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Title: FELIX-2.0: New version of the finite element solver for the time dependent generator coordinate method with the Gaussian overlap approximation

Abstract

The time-dependent generator coordinate method (TDGCM) is a powerful method to study the largeamplitude collective motion of quantum many-body systems such as atomic nuclei. Under the GaussianOverlap Approximation (GOA), the TDGCM leads to a local, time-dependent Schrödinger equation in amulti-dimensional collective space. In this paper, we present the version 2.0 of the code FELIX that solvesthe collective Schrödinger equation in a finite element basis. This new version features: (i) the ability tosolve a generalized TDGCM+GOA equation with a metric term in the collective Hamiltonian, (ii) supportfor new kinds of finite elements and different types of quadrature to compute the discretized Hamiltonianand overlap matrices, (iii) the possibility to leverage the spectral element scheme, (iv) an explicit Krylovapproximation of the time propagator for time integration instead of the implicit Crank–Nicolson methodimplemented in the first version, (v) an entirely redesigned workflow. We benchmark this release on ananalytic problem as well as on realistic two-dimensional calculations of the low-energy fission of240Puand256Fm. Low to moderate numerical precision calculations are most efficiently performed with simplexelements with a degree 2 polynomial basis. Higher precision calculations should instead use the spectralelement method with a degree 4 polynomial basis. We emphasize that in a realistic calculation of fissionmass distributionsmore » of240Pu, FELIX-2.0 is about 20 times faster than its previous release (within a numericalprecision of a few percents).« less

Authors:
ORCiD logo [1];  [2];  [2];  [3]
  1. Université Paris-Sud, Orsay Cedex, (France). Institut de Physique Nucléaire
  2. CEA, DAM, DIF, Arpajon (France).
  3. Lawrence Livermore National Laboratory. (LLNL), Livermore, CA (United States). Nuclear and Chemical Science Division
Publication Date:
Research Org.:
Oak Ridge National Laboratory, Oak Ridge Leadership Computing Facility (OLCF); Lawrence Berkeley National Laboratory, Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC).
Sponsoring Org.:
USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR) (SC-21)
OSTI Identifier:
1463274
DOE Contract Number:  
AC52-07NA27344; AC05-00OR22725; AC02-05CH11231
Resource Type:
Journal Article
Journal Name:
Computer Physics Communications
Additional Journal Information:
Journal Volume: 225; Journal Issue: C; Journal ID: ISSN 0010-4655
Country of Publication:
United States
Language:
English

Citation Formats

Regnier, D., Dubray, N., Verri�re, M., and Schunck, N. FELIX-2.0: New version of the finite element solver for the time dependent generator coordinate method with the Gaussian overlap approximation. United States: N. p., 2018. Web. doi:10.1016/j.cpc.2017.12.007.
Regnier, D., Dubray, N., Verri�re, M., & Schunck, N. FELIX-2.0: New version of the finite element solver for the time dependent generator coordinate method with the Gaussian overlap approximation. United States. doi:10.1016/j.cpc.2017.12.007.
Regnier, D., Dubray, N., Verri�re, M., and Schunck, N. Sun . "FELIX-2.0: New version of the finite element solver for the time dependent generator coordinate method with the Gaussian overlap approximation". United States. doi:10.1016/j.cpc.2017.12.007.
@article{osti_1463274,
title = {FELIX-2.0: New version of the finite element solver for the time dependent generator coordinate method with the Gaussian overlap approximation},
author = {Regnier, D. and Dubray, N. and Verri�re, M. and Schunck, N.},
abstractNote = {The time-dependent generator coordinate method (TDGCM) is a powerful method to study the largeamplitude collective motion of quantum many-body systems such as atomic nuclei. Under the GaussianOverlap Approximation (GOA), the TDGCM leads to a local, time-dependent Schrödinger equation in amulti-dimensional collective space. In this paper, we present the version 2.0 of the code FELIX that solvesthe collective Schrödinger equation in a finite element basis. This new version features: (i) the ability tosolve a generalized TDGCM+GOA equation with a metric term in the collective Hamiltonian, (ii) supportfor new kinds of finite elements and different types of quadrature to compute the discretized Hamiltonianand overlap matrices, (iii) the possibility to leverage the spectral element scheme, (iv) an explicit Krylovapproximation of the time propagator for time integration instead of the implicit Crank–Nicolson methodimplemented in the first version, (v) an entirely redesigned workflow. We benchmark this release on ananalytic problem as well as on realistic two-dimensional calculations of the low-energy fission of240Puand256Fm. Low to moderate numerical precision calculations are most efficiently performed with simplexelements with a degree 2 polynomial basis. Higher precision calculations should instead use the spectralelement method with a degree 4 polynomial basis. We emphasize that in a realistic calculation of fissionmass distributions of240Pu, FELIX-2.0 is about 20 times faster than its previous release (within a numericalprecision of a few percents).},
doi = {10.1016/j.cpc.2017.12.007},
journal = {Computer Physics Communications},
issn = {0010-4655},
number = C,
volume = 225,
place = {United States},
year = {2018},
month = {4}
}