W80 (nuclear weapon)
Implemented in slight variants for three different cruise missiles, the W80 warhead has a selectable yield 5 or 200 KT. It was designed by Los Alamos National Laboratory as a derivative of the B61/W61.
In 2010, it is only available in Mod 1, for the AGM-86 air-launched cruise missile (ALCM). Mod 1 also was the warhead for the AGM-129 stealth cruise missile, being retired. Mod 0 arms the retired UGM-109 submarine-launched cruise missile.
With slight variations among the Mods, it has a weight of 132 kg/290 lbs, length of 800mm/31.4 in, and diameter of 300mm/11.8 in.
A speculative interpretation of the design suggests:
- The fission primary is located in the larger diameter cylindrical part of the body, the aft section of which contains the firing electronics, tritium reservoir, and pulse neutron initiator tube. The spherical thermonuclear secondary is in the smaller diameter rounded "nose" of the warhead.
- The outer weapon casing is made of aluminium and is lined with uranium to form the radiation case.
- The primary consists of a spherical shell of PBX-9502 insensitive high explosive surrounding the pit, which is made of a hollow bonded beryllium/plutonium double shell with a two-point air lens to create the implosion. The void inside the hollow pit is filled with deuterium-tritium gas at detonation time.
- The secondary is a sphere consisting of an outer pusher/tamper layer of oralloy (highly enriched uranium) and an inner shell of lithium-6 deuteride. The secondary is hollow and is filled with deuterium-tritium gas at detonation time to produce "hot spot" ignition at the moment of maximum compression.
In August 2007, the U.S. Air Force lost track of six W80-1 warheads. They were actually on a B-52 flying AGM-129 missiles from Minot Air Force Base to Barksdale Air Force Base for retirement, but the missiles should never have had live nuclear warheads.  Several officers were relieved of duty, effectively ending their careers.
- The W80 Warhead: Intermediate Yield Strategic Cruise Missile Warhead, Nuclear Weapons Archive
- Richard Weitz (25 September 2007), Repercussions from Air Force Nuclear Weapons Incident Continue, www.worldpoliticsreview.com