• Y. Zhang, Y.S. Derbenev, G.A. Krafft, B.C. Yunn
  JLAB, Newport News, Virginia

The conceptual design of a polarized ring-ring electron-ion collider based on the CEBAF recirculated electron SRF linac relies on high repetition rate and high averaged current ion beams with very short bunch length and very small transverse emittance for reaching ultra high collider luminosity, up to middle of 10³⁴ s^-1cm^-2. Nevertheless, making of such ion beams is a significant challenge, depending on various accelerator R&D including ion source, SRF linac, staged electron cooling and crab crossing at interaction points. In this paper, we will present some new ideas and concepts towards to realization of high collider luminosities, as well as preliminary conceptual design of various components of an ion complex that is capable to create such ion beams.

• Y. Zhang, S.M. Cousineau, Y. Liu
  ORNL, Oak Ridge, Tennessee

Experience using laser-wire beam profile measurement to perform transverse beam matching in the SNS superconducting linac is discussed. As the SNS beam power is ramped up to 1 MW, transverse matching should become more critical to control beam loss and residual activation. In our experiments, however, beam loss in the SC linac is not very sensitive to the matching condition. In addition, we have encountered some difficulties in performing a satisfactory transverse beam matching with the envelope model currently available in our XAL software framework. Offline data analysis from multi-particle tracking simulation shows that the accuracy of the current matching algorithm may not be sufficient to the SC linac.