Alcator C-Mod Run 1051110 Information

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Miniproposals
Miniproposal:409
Date Filed: 1/19/2005
Title:Phase Space of the Scrape-off-Layer Plasma
First Author:Brian Labombard
Session Leader:Brian Labombard (shots 1-31)

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

Engineering Operator Run Comment
MP#409 MP#406 PO:Granetz SL:Labombarr EO:Fitzgerald,dekow,Parkin

Session Leader Plans
Entered: Nov 9 2005 09:59:33:803PM
Author: Brian Labombard
Session Leader Run Plan for 1051110

MP#409 "SOL Phase space studies" and MP#406 "Test of new scanning Mach-probe geometry"

Goals
        The goals of today's run are threefold: (1) make productive use of ohmic discharges
that are available early in the campaign when H/D ratios are high (this restricts experiments
with RF heating) and boronization has not yet been performed, (2) test another new probe
geometry for the A-port scanning probe (installed on 11/07/05 - this will provide design
guidance for the new inner wall WASP probe), and (3) make progress towards completing
MP#409 "SOL Phase space studies". The goals of MP#409 are to map out the 'phase space' 
of the SOL plasma, i.e. the relationships between the 'transport state'  (profile shapes,
gradients, cross-field fluxes, advection velocities, turbulence characteristics) and 
theory-based 'control parameters' (local collisionality, magnetic field strengths,
parallel connection length,...) that may determine that state. 

Shot Sequence Outline
     A. First we will dial-up some standard 0.8 MA lower single null and upper single
     null discharges with a rough density scan. This will allow us to cross-check profile
     measurements made by the new scanning probe geometry against previous data taken by
     the old probe. 

     B. Then we will attempt to run some ohmic H-modes using the usual ramp-down
     and ramp-up of the toroidal field (EDA is desired). It will be interesting see if
     the probe is able to record changes in cross-field flows in the shear layer in H vs
     L-mode (assuming that the probe works). The impurity behavior of ohmic H-modes (prior to
     boronization) is also of interest as we are thinking of using ohmic H-modes as a
     diagnostic tool for first-boronization discharges during this fall campaign.

     C. Next, we will hold the field fixed at 4 tesla, and map-out that portion of machine
     parameter spaced called for in MP#409, performing a density scan there in LSN and USN
     discharges.

Run Preparation Tasks (for probe diagnostics)
  - Reconfigure A14 and A12 digitizer connections to outer divertor probe
     array according to file: "put_new_fast_refs_2005_mar01.tcl"
  - Execute TCL>@put_new_fast_refs_2005_mar01.tcl
  - Configure ASP bias supplies: PA93 amplifiers ("DC supply") in standard sweep mode,
     "Sweep A" and "Sweep B" set to -200 volts
  - Use IDL code to switch ASP probe triggering and ASP/FMP power supply biases 
     between one of two modes:
       "Scan" mode  - ASP: N,S,E,W electrodes in current mode, "DC supply"
                           Probe scanning three times during shot, 256k samples/channel
                      FMP: OSD**.p0 probes in current mode,  "Sweep B" supply
                           OSD**.p1 probes in current mode,  "DC -" supply
                           OSD**.p2 probes in floating mode, "DC +" supply
       "Dwell" mode - ASP: W & S electrodes in current mode, "Sweep A" & "Sweep B"
                           N & E electrodes in floating mode
                           Probe in dwell mode, with 512k samples/channel
                      FMP: OSD**.p0 probes in current mode,  "DC -" supply
                           OSD**.p1 probes in current mode,  "DC -" supply
                           OSD**.p2 probes in floating mode, "DC +" supply
         IDL code: mp409_scan.pro
                       undwell_scan_asp.pro
                       set_asp_pa93_sweep.pro
                       set_fmp_sweep.pro
                    mp409_dwell.pro
                       dwell_scan_asp.pro
                       set_asp_fluctuation_mp409.pro
                       set_fmp_fluctuation_mp409.pro

Run Preparation Tasks (for optical diagnostics)
  - Set integration time on Xybion to 1 ms
  - Connect the following fiber views for the fast diodes
        Outer SOL views 1-3,5,7,9-14,31-40 (total of 21)
        Innerwall SOL views B and C
  - Connect the following fiber views for the CHROMEX
        Outer SOL views 18-22,24-29 (total of 11)
        Innerwall SOL views A,D,E,F - otherwise known as 1,4-6
  - Set timing on fastdiode digitizers to 0.1 s after the A-B limiter NINJA puff timing


Plan A - Standard shots
     Reload from shot#1050304024. This shot ran on segment#2. It was a LSN discharge 
     with Ip=0.8 MA, Bt= 5.4 tesla, NL04 = 0.9e20. Note: segment#3 has
     a USN program that we will use (Segment#4 is double-null? will not be used today.)

     ASP, FSP, ISP programmed to scan at 0.65, 0.85, 1.05 seconds
     NINJA gas puff for GPI and boron V spectroscopy entering plasma at 1.1s
     Set NINJA for D2 puff at A-B limiter and B16-001. Plenum pressure of 10 PSI.

Shots  
1,2  LSN, NL04 = 0.6, Scan mode, optimize probe insertion
     NINJA puff at 1.1 s, fast camera at 1.25 s
3,4  USN, NL04 = 0.6, Scan mode, optimize probe insertion
     NINJA puff at 1.1 s, fast camera at 1.25 s

5    USN, NL04 = 0.4, Scan mode
     NINJA puff at 1.1 s, fast camera at 1.25 s
6    LSN, NL04 = 0.4, Scan mode
     NINJA puff at 1.1 s, fast camera at 1.25 s

8    LSN, NL04 = 0.8, Scan mode
     NINJA puff at 1.1 s, fast camera at 1.25 s
9    USN, NL04 = 0.8, Scan mode
     NINJA puff at 1.1 s, fast camera at 1.25 s

10   USN, NL04 = 1.0, Scan mode
     NINJA puff at 1.1 s, fast camera at 1.25 s
11   LSN, NL04 = 1.0, Scan mode
     NINJA puff at 1.1 s, fast camera at 1.25 s


Plan B - Ohmic H-modes
     Use LSN program from above. Reprogram Bt to ramp down and up, as in shot#1000915019.
     Reprogam NL04 = 0.65e20

Shots
12-16  Optimize probe insertions and depths to catch ELM-free and EDA phases


Plan C - Begin 4 tesla, 0.8 MA density scan
     Reload from shot#11 above. Program Bt to 4 tesla and NL04 = 0.6

     ASP, FSP, ISP programmed to scan at 0.65, 0.85, 1.05 seconds
     NINJA gas puff for GPI and boron V spectroscopy entering plasma at 1.1s
     Set NINJA for D2 puff at A-B limiter and B16-001. Plenum pressure of 10 PSI.

Shots  
17,18  LSN, NL04 = 0.6, Scan mode, optimize probe insertion
     NINJA puff at 1.1 s, fast camera at 1.25 s
19,20  USN, NL04 = 0.6, Scan mode, optimize probe insertion
     NINJA puff at 1.1 s, fast camera at 1.25 s

21    USN, NL04 = 0.4, Scan mode
     NINJA puff at 1.1 s, fast camera at 1.25 s
22    LSN, NL04 = 0.4, Scan mode
     NINJA puff at 1.1 s, fast camera at 1.25 s

23    LSN, NL04 = 0.8, Scan mode
     NINJA puff at 1.1 s, fast camera at 1.25 s
24    USN, NL04 = 0.8, Scan mode
     NINJA puff at 1.1 s, fast camera at 1.25 s

Physics Operators Plans
Entered: Nov 9 2005 09:25:38:350PM
Author: Robert Granetz
Engineering setup for Thursday 10 Nov 2005

MP#409: SOL Phase Space and 
MP#406: Test of new scanning Mach-probe geometry

Session leader: B. Labombard
Physics operator: R. Granetz

Overnight ECDC in D2 (not helium), and bake at 60 C.
 
Run begins at 09:00 and ends at 17:00.

Power systems as on 1050304024 (0.8 MA, 5.4 T, lower single null)

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 + 2 psi Ne  Hybrid DISABLED (PG1)
  leave B-side upper     as is           Hybrid DISABLED (PG2)
   fill B-main (C-side)  with 40 psi D2  Hybrid enabled  (PG3)
   fill NINJA            with 10 psi D2  Leave DISABLED

Enable the following gate valves and shutters, assuming no vacuum problems:
  ECE, VUV, Z-bolo shutters
 
Torvac setup: Gate valves open

No between-shot boronization.

Important Diagnostics: ASP, FSP, ISP, Xybion camera, fast H-alpha diode
array, Chromex, Edge TS

-------------------------------------------------------------------------------
ICRF Setup: No RF today; piggybacking is NOT compatible with this run.

-------------------------------------------------------------------------------
Run plan: The goals of today's run are threefold:

(1) Make productive use of ohmic discharges that are available earily in
    the campaign when H/D ratios are high (this restricts experiments with
    RF heating) and boronization has not yet been performed,
(2) Test another new probe geometry for the A-port scanning probe
    (installed on 11/07/05 - this will provide design guidance for the new
    inner wall WASP probe), and
(3) Make progress towards completing MP#409 "SOL Phase space studies".


Session Leader Summaries
Entered: Nov 10 2005 11:28:57:543PM
Author: Brian Labombard
Run Summary for 1051110

MP#409 "SOL Phase space studies" and MP#406 "Test of new scanning Mach probe geometry"
___________________________________________________________________________________
   The tokamak performed very well today - 28 plasma shots. This would have been a
really great run to collect a load of data for MP#409. Unfortunately, the new scanning
Mach probe on the A-port drive did not perform well at all. The new probe
head features a different geometry than the previous versions and is made of out
of ATJ graphite (compared to molybdenum for previous probes). The hope was to get
improved heat-handling performance during off-normal events by avoiding the formation
of the melt layer that shorts out the probe tips on the molybdenum-based probes. The
inner wall scanning probe (ISP) is a good example. It is made out of a carbon fiber weave
material that has proven to be remarkably robust, surviving deep probe insertions beyond
the separatrix (i.e., operator errors!). However, we knew from previous experience with
probes tested on the A-port drive, that carbon redeposition on the head might
also short out the electrodes - if the carbon could deposit deep in the gaps between
electrode and head where plasma could not reach.  The new design attempted to eliminate
these locations by bringing the insulation material (AlO2) flush with the probe body.
However, the design modification was not able to keep the shorts from forming and we
spent the entire run trying to 'burn-off' electrical shots between the body and
electrodes.
   By shot 10, we realized that the electrical shorts on the new probe may never be
eliminated. So we punted on taking data for MP#409 and moved onto dialing up some
ohmic H-modes. Using the usual recipe of ramping Bt down to about 3 tesla (0.8 MA
discharges), we were able to access ELM-free ohmic H-modes. We tried without success
to get some EDA H-modes by ramping up Bt or ramping down Ip, once the H-mode formed.
Nevertheless, these discharges (or higher current ones) may prove useful for studying
changes in impurity source strengths as boronization is applied in a systematic way.

   The carbon probe head on the A-port drive was replaced with a standard molybdenum
one after the run. It should be ready to go for tuesday's run, next week.
Final note: We have not given up entirely on the carbon probe head, and may be back for
another go during this campaign. We would like to try to develop an option for a carbon
probe head before we commit to a final design for Noah's new inner wall scanning probe (WASP).

Quick shot log:

 1 - LSN, NL04= 0.56  no probes scanning.
 2 - LSN, NL04= 0.56, ASP(0), FSP(-5), ISP, at 0.65, 0.85, 1.05 - ASP TR16s were off
 3 - LSN, NL04= 0.6, ASP(+5), FSP(0), ISP, at 0.65, 0.85, 1.05 - ASP a bit deep.
 4 - LSN, NL04= 0.6, ASP(+3), FSP(0), ISP, at 0.65, 0.85, 1.05 - ASP cleaing up
 5 - LSN, NL04= 0.6, ASP(+3), FSP(0), ISP, at 0.65, 0.85, 1.05 - ASP cleaning up, FSP good target, ISP great
 6 - LSN, NL04= 0.6, ASP(+3), FSP(0), ISP, at 0.65, 0.85, 1.05 
 7 - LSN, NL04= 0.6, ASP(+3), FSP(0), ISP, at 0.65, 0.85, 1.05
 8 - LSN, NL04= 0.58, ASP(+6), FSP(0), ISP, at 0.65, 0.85, 1.05
 9 - LSN, NL04= 0.58, ASP(+6), FSP(0), ISP, at 0.65, 0.85, 1.05

10 - LSN, NL04= 0.67, Bt ramp to 3.2T and back up, ASP(+6), FSP(0), ISP, at 0.65, 0.85, 1.05 - ohmic H-mode attempt, no H-modes
11 - LSN, NL04= 0.62, Bt ramp to 3T and back up, ASP(+7), FSP(0), ISP, at 0.65, 0.85, 1.05 - ohmic H-mode attempt, no H-modes
12 - LSN, NL04= 0.65, Bt ramp to 3T, ASP(+5), FSP(0), ISP, at 0.65, 0.85, 1.05 - got multiple H-modes, no NINJA
13 - LSN, NL04= 0.57, Bt ramp to 3T, ASP(+5), FSP(0), ISP, at 0.65, 0.85, 1.05 - H-L-H-L dispution, no NINJA
14 - LSN, NL04= 0.53, Bt ramp to 3T, ASP(+5), FSP(0), ISP, at 0.65, 0.85, 1.05 - many H-modes, no NINJA
15 - LSN, NL04= 0.58, Bt ramp to 3T, ASP(+5), FSP(0), ISP, at 0.65, 0.85, 1.05 - got multiple H-modes with NINJA
16 - LSN, NL04= 0.55, Bt ramp to 3T, ASP(+5 dwell mode), FSP(0), ISP, at 0.65, 0.85, 1.05, intermittent H-Ls, with NINJA
17 - LSN, NL04= 0.56, Bt ramp to 3T, ASP(+5 SCAN mode), FSP(0), ISP, at 0.65, 0.85, 1.05, multiple H-L, with NINJA
18 - LSN, NL04= 0.6, Bt ramp to 3T, ASP(+5 dwell mode), FSP(0), ISP, at 0.65, 0.85, 1.05, H-Ls, disrupts 1.36
19 - LSN, NL04= 0.6, Bt ramp to 3T and then up, ASP(-5 dwell mode), ISP, at 0.65, 0.85, 1.05, one short H-mode
20 - LSN, NL04= 0.6, Bt ramp to 3T and then up, ASP(-5 dwell mode), ISP, at 0.65, 0.85, 1.05, tiny H-mode, disrupts at 1s
21 - LSN, NL04= 0.58, Bt ramp to 3T, ASP(-5 dwell mode), ISP, at 0.65, 0.85, 1.05, multiple H-L 
22 - fizzle
23 - power test
24 - LSN, NL04= 0.6, Bt ramp to 3T, ASP(0 dwell mode), two H-modes late
25 - LSN, NL04= 0.6, Bt ramp to 3T, ASP(+2 dwell mode), a few H-modes
26 - LSN, NL04= 0.6, Bt ramp to 3T, ASP(-2 scan mode)
27 - LSN, NL04= 0.6, Bt ramp to 3T, ASP(-2 scan mode)
28 - LSN, NL04= 0.6, Bt ramp to 3T, ASP(-2 scan mode)
29 - LSN, NL04= 0.57, Bt ramp to 3T, ASP(-2 scan mode) Ramped down Ip after 1s, two H-mode, no EDA
30 - LSN, NL04= 0.6, Bt ramp to 3T, ASP(-2 scan mode) Ramped down Ip after 1s, Argon/Neon off, couple H-modes
31 - fizzle

Physics Operator Summaries
Entered: Nov 10 2005 05:02:56:023PM
Author: Robert Granetz
Physics operator summary for Thursday 10 Nov 2005:

MP#409: SOL Phase Space and 
MP#406: Test of new scanning Mach-probe geometry

Session leader: B. Labombard
Physics operator: R. Granetz
 
The tokamak ran extremely well today, with only two fizzles and no duds.
We managed to get ELMfree ohmic H-modes reliably by ramping the field down
to 3.0 T (Ip=0.8 MA).  We also tried various tricks to try and convert the
short ELMfree ohmic H-modes into longer, steadier ohmic H-modes, but
without noticeable success.

Brian reports that the new carbon-body ASP didn't work as well as he had
hoped, and didn't seem to be improving during the run.  See Brian's report
for details on the probe scan results.

I was constantly monitoring the OH2U coax resistance, which never got to
the worrisome level.  After our first fizzle on shot 22, we did an OH+TF
test on shot 23 (under PLC control) with the OH in the reverse condition
(i.e. positive current on the OH Rogowski), which gave us a steady reading
of 2.0 micro-ohms.  The next shot (24) was a normal plasma with the same
OH2U coax resistance and previous shots today.

Scorecard: 28 plasmas
            0 duds
            2 fizzles
            1 power supply test
           --------------
    Total: 31 shot cycles

Session Leader Comments
Nov 10 2005 03:15:54:617PM1051110001Brian LabombardShot 1 0.8 MA, 5.4 T LSN NL04 = 0.6 No probes scanning.

Nov 10 2005 03:16:55:383PM1051110002Brian LabombardShot 2 0.8 MA, 5.4T LSN NL04 = 0.56 ASP, FSP, ISP scanning at 0.65, 0.85, 1.05s
ASP - some tree nodes were off
FSP - could be deeper
ISP - looks good

Next: repeat
Nov 10 2005 03:17:32:850PM1051110003Brian LabombardShot 3 0.8 MA, 5.4T LSN NL04 = 0.6 ASP, FSP, ISP scanning at 0.65, 0.85, 1.05s
ASP - arcing, but cleaning up
FSP - could be deeper
ISP - looks great

Next: repeat
Nov 10 2005 03:18:03:400PM1051110004Brian LabombardShot 4 0.8 MA, 5.4T LSN NL04 = 0.6 ASP, FSP, ISP scanning at 0.65, 0.85, 1.05s
ASP - arcing, but cleaning up
FSP - could be deeper
ISP - looks great

Next: repeat
Nov 10 2005 03:18:33:257PM1051110005Brian LabombardShot 5 0.8 MA, 5.4T LSN NL04 = 0.6 ASP, FSP, ISP scanning at 0.65, 0.85, 1.05s
ASP - cleaning up
FSP - ok
ISP - looks great

Next: repeat
Nov 10 2005 11:09:50:303AM1051110006Brian LabombardShot 6 0.8 MA, 5.4T LSN NL04 = 0.6 ASP, FSP, ISP scanning at 0.65, 0.85, 1.05s
ASP - cleaning up
FSP - ok
ISP - looks great

The A-port probe is taking a long time to clean up, causing a delay in the run plan.

Next: Repeat
Nov 10 2005 11:19:30:710AM1051110007Brian LabombardShot 7 0.8 MA, 5.4T LSN NL04 = 0.6 ASP, FSP, ISP scanning at 0.65, 0.85, 1.05s
ASP - cleaning up
FSP - ok
ISP - looks great

ASP Still cleaning up.

Next shot: Plunge probe deeper in the hopes of cleaning it up more quickly.
Nov 10 2005 11:42:30:587AM1051110008Brian LabombardShot 8 0.8 MA, 5.4T LSN NL04 = 0.6 ASP, FSP, ISP scanning at 0.65, 0.85, 1.05s
ASP - getting a little better
FSP - ok
ISP - looks great

Next shot: repeat
Nov 10 2005 11:43:25:227AM1051110009Brian LabombardShot 9 0.8 MA, 5.4T LSN NL04 = 0.6 ASP, FSP, ISP scanning at 0.65, 0.85, 1.05s
ASP - getting a little better
FSP - ok
ISP - looks great

Next shot: Change Bt programming to attempt to get ohmic H-modes
Nov 10 2005 12:07:35:117PM1051110010Brian LabombardShot 10 0.8 MA, Bt ramp, LSN NL04 = 0.6 ASP, FSP, ISP scanning at 0.65, 0.85, 1.05s
No H-mode
ASP - still cleaning up
FSP - ok
ISP - looks great

Next shot: Repeat, ramping to lower Bt
Nov 10 2005 12:16:08:023PM1051110011Brian LabombardShot 11 0.8 MA, Bt ramp down to 3T, LSN NL04 = 0.6 ASP, FSP, ISP scanning at 0.65, 0.85, 1.05s
No H-mode
ASP - cleaning up
FSP - ok
ISP - looks great

Next shot: Repeat, ramping to Bt = 3T and then holding at 3T
Nov 10 2005 12:41:25:820PM1051110012Brian LabombardShot 12 0.8 MA, Bt ramp down to 3T and hold, LSN NL04 = 0.6 ASP, FSP, ISP scanning at 0.65, 0.85, 1.05s
Multiple H-L-H-L modes
ASP - not clean yet
FSP - ok
ISP - ok

Next shot: Repeat
Nov 10 2005 12:43:37:947PM1051110013Brian LabombardShot 13 0.8 MA, Bt ramp down to 3T and hold, LSN NL04 = 0.6
A couple H-Ls, Disrupts at 1.02 ASP, FSP, ISP scanning at 0.65, 0.85, 1.05
ASP - not clean yet
FSP - ok
ISP - ok

Next shot: Repeat
Nov 10 2005 01:03:59:820PM1051110014Brian LabombardShot 14 0.8 MA, Bt ramp down to 3T and hold, LSN NL04 = 0.6
Many H-Ls, ASP, FSP, ISP scanning at 0.65, 0.85, 1.05
ASP - not clean yet
FSP - ok
ISP - ok

Next shot: Repeat with NINJA
Nov 10 2005 01:08:54:007PM1051110015Brian LabombardShot 15 0.8 MA, Bt ramp down to 3T and hold, LSN NL04 = 0.6
Many H-Ls, ASP, FSP, ISP scanning at 0.65, 0.85, 1.05
ASP - not clean yet
FSP - ok
ISP - ok

Next shot: Repeat with ASP in dwell mode, 5 mm from separatrix
Nov 10 2005 01:38:57:193PM1051110016Brian LabombardShot 16 0.8 MA, Bt ramp down to 3T and hold, LSN NL04 = 0.6
H-L-H-L, ASP DWELL, FSP, ISP scanning at 0.65, 0.85, 1.05
ASP - not clean yet
FSP - ok
ISP - ok

Next shot: Repeat with ASP in scan mode
Nov 10 2005 01:38:25:710PM1051110017Brian LabombardShot 17 0.8 MA, Bt ramp down to 3T and hold, LSN NL04 = 0.6
H-L-H-L, ASP, FSP, ISP scanning at 0.65, 0.85, 1.05
ASP - not clean yet
FSP - ok
ISP - ok

Next shot: Repeat with ASP in dwell mode
Nov 10 2005 02:19:12:413PM1051110018Brian LabombardShot 18 0.8 MA, Bt ramp down to 3T and hold, LSN NL04 = 0.6
H-L-H-L, disruption. ASP in DWELL mode, ISP scanning at 0.65, 0.85, 1.05
ASP - not clean yet
FSP - ok
ISP - ok

Next shot: Add Bt ramp-up to try to get EDA H-mode. Reduce outer gap.
Nov 10 2005 02:18:37:117PM1051110019Brian LabombardShot 19 0.8 MA, Bt ramp down to 3T and hold, LSN NL04 = 0.6
H-L-H-L ASP in DWELL mode, ISP scanning at 0.65, 0.85, 1.05
ASP - not clean yet
FSP - ok
ISP - ok

Next shot: Repeat with tweak in Bt ramp-up.
Nov 10 2005 03:25:59:180PM1051110024Brian LabombardShot 24 0.8 MA, Bt ramp down to 3T and hold, LSN NL04 = 0.6
Two H-modes late ASP in DWELL mode. SOUTH probe is still shorted.

Next shot: Repeat
Nov 10 2005 03:44:24:007PM1051110025Brian LabombardShot 25 0.8 MA, Bt ramp down to 3T and hold, LSN NL04 = 0.6
A few H-modes ASP in DWELL mode. SOUTH probe is still shorted.

Next shot: Repeat
Nov 10 2005 03:57:32:180PM1051110026Brian LabombardShot 26 0.8 MA, Bt ramp down to 3T and hold, LSN NL04 = 0.6
H-modes ASP in DWELL mode. Maybe more electrodes are now shorted.

Next shot: Repeat with probe scanning.
Nov 10 2005 04:29:59:227PM1051110027Brian LabombardShot 27 0.8 MA, Bt ramp down to 3T and hold, LSN NL04 = 0.6
H-modes ASP scanning at 0.65, 0.85, 1.05s. Electrodes intermittently shorting.

Next shot: Repeat with probe scanning, using DC- supplies
Nov 10 2005 04:29:32:273PM1051110028Brian LabombardShot 28 0.8 MA, Bt ramp down to 3T and hold, LSN NL04 = 0.6
Ohmic H-modes ASP scanning at 0.65, 0.85, 1.05s. Intermittent shorts.

Next shot: Repeat, with current ramping down after 1.0s
Nov 10 2005 05:26:32:757PM1051110029Brian LabombardShot 29 0.8 MA, Bt ramp down to 3T and hold, LSN NL04 = 0.6
Ohmic H-modes ASP scanning at 0.65, 0.85, 1.05s. Intermittent shorts.

Next shot: Repeat, without argon/neon
Nov 10 2005 05:26:56:197PM1051110030Brian LabombardShot 30 0.8 MA, Bt ramp down to 3T and hold, LSN NL04 = 0.6
Ohmic H-modes ASP scanning at 0.65, 0.85, 1.05s. Intermittent shorts.

Physics Operator Comments
Nov 10 2005 08:17:43:953AMRobert GranetzLoaded DPCS from shot 1050304024 (0.8 MA, 5.4 T, 1.0e20 m-2, SNL), and then reloaded segment 1 from
last shot yesterday (1051109024).

Since segment 2 was from early in 2005, I had to "call" all the magnetics-relevant wires to
get the swapped BP16 and ROG signals correctly implemented, and also to zero the offsets in
CLEARIN and IP.

I also reduced the Ar/Ne puff to 50 ms.
Nov 10 2005 08:24:37:110AMRobert GranetzAlso, for the first shot, I decreased the programmed density to nl_04 = 0.6e20 m-2.
Nov 10 2005 09:21:24:610AM1051110001Robert GranetzPlasma. Good shot. Very, very late breakdown, but the current rise looks good.

Next shot: reduce CLEARIN by 2.5 mm, tweak RCUR after t=1.1 s. Leave pre-fill unchanged
at 34 ms.
Nov 10 2005 09:46:56:940AM1051110002Robert GranetzPlasma. Good shot. Good inboard and outboard gaps.

Next shot: no changes. Repeat for Brian's data acquisition.
Nov 10 2005 09:54:38:203AM1051110003Robert GranetzPlasma. Good shot. Density is still remaining good and low.

Next shot: reduce pre-fill by 2 ms (to 32 ms).
Nov 10 2005 10:28:04:267AM1051110004Robert GranetzPlasma. Good shot.

Cell access after this shot for Jim Terry.

Next shot: add 1 ms back to pre-fill because there were some outward bounces on
this shot.
Nov 10 2005 10:44:31:893AM1051110005Robert GranetzPlasma. Good shot. The argon/neon was enabled for the first time on this shot (50 ms).

Next shot: reduce Ar/Ne put to 40 ms, since the shot didn't make it all the way through
the rampdown.
Nov 10 2005 11:05:32:800AM1051110006Robert GranetzPlasma. Good shot. Some hard x-rays.

Next shot: no changes.
Nov 10 2005 11:09:43:130AM1051110007Robert GranetzPlasma. Good shot. Some runaways again.

Next shot: add 1 more ms to the pre-fill
Nov 10 2005 11:31:35:850AM1051110008Robert GranetzPlasma. Good shot. Still some hard x-rays.

Next shot: add 1 more ms to pre-fill.
Nov 10 2005 11:44:55:663AM1051110009Robert GranetzPlasma. Good shot.

Next shot: Try for ohmic H-mode by programming in a partial rampdown of Btor, and then ramp it
back up a bit to try and keep the H-mode. The Btor voltage programming was copied from
segment 2 of 1000915019.
Nov 10 2005 11:59:46:400AM1051110010Robert GranetzPlasma. Good shot. No ohmic H-mode though.

Next shot: ramp Btor down even more (to 3.0 T) during the shot.
Nov 10 2005 12:11:50:243PM1051110011Robert GranetzPlasma. Good shot, but still no ohmic H-mode.

Next shot: keep Btor down at 3.0 T for the remainder of the shot, rather than raising
back up slightly.
Nov 10 2005 12:31:15:383PM1051110012Robert GranetzPlasma. Good shot, and we got a bunch of short ohmic H-modes!! But the shot disrupted
just at the end of programmed flattop.

Next shot: repeat, no changes
Nov 10 2005 12:37:42:977PM1051110013Robert GranetzPlasma. Disrupted at t=1.02 s during an ohmic H-mode and just before the
third probe scan.

Next shot: repeat, except reduce Ar/Ne puff to 30 ms.
Nov 10 2005 12:53:23:400PM1051110014Robert GranetzPlasma. Good shot. Lots of short ohmic H-modes.

Next shot: repeat, no changes
Nov 10 2005 01:03:14:803PM1051110015Robert GranetzPlasma. Good shot. Ohmic H-modes. Disrupted at t=1.51 s. Hard x-rays.

Next shot: repeat, no changes.
Nov 10 2005 01:17:44:367PM1051110016Robert GranetzPlasma. Good shot. More ohmic H-modes. Made it part way down rampdown.

Next shot: repeat, no changes.
Nov 10 2005 01:28:16:913PM1051110017Robert GranetzPlasma. Good shot. Ohmic H-modes.

Next shot: repeat, no changes.
Nov 10 2005 01:47:53:947PM1051110018Robert GranetzPlasma. Disrupted at t=1.36 s.

Next shot: ramp the Btor back up to 3.6 T late in the shot to try and convert
the ELMfree ohmic H-modes to EDA. Also reduce Ar/Ne puff to 20 ms.
Also increase RCUR by 5 mm to reduce the outer gap by 1 cm.
Nov 10 2005 02:03:04:883PM1051110019Robert GranetzPlasma. Good shot. Made it halfway down rampdown. Outer gap reduced by 1 cm, as
requested. Inner gap stayed the same, also as requested. There was only one short
ohmic H-mode, then it reverted back to L-mode as soon as the slight rampup in Btor
occurs.

Next shot: delay the upramp by a bit to see if we get a more robust H-mode that
sticks around for the upramp.
Nov 10 2005 02:19:09:820PM1051110020Robert GranetzPlasma. Disrupted at t=1.00 s.

Next shot: Remove the Btor upramp. Just leave it down at 3.0 T for the
remainder of the shot.
Nov 10 2005 02:29:53:303PM1051110021Robert GranetzPlasma. Good shot. Ohmic H-modes.

Next shot: repeat, no DPCS changes.
Nov 10 2005 02:44:30:023PM1051110022Robert GranetzFizzle. First one of the day.

Next shot: OH and TF only, with OH in reverse direction (positive Rogowski signal), to try
and push together the OH2U coax contacts.
Nov 10 2005 03:11:53:663PM1051110023Robert GranetzTest of OH2U coax resistance, using OH's and TF only, under PLC control.

OH2U coax resistance = 2.0 micro-ohms.

Next shot: back to plasma operation. Add +10 amps to IC_EF4
Nov 10 2005 03:25:15:303PM1051110024Robert GranetzPlasma. Good shot. Ohmic H-modes late in the flattop. OH2U coax resistance is similar to earlier
plasma discharges today.

Next shot: repeat, no DPCS changes.


Nov 10 2005 03:41:35:210PM1051110025Robert GranetzPlasma. Good shot. Ohmic H-modes. Several noticeable projectiles on WIDE2 view.

Next shot: repeat, no DPCS changes.
Nov 10 2005 03:54:06:727PM1051110026Robert GranetzPlasma. Good shot. A few ohmic H-modes.

Next shot: repeat, no DPCS changes.
Nov 10 2005 04:07:23:743PM1051110027Robert GranetzPlasma. Good shot. Numerous ohmic H-modes.

Next shot: repeat, no DPCS changes.
Nov 10 2005 04:23:58:743PM1051110028Robert GranetzPlasma. Good shot. Multiple ohmic H-modes.

Next shot: try ramping down Ip to see if we can get an steadier ohmic H-mode.
Nov 10 2005 04:31:48:867PM1051110029Robert GranetzPlasma. Good shot. Both Bt was ramped down to 3.0 T and then Ip was ramped down to 0.4 MA.
Got a couple of ELMfree ohmic H-modes, but they didn't last as Ip was dropped. Oh well, it
was worth a try.

Next shot: repeat, except turn off the Ar/Ne valve.
Nov 10 2005 04:44:37:193PM1051110030Robert GranetzPlasma. Good shot. I don't think the ohmic H-mode characteristics were
noticeably different.

Next shot: raise nl_04 to 0.75e20 m-2.
Nov 10 2005 05:01:53:337PM1051110031Robert GranetzFizzle. Only the 2nd one of the day.

End of run.

Engineering Operator Comments
ShotTimeTypeStatusComment
109:08:28:267AMPlasmaOk
209:33:42:657AMPlasmaOk
309:50:16:143AMPlasmaOk
410:05:45:550AMPlasmaOk
510:40:38:457AMPlasmaOk
610:53:33:453AMPlasmaOk
711:06:31:800AMPlasmaOk
811:23:07:100AMPlasmaOk
911:38:13:680AMPlasmaOk
1011:51:19:867AMPlasmaOk
1112:05:17:040PMPlasmaOk
1212:18:26:523PMPlasmaOk
1312:32:07:023PMPlasmaOk
1412:45:14:430PMPlasmaOk
1512:58:16:350PMPlasmaOk
1601:11:30:680PMPlasmaOk
1701:24:43:507PMPlasmaOk
1801:37:58:540PMPlasmaOk
1901:51:38:617PMPlasmaOk
2002:05:42:540PMPlasmaOk
2102:19:53:133PMPlasmaOk
2202:33:30:447PMPlasmaOk
2303:04:02:710PMTestOkOHs and TF Shot
2403:17:27:913PMPlasmaOk
2503:30:40:117PMPlasmaOk
2603:43:54:853PMPlasmaOk
2703:57:17:523PMPlasmaOk
2804:10:48:650PMPlasmaOk
2904:25:35:930PMPlasmaOk
3004:38:44:820PMPlasmaOk
3104:52:04:570PMPlasmaOk