Hi everyone;
Is anyone able to explain this log entry?http://lhcportal.com/Forum/posting.php?mode=post&f=4#
The filling scheme has changed in order to inject a pilot bunch in Bunch ID 1 for both beam. The corrected
values for Bunch ID are:
Bunch ID 1 : beam 1 pilot (5e^9) - beam gas
Bunch ID 101 : beam 1 high intensity - gas
Bunch ID ~102.5 : displaced beam1-beam2 high intensity (+11.25m)
Bunch ID 104 : beam 2 high intensity - beam gas
Bunch ID 895 : beam 2 pilot - beam gas
Bunch ID 995 : beam 2 high intensity - beam gas
Bunch ID 1883 : beam 1 high intensity - beam gas
Bunch ID 2209 : beam 1 - beam 2 colliding high intensity
Bunch ID 2774 : beam 1 - beam 2 colliding high intensity
FYI, the Beam Phase and Intensity Monitor now shows the BunchID as measured in LHCb IP8 and the measured
intensity (in ADC counts just for tonight...).
>
> New filling scheme for this evening to avoid problem with the injection kicker:
>
> Bunch ID 1 : beam 1 - gas
> Bunch ID ~2.5 : displaced beam1-beam2 (+11.25m)
> Bunch ID 4 : beam 2 - gas
> Bunch ID 895 : beam 2 - gas
> Bunch ID 1783 : beam 1 - gas
> Bunch ID 2109 : beam 1 - beam 2
> Bunch ID 2674 : beam 1 - beam 2
Thank you
Allan
LHCb Logfile
Re: LHCb Logfile
As you may know, the protons aren't a constant beam, but are split into "bunches". In the end the LHC intends to run [some number over 1000] bunches at once.
If you imagine the LHC as a circle split into quite a few sections, each section being called a "bucket", a bunch can be in any bucket theoretically.
However, you want to be able to put the bunches in position such that they hit the other beam's bunches - so you put them in a specific bucket. You might also want to reserve other bunches/buckets, as they seem to be doing below.
It sounds like they're just changing a few settings, to make things work better
If you imagine the LHC as a circle split into quite a few sections, each section being called a "bucket", a bunch can be in any bucket theoretically.
However, you want to be able to put the bunches in position such that they hit the other beam's bunches - so you put them in a specific bucket. You might also want to reserve other bunches/buckets, as they seem to be doing below.
It sounds like they're just changing a few settings, to make things work better
Re: LHCb Logfile
To add some more information: All the electronic components of the experiment have implemented a counter which basically counts the number of these buckets that have passed the experiment. This information is send out with the measured data by the electronics upon a trigger (command to read out the electronic).
So if you want to find some collision data, you only have to look at data with the corresponding bunch IDs.
So if you want to find some collision data, you only have to look at data with the corresponding bunch IDs.