See ISAC elog entry today.  Keerthi developed a dual-mode tune last night, so that we can run the MWS at will if so desired. Save file: 090624_0930.snapmcisfc6. Emittance scans done. Overnight FC6 also attached. Sophia took the beam at 10:00.

Note: This is an updated emittance plot. The bias voltage was incorrect in the original datafile, therefore so were the emittance calculations. The plot itself is identical.

Supernanogan bias for this run is 16.32KV. After we were finished with source tuning, etc., we conditioned up to 20KV. Then beam was returned and 16O2+ tuned saved as 090623_1730.snapmcisfc6. Next step: Prepare MWS for dual operation. Source open now for source gas installation. Then Keerthi will develop a daul-mode tune, where the B1A bender only need be switched on or off to run either the MCIS or MWS source.

After a first round of source and line tuning for good current with minimum RF power, we have about 8nA of 16O2+ on FC6. Here is an emittance scan of that. Present RF settings are 15.438GHz and -1.0dB with less than 1W of RF power. Bias is 16.32KV. Let's do some bias conditioning for a bit.

We now have about 80nA of 16O2+, using the same source parameters as before. Keep a watch for a while, then tune the source to match user's needs, somewhere in the 10nA range.

Here is a stripchart of the 16O2+ beam for the last half-hour or so., and also the stripchart of it juxtaposed with 16O7+ earlier. Also a first 16O2+ emittance scan for this run. I will do source tuning with it momentarily.

Today is the last day of this set of Supernanogan Development. The source ran at 16KV overnight, in anticipation of 16O2+ delivery later today. I expected more bias sparking, but it appears that it sparked off only once. So I will condition at a higher bias later today. Meanwhile, the operators reported touching up the tune with the magnet and the RF. Perhaps we are seeing some temperature effect on the source, so I will be looking at effects of RF on 16O7+ for the next while.

 Below is a stripchart of the beam (in blue; turquise is RF power) for the last three hours, of which the last 150 minutes are at the present settings. Pretty good, I'd say. I double-checked the range on the RF, and it's exactly the same as the start. Excellent. To round things out, here is a last emittance scan of 16O7+ before we move to 16O2+.

In anticipation of 16O2+ delivery mid-week, we checked 16O2+ production from the Supernanogan source. No problem. We did have to use the tightest slit settings to achieve a low enough current for the user. Here are emittance scans, normal and with our test booster amplifier inline respectively. Subsequently we set up the line to match into the RFQ. Bias is at 16.32KV. Then we returned the mass selection to 16O7+ for the night. A final emittance scan of 16O7+ for today is shown. It clearly needs a stronger signal. With some slight tweaks, there are some 1nA of 16O7+ on FC6 now.

An emittance scan of the 16O7+ beam follows. Also, a stripchart of the same beam on FC6 overnight. Keerthi did some studies over the weekend. He found that the characteristics of the amplifiers behind FC6 and the emittance rig cup differ significantly. That's disconcerting. We did a visual this morning, and confirmed that the amplifiers are identical VME modules in the same crate. He believes it's a scaling thing. We will test again with a current source this afternoon.

Later... The apparent discrepancy between the two amplifiers was in fact a bad patch cable in the test setup. So that's solved. The two amplifiers differ in this way, that FC6 has the updated version with the middle gain ranges and auto-ranging, whereas the emittance cup does not. We will be asking Controls to update this amplifier to the now-ISAC standard. The test setup consisted mainly of a very high gain amplifier. Overall, the tests worked out pretty well, as you will see below in an emittance scan of 16O7+ done with the amplifier in the loop. The second emittance scan is 16O7+ and the highest EPICS gain setting, i.e. 1mA.  Note that Matlab is unable to calculate an emittance here. The third emittance scan is the same beam at the next gain setting, i.e. 1uA. We just about make it, with only a relative handful of data points clipped, and Matlab calculates emittance easily.

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

Keerthi developed a nice 16O7+ beam to FC6 last night. Beam current is about 3nA presently. Here is the first emittance scan from 11:05 today. A little spotty, but it's there. Higher resolution scan at 13:58 follows.

The third plot at 16:12 is 16O6+.

The fourth plot at 17:05 is a 16O5+ scan. However, the emittance rig stopped scanning at position #50, and is frozen at position #0 now. The operators are looking into it, and will reboot IOSIOC. I am ready to restore optics. Later... reboot and restore went well. Continue emittance scans.

The fifth plot at 18:36 is a higher res 16O5+ scan.

The sixth plot at 18:52 is 16O4+ and friends.

The seventh plot at 19:12 is 16O3+. It does not compare well with yesterday's scan of the same beam. Note that recovery from yesterday's IOSIOC reboot required a retuning effort. The source RF was changed in the interim also.

The eigth plot at 19:34 is 16O2+ and friends.

The ninth and final (for tionight) plot at 19:53 is 16O1+ and friends.

As mentioned before, IOSIOC was rebooted yesterday afternoon to unfreeze the emittance rig panel. It cost us our tune, which unfortunately wasn't saved very well. Lesson learned: Save often. I will run a mass scan now and check the mass correlations calibration. Then I will pick up with some 16On+ emittance scans. Keerthi was here until late last night working with the beam also. He will have some results for sure.

The first emittance scan of the day is in, 16O1+ at 10:29.

The second emittance scan of the day is in, 16O2+ at 11:00.

Break for a mass scan to A/q=50. (Fire alarm in ISAC-II rang around 11:30.) Here is the first part. I have run the data in Gabe's Calibrate program and adjusted the two constants slightly. Looks very good. BTW there are some new artefacts in the mass correlation plot that weren't there before. They don't affect anything but the appearance of the plot. However, they do append a few lines of spurious data to the plot data file, which have to be expunged manually.

The third emittance scan: 16O2+ check at 13:08. Looks OK.

The fourth scan : 16O4+ and friends at 13:24.

The fifth scan: 16O5+ at 13:31. This one should be redone.

The sixth scan: 16O3+ at 13:39.

A series of 16On+ emittance scans. Benchmark scan of 16O5+ matched well with same scan done this morning. Subsequent scans beginning with 16O1+ were thwarted by an IOSIOC seizure in the emittance rig EPICS panel, and an IOC reboot was required. ICR restored last saved DRAGON tune. So far, so good. Ah, well, not so fast. I have to go fishing for beam on FC6. This may take a while... That's it for today.

The 16O5+ beam stayed up OK overnight. ICR took some emittance scans this morning. They look interesting. A finer resolution scan is in progress presently. Goals today:

1. Comprehensive mass scan to A/q=100

2. Characterize 16On+ states, including emittance scans where possible.

Mass scan is in progress now. First look is attached below. The full scan is shown in Gabe's Calibrate application. Note the apparent lack of 84Kr, after a night of pumping with the source gas valve closed. A subsequent scan from A/q=0 to 20 is shown next. The same scan zoomed in at yesterday's scale is also shown for comparison of background intensities, particularly 16O5+ with A/q=3.2, which are higher today due to source tweaking this morning. Now I will start a series of emittance scans, starting with 16O5+ as a benchmark. I expect it to be near-identical with this morning's scan.

Keerthi suggested using 16O5+ for optimizing the source. I did a tight mass scan in that area, and 16O5+ is clearly visible. I will use it for some source tweaking. Also, I used Gabe's calibration program to slightly adjust the values of the two constants. There are some 10nA of 16O5+ on FC6 presently. Final settings for today, etc. are attached below.

We began looking at 84Kr this weekend. Keerthi had 84Kr19+ on FC6 this morning, which I was able to tweak up from ~300epA to about 600epA. Not bad! This evening it is down to 100pA at best. I think there is a correlation of multi-charge production and room temperature. (It's warm today.) Keerthi noticed tat an entire mass scan this afternoon was suppressed, where I had a solid scan earlier, the two taken the same way. Let's see what happens to FC6 overnight.

Damien Gallop wrote:

We began looking at 84Kr this weekend. Keerthi had 84Kr19+ on FC6 this morning, which I was able to tweak up from ~300epA to about 600epA. Not bad! This evening it is down to 100pA at best. I think there is a correlation of multi-charge production and room temperature. (It's warm today.) Keerthi noticed tat an entire mass scan this afternoon was suppressed, where I had a solid scan earlier, the two taken the same way. Let's see what happens to FC6 overnight.Beam d

Beam definitely correlated with something overnight. I'm going to say that temperature somehow affects MCIS vacuum, which in turn affects the generation of the higher charge states. We will investigate this further. We did a couple of mass scans this morning. I have closed off the krypton gas bottle to get a background scan. Here is the preliminary one, started a few minutes after closing the hand valve. You can see the clump of 84Kr charge states between approximately masses 4 and 10. Another scan to come shortly, with everything the same except an hour's delay after closing the valve. Here it is, below. The height of the "clump" is less, and it begins more to the right of mass 4 or so than the earlier scan. Note that the small amount of 84Kr remaining after shutting off the source bottle is slightly offset on the plot. I will recalibrate the numbers shortly.

A comment about RF power came up at the presentation this morning. Intense X-rays can be produced not only at the peak efficiency and output of the RF amplifier but also as a function of other parameters including source gas pressure, isotope(s), whatever you can think of. I set the RF at a mid-level power, with power setpoint at 0dB and adjusted the RF for optimal current on FC6. This occurred at 13.0306GHz with 35W power. About 6nA of beam. Take a quick emittance scan.

Presentation this morning in Auditorium. Players:

Keerthi: science

Geoff: engineering

Damien: operation

Cold start-up of source with 17O3+ beam to FC6 in front of an audience worked flawlessly.

Pumping went well overnight. TP3 turned on around noon. Issues with Kepco communications.

Krypton source gas teed directly into ion source. A Nupro valve and tee also added for 17O line. At present, the 17O gas bottle valve is closed. The Kr bottle has an integrated leak, so this bottle is opened to the system now. Pumping in progress. Pressure is already <3e-7 Torr. I will restart the source shortly.

We handed over the beam to Sophia for testing Rick's new tune. Although there are RF issues at the RFQ presently, her feedback to the operators is so far, so good. TBC tomorrow morning. Right now, we will open the OLIS cage and install a couple of source gases in preparation for our presentation on Friday.

Main event this morning so far: mass scans and post-scan analysis using Gabe's tools. We have a pretty good recipe now. Tight scan to mass 20 in progress. Later... good scan. Geoff and I did a dry run of our presentations for Friday morning. We used the Auditorium computers, etc. After some small teething pains, everything went well, including a cold start-up of the source. The 17O3+ emittance scan was taken quickly. Pretty good outcome anyway. The mass scan shows nice peaks at several known points: 1H+, 2H2, 4He, 7Li, 12C, 14N, 16O, 19F and 20Ne. Gabe's Calibrate tool returns values for the two constants that are pretty close to what is there now: -1 and 0.0419 calculated versus 0 and 0.0418 actual.