| Paper | Title | Other Keywords | Page |
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| S18BPA01 | Operational Decoupling in the SSC Collider | coupling, lattice, quadrupole, collider | 576 |
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This paper will summarize a recent study of the effects and correction of linear coupling in the Superconducting Super Collider (SSC) lattice. There are several aspects of the SSC lattice that make direct extrapolation of techniques used on existing machines unreliable. The most obvious aspect of the SSC which departs from previous experience is the small dynamic aperture which lies well within the beampipe. A second aspect is the existence of long arcs with low superperiodicity which allow various sources of skew quadrupole to accumulate to large, and, perhaps, nonlinear values. A third aspect is the relatively large value of systematic skew quadrupole error in the main dipoles. This results from asymmetric placement of the cold mass in the cryostat Coupling must be considered harmful if it leads to irreversible emittance blow-up, a decrease in the dynamic aperture, or inoperability of the machine. These negative effects are generally related to coupling terms that accumulate to large and, hence, nonlinear values prior to correction. The harmful effects can also be caused by the linearly coupled orbits interacting with high-order multipole fields that exist in the other magnets. The errors that lead to linear coupling are well known. They are systematic and random skew quadrupole error fields in the other magnetic elements, angular alignment errors in the quadrupoles and feeddown from the sextupole fields associated with chromaticity correction, and persistent current fields in the dipoles. A study of the relative importance of the various coupling terms for a simplified SSC lattice has been done by Richard Talman.
Operated by the Universities Research Association, Inc., for the U.S. Department of Energy under Contract No. DE-AC35-89ER40486. |
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| DOI • | reference for this paper ※ doi:10.18429/JACoW-ICALEPCS1991-S18BPA01 | ||
| About • | Received ※ 11 November 1991 — Accepted ※ 20 November 1991 — Issued ※ 04 December 1992 | ||
| Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| S18BPA03 | New Controls for the CERN-PS Hadron Injection Process Using Operating Tools and High-Level Accelerator Modelling Programmes | injection, controls, emittance, timing | 583 |
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| A new control system using man-machine interface tools with workstations as consoles has been successfully put into operation for the injection of hadrons in the CERN Proton Synchrotron (PS). This paper mainly focuses on specialized modelling programmes involving complex treatments for an optimum operation of the injection process. These programmes include the control of the injection timings, the measurement of the beam emittance with an estimation of how well the incoming beam is matched, and the correction of oscillations at injection. The infrastructure and the programming environment underlaying the new control system are described elsewhere 3¿ The outstanding feature of the internal structure of all these modelling programmes is that they carry out three kinds of data interaction: the input, that is the measurements (e.g. beam time positions, profiles and trajectories), the physical parameters (e.g. required times for synchronization, beam emittance, beam space position and angle at injection), and the output, mainly the hardware values (e.g. preset counter settings, currents to apply to injection steering magnets). | |||
| DOI • | reference for this paper ※ doi:10.18429/JACoW-ICALEPCS1991-S18BPA03 | ||
| About • | Received ※ 11 November 1991 — Accepted ※ 20 November 1991 — Issued ※ 04 December 1992 | ||
| Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||