Accelerator physics challenges in future linear colliders

Abstract

At the present time, there are a numberof future linear collider designs with a center-of-mass energy of 500 GeV or more with luminosities in excess of 10 34 cm ,2 s ,1 . Many of these designs are at an advanced state of development. However, to attain the high luminosity, the colliders require very small beam emittances, strong focusing, and very goodstability. In this paper, some of the outstanding issues related to producing and maintaining the small beam sizes are discussed. Although the di erent designs are based very di erent rf technologies, many of these problems are common. AbstractAt the present time, there are a number of future linear collider designs with a center-of-mass energy of 500 GeV or more with luminosities in excess of 10 34 cm ,2 s ,1 . Many of these designs are at an advanced state of development. However, to attain the high luminosity, the colliders require very small beam emittances, strong focusing, and very good stability. In this paper, some of the outstanding issues related to producing and maintaining the small beam sizes are discussed. Although the different designs are based very different rf technologies, many of these problems are common.

Intrabeam Scattering in an X-ray FEL Driver

“…Following an argument made in Ref. [5], the IBS energy distribution has a nearly gaussian core (due to soft scatterings) with a long tail (due to hard scatterings). Since we are mostly interested in the energy spread of the gaussian core, we cut off the contribution of the tail by limiting the maximum energy transfer to ∆γ c = γ × 10 −5 , In this case, we change the Coulomb log to…”