{"doi":"10.3389/fphy.2022.816384","title":"Cherenkov Radiation–Based Coincidence Time Resolution Measurements in BGO Scintillators","abstract":"Bismuth germanate oxide (BGO) scintillators can be re-introduced in time-of-flight positron emission tomography (TOF-PET) by exploiting the Cherenkov luminescence emitted as a result from 511 keV interactions. Accessing the timing information from the relatively few emitted Cherenkov photons is now possible due to the recent improvements in enhanced near-ultraviolet high-density (NUV-HD) silicon photomultiplier (SiPM) technology, fast and low noise readout electronics, and the development of efficient data post-processing methods. In this work, we aim to develop a scalable detector element able to achieve excellent coincidence time resolution (CTR) required for TOF-PET using BGO scintillator elements of various lengths. The proposed detector element is optically coupled to 3.14 <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"m1\"><mml:mo>×</mml:mo></mml:math> 3.14 mm 2 NUV-sensitive SiPMs mounted on a custom design circuit board. In particular, we have evaluated the CTR performance of BGO crystal elements of dimensions 3 <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"m2\"><mml:mo>×</mml:mo></mml:math> 3 <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"m3\"><mml:mo>×</mml:mo></mml:math> 3 mm 3 , 3 <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"m4\"><mml:mo>×</mml:mo></mml:math> 3 <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"m5\"><mml:mo>×</mml:mo></mml:math> 5 mm 3 , 3 <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"m6\"><mml:mo>×</mml:mo></mml:math> 3 <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"m7\"><mml:mo>×</mml:mo></mml:math> 10 mm 3 , and 3 <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"m8\"><mml:mo>×</mml:mo></mml:math> 3 <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"m9\"><mml:mo>×</mml:mo></mml:math> 15 mm 3 , with chemically etched surfaces and wrapped in Teflon tape. To achieve excellent CTR performance, we apply state-of-the-art post-processing methods during data analysis. Best values of 156 ± 6 ps, 188 ± 5 ps, 228 ± 8 ps, and 297 ± 8 ps CTR FWHM have been achieved for the 3, 5, 10, and 15 mm length BGO crystals, respectively. These values improve to 105 ± 6 ps, 127 ± 8 ps, 133 ± 4 ps, and 189 ± 8 ps CTR FWHM, when only considering the Cherenkov component of the timing signal, which is extracted by considering the events with the fastest rise time (20% of the total data). The accurate classification of the events based on their rise time is possible; thanks to the implementation of a dual threshold approach that sets the lower threshold below one light photon equivalent level and the upper one above the signal amplitude of a single photon avalanche diode (SPAD).","journal":"Frontiers in Physics","year":2022,"id":246740,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":36,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9621,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2022-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":568962,"name":"Shirin Pourashraf","orcid":"0000-0001-8013-1171","position":1,"is_corresponding":false},{"id":568963,"name":"Joshua W. Cates","orcid":"0000-0002-5649-8691","position":2,"is_corresponding":false},{"id":490894,"name":"Craig S. Levin","orcid":"0000-0002-4575-5074","position":3,"is_corresponding":false},{"id":432755,"name":"Andrea González-Montoro","orcid":"0000-0002-7319-4278","position":0,"is_corresponding":true}],"reference_count":34,"raw_metadata":null,"created_at":"2026-07-19T00:23:48.622830Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}