hub:
  repo_type: generator
  builtin: nuclear-reaction-networks
  tags:
  - banzhaf-yamamoto
chemistries:
- id: nuclear-reaction-networks
  name: Nuclear reaction networks
  intuition: 'Real nuclear physics in the same record as the artificial chemistries, which makes it an
    unusually good validation target. Nuclides and elementary particles are the species, fusion and decay
    the reactions, and measured cross-section libraries exist to check against. The CNO cycle is also
    a textbook catalytic organisation: carbon, nitrogen and oxygen are consumed and regenerated while
    hydrogen is converted to helium, so the catalysts appear on both sides and would vanish from a net
    stoichiometric matrix.

    '
  book: '20.2'
  refs:
  - '[187]'
  family: non-chemical
  kind: generator
  constructive: false
  S:
    repr: nuclides and elementary particles (n, 1H, 2H, ..., e+, e-, nu_e, gamma)
    definition: explicit
  R:
    definition: explicit
    arity:
    - 1
    - 2
    scheme: 'e.g. 1H + 1H -> 2H + e+ + nu_e. The CNO cycle is a genuine CATALYTIC cycle: 12C + 1H -> 13N
      + gamma ; 13N -> 13C + e+ + nu_e ; 13C + 1H -> 14N + gamma ; 14N + 1H -> 15O + gamma ; 15O -> 15N
      + e+ + nu_e ; 15N + 1H -> 12C + 4He.

      '
  A:
    reactor: ode
    dilution: 'open: 1H flows in, 4He, e+, nu_e flow out'
  params:
  - name: network
    type: enum
    default: cno-cycle
    choices:
    - cno-cycle
    - pp-chain
    - big-bang-nucleosynthesis
    role: structural
    meaning: which reaction network to generate
  provides:
  - topology
  - stoichiometry
  - mass-conservation
  fidelity: book+decisions
  decisions:
  - Topology only. Rates depend on temperature and density through cross sections (e.g. REACLIB), which
    the book does not give, so cross_sections, temperature and density are not parameters.
  - cno-cycle is book eq. 20.4, with the book's open boundary (1H in; 4He, e+, nu_e out) recorded in extras.boundary
    rather than as numeric flows. pp-chain is eq. 20.3 completed with the standard pp-I branch. big-bang-nucleosynthesis
    is the standard 12-reaction network among n, 1H, 2H, 3H, 3He, 4He, 7Li, 7Be, standing in for figure
    20.4, which only draws the network.
  - extras.conservation lists baryon number, charge (fully ionised nuclei) and electron lepton number,
    all exact.
  phenomena:
  - the CNO cycle is a closed, self-maintaining organisation with C, N, O as catalysts
  - observed light-element abundances from big-bang nucleosynthesis
  notes: 'An excellent external validation target: real cross-section libraries exist (REACLIB), and the
    CNO cycle is a textbook chemical organisation.

    '