"alpha emitter" meaning in English

{
  "forms": [
    {
      "form": "alpha emitters",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "alpha emitter (plural alpha emitters)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
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          "kind": "other",
          "name": "Entries with translation boxes",
          "parents": [],
          "source": "w"
        },
        {
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          "name": "Terms with Finnish translations",
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          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Portuguese translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Physics",
          "orig": "en:Physics",
          "parents": [
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Radioactivity",
          "orig": "en:Radioactivity",
          "parents": [
            "Nuclear physics",
            "Radiation",
            "Physics",
            "Quantum mechanics",
            "Energy",
            "Sciences",
            "Nature",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "a radioactive substance that decays by emitting alpha particles"
      ],
      "id": "en-alpha_emitter-en-noun-59DDnWgw",
      "links": [
        [
          "physics",
          "physics"
        ],
        [
          "radioactive",
          "radioactive"
        ],
        [
          "alpha particle",
          "alpha particle"
        ]
      ],
      "raw_glosses": [
        "(physics) a radioactive substance that decays by emitting alpha particles"
      ],
      "related": [
        {
          "word": "alpha emission"
        }
      ],
      "topics": [
        "natural-sciences",
        "physical-sciences",
        "physics"
      ],
      "translations": [
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "substance that decays by emitting alpha particles",
          "word": "alfasäteilijä"
        },
        {
          "code": "pt",
          "lang": "Portuguese",
          "sense": "substance that decays by emitting alpha particles",
          "tags": [
            "masculine"
          ],
          "word": "emissor alfa"
        }
      ]
    }
  ],
  "word": "alpha emitter"
}

{
  "forms": [
    {
      "form": "alpha emitters",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "alpha emitter (plural alpha emitters)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "alpha emission"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Entries with translation boxes",
        "Pages with 1 entry",
        "Pages with entries",
        "Terms with Finnish translations",
        "Terms with Portuguese translations",
        "en:Physics",
        "en:Radioactivity"
      ],
      "glosses": [
        "a radioactive substance that decays by emitting alpha particles"
      ],
      "links": [
        [
          "physics",
          "physics"
        ],
        [
          "radioactive",
          "radioactive"
        ],
        [
          "alpha particle",
          "alpha particle"
        ]
      ],
      "raw_glosses": [
        "(physics) a radioactive substance that decays by emitting alpha particles"
      ],
      "topics": [
        "natural-sciences",
        "physical-sciences",
        "physics"
      ]
    }
  ],
  "translations": [
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "substance that decays by emitting alpha particles",
      "word": "alfasäteilijä"
    },
    {
      "code": "pt",
      "lang": "Portuguese",
      "sense": "substance that decays by emitting alpha particles",
      "tags": [
        "masculine"
      ],
      "word": "emissor alfa"
    }
  ],
  "word": "alpha emitter"
}