Passage: The public records for devices that produced the highest proportion of their yield via fusion reactions are the peaceful nuclear explosions of the 1970s, with the 3 detonations that excavated part of Pechora–Kama Canal being cited as 98% fusion each in the Taiga test's 15 kiloton explosive yield devices; that is, a total fission fraction of 0.3 kilotons in a 15 kt device. Others include the 50 megaton Tsar Bomba at 97% fusion, the 9.3 megaton Hardtack Poplar test at 95.2%, and the 4.5 megaton Redwing Navajo test at 95% fusion.On July 19, 1956, AEC Chairman Lewis Strauss said that the Redwing Zuni shot clean bomb test "produced much of importance ... from a humanitarian aspect." However, less than two days after this announcement, the dirty version of Bassoon, called Bassoon Prime, with a uranium-238 tamper in place, was tested on a barge off the coast of Bikini Atoll as the Redwing Tewa shot. The Bassoon Prime produced a 5-megaton yield, of which 87% came from fission. Data obtained from this test, and others, culminated in the eventual deployment of the highest yielding US nuclear weapon known, and the highest yield-to-weight weapon ever made, a three-stage thermonuclear weapon with a maximum "dirty" yield of 25 megatons, designated as the B41 nuclear bomb, which was to be carried by U.S. Air Force bombers until it was decommissioned; this weapon was never fully tested.

Question: what is the output of basson prime
5-megaton yield