Miniproposals

Miniproposal: 355 Date Filed: 11/12/2003 Title: ICRF Testing & Conditioning First Author: Steve Wukitch Session Leader: Yijun Lin (shots 1-30)

Engineering Operator Run Comment

Condition the antennas and work towards reducing H/D; PO: Wukitch, SL: L

Session Leader Plans

Physics Operators Plans

Entered: May 9 2012 04:32:49:103PM

Author: Steve Wukitch

----------------- Engineering Setup ----------------- Run begins at 09:00 and ends at 17:00 Power systems as on: 1120509025 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 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) fill NINJA with 10 psi D2 DISABLED Enable gate-valves and shutters: ECE, VUV, HiREX Sr, Xeus/LoWEUS Leave z-bolo shutter as is (should be open) Torvac gatevalve toggle (yes/no): no Boronization(yes/no): no Overnight ECDC (yes/no): yes ICRF(yes/no): yes LH(yes/no): no Cryopump (yes/no): no DNB (yes/no): not needed Vessel temperature: 35/35/35 ------------------------------ ECDC Parameters ------------------------------ gas and pressure: D2 at 2e-4 Torr sweep: 44/45/103 cm scan: 20/120 s ------------------------------ Run plan: Condition the antennas and work towards reducing H/D. Start with 1120509025 and bring antennas up to ~1 MW/transmitter.

Session Leader Summaries

Entered: May 10 2012 05:00:30:830PM

Author: Yijun Lin

J antenns was broken after reaching power of 2.4 MW (shot 10) The damage is likely on J3 transmission line. We will have to open the transmission to repair it. Then we ran D+E at about 1.6 MW total to clearn up the machine (to remove H). D/E are able to run 1.5 MW separately. Because of the low absorption at high H/D level, overlapping them at high power incured some operational challenge, e.g., 'talking' to each other in the control system and arc protection system.

Physics Operator Summaries

Entered: May 10 2012 05:03:42:487PM

Author: Steve Wukitch

Plasma breakdown was reasonable throughout the day although we had runaways in 002-005,019,024,030 and 029 was a aborted runaway plasma. The H/H+D started at ~10% and rose to greater than 30% by the end of the day. At the end of the day, we had 3 USN discharges. The first ran well but hard x-rays increased on the next few discharges. The FA-J antenna reached 2.5 MW before a persistent arc prevented further operation.

Session Leader Comments

Physics Operator Comments
May 10 2012 09:09:49:690AM	1120510001	Steve Wukitch	001 reload using 1120509032 startup in seg 1 use seg 2 from 1120509025 Load at 9-May-2012 18:19:17.00 result: plasma into rampdown next: lower BT to 5.2 T reduce TF current from 150 kA to 142 kA Load at 10-May-2012 09:08:27.00
May 10 2012 09:22:32:137AM	1120510002	Steve Wukitch	002 demand: repeat with lower BT~5.2 T I_TF=142 kA result: plasma few hards at startup BT~5.18 T next: raise I_TF=142.5 kA enable Ar (B-side lower)
May 10 2012 09:40:06:580AM	1120510003	Steve Wukitch	003 demand: repeat with I_TF raised to 142.5 kA result: plasma into rampdown still have hards next: raise pg3 prepuff at -0.001 s to 70 V from 60 V Load at 10-May-2012 09:32:28.00
May 10 2012 10:08:31:680AM	1120510004	Steve Wukitch	004 demand: repeat with bit more pre-puff result: plasma into rampdown BT is ~5.3 T ?! next: set I_TF to 142.5 kA instead of 145 kA - need to learn to type Load at 10-May-2012 09:52:16.00
May 10 2012 10:17:56:720AM	1120510005	Steve Wukitch	005 demand: repeat result: plasma into rampdown but hards came back BT is ~5.2 next: raise pg3 to 80 V at -0.001 s and 70 V at 0.008 Load at 10-May-2012 10:15:16.00
May 10 2012 10:23:16:513AM	1120510006	Steve Wukitch	006 demand: repeat with more pre-puff from pg3 result: plasma - no hards this time next: raise Ip to 0.9 MA Load at 10-May-2012 10:22:55.00
May 10 2012 10:47:25:477AM	1120510007	Steve Wukitch	007 demand: raise Ip to 0.9 MA result: plasma - no hards - distuption - vertically unstable strike point went higher on the vertical plate next: reduce Ip to 800 kA Load at 10-May-2012 10:45:37.00
May 10 2012 11:06:56:153AM	1120510008	Steve Wukitch	008 demand: lower Ip to 0.8 MA result: plasma - no hards - disruption - vertically unstable late strike point went higher on the vertical plate next: move ZXL down 1.5 cm from 0.5-1.5 s (from -0.01 to -0.025 and -0.02 to -0.03) Load at 10-May-2012 11:05:10.00
May 10 2012 11:22:13:733AM	1120510009	Steve Wukitch	009 demand: move ZXL down 1.5 cm result: plasma - no hards - no disruption - n/n_crit stays low but it is high early next: change ZXL at 0.5 s to -0.0125 Load at 10-May-2012 11:21:06.00
May 10 2012 11:51:54:353AM	1120510010	Steve Wukitch	010 demand: move ZXL at 0.5 s result: plasma - n/n_crit looks better early but not as good late next: ramp ZXL earlier - add point at 1 s set to -0.03 Load at 10-May-2012 11:31:40.00
May 10 2012 12:01:49:377PM	1120510011	Steve Wukitch	011 demand: ramp ZXL earlier - add point at 1 s set to -0.03 result: plasma - n/n_crit looks good density ramp despite little RF next: repeat
May 10 2012 12:25:25:857PM	1120510012	Steve Wukitch	012 demand: repeat result: plasma density ramp despite little RF next: repeat
May 10 2012 12:31:20:800PM	1120510013	Steve Wukitch	013 demand: repeat result: plasma elongation is getting a bit high next: ZXL up and ZXU up, ZCUR ramp to avoid plasma from floating up Load at 10-May-2012 12:30:55.00
May 10 2012 12:45:20:267PM	1120510014	Steve Wukitch	014 demand: lower elongation - raise ZXL(1.5 cm) and ZXU (1.2 cm), ramp ZCUR (-0.5 cm) to prevent plasma from rising during discharge result: plasma elongation down to 1.6 n/n_crit below 1 Zmag stays flatter next: raise Ip to 0.9 MA Load at 10-May-2012 12:44:48.00
May 10 2012 01:01:21:470PM	1120510015	Steve Wukitch	015 demand: Ip to 0.9 MA result: plasma next: raise Ip to 1.0 MA Load at 10-May-2012 13:00:12.00
May 10 2012 01:16:14:727PM	1120510016	Steve Wukitch	016 demand: Ip to 1 MA result: plasma into rampdown next: repeat
May 10 2012 02:11:09:330PM	1120510017	Steve Wukitch	017 demand: repeat result: plasma into rampdown next: repeat
May 10 2012 02:13:15:190PM	1120510018	Steve Wukitch	018 demand: repeat result: plasma into rampdown next: repeat
May 10 2012 02:19:53:830PM	1120510019	Steve Wukitch	019 demand: repeat result: plasma into rampdown hard x-rays came back next: tweak pg3 again Load at 10-May-2012 14:19:30.00
May 10 2012 02:50:22:820PM	1120510021	Steve Wukitch	fizzle
May 10 2012 03:16:56:320PM	1120510022	Steve Wukitch	next: looks like dirt about 10 ms after breakdown stopped the current rise 022 demand: repeat with plasma hopefully result: plasma into rampdown no hard x-rays next: repeat
May 10 2012 03:31:59:547PM	1120510023	Steve Wukitch	023 demand: repeat result: plasma into rampdown H/H+D is reaching 35% next: repeat
May 10 2012 03:46:17:947PM	1120510024	Steve Wukitch	024 demand: repeat result: plasma into rampdown hards are back next repeat without hards I hope
May 10 2012 03:58:58:097PM	1120510025	Steve Wukitch	025 demand: repeat result: plasma into rampdown but disrupted at ~1.6 s hards went away next: switch to USN, 5.4 T, 0.8 MA enable seg4, disabled seg2 Load at 10-May-2012 15:58:20.00
May 10 2012 04:01:57:467PM	1120510026	Steve Wukitch	fizzle
May 10 2012 04:12:35:780PM	1120510026	Steve Wukitch	026 demand: repeat result: fizzle breakdown initiates well CII indicates (Z meter does not) snow flake about ~5 ms later current quenches next: retry with plasma
May 10 2012 04:30:10:700PM	1120510027	Steve Wukitch	027 demand: USN result: plasma into rampdown inner strike point is in the corner after 1 sec next: repeat
May 10 2012 04:54:14:777PM	1120510029	Steve Wukitch	029 demand: repeat USN with RXU ramped by 2 cm after 1 s result: ugly - runaway abort next: repeat sans runaways
May 14 2012 09:55:29:380AM	1120510030	Yijun Lin	there is a delay due to alternator problem.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:56:35:500AM	Plasma	Ok
2	09:09:46:640AM	Plasma	Ok
3	09:27:13:700AM	Plasma	Ok
4	09:45:25:897AM	Plasma	Ok
5	09:58:37:050AM	Plasma	Ok
6	10:16:42:917AM	Plasma	Ok
7	10:30:02:050AM	Plasma	Ok
8	10:48:21:530AM	Plasma	Ok
9	11:09:00:860AM	Plasma	Ok
10	11:24:00:717AM	Plasma	Ok
11	11:47:55:813AM	Plasma	Ok
12	12:02:49:217PM	Plasma	Ok
13	12:17:44:750PM	Plasma	Ok
14	12:32:10:280PM	Plasma	Ok
15	12:48:00:287PM	Plasma	Ok
16	01:08:02:123PM	Plasma	Ok
17	01:28:58:803PM	Plasma	Ok
18	01:56:48:160PM	Plasma	Ok
19	02:11:16:673PM	Plasma	Ok
20	02:25:38:040PM	Plasma	Ok
21	02:40:12:103PM	Plasma	Ok
22	02:55:49:087PM	Plasma	Ok
23	03:10:22:527PM	Plasma	Ok
24	03:27:25:797PM	Plasma	Ok
25	03:40:49:927PM	Plasma	Ok
26	03:59:10:233PM	Plasma	Ok
27	04:12:18:880PM	Plasma	Ok
28	04:25:48:947PM	Plasma	Ok
29	04:40:18:447PM	Plasma	Ok
30	04:53:28:533PM	Plasma	Ok

System Availability

May 10 2012 08:56:15:810AM

System Available Comment Availability Changed Owner Description Who Can Change Active MHD no secured - tagged out Jun 2 2008 11:03:58:433AM (sears) Joe Snipes Active MHD Antenna golfit BES yes BES system is online Nov 22 2011 02:21:12:050PM (bespam) Bill Rowan Beam Emission Spectroscopy bespam,liao,rowan Bolometers yes Midplane diodes functioning properly. Midplane bolometers working and calibrated. DIV bolometers installed but not yet toaster calibrated Apr 20 2012 09:57:29:520AM (mlreinke) Matt Reinke Bolometers hutch,mlreinke Boronization no Bottle has been disconnected from gas lines and plugged. It is being stored in the diborane cabinet. Feb 29 2012 07:47:39:617AM (dekow) Jim Irby Boronization dekow,irby CECE no   Jan 6 2012 03:48:47:060PM  Anne White Correlation ECE whitea CNPA yes Multiple channel CNPA available, no safety risk for in-vessel access Apr 14 2011 12:01:59:693PM (parker) Ron Parker Compact Neutral Analyzer parker Cryopump - Upper Divertor no Off line. Helium dewar to be installed Monday 5/14/12 May 10 2012 08:45:54:900AM (labombard) Brian LaBombard Upper Divertor Cryopump dekow,irby,labombard CXRS yes core-CXRS system is online Nov 22 2011 02:21:22:280PM (bespam) Bill Rowan Charge Exchange Spectroscopy bespam,blip,liao,rachmcd,rowan CXRS edge yes Michael CHurchill has primary responsibility at the moment Apr 19 2011 11:44:46:247AM (blip) Bruce Lipshultz Measurement of CXR light in the pedestal region at both the high- and low-field sides blip,rmchurch D Alpha yes \ha2_bright is available; \SPECTROSCOPY::TOP.VUV.VIS_SIGNALS:MCP_VIS_SIG1 is not available Jul 1 2009 09:45:41:090AM (terry) Jim Terry Balmer Alpha Monitor irby,terry,wolfe Dalsa no system is is installed and aligned, but not functional (appears to be a broken cable) Dec 5 2011 02:41:42:867PM (marmar) Earl Marmar Visible Bremsstrahlung Imaging marmar Disruption Mitigation no gas jet valve disabled on 2012/02/29 Feb 29 2012 08:39:50:010AM (granetz) Robert Granetz Gas Jet granetz,whyte Divertor IR no   Mar 6 2007 10:50:41:677AM  Glen Wurden Divertor IR Digital Video gwurden,terry Divertor IR Spectroscopy no   Mar 6 2007 10:51:39:897AM  Glen Wurden Divertor IR Spectroscopy gwurden,terry DMBolo AXUV diodes yes Diodes are taking usable data. Not all post-processing code is working yet. Feb 1 2012 01:24:23:953PM (golynyk) Geoff Olynyk Set of six AXUV diodes in a toroidal array of midplane wall boxes. golynyk,granetz,mlreinke,whyte DNB no   Feb 29 2012 08:40:05:587AM (granetz) Robert Granetz Diagnostic Neutral Beam dterry,granetz,mochung ECDC yes   Apr 26 2012 03:23:19:057PM (dekow) Jim Irby 2.45 GHz, 3 kW, discharge cleaning system dekow,irby,pfeiffer FRC-ECE no Power off to RF and IF sections- Power on to DA Apr 11 2011 02:54:49:870PM (phillips) Perry Phillips Heterodyne ECE-32 channels bespam,liao,phillips,rowan,whitea FTCI no   Jan 6 2012 04:36:18:507PM  Jim Irby Fast two-color interferometer irby G-Side Ratiomatic yes Installed April 25,2012 May 1 2012 05:03:39:313PM (toland) Brian LaBombard G-side ratiomatic ionization gauge labombard,toland Glow Discharge no HV cables disconnected and power supplies off. Electrical plugs have been disconnected, capped and red tagged. Mar 5 2012 10:21:53:460AM (dekow) Jim Irby 1 kV, 5 A, glow discharge system dekow,dterry,irby GPC yes Operational Apr 27 2012 07:41:46:907AM (hubbard) Amanda Hubbard ECE Polychromater hubbard GPC2 yes Operational Apr 27 2012 07:42:03:317AM (hubbard) Amanda Hubbard ECE Polychromater hubbard GPI yes The Xpt-view, the midplane-view cameras are operational. The innerwall GPI (coupled to the fast-diodes) is available. Jul 1 2009 09:45:50:933AM (terry) Jim Terry Gas Puff Imaging terry,zweben H/D yes system is functional and taking data Dec 5 2011 02:42:29:857PM (marmar) Earl Marmar H/D Ratio marmar HEAT yes   Apr 26 2012 03:23:49:607PM (dekow) Gary Dekow - Machine Heaters - burke,dekow Hirex Jr yes Hirex-Jr has been installed Jun 28 2010 03:36:33:420PM (rice) John Rice High Resolution X-Ray ince,rice Hirex Sr yes Installed and aligned. Will be available for Ti/Vr profiles after focusing tests and locked modes are taken. Dec 6 2011 08:21:02:453AM (ypodpaly) John Rice High Resolution X-Ray cgao,ldelgado,rice,ypodpaly HXR yes 32 Channels operational,, no safety risk for in-vessel access Apr 14 2011 12:05:24:810PM (parker) Ron Parker Hard X-Ray Array faust,parker,schmidt ICRF D-Antenna yes conditioning May 1 2012 10:31:59:277AM (wukitch) Steve Wukitch D-port antenna wukitch,ylin ICRF E-Antenna yes conditioning May 1 2012 10:31:48:860AM (wukitch) Steve Wukitch E-port antenna wukitch,ylin ICRF J-Antenna no secured Feb 29 2012 11:12:32:567AM (wukitch) Steve Wukitch J-port antenna wukitch,ylin Impurity Spectroscopy yes Being upgraded with better optics and new spectrographs. Dan Miller has primary responsibility. Apr 19 2011 11:46:02:193AM (blip) Bruce Lipshultz Measurement of recycling light and impurity source rates at multiple surfaces around the tokamak blip,miller Laser Blow-Off yes Operational and tested Jan 6 2012 03:50:40:790PM (g) Martin Greenwald Impurity Injection System g,nthoward Lower Hybrid no LH is now safe for manned entry into machine. Positioner locked and tagged off. Switches locked in dummy load position. Mar 2 2012 02:34:28:943PM (dterry) Ron Parker Lower Hybrid dterry,parker,wallaceg Lower Hybrid Reflectometer no off Apr 15 2011 08:24:27:930AM (dominguez) Arturo Dominguez Lower Hybrid Reflectometer dominguez,marmar,parker,sgbaek LoWEUS yes LoWEUS viewing the 10-30 nm region, spectral brightness vs. lambda and time are being stored in tree. Apr 20 2012 10:43:34:077AM (mlreinke) Matthew L. Reinke Long Wavelength Extreme Ultraviolet Spectrometer markchil,mlreinke LPI no Beam line removed May 30 2008 02:09:12:833PM (bose) Earl Marmar Lithium Pellet Injector bose,marmar Ly-alpha yes Midplane Lyman-a. New B-PORT Lyman (BPLY) still being debugged. Apr 20 2012 10:44:00:540AM (mlreinke) Matt Reinke Lyman alpha cameras faustian,labombard,mlreinke Magnetics yes   Dec 1 2011 11:51:51:970AM (g) Robert Granetz Bp coils and flux loops for equilibrium control granetz,wolfe McPherson no McPherson viewing the 10-14 nm region for molybdenum monitoring. It's days are numbered as LoWEUS has demonstrated superiority. Apr 20 2012 10:44:10:937AM (mlreinke) Jim Terry VUV Spectrometer markchil,mlreinke,terry Michelson yes Vacuum 3-4e-8 T. Starting with Michelson at reduced speed. Apr 27 2012 07:42:41:960AM (hubbard) Amanda Hubbard ECE Te Profiles hubbard,schmidt MKS yes   Dec 2 2011 12:27:47:163PM (toland) Brian LaBombard Baratron pressure gauges labombard,toland MLP yes Operational. Connected to A-port probe system May 10 2012 08:40:19:910AM (labombard) Brian LaBombard Mirror Langmuir Probe Electronics System labombard MSE yes 2/29/2012 MSE operational. No HV or vacuum safety issues Feb 29 2012 12:26:13:863PM (sscott) Steve Scott Motional Stark Effect jinseok,sscott Neutrons yes Voltage is on for He3 detectors on J port. Remaining voltages will be turned on for the first run. Apr 23 2012 09:31:22:063AM (fiore) Catherine Fiore Neutron Detectors fiore Neuts and Hards yes All detectors Powered On --- Waiting for neutrons for calibration Nov 22 2011 01:05:24:380PM (irby) Jim Irby X-Ray/Neutron Detectors at K-Hor irby NINJA yes C-bottom and new F-bottom system ready. Dec 2 2011 12:28:44:843PM (toland) Brian LaBombard NINJA gas puff labombard,terry,toland PCI yes Operational. May 1 2012 08:31:33:743AM (ntsujii) Miklos Porkolab Phase Contrast Imaging emd,ennever,ntsujii,porkolab Penning Gauges yes HV power supplies turned ON in INIT, off in RECOOL May 10 2012 08:41:03:000AM (labombard) Brian LaBombard Penning Ionization Gauges labombard Plasma TV yes WIDE1, WIDE2 (chan 33), DANT, JANT and DIV are operational. Jul 1 2009 09:46:29:543AM (terry) Jim Terry Video of plasma via several cameras dekow,irby,terry,wolfe Polarimeter yes 3 chords operational but with high noise level Jan 6 2012 04:22:20:903PM (irby) Jim Irby C-Mod Polarimeter irby Power - Alternator Air Switch yes   Apr 26 2012 03:24:21:607PM (dekow) Gary Dekow Alternator to Power Room Power Supply Connection cochran,dekow,dterry,irby Power - PEI yes   Apr 26 2012 03:24:41:250PM (dekow) Gary Dekow PEI System cochran,dekow,dterry,irby Power - TMX yes   Apr 26 2012 03:24:57:153PM (dekow) Gary Dekow Ef2s,. EFCs and A-Coils byford,cochran,dekow,dterry,irby Power Systems yes   Apr 26 2012 03:25:14:497PM (dekow) Jim Irby C-Mod Magnet Supplies byford,cochran,dekow,dterry,irby Probe Array - ISD yes Operational. Some dead probes. May 10 2012 08:41:58:120AM (labombard) Brian Labombard Inner Lower Divertor Probe Array labombard Probe Array - LH yes Operational. 4 out of 6 probes working. May 10 2012 08:41:40:557AM (labombard) Brian LaBombard Lower Hybrid Probe Array labombard Probe Array - OSD yes Operational. May 10 2012 08:42:13:733AM (labombard) Brian LaBombard Outer Lower Divertor Probe Array (F and J) labombard Probe Array - UDIV yes Operational. Some dead probes. May 10 2012 08:42:32:663AM (labombard) Brian LaBombard Upper Divertor Probe Array labombard Reflectometer yes As of 1120508, the 60, 75, 88s, 112, 140 and variable are connected and turned on. May 8 2012 10:33:21:567AM (dominguez) Earl Marmar Reflectometer dominguez,marmar Scanning Probe - ASP yes Operational. A variety of probe heads are ready for use. May 10 2012 08:43:10:937AM (labombard) Brian LaBombard A-Port Scanning Probe labombard Scanning Probe - FSP yes Operational. May 10 2012 08:43:24:887AM (labombard) Brian LaBombard F-Port Scanning Probe labombard Scanning Probe - WASP no Not functioning. Probe tips are melted. Repair not performed during break. May 10 2012 08:44:43:137AM (labombard) Brian LaBombard Inner Wall Scanning Probe labombard,nsmick Shoelace Antenna yes Operational May 10 2012 08:45:08:320AM (labombard) Brian LaBombard High-k active MHD antenna, for QCM, WCM studies golfit,labombard SOL reflectometer yes c-port (top, middle, bottom) and h-port available. Only 1 of 4 locations can be used for each discharge May 1 2012 04:54:58:820PM (cornwall) Cornwall Lau SOL reflectometer cornwall,wukitch,ylin Sparker yes Sparker Power Supply powered up. Connected at K port using red cable 4/23/12 9:25AM Apr 23 2012 12:06:10:983PM (parkin) Jim Irby Field Emission Preionization for C-Mod dekow,irby,parkin Surface Science Station no SSS is up to air, no safety issues. Feb 27 2012 01:51:48:783PM (ochoukov) Bruce Lipschultz Radially scanning probe located on K-port blip,ochoukov TCI no TCI lasers in operation. Observe warning signals. Apr 18 2012 02:55:47:760PM (murray) Jim Irby Two-Color Interferometer irby,murray TS - Core yes Operating with one 50Hz laser, precise density calibration still required. May 9 2012 03:12:32:050PM (jwhughes) Jerry Hughes Core Thomson scattering jrwalk,jwhughes,yma TS - Edge yes Operating with one 50Hz laser, precise density calibration still required. May 9 2012 03:12:51:363PM (jwhughes) Jerry Hughes Millimeter resolution edge Thomson scattering jrwalk,jwhughes,yma Vispec no 350 and 670 nm, 4 spatial channels Nov 28 2007 09:58:35:493AM (agraf) Alex Graf Visible Spectrometer agraf XEUS yes XEUS viewing the 1-6 nm region, spectral brightness vs. lambda and time are being stored in tree. Apr 20 2012 10:43:43:107AM (mlreinke) Matt Reinke X-ray Extended Ultraviolet Spectrometer markchil,mlreinke XTOMO yes ARRAY1->5 available. Specific channels on various arrays display issues. Apr 20 2012 05:36:28:523PM (faustian) Robert Granetz X-Ray Tomography faustian,granetz,mlreinke

May 10 2012 10:40:21:817AM

Until this shot, MSE was set up for 5.4 Tesla, 50 keV. But the TF waveforms were being varied from about 5.4 to 5.0 Tesla. Going forward, the PO assured me that the TF will remain at 5.2 Tesla, so I have instructed the panel to fix the filters for 5.2 Tesla, 50 keV operation. I verified that the APDs were correctly set at 1750 volts on this shot. Not sure whether or not the PEMs had been turned on, but since I didn't turn them off yesterday, I assume the PEMs were on for all shots today.