18646
In December 1940 , Glenn T. Seaborg and Emilio Segrè used the cyclotron to bombard uranium-238 with deuterons producing a new element , neptunium-238 , which decayed by beta emission to form plutonium-238 .
 Glenn T. Seaborg, Emilio Segrè
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Glenn T. Seaborg, Emilio Segrè