Abstract:
:The origin of photons emitted in optical fibres under proton irradiation has been attributed to either entirely Čerenkov radiation or light consisting of fluorescence with a substantial amount of Čerenkov radiation. The source of the light emission is assessed in order to understand why the signal from optical fibres irradiated with protons is reportedly quenching-free. The present study uses the directional emittance of Čerenkov photons in 12 MeV and 20 MeV electron beams to validate a Monte Carlo model for simulating the emittance and transmission of Čerenkov radiation in optical fibres. We show that fewer than 0.01 Čerenkov photons are emitted and guided per 225 MeV proton penetrating the optical fibre, and that the Čerenkov signal in the optical fibre is completely negligible at the Bragg peak. Furthermore, on taking the emittance and guidance of both fluorescence and Čerenkov photons into account, it becomes evident that the reported quenching-free signal in PMMA-based optical fibres during proton irradiation is due to fluorescence.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Brage Christensen J,Almhagen E,Nyström H,Andersen CEdoi
10.1088/1361-6560/aaafadsubject
Has Abstractpub_date
2018-03-09 00:00:00pages
065001issue
6eissn
0031-9155issn
1361-6560journal_volume
63pub_type
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