Alfvén wave heating and runaway discharges in the TCABR tokamak

Recent results of experiments on Alfvén wave heating and runaway discharges carried out in the TCABR tokamak are presented. A new antenna type has been installed to allow wave excitation with higher RF currents and lower dynamic polarization of the antenna straps than for the one previously used. In spite of edge plasma heating, which causes influx of impurities, we have obtained a clear confirmation of wave deposition inside the plasma from a localized increase of the electron temperature measured with the ECE radiometer. Detailed profiles of the plasma density and Ha emission were obtained in runaway disharges with currents around 100 kA. These profiles confirm our model of a low-temperature plasma maintained in equilibrium by the relativistic electron beam. Analysis of the Ha and density spikes indicate that recombination plays a substantial role in the particle and energy balance

Multipoint Thomson Scattering Diagnostic For The Tcabr Tokamak With Centimeter Spatial Resolution

This paper describes a multiapoint Thomson scattering system that is being developed for the TCABR tokamak based on a signal delay technique, which allows the determination of the electron temperature and plasma density radial profiles, with approximately 1 cm spatial resolution, employing just one spectrometer. © 2008 American Institute of Physics.996192198Bellintani Jr., V., Overview of recent results of TCABR (2006) AIP Conference Proceedings, 875, p. 350Alonso, M.P., Wilcock, P.D., Varandas, C.A.F., (1999) Rev. Sci. Instrum., 70, p. 783Bemi, L.A., Alonso, M.P., Oliveira, R.M., (2004) Rev. Sci. Instrum., 75, p. 3884Desilva, W., The evolution of light scattering as a plasma diagnostic (2000) Contrib. Plasma Phys., 40, pp. 23-35Sheffield, J., (1975) Plasma Scattering of Electromagnetic Radiation", , Academic Press Londo

Error Analysis In The Electron Temperature Measurements In Tcabr

An analytical method is proposed to evaluate the experimental uncertainty in the electron temperature measurements in the TCABR tokamak. Solving the integral equation resulting from the convolution of two functions, one representing, the scattered light and the other the spectral apparatus function, i.e., the polychromator, an analytical expression for the electron temperature is obtained, from which the uncertainty in the measured value is readily evaluated. The results show that the major contribution to the error comes from the noise in the signal; the uncertainties in the filters parameters do not contribute significantly to the total error.3701 Instituto de Fisica del Plasma (INFIP),Cons. Nac. Invest. Cient. Tec. (CONICET),Comision Nacional de Energia Atomica (CNEA),Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT),Centro Latino-Americano de Fisica (CLAF)Ruchko, L.F., (2002) Braz. J. Phys., 32 (1), pp. 57-64Nascimento, I.C., (2005) Nucl. Fusion, 45, p. 796Nascimento, I.C., (2007) Nucl. Fusion, 47, p. 1570Severo, J.H.F., Tsypin, V.S., Galvão, R.M.O., Nascimento, I.C., Tendler, M., Fagundes, A.N., (2002) Braz. J. Phys, 32 (1), pp. 13-19Severo, J.H.F., Nascimento, I.C., Tsypin, V.S., Galvão, R.M.O., (2003) Nucl. Fusion, 43, pp. 1047-1056Severo, J.H.F., (2009) Nucl. Fusion, 49, p. 115026Severo, J.H.F., Nascimento, I.C., Tsypin, V.S., Kuznetov, Yu.K., Saettone, E.A., Vannucci, A., Galvão, R.M.O., Mikhailovskii, A.B., (2004) Phys. Plasma, 11 (2), pp. 846-848Alonso, M.P., Figueiredo, A.C.A., Borges, F.O., Elizondo, J.I., Galvão, R.M.O., Severo, J.H.F., Usuriaga, O.C., Machida, M., (2010) Rev. Sci. Inst., 81, pp. 10D529Severo, J.H.F., Nascimento, I.C., Kuznetov, Yu.K., Tsypin, V.S., Galvão, R.M.O., Tendler, M., (2007) Rev. Sci Inst., 78, p. 043509Alonso, M.P., (2010) J. Phys.: Conf. Series, 227, p. 012027Forrest, M.J., Peacock, N.J., Robinson, D.C., Sannikov, V.V., Wilcock, P.D., (1970) Culham Plasma Physics Laboratory Report CLM-R 107, , AbingdonAnashin, A.M., Gorbunov, E.P., Ivanov, D.P., Lysenko, S.E., Peacock, N.J., Robinson, D.C., Sannikov, V.V., Strelkov, V.S., (1971) Sov. Phys. - JETP, 33, p. 1127Rautian, S.G., (1958) Sov. Phys. Uspekhi, 66 (1), p. 245Alonso, M.P., Figueiredo, A.C.A., Berni, L.A., Varandas, C.A.F., (2008) IEEE Trans. Plasma Sci., 36 (4), p. 1094Sheffield, J., (1975) Plasma Scattering of Electromagnetic Radiation, , New York: Academic pres