Jefferson Lab, Newport News, Virginia
TRIUMF, Vancouver
A conceptual design of a ring-ring electron-ion collider based on CEBAF with a center-of-mass energy up to 90 GeV at luminosity up to 1035 cm-2s-1 has been proposed at JLab to fulfil science requirements. Four interaction points on two crossing straight sections of Figure-8 shape rings are planed for collisions of both highly polarized electron and light ion beams. The Green field design of the ion complex including electron cooling and new way of organizing interacting regions are directly aimed at full exploitation of science program. Here, we summarize design progress including collider ring and interaction region optics with chromatic aberration compensation. Stacking of ion beams in an accumulator-cooler ring, beam-beam simulations and a faster kicker for the circulator electron cooler ring are also discussed.
ORNL, Oak Ridge, Tennessee
Beam phase synchronous oscillations and the damping curves of the SNS linac are investigated with linac models and measured with all the linac beam phase monitors. It provides a useful beam diagnostic solution to detect RF cavity phase and/or field amplitude errors in the linac with many independently phased cavities. And the phase damping curves predicted in the longitudinal model could also be utilized to analyze the longitudinal lattice of the superconducting linac, in which each cavity gradient varies widely from the nominal design and smooth the beam longitudinal focusing is very important to preserve beam emittance.
ORNL, Oak Ridge, Tennessee
LBNL, Berkeley, California
Multi-particle tracking simulations for the SNS linac beam dynamics studies are performed with the IMPACT code. Beam measurement results are compared with the simulations, including beam halos and beam loss in the superconducting linac, measurement of beam transverse twiss parameters and beam longitudinal emittance in the SNS linac. And in most cases, the simulations show good agreement with the measured results.
ORNL, Oak Ridge, Tennessee
Most recent beam dynamic studies of the Spallation Neutron Source linac, including the major beam loss reduction efforts in the normal conducting (nc) linac and in the superconducting linac (SCL), simulations and measurements of the longitudinal beam halos and the longitudinal acceptance at the entrance of the SCL are discussed. Oscillation of beam centroid around the linac synchronous phase and the beam phase adiabatic damping curves in the SNS linac are investigated with the linac longitudinal models and measured with all the linac beam phase monitors.