Speaker
Description
A variety of unstable nuclear beams with atomic numbers (Z) up to 92 can be produced by the projectile fragmentation and in-flight fission from high intensity U beams at RIBF. Recently, it was found that 234−238Np can be created by a proton pickup reaction on 1GeV/nucleon 238U beam. Owing to the recent developments of the high-Z beams at BigRIPS, energy dependence of the proton pickup reaction on 238U can be obtained at RIBF. Thus, we conducted an experiment to determine the energy dependence of the production cross section of 237Np. A test of the production of Np isotopes was performed by using the BigRIPS spectrometer at RIBF in March 2022.
Secondary beams around Z = 90 were produced by a 238U beam with energies of 345 and 250 MeV/nucleon impinging on a 1-mm-thick 9Be production target at F0 in BigRIPS.
The particle identification (PID) of the secondary beam was performed using the TOF-Bρ-ΔE method.
To validate the production of the 237Np91+, a two dimensional (2D) Gaussian fitting approach was conducted in accordance with the distribution patterns of neighboring ions of 234U90+,235U90+, and 232Pa89+. It is found that Np isotope can be counted up with contaminated U/Pa isotopes using the 2D Gaussian fitting technique. The production cross sections of 234U, 235U, 236U, 232Pa, and 233Pa as well as Np isotopes were derived.
In this presentation, we will report the analysis status of 345MeV/nucleon.
