top of page
ai-generated-9304796_1920.jpg

Electron Capture Rate Library

This electron capture rate library for use in astrophysical simulations is created by members of the research group of Remco Zegers at the Facility for Rare Isotope Beams, who collaborated with colleagues in nuclear astrophysics and nuclear theory. The first version, created by Chris Sullivan et al., was made available in a sensitivity study of core-collapse supernovae to nuclear electron capture rate. For that work, this library was implemented into the neutrino-interaction library NuLib, by Evan O'Connor.  The second version came after work on nuclei in the N=50 region and was created by Simon Giraud et al., based on earlier work by Rachel Titus et al. The latest version (1.3) of the library became available in October 2024, based on work by Ravlic, Giraud, Paar, and Zegers. It is recommended to use this version. It is also recommended to cite the following papers: 

  • A. Ravlic, S. Giraud, N. Paar, and R.G.T. Zegers, Self-consistent microscopic calculations for electron captures on nuclei in core-collapse supernovae (2024); https://doi.org/10.48550/arXiv.2412.00650 - reference will be updated once published

  • S. Giraud et al., Finite-temperature electron-capture rates for neutron-rich nuclei near 𝑁=50 and effects on core-collapse supernova simulations, Phys. Rev. C 105, 055801 (2022), https://journals.aps.org/prc/abstract/10.1103/PhysRevC.105.055801

  • Sullivan, C., O'Connor, E., Zegers, R. G. T., Grubb, T., & Austin, S. M. (2015), The Sensitivity of Core-Collapse Supernovae to Nuclear Electron Capture, The Astrophysical Journal, 816, 44. http://iopscience.iop.org/article/10.3847/0004-637X/816/1/44​

  • The original rate sets obtained from various sources. All references and links are provided below.

 

The electron capture rate library is based on work supported by the US National Science Foundation, most recently through grant number PHY 2209429 - Windows on the Universe: Nuclear Astrophysics at FRIB.

​

 

For questions, please contact Remco Zegers - zegers@frib.msu.edu

Electron capture rate library for nuclear astrophysics

The different versions of the electron capture rate library are described below. The different rate sets used are shown in the figure above. 

Version 1.3

For nuclei between Z=20 and Z=52, it now includes rates based on self-consistent finite-temperature covariant energy density functional theory with the quasiparticle random phase approximation (EDF), based on the work by Ravlic, Giraud, Paar, and Zegers (2024). Two plain rate tables are available: one in which all rates for nuclei between Z=20 and Z=52 are replaced by the EDF rates, and one in which shell-model calculations for Gamow-Teller transitions for nuclei in the pf shell are used rather than the new rates. Note that the first forbidden transitions from the EDF calculations are still included for these nuclei. 

A single rate table (ascii format) incorporating all the weak rates from the previous library with rates for Z=20-52 replaced with the 2024 EDF rates by Ravlic et al. can be obtained from: 

For use with NuLIB/GR1D, users must download one of the following NuLIB tables and name it "ravlicrates.dat" and place it in the directory "./src/weakrates/tables/", after which the relevant priorities for which rates to use can be set. NuLIB is obtained from this link. 

Version 1.2

After the work on version 1 was completed, the focus was on the region near N=50, which is particularly important for core-collapse supernovae. It resulted in the creation of a new rate set in 2022, which included updated rates in this so-called "diamond region". 

The first sensitivity study was performed in this paper: R. Titus, C. Sullivan, R.G.T. Zegers, B.A. Brown, B. Gao, Impact of electron-captures on nuclei near N=50 on core-collapse supernovae, J. Phys. G: Nucl. Part. Phys 45 (December 2017), 014004, http://iopscience.iop.org/article/10.1088/1361-6471/aa98c1  

The version 1.2 table can be obtained from here. The relevant publication is S. Giraud et al., Finite-temperature electron-capture rates for neutron-rich nuclei near 𝑁=50 and effects on core-collapse supernova simulations, Phys. Rev. C 105, 055801 (2022), https://journals.aps.org/prc/abstract/10.1103/PhysRevC.105.055801

Version 1.1

The first version of the electron capture rate table was published in 2015. The details can be found in Sullivan, C., O'Connor, E., Zegers, R. G. T., Grubb, T., & Austin, S. M. (2015), The Sensitivity of Core-Collapse Supernovae to Nuclear Electron Capture, The Astrophysical Journal, 816, 44. http://iopscience.iop.org/article/10.3847/0004-637X/816/1/44. The whole package can be downloaded from this link. A plain ascii file of the rates can be obtained from here.

The rate table includes the following rates sets:

​

Contact for Remco Zegers

640 South Shaw Lane, East Lansing, MI 48823

zegers@frib.msu.edu

+1-517-908-7473

​

bottom of page