| Paper | Title | Page |
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| THPMN104 | Recent Studies of Dispersion Matched Steering for the ILC Bunch Compressor and Main Linac | 2954 |
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| Beam Based Alignment techniques are expected to play a critical role to the emittance preservation for the ILC. The Dispersion Free Steering (DFS) method is studied in detail in the 2nd statge of the bunch Compressor and in the beginning of the curved Main Linac. It is shown than in absence of cavity tilts (rotations on the YZ plane), DMS provides a unique and stable solution with negligible emittance growth. If cavity tilts are about 200 to 300 micro-radiant, the DMS solution is no longer unique and significant emittance occurs as well. While within the ILC budget, other dynamical effects, such a large beam jitter or sudden ground motion will cause severe performance degradation. A Variant of the DFS algorithm can be used to re-aling cavity supports, leading to better LET performance. In presence of perturbations (klystron jitter, ground motion,.. ) such DFS solutions are easier to maintain and improved if they are stable and unique. Therefore, it is suggested to consider using movers on quadrupole/BPM and, a bit more controversial, for the support system of the r.f. cavities, especially at low energy, where spurious dispersion due to cavity tilts are large. | ||
| THPAN112 | CHEF: A Status Report | 3486 |
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Funding: Authored by Universities Research Association, Inc. under contract No. DE-AC02-76CH03000 with the U. S. Department of Energy. CHEF is both a framework and an interactive application emphasizing accelerator optics calculations. The framework supports, using a common infrastructure, multiple domains of applications: e.g. nonlinear analysis, perturbation theory, and tracking. Its underlying philosophy is to provide infrastructure with minimum hidden implicit assumptions, general enough to facilitate both routine and specialized computational tasks and to minimize duplication of necessary, complex bookkeeping tasks. CHEF was already described in recent conferences. In this paper we present a status report on the most recent developments, including issues related to its application to high energy linacs. |
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| THPAN113 | Mxyzptlk: An Efficient, Native C++ Differentiation Engine | 3489 |
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Funding: Authored by Universities Research Association, Inc. under contract No. DE-AC02-76CH03000 with the U. S. Department of Energy. Mxyzptlk was one of the early and, to this day, limited number of differentiation engines implemented by taking full advantage of a language with operator overloading capabilities. It was created with an eye at enabling accelerator related computations, especially within the realm of perturbation theories. Such computations are supported by (1) a one-to-one correspondence between original mathematical abstractions and the data types and operations used to implement them; (2) the exact computation of high order derivatives. Significant efforts were invested recently in modernizing Mxyzptlk both architecturally and algorithmically. Among other things, these substantially improved performance and usabilty. We present a description of the current Mxyzptlk from both standpoints and describe its current capabilities and performance. |