 Fri Sep 11 23:42:45 2009, Keerthi, Other, General, MCIS turbo pump 
|
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, |
|
Tue Sep 8 15:14:45 2009, Damien Gallop, , , Back from vacation
|
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. |
|
Tue Aug 18 11:16:16 2009, Damien Gallop, , , MCIS "PV" PLC trip overnight
|
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. |
|
Mon Aug 17 15:53:54 2009, Damien Gallop, , , MCIS mass scans & initial emittance scans 11x
|
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 |
|
Mon Aug 17 13:58:35 2009, Damien Gallop, , , Supernanogan Development begins today for one week
|
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 |
|
Fri Aug 14 13:53:34 2009, Damien Gallop, , , MWS 25Mg end of run data 10x
|
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 |
|
Tue Aug 11 09:54:28 2009, Damien Gallop, , , MWS 25Mg operation overnight & MCIS cart installation
|
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 |
|
Mon Aug 10 18:29:32 2009, Damien Gallop, , , MWS source trip & restart
|
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. |
|
Mon Aug 10 18:06:09 2009, Damien Gallop, , , MWS 25Mg reduce intensity with PE
|
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: |
|
Mon Aug 10 17:42:18 2009, Damien Gallop, , , MWS 25Mg emittance scan with original settings 6x
|
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 |
|
Mon Aug 10 17:20:55 2009, Damien Gallop, , , MWS 25Mg emittance scan with zeroed vertical steerers
|
Here is a variation I thought might be appropriate.
Data file: 090810_1724ILTEMIT.txt |
|
Mon Aug 10 17:16:20 2009, Damien Gallop, , , MWS 25Mg emittance scan with downstream quads off
|
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 |
|
Mon Aug 10 16:43:59 2009, Damien Gallop, , , MWS 25Mg emittance scan with slits open
|
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. |
|
Mon Aug 10 16:36:33 2009, Damien Gallop, , , MWS 25Mg emittance scans
|
A series of 25Mg emittance scans for Rick.
Starting scan with everything as-is, i.e. slits closed.
Data file: 090810_1621ILTEMIT.txt |
|
Mon Aug 10 16:12:28 2009, Damien Gallop, , , MWS 25Mg operation over the weekend
|
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 |
|
Fri Aug 7 14:42:29 2009, Damien Gallop, , , MWS 25Mg beam reduction
|
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. |
|
Fri Aug 7 10:16:38 2009, Damien Gallop, , , MWS 25Mg emittance scans 6x
|
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. |
|
Thu Aug 6 17:02:00 2009, Damien Gallop, , , MWS 25Mg tuning to TIGRESS in progress 7x
|
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. |
|
Wed Aug 5 11:29:51 2009, Damien Gallop, , , MWS operation overnight and 25Mg status
|
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. |
|
Tue Aug 4 11:13:04 2009, Damien Gallop, , , MWS source tuning for 25Mg operation 6x
|
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. |