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

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.

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.

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.

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.

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:

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

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.

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.

The DRAGON run ended uneventfully. (That's a good thing.) I ran a few emittance scans on the beam as-is. It is clearly monoisotopic. The shape is a little odd. Keerthi will comment on it in a while. Here are some pix. Below the emittance control panel are pix of the same beam at wider settings. Only the one 16O3+ peak is present. Finally, at the bottom is a pic of various parameters, the most important of which is COL0, which reflects the stability of the total beam from the source.

So. We are preparing for a few days of Supernanogan development. The present run plan is to obtain good emittance scans for higher charge states of 16O, 17O and 18. We may be limited by the loss of MCIS:TP1, but maybe not.

Set up on nom 18kV tune based on last recent save: 090831_1104.snapiosfc6. MCIS HV tickled up to prevent extracted beam surges.

First emittance scan of 16O3+ beam pix. First save: 090915_1053.snapiosfc6.

Also, here is a stripchart of the separator field and FC6 before and after the energy change. The field is nice and stable, and FC6 is consistent.

We noticed a double peak effect in the 16O3+ scan. I will set up the line for 17O3+ and see.

Scan #1: Double peak also visible.

Scan #2: Remove upstream slit altogether. Now profile is twice the size in the opposite direction of the double peak.

Scan #3: Widen emittance parameters in control panel.

Scan #4: Tweak MCIS CBs for FC0.

Scan #5: Optimize EL on FC6.

Scan #6: Lower EL by 10%.

Scan #7: Lower EL by another 20%.

Scan #8: Lower EL to 50% of full scale.

Scan #9: Tune for minimum spill with reasonable quantity on FC6. Save: 090915_1704.snapiosfc6

Final emittance rig control panel.

Here are pix of the same scan: original, then greyscale, then cropped, using The GIMP. Not bad.

0.4nA of 17O+8 is sitting on FC6. Development will continue tomorrow.

090916_1215ILTEMIT.txt    EL increased, ~4.5uA, emittance increases, 50x100   17O+3

090916_1242ILTEMIT.txt  17O+5 has two peaks.

090916_1355ILTEMIT.txt  Repeat same measurement an hour later. (IOS bias was off in-between due to IOC/PLC reboots.)

090916_1206ILTEMIT.txt

Graphics with "color" in the filename will look in print the same as "greyscale" files.

A sustained 33S5+ beam was generated in the Supernanogan on Friday, September 25th. Attached is a trar plot.

Source gas: SO2 through either of two calibrated leaks: 10-4 and 10-5ccm.

FC6 = 1enA.

33S particle rate: 1e9Hz.

A/q = 6.6

Bias used = 13.881kV.

We are taking the opportunity to replace TP1 today. Edi Dalla Valle is on it. Also, Diagnostics has a WP in the queue for looking at the attenuators, so we have prepared IOS for venting.

Later... Cart was removed from cage for access. Pump was replaced successfully, and all volumes are under high vacuum now (17:00). In the end, IOS was not opened at this time.

Beam is stable enough to let Marco set up something to DRAGON. We are a couple of days early.

Also, we tested the attenuators, previously noted to be operating oddly: