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Radionuclide Dosimetric Data Sheets
Niobium-99m
Summary data
General
Classification
Isotope: Nb-99m
Atomic number (Z): 41
Mass number (A): 99
Neutron number (N): 58
Radioactive decay
Decay modes: β-, Internal transition
Half-life: 2.6 [m]
Decay constant: 4.4433e-03 [1/s]
Daughters: Mo-99 (98.0%), Nb-99 (2.0%)
Radioactive daughters: Mo-99, Nb-99
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 1.41475 [MeV]
Mean photon energy: 0.75669 [MeV]
Air kerma rate constant, Γ10: 2.431e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 2.431e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 2.267e-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-:
2.267e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 1.212e-13
[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-99m 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-99m 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-99m 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-99m Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
5.83036e-06 |
6.015e-02 |
X-ray |
|
6.84812e-06 |
8.994e-01 |
X-ray |
|
1.73355e-02 |
1.629e-02 |
X-ray |
|
1.74440e-02 |
3.103e-02 |
X-ray |
|
9.77850e-02 |
6.654e-02 |
Gamma |
|
1.37723e-01 |
1.324e-02 |
Gamma |
|
2.53500e-01 |
3.700e-02 |
Gamma |
|
3.51200e-01 |
2.775e-02 |
Gamma |
|
3.65100e-01 |
1.444e-02 |
Gamma |
|
4.50900e-01 |
1.717e-02 |
Gamma |
|
5.25400e-01 |
1.224e-02 |
Gamma |
|
6.31800e-01 |
1.617e-02 |
Gamma |
|
9.27800e-01 |
1.011e-02 |
Gamma |
|
2.13470e+00 |
1.125e-02 |
Gamma |
|
2.64130e+00 |
3.693e-02 |
Gamma |
|
2.85150e+00 |
3.094e-02 |
Gamma |
|
4.17106e-01 |
3.429e-02 |
Beta |
|
4.45346e-01 |
1.793e-02 |
Beta |
|
4.69493e-01 |
1.509e-02 |
Beta |
|
4.88168e-01 |
1.352e-02 |
Beta |
|
5.08133e-01 |
7.641e-02 |
Beta |
|
6.41818e-01 |
1.176e-02 |
Beta |
|
7.34946e-01 |
1.959e-02 |
Beta |
|
8.45389e-01 |
1.528e-02 |
Beta |
|
1.25074e+00 |
1.176e-02 |
Beta |
|
1.31457e+00 |
1.430e-02 |
Beta |
|
1.36080e+00 |
1.136e-02 |
Beta |
|
1.43722e+00 |
1.019e-02 |
Beta |
|
1.47668e+00 |
1.460e-02 |
Beta |
|
1.48785e+00 |
1.019e-02 |
Beta |
|
1.57063e+00 |
1.469e-02 |
Beta |
|
1.73810e+00 |
6.368e-01 |
Beta |
|
2.53260e-05 |
2.962e-02 |
Auger electron |
|
2.73693e-05 |
4.163e-01 |
Auger electron |
|
1.04817e-04 |
1.541e-02 |
Auger electron |
|
1.07101e-04 |
7.952e-02 |
Auger electron |
|
1.48945e-04 |
1.201e-02 |
Auger electron |
|
1.76168e-04 |
1.899e-01 |
Auger electron |
|
1.95191e-03 |
7.646e-02 |
Auger electron |
|
2.20081e-03 |
1.082e-02 |
Auger electron |
|
1.47064e-02 |
1.241e-02 |
Auger electron |
|
7.78200e-02 |
7.021e-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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