Alice having difficulties?

Questions / discussions specific to the ALICE experiment or science
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Tim Bergel
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Alice having difficulties?

Post by Tim Bergel » Wed Jul 14, 2010 11:27 am

Does anybody know if ALICE is having difficulties? Recently while stable high intensity beams are circulating and all the other detectors are doing PHYSICS, ALICE always seems to be NOT READY.

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chriwi
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Re: Alice having difficulties?

Post by chriwi » Thu Jul 15, 2010 9:03 am

Maybe Alice is not so interested in Proton-Proton-collissions. Alice is mainly desinged to detect heavy-ion-colissions. Maybe they used early cproton-proton only for calibratin and are already making preparations for heavy-ion-collissions planned end of summer.

I am only guessing, but that Alice is minly for heavy-ions thats sure.
bye

chriwi

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DCWhitworth
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Re: Alice having difficulties?

Post by DCWhitworth » Thu Jul 15, 2010 9:05 am

Well they're delilberately not colliding much in ALICE by leaving the seperation bumps in. There could be various reasons for this but I've not heard anything specific.
DC

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zaim
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Re: Alice having difficulties?

Post by zaim » Thu Jul 15, 2010 10:24 am

Alice gets less luminosity in order to avoid pile up. I.e. they dont want more than one collision per crossing. See e.g. the footnote on these figures http://lpc.web.cern.ch/lpc/lumiplots.htm

I visited the Alice cavern a year ago, it was clear that they were not as close to be ready for collisions as the other experiments. They will see their first ion-run in november.

Cheers Anders
BTW: wish me luck, i have my final exam at uni in 1½ h !

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mrgumby
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Re: Alice having difficulties?

Post by mrgumby » Fri Jul 16, 2010 8:40 am

good luck Zaim......but if you know your stuff, you will not need luck....

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