Infomation on depleted Uranium (Or: help I suck at physics)

Pu-239 · Post by **Pu-239** » 2003-01-11 01:15pm

Durandal wrote:Depleted uranium is extremely dense, having an atomic number of 238. This means that a small amount can impact with a huge amount of momentum. That's primarily why it would be considered, especially for tanks. I also think that the A-10's gattling gun uses depleted uranium shells, enabling it to swiss-cheese tanks.

You mean atomic mass. There is no such thing as element 238

willburns84 · Post by **willburns84** » 2003-01-11 09:48pm

Vympel wrote:
Durandal wrote: I also think that the A-10's gattling gun uses depleted uranium shells, enabling it to swiss-cheese tanks.
It does- but really, a lot of people are obsessed with the A-10's 30mm cannon. For one thing, it attacks tanks from behind- a good number of small caliber, non modern weapons can kill a tank from that angle. The A-10 is truly fearsome because of it's AGM-65 Maverick load- that's it's primary armament.

Also attacking from above, where the armor is much much thinner than even from an aft shot.

phongn · Post by **phongn** » 2003-01-11 11:01pm

Darth Wong wrote:Inferior to tungsten in terms of physical properties, but superior in the all-important property of cost

Well, DU has a few useful effects when used as an AP round over W, doesn't it (like igiting, a 'self-sharpening' effect), etc? The US Army had both W and U238 rounds and seemed to consider the latter as a superior round.

phongn · Post by **phongn** » 2003-01-11 11:02pm

Durandal wrote:
Darth Wong wrote:
Durandal wrote:True, but what would depleted deuterium be? Depleted uranium refers to uranium which cannot be used for fission anymore. Depleted deuterium would be tritium.
I'd actually say that depleted deuterium would be ordinary hydrogen. Tritium is one step above deuterium. So maybe this gun would be firing ice pellets
Heh, I only say tritium because it's useless for fusion, same as depleted uranium is useless for fission. It could go either way, I guess.

Tritium can be used in fusion (esp. tritium-deuterium fusion)

phongn · Post by **phongn** » 2003-01-11 11:04pm

Durandal wrote:
Darth Wong wrote:
Durandal wrote:I think it was His Divine Shadow that was telling me of a sci-fi universe which claimed to use "depleted deuterium" in their handguns.

I almost fell off my chair laughing when he told me that.
It would be ridiculously pointless, but at least it's technically possible. That makes it far better than your average Star Trek science gaffe.
True, but what would depleted deuterium be? Depleted uranium refers to uranium which cannot be used for fission anymore. Depleted deuterium would be tritium.

U238 can actually be used in fission, just not very easily. 3-stage nuclear weapons use it to generate the majority of their energy.

Durandal · Post by **Durandal** » 2003-01-11 11:06pm

Pu-239 wrote:
Durandal wrote:Depleted uranium is extremely dense, having an atomic number of 238. This means that a small amount can impact with a huge amount of momentum. That's primarily why it would be considered, especially for tanks. I also think that the A-10's gattling gun uses depleted uranium shells, enabling it to swiss-cheese tanks.
You mean atomic mass. There is no such thing as element 238

The most basic equation in all of nuclear physics is P + N = A, or protons plus neutrons equals atomic number.

Necro99 · Post by **Necro99** » 2003-01-11 11:42pm

http://www.fas.org/man/dod-101/sys/land/du.htm

Raxmei · Post by **Raxmei** » 2003-01-11 11:54pm

Durandal wrote:
Pu-239 wrote:
Durandal wrote:Depleted uranium is extremely dense, having an atomic number of 238. This means that a small amount can impact with a huge amount of momentum. That's primarily why it would be considered, especially for tanks. I also think that the A-10's gattling gun uses depleted uranium shells, enabling it to swiss-cheese tanks.
You mean atomic mass. There is no such thing as element 238
The most basic equation in all of nuclear physics is P + N = A, or protons plus neutrons equals atomic number.

P + N = M, atomic mass. Atomic number is equal to the number of protons. P = A. That's why each element only has one atomic number, despite having a number of different isotopes.

Durandal · Post by **Durandal** » 2003-01-12 12:09am

phongn wrote:U238 can actually be used in fission, just not very easily. 3-stage nuclear weapons use it to generate the majority of their energy.

U238 almost never fissions, as it tends to absorb neutrons and produce plutonium and neptunium. However, it must be used as fuel simply because 99.3% of all naturally-occurring uranium is the U238 isotope, and only 0.7% is U235, which is the ideal candidate for fission. As such, uranium must be artificially enriched to contain more U235 nuclei to increase the probability of a neutron being captured by a useful nucleus. Nuclear reactors do everything they can to guide the neutron toward a U235 nucleus rather than a U238 one.

Durandal · Post by **Durandal** » 2003-01-12 12:12am

Raxmei wrote:P + N = M, atomic mass. Atomic number is equal to the number of protons. P = A. That's why each element only has one atomic number, despite having a number of different isotopes.

You are, of course, correct. I misread what he originally wrote and fucked up the terminology.

Post by **Sea Skimmer** » 2003-01-12 01:36am

Necro99 wrote:http://www.fas.org/man/dod-101/sys/land/du.htm

He said he didn't want a biased source. FAS is very much biased and also renown for its inaccuracies and failures to correct them.

phongn · Post by **phongn** » 2003-01-12 12:50pm

Durandal wrote:
phongn wrote:U238 can actually be used in fission, just not very easily. 3-stage nuclear weapons use it to generate the majority of their energy.
U238 almost never fissions, as it tends to absorb neutrons and produce plutonium and neptunium. However, it must be used as fuel simply because 99.3% of all naturally-occurring uranium is the U238 isotope, and only 0.7% is U235, which is the ideal candidate for fission. As such, uranium must be artificially enriched to contain more U235 nuclei to increase the probability of a neutron being captured by a useful nucleus. Nuclear reactors do everything they can to guide the neutron toward a U235 nucleus rather than a U238 one.

I wasn't talking about controlled fission.

Durandal · Post by **Durandal** » 2003-01-12 01:05pm

phongn wrote:
Durandal wrote:
phongn wrote:U238 can actually be used in fission, just not very easily. 3-stage nuclear weapons use it to generate the majority of their energy.
U238 almost never fissions, as it tends to absorb neutrons and produce plutonium and neptunium. However, it must be used as fuel simply because 99.3% of all naturally-occurring uranium is the U238 isotope, and only 0.7% is U235, which is the ideal candidate for fission. As such, uranium must be artificially enriched to contain more U235 nuclei to increase the probability of a neutron being captured by a useful nucleus. Nuclear reactors do everything they can to guide the neutron toward a U235 nucleus rather than a U238 one.
I wasn't talking about controlled fission.

Controlled or not, U238 doesn't fission. The only difference between controlled and uncontrolled fission is the speed with which the reaction takes place.

Admiral Valdemar · Post by **Admiral Valdemar** » 2003-01-12 01:20pm

DU is simply uranium that has had most all the fissile U-235 removed though it can be enriched through isotope separation for use in nuclear reactors and/or weapons, the waste material is U-238 which can be used in the tank busting DU rounds.

Incidentally the atomic number is 92 and another isotope known as U-233 can be used for nuclear weapons. They are looking for traces of "Yellowcake" in Iraq now I believe which can be made at ammonium plants.

phongn · Post by **phongn** » 2003-01-12 01:45pm

Durandal wrote:Controlled or not, U238 doesn't fission. The only difference between controlled and uncontrolled fission is the speed with which the reaction takes place.

U238 does indeed fission, Durandal, just not as easily as U235.

NWFAQ: "Although it can't be used as a primary fissile material due to the high threshold energy required for neutrons to cause fission, U-238 is still a very important nuclear material.

Due to its high density and atomic weight it is useful in bomb construction as a tamper/reflector for both fission and fusion assemblies. The fact that it *is* fissioned by fast neutrons means that it can boost weapon yield indirectly by multiplying reflected neutrons, or directly by the fast fission of the tamper. About 40% of fission neutrons, and all fusion neutrons, are energetic enough to fission U-238."

Fission-fusion-fission devices use fast-fission of the U238 tamper to greatly increase their yields.

Tatterdemalion · Post by **Tatterdemalion** » 2003-01-13 01:09am

Wow... lot of infomation there.

Thanks guys, this should all come in handy.

Shadowhawk · Post by **Shadowhawk** » 2003-01-13 06:40pm

No one's really addressed the 'dangers' of DU, though.

Claim: DU's radioactive!
Reality: DU is quite low in radioactivity, with a half-life of 4.5 billion years. Granite is said to be more radioactive. The crap we breathe in is more radioactive.

Claim: DU's toxic!
Reality: So is lead and tungsten. All heavy metals are toxic.

Claim: DU dust is toxic!
Reality: It's also very heavy. It doesn't stay airborne for long. DU is a penetrator--contained within less-dense materials. It poses virtually no danger to those handling the ammunition. It is a hazard for those on the receiving end of the rounds (from the fact that it's a 30mm shell moving at 3000fps aimed at your vehicle, the fact that the penetrator vaporizes inside your crew compartment, and that there's the potential of vaporized DU in the air around shell impacts).