When the bounty hunter Boushh threatened to explode a thermal detonator inside Jabba the Hutt's throne room, everyone inside had good reason to cower. No one would have survived the intense explosion. Fortunately, the masked bounty hunter - actually Princess Leia Organa in disguise - had other objectives, namely, to rescue Han Solo from Jabba's clutches.
Thermal detonators are immensely powerful - and strictly regulated - explosive devices. The small metal ball looks like a common grenade, and the device's thermal casing contains the synthetic explosive known as baradium. When the detonator's sliding thumb trigger is pushed, warning lights and alarms are activated as the six-second timer counts down. The detonator can be deactivated at any time by returning the trigger to its original position. The timer also may be reset manually to offer a maximum of five minutes, or the trigger's control pins can be programmed to act as a deadman's switch. In this setting, unless a tiny switch near the indicator light is flipped to the saftey postition, the detonator will explode instantly when the trigger is released.
When a detonator explodes, the baradium's fusion reaction creates a particle field that quickly expands outward, releasing enough energy and heat to virtually disintegrate anything caught in the blast sphere. Within a few seconds, the baradium core burns out and the particle field sphere collapses in on itself. Everything in the blast sphere is gone, while anything beyond the sphere's outer boundary is left nearly untouched.
Standard-issue Imperial detonators have a small baradium core and yield a blast radius of about five meters. The class-A thermal detonator carried by Leia Organa would have resulted in a blast radius of 20 meters. Some criminals have custom-built detonators that have enough baradium to create 100-meter blast spheres.
Baradium is dangerously unstable, sometimes triggering a fusion reaction if the detonator is jarred or exposed to excessive heat. Detonators have been known to explode when dropped or thrown through the air for no apparent reason. As a result, they are strictly military-issue and are illegal for civilian possession, although their usefulness creates intense demand for them, pushing black market prices up to 2,000 credits per detonator.
Since a single blast can disintegrate up to two meters of permacrete, military crews often use detonators for demolition work and detonator booby traps are sometimes used to cover retreating soldiers.
Princess Leia used a thermal detonator to lend credibility to her impersonation of Boushh, since the infamous Ubese bounty hunter was known to be fond of explosives. Leia received the weapon from Lando Calrissian, who used two similar detonators to destroy the opulent palace of Prince Xizor, ruler of the criminal organization known as Black Sun.
Thanks to Star Wars: The Essential guide to Weapons and Technology by Bill Smith