Mark 22 nuclear bomb

The first thermonuclear device test by the University of California Radiation Lab at Livermore was the "Morgenstern" device which was tested in the "Koon" shot of Operation Castle. Morgenstern was the prototype of an intended bomb, the TX-22. Morgenstern failed to achieve anything like its intended yield due to premature heating of the secondary from exposure to neutrons. As the other UCRL test planned for the Castle series, the liquid fueled "Ramrod" device had the same basic design flaw, that test was canceled. Within a month of the Morgenstern failure, the TX-22 was terminated because the AEC realized there was nothing that could be done to salvage the design.