RFQ cooler and buncher for radioactive ion beam

The principle of RFQ (Radiofrequency Quadrupole) cooler and buncher is briefly introduced and some results of simulation by using the SIMION code are given. Compared to the other similar devices around the world, the being designed RFQ cooler and buncher has the following characteristics: much larger characteristic radius, much higher kinetic energy to be allowed to inject in and much higher helium buffer gas, so the difficulties to be overcome are listed.