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Radionuclide Dosimetric Data Sheets

Astatine-205

Summary data

General

Classification

Isotope:  At-205
Atomic number (Z):  85
Mass number (A):  205
Neutron number (N):  120

Radioactive decay

Decay modes:  α, β+, Electron capture
Half-life:  26.2 [m]
Decay constant:  4.4093e-04 [1/s]
Daughters:  Po-205 (90.0%), Bi-201 (10.0%)
Radioactive daughters:  Po-205, Bi-201

Dosimetric constants

Mean alpha energy:  0.602 [MeV]
Mean electron energy:  0.25747 [MeV]
Mean photon energy:  1.14438 [MeV]
Air kerma rate constant, Γ10:  4.848e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair:  5.417e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δwp:  1.377e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα:  9.645e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:  4.125e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp:  1.834e-13 [Gy·kg/Bq·s]

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/At-205 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/At-205 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/At-205 Summary Spectrum.csv

 

Energy [MeV]

Yield [#/nt] if > 0.01

Radiation type

3.84102e-05

1.325e+01

X-ray

2.54186e-03

5.620e-02

X-ray

1.10135e-02

1.703e-02

X-ray

1.11319e-02

1.499e-01

X-ray

1.33474e-02

2.939e-02

X-ray

1.34935e-02

9.336e-02

X-ray

1.58015e-02

1.949e-02

X-ray

7.71271e-02

2.289e-01

X-ray

7.96070e-02

3.811e-01

X-ray

8.95836e-02

4.277e-02

X-ray

9.01425e-02

8.300e-02

X-ray

9.25794e-02

1.031e-02

X-ray

9.27190e-02

2.036e-02

X-ray

1.54198e-01

2.570e-02

Gamma

1.61030e-01

1.037e-02

Gamma

3.11090e-01

4.131e-02

Gamma

3.60910e-01

1.163e-02

Gamma

3.84610e-01

1.218e-02

Gamma

4.48610e-01

1.683e-02

Gamma

5.11000e-01

2.937e-01

Annihilation photon

5.16040e-01

1.285e-02

Gamma

5.20440e-01

4.406e-02

Gamma

6.17800e-01

2.203e-02

Gamma

6.28880e-01

5.600e-02

Gamma

6.59630e-01

2.295e-02

Gamma

6.69410e-01

8.599e-02

Gamma

6.72850e-01

3.213e-02

Gamma

7.19300e-01

3.060e-01

Gamma

7.82800e-01

1.958e-02

Gamma

7.89200e-01

1.285e-02

Gamma

8.72400e-01

3.121e-02

Gamma

1.03169e+00

1.989e-02

Gamma

1.30760e+00

1.071e-02

Gamma

1.32495e+00

1.255e-02

Gamma

1.52542e+00

7.984e-02

Positron

3.94500e-05

3.168e+00

Auger electron

9.71894e-05

4.127e+00

Auger electron

1.74704e-04

2.218e+00

Auger electron

4.34495e-04

5.167e-01

Auger electron

1.06334e-03

1.858e-01

Auger electron

2.01387e-03

1.204e+00

Auger electron

2.30693e-03

1.656e-01

Auger electron

8.45261e-03

3.439e-01

Auger electron

1.10038e-02

1.571e-01

Auger electron

1.35839e-02

1.710e-02

Auger electron

6.07740e-02

7.156e-02

Conversion electron

6.18768e-02

1.857e-02

Auger electron

6.76060e-02

1.172e-01

Conversion electron

7.46184e-02

1.025e-02

Auger electron

1.37280e-01

1.138e-02

Conversion electron

1.44112e-01

3.075e-02

Conversion electron

1.57749e-01

1.021e-02

Conversion electron

2.17666e-01

1.519e-02

Conversion electron

5.90305e+00

1.000e-01

Alpha

1.17550e-01

1.000e-01

Alpha recoil

 

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

 

 

 

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