"And that's BAD." It never gets old. Thank you for Nerd-ing out on the cooler, Love every minute of it. Love your Vid's, keep them coming. Thank you kind Sir.
In most coolers, the overwhelming portion of the heat is absorbed during the phase change from liquid to gas, and a much smaller amount from the subsequent expansion. How much heat is absorbed from the phase change is determined by the "enthalpy of vaporization" of the coolant. Water has a high one, about 40 kJ/mol. Freon's is about 25 kJ/mol. But the intermolecular forces of liquid helium are so low, it's value is only 0.0845 kJ/mol! With such a low enthalpy of vaporization, the expansion of the helium gas becomes much more important for absorbing heat. Also, Volume and Temperature are directly proportional, so these low temperatures make that expansion very effective on small temperature ranges. Going from 4K to 20K implies a 5-fold expansion in just 15K of temperature change. (Not exactly, real gases behave somewhat differently from ideal gases). In our everyday lives, a 15K swing doesn't have a notable effect on gas pressures and volumes because we're used to gases around 300K. So a 15K increase is only about a 5% increase in pressure or volume.
Thank you. Good comment. In case of cooling without a phase change, the adiabatic, near isentropic expansion through a turbine is common, (a rapidly rotating radial inflow turbine, magnetically suspended and work dissipated by induction currents.)
T/To = (p/po)^([gam-1]/gam) gam = 1.66 monoatomic gas Ideal expansion, but with flow pressure losses, Temp. is somewhat higher. Te > T absorbed work density: ho - h = gam/(gam-1) × R/ M ×(To -Te) R = 8.3144 kJ/ mol K M molecular weight. h spec. enthalpy
@@LaunchPadAstronomy sir THANK YOU I've learnt a lot of new stuffs from your channel and love to learn more thank you from the very bottom of my heart... i always want to be a student of you and not just a subscriber... love this youtube science Community
An incredible thank you for pulling this together: this video is one I've been looking forward to for quite some time and the depth and comprehensive overview is greatly appreciated. I'm sure I'll be referencing this video for years to come as we appreciate the scientific wonders that MIRI will open up.
I am so delighted that Webb has gotten this far. Such an incredible amount of effort of engineers and scientists put together to achieve this. A salute to all who made this happened.
This video is terrific. I think most people can relate or understand this cooling system because it relates a bit with our car or house closed loop systems. Thank you for explaining this.
@3:20 don't try holding your hand a few centimeters above a pressure cooker relief valve. A few dozen, maybe. Try it with a slice of cheese and see what happens.
Amazing video Christian! Lot's of information! The complexity of the cryo-cooler is enormous! Thanks for sharing with us! James Webb Space Telescope is one of the most amazing projects so far! Congratulations for the video! -Cheers
"Today on Linus Tech Tips, we've got something special for you ladies and gentlemen. After a YEAR of begging, WE got our hands on the BEST cryocooler ever built, the ONLY spare produced by NASA and JPL, the other one is in the JWST orbiting the L2 Lagrange point, and we're gonna build the absolute **coooolest** gaming PC with it (get it?). And you know what else is cool? Our sponsor for this video, …" Sorry I can't do more of this but you get the idea.
@@TheEvilmooseofdoom To elaborate, such seals as there are will be all metallic ( rather than elastomer ) using either : annealed copper seals clamped between stainless steel rings with a knife-edge profile biting into the copper ring or indium ( = metallic plasticene ) rings squished flat between two surfaces. There will, of course, be the absolute minimum of seals in total since they will inevitably be a weak point.
@@louf7178 There is no heat involved. Indium joints are cold-formed - just a ring of the indium wire (finished by twisting the wire ends together) squashed between two metal flanges (or one flange and a flat surface). The indium cold-flows to fill all the microscopic hollows. The major part of preparing the joint is ensuring that there isn't a radial scratch from outside to inside.
Last weekend I recharged my house A/C using the sub cooling method and I thought I was smart. That was obviously child’s play compared to the MIRI cooler
That's kinda crazy to think about, I mean it's already super duper cold in space but we created a technology that works better when it's even colder...that's pretty neat.
It is so impressive to see how such a complicated system works (albeit in an overlisimplified way). Kudos for NASA to make all this work without a hitch, also because the currently available images are already awesome
As ever, a quick shout out to CSA and ESA. IIRC, MIRI is a European-led instrument with NASA providing this amazing cooler and the mid-IR detector assemblies.
3:20 ish Wait wait wait, is that *really* why the tea kettle steam gets cooler?? Is it not that there’s tons of surface area meeting much cooler room temp air that cools it immediately? I know reality is sometimes unintuitive but this illustration feels real suspect.
If the precooler has the coldhead at the PT tube then it seems the precooler is actually warming (increasing the pressure) of the low side of the JT circuit to maintain slight positive pressure in JT compressor suction and to ensure the JT compressor is always pulling in vapor and never liquid.
Pretty much everything on JWST that isn't just regular spacecraft hardware is either state-of-the-art or JWST-specific (when they've had to shift the art along by quite a way)...
I understand the theory behind the balancing pistons but even the smoothest machines still have SOME vibration. I’m blown away they were able to pull off a real compressor in any form without affecting the telescope’s alignment.
This video is a great explanation of the technology involved in jwst. Most RUclips videos will just rehash the same thing about jwst like Lagrange points, infrared camera and would explain about cooling in last 2 minutes.
Yes! Thank you so much for the nerding! It was mentioned here a lot of times but still, for me you are the best science channel out there! Have a nice day
Great video! This is my favorite part of the JWST, by far. But I'm pretty sure the canned air thing is a different mechanism. It gets cold because of the phase change. It's an example of latent heat. The pressure stays ~relatively constant over the can's useful life.
If you have a pump you have some type of reciprocal movement and cause vibration so how are they dealing with vibration in space and what happens as it gets older and starts to wear the vibration increases.
The two pistons are precisely the same weight and move like clapping hands - the resulting vibrations are equal and cancel each other. The pistons are supported on identical leaf springs which constrain them to move in a dead-straight line. The pistons are 'sealed' by being as perfectly smooth and round as they can be and moving in an equally-precise bore. The clearance is so tiny, and the piston sufficiently long, that by the time leakage is going in one direction the piston has reversed and so has the leakage. The degree of precision involved is exceptional (as is the cost) but there is no wear because there is no contact.
This video would've been very helpful when I was working on simulating the thermal telemetry for JWST mission ops rehearsals, better late than never I guess!
Blue Origin intend to use a cryocooler on their HLS for cooling their LH2 to prevent loss through boil off... do you think that they would be using this technology?
if you took a ship to the James Webb Space Telescope Lagrange point and released a rotating raw chicken breast into space, would it freeze from the vacuum or cook from the sunlight? how fast would it need to rotate in order to cook it the whole way through? good luck
Listen I know you’re a scientist and it’s hard for you to give us readings in Celsius and even harder in Fahrenheit however just go ahead and do it you know for the 90% of us who have no idea what a Kelvin is. Try to remember we made it to the moon and back using the imperial system.
3:20 the kettle example thats not joule thompson effect, thats just the gas cooling as it expands... joule thompson effect is gas cooling as its throttled ie cold gas that is compressed in a compressor to a high pressure getting colder as it expands to ambience via a throttle body! thats why we have the inversion of differential JTE!!
This is EXACTLY how I explained it.....well sorta..... But 'LPA' you explained SO WELL...🥲🥲🥲it got me 'misty-eyed'..... Seriously, Well Done and the drawings are not bad.... if we could imagine the drawings vertical, I would Totally understand it!! 👍👍👍 Glad I 'Subscribed' 👍👍👍
Why not put a huge amount of mercury in space and then spin it to give it a parabolic mirror shape?? It seem we could make a very large telescope that way.
They must be moving Webb to test how long it takes to get the temps back down after position changes. if you go to the Where is Webb page you'll notice the temperatures are very different than they have been lately
Of all the things about this telescope, nothing baffles me more than the fact that a a man made object in space (which I had always just thought of as being absolute zero) requires so many mechanisms to ..cool itself. And then to cool the thing that cools itself...ect.. Glad they had 25 years to figure this out..because it is way beyond me.
Wait a minute!! 3:00 'Ridiculously Oversimplified Block Diagram' ... are you saying we can't handle the proper diagram ... I think we should be the judges of that. Go on, just a peak, please? EDIT - Having just watched it through twice I am still bamboozled by the tech here - I'll trust that the real drawings are disturbingly complex. Great vid though.
1:17 i'm sorry WHAT?!?! I thought hydrofluorocarbons were banned in the 90s for ripping apart our ozone layer?!? don't tell me they're still legal to sell in the USA 😳😳
🔴 Webb's mirrors are fully aligned and in FOCUS!: ruclips.net/video/E-pNS5mDExQ/видео.html
Great video. Very comprehensive and informative.
It's Kelvin, not kelvins
"And that's BAD." It never gets old. Thank you for Nerd-ing out on the cooler, Love every minute of it. Love your Vid's, keep them coming. Thank you kind Sir.
In most coolers, the overwhelming portion of the heat is absorbed during the phase change from liquid to gas, and a much smaller amount from the subsequent expansion. How much heat is absorbed from the phase change is determined by the "enthalpy of vaporization" of the coolant.
Water has a high one, about 40 kJ/mol. Freon's is about 25 kJ/mol. But the intermolecular forces of liquid helium are so low, it's value is only 0.0845 kJ/mol!
With such a low enthalpy of vaporization, the expansion of the helium gas becomes much more important for absorbing heat. Also, Volume and Temperature are directly proportional, so these low temperatures make that expansion very effective on small temperature ranges.
Going from 4K to 20K implies a 5-fold expansion in just 15K of temperature change. (Not exactly, real gases behave somewhat differently from ideal gases).
In our everyday lives, a 15K swing doesn't have a notable effect on gas pressures and volumes because we're used to gases around 300K. So a 15K increase is only about a 5% increase in pressure or volume.
Thank you. Good comment.
In case of cooling without a phase change, the adiabatic, near isentropic expansion through a turbine is common, (a rapidly rotating radial inflow turbine, magnetically suspended and work dissipated by induction currents.)
T/To = (p/po)^([gam-1]/gam)
gam = 1.66 monoatomic gas
Ideal expansion, but with flow pressure losses, Temp. is somewhat higher. Te > T
absorbed work density:
ho - h = gam/(gam-1) × R/ M ×(To -Te)
R = 8.3144 kJ/ mol K
M molecular weight.
h spec. enthalpy
These videos are making me think that $10 billion was actually pretty cheap for all this tech
About the same as 70% of an aircraft carrier....
The engineers and technologists who design and construct these instruments need their own Nobel Prize......
This is consistently one of the best sci-tech channels on RUclips.
I cannot wait for the next video!
Wow, thanks!
8:18 extremely bad oversimplified model was awesom.. 😂😂😂😂😂😂
Lol, thank you!
@@LaunchPadAstronomy sir THANK YOU I've learnt a lot of new stuffs from your channel and love to learn more thank you from the very bottom of my heart... i always want to be a student of you and not just a subscriber... love this youtube science Community
An incredible thank you for pulling this together: this video is one I've been looking forward to for quite some time and the depth and comprehensive overview is greatly appreciated. I'm sure I'll be referencing this video for years to come as we appreciate the scientific wonders that MIRI will open up.
Thanks so much!
I am so delighted that Webb has gotten this far. Such an incredible amount of effort of engineers and scientists put together to achieve this. A salute to all who made this happened.
Such a good content. Keep doing the good work!
Love the in-depth analysis-real and insightful content!
Thank you so much!!!
This video is terrific. I think most people can relate or understand this cooling system because it relates a bit with our car or house closed loop systems. Thank you for explaining this.
This was definitely the 'coolest' exegesis you've given us so far. :-) Well worth the wait.
Before the launch I loved how so many people complained that JWST was outdated technology.
Your videos and ways of presenting information are spectacular. Can't wait for the next ones!
@3:20 don't try holding your hand a few centimeters above a pressure cooker relief valve. A few dozen, maybe. Try it with a slice of cheese and see what happens.
Amazing video Christian! Lot's of information! The complexity of the cryo-cooler is enormous! Thanks for sharing with us! James Webb Space Telescope is one of the most amazing projects so far! Congratulations for the video! -Cheers
Thank you my friend!
Absolutely wonderful explanation. Your presentations are so informative and well presented, thank you!
Thank you so much for those kind words!
"Today on Linus Tech Tips, we've got something special for you ladies and gentlemen. After a YEAR of begging, WE got our hands on the BEST cryocooler ever built, the ONLY spare produced by NASA and JPL, the other one is in the JWST orbiting the L2 Lagrange point, and we're gonna build the absolute **coooolest** gaming PC with it (get it?). And you know what else is cool? Our sponsor for this video, …"
Sorry I can't do more of this but you get the idea.
lol!!!
What is stopping the helium leaking out of any joint or surface in their entire cooling system?
Seals.
@@TheEvilmooseofdoom
To elaborate, such seals as there are will be all metallic ( rather than elastomer ) using either :
annealed copper seals clamped between stainless steel rings with a knife-edge profile biting into the copper ring
or indium ( = metallic plasticene ) rings squished flat between two surfaces.
There will, of course, be the absolute minimum of seals in total since they will inevitably be a weak point.
Brazed joints similar to medical gas piping code?
@@louf7178 There is no heat involved. Indium joints are cold-formed - just a ring of the indium wire (finished by twisting the wire ends together) squashed between two metal flanges (or one flange and a flat surface). The indium cold-flows to fill all the microscopic hollows. The major part of preparing the joint is ensuring that there isn't a radial scratch from outside to inside.
324K to 42K? So impressive!
I really enjoy your explanations on everything but the JWT videos are exceptional!
Wow, thank you!
I'm always ecstatic when I see a new video, absolutely love this channel.
Have a nice weekend, everyone! :)
Thank you!
Thanks a lot for taking time, neurons and work to achieve excellence in teaching technical details... APASIONANTE!
Last weekend I recharged my house A/C using the sub cooling method and I thought I was smart. That was obviously child’s play compared to the MIRI cooler
Not Gunna Lie, I'm bamboozled....yet, can't stop watching.
This is a wonderful instrument, and it is performing beautifully. I am astounded.
Likewise!
I enjoy you all forcing me to calculate the Kelvin to Fahrenheit...
That's kinda crazy to think about, I mean it's already super duper cold in space but we created a technology that works better when it's even colder...that's pretty neat.
That was unbelievably well-explained! Thanks!
My pleasure and thanks!
It is so impressive to see how such a complicated system works (albeit in an overlisimplified way). Kudos for NASA to make all this work without a hitch, also because the currently available images are already awesome
As ever, a quick shout out to CSA and ESA. IIRC, MIRI is a European-led instrument with NASA providing this amazing cooler and the mid-IR detector assemblies.
“Nerding out”? I like “Geeking out” better lol. Great work breaking this down! Your visuals are top notch as well 👍👍
I think it's self-degradating and unhealthy.
3:20 ish Wait wait wait, is that *really* why the tea kettle steam gets cooler?? Is it not that there’s tons of surface area meeting much cooler room temp air that cools it immediately? I know reality is sometimes unintuitive but this illustration feels real suspect.
I think both. IIRC, your contention is why boiling water freezes faster than cold water when thrown into frigid air.
his explanation of Joule Thompson effect is totally wrong! he tried to explain it intuitively but the effect is not an intuitive one!
Rediculously (sic) interesting, even with the misspelling.
If the precooler has the coldhead at the PT tube then it seems the precooler is actually warming (increasing the pressure) of the low side of the JT circuit to maintain slight positive pressure in JT compressor suction and to ensure the JT compressor is always pulling in vapor and never liquid.
and I'd say that explanation was just exactly perfect too! Stars, JWT is 'gonna make em shine'!
Well thanks I appreciate it. It all rolls into one, after all.
So excited for this amazing observatory to begin science operations! Only a few more weeks 🤞
Kelvins? Do you also say Fahrenheits?
No, but I do say “degrees Fahrenheit”
I knew the JWST has a complicated mirror and optical systems, but I wouldn't imagine it's also true for the cooling system to have so many parts...
Pretty much everything on JWST that isn't just regular spacecraft hardware is either
state-of-the-art or JWST-specific (when they've had to shift the art along by quite a way)...
It's rediculous that you can't spell ridiculous.
I understand the theory behind the balancing pistons but even the smoothest machines still have SOME vibration. I’m blown away they were able to pull off a real compressor in any form without affecting the telescope’s alignment.
Amazing how close this is to absolute zero!
I can guarantee the cryo cooler will last the life of the instrument, cuz if the cooler ever breaks... that instrument is dead
Well, that's only the wish.
The plural of Kelvin is Kelvin
That’s what I always thought, until I kept reading “Kelvins” everywhere. Now I’m confused.
I was also thrown off hearing "Kelvins", is this some kind of new usage perhaps related to absolute versus delta temp?
This video is a great explanation of the technology involved in jwst. Most RUclips videos will just rehash the same thing about jwst like Lagrange points, infrared camera and would explain about cooling in last 2 minutes.
Humans engineering 👏🏿👏🏿👏🏿👏🏿👏🏿😎
Yes! Thank you so much for the nerding! It was mentioned here a lot of times but still, for me you are the best science channel out there! Have a nice day
Thank you so much, I really appreciate it!
Great video! This is my favorite part of the JWST, by far.
But I'm pretty sure the canned air thing is a different mechanism. It gets cold because of the phase change. It's an example of latent heat. The pressure stays ~relatively constant over the can's useful life.
What would happen to Miri images above 7k? Noise?
Yes.
"and that's bad."
Yay we get to nerd out about it today!
If you have a pump you have some type of reciprocal movement and cause vibration so how are they dealing with vibration in space and what happens as it gets older and starts to wear the vibration increases.
The two pistons are precisely the same weight and move like clapping hands - the resulting vibrations are equal and cancel each other. The pistons are supported on identical leaf springs which constrain them to move in a dead-straight line. The pistons are 'sealed' by being as perfectly smooth and round as they can be and moving in an equally-precise bore. The clearance is so tiny, and the piston sufficiently long, that by the time leakage is going in one direction the piston has reversed and so has the leakage. The degree of precision involved is exceptional (as is the cost) but there is no wear because there is no contact.
Thank you for your response.
You explanation on these kinds of topics, such as MIRI are the best.
Thanks!
Perfect speed - new sub. Full disclosure - I squeezed by in Thermo Engineering 340 with a D-.
Thank you Scott! And WTG on passing TE340. The truth is that you really don’t start learning this stuff until after you finish school.
It's all cool! :D
You should have said, "My God. It's full of stars!" Like David Bowman said in 2001 a space odyssey.
This video would've been very helpful when I was working on simulating the thermal telemetry for JWST mission ops rehearsals, better late than never I guess!
Space is cool
ahh should have bought that to cool my GPU instead….
Amazing video! Mindblown!! Thanks
Loads of information, but rEdicule? Oops.
Some kind of red shift I guess.
Amazing engineering! Thanks very much for the detailed explanation!
that's cool
Bing Chillin
Blue Origin intend to use a cryocooler on their HLS for cooling their LH2 to prevent loss through boil off... do you think that they would be using this technology?
if you took a ship to the James Webb Space Telescope Lagrange point and released a rotating raw chicken breast into space, would it freeze from the vacuum or cook from the sunlight?
how fast would it need to rotate in order to cook it the whole way through?
good luck
Listen I know you’re a scientist and it’s hard for you to give us readings in Celsius and even harder in Fahrenheit however just go ahead and do it you know for the 90% of us who have no idea what a Kelvin is. Try to remember we made it to the moon and back using the imperial system.
You did not mention a gas's inversion temperature, which for Helium is around 40K.
3:20 the kettle example thats not joule thompson effect, thats just the gas cooling as it expands... joule thompson effect is gas cooling as its throttled ie cold gas that is compressed in a compressor to a high pressure getting colder as it expands to ambience via a throttle body! thats why we have the inversion of differential JTE!!
All that information and all those graphs and drawing to explain things and they spell ridiculously wrong LOL
It’s not “kelvins.” It’s just “kelvin.” Also you spelled “ridiculously” wrong.
Don't be rediculous.
Agreed
How is the captured heat lost from the system? In an Earth bound AC system air or water flows through the condenser coil to remove captured heat.
This is EXACTLY how I explained it.....well sorta.....
But 'LPA' you explained SO WELL...🥲🥲🥲it got me 'misty-eyed'.....
Seriously, Well Done and the drawings are not bad.... if we could imagine the drawings vertical, I would Totally understand it!!
👍👍👍 Glad I 'Subscribed' 👍👍👍
Thanks, and so glad to have you here!
Is there any official document by the nasa explaining about all the instruments
Please stop using your hands while speaking! Are you conducting an orchestra?
Why not put a huge amount of mercury in space and then spin it to give it a parabolic mirror shape?? It seem we could make a very large telescope that way.
I really appreciate the level of detail in these videos..
They must be moving Webb to test how long it takes to get the temps back down after position changes. if you go to the Where is Webb page you'll notice the temperatures are very different than they have been lately
Yes, that was part of the scheduled tests.
That is some serious engineering there.
But Christian, are you Ready?
Lord forbid any blurred images! Wouldn't want to mess up those immaculate diffraction spikes 🤣🤣🤣🤣🤣
When the actual science starts the diffraction spikes will be removed.
Good nerd-talk. Thanks.
You do a wonderful job of making the complex, clear.
Thank you so much, I appreciate it!
Nice addition of the Arthur C Clarke reference.....
Just the fact that this video is explaining a highly complex theory, and you can't even spell "ridiculously" properly, leaves me wondering.
OMG so you take out one word in this 13 minute video to make an issue?? With all due respect, you sir are projecting!!
Or to put it simply, it's really really complicated.
its a cooler that cools cool things that are cooler than cool which is really cool.
Are you certain these aren't Stirling cycle cryo coolers?
Of all the things about this telescope, nothing baffles me more than the fact that a a man made object in space (which I had always just thought of as being absolute zero) requires so many mechanisms to ..cool itself. And then to cool the thing that cools itself...ect..
Glad they had 25 years to figure this out..because it is way beyond me.
The hottest places on Earth get less heat from the Sun than the region of space around Earth...
AMD need take notes for thier gpu and cpu :o
I was just about to mention NightHawkInLight but then you brought him up. Anyway, great video as always.
Thanks!
Excellent detailed video and very well explained such a complex system.
Answer the question or get ignored....
3:09 ridiculously also spelled ridiculously
Wait a minute!! 3:00 'Ridiculously Oversimplified Block Diagram' ... are you saying we can't handle the proper diagram ... I think we should be the judges of that.
Go on, just a peak, please?
EDIT - Having just watched it through twice I am still bamboozled by the tech here - I'll trust that the real drawings are disturbingly complex. Great vid though.
Yeah it’s pretty complex stuff. I have links to the technical papers with more complete diagrams in the description of the video.
@@LaunchPadAstronomy Maybe later?!
1:17 i'm sorry WHAT?!?! I thought hydrofluorocarbons were banned in the 90s for ripping apart our ozone layer?!?
don't tell me they're still legal to sell in the USA 😳😳
They still have limited use in some industries. Aviation, for example.
@@DH-be4ur i understand that but here in europe propane/butane has completely replaced them as a propellant.
Pretty cool 😎
rediculously
A cascade refrigeration cycle
It's no wonder it took 20 years