Equipment to Measure Charge Distributions of Fragments in Low Energy Fission

In order to study charge distributions of fragments in spontaneous fission of 252Cf,a detector system,including a typical grid-ionization chamber and a ΔE-E particle telescope in which a thin grid-ionization chamber is served as the ΔE-section and the E-section is a surface barrier detector,was built up.From the measured four-parameter correlation data,the physical quantities,such as mass number,kinetic energy of fragments and energy deposited by fragments in the gas ΔE detector can be derived.The charge distributions at the fixed mass number A*L and total kinetic energy(TKE) of the light fragments were obtained by the least-squares fiting of the response functions of ΔE detector with multi-Gaussian distributions representing all charge states.The results show that the charge resolution of Z/ΔZ≈40∶1 can be given by this detector system.The measured technique in this work can be used to determine the charge distributions of fragments for other low energy fission reactions such as 235U(n,f) and 239Pu(n,f).