Table 6.

Dose and dose rate contribution (based on kerma free-in-air) of various radiation sources after the explosion over Hiroshima, at ground ranges (distances from the hypocentre of the explosion) of 1,000 and 2,000 m (Rühm et al. 2018). Similar orders of magnitude hold for exposures due to the explosion over Nagasaki

Radiation source	Estimated duration of exposure	Dose (Gy) at 1,000 m	Resulting dose rate (Gy/s) 1,000 m	Dose (Gy) at 2,000 m	Resulting dose rate (Gy/s) 2,000 m	Resulting dose rate (mGy/h) 2,000 m a
Delayed gamma radiation	10 s	2.77	0.277	0.040	4.0 × 10.−3	1.44 × 10.4
Prompt secondary gamma radiation	0.2 s	1.38	6.9	0.035	0.17	6.12 × 10.5
Prompt neutrons	10 µs	0.24	2.4 × 10.4	0.0004	40	1.44 × 109
Prompt primary gamma radiation	1 µs	0.07	7.0 × 10.4	0.002	2.0 × 10.3	7.20 × 109

^a Dose rates in mGy/h are also given, to facilitate comparison with data shown in Fig. 1, although due to the brief nature of the exposure, the rate measure per hour is misleading