Almost all nuclei heavier than iron are produced through neutron capture nucleosynthesis, about half of them by the rapid (r) process. One of the limiting factors in understanding the r-process is the need for neutron capture cross-section measurements on unstable nuclei. As shown with the recent measurement of 88Zr (Shusterman et al., Nature 2019), neutron capture cross-sections can exhibit unpredictable behaviour.
We propose a novel method of measuring neutron capture cross-sections of short-lived nuclei. Neutron-rich nuclei produced via neutron-induced fission inside of a gas-filled stopping cell will form a mass-selected cooled low-energy beam, which will be transported into a linear Paul trap (coined ‘NG-Trap’), forming a target. This ‘cloud target’ of up to 1010 ions (Shusterman et al., Nature 2019) will then be irradiated with neutrons. The reaction products will then be identified and counted using a multiple-reflection time-of-flight mass-spectrometer (MR-TOF-MS), thus extracting the capture cross-sections.
This talk will present a breakthrough achievement towards the goal of generating the required ‘cloud target’. A demonstrator system with an ion capacity of more than 1010 ions will be presented. This system is a major milestone in the plan to install a high-capacity trap at the Soreq Applied Research Accelerator Facility (SARAF), which is currently under construction in Yavne, Israel.
Racah Institute of Physics, The Hebrew University of Jerusalem, Israel