{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,26]],"date-time":"2026-04-26T17:10:07Z","timestamp":1777223407253,"version":"3.51.4"},"reference-count":26,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2023,5,9]],"date-time":"2023-05-09T00:00:00Z","timestamp":1683590400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Research Council of Science &amp; Technology 350 (NST) grant by the Korea government (MSIT)","award":["CAP22041-000"],"award-info":[{"award-number":["CAP22041-000"]}]},{"name":"National Research Council of Science &amp; Technology 350 (NST) grant by the Korea government (MSIT)","award":["50572-2023"],"award-info":[{"award-number":["50572-2023"]}]},{"name":"Korea Institute of Radiologi- 351 cal &amp; Medical Sciences (KIRAMS) grant funded by the Korea government (Ministry of Sciences and 352 ICT)","award":["CAP22041-000"],"award-info":[{"award-number":["CAP22041-000"]}]},{"name":"Korea Institute of Radiologi- 351 cal &amp; Medical Sciences (KIRAMS) grant funded by the Korea government (Ministry of Sciences and 352 ICT)","award":["50572-2023"],"award-info":[{"award-number":["50572-2023"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Although research into ultrahigh dose-rate (UHDR) radiation therapy is ongoing, there is a significant lack of experimental measurements for two-dimensional (2D) dose-rate distributions. Additionally, conventional pixel-type detectors result in significant beam loss. In this study, we developed a pixel array-type detector with adjustable gaps and a data acquisition system to evaluate its effectiveness in measuring UHDR proton beams in real time. We measured a UHDR beam at the Korea Institute of Radiological and Medical Sciences using an MC-50 cyclotron, which produced a 45-MeV energy beam with a current range of 10\u201370 nA, to confirm the UHDR beam conditions. To minimize beam loss during measurement, we adjusted the gap and high voltage on the detector and determined the collection efficiency of the developed detector through Monte Carlo simulation and experimental measurements of the 2D dose-rate distribution. We also verified the accuracy of the real-time position measurement using the developed detector with a 226.29-MeV PBS beam at the National Cancer Center of the Republic of Korea. Our results indicate that, for a current of 70 nA with an energy beam of 45 MeV generated using the MC-50 cyclotron, the dose rate exceeded 300 Gy\/s at the center of the beam, indicating UHDR conditions. Simulation and experimental measurements show that fixing the gap at 2 mm and the high voltage at 1000 V resulted in a less than 1% loss of collection efficiency when measuring UHDR beams. Furthermore, we achieved real-time measurements of the beam position with an accuracy of within 2% at five reference points. In conclusion, our study developed a beam monitoring system that can measure UHDR proton beams and confirmed the accuracy of the beam position and profile through real-time data transmission.<\/jats:p>","DOI":"10.3390\/s23104596","type":"journal-article","created":{"date-parts":[[2023,5,10]],"date-time":"2023-05-10T01:57:51Z","timestamp":1683683871000},"page":"4596","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Development of a Real-Time Pixel Array-Type Detector for Ultrahigh Dose-Rate Beams"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1831-4919","authenticated-orcid":false,"given":"Young Jae","family":"Jang","sequence":"first","affiliation":[{"name":"Research Team of Radiological Physics & Engineering, Korea Institute of Radiological & Medical Sciences, Seoul 01812, Republic of Korea"},{"name":"Department of Accelerator Science, Korea University, Sejong 30015, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tae Keun","family":"Yang","sequence":"additional","affiliation":[{"name":"Research Team of Radiological Physics & Engineering, Korea Institute of Radiological & Medical Sciences, Seoul 01812, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jeong Hwan","family":"Kim","sequence":"additional","affiliation":[{"name":"Research Team of Radiological Physics & Engineering, Korea Institute of Radiological & Medical Sciences, Seoul 01812, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hong Suk","family":"Jang","sequence":"additional","affiliation":[{"name":"Research Team of Radiological Physics & Engineering, Korea Institute of Radiological & Medical Sciences, Seoul 01812, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jong Hwi","family":"Jeong","sequence":"additional","affiliation":[{"name":"Center for ProtonTherapy, National Cancer Center, Goyang 10408, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9672-2424","authenticated-orcid":false,"given":"Kum Bae","family":"Kim","sequence":"additional","affiliation":[{"name":"Research Team of Radiological Physics & Engineering, Korea Institute of Radiological & Medical Sciences, Seoul 01812, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Geun-Beom","family":"Kim","sequence":"additional","affiliation":[{"name":"Research Team of Radiological Physics & Engineering, Korea Institute of Radiological & Medical Sciences, Seoul 01812, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3430-8770","authenticated-orcid":false,"given":"Seong Hee","family":"Park","sequence":"additional","affiliation":[{"name":"Department of Accelerator Science, Korea University, Sejong 30015, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7763-9844","authenticated-orcid":false,"given":"Sang Hyoun","family":"Choi","sequence":"additional","affiliation":[{"name":"Research Team of Radiological Physics & Engineering, Korea Institute of Radiological & Medical Sciences, Seoul 01812, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,5,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"van Marlen, P., Dahele, M., Folkerts, M., Abel, E., Slotman, B.J., and Verbakel, W. 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