How is the quality of the beam being currently improved?

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jmc2000
Posts: 153
Joined: Sun May 08, 2011 2:51 pm

How is the quality of the beam being currently improved?

Post by jmc2000 » Sun Jul 15, 2012 10:13 pm

The LHC is operating at a PPB of 1.45x10^11 compared to 1.525x10^11 before the last technical stop, so they're obviously tweaking the beam injection in someway, possibly after gaining a better understanding of what's causing the losses during the 2m squeeze. Anyone know what they're looking at, or discovered recently and how this affects the beam injection?

On the current fill 2848, I don't quite believe what I'm seeing: both beams of exactly the same current and beautifully superimposed on one another with improved loss over time. Could it be that the losses and beam stability are very sensitive to asymmetrical beam currents?

gilgamorph
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Location: Kenosha, WI

Re: How is the quality of the beam being currently improved?

Post by gilgamorph » Mon Jul 16, 2012 2:07 am

Good catch, I had also noted the reduced bunch intensities. I also noted that a previous fill had an impressively tight range of bunch intensities. They seem to be making strides in the injection process after some earlier problems.

I wonder if they lowered the maximum allowed bunch intensity to limit overheating of the kicker magnets ?
This would leave tightening the bunch intensity distribution as the only way to boost luminosity.

I figured they were trying to both reduce the maximum pileup and limit radiation damage now that the pressure to report five sigma is gone.

*edit - musings should have been in a separate thread*

jmc2000
Posts: 153
Joined: Sun May 08, 2011 2:51 pm

Re: How is the quality of the beam being currently improved?

Post by jmc2000 » Sat Jul 21, 2012 2:04 am

Fill #2861 looks perfect - how did they do it?

I'm sure the morning notes will have a lot more to say about this one.

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