Beam was idle overnight. We took the beam for a while this morning, and ran a mass scan. We opted to not go into the cage to install helium gas lines or fix water lines, because it would mean switching off the source. So we will do the gas tomorrow or so, and fix the water leaks then too.

Note that the separator field is up about 4G from this morning.

Mike declared successful EOB this morning. "Best beam I ever used" or something like that! EOB emittance and mass scans attached. Note that slits are at non-standard positions for 5mm gap.

Now we are going to open the source for some maintenance and continue 4He2+ development after that.

The source ran well overnight and today. There is an issue with an ILE Faraday cup. Tuning is ended for today, and beam is on FC6.

By agreement, we are providing OLIS beam to the Beam Delivery group for the purpose of checking out transmission in the 8pi line. We have set up a 20Ne1+ beam at 28keV. There are some 3nA on FC6.

Here are optics numbers for IOS section:

Quad	    Rick's values	   Optimum values

Q1		1331V			1666V
Q2        	 661V			 580V  
Q3		   0V			   0V
Q4		 732V			 732V
Q5		   0V			   0V
Q6		1770V			1770V
Q7		 660V
Q8		 965V

An initial emittance scan is attached, raw and filtered. A higher resolution follows. Surprisingly, it is grainier than the earlier one. Slits are at 5mm setting.

Milestone note: The commencement of using this beam today at around 14:00 marks the first time in ISAC history that a filament ion source is used to deliver a beam to a user. Hooray!

20Ne+2 beam optics saved as 150914_1117_ios0iosfc6.snap

test

Slit calibration exercise was wound up this morning. MCIS source gases were reconfigured with 19F and 40Ar by request. A "cocktail" beam will be used for HE development over the Thanksgiving weekend. A mass scan is in progress presently.

Source set up for a cocktail beam since yesterday, Sunday.

Cocktail beams continue today.

The 18O source gas bottle is online. The ion source was optimized for 18O4+ and kept the same throughout. Emittance scans of each charge state of 18O were attempted. Visible scans were found for all states up to 6+. At least one more set of scans is desireable. Present beam is 18O4+. Next up: RF frequency survey with 18On+.

The Supernanogan was restarted this morning, after last night's power bump. 18O4+ on FC6, cooking for about an hour. Looks very good. Keerthi is doing frequency scans today to find best resonances. Time permitting, he will do this over a range of 18O charge states. At some point over the weekend (my guess is tomorrow evening), he will open the 17O source gas bottle to the system.

The Supernanogan was restarted this morning, after last night's power bump. 18O4+ on FC6, cooking for about an hour. Looks very good. Keerthi is doing frequency scans today to find best resonances. Time permitting, he will do this over a range of 18O charge states. He is also developing a dual-mode (MCIS/MWS) IOS tune. At some point over the weekend (my guess is tomorrow evening), he will open the 17O source gas bottle to the system.

As noted earlier, we have 17O and 18O source gas attached to the Supernanogan source chamber. Both are valved off presently. The source has been running for a while. I set it to 18O4+ on background, which gives about 125epA on FC6. Now let's stop the source, open the bottle and try the same again.

I opened the 18O valve just around 18:00. Beam is on now, around 150pA. That's a good sign. It's growing too. Even better. The MCIS tank pressure moved from ~6.5e-8 Torr to ~6.6 as I opened the valve, which is located upstream of a calibrated leak. Note that both source gas bottles have 10-5 calibrated leaks in series, so it will take a while to reach equilibrium. I attempted a couple of emittance scans, but it's too early yet.

During the last week we delivered 18O+2 from microwave ion source to Ritu.

Over the week end changed to 40Ar+2.

Ritu informed us 18OH2 is coming with 40Ar+2.

Moving the slits ops managed to reduce 18H2 contaminant from the beam.

Good lesson for the future. Bad combination one after the other.

A/q = 2.25 Field = 704.7G FC6 = <pA

Well, it's there, but pretty faint. The attached stripchart shows no beam then beam. FC6 bias has to be revered to see it.

A/q = 2.25 Field = 702.5G FC6 = not visible

It looks like last night's vacuum trip is biting us here.

Go fishing in the range 2.24-2.26, but no fish in this pond this time. However, there is a relatively strong beam at 2.3.

A/q = 2.3 Field = 711.2 FC6 = 110enA

No emittance scan possible.

I did a check at A/q = 2, and found a strong peak at 2.04 field 668.8 18enA, suggesting that the A/q panel calibration is slightly off for the lower masses, and in the right direction for the above to indeed be 18O8+. Good stuff.

Next stop: 18O6+.

Keerthi did some 18On+ frequency scans this morning. He observed 18O8+! I am attempting to repeat it myself now. Reverse bias on FC6.

Peaks at:

13.0277GHz => 1epA (unstable)

13.1023GHz => 1epA (unstable)

13.1695GHz => 10epA (unstable)

13.1672GHz => 20epA (unstable) stripchart attached

13.006GHz => .7epA stripchart at 17:24 attached

First, optimize current versus frequency and amplitude. Unfortunately at 5dB the beam blinked out. Go fishing, then find it again. Attached is stripchart at 17:30, where I was optimizing, then switched bias to Normal, then watched beam blink out. Then stripchart at 17:49 shows beam back again, reverse bias on the left and normal bias on the right: ~10epA. RF settings also attached. Minutes later, beam is still on. FTR, the original RF is appended at the end.

A/q = 2.25 FC6 at reverse bias MB = 736.9G @ 42.9A

Not enough intensity for an emittance scan. Possibly on the edge of A/q=2.3 (23Na10+?).

Here is a striptool of 18O8+ beam (magenta trace) last evening from about 18:00 to 22:30 when there was a large power bump coincident with a plane crash in Richmond last night. Before the trip, beam current was about 20epA on FC6 (normal bias).