An ion trap for β-delayed neutron spectrum measurement

Abstract

A Beta decay Paul Trap (BPT) has been constructed at Argonne National Laboratory for the precise beta decay measurement. We have demonstrated the capability of producing and transferring a low-energy, bunched, and isotopically pure ions beam. In the trap, ions are cooled to sub-eV energies, and confined in a volume of less than 1 mm³.

The trap has an open geometry which allows four sets of radiation detectors covering a substantial potion of solid angle. In combination with Microchannel Plate (MCP) detector and plastic scintillator detector, BPT is able to measure the beta delayed neutron spectrum to 1% level.