Air-tight vs. Vacuum-tight
ฝัง
- เผยแพร่เมื่อ 13 มี.ค. 2020
- When I'm not making TH-cam videos, I'm growing crystals in a Molecular Beam Epitaxy vacuum chamber held about 12 orders of magnitude below atmospheric pressure. This is the first in what I'm hoping will be a series of videos featuring the MBE chamber, and this time I'm talking about leaks: how to find the tiniest leaks in the most sensitive systems, and how an MBE can be considered basically a perfect pressure vessel with no air leaking in or out at any time. Let me know in the comments if you have any questions about the MBE I could address in future videos!
Check out the other social media for updates and ramblings:
/ alphaphoenixchannel
/ alpha__phoenix
#Vacuum #Materials #Engineering
The MBE Lab is part of the Materials Department at UCSB. Filmed with permission.
Extra graphics in this video:
ConFlat flange diagrams from Kurt J. Lesker and Vacs SEV
Music in this video:
I Dunno by grapes is licensed under a Creative Commons Attribution license (creativecommons.org/licenses/...)
ccmixter.org/files/grapes/16626 - วิทยาศาสตร์และเทคโนโลยี
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Multi-reply:
"cross-tighten with a torque wrench"
- As of this post, I have 40 comments suggesting a torque wrench and approximately 50 recommending a star- or cross-tightening pattern. I hear you. In undergrad (maybe sophomore year?) I was helping to service a piece of vacuum equipment and was actually corrected FROM using the star pattern. I was taught that on these copper conflat flanges, "cutting in" the knife edge linearly by tightening in a circle was the way to go unless you had an absurdly large flange (which this is not). Trying to get a UHV seal with these gaskets is nontrivial, and if you have a system that works, you stick with it. I also know people who cross-tighten their conflat and get great results. In applications like this that are super-finicky, any change to procedure comes with risk. if it aint broke, don't fix it.
- During this opening there were maybe 6 or 8 flanges open, and only one of them leaked, and the flange that DID leak had already been problematically leaky during previous openings, so I don't attribute the leak to a problem in tightening but more than likely, a scratch on the flange knife-edge that requires you to torque the gasket down past spec to fill the extra gap with copper.
- Regarding the torque wrench, in many many locations on this system, it's almost impossible to fit a regular wrench around these flanges, let alone a necessarily bulkier torque wrench. This flange probably could have been handled by an open-end torque wrench, which I guess I assume exists but have never seen, but in general to work on these academic systems you need to develop a feel for it. Notice how I'm barely moving the wrench with each tighten.
"you are wasting helium"
- This is actually an extremely common and extraordinarily critical industrial use for low-purity helium. THIS is what the party balloons should be saved for. This method was developed to detect leaks so small they don't generate bubbles, noises, or other observable airflow. we're talking about a handful of atoms weaving their way through cracks in apparently solid pieces of metal. I've found a leak straight through a stainless tig weld on this system using helium. Amazingly enough, a LOT of the semiconductor industry depends on being able to create high quality vacuums for processing.
interesting that there's still stuff that's just based on what you were passed on and there's not one best way known (like the tightening pattern you use). makes it feel like a learned hard skill rather than just a purely academic pursuit
You did 2 ugga duggas when you should have done 3.
Ultimately conflats are not as finicky as you think. I've reused them on training vessels with a Extremely high vacuum to some success. Landing the groove in the old groove had to play a crucial part in this and the bite was pretty solid. What mattered the most is that we always followed torque specs and when those failed we upped the specs and still followed the cross pattern starting from marked bolt 1. I don't recommend this as a operating guideline, but I'm telling you that those rings are tougher than you think. Following good engineering practice and a little bit of elbow grease you can get a used copper conflat to hold for at least 40 hours in extreme vac. I've seen it done. It did fail, but we only had the one in the training lab so we waited for a batch of new ones to come in, but it will do it.
As someone also in the UHV side of semi, the law of the land where I am is star tighten after it's hand-snug, and always to designed torque. By not doing that you risk dis-leveling the mating surfaces and could end up overcutting a seal, deforming it more than necessary and then actually creating a weaker seal. This leak might have been avoided by proper torquing patterns, but like you said, typically that type of failure can be hidden by deforming the seal even more with additional torque. Just wait until you try baking out the system though, that additional deformation is likely to come back to haunt you.
@@sejongthegreat3044 Does the material expand at all due to tempature changing the torch specs or allowing enough of a gap to make a difference? I don't know why but It instantly popped in my head while reading this all.
"If tightening it doesn't work, tighten it more" -Engineer
unless it is meant to move, in which case lube it
Wd 40 / duct tape
Whack it with a wrench to make it work
How to properly torque a bolt: tighten until the threads strip, then back off a quarter turn.
@@JinKee everything shall be lubed everything
"you may assume a perfect vacuum"
*engineer cries in relief*
lol
Are we allowed to assume spherical cows with their mass concentrated in a single point as well?
@@akrinornoname2769 Also don't forget pi = 3
@@alexcompagnucci8508 gravity = 10 m/s^2
@@alexcompagnucci8508 pi = 3 = e
Im really glad Tom Scott encouraged us to watch this in his most recent newsletter, because its fascinating stuff; I never considered how much such a insignificant leak could multiply so much under a vacuum.
Tom has a newsletter?
@@NoNameAtAll2 Yes, in case you haven't made it there already, it has a few suggested youtube videos and a few other internet articles/ findings and is weekly. Really interesting! (I'm going through a backlog of them currently which is why I'm watching it now, 3 months after the newsletter date)
@@macaronisheep where does one find it?
@@NoNameAtAll2 if you google Tom Scott, his website was the first result for me and right on the front page is a link to sign up to it :)
(Not keen to put link in comments in case spam filters catch me)
this is also the reason Elon Musks "Hyperloop" won't be built.
"hey whats inside this thing?"
"nothing, truly nothing"
Virtual particles: *allow us to introduce ourselves*
Its filled with quantum fluctuation+neutrinos of course
So what's inside this chamber?
SPAAACE
@@Auhrii Ask them to sign your guest card and they just disappear.
@@Z-zl yeah, this engineer guy kinda looks like he did a bump before recording. Or maybe he's high on science
Fantastic video. Clear, methodical, and you walked me along the entire troubleshooting path. Well done!
Yo Destin - I love your channel!
Glad you like the video! I’m not sure why leak-checking an MBE has been deemed viral material but my channel has had a wild week and a half and I’m glad you made it here!
19 min Ago on a one year old video. Is this a clue for something upcoming :D. Or just weird youtube algorithm
I figured we were all getting recommended this around the same time; I know when I see a banger video topic like this pop up in the recommendations out of no where that I am one of many fine lads the algorithm chose to bless today
Nice to see u here
@@AlphaPhoenixChannel because the Titile is really intriguing i want to know what the different b/w air tight and vaccume tight. also that's how mysterious Algorithm works
“I could talk about lab equipment for hours and hours” I for one would love to listen about lab equipment for hours and hours. Even if you posted barely edited ramble style videos about niche and specific lab equipment, i’d definitely watch them
I had the privilege of working on the upgrade of a fusion reactor in the UK. During my time on the project the reactor was being checked for leaks exactly like this. Totally fascinating engineering. Brilliant video :-)
How many working fusion reactors does the UK have?
@@tedmoss I’ve only heard of JET, the joint European torus
I'm jealous. I want my own fusion reactor.
@@tedmoss There's the JET Reactor and MAST Reactor which are in operation. I was part of the upgrade of the MAST Reactor.
how cool is it to just casually say "oh yeah i was working on the upgrade of this nuclear fusion reactor last summer" in conversation
"the world is running out of helium!"
"But what could you need it other than for making squeaky voices?"
"Scientific purposes!"
"Like what?"
"Releasing it into the air so it makes everyone in the lab's voices all squeaky"
You made me laugh while I was eating chocolate and now I have to clean up my desk.
But like for real I’ve had a lot of comments saying this wastes precious helium but THIS is one of those critical industrial uses everybody always talks about…
@@AlphaPhoenixChannel No worries, just use hydrogen, the molecules are even smaller. What could possibly go wrong?
I'm not sure, but we had a helium detector as part of the ion pump AFAIR. I'm also pretty sure the helium nozzle was a calibrated leak, not sure why. But the process was exactly the same back then, 1968. What was impressive was the way the helium alarm would trigger even while you were just setting things up the other side of the lab.
Lmao 🤣
@@daze8410 I've never understood why they don't just collect the helium instead of just flushing it
Gordon doesn't need to hear all this He's a highly trained professional
@@Dezmont01 Ah yes you're right, Gordon we have complete confidence in you
@@jimbow7787 Well, go ahead. Let's let him in now.
Why do we all have to wear these ridiculous ties?
Ah Gordon! Ho grab that wrench over there!
Good, now gently tighten the bolts... Gently.... Geeeeently... *Beeping starts* AHHHHH! Gordon what have you done!?
We have to hope. Otherwise there could be some "Unforeseen Consequences".
I'm in no way, an engineer. But I loved this well explained video. Thanks for bringing us into your lab, and simplifying the process for us!
Previous semiconductor worker who delt with vacuum and pressure tight vessels and pipes.
-Pressure tight is way harder, especially when the differential is 100psi or more, and silane, hydrofluoric acid, anhydrous ammonia...you know the things that dissolve humans or reliably spontaneous combust in air. With a vacuum you have chances to mess up, with pressurized death gases/liquids, you have 0 chances. Also helium and hydrogen pressure tight is the worst, but we usually used helium to test connections of pies to contain worse chemicals before putting them into production. That being said, randomness from the machines vibrating, and human error caused leaks and the fun beganafterwards.
The gasket no atom can pass.
Hydrogen: *is that a challenge?*
Click-bait.
@@DrDeuteron While that's true, hydrogen can chemically diffuse through some metals, making it basically unstoppable. This is especially true at elevated temperatures.
@@DrDeuteron helium is smaller than hydrogen?
@@bladdnun3016 Hydrogen permeates through all materials, especially steel. PTFE aka Teflon has the lowest permeation rate of any material available and hydrogen still permeates through it.
@@peterwill9660 I have seen helium permeate through .250" carbon steel plate. Drove me crazy trying to find the "leak" with a "sniffer" in my welds that I was certain were good.
"We use it to grow crystals"
*breaking bad music plays*
*Breaking Benches*
-These vacuums are pure up to 10^-10 torr. You must be him.
-Say my name.
-Ultra High Vacuum
-you’re goddamn right.
I wonder. Maybe
I started research in a lab this semester using a gravimetric microbalance and mass spectrometers as well, the microbalance uses the same copper gaskets as you are, albeit at a much less perfect vacuum. It is so cool to see the stuff I use in different labs as well
We make quadrupole mass specs at my workplace. I love hearing an outside view on how they work and the leak test process as well!
I finally managed to get a He leak detector for the lab I work at. It is a Varian that was made in about 1985 and needed some work. I managed to get it up and running, and boy am I glad I got it. There is a fancy room that we put together and it took 2 guys 3 weeks to get it mostly leak free (I used that to help justify the leak detector). I later needed to do some modifications to the room which meant finding all of the leaks that were sprung, and it took me about 4hrs to be confident that the room no longer leaks (this included a few leaks that were missed by the previous guys). I put that in there in my status report email as a sort of "I told you so".
GOT EM
A poor man’s leak detector is using a very sensitive pressure sensor (which you will already have in an ultra high vacuum system) and just taking a squirt bottle and spraying IPA around the machine seals and bolts. If there is a leak the IPA will go inside the leak and when the alcohol hits vacuum it “explodes” and you see the pulse on the pressure sensor. I once watched a Russian physicist do this while his He detector was down and he figured out all the leaks without it and was able to achieve better than 10^-9 (it’s been awhile I forget the exact number but it was our personal record) lol
@@latenttweet that's what the first crew was doing. This is also how we leak check our systems with a convection gage.
The problem with this system though is that it has a 200gal reactor on it to act as a huge buffer, but it also uses a very crappy air-referenced vacuum gauge.
This system works from atmosphere down to 100Torr or so.
The He leak detector worked a treat though, but it would take a while for all of the He to get sucked out of the system to allow the leak detector to calm down again.
Glad that this channel is now appearing on my Recommended! Fascinating videos!
⠀
No likes? Impossible
Woah
Hello Eret!
I didn't know you were into engineering
Cool
hey eret!
I used to work for a company that built large vacuum chambers. leak checking and fixing welds is a whole other kinda fun.
When I was working on my chemistry PhD, one of the profs had a ultra high vac system he used for is surface chemistry research. I had a class with him where we covered his to find a leak with He. 10^-12 Torr is tough to obtain. Breaking vacuum, cleaning and pumping down is certainly a lot more involved than with my GC-mass spec.
Gasket: "NONE SHALL PASS"
Hydrogen: "hold my beer"
Helium enters the chat.
@@HappyHarryHardon - brilliant mate, good on ya
More like hold my single electron. I'm going ionic
@@myselfremade lol
Neutrinos: "beesh, please."
Great video! Would love to see more of this. I’m especially curious how such a high vacuum is achieved besides having perfect seals.
I’ve got an ever-changing plan for a video on pumping in the works. There are 7-8 pumps on the system I think and we add two more during servicing.
Video about vac pumps! Looking forward to it!
I had a 160 hour course on the subject while at university.
And that's only the start.
Vaccuum technology is a whole branch of study and engineering.
Pumps only go so far. A molecular sieve system is usually used to remove remaining molecules to get closer to a perfect vacuum.
@einstein9073I assume Roger meant something more along the lines of "Scientists like to do experiments with different shit in vacuum because its cool and cool shit happens" because it would be really stupid if he meant something more like "Scientists like to do experiments on a vacuum... because they are curious as to how nothing keeps doing that weird thing it's doing".
I worked on an STM during undergrad, and it's interesting seeing so many of the principles I learned in that lab being reflected here. Same copper gaskets, same residual gas analysis, same pumps. I mean, that's not surprising for obvious reasons, but it's still interesting to see.
Cool! What were you looking at?
@@AlphaPhoenixChannel We were studying the surface of Ag(111). To be honest, I only got a few hours actually running the STM and never got to do any analysis myself. My efforts were almost entirely focused on building the STM with my professor (and then taking it back apart because the university made him move it).
As someone keeping track at home this is a great watch
I'm surprised you tightened the head bolts sequentially around the head rather than in a star pattern to avoid uneven distortion of the gasket. Any reason for this?
That is correct for initial tightening down to torque spec to insure even forces... but, not so much after proper specs have been reached... the "star pattern" (most commonly used) is to keep the pressures close to the same around the circumference and while increasing the torqued pressures to spec to maintain "flatness" or parallel surfaces. Micro-adjustments afterwards are a completely different story. The torque forces applied at this point are increasing in tiny fractions and are deforming the metal gasket like a "putty" at those pressures, Essentially, instead of applying the forces in the flat plane for maintaining parallelism, you actually want to theoretically "chase around" a minuscule blob of metal to fill in those gaps that are allowing molecules through.
@@edwardpaulsen1074 A fascinating response to a question that had me thinking already. Thank you both!
@@edwardpaulsen1074 but can't you inadvertently still maintain the leak? By chasing/pinching the gasket seal around to a single point (between your start and end locations) can't you effectively create a material imbalance in that area maintaining the leak and making it harder to seal?
@@miamisasquatch well if that happens, don't you just tighten it again?
@@miamisasquatch You can inadvertently do pretty much anything as long as its not what you were planning on but sealing vacuum isn't that much of a challenge to be honest. Your car tires are probably like 40psi or something like that which is a 40 psi difference to atmospheric pressure and they seal just fine for the most part. Absolute vacuum is just -1atmosphere so from outside to inside of the vessel there is just a pressure difference of 14.7 psi. So don't worry about it just huck some copper in there and you're good.
Totally know the feels. Had a vacuum drop in my ToF-SIMS from 10^-11 to 10^-8, which was screwing with our cesium gun.
We were up for maintenance anyway, so we went with the invasive option and just changed all the copper gaskets.
Fortunately after putting it all back, there were no leaks!
name a better combo than anime profile pics & time-of-flight secondary ion mass spectrometry
@@von... ppl come in all shapes, colors and types of hobbies!
Also, it's a game character 😉
That’s quite the vacuum.
How does ToF-SIMS compare to positron annihilation induced Auger spectroscopy? My PhD work is in space physics so I know little about this but my friend works with positron beams measuring what gets knocked off a target and sent down a ToF tube. Both are high vacuum work and seem super cool.
This is so cool! I’m currently doing my PhD in physics and my friend here works with positron annihilation Auger spectroscopy, so they use a UHV system that measures what comes off a target with a ToF tube. He was talking about the flanges and cleaning the system the other day but I never really truly understood the work that goes into maintaining it until now. I do simulations all day so this is all alien to me!
Love all the replies from the scientists in this thread. We’re all just geeking out together and it feels great.
I was in a lab that had both Ebola and Anthrax... So I thought that was pretty fascinating. What was probably more fascinating was how casually I was invited in there..... The professor who worked there told me that once he retired, he planned on making another lab in his old garden shed. I told him "That sounds absolutely wonderful!"
He might already have anthrax in his garden. It lives in soil just fine.
I've just been continuously watching vids on this channel throughout my entire day, I can totally see you hitting 2^20 subscribers very, very soon
@@revan552 it's a thing with this channel that every doubling, a new play button is made by him... Not oddly specific at all
Of course a channel I love would watch channel I love.
@@nutmeggaming11261 it is oddly specific. You're wrong. Take the embarrassment
i watch your videos lol
more like 1^ ... wait...
Mass spectrometer? Making crystals?
*Flashbacks to that one incident in the anomalous materials lab in Sector 7G*
at least it isn't anti-mass!
We assured the administration that *nothing will go wrong*
_Why do we have to use these ridiculous ties?_
@@ghoulbuster1 As in the nothingness (the vacuum) inside the chamber will fail :P
They're waiting for you Dr Freeman, in the test chamber.
I work with a few guys like you, who can just talk and talk and talk about the equipment they work with. Always fun to ask them questions! Really interesting video!
It was one of the best parts of looking for a new job when I last did it. I know enough about a lot of things in order to ask good questions that elicit a ramble about someone's work. Learn new things, get excited about the human endeavor, what's not to love!
As a vacuum engineer for LIGO this was a well done video! Now imagine trying to leak hunt down a 2.5 mile long vacuum arm...
I can’t even imagine! What’s it like working at LIGO? I remember watching the announcement when the first chirp was detected and marveling at the precision of it all
@@AlphaPhoenixChannel Its a blast! Currently feels like one fiasco after the next though. We are in the process of upgrades.
I used to work on an ultra high vacuum system. We regularly had to vent and open the system to replace test samples etc. I'd love to see a video on your method for pumping down the entire system.
You really had to open the entire system every single time you had to change the sample?
@@DocSineBell how else they gonna get it lmao
@@zachmarshall6059 a fast entry chamber. A very small chamber, with a small volume, that can be easily isolated and opened. Takes from minutes to hours to pump perfectly a fast entry. Takes days to a week to pump and bake out perfectly a whole big ass UHV setup.
@@DocSineBell Maybe it wasn't that big a setup. Still, even for small stuff like detail electronics or pacemaker bombing etc. I've seen setups with cutoff valves. The trouble tends to be that even labyrinthing with 1- or 2-mp valves sunk into the build, you're still taking your bloody chances that the seal tightness is going to be sufficient.
@@zachmarshall6059a load lock chamber.
I would literally pay for content of this quality released on a once a month/nile-red-type basis
also, touching on superlative topics, like whatever would be considered a catastrophic failure in this system, would be super interesting.
I used to work at a pharma site looking after their freeze drying plant. We used the exact same method to find leaks on the vacuum chamber, although we attached an external helium leak detector to the equipment.
I absolutely love your videos, and I've only seen a few of them. You're not only good at what you do, but you're really passionate about it and very excited about it, and I love it.
As someone who works in semiconductor equipment manufacturing I cannot imagine trying to keep vacuum flanges clean in a non-clean room environment
Well there is a huge difference between labs and manufacturing plants. An contamination causing an issue in less than 1% of all experiments might be neglected by many scientists, but at high quantities and low margins, 1% might be the difference between earning a lot of and losing a lot of money.
Amazing that molecules can squeeze their way through seals in a near perfect vacuum, considering it's only ~14.7 psi on the chamber.
Nature abhors a vacuum
its still full of neutrinos
@@shadesmarerik4112 - I heard they mutated and are heating up the planet.
@@RFC-3514 u heard? where?
@@shadesmarerik4112 - From a famous Indian scientist: th-cam.com/video/bXdBzpRDR5I/w-d-xo.htmlm33s
When you were talking about the epoxy seal, all I could think was “FLEX SEAL! IT EVEN SEALS TO PERFECT VACUUM”
I know from my experience in the semi conductor industry that He leak checking can take a long time. Patience is golden.
The most problematic leak I encountered was a virtual leak. Corrosion that exists of tiny holes that filles itself when the system is vented and takes forever to pump out.
This is why it is highly recommended to vent systems under vacuum with nitrogen, which does a good job of filling in all those micro cracks and preventing water (which takes orders of magnitude longer to pump out) from filling those cracks instead. Never vent a high vacuum system directly to air if it can be avoided.
I used to work with high vacuum equipment myself--ironically, making parts for quadrupole mass spectrometers! Our vacuum requirements were a little less extreme than yours ("only" in the 10e-7 to 10e-8 torr range, so we could use rubber gaskets) but all the principles were the same. I may point people to this video in the future when I have to talk about my old job!
This was very interesting. You are a charming and effective host. Thank you for sharing!
I lovr watching happy people talking about things they are passionate about. Always charming
Thanks for a very informative video! I spent a couple of years working as a technician at a scientific research facility and often enjoyed wandering through and marvelling at the beam pipes, examining some of the sensor and control equipment and was struck by the constant hum of the various vacuum pumps which had to run continuously to keep the pipes at a near-vacuum as a particle beam was injected.
I think your work related stuff is some of your best content, it may be complex, but you explain it in such a good way that its more entertaining then the less technical stuff.
Thanks for bringing up my memories on working with UHV equipment on university. Memories of many, many bolts, some broken feedthroughs and unreal toughness of platinum wires. And waiting for right pressure to actually start the second and third stage pumps. Good memories :)
I refer to Vac-Seal as "Liquid Shame".
Absolutely fascinating !!! I worked in a company that sold and serviced vacuum equipment.......but nothing quite on the order of what you work with. Regardless, although not part of my responsibilities, I had to learn about vacuum equipment to be able to discuss leakage (and other types of) problems with the engineers who were tasked with producing solutions for our repair people. What I DID learn was that although everyone thoroughly understands pressures above atmospheric pressure, very few people (including many engineers) have a real problem understanding/coping with problems concerning negative pressures. It seems that we're hard-wired to work with positive pressures. I had to sit with some engineers and use my semi-pro knowledge of negative pressures to get those engineers to "re-engineer" their thought processes. They all understood the principles theoretically but couldn't make the mental "leap" to practicality. It was certainly an ego boost for me to be able to see the "light bulb" come on over an engineer's head when my "teaching" finally sank in. Ah, the glory days........before I retired.
What a great vid !!!
One of the generic task I do during my daily job is designing of o ring seals for high vacuum chambers for semiconductor tools.
And this video is very precise, informative and entertaining at the same time.
Keep up the good work 🙌🏻
Selenium huh, What are you making? perfect single crystal optoelectronic components?
IV-VI semiconductors
Selenium is one of my pet hates - it eats stainless steel for breakfast leaving pinholes in the structure. Hastelloy C276 is much better at resisting sulphide and selenide corrosion. (I have done a lot of work with copper selenide slurries…).
I’ve seen enough movies to know selenium kills aliens. Pretty sure he’s preparing to fight aliens.
@@allangibson2408 fascinating. Prototype machinist- and I like seeing how compounds interact with things I work with. Noted- selenium & stainless steel don't get along. I will be looking into how that composition occurs.
@@CaskStrength777 Selenium and Sulphur have a lot in common chemically so anything that has a problem with sulphides will have a problem with selenides.
I knew nothing of vacuum chambers and now I feel like I could machine my own that could be half as good as this. You are an amazing communicator.
I worked in the mineral assay industry for many years, and mass spectrometers were pretty much the pinnacle of available instrumentation for the purpose of trace element analysis... for your machine, it's a leak detection accessory. Mind blown.
I worked with a large scale multilayer optical coating machine. One of three deposition sources was a large (for meting 100 kg MgF) carbon crucible for a thermal source of the MgF. It was hotter than the sun, at 1x10-6 torr. A pinhole water leak in water cooled conductors (copper pipe) to the crucible heaters would degrade our vacuum in a periodic way, as it froze off to stop leaking as it expanded into the vacuum chamber, but would melt off as it carried current. It was only 6" from the thermal source at 2700C. Really showed me how good of an insulator vacuum can be, or really, how little energy is transferred with radiative heat transfer.
“Ultra High vacuum”
Brought to you by the guy who created “extra extra extra large” the size 😂
That’s the best part of scientific/medical terms, everything is categorized and defined the same way. So all the terms sound oversimplified specifically so you know exactly what it means even if you haven’t heard of the concept before. If only English could learn a thing from that.
I´ve actually walked by a clothes stand outside a clothing store where an ungodly amount of X´s were before the "L". 5 or maybe even 7 X´s, i believe.
While i walked by it, i quietly said the size with all the "extra"s to myself under my breath and came to the conclusion that i think a new word should be invented for sizes beyond the second or third "X".
Extra large,
extra, extra large,
extra, extra extra large,
impressive
extra impressive,
extra, extra impressive
momentous...
gargantuan...
royal...
serious...
@@GarretRB Yep, this naming happened with radio bands as well. HF -> VHF -> UHF are high -> very high -> ultra high frequencies.
It keeps going too. SHF - super high frequency, EHF - Extremely high frequency, THF - tremendously high frequency
I'm a little mad it doesn't go Super, Ultra, Mega though.
Its even worse in Biology. They never discover the enzymes that perform sequential steps in a reaction in order, so you get used to struggling with "Enzyme IV coverts A to B, then enzyme II converts B to C, and finally, Enzyme VI coverts C to D; however, sometimes Enzyme I also converts some B to D".
This guy gives me major "Jake from Avatar" vibes, with his appearance and the camera angle and content etc.
Years past, we were amazed to observe the porosity of steel braided Teflon hose terminated with Swage Loc fittings in our thin film vacuum roll coater. Our helium Mass spectrometer and helium as our trace gas. End result the Teflon hose was about as tight as a screen door on a submarine.
I'm just a computer programmer but I used to work with TEM scientists and I could listen to them talk vacuum all day. :)
"Where's the leak, Ma'am."
-Patrick Star
I found this extremely fascinating! The way the gaskets are deformed like that to create that much of a seal is so cool! (I’m such a nerd)
I once connected a helium line to an old GC/MS unit. No technicians in the lab at that time and limited time on the machine so a colleague and I just went for it…
We tightened everything to an amount of torque, we considered reasonable, flushed the system according to the manual and started the first calibration run. It was supposed to show nothing but the helium and maybe trace amounts of gases left in the tubing, instead we got nitrogen, co2, oxygen and a whole bunch of other stuff that looked a lot like air…Another colleague with more experience looked at our connections, smiled, took a wrench and tightened each of them by about two and a half full turns! So I got a pretty good idea about “gas tight” that day, but dude, hard vacuum is just crazy 😉
Thanks! Now I can finally fix that pesky leak in my MBE chamber I keep in my basement.
9/10 customer tech support.
Awesome! I'd love to watch more cool info about your equipments and research. You could explain how it works and the principles behind it. Keep it up please!!
great video! Love hearing you talk about the handling and operation of these high tech devices!
Gordon this is amazing to see! I’m also in the CVD field, and battling leaks is also a constant thing. Thankfully we only stay in the milliTorr range. I want to see more of this!
Thankyou for this discussion and fantastic video. I worked building a free electron laser that had a long waveguide from one room with klystrons to another room with the laser and many conflat joints in between with high vacuum (1x10 ^-9 torr) using ion pumps. Built in sections for testing initially we had a high rate of failure using the helium test, requiring disassembly and gasket replacement The waveguide joints are rectangular and the recommended torque pattern is criscross I changed this to begin with a criscross for halfway thru and finishing with sequential torquing. My theory was that a side of the rectangle was moving laterally across the knife edge when a knee threshhold of pressure was approached, thereby moving the knife edge on the copper gasket laterally. By sequentially tightening in contrast a pressure wave was induced linearly along the knife edge. After I switched methods we had no more failures and the P.I. was amazed
Awesome stuff! What were you pointing the FEL at?
Very interesting video. I would love to see more.
Awesome and interesting insider look. Thanks AP!
Spent the first year of my career in machining at a shop that made components like this for the semiconductor industry, it's nice to finally see someone showing how a knife edge seal works, the thing that was always so mind blowing to me was the hours we spent hand laying the finish in a certain direction on oring seal grooves so that we didn't create a leak path. Very cool video
I’d love to see how these are manufactured - I can attest that edge is fragile. This same spot had leaked more than once so I think it must have gotten scratched during assembly or a previous service
Unfortunately I no longer work at that shop, but the way we cut knife edges was to bolt the plate to a rotary axis and then to tilt that axis by the angle of the knife edge then rotate the whole plate around the center of the knife edge circle , it became a long day when we were doing flanges with 6+ gunports all splayed out at angles from centerline so they'd have clearance for the larger end of the gun
This reminds me of the time where I assembled the caging for the PS-BGI project at CERN for the helium leak test. Now I understand a lot more why I did that and what was happening.
I do indeed find this stuff very interesting. Thanks for sharing it!
Idk how you managed to make a video about fixing a leak interesting, but you did.
Thanks! That was the plan...
Feynman had a great bit something along the lines of “absolutely everything is interesting if you go into it deeply enough”
Soo cool to finally see someone that I can relate to regarding the daily grind. I deal with this on the daily as well. I only work with 1x10-5 in an 18"x18"x18" chamber though. We use a little Varian helium leak detector to check for leaks. Great idea with the bag to concentrate the helium. We're using the ours to perform elevated temperature (2400°F) tensile tests on high temp alloys and more recently single crystal Niobium, so we're in and out of it about 4x/day. Keeping it clean is a chore!
Like so many others, this popped up in my recommendations the other day. So happy to have found this channel. Wish I studied more STEM subjects in high school, I'm really fascinated by the world of applied physics
Keep up the wonderful work, love seeing someone passionate about what they do. And as always, great presentation
This is absolutely fascinating stuff! Thanks!
I like how real you are, you approach your videos as a person living in real life, rather than masquerading as something you're not like most people do
One of my consulting clients was Flexitallic, they made spiral wound metal gaskets for vacuum applications like this, but they mostly made high positive pressure seals for steam and petrochem.
That uhhh, “potato cannon” looked a little sus lololol
Yesssssssssssss! Talk about the work you do that you are able to!
I worked in the Plasma UHV lab at UCLA in the late 1970s. We used the same techniques back then too.
So cool! I'm always amazed at how scientists find simple solutions to problems that seem impossible. Way cool!
Even if what you're explaining is very simple, it is very interesting! Thanks:)
I did indeed find this as interesting as you did!
This takes me back. You might want to jump around when tightening like you would on a tire, rather than just going around the circle. I used to run a very old abused pecvd system and got very used to conflats, as we had to break one to open the system. 😩😵
Yes I do find it as fascinating as you do!
These videos keep blowing my mind! Love it! (Steve Mould sent me)
NEXT EPISODE: Fixing the space station with a steel wire
I did vacuum testing for about 3 years. I was only testing at high vac but we also did thermal testing in our chamber. That brings in a whole different issues with out-gassing. We’d always having issues maintaining our required vacuum level when going to hot temperatures. We also did our leak checks with IPA wipes. It never really worked too well but tightening or replacing a gasket was fairly easy and worked every time. It also takes about forever to heat things in a vacuum when it’s only bolted to a plate.
This IS my new favourite channel! Awesome
Greetings from a fellow MBE engineer :p I work also on the RIBER system :)
What do you grow?
@@AlphaPhoenixChannel elements of III-V group, but it's more machine maintenance and cleaning than growing xD
"Actual engineering" ... "the real science"... you know you're talking to an engineer when they use these terms.
Cuz it’s sorta kinda true...
It's not "obvious" that just because someone works on something, that they find it fascinating. I've run across co-workers in my field of technology who found it an absolutely excruciating bore, but kept at it for the salary. I always felt really sad for those kinds of people. But all of that to say, consider yourself lucky that you're able to work on complex and intricate technology and ALSO find it endlessly fascinating. Cheers!
Really cool video, I had the occasion to test seals for spacial equipment before using a similar method and thought about it immediately but you explained why it's used very well
Yes, more about the system and technology
Amazing content.
Keep it up :D.
As a plumber and gas fitter, leaks are the bane of my existence. This was very interesting.
I am an ion implant engineer and leaks under high vacuum is one of the most common fail modes. This is a killer video
This is supper cool! I would actually love to know what kind of pumps and for how long they need to work to remove “all” atoms inside the system
It’s some fascinating technology - I really want to film a video about achieving ultra high vacuum but don’t know now when it will be possible...
Molecular pumps such as diffusion or turbomolecular pumps, and also cryogenic pumps
imeaktsu7 turbo-molecular pump, rough pump, tight vacuum chamber, gases, heat.
This is my first video but this is such a good video passion is the best entertainment.
Hi friend. You brought back memories from f the MBE work I used to do at UCF. AlGaAs laser diodes grown in a Veeco Gen III. One time we spent two days looking for a leak in our shutter assemblies. Lots of jard work in general.
Thanks for all your content.
Good, interesting video. I used to work at a temperature instrumentation company. We made the cryogenic probes for the shuttle, nuclear industry and more. Had a helium detector to verify the welds at different stages as products were being completed. It like consuming lots of liquid nitrogen. When I was the calibration tech, all the fixtures were sent out for testing.The environmental chamber we used was nice equipment. It ran at atmosphere ( no vacuum or pressure control.) we'd cycle sensors for days. It was fun.