You may be confident that the hydrogen bomb is in about the same state that the uranium bomb was about 1943 or 1944, a year or two before the first atomic explosion. Scientists think it can be done and the Atomic Energy Commission is working on it. Undoubtedly the U.S.S.R. is working on it, too, and may even get there first.

The hydrogen bomb has not been made or exploded. That is a matter for the future.

The hydrogen or superbomb reaction is different from that of the atomic or A-bomb made of fissionable materials, uranium or plutonium. The energy comes from the changing of matter into energy, as Einstein computed, but the lightest elements known are involved in the "fusion" process of the superbomb.

The size of the fission or A-bomb is limited by the circumstance that if too much of the fissionable metals -- uranium 235 or 233 or plutonium -- are brought together they will explode because the neutrons from their exploding atoms will start and maintain a chain reaction. This critical mass is some where between 2.2 and 220 pounds, exactly what is secret. The A-bomb is set off by bringing together suddenly two pieces of less than critical mass which together will be more than the amount that would start the explosion.

Instead of being self-starting, the superbomb needs the high temperature "trigger" of a fission bomb to get it going. It is safe to bring large amounts of the raw material of the superbomb together -- it can weigh a ton or more. Its size is limited only by the amount of hydrogen "fuel" that can be "set fire" in the few billionths of a second of the explosion of the "igniting" A-bomb. The high temperature necessary to set off the superbomb can be provided by the tens of billions of degrees Centigrade of the A-bomb explosion.

The speed with which the hydrogen atoms can react under such heat determines what will make the superbomb.

Certainly the ordinary kind of single-weight hydrogen will not do, for it takes far, far too long. Computations show that such reactions, which keep the sun stoked with energy, extend over billions of years. Billionths of a second are more like what is necessary in the fusion superbomb.

KINDS OF HYDROGEN

It is just as well that there are three kinds of hydrogen. The commonest is the ordinary sort in the waters of the earth. Its heart or nucleus consists of one proton. Then there is heavy hydrogen, or deuterium, which was discovered here in America in 1931, which is naturally present as 1/4500th of hydrogen in nature. This is hydrogen 2, with a nucleus of one proton and one neutron, which as a particle is called a deuteron. Then there is tritium, the third kind of hydrogen, "heavy, heavy hydrogen," which has a nucleus of one proton and two neutrons, called a triton. A team of British physicists first made it in 1934 by atomic bombardment of deuterons with deuterons. It may be produced by neutron bombardment of lithium in an atomic reactor such as those at Hanford. It is still a very rare element, non-existent now in nature since it is radioactive and half of it disappears every 12 years. Yet this a prime stuff of the superbomb to be.

THE THEORY OF THE SUPERBOMB

What happens in the superbomb is that hydrogen is turned into helium. This is what happens, so far as an end result is concerned, in the atomic process that keeps the sun stoked. The transformation in the superbomb is different and direct. It is almost instantaneous and it will happen only when the hydrogen is concentrated and "ignited" by A-bomb heat.

It seems most likely that either a reaction of deuterium with tritium, or tritium with tritium, will be the reaction of choice. Deuterium combined with tritium gives a helium atom and a neutron, while two tritons coming together produce the helium atom (alpha particle) and two neutrons.

The heavier hydrogens are expensive, although the AEC price tags upon them now are not fair values of their cost in the superbomb production. (For research purposes it is possible to buy from the A.E.C. five cubic centimeters of 50% tritium gas at a cost of $1,315 which figures out to something like the fantastic figure of a quarter of a billion dollars per pound.) Deuterium can be concentrated out of ordinary water, but tritium must be made with the use of fissionable material, competing for neutrons with the production of plutonium which is the principal job of the big atomic reactors at Hanford, Wash. Tritium is made by neutron bombardment of the very light metal lithium, much the same way that plutonium is made by bombardment of uranium 238 by neutrons from the controlled fissioning of uranium or plutonium.

Tritium is sold by the A.E.C. for research purposes.

The heavier kinds of hydrogen would be put into the superbomb in as concentrated form as possible, which means that they must be under very great pressure or very cold or both. Or they may be used as solid compounds -- this is speculation but the uranium of the trigger bomb might be combined with the heavy hydrogens to form a solid.

The problems in making the superbomb seem very much more complex than the making of the original uranium bomb must have been. Of course, we know now that the fission (uranium or plutonium) bomb will go off. We are not so sure that the superbomb will explode the way that we expect it. What has been done is so much simpler than what has never been done.

Except for the fear that others will do it first and use it against us, it would be foolish to try to make the hydrogen bomb. Even the making and stockpiling of tritium is a bad business as we shall lose half of our supply every 12 years, due to its radioactive disintegration.

Some scientists argue very strongly that we should not try to make the superbomb. Certainly it has no industrial or peacetime uses that can be foreseen now. Its reaction is just too big, sudden and powerful. There seems to be no way you can use the reaction in a power plant.

If it works, it is devastation beyond man's most hellish dreams.