Download - LHC e - cloud simulations
LHC e- cloud simulations
C.Octavio Domínguez, Giovanni Rumolo, Frank Zimmermann
17th January2011 - e- cloud simulations
2
Contents
1) LHC IR3:
I. State of the art
2) LHC arc dipoles:
II. Emittance scan (onset, build up & energy distribution)
III. Intensity scan (build up & x-flux distribution)
17th January2011 - e- cloud simulations
3
Contents
1) LHC IR3:
I. State of the art
2) LHC arc dipoles:
II. Emittance scan (onset, build up & energy distribution)
III. Intensity scan (build up & x-flux distribution)
17th January2011 - e- cloud simulations
417th January2011 - e- cloud simulations
LHC IR3
First idea Try to reproduce this plot, BUT 4 parameters: P, SEY, emax and R
617th January2011 - e- cloud simulations
LHC IR3 – 8.85 ms
~ Factor 1.1
~ Factor 1.1
No memory effect ??
1017th January2011 - e- cloud simulations
LHC IR3 – Work to do
Look at 28.85 and 38.85 ms
Look at the flux (maybe related to the pressure rise)
Make the study for individual batches of 12, 24 and 36 bunches
…
11
Contents
1) LHC IR3:
I. State of the art
2) LHC arc dipoles:
II. Emittance scan (onset, build up & energy distribution)
III. Intensity scan (build up & x-flux distribution)
17th January2011 - e- cloud simulations
12
LHC arc dipoles - e scan
17th January2011 - e- cloud simulations
Geometry:
Parameters:
Nb = 1.1 · 1011 ppb; B = 0.535 T (dipolar field) ; sz = 0.118 m
emax = 230 eV ; R = 0.7; P=1nTorr
Filling scheme: 1 batch (36 bunches)
22 mm
18 mm
1317th January2011 - e- cloud simulations
LHC arc dipoles - e scan
eN (mm) SEY (onset/significative density)
1 1.9 / 2.3 (~0.5 1011) - 2.4 (~3 1011)
2 1.9 / 2.3 (~0.45 1011) - 2.4 (~3 1011)
3 1.9 / 2.4 (~ 1011)
4 2.0 / 2.4 (~ 1011)
10 2.0 / 2.4 (~ 1011)
21
Contents
1) LHC IR3:
I. State of the art
2) LHC arc dipoles:
II. Emittance scan (onset, build up & energy distribution)
III. Intensity scan (build up & x-flux distribution)
17th January2011 - e- cloud simulations
22
LHC arc dipoles - Nb scan
17th January2011 - e- cloud simulations
Geometry:
Parameters:
eN = 2.3 mm; B = 0.535 T (dipolar field) ; sz = 0.118 m
emax = 230 eV ; R = 0.7; P=1nTorr
SEY=2.5 (above multipacting onset)
Filling scheme: 1 batch (36 bunches)
22 mm
18 mm