The properties of plasma turbulence in a poloidally limited scrape-off layer (SOL) are addressed, with focus on ISTTOK, a large aspect ratio tokamak with a circular cross section. Theoretical investigations based on the drift-reduced Braginskii equations are carried out through linear calculations and non-linear simulations, in two- and three-dimensional geometries. The linear instabilities driving turbulence and the mechanisms that set the amplitude of turbulence as well as the SOL width are identified. A clear asymmetry is shown to exist between the low-field and the high-field sides of the machine. While the comparison between experimental measurements and simulation results shows good agreement in the far SOL, large intermittent events in the near SOL, detected in the experiments, are not captured by the simulations.

1.
P.
Ricci
, “
Simulation of the scrape-off layer region of tokamak devices
,”
J. Plasma Phys.
81
(
02
),
435810202
(
2015
).
2.
T.
Eich
,
A.
Leonard
,
R.
Pitts
,
W.
Fundamenski
,
R.
Goldston
,
T.
Gray
,
A.
Herrmann
,
A.
Kirk
,
A.
Kallenbach
,
O.
Kardaun
,
A.
Kukushkin
,
B.
LaBombard
,
R.
Maingi
,
M.
Makowski
,
A.
Scarabosio
,
B.
Sieglin
,
J.
Terry
, and
A.
Thornton
, “
Scaling of the tokamak near the scrape-off layer H-mode power width and implications for ITER
,”
Nucl. Fusion
53
(
9
),
093031
(
2013
).
3.
A.
Kukushkin
,
H.
Pacher
,
V.
Kotov
,
G.
Pacher
, and
D.
Reiter
, “
Finalizing the ITER divertor design: The key role of SOLPS modeling
,”
Fusion Eng. Des.
86
(
12
),
2865
2873
(
2011
).
4.
ITER Physics Expert Group on Divertor
, ITER Physics Expert Group on Divertor Modelling and Database, and ITER Physics Basis Editors, “
Chapter 4: Power and particle control
,”
Nucl. Fusion
39
(
12
),
2391
2469
(
2002
).
5.
B.
Lipschultz
,
X.
Bonnin
,
G.
Counsell
,
A.
Kallenbach
,
A.
Kukushkin
,
K.
Krieger
,
A.
Leonard
,
A.
Loarte
,
R.
Neu
,
R.
Pitts
,
T.
Rognlien
,
J.
Roth
,
C.
Skinner
,
J.
Terry
,
E.
Tsitrone
,
D.
Whyte
,
S.
Zweben
,
N.
Asakura
,
D.
Coster
,
R.
Doerner
,
R.
Dux
,
G.
Federici
,
M.
Fenstermacher
,
W.
Fundamenski
,
P.
Ghendrih
,
A.
Herrmann
,
J.
Hu
,
S.
Krasheninnikov
,
G.
Kirnev
,
A.
Kreter
,
V.
Kurnaev
,
B.
LaBombard
,
S.
Lisgo
,
T.
Nakano
,
N.
Ohno
,
H.
Pacher
,
J.
Paley
,
Y.
Pan
,
G.
Pautasso
,
V.
Philipps
,
V.
Rohde
,
D.
Rudakov
,
P.
Stangeby
,
S.
Takamura
,
T.
Tanabe
,
Y.
Yang
, and
S.
Zhu
, “
Plasma–surface interaction, scrape-off layer and divertor physics: Implications for ITER
,”
Nucl. Fusion
47
(
9
),
1189
1205
(
2007
).
6.
D.
D'Ippolito
,
J.
Myra
, and
S.
Zweben
, “
Convective transport by intermittent blob-filaments: Comparison of theory and experiment
,”
Phys. Plasmas
18
,
060501
(
2011
).
7.
T.
Ribeiro
and
B.
Scott
, “
Gyrofluid turbulence studies of the effect of the poloidal position of an axisymmetric Debye sheath
,”
Plasma Phys. Controlled Fusion
50
(
5
),
055007
(
2008
).
8.
P.
Tamain
,
H.
Bufferand
,
G.
Ciraolo
,
C.
Colin
,
P.
Ghendrih
,
F.
Schwander
, and
E.
Serre
, “
3D properties of edge turbulent transport in full-torus simulations and their impact on poloidal asymmetries
,”
Contrib. Plasma Phys.
54
(
4–6
),
555
559
(
2014
).
9.
P.
Ricci
and
B.
Rogers
, “
Plasma turbulence in the scrape-off layer of tokamak devices
,”
Phys. Plasmas
20
(
1
),
010702
(
2013
).
10.
G.
Arnoux
,
T.
Farley
,
C.
Silva
,
S.
Devaux
,
M.
Firdaouss
,
D.
Frigione
,
R.
Goldston
,
J.
Gunn
,
J.
Horacek
,
S.
Jachmich
,
P.
Lomas
,
S.
Marsen
,
G.
Matthews
,
R.
Pitts
,
M.
Stamp
, and
P.
Stangeby
, “
Scrape-off layer properties of ITER-like limiter start-up plasmas in JET
,”
Nucl. Fusion
53
(
7
),
073016
(
2013
).
11.
G.
Jackson
,
T.
Casper
,
T.
Luce
,
D.
Humphreys
,
J.
Ferron
,
A.
Hyatt
,
J.
Leuer
,
T.
Petrie
,
F.
Turco
, and
W.
West
, “
Simulating ITER plasma startup and rampdown scenarios in the DIII-D tokamak
,”
Nucl. Fusion
49
(
11
),
115027
(
2009
).
12.
A.
Mosetto
,
F.
Halpern
,
S.
Jolliet
, and
P.
Ricci
, “
Low-frequency linear-mode regimes in the tokamak scrape-off layer
,”
Phys. Plasmas
19
(
11
),
112103
(
2012
).
13.
B.
LaBombard
,
J.
Hughes
,
D.
Mossessian
,
M.
Greenwald
,
B.
Lipschultz
,
J.
Terry
, and
Alcator C-Mod Team
, “
Evidence for electromagnetic fluid drift turbulence controlling the edge plasma state in the Alcator C-Mod tokamak
,”
Nucl. Fusion
45
(
12
),
1658
(
2005
).
14.
B.
Labombard
,
J.
Hughes
,
N.
Smick
,
A.
Graf
,
K.
Marr
,
R.
McDermott
,
M.
Reinke
,
M.
Greenwald
,
B.
Lipschultz
,
J.
Terry
,
D.
Whyte
, and
S.
Zweben
, “
Critical gradients and plasma flows in the edge plasma of Alcator C-Mod
,”
Phys. Plasmas
15
(
5
),
056106
(
2008
).
15.
F.
Halpern
,
J.
Terry
,
S.
Zweben
,
B.
LaBombard
,
M.
Podesta
, and
P.
Ricci
, “
Comparison of 3D flux-driven scrape-off layer turbulence simulations with gas-puff imaging of Alcator C-Mod inner-wall limited discharges
,”
Plasma Phys. Controlled Fusion
57
(
5
),
054005
(
2015
).
16.
C.
Varandas
,
J.
Cabral
, and
J.
Mendonça
, “
Engineering aspects of the tokamak ISTTOK
,”
Fusion Technol.
29
(
1
),
105
115
(
1996
).
17.
C.
Silva
,
P.
Duarte
,
H.
Fernandes
,
H.
Figueiredo
,
I.
Nedzelskij
,
C.
Hidalgo
, and
M.
Pedrosa
, “
Characterization of geodesic acoustic modes in the ISTTOK edge plasma
,”
Plasma Phys. Controlled Fusion
51
(
8
),
085009
(
2009
).
18.
A.
Zeiler
,
J.
Drake
, and
B.
Rogers
, “
Nonlinear reduced Braginskii equations with ion thermal dynamics in toroidal plasma
,”
Phys. Plasmas
4
,
2134
(
1997
).
19.
P.
Ricci
,
F.
Halpern
,
S.
Jolliet
,
J.
Loizu
,
A.
Mosetto
,
A.
Fasoli
,
I.
Furno
, and
C.
Theiler
, “
Simulation of plasma turbulence in scrape-off layer conditions: The GBS code, simulation results and code validation
,”
Plasma Phys. Controlled Fusion
54
(
12
),
124047
(
2012
).
20.
F.
Halpern
,
P.
Ricci
,
S.
Jolliet
,
J.
Loizu
,
J.
Morales
,
A.
Mosetto
,
F.
Musil
,
F.
Riva
,
T.
Tran
, and
C.
Wersal
, “
The GBS code for tokamak scrape-off layer simulations
,”
J. Comput. Phys.
315
,
388
408
(
2016
).
21.
P.
Ricci
,
C.
Theiler
,
A.
Fasoli
,
I.
Furno
,
B.
Labit
,
S.
Muller
,
M.
Podesta
, and
F.
Poli
, “
Langmuir probe-based observables for plasma-turbulence code validation and application to the TORPEX basic plasma physics experiment
,”
Phys. Plasmas
16
(
5
),
055703
(
2009
).
22.
F.
Riva
,
C.
Colin
,
J.
Denis
,
L.
Easy
,
I.
Furno
,
J.
Madsen
,
F.
Militello
,
V.
Naulin
,
A.
Nielsen
,
J.
Olsen
,
J.
Omotani
,
J.
Rasmussen
,
P.
Ricci
,
E.
Serre
,
P.
Tamain
, and
C.
Theiler
, “
Blob dynamics in the TORPEX experiment: A multi-code validation
,”
Plasma Phys. Controlled Fusion
58
(
4
),
044005
(
2016
).
23.
B.
Dudson
,
M.
Umansky
,
X.
Xu
,
P.
Snyder
, and
H.
Wilson
, “
BOUT++: A framework for parallel plasma fluid simulations
,”
Comput. Phys. Commun.
180
(
9
),
1467
1480
(
2009
).
24.
A.
Nielsen
,
G.
Xu
,
J.
Madsen
,
V.
Naulin
,
J.
Juul Rasmussen
, and
B.
Wan
, “
Simulation of transition dynamics to high confinement in fusion plasmas
,”
Phys. Lett. A
379
(
47–48
),
3097
3101
(
2015
).
25.
C.
Silva
,
H.
Figueiredo
,
P.
Duarte
, and
H.
Fernandes
, “
Poloidal asymmetries in the ISTTOK edge plasma
,”
J. Nucl. Mater.
415
(
1
),
S455
S458
(
2011
).
26.
S.
Braginskii
, “
Transport processes in a plasma
,”
Rev. Plasma Phys.
1
(
6
),
205
(
1965
).
27.
F.
Halpern
,
S.
Jolliet
,
J.
Loizu
,
A.
Mosetto
, and
P.
Ricci
, “
Ideal ballooning modes in the tokamak scrape-off layer
,”
Phys. Plasmas
20
(
5
),
052306
(
2013
).
28.
J.
Loizu
,
P.
Ricci
,
F.
Halpern
, and
S.
Jolliet
, “
Boundary conditions for plasma fluid models at the magnetic presheath entrance
,”
Phys. Plasmas
19
(
12
),
122307
(
2012
).
29.
R.
Hastie
,
J.
Ramos
, and
F.
Porcelli
, “
Drift ballooning instabilities in tokamak edge plasmas
,”
Phys. Plasmas
10
(
11
),
4405
4412
(
2003
).
30.
S.
Shchepetov
,
Y.
Kholnov
, and
D.
Vasil'kov
, “
On the phase shift between electric potential and plasma density fluctuations in the edge turbulence
,”
Plasma Phys. Rep.
39
(
2
),
130
138
(
2013
).
31.
A.
Mosetto
,
F.
Halpern
,
S.
Jolliet
,
J.
Loizu
, and
P.
Ricci
, “
Turbulent regimes in the tokamak scrape-off layer
,”
Phys. Plasmas
20
(
9
),
092308
(
2013
).
32.
B.
Rogers
and
P.
Ricci
, “
Low-frequency turbulence in a linear magnetized plasma
,”
Phys. Rev. Lett.
104
(
22
),
225002
(
2010
).
33.
P.
Ricci
,
C.
Theiler
,
A.
Fasoli
,
I.
Furno
,
K.
Gustafson
,
D.
Iraji
, and
J.
Loizu
, “
Methodology for turbulence code validation: Quantification of simulation-experiment agreement and application to the TORPEX experiment
,”
Phys. Plasmas
18
(
3
),
032109
(
2011
).
34.
P.
Ricci
and
B.
Rogers
, “
Turbulence phase space in simple magnetized toroidal plasmas
,”
Phys. Rev. Lett.
104
(
14
),
145001
(
2010
).
35.
P.
Ricci
,
B.
Rogers
, and
W.
Dorland
, “
Small-scale turbulence in a closed-field-line geometry
,”
Phys. Rev. Lett.
97
(
24
),
245001
(
2006
).
36.
J.
Myra
,
D.
D'Ippolito
, and
D.
Russell
, “
Turbulent transport regimes and the scrape-off layer heat flux width
,”
Phys. Plasmas
22
(
4
),
042516
(
2015
).
37.
P.
Ricci
and
B.
Rogers
, “
Three-dimensional fluid simulations of a simple magnetized toroidal plasma
,”
Phys. Plasmas
16
(
9
),
092307
(
2009
).
38.
B.
Rogers
and
W.
Dorland
, “
Noncurvature-driven modes in a transport barrier
,”
Phys. Plasmas
12
(
6
),
062511
(
2005
).
39.
D.
Muller
, “
A method for solving algebraic equations using an automatic computer
,”
Math. Tables Other Aids Comput.
10
(
56
),
208
215
(
1956
).
40.
L.
Lanzani
and
Z.
Shen
, “
On the robin boundary condition for Laplace's equation in Lipschitz domains
,”
Commun. Partial Differ. Equations
29
(
1–2
),
91
109
(
2005
).
41.
C.
Silva
,
J.
Adamek
,
H.
Fernandes
, and
H.
Figueiredo
, “
Comparison of fluctuations properties measured by Langmuir and ball-pen probes in the ISTTOK boundary plasma
,”
Plasma Phys. Controlled Fusion
57
(
2
),
025003
(
2015
).
42.
E.
Sanchez
,
C.
Hidalgo
,
D.
Lopez-Bruna
,
I.
Garcia-Cortes
,
R.
Balbin
,
M.
Pedrosa
,
B.
van Milligen
,
C.
Riccardi
,
G.
Chiodini
,
J.
Bleuel
,
M.
Endler
,
B.
Carreras
,
D.
Newman
, and
B.
Milligen
, “
Statistical characterization of fluctuation wave forms in the boundary region of fusion and nonfusion plasmas
,”
Phys. Plasmas
7
,
1408
(
2000
).
43.
I.
Nanobashvili
,
J.
Gunn
, and
P.
Devynck
, “
Radial profiles of plasma turbulent fluctuations in the scrape-off layer of the Tore Supra tokamak
,”
J. Nucl. Mater.
363–365
(
1–3
),
622
627
(
2007
).
44.
Y.
Xu
,
S.
Jachmich
,
R.
Weynants
, and
TEXTOR Team
, “
On the properties of turbulence intermittency in the boundary of the TEXTOR tokamak
,”
Plasma Phys. Controlled Fusion
47
(
10
),
1841
1855
(
2005
).
45.
G.
Xu
,
V.
Naulin
,
W.
Fundamenski
,
J.
Rasmussen
,
A.
Nielsen
, and
B.
Wan
, “
Intermittent convective transport carried by propagating electromagnetic filamentary structures in nonuniformly magnetized plasma
,”
Phys. Plasmas
17
(
2
),
022501
(
2010
).
46.
I.
Furno
,
C.
Theiler
,
D.
Lançon
,
A.
Fasoli
,
D.
Iraji
,
P.
Ricci
,
M.
Spolaore
, and
N.
Vianello
, “
Blob current structures in torpex plasmas: Experimental measurements and numerical simulations
,”
Plasma Phys. Controlled Fusion
53
(
12
),
124016
(
2011
).
47.
B.
Carreras
,
R.
Balbin
,
B.
van Milligen
,
M.
Pedrosa
,
I.
Garcia-Cortes
,
E.
Sanchez
,
C.
Hidalgo
,
J.
Bleuel
,
M.
Endler
,
H.
Thomsen
,
A.
Chankin
,
S.
Davies
,
K.
Erents
, and
G.
Matthews
, “
Characterization of the frequency ranges of the plasma edge fluctuation spectra
,”
Phys. Plasmas
6
(
12
),
4615
(
1999
).
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