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Radionuclide Dosimetric Data Sheets

Yttrium-85m

Isotope:  Y-85m
Atomic number (Z):  39
Mass number (A):  85
Neutron number (N):  46

Decay modes:  β+, Electron capture
Half-life:  4.86 [h]
Decay constant:  3.9617e-05 [1/s]
Daughters:  Sr-85 (96.0%), Sr-85m (4.0%)
Radioactive daughters:  Sr-85, Sr-85m

Mean alpha energy:  0.0 [MeV]
Mean electron energy:  0.57651 [MeV]
Mean photon energy:  1.32421 [MeV]
Air kerma rate constant, Γ₁₀:  3.094e-17 [Gy·m²/Bq·s]
Air kerma coefficient, K_air:  5.341e-17 [Gy·m²/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δ_wp:  9.237e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δ_α:  0.000e+00 [Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δ_β-,β+,e-:  9.237e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δ_p:  2.122e-13 [Gy·kg/Bq·s]

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/Y-85m DPK.csv

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/Y-85m Summary Spectrum.csv

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/Y-85m Beta Spectrum.csv

 

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/Y-85m Summary Spectrum.csv

 

Energy [MeV]	Yield [#/nt] if > 0.01	Radiation type
2.09353e-05	3.535e+00	X-ray
1.40549e-02	7.451e-02	X-ray
1.41246e-02	1.431e-01	X-ray
1.57867e-02	1.087e-02	X-ray
1.57975e-02	2.119e-02	X-ray
2.31700e-01	1.879e-01	Gamma
5.04400e-01	1.507e-02	Gamma
5.11000e-01	1.161e+00	Annihilation photon
5.35600e-01	3.456e-02	Gamma
5.46700e-01	1.188e-02	Gamma
5.68400e-01	1.674e-02	Gamma
6.11900e-01	1.080e-02	Gamma
6.98000e-01	1.296e-02	Gamma
7.67300e-01	3.618e-02	Gamma
7.68600e-01	1.296e-02	Gamma
7.87900e-01	1.566e-02	Gamma
1.03010e+00	2.020e-02	Gamma
1.12320e+00	1.782e-02	Gamma
1.22050e+00	1.976e-02	Gamma
1.40460e+00	3.078e-02	Gamma
1.58440e+00	1.188e-02	Gamma
1.89220e+00	1.782e-02	Gamma
2.12380e+00	4.968e-02	Gamma
2.17210e+00	2.268e-02	Gamma
9.00615e-01	4.802e-02	Positron
1.00777e+00	5.202e-01	Positron
1.36397e-05	9.853e-01	Auger electron
7.49580e-05	9.826e-01	Auger electron
9.39210e-05	4.173e-01	Auger electron
1.00567e-04	8.989e-02	Auger electron
1.09928e-04	4.762e-02	Auger electron
1.57337e-03	4.108e-01	Auger electron
1.71378e-03	3.653e-02	Auger electron
1.20238e-02	8.515e-02	Auger electron
1.37890e-02	2.885e-02	Auger electron

 

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

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

 

 

 

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