Quantitative evaluation of beam loss based on radiation detection in high-duty beam commissioning of LIPAc RFQ

Using the LIPAc deuteron accelerator, beam loss characteristics were quantitatively assessed through multiple radiation measurement techniques. Elevated shutdown dose rates and isotope production observed at the interface between the MEBT Extension Line (MEL) and the HEBT suggest significant losses of 5 MeV deuterons. In contrast, portable HPGe spectroscopy and energy-dependent calculations indicate that deuterons with an average energy of 3.5–4.0 MeV are lost after being bent by the HEBT dipole magnet. Activation foil data further confirm the presence of beam losses for both high- and low-energy particles. The estimated beam loss is up to 1 × 10−3 relative to the nominal 125 mA beam current. These findings highlight the effectiveness of multimodal radiation diagnostics in characterizing beam loss and enhancing radiation safety in the accelerator environment.