Miniproposals

Miniproposal: 177 Date Filed: 5/2/1997 Title: Exploration of the Prototype Cryopump on Impurity Transport First Author: Bruce Lipschultz Session Leader: Jim Irby (shots 1-38) Session Leader: John Goetz (shots 1-38)

Engineering Operator Run Comment

mp#177 Cryopump &imp. trans Irby-Blip/Snipes

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:17:960PM

Author: To Be Determined

Run 980205 session leader: Irby & Goetz physop: Snipes eng op: Silva/Bertolino Mini-proposal 177: "Exploration of the Effect of the Prototype Cryopump on Impurity Transport' The purpose of this MP was to explore whether the impurity transport characteristics are affected by the protoype cryopump. Ohmic plasmas with medium density and density ramps to divertor detachment and EDA H-mode plasmas were investigated. 'Steady-state' and reproducible conditions were targeted in order to investigate the utility of the cryopump. Argon or krypton and helium-3 was puffed into these types of plasmas with the cryopump on or off. The core impurity ion densities were monitored with x-ray and VUV spectrometers and the divertor impurity neutral densities with an RGA. The run went extremely well. We got good reproducible data with the pump cold and warm, during both H and L mode discharges.The first part of the run was devoted to quantifying the effects the cryopump had on both core and divertor parameters. Generally there are clear differences in the warm and cold cases. The divertor pressures and h-alpha signals are lower, source gas required higher, and densities measurably lower when the cryopump is cold. Note also that the divertor parameters are dramatically different in the warm and cold cases. With the pump cold the density and radiated power are down a factor or two or so and the electron temperature is up a similar amount. Krypton is also pumped well by the cryopump and is again about a factor of two lower with the pump cold. Spencer pointed out that the change in the krypton level may explain many of the effects seen in the divertor and that effects caused by pumping the deuterium may not be the most important ones. Some more data without impurity puffing may be required to sort out these effects. However, unlike our last attempt running mp177, there is no doubt that the pump can have a large effect on divertor operation. In Ohmic plasmas with constant medium density, the core argon and krypton are "pumping out", i.e., the time history of the signal is decaying away. With the cryopump operational, the core argon density is slighlty lower than when the pump is warm. Krypton line brightnesses also show a slight decrease in the equilibrium value with the cryopump operational. When the density in these Ohmic plasmas is ramped to divertor detachment, the krypton line brightness does not change. The penetration factor for puffed krypton entering the core is lower after detachment with the cryopump on than it is after detachment with the cryopump off. This is similar to the results seen for argon in run 980121. Measurements of the neutral particle density in the divertor indicate that the krypton density is not much different with either the pump cold or warm. In EDA H-modes, the "pump out" effect is still evident on the core argon density and there is no difference between plasmas with and without the cryopump operational. Core krypton brightness measurements show no "pump out" behavior. There is a slight decrease in the core krypton brightness with the cryopump operational. There is a slight decrease, <15%, in the divertor neutral krypton with the cryopump operational. Also, there is less krypton in the divertor with an H-Mode plasma than an L-mode plasma. The analysis of the helium-3 data is ongoing. A shot log follows: Shot Result ---- ------ 001 fizzle 002 fizzle 003 dud 004 plasma - fiducial - baseline for pumping experiment - 11msec of Ar 005 plasma - fiducial - baseline for pumping experiment - 35 msec of Ar 006 plasma - disrupts @ 0.23 007 plasma - fiducial - baseline for pumping experiment - 35msec of Ar 008 plasma - fiducial - baseline for pumping experiment - 35msec of Ar 009 fizzle 010 add 2MW RF from 0.5 to 1.2sec; plasma - ELMfree H-modes - 35ms of Ar 011 plasma - many ELMfree-ELMy H-mode intervals - 35ms of Ar 012 plasma - somewhat EDAish H-mode - confinement change @ 0.8sec - 35ms Ar 013 plasma - EDA H-mode - .024Torr-l of Ar 014 plasma - steady state ELMy H-mode - 20ms of 4PSI Kr thru J-bottom 015 plasma - steady-state ELMy H-mode - 17ms of 4PSI Kr thru J-bottom 016 fizzle 017 plasma - steady-state ELMy H-mode - 17ms of 4PSI Kr thru J-Bottom 018 fizzle 019 plasma - 17msec of 4PSI Kr thru J-Bottom - 15ms of He-3 thru B-side-upper - good match to other Ohmic shots 020 fizzle 021 fizzle 022 plasma - 15ms of He-3; 17ms of Kr; acceptable L-mode; mass3 saturated cool down the cryopump 023 plasma - 15ms of He-3; 17ms of Kr; acceptable L-mode; 024 plasma - 15ms of He-3; 17ms of Kr; good match 025 plasma - no impurities puffed 026 plasma - 30ms of Ar - acceptable data 027 plasma - 2.5MW of RF - ELMree H-mode, then ratty 028 plasma - EDAish - .03Torr-l of Ar - trip on HIREX 029 fizzle 030 plasma - EDAish - .03Torr-l of Ar 031 fizzle 032 plasma - ELMy & ELMfree H-mode - 15ms of He-3 and 17ms of Kr 033 plasma - just like 032 - 15ms of He-3 and 17ms of Kr 034 plasma - EDA! - no impurities - baseline for krypton 035 plasma - ramp to Ohmic detachment (not quite) - 15ms of He-3 and 17ms of Kr 036 plasma - detaches @ 0.87 - 15ms of He-3 and 17ms of Kr 037 plasma - detaches @ 0.84 - 15ms of He-3 and 17ms of Ar 038 plasma - detaches @ 0.89 - no impurities for a baseline

Physics Operator Summaries

Entered: Jul 7 2004 04:36:59:003PM

Author: To Be Determined

MP #177 Cryopump and Impurities Session Leaders: Jim Irby and John Goetz Physics Operator: Joseph Snipes Engineer in Charge: Frank Silva Engineering setup: ECDC in D2 for a few hours in the morning engineering setup from shot 980203007 TF under hybrid control Gas setup - fill K-side with 30 PSI of D2, hybrid enabled fill B-top with 6 PSI of D2, hybrid enabled fill B-side-lower with 2 PSI of Ar, hybrid enabled ECE gate valve enabled; others if diagnosticians are ready. Physics to be done: Investigate impurity transport in discharges with cryopumping. Begin with the cryopump warm and setup a fiducial (no RF) to check pumping rates. A good shot is 980203006 (turn off the RF). Cool down the cryopump and take some more fiducials to measure pumping rates. Put in a density ramp to nl04=1.7e20 @ 1.0sec to get divertor detachment. Puff in krypton and helium-3. Measure impurity screening, compression, and enrichment. Toss in enough baselines to ensure that it can be determined that the cryopump is 'doing something' Add 2MW of RF from 0.5 to 1.2sec to get EDA H-mode. Puff in krypton and helium-3. Measure impurity screening, compression, and enrichment. Warm up the cryopump and repeat the above measurements. Guesses for the various gases to be used: 35msec of 2PSI Ar thru B-Side-Lower 20msec of 4PSI Kr thru B-Side-Lower 60msec of 4PSI He-3 thru B-Side-Upper It was a reasonably successful run. The machine ran very well except for a number of fizzles with the vertical and/or radial fields changing shot to shot. There was also more than an hour delay to cool down the cryopump in the middle of the run. The cryopump definitely pumps but the results need to be quantified. The latter part of the run was dedicated to ohmic detachment studies with and without impurity puffing. Scorecard: 38 shots. 28 plasmas. 9 fizzles. 1 duds. Shot 1: Copy of shot 980203007 without RF. Fizzle. Shot 2: Raised Br by 1 mT to 7 mT. Raised EF4 current from -1345 to -1330 A. Fizzle! Shot 3: Returned EF4 to -1345 A. Increased pre-puff by 4 msec to 20 msec. OH2 and EF2 came on early around -0.07 sec. Hybrid seems to be asking for strange waveforms. Shot 4: Wolfe did some Hybrid test shots and seems to have reset the hybrid to a reasonable state. Try again. Good shot. Shot 5: Copied segment 4 to segment 2 and changed Ar gas puff from 11 msec duration to 35 msec duration. Good shot. Wolfe noticed that the TF was at 5.8 T and that the TF was under PLC control rather than Hybrid control as requested. Shot 6: TF changed to Hybrid control and set at 156 kA which should give about 5.6 T. Disrupted at 0.24 sec. Shot 7: Moved RCUR and CLEARIN out a bit around 200 msec to reduce the inner wall interaction during the current rise. Good shot. Shot 8: Reduced TF current to 154 kA to get 5.6 T. Modified current rise ZXL and ZXU to try to elongate the plasma a bit more early to avoid the current rise locked mode that was coming in at 0.1 sec. Good shot. Shot 9: Increased K side gas voltage programming between 0.5 and 1 sec to 50 V. Increased Ip gain during the current rise to get the requested rate of rise of the current. Phys A out had 150 kA more current at 0.08 sec. Fizzle! Shot 10:Increased Br offset to 6.5 mT. Increased EF4 current to -1330 A. Reduced pre-puff to 17 msec duration. Good shot. RF at 1.8 - 2 MW. ELM-free and ELMy H-modes. Shot 11:Moved RXL in by 1 mm from 0.006 to 0.005 and increased nl04 to 1.2 x 10^20 m^-2 to try to obtain EDA H-mode. Nearly steady alternating ELM-free and Type III ELMy H-mode from 0.53 - 1.22 sec. Shot 12:Increased K-side gas voltage programming to 60 V from 0.45 to 1 sec. Increased requested nl04 to 1.4 x 10^20 m^-2. Mild EDA H-mode. Shot 13:Try reducing Ar puff to 30 msec duration. Good shot. Very steady EDA. Shot 14:Put 4 psi of Kr into J bottom and enabled it with 20 msec from 0.3 sec on pulse gas 5. Disabled B side lower Ar puff. Steady state ELMy. Shot 15:Wolfe suggested an early gas puff to avoid the Moly injection at 0.14 sec. So, I added a bit of early gas programming. Reduced Kr puff to 17 msec duration. Good shot. Steady state ELMy. Shot 16:Repeat. Fizzle! Shot 17:Try reducing pre-puff to 15 msec. Good shot. Steady state ELMy. Shot 18:Repeat. Fizzle! Shot 19:Reloaded segment 2 from shot 8 then set up Kr puff with 17 msec duration at 0.3 sec. Added He3 puff at 0.3 sec for 15 msec. Turned off RF for L-mode shot. Good shot. Shot 20:Added early gas voltage programming to remove the Moly injection again. Fizzle! Shot 21:Increased EF4 current to -1315 A. Fizzle! Shot 22:Reduced EF4 current to -1345 A. Good shot. Shot 23:Restart after delay to cool down the cryopump. Good shot. There appears to be some pumping. Shot 24:Repeat to check reproducibility. Good shot. Shot 25:Disabled B-side upper (He3) and J bottom (Kr) and re-enabled B side lower (Ar). Set Ar puff to 30 msec duration starting at 0.3 sec. Good shot. Ar was not enabled. Shot 26:Repeat with Ar enabled. Good shot. Shot 27:Turn on RF and repeat. ELM-free and ELMy H-modes. Shot 28:Reload segment 2 of shot 17 to try to return to a more constant H-mode. EDA-like H-mode with Type III ELMs in short bursts. Shot 29:Repeat. Fizzle! Shot 30:Reduced pre-puff to 15 msec duration. EDA-like H-mode with Type III ELMs in short bursts. Shot 31:Disabled B side lower (D) and enabled B side upper (Kr) and J bottom (He3). Fizzle! Shot 32:Try again. Good shot. Nearly constant Type III ELMy H-mode with short ELM-free phases interspersed. Shot 33:Good shot. Similar to 32. Shot 34:Lower Br offset to 5.5 mT. Disabled all impurity gas puffing. Good shot. Nice steady EDA H-mode without impurities. Shot 35:Requested nl04 to ramp from 1 to 1.7 x 10^20 m^-2 from 0.4 to 1.1 sec. Added more gas voltage programming up to 60 V from 0.5 to 1 sec. Good shot. RF turned off. Shot 36:Increased gas voltage programming to more than 70 V from 0.5 to 1 sec. Good shot. Shot 37:Raised final density to 1.8 x 10^20 m^-2 and added more gas voltage programming to more than 80 V. Good shot. Shot 38:Repeat without impurity puffing. Good shot.

Session Leader Comments
Feb 5 1998 08:20:19:860AM		John Goetz	Run Plan for 980205 -- MP #177 Cryopump and Impurities Physics to be done: Investigate impurity transport in discharges with cryopumping. Begin with the cryopump warm and setup a fiducial (no RF) to check pumping rates. A good shot is 980203006 (turn off the RF). Cool down the cryopump and take some more fiducials to measure pumping rates. Put in a density ramp to nl04=1.7e20 @ 1.0sec to get divertor detachment. Puff in krypton and helium-3. Measure impurity screening, compression, and enrichment. Toss in enough baselines to ensure that it can be determined that the cryopump is 'doing something' Add 2MW of RF from 0.5 to 1.2sec to get EDA H-mode. Puff in krypton and helium-3. Measure impurity screening, compression, and enrichment. Warm up the cryopump and repeat the above measurements.
Feb 5 1998 08:45:50:650AM	980205001	John Goetz	Shot 001 - start from 980203006, a fiducial fizzle
Feb 5 1998 08:47:54:160AM	980205002	John Goetz	Shot 002 - start from 980203006, a fiducial fizzle
Feb 5 1998 09:24:18:290AM	980205003	John Goetz	Shot 003 - try again dud
Feb 5 1998 09:37:15:800AM	980205004	John Goetz	Shot 004 - try again plasma - a fiducial baseline for pumping experiment
Feb 5 1998 09:46:24:700AM	980205005	John Goetz	Shot 005 - plasma - a fiducial baseline for pumping experiment
Feb 5 1998 09:52:19:980AM	980205006	John Goetz	Shot 006 - plasma - disrupts @ 0.23sec
Feb 5 1998 10:06:03:330AM	980205007	John Goetz	Shot 007 - plasma - a fiducial Ohmic baseline for pumping experiment
Feb 5 1998 10:24:21:100AM	980205008	John Goetz	Shot 008 - plasma - a fiducial Ohmic baseline for pumping experiment
Feb 5 1998 10:30:36:500AM	980205009	John Goetz	Shot 009 - fizzle
Feb 5 1998 10:44:45:440AM	980205010	John Goetz	Shot 010 - plasma - target density = 1e20 2MW of RF from 0.5 to 1.2s ELMfree H-modes
Feb 5 1998 10:58:50:290AM	980205011	John Goetz	Shot 011 - plasma - target density = 1.2e20 many ELMfree-ELMy H-mode intervals
Feb 5 1998 11:11:49:130AM	980205012	John Goetz	Shot 012 - plasma - target density = 1.3e20 somewhat EDA H-mode confinement changes @ ~0.80sec
Feb 5 1998 11:22:46:100AM	980205013	John Goetz	Shot 013 - plasma - target density = 1.3e20 good EDA H-mode .024Torr-l of Ar puffed
Feb 5 1998 11:39:11:430AM	980205014	John Goetz	Shot 014 - plasma - target density = 1.3e20 'steady-state' ELMy H-mode 20ms of 4PSI Kr puffed throught J-Bottom
Feb 5 1998 11:49:50:960AM	980205015	John Goetz	Shot 015 - plasma - target density = 1.3e20 'steady-state' ELMy H-mode 17ms of 4PSI Kr puffed throught J-Bottom last two shots are pretty good for RF background shots
Feb 5 1998 11:53:05:260AM	980205016	John Goetz	Shot 016 - fizzle
Feb 5 1998 12:12:17:930PM	980205017	John Goetz	Shot 017 - Plasma same 'steady-state' H-mode behavior (ELMy) Kr thru J-Bottom (17msec)
Feb 5 1998 12:18:44:270PM	980205018	John Goetz	Shot 018 - Fizzle
Feb 5 1998 12:36:16:850PM	980205019	John Goetz	Shot 019 - Plasma good match to other Ohmic shots 17msec of 4PSI krypton thru J-Bottom 15msec of 12PSI helium-3 thru B-side-upper
Feb 5 1998 12:50:55:770PM	980205020	John Goetz	Shot 020 - Fizzle
Feb 5 1998 12:50:37:370PM	980205021	John Goetz	Shot 021 - Fizzle
Feb 5 1998 01:01:14:170PM	980205022	John Goetz	Shot 022 - Plasma good match to the other Ohmic shots (pump warm) 15msec of He-3 thru B-side-lower 17msec of Kr thru J-bottom (saturated mass 3 on the RGA)
Feb 5 1998 02:23:11:430PM	980205023	John Goetz	Shot 023 - >1hr wait for cryo cooling Plasma good start for pump cold Ohmic data 15msec of He-3 thru B-side-lower 17msec of Kr thru J-bottom krypton pumps out of plasma faster according to VUV measurements (comparing shots 19 and 23)
Feb 5 1998 02:30:24:710PM	980205024	John Goetz	Shot 024 - Plasma good match for pump cold Ohmic data 15msec of He-3 thru B-side-lower 17msec of Kr thru J-bottom
Feb 5 1998 02:41:29:150PM	980205025	John Goetz	Shot 025 - Plasma good match for pump cold Ohmic data no impurities puffed
Feb 5 1998 02:53:33:640PM	980205026	John Goetz	Shot 026 - Plasma good match for pump cold Ohmic data 30ms of Ar puffed
Feb 5 1998 03:03:28:870PM	980205027	John Goetz	Shot 027 - Plasma ELMfree H-mode, then ratty H-modes after that 30ms of Ar puffed
Feb 5 1998 03:12:21:900PM	980205028	John Goetz	Shot 028 - Plasma sort of EDAish, then ELMfree 30ms of Ar puffed [.03Torr-l]
Feb 5 1998 03:27:28:350PM	980205029	John Goetz	Shot 029 - fizzle
Feb 5 1998 03:40:46:680PM	980205030	John Goetz	Shot 030 - plasma sort of EDAish 30ms of Ar puffed [.03Torr-l]
Feb 5 1998 03:47:31:460PM	980205031	John Goetz	Shot 031 - fizzle
Feb 5 1998 03:57:58:180PM	980205032	John Goetz	Shot 032 - plasma ELMy - ELMfree H-mode 15ms of He-3 and 17ms of Kr
Feb 5 1998 04:05:06:350PM	980205033	John Goetz	Shot 033 - plasma ELMy - ELMfree H-mode 15ms of He-3 and 17ms of Kr eerily reminiscent of 032
Feb 5 1998 04:19:12:240PM	980205034	John Goetz	Shot 034 - plasma EDA H-mode! no impurities baseline for krypton and helium-3
Feb 5 1998 04:34:09:070PM	980205035	John Goetz	Shot 035 - plasma - looks o.k. ramping the density toward Ohmic detachment - not quite there 15ms of He-3 and 17ms of Kr
Feb 5 1998 04:42:52:830PM	980205036	John Goetz	Shot 036 - plasma - looks o.k. ramping the density toward Ohmic detachment - detachment @ 0.87s 15ms of He-3 and 17ms of Kr
Feb 5 1998 04:56:51:020PM	980205037	John Goetz	Shot 037 - plasma - looks o.k. ramping the density toward Ohmic detachment - detachment @ 0.84s 15ms of He-3 and 17ms of Kr VUV Kr signal shows no change at detachment - cryopump is working at holding down the impurity level
Feb 5 1998 05:06:55:280PM	980205038	John Goetz	Shot 038 - plasma - looks o.k. ramping the density toward Ohmic detachment - detachment @ 0.89s no impurities for a baseline

Physics Operator Comments
Feb 5 1998 08:46:14:270AM		Joseph Snipes	MP #177 Cryopump and Impurities Session Leaders: Jim Irby and John Goetz Physics Operator: Joseph Snipes Engineer in Charge: Frank Silva Engineering setup: ECDC in D2 for a few hours in the morning engineering setup from shot 980203007 TF under hybrid control Gas setup - fill K-side with 30 PSI of D2, hybrid enabled fill B-top with 6 PSI of D2, hybrid enabled fill B-side-lower with 2 PSI of Ar, hybrid enabled ECE gate valve enabled; others if diagnosticians are ready.
Feb 5 1998 08:46:29:580AM		Joseph Snipes	Physics to be done: Investigate impurity transport in discharges with cryopumping. Begin with the cryopump warm and setup a fiducial (no RF) to check pumping rates. A good shot is 980203006 (turn off the RF). Cool down the cryopump and take some more fiducials to measure pumping rates. Put in a density ramp to nl04=1.7e20 @ 1.0sec to get divertor detachment. Puff in krypton and helium-3. Measure impurity screening, compression, and enrichment. Toss in enough baselines to ensure that it can be determined that the cryopump is 'doing something' Add 2MW of RF from 0.5 to 1.2sec to get EDA H-mode. Puff in krypton and helium-3. Measure impurity screening, compression, and enrichment. Warm up the cryopump and repeat the above measurements. Guesses for the various gases to be used: 35msec of 2PSI Ar thru B-Side-Lower 20msec of 4PSI Kr thru B-Side-Lower 60msec of 4PSI He-3 thru B-Side-Upper
Feb 5 1998 08:45:42:970AM	980205001	Joseph Snipes	Shot 1: Copy of shot 980203007 without RF. Fizzle.
Feb 5 1998 08:55:19:280AM	980205002	Joseph Snipes	Shot 2: Raised Br by 1 mT to 7 mT. Raised EF4 current from -1345 to -1330 A. Fizzle!
Feb 5 1998 09:10:53:350AM	980205003	Joseph Snipes	Shot 3: Returned EF4 to -1345 A. Increased pre-puff by 4 msec to 20 msec. OH2 and EF2 came on early around -0.07 sec. Hybrid seems to be asking for strange waveforms.
Feb 5 1998 09:36:20:380AM	980205004	Joseph Snipes	Shot 4: Wolfe did some Hybrid test shots and seems to have reset the hybrid to a reasonable state. Try again. Good shot.
Feb 5 1998 09:47:38:620AM	980205005	Joseph Snipes	Shot 5: Copied segment 4 to segment 2 and changed Ar gas puff from 11 msec duration to 35 msec duration. Good shot. Wolfe noticed that the TF was at 5.8 T and that the TF was under PLC control rather than Hybrid control as requested.
Feb 5 1998 09:57:46:870AM	980205006	Joseph Snipes	Shot 6: TF changed to Hybrid control and set at 156 kA which should give about 5.6 T. Disrupted at 0.24 sec.
Feb 5 1998 10:02:22:150AM	980205007	Joseph Snipes	Shot 7: Moved RCUR and CLEARIN out a bit around 200 msec to reduce the inner wall interaction during the current rise. Good shot.
Feb 5 1998 10:15:38:130AM	980205008	Joseph Snipes	Shot 8: Reduced TF current to 154 kA to get 5.6 T. Modified current rise ZXL and ZXU to try to elongate the plasma a bit more early to avoid the current rise locked mode that was coming in at 0.1 sec. Good shot.
Feb 5 1998 10:38:47:410AM	980205009	Joseph Snipes	Shot 9: Increased K side gas volatage programming between 0.5 and 1 sec to 50 V. Increased Ip gain during the current rise to get the requested rate of rise of the current. Phys A out had 150 kA more current at 0.08 sec. Fizzle!
Feb 5 1998 10:43:59:400AM	980205010	Joseph Snipes	Shot 10:Increased Br offset to 6.5 mT. Increased EF4 current to -1330 A. Reduced pre-puff to 17 msec duration. Good shot. RF at 1.8 - 2 MW. ELM-free and ELMy H-modes. Current rise looks better too.
Feb 5 1998 10:58:21:930AM	980205011	Joseph Snipes	Shot 11:Moved RXL in by 1 mm from 0.006 to 0.005 and increased nl04 to 1.2 x 10^20 m^-2 to try to obtain EDA H-mode. Nearly steady alternating ELM-free and Type III ELMy H-mode from 0.53 - 1.22 sec.
Feb 5 1998 11:14:55:140AM	980205012	Joseph Snipes	Shot 12:Increased K-side gas voltage programming to 60 V from 0.45 to 1 sec. Increased requested nl04 to 1.4 x 10^20 m^-2. Mild EDA H-mode.
Feb 5 1998 11:30:54:790AM	980205013	Joseph Snipes	Shot 13:Try reducing Ar puff to 30 msec duration. Good shot. Very steady EDA H-mode.
Feb 5 1998 11:31:21:640AM	980205014	Joseph Snipes	Shot 14:Put 4 psi of Kr into J bottom and enabled it with 20 msec from 0.3 sec on pulse gas 5. Disabled B side lower Ar puff. Steady state ELMy.
Feb 5 1998 11:41:46:620AM	980205015	Joseph Snipes	Shot 15:Wolfe suggested an early gas puff to avoid the Moly injection at 0.14 sec. So, I added a bit of early gas programming. Reduced Kr puff to 17 msec duration. Good shot. Steady state ELMy.
Feb 5 1998 12:13:14:130PM	980205016	Joseph Snipes	Shot 16:Repeat. Fizzle!
Feb 5 1998 12:13:43:370PM	980205017	Joseph Snipes	Shot 17:Try reducing pre-puff to 15 msec. Good shot. Steady state ELMy.
Feb 5 1998 12:14:31:870PM	980205018	Joseph Snipes	Shot 18:Repeat. Fizzle!
Feb 5 1998 12:27:06:430PM	980205019	Joseph Snipes	Shot 19:Reloaded segment 2 from shot 8 then set up Kr puff with 17 msec duration at 0.3 sec. Added He3 puff at 0.3 sec for 15 msec. Turned off RF for L-mode shot. Good shot.
Feb 5 1998 12:41:35:210PM	980205020	Joseph Snipes	Shot 20:Added early gas voltage programming to remove the Moly injection again. Fizzle!
Feb 5 1998 12:55:45:540PM	980205021	Joseph Snipes	Shot 21:Increased EF4 current to -1315 A. Fizzle!
Feb 5 1998 12:56:20:580PM	980205022	Joseph Snipes	Shot 22:Reduced EF4 current to -1345 A. Good shot.
Feb 5 1998 02:21:28:710PM	980205023	Joseph Snipes	Shot 23:Restart after delay to cool down the cryopump. Good shot. There appears to be some pumping.
Feb 5 1998 02:30:01:590PM	980205024	Joseph Snipes	Shot 24:Repeat to check reproducibility. Good shot.
Feb 5 1998 02:44:28:830PM	980205025	Joseph Snipes	Shot 25:Disabled B-side upper (He3) and J bottom (Kr) and re-enabled B side lower (Ar). Set Ar puff to 30 msec duration starting at 0.3 sec. Good shot. Ar was not enabled.
Feb 5 1998 02:49:54:770PM	980205026	Joseph Snipes	Shot 26:Repeat with Ar enabled. Good shot.
Feb 5 1998 03:06:39:250PM	980205027	Joseph Snipes	Shot 27:Turn on RF and repeat. ELM-free and ELMy H-modes.
Feb 5 1998 03:13:47:740PM	980205028	Joseph Snipes	Shot 28:Reload segment 2 of shot 17 to try to return to a more constant H-mode. EDA-like H-mode with Type III ELMs in short bursts.
Feb 5 1998 03:40:17:450PM	980205029	Joseph Snipes	Shot 29:Repeat. Fizzle!
Feb 5 1998 03:40:38:250PM	980205030	Joseph Snipes	Shot 30:Reduced pre-puff to 15 msec duration. EDA-like H-mode with Type III ELMs in short bursts.
Feb 5 1998 03:46:42:870PM	980205031	Joseph Snipes	Shot 31:Disabled B side lower (D) and enabled B side upper (Kr) and J bottom (He3). Fizzle!
Feb 5 1998 03:53:43:660PM	980205032	Joseph Snipes	Shot 32:Try again. Good shot. Nearly constant Type III ELMy H-mode with short ELM-free phases interspersed.
Feb 5 1998 04:04:00:250PM	980205033	Joseph Snipes	Shot 33:Good shot. Similar to 32.
Feb 5 1998 04:17:45:980PM	980205034	Joseph Snipes	Shot 34:Lower Br offset to 5.5 mT. Good shot. Nice steady EDA H-mode without impurities.
Feb 5 1998 04:44:35:470PM	980205035	Joseph Snipes	Shot 35:Requested nl04 to ramp from 1 to 1.7 x 10^20 m^-2 from 0.4 to 1.1 sec. Added more gas voltage programming up to 60 V from 0.5 to 1 sec. Good shot. RF turned off.
Feb 5 1998 04:45:22:760PM	980205036	Joseph Snipes	Shot 36:Increased gas voltage programming to more than 70 V from 0.5 to 1 sec. Good shot.
Feb 5 1998 04:58:57:670PM	980205037	Joseph Snipes	Shot 37:Raised final density to 1.8 x 10^20 m^-2 and added more gas voltage programming to more than 80 V. Good shot.
Feb 5 1998 05:03:55:480PM	980205038	Joseph Snipes	Shot 38:Repeat without impurity puffing. Good shot.
Feb 5 1998 05:04:22:780PM	980205038	Joseph Snipes	It was a reasonably successful run. The machine ran very well except for a number of fizzles with the vertical and/or radial fields changing shot to shot. There was also more than an hour delay to cool down the cryopump in the middle of the run. The cryopump definitely pumps but the results need to be quantified. The latter part of the run was dedicated to ohmic detachment studies with and without impurity puffing.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:34:51:370AM	Plasma	Ok	no faults/no plasma
2	08:45:40:050AM	Plasma	Ok	no faults
3	08:55:39:390AM	Plasma	Ok	no faults
4	09:27:15:650AM	Plasma	Ok	no faults/plasma
5	09:38:26:910AM	Plasma	Ok	no faults/plasma/ tf was not in hybrid control for shots 1 thru 5
6	09:49:07:720AM	Plasma	Ok	no faults/plasma/tf under hybrid control
7	09:58:37:330AM	Plasma	Ok	no faults/plasma
8	10:13:48:980AM	Plasma	Ok	no faults/plasma
9	10:27:20:260AM	Plasma	Ok	no faults/plasma
10	10:36:47:430AM	Plasma	Ok	no faults/plasma
11	10:48:55:950AM	Plasma	Ok	no faults/plasma
12	11:04:42:510AM	Plasma	Ok	no faults/plasma
13	11:14:26:690AM	Plasma	Ok	no faults/plasma
14	11:25:17:250AM	Plasma	Ok	no faults/plasma
15	11:38:40:610AM	Plasma	Ok	no faults/plasma
16	11:50:22:720AM	Plasma	Ok	no faults
17	11:59:27:360AM	Plasma	Ok	no faults/plasma
18	12:12:50:880PM	Plasma	Ok	no faults
19	12:25:11:080PM	Plasma	Ok	no faults
20	12:35:15:010PM	Plasma	Ok	no faults
21	12:44:31:870PM	Plasma	Ok	no faults
22	12:53:59:600PM	Plasma	Ok	no faults
23	02:11:39:940PM	Plasma	Ok
24	02:21:51:160PM	Plasma	Ok
25	02:33:00:490PM	Plasma	Ok
26	02:45:17:260PM	Plasma	Ok
27	02:55:42:310PM	Plasma	Ok
28	03:06:12:700PM	Plasma	Ok
29	03:23:08:950PM	Plasma	Ok
30	03:31:12:280PM	Plasma	Ok
31	03:41:16:430PM	Plasma	Ok
32	03:49:01:550PM	Plasma	Ok
33	03:59:25:120PM	Plasma	Ok
34	04:12:58:410PM	Plasma	Ok
35	04:26:38:450PM	Plasma	Ok
36	04:37:10:860PM	Plasma	Ok
37	04:48:05:220PM	Plasma	Ok
38	05:00:15:550PM	Plasma	Ok