DIY Atomic Beam Oven: The Stern Gerlach Experiment Pt. 3
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- Опубліковано 28 лют 2023
- After a long time there is again a video about the Stern-Gerlach experiment. With this experiment one can demonstrate quantum mechanical effects by deflecting atoms in a high vacuum, depending on the spin of the electrons.
Today's video is about the atomic beam furnace, which is used to generate an atomic beam from potassium atoms.
If you want, you can join my patreon to help me working on my projects. I would really appreciate it! / advancedtinkering
Here you can find the paper about the atomic beam oven: aip.scitation.org/doi/10.1063...
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I really love how the entire engineering / tinker geek / mad scientist community helps each other out on projects for things all over the world. I think we are quickly approaching an age where major discoveries and innovations will start happening out of people's garages backed by this community's collective works.
I love it when super geniuses make UA-cam videos. Thank you
Definitely not a super genius but thank you!
Love this project!
Any news or progress? Hoping for a part 4 😁
I'm hoping he decides to vaporize Cesium at a plate of Fe2O3 for part 5
Die magische Unterlegscheibe :D Passiert mir auch ständig xD
Looking forward to seeing the actual experiment. Keen to know if spin is actually “quantum” or if the beam just gets split enough in both directions to separate.
Heck yeah! So excited to see this. You peaked my interest last time and I've done a lot of reading on this topic since
This is an exciting project, I'm glad your making progress with it
Super cool project! Hoping to see a part 4 soon :)
Not really sure what this is just yet (about to check out the other video mentioned), but been kinda eyeballing your work for a while, this video got the subscribe, as I both want to know the deal on this and appreciate your attention to detail. Looking forward to more
Aha! A new video from AT. I feel like I am getting a gift... Damn, I am really getting a gift! Thank you! 😊
Haha, thank you! I'm glad you like the videos!
You'll need a small cooling jacket around the oring ring on the furnace, viton will not survive going above ~140C for a long period of time(minutes). Stainless is a really bad heat conductor so it'll be easy to cool it by adding a small heatsink to it, or just soldering a copper tube with some water running through.
It's good to know that the viton O-ring will not survive those temperatures for long. Thanks! I will probably try to air cool it and if it is not sufficient, I will try water cooling it.
Find someone with a lathe, put a groove down to nearly the diameter of the hole in the middle.
Then K reservoir and flange are only attached with like a 2mm wall thickness tube of stainless steel and the reservoir can easily be heated with bunsen burner, whatever....
@@AdvancedTinkering Yes, can confirm. Viton can briefly handle that temperature if not compressed. If it is exposed for extended time while trying to seal it will suffer compression set and either seal unreliably or not at all. I busted a couple valves that way.
FKM (Viton) is actually rated up to 220 C. A quick search proves that.
Forced air cooling with a fan should be sufficient.
@@ivankundrata3837 It can't handle that temperature while maintaining its properties.
You may find a figure 8 movement gives you better results when lapping. It helps prevent rounding which can occur when doing circles
Thanks for the advice!
Ive had a similar problem with an ill-fitting kf flange centering ring groove. Another way to solve the problem is to sand off the centering lip on one side of the centering ring. It makes clamping a little more fiddly, but it still works fine.
Awesome!
But would the potassium-atoms not just bounce around the tiny steel pipes and then scatter after exiting? If you can keep the tubes cool you may be able to let the atoms resublimate on their surface. Thus catching the rouge atoms and making the beam more beamy.
Hallo! Schön, dass es stetig vorangeht. Drücke die Daumen... Ich würde nur nicht 90 Euro für einen simplen Spektroskopie-Spalt ausgeben. Für all meine Spektroskope habe ich mir den Spalt aus zwei Rasierklingen selbst gebastelt. Funktioniert ohne Probleme, auch bis zum Beispiel 50 µm runter 😉
Danke! Ja es geht langsam voran aber dafür stetig.
Darüber habe ich auch schon nachgedacht aber war mir unsicher wie ich sie Vakuumtauglich fixieren soll. Eventuell mit JB-Weld. Das soll recht wenig im Vakuum ausgasen. Wie stellst du den Abstand sicher? Mit einer Fühllehre?
@@AdvancedTinkering Hallo! Den Abstand stelle ich ohne jegliches Hilfsmittel rein manuell ein. Überprüfen kann man dann den Abstand ja mittels Laser und dem Beugungsmuster am Spalt. Da kannst du dann auch gleich die Spaltbreite berechnen. Ich fixiere meine beiden rasierklingen immer mit Schrauben auf einer Trägerplatte. Gutes gelingen weiterhin, bin sehr gespannt welche Hürden du noch meistern wirst müssen 😉
As long as you control (or at least measure) the temperature of the dissimilar metal junction you can solder or use any other connector for thermocouples. Although not all thermocouple wires are solderable with ordinary fluxes. You can't get very highest accuracy that way but more than good enough for most purposes if you've got a good setup and check that it works like you think it does. I needed a few dozen thermocouples, some of them in vacuum requiring feedthroughs for my first big project and I absolutely did not shell out for the "correct" way to do it.
Very cool channel and projects! Subscribed! what happened to your Gerlach experiment ? how did you plan on detecting potassium ions ? Thanks!
Thank you! I appreciate hearing that!
I have to admit that I've somewhat neglected the Stern Gerlach project. The issue is that I need a picoammeter for the detector, which I don't have. For the detection of potassium atoms, I wanted to use a Langmuir-Taylor detector.
@@AdvancedTinkering picometers are rare and expensive your right.. how about a Faraday cup and an electrometer for nano volts range? Or a simple photomuliplier tube and chain resistance? Since you already operate at low pressure, the PMT could be cut open ? What accelerating voltage are you going to use? If any?
@@AdvancedTinkering The picoammeter is probably the cheapest, easiest part of the project, so you shouldn't let that stop you! You don't have the benefit of an electron multiplier, unfortunately, as found in actual cesium beam tubes. But you should still be able to detect a signal, given some additional integration time. Do a search for 'picoammeter transimpedance amplifier' for some ideas.
The solid state relay wont work when you supply it with DC. It uses a triac switch that can only open in the zero crossing of a AC supply.
Yes, I realized that it's an AC relay a few minutes later and replaced it with one suitable for DC.
10:03 - Thats a clever idea... hope it works... I think this could be machined.
If you need to know potassium flux, you might want a less lossy oven design. I'm not sure, I haven't thought it through. Possibly you could get a short length of bellows with kf flanges and solder one flange to your thing, so you have a better heat break from rest of system which must be cool and consequently the possibility of more uniform temperature and make it easier to not cook o-rings.
No Problemo!
Instead of replacing sandpaper after sandpaper, buy a high quality diamond sanding plate is much better solution. BTW, after sanding, using electro polishing is much better solution to get the job done flawlessly.
Does your beam need to be both horizontally and vertically collimated? You might get better flux out of your oven if you used a stack of parallel plates instead of the tube bundle design you are currently using. You could build one fairly easily out of a stack of thin sheets of steel/aluminum and spacers. You could adjust how fine of collimation you get using different thickness of spacers between the plates. Also, pinhole VCR gaskets might be a cheaper option compared to an optical slit if you don't need a line shaped beam profile.
Some of those turbos have a oil wick at the bottom bearing and also some draws oil up through the shaft rotation to lube the top bearing.
It was probably just dry and got a bit lubed. It might pay to open it and check the oil.
Isn't this supposed to be pt.3? And if you want to monitor your SSRelay, add an external resistor+LED in parallel with its output, and mount the LED on the front of the case; if it shorts to closed, the LED remains on.
You are absolutely right, thanks! I just changed the title.
Using a LED to monitor the SSR is a great idea, thanks!
@@AdvancedTinkering Many PID controllers have an output that can be triggered for some sort of alarm state (setpoint high). If you setup a high temperature alarm, you can use the output to drive a relay to cut power to the SSR, which would protect your heaters from burning out if the SSR fails closed.
You don't need very rapid response, so let me offer this, which may be overthinking it compared to whatever cheap 3d printers use. For some of my temperature control I've used cheap no-name DC-DC converters with variable steady output set over serial or other communication to just dial a steady power level manually. You could use that, possibly including some slow automation loop (microcontroller, computer, etc). If the problem is well in hand just ignore me.
90 bucks is a good chunk towards a cheap hobby mill. Can get more precision than you need for most things.
14:00 how would a slit in the thread vent out an air i don't understand, shouldn't it be a through hole in the screw instead?
Both is possible. You just need a path for the air molecules to escape.
Is silicone not okay for your vacuum? The temperature range is a lot better for silicone o-rings.
Silicone will out gas and contaminate the vacuum. Viton is really the only option outside of copper seals.
Will that atomic source produce macroscopic amounts of potassium? If so, the hypodermic needles or your optical slit might close up from deposition over time.
That's also one of my concerns. To be honest: I don't know and I will have to try. I think as long as the temperature is not high enough to "boil" the potassium it should work for some time.
@@AdvancedTinkering you might also want to test how hot the needles will get in vacuum. They appear to be thermally connected to the oven. If they are too hot, they will likely not work properly as collimators.
Another thing to think about: beam alignment. If the needles do a good job at collimating, they need to be aligned quite well with the slit. Putting a light source in the oven can help with that for checking, but optical alignment with reflective surfaces don't necessarily show true alignment :/
You can control the vapor pressure based on the temperature of the furnace. Since you are running the vacuum chamber at ~1e-6 torr, you just need to operate your furnace at the temperature corresponding to a potassium vapor pressure of about 1e-6 (maybe a bit higher to get better flux). NIST has tabulated Antoine equation parameters for most substances, but you may need to look around for a parameter set valid at low (I.E. high vacuum) pressures.
@@AdvancedTinkering Have you considered using two slits instead of a slit + collimator? With such a large mean free path, I don't see any reason to use long tubes, especially since the metal will condense on them when it impacts it. Also, how are you preparing the potassium? The coating of oil and/or potassium oxide may be an issue.
Could you use a knife edge metal seal instead of viton?
Yes. In the paper I referenced they used a CF flange. But since my whole construction uses KF Flanges, I wanted to use those for the oven too.
@@AdvancedTinkering I'm sure I've seen people use metal seals on KF pretty regularly, I think it needs different clampy clamps is all... I'll see if I can find a part number
I believe metal seals are one use only and if so, he would have to buy a new seal every time he needs to restock the chamber with potassium which probably wouldn't be very cheap in the long run
@@matiastripaldi406 yep makes sense, unless it could be loaded in a different location
Pass mit den SSRs auf. Die lassen immer etwas Spannung durch, kannst dir mieß eine Fangen. Also bitte das ganze Kunstruckt erden
Das SSR schaltet ja nur 24V. Da habe ich keine Sorge. Aber der komplette Aufbau ist sowieso geerdet.
@@AdvancedTinkering Du solltest aber auch dein - vom 24V NT erden und daraus nen PELV machen. Billigere SMPS haben da oft nen kleines Problem, nicht unbedingt am Anfang aber das kommt dann.
@@AdvancedTinkering zudem Bau doch bitte nen B10 oder B16 Automaten auf die 24V Seite :)
If you are from Berlin and you're looking for lab technician Job, let me know :)
Haha thanks for the offer! But I am currently very busy with my studies and making my videos :)
SSR können teilweise kein DC
Ja, das war bei dem ersten Relais das Problem. Habe dann eines gekauft, das für DC geeignet ist.
Fuck no, don't put a dremel to a nicely machined part, find someone with a lathe!!!
It's okay, I mean technically you don't even need centering ring or clamps for kf flanges as the vacuum will hold oring in place on it's own or the surrounding air pressure
Still I think he would benefit from a mini lathe or a cnc mill so long as its rigid enough for making stainless steel parts
What are you studying?
Very impressive for a student.