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Abstract

A FORTRAN 90 program is presented which calculates the total cross sections, and the electron energy spectra of the singly and doubly differential cross sections for the single target ionization of neutral atoms ranging from hydrogen up to and including argon. The code is applicable for the case of both high and low Z projectile impact in fast ion–atom collisions. The theoretical models provided for the program user are based on two quantum mechanical approximations which have proved to be very successful in the study of ionization in ion–atom collisions. These are the continuum-distorted-wave (CDW) and continuum-distorted-wave eikonal-initial-state (CDW-EIS) approximations. The codes presented here extend previously published codes for single ionization of target hydrogen [Crothers and McCartney, Comput. Phys. Commun. 72 (1992) 288], target helium [Nesbitt, O'Rourke and Crothers, Comput. Phys. Commun. 114 (1998) 385] and target atoms ranging from lithium to neon [O'Rourke, McSherry and Crothers, Comput. Phys. Commun. 131 (2000) 129]. Cross sections for all of these target atoms may be obtained as limiting cases from the present code.Title of program: ARGONCatalogue identifier: ADSEProgram summary URL: http://cpc.cs.qub.ac.uk/cpc/summaries/ADSEProgram obtainable from: CPC Program Library, Queen's University of Belfast, N. IrelandLicensing provisions: noneComputer for which the program is designed and others on which it is operable:Computers: Four by 200 MHz Pro Pentium Linux server, DEC Alpha 21164; Four by 400 MHz Pentium 2 Xeon 450 Linux server, IBM SP2 and SUN Enterprise 3500Installations: Queen's University, BelfastOperating systems under which the program has been tested: Red-hat Linux 5.2, Digital UNIX Version 4.0d, AIX, Solaris SunOS 5.7Compilers: PGI workstations, DEC CAMPUSProgramming language used: FORTRAN 90 with MPI directivesNo. of bits in a word: 64, except on Linux servers 32Number of processors used: any numberHas the code been vectorized or parallelized?: Parallelized using MPINo. of bytes in distributed program, including test data, etc.: 32 189Distribution format: tar gzip fileKeywords: Single ionization, cross sections, continuum-distorted-wave model, continuum-distorted-wave eikonal-initial-state model, target atoms, wave treatmentNature of physical problem: The code calculates total, and differential cross sections for the single ionization of target atoms ranging from hydrogen up to and including argon by both light and heavy ion impact.Method of solution: ARGON allows the user to calculate the cross sections using either the CDW or CDW-EIS [J. Phys. B 16 (1983) 3229] models within the wave treatment.Restrictions on the complexity of the program: Both the CDW and CDW-EIS models are two-state perturbative approximations.Typical running time: Times vary according to input data and number of processors. For one processor the test input data for double differential cross sections (40 points) took less than one second, whereas the test input for total cross sections (20 points) took 32 minutes.Unusual features of the program: none