Accelerator physics codes

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A charged particle accelerator is a complex machine that takes elementary charged particles and accelerates them to very high energies. Accelerator physics is a field of physics encompassing all the aspects required to design and operate the equipment and to understand the resulting dynamics of the charged particles. There are software packages associated with each such domain.

Single particle dynamics codes[edit]

For many applications it is sufficient to track a single particle through the relevant electric and magnetic fields. Some such codes include:

Collective effects codes[edit]

The interactions between the particles in the beam can have important effects on the behavior, control and dynamics. In some cases, the physical quantities may be found out of a single particle dynamics code. In others, a multiparticle code itself may be built that has both the single particle tracking through the electromagnetic fields from the machine and also the interaction with the rest of the beam.

Beam growth and instability calculation[edit]

The self interaction (e.g. space charge) of the charged particle beam can cause growth of the beam, such as with bunch lengthening or intrabeam scattering, or it may cause an instability and associated beam loss. Many scientists have written special purpose codes to compute these growth values and instability thresholds. Codes include

Impedance computation codes[edit]

An important class of collective effects may be summarized in terms of the beams response to an "impedance". An important job is thus the computation of this impedance for the machine. Codes for this computation include

Magnet and other hardware-modeling codes[edit]

To control the charged particle beam, appropriate electric and magnetic fields must be created. There are software packages to help in the design and understanding of the magnets, RF cavities, and other elements that create these fields. Codes include

Lattice file format and data interchange issues[edit]

Given the variety of modelling tasks, there is not one common data format that has developed. For describing the layout of an accelerator and the corresponding elements, one uses a so-called "lattice file". There have been numerous attempts at unifying the lattice file formats used in different codes. One unification attempt is the Accelerator Markup Language, and the Universal Accelerator Parser, described here. Another attempt at a unified approach to accelerator codes is the UAL or Universal Accelerator Library.[6]

The file formats used in MAD may be the most common, with translation routines available to convert to an input form needed for a different code. Associated with the Elegant code is a data format called SDDS, with an associated suite of tools. If one uses a Matlab based code, such as Accelerator Toolbox, one has available all the tools within Matlab.

Codes in applications of particle accelerators[edit]

There are many applications of particle accelerators. For example, two important applications are elementary particle physics and synchrotron radiation production. When performing a modeling task for any accelerator operation, the results of charged particle beam dynamics simulations must feed into the associated application. Thus, for a full simulation, one must include the codes in associated applications. For particle physics, the simulation may be continued in a detector with a code such as Geant4. For a synchrotron radiation facility, for example, the electron beam produces an x-ray beam that then travels down a beamline before reaching the experiment. Thus, the electron beam modeling software must interface with the x-ray optics modelling software such as SRW, Shadow, McXTrace, or Spectra.

See also[edit]

References[edit]

  1. ^ ELEGANT,a Flexible SDDS Compliant Code for Accelerator Simulation software
  2. ^ See here for atcollab site
  3. ^ TRANFT user's manual, BNL--77074-2006-IR http://www.osti.gov/scitech/biblio/896444
  4. ^ THE MULTIPARTICLE TRACKING CODES SBTRACK AND MBTRACK. R. Nagaoka, PAC '09 paper here
  5. ^ T. Weiland, DESY
  6. ^ See references by N. Malitsky and Talman such as this manual from 2002.