Developments of muonic X-ray measurement system for historical-cultural heritage samples in Japan Proton Accelerator Research Complex (J-PARC)

Abstract

Abstract Negative muon elemental analysis, which can measure depth-wise elemental composition from 100 nm to several centimeters with a depth resolution of order µm, is a revolutionary technology that enables the nondestructive analysis of materials. In recent years, this technique has begun to apply to understand historical cultural heritage. We have studied the Japanese archaeological heritage to provide new insights into Japanese archaeological research. Here, we report the progress on development of intense (high speed) negative muon X-ray measurement system at KEK Muon Science Laboratory (MSL) in the Japan Proton Accelerator Research Complex (J-PARC). For this purpose, the efficiency of detectors (wide energy range and high resolution) were improved by preparing a high-purity multi-arrayed germanium semiconductor detectors (HP Ge) to detect one photon or less per muon pulse available in J-PARC. In addition, by increasing the number of detectors and suppressing the noise sources, we have succeeded to enhance the detection efficiency by about 10 times compared to conventional systems.