Estimates of dispersive effects in a bent NLC main linac

An alternative being considered for the Next Linear Collider (NLC) is not to tunnel in a straight line but to bend the Main Linac into an arc so as to follow an equipotential. We begin here an examination of the effects that this would have on vertical dispersion, with its attendant consequences on synchrotron radiation and emittance growth by looking at two scenarios: a gentle continuous bending of the beam to follow an equipotential surface, and an introduction of sharp bends at a few sites in the linac so as to reduce the maximum sagitta produced.Comment: LINAC2000 conference; MOA1

Determining β * in the Tevatron

Abstract Using the two additional Beam Position Monitors (BPM's) found on either side of one of the Interaction Points (the so-called Collision Point Monitors), one can determine, in principle, the single-turn matrix for one BPM location or the other and, hence, the lattice functions at that location. Once the amplitude function and its slope at one BPM is found, it is straight forward to compute the amplitude function through the collision hall and the location of its minimum, and the value of the function at the collision point (β * )

Lattice/beam dynamics working group. Summary report

The Lattice/Beam Dynamics Working Group was charged with reviewing and identifying technical issues and their potential solutions for (a) a 2 x 2 TeV high luminosity p-pbar collider, and (b) a 30 x 30 TeV high luminosity pp collider. Rather than attempting to solve very specific problems for these devices in the relatively short time scale of a workshop, the group attempted to look at more general questions to try to indicate in which directions future work in these areas should proceed. The emphasis of the group tended toward lattice issues and general accelerator design issues for the above two cases, with more specific questions being addressed as directed by the needs seen by the Workshop Synthesizers

Degradation of Multibunch Luminosity in a Linear Collider Due to Cumulative Beam Breakup

Beam-excited transverse wakes in accelerating radiofrequency structures will influence the transverse offsets of each bunch in a multibunch train, causing the projected emittance of the bunch train to grow. An analytic theory of this phenomenon that includes the mitigating influence of a correlated energy spread across the bunch train was recently devised and applied to electron-positron linear colliders. We use the results of this theory to estimate analytically the associated degradation of multibunch luminosity in terms of top-level parameters for the two beams, the two accelerators, and the final-focus system. Then we compare the estimates with results from GUINEA-PIG, a code that includes the detailed physics of beam-beam interactions

Accelerator physics issues for the Very Large Hadron Collider

The goal of the Very Large Hadron Collider (VLHC) is to extend the energy frontier beyond LHC. The proposed design center of mass energy for the VLHC pp collider is 100 TeV, with a luminosity of 1*10/sup 34 / cm/sup -2/ sec/sup -1/ and an integrated luminosity of about 100 fb /sup -1/ per year. In this paper we present a summary of work conducted during a workshop and issues we feel are most important. Accelerator Physics issues and design aspects specific to both the high field and low field magnet technologies were studied, including the general accelerator parameters, beam stability issues, magnet field quality and the R&D needed to relax the accelerator component tolerances. This paper summarizes the accelerator physics R&D the VLHC Accelerator Physics Working Group members are undertaking. (13 refs)

Fermilab Proton Beam for Mu2e

Plans to use existing Fermilab facilities to provide beam for the Muon to Electron Conversion Experiment (Mu2e) are under development. The experiment will follow the completion of the Tevatron Collider Run II, utilizing the beam lines and storage rings used today for antiproton accumulation without considerable reconfiguration. The proposed Mu2e operating scenario is described as well as the accelerator issues being addressed to meet the experimental goals