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Title: Toward an SSC test lattice design with two chromatic clusters of interaction regions

Abstract

Various ideas on how to design a cluster of interaction regions (IR) with local chromaticity correction were investigated, all of them employing pairs of sextupoles with betatron phase advances of (2n+{lambda}){pi} between them so that their geometric aberrations cancel. Some of these ideas were discarded. Even when, at the sextupoles, one amplitude function is made very small as compared to the other, and the two interleaving pairs are thus decoupled regarding their horizontal and vertical chromaticity correction, they can still not be considered `non-interleaved` regarding their compensation of chromatic aberrations. What remains, then, are schemes that have one or more complete sextupole pairs in a periodic focusing structure between interaction points. This periodic structure may be specially tailored to suit the purpose, or it may even be the normal arc FODO structure. In any case, it must have a strong horizontal dispersion for the sextupoles to act on. Probably the best and most elegant structure the authors found is the one described at the end of this note; it has a 2200 m long periodic channel of arc cells with four pairs of sextupoles between interaction points. In this scheme, the three interaction points forming a `cluster` are within fivemore » miles of each other, and thus the denotation may still be justified. However, the FODO channels may be increased in this scheme to any length, until an equidistant spacing of IR`s is obtained. The elegance of the scheme lies in the way the vertical separation and the horizontal and vertical dispersions are handled at the end of the FODO channel and matched into the interaction region, and it is applicable to clustered as well as distributed IR`s. However at first a simpler scheme will be described which has only one pair of sextupoles between IR`s, placed in a specially tailored FODO channel with long cells and very large dispersion.« less

Authors:
;
Publication Date:
Research Org.:
Superconducting Super Collider Lab., Waxahachie, TX (United States)
OSTI Identifier:
93785
Report Number(s):
SSC-SR-1015
ON: DE95011078; TRN: 95:005454-0009
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Oct 1985; Related Information: Is Part Of Report of the workshop on realistic SSC lattices; PB: 156 p.
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; SUPERCONDUCTING SUPER COLLIDER; DESIGN; BEAM OPTICS; SUPERCONDUCTING MAGNETS; CONFIGURATION; COLLIDING BEAMS

Citation Formats

Garren, A., and Steffen, K. Toward an SSC test lattice design with two chromatic clusters of interaction regions. United States: N. p., 1985. Web. doi:10.2172/93785.
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Garren, A., & Steffen, K. Toward an SSC test lattice design with two chromatic clusters of interaction regions. United States. doi:10.2172/93785.
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Garren, A., and Steffen, K. Tue . "Toward an SSC test lattice design with two chromatic clusters of interaction regions". United States. doi:10.2172/93785. https://www.osti.gov/servlets/purl/93785.
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@article{osti_93785,
title = {Toward an SSC test lattice design with two chromatic clusters of interaction regions},
author = {Garren, A. and Steffen, K.},
abstractNote = {Various ideas on how to design a cluster of interaction regions (IR) with local chromaticity correction were investigated, all of them employing pairs of sextupoles with betatron phase advances of (2n+{lambda}){pi} between them so that their geometric aberrations cancel. Some of these ideas were discarded. Even when, at the sextupoles, one amplitude function is made very small as compared to the other, and the two interleaving pairs are thus decoupled regarding their horizontal and vertical chromaticity correction, they can still not be considered `non-interleaved` regarding their compensation of chromatic aberrations. What remains, then, are schemes that have one or more complete sextupole pairs in a periodic focusing structure between interaction points. This periodic structure may be specially tailored to suit the purpose, or it may even be the normal arc FODO structure. In any case, it must have a strong horizontal dispersion for the sextupoles to act on. Probably the best and most elegant structure the authors found is the one described at the end of this note; it has a 2200 m long periodic channel of arc cells with four pairs of sextupoles between interaction points. In this scheme, the three interaction points forming a `cluster` are within five miles of each other, and thus the denotation may still be justified. However, the FODO channels may be increased in this scheme to any length, until an equidistant spacing of IR`s is obtained. The elegance of the scheme lies in the way the vertical separation and the horizontal and vertical dispersions are handled at the end of the FODO channel and matched into the interaction region, and it is applicable to clustered as well as distributed IR`s. However at first a simpler scheme will be described which has only one pair of sextupoles between IR`s, placed in a specially tailored FODO channel with long cells and very large dispersion.},
doi = {10.2172/93785},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Oct 01 00:00:00 EDT 1985},
month = {Tue Oct 01 00:00:00 EDT 1985}
}
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Technical Report:
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DOI:  10.2172/93785
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  • The authors review the important changes made to the optics of the Interaction Regions (IRs) in the collider since the conceptual design (SCDR) of 1990. The most significant modification is a new procedure for the {beta} squeeze. Three additional families of independently powered quadrupoles change the optics from injection to collision while the strengths of the final focus triplet quadrupoles are held constant. The phase advance from the interaction point (IP) to the arc quadrupoles is optimized to provide more effective positions of the local correctors for the IR. Two secondary foci where the IP is imaged have been incorporatedmore » symmetrically on both sides of the IP. Other changes include a significant reduction in the {beta}{sub peak} at injection, optimized configuration of the M = -I section, quadrupoles with 5 cm bore, minimized number of quad families, standard design of the vertical bends and reduced total length of the magnets. The optics allows for a wide range of values for a detector space at each IP. The time scenario for the {beta} squeeze is considered as well.« less

  • ;
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  • Three six-fold lattices for 3 T superferric SSC have been generated at TAC. The program based on the first order canonical transformation was used to compare lattices. On this basis the realistic race-track lattices were generated.

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