7E10 single injections

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Xymox
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7E10 single injections

Post by Xymox » Sat Apr 10, 2010 9:29 am

Well,,, another exciting record..

7e10 protons in one injection... In one bunch...

VERY impressive.. I dont know what the limit is for one bunch but this was, at least for me, completly unexpected. I had no idea they could do that...

If they do 7E10 per bunch and then do 43 bunches per beam... Wow... can you say luminosity ?

Exciting stuff.. Just TONS of collisions for the physicists..

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Re: 7E10 single injections

Post by Xymox » Sat Apr 10, 2010 9:43 am

Hi Chris,

We have a bit of work to do before getting bunches of that size to high energy in physics – but its a start.

The nominal bunch intensity is 1.15x10+11 this is what we will eventually be aiming for. We also have a plan to increase this to 1.7x10+11 per bunch. Beyond this needs some serious upgrades on some of the systems.

The realistic limit for an eventual 25ns bunch spacing is around 2.3x10+11 per bunch – but if we put fewer bunches in the machine we could probably increase this. Our planned injector upgrade aims for around 3x10+11.
N I C E...

You gotta love luminosity !

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Re: 7E10 single injections

Post by Xymox » Sat Apr 10, 2010 10:02 am

Also....

I understand that the experiments current are just accepting all collisions with the event filters almost turned off, so the 100/second is the current raw rate. More or less..

However the plan is to get to 600,000,000 collisions / second.. WHich will require using the event filters to just get the events that are interesting..

So they have a ways to go.. But thats the next step in the weeks/months ahead..

Luminosity....

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Re: 7E10 single injections

Post by CharmQuark » Sat Apr 10, 2010 1:21 pm

Great stuff :D
Anyone who doesn't take truth seriously in small matters cannot be trusted with large ones either by Albert Einstein.

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Re: 7E10 single injections

Post by Kasuha » Sat Apr 10, 2010 2:58 pm

I think the period of low event rates is good for them to fine-tune their filters. Nobody will be looking at filtered-out events later.

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mrgumby
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Re: 7E10 single injections

Post by mrgumby » Sun Apr 11, 2010 6:05 am

We are seeing the LHC take its first wobbly baby steps......2 or 3 lurches then sit down on its bum quickly.......wait till it learns how to FLY.....WEEEeeeeeee! Then watch the records collapse in a heap!......No I don't care about mixed metaphors.

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Re: 7E10 single injections

Post by chriwi » Mon Apr 12, 2010 5:58 am

Nobody will be looking at filtered-out events later.
Thats true, but not as bad as it sounds, because they also later have at least one filterchanel which accepts a small procentage of random collission events only to make sure that the filters not cancel out something unexpected but nevertheless interesting.
I belive that even at higher collisisonrates only this channel will deliver more random collissin events than the total number of collisions today.
bye

chriwi

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mrgumby
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Re: 7E10 single injections

Post by mrgumby » Mon Apr 12, 2010 11:43 pm

Can someone enlighten me as to what "1.87e+10" and other similar numbers actually means?

I know it refers to beam intensity and I assume that it is a mathematical shortcut for a particular number of Protons.....But I don't know what "e" is and I don't really know what "+10" means (10 zeros?) my math education stopped way before I learnt that stuff. (googling "e" doesn't help)

:?

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Re: 7E10 single injections

Post by pixelmasseuse » Tue Apr 13, 2010 12:47 am

mrgumby wrote:Can someone enlighten me as to what "1.87e+10" and other similar numbers actually means?

I know it refers to beam intensity and I assume that it is a mathematical shortcut for a particular number of Protons.....But I don't know what "e" is and I don't really know what "+10" means (10 zeros?) my math education stopped way before I learnt that stuff. (googling "e" doesn't help)

:?
1.87E+10 is shorthand for 1.87 X 10^10, or 1.87 X 10,000,000,000. Just move the decimal point to the right 10 places - adding zeros as needed to prevent magnetic hole formation - voila, 18,700,000,000.

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Re: 7E10 single injections

Post by mrgumby » Tue Apr 13, 2010 1:16 am

Thanks for that pixelmasseuse...Its good to have that confirmed.
I'm still curious what "e" stands for tho....

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Re: 7E10 single injections

Post by pixelmasseuse » Tue Apr 13, 2010 1:28 am

"exponent" - you might want to take a look at the Wikipedia entry for scientific notation

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mrgumby
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Re: 7E10 single injections

Post by mrgumby » Tue Apr 13, 2010 3:06 am

pixelmasseuse.....thankyou...it is all clear now......I should explain...i left school at 15...47 years ago so i missed some of the real basic stuff. I'm picking it up slowly now thanks to people like you. Thanks again.

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Re: 7E10 single injections

Post by pixelmasseuse » Tue Apr 13, 2010 3:16 am

no prob.. you're welcome, mrgumby!

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Re: 7E10 single injections

Post by Bornerdogge » Wed Apr 14, 2010 8:33 pm

I read they wanted to put +- 2800 bunches of 10e11 into the machine... But that was before the accident; how many bunches should we expect for this run??

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Re: 7E10 single injections

Post by Kasuha » Wed Apr 14, 2010 9:22 pm

They still plan to put 2800 bunches into the machine ... when they are sure they'll not destroy it. For the time being they're slowly commisioning beam parameters - squeeze at experiments and injections of single high intensity bunches with plans to slowly increase numbers of bunches soon. See here for more details.

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