1. New Experimental Results Obtained using Microwave Reflectometry in HL-2A Tokamak W.W. Xiao1), X.T. Ding1), X.L. Zou2), Z.T. Liu1), Y.D. Gao1), J.Q. Dong1), L.H. Yao1), B.B. Feng1), X.M. Song1), S.D. Song2), Y. Zhou1), C.Y. Chen1), L.W. Yan1), Q.W. Yang1), Yi Liu1), X.R. Duan1), C.H. Pan1), Yong Liu1) 1)Southwestern Institute of Physics(SWIP), Chengdu, China 2)Association Euratom-CEA, CEA/DSM/IRFM,CEA/Cadarache, 13018 St Paul-lez-Durance, France IRW9 (Lisbon, Portugal) 4-6th May 2009, W.W. Xiao 1

2. Plasma density perturbation Particle source position confirm Particle transport coefficients using analysis code Plasma rotation profils Summary and outlook Outline IRW9 (Lisbon, Portugal) 4-6th May 2009, W.W. Xiao 2

3. Plasma density perturbation In shot 3875, the density perturbation at different minor radius during the pulse molecular beam injection. Ip=349 kA, =2.3 T, from the top down r=26.5,27,28,29,30,31,32,33,34,35 and 36 cm.[1] IRW9 (Lisbon, Portugal) 4-6th May 2009, W.W. Xiao 3

4. Particle source position confirm Shot No. 3825Shot No. 3875 Ip320kA349kA Bt2.3T a40cm density 2.16×10 19 m -3 2.18×10 19 m -3 Gas pressure 0.55MPa Comparative results of the Ha intensity profile and the phase profile for shots 3825 (the close square) and 3875 (the close circular) in the similar discharge conditions. The particle source deposition place is about r~28cm.[1] The contour image of the density variational ratio with discharge time in different radii, for shot 3875 IRW9 (Lisbon, Portugal) 4-6th May 2009, W.W. Xiao 4

5. Particle transport simulation The experimental and simulations results in different source width, shot 3875. [2] IRW9 (Lisbon, Portugal) 4-6th May 2009, W.W. Xiao 5

6. Particle transport coefficients D & V The diffusion coefficients and the convection velocities profiles in different domains, A,B and C for shot 3875. [2] In shot 3875, Ln~5-50cm for region r~26-30cm. The blue region is better than that in the red region as shown in above picture. IRW9 (Lisbon, Portugal) 4-6th May 2009, W.W. Xiao 6

7. Sensitivity to D & V I II III simulation for the shot 7543 about the sensitivity to D & V f 0 =9.6 Hz, r dep =27.5 cm; Domain I: D 1 =0.2 m2/s, V 1 =-0.05m/s Domain II: D 2 =0.25m2/s, V 2 =-2.2m/s; Domain III: D 3 =0.25 m2/s, V 3 =-4.2m/s (A) (B) (C) IRW9 (Lisbon, Portugal) 4-6th May 2009, W.W. Xiao 7

8. Plasma rotation in HL-2A One multi-step Doppler reflectometry system has been operated first time in HL-2A tokamak, 26.5-40GHz, O-Mode, homodyne. Time evolution of the line-averaged density for shot 8655. (a) The line average density of 1.9×10 19 m -3. (b) The control voltage for microwave frequency of the Doppler reflectometry system. (c) The initial signal from the Doppler system. [3] IRW9 (Lisbon, Portugal) 4-6th May 2009, W.W. Xiao 8

9. Switch off the gas feed & density profile Shot: 7243 Profile ○： 240ms, no barrier, the density is lower than 2.210e19m-3 Profiles 1, 2, 3 and 4 as shown in above figure, a stable barrier formed. IRW9 (Lisbon, Portugal) 4-6th May 2009, W.W. Xiao 9

10. Poloidal cross-section showing O-mode (solid line)cut-off surfaces at 26, 35.8 and 37.7 GHz for shot 8614 (Bt = 1.56T, nl = 2.8×10 19 m -3 ) with antenna lines of sight. Dashed curves are ray-tracing predictions from REMA code. One can estimate similar circular cross section for the plasma shape. IRW9 (Lisbon, Portugal) 4-6th May 2009, W.W. Xiao 10 Ray-trace analysis in HL-2A

11. Radial profiles of the E×B flow velocity in different line average densities. The E×B flow velocity increases in the range 24<r <36 cm in shot 8655, line average density is about 1.9×10 19 m -3. A drastic change of the E×B flow velocity in the range 28<r<30cm in shots 8618 (n l ~2.6×10 19 m -3 ), and 8614 (n l ~2.8×10 19 m -3 ). The dashed line shows the position of the velocity change. IRW9 (Lisbon, Portugal) 4-6th May 2009, W.W. Xiao 11 Plasma rotation profiles in different density

12. IRW9 (Lisbon, Portugal) 4-6th May 2009, W.W. Xiao 12 Ln during different density

13. Particle transport studies using microwave reflectometry and SMBI is a good method because of the local particle source can be induced by the SMBI. The particle source position has been confirm in different ways Ha and the dn/dt. The particle transport coefficients, D and V have been obtained using the analysis code[2]. Plasma rotation profiles have been measured in HL- 2A,and the plasma rotation profile will be changed even in pure Ohmic discharge. Next step experiments will be done during H-mode phase in HL-2A tokamak. Summary and Outlook IRW9 (Lisbon, Portugal) 4-6th May 2009, W.W. Xiao 13 [1]Yao Lianghua et al., Nucl. Fusion, 47 (2007) 1399 [2]S.P. Eury et al., Phys. Plasmas, 12 (2005) 102511 [3]W.W. Xiao, X.L. Zou, X.T. Ding, et al., Chin. Phys. Lett., 26 (2009) 035201