Alcator C-Mod Run 1010801 Information

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Miniproposals
Miniproposal:291a
Date Filed: 5/24/2001
Title:Double Transport Barrier Plasma Formation with Low Field Side ICRF
First Author:John Rice
Session Leader:John Rice (shots 1-27)

Operators
Session leader(s):John Rice
Physics operator(s):Robert Granetz
Engineering operator(s):Bill Parkin,Ed Fitzgerald,Gary Dekow

Engineering Operator Run Comment
MP #291A -- ITB's with 70 MHz off-axis heating; SL:Rice; PO:Granetz; EO:

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:28:197PM
Author: To Be Determined
Session Leader Summary for Run 1010801 (Wednesday):

MP #291A -- ITB's with 70 MHz off-axis heating

Session leader: J. Rice
Physics operator: R. Granetz
Engineer in charge: G. Dekow/W. Parkin/E. Fitzgerald

This run day was extremely successful from the standpoint of
accomplishing objectives of the mini-proposal and learning more about
plasma conditions under which the density barrier and internal
transport barrier (ITB) modes can be produced in C-Mod. The density
barrier mode was produced with off-axis ICRF heating (70 MHz) on BOTH
the tokamak high field side (HFS) at 3.9 T and the low field side
(LFS) at 5.4 T. Preliminary attempts were also made at heating The LFS
density barrier with on-axis ICRF power at 80 MHz.

The density barrier mode was first produced at lower B_t = 3.9 T using
1.5 MW of off-axis ICRF heating power from the J-port antenna,
driven at 70 MHz [see shots 1010801005 and 1010801011]. The central
density was observed to rise to ne_TS(0) = 6 X 10^20 m^{-3} and the
toroidal rotation velocity (v_tor) from HIREX decreased to zero and
reversed direction (becoming counter-current. The central ion
temperature (deduced from neutrons) increased slightly to 1.25 keV
during the barrier formation. Interestingly, the value of B_t where
the barrier formed at 70 MHz, scales nicely from the critical B_t for
barrier formation at 80 MHz, that is:

B_t = (70 MHz / 80 Mhz) * 4.5 T = 3.93 T.

This places the minority hydrogen cyclotron resonance at about the
same position on the HFS (12 cm) as it was at 4.5 T and 80 MHz. The
toroidal field was varied around 3.9 T and this appears to be the
threshold value of B_t for producing the ITB at 70 MHz. For example,
at 4.0T, the density barrier would not form [see for example discharge
1010801013].

During the second phase of the run, B_t was increased up to 5.4 T and
a density barrier mode was eventually produced on shot 1010801025. The
J-port heating power used in this shot was only 1.35 MW because antenna
arcing problems were experienced at higher J-port power levels as B_t
was increased. ITB formation was again characterized by peaking density
profile with ne_TS(0) = 6 X 10^20 m^{-3} and ne(0) / ne(ave) > 2.
Formation of the density barrier at both 3.9T and 5.4T was preceeded by
a transition to an H-mode phase.

The 80 MHz power was also turned on for the final two plasmas of the
day [shots 1010801026 and 1010801027] in an attempt to heat the LFS
density barrier mode at 5.4 T. On shot 1010801026, there may be some
evidence of heating within the barrier from the 80 MHz power (at the
0.5 MW level). The neutron rate more than tripled and the central
density increase was arrested at ne_TS(0) = 3.5 X 10^20 m^{-3} during
application of the on-axis ICRF power. These results are somewhat
muddled however because there were two H->L back transitions at 0.81
sec and 0.91 sec, which prevented the initial barrier mode from
becoming well - developed (i.e., peaked). Finally, shot 1010801027
is an excellent example of a P-mode produced by a pellet injection at
about 1.3 sec.


Physics Operator Summaries
Entered: Jul 7 2004 04:37:14:567PM
Author: To Be Determined
Physics operator summary for run 1010801 (Wednesday):

MP #291A -- ITB's with 70 MHz off-axis heating

Session leader: J. Rice
Physics operator: R. Granetz
Engineer in charge: G. Dekow/W. Parkin/E. Fitzgerald

Summary: The tokamak ran well, the J-antenna RF ran well (at 1.5 MW), and the
DNB ran well. We did the B-field scan and got ITB's with the RF
resonance on both the inboard and outboard sides (shots 5 and 25
respectively). See John's summary for the physics results. H/D
remained low (4-5%) throughout the entire day.

The one problem that cropped up a couple of times was a high
resistance reading on the OH2U coax (2.5 micro-ohms). The
joint temperature rise was not noticeably different than normal, so
we continued operating, and the problem abated somewhat.

Scorecard: 24 plasmas
3 fizzles
0 duds
0 tests
0 aborted and/or screwed up by computer problems
----------
27 total

-------------------------------------------------------------------------------

Engineering setup for Wednesday 01 August 2001

MP #291A -- ITB's with 70 MHz off-axis heating

Session leader: J. Rice
Physics operator: R. Granetz

ECDC in D2 overnight, stopping by 8:00 am.

Run begins at 09:00 and ends at 19:00.

Power systems the same as for shot 1010730012.

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC)
fill C-side with 30 psi D2 Hybrid enabled (PG3)
fill J-Bottom with 30 psi He Hybrid DISABLED (PG5)

Enable the following gate valves, assuming no vacuum problems:
ECE, DNB, VUV

-------------------------------------------------------------------------------

RF Setup:

Transmitters 1 and 2 in run-on started at 08:00.
Transmitters 3 and 4 in run-on started at 08:00.

RF Waveforms: 2+ MW from J only, flattop from t=0.6 to 1.4 s. If J is
having problems, switch to D and E.

-------------------------------------------------------------------------------
Run Plan:

MP 291A originally called for 80 MHz operation of D, E, and J at nearly
full power, and toroidal field operation up to 6.0 tesla. Since J is now
at 70 MHz, this run will concentrate instead on getting ITB's with J
only, with toroidal fields starting at 4.5 T, dropping down by 0.2 T each
shot to 3.5 T, then back up to 5.5 T. Primary goal is to get an ITB with
70 MHz ICRF resonance on the high-field side. If successful, then try
for an ITB with 70 MHz ICRF resonance on the low-field side.

We will also put in a helium puff for DNB CXRS.

-------------------------------------------------------------------------------

Overnight ECDC in D2 was done.

Hybrid coldstart done; no errors found

Loaded PCS segment 1 from shot 1010731017, segment 2 from 1010730012.
Added 100 ms helium puff from J-bottom starting at t=0.2 s. The valve
is disabled for the beginning of the run.

-------------------------------------------------------------------------------

Shot 01 -- Plasma. Disrupted at t=0.67 s. Killed by injection from the top
of J-antenna, similar to yesterday. Pre-fill was too low because
it was adjusted assuming DNB would be on, which is wasn't. H/D=3%.
Prf=2.0 MW from J.

Next shot: turn on DNB; increase pre-fill by 1 ms also. Enable
helium puff from J-bottom valve.

Shot 02 -- Plasma. Good shot. No ITB, as expected. J-bottom puffed, but
CXRS didn't see any helium signals. H/D=5-6% Prf=1.4 MW (J).
DNB fired at t=0.4 s.

Next shot: reduce Btor by 0.2 T to 4.3 T (118 kA). Increase helium
puff to 200 ms, and add a negative 30 volt bias to keep it from
chattering when off.

ECDC in D2 is on between shots now.

Shot 03 -- Plasma. Good shot. Btor=4.3 T. Prf=1.5 MW (J). H/D=5%.
DNB fired. Bill Rowan saw helium signals from top periscope.

Next shot: reduce Btor by 0.2 T to 4.1 T (113 kA). Move helium
puff earlier by 100 ms (now goes from t=0.1 to 0.3 s). Jim Terry
will adjust Chromex to span the He 4686 region.

ECDC in D2 is on between shots now.

Shot 04 -- Plasma. Good shot. Btor=4.12 T. No ITB, as expected. DNB fired.
Prf=1.5 MW (J). H/D=5%. Chromex sees He 4686 during first part
of shot.

Next shot: reduce Btor by 0.2 T to 3.9 T (107 kA). Reduce helium
puff to 150 ms, still starting at t=0.1 s.

ECDC in D2 is on between shots now.

Shot 05 -- Plasma. Disrupted at t=1.5 s after an injection. This one might
have had an ITB, which would not be unexpected. Btor=3.91 T.
Prf=1.45 MW (J). H/D= %. DNB fired.

Next shot: reduce Btor by 0.2 T to 3.7 T (101 kA). DNB will move
to later in the shot (t=0.9 s), so I will add 1 ms to the pre-fill
puff.

ECDC in D2 is on between shots now.

Shot 06 -- Fizzle. Pre-fill pressure was a little low (0.05 mTorr).

Next shot: increase pre-fill puff by another 2 ms. Also enable
the LPI gate valve.

Shot 07 -- Plasma. Disrupted at t=1.45 s. Multiple H-L transitions. Lithium
pellet injected at t=1.41 s. Btor=3.71 T. Startup still needs
improvement. Pre-fill pressure is still low. H/D=5%
Prf=1.5 MW (J).

OH2U coax resistance warning came up; 2.5 micro-ohms. Jim Irby is
studying it.

Next shot: raise Btor by 0.1 T to 3.8 T (104 kA). Also increase
pre-fill puff another 2 ms.

ECDC in D2 is on between shots now.

The OH2U coax resistance is real. The joint temperature rise doesn't seem
abnormal though. We'll shorten the fizzle detector delays and continue with
plasma operation.

Shot 08 -- Fizzle. Pre-fill pressure is 0.06 mTorr, which should be fine.
OH2U coax resistance dropped to 0.9 micro-ohms.

Next shot: increase pre-fill puff another 2 ms (to 24 ms).

Shot 09 -- Plasma. Good shot. Multiple H-L transitions. Btor=3.81 T.
Prf=1.5 MW (J). Startup was still shaky. DNB fired at t=0.9 s.

We got another OH coax resistance warning.

Next shot: increase Btor by 0.1 T to 3.9 T.

ECDC in D2 is on between shots now.

Shot 10 -- Plasma. Disrupted at t=0.56 s, before the RF came on. Good startup
on this one. Btor=3.91 T.

Coax resistances were somewhat lower on this shot.

Next shot: no changes.

ECDC in D2 is on between shots now.

Shot 11 -- Plasma. Good shot. Disrupted at t=1.44 s. Btor=3.91 T.
Prf=1.5 MW (J). No DNB. H/D=5%. Got an ITB.

Next shot: no changes; fire lithium pellet into ITB.

ECDC in D2 is on between shots now.

Shot 12 -- Plasma. Killed by lithium pellet at t=1.33 s. Prf=1.5 MW (J).
DNB fired at t=0.9 s. Chromex bin 7 sees a doubling of signal
during the beam. H/D=5%.

Next shot: increase Btor by 0.1 T to 4.0 T.

ECDC in D2 is on between shots now.

Shot 13 -- Plasma. Good shot. Btor=4.0 T. Prf=1.5 MW (J). DNB fired.
H/D=5-6%.

Next shot: raise Btor to 4.7 T (130.5 kA)

ECDC in D2 is on between shots now.

Shot 14 -- Plasma. Good shot. Btor=4.71 T. Prf=1.44 MW (J). DNB fired.
H/D=5%.

Next shot: raise Btor to 4.9 T (136.5 kA)

ECDC in D2 is on between shots now.

Shot 15 -- Plasma. Good shot. Btor=4.9 T. Prf=1.46 MW (J). H/D=5%.
DNB fired.

Next shot: raise Btor to 5.1 T (142.5 kA)

ECDC in D2 is on between shots now.

Shot 16 -- Plasma. Good shot. Btor=5.1 T. Prf=1.5 MW (J). No ITB.
DNB fired.

Next shot: raise Btor to 5.3 T (148.5 kA). Reduce helium puff
to 75 ms.

ECDC in D2 is on between shots now.

Shot 17 -- Plasma. Good shot. Btor=5.3 T. Prf=1.45 MW (J). DNB fired.
H/D=4%.

Next shot: raise Btor by 0.1 T to 5.4 T (151500 kA). Set helium
puff to 150 ms, starting at t=0.70 s. DNB will fire at t=1.0 s.

ECDC in D2 is on between shots now.

Shot 18 -- Plasma. Disrupted at t=1.21 s. Btor=5.4 T. DNB fired at t=1.0 s.
Helium puffed at t=0.7 s. H/D=4%.

Next shot: move helium puff back to t=0.10-0.25 s. (DNB will move
back to t=0.9 s)

ECDC in D2 is on between shots now.

Shot 19 -- Plasma. Good shot. Btor=5.4 T. Prf=1.16 MW (J). DNB fired at
t=0.9 s. Helium puffed at t=0.1 s. H/D=4%

Next shot: Prf will be raised back up to 1.5 MW.

ECDC in D2 is on between shots now.

Shot 20 -- Plasma. Disrupted at t=1.29 s. Btor=5.4 T. Prf=1.34 MW (J).
DNB fired at t=0.9 s.

Next shot: no changes.

ECDC in D2 is on between shots now.

Shot 21 -- Plasma. Good shot. Btor=5.4 T. Prf=1.33 MW (J). DNB fired.
Two EN modes.

Next shot: increase Btor by 0.1 T to 5.5 T.

ECDC in D2 is on between shots now.

Shot 22 -- Plasma. Good shot. Btor=5.5 T. Prf=1.35 MW (J). DNB fired.
Almost completely L-mode. H/D=3.5%

Next shot: reduce Btor by 0.1 T to 5.4 T. Reduce target density
to nl_04=1.0e20 m-2 (was 1.1).

ECDC in D2 is on between shots now.

Shot 23 -- Fizzle. Nothing obviously wrong.

Next shot: repeat with no changes.

Shot 24 -- Plasma. Good shot. Btor=5.4 T. Prf=1.33 MW (J). DNB fired.

Next shot: add 1 ms to pre-fill.

ECDC in D2 is on between shots now.

Shot 25 -- Plasma. Good shot. Very clear ITB. Btor=5.4 T. Prf=1.35 MW (J).
DNB fired at t=0.9 s. H/D=4-5%. Target nl_04=1.0e20 m-2.

Next shot: repeat with no changes (John's HIREX had a high-voltage
trip).

ECDC in D2 is on between shots now.

Shot 26 -- Plasma. Good shot. Btor=5.4 T. Prf=1.4 MW (J) + a little from
D and E after t=1.0 s. No ITB. DNB fired. H/D=4-5%.

Next shot: repeat with no changes.

ECDC in D2 is on between shots now.

The LOGBOOK database server has stopped working. Don Nelson and Josh
Stillerman are looking into it from home, but we'll go ahead and try for
another shot anyway.

SQL database server began working again after Don rebooted node RED.

Shot 27 -- Plasma. Good shot. Btor=5.4 T. No ITB. Li pellet at t=1.3 s.
Prf=1.37 MW (J) + some from D and E after t=1.1 s. DNB fired.
H/D=5%.

End of run.

Session Leader Comments
Aug 1 2001 09:30:05:957AM1010801001John Ricedisrupted early
2.0 MW from J too much
Aug 1 2001 09:30:38:643AM1010801002John Rice4.5 T, steady rotation, no ITB
1.5 MW from J
Aug 1 2001 09:48:05:130AM1010801003John Rice4.3 T, steady rotation, no ITB
1.5 MW from J
Aug 1 2001 10:07:42:723AM1010801004John Rice4.1 T, steady rotation, no ITB
1.5 MW from J
Aug 1 2001 10:34:15:537AM1010801004John Rice3.9 T, rotation drops with ITB formation
1.5 MW from J
Aug 1 2001 11:07:42:427AM1010801005John Rice3.9 T, rotation drops with ITB formation
1.5 MW from J
Aug 1 2001 11:08:16:673AM1010801007John Rice3.7 T, rotation drops with ITB formation, H-L transitions
1.5 MW from J
Aug 1 2001 12:04:36:630PM1010801009John Rice3.8 T, rotation drops with ITB formation, H-L transitions
1.5 MW from J
Aug 1 2001 12:50:13:237PM1010801009John Rice3.9 T, disrupted before RF
Aug 1 2001 12:49:25:660PM1010801011John Rice3.9 T, rotation drops with ITB formation
1.5 MW from J
Aug 1 2001 01:07:32:190PM1010801012John Rice3.9 T, H-L transition
1.5 MW J port
Aug 1 2001 01:28:33:393PM1010801013John Rice4.0 T, steady rotation, no ITB
1.5 MW J port
Aug 1 2001 01:57:18:003PM1010801014John Rice4.7 T, steady rotation, no ITB
1.5 MW J port
Aug 1 2001 02:19:02:713PM1010801015John Rice4.9 T, steady rotation, no ITB
1.5 MW J port
Aug 1 2001 02:44:11:170PM1010801016John Rice5.1 T, steady rotation, no ITB, some trips
1.5 MW J port
Aug 1 2001 03:13:40:803PM1010801017John Rice5.3 T, several RF trips, ambiguous regarding ITB formation
1.5 MW J port
Aug 1 2001 03:40:59:403PM1010801018John Rice5.4 T, several RF trips
1.5 MW J port
Aug 1 2001 04:03:21:367PM1010801019John Rice5.4 T, late H-mode due to lower power, one RF trip
1.2 MW J port
Aug 1 2001 04:24:55:973PM1010801020John Rice5.4 T, one RF trip, rotation drop and ITB formation
1.4 MW J port
Aug 1 2001 04:55:12:467PM1010801021John Rice5.4 T, one RF trip, rotation drop and ITB formation
1.4 MW J port
Aug 1 2001 05:15:08:927PM1010801022John Rice5.5 T, no H-mode
1.4 MW J port
Aug 1 2001 05:54:17:393PM1010801024John Rice5.4 T, rotation slows and 'possible' ITB formation
1.3 MW J port
Aug 1 2001 06:12:25:503PM1010801025John Rice5.4 T, 'oh yeah' ITB formation
1.4 MW J port
Aug 1 2001 07:01:29:940PM1010801027John Rice5.4 T, rotation slowing, ITB formation, density peaking
1.4 MW J port plus D and E ramp, stabilizing barrier

Physics Operator Comments
Jul 31 2001 02:42:58:280PMRobert Granetz
Engineering setup for Wednesday 01 August 2001

MP #291A -- ITB's with 70 MHz off-axis heating

Session leader: J. Rice
Physics operator: R. Granetz

ECDC in D2 overnight, stopping by 8:00 am.

Run begins at 09:00 and ends at 19:00.

Power systems the same as for shot 1010730012.

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC)
fill C-side with 30 psi D2 Hybrid enabled (PG3)
fill J-Bottom with 30 psi He Hybrid DISABLED (PG5)

Enable the following gate valves, assuming no vacuum problems:
ECE, DNB, VUV

-------------------------------------------------------------------------------

RF Setup:

Transmitters 1 and 2 in run-on started at 08:00.
Transmitters 3 and 4 in run-on started at 08:00.

RF Waveforms: 2+ MW from J only, flattop from t=0.6 to 1.4 s. If J is
having problems, switch to D and E.
Jul 31 2001 02:43:08:110PMRobert GranetzRun Plan:

MP 291A originally called for 80 MHz operation of D, E, and J at nearly
full power, and toroidal field operation up to 6.0 tesla. Since J is now
at 70 MHz, this run will concentrate instead on getting ITB's with J
only, with toroidal fields starting at 4.5 T, dropping down by 0.2 T each
shot to 3.5 T, then back up to 5.5 T. Primary goal is to get an ITB with
70 MHz ICRF resonance on the high-field side. If successful, then try
for an ITB with 70 MHz ICRF resonance on the low-field side.

We will also put in a helium puff for DNB CXRS.
Aug 1 2001 08:50:40:050AMRobert Granetz Overnight ECDC in D2 was done.

Hybrid coldstart done; no errors found

Loaded PCS segment 1 from shot 1010731017, segment 2 from 1010730012.
Added 100 ms helium puff from J-bottom starting at t=0.2 s. The valve
is disabled for the beginning of the run.
Aug 1 2001 09:18:55:363AM1010801001Robert GranetzShot 01 -- Plasma. Disrupted at t=0.67 s. Killed by injection from the top
of J-antenna, similar to yesterday. Pre-fill was too low because
it was adjusted assuming DNB would be on, which is wasn't. H/D=3%.
Prf=2.0 MW from J.

Next shot: turn on DNB; increase pre-fill by 1 ms also. Enable
helium puff from J-bottom valve.
Aug 1 2001 09:58:55:160AM1010801002Robert GranetzShot 02 -- Plasma. Good shot. No ITB, as expected. J-bottom puffed, but
CXRS didn't see any helium signals. H/D=5-6% Prf=1.4 MW (J).
DNB fired at t=0.4 s.

Next shot: reduce Btor by 0.2 T to 4.3 T (118 kA). Increase helium
puff to 200 ms, and add a negative 30 volt bias to keep it from
chattering when off.

ECDC in D2 is on between shots now.
Aug 1 2001 09:58:31:597AM1010801003Robert GranetzShot 03 -- Plasma. Good shot. Btor=4.3 T. Prf=1.5 MW (J). H/D=5%.
DNB fired. Bill Rowan saw helium signals from top periscope.

Next shot: reduce Btor by 0.2 T to 4.1 T (113 kA). Move helium
puff earlier by 100 ms (now goes from t=0.1 to 0.3 s). Jim Terry
will adjust Chromex to span the He 4686 region.

ECDC in D2 is on between shots now.
Aug 1 2001 10:19:46:283AM1010801004Robert GranetzShot 04 -- Plasma. Good shot. Btor=4.12 T. No ITB, as expected. DNB fired.
Prf=1.5 MW (J). H/D=5%. Chromex sees He 4686 during first part
of shot.

Next shot: reduce Btor by 0.2 T to 3.9 T (107 kA). Reduce helium
puff to 150 ms, still starting at t=0.1 s.

ECDC in D2 is on between shots now.
Aug 1 2001 10:36:34:410AM1010801005Robert GranetzShot 05 -- Plasma. Disrupted at t=1.5 s after an injection. This one might
have had an ITB, which would not be unexpected. Btor=3.91 T.
Prf=1.45 MW (J). H/D= %. DNB fired.

Next shot: reduce Btor by 0.2 T to 3.7 T (101 kA). DNB will move
to later in the shot (t=0.9 s), so I will add 1 ms to the pre-fill
puff.

ECDC in D2 is on between shots now.
Aug 1 2001 11:00:56:923AM1010801006Robert GranetzShot 06 -- Fizzle. Pre-fill pressure was a little low (0.05 mTorr).

Next shot: increase pre-fill puff by another 2 ms. Also enable
the LPI gate valve.
Aug 1 2001 11:18:25:300AM1010801007Robert GranetzShot 07 -- Plasma. Disrupted at t=1.45 s. Multiple H-L transitions. Lithium
pellet injected at t=1.41 s. Btor=3.71 T. Startup still needs
improvement. Pre-fill pressure is still low. H/D=5%
Prf=1.5 MW (J).

OH2U coax resistance warning came up; 2.5 micro-ohms. Jim Irby is
studying it.

Next shot: raise Btor by 0.1 T to 3.8 T (104 kA). Also increase
pre-fill puff another 2 ms.

ECDC in D2 is on between shots now.
Aug 1 2001 11:40:02:067AM1010801007Robert GranetzThe OH2U coax resistance is real. The joint temperature rise doesn't seem
abnormal though. We'll shorten the fizzle detector delays and continue with
plasma operation.
Aug 1 2001 11:49:50:380AM1010801008Robert GranetzShot 08 -- Fizzle. Pre-fill pressure is 0.06 mTorr, which should be fine.
OH2U coax resistance dropped to 0.9 micro-ohms.

Next shot: increase pre-fill puff another 2 ms (to 24 ms).
Aug 1 2001 12:28:37:270PM1010801009Robert GranetzShot 09 -- Plasma. Good shot. Multiple H-L transitions. Btor=3.81 T.
Prf=1.5 MW (J). Startup was still shaky. DNB fired at t=0.9 s.

We got another OH coax resistance warning.

Next shot: increase Btor by 0.1 T to 3.9 T.

ECDC in D2 is on between shots now.
Aug 1 2001 12:29:27:690PM1010801010Robert GranetzShot 10 -- Plasma. Disrupted at t=0.56 s, before the RF came on. Good startup
on this one. Btor=3.91 T.

Coax resistances were somewhat lower on this shot.

Next shot: no changes.

ECDC in D2 is on between shots now.
Aug 1 2001 12:49:07:380PM1010801011Robert GranetzShot 11 -- Plasma. Good shot. Disrupted at t=1.44 s. Btor=3.91 T.
Prf=1.5 MW (J). No DNB. H/D=5%. Got an ITB.

Next shot: no changes; fire lithium pellet into ITB.

ECDC in D2 is on between shots now.
Aug 1 2001 01:16:36:083PM1010801012Robert GranetzShot 12 -- Plasma. Killed by lithium pellet at t=1.33 s. Prf=1.5 MW (J).
DNB fired at t=0.9 s. Chromex bin 7 sees a doubling of signal
during the beam. H/D=5%.

Next shot: increase Btor by 0.1 T to 4.0 T.

ECDC in D2 is on between shots now.
Aug 1 2001 02:22:47:597PM1010801013Robert GranetzShot 13 -- Plasma. Good shot. Btor=4.0 T. Prf=1.5 MW (J). DNB fired.
H/D=5-6%.

Next shot: raise Btor to 4.7 T (130.5 kA)

ECDC in D2 is on between shots now.
Aug 1 2001 02:22:57:970PM1010801014Robert GranetzShot 14 -- Plasma. Good shot. Btor=4.71 T. Prf=1.44 MW (J). DNB fired.
H/D=5%.

Next shot: raise Btor to 4.9 T (136.5 kA)

ECDC in D2 is on between shots now.
Aug 1 2001 03:05:28:113PM1010801016Robert GranetzShot 16 -- Plasma. Good shot. Btor=5.1 T. Prf=1.5 MW (J). No ITB.
DNB fired.

Next shot: raise Btor to 5.3 T (148.5 kA) Reduce helium puff
to 75 ms.

ECDC in D2 is on between shots now.
Aug 1 2001 03:16:07:137PM1010801017Robert GranetzShot 17 -- Plasma. Good shot. Btor=5.3 T. Prf=1.45 MW (J). DNB fired.
H/D=4%.

Next shot: raise Btor by 0.1 T to 5.4 T (151500 kA). Set helium
puff to 150 ms, starting at t=0.70 s. DNB will fire at t=1.0 s.

ECDC in D2 is on between shots now.
Aug 1 2001 03:44:56:630PM1010801018Robert GranetzShot 18 -- Plasma. Disrupted at t=1.21 s. Btor=5.4 T. DNB fired at t=1.0 s.
Helium puffed at t=0.7 s. H/D=4%.

Next shot: move helium puff back to t=0.10-0.25 s. (DNB will move
back to t=0.9 s)

ECDC in D2 is on between shots now.
Aug 1 2001 04:27:17:413PM1010801020Robert GranetzShot 20 -- Plasma. Disrupted at t=1.29 s. Btor=5.4 T. Prf=1.34 MW (J).
DNB fired at t=0.9 s.

Next shot: no changes

ECDC in D2 is on between shots now.
Aug 1 2001 04:54:29:980PM1010801021Robert GranetzShot 21 -- Plasma. Good shot. Btor=5.4 T. Prf=1.33 MW (J). DNB fired.
Two EN modes.

Next shot: increase Btor by 0.1 T to 5.5 T.

ECDC in D2 is on between shots now.
Aug 1 2001 05:19:12:827PM1010801022Robert GranetzShot 22 -- Plasma. Good shot. Btor=5.5 T. Prf=1.35 MW (J). DNB fired.
Almost completely L-mode. H/D=3.5%

Next shot: reduce Btor by 0.1 T to 5.4 T. Reduce target density
to nl_04=1.0e20 m-2 (was 1.1).

ECDC in D2 is on between shots now.
Aug 1 2001 05:38:56:957PM1010801023Robert GranetzShot 23 -- Fizzle. Nothing obviously wrong.

Next shot: repeat with no changes.
Aug 1 2001 05:51:41:403PM1010801024Robert GranetzShot 24 -- Plasma. Good shot. Btor=5.4 T. Prf=1.33 MW (J). DNB fired.

Next shot: add 1 ms to pre-fill.

ECDC in D2 is on between shots now.
Aug 1 2001 06:20:02:457PM1010801025Robert GranetzShot 25 -- Plasma. Good shot. Very clear ITB. Btor=5.4 T. Prf=1.35 MW (J).
DNB fired at t=0.9 s. H/D=4-5%. Target nl_04=1.0e20 m-2.

Next shot: repeat with no changes (John's HIREX had a high-voltage
trip).

ECDC in D2 is on between shots now.
Aug 1 2001 07:02:00:473PM1010801026Robert GranetzShot 26 -- Plasma. Good shot. Btor=5.4 T. Prf=1.4 MW (J) + a little from
D and E after t=1.0 s. No ITB. DNB fired. H/D=4-5%.

Next shot: repeat with no changes.

ECDC in D2 is on between shots now.
Aug 1 2001 07:02:19:503PM1010801026Robert GranetzThe LOGBOOK database server has stopped working. Don Nelson and Josh
Stillerman are looking into it from home, but we'll go ahead and try for
another shot anyway.
Aug 1 2001 07:10:48:880PM1010801027Robert GranetzSQL database server began working again after Don rebooted node RED.
Aug 1 2001 07:12:00:180PM1010801027Robert GranetzShot 27 -- Plasma. Good shot. Btor=5.4 T. No ITB. Li pellet at t=1.3 s.
Prf=1.37 MW (J) + some from D and E after t=1.1 s. DNB fired.
H/D=5%.

End of run.

Engineering Operator Comments
ShotTimeTypeStatusComment
109:01:43:473AMPlasmaOk
209:21:19:753AMPlasmaOk
309:40:24:970AMPlasmaOk
410:01:30:130AMPlasmaOk
510:24:46:740AMPlasmaOk
610:48:02:957AMPlasmaOk
711:02:45:597AMPlasmaOk
811:40:25:253AMPlasmaOk
911:55:26:707AMPlasmaOk
1012:17:18:643PMPlasmaOk
1112:39:05:880PMPlasmaOk
1201:01:02:237PMPlasmaOk
1301:24:25:287PMPlasmaOk
1401:49:06:037PMPlasmaOk
1502:14:21:267PMPlasmaOk
1602:38:19:220PMPlasmaOk
1703:02:20:110PMPlasmaOk
1803:27:05:453PMPlasmaOk
1903:52:31:127PMPlasmaOk
2004:16:26:800PMPlasmaOk
2104:38:22:980PMPlasmaOk
2205:02:56:467PMPlasmaOk
2305:27:36:700PMPlasmaOk
2405:42:06:353PMPlasmaOk
2506:06:16:980PMPlasmaOk
2707:06:05:527PMTestBad