Atomic and nuclear properties of materials:
Erbium (Er)
QuantityValueUnits ValueUnits
Atomic number 68     
Atomic mass 167.259(3) g mole-1   
Density 9.07 g cm-3   
Mean excitation energy 658.0 eV   
Minimum ionization 1.168 MeV g-1cm2 10.59 MeV cm-1
Nuclear collision length 107.6 g cm-2 11.86 cm
Nuclear interaction length 186.1 g cm-2 20.53 cm
Pion collision length 131.2 g cm-2 14.48 cm
Pion interaction length 213.1 g cm-2 23.50 cm
Radiation length 7.14 g cm-2 0.7881 cm
Critical energy 8.73 MeV (for e-) 8.41 MeV (for e+)
Molière radius 17.36 g cm-2 1.915 cm
Plasma energy 55.32 eV   
Muon critical energy 163. 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
Table of isotopes Warning: may not be current
x ray mass attenuation coefficients