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Radionuclide Dosimetric Data Sheets
Niobium-99
Summary data
General
Classification
Isotope: Nb-99
Atomic number (Z): 41
Mass number (A): 99
Neutron number (N): 58
Radioactive decay
Decay modes: β-
Half-life: 15.0 [s]
Decay constant: 4.6210e-02 [1/s]
Daughters: Mo-99 (100.0%)
Radioactive daughters: Mo-99
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 1.51322 [MeV]
Mean photon energy: 0.17425 [MeV]
Air kerma rate constant, Γ10: 1.249e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 1.249e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 2.424e-13 [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-:
2.424e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 2.792e-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/Nb-99 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/Nb-99 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/Nb-99 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/Nb-99 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
6.84811e-06 |
6.549e+00 |
X-ray |
|
2.28400e-03 |
1.352e-02 |
X-ray |
|
1.73355e-02 |
1.194e-01 |
X-ray |
|
1.74440e-02 |
2.275e-01 |
X-ray |
|
1.95554e-02 |
1.854e-02 |
X-ray |
|
1.95734e-02 |
3.608e-02 |
X-ray |
|
9.77850e-02 |
4.322e-01 |
Gamma |
|
1.37723e-01 |
9.046e-01 |
Gamma |
|
1.45197e+00 |
1.000e+00 |
Beta |
|
2.73686e-05 |
3.032e+00 |
Auger electron |
|
1.05007e-04 |
1.136e-01 |
Auger electron |
|
1.07068e-04 |
5.788e-01 |
Auger electron |
|
1.76172e-04 |
1.382e+00 |
Auger electron |
|
2.17824e-04 |
1.323e-02 |
Auger electron |
|
1.95192e-03 |
5.563e-01 |
Auger electron |
|
2.20085e-03 |
7.874e-02 |
Auger electron |
|
1.47064e-02 |
9.099e-02 |
Auger electron |
|
1.69714e-02 |
3.371e-02 |
Auger electron |
|
7.78200e-02 |
4.560e-01 |
Conversion electron |
|
9.49385e-02 |
4.189e-02 |
Conversion electron |
|
9.51555e-02 |
2.184e-02 |
Conversion electron |
|
9.52640e-02 |
2.841e-02 |
Conversion electron |
|
9.73934e-02 |
1.692e-02 |
Conversion electron |
|
1.17758e-01 |
8.347e-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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