ORNL, Oak Ridge, Tennessee, USA
The 248-meter Spallation Neutron Source (SNS) accumulator ring has accumulated up to 1.55·1014, 1 GeV protons. At this intensity, space charge effects contribute significantly to the beam dynamics. Here we present observations of space charge effects in the SNS ring, with emphasis on space charge effects and e-p instabilities.
ORNL, Oak Ridge, Tennessee, USA
A non-destructive profile monitor has been installed and commissioned in the accumulator ring of the Spallation Neutron Source (SNS). The SNS Ring accumulates high intensity proton bunches of up to 1.5·1014 protons with a typical peak current of over 50 A and a bunch length of about 0.7 us during a 1 ms cycle. The profile monitor consists of two systems, one for each plane, with electron guns, correctors, defectors, and quadrupoles to produce pulsed electron beams that scan through the proton bunch. The proton bunch EM fields alter the trajectory of the electrons and their projection on a fluorescent screen. The projection is analyzed to determine the transverse profile of the proton bunch. The speaker will describe the theory, hardware, software, analysis, results, and improvements to these electron scanners. The results include a comparison to wire scanner profiles of extracted ring beam.