Simulations that Explain and Predict Beam-Beam Effects in the Tevatron Alexander Valishev Fermilab,...

Simulations that Explain and Predict Simulations that Explain and Predict Beam-Beam Effects in the TevatronBeam-Beam Effects in the Tevatron

Alexander ValishevFermilab, Batavia, IL 60510

LARP Mini-Workshop on Beam-Beam CompensationJuly 2-4, 2007

LARP Beam-Beam Compensation Mini-Workshop 7/2/07 – A.Valishev 2

OutlineOutline LIFETRAC code Simulations

Fast emittance blowupProton lifetimeAntiproton lifetime


Beam-Beam Code LIFETRACBeam-Beam Code LIFETRAC

Weak-strong, Gaussian strong bunch Macro-particle weak bunch, typically 10000

particles Full details of the machine optics and collision

pattern with all 72 IPs Effects of random noise Parallel, up to 107 turns

• D.Shatilov et al., TPAT084, PAC05• A.Valishev et al., TPAT083, PAC05


Optics Measurements with LOCO #Optics Measurements with LOCO #

# V.Sajaev et al., PAC2005

*x *

y (cm)

(cm)

CDF 32.0 37.1

D0 35.8 40.0


Fast Bunch-by-Bunch Effects: OrbitFast Bunch-by-Bunch Effects: Orbit


Fast Bunch-by-Bunch Effects: Fast Bunch-by-Bunch Effects: Emittance Growth (Scallops)Emittance Growth (Scallops)


Scallops: SimulationScallops: Simulation


Effect of the Helix Size on LifetimeEffect of the Helix Size on Lifetime

90 95 100 105 1100.0

0.2

0.4

0.6

0.8

1.0

Ant

ipro

ton

NL

Los

s R

ate

[%

/ hr

]

Stores #4021 - #4109

Helix size [% of nominal]

Average Antiproton Non-Luminous Loss Rate vs Helix Size


Effect of Betatron Tune ChromaticityEffect of Betatron Tune Chromaticity


Luminosity Evolution Store 5008, Luminosity Evolution Store 5008, L=2.07E32L=2.07E32

New Helix. High Proton TuneNew Helix. High Proton Tune


Simulation for Proton Bunch 6: Simulation for Proton Bunch 6: Effect of Corrected C2Effect of Corrected C2


Simulation for Antiproton Bunch 6: Simulation for Antiproton Bunch 6: Effect of Corrected C2Effect of Corrected C2


Comparison of Antiproton Bunch 6 Parameters Comparison of Antiproton Bunch 6 Parameters for 3 Working Points: Present Proton Intensityfor 3 Working Points: Present Proton Intensity


Comparison of Antiproton Bunch 6 Parameters for 3 Comparison of Antiproton Bunch 6 Parameters for 3 Working Points: Proton Intensity Increased by 30%Working Points: Proton Intensity Increased by 30%


SummarySummary

Weak-strong simulation for Tevatron has been extensively used to validate proposed changes. Results are consistent with experimental data

Fast (~1-5 min) effects can be simulated with high detail level

Longer time (~2 hours) can be simulated by artificially increasing random noise rate


Effect of TEL on Proton LifetimeEffect of TEL on Proton Lifetime


Effect of TEL on Proton SpectrumEffect of TEL on Proton Spectrum


Strong-Strong SimulationStrong-Strong Simulation

2.7e-05

2.8e-05

2.9e-05

3e-05

3.1e-05

3.2e-05

3.3e-05

3.4e-05

3.5e-05

3.6e-05

3.7e-05

0 1000 2000 3000 4000 5000 6000 7000 8000

y rms by turn 4.4e11

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Simulations that Explain and Predict Beam-Beam Effects in the Tevatron Alexander Valishev Fermilab,...

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