Beam diagnosis using a Delta E-E counter telescope at a new beam line in the MC-50 cyclotron of the Korea Cancer Center Hospital

Abstract

A new target room and a new beam line have been constructed for basic nuclear science experiments at the MC-50 cyclotron of the Korea Cancer Center Hospital (KCCH). The new beam line from a main switching magnet to the new target room is deviated by 52 degrees from the zero-degree line (neutron therapy line), and consists of one switching magnet and three sets of quadrupole magnets. We designed the new beam line by performing two different beam-optic solvers. The transfer matrix of the new beam line was obtained by using the TRANSPORT code. Simulation of the charged particle trajectory was performed by using the TURTLE code based on the ray-tracing method. For the purpose of beam diagnosis, we detected the alpha beam extracted from the MC-50 cyclotron with a DeltaE - E counter telescope. The telescope was made of a 150-mum-thick silicon surface barrier (SSB) counter as a DeltaE counter and a 300-mum-thick SSB detector as an E counter. A 35-MeV alpha beam was bombarded on a C-12 target. Outgoing protons and alpha particles scattered from the target we re identified with the telescope.