The Properties of 86-Second I(136)

Abstract

A short-lived iodine which was discovered by Strassmann and Hahn as a U fission product was shown to have a half-life of 86± 1 seconds. It emits 6.S-Mev beta-rays and 2.9-Mev gamma-rays. The fission yields in U23., PU 239 , and U233 are 3.1 percent, 1.9 percent, and 1.7 percent, respectively. A mass assignment to 136 has been shown to be the most likely one. The observed 86-sec. I activity does not originate from a Te parent whose half-life is greater than 20 seconds. 11 This method is a modification of a procedure used previously to measure the U 231i fission yield of 6.7-hr.

Discovery of palladium, antimony, tellurium, iodine, and xenon isotopes

“…The isotopes were separated and identified with the BigRIPS superconducting in-flight separator. "We observed the production of two new isotopes 125 Pd and 126 Pd, even though the uranium beam intensity was far from the goal for the RIBF and the total observation time was only about a day." 127,128 Pd…”

“…The discovery of 125 Pd and 126 Pd was reported in the 2008 article "Identification of new isotopes 125 Pd and 126 Pd produced by in-flight fission of 345 MeV/nucleon 238 U: First results from the RIKEN RI beam factory " by Ohnishi et al [45]. The experiment was performed at the RI Beam Factory at RIKEN, where the new isotopes were created by in-flight fission of a 345 MeV/nucleon 238 U beam on a beryllium target.…”

“…It should be mentioned that in 1949 Kerr et al [70] measured spectra of 125 Sb referring to the known half-life of 125 Sb from the Plutonium Project work. 126…”

“…The 1956 article "Ein neues Antimonisotop, 126 Sb" by Fränz et al described the discovery of 126 Sb [71]. A tellurium target was bombarded with 28 MeV deuterons from the Buenos Aires synchrocyclotron and 126 Sb was formed in the reaction 128 Te(d,α).…”

“…The 1956 article "Ein neues Antimonisotop, 126 Sb" by Fränz et al described the discovery of 126 Sb [71]. A tellurium target was bombarded with 28 MeV deuterons from the Buenos Aires synchrocyclotron and 126 Sb was formed in the reaction 128 Te(d,α). Following chemical separation β-and γ-ray spectra were measured with a Geiger-Müller counter and a single-channel scintillation spectrometer, respectively.…”