论文信息 - Dielectric losses in CVD diamonds in the millimeter-wave range at temperatures 300–900 K

Dielectric losses in CVD diamonds in the millimeter-wave range at temperatures 300–900 K

We study losses in different CVD diamonds in the frequency range 50–210 GHz at temperatures 300– 900 K by using a high-Q open Fabry-Perot cavity. It is found that the effective activation energies determining a sharp increase in losses at high temperatures are distributed in the range 0.4–0.8 eV. We propose a formula which relates the frequency and temperature dependences of losses for different CVD-diamond specimens in the first approximation. Suggestions on the nature of these losses are put forward.

[1] A. Maradudin,et al. Theory of dielectrics , 1949 .

[2] A. G. Litvak,et al. Megawatt Gyrotrons for ECR Heating and Current-Drive Systems in Controlled-Fusion Facilities , 2003 .

[3] S. N. Vlasov,et al. The absorption investigation in CVD-diamond plates and windows at 50-200 GHz , 2002 .

[4] Igor I. Vlasov,et al. Large-area diamond deposition by microwave plasma , 1997 .

[5] Manfred Thumm,et al. MW gyrotron development for fusion plasma applications , 2003 .

[6] B. M. Garin,et al. Nature of millimeter wave losses in low loss CVD diamonds , 2003 .

[7] S. N. Vlasov,et al. Open resonators for low dielectric loss measurements , 2002 .

[8] V. V. Parshin,et al. A method to measure dielectric parameters in 5–0.5 millimeter wavelength band , 1992 .

[9] V. Konov,et al. Losses in diamond in the millimeter range , 1999 .

[10] Modern Millimeter-Wave Resonator Spectroscopy of Broad Lines , 2000 .