The
americium 241 (from Americas); Am; atomic mass 241,056822; atomic n° 95; melting
point 1176°C; boiling point 2011°C; specific gr. 13,67 (20°C); period of 432 years;
3,435 Ci/gr; 0,29 gr/Ci; α; 5,476 MeV; range particle in tissues ~50
μ.
NB. 0,693147*6,0221415E+23/(241*432*365,25*24*60*60)
= 1,270E11 Bq/gr or 3,4338 Ci/gr and 0,2912 gr/Ci.
Or (0,693147/(432*365,25*24*60*60)) * (6,0221415E+23/241) = 5,084E-11 λ *
2,4988E21 = 1,2705E11 Bq/gr
Or
more simply 0,693147*6,0221415E+23/(365,25*24*60*60) = 1,322734E16 -->
1,322734E16/(241 * 432) = 1,270E11 Bq/gr (0,693147*6,0221415E+23/(365,25*24*60*60*37E9)
= 357495,6203 --> 357495,6203/(241 * 432) = 3,434 Ci/gr)
Or
(6,0221415E+23/241)*(1-(Exp(1*-Ln(2)/(432*365,25*24*60*60)))) = 1,270E11
Bq/gr
The americium 241 have a physical
half-life of 432 years, a biological half-life of 200 years, an effective
half-life of 136,7 years.
(λ physic 5,086E-11, λ
biologic 1,099E-10, λ effective 1,608E-10.)
Assessing the irrationality
of official internal dose factor. Or what body mass is necessary to explain the IRCP dose factor for this element ?
An internal dose factor (Sv/Bq) is calculate taking account all the “effectives”
disintegrations that occurs in 50 years produce by the incorporation of a
matter mass which initially emitted 1 Bq.
The incorporation of 1 Bq of americium
241 conduce after 50 years to suffer (1 Bq/1,608E-10 λe)
* 1-(EXP(50*31536000*-1,608E-10)) = 1,393E9 disintegrations α
and absorb 1,39E9 disintegrations * 5,476 MeV * 1,602E-13 Joule per MeV = 0,0122
Joule and 122200 Erg which dissipate, for IRCP, in a body mass of 313,33
kg... ((1,39E9 Emissions * 5,4760 MeV * 1,602E-6 Erg par
MeV * 10 EBR)/(3,900E-5 Sv/Bq * 1 Bq * 100 Erg/gr * 100 Rad/Sv) = 313,33 kg)
with a radius of (313333,3587 cm3/(4/3*3,14159))(1/3) = 42,1347
cm. The particle α
which do not penetrate in tissues more than 50 μ travel in “rational”
calculation 8426,9 times
far away it can physically go... (421346,45 μ/50 μ = 8426,9.) In other words the real
absorbed dose is reduce 598,42 billions times. (8426,933 = 5,98E11 or
3,13E5 gr/5,24E-7 gr = 5,98E11.)
********
Calculating
the real dose produce by one α particle with 5,476 MeV energy and 50 μ
penetration capacity in tissues: (1 Bq * 5,4760 MeV * 1,602E-6 Erg par MeV * 10
EBR)/((4/3 * 3,14159 * (50 * 0,00013)) gr * 100 Erg/gr * 100 Rad/Sv)
= 1,68E-2 Sv/Bq or 16,76 milliSievert per Becquerel. The committed dose for 1
Bq in 50 years is then (1 Bq/1,608E-10 λe s-1 * (1-Exp(50*365*24*60*60 *
-1,608E-10 λe)))
* 1,68E-2 Sv/Bq) = 2,33E7 Sv/Bq or 23,34 millions Sievert per Becquerel. Have a nice smell.
Official
internal dose factors are like SS which name shower a chamber gas.
