Hello, looking at the vistars (meltronx.com) in one of the LHC dashboard panels you can see Tune and Losses. I tried but could not understood some of the panels, if someone is so kind to explain It will be very welcomed. http://lhclite.meltronx.com/dash.html
How Tune is read? Why are there multiple spots from time to time?
Same thing for Losses, I someone can explain how is it read it will be great.
Thanks very much.
Regards;
fernando
Tine and Losses Panel in vistars
Re: Tine and Losses Panel in vistars
The following is just my understanding of what you ask, someone please correct me if I am totally off-track.
You can find excellent description of the tune here among other beam parameters. Vertical position of the tune dot represents measured vertical tune and horizontal position of the dot the horizontal tune Lines crossing the graph represent resonance lines, so you don't want your dot to be at one. Resonance-free region (the box shown) is fairly small so good control of the tune is obviously required.
I think that multiple dots are due to that tune amplitude becomes low when transverse damper gain is turned up to stabilize the beam, so tune measurement becomes inaccurate.
Loss plot shows how much energy is lost from the beam to collimators and magnets etc. Unit is Gray = 1 Gy which means 1 J/(kg*s) = 1 W*s/kg. Less losses one sees, better the situation. The most losses are concentrated around points 3 (off-momentum collimators to clean out particles with wrong momentum) and 7 (transverse (betatron) collimators to clean out transversely off particles). There are also luminosity induced losses around experiments, which you can see around points 1, 2, 5 and 8.
Regards,
Janne
You can find excellent description of the tune here among other beam parameters. Vertical position of the tune dot represents measured vertical tune and horizontal position of the dot the horizontal tune Lines crossing the graph represent resonance lines, so you don't want your dot to be at one. Resonance-free region (the box shown) is fairly small so good control of the tune is obviously required.
I think that multiple dots are due to that tune amplitude becomes low when transverse damper gain is turned up to stabilize the beam, so tune measurement becomes inaccurate.
Loss plot shows how much energy is lost from the beam to collimators and magnets etc. Unit is Gray = 1 Gy which means 1 J/(kg*s) = 1 W*s/kg. Less losses one sees, better the situation. The most losses are concentrated around points 3 (off-momentum collimators to clean out particles with wrong momentum) and 7 (transverse (betatron) collimators to clean out transversely off particles). There are also luminosity induced losses around experiments, which you can see around points 1, 2, 5 and 8.
Regards,
Janne
Re: Tine and Losses Panel in vistars
I could just add that in the loss map, the red marks represent the dump threshold or maximum allowed losses for each of the monitors. If the losses (green bars) reach the red mark at any point, the beam will be dumped.
Re: Tine and Losses Panel in vistars
Thank you both for this information; the red marks had confused me for quite awhile.
Re: Tine and Losses Panel in vistars
So what are the blue bars?adam_jeff wrote:I could just add that in the loss map, the red marks represent the dump threshold or maximum allowed losses for each of the monitors. If the losses (green bars) reach the red mark at any point, the beam will be dumped.
Re: Tine and Losses Panel in vistars
Thanks very much Janne & Adam.jahonen wrote:The following is just my understanding of what you ask, someone please correct me if I am totally off-track.
You can find excellent description of the tune here among other beam parameters. Vertical position of the tune dot represents measured vertical tune and horizontal position of the dot the horizontal tune Lines crossing the graph represent resonance lines, so you don't want your dot to be at one. Resonance-free region (the box shown) is fairly small so good control of the tune is obviously required.
I think that multiple dots are due to that tune amplitude becomes low when transverse damper gain is turned up to stabilize the beam, so tune measurement becomes inaccurate.
Loss plot shows how much energy is lost from the beam to collimators and magnets etc. Unit is Gray = 1 Gy which means 1 J/(kg*s) = 1 W*s/kg. Less losses one sees, better the situation. The most losses are concentrated around points 3 (off-momentum collimators to clean out particles with wrong momentum) and 7 (transverse (betatron) collimators to clean out transversely off particles). There are also luminosity induced losses around experiments, which you can see around points 1, 2, 5 and 8.
Regards,
Janne
Really appreciate.
Cheers.
fernando