A PIN detector array for the determination of boron using nuclear reaction analysis at a nuclear microprobe

Complete text of publication follows. A new micro-NRA set-up for boron analysis via α-particle detection from the 11B(p,α)8Be nuclear reaction has been developed at the Debrecen scanning nuclear micro- probe facility [1]. The set-up consists of four large area PIN silicon photodiodes in an optimised geometrical arrangement providing 1.87 sr solid angle. This solid angle is slightly larger than the ever reported values (1,63 sr) for annular surface barrier detectors, which detectors are conventionally used for charged particle detection. The new set-up was calibrated for boron with NIST type glass standards and also with a macusanite glass standard in the low concentration region. The calculated MDL value for boron was 5 μg/g for 1 μC accumulated charge in a glassy matrix. The capability of this set-up for precise concentration measurement was demonstrated via the analysis of geological obsidian samples with less than 160 μg/g boron content. Support from the 5FP project NAS-MICRO-XRF (Contract No. G4RDCT-2000- 00402) as well as the Hungarian Research Foundation (OTKA) under contract NOS. A 080, M 041939 and M 36324 are gratefully acknowledged. (author)