Risk with Am241/Be source?

["Björn Cedervall" <bjorn_cedervall@hotmail.com>]

Radsafers,



A friend of mine recently asked about the potential radiation risks with 
Americium (241)-Beryllium neutron generators. The probe device is used 
for measuring moisture and density in soil etc. The probe contains 30 
mCi 241-Am/Beryllium (the half-life of 241-Am is about 458 y) as well as 
1 mCi cesium 137. The neutron yield can probably be taken as (??) 
2.5x10E6 neutrons/(second,Ci).



The question is what the radiation exposure (neutrons and gamma, what 
would the energies of the neutrons and gamma components be?, weighted 
whole body mSv/h?) whould amount to if the probe is taken out of its 
protective shield (which I understand has to be done in order to perform 
certain types of calibration measurements). Reasonable assumptions are 
that the person in question - "the point target?" will stand 1 meter (m) 
from the probe which can be considered as a point source.



Many thanks in advance,



Bjorn Cedervall,

PhD (Karolinska Institutet)

Fax: Int + 46 8 33 64 14

email: bjorn_cedervall@hotmail.com

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