Question: what is the name of the source of alpha radiation in a smoke alarm
[{'answer': 'americium - 241'}, {'provenance': [{'wikipedia_id': '341287', 'title': 'Smoke detector', 'start_paragraph_id': 15, 'start_character': 0, 'end_paragraph_id': 15, 'end_character': 753, 'bleu_score': 0.9230276775549351, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3074872188591639115}, 'section': 'Section::::Design.:Ionization.\n'}]}]