THERMAL-NEUTRON CAPTURE AND FISSION CROSS-SECTIONS AND RESONANCE INTEGRALS FOR CM-243

The thermal-neutron capture cross section and capture resonance integral for **2**4**3Cm have been measured in cobalt-monitored reactor irradiations of nearly isotopically pure **2**4**3Cm (99. 94%) using cadmium filter techniques. The thermal-neutron absorption (capture plus fission) cross section and corresponding resonance integral for **2**4**3Cm have also been measured in a separate experiment relative to **2**4**8Cm. Values of sigma //2//2//0//0(n, gamma ) equals 130. 7 plus or minus 9. 6, sigma //2//2//0//0(n,f) equals 609. 6 plus or minus 25. 9, I(n, gamma ) equals 214. 7 plus or minus 20. 3, and I(n,f) equals 1575 plus or minus 136 b are reported. Neutron cross sections for capture and fission for the transactinium nuclides are required to quantitatively account for the buildup and destruction of these nuclides in the fuel of nuclear power reactors.