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Radionuclide Dosimetric Data Sheets
Tungsten-181
Summary data
General
Classification
Isotope: W-181
Atomic number (Z): 74
Mass number (A): 181
Neutron number (N): 107
Radioactive decay
Decay modes: Electron capture
Half-life: 121.2 [d]
Decay constant: 6.6193e-08 [1/s]
Daughters: Ta-181 (100.0%)
Radioactive daughters: None
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.01289 [MeV]
Mean photon energy: 0.04042 [MeV]
Air kerma rate constant, Γ10: 2.238e-18 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 2.238e-18 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 2.065e-15 [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-:
2.065e-15 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 6.476e-15
[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/W-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/W-181 Summary 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/W-181 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
2.49369e-05 |
1.238e+01 |
X-ray |
|
1.70807e-03 |
4.074e-02 |
X-ray |
|
6.24000e-03 |
1.030e-02 |
Gamma |
|
8.07690e-03 |
1.096e-02 |
X-ray |
|
8.13762e-03 |
9.674e-02 |
X-ray |
|
9.36070e-03 |
5.479e-02 |
X-ray |
|
9.64848e-03 |
1.698e-02 |
X-ray |
|
1.09205e-02 |
1.008e-02 |
X-ray |
|
5.64020e-02 |
1.865e-01 |
X-ray |
|
5.76858e-02 |
3.251e-01 |
X-ray |
|
6.51037e-02 |
3.479e-02 |
X-ray |
|
6.53809e-02 |
6.722e-02 |
X-ray |
|
6.71676e-02 |
1.524e-02 |
X-ray |
|
1.19854e-05 |
1.087e+00 |
Auger electron |
|
2.73581e-05 |
1.542e+00 |
Auger electron |
|
1.60406e-04 |
4.217e+00 |
Auger electron |
|
3.02094e-04 |
1.399e-01 |
Auger electron |
|
3.14052e-04 |
8.260e-01 |
Auger electron |
|
5.83490e-04 |
1.959e-01 |
Auger electron |
|
1.41944e-03 |
1.882e+00 |
Auger electron |
|
1.60306e-03 |
1.098e-01 |
Auger electron |
|
4.05590e-03 |
5.831e-01 |
Conversion electron |
|
6.24000e-03 |
1.430e-01 |
Conversion electron |
|
6.33769e-03 |
4.132e-01 |
Auger electron |
|
8.02749e-03 |
1.559e-01 |
Auger electron |
|
9.74887e-03 |
1.476e-02 |
Auger electron |
|
4.58458e-02 |
1.986e-02 |
Auger electron |
|
5.47234e-02 |
1.035e-02 |
Auger 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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