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

I'm back from vacation. Physically, anyway. Keerthi did comprehensive emittance scans during Supernanogan Development over the last couple of weeks. He is very happy with the results so far. We are doing come post-analysis comparisons presently. Meanwhile, DRAGON is taking 16O3+. Some sideshows, including power bumps this morning which knocked out MCIS and many other systems. The mag stab facility was offline while I was away. I restarted it around noon. Some source tuning for current changes and stability from time to time, done by Keerthi.

We still have this water interlock issue on the IOS bias supply, preventing us from turning it on. I left a note about it before I left. Must follow that up tomorrow.

Later... Here are a couple of stripcharts of magstab performance, before and after the TP1 trip that occurred on Friday, September 11th, noted elsewhere. Spikes are DRAGON's automatic Faraday cup readings.

Another in the on-going saga of MCIS:PV1 trips occurred again this morning. The operators recovered most of the vacuum devices except for the IM section gate valves. We had an in-person discussion about them, the order in which they should be opened, and the existence of a hand valve in the IM roughing line. An ION note is needed.

Lots of other things were different, and beam was off. Restoring the tune basically restored beam. Whatever. Here are two emittance scans, one after restoration, one after further work. 18O4+ as before, but RF power arbitrary, and probably not identical to yesterday.

090818_0957ILTEMIT.txt

Ack! EL keeps tripping... Stay tuned.

Later... Jane is alpha-testing an application for our development. She is using the source presently. Development on hold.

High resolution zero to 25. Save file: masscorr_mcis_090817-highres.txt

Ack! Elog server went down at ~17:00!!!

18O4+ emittance scan at 22.44kV and slits open: 090817_1707ILTEMIT.txt

Note that in preparation for this scan I steered beam in X then in Y onto FC3 and FC6 respectively, looking for all beam through each slit. There was flat-topping evident in both directions for both cups. I would like to repeat the study for well-defined X beam through each slit by scanning with the 1mm slit and noting the drop-off at the tails. For what they're worth, I am appending the stripcharts for each cup. Data files are here:

mcis_strip_steering_fc3_090817.dat

mcis_strip_steering_fc6_090817.dat

Supernanogan Development begins. It will be a marathon. Main goals are high-charge emittance scans and RF frequency scans. Tall order.

Meanwhile, the MWS came out as planned. Thank goodness for the quartz liner, which took most of the hit from the magnesium. IOS optics are another story. We are running with an alternate tune for Q1/Q2/Q3, as noted elsewhere. The Supernanogan, already at vacuum, pumped down nicely, as did IOS and the IM section. Basically it was a weekend of HV conditioning. Mostly as expected. We got to a solid 27kV. Plasma lit and 22Ne2+ beam tune installed and beam on FC6 for hours. I'll include a stripchart if I can find one.

Preliminary mass scan. It looks okay. Slits are wide-open. Yes, I found a 22Ne2+ FC6 stripchart too.

Next:

• Slits in: done.
• Check A/q calibration: change const22 from .04156 to 0.041777 based on 22Ne position.
• Mass scan:

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.

As noted earlier, the MWS beam dropped out at some point after yesterday afternoon's playtime, due to insufficient PE. Plasma was lost. I restarted the source remotely. The present combination of Ne flow SP = 1.2ccm and PE = 48V works well. Plasma will persist regardless of Mg presence or PE setting. That's a good thing. Then using the PE we can control how the plasma ionizes the Mg material. Note the attached stripcharts. At the lower PE settings, the Mg loading on the EE is much reduced and indefinitely sustainable at those levels.

Presently the source is off for Supernanogan cart installation. We will have it in and buttoned up by around noon.

Well, so it goes. As I was penning a note for OPS, the source tripped. It easily reignited with a little extra Ne. I left the flow slightly higher, from 1.1 to 1.2ccm and the PE at 41V.

So... we have had this on-going problem with intense Mg beam coating our optics. Keerthi found a good recipe last week with PE on and a somewhat large support gas flow. We have been running with several tens of nA since. Since yesterday's trip, I have been gradually lowering the PE from my initial value of 100V to 30V presently with about 10nA on FC6. Beam looks like it will be very stable, and the EE will maintain indefinitely like this. The first test: Marco just made overtures to use the beam for checking TIGRESS tune.

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 a variation I thought might be appropriate.

Data file: 090810_1724ILTEMIT.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

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

A series of 25Mg emittance scans for Rick.

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

Data file: 090810_1621ILTEMIT.txt

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

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.

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.

Tuning has been on-going through the day. Here are a couple of emittance scans taken in-between heartbeats. The first is zoomed out, the second zoomed in a little close. We managed to sneak in a third also.

So... there evidently was a power bump overnight, because the stability power supply was "disconnected" from the system. This happens every time there is a power bump. It's a serial port thing. Meanwhile, the source also tripped. Upon restart, nothing was the same. This morning, we found that Q3 was current-limiting on one element. We have asked Rick to develop an alternate tune for us.

Keerthi did some source tuning early this morning. We since shut it off for the swake of Q3. I have restarted it now temporarily. Here is an emittance scan with slits open and Q3 off. Now we will shut off again to prepare Q1 & Q2 supplies for new numbers.

Tuning...

The source stayed up overnight just fine, with a little 25Mg beam on FC6. This morning I did a few mass scans to get a fix on Mg positions. Short story: There are some 3nA of 25Mg on FC6 presently, with things less than optimal. Stay tuned.

Attached is an early graph of Mg beams produced with the MWS almost exactly five years ago. Best I could find for now.

Later... Tuning went well. I ultimately had to tune in the ICR due to network response outside as people came in, etc. There are some 10nA of 25Mg on FC6 now, and the tune is set up for RFQ delivery. Snap: 090804_1240.snapiosfc6. I tweaked the upstream vertical steers slightly afterwards. The front-end differs from Rick's numbers by a bit, but it's necessary to keep down spills onto optics and get the beam through. I'll attach the differences below. Meanwhile, here are stripcharts of FC6 for the morning. In the latter part you can see where I turned down the microwave power from 600W to 500W. Slightly more than 500W seems about right for equilibrium. But to avoid boiling let's leave it at 500W for now.

A decent emittance scan is in the ISAC elog, albeit I ran it with slits closed down, so it should be repeated at some point with slits open.