Expand description
Trace-detectability analysis for neutron resonance imaging.
Answers the pre-experiment question: “Can I detect X ppm of isotope B in a matrix of isotope(s) A across a given energy window?”
§Core concept
For a given matrix + trace isotope pair, compute the peak spectral SNR as a function of trace concentration:
SNR_peak(c) = max_E |ΔT(E, c)| / σ_noise
where ΔT is the signed transmission difference:
ΔT(E, c) = T(E, n_matrix, 0) − T(E, n_matrix, n_trace = c·n_matrix)
and σ_noise ≈ 1/√I₀ (off-resonance Poisson approximation).
The stored delta_t_spectrum and all derived metrics (peak_delta_t_per_ppm,
peak_snr) use |ΔT|, discarding the sign.
§Reference
Motivated by the observation that Fe-56 + Mn-55 have no resolved resonances in 1–50 eV, while W-182 + Hf-178 give strong contrast in the same window. VENUS can resolve up to ~1 keV, so many more pairs become accessible at higher energies (e.g., Mn-55 resonance at ~337 eV).
Structs§
- Trace
Detectability Config - Configuration for a trace-detectability analysis.
- Trace
Detectability Report - Result of a trace-detectability analysis for a single matrix+trace pair.
Functions§
- trace_
detectability - Compute trace-detectability for a single matrix+trace isotope pair.
- trace_
detectability_ survey - Survey multiple trace candidates against a matrix (single or multi-isotope).