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PS Bunch Profiles:Bunch Lengthening Mode (Non-Standard Charge Distributions) C. M. Bhat et. al. E-Cloud Meeting 7/29/2011 Bunch Profiles for V2/V1= 0 to 0.5 V1=40kV to 100kV Bunch Profiles during the splitting Bunch Int.= 1.36E11ppb Start of e-cloud
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C. M. Bhat et. al. E-Cloud Meeting
PS e-Cloud Simulations Non-Standard Charge Distributions
C. M. Bhat, H. Maury Cuna, H. Damerau, S. Hancock, E. Mahner,
F. Caspers and F. Zimmermann
e-cloud simulation meeting July 29, 2011
7/29/2011
C. M. Bhat et. al. E-Cloud Meeting
PS-e-cloud data of 20110608: BLM
7/29/2011
eCloudStudiesC2320_ 100kV_ 50kV_counter _c.dat
Trace 104
Trace 140
Trace 140
Trace 104
Trace 109
0 2 0 40 6 0 80 100 1 2 0 2
1
0
1
2
3
Time n s
Amplitu
deV
Trace 120
0 20 40 60 80 10 0 12 0 2
1
0
1
2
3
Time n s
Amplitu
deV
0 20 40 6 0 80 100 120 2
1
0
1
2
3
Time n s
Amplitude
V
0 20 40 60 80 100 1 20 2
1
0
1
2
3
Time ns
Amplitu
deV
Trace 13 0
0 20 4 0 60 80 10 0 1 20 2
1
0
1
2
3
Time ns
Amplitu
deV
Beam Int.= 980E10/72 bunchesBunch Int.= 1.36E11ppb
Trace 135
PS Bunch Profiles:Bunch Lengthening Mode(Non-Standard Charge Distributions)
C. M. Bhat et. al. E-Cloud Meeting 7/29/2011
Bunch Profilesfor V2/V1= 0 to 0.5V1=40kV to 100kV
Bunch Profilesduring the splitting
Bunch Int.= 1.36E11ppb
Start of e-cloud
C. M. Bhat et. al. E-Cloud Meeting 7/29/2011
Bunch Profilesfor V2/V1= 0 to -0.5V1=40kV to 100kV
Bunch Profilesduring the splitting
Maximum e-cloud
Bunch Int.= 1.4E11ppb(4% larger than BLM case)
PS Bunch Profiles:Bunch Shortening Mode(Non-Standard Charge Distributions)
Start of e-cloud
C. M. Bhat et. al. E-Cloud Meeting 7/29/2011
Bunch Profilesfor V2/V1= 0
V1=40kV to 100kV
Bunch Profilesduring the splitting
Bunch Int.= 1.36E11ppb(1% less than BLM case)
PS Bunch Profiles: LHC25 (Non-Standard Charge Distributions)
Start of e-cloud
ECLOUD: Standard Version and Changed Version
Standard Charge Distributions in ECLOUD (idistr) Gaussian (idistr=1) Uniform (idistr=0) Symmetric Trapezium (idistr=2) Parabolic (idistr=3)In all these cases the “bweight” (which determines the longitudinal
distribution function) is calculated using analytical formulae.
The PS data demands changes to ECLOUD code to handle Non-standard Charge Dists. This led to “ecloud_last_gfortran_modifiedon20110722-beta.f” Non-standard filling pattern up to 10 non-standard pattern which
can repeat “n” number of time Now it can take any charge distribution by reading “bweight”s from
an external file “idistr7arbbnchprofile.dat” (idistr=7)
C. M. Bhat et. al. E-Cloud Meeting 7/29/2011
Non-standard Filling pattern
C. M. Bhat et. al. E-Cloud Meeting 7/29/2011
12b
1224b
8
24b
16 72b
12
8b
8
Tests with Different Charge Distributions treated in two ways
C. M. Bhat et. al. E-Cloud Meeting 7/29/2011
Conclusion: Now ECLOUD can take any type of charge distributions
Gaussian Bunch
Trapezium Bunch
Triangle Bunch.
Uniform Bunch
Normalized to Area=1
Tests with Different Charge Distributions
C. M. Bhat et. al. E-Cloud Meeting 7/29/2011
x10
Conclusion: Now ECLOUD can take any type of charge distributions
Gaussian Bunch
Trapezium Bunch
Triangle Bunch.
Uniform Bunch
x4
ECLOUD Simulations on PS data
C. M. Bhat et. al. E-Cloud Meeting 7/29/2011
Standard Profiles
“bweight” input to ECLOUD
Start of e-cloud
12.6 meters
1st Attempt with ECLOUD on the PS data
C. M. Bhat et. al. E-Cloud Meeting 7/29/2011
eCloudStudiesC2320_ 100kV_ 50kV_counter _c.dat
nbstep= 85nistep=1000
Summary
The analysis of the PS e-cloud data demands improvements in the ECLOUD to handle non-standard charge distributions ECLOUD is modified toRead any arbitrary charge distributions (idistr=7)Any arbitrary filling pattern up to 10 non standard
pattern
Made a first attempt to simulate the PS e-cloud data
C. M. Bhat et. al. E-Cloud Meeting 7/29/2011
C. M. Bhat et. al. E-Cloud Meeting
ESME Simulations
7/29/2011
40 MHz rf (h=1)80 MHz rf (h=2)0 V
50kV
100kV RF Manipulation in the PS at 26 GeV