Double-multilayer monochromators for high-energy and large-field X-ray imaging applications with intense pink beams at SPring-8 BL20B2
Takahisa Koyama, Yasunori Senba, Hiroshi Yamazaki, Tomoyuki Takeuchi, Masayuki Tanaka, Yasuhiro Shimizu, Koji Tsubota, Yasuhisa Matsuzaki, Hikaru Kishimoto, Takanori Miura, Satsuki Shimizu, Takamitsu Saito, Hirokatsu Yumoto, Kentaro Uesugi, Masato Hoshino, Jumpei Yamada, Taito Osaka, Michihiro Sugahara, Nobuteru Nariyama, Yasuhide Ishizawa, Hiroko Nakano, Choji Saji, Kyo Nakajima, Koji Motomura, Yasumasa Joti, Makina Yabashi, Haruhiko Ohashi
Abstract
In this study, double-multilayer monochromators that generate intense, high-energy, pink X-ray beams are designed, installed and evaluated at the SPring-8 medium-length (215 m) bending-magnet beamline BL20B2 for imaging applications. Two pairs of W/B 4 C multilayer mirrors are designed to utilize photon energies of 110 keV and 40 keV with bandwidths of 0.8% and 4.8%, respectively, which are more than 100 times larger when compared with the Si double-crystal monochromator (DCM) with a bandwidth of less than 0.01%. At an experimental hutch located 210 m away from the source, a large and uniform beam of size 14 mm (V) × 300 mm (H) [21 mm (V) × 300 mm (H)] was generated with a high flux density of 1.6 × 10 9 photons s −1 mm −2 (6.9 × 10 10 photons s −1 mm −2 ) at 110 keV (40 keV), which marked a 300 (190) times increase in the photon flux when compared with a DCM with Si 511 (111) diffraction. The intense pink beams facilitate advanced X-ray imaging for large-sized objects such as fossils, rocks, organs and electronic devices with high speed and high spatial resolution.