New Gas Slowing Technology for Examination of New Exotic Isotopes

Abstract

The ability to make high precision mass measurements will soon be realized at the National Superconducting Cyclotron Laboratory at Michigan State University. The Low Energy Beam and Ion Trap (LEBIT) project will have the capabilities to measure masses of the most exotic nuclei produced in today's world. At the NSCL, the Coupled Cyclotron facility will be able to produce beams of 100+ MeV/nucleon. However, certain nuclear physics experiments require energies in the range of ~ 5 ke V / A. In order to reduce the energy, the ions produced in the NSCL's coupled cyclotrons will travel to the Gas Stopping Station where the nuclei will be slowed using two types of degraders and a gas cell, containing ~1 bar He. Upon being stopped in the gas the ions will be thermalized and extracted with a DC gradient and ejected into a RF multipole system, which will then guide the ions to the Penning Trap for mass measurements. Efficient and quick extraction of ions from the gas cell will be required to measure the half-lives of nuclei as low as 10 milliseconds.