ORNL, Oak Ridge, Tennessee
The 248 meter Spallation Neutron Source accumulator ring is designed to operate with a beam intensity of 1.5·1014 ppp. A major concern for high intensity operation is the possibility of beam instabilities. Recently a series of experiments have been performed to systematically map out the instability parameter space. Beam instabilities have been measured versus betatron tune, ring RF voltage, lattice chromaticity, and beam intensity. The results of these studies are presented here
ORNL, Oak Ridge, Tennessee
Operating at 0.5 MW beam power on target, the Spallation Neutron Source (SNS) is already the world's most powerful pulsed neutron source. However, we are only one third of the way to full power. As we ramp toward full power, the control of the beam and beam loss in the ring will be critical. In addition to practical considerations, such as choice of operating point, painting scheme, and rf bunching, it may be necessary to understand and mitigate collective effects due to space charge, impedances, and electron clouds. In dedicated high intensity beam study shifts, we have already observed resistive wall, impedance driven, and electron cloud activity. The analysis and simulation of this data are important ongoing activities at SNS. This talk will discuss the status of this work, as well as other considerations necessary to the successful full power operation of SNS.
ORNL, Oak Ridge, Tennessee
With the increase of average power of present and future high intensity proton rings and rapid progress of laser technology, laser-assisted stripping become a real alternative for carbon foils that are used for charge-exchange injection. High efficiency laser stripping, achieved experimentally at Spallation Neutron Source in Oak Ridge, TN, paved the way to full scale devices of such type. This paper presents overview of machines and choices of parameters for future powerful accelerators with possible laser stripping use.