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Radionuclide Dosimetric Data Sheets
Hafnium-181
Summary data
General
Classification
Isotope: Hf-181
Atomic number (Z): 72
Mass number (A): 181
Neutron number (N): 109
Radioactive decay
Decay modes: β-
Half-life: 42.39 [d]
Decay constant: 1.8926e-07 [1/s]
Daughters: Ta-181 (100.0%)
Radioactive daughters: None
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.20523 [MeV]
Mean photon energy: 0.53242 [MeV]
Air kerma rate constant, Γ10: 2.022e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 2.022e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 3.288e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα: 0.000e+00
[Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:
3.288e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 8.530e-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/Hf-181 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/Hf-181 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/Hf-181 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/Hf-181 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
2.49831e-05 |
6.053e+00 |
X-ray |
|
1.70997e-03 |
1.988e-02 |
X-ray |
|
8.13762e-03 |
6.161e-02 |
X-ray |
|
9.36070e-03 |
5.417e-02 |
X-ray |
|
9.64848e-03 |
1.081e-02 |
X-ray |
|
5.64020e-02 |
9.183e-02 |
X-ray |
|
5.76858e-02 |
1.600e-01 |
X-ray |
|
6.51037e-02 |
1.713e-02 |
X-ray |
|
6.53809e-02 |
3.310e-02 |
X-ray |
|
1.33021e-01 |
4.331e-01 |
Gamma |
|
1.36260e-01 |
5.852e-02 |
Gamma |
|
3.45930e-01 |
1.512e-01 |
Gamma |
|
4.82180e-01 |
8.050e-01 |
Gamma |
|
1.19407e-01 |
6.965e-02 |
Beta |
|
1.20654e-01 |
9.254e-01 |
Beta |
|
1.18884e-05 |
5.312e-01 |
Auger electron |
|
2.73575e-05 |
7.523e-01 |
Auger electron |
|
1.60659e-04 |
2.063e+00 |
Auger electron |
|
3.01584e-04 |
6.862e-02 |
Auger electron |
|
3.15500e-04 |
4.146e-01 |
Auger electron |
|
7.41826e-04 |
6.487e-02 |
Auger electron |
|
1.42267e-03 |
9.171e-01 |
Auger electron |
|
1.60891e-03 |
5.381e-02 |
Auger electron |
|
1.71590e-03 |
3.491e-02 |
Conversion electron |
|
3.90000e-03 |
1.016e-02 |
Conversion electron |
|
6.37738e-03 |
2.833e-01 |
Auger electron |
|
8.06525e-03 |
1.070e-01 |
Auger electron |
|
9.78275e-03 |
1.012e-02 |
Auger electron |
|
6.54560e-02 |
2.120e-01 |
Conversion electron |
|
6.86950e-02 |
8.196e-02 |
Conversion electron |
|
6.92950e-02 |
1.326e-02 |
Conversion electron |
|
1.21365e-01 |
2.228e-02 |
Conversion electron |
|
1.21858e-01 |
1.271e-01 |
Conversion electron |
|
1.23142e-01 |
1.051e-01 |
Conversion electron |
|
1.24604e-01 |
1.160e-02 |
Conversion electron |
|
1.30837e-01 |
6.386e-02 |
Conversion electron |
|
1.33021e-01 |
1.760e-02 |
Conversion electron |
|
4.14615e-01 |
1.830e-02 |
Conversion electron |
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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