Report of the advisory panel on the prospects for e+e- colliders in the TeV range

This is the concluding report of the Advisory Panel on the Prospects for e+e- Colliders in the TeV range, a panel set up by the CERN Long-Range Planning Committee chaired by C. Rubbia. The report covers general considerations, particle sources and the final focus and interaction point, before looking at various possible acceleration methods in some detail - normal rf linacs, superconducting acceleration structures, structures excited by opto-electrical switches, wake-field acceleration, and plasma beat-wave acceleration. It is concluded that one approach to a TeV collider, based on a normal conducting linear accelerator at a frequency of approximately 30 GHz and with a gradient of about 100 MeV/m, seems to give promise of leading to a real project in three to five years if enough manpower and money were invested in research and development. In the scheme outlined in the report, the drive power is obtained from an auxiliary beam of a few GeV, which in turn is accelerated by superconducting cavities identical to the ones now under construction for LEP 200. The panel also proposes that sufficient effort be devoted to continuing the research on more exotic schemes of acceleration, which in the longer term may lead to much higher gradients. The report was originally issued as CLIC note 38, and a complete list of these internal reports is given as an appendix. (orig.)