Q: In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.
Passage: Trinity was the code name of the first detonation of a nuclear weapon. It was conducted by the United States Army at 5:29 a.m. on July 16, 1945, as part of the Manhattan Project. The test was conducted in the Jornada del Muerto desert about 35 miles (56 km) southeast of Socorro, New Mexico, on what was then the USAAF Alamogordo Bombing and Gunnery Range, now part of White Sands Missile Range. The only structures originally in the vicinity were the McDonald Ranch House and its ancillary buildings, which scientists used as a laboratory for testing bomb components. A base camp was constructed, and there were 425 people present on the weekend of the test.
The code name "Trinity" was assigned by Robert Oppenheimer, the director of the Los Alamos Laboratory, inspired by the poetry of John Donne. The test was of an implosion-design plutonium device, informally nicknamed "The Gadget", of the same design as the Fat Man bomb later detonated over Nagasaki, Japan, on August 9, 1945. The complexity of the design required a major effort from the Los Alamos Laboratory, and concerns about whether it would work led to a decision to conduct the first nuclear test. The test was planned and directed by Kenneth Bainbridge.
Fears of a fizzle led to the construction of a steel containment vessel called Jumbo that could contain the plutonium, allowing it to be recovered, but Jumbo was not used. A rehearsal was held on May 7, 1945, in which 108 short tons (96 long tons; 98 t) of high explosive spiked with radioactive isotopes were detonated. The Gadget's detonation released the explosive energy of about 22 kilotons of TNT (92 TJ). Observers included Vannevar Bush, James Chadwick, James Conant, Thomas Farrell, Enrico Fermi, Richard Feynman, Leslie Groves, Robert Oppenheimer, Geoffrey Taylor, and Richard Tolman.
The test site was declared a National Historic Landmark district in 1965, and listed on the National Register of Historic Places the following year.
A:
What is the last name of the person who came up with the code name for the first detonation of a nuclear weapon?