University of Hamburg, Hamburg, Germany
DESY, Hamburg, Germany
DESY Zeuthen, Zeuthen, Germany
In the baseline design of the International Linear Collider (ILC) an undulator-based positron source is foreseen. The proposed luminosity of the recently chosen first energy stage with √{s}=250 GeV requires an improvement by a factor of 2500 to the world’s first linear collider, the past SLC experiment. This ambitious luminosity goal can only be achieved, if all technological boundaries are being pushed. One such area is the captured positron number, which is primarily determined in the capture section within the positron source and specifically by its optical matching device. It is responsible for transforming the phase-space of the outgoing particles produced in the target for the succeeding accelerator sections. The plasma lens is a new candidate for this task. It being an especially adequate method due its magnetic field being azimuthal. Optimizing an idealised tapered active plasma lens for the ILC led us to a design with improved captured positron yield, outperforming ILC’s currently proposed quarter wave transformer by approximately 50%. The captured yield also proved to be stable within ±1.5% for deviations in design parameters of ±10%.
CERN, Geneva, Switzerland
DESY, Hamburg, Germany
GSI, Darmstadt, Germany
Various physical and technology-dependent limits are encountered for key performance parameters of accelerators such as high-gradient acceleration, high-field bending, beam size, beam brightness, beam intensity and luminosity. This paper will review these limits and the associated challenges. Possible figures-of-merit and pathways to ultimate colliders will also be explored.
BNL, Upton, New York, USA
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
Stony Brook University, Stony Brook, USA
We present a new ’green energy’ approach to the Energy Recovery Linac (ERL) and Recirculating Linac Accelerators (RLA) for the future Electron Ion Colliders (EIC) using single beam line made of very strong focusing combined function permanent magnets and the Fixed Field Alternating Linear Gradient (FFA-LG) principle. We are basing our design on recent very successful commissioning results of the Cornell University and Brookhaven National Laboratory ERL Test Accelerator.