Albedo factors of 123, 320, 511, 662 and 1115 keV gamma photons in carbon, aluminium, iron and copper K. U. Kiran, K. Ravindraswami, K. M. Eshwarappa and H. M. Somashekarappa Eur. Phys. J. Plus, 131 4 (2016) 87 Published online: 11 April 2016 DOI: 10.1140/epjp/i2016-16087-5