|
Post by Kerr on Sept 3, 2018 13:37:59 GMT
Radiation intensities don't have to do with anything here unless you are talking about focusing tera-petawatt pulses down to milli-micrometer spot sizes, the photon energy of fission reactions is usually around 1 MeV, insufficient to photodisintegrate anything really.
|
|
|
Post by AtomHeartDragon on Sept 3, 2018 14:47:52 GMT
Radiation intensities don't have to do with anything here Reaction cross section. Even if reaction could occur the intensity may be too weak for it to be of practical importance because of too few cases of reaction actually occurring to worry about. Good to know, I'm not a nuclear physics expert.
|
|
|
Post by Kerr on Sept 3, 2018 15:08:01 GMT
Radiation intensities don't have to do with anything here Reaction cross section. Even if reaction could occur the intensity may be too weak for it to be of practical importance because of too few cases of reaction actually occurring to worry about. Good to know, I'm not a nuclear physics expert. I thought you meant intensity in terms of causing photodisintegration or not, my bad. Also, after looking over absorption/attenuation and neutron capture cross-section lithium doesn't too great as a neutron shield.
|
|
|
Post by The Astronomer on Sept 3, 2018 15:20:22 GMT
Kerr so no lithium-6 neutron shield absurdity irl?
|
|
|
Post by apophys on Sept 3, 2018 15:22:36 GMT
Also, your comment about molten lithium 6 sounds like you haven't considered how thick said lithium shield would have to be. It takes ~6.87688 cm of liquid lithium to reduce the neutron flux by 50%. Where are you getting this? In CoaDE, it takes 137 micrometers of lithium-6 (solid, but that shouldn't make much difference) to reduce neutron flux of fast neutrons by 50%.
1 cm reduces the neutron flux of fast neutrons passing through by a factor of 1.21*10-22, and thermal neutrons 3.3*10-2. Is this wrong?
Googling tells me that Li-6 and B-10 are commonly used for neutron capture in real life radiation shielding, so I didn't think the performance here was anything out of the ordinary.
If you could tell me how lithium hydride and lithium borohydride perform, that would also be great.
|
|
|
Post by Kerr on Sept 3, 2018 15:30:59 GMT
Kerr so no lithium-6 neutron shield absurdity irl? Doesn't look like it, it even looks like Li-6 isn't that much better at attenuating neutrons than lithium-7 is.
|
|
|
Post by The Astronomer on Sept 3, 2018 15:38:12 GMT
> How good is lithium at absorbing neutrons?
|
|
|
Post by AtomHeartDragon on Sept 3, 2018 15:50:48 GMT
Reaction cross section. Even if reaction could occur the intensity may be too weak for it to be of practical importance because of too few cases of reaction actually occurring to worry about. Good to know, I'm not a nuclear physics expert. I thought you meant intensity in terms of causing photodisintegration or not, my bad. No, I understand that this is determined by individual photon energy, although it doesn't help being clueless about the actual energies needed. From energy conservation I would expect something in the order of gammas from radioactive sources (other than nuclear isomers).
|
|
|
Post by Anon1 on Sept 3, 2018 18:24:07 GMT
Kerr so no lithium-6 neutron shield absurdity irl? Nope.
By doing the actual neutron shielding calculations. The 500 MW ITER will produce ~400 MW of neutrons and incorporates 1 meter thick lithium blankets in addition to the other materials in the reactor. It takes mass to stop fast moving sub-atomic particles.
For Z (aka atomic number) less than or equal to 8:
Dose=Dose Initial*e^(-(0.19*Z^-0.743)*density*thickness)
For Z greater than 8: Dose=Dose Initial*e^(-(0.125*Z^-0.565)*density*thickness)
No it isn't. You shouldn't expect a video game to be realistic. It is limited by both the knowledge of the game developer and the desire to produce an entertaining game.
A 1.02 meV photon is sufficient to cause pair production (electron-positron pair). Below 1.02 meV, the gamma ray photon will cause beta production (1 meV equals free relativistic electrons traveling at 0.86 c), which is ionizing radiation. The effect of the beta radiation on the matter that it strikes varies depending on what it is hitting and how fast. You get more bremsstrahlung with higher atomic number atoms than with lower atomic number atoms. These gamma rays are using the photoelectric effect to produce relativistic electrons. Keep this up for an extended period of time and you probably should not expect for there to be no nuclear transmutation of the surrounding matter when you are pumping out gigawatts of gamma radiation.
|
|
|
Post by AtomHeartDragon on Sept 3, 2018 21:01:24 GMT
A 1.02 meV photon is sufficient to cause pair production (electron-positron pair). Below 1.02 meV, the gamma ray photon will cause beta production (1 meV equals free relativistic electrons traveling at 0.86 c), which is ionizing radiation. I think there might be a subtle difference between meV and MeV.
|
|
|
Post by Anon1 on Sept 3, 2018 22:05:28 GMT
A 1.02 meV photon is sufficient to cause pair production (electron-positron pair). Below 1.02 meV, the gamma ray photon will cause beta production (1 meV equals free relativistic electrons traveling at 0.86 c), which is ionizing radiation. I think there might be a subtle difference between meV and MeV. Considering that I am talking about megaelectron volts, and the electron mass is 0.510 megaelectron volts, then I don't think so.
|
|
|
Post by AtomHeartDragon on Sept 3, 2018 22:13:46 GMT
I think there might be a subtle difference between meV and MeV. Considering that I am talking about megaelectron volts, and the electron mass is 0.510 megaelectron volts, then I don't think so. meV is milielectronvolt and the thought of this range of energies being sufficient for pair production would be positively frightening. Learn your SI prefixes.
|
|
|
Post by Anon1 on Sept 4, 2018 0:29:59 GMT
Considering that I am talking about megaelectron volts, and the electron mass is 0.510 megaelectron volts, then I don't think so. meV is milielectronvolt and the thought of this range of energies being sufficient for pair production would be positively frightening. Learn your SI prefixes.
Learn to get that object unstuck out of your rectum.
Given that gamma rays exist in the megaelectronvolt range and not the millielectronvolt range, the context was clear. You are just trying to be seen, while adding nothing of substance. Quite pathetic actually.
|
|
|
Post by The Astronomer on Sept 4, 2018 6:18:01 GMT
> Rude Smartass Simulator 101
Pretty sure the desire to produce an entertaining game has nothing to do with OP material, or that the dev wanted this game to be entertaining more than educational. It seems like there is something about neutron capture that this game doesn't account for. Let's tell the dev. I'm sure they'll be glad to fix it. YES, I know this game isn't as realistic as real life, but surely it has seen more efforts and is better than your attempts to defend/justify your failure to correctly capitalize a character.
|
|
|
Post by apophys on Sept 4, 2018 7:26:31 GMT
This game was explicitly intended to be realistic, not to have entertaining gameplay. Some things are hard to model, but in a case like this where it is already modeled, inaccuracies are a bug, not a feature. qswitched , please take a look at radiation modeling, especially with regard to lithium-6.
|
|