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Re: 7E10 single injections
Posted: Thu Apr 15, 2010 2:55 pm
by Anitusar
chriwi wrote: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.
The primary concern is (at least this is what i heard from LHCb) that one creates a bias in the data selection., e.g. the lifetime of a b-meson appears to be larger in the selected events than in reality. This can be caused by a momentum cut or cuts on the vertex reconstruction. To study this effects, one needs a "clean" sample, the minimum bias sample, which is just a random trigger.
Re: 7E10 single injections
Posted: Thu Apr 15, 2010 10:29 pm
by tomey36
how much harder is it to run the lhc with higher intensity beems like 11e10. is it takeing them longer to increase the beam intensity becuase they are worried about damgeing the machine or is it becuase it is more chalengeing to run with higher intensites.
Re: 7E10 single injections
Posted: Thu Apr 15, 2010 11:50 pm
by tswsl1989
A bit of both to be honest
Re: 7E10 single injections
Posted: Fri Apr 16, 2010 1:43 am
by pixelmasseuse
looks like they are alternating between physics fills (with squeeze studies) and high-intensity injection/dump studies. this physics fill intensities are edging up... the present fill is ~ 3E10.
also, it looks like there is a lot of intensity loss in the squeeze studies, especially when they get down to 2m.
Re: 7E10 single injections
Posted: Fri Apr 16, 2010 1:56 am
by Harbles
Re: 7E10 single injections
Posted: Fri Apr 16, 2010 6:19 am
by chriwi
Hi Harbles,
what exactly do you mean with your last post? Do you have any confirmation that there isn't anything more exiting than 3.5TeV collissions all the time is going on in the next days?
Or is it rather like that that thescheduel posted is already a few days old and is object to changes like many older schedels before. By the way, ehwn there wil be a new one?
Re: 7E10 single injections
Posted: Fri Apr 16, 2010 7:46 am
by mrgumby
I suspect that Harbles means....Don't rush at things, take things slowly and gently, and ultimately you will reach your goal.