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

Low-angle Thomson Scattering Experiment For Determination Of Plasma Electron Density And Temperature

In this work we show results of measurements of the electron density ne and temperature Te by using small-angle Thomson scattering in a theta-pinch plasma. The method of measurement and analysis developed here is based on integration of only two ranges of the scattering profile. This method simplifies the experimental set up, because it needs only two detectors for simultaneous determination of ne and Te, instead of the commonly 5-7 detectors used in 90° experiments. The results obtained for low-angle scattering are compared with the measurements at 90° using single pass and multipass under the same plasma conditions.25601/02/15437441Berni, L.A., Campos, D.O., Machida, M., Moshkalyov, S.A., Lebedev, S.V., Molecular Rayleigh scattering as calibration method for Thomson scattering experiments (1996) Brazilian Journal of Physics, 26 (4), p. 755Campos, D.O., Machida, M., Berni, L.A., Moshkalyov, S.A., Lebedev, S.V., The feasibility study of a low-angle Thomson scattering for determination of plasma electron density and temperature (1995) 3o, Encontro Brasileiro de Física dos Plasmas - Fifth Brazilian Plasma Astrophysics Workshop, , Águas de Lindóida, SP, 4-6 December 1995Campos, D.O., Machida, M., Berni, L.A., Kantor, M., Moshkalyov, S.A., Lebedev, S.V., Experimental study of conventional and multipass Thomson scattering diagnostics (1996) Japanese Journal of Applied Physics, 35 (12 A), p. 6273Campos, D.O., Machida, M., Berni, L.A., Kantor, M., Moshkalyov, S.A., Lebedev, S.V., The application of a multipass system for Thomson scattering diagnostics in magnetically confined plasmas (1996) Brazilian Journal of Physics, 26 (4), p. 742Sheffield, J., (1975) Plasma Scattering of Electromagnetic Radiation, , Academic Press, New Yor

Comparison of two multipass configurations for scattered light amplification

Scattered light amplification by using multipass method is a very useful technique to increase Thomson and Rayleigh scattering signals for local plasma electron temperature and density measurements. Using Rayleigh scattering in nitrogen neutral gas chamber, the well-known technique of multipass system with two concentrical spherical mirrors is compared with new configuration by using two sets of lens and at mirrors. The focusing capability of both configurations makes the difference to stray light and scattered signal related to spectrometer slit aperture and number of multipass. For the same number of laser beam pass and best slit aperture, the lens and plan mirrors new configuration presented lower stray light and higher scattered signal, although the gain of the usual two spherical mirrors still remains higher.502506Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Molecular Rayleigh Scattering As Calibration Method For Thomson Scattering Experiments

This work presents the results obtained with Rayleigh scattering as method of calibration for the Thomson scattering diagnostic in the determination of density and temperature on the field-reversed theta-pinch TC-1 at UNICAMP. The methods employed to reduce the presence of stray light, as well as quest for best scattering geometry, are also described.264755759Sheffield, J., (1975) Plasma Scattering of Electromagnetic Radiation, , Academic Press, IncEvans, D.E., Katzenskein, J., (1969) Rep. Prog. Phys., 32, p. 207Kunze, H.J., The laser as a tool for plasma diagnostic (1968) Plasma Diagnostics, , North-Holland Publ.cap. 9Long, D.A., (1977) Raman Spectroscopy, , McGraw-HillHoward, J., James, B.W., Smith, W.I.B., (1979) J. Phys., 12, p. 1435Aramaki, E.A., Berni, L.A., Honda, R.Y., Doi, I., Machida, M., Optimization of the implosion phase on T.C.-1 by light Emission Analysis (1992) Nuclear Instruments Methods in Physics ResearchA, 280, p. 597Machida, M., Honda, R.Y., (1990) Revista de Física Aplicada e Instrumentação, 5, p. 477DeSilva, A.W., Goldenbaum, G.C., Plasmas Diagnostics by Light Scattering (1970) Methods of Experimental Physics, 9 (PART A). , Academic Presscap.

Optical Diagnostics For The Study Of Plasma Evolution In Linear Theta-pinch Tc-1

The plasma generated in the field reversed theta-pinch TC-1 discharge was investigated by means of a number of optical diagnostics: CO2 laser-based interferometry, visible-VUV spectroscopy and ruby laser Thomson scattering. The evolution of the local electron density was studied by CO2 laser intereferometry. Thomson scattering was employed for measurements of the electron density and temperature with high spatial resolution. The temporal behavior of line emission of oxygen and carbon in various ionization stages was studied by VUV spectroscopy. The time dependence of the electron temperature was evaluated from the analysis of the time history of line emission of impurity ions. The ion temperature was measured from the Doppler-broadened oxygen line emission profiles.264747754Aramaki, E.A., Porto, P., Berni, L., Honda, R.Y., Ueda, M., Doi, I., Machida, M., (1989) Nucl. Instr. Meth. Phys. Res., A, 280, p. 597Tuszewski, M., (1988) Nuclear Fusion, 28, p. 2033Campos, D.O., Machida, M., Berni, L.A., Kantor, M.Yu., Moshkalyov, S.A., Lebedev, S.V., (1995) Proc. de 30 Encontro Bras. de Física dos Plasmas, p. 90. , Águas de Lindóia, SP, BrasilBerni, L.A., Campos, D.O., Machida, M., Moshkalyov, S.A., Lebedev, S.V., Monteiro, M.J.R., Zibordi, R., (1995) Proc. de 30 Encontro Bras. de Física dos Plasmas, p. 79. , Águas de Lindóia, SP, BrasilMoshkalyov, S.A., Machida, M., Lebedev, S.V., Campos, D.O., (1995) Revista Bras. de Física Appl. Instr., 10, p. 107Greve, P., Kato, M., Kunze, H.-J., Hornady, R.S., (1981) Phys.Rev., A, 24, p. 429Kunze, H.-J., (1971) Phys.Rev., A, 3, p. 93

The Application Of A Multipass System For Thomson Scattering Diagnostics In Magnetically Confined Plasmas

Multipass systems are helpfull on Thomson scattering measurements for determination of electron temperatures and densities in plasmas, increasing the intensity of the scattered spectrum. A low cost, simple and effective multipass construction originally developed for aplications in tokamak plasmas was built and tested for the first time in a theta-pinch device, the compact torus TC-1. A detailed analysis about the gain on the scattered signal provided by the multipass system is discussed. The use of multipass for Thomson scattering experiments in theta-pinch devices or in more dense plasmas as well as in plasmas with higher Z eff can be recommended for reduction of the relation between laser and bremsstrahlung signals. The successfull results obtained are shown. Multipass and single pass measurements are compared. The application of this system on the recently installed tokamak NOVA-UNICAMP is also discussed.264742746Sheffield, J., (1975) Plasma Scattering of Eletromagnetic Radiation, , Academic Press, N.YDe Michelis, C., Papoular, R., (1975) Plasma Phys., 17, p. 1155Doebele, H.F., Gindele, K., (1977) Appl. Opt., 16 (9), p. 2403Barth, C.J., Chu, C.C., Donne, A.J.H., (1995) Rev. Sci. Instrum., 66, p. 501Akatova, T.Yu., Bulyginskii, D.G., Zavadskii, V.M., Kantor, M.Yu., Levin, L.S., Petrov, Yu.V., Razdobarin, G.D., Shustova, N.V., (1992) Soviet Journal of Plasma Physics, 18 (2), p. 89Aramaki, E.A., Porto, P., Berni, L.A., Honda, R.Y., Ueda, M., Doi, I., Machida, M., (1989) Nucl. Instrum. and Methods in Phys. Res., A280, p. 597Fukao, M., Fujiwara, Y., Zushi, H., Suemitsu, H., Terumishi, Y., Nishihara, H., (1977) Memo. Fac. Eng., 39, p. 431. , Kyoto Uni