{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,24]],"date-time":"2025-12-24T12:18:02Z","timestamp":1766578682145,"version":"build-2065373602"},"reference-count":21,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2021,4,27]],"date-time":"2021-04-27T00:00:00Z","timestamp":1619481600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003009","name":"Science and Technology Development Fund","doi-asserted-by":"publisher","award":["23085"],"award-info":[{"award-number":["23085"]}],"id":[{"id":"10.13039\/501100003009","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002347","name":"Bundesministerium f\u00fcr Bildung und Forschung","doi-asserted-by":"publisher","award":["GERF"],"award-info":[{"award-number":["GERF"]}],"id":[{"id":"10.13039\/501100002347","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this paper, open loop and closed loop Tunneling Magnetoresistance (TMR) DC Current Transformers (DCCTs) for ion beam diagnostics are presented. The DCCTs employ MR sensors to measure the DC component of the accelerator\u2019s ion beam. A comparative study between Giant Magnetoresistance (GMR) and TMR sensors is presented to illustrate the sensor selection criterion for the DCCT application. The two proposed DCCTs are studied in open and closed loop configurations. A closed loop feedback electronic system is designed to generate a feedback current equivalent to the ion beam current such that the sensor operates at zero flux. Furthermore, theoretical and experimental results for the TMR-based DCCT including noise analysis are presented for both open loop and closed loop configurations. Both configurations\u2019 minimum detectable currents are in the range of microampere. The proposed closed loop hardware prototype has a settling time of less than 15 \u03bcs. The measured minimum detectable currents for the open and closed loop TMR-based DCCTs are 128.2 \u03bcA\/Hz and 10.14 \u03bcA\/Hz at 1 Hz, respectively.<\/jats:p>","DOI":"10.3390\/s21093043","type":"journal-article","created":{"date-parts":[[2021,4,27]],"date-time":"2021-04-27T06:19:11Z","timestamp":1619504351000},"page":"3043","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Tunneling Magnetoresistance DC Current Transformer for Ion Beam Diagnostics"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5558-6948","authenticated-orcid":false,"given":"Eman","family":"Azab","sequence":"first","affiliation":[{"name":"Electronics Department, Faculty of Information Engineering Technology, German University in Cairo, New Cairo 11835, Egypt"}]},{"given":"Yasser G.","family":"Hegazy","sequence":"additional","affiliation":[{"name":"Electronics Department, Faculty of Information Engineering Technology, German University in Cairo, New Cairo 11835, Egypt"}]},{"given":"Hansjoerg","family":"Reeg","sequence":"additional","affiliation":[{"name":"Beam Instrumentation Department, GSI Helmholtzzentrum, 64291 Darmstadt, Germany"}]},{"given":"Marcus","family":"Schwickert","sequence":"additional","affiliation":[{"name":"Beam Instrumentation Department, GSI Helmholtzzentrum, 64291 Darmstadt, Germany"}]},{"given":"Klaus","family":"Hofmann","sequence":"additional","affiliation":[{"name":"Electrical Engineering and Information Technology Department, Technical University Darmstadt, 64283 Darmstadt, Germany"}]}],"member":"1968","published-online":{"date-parts":[[2021,4,27]]},"reference":[{"key":"ref_1","unstructured":"Forck, P. 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