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Radionuclide Dosimetric Data Sheets
Astatine-220
Summary data
General
Classification
Isotope: At-220
Atomic number (Z): 85
Mass number (A): 220
Neutron number (N): 135
Radioactive decay
Decay modes: α, β-
Half-life: 3.71 [m]
Decay constant: 3.1139e-03 [1/s]
Daughters: Rn-220 (92.0%), Bi-216 (8.0%)
Radioactive daughters: Rn-220, Bi-216
Dosimetric constants
Mean alpha energy: 0.4842 [MeV]
Mean electron energy: 1.213 [MeV]
Mean photon energy: 0.44965 [MeV]
Air kerma rate constant, Γ10: 1.912e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 1.912e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 2.719e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα: 7.758e-14
[Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:
1.943e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 7.204e-14
[Gy·kg/Bq·s]
Dose point kernels (plot)
Dose point kernel source: Graves, et al. Medical Physics. 2019 Nov.; 46(11):5284-5293.
Note: Bins are spaced every 0.1 mm until a radius of 10 cm, and every 1 mm until a radius of 2 m.
Download tabulated dose point kernel file here: www.mirdsoft.org/products/MIRDspecs/At-220 DPK.csv
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-220 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-220 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-220 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
5.01060e-05 |
2.668e+00 |
X-ray |
|
2.71660e-03 |
1.240e-02 |
X-ray |
|
1.17297e-02 |
2.745e-02 |
X-ray |
|
1.43744e-02 |
3.184e-02 |
X-ray |
|
8.13681e-02 |
2.881e-02 |
X-ray |
|
8.41450e-02 |
4.749e-02 |
X-ray |
|
9.52461e-02 |
1.043e-02 |
X-ray |
|
2.40970e-01 |
6.891e-01 |
Gamma |
|
2.92710e-01 |
2.963e-01 |
Gamma |
|
3.18300e-01 |
2.481e-02 |
Gamma |
|
4.04800e-01 |
1.654e-02 |
Gamma |
|
4.22260e-01 |
1.861e-01 |
Gamma |
|
5.33800e-01 |
1.998e-02 |
Gamma |
|
5.92300e-01 |
1.585e-02 |
Gamma |
|
6.45600e-01 |
3.859e-02 |
Gamma |
|
6.68000e-01 |
3.032e-02 |
Gamma |
|
6.97600e-01 |
4.134e-02 |
Gamma |
|
1.14568e+00 |
5.470e-02 |
Beta |
|
1.17802e+00 |
1.890e-01 |
Beta |
|
1.23305e+00 |
3.382e-01 |
Beta |
|
1.35832e+00 |
3.382e-01 |
Beta |
|
3.69159e-05 |
6.867e-01 |
Auger electron |
|
1.13409e-04 |
7.874e-01 |
Auger electron |
|
1.80289e-04 |
4.356e-01 |
Auger electron |
|
4.63192e-04 |
1.061e-01 |
Auger electron |
|
1.49933e-03 |
2.385e-02 |
Auger electron |
|
2.12842e-03 |
2.371e-01 |
Auger electron |
|
2.46206e-03 |
3.556e-02 |
Auger electron |
|
9.09819e-03 |
6.705e-02 |
Auger electron |
|
1.18445e-02 |
3.166e-02 |
Auger electron |
|
1.42206e-01 |
7.664e-02 |
Conversion electron |
|
1.93946e-01 |
2.165e-02 |
Conversion electron |
|
2.22928e-01 |
1.256e-02 |
Conversion electron |
|
2.23574e-01 |
4.872e-02 |
Conversion electron |
|
2.26351e-01 |
2.453e-02 |
Conversion electron |
|
2.37452e-01 |
2.283e-02 |
Conversion electron |
|
5.94288e+00 |
8.000e-02 |
Alpha |
|
1.10125e-01 |
8.000e-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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