| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Dennis Whyte |
| Physics operator(s): | Bill Rowan |
| Engineering operator(s): | Sam Pierson,Bill Cochran,Gary Dekow |
| Engineering Operator Run Comment |
| automatically entered by signon - please replace with real comment |
| Session Leader Plans |
| Entered: Nov 19 2009 05:11:48:530PM |
| Author: Dennis Whyte |
|
Characterization and Optimization of I-mode: J-ant @ 50 MHz ---------------------------------- Day 3 I-mode Exploration at reduced B and 50 MHz J-antennae ------------------------------------------------------ The overall purpose of these experiments is to characterize the necessary parameters to obtain I-mode (a.k.a. enhanced L-mode) while documenting I-mode plasma characteristics and optimizing I-mode towards its application in Alcator C-Mod for high confinement at low density. The experiment will focus on expanding the available I-mode operating space by exploring the effects of shaping, density, q95, and Ip with a goal of obtaining basic scaling relationships for further use on C-Mod and possible exploration on other devices. This day builds on the experiences of our last run days (e.g. 1090915, 1091016) which were performed near full field with on-axis H-minority ICRF at ~80 MHz. The H-mode threshold appeared to have an unexpected strong q dependence, a weaker B dependence and little Ip dependence. Also the clear signatures of the I-mode (Te pedestal, 200-300 MHz quasi-coherent oscillations) appear to favor lower q95 (~2.9-3.5). However the Ip/Bt scan at fixed q was very limited due to on-axis heating requirements The retuning of the J-ant this week to 50 MHz provides us with a chance to better explore the inter-dependencies of q, B and I In addition we found in 1091016 that neon seeding was very beneficial to reducing impurity bursts and in improving overall ICRH reliability. We'll continue to use this today given our large ICRF heating requirements Shots USN Reference shot: 1091016033 (good I-mode shot from this year with good early density control) Cryopump ON Working Gas Species: D2 Neon injection in each shot 3-He injection in standby for possible minority heating at full field with J-ant. Density: Target NL04 densities from 0.3 to 1.3 (1e20) Boronization Requested: NO Toroidal Field: 5.0 - 5.8 T (clockwise) Plasma Current: 0.5 - 1.3 MA ICRF Power: J-antennae: 50 MHz, 2.6 MW maximum available D&E antennae: 80 MHz, 3 MW maximum available RF power steps programmed as in 1091016 run Slower Prf rampup, then four steps of 200 ms each. Diagnostics: ------------ ECE with varying B field Edge TS with alignment for pedestal/edge as reference shot Note: DNB is offline so no pedestal diagnosis available from CXRS but use D2 inner wall puffing Run Plan Today will focus on obtaining the dependences of I-mode on plasma parameters at fixed shape of 1091016033. This will follow the logic of the scans at full field with a few variations. We start with a density scan at q95 ~ 3.2 and 3.3 T (as reference shot) since operationally the density is biggest uncertainty (i.e. what will be the "natural" density of I-mode at reduced Ip) I'll guess that this density is about 1/2 to 3/4 of our full field NL04~1e20 sweet spot. Also we'll see if J-ant by itself has enough power to get us an H-mode transition. 1. Density scan @ B=3.3 T , Ip = 0.7 MA, q95~ 3.2 P_rf steps: J-ant: 1.6, 1.8, 2.0, 2.2 MW (may increase depending on results) a) NL04 = 0.4e20 b) NL04 = 0.5e20 c) NL04 = 0.6e20 d) NL04 = 0.7e20 e) NL04 = 0.8e20 2. Ip / q scan at fixed B NL04 based on Step 1 experience. a) Ip= 0.5 MA, q95 ~ 4.8 P_rf: Jant: 1.4, 1.6, 1.8, 2.0 b) Ip = 0.6 MA, q95 ~ 3.7 P_rf: Jant: 1.4, 1.6, 1.8, 2.0 c) Ip = 0.8 MA, q95 ~ 2.8 P_rf: Jant: 1.8, 2.0, 2.2, 2.4 3. Ip / B scan at fixed q95 ~3.2 NL04 based on Step 1 experience. a) B = 2.9 T, Ip = 0.61 MA, q95 ~ 3.2 P_rf: Jant: 1.4, 1.6, 1.8, 2.0 a) B = 3.6 T, Ip = 0.76 MA, q95 ~ 3.2 P_rf: Jant: 1.4, 1.6, 1.8, 2.0 ***************** At this point in the run plan we need to make a decision based on the results of Steps 1-3. It is uncertain if we will a) Have enough power to get LH transitions b) Get I-mode under these low field / low Ip conditions. The branching points are basically the following: A) If we do not have enough power to get H-mode transitions (for example in step 1) then we might have to switch to B=2.9 T so that we can use D&E in 2nd harmonic (off-axis) and get an extra 2-3 MW of heating power. If we do this as a result of the step 1, then 2 and 3 will be adjusted to allow q and I scans. B) If we are successful at getting LH thresholds AND we have found definitive evidence of I-mode, then after step 3 we should take advantage of the multiple ICRH tunings that we have today and perform Contingent Step 4 below, otherwise go to step 5. Namely we may be able to alter the sawtooth period by moving the ICRF resonances around the q=1 surface. The giant sawteeth are a problem for triggering H-mode in I-mode. This may point to a mitigation method by altering ICRH resonance locations and phasing. This is outside the scope of the original MP but is probably worth a few shots 4. (Contingent) Pick "best" I-mode density and q95 / Ip condition from previous scans. The scope of the ICRH tuning depends on what power levels we need, but a rough outline would be a) J-ant: On-axis heating, constant heating to get I-mode, change phasing during I-mode b) J-ant: Off-axis heating (same q as a) " " c) D&E, + J at 2.9 T: both off-axis, change J-phasing in shot ********************** Return to near full field to continue standard I-mode MP A challenge here is that with J-ant at 50 MHz we'll have to use 3-He minority near full field. 5. Document/assure access to I-mode in known condition when we had all on-axis H minority heating, so repeat 1091015033 with J-ant at 50 MHz B=5.6 T, Ip = 1.2 MA, Prf as reference shot /w 3He puffing If successful (i.e that we see I-mode as before we continue with regular run plan) 5. Density scan at low Ip / high q95 (3b forms part of scan) Reference shape: #1080416015, Ip = 1.0 MA, Bt = 5.63 T 6 shots a) NL04 = 0.3e20, Prf steps: 3.1, 3.2, 3.3, 3.4 (or lowest density achievable) b) NL04 = 0.4e20, Prf steps: 3.1, 3.2, 3.3, 3.4 c) NL04 = 0.5e20, Prf steps: 3.1, 3.2, 3.3, 3.4 d) NL04 = 0.6e20, Prf steps: 3.1, 3.2, 3.3, 3.4 e) NL04 = 0.7e20, Prf steps: 3.1, 3.2, 3.3, 3.4 f) NL04 = 1e20, Prf steps: 3.1, 3.2, 3.3, 3.4 While highly unlikely that we get past here, the shaping study that follows is 6. Increase κ to ~1.7, same triangularity ~ 0.6 as Day 1 (Circle 2 Fig. 3) 3 shots a) Ip = 1 MA, Bt = 5.63 T, q95 ~ 3.9, NL04 = 0.8e20, Prf steps: 3.1, 3.2, 3.3, 3.4 b) Ip = 1 MA, Bt = 5.63 T, q95 ~ 3.9, NL04 = 0.5e20 (or lowest possible) , Prf steps: 3.1, 3.2, 3.3, 3.4 c) Ip = 1.35 MA, Bt = 5.63 T, q95 ~ 2.9, NL04 = 0.8e20, Prf steps: 4.3, 4.6, 4.9, 5.2 7. Increase κ to ~1.8 (or max.), same triangularity ~ 0.6 as Day 1 (Circle 3 Fig. 3) 3 shots a) Ip = 1 MA, Bt = 5.63 T, q95 ~ 3.9, NL04 = 0.8e20, Prf steps: 3.1, 3.2, 3.3, 3.4 b) Ip = 1 MA, Bt = 5.63 T, q95 ~ 3.9, NL04 = 0.5e20 (or lowest possible) , Prf steps: 3.1, 3.2, 3.3, 3.4 c) Ip = 1.35 MA, Bt = 5.63 T, q95 ~ 2.9, NL04 = 0.8e20, Prf steps: 4.3, 4.6, 4.9, 5.2 8. Keep κ at ~1.8 (or max.), increase triangularity to 0.8 (Circle 4 Fig. 3) 3 shots a) Ip = 1 MA, Bt = 5.63 T, q95 ~ 3.9, NL04 = 0.8e20, Prf steps: 3.1, 3.2, 3.3, 3.4 b) Ip = 1 MA, Bt = 5.63 T, q95 ~ 3.9, NL04 = 0.5e20 (or lowest possible) , Prf steps: 3.1, 3.2, 3.3, 3.4 c) Ip = 1.35 MA, Bt = 5.63 T, q95 ~ 2.9, NL04 = 0.8e20, Prf steps: 4.3, 4.6, 4.9, 5.2 9. Reduce κ to ~1.7 (or max.), keep triangularity at 0.8 (Circle 5 Fig. 3) 3 shots a) Ip = 1 MA, Bt = 5.63 T, q95 ~ 3.9, NL04 = 0.8e20, Prf steps: 3.1, 3.2, 3.3, 3.4 b) Ip = 1 MA, Bt = 5.63 T, q95 ~ 3.9, NL04 = 0.5e20 (or lowest possible) , Prf steps: 3.1, 3.2, 3.3, 3.4 c) Ip = 1.35 MA, Bt = 5.63 T, q95 ~ 2.9, NL04 = 0.8e20, Prf steps: 4.3, 4.6, 4.9, 5.2 |
| Physics Operators Plans |
| Entered: Nov 20 2009 06:59:10:047AM |
| Author: Bill Rowan |
|
MP579, Characterization and Optimization of I mode SL: Whyte PO: Rowan ----------------- Engineering Setup ----------------- Run begins at 09:00 and ends at 17:00 Power systems as on:1091016033, upper null Acoil: +Dtop -Dbot -Jtop +Jbot (standard) Hybrid Enabled Gas setup: Fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ne Hybrid DISABLED (PG1) leave B-side upper with 15 psi helium-3 Hybrid DISABLED (PG2) fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3) fill NINJA with 10 psi D2 DISABLED Enable gatevalves and shutters: ECE, VUV, DNB, Z-bolo Torvac gatevalve toggle (yes/no): NO Boronization(yes/no): no Overnight ECDC (yes/no): YES ICRF(yes/no): yes LH(yes/no): no DNB(yes/no): yes Cryopump (yes/no): YES Vessel temperature: 35/35/35 ------------------------------ ECDC Parameters (if requested) ------------------------------ gas and pressure: He at 5e-5 Torr sweep: 44/45/103 cm scan: 20/120 s |
| Session Leader Summaries |
| Entered: Nov 20 2009 05:55:49:150PM |
| Author: Dennis Whyte |
| A productive day as far as the machine. A lot
of shots at B ~ 3 - 3.4 Tesla. Also some good physics results, although of course at low B / Ip we were not setting any performance records for I=mode. We got a very nice q95 scan both by varying B and Ip. We got all the way down to q95 ~ 2.4 Highlights - The LH power threshold clearly best organized to q95, as was suggested from the data at normal B. In particular the threshold P_SOL increased monotonically with q95 from 3.3 to 2.4. There was little to no dependence on density today as before. Also we established low q95 situations by reducing B, and based on a quick guess of today's P_Lh level compared to the the ~5.4 T results, the q95 dependence appears much stronger than the B dependence for threshold. This suggests magnetic shear as playing a dominant role. - Edge reflectometry found signs of I-mode, particularly at low q95 (where I-mode seems to live) The qualitative characteristics are similar to normal B (see shot 27). The broadband low frequency L-mode fluctuations suddenly decrease and a quasi^2 coherent mode spins up at the I-mode and then fluctuations are strongly reduced at H-mode. Arturo noted interesting changes in these characteristics with frequency (i.e. cutoff position) - It was hard to establish a Te pedestal as obvious as the I-mode cases at normal b, but we did see some improvement in confinement and the stored energy increased faster than P^0.4-0.5, indicating that global confinement does not have as strong power degradation coefficient as standard scalings. - We got a small amount of experience with off-axis ICRH using J at 50 MHZ and E at 2nd harmonic at MHz off axis. This clearly seemed to affect the sawtooth period, raising hope this may be used to control sawtooth crash size. - Density control was critical for getting RF to work well. There was a "sweet spot": if density was too low coupling was good by Prad was too high. At higher density coupling was bad and RF kept tripping. |
| Physics Operator Summaries |
| Entered: Nov 23 2009 08:29:47:787AM |
| Author: Bill Rowan |
|
This was day 3 for MP579, Characterization and Optimization of I mode. The experiment required an upper null with cryopump and employed density scans at TF settings that are lower than typical for C-Mod. ECDC was in helium since the target density for the experiments was low. Segment 1 was taken from 1091119025. Breakdown was at high field, and then the TF was lowered to required values in the vicinity of 3T. This allowed enough time for experiments possibly excepting some shots near the end of the run. The initial physop plan was to use a discharge from 1091118 which was Kessel's low field startup. Unfortunately, this plan was abandoned before the run began because the low field startup was intended for early divert into a lower null plasma. It would be useful to have a low field startup without early divert so that it could be pasted onto the front of either lower or upper null discharges. The shape required for the discharge was included using segment 2 from 1091016033. The shape was tweaked late in the run to flatten the triangularity during the constant BT portion of the discharge. Both argon and neon puffing were required. They were mixed in the PG1 plenum and then puffed together. As for 1091119, neon was not observed spectroscopically in the soft x-ray where evidence of its presence was sought. Argon was observed in the discharge. Shot 001 had a locked mode (see FRCECE) which ended in a disruption. A fixed gas puff was added in segment 1, PG3 to avoid this on later shots. Several shots were taken without the cryo. These are 015 through 019. Marfes appeared on several shots. These were either due to fixed puffing from Pg3 in shots without cryo or to the Ninja. Removal of the fixed puff or turning the Ninja off elimnated the marfes.. 31 plasmas; disruptions before ramp down on 001, 002, 013, 016, 017, 0 fizzles 0 duds 0 no power 31 total |
| Session Leader Comments | |||
| Nov 20 2009 09:36:45:897AM | 1091120001 | Dennis Whyte | Early disruption. Probably a locked mode
from too low density in early phase due to cryopump. Should give more gas in this phase. |
| Nov 20 2009 10:01:46:677AM | 1091120002 | Dennis Whyte | Early disruption again, but it went longer than shot 1.
Ask for higher early density and then drop to NL04=0.5 for flattop to try and avoid locked mode. |
| Nov 20 2009 10:17:20:100AM | 1091120003 | Dennis Whyte | Good shot.
NL04 = 0.5 e20 Good density control with cryopump and impurities were OK Did not get an H-mode transition up to 2.2 MW. The H factors are going up with each RF step, indicating that the power degradation coefficient is weaker than 1/P^0.5- 0.65 used in the confinement scalings. H98 ~ 0.75 at 2.2 MW |
| Nov 20 2009 11:00:42:770AM | 1091120005 | Dennis Whyte | Good shot at NL=0.5e20
Very similar to last shot 1b in shot plan No H-mode transition up to Prf = 2.7 MW. We've maxed out J-antennae power The LH scaling law gives ~1 MW as threshold so we should be close to getting ohmic H-modes. Not clear if we're well below the low density limit While H98 ~ 0.8, there is no sign of an edge thermal barrier from ECE or DTS. |
| Nov 20 2009 11:02:16:460AM | 1091120006 | Dennis Whyte | Good shot at NL=0.5e20
Better density feedback control gave us very flat density No H-mode transition up to Prf = 2.8 MW! This is probably best shot of 1b in shot plan given better density control. |
| Nov 20 2009 11:14:00:600AM | 1091120007 | Dennis Whyte | Good shot at NL=0.4e20, Shot 1a in plan
No H-mode transition up to Prf = 2.6 MW |
| Nov 20 2009 11:28:44:537AM | 1091120008 | Dennis Whyte | Good shot at NL=0.6e20, Shot 1c in plan
No H-mode transition up to Prf = 2.8 MW We tried to turn the power on full from the beginning of this shot. This unintentionally gave us a density scan at fixed max. power. Some evidence of prompt fast ion losses at these low densities. |
| Nov 20 2009 11:39:14:833AM | 1091120009 | Dennis Whyte | Good shot at NL=0.7e20,
RF was ratty, need to retune But no H-mode up Prf ~ 2.5 MW (but intermittent) |
| Nov 20 2009 11:57:58:630AM | 1091120010 | Dennis Whyte | Good shot at NL=0.7e20,
Got H-mode transition at ~2.8 MW near end of shot Hard pressed to see the effect on edge Te of the H-mode Prad is now ~1 MW, so we clearly notched this down compared to previous lower densities. Suggests that we could not get H-mode (or I-mode) due to fact that we were radiating too large fraction of power. RF and density were wobbling around so hard to see any trends or detect I-mode Will try again with RF tuning and density feedback adjusted. |
| Nov 20 2009 12:13:50:820PM | 1091120011 | Dennis Whyte | NL=0.7e20,
Got H-mode transition at ~2.5 MW Density control is poorer. We are getting a "hot" edge, but not clearly an I-mode based on confinement. |
| Nov 20 2009 12:33:27:460PM | 1091120012 | Dennis Whyte | NL=0.8e20,
No H-mode, but RF is very trippy Will try neon seeding on next shot |
| Nov 20 2009 01:06:48:570PM | 1091120013 | Dennis Whyte | RF too trippy, basically ohmic.
NL04 = 0.8e20 |
| Nov 20 2009 01:06:35:943PM | 1091120014 | Dennis Whyte | NL04=0.8e20
Reduced initial neon did not help. See no signs of neon in core plasma (probably from pumping) going to try no cryopumping in next shot |
| Nov 20 2009 01:37:43:897PM | 1091120015 | Dennis Whyte | Got mini H-modes at 2.2 MW
But several MARFES during shot. |
| Nov 20 2009 01:38:46:990PM | 1091120016 | Dennis Whyte | MARFES again. No cryo
The RF was steady at higher densities No H-mode |
| Nov 20 2009 01:52:56:850PM | 1091120017 | Dennis Whyte | MARFES again. No cryo
Turn off more fueling |
| Nov 20 2009 01:59:31:630PM | 1091120018 | Dennis Whyte | No Cryo. Got rid of Marfes
Neon injection on NL04 = 0.8e20 Rf still ratty but better than before H-mode at Prf = 2.5 MW |
| Nov 20 2009 02:28:06:257PM | 1091120019 | Dennis Whyte | No Cryo.
Blahh! RF is intermittent we cannot make anything out here punting on the density scan, go to Ip/q scan. |
| Nov 20 2009 02:31:53:567PM | 1091120020 | Dennis Whyte | Cyro ON again.
NL04=0.7e20 (where we saw decent RF and low Prad before) Ip = 0.8 MA, q95 ~ 2.95 Something that is more "I-mode" like near 1.4 s. The neutron rate and stored energy and edge TE break slope, but was interrupted by RF trip at 2.5 MW. |
| Nov 20 2009 02:50:39:397PM | 1091120021 | Dennis Whyte | Cyro ON
NL04=0.7e20 Had 0.5 second of constant Prf ~2.4 MW Ip = 0.8 MA, q95 ~ 2.99 Again there's an appearance of a break in slope around 1.4 s. No H-mode transition at 2.5 MW |
| Nov 20 2009 03:01:49:833PM | 1091120022 | Dennis Whyte | Cyro ON
NL04=0.7e20 Ip = 0.85 MA, q95~2.8 Asked for constant power at max. of J-ant. Was fairly steady throughout although a couple of trips No H-mode up to 2.8 MW Again there is an uptick in the stored energy, neutrons, edge Te near the end of the shot..but we've run out of power on J-ant. Clearly things look more interesting at higher Ip, lower q |
| Nov 20 2009 03:26:30:083PM | 1091120023 | Dennis Whyte | Cyro ON, but it went warm and we ended
up with NL04~ 0.8e20 Ip = 0.85 MA, q95~2.8 Late H-mode transition at Prf ~ 2.5 MW. Hints of I-mode: increasing confinement and edge Te after 1.25 seconds when the RF becomes constant Reflectometry shows signs of a coherent mode near 100 kHz Interesting that this accidental increased density decreased the radiated power and the shot performed better. |
| Nov 20 2009 03:31:34:100PM | 1091120024 | Dennis Whyte | Cyro ON,
NL04~ 0.6e20 Ip = 0.85 MA, q95~2.8 No H-mode. RF is clean, but we get high radiated power so net power is reduced. We're between the rock and hard place with density today. Too high: RF trips Tot low: Prad/Pin too high. No hints of I=mode at this condition. Next shot: tweak up density to NL04~0.75e20 to try and hit the sweet spot. |
| Nov 20 2009 04:16:52:433PM | 1091120027 | Dennis Whyte | Cyro ON,
NL04~ 0.75e20 Ip = 0.9 MA, q95~2.6 Constant triangularity Got I-mode and H-modes in this shot based on reflectometry fluctuations. Clear abrupt changes in broadband fluctuations and appearance of QQC Transiently got H98~0.8, neutron rate ~1e13 /s However difficult to argue for a strong Te pedestal. |
| Nov 20 2009 04:28:00:310PM | 1091120028 | Dennis Whyte | Cyro ON,
NL04~ 0.75e20 Ip = 0.8 MA, B~ 3.15 q95~2.75 We wanted to put in E antennae but B field only went to 3.15 (we requested 3 T) This put 2nd harmonic too far outside, so weak effect of heating J: R=66 cm E: R=80 cm No H-mode but uncertain how much we heated. Note though that near end of flattop the stored energy and neutrons increased substantially with E-ant power increasing Triangularity drifted a bit Weak signs on reflectometer |
| Nov 20 2009 04:56:21:230PM | 1091120030 | Dennis Whyte | Cyro ON,
NL04~ 0.75e20 Ip = 0.8 MA, B~ 2.95 q95~2.65 This brought E closer to the axis. Looks like we are modifying the sawtooth period. Got some H-mode transitions: Prf ~3.5 MW Good data point for LH threshold at low q95 |
| Nov 20 2009 05:37:31:590PM | 1091120031 | Dennis Whyte | Cyro ON,
NL04~ 0.75e20 Ip = 0.9 MA, B~ 2.95 q95~2.4 Very complicated dithering H-mode transitions: Although we get up to 4 MW with E-ant added in and then we are clearly not in H=mode (at ~ 1.3 s) Good data point for LH threshold at low q95 |
| Physics Operator Comments | |||
| Nov 20 2009 10:47:31:053AM | Bill Rowan | changed the startup to last shot from yesterday | |
| Nov 20 2009 10:48:00:443AM | Bill Rowan | run plan 1a
set nl_04 to 0.4e+20 reduced tf current from 156400 (5.6 T) to 92164 (3.3T) reduced ip from 1 MA to 0.7 MA | |
| Nov 20 2009 10:48:26:443AM | Bill Rowan | load 1091016033
load seg 1 from 1091117005 for the low field startup change prepuff from 17 ms to 57 ms, approx value used for cryo ops yesterday | |
| Nov 20 2009 10:59:27:020AM | Bill Rowan | 006. plasma
disruption in ramp down Next shot. nl_04 down to 0.35e+20 at request of SL attempting to get closer to nl_04=0.4e+20 | |
| Nov 20 2009 09:38:53:257AM | 1091120001 | Bill Rowan |
001. disruption at 0.3 s Next shot. change pg3 to a square wave from 25 ms to 100 ms. |
| Nov 20 2009 09:58:07:770AM | 1091120002 | Bill Rowan | 002. Disruption at 0.5 s
next shot nl_04 increased to 0.8e+20 and then down to 0.5e+20 at 0.5 s |
| Nov 20 2009 10:14:14:507AM | 1091120003 | Bill Rowan | 003. nl_04 = 0.5e+20
ip = 0.7 MA Bt = 3.4 T q95 ~3.3 Next shot. PG1: 0.5 psi argon, 1 psi neon PG1 in segment 1: on at 0.55 and off at 0.65 enabled pg1 |
| Nov 20 2009 10:27:35:473AM | 1091120004 | Bill Rowan | 004. full length plasma
Next shot. pg1 changed to 300 ms: 0.550 to 0.850 pg1: 1 psi of argon |
| Nov 20 2009 10:51:51:303AM | 1091120005 | Bill Rowan | 005. plasma
Next shot. nl_04 down to 0.4e+20 PG1 350 ms to 550 ms |
| Nov 20 2009 11:14:43:100AM | 1091120006 | Bill Rowan | 006. plasma
disruption in ramp down Next shot. nl_04 down to 0.35e+20 at request of SL attempting to get closer to nl_04=0.4e+20 |
| Nov 20 2009 11:13:55:507AM | 1091120007 | Bill Rowan | 007. plasma
nl_04 = 0.4e+20 next shot. nl_04 demand 0.45e+20 to get nl_04 = 0.5e+20 based on setting/result discrepancy for previous shots. |
| Nov 20 2009 11:24:48:693AM | 1091120008 | Bill Rowan | 008. plasma
nl_04 ~ 0.5e+20 next shot. nl_04 demand 0.65e+20 to get nl_04 = 0.7e+20 |
| Nov 20 2009 11:39:00:600AM | 1091120009 | Bill Rowan | 009. plasma
Next shot. No PCS changes |
| Nov 20 2009 11:58:25:583AM | 1091120010 | Bill Rowan | 010. Plasma
Next shot. No pcs changes |
| Nov 20 2009 12:08:29:960PM | 1091120011 | Bill Rowan | 011. Plasma
3 small h-modes after 1 s Next shot nl_04 demand to 0.8e+20 |
| Nov 20 2009 12:23:57:583PM | 1091120012 | Bill Rowan | 012. Plasma
Next shot. Change the gas mixture that is coming in through b-side lower (PG1) 1 psi Ar and 0.5 psi neon |
| Nov 20 2009 12:52:38:617PM | 1091120013 | Bill Rowan | 013. Plasma
disruption at 0.77 s Next shot. pg1 reduced to 100 ms: 350 ms to 450 ms |
| Nov 20 2009 01:10:26:553PM | 1091120014 | Bill Rowan | 014. Plasma
Next shot. Cryo pump is off Prefill down to 20 ms |
| Nov 20 2009 01:21:43:787PM | 1091120015 | Bill Rowan | 015. Plasma
Next shot. PG3 pulse from 25 ms to 100 ms removed to see affect on marfes cryo pump is off |
| Nov 20 2009 01:35:16:960PM | 1091120016 | Bill Rowan | 016.Plasma.
Early marfe is now gone. Disruption at 1.02 s Next shot. changed the derivative gain from 10 to 9 on nl_04 changed the proportional gain to 6 (constant in time) on nl_04 |
| Nov 20 2009 01:46:12:410PM | 1091120017 | Bill Rowan | 017. Plasma
Disruption at 1.02 s Next shot. PG3 puff at 0.3s is now removed Ninja is turned off |
| Nov 20 2009 01:58:51:333PM | 1091120018 | Bill Rowan | 018. Plasma
Full length Next shot. Increase pg1 from 100 ms to 150 ms |
| Nov 20 2009 02:12:23:583PM | 1091120019 | Bill Rowan | 019. Plasma
full length Next shot. Reload 010 turn cryo on increase ip to 0.8MA |
| Nov 20 2009 02:47:12:727PM | 1091120020 | Bill Rowan | 020. Plasma
full length Next shot. no pcs changes |
| Nov 20 2009 02:46:58:443PM | 1091120021 | Bill Rowan | 021. Plasma
full length Next shot. raise current to 0.85 MA becoming concerned at the nearness of q95 to 3.0 |
| Nov 20 2009 03:00:32:693PM | 1091120022 | Bill Rowan | 022. Plasma
Next shot. nl_04 demand 0.55e+20 to get nl_04 = 0.6e+20 |
| Nov 20 2009 03:12:37:803PM | 1091120023 | Bill Rowan | 023. Plasma
Some problems with cryo just before the shot. Pressure went as high as 1e-05 but was at 2e-06 at the time of the shot. Next shot. No PCS changes |
| Nov 20 2009 03:28:56:490PM | 1091120024 | Bill Rowan | 024. Plasma
Next shot. Nl_04 demand set to 0.7e+20 to get 0.75e+20 |
| Nov 20 2009 03:41:45:960PM | 1091120025 | Bill Rowan | 025. Plasma
nl_04 = 0.75e+20 next shot ip = 0.9 MA |
| Nov 20 2009 03:54:34:783PM | 1091120026 | Bill Rowan | 026. Plasma
q95 = 2.7 next shot. remove jog in rxu at 1.09 s to flatten triangularity |
| Nov 20 2009 04:04:47:297PM | 1091120027 | Bill Rowan | 027. Plasma
next shot bt = 3.0T ip = 0.8 MA |
| Nov 20 2009 04:40:37:683PM | 1091120029 | Bill Rowan | 029. Plasma
Bt = 2.95 T Next shot. SL: tweak BT to be intermediate between shots 27 and 28 |
| Nov 20 2009 04:52:59:713PM | 1091120030 | Bill Rowan | 030. Plasma
Next shot IP = 0.9 MA |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:24:51:727AM | Plasma | Ok | |
| 2 | 09:45:47:727AM | Plasma | Bad | PF breaker opened during shot |
| 3 | 09:59:51:270AM | Plasma | Ok | |
| 4 | 10:15:05:787AM | Plasma | Ok | |
| 5 | 10:36:29:070AM | Plasma | Ok | |
| 6 | 10:52:41:350AM | Plasma | Ok | |
| 7 | 11:05:38:477AM | Plasma | Ok | |
| 8 | 11:19:05:600AM | Plasma | Ok | |
| 9 | 11:32:40:397AM | Plasma | Ok | |
| 10 | 11:46:45:820AM | Plasma | Ok | |
| 11 | 11:59:31:053AM | Plasma | Ok | |
| 12 | 12:16:22:257PM | Plasma | Ok | |
| 13 | 12:42:30:477PM | Plasma | Ok | |
| 14 | 12:56:55:270PM | Plasma | Ok | |
| 15 | 01:11:45:397PM | Plasma | Ok | |
| 16 | 01:26:01:990PM | Plasma | Ok | |
| 17 | 01:39:04:943PM | Plasma | Ok | |
| 18 | 01:51:58:317PM | Plasma | Ok | |
| 19 | 02:04:38:333PM | Plasma | Ok | |
| 20 | 02:17:38:037PM | Plasma | Ok | |
| 21 | 02:36:47:880PM | Plasma | Ok | |
| 22 | 02:50:30:007PM | Plasma | Ok | |
| 23 | 03:03:24:960PM | Plasma | Ok | |
| 24 | 03:19:34:367PM | Plasma | Ok | |
| 25 | 03:32:51:990PM | Plasma | Ok | |
| 26 | 03:47:06:430PM | Plasma | Ok | |
| 27 | 04:00:00:327PM | Plasma | Ok | |
| 28 | 04:12:57:120PM | Plasma | Ok | |
| 29 | 04:26:25:747PM | Plasma | Ok | |
| 30 | 04:41:36:573PM | Plasma | Ok | |
| 31 | 04:54:47:713PM | Plasma | Ok | |
| System Availability | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nov 20 2009 09:10:48:613AM | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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