Keerthi started the Supernanogan source today. His primary goal was to test out Rick's theoretical tune calculations. He was ecstatic with the results. Rick's table gives a tentitive value for the Einzel lens. In fact the ideal value is at or even higher than the bias voltage. However, Keerthi experieced sparkdowns at those voltages. Rick's calculation gives a reasonable number for better than 50% transmission between MCIS:FC0 and IOS:FC3. The Enzel lens at full chat (10KV with the present power supply) gives a transmission of close to 90% with 11.5KV bias. So far, there are no sparkdowns. Keerthi suspects a resonance effect with the earlier sparkdowns. Presently we are observing beam and optics stability, with about 16nA of 17O3+ on IOS:FC6. I'll do some scans in a while.

Happy Canada Day!

I noticed a long-term trend in beam intensity. I have every reason to believe that the source itself is rock-solid. I think it is temperature variation affecting the Philtek power suply on the separator magnet. What bothers me is that the stability program appears to not be compensating for this. I am looking into this now. Here is a plot of beam current, mag field and temperature (at AHU-1, the best I could do). There appears to be a delayed response to temperature. I have turned off our Hall probe for an hour or so to watch the response on a stripchart.

Well, there were results, but not what I expected. The beam became nearly out of control while the stability program was disabled. What's more is that the correct field came back immediately upon turning on our Hall probe again. Here are a couple of stripcharts, one snapped right after turning on the probe, and again a while later The stability program was disabled during the middle couple of hours or so. Note that the beam is oddly more stable in the short term now also.

Proposed run plan for this time:

• Document TIGRESS tune.
• 18O4+ emittance scan.
• Mass scan A/q = 0 to 25.
• Repeat 18On+ emittance scans at present RF frequency. 
• 16On+ emittance scans at present frequency.
• Plot 16On+ & 18On+ emittance on one graph.
• If indicated, then do 17On+ background study.
• Open 17O gas bottle to system.
• 17On+ resonance survey based on 18On+ results.
• 17On+ emittance scans.
• Add 17On+ emittance values to graph.

Beam switched back to 18O4+ by 11:00 as agreed. Some glitches. Here are snapshots of how it looked at handover time.

Later... Sophia prefers using all previously-saved files including ion source. Okay.

Note: For fun, Controls took away isacwserv mid-morning. The ICR did not communicate to them that I was the user... Workaround done with Keiko.

As noted, Keerthi was called to restart the source after a power bump. He continued Supernanogan development through the night (can you imagine?!?). He made some great progress. Here is a partial summary of his findings.

Actions taken: frequency scans across the entire range from 12-16GHz for each charge state of 18O.

For 18O4+, the "perfect" resonance occurred at 13.00GHz, with other resonances at 13.26, 13.54, 13.74... i.e. at about 26MHz intervals. The lowest resonance is the least noisy. However, if it trips, it is also impossible to restart it without playing with the RF. Based on Keerthi's instructions, I have written up a draft of an ION note for Operations, describing how to restart the Supernanogan source if it trips. I have asked the operators to critique the draft. The present RF state is attached below.

Supernanogan development for 33S started. All MW and MW and MCIS power sypplies are off.

Gas for microwave source also closed from hand valve

Later... separator field stability development. Local Hall probe is online. Let it cook.

By agreement, the source came down this morning for continuing Supernanogan development. Main event: leak detecting.

Later... Robert and Tim lead leak detectors. Synopsis: A minute leak at waveguide flange on plasma chamber. We decided to seal it with a drop of vacuum sealant. Worked like a jet. Once Supernanogan beams are done for this beam schedule, we will remove the waveguide and re-machine and weld the flange. We also believe there is a minute leak at the bellows joining MCIS and IOS. TBC.

Leak checking on the Supernanogan continues today. We are preparing for an up-coming 33S run, for which we want "perfect" vacuum. We're close.

Later... MCIS backing line is now running on leak detector only. Calibration in progress... Done.

There was a short MCIS vacuum excursion at ~09:15. There were two similar ones overnight. Probable cause: sealant outgassing.

Later... MCIS leakcheck tested excellent. Our fix was good, and there were no signs of a leak after all in the bellows area. We are good to go.

Next item: IOS leakcheck if possible. At somepoint we also want to test out the solid target tube on the MCIS plasma chamber.

Later... IOS leakcheck in progress. Leak found at water feedthroughs on DB3 and touched up with same sealant as above. Sealed. Continuing down the line...

Later... We determined a small leak on the top flange of IOS:DB6, which we were able to help from outside. We also observed a significant gas loading from downstream of IOS:IV7. It is indeterminate at this time whether or not there is a specific leak. However, we also observed a fairly high pressure downstream of ILE:IV6. Closing that valve, however, had no effect at IOS.

At about 16:45, Colin requested beam for an energy check. We are doing a last leakcheck between IOS:MB and IOS:IV7 before we close it down and prepare for beam.

At 1about 17:15, MWS lit. >2enA of 22Ne2+ on FC6.

I have been testing various RF power settings for cold starts and beam stability. No surprise, the best tuner setting is approximately midway at about 58%. Different slit selections tested. Emittance scans in progress. Done.

Cart removed for source servicing. Source opened and split at front seal. Ground and plasma electrodes removed. All internal areas cleaned. Source reassembled. Initial pumping in progress. Leak-up curve a little soft, but reasonable given the cleaning materials used: methanol, acetone, Simple Green.

Supernanogan development starts today. The TACTIC run, which ended around 08:30 today, appears to have been a success. TACTIC used our beam for setup and pilot, then took 8Li from downstairs. Marco is doing some EOB checks now. We will begin at 10:00. First part of our run plan will be to compare the present 16O2+ beam with how it looked when we started, and identify what might have changed.

Proposed Run Plan for Today &ff

1. Compare present 16O2+ beam with start of TACTIC run and identify change factors.
2. RF frequency scans versus each charge state of 16O.
3. Identify frequency with largest bandwidth for each state.
4. Emittance scan for best beam of each state.
5. Compare with earlier emittance scans.
6. Select one clean beam and test whether or not RF amplitude changes best frequency.
7. Comprehensive mass scan.
 

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:

Swiched off all the pumps and ion gauge for oven installation.

IOS mass scan does not work.

A/Q            FC6                X          Y          CCB1

1                2.07e-7        167      97       500

2                2.18e-7         308     247

2.14          1e-11             388     277 

2.246       2.07e-8         358     227

2.30          2e-9             378      227 

2.366       1.28e-8         388     277

2.392        2.1e-11        388     277

2.4641      1.98e-11     388     277

2.5345      6.49e-11     398     277

2.5614     1.81e-10      398    227

2.6263     2.95e-7         398   227

2.7522     2.07e-8         398   227

2.7896     2.06e-10       398   227

2.8652     3.22e-11       398   227

2.9515     8.52e-8         398   237

Here is a list of 16On+ emittance scans for today. Although IOSIOC got rebooted, restored tune was identical and trouble-free, and RF was untouched. Save file: 090619_0859.snapmcisfc6. Emittance values: pi-mm-mrad at 39%, 63%, 86% and 90% respectively. Here we go.

16O1+ datafile profile emittance 6.19 10.8 16.6 17.6

16O2+ datafile profile emittance 2.94 5.51 8.96 9.62

16O3+ datafile profile emittance 2.47 4.57 7.62 8.22

16O4+ datafile profile emittance 1.88 3.62 6.28 6.82

16O5+ datafile profile emittance 1.62 3.13 5.57 6.08

16O6+ datafile profile emittance 1.55 2.99 5.25 5.7

16O7+ datafile profile emittance 0.779 1.42 2.14 2.27

Chris confirmed the first SIS beam would be Na+1. Next Rb+1 and then Li+1

A new SIS source has been installed.  The oven has been loaded with Sodium Hydrogen Carbonate (Alfa Aesar 10863) and Rubidium Nitrate.

Pictures are located in 2014-11-13 Source and PS Pics

A water leak was reported inside the HV cage (FR#8079).  The cage was accessed to determine the source of the leak (WP#I2015-04-27-1).

The WMS cusp cooling line was leaking.  It was close to the MCIS cart (at ground) and had sparked through.  The hose was cut at the puncture location and re-connected. to the fitting.  It was re-routed to be further away from the MCIS cart.

16O2+ beam on FC6 = 10nA as before. Move to 16O3+ A/q = 5.33...

A frequency scan between 13 & 14GHz. I panned closer around two peaks at 13.11 and 13.12GHz. Best frequency so far is 13.1321GHz, which provides a reasonably stable 150pA of 16O3+.

Later... more scans, etc. One of several possible solutions for 16O3+: ~450pA at 13.6348GHz. Let it cook for a while.