tə sˈɑːlv ðɪs pɹˈɑːbləm, dɪtˈɛktɚz ˈɑːpɚɹˌeɪɾɪŋ əbˌʌv tˈɛn ɔːɹ wˈʌnhˈʌndɹɪd kˈiː vˈiː wɜːɹ ˈɔfən sɚɹˈaʊndᵻd baɪ ɐn ˈæktɪv ˌæntɪkoʊˈɪnsɪdəns ʃˈiːld mˌeɪd ʌv sˌʌm ˈʌðɚ dɪtˈɛktɚ, wˌɪtʃ kʊd biː jˈuːzd tə ɹᵻdʒˈɛkt ðɪ ʌnwˈɔntᵻd bˈækɡɹaʊnd ᵻvˈɛnts.
To solve this problem, detectors operating above 10 or 100 keV were often surrounded by an active anticoincidence shield made of some other detector, which could be used to reject the unwanted background events.