IPAC2013 - List of Authors (Bogomyagkov, A.V.)

Paper	Title	Page
TUPFI014	HLLHCV1.0: HL-LHC Layout and Optics Models for 150 mm Nb3Sn Triplets and Local Crab-cavities	1358
	R. De Maria, S.D. Fartoukh CERN, Geneva, Switzerland A.V. Bogomyagkov BINP SB RAS, Novosibirsk, Russia M. Korostelev The University of Liverpool, Liverpool, United Kingdom
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The paper presents the latest layout and optics models for the HL-LHC upgrade project. As an evolution from the previous version SLHCV3.1b, it integrates the new Nb3Sn triplet (140T/m, 150mm) with all the additional magnets needed to be compatible with a β^* reach of 15cm and beyond. The collision optics implements the ATS* scheme which is able to provide very low value of β^* and at the same time warrants outstanding control of the chromatic aberrations within the strength limits of the existing arc sextupole scheme of the LHC. The optics models include the injection and collision optics for proton and ion operations foreseen for the HL-LHC, with improved squeeze-ability of the existing IR2 and IR8 insertions, and all the corresponding optic transitions. An aperture model and a series of optics matched in thin lenses complete the needs for a large range of dedicated beam dynamic studies (dynamic aperture, beam-beam effects, collimation). * S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

TUPFI015	Study of the IR2 and IR8 Squeezeability for HL-LHC Upgrade	1361
	A.V. Bogomyagkov BINP SB RAS, Novosibirsk, Russia R. De Maria CERN, Geneva, Switzerland
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The paper presents the results of the study of different optics configurations which allow to reach smaller beta functions at the IP2 and IP8 in the framework of the HL-LHC project. The variants at collision energies must be compatible with the ATS* scheme which provides small beta function at the IP1 and IP5 or provide low beta function for Alice and LHCb during ion operatations. The ones at injection must satisfy injection transfer lines and aperture constraints. The final goal is to find the overlap between the phase advances of all the configuration for IR2 and IR8 respectively, in order to mainting the LHC working point without rematching the remaining insertions. * S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

TUPFI023	Optics Design and Lattice Optimisation for the HL-LHC	1385
	B.J. Holzer, R. De Maria, S.D. Fartoukh CERN, Geneva, Switzerland R. Appleby, S. Kelly, M.B. Thomas, L.N.S. Thompson UMAN, Manchester, United Kingdom A.V. Bogomyagkov BINP SB RAS, Novosibirsk, Russia A. Chancé CEA, Gif-sur-Yvette, France B. Dalena CEA/IRFU, Gif-sur-Yvette, France A. Faus-Golfe, J. Resta IFIC, Valencia, Spain K.M. Hock, M. Korostelev, L.N.S. Thompson, A. Wolski Cockcroft Institute, Warrington, Cheshire, United Kingdom C. Milardi INFN/LNF, Frascati (Roma), Italy J. Payet CEA/DSM/IRFU, France A. Wolski The University of Liverpool, Liverpool, United Kingdom
	Funding: The HiLumi LHC Design Study is included in the High Luminosity LHC project and is partly funded by the European Commission within the Framework Programme 7 Cap. Spec. Progr, Grant Agreement 284404. The luminosity upgrade project of the LHC collider at CERN is based on a strong focusing scheme to reach smallest beam sizes at the collision points. Depending on the available magnet technology (Nb3Sn or NbTi) a number of beam optics has been developed to define the specifications for the new super conducting quadrupoles. In the context of the optics matching new issues have been addressed and new concepts have been used: Quadrupole strength flexibility and chromatic corrections have been studied, as well as the influence of quadrupole fringe fields. The lattice has been optimised including the needs of the foreseen crab cavities and the transition between injection and low β optics had to guarantee smooth gradient changes over a wide range of β* values. Tolerances on misalignments and power converter ripple have been re-evaluated. Finally the combination of the quadrupole strengths in the high luminosity matching sections with those in the neighboring sectors is explained, a key concept of the ATS to reach smallest β* values. This paper presents the results obtained within the HiLumi collaboration Task 2.2 and summarises the main parameters of the project.

WEPEA049	Analysis of the Non-linear Fringe Effects of Large Aperture Triplets for the HL LHC Project	2615
	A.V. Bogomyagkov, E.B. Levichev, P.A. Piminov BINP SB RAS, Novosibirsk, Russia A. Chancé, B. Dalena, J. Payet CEA/IRFU, Gif-sur-Yvette, France R. De Maria, S.D. Fartoukh, M. Giovannozzi CERN, Geneva, Switzerland
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The HL-LHC project relies on large aperture quadrupoles which are compatible with the very large beam sizes in the inner triplets resulting from the strong reduction of β^*. As a result the beam is much more sensitive to non-linear perturbations in this region, such as those induced by the fringe fields of the low-beta quadrupoles. The spatial extension of these fringe fields increases as well more or less linearly with the coil aperture, which is an additional motivation to analyse this aspect in detail in the framework of the High Luminosity LHC design study. This paper will quantify this effect both by direct analytical estimates using first order Hamiltonian perturbation theory, and via numerical studies thanks to the dedicated implementation of a fringe field symplectic integrator in SixTrack.

Paper

Title

Page

HLLHCV1.0: HL-LHC Layout and Optics Models for 150 mm Nb3Sn Triplets and Local Crab-cavities

1358

R. De Maria, S.D. Fartoukh
CERN, Geneva, Switzerland
A.V. Bogomyagkov
BINP SB RAS, Novosibirsk, Russia
M. Korostelev
The University of Liverpool, Liverpool, United Kingdom

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
The paper presents the latest layout and optics models for the HL-LHC upgrade project. As an evolution from the previous version SLHCV3.1b, it integrates the new Nb3Sn triplet (140T/m, 150mm) with all the additional magnets needed to be compatible with a β^* reach of 15cm and beyond. The collision optics implements the ATS* scheme which is able to provide very low value of β^* and at the same time warrants outstanding control of the chromatic aberrations within the strength limits of the existing arc sextupole scheme of the LHC. The optics models include the injection and collision optics for proton and ion operations foreseen for the HL-LHC, with improved squeeze-ability of the existing IR2 and IR8 insertions, and all the corresponding optic transitions. An aperture model and a series of optics matched in thin lenses complete the needs for a large range of dedicated beam dynamic studies (dynamic aperture, beam-beam effects, collimation).
* S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

TUPFI015

Study of the IR2 and IR8 Squeezeability for HL-LHC Upgrade

1361

A.V. Bogomyagkov
BINP SB RAS, Novosibirsk, Russia
R. De Maria
CERN, Geneva, Switzerland

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
The paper presents the results of the study of different optics configurations which allow to reach smaller beta functions at the IP2 and IP8 in the framework of the HL-LHC project. The variants at collision energies must be compatible with the ATS* scheme which provides small beta function at the IP1 and IP5 or provide low beta function for Alice and LHCb during ion operatations. The ones at injection must satisfy injection transfer lines and aperture constraints. The final goal is to find the overlap between the phase advances of all the configuration for IR2 and IR8 respectively, in order to mainting the LHC working point without rematching the remaining insertions.
* S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

TUPFI023

Optics Design and Lattice Optimisation for the HL-LHC

1385

B.J. Holzer, R. De Maria, S.D. Fartoukh
CERN, Geneva, Switzerland
R. Appleby, S. Kelly, M.B. Thomas, L.N.S. Thompson
UMAN, Manchester, United Kingdom
A.V. Bogomyagkov
BINP SB RAS, Novosibirsk, Russia
A. Chancé
CEA, Gif-sur-Yvette, France
B. Dalena
CEA/IRFU, Gif-sur-Yvette, France
A. Faus-Golfe, J. Resta
IFIC, Valencia, Spain
K.M. Hock, M. Korostelev, L.N.S. Thompson, A. Wolski
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C. Milardi
INFN/LNF, Frascati (Roma), Italy
J. Payet
CEA/DSM/IRFU, France
A. Wolski
The University of Liverpool, Liverpool, United Kingdom

Funding: The HiLumi LHC Design Study is included in the High Luminosity LHC project and is partly funded by the European Commission within the Framework Programme 7 Cap. Spec. Progr, Grant Agreement 284404.
The luminosity upgrade project of the LHC collider at CERN is based on a strong focusing scheme to reach smallest beam sizes at the collision points. Depending on the available magnet technology (Nb3Sn or NbTi) a number of beam optics has been developed to define the specifications for the new super conducting quadrupoles. In the context of the optics matching new issues have been addressed and new concepts have been used: Quadrupole strength flexibility and chromatic corrections have been studied, as well as the influence of quadrupole fringe fields. The lattice has been optimised including the needs of the foreseen crab cavities and the transition between injection and low β optics had to guarantee smooth gradient changes over a wide range of β* values. Tolerances on misalignments and power converter ripple have been re-evaluated. Finally the combination of the quadrupole strengths in the high luminosity matching sections with those in the neighboring sectors is explained, a key concept of the ATS to reach smallest β* values. This paper presents the results obtained within the HiLumi collaboration Task 2.2 and summarises the main parameters of the project.

WEPEA049

Analysis of the Non-linear Fringe Effects of Large Aperture Triplets for the HL LHC Project

2615

A.V. Bogomyagkov, E.B. Levichev, P.A. Piminov
BINP SB RAS, Novosibirsk, Russia
A. Chancé, B. Dalena, J. Payet
CEA/IRFU, Gif-sur-Yvette, France
R. De Maria, S.D. Fartoukh, M. Giovannozzi
CERN, Geneva, Switzerland

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
The HL-LHC project relies on large aperture quadrupoles which are compatible with the very large beam sizes in the inner triplets resulting from the strong reduction of β^*. As a result the beam is much more sensitive to non-linear perturbations in this region, such as those induced by the fringe fields of the low-beta quadrupoles. The spatial extension of these fringe fields increases as well more or less linearly with the coil aperture, which is an additional motivation to analyse this aspect in detail in the framework of the High Luminosity LHC design study. This paper will quantify this effect both by direct analytical estimates using first order Hamiltonian perturbation theory, and via numerical studies thanks to the dedicated implementation of a fringe field symplectic integrator in SixTrack.