Atomic and nuclear properties of materials:
Promethium (Pm)
QuantityValueUnits ValueUnits
Atomic number 61     
Atomic mass [144.9127] g mole-1   
Specific gravity 7.22 g cm-3   
Minimum ionization 1.240 MeV g-1cm2 8.954 MeV cm-1
Nuclear collision length 103.5 g cm-2 14.34 cm
Nuclear interaction length 177.7 g cm-2 24.61 cm
Radiation length 7.51 g cm-2 1.041 cm
Critical energy 9.83 MeV (for e-) 9.49 MeV (for e+)
Molière radius 16.21 g cm-2 2.245 cm
Plasma energy 50.24 eV   
Muon critical energy 180. GeV   
For muons, dE/dx = a(E) + b(E) E. Tables of b(E): PS PDF TEXT
Table of muon dE/dx and Range: PS PDF TEXT
Explanation of some entries
Note: Since there is no stable isotope, given atomic mass is that of the longest-lived known isotope as of Jan 2007.
Table of isotopes
x ray mass attenuation coefficients