摘要:

The Working Group on single-particle nonlinear dynamics has developed a set of tools to study nonlinear dynamics in a particle accelerator. The design of rings with large dynamic apertures is still far from automatic. The Working Group has concluded that nonlinear single-particle dynamics limits the performance of acclerators. (AIP)

ISSN:0094-243X    

DOI:10.1063/1.58424

出版商:AIP    

年代:1999

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.58404

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

The Frequency Map analysis is applied to the Particle-Core model for an intense beam in a FODO cell. We show that the Frequency Map allows to get an useful picture of the phase space even in the unmatched cases and we point out the importance of the resonances between the betatronic frequencies and the envelope frequencies in the stability problem of a test particle near the beam core. We introduce a dynamics aperture for the halo formation and we compare the results of Frequency Map analysis with the results of a direct tracking on a simple model of a FODO cell. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58408

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

The Stanford Synchrotron Radiation Laboratory is investigating an accelerator upgrade project that would replace the present 130 nm⋅rad FODO lattice with an 18 nm⋅rad double bend achromat (DBA) lattice: SPEAR 3. The low emittance design yields a high brightness beam, but the stronger focusing in the DBA lattice increases chromaticity and beam sensitivity to machine errors. To ensure efficient injection and long Touschek lifetime, an optimization of the design lattice and dynamic aperture has been performed. In this paper, we review the methods used to maximize the SPEAR 3 dynamic aperture including necessary optics modifications, choice of tune and phase advance, optimization of sextupole and coupling correction, and modeling effects of machine errors, wigglers and lattice periodicity. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58417

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

In this paper we present applications of methods from wavelet analysis to polynomial approximations for a number of accelerator physics problems. According to a variational approach in the general case we have the solution as a multiresolution (multiscales) expansion on the base of compactly supported wavelet basis. We give an extension of our results to the cases of periodic orbital particle motion and arbitrary variable coefficients. Then we consider more flexible variational method which is based on a biorthogonal wavelet approach. Also we consider a different variational approach, which is applied to each scale. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58425

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

In this paper we consider applications of methods from wavelet analysis to nonlinear dynamical problems related to accelerator physics. In our approach we take into account underlying algebraical, geometrical and topological structures of corresponding problems. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58428

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

This contribution examines some themes for an easy computer approach to betatronic motion. A synthetic geometrical model of this motion is presented. I shall take the starting-point for my proposal from geometrical optical simulation. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58429

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

A photo cathode rf gun has been studied in the SPring-8 Linac to obtain a lower emittance beam. In order to perform a comparison with the beam characteristics, a beam tracking simulation code for an rf gun test apparatus has also been developed. In this code, the electric and magnetic forces between all particles are calculated. Accordingly, a lot of time is required, but a high accuracy can be expected in the calculations in comparison with other codes like PIC. In this paper, we describe the above rf gun test apparatus in the SPring-8, the simulation code, and present some calculation results such as the emittance of the emitted beam compared with MAFIA’s data. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58426

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

In order to understand the dynamic aperture limitations in LHC optics versions 4 and 5 at injection energy (450 GeV), a thorough resonance analysis is performed through Lie perturbation methods and Normal Form construction. In this respect, a simple numerical tool has been developed, the Graphical Representation of Resonances (GRR), allowing the evaluation and graphical representation of the resonance strengths and detuning, up to a desired order. The resonance analysis performed by means of GRR enabled us to understand the effect of the large errors in some special quadrupoles of LHC optics version 5. We were also able to identify and minimize the resonance which was correlated with the drop of the dynamic aperture, following the introduction of a large skew octupole bias in the LHC optics version 5, using the “target” error table. As shown by subsequent tracking studies, the proposed correction procedures led to a considerable improvement of the dynamic aperture of the studied LHC models. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58427

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

This paper shows measurements of the momentum aperture of the Advanced Light Source (ALS) based on Touschek lifetime measurements. The measured data is compared with tracking simulations and a simple model for the apertures will help to explain the observed effects. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58403

出版商:AIP    

年代:1999

数据来源: AIP