X-ray fluorescence analysis harmless to cultural heritages for the next 100-1,000 years

2022 Fiscal Year Final Research Report

• Project/Area Number: 18H00753
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 03060:Cultural assets study-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Oguri Yoshiyuki 東京工業大学, 科学技術創成研究院, 教授 (90160829)
• Co-Investigator(Kenkyū-buntansha): 長谷川 純 東京工業大学, 科学技術創成研究院, 准教授 (90302984) ; 羽倉 尚人 東京都市大学, 理工学部, 准教授 (00710419)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 蛍光X線分析 / 陽子線励起X線放出 / 吸収端 / 検出下限 / 放射線損傷 / 吸収線量 / 文化財 / 無機系顔料

Outline of Final Research Achievements

As a low-dose high-sensitivity trace element analytical method for precious cultural heritage samples, we constructed and tested an X-ray fluorescence spectrometry system which uses quasi-monochromatic X-rays generated by irradiating a metal target with a proton beam as an excitation source. Cu-containing standard samples simulating Japanese paintings were measured and the detection limit for Cu was evaluated. As a result, it was found that by matching the energy of the primary X-ray to the absorption edge of the element to be measured, the dose to obtain the same detection limit performance as compared to conventional XRF can be significantly reduced. A simulated sample containing a mixture of Cu- and Co-based pigments was also measured, and we found that Co could be selectively measured with high accuracy and low dose using a Cu target.

Free Research Field

イオンビーム応用工学

Academic Significance and Societal Importance of the Research Achievements

人文科学と理工学の境界領域に位置する横断的分野の研究課題であり，従来医療や機器分析等で用いられてきた一般的なX線装置では利用されなかったMeV級イオンビーム技術を積極的に採用したことに技術的特徴がある．従来とは異なるメカニズムを用いて比較的低コストで単色の高品質なX線を発生させ，これにより文化財に含まれる微量元素の高感度・低線量分析を可能とした点に学術的意義がある．貴重な人類の文化遺産を傷つけることなく，より精密に測定評価して後世に伝えてゆくための有効な手法を提案したもので，文化財科学だけでなく，将来は体内微量物質の直接測定等，様々な技術分野への展開も期待される点で社会的意義も大きい．