next up previous contents index
Next: General Structure of Input Up: No Title Previous: Contents



CAIN is a stand-alone FORTRAN Monte-Carlo code for the interaction involving high energy electron, positron, and photons. Originally, it started with the name ABEL[1] in 1984 for the beam-beam interaction in tex2html_wrap_inline7170 linear colliders. At that time the main concern was the beam deformation due to the Coulomb field and the synchrotron radiation (beamstrahlung). Later, the pair creation by particle-particle collision was added, and, it was renamed to CAIN when the interaction with laser beams (radiation by electrons/positrons and pair creation by photons in a strong laser field) was added for the tex2html_wrap_inline7172-tex2html_wrap_inline7172 colliders.

The first version CAIN 1.1[2], which is a combined program of modified ABEL and a laser QED code, is limited because it cannot handle the laser interaction and the tex2html_wrap_inline7170 interaction simultaneously and does not accept mixed tex2html_wrap_inline7170 beams. To overcome these problems, CAIN 2.0 was written from scratch. It now allows any mixture of etex2html_wrap_inline7180, etex2html_wrap_inline7182, tex2html_wrap_inline7172 and lasers, and multiple-stage interactions. The input data format has been refreshed completely.

The physical objects which appear in the present version CAIN are two particle beams, lasers, and external fields. Each of the two beams may consist of high-energy electrons, positrons and photons. One of the beams may be absent. A basic assumption is that each beam must be a `beam', i.e., most particles in each beam go almost parallel. (CAIN assumes the two beams go opposite direction. For the case they make a large angle, you can apply CAIN command for Lorentz transformation so that the collision looks head-on.) The lasers can go any direction. The present version accepts only constant external fields.

The interactions that can be treated by the present version CAIN2.1tex2html_wrap_inline7162are

  1. Classical interaction (orbit deformation) due to the Coulomb field.
  2. Luminosity between (etex2html_wrap_inline7180 etex2html_wrap_inline7182 tex2html_wrap_inline7172).
  3. Synchrotron radiation (beamstrahlung), and pair creation by high energy photons (coherent pair creation) due to the beam field.
  4. Interaction of high energy photon or electron/positron beams with laser field, including the nonlinear effect of the field strength.
  5. Classical and quantum interactions with a constant external field.
  6. Incoherent tex2html_wrap_inline7170 pair creation by photons, electrons and positrons.
  7. In almost all interactions the polarization effects can be included.

next up previous contents index
Next: General Structure of Input Up: No Title Previous: Contents

Toshiaki Tauchi
Thu Dec 3 17:27:26 JST 1998