter bends are the main source of loss for these highly overmoded, corrugated, cylindrical waveguide TLs. Previous estimates have used only a pure HE11 mode for the analysis of the loss due to a miter bend, however higher order modes (HOMs) must be considered for a practical analysis. For the linearly-polarized, Gaussian-like beam from a gyrotron, the LPmn mode basis set should be used to describe the fields in the corrugated waveguide. The HOM content greatly affects the propagation of HE11 content in a miter bend, with a large emphasis placed on the percentage of HOMs and the phase difference between HE 11 and each HOM. By considering LP modes, a complete basis set is used to investigate the HOM effects on HE11 loss in a miter bend. We also present a new conservation theorem relating the power centroid offset and propagation angle due to any two LPmn modes propagating in the corrugated waveguide.
AB - The ITER transmission lines (TLs) must be designed to deliver 20 MW from a 24 MW, 170 GHz gyrotron system. Miter bends are the main source of loss for these highly overmoded, corrugated, cylindrical waveguide TLs. Previous estimates have used only a pure HE11 mode for the analysis of the loss due to a miter bend, however higher order modes (HOMs) must be considered for a practical analysis. For the linearly-polarized, Gaussian-like beam from a gyrotron, the LPmn mode basis set should be used to describe the fields in the corrugated waveguide. The HOM content greatly affects the propagation of HE11 content in a miter bend, with a large emphasis placed on the percentage of HOMs and the phase difference between HE 11 and each HOM. By considering LP modes, a complete basis set is used to investigate the HOM effects on HE11 loss in a miter bend. We also present a new conservation theorem relating the power centroid offset and propagation angle due to any two LPmn modes propagating in the corrugated waveguide.
UR - http://www.scopus.com/inward/record.url?scp=72749104621&partnerID=8YFLogxK
U2 - 10.1109/ICIMW.2009.5324643
DO - 10.1109/ICIMW.2009.5324643
M3 - Conference contribution
AN - SCOPUS:72749104621
SN - 9781424454174
T3 - 34th International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz 2009
BT - 34th International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz 2009
T2 - 34th International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz 2009
Y2 - 21 September 2009 through 25 September 2009
ER -
