RSICC CODE PACKAGE PSR-227
1. NAME AND TITLE
ECIS-06: Code System to Solve Coupled Differential Equations Arising in Nuclear Model Calculations.
2. CONTRIBUTORS
CEA/CEN Service de Physique Theorique, Saclay, France, through the OECD Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France. RSICC obtained ECIS06 through the NEADB where it is distributed as NEA-0850/18.
3. CODING LANGUAGE AND COMPUTER
Fortran 77 and 95; PCs running Linux or Windows. (P00227/MNYCP/01)
4. NATURE OF PROBLEM SOLVED
The ECIS code has been developed over a period of more the fifteen years, and several earlier versions exist. The statistical model part is based on ANLECIS, developed by P. Moldauer. There is no new formal report for ECIS06, but there is a “how to use” feature integrated into the program.
ECIS-95 was a generalization of ECIS-79: for the rotational model vibrational bands are included. An option for solving the Dirac equation has been added. It also contains the statistical model including width fluctuation corrections as formulated by Peter Moldauer. While ECIS-94 is an update of ECIS-88 and obsoletes that version, ECIS-79 is still a valid version. Besides the use of Bessel expansion for form factors, the use of deformation lengths, and the use of “symmetrized” Woods-Saxon potentials, it includes:
o two bound state transitions for particle-mode excitations with the possibility of the particle in the continuum
o expression of cross sections in terms of Legendre polynomials
o possibility of angular distribution for uncoupled states without giving explicity all the reduced nuclear matrix elements
o for Coulomb excitation, use of the magnetic multipole.
ECIS03 differed from previous version in the following features:
o The whole program was converted to double-precision.
o All FORMATS were converted from Hollerith notation into 'quotes' notation.
o In ECIS03 the dispersion relation as described by "C. Mahaux and R. Sartor in Nucl. Phys A528 (1991) 253", is added to the real potencial, (it is a generalisation of the dispersion relation as described in "C. Mahaux and R. Sartor, Nucl. Phys. A458 (1986) 25" already introduced in ECIS96 and 97).
ECIS06 is primarily ECIS03 modified for the use of a different relativistic 'reduced mass' in front of 'scalar' potentials, differing from the one used in front of Coulomb potentials. It is the application to coupled equations of the principles described in 'DWBA05' announced in the Workshop 'Perspectives on Nuclear Data in the Next Decade', on the 26-28/9/2005 at Bruyeres-le-Chatel, France. Some generalizations have been introduced, in particular for the dispersion relation. ECIS06 contains the following features:
o The Fortran source was updated to be compatible with current compilers.
o The LOG tables description has been updated.
o The re-start of a search parameter calculation by a different job was not possible. This new version fixes this problem.
o Automatic self-protecting features have been updated: in uninteresting situations, stop for low energy and external potential have been suppressed.
5. METHOD OF SOLUTION
The ECIS method is designed to solve sets of coupled differential equations when the coupling terms are not too strong. The iteration technique searches for the one required solution among the many which are mathematically possible. The method supposes some ordering of the channels: first the ground state, then the state most strongly coupled to it. All channels must be coupled to some preceding one. The result of each iteration depends on this chosen order. If there is more than one equation related to the ground state, the whole calculation must be repeated. The efficiency of the method is proportional to the ratio of the total number of equations to the number of those related to the ground state. The usual methods can also be used, but the iteration method is compulsory for spin-orbit deformation and Dirac formalism.
6. RESTRICTIONS OR LIMITATIONS
None noted.
7. TYPICAL RUNNING TIME
CPU time requirements are very problem-dependent.
8. COMPUTER HARDWARE REQUIREMENTS
ECIS-06 is operable on personal computers.
9. COMPUTER SOFTWARE REQUIREMENTS
ECIS-06 runs on PC’s under Windows or Linux. The package includes Fortran and C source files plus a Windows executable created with Intel Visual Fortran Compiler Professional Edition Version 9 and a Linux executable created with Lahey/Fujitsu Fortran 95 Compiler Release 5.50h. ECIS06 was recompiled and tested by RSICC on the systems listed below.
Pentium PC running Windows XP and with Lahey-Fujitsu lf95 v7.1
Pentium PC running Windows VISTA with Compaq Digital Visual Fortran 6.6C
Pentium PC running Ubuntu 7.04 with GNU Fortran 95 (GCC) 4.1.2
Pentium PC running Fedora 7 with 32-bit g77 3.4.6
AMD Opteron running Red Hat Enterprise Linux 4 with pgf95 vers 6.1-6
AMD Athlon running RedHat Linux 7.3(Valhalla) with Lahey-Fujitsu lf95 vL6.10a
10. REFERENCES
10.a included in distribution files and in P227.pdf:
J. Raynal, “Notes on ECIS94,” CEA-N-2772 (September 1994).
J. Raynal,
“ECIS96”, Proceedings of the Specialists' Meeting on the Nucleon
Nucleus Optical Model up to 200 MeV, 13-15 November 1996, Bruyères-le-Chatel, France
Publication 19 Nuclear Energy Agency, 1997 (p.159-166).
(http://www.nea.fr/html/science/om200/raynal.pdf)
J. Raynal, “DWBA05,” Workshop Perspectives on Nuclear Data in the Next Decade on the 26-28/9/2005 at Bruyeres-le-Chatel, France.
10.b included in distribution files:
K. Amos, et al. and J. Raynal correspondence (Dec. 2003 to Jan. 2004).
11. CONTENTS OF CODE PACKAGE
Included are the referenced documents and one CD-Rom disc, written in tar format, which contains the source program, PC executables for Linux and Windows users, and sample problems input and output.
12. DATE OF ABSTRACT
May 1986; revised August 1988, April 1995, January 1998, September 2007.
KEYWORDS: NUCLEAR MODELS; DIFFERENTIAL EQUATIONS SOLVING; WORKSTATION; MICROCOMPUTER.