They don't, there's not enough space on a screen to show all the nuclei, so all the enriched nuclei would be used up pretty quickly, the simulation replaces them to keep the ratio of U-235 at 5%
Oh that's why when Vsauce talk about hiroshima he said that most of the fissible material was blown away and only 1% or something reacted. It's because it was not dense enough, pressurized by compressing explosions on all side to contain the fissible material. I get it now.
Fantastic video! Also the tamper is forced inwards by the compression explosion, so it provides more compressive kinetic energy to keep the core together for a bit longer.
Nice simulations, but why did you use graphite for the neutron reflector? Graphite is a great neutron moderator, but that is the last thing you want to do to neutrons in a bomb. Little boy used tungsten carbide and the Gadget used depleted uranium. FYI, I have all the calculations solving the neutron diffusion equation to determine the critical mass on my channel.
Hey thanks for letting me know. If you can find me your specific video, I'll add that as a video-link-popup - whatever it's called. But anyways I chatted with Alex Wellerstein. He said the same thing as you, graphite is not correct for an atomic bomb. I didn't know, but I just wanted to name an example material for moderation. Miss on my side. Btw love your channel. Let me know if we should do something one day. I'm currently working on using these simulations of the Chernobyl disaster.
@@Higgsinophysics thanks for sharing with your viewers. The video is titled "How to calculate an atomic bomb's critical mass," which can be easily found on my channel. I wanted to share the direct link but RUclips only lets the channel owner to include URLs in comments. I also got in touch with Alex when I made my videos about critical mass, I asked his permission to show his Critical Assembly simulator. I started writing the code for my own simulation but I realized that it would be too time consuming and ended up just using Alex's simulator. I am glad you liked my channel, I just discovered yours, subscribed right away. Collaborating in the future would be neat!
Isn't the n,f cross-section for thermals ~700 barn where fast neutrons are ~7 barn? Or does the ~100 barn n,g reduce the yield despite the increase in cross-section?
This channel has been an excellent find! I’ve become really interested in all things nuclear after watching Plainly Difficult videos, then finding Kyle Hill. A bit late as I’m already retiring age! This was another amazing simulation and a great way to explain the workings of an atomic bomb. You’ll have to do a simulation to explain the so called hydrogen bomb next 😊.
Small gripe: fission of U-235 doesn’t always release 3 neutrons. It’s 2 or 3 neutrons, averaging ~2.4 neutrons every fission. (I wanna say it’s 2.41 neutrons, but it’s been a long time since I’ve dealt with fission).
Thank you for additional information. I guess he wanted to keep things as simple as possible. Most viewers are just enthusiastic about nuclear science because of Chernobyl NPP. =)
To be clear, it's not always these fission products -- there's a distribution (which affects the avg. number of neutrons per fission) -- the heat of the fuel rods themselves are self-annealing (but also some if the fission products, like Kr, Xe etc. are gasseous so degas themselves+ must be accounted for in reactor design)
@@ThomasHaberkorn the self annealing answered your question. Yes fission products introduce stresses into the crystal structure (due to volume changes) but the rods are hot enough that this resolves itself in terms of impurity placement + gaseous elements escaping from the metal/ceramic
I just want you to know that even my cats love watching your videos. I like to program animations of little balls bouncing around, kind of like the way the animations in this video look. My cats would sit and watch them for hours. Something like simulation of brownian motion, for example.
Nuclei absorbing neutrons eventually becomes unstable. So it will have to be replaced at some time. I guess we could have a look at the decay channel of boron-10. But control rods rarely absorbs enough to loose their effectiveness, and are instead retired due to structural issues
Well if B-10 (typically used in reactors) absorb a neutron it may becomes B-11 which is still stable, and if that absorb another one it still quickly decays to C-12 which is stable again. So it is remarkably resistant to activation. Still may affected by neutron embrittlement. (not in the case of boric acid though)
Your quip at 11:09 was really dumb for a scientist. Fun fact that "problem" you're alluding to was actually fixed by making those "evil" graphite tips 1.7 meters LONGER. And several RBMKs continue to operate just fine to this day in that arrangement. This is possible because the graphite tips in an RBMK reactor are not stupid or accidental parts of the design; and in fact perform many key functions in normal operation. The material didn't get to the bottom of the control rods due to random chance or incompetence.
Not sure either, I don't have any great explanations other than we can calculate the scattering cross section and see it's high for neutron-graphite reactions :D
Not gonna lie, it wouldn't be my frist idea for a reflector, tungsten, berylium rather these sort of things. That being said graphite is surely a good moderator, and since moderation requires elastic scattering...
Sorry but this "simulation" is not remotely accurate. It makes important assumptions that are not true. Also there is an upper limit to k, and it is much lower than your graph shows.
@@Higgsinophysics well that's good at least, I'm just noticing inflections between certain sentences that sound exactly like AI generated voice. Either way I enjoy your videos, thanks for the content.
Support me per video here: www.patreon.com/Higgsino (multiple benefits)
One-time-tip here: ko-fi.com/higgsino
just one thing i'm thinking about: why do the non-fissile products go back to fissile fuel after a while?
They don't, there's not enough space on a screen to show all the nuclei, so all the enriched nuclei would be used up pretty quickly, the simulation replaces them to keep the ratio of U-235 at 5%
Thanks
Comes back with an absolutely amazing video. Love your content
Glad you liked it. Thank you :D
Oh that's why when Vsauce talk about hiroshima he said that most of the fissible material was blown away and only 1% or something reacted. It's because it was not dense enough, pressurized by compressing explosions on all side to contain the fissible material. I get it now.
Absolutely phenomenal video!! Great to see you back!
Thank you zap! I'm glad to be back again, we should do a collab again sometime :) !
Fantastic video! Also the tamper is forced inwards by the compression explosion, so it provides more compressive kinetic energy to keep the core together for a bit longer.
Welcome to the watchlist, everyone!
how original 👏👏👏
@@UNICORN69HO What color is jealousy?
@@NorthForkFisherman Oh yes, I'm jealous of your lack of brain cells indeed, It must be such a simple life for you being a fucking oblivious mong
@@NorthForkFisherman incel
@@NorthForkFisherman
Watching this after the Cody's Lab refining uranium video. I should be expecting a visit soon.
Man such an under-subscribed channel! Amazing videos!!
Nice simulations, but why did you use graphite for the neutron reflector? Graphite is a great neutron moderator, but that is the last thing you want to do to neutrons in a bomb. Little boy used tungsten carbide and the Gadget used depleted uranium. FYI, I have all the calculations solving the neutron diffusion equation to determine the critical mass on my channel.
Hey thanks for letting me know. If you can find me your specific video, I'll add that as a video-link-popup - whatever it's called.
But anyways I chatted with Alex Wellerstein. He said the same thing as you, graphite is not correct for an atomic bomb. I didn't know, but I just wanted to name an example material for moderation. Miss on my side.
Btw love your channel. Let me know if we should do something one day. I'm currently working on using these simulations of the Chernobyl disaster.
Also, this is hilarious haha imgur.com/a/pswEp5P
@@Higgsinophysics thanks for sharing with your viewers. The video is titled "How to calculate an atomic bomb's critical mass," which can be easily found on my channel. I wanted to share the direct link but RUclips only lets the channel owner to include URLs in comments.
I also got in touch with Alex when I made my videos about critical mass, I asked his permission to show his Critical Assembly simulator. I started writing the code for my own simulation but I realized that it would be too time consuming and ended up just using Alex's simulator.
I am glad you liked my channel, I just discovered yours, subscribed right away. Collaborating in the future would be neat!
😮😢😮😢🎉😢😢😊🎉😅😂😢😊🎉😢😅😂😢😂😢😮😂😢😮😅😂😢😢😢😢🎉😢🎉🎉😢😮😂😢🎉😢😮😂😢😮😢😮😂😢😢😅😂😢😂😅😂😢😅🎉😢😮😢😮😢
Isn't the n,f cross-section for thermals ~700 barn where fast neutrons are ~7 barn? Or does the ~100 barn n,g reduce the yield despite the increase in cross-section?
This channel has been an excellent find! I’ve become really interested in all things nuclear after watching Plainly Difficult videos, then finding Kyle Hill. A bit late as I’m already retiring age! This was another amazing simulation and a great way to explain the workings of an atomic bomb. You’ll have to do a simulation to explain the so called hydrogen bomb next 😊.
glad to have u back!!
it's great to be back. Thank you!
Love your video style
2:51 On the contrary, it would be great for bowling.
thanks helped me a lot,now i know why it didnt work as expected
This is one of the coolest videos ive ever seen on Nuclear physics.
This is best explanation I ever heard!
Thank you for your video, really enlightened me about nuclear
Subscribed. Pure and great.
Hey, awesome simulation!!
Thank you for an enlightening video.
3 years waiting for the return!
Hopefully the next wait will be a bit shorter... Happy you are still here!
Wow, what an incredibly interesting video!!!! 👍
Small gripe: fission of U-235 doesn’t always release 3 neutrons. It’s 2 or 3 neutrons, averaging ~2.4 neutrons every fission. (I wanna say it’s 2.41 neutrons, but it’s been a long time since I’ve dealt with fission).
Thank you for additional information. I guess he wanted to keep things as simple as possible. Most viewers are just enthusiastic about nuclear science because of Chernobyl NPP. =)
I thought it was 2.9?
CONGRATULATIONS. Very good video and easy comprehensible explanation!
THANK YOU. Glad you liked it !
Simply Excellent
Now I understand how control rods work!
I love the lil reference to chernobyl
Well explained thanks.
Awesome, awesome video
How close to k = 1 do power plants keep their reactors at?
Hello, please make a video about H-bomb. Great job!
Incredibly well explained! Maybe You could do a material about breeder reactors?
1:44 Regarding the split of U235 into Kr92 and Ba141: do the fission products occupy a larger/smaller/same volume than the original U235?
To be clear, it's not always these fission products -- there's a distribution (which affects the avg. number of neutrons per fission) -- the heat of the fuel rods themselves are self-annealing (but also some if the fission products, like Kr, Xe etc. are gasseous so degas themselves+ must be accounted for in reactor design)
@@NZAnimeManga very interesting, but not what I'd like to have found out
@@ThomasHaberkorn the self annealing answered your question. Yes fission products introduce stresses into the crystal structure (due to volume changes) but the rods are hot enough that this resolves itself in terms of impurity placement + gaseous elements escaping from the metal/ceramic
I enjoyed that thank you
Appreciate ya. Thanks for sharing.
Excellent.
nice explanation
I just want you to know that even my cats love watching your videos.
I like to program animations of little balls bouncing around, kind of like the way the animations in this video look. My cats would sit and watch them for hours. Something like simulation of brownian motion, for example.
Awesome, now please do nucl fusion
Can we get the source code pls
1:04 👍👍🙏
What program did you use to simmulate this? Unity and C# or just pure code?
There are numerous programs you can use, but would be easy in Unity or Unreal.
What happens to the control rod's material as it keeps absorbing neutrons?
Nuclei absorbing neutrons eventually becomes unstable. So it will have to be replaced at some time. I guess we could have a look at the decay channel of boron-10. But control rods rarely absorbs enough to loose their effectiveness, and are instead retired due to structural issues
Well if B-10 (typically used in reactors) absorb a neutron it may becomes B-11 which is still stable, and if that absorb another one it still quickly decays to C-12 which is stable again. So it is remarkably resistant to activation. Still may affected by neutron embrittlement. (not in the case of boric acid though)
Great channel, should work on the audio a bit
very good video
thank you, much appreciated.
kaeri nuclear table reminds me of my graduation
Your quip at 11:09 was really dumb for a scientist. Fun fact that "problem" you're alluding to was actually fixed by making those "evil" graphite tips 1.7 meters LONGER. And several RBMKs continue to operate just fine to this day in that arrangement.
This is possible because the graphite tips in an RBMK reactor are not stupid or accidental parts of the design; and in fact perform many key functions in normal operation. The material didn't get to the bottom of the control rods due to random chance or incompetence.
I am trying to specialize post grad in Applied Statistics 😂 it seems criticality gets a lot into probability too. I might be super super wrong.
The probability math of criticality is very hard. Took decades to crack. Hope you are very good at probability generating functions.
Que bonito video
Hmm wonder why graphite can reflect neutrons...
Not sure either, I don't have any great explanations other than we can calculate the scattering cross section and see it's high for neutron-graphite reactions :D
Not gonna lie, it wouldn't be my frist idea for a reflector, tungsten, berylium rather these sort of things. That being said graphite is surely a good moderator, and since moderation requires elastic scattering...
Don’t ask why the nuclear force does what it does. It’s never gonna make much sense.
ur awesome
I love nuclear weapons so much guys
11:05 😂😂😂😂❤❤❤
Excellent. But please talk a wee bit slower. I have to rewind too often. lol
Sorry but this "simulation" is not remotely accurate. It makes important assumptions that are not true. Also there is an upper limit to k, and it is much lower than your graph shows.
He's not trying to simulate reality with 100% accuracy. He's using abstraction to make it understandable to the average person.
Who?
Soccer ball
ai voice kinda sux
this isn't ai voice
@@Higgsinophysics Oh really? You sure about that?
@@justin2221 I'm flattered you think it's AI.
@@Higgsinophysics well that's good at least, I'm just noticing inflections between certain sentences that sound exactly like AI generated voice. Either way I enjoy your videos, thanks for the content.