The yields of various fission products in the 11. 5, 13.4, 15.0 and 17.3 MeV bremsstrahlunginduced fission of 238 U have been determined by recoil catcher and an off-γ-ray spectrometric technique using the electron linac, SAPHIR at CEA, Saclay, France. The mass yield distributions were obtained from the fission product yields using charge-distribution corrections. The peak-to-valley (P/V) ratio, average light mass and heavy mass and average number of neutrons in the bremsstrahlung-induced fission of 238 U at different excitation energies were obtained from the mass yield data. From the present and literature data in the 238 U(γ, f) and 238 U(n, f) reactions at various energies, the following observations were obtained: i) The mass yield distributions in the 238 U(γ, f) reaction at various energies of the present work are double-humped, similar to those of the 238 U(n, f) reaction of comparable excitation energy. ii) The yields of fission products for A = 133-134, A = 138-140, and A = 143-144 and their complementary products in the 238 U(γ, f) reaction are higher than other fission products due to the nuclear structure effect. iii) The yields of fission products for A = 133-134 and their complementary products are slightly higher in the 238 U(γ, f) than in the 238 U(n, f), whereas for A = 138-140 and 143-144 and their complementary products are comparable. iv) With excitation energy, the increase of yields of symmetric products and the decrease of the peak-to-valley (P/V ) ratio in the 238 U(γ, f) reaction is similar to the 238 U(n, f) reaction. v) The increase of 〈υ〉 with excitation energy is also similar between the 238 U(γ, f) and 238 U(n, f) reactions. However, it is surprising to see that the 〈A L 〉 and 〈A H 〉 values with excitation energy behave entirely differently from the 238 U(γ, f) and 238 U(n, f) reactions.
