The role of divertor collisionality on SOL transport: A study on the ITER stepladder

D. Carralero, H.W. Müller, M. Groth, M. Komm, J. Adamek, Leena Aho-Mantila, G. Birkenmeier, M. Brix, F. Jankyc, P. Hacek, S. Marsen, F. Reymold, C. Silva, U. Stroth, M. Wischmeier, E. Wolfrum, ASDEX Update Group, JET Contributors

Research output: Contribution to journalOther journal contributionScientific

Abstract

The L-mode SOL density transition is experimentally investigated in three tokamaks of the ITER stepladder (COMPASS, AUG and JET). The results confirm the relevance of divertor detachment in the SOL profile transition: Both AUG and JET show significant changes in the outer midplane density profiles and increase in the size and velocity of filaments at the same densities in which the LFS divertor surpasses its ion saturation roll-over. Meanwhile, the COMPASS divertor remains attached and no clear signs of transition are observed in the midplane. Furthermore, according to a filament model by Myra et al., only the changes of collisionality in the divertor are sufficient to trigger the transition in both cases. An extrapolation from these results indicates that this broadening is to be expected in ITER despite having a collisionless SOL in the main chamber, since the disconnection of filaments will take place in the partially detached divertor.
Original languageEnglish
Article numberTO3.00005
Number of pages1
JournalBulletin of the American Physical Society
Volume59
Issue number15
Publication statusPublished - 2014
MoE publication typeB1 Article in a scientific magazine
Event56th Annual Meeting of the APS Division of Plasma Physics, DDP14 - New Orleans, United States
Duration: 27 Oct 201431 Oct 2014
Conference number: 56

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COMPASS (programming language)
filaments
profiles
detachment
extrapolation
actuators
chambers
saturation
ions

Cite this

Carralero, D., Müller, H. W., Groth, M., Komm, M., Adamek, J., Aho-Mantila, L., ... JET Contributors (2014). The role of divertor collisionality on SOL transport: A study on the ITER stepladder. Bulletin of the American Physical Society, 59(15), [TO3.00005].
Carralero, D. ; Müller, H.W. ; Groth, M. ; Komm, M. ; Adamek, J. ; Aho-Mantila, Leena ; Birkenmeier, G. ; Brix, M. ; Jankyc, F. ; Hacek, P. ; Marsen, S. ; Reymold, F. ; Silva, C. ; Stroth, U. ; Wischmeier, M. ; Wolfrum, E. ; ASDEX Update Group ; JET Contributors. / The role of divertor collisionality on SOL transport : A study on the ITER stepladder. In: Bulletin of the American Physical Society. 2014 ; Vol. 59, No. 15.
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title = "The role of divertor collisionality on SOL transport: A study on the ITER stepladder",
abstract = "The L-mode SOL density transition is experimentally investigated in three tokamaks of the ITER stepladder (COMPASS, AUG and JET). The results confirm the relevance of divertor detachment in the SOL profile transition: Both AUG and JET show significant changes in the outer midplane density profiles and increase in the size and velocity of filaments at the same densities in which the LFS divertor surpasses its ion saturation roll-over. Meanwhile, the COMPASS divertor remains attached and no clear signs of transition are observed in the midplane. Furthermore, according to a filament model by Myra et al., only the changes of collisionality in the divertor are sufficient to trigger the transition in both cases. An extrapolation from these results indicates that this broadening is to be expected in ITER despite having a collisionless SOL in the main chamber, since the disconnection of filaments will take place in the partially detached divertor.",
author = "D. Carralero and H.W. M{\"u}ller and M. Groth and M. Komm and J. Adamek and Leena Aho-Mantila and G. Birkenmeier and M. Brix and F. Jankyc and P. Hacek and S. Marsen and F. Reymold and C. Silva and U. Stroth and M. Wischmeier and E. Wolfrum and {ASDEX Update Group} and {JET Contributors}",
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language = "English",
volume = "59",
journal = "Bulletin of the American Physical Society",
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Carralero, D, Müller, HW, Groth, M, Komm, M, Adamek, J, Aho-Mantila, L, Birkenmeier, G, Brix, M, Jankyc, F, Hacek, P, Marsen, S, Reymold, F, Silva, C, Stroth, U, Wischmeier, M, Wolfrum, E, ASDEX Update Group & JET Contributors 2014, 'The role of divertor collisionality on SOL transport: A study on the ITER stepladder', Bulletin of the American Physical Society, vol. 59, no. 15, TO3.00005.

The role of divertor collisionality on SOL transport : A study on the ITER stepladder. / Carralero, D.; Müller, H.W.; Groth, M.; Komm, M.; Adamek, J.; Aho-Mantila, Leena; Birkenmeier, G.; Brix, M.; Jankyc, F.; Hacek, P.; Marsen, S.; Reymold, F.; Silva, C.; Stroth, U.; Wischmeier, M.; Wolfrum, E.; ASDEX Update Group; JET Contributors.

In: Bulletin of the American Physical Society, Vol. 59, No. 15, TO3.00005, 2014.

Research output: Contribution to journalOther journal contributionScientific

TY - JOUR

T1 - The role of divertor collisionality on SOL transport

T2 - A study on the ITER stepladder

AU - Carralero, D.

AU - Müller, H.W.

AU - Groth, M.

AU - Komm, M.

AU - Adamek, J.

AU - Aho-Mantila, Leena

AU - Birkenmeier, G.

AU - Brix, M.

AU - Jankyc, F.

AU - Hacek, P.

AU - Marsen, S.

AU - Reymold, F.

AU - Silva, C.

AU - Stroth, U.

AU - Wischmeier, M.

AU - Wolfrum, E.

AU - ASDEX Update Group

AU - JET Contributors

N1 - CA2: BA2121

PY - 2014

Y1 - 2014

N2 - The L-mode SOL density transition is experimentally investigated in three tokamaks of the ITER stepladder (COMPASS, AUG and JET). The results confirm the relevance of divertor detachment in the SOL profile transition: Both AUG and JET show significant changes in the outer midplane density profiles and increase in the size and velocity of filaments at the same densities in which the LFS divertor surpasses its ion saturation roll-over. Meanwhile, the COMPASS divertor remains attached and no clear signs of transition are observed in the midplane. Furthermore, according to a filament model by Myra et al., only the changes of collisionality in the divertor are sufficient to trigger the transition in both cases. An extrapolation from these results indicates that this broadening is to be expected in ITER despite having a collisionless SOL in the main chamber, since the disconnection of filaments will take place in the partially detached divertor.

AB - The L-mode SOL density transition is experimentally investigated in three tokamaks of the ITER stepladder (COMPASS, AUG and JET). The results confirm the relevance of divertor detachment in the SOL profile transition: Both AUG and JET show significant changes in the outer midplane density profiles and increase in the size and velocity of filaments at the same densities in which the LFS divertor surpasses its ion saturation roll-over. Meanwhile, the COMPASS divertor remains attached and no clear signs of transition are observed in the midplane. Furthermore, according to a filament model by Myra et al., only the changes of collisionality in the divertor are sufficient to trigger the transition in both cases. An extrapolation from these results indicates that this broadening is to be expected in ITER despite having a collisionless SOL in the main chamber, since the disconnection of filaments will take place in the partially detached divertor.

M3 - Other journal contribution

VL - 59

JO - Bulletin of the American Physical Society

JF - Bulletin of the American Physical Society

SN - 0003-0503

IS - 15

M1 - TO3.00005

ER -