K. Nakane

K. Taniguchi

M. Goto

R. Idei

S. Sawada

National Institute for Fusion Science (NIFS-Repository)

A tom ic an d m olecu lar hydrogen sp ec-●troscopy ln IJH D p lasm aSaw ada, S., T anlguChi, K ., Idei, 氏., N akane, K .(Shinshu U niv.),G oto , M .In the LH D visible spectroscoplC m eaSurem entS , alot of em ission lines w hich seem to be orlglnated fromm olecular hydrogen are observed. H ow ever, the identi一Bcation of them w as not done. If the upper and low erlevels of the transitions of the m olecular em issions areidentiBed , their intensities can be used to determ ine theelectron tem perature Te and density n e , the m oleculardensity n H 2 , Vibrational tem perature Tv and rotationaltem perature n ot in the ground electronic state.W e have already constructed a collisiona1-radiativem odelofm olecular hydrogen in w hich the electronic andvibrational states are resolved , w here the m ain concernis to produce the effective reaction rate coefBcients ofm olecular hydrogen w hich are used in neutraltransportcodes. In order to calculate the intensity of m olecularem ission lines in the visible w avelength reglOn , W e haveim proved the m odelto include the rotationalstate in ad-dition･ In the revised m odel, as.suT ing H und'S (b) case,the levels are labeled by the prlnClpal quantum num bern , and A , N , and J . T he num ber of 4133 levels fornH l妄言a,reBllnZIIu,decdl'HLu?vBl/le芸ef,glLsIEfu デF llHE9g: ,JqAK glEagI gtaken from R ef.1. For other n < 4 states, levelenergleSare taken from R ef.2. W e calculated those for n - 5 , 6from electronic potentials. Spontaneous transition prob-言3bA igtiel ec33EHIu ,7 1aH3gE gと dc31HHuJ anad3EJg: A %; Hl i lE3uH luiR ef.3 are included in the m odel. T he values for othertransitions are calculated according to R ef.4. Transitionprobabilities to continuum of X l∑g+and b3E吉are alsocalculated. T he vibrationally resolved excitation crosssection from X l∑g+ to B l∑吉 , B /1∑吉 , B 〝1∑吉, C IIl u ,D IIl u , D /lIlu in R ef･5 are included in the m odel･ Forthe excitation to other states, data in R efs.6 and 7 areused. W e assum e that the rate coefBcients are propor-tionalto Franck-C ondon factor. In the rotationalexcita-tion,△Ⅳ - 0or△Ⅳ - ±1 are assum ed,considerlng theconservation ofαand S sym m etry. E xcitation cross sec-tions betw een excited states are estim ated from unitedatom helium cross sections.For the test ofthe m odel, w e applied the collisiona1-radiative m odel to an R F plasm a in Shinshu U niver-sity. In order to determ ine Te and n e from intensitiesof helium em ission lines, 35 sccm helium gas w as intro-duced w ith 15 sccm hydrogen gas. Te - 8.5 eV andn e - 1.3 ×1010cm -3 w as obtained from the helium lineintensities m easured by an echelle spectrom eter, w hichcovers the range of 380 nm 1800 nm . From the Fulcherband intensity,㌔ and n ot w ere determ ined to be 4200K and 350 K ,respectively. C alculated em ission lines in380 nm -800 nm uslng these param eters are com paredw ith the observed em ission lines. W ith the help of thecalculated w avelength and intensity ofthe em ission lines,W e identiBed the observed em ission lines. F igure 1(a) isan exam ple of the identiBcation.N ext, W e applied the m odel to the LH D plasm as.W avelength range of 400 nm 1860 nm w as observed w ith24 shot by shot m easurem ents. T he calculation roughlyreproduced m olecular em ission lines in the rangesof470-490 nm and 607-630 nm (F ig. 1(b)). H ow ever, the otherobserved lines w ere not reproduced w ell. Tb start w ith ,w e w ill im prove the w avelength calibration of the LH Dspectrom eter.F ig. 1: Spectra of (a) R F plasm a (upper) and (b)LH D (low er). C alculation (thick , gray) and E xperim ent(thin).1) D .B ailly, E .∫.Salum bides,M .V ervloet, W .U bachs,M olecular P hysics 108 , 827-846 (2010).2) H . M . C rossw hite, T he H ydrogen M olecule W ave1length T ables of G E R H A R D H E IN R IC H D IE K E ,John W iley 良 Sons lnc (1972).3) S.A .A stashkevich et.a1.,∫.Q uant.Spectrosc.R adiat.Transfer 56 , 725 (1996).4) Jam es K .G . W atson , Journal of M olecular Spec-troscopy 252 5 (2008).5) 氏.C eliberto , 氏.K .Janev et.a1.,A tom ic D ata and N u-clear D ata T ables 77 , 161 (2001).6) 氏. Janev , D . R eiter, and U . Sam m , R eportForschungszentrum Jtilich JU E L 4105 , (2003).7) W .T . M iles, 氏. T hom pson , and A .E .S. G reen , ∫.A ppl.P hys.4 3 , 678 (1972).112§1. Atomic and Molecular Hydrogen Spectr scopy in LHD PlasmaSawada, S., Taniguchi, K., Idei, R., Nakane, K. (Shinshu Univ.), Goto, M.(7) Atomic and Molecular Process

Atomic and Molecular Hydrogen Spectroscopy in LHD Plasma

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