Speaker
Description
This view is, of course, inevitably a personal one, and I apologise for being incomplete, subjective, and overly focused on selected highlights in the area of linear accelerators.
In 1953, the MURA (Midwestern Universities Research Association) project was founded in the Chicago area. It is often seen as a pioneering effort in the field of synchrotrons and storage rings, including early space-charge calculations and collective effects. However, rivalries and political decisions were not favourable for MURA. A few years later considerable indirect impetus—in terms of funding —was given to science in general and accelerators in particular by the Sputnik shock of 1957, which gave Western countries, especially the US, the feeling that they were lagging behind.
In these early days, space charge was mostly understood in terms of the “Laslett tune shift”. Obviously, higher intensity was required, triggering increasing interest in more advanced space-charge effects beyond “single-particle resonances”. In 1977, the emerging interest in using high-intensity linear accelerators for heavy ions to drive inertial fusion (HIF), with the lead laboratory in Berkeley, stimulated the first studies of “space-charge-driven instabilities”. HIF continued as a study project in Europe, starting in 1995 and ending in 1998. CERN (on the initiative of Carlo Rubbia), GSI, and a number of other laboratories and universities have been engaged in it. A major impetus was given to the whole field of space charge by the development of high-intensity linear proton accelerators. The Oak Ridge SNS project triggered efforts to control coherent resonances and instabilities of various orders, Landau damping, bunch anisotropy effects, halo, and beam loss. Together with subsequent similar projects in Europe and Asia a broader basis for the understanding and control of space charge was created.
Looking through the book of abstracts of this 2026 Space Charge Workshop, it is impressive to see how many topics are still under discussion—both in the areas of linear and circular accelerators.