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Radionuclide Dosimetric Data Sheets
Astatine-204
Summary data
General
Classification
Isotope: At-204
Atomic number (Z): 85
Mass number (A): 204
Neutron number (N): 119
Radioactive decay
Decay modes: α, β+, Electron capture
Half-life: 9.2 [m]
Decay constant: 1.2557e-03 [1/s]
Daughters: Po-204 (96.2%), Bi-200 (3.8%)
Radioactive daughters: Po-204, Bi-200
Dosimetric constants
Mean alpha energy: 0.2306 [MeV]
Mean electron energy: 0.44849 [MeV]
Mean photon energy: 2.32336 [MeV]
Air kerma rate constant, Γ10: 8.857e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 9.800e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 1.088e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα: 3.695e-14
[Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:
7.186e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 3.722e-13
[Gy·kg/Bq·s]
Summary spectra (plot)
Spectra source: ICRP Publication 107: Nuclear Decay Data for Dosimetric Calculations. Ann. ICRP 2008, 38 (3).
Download tabulated summary spectra file here: www.mirdsoft.org/products/MIRDspecs/At-204 Summary Spectrum.csv
Beta spectra (plot)
Spectra source: ICRP Publication 107: Nuclear Decay Data for Dosimetric Calculations. Ann. ICRP 2008, 38 (3).
Download tabulated beta spectra file here: www.mirdsoft.org/products/MIRDspecs/At-204 Beta Spectrum.csv
Tabulated data
Summary spectra (table)
Spectra source: ICRP Publication 107: Nuclear Decay Data for Dosimetric Calculations. Ann. ICRP 2008, 38 (3).
Note: Radiations with yield < 0.01 are excluded from the table, but are available in the linked *.csv data.
Download tabulated summary spectra file here: www.mirdsoft.org/products/MIRDspecs/At-204 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
3.84092e-05 |
1.514e+01 |
X-ray |
|
2.55241e-03 |
6.052e-02 |
X-ray |
|
1.10135e-02 |
1.398e-02 |
X-ray |
|
1.11319e-02 |
1.231e-01 |
X-ray |
|
1.33474e-02 |
2.413e-02 |
X-ray |
|
1.34935e-02 |
8.077e-02 |
X-ray |
|
1.58015e-02 |
1.686e-02 |
X-ray |
|
7.71271e-02 |
1.817e-01 |
X-ray |
|
7.96070e-02 |
3.024e-01 |
X-ray |
|
8.95836e-02 |
3.395e-02 |
X-ray |
|
9.01425e-02 |
6.587e-02 |
X-ray |
|
9.27189e-02 |
1.616e-02 |
X-ray |
|
2.61440e-01 |
2.320e-02 |
Gamma |
|
3.27690e-01 |
3.323e-02 |
Gamma |
|
3.35210e-01 |
3.532e-02 |
Gamma |
|
3.51700e-01 |
2.916e-02 |
Gamma |
|
4.26240e-01 |
6.751e-01 |
Gamma |
|
4.89520e-01 |
2.727e-02 |
Gamma |
|
5.11000e-01 |
4.871e-01 |
Annihilation photon |
|
5.16320e-01 |
9.032e-01 |
Gamma |
|
5.88300e-01 |
6.874e-02 |
Gamma |
|
6.09140e-01 |
2.462e-01 |
Gamma |
|
6.50660e-01 |
1.647e-02 |
Gamma |
|
6.62720e-01 |
1.382e-02 |
Gamma |
|
6.84340e-01 |
9.468e-01 |
Gamma |
|
7.61650e-01 |
4.734e-02 |
Gamma |
|
7.61650e-01 |
4.734e-02 |
Gamma |
|
7.61650e-01 |
4.734e-02 |
Gamma |
|
8.41060e-01 |
8.237e-02 |
Gamma |
|
8.44660e-01 |
1.392e-02 |
Gamma |
|
8.58180e-01 |
1.041e-02 |
Gamma |
|
8.67800e-01 |
1.875e-02 |
Gamma |
|
8.99390e-01 |
2.481e-02 |
Gamma |
|
9.26340e-01 |
1.335e-02 |
Gamma |
|
9.50250e-01 |
1.004e-02 |
Gamma |
|
1.41586e+00 |
1.709e-02 |
Positron |
|
1.43447e+00 |
6.837e-02 |
Positron |
|
1.56291e+00 |
2.137e-02 |
Positron |
|
1.70867e+00 |
5.341e-02 |
Positron |
|
1.71415e+00 |
3.205e-02 |
Positron |
|
3.94954e-05 |
3.654e+00 |
Auger electron |
|
9.78549e-05 |
4.683e+00 |
Auger electron |
|
1.75588e-04 |
2.571e+00 |
Auger electron |
|
4.43827e-04 |
7.079e-01 |
Auger electron |
|
1.07764e-03 |
1.488e-01 |
Auger electron |
|
2.03349e-03 |
1.309e+00 |
Auger electron |
|
2.34150e-03 |
1.837e-01 |
Auger electron |
|
8.46693e-03 |
2.853e-01 |
Auger electron |
|
8.71850e-03 |
3.743e-01 |
Conversion electron |
|
1.10188e-02 |
1.303e-01 |
Auger electron |
|
1.20000e-02 |
1.180e-01 |
Conversion electron |
|
1.35999e-02 |
1.419e-02 |
Auger electron |
|
5.77030e-02 |
1.078e-02 |
Conversion electron |
|
6.18768e-02 |
1.474e-02 |
Auger electron |
|
1.68016e-01 |
1.244e-02 |
Conversion electron |
|
2.41786e-01 |
1.140e-02 |
Conversion electron |
|
3.32816e-01 |
2.108e-02 |
Conversion electron |
|
4.22896e-01 |
1.892e-02 |
Conversion electron |
|
5.15716e-01 |
1.620e-02 |
Conversion electron |
|
5.90916e-01 |
1.132e-02 |
Conversion electron |
|
5.95090e+00 |
3.800e-02 |
Alpha |
|
1.19095e-01 |
3.800e-02 |
Alpha recoil |
Useful Links
Isotope decay characteristics are periodically updated as better measurements can be made - changes that may not be reflected on this page. Please see useful links:
National Nuclear Data Center (NNDC): https://www.nndc.bnl.gov/nudat3/mird/
International Atomic Energy Agency (IAEA) Livechart: https://www-nds.iaea.org/relnsd/vcharthtml/VChartHTML.html
Reference Links
ICRP Report 107: https://www.icrp.org/publication.asp?id=ICRP%20Publication%20107
Graves et al. Dose Point Kernels: https://doi.org/10.1002/mp.13789
MIRD Decay Schemes 2nd Edition: https://sites.snmmi.org/SNMMI-MAIN/iCore/Store/StoreLayouts/Item_Detail.aspx?iProductCode=0-932004-80-6
MIRDsoft MIRDspecs version 20250101 (www.mirdsoft.org)
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