| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Yijun Lin,Steve Scott |
| Physics operator(s): | Robert Granetz |
| Engineering operator(s): | Andy Pfeiffer,Gary Dekow,Bill Byford |
| Engineering Operator Run Comment |
| MP#486 ICRF impurity generation (1/2 day) MP#491 MSE plasma calibrations |
| Session Leader Plans |
| Entered: Jun 28 2007 08:49:49:130PM |
| Author: Yijun Lin |
| MP#486 investigation of ICRF impurity generation and B erosion
0.5 day SL Plan: Verify Nb can be observed and related to J antenna operation. Using a standard discharge (5.4 T, 1 MA, nl_04~0.9e20 m-2 , 1 cm outer gap): Run J power to its max in several shots (~1.5 MW). Repeat with D+E antennas without J (2-3 shots), 1.5 MW total power. Repeat with D+E+J antennas at 3.5 MW. (2 shots). Run 3 shots at D+E, E+J, and D+J, repectively, 2 MW total power. If time permits, we may try several shots for the 2nd part of the MP: "Use standard, LSN discharge with J @1 MW and D+E @2 MW. Track Nb and Mo concentration and P_rad /P_input versus discharge and integrated Joules till Nb concentration saturates or discharge performance degrades." |
| Entered: Jun 29 2007 12:05:45:430PM |
| Author: Jin-Seok Ko |
1070629 1/2 day SL_PLAN (ORIGINAL). MP491 MSE Calibrations
SL : Steve Scott, Jinseok Ko
PO : Bob Granetz
Executive summary
A. Beam-into-plasma calibration with Ip ramp with a normal discharge (3 shots)
B. Beam-into-plasma calibration with Ip ramp with a 3-sec discharge (2 shots)
C. Beam-into-plasma calibration with plasma sweeping (maximum 10 shots)
Total expected number of shots: 15 shots
A. Beam-into-plasma calibration with Ip ramp with a normal discharge - 2 shot
Maintaining the plasma shape, only the Ip ramps down during a shot. Using the
EFIT-calculated pitch angle at the edge channel, the MSE edge channel is
calibrated. Using the sawtooth inversion radii inferred from FRCECE + EFIT,
some of the internal MSE channels will be calibrated.
Reference 1070615019 (or 1070615020) but with higher NeL (0.6 - 0.7e20 m^2)
DNB: 0.2 - 1.9 sec modulated as on/off = 70/35 msec
BT : as constant 5.4 T as possible during DNB (0.2 - 1.9 sec)
No ICRF/LHCD
MSE: HV 1750V for all
Make sure FRCECE is available
Expected result:
Ip: 0.8 MA @ 1.0 sec
0.1 MA @ 1.9 sec
B. Beam-into-plasma calibration with Ip ramp with a 3-sec discharge - 1 shot
Same principle with Part A, but with a larger range of the pitch angle
Reference 1070615023 but (maybe) with higher NeL (0.6 - 0.7e20 m^2)
DNB: 0.8 - 2.9 sec modulated as on/off = 70/35 msec
BT : constant 5.4 T during DNB (0.8 - 2.9 sec)
No ICRF/LHCD
MSE: HV 1750V for all, DAQ time 2 -> 3 sec (2048 -> 3000)
Make sure other diagnostics are available for 3 sec (ECE, TS, H_alpha etc)
Expected result:
Ip: 1.0 MA @ 1.0 sec
0.4 MA @ 2.3 sec
and more
Repeat B - 1 shot
Repeat A - 1 shot (Make sure all the diagnostics are back to normal)
C. Beam-into-plasma calibration with plasma sweeping : maximum 10 shots
The plasma edge is swept past each of the MSE channel locations by ramping the plasma's
major and minor radii. Unlike the Ip-ramp plasma calibration, this provides the
direct calibration data for inner channels. Many setup shots may be required.
Reference 1060412022, 1070504004, 1070504010, or 1070504011
Gas: Deuterium plasma (try for ~ constant nebar)
DNB: 0.2 - 1.9 sec modulated as on/off = 70/35 msec
BT : as constant 5.4 T as possible during DNB (0.2 - 1.9 sec) desirable
kappa: try for a constant (~ 1.23)
No ICRF/LHCD
MSE: HV 1750V for all
C1: partial sweep (a = 22 -> 14 cm) with constant qpsi (2 ~ 4 shots)
C2: full sweep (a = 22 -> 11 cm) with constant qpsi (2 ~ 4 shots)
C3: partial sweep (a = 22 -> 14 cm) with constant Ip = 0.23 MA (2 ~ 3 shots)
C4: full sweep (a = 22 -> 11 cm) with constant Ip = 0.23 MA (2 ~ 3 shots)
Details:
C1: Reference ~ 1070504010 or 1070504011
Rmajor 65.7 cm @ 0.6 sec -> 58.0 cm @ 1.7 sec
a 21.7 cm @ 0.6 sec -> 14.0 cm @ 1.7 sec
Ip 0.78 MA @ 0.6 sec -> 0.348 MA @ 1.7 sec (for constant qpsi)
C2: Reference ~ 1070504010 or 1070504011
Rmajor 65.7 cm @ 0.6 sec -> 55.0 cm @ 1.7 sec
a 21.7 cm @ 0.6 sec -> 11.0 cm @ 1.7 sec
Ip 0.78 MA @ 0.6 sec -> 0.227 MA @ 1.7 sec (for constant qpsi)
C3: Rmajor 65.7 cm @ 0.6 sec -> 58.0 cm @ 1.7 sec with constant Ip = 0.23 MA
a 21.7 cm @ 0.6 sec -> 14.0 cm @ 1.7 sec with constant Ip = 0.23 MA
C4: Rmajor 65.7 cm @ 0.6 sec -> 55.0 cm @ 1.7 sec with constant Ip = 0.23 MA
a 21.7 cm @ 0.6 sec -> 11.0 cm @ 1.7 sec with constant Ip = 0.23 MA
If time permits, repeat A - 1 shot
|
| Entered: Jun 29 2007 12:06:08:913PM |
| Author: Jin-Seok Ko |
1070629 1/2 day SL_PLAN (REVISED). MP491 MSE Calibrations
SL : Steve Scott, Jinseok Ko
PO : Bob Granetz
Executive summary
A. Beam-into-plasma calibration with plasma sweeping (maximum 10 shots)
B. Beam-into-gas calibration with different DNB configurations (7 shots)
C. Optimization of torus gas pressure for beam-into-gas calibration (2 shots)*
*If time permits
Total expected number of shots: 17 ~ 19 shots
A. Beam-into-plasma calibration with plasma sweeping : maximum 10 shots
The plasma edge is swept past each of the MSE channel locations by ramping the plasma's
major and minor radii. Unlike the Ip-ramp plasma calibration, this provides the
direct calibration data for inner channels. Many setup shots may be required.
Reference 1060412022, 1070504004, 1070504010, or 1070504011
Gas: Deuterium plasma (try for ~ constant nebar)
DNB: 0.2 - 1.9 sec modulated as on/off = 70/35 msec
BT : as constant 5.4 T as possible during DNB (0.2 - 1.9 sec) desirable
kappa: try for a constant (~ 1.23)
No ICRF/LHCD
MSE: HV 1750V for all
C1: partial sweep (a = 22 -> 14 cm) with constant qpsi (2 ~ 4 shots)
C2: full sweep (a = 22 -> 11 cm) with constant qpsi (2 ~ 4 shots)
C3: partial sweep (a = 22 -> 14 cm) with constant Ip = 0.23 MA (2 ~ 3 shots)
C4: full sweep (a = 22 -> 11 cm) with constant Ip = 0.23 MA (2 ~ 3 shots)
Details:
C1: Reference ~ 1070504010 or 1070504011
Rmajor 65.7 cm @ 0.6 sec -> 58.0 cm @ 1.7 sec
a 21.7 cm @ 0.6 sec -> 14.0 cm @ 1.7 sec
Ip 0.78 MA @ 0.6 sec -> 0.348 MA @ 1.7 sec (for constant qpsi)
C2: Reference ~ 1070504010 or 1070504011
Rmajor 65.7 cm @ 0.6 sec -> 55.0 cm @ 1.7 sec
a 21.7 cm @ 0.6 sec -> 11.0 cm @ 1.7 sec
Ip 0.78 MA @ 0.6 sec -> 0.227 MA @ 1.7 sec (for constant qpsi)
C3: Rmajor 65.7 cm @ 0.6 sec -> 58.0 cm @ 1.7 sec with constant Ip = 0.23 MA
a 21.7 cm @ 0.6 sec -> 14.0 cm @ 1.7 sec with constant Ip = 0.23 MA
C4: Rmajor 65.7 cm @ 0.6 sec -> 55.0 cm @ 1.7 sec with constant Ip = 0.23 MA
a 21.7 cm @ 0.6 sec -> 11.0 cm @ 1.7 sec with constant Ip = 0.23 MA
B. Beam-into-gas calibration with different DNB configurations : 7 shots
This addresses the issue whether the low beam current is the cause of the lack
of reproducibility or not. 3 different beam configurations will be tried with
other conditions constant. Each configuration has two shots.
Common conditions: Load 1070615011 and adjust the following
Gas: He4 with g-side rat = 0.4 mTorr
BT: constant 5.4T during DNB pulse
EF3: constant 8 kA during DNB pulse*
EF4: constant 0 kA during DNB pulse
EF3 flattop should start at least 0.3 sec before the DNB start time.
DNB pulse: 0.1 - 1.5 sec
B1. DNB no modulation with the current ~ 5A)
B2. DNB modulated with ON/OFF = 70/35 msec with its maximum current (hopefully > 6A)
B3. DNB modulated with ON/OFF = 70/35 msec with the current in B1
Repeat
B1
B2
B3
Repeat one more shot with the best out of B1, B2, and B3
C. Optimization of torus gas pressure for beam-into-gas calibration : 2 shots
This is the torus pressure scan within a shot with a constant pitch angle
to find an optimized torus pressure that can minimize secondary-beam-neutral
effect. The torus pressure found in these shots will be used in the folloing
beam-into-gas shots.
After the shot, pitch angle vs pressure plot is investigated. Hopefully, we
will find a largest pressure that maintains the pitch angle constant.
Reference : Load 1070615003 or 1070615005
Gas: He4 (0.04 - 0.3 mTorr)
DNB: the best out of B1, B2, and B3
BT : constant 5.4 T during DNB flattop (0.1 - 1.5 sec)
EF3: constant 0 kA during DNB flattop (0.1 - 1.5 sec)
EF4: constant -2 kA during DNB flattop (0.1 - 1.5 sec)
torus pressure: constant 0.04 mTorr from 0.1 - 0.7 sec
increase to 0.1 mTorr till 1.1 sec
constant 0.1 mTorr from 1.1 - 1.3 sec
increase to 0.3 mTorr till 1.5 sec
|
| Physics Operators Plans |
| Entered: Jun 28 2007 02:51:59:833PM |
| Author: Robert Granetz |
Engineering setup for Friday 29 June 2007
MP#486 ICRF impurity generation (1/2 day)
MP#491 MSE plasma calibrations (1/2 day)
Session leaders: Y. Lin (MP#486), S. Scott (MP#491)
Physics operator: R. Granetz
ECDC overnight in D2, pressure=2e-4 Torr. Rmin/Rdwell/Rmax = 44/45/103 cm.
Bake at 60 C.
Power systems as on 1070620001 (1 MA, 5.4 T, 1.0e20 m-2, LSN)
A-coil configuration: normal [Dtop -Dbot -Jtop +Jbot] and enabled.
Gas Setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid DISABLED (PG1)
leave B-side upper as is Hybrid DISABLED (PG2)
fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3)
leave NINJA as is DISABLED
Enable the following gate valves and shutters, assuming no vacuum problems:
ECE, VUV, DNB, Z-bolo shutters
Torvac setup: Gate valves open after the shot
Specific diagnostics: spectroscopic diagnostics for monitoring niobium and
molybdenum, Zeff, MSE (2nd half day)
-------------------------------------------------------------------------------
ICRF Setup: All available transmitter in run-on by 08:30
LH Setup: No LH for this run
DNB: yes, for the 2nd half day
Cryopump: No cryopump for this run
-------------------------------------------------------------------------------
Run plan:
1st half day: Determine whether we can really see Nb, and set up some
shots to be compared with later reversed field plasmas.
Start from 1070620001 (1 MA, 5.4 T, 1.0e20 m-2, LSN).
2nd half day: Do another Ip scan, this time with FRCECE; then run limiter
plasmas and scan the radial location of the outboard edge
by shrinking and growing the plasma size. Get MSE
measurements, particularly at the edge.
Start from 1070615023 (Ip ramp, 1.0 -> 0.4 MA). Be sure
that engineering parameters are set properly for this
extended length discharge.
For limiter plasmas, start from 1070504004.
|
| Session Leader Summaries |
| Entered: Jun 29 2007 01:14:45:590PM |
| Author: Yijun Lin |
| Sl summary: MP486 investigation of ICRF impurity generation and B erosion
0.5 day. shot 1-17. Summary: 1. All shots are good plasma shots. 2. J antenna was running well (except some earlier shots having power limitation problem with the lower 480 V line). total 15 MJ J port power to the plasmas. No Nb observed at normal 1 MA, 5.4 T, 1.0 nl04 plasmas. With J only, or J + D + E. No Nb observed at 5.4 T, 1.0 nl04 plasma with Ip ramp from 1.2 to 0.8 MA, with J + D+E. Nb was observed onece as an injection before RF on shot 5. Nb was observed when the strike-point was delibrated moved to the divertor nose, closer to the Nb tile on shot 17. Conclusion: 1. There is still Nb in vessel. Probably still on the Nb coated tiles. 2. We have not been able to generate observable Nb using the available RF power (1.3 MW from J and total about 3 MW). |
| Entered: Jun 29 2007 03:23:38:020PM |
| Author: Steve Scott |
| Reasonable shot: disrupted at about 1.7 sec. A small wiggle on Ip at about 0.8 sec. Pretty good DNB at almost 6 amps. |
| Entered: Jun 29 2007 03:32:42:197PM |
| Author: Steve Scott |
| NO dnb injection on this shot. disrupted at little before 1.5 sec. |
| Entered: Jun 29 2007 03:48:16:100PM |
| Author: Steve Scott |
| Good shot with Rmajor ramp to ~60 cm!! Good DNB, no faults, about 5.2 - 5.8 amps. This shot doesn't have the distress that affected the previous shot at about 0.7 - 0.8 sec. We did blow some fuses. Will take one more of these, then move on to a faster and larger sweep in major radius. |
| Entered: Jun 29 2007 04:53:24:587PM |
| Author: Steve Scott |
| Disrupted early, at about 0.9 sec. Steve Wolfe reports that the early profiles were were hollow. We lost the DNB data on this shot, so we'll have to make up fake DNB timing. Got no MSE data on this shot ... |
| Entered: Jun 29 2007 04:58:22:857PM |
| Author: Steve Scott |
| Clean startup - better than 28. This shot disrupted at about 1.6 sec. DNB: good. Current during early phase was lower than on shot 28: about 5.0 amps. But the current by the end of the dnb reached 6.0 amps. Rats ... MSE had a camac problem. we did not get MSE data on this shot. Next shot: repeat. |
| Entered: Jun 29 2007 05:33:55:227PM |
| Author: Steve Scott |
| This was our first attempt at the portion of MP491 that uses 'sweeps' in major and minor radius to move the plasma edge past each MSE channel. Basically, this half-day was a success: we demonstrated that it is possible to sweep an inner-wall-limited plasma down to a minor radius of 15.5 cm. Good MSE data was acquired on a number of shots. The data we took today should be sufficient for us to evaluate whether major-radius sweeps will be helpful in calibrating MSE. Limitations and problems: 1. A significant fraction of the plasmas had 'distress' in the early phase, 0.1 - 0.5, with divots taken Ip. The profiles were sometimes hollow during this period. One shot, 30, did not have this problem. 2. A signifcant fraction of the plasmas disrupted during the ramp-down phase. We had only one shot with a large ramp on Rmajor that didn't disrupt at all (shot 28). A number of other shots did survive for most of the ramp. These include shots 27, 30, and 31. 3. We lost a couple of shots due to a camac problem. Initially, this affected shot 29 (no DNB injected and no MSE data acquired). But we also lost the usefulness of shot 30 because the camac problem shut down our control of the MSE hardware, which was not realized until after the shot. 4. Given the problems with disruptions late in the discharges, the outlook for stable plasmas with even larger ramps in major radius (which would be needed to calibrate the most interior MSE channels) is not so good. shot DNB Ramp disruption comment 018 ok flat ok 019 ok flat 0.45 020 none test shot 021 ok flat ok 022 ok flat 0.35 023 faults small ok 024 none moderate 1.3 025 none moderate 1.5 026 ok moderate 1.55 027 ok moderate 1.72 028 ok moderate ok This is the trophy shot of the day. 029 none moderate 0.92 camac problem --> no DNB, no MSE 030 ok moderate 1.6 residual MSE problem caused by earlier camac. no mse data. 031 none moderate 1.72 alas, DNB did not fire. |
| Physics Operator Summaries |
| Entered: Jun 29 2007 05:32:08:007PM |
| Author: Robert Granetz |
Run summary for Friday 29 June 2007
MP#486: ICRF impurity generation (niobium) - 1/2 day
MP#491: MSE plasma calibrations - 1/2 day
Session leaders: Y. Lin (MP#486), S. Scott (MP#491)
Physics operator: R. Granetz
Early this morning we ran out of LHe before the DNB cryopumps were
sufficiently cooled down. Fortunately, the C-Mod cryopump dewar still had
90 liters left, so that dewar was hooked up to the DNB and a transfusion
brought the DNB back into operation.
The first half-day run used a standard 1 MA, 5.4 T, lower single null
configuration, with 1.2 MW from J-antenna. The machine ran extremely
reliably with this standard discharge. No niobium was seen from RF sheaths
along flux tubes that connect J and the niobium-coated tiles. We also
tried ramping Ip from 1.2 to 0.8 MA to sweep different flux tubes past the
niobium, in case the mapping was slightly different than expected. No
niobium. But putting the strike point up on the outer nose did yield a bit
of niobium, proving that the coating is still on the tiles.
The second half-day run involved running limiter plasmas and sweeping the
outboard edge inward past the MSE channels, while also sweeping Ip to keep
q_edge approximately constant. This took a lot of physop work,
particularly to overcome plasma vertical stability problems, and to keep
power supplies from railing. We eventually got some pretty good
discharges, with the trophy shot being 1070629028, for which the DNB worked
well and the MSE got good data. We did lose a few shots at the end of the
day due to some blown fuses, as well as a problem with camac highways.
Scorecard: 30 plasmas
0 duds
0 fizzles
0 power supply tests
1 no-power MDS shot cycles
--------------
Total: 31 shot cycles
|
| Session Leader Comments | |||
| Jun 29 2007 09:19:03:090AM | 1070629001 | Yijun Lin | Ran J port at 0.8 to 1.5 MW ramp, from .7 to 1.3 sec. (Note: boronization done on 1070627 night. Only D port was run for several shots at 0.5 MW on 1070628). It should be close to a fresh boron layer as far as J and E are concerned.
Result: J4 was tested to dummy load before this shot that it was ale to run to 1.5 MW. However, during the plasma shot, voltages on IPA anode, driver screen and FPA screen were sagging so much that the system was only able to deliver 0.8 MW power. No Nb observed. next shot: try again. Program J to start earlier. |
| Jun 29 2007 09:29:55:800AM | 1070629002 | Yijun Lin | Ran J port at 0.8 to 1.5 MW ramp, from .7 to 1.3 sec. (Note: boronization done on 1070627 night. Only D port was run for several shots at 0.5 MW on 1070628). It should be close to a fresh boron layer as far as J and E are concerned.
Result: Power to 1.1 MW. J4 had HV fault at the end of pulse. There is an H-mode later. next shot: start J at 1 MW. then ramp up. |
| Jun 29 2007 09:34:06:303AM | 1070629002 | Yijun Lin | Ran J port at 0.8 to 1.5 MW ramp, from .7 to 1.3 sec. (Note: boronization done on 1070627 night. Only D port was run for several shots at 0.5 MW on 1070628). It should be close to a fresh boron layer as far as J and E are concerned.
Result: Power to 1.1 MW. J4 had HV fault at the end of pulse. There is an H-mode later. No Nb. We need to erode the boron layer first. next shot: run J at 1.2 MW. 0.6 to 1.5 sec. |
| Jun 29 2007 09:53:13:617AM | 1070629003 | Yijun Lin | J port at 1.2 MW (from .6 to 1.5 sec). total 1 MJ RF energy (total 2 MJ including
shot 1 and 2). Somehow, the voltage drops were less significant. No Nb. next shot: repeat. |
| Jun 29 2007 10:01:10:280AM | 1070629004 | Yijun Lin | J port at 1.1 MW (from .6 to 1.5 sec). total .9 MJ RF energy (total ~ 3 MJ today).
No Nb. next shot: repeat. |
| Jun 29 2007 10:14:49:820AM | 1070629005 | Yijun Lin | J port at 1.1 MW (from .6 to 1.5 sec). total .9 MJ RF energy (total ~ 3.8 MJ today).
A little Nb injection at 0.5 sec on Hirex. (OK. there is still Nb invessel). McPherson tripped. no data. next shot: repeat. (lower outer gap to 1.0 cm, so it is closer to what Steve called for in the MP). |
| Jun 29 2007 10:29:52:973AM | 1070629006 | Yijun Lin | J port at 1.3 MW (from .6 to 1.5 sec). total 1.05 MJ RF energy (total ~ 4.9 MJ today).
No Nb. next shot: repeat. Let's try 2 more shots with J only. If we don't see Nb then, we will run all antennas. |
| Jun 29 2007 10:42:42:733AM | 1070629007 | Yijun Lin | J port at 1.3 MW (from .6 to 1.5 sec). total 1.1 MJ RF energy (total ~ 6 MJ today).
No Nb. next shot: repeat one more shot with J only. Then we will blast with all antennas until we see Nb. |
| Jun 29 2007 11:06:59:813AM | 1070629009 | Yijun Lin | J port at 1.3 MW (from .6 to 1.5 sec). total 1. MJ RF energy (total ~ 8.1 MJ today).
D and E faulted out due to mismatch. No Nb. next shot: repeat. |
| Jun 29 2007 11:22:30:467AM | 1070629010 | Yijun Lin | J port at 1.1 MW (from .6 to 1.5 sec). total 1. MJ RF energy (total ~ 9.1 MJ today from J).
E at 1.0 MW, 0.9 MJ. D mismatched. Failed in retries No Nb. next shot: repeat. try to make D run. |
| Jun 29 2007 11:48:44:137AM | 1070629011 | Yijun Lin | J port at 1.1 MW (from .6 to 1.5 sec). total 1. MJ RF energy (total ~ 9.1 MJ today from J).
E at 1.0 MW, 0.9 MJ. D mismatched. No Nb. (Faint glimmer of a possibility of some transient Nb at 0.9 seconds on HIREX-SR according to M. Reinke) next shot: repeat. make D run. |
| Jun 29 2007 12:02:42:333PM | 1070629012 | Yijun Lin |
J 0.96 MJ, total 10 MJ today E 0.9 MJ. total 2.7 MJ today D 0.55 MJ, total 0.6 MJ today No Nb. next shot: repeat. |
| Jun 29 2007 12:02:31:457PM | 1070629013 | Yijun Lin |
J 1 MJ, total 11 MJ today E 0.9 MJ. total 3.6 MJ today D 0.02 MJ, total 0.62 MJ today. No Nb. next shot: ramp current 1.2 MA to 0.8 MA from 0.6 sec to 1.5 sec. In this way, the Nb coated tiles must be mapped to the antennas at some point. |
| Jun 29 2007 12:18:24:843PM | 1070629014 | Yijun Lin | Ip from 1.2 MA to 0.8 MA ramping from .6 to 1.5 sec
J 1 MJ, total 12 MJ today E .9 MJ. total 4.5 MJ today D 0.01 MJ, total 0.63 MJ today. matching bad. No Nb. next shot: repeat. |
| Jun 29 2007 12:40:42:533PM | 1070629015 | Yijun Lin | Ip from 1.2 MA to 0.8 MA ramping from .6 to 1.5 sec
J: 1 MJ, total 13 MJ today E: .9 MJ. total 5.4 MJ today D: 0.7 MJ, total 1.3 MJ today. matching bad. No Nb. next shot: repeat. |
| Jun 29 2007 12:49:43:620PM | 1070629016 | Yijun Lin | Ip from 1.2 MA to 0.8 MA ramping from .6 to 1.5 sec
J: 1 MJ, total 14 MJ today E: .1 MJ. total 5.5 MJ today D: 0.75 MJ, total 2.1 MJ today. matching bad. Result: still no Nb. Next shot: run plasma strike point at the Nb coated tile, and see if there is any Nb at all. |
| Jun 29 2007 01:04:58:817PM | 1070629017 | Yijun Lin | Ip from 1 MA. Striking point at the divertor nose.
J: 1 MJ, total 15 MJ toda E: .9 MJ. total 6.5 MJ today D: 0.03 MJ, total 2.4 MJ today. Result: saw Nb betwen 0.9 and 1.0 sec. Conclusion: there is still some Nb left. However, we have not been able to get it with the available RF power, configuration, and current scan. Next shot: End of this part of run. |
| Jun 29 2007 01:23:01:457PM | 1070629018 | Steve Scott | Setup for plasma sweeps. First shot will be a 'duplicate' of 1070504004 with just a few tweeks: a. extend BT flattop to 1.8 sec. b. increase minor radius a little, to increase qpsi (shot 1070504004 was dangerously close to 3.0) c. Nel feedback to 0.8e20. Results: a. We got the extended BT flattop and aminor is about 22.2, but we lost a little on kappa (now about 1.14 - 1.18), so the qpsi still gets pretty close to 3.0. b. Some power supplies saturated ... physics operator needs some adjustments. c. DNB was good - no faults - but current is only 4.8 - 5.5. d. Density is 0.9e20 early on, then decaying to 0.80 late in the shot. e. MSE data looks pretty good. APD voltages set about right. |
| Jun 29 2007 01:34:42:513PM | 1070629019 | Steve Scott | Plasma in distress early (0.28 sec), and disrupts at about 0.42. DNB: no faults. current is 4.7 early, rising to 5.7 late. |
| Jun 29 2007 02:06:42:100PM | 1070629021 | Steve Scott | Result: got pretty much what we wanted: kappa to 1.25 --> 1.16, nel = 0.9 --> 0.8, qpsi = 3.3. DNB: no faults, and the current is higher than before: 5.2 --> 5.8. So on the next shot, we will proceed to actually asking for a ramp in major radius. |
| Jun 29 2007 02:12:00:340PM | 1070629022 | Steve Scott | Disrupted very early. Distress at 0.22, then disrupts at 0.32. this is well before we asked for the start of the ramp in major radius. |
| Jun 29 2007 02:37:06:700PM | 1070629023 | Steve Scott | Got a good Rmajor ramp of about 4 cm. But DNB faulted about half-way through. So next shot, we'll try a full 8 cm ramp. We will not have the DNB, which will be conditioning. |
| Jun 29 2007 02:41:17:673PM | 1070629024 | Steve Scott | Tried for a 'modest' sweep in Rmajor. Disrupted at about 1.2 sec. DNB was in conditioning mode (no injection into the plasma). DNB waveform looks pretty good. |
| Jun 29 2007 03:33:53:480PM | 1070629026 | Steve Scott | Injected DNB into plasma. Disrupted at about 1.55 sec ... making progress. A few glitches on the DNB waveform. |
| Jun 29 2007 05:08:56:317PM | 1070629031 | Steve Scott | Plasma was more or less successful: a little ratty at0.2-0.6 sec, but the plasma does OK out to about 1.7 seconds. Alas, the DNB did not fire. End-of-run |
| Physics Operator Comments | |||
| Jun 29 2007 08:15:01:727AM | Robert Granetz | Loaded previously prepared DPCS tree from /home/granetz/pcs_scratch. | |
| Jun 29 2007 08:16:35:057AM | Robert Granetz | There's no liquid helium to fill the DNB cryopumps. The MIT Cryo Lab doesn't have any. Dave Arsenault is trying to hunt some down. Maybe we can swipe some of the cryopump's supply? | |
| Jun 29 2007 09:24:38:750AM | 1070629001 | Robert Granetz | Shot 01 -- Plasma. Good shot. 1 MA, 5.4 T, 1.0e20 m-2, LSN. Prf=0.6 MW from J4. It should have been 1.5 MW, but the NSTAR line voltage is sagging excessively. Next shot: no DPCS changes |
| Jun 29 2007 09:33:53:803AM | 1070629002 | Robert Granetz | Shot 02 -- Plasma. Good shot. Prf = 1.0 MW. Only J4 is being used because that's the antenna that maps to the niobium-coated tiles. Matt Reinke thinks we have some boron that needs to be eroded away before we see any niobium. Next shot: no DPCS changes. |
| Jun 29 2007 09:45:44:000AM | 1070629003 | Robert Granetz | Shot 03 -- Plasma. Good shot. Prf=1.1-1.2 MW from t=0.6 to 1.5 s. Next shot: no DPCS changes |
| Jun 29 2007 10:00:54:590AM | 1070629004 | Robert Granetz | Shot 04 -- Plasma. Good shot. Prf=1.2 MW for 0.9 s. Next shot: no DPCS changes |
| Jun 29 2007 10:11:51:257AM | 1070629005 | Robert Granetz | Shot 05 -- Plasma. Good shot. Prf=1.0-1.1 MW for 0.9 s. Next shot: reduce outer gap by 5 mm (increase RCUR in Seg2 by 2.5 mm) |
| Jun 29 2007 10:26:24:343AM | 1070629006 | Robert Granetz | Shot 06 -- Plasma. Good shot. Prf_J = 1.3-1.4 MW for 0.9 s. Outer gap is smaller, as requested. Next shot: no DPCS changes |
| Jun 29 2007 10:36:13:477AM | 1070629007 | Robert Granetz | Shot 07 -- Plasma. Good shot. Prf_J=1.3-1.4 MW for 0.9 s. Next shot: no DPCS changes |
| Jun 29 2007 10:55:16:977AM | 1070629008 | Robert Granetz | Shot 08 -- Plasma. Good shot. Prf_J=3.3 MW for 0.9 s. Still no sign of niobium. Next shot: no DPCS changes |
| Jun 29 2007 11:14:58:553AM | 1070629009 | Robert Granetz | Shot 09 -- Plasma. Good shot. Prf_J=1.2 MW. Next shot: no DPCS changes |
| Jun 29 2007 11:22:20:183AM | 1070629010 | Robert Granetz | Shot 10 -- Plasma. Good shot. Both J and E antennas are now on. Prf=2.0 MW. Next shot: no DPCS changes |
| Jun 29 2007 11:32:16:860AM | 1070629011 | Robert Granetz | Shot 11 -- Plasma. Good shot. J and E antennas fired. D-antenna is still having problems. Next shot: no DPCS changes |
| Jun 29 2007 11:48:13:853AM | 1070629012 | Robert Granetz | Shot 12 -- Plasma. Good shot. D, E, and J antenna systems are all on now. Prf=2.8 MW for 0.9 s. Next shot: no DPCS changes |
| Jun 29 2007 12:04:54:147PM | 1070629013 | Robert Granetz | Shot 13 -- Plasma. Good shot. E and J fired; D wouldn't stay on. Next shot: program an Ip ramp: 1.2 --> 0.8 MA from t=0.6 to 1.5 s. The idea is to sweep the connecting flux tubes past the niobium tiles, just in case the presumed mapping was not exactly correct. |
| Jun 29 2007 12:12:29:010PM | 1070629014 | Robert Granetz | Shot 14 -- Plasma. Good shot. Ip ramped from 1.2 MA down to 0.8 MA. The idea is to sweep the flux tubes from J-antenna past the niobium tiles, in case the presumed geometry was slightly incorrect. E and J fired; D won't stay on. Next shot: no DPCS changes |
| Jun 29 2007 12:36:11:123PM | 1070629015 | Robert Granetz | Shot 15 -- Plasma. Good shot. Ip ramped from 1.2 to 0.8 MA. D, E, and J antennas were all on. Prf=2.8 MW for 0.9 s. Still don't see any Nb. Next shot: no DPCS changes. |
| Jun 29 2007 12:55:32:420PM | 1070629016 | Robert Granetz | Shot 16 -- Plasma. Good shot. Ip ramped from 1.2 to 0.8 MA. Prf=2.0 MW for 0.9 s from D and J. No niobium. Next shot: remove Ip ramp and set Ip back to 1.0 MA. Move RXL out by 3 cm and ZXL up to 2 cm. The idea this time is to move the strike point close to the Nb-coated tiles. |
| Jun 29 2007 01:04:54:380PM | 1070629017 | Robert Granetz | Shot 17 -- Plasma. Good shot. Ip=1.0 MA. Strike point is on the outboard nose tile. Finally saw a tiny amount of niobium. End of MP 486. Next shot: switch to MP 491, MSE plasma calibrations. Turn on segment 4, an inboard-limited plasma. Increase RCUR by 1 cm, but leave it constant during the shot. Set nl_04 to 0.8e20 m-2. Extend TF invert time to 1.8 s and TF flattop programming to 1.8 s. |
| Jun 29 2007 01:23:54:833PM | 1070629018 | Robert Granetz | Shot 18 -- Plasma. Good shot. Inboard limited. Elongation was only 1.2. OH2's and EF4 railed. DNB at 5.0 A. Next shot: change PLC limit on OH2's from -26 to -30 kA. Change IC_EF4 programming down by about 1 kA. Increase CLEARIN by 1.5 cm to try raising the elongation. |
| Jun 29 2007 01:36:10:420PM | 1070629019 | Robert Granetz | Shot 19 -- Plasma. Disrupted early (0.42 s). There were injections around t=0.28 s. Not sure if they caused the disruption. Kappa was higher (1.25), as requested. Next shot: try again. Reduce prefill by 2 ms for disruption recovery. |
| Jun 29 2007 01:41:49:550PM | 1070629020 | Robert Granetz | Shot 20 -- No power shot because EF3 breaker pulled out in INIT. Next shot: try again |
| Jun 29 2007 02:08:04:413PM | 1070629021 | Robert Granetz | Shot 21 -- Plasma. Good shot. Inboard limited. Next shot: program in a downward RCUR ramp and a downward Ip ramp to keep q(a) constant. Ramp goes from t=0.6 to 1.7 s. Turn off density feedback after t=0.7 s. |
| Jun 29 2007 02:18:25:170PM | 1070629022 | Robert Granetz | Shot 22 -- Plasma. Disrupted very early (0.32 s) due to inpurity injection. Next shot: reduce pre-fill by 2 ms for disruption recovery |
| Jun 29 2007 02:34:54:107PM | 1070629023 | Robert Granetz | Shot 23 -- Plasma. Good shot. Got the Ip and RCUR ramps, and qedge was sort of constant. Density was okay also, even with the feedback off. Elongation increases by about 0.1. Next shot: program an 8 cm downward ramp of RCUR and a corresponding ramp of Ip (to 0.44 MA) to keep qedge about constant. |
| Jun 29 2007 02:46:04:270PM | 1070629024 | Robert Granetz | Shot 24 -- Plasma. Disrupted at t=1.3 s, well into the RCUR and Ip ramps. N/NCRIT rises well over unity, and kappa ramps up to 1.35. Maybe it's getting vertically unstable. Next shot: program CLEARIN to ramp more negative during the RCUR and Ip ramps. |
| Jun 29 2007 03:01:38:767PM | 1070629025 | Robert Granetz | Shot 25 -- Plasma. Pretty good ramps, and it gets farther than the previous shot. It went unstable at t=1.5 s. Next shot: increase amplitude of CLEARIN ramp |
| Jun 29 2007 03:21:20:220PM | 1070629026 | Robert Granetz | Shot 26 -- Plasma. Good shot. Ramps a little farther down. qpsi stays very constant. Beam fired into plasma. Good MSE data. Next shot: raise PLC limits on OH2's to -35 kV (from -30 kV). Ramps CLEARIN even more. |
| Jun 29 2007 03:33:50:900PM | 1070629027 | Robert Granetz | Shot 27 -- Plasma. Good shot. Ramps went all the way, with the little plasma finally disrupting at t=1.72 s. Good beam, good MSE data. There's some thought that the plasma current might have been hollow early in the discharge. Next shot: same, except add 1 ms to prefill. |
| Jun 29 2007 03:54:55:090PM | 1070629028 | Robert Granetz | Shot 28 -- Plasma. Good shot. Made it just about all the way down. Good beam, good MSE data. This is a trophy shot for this MP. Power room access needed because we blew two fuses in OH1. It crowbarred. Next shot: repeat, no changes. |
| Jun 29 2007 04:29:50:897PM | 1070629029 | Robert Granetz | Shot 29 -- Plasma. Disrupted at t=0.92 s, partway through the ramps. Probably an impurity injection. The CAMAC highway that the DNB uses apparently crashed before the shot, so there was no DNB, nor any DNB data. Next shot: try one last time; no changes. |
| Jun 29 2007 04:57:26:683PM | 1070629030 | Robert Granetz | Shot 30 -- Plasma. Good shot. Nearly the entire ramp was accomplished. Disrupted at t=1.58 s. Good DNB, but MSE data was bad, apparently because of a glitch in the timing. The plasma was cleaner on this shot. Next shot: repeat one last time; no changes |
| Jun 29 2007 05:09:58:913PM | 1070629031 | Robert Granetz | Shot 31 -- Plasma. Good shot, although the early plasma had a hollow Te profile. Ramped all the way down. It would have been another trophy shot (in addition to 028), except that the Russian control program didn't trigger, so there was no beam. End of run. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:08:24:113AM | Plasma | Ok | |
| 2 | 09:22:52:077AM | Plasma | Ok | |
| 3 | 09:37:20:527AM | Plasma | Ok | |
| 4 | 09:51:21:537AM | Plasma | Ok | |
| 5 | 10:03:55:263AM | Plasma | Ok | |
| 6 | 10:17:42:430AM | Plasma | Ok | |
| 7 | 10:32:04:363AM | Plasma | Ok | |
| 8 | 10:44:30:297AM | Plasma | Ok | |
| 9 | 11:00:43:357AM | Plasma | Ok | |
| 10 | 11:13:08:740AM | Plasma | Ok | |
| 11 | 11:26:11:547AM | Plasma | Ok | |
| 12 | 11:39:21:167AM | Plasma | Ok | |
| 13 | 11:53:04:983AM | Plasma | Ok | |
| 14 | 12:08:05:337PM | Plasma | Ok | |
| 15 | 12:22:03:300PM | Plasma | Ok | |
| 16 | 12:37:03:720PM | Plasma | Ok | |
| 17 | 12:52:52:043PM | Plasma | Ok | |
| 18 | 01:10:58:243PM | Plasma | Ok | |
| 19 | 01:24:54:020PM | Plasma | Ok | |
| 20 | 01:37:23:967PM | Plasma | Ok | |
| 21 | 01:52:29:183PM | Plasma | Ok | |
| 22 | 02:08:04:820PM | Plasma | Ok | |
| 23 | 02:20:41:813PM | Plasma | Ok | |
| 24 | 02:36:26:403PM | Plasma | Ok | |
| 25 | 02:50:19:320PM | Plasma | Ok | |
| 26 | 03:02:50:347PM | Plasma | Ok | |
| 27 | 03:20:23:517PM | Plasma | Ok | |
| 28 | 03:33:17:417PM | Plasma | Ok | |
| 29 | 04:16:23:527PM | Plasma | Ok | |
| 30 | 04:47:02:893PM | Plasma | Ok | |
| 31 | 05:05:25:690PM | Plasma | Ok | |
| System Availability | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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