{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,2]],"date-time":"2026-05-02T23:31:58Z","timestamp":1777764718656,"version":"3.51.4"},"reference-count":40,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T00:00:00Z","timestamp":1777420800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"JSPS KAKENHI","award":["19H00672"],"award-info":[{"award-number":["19H00672"]}]},{"name":"JSPS KAKENHI","award":["20K20488"],"award-info":[{"award-number":["20K20488"]}]},{"name":"JSPS KAKENHI","award":["22H04961"],"award-info":[{"award-number":["22H04961"]}]},{"name":"JSPS KAKENHI","award":["19H00881"],"award-info":[{"award-number":["19H00881"]}]},{"name":"JSPS KAKENHI","award":["19K1262"],"award-info":[{"award-number":["19K1262"]}]},{"name":"JST CREST","award":["JPMJCR2331"],"award-info":[{"award-number":["JPMJCR2331"]}]},{"name":"JAEA Nuclear Energy S & T and Human Resource Development Project","award":["JPJA23P23813521"],"award-info":[{"award-number":["JPJA23P23813521"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>We report the development of bundled optical-guiding crystal scintillators (OCSs) with ultrafine and uniform scintillator cores (~12 \u03bcm) for high-resolution X-ray imaging. Conventional OCS fabrication using iodide scintillators often suffers from iodine volatilization, bubble formation, and core discontinuities, which limit structural uniformity and device reliability. To address these limitations, a hollow-fiber-based fabrication strategy was introduced. Hollow glass fibers were first bundled and drawn without scintillator materials, followed by capillary infiltration of a Tl-doped Cs3Cu2I5 (Tl: CCI) melt. This approach enabled the stable formation of densely packed bundled OCS structures with uniform core diameters of 10\u201312 \u03bcm while suppressing volatilization-induced defects. Radioluminescence measurements confirmed a broad emission peak at ~442 nm, consistent with Tl:CCI scintillation. X-ray imaging experiments demonstrated superior spatial resolution and image contrast compared with a commercial CsI:Tl columnar scintillator. The bundled OCS exhibited an average contrast transfer function (CTF) of 30.7% at ~10 lp\/mm, exceeding the reference value. These results demonstrate that the hollow-fiber architecture provides an effective route toward scalable ultrafine-core scintillators and highlight the potential of Tl:CCI-filled OCSs for next-generation high-resolution X-ray imaging.<\/jats:p>","DOI":"10.3390\/ma19091834","type":"journal-article","created":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T15:01:18Z","timestamp":1777474878000},"page":"1834","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Development of Optical-Guiding Scintillators with Ultrafine (~12 \u03bcm) Uniform Scintillator Cores for High-Resolution X-Ray Imaging"],"prefix":"10.3390","volume":"19","author":[{"given":"Kei","family":"Kamada","sequence":"first","affiliation":[{"name":"New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Miyagi, Japan"},{"name":"C&A Corporation, 1-16-23 Ichibancho, Aoba-ku, Sendai 980-0811, Miyagi, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Masao","family":"Yoshino","sequence":"additional","affiliation":[{"name":"New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Miyagi, Japan"},{"name":"Institute for Material Research, Tohoku University, 2-1-1 Katahira Aoba-ku, Sendai 980-8577, Miyagi, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuhei","family":"Nakata","sequence":"additional","affiliation":[{"name":"Institute for Material Research, Tohoku University, 2-1-1 Katahira Aoba-ku, Sendai 980-8577, Miyagi, Japan"},{"name":"Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Miyagi, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-8995-8771","authenticated-orcid":false,"given":"Testuo","family":"Kudo","sequence":"additional","affiliation":[{"name":"C&A Corporation, 1-16-23 Ichibancho, Aoba-ku, Sendai 980-0811, Miyagi, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7686-8568","authenticated-orcid":false,"given":"Yoshiyuki","family":"Usuki","sequence":"additional","affiliation":[{"name":"C&A Corporation, 1-16-23 Ichibancho, Aoba-ku, Sendai 980-0811, Miyagi, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Naoko","family":"Kutsuzawa","sequence":"additional","affiliation":[{"name":"C&A Corporation, 1-16-23 Ichibancho, Aoba-ku, Sendai 980-0811, Miyagi, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2387-2410","authenticated-orcid":false,"given":"Kyoung Jin","family":"Kim","sequence":"additional","affiliation":[{"name":"New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Miyagi, Japan"},{"name":"C&A Corporation, 1-16-23 Ichibancho, Aoba-ku, Sendai 980-0811, Miyagi, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2825-4243","authenticated-orcid":false,"given":"Rikito","family":"Murakami","sequence":"additional","affiliation":[{"name":"C&A Corporation, 1-16-23 Ichibancho, Aoba-ku, Sendai 980-0811, Miyagi, Japan"},{"name":"Institute for Material Research, Tohoku University, 2-1-1 Katahira Aoba-ku, Sendai 980-8577, Miyagi, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1266-0148","authenticated-orcid":false,"given":"Satoshi","family":"Ishizawa","sequence":"additional","affiliation":[{"name":"C&A Corporation, 1-16-23 Ichibancho, Aoba-ku, Sendai 980-0811, Miyagi, Japan"},{"name":"Institute for Material Research, Tohoku University, 2-1-1 Katahira Aoba-ku, Sendai 980-8577, Miyagi, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Akira","family":"Yoshikawa","sequence":"additional","affiliation":[{"name":"New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Miyagi, Japan"},{"name":"C&A Corporation, 1-16-23 Ichibancho, Aoba-ku, Sendai 980-0811, Miyagi, Japan"},{"name":"Institute for Material Research, Tohoku University, 2-1-1 Katahira Aoba-ku, Sendai 980-8577, Miyagi, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"126","DOI":"10.1016\/j.ejmp.2020.10.030","article-title":"Photon-counting CT review","volume":"79","author":"Flohr","year":"2020","journal-title":"Phys. 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