Some information on ion range calculations

This WWW page provides a collection of links to some information on ion range calculations in the keV and MeV energy range.

If you want a fairly general introduction to the physics involved, try reading this short essay. The essay also discusses repulsive interatomic potentials and range simulation methods. (If you are an expert in the field, please take into account that I have tried to write the essay for an average physicist and for clarity may have made a few things sound simpler than they really are).

If you are wondering how good TRIM really is, what other simulation programs are available or so, here is an answer I've posted to USENET news every now and then which may help you out a bit. Much of the info in the answer is the same as in the essay.

If you are primarily interested in ranges in Si, the REED MD code by Keith Beardmore and Niels Gronbech Jensen may also be of interest to you.

Our range calculation method

We (J. Sillanpää, J. Peltola and myself) have written a program, MDRANGE, which calculates ion ranges using MD simulations, in a manner similar to TRIM. Because the method is based on MD simulations it overcomes some drawbacks of TRIM and other BCA simulations, especially the sometimes troublesome parameter dependence of the results. However, it is also about 10-20 times slower than BCA codes.

MDRANGE has an easy-to-use user interface mdsetup, which creates all the necessary input files for the actual simulation code mdh for straightforward simulation cases. So you should be able to learn to use the code easily. If you want it, just email me a note and I will tell you how to fetch it (I keep a list of who have obtained the code, which is why I prefer to have people ask for it).

The method we use is described in detail in the publication titled Molecular dynamics simulations of ion ranges in the 1-100 keV energy region (Comput. Mater. Sci. 3 (1995) 448-). A preprint of the paper is available in here. Also, a description of the program itself and its source code is available in hypertext.

Reprints of a few other papers (many of which contain examples of applications of the range calculation method to practical cases) can be obtained from my publication database.

References, with annotations

[5] K. Nordlund, Molecular dynamics simulation of ion ranges in the 1 -- 100 keV energy range, Comput. Mater. Sci. 3, 448 (1995).

The original paper on the method, and the basic paper to cite for MDRANGE

[9] P. Haussalo, K. Nordlund, and J. Keinonen, Stopping of 5 -- 100 keV helium in tantalum, niobium, tungsten, and AISI 316L steel, Nucl. Instr. Meth. Phys. Res. B 111, 1 (1996).

Explains how the nuclear stopping power can be evaluated from MDRANGE

[39] J. Sillanpää, K. Nordlund, and J. Keinonen, Electronic stopping of Silicon from a 3D Charge Distribution, Phys. Rev. B 62, 3109 (2000)

introduces the use of 3D charge distributions

[58] J. Sillanpää, J. Peltola, K. Nordlund, J. Keinonen, and M. J. Puska, Electronic stopping calculated using explicit phase shift factors, Phys. Rev. B 63, 134113 (2000).

introduces the "Puska" or PENR pair-specific stopping model

[78] J. Peltola, K. Nordlund, and J. Keinonen, Effects of damage build-up in range profiles in crystalline Si; molecular dynamics simulations, Nucl. Instr. Meth. Phys. Res. B (2002), accepted for publication.

the MDRANGE damage buildup model

[92] J. Peltola, K. Nordlund, and J. Keinonen, Molecular dynamics simulation method for calculating fluence-dependent range profiles, Nucl. Instr. Meth. Phys. Res. B (2002), COSIRES 2002 conference paper, submitted for publication.

Introduces a modified way to handle cell shifting