{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T02:51:22Z","timestamp":1760237482104,"version":"build-2065373602"},"reference-count":24,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2020,5,23]],"date-time":"2020-05-23T00:00:00Z","timestamp":1590192000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000266","name":"Engineering and Physical Sciences Research Council","doi-asserted-by":"publisher","award":["EP\/R026084\/1"],"award-info":[{"award-number":["EP\/R026084\/1"]}],"id":[{"id":"10.13039\/501100000266","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Nuclear Security Network (NuSec)","award":["N\/A"],"award-info":[{"award-number":["N\/A"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Threat assessments continue to conclude that terrorist groups and individuals as well as those wanting to cause harm to society have the ambition and increasing means to acquire unconventional weapons such as improvised nuclear explosive devices and radiological disposal devices. Such assessments are given credence by public statements of intent by such groups\/persons, by reports of attempts to acquire radioactive material and by law enforcement actions which have interdicted, apprehended or prevented attempts to acquire such material. As a mechanism through which to identify radioactive materials being transported on an individual\u2019s person, this work sought to develop a detection system that is of lower-cost, reduced form-factor and more covert than existing infrastructure, while maintaining adequate sensitivity and being retrofittable into an industry standard and widely utilised Gunnebo Speed Gate system. The system developed comprised an array of six off-set Geiger\u2013Muller detectors positioned around the gate, alongside a single scintillator detector for spectroscopy, triggered by the systems inbuilt existing IR proximity sensor. This configuration served to not only reduce the cost for such a system but also allowed for source localisation and identification to be performed. Utilising the current setup, it was possible to detect a 1 \u00b5Sv\/h source carried into the Speed Gate in all test scenarios, alongside locating and spectrally analysing the material in a significant number.<\/jats:p>","DOI":"10.3390\/s20102957","type":"journal-article","created":{"date-parts":[[2020,5,25]],"date-time":"2020-05-25T11:42:02Z","timestamp":1590406922000},"page":"2957","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Project Gatekeeper: An Entrance Control System Embedded Radiation Detection Capability for Security Applications"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3395-8656","authenticated-orcid":false,"given":"Peter G.","family":"Martin","sequence":"first","affiliation":[{"name":"Interface Analysis Centre, School of Physics, HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK"}]},{"given":"Yannick","family":"Verbelen","sequence":"additional","affiliation":[{"name":"Interface Analysis Centre, School of Physics, HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK"}]},{"given":"Elia","family":"Sciama Bandel","sequence":"additional","affiliation":[{"name":"School of Physics, HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK"}]},{"given":"Mark","family":"Andrews","sequence":"additional","affiliation":[{"name":"Gunnebo UK Ltd., Fairfax House, Pendeford Business Park, Wolverhampton WV9 5HA, UK"}]},{"given":"Thomas B.","family":"Scott","sequence":"additional","affiliation":[{"name":"Interface Analysis Centre, School of Physics, HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK"}]}],"member":"1968","published-online":{"date-parts":[[2020,5,23]]},"reference":[{"key":"ref_1","unstructured":"Nuclear Threat Initiative (NTI) (2016). Radiological Security Progress Report, Nuclear Threat Initiative."},{"key":"ref_2","unstructured":"Dell (2015). Dell Security Annual Threat Report | 2015, Dell."},{"key":"ref_3","unstructured":"Warrick, J. (2017). Nuclear Security: Use of Weaponized Drones by ISIS Spurs Terrorism Fears, Washington Post."},{"key":"ref_4","unstructured":"IAEA (2011). Nuclear Security Recommendations on Physical Protection of Nuclear Material and Nuclear Facilities, IAEA."},{"key":"ref_5","unstructured":"The Remote Control Project (2016). The Hostile Use of Drones by Non-State Actors Against British Targets, Open Briefing."},{"key":"ref_6","unstructured":"IAEA (2016, August 19). IAEA Incident and Trafficking Database (ITDB). Available online: https:\/\/www.iaea.org\/resources\/databases\/itdb."},{"key":"ref_7","unstructured":"Interational Atomic Energy Agency (2007). Combating Illicit Trafficking in Nuclear and other Radioactive Material, Interational Atomic Energy Agency."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Chambers, W.H., Atwater, H.F., Fehlau, P.E., Hastings, R.D., Henry, C.N., Kunz, W.E., Sampson, T.E., Whittlesey, T.H., and Worth, G.M. (1974). Portal Monitor for Diversion Safeguards.","DOI":"10.2172\/4232001"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Geelhood, B.D., Ely, J.H., Hansen, R.R., Kouzes, R.T., Schweppe, J.E., and Warner, R.A. (2003, January 19\u201325). Overview of portal monitoring at border crossings. Proceedings of the 2003 IEEE Nuclear Science Symposium: Conference Record, Portland, OR, USA.","DOI":"10.1109\/NSSMIC.2003.1352095"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1038\/scientificamerican0408-98","article-title":"Detecting nuclear smuggling","volume":"298","author":"Cochran","year":"2008","journal-title":"Sci. Am."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"422","DOI":"10.1511\/2005.55.422","article-title":"Detecting illicit nuclear materials: The installation of radiological monitoring equipment in the united states and overseas is helping thwart nuclear terrorism","volume":"93","author":"Kouzes","year":"2005","journal-title":"Am. Sci."},{"key":"ref_12","unstructured":"Kouzes, R.T., Ely, J.H., Milbrath, B.D., Schweppe, J.E., Siciliano, E.R., and Stromswold, D.C. (2005, January 23\u201329). Spectroscopic and non-spectroscopic radiation portal applications to border security. Proceedings of the IEEE Nuclear Science Symposium Conference Record, Fajardo, Puerto Rico."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"79","DOI":"10.13182\/NT09-A9104","article-title":"Current State of Commercial Radiation Detection Equipment for Homeland Security Applications","volume":"168","author":"Klann","year":"2017","journal-title":"Nucl. Technol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"647","DOI":"10.1016\/j.nima.2005.05.056","article-title":"Comparison of PVT and NaI(Tl) scintillators for vehicle portal monitor applications","volume":"550","author":"Siciliano","year":"2005","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. A Accel. Spectrom. Detect. Assoc. Equip."},{"key":"ref_15","unstructured":"Fehlau, P.E., and Eaton, M.J. (1979, January 26). Passive nuclear material detection in a personnel portal. Proceedings of the ANS topical conference, Kiawah Island, SC, USA."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Petrenko, V., Yuldashev, B.S., Ismailov, U., Shipilov, N.N., and Avezov, A.D. (2009). Radiation monitoring at the borders of republic of Uzbekistan with the use of portal monitors. New Techniques for the Detection of Nuclear and Radioactive Agents, Springer.","DOI":"10.1007\/978-1-4020-9600-6_10"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1016\/j.nima.2015.03.088","article-title":"Organic liquid scintillation detectors for on-the-fly neutron\/gamma alarming and radionuclide identification in a pedestrian radiation portal monitor","volume":"789","author":"Paff","year":"2015","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. A Accel. Spectrom. Detect. Assoc. Equip."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1177\/0361198196153800104","article-title":"Field Studies of Pedestrian Walking Speed and Start-Up Time","volume":"1538","author":"Knoblauch","year":"1996","journal-title":"Transp. Res. Rec. J. Transp. Res. Board"},{"key":"ref_19","unstructured":"Hamamatsu Photonics, K.K. (2020). Hamamatsu C12137-Series Specification, Hamamatsu Photonics."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Lowdon, M., Martin, P.G., Hubbard, M.W.J., Taggart, M.P., Connor, D.T., Verbelen, Y., Sellin, P.J., and Scott, T.B. (2019). Evaluation of Scintillator Detection Materials for Application within Airborne Environmental Radiation Monitoring. Sensors, 19.","DOI":"10.3390\/s19183828"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/j.radmeas.2015.12.029","article-title":"Operator related attenuation effects in radiometric surveys","volume":"86","author":"Buchanan","year":"2016","journal-title":"Radiat. Meas."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1016\/j.apradiso.2017.12.005","article-title":"On the ratio distribution of energy windowing algorithms for radiation portal monitors","volume":"132","author":"Grisa","year":"2018","journal-title":"Appl. Radiat. Isot."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1016\/j.radmeas.2013.08.004","article-title":"Investigation of energy windowing algorithms for effective cargo screening with radiation portal monitors","volume":"58","author":"Hevener","year":"2013","journal-title":"Radiat. Meas."},{"key":"ref_24","unstructured":"IAEA (1991). Airborne Gamma Ray Spectrometer Surveying, IAEA."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/10\/2957\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:31:45Z","timestamp":1760175105000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/10\/2957"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,5,23]]},"references-count":24,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2020,5]]}},"alternative-id":["s20102957"],"URL":"https:\/\/doi.org\/10.3390\/s20102957","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2020,5,23]]}}}