Network Generator

What is NetGen?

Welcome to the Network Generator

NetGen is a tool to help astrophysicists

This tool makes use of an extended database maintained at the Institut d'Astronomie et d'Astrophysique (Université Libre de Bruxelles). It covers about 9200 isotopes, from the proton- to the neutron-drip lines, and from Z=1 up to Z=110. The astrophysical reaction rates are provided for a large variety of nuclear reactions of interest for big-bang nucleosynthesis, stellar hydrogen-, helium- and later burning phases (hydrostatic and explosive), as well as for the synthesis of heavy nuclei (s-, r-, p-, rp-, alpha-processes). Those include light-particle (mostly n, p, alpha) induced reactions and nucleus-nucleus reactions, photodisintegrations, as well as beta-decay and electron capture rates.

The rates are selected from the sources we consider now as the most reliable ones. For particle-induced reactions, rates based on experimental data or, when no such experimental data exist, on detailed microscopic calculations (nuclear Hauser-Feshbach reaction rate predict by TALYS) are generally preferred. For experimential reaction rates, various choices are possible as well (consult the user manual to learn how to select them). Laboratory values and different theoretical estimates (using statistical or microscopic nuclear models) are used for the weak interaction rates. Photodisintegrations and some particle induced reaction rates are computed from their reverse reaction rates, the partition functions are used for evaluating reverse reaction rates. The appropriate Q values are derived from Audi et al. (AME 2010) or, if not available, from Goriely et al. HFB-17 mass table. Stellar enhancement factors (SEF) are included for most laboratory experimental reactions (exceptions are reactions from the CF88 library, and Descouvemont et al. compilation) and the values used are clearly documented (Note that for TALYS Hauser-Feshbach rates the SEFs are already included in the tabulated values).

The following database, including experimental and theoretical reaction rates, partition functions, and nuclear mass tables, are currently available to NetGen:

  1. NACRE (The European Nuclear Astrophysics Compilation of REaction Rates)
  2. The Iliadis et al. table of proton-capture rates on 20 < A < 40 nuclei (2001, ApJS 134, 151)
  3. Descouvemont et al. compilation of Big Bang nucleosynthesis reaction rates (2004, Atomic Data Nuclear Data Tables 88, 203).
  4. Caughlan and Fowler 1988 (CF88) for the reaction rates and various sources for reactions involving charged particles [including (n,p) and (n,α) reactions] which are not included in NACRE or in CF88, or when those sources supersede CF88.
  5. Experimental radiative neutron-capture rates before 2000 (from the Bao et al. table ).
  6. Experimental radiative neutron-capture rates from the year 2000 to 2011 which are not included in table of Bao et al.
  7. NACRE II, An Update and Extension of the NACRE Compilation of Charged-particle-induced Thermonuclear Reaction Rates for Astrophysics (2013, NPA 918, 61)
  8. Iliadis et al.: The 2010 Evaluation of Monte Carlo based Thermonuclear Reaction Rates (2010, NPA 841, 1)
  9. Hauser-Feshbach Reaction Rates calculated with the code TALYS.
  10. Beta-decay rates from Goriely (1999, Astron. Astrophys. 342, 881; Table available in electronic form here
  11. Beta-decay rates from Takahashi & Yokoi (1987, Atomic Data Nucl. Data Tables 36, 375).
  12. Specific electron capture rates from various published sources
  13. Experimental Beta-decay rates: Nishimura S. (2011), Phys. Rev. Lett 106, 052502, and Katakura J. (1996) Chart of the Nuclides (Japanese Nuclear Data Committee and Nuclear Data Center, Japan Atomic Energy Research Institute).
  14. Beta-decay rates complemented by theoretical calculated with ervised Gross Theory (GT2)+ Qbeta from HFB-14 mass model, branching factor for delayed particle emission included. Tachibana et al., (1990) Prog. Theor. Phys. 84, 641.
  15. Beta-decay rates complemented by theoretical calculated with QRPA + FRDM models. Moeller, Nix & Kratz (1997), (Ref: LA-UR-94-3898).
  16. Density- and temperature-dependent Beta-decay rates from Oda et al. (1994, Atomic Data Nuclear Data Tables 56, 231)
  17. Density- and temperature-dependent Beta-decay rates from Langanke & Martinez (2000, Nucl. Phys. A 673, 481).
  18. Nuclear masses predicted by the HFB-17 mass model.
  19. Nuclear partition function for reverse reaction rate evaluation.

Instructions on how to use the network generator are available here, in particular how to select the various non-default rates, using the bibliographic index