Light Ion Guide
Texas A&M University is currently configuring a scheme for the production of radioactive-ion beams that incorporates a light-ion guide (LIG) coupled with an ECRIS constructed for charge-boosting (CB-ECRIS). This scheme is part of an upgrade to the Cyclotron Institute and is intended to produce radioactive beams suitable for injection into the K500 superconducting cyclotron.
The Light-Ion Guide (LIG) will produce radioactive species mainly from (p,n) reactions. The beam (a proton beam around 30 MeV) interacts with a production target (e.g. 27Al) placed in a gas cell. In the gas cell helium gas is flowing continuously at constant pressure of 500 mbar maximum. The recoil ions [e.g. 27Si from 27Al(p,n)27Si)] are trapped in the buffer gas and ejected at a 90° direction (with respect to the beam direction) through a small exit hole. All ions created in the gas cell are collected and transported by a rf-only hexapole: a resonant structure similar to the RFQ in a residual gas analyzer. The large flow of helium gas is evacuated by a differential pumping system. The ions are then injected into a cCharge-breeding ECRIS (CB-ECRIS) source which will ionize them to higher charge states. The radioactive species are injected into the K500 Cyclotron and re-accelerated. The primary beam (proton beam) will exit the gas cell and will be stopped in the beam dump.