Progress Report DITS project : 13 July 2007 1 TORE SUPRA Association Euratom-Cea A. Ekedahl et al Operational Limits during the TPL Deuterium Loading Experiment _______________________ F. Saint-Laurent, F. Rimini, A. Ekedahl, E. Tsitrone, A. Triay-Alcouffe, P. Monier-Garbet et al Overview of the 10 days experiment (talk E. Tsitrone) Main Limitation: Disruptions Revised scenario Probability of UFOs and Disruptions Appearance of UFOs Origin of UFOs Analysis of IR and CCD films Conclusions
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1 TORE SUPRA Association Euratom-Cea A. Ekedahl et al Progress Report DITS project : 13 July 2007 Operational Limits during the TPL Deuterium Loading Experiment.
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Progress Report DITS project : 13 July 2007 1
TORE SUPRA
AssociationEuratom-Cea
A. Ekedahl et al
Operational Limits during the TPL Deuterium Loading Experiment
_______________________
Operational Limits during the TPL Deuterium Loading Experiment
_______________________
F. Saint-Laurent, F. Rimini, A. Ekedahl, E. Tsitrone, A. Triay-Alcouffe, P. Monier-Garbet et al
Overview of the 10 days experiment (talk E. Tsitrone)
Main Limitation: Disruptions Revised scenario
Probability of UFOs and Disruptions
Appearance of UFOs
Origin of UFOs Analysis of IR and CCD films
Conclusions
Progress Report DITS project : 13 July 2007 2
TORE SUPRA
AssociationEuratom-Cea
A. Ekedahl et al
0
20
40
60
80
100
120
140
1 2 3 4 5 6 7 8 9 10
nb of disruption shot > 120 s
60< shot < 120 s percentage disruption
nb of UFOs
Performance evolution over 10 daysPerformance evolution over 10 days
[F. Saint-Laurent, F. Rimini]
Day
Number of UFOs
% Disruptions
Scenario 2
Scenario 1: Ip = 0.6MA, PLH = 2MW, 120 s pulse duration
Scenario 2: PLH reduced, ~80 s duration
Progress Report DITS project : 13 July 2007 3
TORE SUPRA
AssociationEuratom-Cea
A. Ekedahl et al
Probability of UFOs and disruptionsProbability of UFOs and disruptions
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
1 2 3 4 5 6 7 8 9 10
# of UFOs per 100s Disruption per 100s (*5)
Day
Disruption probability follows the number of UFOs. 10-20% of UFOs lead to disruption
Definition of UFO: Increase in Prad > 20%
34 34.5 350
0.5
1
1.5
2TS #39928
Prad (MW)
Time (s)
threshold
# of UFOs per 100s of plasma# of disruption per 100s of plasma
Progress Report DITS project : 13 July 2007 4
TORE SUPRA
AssociationEuratom-Cea
A. Ekedahl et al
23/05/07 (Day 3) : clean pulses
Appearance of UFOs: Scenario 1Appearance of UFOs: Scenario 1
[E. Tsitrone]
Progress Report DITS project : 13 July 2007 5
TORE SUPRA
AssociationEuratom-Cea
A. Ekedahl et al
23/05/07 (day 3) : almost no UFOs …01/06/07 (Day 7): lots of UFOs, and disruptions.UFOs appear when PLH is first applied, then more sporadic
Appearance of UFOs: Scenario 1Appearance of UFOs: Scenario 1
[E. Tsitrone]
LH power is switched off by the safety system when UFOs appear
Progress Report DITS project : 13 July 2007 6
TORE SUPRA
AssociationEuratom-Cea
A. Ekedahl et al
Day 10 : Search of power limit Day 10 : Search of power limit
Scenario 2: PLH limited to 1.6-1.8 MW
[E. Tsitrone]
Reduced PLH No UFOs
Progress Report DITS project : 13 July 2007 7
TORE SUPRA
AssociationEuratom-Cea
A. Ekedahl et al
Time distribution of UFOsTime distribution of UFOs
29 shots with LH power 117 UFOs
24 shots with LH power 33 UFOs
Day 7
Day 3
3 disruptions
19 disruptions
Progress Report DITS project : 13 July 2007 8
TORE SUPRA
AssociationEuratom-Cea
A. Ekedahl et al
IR analysis of disruptionsIR analysis of disruptions
Number of disruptions 62Disruptions with IR data available 59
1st originArcs in front of launcher prior to disruption 18 30%Carbon flakes from side protections prior to arcing 10
2nd originHot spot on TPL prior to disruption (Q6 and Q5) 14Hot spot on TPL prior to disruption (Q6 => 1/6 of TPL) 10 17%
Both origins simultaneously 0
IR cameras to monitor : both LH launchers 1/6 of the TPL (Q6) ~1/18 of the TPL with high resolution (Q5)
Heating on high field side on TPL prior to disruption
Overheating of co-deposited layers prior to disruption
Progress Report DITS project : 13 July 2007 12
TORE SUPRA
AssociationEuratom-Cea
A. Ekedahl et al
bolo3/bolo14
HFSLFS
314
PLH
Zeff-2
Ip
b3/b14
nl
0-100ms before LH is cut off
steady phase
TS39868
A MARFE is triggered before the disruption
A MARFE is triggered before the disruption
[P. Monier-Garbet]The ratio of the signals from two bolometer sight-lines indicate the roll-over of the radiation towards the HFS (MARFE)
Progress Report DITS project : 13 July 2007 13
TORE SUPRA
AssociationEuratom-Cea
A. Ekedahl et al
Appearance of UFO (IR camera)Appearance of UFO (IR camera)
Overheating of CFC tile on TPL => UFO
Hot spot on TPL appears at ~48.3s. Increase of electron density and radiated power (UFO). Then the tile remains overheated, but ne and Prad are recovered until the plasma disrupts ~50s later.
39922, t = 48.5s
Q6A
Progress Report DITS project : 13 July 2007 14
TORE SUPRA
AssociationEuratom-Cea
A. Ekedahl et al
Appearance of UFOs (visible CCD camera)
Appearance of UFOs (visible CCD camera)
T1T2
T3T4
T5 T6
OriginUnknown : 30 %From TPL : 70 %
Localisation of UFOs from TPL for 2 days1/3rd of TPL is observed
0
5
10
15
20
25
30
35
40
45
50
0 1 2 3 4 5 6 7
ovni010607 ovni070607
Number of UFOs :01/06/07 (day 7) : 598 (CCD) [117 from Prad]07/06/07 (day 10) : 325 (CCD) [80 from Prad]
1/18th = if equal repartition
T1 T2 T3 T4 T5 T6
Per
cen
tag
e
[A. Triay-Alcouffe]
Progress Report DITS project : 13 July 2007 15
TORE SUPRA
AssociationEuratom-Cea
A. Ekedahl et al
ConclusionsConclusions
The TPL loading campaign was limited by disruptions, induced by UFOs.
Two strategies were applied :- Modified impurity safety system (fast switch-off of LH power) PLH reduced for all impurity influx (C, Cu, Fe, …) not enough.
- Reduced PLH in beginning of pulse, followed by slow PLH ramp-up 80s pulse duration OK until end of campaign.
LH power limit : ~1.6 MW at the end of the campaign.
- Statistical limit : associated with the probability of UFOs to appear. 10-20% of the UFOs lead to disruption.- Dynamical limit : the power threshold seemed to decreased with time.
Analysis of CCD and IR films indicate that most UFOs seem to originate from the TPL.