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

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3

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Amplitu

deV

Trace 120

0 20 40 60 80 10 0 12 0 2

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1

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0 20 40 6 0 80 100 120 2

1

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V

0 20 40 60 80 100 1 20 2

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Trace 13 0

0 20 4 0 60 80 10 0 1 20 2

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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