Samuel T. Cohen, the "father of the neutron bomb", claimed for a long time that red mercury is a powerful explosive-like chemical known as a ballotechnic. The energy released during its reaction is allegedly enough to directly compress the secondary without the need for a fission primary in a thermonuclear weapon. He claimed that he learned that the Soviet scientists perfected the use of red mercury and used it to produce a number of softball-sized pure fusion bombs weighing as little as , which he claimed were made in large numbers.