Overview of ASDEX upgrade results

D. Aguiam, Leena Aho-Mantila, C. Angioni, N. Arden, R. Arredondo Parra, O. Asunta, M. De Baar, M. Balden, K. Behler, A. Bergmann, J. Bernardo, M. Bernert, M. Beurskens, A. Biancalani, R. Bilato, G. Birkenmeier, V. Bobkov, A. Bock, A. Bogomolov, T. BolzonellaB. Böswirth, C. Bottereau, A. Bottino, H. Van Den Brand, S. Brezinsek, D. Brida, F. Brochard, C. Bruhn, J. Buchanan, A. Buhler, A. Burckhart, D. Cambon-Silva, Y. Camenen, P. Carvalho, G. Carrasco, C. Cazzaniga, M. Carr, D. Carralero, L. Casali, C. Castaldo, M. Cavedon, C. Challis, A. Chankin, I. Chapman, F. Clairet, I. Classen, S. Coda, R. Coelho, Antti H. Hakola, Antti Salmi, A. Kallenbach, ASDEX Upgrade Team,

    Research output: Contribution to journalReview ArticleScientificpeer-review

    24 Citations (Scopus)

    Abstract

    The ASDEX Upgrade (AUG) programme is directed towards physics input to critical elements of the ITER design and the preparation of ITER operation, as well as addressing physics issues for a future DEMO design. Since 2015, AUG is equipped with a new pair of 3-strap ICRF antennas, which were designed for a reduction of tungsten release during ICRF operation. As predicted, a factor two reduction on the ICRF-induced W plasma content could be achieved by the reduction of the sheath voltage at the antenna limiters via the compensation of the image currents of the central and side straps in the antenna frame. There are two main operational scenario lines in AUG. Experiments with low collisionality, which comprise current drive, ELM mitigation/suppression and fast ion physics, are mainly done with freshly boronized walls to reduce the tungsten influx at these high edge temperature conditions. Full ELM suppression and non-inductive operation up to a plasma current of Ip = 0.8 MA could be obtained at low plasma density. Plasma exhaust is studied under conditions of high neutral divertor pressure and separatrix electron density, where a fresh boronization is not required. Substantial progress could be achieved for the understanding of the confinement degradation by strong D puffing and the improvement with nitrogen or carbon seeding. Inward/outward shifts of the electron density profile relative to the temperature profile effect the edge stability via the pressure profile changes and lead to improved/decreased pedestal performance. Seeding and D gas puffing are found to effect the core fueling via changes in a region of high density on the high field side (HFSHD). The integration of all above mentioned operational scenarios will be feasible and naturally obtained in a large device where the edge is more opaque for neutrals and higher plasma temperatures provide a lower collisionality. The combination of exhaust control with pellet fueling has been successfully demonstrated. High divertor enrichment values of nitrogen EN ≥ 10 have been obtained during pellet injection, which is a prerequisite for the simultaneous achievement of good core plasma purity and high divertor radiation levels. Impurity accumulation observed in the all-metal AUG device caused by the strong neoclassical inward transport of tungsten in the pedestal is expected to be relieved by the higher neoclassical temperature screening in larger devices.

    Original languageEnglish
    Article number102015
    JournalNuclear Fusion
    Volume57
    Issue number10
    DOIs
    Publication statusPublished - 28 Jun 2017
    MoE publication typeA2 Review article in a scientific journal

    Fingerprint

    straps
    tungsten
    refueling
    antennas
    inoculation
    pellets
    physics
    retarding
    nitrogen
    electron density profiles
    plasma currents
    high temperature plasmas
    sheaths
    temperature profiles
    plasma density
    purity
    screening
    injection
    degradation
    impurities

    Keywords

    • DEMO
    • ITER
    • nuclear fusion
    • tokamak physics

    Cite this

    Aguiam, D., Aho-Mantila, L., Angioni, C., Arden, N., Arredondo Parra, R., Asunta, O. (2017). Overview of ASDEX upgrade results. Nuclear Fusion, 57(10), [102015]. https://doi.org/10.1088/1741-4326/aa64f6
    Aguiam, D. ; Aho-Mantila, Leena ; Angioni, C. ; Arden, N. ; Arredondo Parra, R. ; Asunta, O. ; De Baar, M. ; Balden, M. ; Behler, K. ; Bergmann, A. ; Bernardo, J. ; Bernert, M. ; Beurskens, M. ; Biancalani, A. ; Bilato, R. ; Birkenmeier, G. ; Bobkov, V. ; Bock, A. ; Bogomolov, A. ; Bolzonella, T. ; Böswirth, B. ; Bottereau, C. ; Bottino, A. ; Van Den Brand, H. ; Brezinsek, S. ; Brida, D. ; Brochard, F. ; Bruhn, C. ; Buchanan, J. ; Buhler, A. ; Burckhart, A. ; Cambon-Silva, D. ; Camenen, Y. ; Carvalho, P. ; Carrasco, G. ; Cazzaniga, C. ; Carr, M. ; Carralero, D. ; Casali, L. ; Castaldo, C. ; Cavedon, M. ; Challis, C. ; Chankin, A. ; Chapman, I. ; Clairet, F. ; Classen, I. ; Coda, S. ; Coelho, R. ; Hakola, Antti H. ; Salmi, Antti ; Kallenbach, A. ; ASDEX Upgrade Team. / Overview of ASDEX upgrade results. In: Nuclear Fusion. 2017 ; Vol. 57, No. 10.
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    abstract = "The ASDEX Upgrade (AUG) programme is directed towards physics input to critical elements of the ITER design and the preparation of ITER operation, as well as addressing physics issues for a future DEMO design. Since 2015, AUG is equipped with a new pair of 3-strap ICRF antennas, which were designed for a reduction of tungsten release during ICRF operation. As predicted, a factor two reduction on the ICRF-induced W plasma content could be achieved by the reduction of the sheath voltage at the antenna limiters via the compensation of the image currents of the central and side straps in the antenna frame. There are two main operational scenario lines in AUG. Experiments with low collisionality, which comprise current drive, ELM mitigation/suppression and fast ion physics, are mainly done with freshly boronized walls to reduce the tungsten influx at these high edge temperature conditions. Full ELM suppression and non-inductive operation up to a plasma current of Ip = 0.8 MA could be obtained at low plasma density. Plasma exhaust is studied under conditions of high neutral divertor pressure and separatrix electron density, where a fresh boronization is not required. Substantial progress could be achieved for the understanding of the confinement degradation by strong D puffing and the improvement with nitrogen or carbon seeding. Inward/outward shifts of the electron density profile relative to the temperature profile effect the edge stability via the pressure profile changes and lead to improved/decreased pedestal performance. Seeding and D gas puffing are found to effect the core fueling via changes in a region of high density on the high field side (HFSHD). The integration of all above mentioned operational scenarios will be feasible and naturally obtained in a large device where the edge is more opaque for neutrals and higher plasma temperatures provide a lower collisionality. The combination of exhaust control with pellet fueling has been successfully demonstrated. High divertor enrichment values of nitrogen EN ≥ 10 have been obtained during pellet injection, which is a prerequisite for the simultaneous achievement of good core plasma purity and high divertor radiation levels. Impurity accumulation observed in the all-metal AUG device caused by the strong neoclassical inward transport of tungsten in the pedestal is expected to be relieved by the higher neoclassical temperature screening in larger devices.",
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    author = "D. Aguiam and Leena Aho-Mantila and C. Angioni and N. Arden and {Arredondo Parra}, R. and O. Asunta and {De Baar}, M. and M. Balden and K. Behler and A. Bergmann and J. Bernardo and M. Bernert and M. Beurskens and A. Biancalani and R. Bilato and G. Birkenmeier and V. Bobkov and A. Bock and A. Bogomolov and T. Bolzonella and B. B{\"o}swirth and C. Bottereau and A. Bottino and {Van Den Brand}, H. and S. Brezinsek and D. Brida and F. Brochard and C. Bruhn and J. Buchanan and A. Buhler and A. Burckhart and D. Cambon-Silva and Y. Camenen and P. Carvalho and G. Carrasco and C. Cazzaniga and M. Carr and D. Carralero and L. Casali and C. Castaldo and M. Cavedon and C. Challis and A. Chankin and I. Chapman and F. Clairet and I. Classen and S. Coda and R. Coelho and Hakola, {Antti H.} and Antti Salmi and A. Kallenbach and {ASDEX Upgrade Team}",
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    Aguiam, D, Aho-Mantila, L, Angioni, C, Arden, N, Arredondo Parra, R, Asunta, O, De Baar, M, Balden, M, Behler, K, Bergmann, A, Bernardo, J, Bernert, M, Beurskens, M, Biancalani, A, Bilato, R, Birkenmeier, G, Bobkov, V, Bock, A, Bogomolov, A, Bolzonella, T, Böswirth, B, Bottereau, C, Bottino, A, Van Den Brand, H, Brezinsek, S, Brida, D, Brochard, F, Bruhn, C, Buchanan, J, Buhler, A, Burckhart, A, Cambon-Silva, D, Camenen, Y, Carvalho, P, Carrasco, G, Cazzaniga, C, Carr, M, Carralero, D, Casali, L, Castaldo, C, Cavedon, M, Challis, C, Chankin, A, Chapman, I, Clairet, F, Classen, I, Coda, S, Coelho, R, Hakola, AH, Salmi, A, Kallenbach, A, ASDEX Upgrade Team 2017, 'Overview of ASDEX upgrade results', Nuclear Fusion, vol. 57, no. 10, 102015. https://doi.org/10.1088/1741-4326/aa64f6

    Overview of ASDEX upgrade results. / Aguiam, D.; Aho-Mantila, Leena; Angioni, C.; Arden, N.; Arredondo Parra, R.; Asunta, O.; De Baar, M.; Balden, M.; Behler, K.; Bergmann, A.; Bernardo, J.; Bernert, M.; Beurskens, M.; Biancalani, A.; Bilato, R.; Birkenmeier, G.; Bobkov, V.; Bock, A.; Bogomolov, A.; Bolzonella, T.; Böswirth, B.; Bottereau, C.; Bottino, A.; Van Den Brand, H.; Brezinsek, S.; Brida, D.; Brochard, F.; Bruhn, C.; Buchanan, J.; Buhler, A.; Burckhart, A.; Cambon-Silva, D.; Camenen, Y.; Carvalho, P.; Carrasco, G.; Cazzaniga, C.; Carr, M.; Carralero, D.; Casali, L.; Castaldo, C.; Cavedon, M.; Challis, C.; Chankin, A.; Chapman, I.; Clairet, F.; Classen, I.; Coda, S.; Coelho, R.; Hakola, Antti H.; Salmi, Antti; Kallenbach, A. (Corresponding Author); ASDEX Upgrade Team.

    In: Nuclear Fusion, Vol. 57, No. 10, 102015, 28.06.2017.

    Research output: Contribution to journalReview ArticleScientificpeer-review

    TY - JOUR

    T1 - Overview of ASDEX upgrade results

    AU - Aguiam, D.

    AU - Aho-Mantila, Leena

    AU - Angioni, C.

    AU - Arden, N.

    AU - Arredondo Parra, R.

    AU - Asunta, O.

    AU - De Baar, M.

    AU - Balden, M.

    AU - Behler, K.

    AU - Bergmann, A.

    AU - Bernardo, J.

    AU - Bernert, M.

    AU - Beurskens, M.

    AU - Biancalani, A.

    AU - Bilato, R.

    AU - Birkenmeier, G.

    AU - Bobkov, V.

    AU - Bock, A.

    AU - Bogomolov, A.

    AU - Bolzonella, T.

    AU - Böswirth, B.

    AU - Bottereau, C.

    AU - Bottino, A.

    AU - Van Den Brand, H.

    AU - Brezinsek, S.

    AU - Brida, D.

    AU - Brochard, F.

    AU - Bruhn, C.

    AU - Buchanan, J.

    AU - Buhler, A.

    AU - Burckhart, A.

    AU - Cambon-Silva, D.

    AU - Camenen, Y.

    AU - Carvalho, P.

    AU - Carrasco, G.

    AU - Cazzaniga, C.

    AU - Carr, M.

    AU - Carralero, D.

    AU - Casali, L.

    AU - Castaldo, C.

    AU - Cavedon, M.

    AU - Challis, C.

    AU - Chankin, A.

    AU - Chapman, I.

    AU - Clairet, F.

    AU - Classen, I.

    AU - Coda, S.

    AU - Coelho, R.

    AU - Hakola, Antti H.

    AU - Salmi, Antti

    AU - Kallenbach, A.

    AU - ASDEX Upgrade Team

    PY - 2017/6/28

    Y1 - 2017/6/28

    N2 - The ASDEX Upgrade (AUG) programme is directed towards physics input to critical elements of the ITER design and the preparation of ITER operation, as well as addressing physics issues for a future DEMO design. Since 2015, AUG is equipped with a new pair of 3-strap ICRF antennas, which were designed for a reduction of tungsten release during ICRF operation. As predicted, a factor two reduction on the ICRF-induced W plasma content could be achieved by the reduction of the sheath voltage at the antenna limiters via the compensation of the image currents of the central and side straps in the antenna frame. There are two main operational scenario lines in AUG. Experiments with low collisionality, which comprise current drive, ELM mitigation/suppression and fast ion physics, are mainly done with freshly boronized walls to reduce the tungsten influx at these high edge temperature conditions. Full ELM suppression and non-inductive operation up to a plasma current of Ip = 0.8 MA could be obtained at low plasma density. Plasma exhaust is studied under conditions of high neutral divertor pressure and separatrix electron density, where a fresh boronization is not required. Substantial progress could be achieved for the understanding of the confinement degradation by strong D puffing and the improvement with nitrogen or carbon seeding. Inward/outward shifts of the electron density profile relative to the temperature profile effect the edge stability via the pressure profile changes and lead to improved/decreased pedestal performance. Seeding and D gas puffing are found to effect the core fueling via changes in a region of high density on the high field side (HFSHD). The integration of all above mentioned operational scenarios will be feasible and naturally obtained in a large device where the edge is more opaque for neutrals and higher plasma temperatures provide a lower collisionality. The combination of exhaust control with pellet fueling has been successfully demonstrated. High divertor enrichment values of nitrogen EN ≥ 10 have been obtained during pellet injection, which is a prerequisite for the simultaneous achievement of good core plasma purity and high divertor radiation levels. Impurity accumulation observed in the all-metal AUG device caused by the strong neoclassical inward transport of tungsten in the pedestal is expected to be relieved by the higher neoclassical temperature screening in larger devices.

    AB - The ASDEX Upgrade (AUG) programme is directed towards physics input to critical elements of the ITER design and the preparation of ITER operation, as well as addressing physics issues for a future DEMO design. Since 2015, AUG is equipped with a new pair of 3-strap ICRF antennas, which were designed for a reduction of tungsten release during ICRF operation. As predicted, a factor two reduction on the ICRF-induced W plasma content could be achieved by the reduction of the sheath voltage at the antenna limiters via the compensation of the image currents of the central and side straps in the antenna frame. There are two main operational scenario lines in AUG. Experiments with low collisionality, which comprise current drive, ELM mitigation/suppression and fast ion physics, are mainly done with freshly boronized walls to reduce the tungsten influx at these high edge temperature conditions. Full ELM suppression and non-inductive operation up to a plasma current of Ip = 0.8 MA could be obtained at low plasma density. Plasma exhaust is studied under conditions of high neutral divertor pressure and separatrix electron density, where a fresh boronization is not required. Substantial progress could be achieved for the understanding of the confinement degradation by strong D puffing and the improvement with nitrogen or carbon seeding. Inward/outward shifts of the electron density profile relative to the temperature profile effect the edge stability via the pressure profile changes and lead to improved/decreased pedestal performance. Seeding and D gas puffing are found to effect the core fueling via changes in a region of high density on the high field side (HFSHD). The integration of all above mentioned operational scenarios will be feasible and naturally obtained in a large device where the edge is more opaque for neutrals and higher plasma temperatures provide a lower collisionality. The combination of exhaust control with pellet fueling has been successfully demonstrated. High divertor enrichment values of nitrogen EN ≥ 10 have been obtained during pellet injection, which is a prerequisite for the simultaneous achievement of good core plasma purity and high divertor radiation levels. Impurity accumulation observed in the all-metal AUG device caused by the strong neoclassical inward transport of tungsten in the pedestal is expected to be relieved by the higher neoclassical temperature screening in larger devices.

    KW - DEMO

    KW - ITER

    KW - nuclear fusion

    KW - tokamak physics

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    M3 - Review Article

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    JO - Nuclear Fusion

    JF - Nuclear Fusion

    SN - 0029-5515

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    Aguiam D, Aho-Mantila L, Angioni C, Arden N, Arredondo Parra R, Asunta O et al. Overview of ASDEX upgrade results. Nuclear Fusion. 2017 Jun 28;57(10). 102015. https://doi.org/10.1088/1741-4326/aa64f6