To produce intense metal ion beams (e.g. Ti13+, V12+,13+, U35+ ) for super-heavy element search and RIBF experiments at RIKEN, we tried to optimize the RIKEN 28 GHz SC-ECRIS performance. We systematically measured the beam intensity of various heavy ions as a function of Binj, Br and Bext with 14, 18 and 28 GHz microwaves for various heavy ions. In these experiments, we observed that (1) optimum Binj>1.6~2 Bext, (2) optimum Br>1.2~1.4 Bext and (3) optimum Bext is dependent on the charge state.
Using this systematics, we obtained ~400emicroA of V13+ at low RF power of ~2kW and very low magnetic field (Bext~1.4 T with 28 GHz). For long term operation (one month), we successfully produced very stable beam of 100~200 e micro A of V13+ ion. Based on the systematics, we also produced ~225 e micro A of U33+ ion beam and ~200 e micro A of U35+ ion beam at only 2.2~2.6 kW of RF power.
In this contribution, we discuss the mechanism to obtain these systematics using simple model calculation. And we report the experimental results and how to produce intense metal ion (Ti, V, and U ions) beams in detail.
|Category of your contribution||Production of highly charged ion beams|