ðə fjˈuːʒən fjˈuːəl jˈuːzd baɪ ðə bˈɑːm wʌz nˈaɪnti fˈaɪv pɚsˈɛnt ɛnɹˈɪtʃt lˈɪθiəm ˈaɪsətˌoʊp sˈɪks lˈɪθiəm djˈuːɾɚɹˌaɪd, wˌɪtʃ æt ðə tˈaɪm wʌzɐ skˈɛɹs ɹᵻsˈoːɹs, ðɪs skˈɛɹsᵻɾi bˌiːɪŋ tʃˈiːfli ɹᵻspˈɑːnsᵻbəl fɔːɹ ɪts lˈɪmɪɾᵻd dᵻplˈɔɪmənt.
The fusion fuel used by the bomb was 95% enriched Lithium isotope 6 lithium deuteride, which at the time was a scarce resource, this scarcity being chiefly responsible for its limited deployment.