Table 1.

Longitudinal shift in the BP for all materials and all concentrations for an energy of 60 and 226 MeV.

Material	Longitudinal shift in the BP (mm)
	6.5 mg ml−1		0.1 mg ml−1		0.01 mg ml−1
	60 MeV	226 MeV	60 MeV	226 MeV	60 MeV	226 MeV
Ag	0.34  ±  0.01	3.7  ±  0.1	0.09  ±  0.01	0.9  ±  0.1	0.04  ±  0.01	0.5  ±  0.1
Au	0.40  ±  0.01	4.7  ±  0.1	0.11  ±  0.01	1.3  ±  0.1	0.05  ±  0.01	0.6  ±  0.1
Pt	0.43  ±  0.01	5.3  ±  0.1	0.12  ±  0.01	1.4  ±  0.1	0.06  ±  0.01	0.7  ±  0.1