Dose of radiation from the neutron source

Hi All. Could you help me with following:

The problem statement, all variables and given/known data
We have:

Neutron source Cf-252

Activity of Neutron source Cf-252 = 200 kBq

The thickness of the protection of water-based = 30 cm

Weight of the man = 80 kg

Distance to a source = 1 m

Questions

How to calculate the absorbed dose for this men,if we know only activity of Cf-252, distance to a source, thickness of protection and weight of man.

How to calculate the absorbed dose from neutron source for human body? With shield and without.

If I correctly understand:

1) at first it is necessary to calculate how many energies lose neutrons transiting through protection. Whether all neutrons are decelerated transiting through protection.

2)Then, when will be known, what energy have neutrons after passage through protection, is possible to start to consider the absorbed dose

Could you help me with this problem and could me advise where i can read about how to calculate radiation dose from neutron source.

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 Maybe I should ask my question in High Energy, Nuclear, Particle Physics section ??

 Tags absorbed dose, neutron source