[en] Short communication

[en] The neutron capture cross section of ²³⁷Np was measured from 0.01 eV to 200 keV. These measurements cover the neutron energy range important to both thermal and fast reactors. 26 refs

[en] The cross section σ_f of ²³⁷Np fission induced by neutrons with energies below 500 eV is measured by the time-of-flight technique using the IBR-30 JINR booster as a pulsed neutron source. The values of σ_f for resonance clusters are in agreement with the Kyoto University data, but are three times higher than the Saclay data. However, the intercluster values of σ_f virtually coincide with the Saclay values. 8 refs., 1 fig., 1 tabs

[en] Measurement of the fission cross section of ²³⁷ Np up to neutron energy of 500 eV were performed by using a time-of-flight method

[en] The spectra of neutrons that accompany ²³⁷Np fission induced by primary neutrons of energy 2.9 and 14.7 MeV are measured using the time-of-flight technique. The data are compared with those obtained under analogous conditions for ²³²Th and ^235,238U nuclei and with data on proton-induced fission of ^235,238U nuclei. The regularities of the emission fission at low excitation energies are emphasized. 21 refs., 6 figs., 2 tabs

[en] In a ²⁵²Cf neutron field, ratios of spectrum-averaged fission cross sections have been measured by back-to-back counting in a double fission ionization chamber with interchangeable deposits of ²³⁵U, ²³⁸U, ²³⁹Pu, and ²³⁷Np. These ratio measurements provide integral tests for evaluated cross section data. The dominant error in the ratio measurements was the +-1.4 percent to +-2.1 percent uncertainty in the fissionable deposit masses. Redundant mass assay methods were employed for all deposit nuclides. Corrections of up to (1.4 +- 0.7) percent were necessary for inelastic scattering effects on the neutron energy distribution in the cases of ²³⁸U and ²³⁷Np. For ²³⁵U and ²³⁹Pu fission rates, a correction of (0.45 + 0.20) percent was made for the contribution of neutrons moderated and back-scattered by laboratory structures. The cross section ratios observed in the present measurements were as follows: 1.000: 0.266 +- 1.7 percent: 1.500 +- 1.6 percent: 1.105 +- 2.2 percent for ²³⁵U: ²³⁸U: ²³⁹Pu: ²³⁷Np, respectively. In comparison to the observed integral cross section ratios, the corresponding values derived from ENDF/B-IV data were 2.3 percent to 6.0 percent lower. 4 tables, 1 figure

[en] The method for preparing ²³⁷Np targets with varying mass thickness from almost carrier-free up to 700 μg/cm² is studied. ²³⁷Np is deposited almost quantitatively on nickel foils from the solution of their nitrates in isopropyl alcohol by this method. Voltage, electric current and water content in the electrodeposition system which will influence on the deposition yield are investigated. A procedure for purification of ²³⁷Np by extraction and ion exchange is also used

No abstract available

No abstract available

[en] The ²³⁷Np/²³⁵U fission cross section ratio has been measured from 0.02 to 30 MeV. Using the threshold method, a value of 1.294 +- 0.019 is obtained for the average cross section ratio in the interval from 1.75 to 4.00 MeV