248
B. J. Holzer et al.
• Collective instabilities and interaction with environment (impedance)
• Beam-beam effects in case of particle colliders, i.e. the interactions with the fields
produced by the counter-rotating beam.
• Electron cloud effects, i.e. secondary electron production by synchrotron radiation
A key issue for multi particle simulation codes is the evaluation of the electromagnetic fields produced by the beams or the environment. New techniques and the
availability of parallel computing facilities have allowed vast progress in this field
in the last 20 years.
6.6.6 Machine Protection
For large energy and high intensity machines the protection of the machine elements
becomes an important part of the design. Simulation codes have to include the
interaction of particles with matter.
6.7 Electron-Positron Circular Colliders
M. E. Biagini · J. M. Jowett
Electron-positron (e + e − ) collider rings have been a mainstay of both discovery
and precision physics for half a century: discovery, since the simple initial state
can create any particle coupled to the electromagnetic field; precision, from the
combination of high luminosity and large cross-sections at a rich spectrum of
resonances up to
√
s 200 GeV. While the fundamentals of these machines have
remained in essence the same, the technology has matured to the point where
luminosities of the latest “factories” exceed what was thought possible in the 1970s
and early 1980s by 2–3 orders of magnitude.
These colliders are based on the principle of the synchrotron (Sect. 1.2.6)
although the name is barely appropriate for those which enjoy the advantage of
full-energy injection. Beams are necessarily bunched by an RF system, which must
provide sufficient voltage to compensate the energy lost by synchrotron radiation.
6.7.1 Physics of Electron-Positron Rings
Consider an ideal storage ring constructed with bending and focussing magnets
such that a particle of charge e and constant momentum p 0 could circulate on a
stable closed orbit, O xy , in transverse phase space (x, p x , y, p y ), with local radius of
B. J. Holzer et al.
• Collective instabilities and interaction with environment (impedance)
• Beam-beam effects in case of particle colliders, i.e. the interactions with the fields
produced by the counter-rotating beam.
• Electron cloud effects, i.e. secondary electron production by synchrotron radiation
A key issue for multi particle simulation codes is the evaluation of the electromagnetic fields produced by the beams or the environment. New techniques and the
availability of parallel computing facilities have allowed vast progress in this field
in the last 20 years.
6.6.6 Machine Protection
For large energy and high intensity machines the protection of the machine elements
becomes an important part of the design. Simulation codes have to include the
interaction of particles with matter.
6.7 Electron-Positron Circular Colliders
M. E. Biagini · J. M. Jowett
Electron-positron (e + e − ) collider rings have been a mainstay of both discovery
and precision physics for half a century: discovery, since the simple initial state
can create any particle coupled to the electromagnetic field; precision, from the
combination of high luminosity and large cross-sections at a rich spectrum of
resonances up to
√
s 200 GeV. While the fundamentals of these machines have
remained in essence the same, the technology has matured to the point where
luminosities of the latest “factories” exceed what was thought possible in the 1970s
and early 1980s by 2–3 orders of magnitude.
These colliders are based on the principle of the synchrotron (Sect. 1.2.6)
although the name is barely appropriate for those which enjoy the advantage of
full-energy injection. Beams are necessarily bunched by an RF system, which must
provide sufficient voltage to compensate the energy lost by synchrotron radiation.
6.7.1 Physics of Electron-Positron Rings
Consider an ideal storage ring constructed with bending and focussing magnets
such that a particle of charge e and constant momentum p 0 could circulate on a
stable closed orbit, O xy , in transverse phase space (x, p x , y, p y ), with local radius of