ecloud simulations update
DESCRIPTION
E-cloud Simulation Meeting. Ecloud Simulations Update. Humberto Maury Cuna. Thanks to L. Taviant , G. Iadarola , D. Sagan. G. Dugan, F. Zimmermann. Janaury 11 th , 2013. Outline. Heat load benchmarking at 4 TeV and 25-ns bunch spacing. Future work: Photon distribution. - PowerPoint PPT PresentationTRANSCRIPT
Ecloud Simulations Update
Humberto Maury Cuna
E-cloud Simulation Meeting
Janaury 11th, 2013
Thanks to L. Taviant, G. Iadarola, D. Sagan. G. Dugan, F. Zimmermann
OutlineHeat load benchmarking at 4 TeV
and 25-ns bunch spacing.Future work: Photon distribution
Heat-load benchmarking at 4 TeV and 25 nsFill number
Bunch intensity
(x1011)
Fill pattern R0 SEY
34253427342834293436
1.1 (84b)1.2 (156b)1.1 (372b)1.06 (804b)0.91 (804b)
25ns_84b_72_0_0_BBMD125ns_156b_72_72_72_BBMD225ns_372_72bpi_6inj_2012_MD25ns_804b_72bpi_12inj_2012_MD25ns_804b_72bpi_12inj_2012_MD
0.3-
0.7
1.3-
1.7
Only dipoles considered.Simulations done with PyECLOUD.
Measured heat load
0 5 10 15 20 25 300.0
0.1
0.2
0.3
0.4
0.5
Qec
ave
rage
(W/m
per
aper
ture
)
Time (h)
Fill 3429Fill 3436
Thanks to Laurent Tavian
1.30 1.35 1.40 1.45 1.50 1.55 1.60 1.65 1.700.30
0.35
0.40
0.45
0.50
0.55
0.60
0.65
0.70
Low
-energ
y e
lectr
on R
eflectivity (R
0)
Secondary emission yield (max
)
0.00300
0.0494
0.0958
0.142
0.187
0.235
0.281
0.328
0.374
Heat load (W/m)
Heat load values at 4 TeV - 25 ns - Fill 3428
δmax = 1.58
1.30 1.35 1.40 1.45 1.50 1.55 1.60 1.65 1.700.30
0.35
0.40
0.45
0.50
0.55
0.60
0.65
0.70
Low
-ener
gy
elec
tron refl
ectivi
ty (R
0)
Secondary emission yield (max
)
0.010
0.11
0.21
0.34
0.41
0.50
0.60
0.70
0.80
Heat load (W/m)
Heat load values at 4 TeV - 25 ns - Fill 3429
δmax = 1.54
1.30 1.35 1.40 1.45 1.50 1.55 1.60 1.65 1.700.30
0.35
0.40
0.45
0.50
0.55
0.60
0.65
0.70
Low
-ener
gy
elec
tron refl
ectivi
ty (R
0)
Secondary emission yield (max
)
0.0040
0.092
0.18
0.27
0.36
0.45
0.53
0.62
0.71
Heat load values at 4 TeV - 25 ns - Fill 3436
Heat load (W/m)
δmax = 1.51
SEY time evolution (1):
0 5 10 15 20 25 30 351.50
1.52
1.54
1.56
1.58
1.60
Sec
ondar
y em
issi
on y
ield
( m
ax)
Time (h)
0.5
R0
SEY time evolution (1):
0 5 10 15 20 25 30 351.50
1.52
1.54
1.56
1.58
1.60
Sec
ondar
y em
issi
on y
ield
( m
ax)
Time (h)
0.5
R0
What about if R0 is higher?
SEY time evolution (II):
0 5 10 15 20 25 30 351.42
1.44
1.46
1.48
1.50
1.52
1.54
1.56
1.58
1.60
Secondary
em
issio
n y
ield
( m
ax)
Time (h)
0.5 0.7
R0
~4-5%
SEY time evolution (III):
0 5 10 15 20 25 30 351.40
1.42
1.44
1.46
1.48
1.50
1.52
1.54
1.56
1.58
1.60
Sec
ondary
em
issi
on y
ield
( m
ax)
Time (h)
0.5 0.7
R0R0
< 3%
< 3%
3x photo emission yield
OutlineHeat load benchmarking at 4 TeV
and 25-ns bunch spacing.Future work: Synrad3d
Synrad3D It simulates the production and scattering of
synchrotron radiation generated by an electron (or proton) beam in a high energy machine.
Developed at Cornell University by David Sagan and Gerry Dugan.
It can handle any planar lattice and a wide variety of vacuum chamber profiles.
• It uses Monte Carlo techniques to generate photons based on the standard synchrotron radiation formulas for dipoles, quadrupoles and wigglers.
• Photons are tracked to the vacuum chamber wall, where the probability of being scattered is determined by the angle of incidence, the energy of the photon, and the properties of the wall’s surface.
Photon emission throughout the ring, averaged over different magnetic environments.
Actual Cesr vacuum chamber, specular reflection only, beam energy 2.1 GeV
SYNRAD3D predictions for photon absorption site distributions
polar angle
chamber wall
Thanks to G. Dugan
MotivationEmploy Synrad3d to simulate the
photon distribution for future machines as LEP III
LHC (coming soon) and LHC-like machines.
ConclusionsFor R0 = 0.5 SEY = 1.51For R0 = 0.7 SEY = 1.45Changing 3x peef only decrease
SEY’s values less than 3%.Synrad3D is a useful tool to find
the photon distribution and then use it as input file to Ecloud or PyEcloud.
Thank you for your attention