. 2021 May 12;35(7):753–766. doi: 10.1007/s12149-021-01619-2

Table 1.

Physical properties of ²¹¹At

Half-life	Decay mode	Maximum alpha energy (MeV) and emission rate	Main photon energy (MeV) and emission rate	Emission of internal conversion electrons per 100 disintegrations (%)	Effective dose rate constant (μSv・m²・MBq⁻¹・h⁻¹)
7.214 h Daughter ²⁰⁷Bi ^*211Po	α EC	5.867–41.8% Others 58.20%	0.670–0.0035% 0.743–9.5 × 10^–4% 0.687–0.26% 0.0787–31.1% Po-K_α 0.0906–8.5% Po-K_β 0.0124–18.9% Po-L	0.015	0.00580 0.00644^*

Half-life

Decay
mode

Maximum alpha energy (MeV) and emission rate

Main photon energy (MeV) and emission rate

Emission of internal conversion electrons per 100 disintegrations
(%)

Effective dose rate constant (μSv・m²・MBq⁻¹・h⁻¹)

7.214 h

Daughter ²⁰⁷Bi

^*211Po

5.867–41.8%

Others

58.20%

0.670–0.0035%

0.743–9.5 × 10^–4%

0.687–0.26%

0.0787–31.1% Po-K_α

0.0906–8.5% Po-K_β

0.0124–18.9% Po-L

0.015

0.00580

0.00644^*

*Includes contribution from ²¹¹Po, which is in radioactive equilibrium

[Source: Radioisotope Pocket Data Book (12th Edition) published by the Japan Radioisotope Association, 2020]