Relation between Hard X-Ray Emission and Runaway Electrons in Damavand Tokamak

Moslehi Fard, M; Alinejad, N

Relation between Hard X-Ray Emission and Runaway Electrons in Damavand Tokamak

Document Type : Research Paper

Authors

M Moslehi Fard

N Alinejad

Abstract

In this experimental work, hard x-ray emission in Damavand tokamak along with the temporal evolution of plasma current and loop voltage have been studied for shots in which plasma current varies from 17 to 32kA. The time evolution of plasma current from beginning of the discharge to the disruption phase, loop voltage, and hard x-ray emission has been anlalyzed. The hard x-ray emission for the plasma current less than 20kA has been observed during the disruption phase, where the discharge duration is less than 10ms. For plasma current is more than 20kA, however, hard x-ray can be observed at the beginning to the disruption phase and it persists for 20ms. Two kinds of regimes can be realized for the runaway electron production in this tokamak. The first regime is similar to other tokamaks and takes place during the disruption phase. This regime is understood by Dreicer theory of runaway electron production. The second regime which is observed from the beginning to the end of discharge is related to the avalanche event.

Highlights

1. B.B. Kadomtsev, “Magnetic field line reconnection,” Rep. Prog Phys, 50, 115-143 (1987).

2. F. Porcelli, “Collisionless m=1 tearing mode,” Phys. Rev. Lett, 66, 425 (1991).

3. J. Wesson, “Sawtooth reconnenction,” Nuclear Fusion, Vol 30, Issue 12, December (1990).

4. D. Grasso, M. Ottaviani, F. Porcelli, “Growth and stabilisation of drift-tearing modes in weakly collisional plasma,” Nuclear Fusion, 42, 1067-1074 (2002).

5. J. Brin, J.F. Drake, M.A. Shay, B.N. Rogers, R.E. Denton, P.L. Pritchett, “Geospace environmental modeling (GEM) magnetic reconnection challenge,” J. Geophys. Res (A3) 3715-3719 (2001).

6. H. Ji, S. Terry, M. Yamada, R. Kulsrud, A. Kurisyn, Y. Ren, “Electromagnetic fluctuations during fast reconnection in a laboratory plasma,” phys. Rev. Lett, 115001 (2004).

7. A. Bhattachargee, K. Germaschewski, C.S. Ng, “Currentsingularities: Driversof impulsive reconnection,” Physics of Plasmas, 12, 042305 (2005).

8. Y. Saito, T. Mukai, T. Tersawa, A. Nishida, S. Machida, M. Hirahara, K. Maezawa, S. Kokubun, T. Yamamoto, “Slow-mode shocks in the magnetotail,” J. Geophys. Res, 100, 23567 (1995).

9. Y. Ono, M. Inomotov, Y. Ueda, T. Matsuyama, “Fast magnetic reconnection with anomalous ion heating and its-application,” Science and Technology of Advanced Material, Vol 2, Issues 3-4, 473-482 (2001).

10. R.V. Savrukhin, F. Porcelli, A.V. Sushkov, S.V. Tsaun, V.V. Volkov, “Analysis of the small-scale plasma perturbation-during-density limit disruption in T-10 tokamak,” Nucl Fusion, 44, 761-771 (2004).

11. D.A. Kislov, Yu.V. Esipchuk, N.A. Kimeva, Yu.D. Pavlov, A.A. Subbotin, V.V. Alikaev. A.A. Borshegovskiy, Yu. V. Gott, S.V. Krilov, T.B. Myalton, I.N. Roy, E.V. Trukhina, V.V. Volkov, T-10 Team, “Beta limit due to resistive tearing modes in T-10, Nuclear Fusion, 41, 1691-1624 (2001).

12. P.V. Savrukhin, “Observation of suprathermal electrons during magnetic reconnection,” Phys. Plasma, 9, 3421 (2002).

13. “ITER physics expert group disruption plasma control and MHD, MHD stability, operational limits and disruptions,” Nucl. Fusion, 39, 2251 (1999).

14. R. Jasper, N.J. Lopes Cardezo, F.C. Schuller, K.H. Finken, T. Grewe, G. Mank, “Disruption generated Runaway-electrons in TEXTOR and ITER,” Nucl. Fusion, 36, 367 (1996).

15. Yu.K. Kuznetsov, R.M.O. Galvao, V. Bellintanijr, A.A. Ferrira, A.M.M. Fonseca, I.C. Nascimento, L.F. Ruchko, E.A.O. Saetton, V.S. Tsypin, O.C. Usuriage, “Runaway discharges in TCABR,” Nucl. Fusion, 44, 631-644 (2004).

16. A.G. Elfimov and R.M.O. Galvao, “Whistler instability driven by relativistic electron tail in tokamaks,” Plasma Phys. Control. Fusion, 45, L63, L70 (2003).

Keywords

Hard X-Ray

Runaway Electrons

Tokamak

Plasma Disruptio

1. B.B. Kadomtsev, “Magnetic field line reconnection,” Rep. Prog Phys, 50, 115-143 (1987).

2. F. Porcelli, “Collisionless m=1 tearing mode,” Phys. Rev. Lett, 66, 425 (1991).

3. J. Wesson, “Sawtooth reconnenction,” Nuclear Fusion, Vol 30, Issue 12, December (1990).

4. D. Grasso, M. Ottaviani, F. Porcelli, “Growth and stabilisation of drift-tearing modes in weakly collisional plasma,” Nuclear Fusion, 42, 1067-1074 (2002).

5. J. Brin, J.F. Drake, M.A. Shay, B.N. Rogers, R.E. Denton, P.L. Pritchett, “Geospace environmental modeling (GEM) magnetic reconnection challenge,” J. Geophys. Res (A3) 3715-3719 (2001).

6. H. Ji, S. Terry, M. Yamada, R. Kulsrud, A. Kurisyn, Y. Ren, “Electromagnetic fluctuations during fast reconnection in a laboratory plasma,” phys. Rev. Lett, 115001 (2004).

7. A. Bhattachargee, K. Germaschewski, C.S. Ng, “Currentsingularities: Driversof impulsive reconnection,” Physics of Plasmas, 12, 042305 (2005).

8. Y. Saito, T. Mukai, T. Tersawa, A. Nishida, S. Machida, M. Hirahara, K. Maezawa, S. Kokubun, T. Yamamoto, “Slow-mode shocks in the magnetotail,” J. Geophys. Res, 100, 23567 (1995).

9. Y. Ono, M. Inomotov, Y. Ueda, T. Matsuyama, “Fast magnetic reconnection with anomalous ion heating and its-application,” Science and Technology of Advanced Material, Vol 2, Issues 3-4, 473-482 (2001).

10. R.V. Savrukhin, F. Porcelli, A.V. Sushkov, S.V. Tsaun, V.V. Volkov, “Analysis of the small-scale plasma perturbation-during-density limit disruption in T-10 tokamak,” Nucl Fusion, 44, 761-771 (2004).

11. D.A. Kislov, Yu.V. Esipchuk, N.A. Kimeva, Yu.D. Pavlov, A.A. Subbotin, V.V. Alikaev. A.A. Borshegovskiy, Yu. V. Gott, S.V. Krilov, T.B. Myalton, I.N. Roy, E.V. Trukhina, V.V. Volkov, T-10 Team, “Beta limit due to resistive tearing modes in T-10, Nuclear Fusion, 41, 1691-1624 (2001).

12. P.V. Savrukhin, “Observation of suprathermal electrons during magnetic reconnection,” Phys. Plasma, 9, 3421 (2002).

13. “ITER physics expert group disruption plasma control and MHD, MHD stability, operational limits and disruptions,” Nucl. Fusion, 39, 2251 (1999).

14. R. Jasper, N.J. Lopes Cardezo, F.C. Schuller, K.H. Finken, T. Grewe, G. Mank, “Disruption generated Runaway-electrons in TEXTOR and ITER,” Nucl. Fusion, 36, 367 (1996).

15. Yu.K. Kuznetsov, R.M.O. Galvao, V. Bellintanijr, A.A. Ferrira, A.M.M. Fonseca, I.C. Nascimento, L.F. Ruchko, E.A.O. Saetton, V.S. Tsypin, O.C. Usuriage, “Runaway discharges in TCABR,” Nucl. Fusion, 44, 631-644 (2004).

16. A.G. Elfimov and R.M.O. Galvao, “Whistler instability driven by relativistic electron tail in tokamaks,” Plasma Phys. Control. Fusion, 45, L63, L70 (2003).