Final answer:
The HEDP rocket contains a type of explosive known as High Explosive lenses, which are used in the implosion assembly method.
Step-by-step explanation:
The HEDP rocket contains a type of explosive known as High Explosive lenses.
These lenses are used in the implosion assembly method, where multiple explosives are arranged in a specific pattern to implode the plutonium core, compressing it into a smaller volume to form a critical mass.
The implosion technique is faster and more effective than the gun-type bomb, as it compresses three-dimensionally.