Beam Energy and Longitudinal Beam Profile Measurement System at RIBF

Abstract

Monitors that use plastic scintillator material (scintillation monitors) were fabricated to measure the energy and longitudinal profiles of heavy-ion beams at the RIKEN RI beam factory (RIBF). Six pairs of scintillation monitors (12 monitors) installed in the transport lines were used to measure the particle time-of-flight (TOF) to determine the acceleration energy of the heavy-ion beams. In addition, five scintillation monitors were installed to optimize the phase between the rebuncher cavities and the beam for the beam injection to the cyclotrons. Longitudinal beam profiles were obtained by using a time-to-digital converter (TDC), which digitizes the detected signals from the scintillator and the RF clock. The energy of the beam can be calculated from the measured TOF of the beam by using a scintillation monitor pair. Recently, to help users operate the system more easily, a new embedded processor with a higher-performance CPU was introduced, and LabVIEW programs were newly written or greatly improved. Development of the scintillation monitor system and results of experimental measurements of heavy-ion beams are reported.