Fermilab, Batavia, Illinois
International Linear Collider (ILC) is a proposed electron-positron accelerator requiring very small spot-size at the interaction point, and thus necessitates very tight tolerances on beamline elements. For static tuning of the machine a few methods like dispersion-free steering (DFS) or kick minimization (KM) techniques was proposed. The further suppression of emittance growth can be achieved by using close orbit emittance bumps. Stability of ILC is determined by the stability of the site, additional noises of beamline component, energy and kicker jitter and performance of the train-to-train and intra-train feedback. We discuss the performances of the Adaptive Alignment technique, which keeps accelerator dynamically aligned in presence of ground motion an technical noises. This presentation is an overview of two posters THPMN107 and THPMN108, presented at PAC07.
Fermilab, Batavia, Illinois
This paper reports the studies of using global emittance tuning bumps to limit the emittance growth to very small values in the main linac of the proposed International Linear Collider (ILC) machine. Simulation studies indicate that closed-orbit emittance bumps, when used after local or quasi-local beam based alignment techniques, can be utilized to further suppress the emittance growth in the ILC main linac. A series of simulations are performed to find the optimal number of bumps and their locations. A more general method of optimizing the emittance bumps in the ILC main linac is also discussed.
Fermilab, Batavia, Illinois
The proposed International Linear Collider (ILC) machine requires extremely small transverse emittances of the beam to achieve desired luminosity. A very precise alignment of the beamline elements, both in main linac and in beam delivery system, is required to limit the emittance growth. However, ground motion (GM) and technical noise continuously misaligns the elements and hence spoils the effect of alignment. It is thus very important to understand and analyze the effect of GM on the performance of ILC. Also, it is imperative to find an effective dynamic alignment procedure to preserve the transverse emittances in the presence of GM. In this paper we study the effect of GM and technical noise on the proposed ILC main linac. Initial alignment of the Linac is performed through one-to-one and dispersion free steering (DFS). We then study "Adaptive Alignment" method to mitigate the effects of GM and technical noise.
Uppsala University, Uppsala
KEK, Ibaraki
CERN, Geneva
Fermilab, Batavia, Illinois
DESY, Hamburg
SLAC, Menlo Park, California
In an effort to compare beam dynamics and create a ‘‘benchmark'' for Dispersion Free Steering (DFS) a comparison was made between different International Linear Collider (ILC) simulation programs while performing DFS. This study consisted of three parts. First, a simple betatron oscillation was tracked through each code. Secondly, a set of component misalignments and corrector settings generated from one program was read into the other to confirm similar emittance dilution. Thirdly, given the same set of component misalignments DFS was performed independently in each program and the resulting emittance dilution was compared. Performance was found to agree exceptionally well in all three studies.