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Task 2.3 - particle simulations studies: progress report

M. Giovannozzi

Objectives• To study the field quality tolerances for new magnetic

elements for the LHC upgrade • To evaluate the dynamic aperture and tolerances of the

correction circuit settings

PartnersBINP, CEA, CERN, CSIC-IFIC, EPFL, INFN-Frascati, SLAC,

Uni-Liv, Uni-Man WP2 TLM - 2.3 - MG

07/05/2012

Main achievements - I• Injection

– Specification of the FQ for IT and matching section magnets.

• Collision– IT field quality specified.– Specification of triplets’ correctors (well ahead of

milestone).– Dynamic aperture vs. beta*– First look at impact of insertion magnets field

quality.– First look at impact of non-linear stray fields.

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Main achievements - II

• Other topics– Analysis of scaling laws for the evolution of the

dynamic aperture with time.– Plans for the development of the SixTrack code.– Analysis of possible numerical errors in tracking

simulations and their impact on the dynamic aperture simulation results.

– Alternative approaches to the simulation of the field quality of crab cavities.

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• Study of impact of b6 and b10 at injection based on ET’s estimate of links between the two components.

• Error tables at injection for D1/2, Q4/5 prepared by Stephan (based on measured FQ of existing magnets). Tracking performed by Riccardo.

• The error tables used are fine as far as tracking results are concerned. They will be presented at next joint WP2/3 meeting (to be held on 2 July 2012).

Injection studies

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Courtesy R. de Maria

Now also a paper at IPAC13

Collision Studies - I• Optimisation of IT FQ

– Starting point: WP3 estimated table (E. Todesco).

– Scan over multipoles to determine maximum interval acceptable.

– NB: in layout SLHCV3.01 the triplet correctors do not include a5, b5, a6.

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Courtesy Y. Nosochkov

Collision Studies - II• Triplets correctors

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• Impact of beta* on dynamic aperture:– Linear below beta*=1 m– Constant otherwise– Same slope for two sets of IT

FQ tables.– Offset of 1.5 sigma between

the two sets of IT FQ tables.

Collision studies - III

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• Impact of field quality of other insertion magnets:– IT set to optimised FQ.– Introduced other magnets.– D1, D2, most relevant, Q4

much less (Q5 almost irrelevant).

7.007.508.008.509.009.50

10.0010.5011.0011.5012.0012.5013.00

0 1 2 3 4 5 6 7 8 9 10

DA (s

igm

a)

Effect of D1, D2, Q4, Q5 errors set @1.0IT errors are always ON using table "target65"

D1,D2

Q4,Q5

D1 D2

Q4

Q5

OFF

DAave

DAmin

D2,Q4,Q5

Q4,Q5

D1,D2

9.00

9.50

10.00

10.50

11.00

11.50

12.00

12.50

13.00

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

DA (s

igm

a)

n

For a given "n" the D1 errors are ON for orders "n" to 15IT error table "target65"; D2, Q4, Q5 errors OFF

DAave

DAmin

Collision studies - IV

Courtesy Y. Nosochkov

Next steps - I• Original plans

– SLAC to work on SLHCV3.01– Other teams to work on SLHCV3.1b

• Comments:– Work on SLHCV3.1b has been done mainly by CERN team.– HLLHCV1.0 is available now (but all the tools need to be

developed)!• Proposed scenario:

– SLAC to continue working on SLHCV3.01 (some tools to be reviewed, though).

– CERN team will apply SLAC results to SLHCV3.1b.– Once tools ready, other teams will start working on

HLLHCV1.0, applying SLAC results to that lattice.

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Next steps - II• In parallel:

– Activity on non-linear stray fields should continue (CEA and CERN teams).

– Discussion with WP3 about error tables for all insertion magnets:• New tables for collision will be provided within days

(E. Todesco).– Review of analysis tools for numerical simulations.

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References• Y. Nosochkov, et al., “Optimization of Triplet Quadrupoles Field Quality for the LHC High

Luminosity Lattice at Collision Energy”, TUPFI016, in IPAC13 proceedings.• M. Giovannozzi, S. Fartoukh, R. De Maria, “Specification of a System of Correctors for the

Triplets and Separation Dipoles of the LHC Upgrade”, WEPEA048, in IPAC13 proceedings.• M. Giovannozzi, et al., “Dynamic Aperture Performance for Different Collision Optics

Scenarios for the LHC Luminosity Upgrade”, WEPEA047, in IPAC13 proceedings.• A. Bogomyagkov , et al., “Analysis of the Non-linear Fringe Effects of Large Aperture Triplets

for the HL LHC Project”, WEPEA049, in IPAC13 proceedings.• Y. Nosochkov, et al., “Evaluation of Field Quality for Separation Dipoles and Matching Section

Quadrupoles for the LHC High Luminosity Lattice at Collision Energy”, TUPFI017, in IPAC13 proceedings.

• R. De Maria, S. Fartoukh, M. Giovannozzi, “Specifications of the Field Quality at Injection Energy of the New Magnets for the HL-LHC Upgrade Project”, WEPEA045, in IPAC13 proceedings.

• M. Giovannozzi, R. De Maria, F. Lang, “Analysis of Possible Functional Forms of the Scaling Law for Dynamic Aperture as a Function of Time”, WEPEA050, in IPAC13 proceedings.

• R. De Maria et al., “Recent Developments and Future Plans for SixTrack”, MOPWO02, in IPAC13 proceedings.

• R. De Maria, M. Giovannozzi, E. McIntosh, “Investigation of Numerical Precision Issues of Long Term Single Particle Tracking”, MOPWO026, in IPAC13 proceedings.

• D. R. Brett, et al., “Comparison of Taylor Maps with RF Multipoles in a Thin Lens 6D Tracking Code”, WEPEA076, in IPAC13 proceedings.

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