講演情報
[2B06]Integration and Performance Evaluation of a TlBr X-ray Imager for CT Imaging Systems
*Moh Hamdan1, Kenji Shimazoe1, Hiroyuki Takahashi1, Mitsuhiro Nogami2, Keitaro Hitomi2, Takanori Tsunashima3, Takashi Nakamura3 (1. The University of Tokyo, 2. Tohoku University, 3. Japan Display Inc.)
キーワード：
Thallium Bromide (TlBr)、Flat Panel Detectors、X-ray Imaging、Computed Tomography
Thallium Bromide (TlBr) is an attractive material for direct-conversion flat-panel detectors (FPDs) due to its suitable energy bandgap (2.68 eV), high atomic numbers (Z Tl = 81, Z Br = 35), and high density ( 7.56 g/cm³), enabling efficient X-ray absorption. This study focuses on the development and evaluation of an FPD with a TlBr film, ranging from 25 to 50 µm in thickness, for computed tomography (CT) imaging systems. The TlBr film, deposited via the evaporation method, features an active area of 29.61 × 39.48 mm². A pixelated sensor matrix with 168 × 126 pixels, each measuring 235 × 235 µm² , was fabricated using low-temperature polysilicon thin-film transistor (LTPS TFT) technology. Spatial resolution, measured using the slanted-edge method, achieved a Full Width at Half Maximum (FWHM) of 222 to 280 µm. CT imaging was performed with a cone beam X-ray source (25–50 kV, 0.25–2 mA), a source-to-detector distance of ~75 cm, and a rotation pitch of ~1°. Reconstruction using the Filtered Back Projection (FBP) method assessed the detector's sensitivity by imaging plastics and metals of varying densities.