Nuclear Bomb pics

[lona]

A bomb that uses the energy of the nucleus to release energy can safely be called a “nuclear bomb.” President Harry Truman referred to the bombs dropped over Japan as “Atomic bombs.” This name is still used.

The bomb based on fusion of hydrogen is often referred to as a “hydrogen bomb.” A name typically used by scientists is “thermonuclear bomb.” The word thermonuclear refers to the fact that the fusion takes place because of the high temperature (that’s the thermo part).

[lona]

I got some clarification from the net:

Uranium bomb

The nuclear bomb that destroyed Hiroshima was a “gun” type bomb. By this I mean that a piece of U-235 was shot by a cannon at another piece of U-235; the combination was above the critical mass. The entire bomb, including cannon, weighed 4 tons. The energy release from the chain reaction was 13 kilotons of TNT equivalent. The day after Hiroshima was destroyed, President Harry Truman mistakenly announced the yield was 20 kilotons. This was the first uranium device ever exploded. It had not been tested. (The Alamogordo test was of a plutonium bomb.) The design was so simple that a test was decided to be a waste of uranium. After the bomb was dropped, there was not yet enough new uranium to make a new one, although the Oak Ridge plants were producing enough that a new bomb could be ready soon.

Plutonium bomb are more difficult (see next section). For that reason, a bomb that uses uranium is the material of choice for a terrorist, since the design is so simple. But such a bomb requires highly enriched U-235, and that is not easy to make. When you dig uranium from the ground, it is 99.3% U-238, and only 0.7% U-235. It is only the rare isotope U-235 that can be used for a bomb. Separating this isotope is extremely difficult to do.

When the United States defeated Iraq in 1991, one of the conditions that Saddam Hussein agreed to was inspections of his nuclear facilities. The U.S. discovered that he had developed devices to separate U-235 from natural uranium. But these devices, in stead of being the modern centrifuge or laser systems that we had anticipated, were Calutrons. This is short for "California utron", and it was the slow but sure method invented by Ernest Lawrence (after whom is named the Lawrence Berkeley Laboratory). Lawrence had invented this method during World War II, and his system had separated virtually all the U-235 that was used in the attack on Hiroshima.

Prior to the Hiroshima attack, a nuclear weapon had been tested in Alamogordo, New Mexico. That was the first nuclear explosion. But the Alamogordo test did not use U-235. It used an isotope of plutonium, Pu-239.

Plutonium bomb

The bomb tested at Alamogordo, and the one dropped on Nagasaki, were both plutonium bombs, using Pu-239. Plutonium is relatively easy to get: it is produced in most nuclear reactors, including those intended to produce electric power, and then it can be separated using chemistry. However it normally has a high component of Pu-240, which is highly radioactive. This radioactivity tends to pre-detonate the bomb, i.e. make it explode before the chain reaction is complete. As a result, a special design had to be used: implosion. This is extremely difficult to design and engineer and build, and probably could not be built by a small organization such as a terrorist group. The resources of a full country (Pakistan, North Korea) are probably necessary.

The bomb dropped on Nagasaki yielded 20 kilotons of explosion. It used only 6 kg of plutonium (about 13.5 pounds). That much plutonium could easily fit in a coffee cup. The higher yield per gram (compared to uranium) results from the fact that plutonium emits more neutrons in fission than does uranium, so the reaction goes faster, and we get a more complete chain reaction before the plutonium is blown apart.

The plutonium is often arranged as a hollow shell, with explosives on the outside. The explosives drive the shell into a little blob, and compress it (even though it is solid). The compression pushes the atoms close enough together that neutrons produced in the chain reaction are unlikely to be able to leak in between them. Thus compressed plutonium has a smaller critical mass than uncompressed plutonium.

The explosives often use a special kind of explosive "lens" (a special shape in the explosive that tends to make the explosion converge on a point).

According to the chief nuclear weapons designer of Saddam Hussein, a U.S. trained physicist named Khidhir Hamza, the Iraqi bomb was not going to be a gun-style design. Instead, they would use uranium, but do an implosion in order to reduce the critical mass.[19]

Thermonuclear weapon or "Hydrogen Bomb"

In the hydrogen bomb, deuterium and tritium are heated by a plutonium or uranium fission bomb, to the point where they overcome their natural repulsion (the nuclei of both are positively charged) and fuse. This releases energy, and neutrons. The high energy neutrons cause fission in a uranium case (usually just U-238), and that releases even more energy. The biggest hydrogen bomb ever tested (they have never been used in war) released an energy over 50 million tons of TNT. That is million, not thousand!

The "secret" of the hydrogen bomb, kept highly classified until just a few years ago, is that the plutonium bomb emits enough x-rays that they can be used, after bouncing off the uranium cases, to compress and ignite the tritium/deuterium combination. There is a second secret, although this has been public for a longer period. Instead of using tritium, the bomb can contain a stable (not radioactive) isotope of lithium called Li-6. This is a solid, which means that the material is stored at high density. The neutrons from the fission weapon break up the Li-6 to make the tritium. Thus the fuel is created in the same microsecond that the bomb is exploding. The fusion fuel is usually lithium combined with deuterium, called lithium deuteride.

[kelstorm]

lona, i beginning to suspect how come u so interested in A-bombs.. dun bring it with u when u go diving with me... those coming from the rear end ok??? hahahah

tks for the info...

[lona]

no no no... ...those coming out from the rear end are the hydrogen bombs! (Actually more like methane, but explosive all the same kekeke..)

50 Megaton rating.

you have been warned.

[kelstorm]

i only want to breathe in nitrogen...

[Tanzy]

The Atom Bomb dome in Hiroshima by night with full moon.

[Tanzy]

A-Bomb dome by day.

[Tanzy]

Close up of the dome.

[Tanzy]

Sakura in full bloom.

[Tanzy]

Probably a better shot of the flowers.

Just want to add that 1 in 10 of the victims are Koreans and numerous are chinese too. They are slaves captured by the Japanese to work in Hiroshima.

The exhibit at the Peace Park is quite disturbing but I feel that it is overhyped. The number of people killed by the A-bomb is less than 1% of those lost to conventional bombing of Japan by American B-29s. Nobody pays much attention to the civilians who were burnt to death in Yokohama or Fukuoka or other cities. I guess the whole idea is to gain sympathy for Hiroshima and incite feelings against nuclear weapons but I don't buy it all. The A-bomb was pretty devastating but its not that big a tragedy compared to the bigger picture.

[Jimaroon]

Nice flowers!!!

Hope they are not radio-active