High-brightness injectors for hadron colliders

Conference · Mon Jan 01 00:00:00 EST 1990

OSTI ID:5233751

Wangler, T P

The counterrotating beams in collider rings consist of trains of beam bunches with N{sub B} particles per bunch, spaced a distance S{sub B} apart. When the bunches collide, the interaction rate is determined by the luminosity, which is defined as the interaction rate per unit cross section. For head-on collisions between cylindrical Gaussian beams moving at speed {beta}c, the luminosity is given by L = N{sub B}{sup 2}{beta}c/4{pi}{sigma}{sup 2}S{sub B}, where {sigma} is the rms beam size projected onto a transverse plane (the two transverse planes are assumed identical) at the interaction point. This beam size depends on the rms emittance of the beam and the focusing strength, which is a measure of the 2-D phase-space area in each transverse plane, and is defined in terms of the second moments of the beam distribution. Our convention is to use the rms normalized emittance, without factors of 4 or 6 that are sometimes used. The quantity {tilde {beta}} is the Courant-Synder betatron amplitude function at the interaction point, a characteristic of the focusing lattice and {gamma} is the relativistic Lorentz factor. Achieving high luminosity at a given energy, and at practical values of {tilde {beta}} and S{sub B}, requires a large value for the ratio N{sub B}{sup 2}/{var epsilon}{sub n}, which implies high intensity and small emittance. Thus, specification of the luminosity sets the requirements for beam intensity and emittance, and establishes the requirements on the performance of the injector to the collider ring. In general, for fixed N{sub B}, the luminosity can be increased if {var epsilon}{sub n} can be reduced. The minimum emittance of the collider is limited by the performance of the injector; consequently the design of the injector is of great importance for the ultimate performance of the collider.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5233751
• Report Number(s): LA-UR-91-3012; CONF-901165-2; ON: DE92000208
• Resource Relation: Conference: 4. joint US-CERN school on particle accelerators: course on frontiers of particle beams: intensity limitations, Hilton Head Island, SC (United States), 7-14 Nov 1990
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
SUPERCONDUCTING SUPER COLLIDER
BEAM INJECTION
BEAM BUNCHING
BEAM EMITTANCE
BEAM LUMINOSITY
BEAM TRANSPORT
COLLIDING BEAMS
HYDROGEN 1 MINUS BEAMS
ION SOURCES
SPACE CHARGE
BEAM DYNAMICS
BEAMS
ION BEAMS
STORAGE RINGS
430302* - Particle Accelerators- Injection & Extraction Systems