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Wall conditioning of the Thor Tokamak

Кондиционирование стенок для токамака «ТОР»

  • Published:
Il Nuovo Cimento B (1971-1996)

Summary

The conditioning of the walls of Thor container by means of cleaning hydrogen discharges allowed a reduction of the influence of light impurities as oxygen and carbon on the plasma; as a consequenceZ eff was also reduced. The experimental results seem to confirm the correlation between the cleaning and the amount of water and methane in the discharge. The build-up of these compounds is explained by supposing low-energy chemical reactions induced by hydrogen ion and atom bombardment. In particular water production is related to metal oxide layers on the walls. The cleaning discharge efficiency has been found to depend on the plasma temperature. High-energy cleaning discharges are not convenient as they increase the dissociation of water molecules and the container wall activation.

Riassunto

Il condizionamento mediante scariche pulitrici in idrogeno delle pareti del contenitore della macchina Thor ha permesso di ridurre l’influenza sul plasma delle impurezze leggere quali ossigeno e carbonio con conseguente riduzione delloZ eff. I risultati sperimentali sembrano confermare che l’efficienza della pulitura sia da correlare con l’ottimizzazione della produzione di acqua e metano. La comparsa di questi composti viene giustificata ipotizzando l’esistenza di reazioni chimiche a bassa energia indotte dal bombardamento di ioni ed atomi di idrogeno. In particolare, la produzione di acqua è messa in relazione con la presenza di strati di ossidi metallici sulle pareti. È stato trovato che l’efficienza delle scariche pulitrici dipende dalla temperatura del plasma. Scariche pulitrici ad alta energia risultano deleterie favorendo la dissociazione delle molecole di acqua prodotte e l’attivazione delle pareti del contenitore.

Резюме

Кондиционирование стенок контейнера «ТОР» с помощью очищающих водородных разрядов позволяет уменьшить влияние легких примесей (кислорода и углерода) на плазму. В результате этого также уменьшаетсяZ эфф. Экспериментальные результаты, по-видимому, подтверждают корреляцию между очисткой и количеством воды и метана в разряде. Объясняется образование этих соединений, предполагая низкоэнергетические химические реакции, индуцированные ионами водорода и бомбардирующими атомами. В частности, образование воды связано со слоями металлических окислов на стенках. Обнаружено, что эффективность очищающего разряда зависит от температуры плазмы. Очищающие разряды при высокои энергии не являются подходящими, т.к. они увеличивают диссоциацию молекул воды и активацию стенок контеинера.

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References

  1. D. M. Meade:Nucl. Fusion,14, 289 (1974).

    Article  Google Scholar 

  2. R. J. Hawryluk andJ. A. Schmidt:Nucl. Fusion,16, 775 (1976).

    Article  ADS  Google Scholar 

  3. M. Murakami et al.: inProceedings of the VII International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Innsbruck, 1978 (to be published by IAEA, Vienna).

  4. TFRGroup: inProceedings of the International Symposium on Plasma Wall Interactions, Julich 1976 (London, 1977), p. 3.

  5. Petula Group: EUR-CEA-FC-816 (1976).

  6. E. B. Meservey, B. Bretz, D. L. Dimock andE. Hinnov: Princeton Plasma Physics Laboratory Report MATT-1203 (1976).

  7. P. E. Stott, C. C. Daughney andR. A. Ellis jr.: Princeton Plasma Physics Laboratory Report MATT 1111 (1975).

  8. S. Konoshima, N. Fujisawa, M. Maeno, N. Suzuki, T. Yamamoto, Y. Gomay, T. Hirayama, M. Shimada, K. Uehara, A. Funahashi, T. Matoba, T. Kawakami, K. Takahashi, T. Shoji, K. Kumagai, S. Kasai, H. Takeuchi, T. Yamauchi, T. Sugie, M. Shiho andA. Nagashima:J. Nucl. Mat.,76–77, 581 (1978).

    Article  Google Scholar 

  9. S. J. Fielding, J. Hugill, G. M. McCracken, J. W. M. Paul, R. Prentice andP. E. Stott: Culham Laboratory Report CLM-P493 (1977).

  10. R. Calder, A. Grillot, F. Le Normand andA. Mathewson: inProceedings of the VII International Vacuum Congress and III International Conference on Solid Surfaces (Vienna, 1977), p. 231.

  11. R. P. Gavier andG. M. McCracken:J. Vac. Sci. Technol.,7, 552 (1970).

    Article  ADS  Google Scholar 

  12. V. S. Strelkov: inProceedings of the IX European Conference on Controlled Fusion and Plasma Physics, Oxford, 1979 (to be published).

  13. TFR Group: inProceedings of the VII International Vacuum Congress and III International Conference on Solid Surfaces (Vienna, 1977), p. A-2683.

  14. A. G. Mathewson:Plasma wall interactions, inProceedings of the International Symposium, Julich 1976 (Oxford, 1977), p. 517.

  15. R. E. Clausing, L. C. Emerson andL. Heatherly:J. Vac. Sci. Technol.,13, 437 (1976).

    Article  ADS  Google Scholar 

  16. W. Poschenrieder: inEuropean Contributions to the II Meeting of the Intor Workshop, Vol. 1 (Vienna, 1979), p. 337.

  17. L. Oren andR. J. Taylor:Nucl. Fusion,17, 1143 (1977).

    Article  ADS  Google Scholar 

  18. R. J. Taylor:J. Nucl. Mat.,76/77, 41 (1978).

    Article  ADS  Google Scholar 

  19. TFR Group:J. Nucl. Math.,76/77, 587 (1978).

    Article  ADS  Google Scholar 

  20. V. Arunasalam et al.: inProceedings of the VIII European Conference on Controlled Fusion and Plasma Physics (Praga, 1977), p. 17.

  21. Y. Gomay, R. E. Clausing, R. S. Colchin, L. C. Emerson, L. Heatherly, W. Namkung andJ. E. Simpkins: General Atomic Company Report GA-A 15072 (1978).

  22. Thor Group andP. A. Worsnop, B. S. Ingram, A. J. Hoskins andP. F. Little: inProceedings of the IX Symposium on Fusion Technology, Garmisch, 1976 (London, 1976), p. 281.

  23. G. Bonizzoni: inProceedings of the VI National Congress on Vacuum Science and Technology, Bari, 1979 (to be published).

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Authors and Affiliations

  1. Laboratorio di Fisica del Plasma, Associazione CNR-EURATOM, Via Bassini 15, 20133, Milano

    G. Bonizzoni & S. Cirant

  2. Istituto di Scienze Fisiche dell’Università, Via Celoria 16, 20133, Milano

    M. Fontanesi

Authors
  1. G. Bonizzoni
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  2. S. Cirant
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  3. M. Fontanesi
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Bonizzoni, G., Cirant, S. & Fontanesi, M. Wall conditioning of the Thor Tokamak. Nuov Cim B 57, 82–94 (1980). https://doi.org/10.1007/BF02722403

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