Nuclide reference
As-74 — Arsenic-74
The half-life of As-74 is 17.77 d. Main decay mode: β⁺ decay / electron capture to Ge-74 (66%).
Identification
- Element
- Arsenic (As)
- Atomic number Z
- 33
- Mass number A
- 74
- State
- Radioactive
Key quantities
- Half-life
- 17.77 d
- Specific activity
- 3.674e+15 Bq/g
- Gamma constant Γ
- —
- A1 / A2 for transport (SSR-6, НП-053-16)
- 1 TBq / 0.9 TBq
- D-value (НП-067-24)
- 0.09 TBq
Decay modes
- β⁺ decay / electron capture → Ge-74 — 66 %
- β⁻ decay → Se-74 — 34 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 595.83 | 59.4 |
| 510.999 · annihilation 511 keV | 58.22 |
| 634.78 | 15.35 |
| 9.887 · X-ray line | 9.877 |
| 9.856 · X-ray line | 5.088 |
| 608.43 | 0.5524 |
| 1,204.35 | 0.2851 |
| 635 | 0.0357 |
| 887 | 0.02554 |
| 993.46 | 0.01841 |
Lines of the bare nuclide (ENDF/B-VIII.0), without daughter ingrowth.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 1,352.8 | 18.59 |
| 718.02 | 15.39 | |
| β⁺, E max | 944.64 | 26.08 |
| 1,540.5 | 3.01 | |
| 336.14 | 0.01605 |
For β⁻ and β⁺ the endpoint (maximum) energy of the spectrum is given. ENDF/B-VIII.0.
Related calculators
Reference data vs computed valuesHalf-life, gamma lines and D-value are reference data (ENDF/B-VIII.0, НП-067-24).Gamma constant Γ is H*(10) at 1 m computed from ICRP-107 spectra (NIST µ_en/ρ, ICRP-74 Table A.21) including short-lived progeny in equilibrium (e.g. Cs-137/Ba-137m, Ra-226 series); specific activity uses molar mass M ≈ mass number A.K-series X-ray energies are from NIST SRD 128 (Deslattes et al., 2003): in ENDF/B-VIII.0 they are given to 1 % and shifted by up to 0.7 keV for heavy elements. L-series lines and all yields are ENDF/B-VIII.0.