Abstract
Based on new measurements of the ratio of cumulative spectra of \(\beta\) particles fission products \({}^{235}\text{U}/{}^{239}\) Pu performed at the National Research Centre Kurchatov Institute (KI), the cumulative spectra of \(\beta\) particles fission products of \({}^{235}\) U, \({}^{239}\) Pu, and \({}^{238}\) U isotopes are updated. The presented spectra of \(\beta\) -particles \({}^{235}\) U and \({}^{239}\) Pu of KI are compared with similar spectra measured at the Institute Laue–Langevin (ILL), and the spectrum of \(\beta\) particles fission products \({}^{238}\) U of KI are compared with the measurements performed at the Technical University of Munich (TUM). It is shown that the ILL ratio of spectra of \(\beta\) -particles \({}^{235}\) U/ \({}^{239}\) Pu is mistakenly overestimated by \({\approx}5.4\%\) .
