Muon radiative energy loss (in 1.0E06 cm^2/g) in protactinium (Pa) with Z = 91, A = [231.03588(2)] (f12.0,4f12.4) E (GeV) b_brem b_pair b_nucl b_total 2. 2.1226 0.3143 0.3591 2.7961 5. 2.9495 1.9739 0.3833 5.3067 10. 3.6252 3.2648 0.3759 7.2658 20. 4.3186 4.4493 0.3626 9.1305 50. 5.2249 6.2661 0.3478 11.8388 100. 5.8683 7.4621 0.3408 13.6712 200. 6.4542 8.5192 0.3375 15.3109 500. 7.1094 9.4846 0.3377 16.9317 1000. 7.5023 9.9943 0.3430 17.8396 2000. 7.8068 10.3609 0.3512 18.5189 5000. 8.0880 10.6668 0.3661 19.1210 10000. 8.2266 10.8077 0.3810 19.4153 20000. 8.3181 10.8997 0.3983 19.6161 50000. 8.3936 10.9676 0.4253 19.7866 100000. 8.4269 10.9962 0.4485 19.8716