Alcator C-Mod Run 1050407 Information

Miniproposals

Miniproposal: 397

Date Filed: 4/9/2004

Title: Comparison of C-Mod EDA regime with JFT2-M HRS regime

First Author: Amanda Hubbard

Session Leader: Amanda Hubbard (shots 1-28)

Operators
Session leader(s):	Amanda Hubbard
Physics operator(s):	Steve Wolfe
Engineering operator(s):	Bill Cochran,Bill Byford

Engineering Operator Run Comment
MP#397

Session Leader Plans

Entered: Apr 6 2005 04:10:43:757PM

Author: Amanda Hubbard

Run Plan for 1050407: MP 397 Comparison of C-Mod EDA regime with
JFT2M HRS regime - Pre-boron comparison

Session Leaders: Amanda Hubbard, Naoyuki Oyama, Kensaku Kamiya
Physics Operator: Steve Wolfe

Purpose: On both C-Mod and JFT2-M, boronization has operationally
been found to be a necessary condition for steady EDA or HRS regimes.
However, the corresponding physics reason is not very well understood,
since we have for several years mostly been running with boronized
walls.

For this run, we plan to revisit the plasma shape and bulk parameters
of a previous successful comparison with JFT2M at q_95=3.4 (on
1040416). We will scan density and increase power, comparing the edge
temperature, collisionality and fluctuations with those observed with
boronized conditions. If time permits, we will repeat at higher q_95
= 4.8, in anticipation of future post-boronization scans at this q.
While not part of the original mini-proposal, this run day will
exploit the current all-metal machine conditions and should contribute
to the JOULE milestone to study the effects of removing boron from
C-Mod.

Run Plan:

1) Start with plasma equilibrium, shape from 1040416016, density from
1040416011 (EDA+"Type II" ELMS) (5.4 T, 940 kA, target nel 9x10^19 m-2).
Check shape and tweak if necessary given changes to control system.
Tune RF
(2 shots).

2) Add 3 MW RF, to make H-mode. Compare pedestal density to that of
1040416011 (ne_95=1.85e20 m-3). Adjust target if necessary to
match. (2 shots)

3) Power scan, shot to shot: 2 MW, 3 MW, 4 MW, 5(if avail) MW. Monitor edge
pedestals (Edge TS, ECE), edge fluctuations (PCI), ELMs (D_alpha,
magnetics), radiation profiles (bolos) (6 shots).
If needed, use between shot ECDC to keep H/D below 5%.

4) Reduce target ne to that of 1040416016 (7x10^19 m-2). Check if
sustained H-modes are achieved, at ~ 3 MW. If so, repeat limited power
scan. (3 shots)

5) Reduce density shot to shot to find low ne limit (ideally to that
of 1040416026 (which previously gave large ELMs), target 4x10^19
m-2. Repeat RF scan, look for edge Te, nu*, ELMs. (6 shots.)

Time permitting, in anticipation of future post-boronization run:

6) Reduce current to 660 kA, should give q_95=4.8. If needed, tweak
Ip and shape. Tune RF (2 shots).

7) Repeat prior density and power scans, again starting with nel=7e19
m-2. (We will let prior experience guide our choices of parameters).

Physics Operators Plans

Entered: Apr 6 2005 05:04:10:360PM

Author: Steve Wolfe

Physics Operator Plan for Thursday, 7-Apr-2005 MP#397 Comparison of C-Mod EDA regime with JFT2-M HRS regime SL: Hubbard, Oyama, Kimiya PO: wolfe Engineering setup: ------------------ Overnight ECDC, bake at 60C Run begins at 09:00 and ends at 17:00 (EDT) Power systems as on 1040416019 A-coil in standard configuration (+Dtop -Dbot -Jtop +Jbot) C-coil Start=0.3sec, Invert=2.0sec Transmitters #1,2,3,4 in RUN-ON by 08:30 Gas setup: fill B-top 6psi D2 Hybrid Enabled (PG4) fill B-side lower 1psi Argon Hybrid Enabled (PG1) leave B-side Upper alone Hybrid DISABLED (PG2) fill B-main 30psi D2 Hybrid Enabled (PG3) Enable (assuming no vacuum problems): ECE, VUV, Z-bolo shutter We WILL be running ECDC for 5 minutes between shots until we decide not to. We will NOT be closing the gate valves in pulse. ---------------------- Plan: Load seg2 from 1040416019 Update offsets, predictors Change nl04 target to 9e19 Program an A-coil waveform Load seg1 from a decent startup from 1050406 1) Check and tweak shape, wait for RF to get tuned 2) At 3MW rf, tweak nl04 to match pedestal density of 1.7e20/m^3 3) Power scan 2-5 MW 4) Reduce target nl04 to 7e19, Prf=3MW; may do limited power scan 5) Reduce nl04 to lower limit, e.g. 4e19/m^2; repeat power scan 6) Ip to 660kA (q95~4.8),nl04=7e19; tweak Ip and/or shape to taste. 7) Scan nl04 and RF power until we run out of time.

Session Leader Summaries

Entered: Apr 8 2005 02:18:44:450PM

Author: Amanda Hubbard

Run summary for 1050407: MP 397 Comparison of C-Mod EDA regime with
JFT2M HRS regime - Pre-boron comparison

Session Leaders: Amanda Hubbard, Naoyuki Oyama (JAERI), Kensaku Kamiya (JAERI)
Physics Operator: Steve Wolfe

Purpose: On both C-Mod and JFT2-M, boronization has operationally
been found to be a necessary condition for steady EDA or HRS regimes.
However, the corresponding physics reason is not very well understood,
since we have for several years mostly been running with boronized
walls.

For this run, we plan to revisit the plasma shape and bulk parameters
of a previous successful comparison with JFT2M at q_95=3.4 (on
1040416). We will scan density and increase power, comparing the edge
temperature, collisionality and fluctuations with those observed with
boronized conditions. If time permits, we will repeat at higher q_95
= 4.8, in anticipation of future post-boronization scans at this q.
While not part of the original mini-proposal, this run day will
exploit the current all-metal machine conditions and should contribute
to the JOULE milestone to study the effects of removing boron from
C-Mod.

Results:

Overall, quite a successful day. The machine and RF generally ran
well, and we covered essentially the planned operational space at
q_95=3.4. Given the extra shots needed for RF tuning etc, we did not
get to the high q part of the run.

To summarize, we carried out density and power scans with JFT-2M like
shape at IP/BT~0.9MA/5.4T (q95~3.4). As previously observed before
boronization, the global character was that of standard ELM-free
H-modes, with increasing density and radiated power which are
terminated by H-L transitions, sometimes preceded by small
Type-III-like ELMs. The pedestal electron pressure, pe,ped, was
limited at almost constant pe,ped in over a wide range of
collisionality, nu*e,ped, (~0.2-5.0). The pedestal density and line
averaged density overlap well the ranges of the previous boronized
plasmas on 1040416. The apparent pedestal density is lower, but the
TS density calibration is currently uncertain; this needs to be
resolved by better edge cross-calibration and/or Raman scattering to
allow conclusions about the relative pedestal pressures which may
shed light on the reasons for the different H-mode behaviour without boronization.

An interesting result was that the 'QC-mode', a key signature of
Endhanced D_alpha H-mode, was seen by PCI, at f~150 kHz, only at
higher nu*e,ped during 'ELM-free' periods. Its
amplitude increase with density, particularly during the later shots
with gas puffing (27 and 28). Its amplitude was rather weak and
apparently not sufficient to stabilize the density rise, although it was noted
that dne/dt decreased. Shots 14-17 are good examples with target ne 9e19 m-2;
17 had the best RF. The QC mode was not noted in prior experiments at
standard C-Mod shape (eg 1050406), though we should go back
and reexamine the PCI data. H-factors were up to 1.6
transiently in the first H-mode, but ~1 in steady periods).

At lower target density, the H-modes consisted of very short
'dithers', triggered by, and lasting only for the duration of, large
sawtooth heat pulses. There were strong buildups of edge radiation,
expelled at the back-transitions. However, in contrast to prior runs,
this seemed to give a 'quasi-steady' state with near-constant density
and radiation, with the back-transitions filling the usual role of
ELMs or QC-mode (which was not present). Energy confinement was
better, with H up to 1.5 transiently and 1.3 for long
periods, as good as we have seen pre-boronization. Shots 18-20 had
target nel 7e19 m-2, shot 19 has the cleanest RF (3 MW) and 20 the
highest (4 MW). Te_95 was 400-600 eV. Shot 21
had the lowest density (5e19 m-2 target, 8e19 H-mode), and hottest
pedestal (up to 800 eV). Dropping the density further resulted in a
nasty disruption (shot 22), which took a few shots to recover from (23-26).

Further analysis of the kinetic and radiation profiles, both of which
require improved absolute calibrations, are needed. We are optimistic
that this will help resolve the physical differences pre and post
boronization H-modes, and thank all participants (especially machine and RF
operators, ETS, bolometry and PCI diagnostics) for their capable
operation and assistance.

Physics Operator Summaries

Entered: Apr 7 2005 06:26:30:847PM

Author: Steve Wolfe

Physop Summary 1050407 MP#397 JFT2-M / C-Mod Comparison (pre-boron special edition) SL: Hubbard, Kamiya, Oyama PO: wolfe EO: the Bills (Cochran, Byford, Parkin) This was a pretty good run from the operational standpoint, and we got much of the planned program done, despite some early difficulties. All of the steps at q=3.4 were addressed. It took a few more shots than anticipated to match the shape and q=3.4 of the 1040416 experiment. The shape started out quite close, and only required some small tweaks, but for some reason the current had to be reduceed to 900kA (from program value of 960 in the old shot) to get the q95=3.4 value. There was also a problem at the start of the day with the J4 crowbar system. Apparently a low voltage supply had failed. This required a number of power room accesses, as well as trips to the high yard, to repair. J-port became available at shot#8. I initially had some difficulty raising the density to the requested value. It behaved as if the gain on the nl04 feedback was insufficient. It was necessary to provide a substantial maintenance pg3 level (>60V) to get nl04 above 1e20. Once I did that the target density came out as programmed. Of course the maintenance level had to be reduced when we went to lower density. We used five minutes of ecdc between most shots, and the H/D was maintained pretty stable as a result. We actually got H/D down to ~3% at the higher density end of the scans. On several shots the engineers were unable to get the between-shot ecdc started because of some interlock problem, so we skipped those rather than delay things further. I didn't wait for the base pressure to come down after ecdc as far as I had on Tuesday. It worked just fine if I only held off pushing the button until 3 to 4e-6. Startup was reasonably robust all day, but despite trying everything I could think of (see logbook), I was unable to do anything about the runaways. There still seems to be a slight tendency for Bz to rise by 1-2 mT over the course of the day, which I compensated by raising IC_EF4U by 10Amps on two occasions. Things were going pretty smoothly until we pushed our luck going to low density and high power on shot#22. This resulted in a hard disruption during the RF pulse, which took two fizzles and two short (~200ms) disruptions to recover from. The last shots #27 and 28 returned to a higher target density and used puffing into the h-mode to try to increase the collisionality and provoke a QC mode. This may actually have worked (see SL summary). The best shot of the day was a low collisionality case on shot#21, which achieved very high pedestal temperatures and a semi-decent H-factor, with Wmhd~115kJ and Rneut~1.5e13/sec. Scorecard: Tests 1 Duds 1 (No TF) Fizzles 3 Short disruptions 2 Plasmas 21 ============= === Shots 28

Session Leader Comments

Apr 7 2005 09:38:56:783AM 1050407002 Amanda Hubbard Full length plasma. 0.95 MA, 5.34 T. q_95 =3.2, a little low. Shape close, requires slight change in
x-pt position. nel0.8-1.2 e20 m-2.

ETS channels out of pedestal.

Apr 7 2005 09:57:23:350AM 1050407003 Amanda Hubbard Good shot. 0.95 MA, 5.34 T. q_95 =3.2, still a little low. nel0.8-1.4 e20 m-2.
RF 2.3 MW, many trips.

Series of what look like ELM-free H-modes. But, what looks like a QC mode is reported on PCI during H-modes,
at around 150 kHz.

Jery and Ted will adjust ETS fiber positions. Repeat.

Apr 7 2005 10:39:00:917AM 1050407004 Amanda Hubbard Good shot- similar ELM-free series. 0.945 MA, 5.44 T. q_95 =3.23, still a little low. nel0.8-1.3 e20 m-2.,
nebar 2.3e20 m-3.

"strong QC mode". But, ne and Prac are rising rapidly.
RF 2.2 MW, sereral trips.

Edge TS positions seem better (trouble plotting profiles). ne_95 up to 1.4e20 m-3. (BUT calibration may be low!)
Te_95 0.43-0.6 keV. (this is hotter than yesterday).

Apr 7 2005 10:42:04:903AM 1050407004 Amanda Hubbard Good shot- similar ELM-free series. 0.92 MA, 5.44 T. q_95 =3.33, still a little low. nel0.85-1.3 e20 m-2.,
nebar 2.5e20 m-3. - about the same as 1040416016

RF has more trips. 2.7 MW max, this seems to be the limit (note that J-port transmitter out of action for now.)
Te_95 up to 560 eV,

Apr 7 2005 11:57:03:110AM 1050407005 Amanda Hubbard H-modes similar to shot 4. Got q=3.3.5 (920 kA).

Apr 7 2005 10:55:29:987AM 1050407006 Amanda Hubbard Similar, but q_95 now up to 3.4 as desired. 900 kA. I'm unclear why we need lower Ip this run, since shape appears
to be the same.

D-port is staying on well, E has a lot of trips. 2.6 MW max. Many ELM-free H-modes.

Next shot: raise target ne, back off on E power.

Apr 7 2005 11:31:43:447AM 1050407007 Amanda Hubbard Good. RF 2.5 MW, much cleaner. Density slightly higher, but not as much as requested:

nel 9e19 m-2 target, 1.46 peak.

QC mode appears about 0.75 secs, midway through first H-mode. Global character still appears as series
of ELM-free H-modes, ne and Prad increasing. nebar up to 2.9 m-3, close to previous EDA range.

Te_95 400 eV,

Apr 7 2005 11:47:32:447AM 1050407008 Amanda Hubbard Steve's gas changes mean nel got to programmed nel 1.1e20 m-2, by 0.7 secs.
Unfortunately, RF tune didn't like this, got no power.
Retune, retry.

Apr 7 2005 12:03:57:800PM 1050407009 Amanda Hubbard Early gas results in MARFE, nel up to 1.5e20. Not surprisingly, RF unhappy - 1 MW, (E only), L-mode.

Apr 7 2005 12:17:44:037PM 1050407010 Amanda Hubbard Fizzle

Apr 7 2005 12:41:57:213PM 1050407011 Amanda Hubbard Plasma. Got target 1.0e20 m-2 (nebar 2e20). RF starts 2 MW, mopstly just 1 MW.
3 H-modes, very brief. First seems to start with an extended Type III ELmy period, gradual ne rise.
Retune, retry.

Apr 7 2005 12:48:03:563PM 1050407012 Amanda Hubbard No TF

Apr 7 2005 01:12:49:623PM 1050407013 Kamiya There is no clear QC-mode on PCI, except for a weak broadband one in frquency range between f~100-200.

Apr 7 2005 01:14:17:660PM 1050407013 Amanda Hubbard Good shot. 2-3 MW RF. Several apparently ELM-free H-modes.
No QC mosde appareent. Ne rise rate larger than in previous shots with weak QC mode.
Te_95 ~ 400 eV. GPC is back, can see the erosion in edge T during each H-mode, as Prad rises.

Apr 7 2005 01:26:54:553PM 1050407014 Amanda Hubbard Good shot. 2.8 MW RF, with a lot of trips (J unhappy). Several apparently ELM-free H-modes.
No QC mosde appareent.
No ECE- valve closed.

This is likely as much power as we will get at this ne. Go back to target 9e19 m-3, as for shot 7.
Try for 3 MW power.

Apr 7 2005 01:42:49:587PM 1050407014 Kamiya Weak QC-mode is visible during ELM-free phase

Apr 7 2005 01:45:17:730PM 1050407015 Kamiya Similar QC-mode activities with previous one (1050407014)

Apr 7 2005 01:54:38:750PM 1050407016 Kamiya Similar QC-mode activities with previous one

Apr 7 2005 01:59:54:510PM 1050407016 Amanda Hubbard Better RF, 2.8 MW, more steady. Still multiple, short H-modes.
RF seems to prefer the slightly larger gap. Retune, increase power.
Te_95 ~ 400 eV

Apr 7 2005 02:09:51:790PM 1050407017 Kamiya QC-mode channged to be somewhat stronger than that seen in previous shot.

Apr 7 2005 02:23:41:183PM 1050407018 Kamiya No clear QC-mode

Apr 7 2005 02:38:46:547PM 1050407018 Amanda Hubbard

Target 7e19 m-2, as requested. Rather different H-mode character. 3 MW RF.
From D_alpha, and edge Te, seems we are getting very short H-modes at each
sawtooth. But, density and Prad are quasi-steady (nel 1e20 m-2, nebar 2.1e20 m-3). 2pi foil bolo 3.1 MW (high), prad_main 1.5 MW.

Edge is hotter, Te_95 (ETS) 400-600 eV (check). 100 kJ, H 1.5 (transient),
1.2 (steady)

Apr 7 2005 02:43:06:373PM 1050407019 Kamiya No clear QC-mode

Apr 7 2005 02:51:57:137PM 1050407019 Amanda Hubbard
Very nice, steady 3 MW RF. Again, quasi-steady 'dithering' H-mode.
108 kJ, Te8 680 ev( at sawtooth pulse/dither).

Note nebar=2.1e20, comparable to 1040416022. Te_95 (ETS) 400-600 eV.
H 1.5 (transient), 1.2 (steady)

Apr 7 2005 03:06:30:347PM 1050407020 Kamiya No clear QC-mode

Apr 7 2005 04:06:36:247PM 1050407020 Amanda Hubbard Similar to 19, but with up ro 4 MW RF - many trips however.

nel 0.7-1.1 e20 m-2. Note dithes more regular, and ne climbing slightly, in
later period with higher RF. Te8 600 eV (pulse peak). Te_95 400 eV,

Apr 7 2005 03:17:10:173PM 1050407021 Kamiya No clear QC-mode

Apr 7 2005 03:30:20:457PM 1050407021 Amanda Hubbard Good. 0.5e20 target, 0.8 in quasi-steady dithering H-mode.
nebar 1.7e20 (comparable to previous Type I ELM shots)

Big D_alpha oscillations early, (ELM-s or dithers??).
112 kJ, H=1.47 transient, 1.3 steady.

Apr 7 2005 03:47:48:057PM 1050407022 Amanda Hubbard Lower target to 4e19 m-2. RF is high (4 MW), but the plasma is not happy-
very high Prad from beginning of RF, cooling edge. 2pi_foil 4.9 MW!

Disrupts at 0.82 secs.

Looks like a sort of dithering H-mode again, nel only 6e19 m-2, nebar 1.27 m-3;
transition not clear, might be an L-mode. H does get to 1.3, then decreases.
Think we've hit the useful low ne limit. Now try to get some high ne (and nu*)
ponts by returning to shot 17, puffing into H-mode.

Apr 7 2005 05:04:27:220PM 1050407024 Amanda Hubbard Fizzle

Apr 7 2005 04:53:24:927PM 1050407025 Amanda Hubbard Disrupts 0.2 secs. Big injection starting at 0.11

Apr 7 2005 05:07:54:897PM 1050407028 Kamiya QC-mode is visible

Apr 7 2005 05:11:42:590PM 1050407028 Amanda Hubbard Even better shot. Target density 9e19 m-2, puffing into H-modes, 0.78-1.3 secs (via ne feedback).

Five H-modes. D-alpha level is rising, rate of ne rise decreasing, as ne
progresses. The QC mode does get stronger, as we hoped! Looking as EDAish
as anything I've seen this campaign.

Got high ne than previous, nel to 1.65e20, nebar to 3.5e20, RF up to 3 MW,
still some trips but better. Gives up at 1.05 sec (then L-mode).

That's all folks - thanks

Physics Operator Comments

Apr 7 2005 08:43:34:803AM Steve Wolfe
Setting up for 1050407 - MP#397 (pre-boronization exploitation) Import seg2 from 1040416019 call_alg on ZCUR (2 & 3), CLEARIN, IP change title to "JFT2-M shape" Change density to nl04=9e19 copy A-coil waveform from seg3 (start at .2sec,to 2000@0.6sec) change DC level on Chopper voltage from 100V to 0V Import seg1 from 1050406005 PG4 is 20ms; leave it for now. Earl reduced the PG3 level between 35ms and .1s to 55-50V; put it back up to 80V until .075s Change final chopper voltage from 150V to 0. Touch wire2 in seg1 to fix timestamp Load at 7-Apr-2005 07:21:57.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done

Apr 7 2005 09:12:54:910AM 1050407001 Steve Wolfe
Shot#1: Cycle test. Successful. Gas puff seems to have been too big, got .062mTorr . Plenum was at 6.7psi, but that's not enough to explain it. Have them pump it down to 6psi and see what happens on the first real shot.

Apr 7 2005 09:17:22:480AM 1050407001 Steve Wolfe
There is a problem with the crowbar circuit on J4, so we're starting the day with only D&E. It may take a two hour turnaround to get J back on the air, later in the day.

Apr 7 2005 09:31:00:510AM 1050407002 Steve Wolfe
Shot#2: Plasma attempt plasma full length. Got H-modes. nl04 is a little low. shape is pretty close. q95~3.2 instead of 3.4 rxl is a little more positive, and top is a little high Tweak up shape. ECDC 5 minutes

Apr 7 2005 09:43:45:333AM 1050407003 Steve Wolfe
Shot#3: RXL=-.045 from -.04 ZXU= .08 from .07 nl04 to 1e20 Plasma full length. RF having some faults. qpsi=3.2, Could stand a little bit more off the top. Jerry will move fiber locations for edge TS.

Apr 7 2005 10:12:21:230AM 1050407004 Steve Wolfe
Shot#4: RXU out by .01 (-.015 from -.025) RXL in by another 5mm to -.050 TF_CURRENT to 150kA from 147. Tweak startup RCUR waveform to start 1cm in (.65 from .66) to try to deal with runaways. Plasma full length. q is still too low, ~3.25-3.3 Shape looks pretty good, maybe a tiny bit high all around Runaways still bad.

Apr 7 2005 10:31:45:487AM 1050407005 Steve Wolfe
Shot#5: No ECDC this time, some problem with PEI plc setup. Ip from .96 to .92e6 to try to get q closer raise Pg3 puff in seg 1 to 100V Plasma full length. q=3.3 to 3.35, shape looks good, could use another 20kA off Runaways still bad.

Apr 7 2005 10:52:46:160AM 1050407006 Steve Wolfe
Shot#6: Ip from 920 to 900kA Program RCUR further in in seg1: Start at .63 until 10msec then out to .64 Plasma full length. q=3.4 next shot: up in density by 0.2e20

Apr 7 2005 11:34:06:057AM 1050407007 Steve Wolfe
Shot#7: nl04 from 1.0 to 1.2e20, add some pg3 maintenance level rcur offset from 2500 to 3000 (still working on runaways) plasma full length, density still low? Did I forget to load? No it just needs more gas to get there. Try raising the pre-program by 40V Long delay for RF work in power room ECDC back on now.

Apr 7 2005 11:50:55:133AM 1050407008 Steve Wolfe
Shot#8: nl04 from 1.0 to 1.2e20, add some pg3 maintenance level Raise pg3 maintenance pre-program by 40V to 65V Plasma disrupted at 1.5sec Looks like it actually got to 1.2e20 but only after .75sec No rf. EF3 is seems to be on the rail after 1.3sec, although it only reads 11kA instead of 12kA; outer gap went to zero before the disruption. Raise Ef3 current limit to 15kA Ask for density to come up faster and hope it doesn't marfe

Apr 7 2005 12:07:30:033PM 1050407009 Steve Wolfe
Shot#9: Raise Ef3 current limit to 15kA Ask for density to come up faster and hope it doesn't marfe plasma, but did get a marfe, and it disrupted at 1.55 too much density early. This time oh2u railed, causing loss of vertical control and disruption. Startup is getting a little dicey, and no real progress on runaways Back off on density demand.

Apr 7 2005 12:16:50:117PM 1050407010 Steve Wolfe
Shot#10: nl04 to 1.0e20, leave pg3 pre-program, put early target back down lower to avoid marfe fizzle. breakdown a little later, slow current rise, bz may be creeping up. No pcs changes, just run it around again (no ECDC this time)

Apr 7 2005 12:33:14:907PM 1050407011 Steve Wolfe
Shot#11: nl04 to 1.0e20, leave pg3 pre-program, put early target back down lower to avoid marfe plasma full length, nl04=1e20 as requested, rf not too happy, some brief h-modes startup still a little hesitation. next shot: same density, rf will try to tune

Apr 7 2005 12:43:13:230PM 1050407012 Steve Wolfe
Shot#12:initial seg2 pg3 point to 40V ef4 from -1325 to -1335 No tf => No plasma Once more, with feeling!

Apr 7 2005 12:58:50:323PM 1050407013 Steve Wolfe
Shot#13:initial seg2 pg3 point to 40V ef4 from -1325 to -1335 Plasma full length, h-modes. Still trying to get rf to match. Bz came down, but there's still a hesitation. Put rcur offset back to 2500A-m

Apr 7 2005 01:23:32:790PM 1050407014 Steve Wolfe
Shot#14: Rcur offset back to 2500 Plasma full length, h-modes ECE gate valve closed RF trying, but not staying on very well startup still not great; still have hards. next shot: lower density to 9e19

Apr 7 2005 01:40:56:607PM 1050407015 Steve Wolfe
Shot#15: NL04 to 9e19, no startup tweaks plasma, full length, got 9e19, J seems a litle happier D&E still faulting Startup a little better (did nothing) still lots of runaways. next shot: Wookie trying to improve match on D

Apr 7 2005 01:55:20:400PM 1050407016 Steve Wolfe
Shot#16: Increase gap. reduce rcur by .0015m to .6625 plasma full length, outer gap is bigger, swinging less. E still faulting, other RF is happy. Startup better again (still doing nothing), Still getting runaways though. One more shot with more power (we hope)

Apr 7 2005 02:04:35:107PM 1050407017 Steve Wolfe
Shot#17: No pcs changes plasma full length, multiple h-modes next shot: nl04 down to 7e19

Apr 7 2005 02:29:52:580PM 1050407018 Steve Wolfe
shot#18: nl04 from 9 to 7e19, pg3 maint. level from ~60 to 30V seg1 pg4 from 20 to 22msec Plasma full length, got the density, D&J stayed on, E faulting. Type III's or dithers? Looks better than before, hotter at least. Still have runaways, startup looks ok. next shot: More power

Apr 7 2005 02:44:37:330PM 1050407019 Steve Wolfe
shot#19: No pcs changes plasma full length, no flickers Wmhd higher ~107kJ, 3MW steady from the RF startup a little hesitant on this one next shot: go for 4MW

Apr 7 2005 03:04:26:320PM 1050407020 Steve Wolfe
shot#20: Drop pg4 back to 20ms plasma full length, not as steady 4MW but not staying on. still hesitation in startup. Bz does seem to be creeping up again. next shot: ef4 10A more negative nl04 to 5e19

Apr 7 2005 03:21:37:797PM 1050407021 Steve Wolfe
shot#21: ef4 10A more negative nl04 to 5e19, pg3 maint. level to 10V from 30V plasma full length, got an h-mode (or maybe a few hundred of them?), slowly increasing density through the RF pulse; Prf=3MW steady. Wmhd~112MW, Prad~1.7. Te(8) up to 800eV. Neutron rate above 1.5e13. No ECDC after this one (wouldn't turn on) Lower density on next shot

Apr 7 2005 03:38:18:297PM 1050407022 Steve Wolfe
shot#22: nl04 to 4e19, pg3 maint to 0.0 Disrupted at 0.8sec, big injection? RF was at 4MW steady right to the end. Possible locked mode at 0.81, but halpha has already started up at 0.80sec next shot: Go back to #17 and puff into H-mode to raise density, and collisionality

Apr 7 2005 03:49:59:790PM 1050407023 Steve Wolfe
shot#23: reload seg2 from #17 and ask for 2e20 between .75s and 1.3sec, so it will puff into the H-mode No change to startup fizzle. Should probably have dropped the fill after the disruption CIII light more than doubled. next shot: try again

Apr 7 2005 04:04:22:153PM 1050407024 Steve Wolfe
shot#24: target nl04=9e19 and ask for 2e20 between .78s and 1.3sec, (slight change in waveform from 23) so it will puff into the H-mode No change to startup, but ECDC after the fizzle. Another fizzle. CIII still high. next shot: No ecdc, lower pre-puff

Apr 7 2005 04:26:25:317PM 1050407025 Steve Wolfe
shot#25: No ecdc, pg4 from 20 to 18ms Early disruption? .22sec. Startup looks ok, but gets hit with something. May also have some current rise MHD.

Apr 7 2005 04:36:05:987PM 1050407026 Steve Wolfe
shot#26: ecdc for 5minutes, no pcs changes Still trying to get to puff into the H-mode Just the same. Short disruption at 0.2sec but in trouble at 0.2 sec. next shot: reduce seg1 pg3 puff by factor of 2 and the first point in seg2 to 32V

Apr 7 2005 04:54:07:617PM 1050407027 Steve Wolfe
shot#27: ecdc for 5minutes, reduce seg1 pg3 puff by factor of 2 and the first point in seg2 to 32V plasma to 1.7sec. Didn't stay in H-mode long. Got the puff into the H-mode, RF tripped out though. next shot: repeat?

Apr 7 2005 05:11:36:870PM 1050407028 Steve Wolfe
shot#28: ecdc for 5minutes, slow down density demand in H-mode to .85sec for 1.7e20 plasma to 1.7sec, bite out of the current around .65sec, but it recovered. Density rising until 1.05sec, then RF trips off for good (or ill) Actually E stays onm but we lose the h-mode. Better than 27, not wonderful. Probably got the high edge collisionality case; Te(8) down to 400eV. End of run.

Engineering Operator Comments

Shot Time Type Status Comment

1 08:56:43:837AM Test Ok

2 09:19:31:350AM Plasma Ok

3 09:36:57:403AM Plasma Ok

4 10:01:34:557AM Plasma Ok

5 10:23:49:410AM Plasma Ok

6 10:48:13:467AM Plasma Ok

7 11:04:28:763AM Plasma Ok

8 11:39:40:540AM Plasma Ok

9 11:55:08:723AM Plasma Ok

10 12:12:10:113PM Plasma Ok

11 12:24:47:540PM Plasma Ok

12 12:40:57:183PM Plasma Bad No TF Supply Current

13 12:53:16:900PM Plasma Ok

14 01:13:56:373PM Plasma Ok

15 01:29:06:617PM Plasma Ok

16 01:46:18:370PM Plasma Ok

17 02:02:39:610PM Plasma Ok

18 02:18:16:967PM Plasma Ok

19 02:37:10:947PM Plasma Ok

20 02:52:17:030PM Plasma Ok

21 03:09:54:770PM Plasma Ok

22 03:24:32:673PM Plasma Ok

23 03:46:07:897PM Plasma Ok

24 04:01:17:007PM Plasma Ok

25 04:13:47:990PM Plasma Ok

26 04:30:12:760PM Plasma Ok

27 04:46:59:140PM Plasma Ok

28 05:03:11:017PM Plasma Ok

Session Leader Comments
Apr 7 2005 09:38:56:783AM	1050407002	Amanda Hubbard	Full length plasma. 0.95 MA, 5.34 T. q_95 =3.2, a little low. Shape close, requires slight change in x-pt position. nel0.8-1.2 e20 m-2. ETS channels out of pedestal.
Apr 7 2005 09:57:23:350AM	1050407003	Amanda Hubbard	Good shot. 0.95 MA, 5.34 T. q_95 =3.2, still a little low. nel0.8-1.4 e20 m-2. RF 2.3 MW, many trips. Series of what look like ELM-free H-modes. But, what looks like a QC mode is reported on PCI during H-modes, at around 150 kHz. Jery and Ted will adjust ETS fiber positions. Repeat.
Apr 7 2005 10:39:00:917AM	1050407004	Amanda Hubbard	Good shot- similar ELM-free series. 0.945 MA, 5.44 T. q_95 =3.23, still a little low. nel0.8-1.3 e20 m-2., nebar 2.3e20 m-3. "strong QC mode". But, ne and Prac are rising rapidly. RF 2.2 MW, sereral trips. Edge TS positions seem better (trouble plotting profiles). ne_95 up to 1.4e20 m-3. (BUT calibration may be low!) Te_95 0.43-0.6 keV. (this is hotter than yesterday).
Apr 7 2005 10:42:04:903AM	1050407004	Amanda Hubbard	Good shot- similar ELM-free series. 0.92 MA, 5.44 T. q_95 =3.33, still a little low. nel0.85-1.3 e20 m-2., nebar 2.5e20 m-3. - about the same as 1040416016 RF has more trips. 2.7 MW max, this seems to be the limit (note that J-port transmitter out of action for now.) Te_95 up to 560 eV,
Apr 7 2005 11:57:03:110AM	1050407005	Amanda Hubbard	H-modes similar to shot 4. Got q=3.3.5 (920 kA).
Apr 7 2005 10:55:29:987AM	1050407006	Amanda Hubbard	Similar, but q_95 now up to 3.4 as desired. 900 kA. I'm unclear why we need lower Ip this run, since shape appears to be the same. D-port is staying on well, E has a lot of trips. 2.6 MW max. Many ELM-free H-modes. Next shot: raise target ne, back off on E power.
Apr 7 2005 11:31:43:447AM	1050407007	Amanda Hubbard	Good. RF 2.5 MW, much cleaner. Density slightly higher, but not as much as requested: nel 9e19 m-2 target, 1.46 peak. QC mode appears about 0.75 secs, midway through first H-mode. Global character still appears as series of ELM-free H-modes, ne and Prad increasing. nebar up to 2.9 m-3, close to previous EDA range. Te_95 400 eV,
Apr 7 2005 11:47:32:447AM	1050407008	Amanda Hubbard	Steve's gas changes mean nel got to programmed nel 1.1e20 m-2, by 0.7 secs. Unfortunately, RF tune didn't like this, got no power. Retune, retry.
Apr 7 2005 12:03:57:800PM	1050407009	Amanda Hubbard	Early gas results in MARFE, nel up to 1.5e20. Not surprisingly, RF unhappy - 1 MW, (E only), L-mode.
Apr 7 2005 12:17:44:037PM	1050407010	Amanda Hubbard	Fizzle
Apr 7 2005 12:41:57:213PM	1050407011	Amanda Hubbard	Plasma. Got target 1.0e20 m-2 (nebar 2e20). RF starts 2 MW, mopstly just 1 MW. 3 H-modes, very brief. First seems to start with an extended Type III ELmy period, gradual ne rise. Retune, retry.
Apr 7 2005 12:48:03:563PM	1050407012	Amanda Hubbard	No TF
Apr 7 2005 01:12:49:623PM	1050407013	Kamiya	There is no clear QC-mode on PCI, except for a weak broadband one in frquency range between f~100-200.
Apr 7 2005 01:14:17:660PM	1050407013	Amanda Hubbard	Good shot. 2-3 MW RF. Several apparently ELM-free H-modes. No QC mosde appareent. Ne rise rate larger than in previous shots with weak QC mode. Te_95 ~ 400 eV. GPC is back, can see the erosion in edge T during each H-mode, as Prad rises.
Apr 7 2005 01:26:54:553PM	1050407014	Amanda Hubbard	Good shot. 2.8 MW RF, with a lot of trips (J unhappy). Several apparently ELM-free H-modes. No QC mosde appareent. No ECE- valve closed. This is likely as much power as we will get at this ne. Go back to target 9e19 m-3, as for shot 7. Try for 3 MW power.
Apr 7 2005 01:42:49:587PM	1050407014	Kamiya	Weak QC-mode is visible during ELM-free phase
Apr 7 2005 01:45:17:730PM	1050407015	Kamiya	Similar QC-mode activities with previous one (1050407014)
Apr 7 2005 01:54:38:750PM	1050407016	Kamiya	Similar QC-mode activities with previous one
Apr 7 2005 01:59:54:510PM	1050407016	Amanda Hubbard	Better RF, 2.8 MW, more steady. Still multiple, short H-modes. RF seems to prefer the slightly larger gap. Retune, increase power. Te_95 ~ 400 eV
Apr 7 2005 02:09:51:790PM	1050407017	Kamiya	QC-mode channged to be somewhat stronger than that seen in previous shot.
Apr 7 2005 02:23:41:183PM	1050407018	Kamiya	No clear QC-mode
Apr 7 2005 02:38:46:547PM	1050407018	Amanda Hubbard	Target 7e19 m-2, as requested. Rather different H-mode character. 3 MW RF. From D_alpha, and edge Te, seems we are getting very short H-modes at each sawtooth. But, density and Prad are quasi-steady (nel 1e20 m-2, nebar 2.1e20 m-3). 2pi foil bolo 3.1 MW (high), prad_main 1.5 MW. Edge is hotter, Te_95 (ETS) 400-600 eV (check). 100 kJ, H 1.5 (transient), 1.2 (steady)
Apr 7 2005 02:43:06:373PM	1050407019	Kamiya	No clear QC-mode
Apr 7 2005 02:51:57:137PM	1050407019	Amanda Hubbard	Very nice, steady 3 MW RF. Again, quasi-steady 'dithering' H-mode. 108 kJ, Te8 680 ev( at sawtooth pulse/dither). Note nebar=2.1e20, comparable to 1040416022. Te_95 (ETS) 400-600 eV. H 1.5 (transient), 1.2 (steady)
Apr 7 2005 03:06:30:347PM	1050407020	Kamiya	No clear QC-mode
Apr 7 2005 04:06:36:247PM	1050407020	Amanda Hubbard	Similar to 19, but with up ro 4 MW RF - many trips however. nel 0.7-1.1 e20 m-2. Note dithes more regular, and ne climbing slightly, in later period with higher RF. Te8 600 eV (pulse peak). Te_95 400 eV,
Apr 7 2005 03:17:10:173PM	1050407021	Kamiya	No clear QC-mode
Apr 7 2005 03:30:20:457PM	1050407021	Amanda Hubbard	Good. 0.5e20 target, 0.8 in quasi-steady dithering H-mode. nebar 1.7e20 (comparable to previous Type I ELM shots) Big D_alpha oscillations early, (ELM-s or dithers??). 112 kJ, H=1.47 transient, 1.3 steady.
Apr 7 2005 03:47:48:057PM	1050407022	Amanda Hubbard	Lower target to 4e19 m-2. RF is high (4 MW), but the plasma is not happy- very high Prad from beginning of RF, cooling edge. 2pi_foil 4.9 MW! Disrupts at 0.82 secs. Looks like a sort of dithering H-mode again, nel only 6e19 m-2, nebar 1.27 m-3; transition not clear, might be an L-mode. H does get to 1.3, then decreases. Think we've hit the useful low ne limit. Now try to get some high ne (and nu*) ponts by returning to shot 17, puffing into H-mode.
Apr 7 2005 05:04:27:220PM	1050407024	Amanda Hubbard	Fizzle
Apr 7 2005 04:53:24:927PM	1050407025	Amanda Hubbard	Disrupts 0.2 secs. Big injection starting at 0.11
Apr 7 2005 05:07:54:897PM	1050407028	Kamiya	QC-mode is visible
Apr 7 2005 05:11:42:590PM	1050407028	Amanda Hubbard	Even better shot. Target density 9e19 m-2, puffing into H-modes, 0.78-1.3 secs (via ne feedback). Five H-modes. D-alpha level is rising, rate of ne rise decreasing, as ne progresses. The QC mode does get stronger, as we hoped! Looking as EDAish as anything I've seen this campaign. Got high ne than previous, nel to 1.65e20, nebar to 3.5e20, RF up to 3 MW, still some trips but better. Gives up at 1.05 sec (then L-mode). That's all folks - thanks

Physics Operator Comments
Apr 7 2005 08:43:34:803AM		Steve Wolfe	Setting up for 1050407 - MP#397 (pre-boronization exploitation) Import seg2 from 1040416019 call_alg on ZCUR (2 & 3), CLEARIN, IP change title to "JFT2-M shape" Change density to nl04=9e19 copy A-coil waveform from seg3 (start at .2sec,to 2000@0.6sec) change DC level on Chopper voltage from 100V to 0V Import seg1 from 1050406005 PG4 is 20ms; leave it for now. Earl reduced the PG3 level between 35ms and .1s to 55-50V; put it back up to 80V until .075s Change final chopper voltage from 150V to 0. Touch wire2 in seg1 to fix timestamp Load at 7-Apr-2005 07:21:57.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done
Apr 7 2005 09:12:54:910AM	1050407001	Steve Wolfe	Shot#1: Cycle test. Successful. Gas puff seems to have been too big, got .062mTorr . Plenum was at 6.7psi, but that's not enough to explain it. Have them pump it down to 6psi and see what happens on the first real shot.
Apr 7 2005 09:17:22:480AM	1050407001	Steve Wolfe	There is a problem with the crowbar circuit on J4, so we're starting the day with only D&E. It may take a two hour turnaround to get J back on the air, later in the day.
Apr 7 2005 09:31:00:510AM	1050407002	Steve Wolfe	Shot#2: Plasma attempt plasma full length. Got H-modes. nl04 is a little low. shape is pretty close. q95~3.2 instead of 3.4 rxl is a little more positive, and top is a little high Tweak up shape. ECDC 5 minutes
Apr 7 2005 09:43:45:333AM	1050407003	Steve Wolfe	Shot#3: RXL=-.045 from -.04 ZXU= .08 from .07 nl04 to 1e20 Plasma full length. RF having some faults. qpsi=3.2, Could stand a little bit more off the top. Jerry will move fiber locations for edge TS.
Apr 7 2005 10:12:21:230AM	1050407004	Steve Wolfe	Shot#4: RXU out by .01 (-.015 from -.025) RXL in by another 5mm to -.050 TF_CURRENT to 150kA from 147. Tweak startup RCUR waveform to start 1cm in (.65 from .66) to try to deal with runaways. Plasma full length. q is still too low, ~3.25-3.3 Shape looks pretty good, maybe a tiny bit high all around Runaways still bad.
Apr 7 2005 10:31:45:487AM	1050407005	Steve Wolfe	Shot#5: No ECDC this time, some problem with PEI plc setup. Ip from .96 to .92e6 to try to get q closer raise Pg3 puff in seg 1 to 100V Plasma full length. q=3.3 to 3.35, shape looks good, could use another 20kA off Runaways still bad.
Apr 7 2005 10:52:46:160AM	1050407006	Steve Wolfe	Shot#6: Ip from 920 to 900kA Program RCUR further in in seg1: Start at .63 until 10msec then out to .64 Plasma full length. q=3.4 next shot: up in density by 0.2e20
Apr 7 2005 11:34:06:057AM	1050407007	Steve Wolfe	Shot#7: nl04 from 1.0 to 1.2e20, add some pg3 maintenance level rcur offset from 2500 to 3000 (still working on runaways) plasma full length, density still low? Did I forget to load? No it just needs more gas to get there. Try raising the pre-program by 40V Long delay for RF work in power room ECDC back on now.
Apr 7 2005 11:50:55:133AM	1050407008	Steve Wolfe	Shot#8: nl04 from 1.0 to 1.2e20, add some pg3 maintenance level Raise pg3 maintenance pre-program by 40V to 65V Plasma disrupted at 1.5sec Looks like it actually got to 1.2e20 but only after .75sec No rf. EF3 is seems to be on the rail after 1.3sec, although it only reads 11kA instead of 12kA; outer gap went to zero before the disruption. Raise Ef3 current limit to 15kA Ask for density to come up faster and hope it doesn't marfe
Apr 7 2005 12:07:30:033PM	1050407009	Steve Wolfe	Shot#9: Raise Ef3 current limit to 15kA Ask for density to come up faster and hope it doesn't marfe plasma, but did get a marfe, and it disrupted at 1.55 too much density early. This time oh2u railed, causing loss of vertical control and disruption. Startup is getting a little dicey, and no real progress on runaways Back off on density demand.
Apr 7 2005 12:16:50:117PM	1050407010	Steve Wolfe	Shot#10: nl04 to 1.0e20, leave pg3 pre-program, put early target back down lower to avoid marfe fizzle. breakdown a little later, slow current rise, bz may be creeping up. No pcs changes, just run it around again (no ECDC this time)
Apr 7 2005 12:33:14:907PM	1050407011	Steve Wolfe	Shot#11: nl04 to 1.0e20, leave pg3 pre-program, put early target back down lower to avoid marfe plasma full length, nl04=1e20 as requested, rf not too happy, some brief h-modes startup still a little hesitation. next shot: same density, rf will try to tune
Apr 7 2005 12:43:13:230PM	1050407012	Steve Wolfe	Shot#12:initial seg2 pg3 point to 40V ef4 from -1325 to -1335 No tf => No plasma Once more, with feeling!
Apr 7 2005 12:58:50:323PM	1050407013	Steve Wolfe	Shot#13:initial seg2 pg3 point to 40V ef4 from -1325 to -1335 Plasma full length, h-modes. Still trying to get rf to match. Bz came down, but there's still a hesitation. Put rcur offset back to 2500A-m
Apr 7 2005 01:23:32:790PM	1050407014	Steve Wolfe	Shot#14: Rcur offset back to 2500 Plasma full length, h-modes ECE gate valve closed RF trying, but not staying on very well startup still not great; still have hards. next shot: lower density to 9e19
Apr 7 2005 01:40:56:607PM	1050407015	Steve Wolfe	Shot#15: NL04 to 9e19, no startup tweaks plasma, full length, got 9e19, J seems a litle happier D&E still faulting Startup a little better (did nothing) still lots of runaways. next shot: Wookie trying to improve match on D
Apr 7 2005 01:55:20:400PM	1050407016	Steve Wolfe	Shot#16: Increase gap. reduce rcur by .0015m to .6625 plasma full length, outer gap is bigger, swinging less. E still faulting, other RF is happy. Startup better again (still doing nothing), Still getting runaways though. One more shot with more power (we hope)
Apr 7 2005 02:04:35:107PM	1050407017	Steve Wolfe	Shot#17: No pcs changes plasma full length, multiple h-modes next shot: nl04 down to 7e19
Apr 7 2005 02:29:52:580PM	1050407018	Steve Wolfe	shot#18: nl04 from 9 to 7e19, pg3 maint. level from ~60 to 30V seg1 pg4 from 20 to 22msec Plasma full length, got the density, D&J stayed on, E faulting. Type III's or dithers? Looks better than before, hotter at least. Still have runaways, startup looks ok. next shot: More power
Apr 7 2005 02:44:37:330PM	1050407019	Steve Wolfe	shot#19: No pcs changes plasma full length, no flickers Wmhd higher ~107kJ, 3MW steady from the RF startup a little hesitant on this one next shot: go for 4MW
Apr 7 2005 03:04:26:320PM	1050407020	Steve Wolfe	shot#20: Drop pg4 back to 20ms plasma full length, not as steady 4MW but not staying on. still hesitation in startup. Bz does seem to be creeping up again. next shot: ef4 10A more negative nl04 to 5e19
Apr 7 2005 03:21:37:797PM	1050407021	Steve Wolfe	shot#21: ef4 10A more negative nl04 to 5e19, pg3 maint. level to 10V from 30V plasma full length, got an h-mode (or maybe a few hundred of them?), slowly increasing density through the RF pulse; Prf=3MW steady. Wmhd~112MW, Prad~1.7. Te(8) up to 800eV. Neutron rate above 1.5e13. No ECDC after this one (wouldn't turn on) Lower density on next shot
Apr 7 2005 03:38:18:297PM	1050407022	Steve Wolfe	shot#22: nl04 to 4e19, pg3 maint to 0.0 Disrupted at 0.8sec, big injection? RF was at 4MW steady right to the end. Possible locked mode at 0.81, but halpha has already started up at 0.80sec next shot: Go back to #17 and puff into H-mode to raise density, and collisionality
Apr 7 2005 03:49:59:790PM	1050407023	Steve Wolfe	shot#23: reload seg2 from #17 and ask for 2e20 between .75s and 1.3sec, so it will puff into the H-mode No change to startup fizzle. Should probably have dropped the fill after the disruption CIII light more than doubled. next shot: try again
Apr 7 2005 04:04:22:153PM	1050407024	Steve Wolfe	shot#24: target nl04=9e19 and ask for 2e20 between .78s and 1.3sec, (slight change in waveform from 23) so it will puff into the H-mode No change to startup, but ECDC after the fizzle. Another fizzle. CIII still high. next shot: No ecdc, lower pre-puff
Apr 7 2005 04:26:25:317PM	1050407025	Steve Wolfe	shot#25: No ecdc, pg4 from 20 to 18ms Early disruption? .22sec. Startup looks ok, but gets hit with something. May also have some current rise MHD.
Apr 7 2005 04:36:05:987PM	1050407026	Steve Wolfe	shot#26: ecdc for 5minutes, no pcs changes Still trying to get to puff into the H-mode Just the same. Short disruption at 0.2sec but in trouble at 0.2 sec. next shot: reduce seg1 pg3 puff by factor of 2 and the first point in seg2 to 32V
Apr 7 2005 04:54:07:617PM	1050407027	Steve Wolfe	shot#27: ecdc for 5minutes, reduce seg1 pg3 puff by factor of 2 and the first point in seg2 to 32V plasma to 1.7sec. Didn't stay in H-mode long. Got the puff into the H-mode, RF tripped out though. next shot: repeat?
Apr 7 2005 05:11:36:870PM	1050407028	Steve Wolfe	shot#28: ecdc for 5minutes, slow down density demand in H-mode to .85sec for 1.7e20 plasma to 1.7sec, bite out of the current around .65sec, but it recovered. Density rising until 1.05sec, then RF trips off for good (or ill) Actually E stays onm but we lose the h-mode. Better than 27, not wonderful. Probably got the high edge collisionality case; Te(8) down to 400eV. End of run.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:56:43:837AM	Test	Ok
2	09:19:31:350AM	Plasma	Ok
3	09:36:57:403AM	Plasma	Ok
4	10:01:34:557AM	Plasma	Ok
5	10:23:49:410AM	Plasma	Ok
6	10:48:13:467AM	Plasma	Ok
7	11:04:28:763AM	Plasma	Ok
8	11:39:40:540AM	Plasma	Ok
9	11:55:08:723AM	Plasma	Ok
10	12:12:10:113PM	Plasma	Ok
11	12:24:47:540PM	Plasma	Ok
12	12:40:57:183PM	Plasma	Bad	No TF Supply Current
13	12:53:16:900PM	Plasma	Ok
14	01:13:56:373PM	Plasma	Ok
15	01:29:06:617PM	Plasma	Ok
16	01:46:18:370PM	Plasma	Ok
17	02:02:39:610PM	Plasma	Ok
18	02:18:16:967PM	Plasma	Ok
19	02:37:10:947PM	Plasma	Ok
20	02:52:17:030PM	Plasma	Ok
21	03:09:54:770PM	Plasma	Ok
22	03:24:32:673PM	Plasma	Ok
23	03:46:07:897PM	Plasma	Ok
24	04:01:17:007PM	Plasma	Ok
25	04:13:47:990PM	Plasma	Ok
26	04:30:12:760PM	Plasma	Ok
27	04:46:59:140PM	Plasma	Ok
28	05:03:11:017PM	Plasma	Ok