1. Li collection experiments on T-11M and T-10 in framework of Li closed loop concept S.V.Mirnov1, A.G.Alekseev1, A.M.Belov1, N.T.Djigailo1, A.N.Kostina2, V.B.Lazarev1, I.E.Lyublinski3, V.M.Nesterenko1, A.V.Vertkov3, V.A.Vershkov4. 1 GSC PF TRINITI 142 190 Troitsk Mosc. Reg. Russia. 2 NRNU MEPhI, Kashirskoye sh., 31,Moscow, 115409 Russia 3 FSUE “Red Star”, Elektrolitnyj pr. 1A, Moscow, 113 230 Russia 4 RSC “Kurchatov Institute” Kurchatov Acad. Sc. 1 Moscow 123 192 Russia The 2nd International Symposium on Lithium Applications for Fusion Devices April 27-29, 2011 Princeton Plasma Physics Laboratory Princeton, NJ, USA

2. The concept of a steady state tokamak with plasma facing components (PFC) on the basis of the closed loop of liquid lithium circulation demands the technological decision of three tasks: lithium injection to the plasma, lithium ions collection before their deposition on the vacuum vessel and Li returning from collector to the injection zone. Main subject of paper is the investigations of Li collection by different types limiters, intersected the scrape-of-layer (SOL) of T-10 and T-11M tokamaks. For practical solution of this problem in Т-11М and Т-10 tokamak experiments have been applied Li-, C-rail limiters and special ring SS R- limiter-collector (T-11M). The quantitative analysis of the sample-witnesses located on Т-11М limiters showed, that nearby 60±20% of the lithium injected during plasma operating of Т-11М had been collected by limiters. It confirms a potential opportunity of collection of the main part of the injected lithium by the limiters-collectors located in the SOL area of steady state tokamak.

3. T-11M and T-10 tokamaks

4. T-11M: R/a=0.7/0.25m, Jp=50-100kA, B T =1.2T, Δt=0.2s T-10: R/a=1.5/0.35m, Jp=200-300kA, B T =2.5T, Δt=1s

6. T-10 experiment

7. T-10 lithiation

8. Li closed loop concept

9. Dust explosion in LHD (1641sec)

12. Li CPS emitter T-11M experiment

13. Scheme of new “W-Li limiter” of T-11M with water cooling/heating in steady state regime Li tank W - felt Water cooling 200 o C TOKAMAK PLASMA

14. W Li limiter test on Т-11М 29.03.2011 12:44:41 Video registration Parameters of video registration: 640 × 480 points Frequency -250Hz, exposition 4ms in light LiI (670,8 nm);

15. n e ~1-2 10 19 m -3 Jp=50kA t~160ms

16. Li limiter in T-11M chamber Field of view

49. Li collection by lateral sides of W-Li CPS limiter

51. The quantitative analysis of the sample-witnesses located on Т- 11М limiters showed, that 200+/- 30 mg lithium, which is nearby 60±20% of the lithium injected during plasma operating (~1000 shots) of Т-11М had been collected by lateral sides (e+i) of single W-Li CPS rail limiter.

52. Li distribution in SOL of rail limiters

53. a- exponential decrease with dept ~6cm, b-second decrease with dept ~1 cm – as result of Li collection by C-ring limiter

54. T-11M experiment with second ring limiter (R limiter) as Li collector

58. The quantitative analysis showed: 1. that a total amount of Li collected by lateral sides (e+i) of W-Li CPS rail limiter during next ~1000 shots decreases roughly two times, up to 110 mg 2. the R-limiter collected ~ 100 mg, that is in sum roughly 200mg again, which is again nearby 60±20% of the lithium injected during plasma operating. That means the R-limiter can be used in future as high effective Li collector

60. The next steps

61. Plasma-rail limiter interaction T-11M Cold exposition initial T lim 200C

63. “Badminton model” Several identical Li-limiters in tokamak chamber can be used as emitters and collectors in turn by periodical change their relative mechanical position in SOL or by use of local magnetic perturbations

65. KRAMER G.J., BUDNY B.V., GORELENKOVA M. et al. “Fast ion Effects during Test Blanket Module Simulation Experiments in DIII-D” APS 52nd Annual Meeting DPP Nov. 2010 55 № 15 XO4 4 p375.

68. Two kinds of lithiation procedure were successfully tested in T-11M and T-10 tokamaks: the conventional “passive” method with preliminary coating of some part of tokamak PFC by lithium and “in-situ” coating by the permanent use of lithium rail limiter during tokamak discharge (T-11M). The last method seems as useful for future tokamak steady state operation. Two kinds of lithium collection were tested in T-11M experiments: by lateral surfaces of rail lithium limiter and by circular R-limiter introduced in shadow of rail limiter Conclusions 1

69. Conclusions 2 The T-11M experiments with Li collection by lateral sides of rail limiter with W-wings showed that a significant part (60+/- 20%) of Li, injected to the plasma and diffused than out plasma column, can be collected by this way. The T-11M experiments with a circular Li R-collector, inserted into plasma SOL in the shadow of main tokamak rail limiter, showed that this kind of collector can accumulate the significant part (up to 50%) of Li diffused out plasma column. The both kinds of collectors can be used for closing of lithium loop circulation in future.

70. Conclusions 3 Lithium emitter-collector concept with several identical Li-limiters, which can change their emitter and collector role in turn ( “badminton model”) can be suggested for use in SOL of ITER- like tokamak-reactor. T-10 experiments showed that migration of Li deposit around the torus from lithiation (gettering) region was low. Li films was absent in the vacuum port of T-10 opposite to the lithiation port.

71. Thank you for attention

72. J.Bohdansky and J.Roth Temperature dependence of sputtering behavior of Cu-Li alloys Nucl. Instr.and Methods in Physics Research B23 (1987) 518