RIPL optical model database

Physics and data included in the Reference Input Parameter Library, which is devoted to input parameters needed in calculations of nuclear reactions and nuclear data evaluations are described in the RIPL reference paper. Advanced modelling codes require substantial numerical input, therefore the International Atomic Energy Agency (IAEA) has worked extensively since 1993 on a library of validated nuclear-model input parameters, referred to as the Reference Input Parameter Library (RIPL). A final RIPL coordinated research project (RIPL-3) was brought to a successful conclusion in December 2008, after 15 years of challenging work carried out through three consecutive IAEA projects. The RIPL-3 library was released in January 2009, and is available on the Web through https://nds.iaea.org/RIPL/. This work and the resulting database are extremely important to theoreticians involved in the development and use of nuclear reaction modelling (ALICE, EMPIRE, GNASH, UNF, TALYS) both for theoretical research and nuclear data evaluations.

The optical model segment of the database contains an optical model parameters database including a C/Fortran retrieval code (omget) that can retrieve optical model potentials and automatically produce the inputs for cross section calculations using ECIS and/or OPTMAN solvers. The whole OMP database together with the retrieval code are available here. See the file ominput.readme for a short description, and the file om-index.txt for the whole list of stored OMPs.

In the same zip file a FORTRAN source version of the ECIS06 code (ecis06fullm.f by J. Raynal) is distributed. The retrieval code can produce the input file to run the ECIS code and calculate the scattering cross sections. 

Please contact Roberto Capote (r.capotenoy@iaea.org) for further information. 

Citations:

R. Capote, M. Herman, P. Oblozinsky, P.G. Young, S. Goriely, T. Belgya, A.V. Ignatyuk, A.J. Koning, S. Hilaire, V.A. Plujko, M. Avrigeanu, O. Bersillon, M.B. Chadwick, T. Fukahori, Zhigang Ge, Yinlu Han, S. Kailas, J. Kopecky, V.M. Maslov, G. Reffo, M. Sin, E.Sh. Soukhovitskii, P. Talou “RIPL – Reference Input Parameter Library for Calculation of Nuclear Reactions and Nuclear Data Evaluations,” Nuclear Data Sheets 110 (2009) 3107-3214

Excel spreadsheet with various optical potentials

Work in progress by Ben Kay (kay@anl.gov) -- suggestions are  welcome.

By entering a specific target, outgoing ion, beam energy, and excitation energy of the final state (yellow cells), this will automatically calculate the parameters you require for each potential. You can then simply cut and paste the output into (for example) Ptolemy. The validity of each potential and the corresponding citation are also specified in the spreadsheet. This a simple but useful tool that keeps evolving. Suggestions, corrections, and additions are welcome.

Link to download the excel spreadsheet (the functions used in this excel spreadsheet do not work when opened as a google spreadsheet, you need to download it to be able to use it): https://docs.google.com/spreadsheets/d/1fFDyJvTu4gAc8hc4gSqU7e7sp_mO_aK9/edit?usp=sharing&ouid=111193748903891871156&rtpof=true&sd=true 

Koning-Delaroche Uncertainty Quantified and Chapel Hill '89 Uncertainty Quantified  (KDUQ and CHUQ)

KDUQ (Koning-Delaroche, Uncertainty Quantified) and CHUQ (Chapel Hill '89, Uncertainty Quantified) extend the global spherical proton and neutron OMPs of Koning-Delaroche (KD) and CH89 with uncertainty quantification of the potential parameters. Rather than a single 'best-fit' of potential parameters, KDUQ and CHUQ are ensembles of hundreds of parameter-vector samples spanning the parameter-space region near the canonical 'best-fit' minimum. Each sample can be used the same way that the canonical KD and CH89 potentials would be used: enter the N and Z of the target, incident projectile energy, and projectile identity (n or p). By performing repeated calculations over many samples, users can forward-propagate the parametric uncertainty associated with the OMP to their application of choice. Integration with Hauser-Feshbach code YAHFC is currently under development.

Mass validity: Same as original KD and CH89 potentials: 27 < A < 209 (KDUQ);  40 < A < 209 (CHUQ)

Energy validity: Same as original KD and CH89 potentials: 0.001 MeV < E < 200 MeV (KDUQ); 10 MeV < E < 65 MeV (CHUQ)

The pre-print describing KDUQ and CHUQ is available here. The OMP samples and tools for sampling are available as supplemental material.

Citation:

• C. D. Pruitt, J. E. Escher and R. Rahman, Phys. Rev. C 107, 014602 (2023).

Global nonlocal dispersive optical model for neutron from 1keV to 250 MeV  (Morillon et al.)

Global nonlocal and dispersive optical model potential for neutron scattering off spherical nuclei with incident energies up to 250 MeV. This optical model is an extension of the nondispersive Perey-Buck potential. The imaginary components are chosen to be energy dependent and the dispersive constraints are taken into account. The surface imaginary part is nonlocal, whereas the volume imaginary part above 10 MeV is local, allowing one to reproduce total cross sections and scattering data for high energies. A good description of scattering observables is obtained for target nuclei ranging from 𝐴=16 up to 209. The inclusion of a nonlocal spin-orbit term enables a better description of the analyzing power data relative to the local dispersive model.

Mass validity: 16 < A < 209 

Energy validity: 0.001 MeV < E < 250 MeV

Citation:

• B. Morillon, G. Blanchon, P. Romain, and H. F. Arellano, Phys. Rev. C 109, 044611 (2024)

Whitehead-Lim-Holt (WLH) potential 

Microscopic global nucleon-nucleus optical potential with quantified uncertainties suitable for analyzing nuclear reaction experiments at next-generation rare-isotope beam facilities.  This optical potential is  based on two- and three-nucleon interactions from chiral effective field theory.  The global optical potential is expressed as a function composed of local Woods- Saxon terms with parameters that vary smoothly in energy E, mass A, and isospin asymmetry δ, which can be easily implemented into modern reaction theory codes. 

Mass validity: 12 ≤ A ≤ 242

Energy validity: 0 ≤ E ≤ 150 MeV

A python script for using the WLH global optical potential can be downloaded at https://www.trwhitehead.com/WLH.html

Citation:

• T. R. Whitehead, Y. Lim, and J. W. Holt, Phys. Rev. Lett. 127, 182502 (2021)

Isospin Dependent Optical Potential for nucleon-nucleus scattering 

Phenomenological nucleon-nucleus optical potential, it was built with these features:

• It is isospin dependent: for N=Z nuclei, it uses the same parameterization for proton or neutron potentials, if N is not equal to Z, it includes a (N-Z) term. It can useful for mirror nuclei studies and asymmetry studies.

• It has been fit to exotic nuclei.

Mass validity: 12 ≤ A ≤ 60

Energy validity: 30 MeV ≤ E ≤ 160 MeV

It has an easy to use calculator found at  http://home.eckerd.edu/~weppnesp/optical/ as a Java jar file. This calculates any elastic observable or total inelastic observables.

Citation:

• S. P. Weppner, R. B. Penney, G. W. Diffendale, and G. Vittorini, Phys. Rev. C 80, 034608 (2009).

• S. P. Weppner, R. B. Penney, G. W. Diffendale, and G. Vittorini, Erratum Phys. Rev. C 89, 049904 (2014).

BiFold: density-dependent or independent double-folded potentials

Abstract: BiFold calculates density-dependent (DDM3Yn, BDM3Yn, CDM3Yn) or independent double-folded potentials between two colliding spherical nuclei. It is written in a Python package form to give the ability to use the potentials directly in a nuclear reaction/structure code. In addition to using Woods-Saxon/Fermi or Gaussian functions, the code also allows the definition of nuclear matter densities using pre-calculated densities in a data file. The manuscript provides an overview of the double folding model and the use of the code.

Code available in https://doi.org/10.1016/j.cpc.2022.108613

Citation:

• M. Karakoç, Computer Physics Communications 284, 108613 (2023).

São Paulo potential version 2 (SPP2) and Brazilian nuclear potential (BNP)

Abstract: The REGINA code calculates the São Paulo potential version 2 (SPP2) and the Brazilian nuclear potential (BNP). The code also provides nuclear densities obtained from the Dirac-Hartree-Bogoliubov model, which are used to calculate the nuclear potentials. Elastic scattering cross sections are obtained within the context of the optical model, with different options for the real and imaginary parts of the optical potential. In this manuscript, we provide a summary of the theoretical framework and information about the use of the code.

Code available in https://data.mendeley.com/datasets/vfkkjb8dv7/1

Citation:

• L. C. Chamon, B. V. Carlson and L. R. Gasuqes, Computer Physics Communications 267, 108061 (2021).

Predictions for radial densities -- input to double-folding codes

In the TALYS data base, Stephane Goriely and Stephane Hilaire have provided radial matter densities from dripline to dripline. They are stored

in talys/structure/optical/jlm/. The details of the organization of these files can be found in the talys manual

Link to the github: https://github.com/arjankoning1/talys

Citation:

• A. Koning, S. Hilaire and S. Goriely, TALYS: modeling of nuclear reactions, European Journal of Physics A 59 (6), 131 (2023).