TY - RPRT TI - Mass energy-transfer and mass energy-absorption coefficients, including in-flight positron annihilation for photon energies 1 keV to 100 MeV AU - Higgins, P D AU - Attix, F H AU - Hubbell, J H AU - Seltzer, S M AU - Berger, M J AU - Sibata, C H PY - 1991 PB - National Institute of Standards and Technology CY - Gaithersburg, MD SN - NIST IR 4680 DO - 10.6028/NIST.IR.4680 ER -