摘要:

Experimental techniques and observations of nonlinear dynamics in particle accelerators since the invention of the phase‐space monitor in 1985 are briefly surveyed. To show recent achievements in experimental techniques and observations of nonlinear dynamics in lepton machines, a series of beam experiments conducted at the TRISTAN MR during the autumn of 1993 are presented. The treated issues are the dynamic aperture with tracking results, the amplitude‐dependent tune shift, the beam‐based measurement of errors and so on.

ISSN:0094-243X    

DOI:10.1063/1.48980

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A review of the beam‐beam effects in storage rings is given with emphasis on experimental results and new simulation techniques.

ISSN:0094-243X    

DOI:10.1063/1.48981

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We take an overview of recently developed methods for studying single particle orbits in accelerators and discuss some physics underlying those which involve Lie operators. It will be further argued that object‐oriented programming provides the appropriate computing strategy in which to model accelerators and to implement these techniques.

ISSN:0094-243X    

DOI:10.1063/1.48965

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Experiments on single‐particle non‐linear dynamics are conducted since several years in existing accelerators. The aim is to observe the practical implications on beam stability of the unavoidable non‐linear field present in modern lepton or hadron accelerators. Appropriate experimental devices and techniques have been invented and are used in various High Energy Physics Laboratories in the world.

ISSN:0094-243X    

DOI:10.1063/1.48966

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The beam‐beam interaction in e+e−colliders is not well understood This affects the p;erformance of existing colliders and could lead to surprises in new ones. Developing ideas for calculations, simulations and experiments which could illuminate the details olf the beam‐beam interaction was the primary activity of this Working Group on beam‐beam interactions. (AIP) ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.48967

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

With the planned construction of a large hadron collider (LHC) and a major upgrade of LEP (LEP‐II) at CERN, a &Fgr;‐factory at Frascatti, and B‐factories at SLAC (PEP‐II) and KEK (KEK‐B), we are now entering new energy and intensity regimes in both electron and proton circular colliders. Understanding and accurately estimating dynamic apertures and particle loss rates under both injection and colliding beam conditions is of primary importance. This paper summarizes discussions on Understanding Nonlinear Effects and Losses that took place in Working Group Three at the September 1994 Conference on Nonlinear Dynamics in Particle Accelerators at Arcidosso, Italy. Questions addressed were: ‘‘What do simulations indicate as the underlying causes of particle loss?’’ and ‘‘Do experiments agree with simulations—and if not, why not?’’ Special attention was given to a discrepancy between dynamic aperture measurements and theoretical predictions at HERA.

ISSN:0094-243X    

DOI:10.1063/1.48968

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A summary report is given on the discussions in the fourth group of theWorkshoponNonLinearDynamicsinParticleAccelerator:TheoryandExperiments. This group has been devoted to issues related toTheoreticalandComputationalTechniqueswhich help to understand and improve existing machines and which can help in the design of new accelerator projects. The goal has been to identify the relevant problems, to summarize what has been achieved in recent years and to study promising new techniques.

ISSN:0094-243X    

DOI:10.1063/1.48969

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We consider an area preserving map whose linear frequency is stochastically perturbed. When no low order resonances are present a Fokker‐Planck equation for the action diffusion is written and its solution agrees with the simulation of the process. The key point is the description of the map with an interpolating hamiltonian for which the action diffusion coefficient can be analytically computed. When the frequency has a slow periodic modulation, then for low amplitudes the diffusion is limited to the action interval swept by a chain of islands, whereas for large amplitudes the diffusion reaches the dynamic aperture as in the stochastic case.

ISSN:0094-243X    

DOI:10.1063/1.48970

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We analyse the particle diffusion in the betatronic motion due to a random noise in the tune parameter. We explicitly consider the lattice of the CERN Super Proton Synchrotron in the special set up used in the experimental sessions to study the beam stability. A Fokker‐Planck equation is derived for the distribution function in the action variables. We compare the results of the tracking with the analytical results in the flat beam approximation.

ISSN:0094-243X    

DOI:10.1063/1.48971

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

DA&fgr;NE, the Frascati &fgr;‐factory, is a twin ring e=e−collider. A discussion of nonlinear effects on the beams from fringing fields in the low‐beta quadrupoles is given. A multipolar expansion of the fringing field can be deduced from the longitudinal behavior of the beam‐beam interaction region (IR) quadrupole field gradients, and introduced in the IR optics description. (AIP) ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.48972

出版商:AIP    

年代:1995

数据来源: AIP