VUV spectral line emission measurements in the TCABR tokamak

The study of tokamak plasma light emissions in the vacuum ultraviolet (VUV) region is an important subject since many impurity spectral emissions are present in this region. These spectral emissions can be used to determine the plasma ion temperature and density from different species and spatial positions inside plasma according to their temperatures. We have analyzed VUV spectra from 500 Å to 3200 Å wavelength in the TCABR tokamak plasma including higher diffraction order emissions. There have been identified 37 first diffraction order emissions, resulting in 28 second diffraction order, 24 third diffraction order, and 7 fourth diffraction order lines. The emissions are from impurity species such as OII, OIII, OIV, OV, OVI, OVII, CII, CIII, CIV, NIII, NIV, and NV. All the spectra beyond 1900 Å are from higher diffraction order emissions, and possess much better spectral resolution. Each strong and isolated spectral line, as well as its higher diffraction order emissions suitable for plasma diagnostic is identified and discussed. Finally, an example of ion temperature determination using different diffraction order is presented.39227027

Reconstruction Activities And First Results From The Thomson Scattering Diagnostic On The Tcabr Tokamak

An incoherent and infrared Thomson scattering diagnostic (ITS) was transferred from ISTTOK (Lisboa) and reconstructed on TCABR (S. Paulo). In the first phase of this international collaboration, the diagnostic uses a Neodymium:Glass laser with up to 10 Joules per laser pulse and a first generation polychromator with three pairs of interference filters and avalanche photodiodes. It measures 90° scattered radiation in a single volume of observation with a single laser pulse to obtain the instant plasma electron temperature. This paper reports the reconstruction activities already carried out and presents the first experimental results. These activities include: new data model performance, laser refurbishing, new laser delivery system, stray-light reduction in the vacuum vessel, new collection lens and relative diagnostic calibration. A long run of experiments with this diagnostic shows consistency and coherence with the other TCABR diagnostics and gives indications to be able to contribute effectively to the Alfven heating program of this tokamak. © 2010 IOP Publishing Ltd.227Alonso, M.P., Wilcock, P.D., Varandas, C.A.F., (1999) Rev. Sci. Inst., 70 (1), p. 783Alonso, M.P., Berni, L., Severo, J.H., Borges, F.O., Elizondo, J.I., MacHida, M., Varandas, C.A.F., Galvo, R.M.O., (2008) Plasma Fusion. Sci., 996, p. 192Alonso, M.P., Figueiredo, A.C.A., Berni, L.A., Varandas, C.A.F., (2008) Plas. Sci. IEEE Trans. Plasma Sci., 36 (4), p. 11094Bellintani, J.V., Elfimov, A.G., Elizondo, J.I., Fagundes, A.N., Fonseca, A.M.M., Galvo, R.M.O., Guidolin, L., MacHida, M., (2006), 875, p. 350Berni, L.A., Alonso, M.P., Oliveira, R.M., (2004) Rev. Sci. Inst., 75 (10), p. 388

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

Electron Temperature And Density Measurements By The Unicity Of Particle Confinement Time On The Tcabr Tokamak

The electron temperature Te and density ne at inner border side of plasma on TCABR tokamak are determined using the unicity of particle confinement time τp. In this method, the signals from hydrogen Balmer series emissions like H alfa, beta and gama are measured with an absolutely intensity calibrated spectrometer during the discharge and the particle confinement time then is evaluated using these three emissions for large range of electron temperature and density, until the unique value of τp is achieved. The results show that during the current plateau, the values of the edge electron density and temperature in high fill density discharge, present much strong variations compared to the low fill pressure because of larger edge turbulence activity. © 2006 American Institute of Physics.87513914

Comparison Of Plasma Visible Spectral Emissions Between Nova-unicamp And Tcabr Tokamaks

A comparison between the visible spectrum emissions observed on the Nova-UNICAMP and TCABR tokamak plasmas has been made in this work using a hand top HR4000 Ocean Optics spectrometer equipped with a CCD detector. A number of 58 emission lines, in which 22 are common to both machines, have been observed and identified. The differences in the observed spectrum can be explained by the difference in the time integration used in these measurements and by the materials compositions of the limiter and electrode in the TCABR tokamak. Nearby peak emissions have been separated using multi-peak Gaussian fit curves obtaining separation between peak centres with the same order of the spectrometer resolution. The HR4000 spectrometer can be routinely used to monitor the impurity species in the visible spectrum from the different tokamak windows.5111Machida, M., Arsioli, B.S., Nascimento, F., (2009) J. Plasma Fusion Res. SERIES, 8, pp. 636-639Daltrini, A.M., Machida, M., (2002) Brazilian J. Phys., 32 (1), pp. 26-29. , 10.1590/S0103-97332002000100005 0103-9733Daltrini, A.M., Machida, M., (2005) Rev. Sci. Instrum., 76 (5), p. 053508. , 10.1063/1.1899403 0034-6748Monteiro, M.J.R., Machida, M., Daltrini, A.M., (2002) Brazilian J. OfPhys., 32, pp. 54-56Machida, M., Daltrini, A.M., Severo, J.H.F., (2008) Plasma Fusion Sci. Book Ser.: AIP Conference Proceedings, 996, p. 235. , 10.1063/1.2917017 0094-243XGalväo, R.M.O., Kuznetsov Yu, K., (2001) PlasmaPhys. and Controlled Fusion Ai, pp. 1181-1190Ruchko, L.F., Lerche, E.A., Galväo, R.M.O., (2002) Brazilian J. Phys., 32 (1), pp. 57-64. , 10.1590/S0103-97332002000100012 0103-9733Severo, J.H.F., Nascimento, I.C., Tsypin, Y.S., (2004) Phys. Plasma, 11 (2), pp. 846-848. , 10.1063/1.1637919 1070-664XHeller, M.V.A.P., Caldas, I.L., Ferreira, A.A., (2005) Czechoslovak J. Phys., 55 (3), pp. 265-270. , 10.1007/s10582-005-0039-5 0011-4626Nascimento, I.C., Kuznetsov, Yu.K., (2007) Nucl. Fusion, 47 (11), pp. 1570-1576. , 0029-5515 019Severo, J.H.F., Tsypin, V.S., Galväo, R.M.O., (2002) Brazilian J. Phys.il, pp. 13-19Severo, J.H.F., Nascimento, I.C., (2007) Rev. Sci. Instrum., 78 (4), p. 043509. , 10.1063/1.2723749 0034-6748Severo, J.H.F., Nascimento, I.C., Kuznetsov Yu, K., (2009) Nucl. Fusion, 49 (11), p. 115026. , 0029-5515 115026http://www.nist.gov/physlab/data/asd.cf

Spectral Line Profile Analysis Using Higher Diffraction Order In Vacuum Ultraviolet Region

Using a one meter VUV spectrometer and a MCP coupled to a CCD detector on TCABR tokamak, ion temperatures from impurity species have been measured and much better spectral resolution was obtained using higher order diffraction lines. Due to very small Doppler effect in the VUV region compared to large instrumental broadening, ion temperatures obtained from first order diffraction present large errors. The use of second, third and fourth order diffraction emissions increases the line broadening and results in lower error temperature measurements. © 2008 American Institute of Physics.996235240Daltrini, A.M., Machida, M., (2007) Rev. Sci. Instrum., 78, p. 066101Nascimento, I.C., Kuznetsov, Y.K., Severo, J.H.F., Machida, M., Galv, R.M.O., Sanada, E.K., Ferreira, A.A., (2005) Nucl. Fusion, 45, p. 796To be published at same proceedingKubo, H., (1993) Nucl. Fusion, 33, p. 427Isler, R.C., (1997) Fusion Enginnering and Design, 115, pp. 34-35Biel, W., Bertschinger, G., Textor team (2004) Rev. Sci. Instrum., 57, p. 2471Field, A.R., Fink, J., Fussmann, G., Wenzel, U., (1995) Rev. Sci. Instrum., 66, p. 543

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