Atomic and nuclear properties of materials:
Barium (Ba)

Quantity	Value	Units	Value	Units
Atomic number	56
Atomic mass	137.327(7)	g mole-1
Specific gravity	3.50	g cm-3
Minimum ionization	1.231	MeV g-1cm2	4.307	MeV cm-1
Nuclear collision length	102.0	g cm-2	29.16	cm
Nuclear interaction length	174.6	g cm-2	49.89	cm
Radiation length	8.31	g cm-2	2.373	cm
Critical energy	10.98	MeV (for e-)	10.62	MeV (for e+)
Molière radius	16.04	g cm-2	4.583	cm
Plasma energy	34.43	eV
Muon critical energy	194.	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
x ray mass attenuation coefficients