Time: 2021 Oct 22 23:50:47
Found 2665 logbook entries, displaying most recent 100
Logbook Contents (Most Recent Entries)
18 Oct 2021 Monday 16:11 [Leblanc] Testing stripper foils using Alphas at 2.2 MeV. LE current approx 600 nA. HE currents as follows: Foil 56 approx 100nA. Foil 57 approx 420nA. Foil 58 approx 40nA. Foil 59 approx 50nA. Foil 60 approx 420nA. Foil 61 approx 380nA. Foil 62 approx 50nA. Foil 63 approx 55nA. Foil 64 aprox 55nA. Foil 65 approx 60nA. Foil 66 aprox 70nA. Foil 77 approx 550nA. Careful tuning may produce better results. Left stripper on position 57.
18 Oct 2021 Monday 15:14 [carter] The phase A,B,C logged voltages are derived from the main power disconnect of the analyzing magnet. When this breaker is off, phase voltages A,B and C are recorded as zero.
14 Oct 2021 Thursday 11:28 [Leblanc] LE Extension ion gauge failed. Will requre venting to atmosphere, regenerating cryopump, roughing and restarting high vacuum pumping. Machine will not be operational again today.
12 Oct 2021 Tuesday 20:53 [leblanc] Added 3 liters of water to the sputter source loop, and the alarm cleared. Perhaps the leak is not yet fixed.
12 Oct 2021 Tuesday 08:43 [Ingram] Source cooling water low alarm going off, acknowledged but still red. No obvious reason for the alarm. Water level looks okay. Will wait for Greg.
11 Oct 2021 Monday 13:40 [Leblanc, Carter, Massey] Quarterly Safety Checks DRD: 3.46 mRem
08 Oct 2021 Friday 17:03 [Ingram] 15L beamline pump not working. HV valve closed. Diff pump and baffle turned off. Backing pressure >200mTorr according to guage.
17 Sep 2021 Friday 08:27 [Tom Massey] The low water alarm for the source has sounded. I am shutting down the source to check the problem.
16 Sep 2021 Thursday 09:45 [Tom Massey] The loss of beam and the poor pulsing and bunching seen was due to a change in the source. The inflection magnet value and changed slighly causing a factor of 2 loss in beam. This was retuned to give back 13 microamps DC in the LE cup. The run was able to continue after retunin and redoing pulsing and bunching.
15 Sep 2021 Wednesday 07:56 [Justin Warren] At approximately 5:30 AM 09/15/21, beam current for the LLLNL experiment went from ~85 nA -> 30 nA and became unstable. Data collection stopped at 5:50 AM. Current remained unstable until accelerator shutdown. At ~5:20, sputter target current 5 mA -> 8 mA, then 8 mA -> 4 mA around 5:30.
30 Aug 2021 Monday 13:21 [Leblanc] Added 1 gallon of water to the sputter source cooling loop this morning. Need to try to find the tiny leak.
29 Aug 2021 Sunday 20:28 [alarm: source cool water low] Got to lab around 8 pm to fill HPGe detectors and "source cooling water low" alarm on E1 panel was going off. Hit awk and the alarm did not repeat. Book says to contact staff for adding water to the loop. -KB
26 Aug 2021 Thursday 12:11 [Tom Massey] Analyzing Magnet is having control problems. The current jumps slightly ~31.02 to 31.04 in NMR. This has been seen recently and should go away as the regulation electronics warm up. We have recycled tha magnet after the last jump in current. We are still seeing the current jumps. We will wait for this system to warm up.
26 Aug 2021 Thursday 07:28 [Gula Hamad] This morning when I came in the source water cooling alarm was on. I silenced the audible alarm and sent a message to Greg about the alarm. Thanks
19 Aug 2021 Thursday 10:35 [Tom Massey] We have 30 mR in the Source Radiation Monitor. This is with 7 MeV deuterons and a Be target. This 2.5 MeV deuterons can make neutrons and gammas. This may not be a problem with the LE tube .
18 Aug 2021 Wednesday 09:02 [Leblanc] Refreshed Cesium after outage last week. Beam came back to > 20uA at LE. New looser tent seems to work well, reduced temperature to 130 C and maintained good beam.
17 Aug 2021 Tuesday 15:04 [Carter] Checked over the buncher 2.5KV 150mA power supply. Removed the 4uF 3KV filter capacitor and replaced it with an 8uF 2KV unit in an attempt to reduce any ripple on the buncher plate supply hoping to reduce pulsed beam tails. Placed a reminder label not to operate the plate voltage above 2KV, which we never need in our normal operation. Replaced the HV feed-thru bushing that looked like it had been possibly leaking to ground. Also replaced the 4" fan that was cooling the bottom chopper electronics and that seemed to cure the double pulsing problem of the chopper.
14 Aug 2021 Saturday 11:11 [Tom Massey] The target current has dropped overnight following the vacuum problem in the sputter source. A new pellet was put in after the problem and had 1.5 microamps initiall. The LE current dropped overnight as the target current. We have shutdown the source for maintance.
13 Aug 2021 Friday 13:41 [Tom Massey] The control power for the cesium sputter source turned off. There was a small rise in vacuum in the LE extension just before this. The vacuum was bad at the source box and the ion gauges did not stay on. The gate valve for the between the source box an the diffusion pump closed. The vacuum system was restarted the diffusion pump warmed up and good vacuum was achieved shortly
12 Aug 2021 Thursday 11:04 [Tom Massey] The radiation detector at the low energy end of the tandem is reading 20 mR/hr. This is associated with beam in the tandem. The reading is much lower with the LE cup in. We are running 7.0 MeV deuterons on Be with the Vault radiation monitor off scale.
11 Aug 2021 Wednesday 21:00 [Joseph Derkin] Ludlum dosimeter warning alarm went off at 8:45pm. Accumulated dose reads 0.19 mR/h. Suspected low battery.
10 Aug 2021 Tuesday 10:06 [Leblanc] Removed D- pellet, found pellet completely depleted. Installed H- pellet from last week. Good beam current within 1hr, indicating no problems with source. Installed new D- pellet, waiting for beam.
10 Aug 2021 Tuesday 08:38 [Leblanc] Came in to find beam current had dropped from 10 uA at 5PM to 4uA at 8AM. Target current around 8mA, with peaks of 20mA overnight, though no logged sags in target voltage. Given that this pellet was new just 92 hours ago, I suspect that the source needs to be cleaned.
05 Aug 2021 Thursday 17:23 [Leblanc] Alphatross source ran M,T,W this week, giving > 1uA of current at the LE cup. Plasma bottle inspected on Thursday AM, looked clean. Button inspected with barely a trace of Rb on the surface. Reassembled and pumped down. Ion gauge relay output to control computer not working properly, not sure of the cause, but has no effect on operations.
30 Jul 2021 Friday 16:07 [Leblanc, Carter] Alphatross source operating. Found some instability in the bias voltage/current. Instability was minimal below 16.5kV. Tuned system and achieved approximately 400 nA of DC beam at the LE cup without excessive beam instability. Oven voltage was only at 80V, leading to a chamber temp of 55 and an oven temp of 176.
30 Jul 2021 Friday 12:43 [Leblanc] Alphatross rebuilt. All parts cleaned through cooling flanges. Fresh Rb loaded. Reused canal and insulator. Hour meter at 17777.3
26 Jul 2021 Monday 16:59 [Leblanc, Carter] Inspected Cs Sputter source today. Found a baffle installed what looks to be backwards, based on a newly discovered drawing. Reassembled correctly, with all screws tight. System is under vacuum and will be started tomorrow.
26 Jul 2021 Monday 16:57 [Leblanc] Alphatross heating loop blew a hose on Friday. Left oil dry out to soak up the mess over the weekend. Further work is on-hold until parts arrive.
21 Jul 2021 Wednesday 12:06 [Leblanc] Shutdown and inspected alphatross source. Found Rb contamination throughout the plasma bottle. Cleaned and reassembled source. Reduced LOBS loop temperature from 40 to 35 centigrade.
21 Jul 2021 Wednesday 09:05 [Leblanc, Carter] Alphatross probe short Monday afternoon. Source turned off on Monday. Tuesday, source backfilled and bottle removed. Found dark grey deposits on the inside of the plasma bottle, which disappeared on exposure to air. Bottle cleaned, canal and BN insulator replaced, vacuum restored. Current unstable at first, but eventually nearly 1uA in the LE cup, fairly stable. Left source running overnight. Wednesday morning, no beam current. Found probe had developed a short starting around 4 AM. Short was intermittent until around 7, at which point it became steady and pulled the probe voltage down to around 1kV.
08 Jul 2021 Thursday 10:28 [Tom Massey] 7/8/2021 Operator DRD reset 0.42 mr reading.
21 Jun 2021 Monday 23:47 [Yenuel Jones-Alberty] Target current sharply increased at around 10:30 pm tonight, and then plummeted to zero. Control milliampere light on Target Glasmann was then observed to be on. We swapped the deuterium pellet for a fresh pellet, and are currently turning the source back on. The old pellet appears to still have some titanium deuteride.
17 Jun 2021 Thursday 10:12 [Tom Massey] Survey for 9Be(d,n) reaction on swinger 30 nA beam. No detectable neutrons or gamma at Small Target Room Door. Larget targe Room 25 cts neutrons at 15 R beam leg opening no gamma detected. Garage area 25 cts thermal and 50 cts fast neutrons at door wheel wells, no gamma.
14 Jun 2021 Monday 09:56 [Leblanc] Duterium pellet removed from source. Pellet appeared depleted. New pellet installed. Turning on HV supplies causes target PSU to go into current limiting mode. Need to service the source.
11 Jun 2021 Friday 18:20 [Tom Massey] The target high voltage shorted out and is now in current control mode. I turned the target voltage down and this did not change the current reading. I shut the source down and the target current dropped when the ionizer was turned down. The short came back when the target current was turned on and stayed on. The source has been shut down.
10 Jun 2021 Thursday 16:06 [Carter/LeBlanc] The new AMI Oxygen Deficiency monitors are installed and calibrated, one on the dock and one in the pit. The the display value for normal oxygen level will read 20.9% locally on these monitors. A green LED on the front of the unit indicates normal safe condition. If the level drops to 20.0% the status LED will change from green to yellow. Then, if the level drops to below 19.5%, the status LED will turn red and a 95dB local alarm will sound. Pressing "Silence" will silence the alarm for one minute. Leave the area immediately and call for help. If the status LED is flashing red, AC power has been lost and the unit will continue to operate for about one hour. The oxygen sensor data is logged and a plot available on the real-time data plots under the "Miscellaneous" section labeled "Pit_O2" and "Dock_O2".
04 Jun 2021 Friday 16:34 [Leblanc] Alphatross source cleaned and rubidium charge replaced. Pumped to high vacuum until about 2PM today, then started source. Obtained approximately 5uA of current at the source cup, but only 9nA at the LE cup. Turned Rb oven off, letting plasma run over the weekend.
04 Jun 2021 Friday 16:21 [Carter/LeBlanc] Remote logging of the vault pit O2 monitor connected and functioning. O2 levels and alarm status can be viewed in the control room for the vault pit O2 monitor.
04 Jun 2021 Friday 11:59 [Carter/LeBlanc] New AMI Model 221R O2 oxygen deficiency monitors installed and functional in local mode. Remote mode communications and software has been tested but wires will need to be run for remote monitoring connections to the control room computer. One unit is in the accelerator pit and one on the accelerator dock area and have local readouts and alarms for the respective areas.
01 Jun 2021 Tuesday 17:56 [Greg] Trouble with the alphatross source today. Plasma color looks purple/pink on the monitor, and beam current is very low. Probe current appears within normal range. Current PV 6kV, PC 3mA, EV 5.5kV, Oven at 80V, Bias at 49kV. Chamber temp is 49 Celsius, oven temp 172 Celsius, 0.2 SCCM He4. Resulting negative beam current of 6.5nA. Disconnected probe leads and used megger to test for current through the plasma bottle, no current, no plasma induced. Back filled source with argon and checked for and found Ar flow through the He inlet. Roughed and pumped source down, plasma color still off, current still low. Turning off source, leaving "water" on overnight to try to keep the chamber warm for the morning. Need to determine next steps.
17 May 2021 Monday 17:25 [Greg, Tom, Nisha] Spent time today checking telescope alignment at swinger. Carefully set height using movable device, and checked alignment on fixed telescope. Made SMALL adjustment to level and yaw on fixed telescope. Alignment is complete the best of our ability given current tooling. Inscribed marks on the back of the tunnel appear to be correct.
15 May 2021 Saturday 18:21 [Tom Massey] I spilled some water near the oxygen sensor in the Garage area. The system gave an alert several minutes afterwards. It shows as trouble on the pannel.
13 May 2021 Thursday 11:09 [Carter/LeBlanc] Problem with analyzing magnet polarity reversal was diagnosed and repaired. Mechanical obstruction from drooping high current magnet wire was interfering with the contact mechanism. Obstructing wire moved and secured away from the contact.
06 May 2021 Thursday 11:09 [Greg, Yenuel] Came in this morning and inspected the pellet. Looked "icky", see https://photos.app.goo.gl/tWauxzzaVLHh5csv5 Made new pellet, loaded into sputter source. Short seems to have cleared, new pellet is warming up now.
05 May 2021 Wednesday 20:55 [Justin Warren] Update Dropping the cesium resivoir current did not reduce the target current after ~30 minutes and beam was not regained on the low energy cup. Proceeded to shut down the sputter source and accelerator. During the shutdown of the sputter source, while dropping the ionizer current, the target current dropped to 0 mA.
05 May 2021 Wednesday 20:06 [Justin Warren] At approximately 7:30 PM on 05/5/21, the target current on the sputter source reached ~21 mA, and the target voltage went to current control mode. The target voltage and resivoir current were reduced to 0 to attempt to fix the issue. Further update in 30 minutes.
05 May 2021 Wednesday 09:31 [csrter] Just documenting that the sputter source oven heater is 115 VAC 200W with a cold resistance of 75 ohms.
05 May 2021 Wednesday 08:36 [Tom Massey] Debugging the sputter source. The cesium resivoir heater was checked. It checked good but was replaced. The resistances on the sputter source acceleration tube were checked. The proton pellet was replaced with an old deuterium pellet. This pellet gave 6 microamps in two hours. A new proton pellet was made. This pellet was placed in the bell jar and the pressure reduced to roughing vacuum. The bell jar was backfilled with dry nitrogen. This pellet gave 2 microampers of beam in under a half hour. The temperature on the cesium oven was raised from 117 to 120 degrees. This gave a factor of ~4 increase in beam current on target.
04 May 2021 Tuesday 09:29 [Greg] Low current from sputter source yesterday. After some testing, we decided to check cesium level, found reservoir empty. Refilled with 1g of Cesium, restarted source to run overnight. Beam current still low this morning, still trying to troubleshoot.
29 Apr 2021 Thursday 11:02 [carter] I have replaced the suspect component causing instabilities in the voltage display of the sputter source extractor supply. Testing did not reveal the previous symptoms of instability. As of this time you can believe the voltage reading unless symptoms re-appear. If you see instabilities we previously saw, let me know and go back to the voltage set dial for setting the supply. As a rough approximation, 16 KV per dial revolution of the voltage set.
28 Apr 2021 Wednesday 11:45 [carter] When moving the swinger, watch the cables and hoses near the rotating seal end (beam injection side) and make sure they don't catch on anything as the swinger moves. A temporary repair has been made on the damaged cable and will be made more permanent when time permits.
28 Apr 2021 Wednesday 11:20 [carter] As mentioned by Tom in the Monday lab meeting, the sputter source extraction power supply voltage meter seems to be unstable. The supply however seems to be working OK and stable, so until further notice, use the calibrated voltage set dial to set the voltage. The supply output voltage = (control dial setting / 10) * 160KV. Dial setting = (desired voltage / 160) * 10. The dial is a 10 turn dial so the integer is the displayed number and the fraction is read from the dial. Example for 58 KV, (58 / 160) * 10 = 3.625 on the voltage set dial.
28 Apr 2021 Wednesday 10:48 [carter/massey/subedi] Roughing pump control cable had snagged when swinger was rotated and mechanically damaged. Repaired and pump now runs. The ion gauge was leaking between the 2 swinger magnets and was replaced. Swinger now pumping down.
27 Apr 2021 Tuesday 23:23 [Tom Massey] The turbo pump controller shows 0 RPM and an erorr code of E006. The turbo pump's roughing pump was not running and was cold when the turbo pump was on.
27 Apr 2021 Tuesday 23:10 [Tom Massey] The swinger was moved to zero degrees. The vacuum interlock between the target and turbo section of the swinger shut the valve. The beamline gate valve also closed. I was called ot check the status. The turbo roughing vacuum read atmosphere when I arrived. There was good vacuum yet in the turbo section of the swinger. There was good roughing vacuum in the target section. We were unable to open the valve between the target and turbo section. The turbo pump was turned off for safety as the roughing vacuum pumb was not running. The ion guage was bumped in the debugging of the problem and it shorted out.
26 Apr 2021 Monday 12:13 [Tom Massey] Conditioned the tandem to 4.6 MeV on GVM. This went smootly with no large outgasing. This was done at 50 keV per each 5 minutes from 4.0 MeV GVM. The Dell high voltage supply had been showing swings of voltage from 37-42 keV on the display. The current is very stable. This may indicate a problem with the gauge rather than with the stablity of the system. However, the actual voltage is not clear. Manual programing shows 3.2 on the dial.
15 Apr 2021 Thursday 15:30 [Tom Massey] We began running 8 MeV alphas. This gave a analyzer magnet current of 93.9 Amps. During tuning and at the begining of the run the current increased several times up to 94.1 Amps. This caused the loss of the beam. It could be recovered by adjustment of the switcher current. After 3 hours the magnet current settled down, the swings of current are now absent.
05 Apr 2021 Monday 11:13 [Greg] Tom, Yenuel, and Doug found bad vacuum on the analyzer leg this morning. I investigated a little and found rough vacuum was OK, but gate valve on the cryo pump didn't want to open. Bypassed interlock and let it pump down for a while. Vacuum all seems OK at this point, though not as low as normal operating (probably just needs time). Opened the nearby gate valves to maximize pumping speed. Vacuum is low enough for Doug to tune alphas for UGL.
23 Mar 2021 Tuesday 14:26 [Greg] 4 bottles of SF6 (total weight, approximately 460 lbs, 210kg) transferred into storage tank. Current storage tank pressure is approximately 25 PSI. This should allow us to increase the pressure in the tank by as much as 16PSI. Current pressure is running about 79 PSI. I think the new SF6 should be dried before being added to the accelerator, which will require about 3-4 days without running the accelerator. We should attempt to do this before running at the full 4.5MV, though the runs at 3.5MV have shown no signs of insufficient insulation.
22 Mar 2021 Monday 17:36 [Don, Greg] Buncher 4-65A output tube drawing grid current, shutting down at 1.2 KV. Replaced with new tube and now operating normally again. Note: the first replacement tube (NOS) was defective producing no grid drive so another NOS tube was installed.
22 Mar 2021 Monday 09:40 [Greg] Alphatross interlock controller had a blown fuse 1A/250V fuse. Replaced the fuse and was able to start normally. Will write up troubleshooting instructions.
22 Mar 2021 Monday 09:05 [carter] BCI counter 10's digit repaired.
21 Mar 2021 Sunday 16:28 [Ingram] LE cyropump working normally. 10L scattering chamber vacuum looks okay now the ion gauge has been outgassed. Alphatross vacuum still shutdown.
21 Mar 2021 Sunday 12:54 [Ingram] LE cryopumps did not start properly, iced up and not at temperature. Have warmed them for three hours and then restarted. The He pressure looks looks low to me 60-70 psi. We may have a leak. HE cryopumps on and pumping the beam lines and tandem. 15L beamline chamber has higher pressure than normal. It is in the mid 10-5 range. There is a mist of oil droplets in the chamber. Could be that the rotary pump burped and oil from the diffusion pump finished up the chamber and the ion gauge is contaminated (best case). Worst case is we have rotary and diff pump oil in the chamber. May need to clean the pump and chamber.
20 Mar 2021 Saturday 20:00 [Ingram] Came in about 7:30 PM. Restarted the LE cryopumps. Sputter source looks like it survived the outage. The HE pumps may have restarted themselves and then shutdown. They need longer to warm up. There is ice on the outside. The LE pumps had no condensation on them. The alpha source vacuum system was off. I tried to restart it but failed. We need to write-up the procedure to restart it. I will come in on Sunday to restart the HE vacuum.
20 Mar 2021 Saturday 18:10 [Gula Hamad] Hello Everyone, There was a power outage today when I entered the lab to refill the HPGe detector and I am not sure how long the power was out. The power came back while I was there and couple of Alarms started . I stopped (reset) the Alarms.
19 Mar 2021 Friday 12:29 [Tom Massey] Pulsing and bunching working! The switch for buncher tubes was in between positions. We now have good signals for pulsing and bunching!!!!
19 Mar 2021 Friday 11:58 [Tom Massey] Started work for pulsing and bunching. We had zero for the buncherf output. Both 24 cm and 8 cm positions were checked. No buncher output was seen in either position. The switch sounded like it was making contact. We stopped the experiment until this is understood.
18 Mar 2021 Thursday 17:00 [carter] BCI counter 10's digit repaired.
18 Mar 2021 Thursday 12:38 [Greg] Fan resecured to process chiller. Shaft key still missing, but set screws will hold it until a key can be found. Everything ready to run.
16 Mar 2021 Tuesday 17:08 [Greg, Don] Impeller to shaft key had sheared off (probably age/corrosion). Mike Myers was able to find a replacement key, nut, and washer, and pump is reassembled using spare pump seal. Pump is running and process chiller has loop temps back to normal. The fan on FC1 on the process chiller is loose on the motor shaft. Will need to repair Thursday.
16 Mar 2021 Tuesday 12:59 [Greg, Don] Investigation of the process water chiller shows that it is not running due to the flow switch not being made. Redundant flow switch also indicating no flow. No pressure change seen at process chiller between motor on and motor off. No current change at motor when closing an isolation valve at the pump. Motor current 4.3A, logbook entry indicates expected motor current is 7.5A. Current working hypothesis is that the pump has failed somehow. Will try to diagnose further after lunch.
15 Mar 2021 Monday 17:50 [Greg] Replacement pump installed for the utility water loop. Everything looks good, need to update the pump model number, and review replacement parts with Doug. Tom noticed the cryo pump on right 45 started making a strange noise. We turned it off, will investigate when time permits. Air/Water alarms started going off this evening. Further investigation shows that the process chiller is calling for all 3 stages to run, but none are running. Will investigate tomorrow.
11 Mar 2021 Thursday 13:21 [Tom Massey] The beam stop in the solid target chamber on the swinger has had a 0.1 mm gold plate added to reduce the gamma-ray background.
03 Mar 2021 Wednesday 15:36 [Tom Massey] Alpha source hasd 750 na DC. Swinger Be target 12 channels 2.4 ns width with 12 nA on target!
03 Mar 2021 Wednesday 15:08 [Tom Massey] Alpha Pulsing and bunching. F/4 had 12 na on target. The gamma-width was 12 channels ~2.4 ns.
02 Mar 2021 Tuesday 16:55 [Greg] Sputter source ion gauge was not working. Replaced gauge, found bad gauge. Replaced gauge again, still not working. Controller has failed. Swapped with Lesker controller that was on 45R, leaving 45R with no ion gauge at the moment. Not sure how to adjust the set points on this controller, or what controller to use on 45R. Cooling water pump is also leaking at the shaft seal. Pump is currently shut off, which allows cooling to function with no load, and reduces the volume of the leak. Can turn the pump back on to run, but needs to be swapped for the replacement, and a new seal ordered so that we can have a backup.
26 Feb 2021 Friday 17:13 [Greg] Doug was able to re-manufacture the utility loop water pump and make it run. Installed it, along with 4 new ball valves, and got the utility cooling loop back up and running. Pressures look good, and I bled some air out of the system. Heat exchanger seems to have brought the temperature down to normal. Replacement pump ordered and arrived today to receiving, should be at the lab on Monday. Will work to get it ready to plug in quickly, should this pump fail or develop a leak.
23 Feb 2021 Tuesday 09:28 [Greg] Found water pump making noise this morning, working to investigate. Facilities electricians and controls guys are here to work on the HVAC systems as well.
17 Feb 2021 Wednesday 09:58 [Justin Warren] Came in this morning (2-17-21 @ 9:30) to check the status of my experiment and both alarm panels were in alarm. On the shutdown module, the Cup In light was on, no lights were on main alarm panel. I reset both systems as per the manual and no further alarms occured.
02 Feb 2021 Tuesday 11:27 [Greg] Backfilled Alphatross with Ar, and found that the orifice was not completely plugged. More investigation found some rubidium compound was built up on the canal holder (part 20) and some obstruction of the canal for the RF source (part 24). The source exit flange (part 21) also appeared to have some buildup of rubidium compounds. I was able to clear out the canal, and poke some of the compounds out of the exit flange, but saw some minor sparking, and decided to stop. Source is reassembled now, and pumping down to high vacuum. Can try to start plasma and produce beam, but the source almost certainly need to be torn down and cleaned.
01 Feb 2021 Monday 14:42 [Greg, Don] Still having problems with alphasource. Probe current limited out at 7.5mA several times, forcing a lower probe voltage. Currently shutting down source (2021-02-01 14:30). Once cooled, we will back-fill with Ar and check for blockage of the orifice between the plasma bottle and the charge exchange chamber. Symptoms seem similar to the last blockage, though not identical.
29 Jan 2021 Friday 14:28 [Greg] Monthly safety inspection found that the emergency backup light in the tunnel had failed. I got the spare from Don and will replace it. I'll put together a procurement request for 1 spare to put on the shelf.
27 Jan 2021 Wednesday 08:56 [Greg] Started Alpha source. Left Probe at 6kV, current was around 3mA. Did not start oven yet, but plasma is running well.
26 Jan 2021 Tuesday 17:02 [carter,Greg] Documenting alphatross heater voltages and currents for proper operation. Heater is 120V 200W. At 200W, 120V would be 1.666A. Resistance = 72ohm. Test values using type K thermocouple to confirm temperature probe... 3.1 mV = 95C, 4.0mV = 120C, 5.2 mV = 146C, 7.4 mV = 175C. 75 volts on the supply voltmeter gives 1.04 Amps on the supply ammeter.
25 Jan 2021 Monday 12:47 [Greg, Don] Power outage recovery this morning. Diffusion pump on 15L beamline was not working. Troubleshooting found failed temp switch; replaced with spare from pump in the LTR. Backing pump for 15L beamline also was not operating. Need to replace circuit breaker. Cryo-pump compressor on 45R beamline was low on UHP He. Warmed, refilled, roughed, and restarted compressor. All vacuum systems now operating properly.
23 Jan 2021 Saturday 16:55 [Ingram] LE and HE extensions pumping down.
23 Jan 2021 Saturday 12:33 [Ingram] Sputter source pumping on its diffusion pump. Alphatross now on turbo, I figured out how to start it. Beamline cryopumps cooling down. 15L beamline diffusion pump cold, target chamber diffusion pump working. Ion source cooling on.
23 Jan 2021 Saturday 10:58 [carter] Checked and restored power to electrical and computer systems after power outage. Restarted accelerator logging and alphatross logging.
23 Jan 2021 Saturday 08:18 [Ingram] Power back about 1:30 AM. Came in about 7:30 AM. Reset all alarms. Started all secondary water pumps. Primary water and HVAC all look good. Turned off beam line cryopumps to regenerate. Will come back later to restart cryopumps. Sputter source backing pump and freon compressor on. Alphatross vacuum power on but I don't know how to turn the turbo on.
21 Jan 2021 Thursday 11:23 [carter, Greg] After alphatross repair last Friday we achieved 550 nA DC alphas from the source yesterday 20 Jan 2021. We noticed reduced RF amplitude on the RF meter so made some adjustments in the alligator clip positions on the tank coil and it increased the RF level back close to the previous value which was very close to the red area on the meter. We moved each alligator clip approximately 0.25" to the right facing the source.
21 Jan 2021 Thursday 11:15 [carter] Added alphatross heater voltage plot to the web based monitoring page.
15 Jan 2021 Friday 16:46 [Greg, Don] TL;DR: Alphasource troubles Thursday and Friday. Some problems found and corrected, will try to run the source on Tuesday. Troubleshooting the Alphasource this morning. After overnight vacuum pumping, vacuum levels in the 10^-8 Torr range were achieved. Don and I isolated the probe voltage terminal, and applied voltage to ground. We read high resistance at the 250V and 500V settings, but on the 1000V setting a plasma was induced in the bottle, glowing purple. Based on the wikipedia entry for gas-discharge lamps, it could be argon, nitrogen, or oxygen. This would seem to match with the symptoms that we experienced yesterday working with Tom and Nisha, in that we created a current limiting discharge somewhere around 1000V. This would also seem to indicate that there is something in the plasma bottle other than vacuum or helium, as vacuum shouldn't arc and the helium supply is off, and the plasma is the wrong color. We also noticed that adjusting the mass flow on the helium did not affect the vacuum reading at the ion gauge. Ran roughing vacuum on plasma bottle, and back-filled source with argon. Removed plasma bottle and found no flow of argon. Used 1.58mm rod that Don obtained to clear out the 2mm diameter opening between the plasma bottle and the cesium vapor chamber, at which point argon was able to flow out. Reinstalled the plasma bottle, disconnected argon, rough pumped and allowed the turbo to pump on the source. Pressure currently 2 x 10^-7 Torr and falling. Megger applied to probe voltage contacts, and previously observed discharge is now gone, indicating improved condition. Plan to allow the vacuum to pump until Monday, when we will try to restart the source again.
08 Jan 2021 Friday 14:54 [Greg] Ran windows update on VESDA system, and paused updates until February. Also managed to fix the audio driver, by rolling back to an older version.
06 Jan 2021 Wednesday 08:50 [Greg] Walkthrough of the lab this morning. Backing pump on the swinger seems louder than I remember. This is the pump that we replaced the bearings and coupler on before break. Did not seem excessively warm, nor did I detect excessive vibration. Will monitor.
23 Dec 2020 Wednesday 10:25 [Ingram] Got 1.2 uA in LE cup of 60 keV 4He- and 1.5 uA in HE cup through the machine at 1MV. Analyszer magnet control not working.
23 Dec 2020 Wednesday 07:48 [Ingram] Alphatross Testing Plasma started at about 5 kV on the probe today, yesterday it started when the rf came on. Oven temp is 165 C and I already have 0.2 uA and increasing. Gas still at .35 sccm. Dropping the flow to 0.2 sccm increased the beam to 0.4 uA, oven now 170 C.
22 Dec 2020 Tuesday 17:24 [Ingram] After source shutdown I went out to check on the 4He MFC. It had readings that make sense now. psia 27 degC 22.6 set pt. 0.000 main display 0.000 SCCM He 0.00 ccm 0.000 sccm I think the 4He MFC had to go through some sort of reset for it to work normally. Go figure. David
22 Dec 2020 Tuesday 16:39 [Ingram] Alphatross testing Gas left running all night, no change in pressure still 3E-5 Torr. Shutdown. Went out to check the MFCs. Only strange thing are some negative numbers for flow on the 4He controller. Noted the 3He MFC had 4 psia. Tried to run 3He MFC. at .35 sccm the pressure went to 2E-5 Torr, looks like the same problem. Tried to run down 3He controller and turn off its flow, but, although it was off, it showed a non zero flow of about 0.15 sccm. Used Run All Down and source off and eventually it went to zero. Tried the 4He MFC again and it was working properly, 0.35 sccm 1.6E-6 Torr. Shutdown and reverted to proper control of the source, CB1 plugged back in etc. Started source and it worked as described in the manual. Ran for several hours at 0.2 uA, after 6 hours refocused and re-tuned magnet and got the beam to 0.65 uA. What worked? Cycling the MFCs and the source controls appeared to fix the problem but why? All this time the turbo has been running at 820 Hz. I kept checking just to make sure that the turbo was not the problem with the pressure.
21 Dec 2020 Monday 10:22 [Ingram] Testing Alphatross. The ion gauge pressure is still reading 3E-5 when the gas starts to flow. The pressure is rising to that level within ten seconds of the source being turned on. The pressure is real and can be seen at the inflection magnet when the gate valve to the source is open - same reading 3E-5. Background pressure at the inflection magnet is 3E-6. Running Alphatross from wall power. The MFC is reading correctly and is set for He. The regulator pressure close to the MFC is reading 10 psi, it was reading 16 psi earlier, probably because the source was not taking any gas and the bottle on the wall is set at about 20 psi. Will leave the gas flowing in this mode for 24 hours, all other supplies are off, CB1 is unplugged. Other - the Alphatross ion gauge on the real time data in the control room is difficult to read owing to some high values last week. Other - facilities just came through to turn the steam/hot water back on in the mechanical room.