Summary: good.

Details: A trip occurred at some point. I restarted the source over the weekende remotely. I have been tweaking down the PE since. Looking mighty fine. Stripcharts attached. Separator field nicely flat too, with stability program running. Save: 090810_1605.snapiosfc6

Marco gave us the all-clear this morning to shut down the MWS. We are preparing to remove the MWS head from the Y-box and blank it off, in order to maximize the vacuum around the Supernanogan. I have advised Marco of our intention to do this and that there is no going back. He is good with that. More in a bit.

Here is a stripchart of the 25Mg beam. The EE was off for the night. Turning it on restored beam immediately. It reached equilibrium after about three hours. pretty good, and pity that we have to shut it down now. Save: 090814_1352.snapiosfc6.

Emittance scans with beam as-is and with slits out. Best I could do, Rick.

P.S. At the bottom I added a couple of charts of the separator field. The stability system is working very well indeed. You can see it active and inactive over the last few days in the trar plot.

While there is an SC cavity issue, I have been repeating last evening's emittance scans. Here is the best one. About 70nA of 25Mg on FC6 presently. Note that emittance rig Faraday cup is reverse-biased. Also, overnight stripchart appended. You can see a gradual increase in current draw on the EE power supply as there is a build-up of Mg.

Later... Rick analyzed this scan and came up with his own numbers, with which he is happy. Here is his pic.

A series of 25Mg emittance scans for Rick.

Starting scan with everything as-is, i.e. slits closed.

Data file: 090810_1621ILTEMIT.txt

Here is a variation I thought might be appropriate.

Data file: 090810_1724ILTEMIT.txt

Before proceeding, I nudged in each of the slits, watching for first clipping. With the current emittance (nice), the beam cleared both slits completely; the upstream slit began clipping at about 1.5mm, and the downstream one at about 2mm. Also, FC6 current with slits in/out was: ~30nA / ~57nA. Note: I had to change the scanner parameters a little.

Data file: 090810_1648ILTEMIT.txt

Finally, here is the "original" beam. Can you tell the difference (side-by-side at bottom)? I can't.

Data file: 090810_1738.ILTEMIT.txt

Here is the emittance scan that Rick requested, beam with Q4/5/6 off. Note that present numbers for these quads do not match theoretical. I repeated my slit nudge check for clipping, just in case. As before, no clipping for the first mm or more.

Data file: 090810_1713.txt

Around noon, Keerthi adjusted the PE down to reduce the intensity of the Mg beam, as we are running with attenuators in. He ended up with about a 30% reduction, and improved the noise band by about 3x in the process.  Here is a repeat emittance scan. Both sets of slits are at 2.5mm position. I also took the opportunity to reset the separator stability equipment again.

Interesting, the beam took a step down a couple of minutes after hands-off. A tweak on the separator suggests that it's already about optimized. Well...

Sophia is back to tuning now.

Conveniently scheduled for BC Day, we are preparing to switch over the MWS to sputter operation with MG source material. Operations has saved present 21Ne tune.

Later... Done! Source is relit with 21Ne beam on FC6.

Summary:

• Vent IOS to Ar
• Remove MWS backplate
• Machine Mg metal disk (source material) for mounting screws
• Hand-cut Mg disk in two halves and clean
• Clean backplate
• Attach disk halves to backplate
• Clean assembly
• Reassemble at OLIS
• Pump - roughout was fast
• Pump - turbos on
• Minor MRO
• Button up and go with previous settings.

We will let it run this way overnight and shoot for an Mg plasma and beam tomorrow.

Attached below are plots of the last few hours of 21Ne beam. PDG, I'd say. Note the variation in sync with room temperature.

I ran through a calibration exercise for the IOS slits. Here is my data. I have moved each set to the midpoint of the largest (5mm) slit position. This does not necessarily agree with the book value. Never mind. Leave 'em alone, even though it appears that the numbers are switched (they're not).

Check 18O4+ emittance and compare with yesterday: good. Note again that emittance rig is running with manually-fitted reverse bias.

MCIS TP3 foumd off by 1:00 pm.  Restarted without a problem

Before TP3 is on MCIS:IG1 is 5.47e-8 Torr.

After MCIS:TP3 = 5.21e-8 Torr

The MCIS vacuum system tripped last night again. Fortunately the operators noticed it and restarted stuff. Otherwise we'd be having a very long day today. This looks exactly like the same MCIS:PV1 trip we've experienced before. Attached is the FC6 beam recovery.

An MCIS vacuum trip occurred somewhere around 15:30. Sophia observed a drop-off in beam. The cause looks like the PLC-related business that we have experienced many times before. This fault has not manifested itself for quite a while, since Controls firewalled the MCIS portion of the network on March 30th.

MCIS:TP1 = 12W

MCIS:TP2 = 11W

MCIS TP1 is not running well. Needs investigation as soon as S1219 is completed.

Later... TP1 failed completely, and we are running without it. Starting late Saturday night, DRAGON began to observe a certain instability. We correlated it to MCIS:COL0, which skims total current continuously. It is pretty evident that the source is now toggling between two adjacent plasma modes, due to the somewhat higher vacuum at MCIS. Vacuum was something in the 7-8e-8 Torr range before, but has settled out at some 1.25e-7 Torr now. General consensus is to continue running like this, as it is a minor effect, as you can see below (blue trace). DMG

Keerthi has reinstalled the SO2 source gas bottle onto MCIS. Presently it is closed off to the source. We have restarted the plasma. Present goal: a good setup for 33S5+ with background levels (hopefully near zero) on FC6. Source pressure was 4.xe-8 Torr this morning, and has crept up to 5.0e-8 since we restarted the RF.

Later... We scaled a A/q=5.5 tune up to A/q=6.6 (33/5). Separator field = 1459.9G. Tuning in progress.

Later... First pass, shown below. Skimmers < 5uA. Snap: 091013_1651.snapiosfc6

Source switched off for the night.

Supernanogan is running with oven no heat, without 76selenium. MCIS:IG1=3e-7Torr.

Tune saved as 141101_1318_76Se+11tune.snap

MCIS steering  X=330, Y=226, CCB1=500, MCISEL=4171/5157, PE=11.5/23, FC6=76nA(16O+7)

We completed 33S operation last night, and roughed in a setup for 17O. We had 17O3+ on FC6 overnight; chart attached. It grew nicely. Keerthi is working with the beam now.

Beam was quiet overnight. Keerthi touched up the tune this morning, and it is quieter yet and a little more of it too.

Later... Handover to Sophia occurred as scheduled. Save: 091105_1203.snapiosdragon

An IOSIOC reboot occurred sometime over the lunch hour. The usual suspects went down, plus the field stability correction power supply went to its lower limit. Reset this 'n' that and we're back. ~2e˜µA at FC6.

Later... Latest save: 091105_1449.snapiosdragon