A.V." Krasilnikov

M. Isobe

M. Sasao

T. "Saida

National Institute for Fusion Science (NIFS-Repository)

§26. Viewing Chord Dependence of Effective High Energy Proton Temperature Teff during ICRF Heating on LHD Saida, T. (Grad Univ.), Sasao, M., Isobe, M., Krasilnikov, A.V. (TRINITI) We report Stix parameter [1] dependence of effective temperature Teff of lCRF -driven high energy proton tail as regards two types of lCRF resonance layer configuration in case of toroidal magnetic field Bt 2.5T and 2.75T, respectively, of Rax = 3.6m. The high energy proton spectra by taking into account of charge exchange cross sections are obtained from the fast neutral spectra measured with Natural Diamond Detectors (NDDs) [2]. The discharge scenario is self-sustained by lCRF with hydrogen minority and helium majority. The NDDs are installed with perpendicular viewing channel at major mdius R = 3.68m (center chord) and 3.92m (outer chord) as shown in Fig. 1. Fig. 2. shows effective ion temperature of lCRF -driven minority proton kIT versus Stix parameter [3] defined as lCRF energy given per a minority proton. The electron density is (0.4-0.8) x I019m3 . The minority concentration is 10 ,..., 20% because the lCRF heating efficiency has maximum value at the concentration 0 - 20% [4]. As to viewing chord dependence, in case of both Bt = 2.5T and 2.7 5T, the TeIT on center chord was higher than that on outer chord. 1dr of high energy proton are increasing with Stix parameter. The two linear dash lines on Fig.2. show the proportional region of Teff on center chord. In case of both Bt = 2.5T and 2.75T kIT on center chord were put in the same proportional region. However saturation states of Teff on center chord are different in both lCRF resonance layer configuration. The mechanism why Teff of high energy proton are saturated on Stix paremeter dependence is mainly under investigation. 30 D n d i aDId detectors Fig.I. Line of sights of NDDs on a perpendicular diagnostics port on LHD. • Teff@ outer chord @2.5T o Teff@ center chord @2.ST • Teff@outer chord @2.75T 60 0 Teff@ cen r chord 2.75T :: : : t I i<t;~ttt:: ! ~ ,~ ~ J. 0; ! 0 : 30 . · ····· ·l -· · · ·· · ·~·~ ······-t/· · ·+····· .. -1--... ····~···.····· t ···· ·· ·· i l i ~ ' : . : j/):~.~ Wj~ j -1 a /f· :-' -·r~- ; j-o ~~--~~--~--~~--~--20 o 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 PTJ2nm,n [MWS/1013cm,3] stix parameter Fig.2. Stix parameter dependence of effective temperature of lCRF-driven high energy proton Teff. 1) Stix.T.H, NucLFus. 15, (1975) 737 2) lsobe. M, Rev. Sci. lnstrum. 72, (2000) 611 3) A.Y.Krasilnikov, NucLFus. 42, (2002) 759 4) Saito.K., PhD thesis, Nagoya Univ 

Viewing Chord Dependence of Effective High Energy Proton Temperature Teff during ICRF Heating on LHD

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