Alcator C-Mod Run 1031218 Information

Miniproposals

Miniproposal: 304

Date Filed: 6/19/2002

Title: H-Mode Regimes

First Author: Martin Greenwald

Session Leader: Dmitri Mossessian (shots 1-30)

Operators
Session leader(s):	Dmitri Mossessian
Physics operator(s):	Bill Rowan
Engineering operator(s):	Unknown

Engineering Operator Run Comment
MP# 304---H-Mode Regimes

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:35:493PM

Author: Dmitri Mossessian

Run summary for 1031218 - MP#304 H-mode regime boundaries.

The purpose of the run was to explore the boundary between EDA and ELMing regimes in plasma
current/shape/pedestal density/pedestal temperature space. To obtain the transition between
EDA and ELMy regimes high pedestal density (above 2e20) and temperature (above 500 eV) are
generally required. This kind of pedestal was achieved previusly in discharges with normalized
beta above 1.2. Threfore, high performance plasmas are necessary for successful completion of
this experiment. Unfortunately, we were not able to obtain high performance EDA discharges
that would be comparable to the discharges where ELMs were previously observed. Therefore, no
progress at all was made in carrying out the MP#304.
However, some progress was achieved in understanding the peculiarities of RF heating
and we were able to obtain first long steady state EDA H-modes in this run campaign.
Obtaining steady state EDA H-mode proved to be rather difficult in the present state of the machine.
We started from 1 MA discharge with target line integral density of about 1.1e20, 4 MW RF power lower
triangularity around 0.6 and upper triangularity around 0.4 - a configuration that produced high
performance EDA during 2000 run campaign. This discharge had multiple
transiennt H-modes that terminated when radiated power exceeded input power.
Although QC-mode was present in all H-modes (according to PCI) radiated power
was rising exponentially, cooling the pedestal quickly to temperatures at or
below 300 eV despite high input power. Changing shape (lowering both upper and lower
triangularities) and increasing target density did not improve the situation.
We also tried ECDC between shots attempting to lower the impurity level, but
it did not help. Eventually, we lowered the current to 0.9 MA, which, in
combination with high target density (1.2e20) did produce steady state EDA but
with stored energy of only about 100 kJ at 4 MW input power. The radiated
power on this shot decreased by a factor of 2 comparec to maximum level on
previous shots. It is not clear whether the current change is
the real reason why steady state EDA appeared since after that we were able to
achieve long steady state EDA at 1MA. Most likely first 11 discharges (may be
in combination with ECDC) conditionned the walls enough to produce better QC
mode and lower impurity level.
After obtaining steady state EDA at 1 MA we attempted target density and power scan to
optimize plasma performance. Raising targt density as high as 1.3e20 and
increasing RF power to 6.2 MW we were able to achieve only 150 kJ of stored
energy. Basically, all the discharges we had are on the lower edge of the
deltaW vs P_rf curve indicating very poor machine performance.
Finally, we attempted to evaluate the realtive contribution of J-port power
to the heating. First, the discharge was ran with 3.2 MW power from D and E
antennas only. It had an EDA with W=120 kJ - only 30 kJ lower than the shot
with 6.2 MW RF power. Then we repeated the same plasma with 3.2 MW from J-port
only. Although J-port antenna did not run well without D and E, it looks like
3 MW from J can produce about the same stored energy as similar power from D
and E. The conclusion seems to be that RF heating is efficient below 3 MW, but
the efficiency drops nonlinearly as the power is raised above 3 MW level.

Details:

----------------------------------------------------------------------------
1031218001 mossessian SESSION_LEADER Dec 18 2003 9:41:52:630AM
. . . . . . . . . . . . . . . . . . . .
Multiple H-modes - RF trips a lot. nl=9.3e19

Next shot: increase target nl to 1.1e20, ask for 2 levels of RF - 4 MW from
0.6 to 1 sec, 5 MW from 1 to 1.5 sec
Also increase right gap by 2 mm for better RF coupling.
----------------------------------------------------------------------------
1031218002 mossessian SESSION_LEADER Dec 18 2003 9:45:37:226AM
. . . . . . . . . . . . . . . . . . . .
Multiple H-modes again. QC mode is seen on PCI, but radiation kills H-modes -
no steady state EDA.

Next shot - try to incraese nl more.
----------------------------------------------------------------------------
1031218003 mossessian SESSION_LEADER Dec 18 2003 9:56:05:856AM
. . . . . . . . . . . . . . . . . . . .
J-port did not work. RF levels are 2 and 2.5 MW.
In both phases strong QC mode on PCI, but the second segment (2.5 MW)
is interrupted by bursts of ELMs (type III ?).
Radiation is our main problem.

Next shot - try to move lower x-point out va little to decrease delta to 0.53
and move
strike point onto the vertical plate
----------------------------------------------------------------------------
1031218004 mossessian SESSION_LEADER Dec 18 2003 10:31:31:010AM
. . . . . . . . . . . . . . . . . . . .
Rf is better but trips a lot. Got EDAs, but radiation kills it quick,
destroying QC mode into type III.

Next shot - repeat with better RF
----------------------------------------------------------------------------
1031218005 mossessian SESSION_LEADER Dec 18 2003 10:31:44:790AM
. . . . . . . . . . . . . . . . . . . .
Fizzle.
----------------------------------------------------------------------------
1031218006 mossessian SESSION_LEADER Dec 18 2003 10:39:48:153AM
. . . . . . . . . . . . . . . . . . . .
RF is bad again. Also P_rad is so high that Te_ped is only about 300 eV at 5
MW.
QC mode is again killed by radiation.

Next shot - ECED between shots for 10 min.
----------------------------------------------------------------------------
1031218007 mossessian SESSION_LEADER Dec 18 2003 11:05:33:786AM
. . . . . . . . . . . . . . . . . . . .
ECDC seems to make things a little better - we got somewhat longer EDAs, but
the radiation is still
very high and, although we are going from 4 to 5 MW, Te_ped falls and QC mode
deteriorates into type III ELMs.

Next shot - keep doing ECDC. Tune RF to get steadyer 5 MW level.
----------------------------------------------------------------------------
1031218010 mossessian SESSION_LEADER Dec 18 2003 12:19:28:816PM
. . . . . . . . . . . . . . . . . . . .
Smaller upper delta (0.37) makes weeker QC mode. But generally, the situation
is
the same as on previous shots - radiation is too high and H-modes are too
short with
very low pedestal temperature.

Next shot - lower RF power (3 MW and 4 MW instead of 4 and 5)
----------------------------------------------------------------------------
1031218009 mossessian SESSION_LEADER Dec 18 2003 12:24:43:506PM
. . . . . . . . . . . . . . . . . . . .
Similar to 8.

Next shot - reduce upper triangularity to 0.35
----------------------------------------------------------------------------
1031218011 mossessian SESSION_LEADER Dec 18 2003 12:49:07:813PM
. . . . . . . . . . . . . . . . . . . .
Same thing.
Next shot - raise q by going to 0.9 MA, decrease left gap to 1 cm.
----------------------------------------------------------------------------
1031218012 mossessian SESSION_LEADER Dec 18 2003 1:06:21:976PM
. . . . . . . . . . . . . . . . . . . .
Higher q makes H-mode more EDA-like. But w is down to 100 kJ
and pedestal density is down to 1.5e20.

Next shot - raise target nl to 1.2 e20 to get higher pedestal
----------------------------------------------------------------------------
1031218013 mossessian SESSION_LEADER Dec 18 2003 1:12:02:743PM
. . . . . . . . . . . . . . . . . . . .
Good steady EDA, but with low W (90 kJ) and very low pedestal density (1.2e20)
and temperature (300 eV)

Next - try to get more RF
----------------------------------------------------------------------------
1031218014 mossessian SESSION_LEADER Dec 18 2003 1:26:07:623PM
. . . . . . . . . . . . . . . . . . . .
Good steady EDA, as on shot 13. RF is still bad

Next shot - try to improve Rf
----------------------------------------------------------------------------
1031218015 mossessian SESSION_LEADER Dec 18 2003 1:43:57:223PM
. . . . . . . . . . . . . . . . . . . .
Good steady EDA, as on shot 14. RF is still bad

Next shot - change shape (delta_u 0.37 -> 0.3, delta_l 0.5 -> 0.55) to change
RF coupling
----------------------------------------------------------------------------
1031218016 mossessian SESSION_LEADER Dec 18 2003 1:56:48:073PM
. . . . . . . . . . . . . . . . . . . .
J port did not run because of high pressure. D and E are OK, making EDA at 2
MW

Next - reduce target 1.1e20 to make it easier for J
----------------------------------------------------------------------------
1031218017 mossessian SESSION_LEADER Dec 18 2003 2:06:44:700PM
. . . . . . . . . . . . . . . . . . . .
Power is back up. The EDa is better than previous shot, W=100 kJ, Te_ped = 400
eV with 3 MW, but
300 eV at 4 MW !

Next shot - go back to 1 MA leaving everything else as is.
----------------------------------------------------------------------------
1031218020 mossessian SESSION_LEADER Dec 18 2003 2:50:02:233PM
. . . . . . . . . . . . . . . . . . . .
Two H-modes, the first is more ELM-free, the second is steady EDA but with
lower Te_ped, although RF is higher.

Next - 4 MW of RF from the beginning.
----------------------------------------------------------------------------
1031218021 mossessian SESSION_LEADER Dec 18 2003 3:01:41:753PM
. . . . . . . . . . . . . . . . . . . .
First H-mode is steady state but is terminated by a large injection. Second
has lower Te_ped as usual.

Next shot - repeat
----------------------------------------------------------------------------
1031218022 mossessian SESSION_LEADER Dec 18 2003 3:19:10:200PM
. . . . . . . . . . . . . . . . . . . .
In first H-mode P_rad is rising linearly and destroys H-mode while density is
almost
constant. It means that the radiation comes from high Z impurities in EDA
H-mode.
Second H-mode has lower Te_ped as usual.

Next shot - increase target nl to 1.3e20
----------------------------------------------------------------------------
1031218023 mossessian SESSION_LEADER Dec 18 2003 3:29:53:013PM
. . . . . . . . . . . . . . . . . . . .
Steady state EDA for the duration of RF (4 MW). Confinement is bad - W=125 kJ

Next shot - higher RF power
----------------------------------------------------------------------------
1031218024 mossessian SESSION_LEADER Dec 18 2003 4:23:54:066PM
. . . . . . . . . . . . . . . . . . . .
Long steady EDA with 5.5 MW RF, W=134 kJ

Next shot - more power
----------------------------------------------------------------------------
1031218025 mossessian SESSION_LEADER Dec 18 2003 4:24:28:880PM
. . . . . . . . . . . . . . . . . . . .
Long steady EDA with 6.2 MW RF, W=150 kJ

Next shot - turn J port antenna off
----------------------------------------------------------------------------
1031218026 mossessian SESSION_LEADER Dec 18 2003 4:25:57:520PM
. . . . . . . . . . . . . . . . . . . .
Long steady EDA with 3.2 MW RF, W=121 kJ - only 30 kJ lower than with
additional 2 MW from J

Next shot - turn D and E on for short period and then leave only J port on
----------------------------------------------------------------------------
1031218028 mossessian SESSION_LEADER Dec 18 2003 4:53:40:140PM
. . . . . . . . . . . . . . . . . . . .
J port does not wotk at this target density.

Next shot - lower target nl to 1e20. Run only D and E at 3 MW
----------------------------------------------------------------------------
1031218029 mossessian SESSION_LEADER Dec 18 2003 4:54:19:390PM
. . . . . . . . . . . . . . . . . . . .
Short H-mode with rising P_rad. W=118 kJ at 2.8 MW from D and E only
----------------------------------------------------------------------------
1031218030 mossessian SESSION_LEADER Dec 18 2003 5:02:02:956PM
. . . . . . . . . . . . . . . . . . . .
Trying the same thing with J port only.

J port worked for 100 msec only 100 msec, but confinement is comparable to
previous shot with D and E.
----------------------------------------------------------------------------
1031218027 mossessian SESSION_LEADER Dec 23 2003 3:01:56:836PM
. . . . . . . . . . . . . . . . . . . .
J port did not work at all, but we got long H-mode with type III ELMs on Ohmic
power only

Next shot - try to repeat with longer period of D and E to make J running

Physics Operator Summaries

Entered: Jul 7 2004 04:37:20:100PM

Author: Bill Rowan

Physics Operator Summary for Thursday, December 18, 2003
Run 1031218

Purpose: MP# 304 --- H-Mode Regimes

Physics operator: Rowan
Session leader : Mossessian

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Summary-----------------------------------------------------------------

The intent in this run was to scan the boundaries of EDA H-mode. The mode
was not obtained until late in the run. The absorbed power was low thus
isolating the work in a regime that the SL found uninteresting for the purposes
of the miniproposal. Some progress was made in simply finding the right
conditions to produce EDA.

Machine prep for the run consisted of ECDC in helium and baking. Shot 1031217019
(SNL) was loaded from the previous run. There were H-modes, but they ended
due to excess radiated power: After the formation of the H-mode, the bolometer
signal reached a peak and suddenly collapsed to a lower level as the plasma
transitioned out of H-mode. QC mode was clearly visible on the PCI diagnostic.

For a handful of sequential shots, ECDC in D2 was applied between shots. After
that, we made slight changes in shape. The EDA H-mode appeared for parameters
that we covered earlier in the day. See the SL log for details.

Score Card--------------------------------------------------------------
Plasmas 29 (001-004, 006-030)
Early disruptions 0
Fizzles 1
Duds 0

Total 30

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Engineering Setup--------------------------------------------------------------
ECDC overnight in He at 9e-5 Torr, stopping at 7 AM
Bake at 60 C overnight

Run begins at 09:00 and ends at 17:00.

Power systems the same as on 1031217019.

A-coils should be hooked up as on 1031204021 and the power supply should be enabled.

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
leave B-side upper as is Hybrid DISABLED (PG2)
fill C-side with 30 psi D2 Hybrid enabled (PG3)

Enable gatevalves (there will be no vacuum problems): ECE, VUV, DNB

-------------------------------------------------------------------------------
RF Setup: All 4 transmitters in Run On by 08:00
-------------------------------------------------------------------------------
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Run plan for 1031218, MP 304 H-mode regimes-----------------------------

We will try to explore ELMy boundaries depending on triangularity and q. We
should start with a single null shot (one from 1031217) with
target nl=1.2e20, Ip=1 MA, upper delta=0.3, lower delta=0.5, and max RF power
(6 MW ?) establishing high performance discharge. When we get beta_norm above
1.3 (and hopefully see ELMs) we will do the RF power scan (two or three levels
of RF power in one shot) establishing the power boundary between ELMs and EDA.
The scan should be repeated for different values of delta and current. We will
use three values for upper delta (0.2, 0.4 and 0.7) and two values for lower
delta (0.5 and 0.7) at three plasma currents (0.7 MA, 1 MA and 1.2 MA)
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Log---------------------------------------------------------------------

Overnight ECDC in helium. ECDC off at 7am

001. Plasma.

Next shot.
nl_04 to 1.1e+20
Increase the outer gap by 2 mm (reduce RCUR by 1 mm)

002. Plasma
nl_04 = 1.0e+20
outer gap approx 1 cm

Next shot.
nl_04 = 1.2e+20

003. Plasma
nl_04 = 1.2e+20 just before the RF

Next shot.
Move rxl out by 1 cm.

004.
lower triangularity is 0.53
shot 003 was approx 0.6

Next shot Repeat to improve RF

005. Fizzle

Next shot.
Reduced the prefill from 25 ms to 20 ms.

006. Plasma

Next shot. ECDC in D2

007. Plasma.

Next shot. ECDC in D2 for 10 minutes

008. Plasma

Next shot,
ECDC in D2 for 10 minutes.
Reduce the nl_04 demand to 1.1e+20

009. Plasma

Next shot. ECDC in D2 for 10 minutes
Reduced upper triangularity: RXU increased by 2 cm
Reduce the nl_04 demand to 1.0e+20

010. Plasma
Upper triangularity is approx 0.37

Next shot. ECDC in D2 for 10 minutes

011. Plasma

Next shot:
Decrease the plasma current to 0.9 MA
Decrease the inner gap by 1 cm.

012. Plasma
Inner gap is 1 cm.
Ip is 0.9 MA

Next shot.
Increase the target nl_04 to 1.2e+20

013. Plasma

Next shot.
No PCS changes.

014. Plasma.

Next shot.
No PCS changes

015. Plasma

Next shot.
Decrease RXL by 0.5 cm
Increase RXU by 1 cm

016. Plasma
upper triangularity = 0.318
lower triangularity = 0.53

Next shot.
nl_04 demand = 1.1e+20

017. Plasma
nl_04 = 1.1e+20

Next shot.
Increase IP to 1 MA

018. Plasma

Next shot.
No successful PCS changes

019. Plasma

Next shot.
Increase nl_04 demand to 1.2e+20

020. Plasma

Next shot.
No pcs changes

021. Plasma.
Injection at 0.76s

Next shot
No changes

022. Plasma

Next shot.
Increase nl_04 demand to 1.3e+20

023. Plasma.

Next shot.
No pcs changes

024. Plasma

Next shot.
No pcs changes

025. Plasma

Next shot.
No pcs changes.

026. Plasma

Next shot
No pcs changes

027. Plasma

Next shot.
No pcs changes

028. Plasma

Next shot.
nl_04 = 1.0e+20

029. Plasma

Next shot.
No pcs changes

030. Plasma.

Session Leader Comments

Dec 18 2003 09:41:52:630AM 1031218001 Dmitri Mossessian Multiple H-modes - RF trips a lot. nl=9.3e19

Next shot: increase target nl to 1.1e20, ask for 2 levels of RF - 4 MW from 0.6 to 1 sec, 5 MW from 1 to 1.5 sec
Also increase right gap by 2 mm for better RF coupling.

Dec 18 2003 09:45:37:227AM 1031218002 Dmitri Mossessian Multiple H-modes again. QC mode is seen on PCI, but radiation kills H-modes - no steady state EDA.

Next shot - try to incraese nl more.

Dec 18 2003 09:56:05:857AM 1031218003 Dmitri Mossessian J-port did not work. RF levels are 2 and 2.5 MW.
In both phases strong QC mode on PCI, but the second segment (2.5 MW)
is interrupted by bursts of ELMs (type III ?).
Radiation is our main problem.

Next shot - try to move lower x-point out va little to decrease delta to 0.53 and move
strike point onto the vertical plate

Dec 18 2003 10:31:31:010AM 1031218004 Dmitri Mossessian Rf is better but trips a lot. Got EDAs, but radiation kills it quick, destroying QC mode into type III.

Next shot - repeat with better RF

Dec 18 2003 10:31:44:790AM 1031218005 Dmitri Mossessian Fizzle.

Dec 18 2003 10:39:48:153AM 1031218006 Dmitri Mossessian RF is bad again. Also P_rad is so high that Te_ped is only about 300 eV at 5 MW.
QC mode is again killed by radiation.

Next shot - ECED between shots for 10 min.

Dec 18 2003 11:05:33:787AM 1031218007 Dmitri Mossessian ECDC seems to make things a little better - we got somewhat longer EDAs, but the radiation is still
very high and, although we are going from 4 to 5 MW, Te_ped falls and QC mode deteriorates into type III ELMs.

Next shot - keep doing ECDC. Tune RF to get steadyer 5 MW level.

Dec 18 2003 12:24:43:507PM 1031218009 Dmitri Mossessian Similar to 8.

Next shot - reduce upper triangularity to 0.35

Dec 18 2003 12:19:28:817PM 1031218010 Dmitri Mossessian Smaller upper delta (0.37) makes weeker QC mode. But generally, the situation is
the same as on previous shots - radiation is too high and H-modes are too short with
very low pedestal temperature.

Next shot - lower RF power (3 MW and 4 MW instead of 4 and 5)

Dec 18 2003 12:49:07:813PM 1031218011 Dmitri Mossessian Same thing.
Next shot - raise q by going to 0.9 MA, decrease left gap to 1 cm.

Dec 18 2003 01:06:21:977PM 1031218012 Dmitri Mossessian Higher q makes H-mode more EDA-like. But w is down to 100 kJ
and pedestal density is down to 1.5e20.

Next shot - raise target nl to 1.2 e20 to get higher pedestal

Dec 18 2003 01:12:02:743PM 1031218013 Dmitri Mossessian Good steady EDA, but with low W (90 kJ) and very low pedestal density (1.2e20) and temperature (300 eV)

Next - try to get more RF

Dec 18 2003 01:26:07:623PM 1031218014 Dmitri Mossessian Good steady EDA, as on shot 13. RF is still bad

Next shot - try to improve Rf

Dec 18 2003 01:43:57:223PM 1031218015 Dmitri Mossessian Good steady EDA, as on shot 14. RF is still bad

Next shot - change shape (delta_u 0.37 -> 0.3, delta_l 0.5 -> 0.55) to change RF coupling

Dec 18 2003 01:56:48:073PM 1031218016 Dmitri Mossessian J port did not run because of high pressure. D and E are OK, making EDA at 2 MW

Next - reduce target 1.1e20 to make it easier for J

Dec 18 2003 02:06:44:700PM 1031218017 Dmitri Mossessian Power is back up. The EDa is better than previous shot, W=100 kJ, Te_ped = 400 eV with 3 MW, but
300 eV at 4 MW !

Next shot - go back to 1 MA leaving everything else as is.

Dec 18 2003 02:50:02:233PM 1031218020 Dmitri Mossessian Two H-modes, the first is more ELM-free, the second is steady EDA but with lower Te_ped, although RF is higher.

Next - 4 MW of RF from the beginning.

Dec 18 2003 03:01:41:753PM 1031218021 Dmitri Mossessian First H-mode is steady state but is terminated by a large injection. Second has lower Te_ped as usual.

Next shot - repeat

Dec 18 2003 03:19:10:200PM 1031218022 Dmitri Mossessian In first H-mode P_rad is rising linearly and destroys H-mode while density is almost
constant. It means that the radiation comes from high Z impurities in EDA H-mode.
Second H-mode has lower Te_ped as usual.

Next shot - increase target nl to 1.3e20

Dec 18 2003 03:29:53:013PM 1031218023 Dmitri Mossessian Steady state EDA for the duration of RF (4 MW). Confinement is bad - W=125 kJ

Next shot - higher RF power

Dec 18 2003 04:23:54:067PM 1031218024 Dmitri Mossessian Long steady EDA with 5.5 MW RF, W=134 kJ

Next shot - more power

Dec 18 2003 04:24:28:880PM 1031218025 Dmitri Mossessian Long steady EDA with 6.2 MW RF, W=150 kJ

Next shot - turn J port antenna off

Dec 18 2003 04:25:57:520PM 1031218026 Dmitri Mossessian Long steady EDA with 3.2 MW RF, W=121 kJ - only 30 kJ lower than with additional 2 MW from J

Next shot - turn D and E on for short period and then leave only J port on

Dec 23 2003 03:01:56:837PM 1031218027 Dmitri Mossessian J port did not work at all, but we got long H-mode with type III ELMs on Ohmic power only

Next shot - try to repeat with longer period of D and E to make J running

Dec 18 2003 04:53:40:140PM 1031218028 Dmitri Mossessian J port does not wotk at this target density.

Next shot - lower target nl to 1e20. Run only D and E at 3 MW

Dec 18 2003 04:54:19:390PM 1031218029 Dmitri Mossessian Short H-mode with rising P_rad. W=118 kJ at 2.8 MW from D and E only

Dec 18 2003 05:02:02:957PM 1031218030 Dmitri Mossessian Trying the same thing with J port only.

J port worked for 100 msec only 100 msec, but confinement is comparable to previous shot with D and E.

Dec 18 2003 09:04:30:633AM 1031218033 Dmitri Mossessian Run plan for 1031218, MP 304 H-mode regimes

We will try to explore ELMy boundaries depending on triangularity and q.
We should start with a single null shot (one from 1031217) with
target nl=1.2e20, Ip=1 MA, upper delta=0.3, lower delta=0.5, and max RF power (6 MW ?)
establishing high performance discharge. When we get beta_norm above 1.3 (and hopefully see ELMs)
we will do the RF power scan (two or three levels of RF power in one shot) establishing
the power boundary between ELMs and EDA. The scan should be repeated for different values of
delta and current. We will use three values for upper delta (0.2, 0.4 and 0.7) and two values
for lower delta (0.5 and 0.7) at three plasma currents (0.7 MA, 1 MA and 1.2 MA)

First shot is 1031217019 - the best EDA from yesterday with delta_u=0.48, delta_l=0.6, 1 MA, nl=1e20

Physics Operator Comments

Dec 18 2003 07:49:02:917AM Bill Rowan Engineering setup for Thursday, December 18, 2003

MP# 304 --- H-Mode Regimes

Session leader : Mossessian
Physics operator: Rowan

ECDC overnight in He at 9e-5 Torr, stopping at 7 AM
Bake at 60 C overnight

Run begins at 09:00 and ends at 17:00.

Power systems the same as on 1031217019.

A-coils should be hooked up as on 1031204021 and the power supply should be enabled.

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
leave B-side upper as is Hybrid DISABLED (PG2)
fill C-side with 30 psi D2 Hybrid enabled (PG3)

Enable gatevalves (there will be no vacuum problems): ECE, VUV, DNB

-------------------------------------------------------------------------------
RF Setup: All 4 transmitters in Run On by 08:00
-------------------------------------------------------------------------------

Run plan for 1031218, MP 304 H-mode regimes

We will try to explore ELMy boundaries depending on triangularity and q. We
should start with a single null shot (one from 1031217) with
target nl=1.2e20, Ip=1 MA, upper delta=0.3, lower delta=0.5, and max RF power
(6 MW ?) establishing high performance discharge. When we get beta_norm above
1.3 (and hopefully see ELMs) we will do the RF power scan (two or three levels
of RF power in one shot) establishing the power boundary between ELMs and EDA.
The scan should be repeated for different values of delta and current. We will
use three values for upper delta (0.2, 0.4 and 0.7) and two values for lower
delta (0.5 and 0.7) at three plasma currents (0.7 MA, 1 MA and 1.2 MA)

Overnight ECDC in helium. ECDC off at 7am

Dec 18 2003 09:12:58:777AM 1031218001 Bill Rowan 001. Plasma.

Dec 18 2003 09:20:50:230AM 1031218001 Bill Rowan
Next shot.
nl_04 to 1.1e+20
Increase the outer gap by 2 mm (reduce RCUR by 1 mm)

Dec 18 2003 09:29:15:343AM 1031218002 Bill Rowan 002. Plasma
nl_04 = 1.0e+20
outer gap approx 1 cm

Dec 18 2003 09:37:10:910AM 1031218002 Bill Rowan
Next shot.
nl_04 = 1.2e+20

Dec 18 2003 09:42:37:553AM 1031218003 Bill Rowan
003. Plasma
nl_04 = 1.2e+20 just before the RF

Dec 18 2003 09:56:01:167AM 1031218003 Bill Rowan
Next shot.
Move rxl out by 1 cm.

Dec 18 2003 10:05:13:907AM 1031218004 Bill Rowan 004.
lower triangularity is 0.53
shot 003 was approx 0.6

Next shot Repeat to improve RF

Dec 18 2003 10:30:40:057AM 1031218005 Bill Rowan
005. Fizzle

Next shot.
Reduced the prefill from 25 ms to 20 ms.

Dec 18 2003 10:38:50:870AM 1031218006 Bill Rowan 006. Plasma

Next shot. ECDC in D2

Dec 18 2003 11:00:42:100AM 1031218007 Bill Rowan 007. Plasma.

Next shot. ECDC in D2 for 10 minutes

Dec 18 2003 11:24:08:810AM 1031218008 Bill Rowan 008. Plasma

Dec 18 2003 11:29:24:170AM 1031218008 Bill Rowan
Next shot,
ECDC in D2 for 10 minutes.
Reduce the nl_04 demand to 1.1e+20

Dec 18 2003 11:55:42:290AM 1031218009 Bill Rowan Reduce the nl_04 demand to 1.0e+20

Dec 18 2003 12:47:51:920PM 1031218011 Bill Rowan 011. Plasma

Next shot:
Decrease the plasma current to 0.9 MA
Decrease the inner gap by 1 cm.

Dec 18 2003 01:00:14:097PM 1031218012 Bill Rowan 012. Plasma
Inner gap is 1 cm.
Ip is 0.9 MA

Next shot.
Increase the target nl_04 to 1.2e+20

Dec 18 2003 01:09:49:553PM 1031218013 Bill Rowan 013. Plasma

Next shot.
No PCS changes.

Dec 18 2003 01:26:12:013PM 1031218014 Bill Rowan 014. Plasma.

Next shot.
No PCS changes

Dec 18 2003 01:45:00:880PM 1031218015 Bill Rowan 015. Plasma

Next shot.
Decrease RXL by 0.5 cm
Increase RXU by 1 cm

Dec 18 2003 01:55:16:197PM 1031218016 Bill Rowan 016. Plasma
upper triangularity = 0.318
lower triangularity = 0.53

Next shot.
nl_04 demand = 1.1e+20

Dec 18 2003 02:07:12:560PM 1031218017 Bill Rowan 017. Plasma
nl_04 = 1.1e+20

Next shot.
Increase IP to 1 MA

Dec 18 2003 02:32:54:023PM 1031218018 Bill Rowan 018. Plasma

Next shot.
No successful PCS changes

Dec 18 2003 03:02:46:440PM 1031218019 Bill Rowan 019. Plasma

Next shot.
Increase nl_04 demand to 1.2e+20

Dec 18 2003 02:49:20:860PM 1031218020 Bill Rowan 020. Plasma

Next shot.
No pcs changes

Dec 18 2003 03:01:31:143PM 1031218021 Bill Rowan 021. Plasma.
Injection at 0.76s

Next shot
No changes

Dec 18 2003 03:17:22:527PM 1031218022 Bill Rowan 022. Plasma

Next shot.
Increase nl_04 demand to 1.3e+20

Dec 18 2003 03:28:57:670PM 1031218023 Bill Rowan 023. Plasma.

Next shot.
No pcs changes

Dec 18 2003 03:42:24:940PM 1031218024 Bill Rowan 024. Plasma

Dec 18 2003 03:44:33:490PM 1031218024 Bill Rowan 024. Plasma

Next shot.
No pcs changes

Dec 18 2003 04:06:10:933PM 1031218025 Bill Rowan 025. Plasma

Next shot.
No pcs changes.

Dec 18 2003 04:06:57:170PM 1031218026 Bill Rowan 026. Plasma

Next shot
No pcs changes

Dec 18 2003 04:23:30:410PM 1031218027 Bill Rowan 027. Plasma

Next shot.
No pcs changes

Dec 18 2003 04:29:40:850PM 1031218028 Bill Rowan 028. Plasma

Next shot.
nl_04 = 1.0e+20

Dec 18 2003 04:47:31:840PM 1031218029 Bill Rowan 029. Plasma

Next shot.
No pcs changes

Dec 18 2003 04:55:30:720PM 1031218030 Bill Rowan 030. Plasma.

Last shot.

Engineering Operator Comments

Shot Time Type Status Comment

1 09:10:26:137AM Plasma Ok

2 09:23:20:403AM Plasma Ok

3 09:38:03:927AM Plasma Ok

4 09:59:57:480AM Plasma Ok

5 10:13:06:313AM Plasma Ok

6 10:31:17:883AM Plasma Ok

7 10:56:35:080AM Plasma Ok

8 11:21:37:653AM Plasma Ok

9 11:47:49:570AM Plasma Ok

10 12:12:47:330PM Plasma Ok

11 12:37:29:543PM Plasma Ok

12 12:51:33:970PM Plasma Ok

13 01:04:47:770PM Plasma Ok

14 01:17:28:510PM Plasma Ok

15 01:35:45:237PM Plasma Ok

16 01:48:26:053PM Plasma Ok

17 02:01:12:073PM Plasma Ok

18 02:13:44:063PM Plasma Ok

19 02:26:37:193PM Plasma Ok

20 02:43:10:497PM Plasma Ok

21 02:55:33:907PM Plasma Ok

22 03:08:21:333PM Plasma Ok

23 03:21:32:463PM Plasma Ok

24 03:34:31:797PM Plasma Ok

25 03:47:12:223PM Plasma Ok

26 04:00:00:620PM Plasma Ok

27 04:12:39:830PM Plasma Ok

28 04:26:19:817PM Plasma Ok

29 04:39:47:430PM Plasma Ok

30 04:52:35:170PM Plasma Ok

Session Leader Comments
Dec 18 2003 09:41:52:630AM	1031218001	Dmitri Mossessian	Multiple H-modes - RF trips a lot. nl=9.3e19 Next shot: increase target nl to 1.1e20, ask for 2 levels of RF - 4 MW from 0.6 to 1 sec, 5 MW from 1 to 1.5 sec Also increase right gap by 2 mm for better RF coupling.
Dec 18 2003 09:45:37:227AM	1031218002	Dmitri Mossessian	Multiple H-modes again. QC mode is seen on PCI, but radiation kills H-modes - no steady state EDA. Next shot - try to incraese nl more.
Dec 18 2003 09:56:05:857AM	1031218003	Dmitri Mossessian	J-port did not work. RF levels are 2 and 2.5 MW. In both phases strong QC mode on PCI, but the second segment (2.5 MW) is interrupted by bursts of ELMs (type III ?). Radiation is our main problem. Next shot - try to move lower x-point out va little to decrease delta to 0.53 and move strike point onto the vertical plate
Dec 18 2003 10:31:31:010AM	1031218004	Dmitri Mossessian	Rf is better but trips a lot. Got EDAs, but radiation kills it quick, destroying QC mode into type III. Next shot - repeat with better RF
Dec 18 2003 10:31:44:790AM	1031218005	Dmitri Mossessian	Fizzle.
Dec 18 2003 10:39:48:153AM	1031218006	Dmitri Mossessian	RF is bad again. Also P_rad is so high that Te_ped is only about 300 eV at 5 MW. QC mode is again killed by radiation. Next shot - ECED between shots for 10 min.
Dec 18 2003 11:05:33:787AM	1031218007	Dmitri Mossessian	ECDC seems to make things a little better - we got somewhat longer EDAs, but the radiation is still very high and, although we are going from 4 to 5 MW, Te_ped falls and QC mode deteriorates into type III ELMs. Next shot - keep doing ECDC. Tune RF to get steadyer 5 MW level.
Dec 18 2003 12:24:43:507PM	1031218009	Dmitri Mossessian	Similar to 8. Next shot - reduce upper triangularity to 0.35
Dec 18 2003 12:19:28:817PM	1031218010	Dmitri Mossessian	Smaller upper delta (0.37) makes weeker QC mode. But generally, the situation is the same as on previous shots - radiation is too high and H-modes are too short with very low pedestal temperature. Next shot - lower RF power (3 MW and 4 MW instead of 4 and 5)
Dec 18 2003 12:49:07:813PM	1031218011	Dmitri Mossessian	Same thing. Next shot - raise q by going to 0.9 MA, decrease left gap to 1 cm.
Dec 18 2003 01:06:21:977PM	1031218012	Dmitri Mossessian	Higher q makes H-mode more EDA-like. But w is down to 100 kJ and pedestal density is down to 1.5e20. Next shot - raise target nl to 1.2 e20 to get higher pedestal
Dec 18 2003 01:12:02:743PM	1031218013	Dmitri Mossessian	Good steady EDA, but with low W (90 kJ) and very low pedestal density (1.2e20) and temperature (300 eV) Next - try to get more RF
Dec 18 2003 01:26:07:623PM	1031218014	Dmitri Mossessian	Good steady EDA, as on shot 13. RF is still bad Next shot - try to improve Rf
Dec 18 2003 01:43:57:223PM	1031218015	Dmitri Mossessian	Good steady EDA, as on shot 14. RF is still bad Next shot - change shape (delta_u 0.37 -> 0.3, delta_l 0.5 -> 0.55) to change RF coupling
Dec 18 2003 01:56:48:073PM	1031218016	Dmitri Mossessian	J port did not run because of high pressure. D and E are OK, making EDA at 2 MW Next - reduce target 1.1e20 to make it easier for J
Dec 18 2003 02:06:44:700PM	1031218017	Dmitri Mossessian	Power is back up. The EDa is better than previous shot, W=100 kJ, Te_ped = 400 eV with 3 MW, but 300 eV at 4 MW ! Next shot - go back to 1 MA leaving everything else as is.
Dec 18 2003 02:50:02:233PM	1031218020	Dmitri Mossessian	Two H-modes, the first is more ELM-free, the second is steady EDA but with lower Te_ped, although RF is higher. Next - 4 MW of RF from the beginning.
Dec 18 2003 03:01:41:753PM	1031218021	Dmitri Mossessian	First H-mode is steady state but is terminated by a large injection. Second has lower Te_ped as usual. Next shot - repeat
Dec 18 2003 03:19:10:200PM	1031218022	Dmitri Mossessian	In first H-mode P_rad is rising linearly and destroys H-mode while density is almost constant. It means that the radiation comes from high Z impurities in EDA H-mode. Second H-mode has lower Te_ped as usual. Next shot - increase target nl to 1.3e20
Dec 18 2003 03:29:53:013PM	1031218023	Dmitri Mossessian	Steady state EDA for the duration of RF (4 MW). Confinement is bad - W=125 kJ Next shot - higher RF power
Dec 18 2003 04:23:54:067PM	1031218024	Dmitri Mossessian	Long steady EDA with 5.5 MW RF, W=134 kJ Next shot - more power
Dec 18 2003 04:24:28:880PM	1031218025	Dmitri Mossessian	Long steady EDA with 6.2 MW RF, W=150 kJ Next shot - turn J port antenna off
Dec 18 2003 04:25:57:520PM	1031218026	Dmitri Mossessian	Long steady EDA with 3.2 MW RF, W=121 kJ - only 30 kJ lower than with additional 2 MW from J Next shot - turn D and E on for short period and then leave only J port on
Dec 23 2003 03:01:56:837PM	1031218027	Dmitri Mossessian	J port did not work at all, but we got long H-mode with type III ELMs on Ohmic power only Next shot - try to repeat with longer period of D and E to make J running
Dec 18 2003 04:53:40:140PM	1031218028	Dmitri Mossessian	J port does not wotk at this target density. Next shot - lower target nl to 1e20. Run only D and E at 3 MW
Dec 18 2003 04:54:19:390PM	1031218029	Dmitri Mossessian	Short H-mode with rising P_rad. W=118 kJ at 2.8 MW from D and E only
Dec 18 2003 05:02:02:957PM	1031218030	Dmitri Mossessian	Trying the same thing with J port only. J port worked for 100 msec only 100 msec, but confinement is comparable to previous shot with D and E.
Dec 18 2003 09:04:30:633AM	1031218033	Dmitri Mossessian	Run plan for 1031218, MP 304 H-mode regimes We will try to explore ELMy boundaries depending on triangularity and q. We should start with a single null shot (one from 1031217) with target nl=1.2e20, Ip=1 MA, upper delta=0.3, lower delta=0.5, and max RF power (6 MW ?) establishing high performance discharge. When we get beta_norm above 1.3 (and hopefully see ELMs) we will do the RF power scan (two or three levels of RF power in one shot) establishing the power boundary between ELMs and EDA. The scan should be repeated for different values of delta and current. We will use three values for upper delta (0.2, 0.4 and 0.7) and two values for lower delta (0.5 and 0.7) at three plasma currents (0.7 MA, 1 MA and 1.2 MA) First shot is 1031217019 - the best EDA from yesterday with delta_u=0.48, delta_l=0.6, 1 MA, nl=1e20

Physics Operator Comments
Dec 18 2003 07:49:02:917AM		Bill Rowan	Engineering setup for Thursday, December 18, 2003 MP# 304 --- H-Mode Regimes Session leader : Mossessian Physics operator: Rowan ECDC overnight in He at 9e-5 Torr, stopping at 7 AM Bake at 60 C overnight Run begins at 09:00 and ends at 17:00. Power systems the same as on 1031217019. A-coils should be hooked up as on 1031204021 and the power supply should be enabled. Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid enabled (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill C-side with 30 psi D2 Hybrid enabled (PG3) Enable gatevalves (there will be no vacuum problems): ECE, VUV, DNB ------------------------------------------------------------------------------- RF Setup: All 4 transmitters in Run On by 08:00 ------------------------------------------------------------------------------- Run plan for 1031218, MP 304 H-mode regimes We will try to explore ELMy boundaries depending on triangularity and q. We should start with a single null shot (one from 1031217) with target nl=1.2e20, Ip=1 MA, upper delta=0.3, lower delta=0.5, and max RF power (6 MW ?) establishing high performance discharge. When we get beta_norm above 1.3 (and hopefully see ELMs) we will do the RF power scan (two or three levels of RF power in one shot) establishing the power boundary between ELMs and EDA. The scan should be repeated for different values of delta and current. We will use three values for upper delta (0.2, 0.4 and 0.7) and two values for lower delta (0.5 and 0.7) at three plasma currents (0.7 MA, 1 MA and 1.2 MA) Overnight ECDC in helium. ECDC off at 7am
Dec 18 2003 09:12:58:777AM	1031218001	Bill Rowan	001. Plasma.
Dec 18 2003 09:20:50:230AM	1031218001	Bill Rowan	Next shot. nl_04 to 1.1e+20 Increase the outer gap by 2 mm (reduce RCUR by 1 mm)
Dec 18 2003 09:29:15:343AM	1031218002	Bill Rowan	002. Plasma nl_04 = 1.0e+20 outer gap approx 1 cm
Dec 18 2003 09:37:10:910AM	1031218002	Bill Rowan	Next shot. nl_04 = 1.2e+20
Dec 18 2003 09:42:37:553AM	1031218003	Bill Rowan	003. Plasma nl_04 = 1.2e+20 just before the RF
Dec 18 2003 09:56:01:167AM	1031218003	Bill Rowan	Next shot. Move rxl out by 1 cm.
Dec 18 2003 10:05:13:907AM	1031218004	Bill Rowan	004. lower triangularity is 0.53 shot 003 was approx 0.6 Next shot Repeat to improve RF
Dec 18 2003 10:30:40:057AM	1031218005	Bill Rowan	005. Fizzle Next shot. Reduced the prefill from 25 ms to 20 ms.
Dec 18 2003 10:38:50:870AM	1031218006	Bill Rowan	006. Plasma Next shot. ECDC in D2
Dec 18 2003 11:00:42:100AM	1031218007	Bill Rowan	007. Plasma. Next shot. ECDC in D2 for 10 minutes
Dec 18 2003 11:24:08:810AM	1031218008	Bill Rowan	008. Plasma
Dec 18 2003 11:29:24:170AM	1031218008	Bill Rowan	Next shot, ECDC in D2 for 10 minutes. Reduce the nl_04 demand to 1.1e+20
Dec 18 2003 11:55:42:290AM	1031218009	Bill Rowan	Reduce the nl_04 demand to 1.0e+20
Dec 18 2003 12:47:51:920PM	1031218011	Bill Rowan	011. Plasma Next shot: Decrease the plasma current to 0.9 MA Decrease the inner gap by 1 cm.
Dec 18 2003 01:00:14:097PM	1031218012	Bill Rowan	012. Plasma Inner gap is 1 cm. Ip is 0.9 MA Next shot. Increase the target nl_04 to 1.2e+20
Dec 18 2003 01:09:49:553PM	1031218013	Bill Rowan	013. Plasma Next shot. No PCS changes.
Dec 18 2003 01:26:12:013PM	1031218014	Bill Rowan	014. Plasma. Next shot. No PCS changes
Dec 18 2003 01:45:00:880PM	1031218015	Bill Rowan	015. Plasma Next shot. Decrease RXL by 0.5 cm Increase RXU by 1 cm
Dec 18 2003 01:55:16:197PM	1031218016	Bill Rowan	016. Plasma upper triangularity = 0.318 lower triangularity = 0.53 Next shot. nl_04 demand = 1.1e+20
Dec 18 2003 02:07:12:560PM	1031218017	Bill Rowan	017. Plasma nl_04 = 1.1e+20 Next shot. Increase IP to 1 MA
Dec 18 2003 02:32:54:023PM	1031218018	Bill Rowan	018. Plasma Next shot. No successful PCS changes
Dec 18 2003 03:02:46:440PM	1031218019	Bill Rowan	019. Plasma Next shot. Increase nl_04 demand to 1.2e+20
Dec 18 2003 02:49:20:860PM	1031218020	Bill Rowan	020. Plasma Next shot. No pcs changes
Dec 18 2003 03:01:31:143PM	1031218021	Bill Rowan	021. Plasma. Injection at 0.76s Next shot No changes
Dec 18 2003 03:17:22:527PM	1031218022	Bill Rowan	022. Plasma Next shot. Increase nl_04 demand to 1.3e+20
Dec 18 2003 03:28:57:670PM	1031218023	Bill Rowan	023. Plasma. Next shot. No pcs changes
Dec 18 2003 03:42:24:940PM	1031218024	Bill Rowan	024. Plasma
Dec 18 2003 03:44:33:490PM	1031218024	Bill Rowan	024. Plasma Next shot. No pcs changes
Dec 18 2003 04:06:10:933PM	1031218025	Bill Rowan	025. Plasma Next shot. No pcs changes.
Dec 18 2003 04:06:57:170PM	1031218026	Bill Rowan	026. Plasma Next shot No pcs changes
Dec 18 2003 04:23:30:410PM	1031218027	Bill Rowan	027. Plasma Next shot. No pcs changes
Dec 18 2003 04:29:40:850PM	1031218028	Bill Rowan	028. Plasma Next shot. nl_04 = 1.0e+20
Dec 18 2003 04:47:31:840PM	1031218029	Bill Rowan	029. Plasma Next shot. No pcs changes
Dec 18 2003 04:55:30:720PM	1031218030	Bill Rowan	030. Plasma. Last shot.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	09:10:26:137AM	Plasma	Ok
2	09:23:20:403AM	Plasma	Ok
3	09:38:03:927AM	Plasma	Ok
4	09:59:57:480AM	Plasma	Ok
5	10:13:06:313AM	Plasma	Ok
6	10:31:17:883AM	Plasma	Ok
7	10:56:35:080AM	Plasma	Ok
8	11:21:37:653AM	Plasma	Ok
9	11:47:49:570AM	Plasma	Ok
10	12:12:47:330PM	Plasma	Ok
11	12:37:29:543PM	Plasma	Ok
12	12:51:33:970PM	Plasma	Ok
13	01:04:47:770PM	Plasma	Ok
14	01:17:28:510PM	Plasma	Ok
15	01:35:45:237PM	Plasma	Ok
16	01:48:26:053PM	Plasma	Ok
17	02:01:12:073PM	Plasma	Ok
18	02:13:44:063PM	Plasma	Ok
19	02:26:37:193PM	Plasma	Ok
20	02:43:10:497PM	Plasma	Ok
21	02:55:33:907PM	Plasma	Ok
22	03:08:21:333PM	Plasma	Ok
23	03:21:32:463PM	Plasma	Ok
24	03:34:31:797PM	Plasma	Ok
25	03:47:12:223PM	Plasma	Ok
26	04:00:00:620PM	Plasma	Ok
27	04:12:39:830PM	Plasma	Ok
28	04:26:19:817PM	Plasma	Ok
29	04:39:47:430PM	Plasma	Ok
30	04:52:35:170PM	Plasma	Ok