Development and application of position-sensitive double parallel-plate avalanche counter

Double parallel-plate avalanche counters (DPPACs), each comprising two PPACs with delay-line readout for two-dimensional position determination, have been developed at Institute of Modern Physics, Chinese Academy of Sciences. The detector was tested with a standard α source, achieving a position resolution of about 0.4 mm. Each PPAC measures particle hit positions in two dimensions, with the dual configuration enhancing overall detection efficiency. Two DPPACs were deployed in a month-long experimental campaign at the Radioactive Ion Beam Line in Lanzhou (RIBLL1) with secondary beams of ¹⁰Be and ^10,11,16C, and faint ¹⁸O primary beam at typical intensities of 1.2–1.5 × 10⁵ Hz, yielding a stable single DPPAC-detection efficiency > 90% and a typical in-beam position resolution ≈ 0.56 mm. This successful deployment addresses a critical domestic need for reliable, high-resolution beam monitoring and establishes a robust technological foundation for future experiments.