Beam delivery and final focus systems for multi-TeV advanced linear colliders

Abstract

The Beam Delivery System (BDS) is a critical component of a high-energy linear collider. It transports the beam from the accelerator and brings it to a focus at the Interaction Point. The BDS system includes diagnostic sections for measuring the beam energy, emittance, and polarization, as well as collimators for machine protection. The length of the BDS increases with collision energy. Higher collision energies also require higher luminosities, and this is a significant constraint on the design for energy-frontier machines. Here, we review BDS designs based on traditional quadrupole magnets and examine the challenges involved in extending these to the Multi-TeV regime consistent with requirements for advanced accelerator concepts.

A “Cool” route to the Higgs boson and beyond. The Cool Copper Collider

“…During the timeline of the C 3 R&D demonstration plan and the eventual preparation of a C 3 TDR, advanced and novel accelerators will be working towards furthering their own technical milestones for laser and beam driven plasma wakefield and structure wakefield [56][57][58]. These studies may be advanced enough to inform future requirements on the facility (for example tunnel diameter, configuration of the BDS, distribution of power and cooling) that may be minimally invasive during initial construction, but prohibitively expensive for a future upgrade.…”

A hybrid, asymmetric, linear Higgs factory based on plasma-wakefield and radio-frequency acceleration

“…According to the prescription of Raimondi and Seryi [67], the final-focus part of the BDS length scales with energy somewhere between E 2/5 and E 7/10 , depending on assumptions as to how the normalised emittance changes with energy. Other parts of the BDS scale proportional to energy or even the square of the energy [68]. Each arm of the ILC BDS, which was designed to be upgraded to 500 GeV beams without changes in length, is around 2.25 km long.…”

Towards a PWFA linear collider — opportunities and challenges

“…The luminosities in figure 5 have been simulated assuming that the 𝛽 * can be achieved. However, in order to profit from the luminosity enhancement, novel beam delivery systems would need to be designed in order to provide the required 𝛽 * [1]. Another question is whether flat beams, with high horizontal to vertical size ratios [6,7], are well suited for PWFA, especially in the case of positron acceleration where the beam loading and beam quality may be different in each plane [54].…”

“…Plasma lenses: experimental results show that both active [77,78] and passive [79] plasmas lenses are gradually becoming more mature, with potential for multi-kT/m axial symmetric, linear strong focusing fields. This progress may open up new paths towards improved BDS design [1], cf. the above discussion.…”