The recent North Korean nuclear test has an estimated yield in the neighborhood of about 100 KT. This is greater than their previous tests, and has led to the statement that North Korea tested a true multi-staged hydrogen bomb. However, a simpler fusion boosted design, rather than a true hydrogen bomb, could have a similar yield. Edward Teller proposed such a design before the Teller-Ulam breakthrough was achieved. Many of our weapons use such a design where Tritium or Lithium Deuteride is added to obtain a marked improvement in the yield. In order to achieve multi-megaton yields, a true staged thermonuclear design is needed.
This is not to denigrate what North Korea achieved; however, there is little evidence that North Korea tested a true hydrogen weapon.
Allan M. Salzberg, MD, PhD, Boise