Irradiation system for biological experiments on BL14B1 at SPring-8

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2024-12, Vol.1069, p.169931, Article 169931
• Main Authors: Shiro, Ayumi, Kusumoto, Tamon, Nara, Shintaro, Hirayama, Ryoichi, Maeda, Munetoshi, Tomita, Masanori, Kondo, Takashi, Saitoh, Hiroyuki
• Format: Article
• Language: English
• Subjects: Auger electrons; Dosimetry; Monochromatic X-rays; SPring-8; White X-rays
• ISSN: 0168-9002
• DOI: 10.1016/j.nima.2024.169931

We present an irradiation system for biological experiments on BL14B1 beam line of SPring-8, where enables to use white and monochromatic X-rays (from 5 to 90 keV). An effective energy of white X-rays is assessed as 120 keV and their average dose rate is determined as approximately 170 Gy/s using a l-alanine dosimeter. Also, we speak about dosimetry of monochromatic X-rays using an optical stimulated luminescence detector. Average dose rates of monochromatic X-rays with 33.0, 33.2, 33.4 and 34.0 keV are estimated as 0.099 ± 0.006 Gy/s. The irradiation dose of white and monochromatic X-rays, of course, can be monitored using ionization chamber. When we use monochromatic X-rays with 33.2 keV, where is the K-shell absorption edge of iodine, Auger electrons are emitted, leading significant improvement of biological effectiveness. Thus, we have estimated the absorbed dose low-energy secondaries, such as Auger electrons and characteristic X-rays, emitted from iodine as 1.3 × 10−2 Gy/mM/min at BL14B1, depending on iodine concentration.