FIAS Scientific Report 2011 - Frankfurt Institute for Advanced Studies ...

Monte-Carlo code for channeling dynamics and radiation
Collaborators: A.Kostyuk 1 , A.V. Korol 1 , A.V. Solov’yov 1 , Walter Greiner 1 , H. Backe 2 , W. Lauth 2
1 Frankfurt Institute for Advanced Studies, 2 Johannes Gutenberg-Universität Mainz, Germany
The FORTRAN 95 code has been used for a comprehensive numerical study of the channeling process of ultrarelativistic
particles as well as of the properties of radiation formed in a crystalline undulator [1]. Currently
the algorithm is being further developed and refined for the Monte-Carlo simulation of the dynamics of relativistic
particle channeling in straight and periodically bent crystals. The algorithm accounts for a number
of phenomena: the action of the interplanar and centrifugal potentials combined with the stochastic force due
to the random scattering from lattice electrons and nuclei, the transition between axial and planar channeling,
the rechanneling effect as well as the influence of the temperature on the channeling process. The algorithm is
combined with another one that allows to calculate spectral-angular distribution of the electromagnetic radiation
produced by a relativistic charged particle in its motion along the simulated trajectory.
Presently, the code is able to simulate planar channeling of relativistic electrons and positrons in straight and
bent crystals. Examples of the simulated electron trajectories in a periodically bent crystal are shown in the
figure. A number of parameters can be varied: the energy of the projectile, the type and size of the crystal and
its orientation relative to the beam direction. The analysis routine allows to estimate the dechanneling length
and analyse the probability distributions of the channeling and dechanneled particles [2,3]. Spectral and angular
distribution of the emitted photons can be calculated.
Recently, the code has been modified and supplemented with Linux shell scripts to allow for parallel running
of the calculations on hundreds of processor cores within a Linux cluster.
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Figure 1: Examples of the simulated trajectories of electrons in an oriented crystal.
1. A. Kostyuk, A. Korol, A. Solov’yov, W. Greiner, Planar channeling of 855 MeV Electrons in Silicon:
Monte-Carlo simulations, J. Phys. B: At. Mol. Opt. Phys. 44, 075208 (2011).
2. A. Kostyuk, A.V. Korol, A.V. Solov’yov, Walter Greiner, Planar channelling of electrons: Numerical
analysis and theory, Nuovo Cimento C 34, 167–174 (2011).
3. A. Kostyuk, A.V. Korol, A.V. Solov’yov, W. Greiner, Monte Carlo Simulations of electron channelling
in bent (110) channel in Silicon, The preprint see at http://arxiv.org/abs/1104.3890 (2011).
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