How to Turn $10000 into Gas

drd1135

Zen Snapshooter
Jul 13, 2011
124
Lexington, Virginia
Steve
This is what $10000 worth of liquid Helium looks like.
helium.jpg
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We will waste most of it cooling the superconducting magnet of our new NMR to 4 Kelvin (-452 F). The magnet is the thermos on legs in the middle. The tank in the front right is a Dewar of liquid nitrogen that we are using to get the damned thing down to 90 K before we add the liquid helium. All told, we will boil off about $20K worth of cryogenic liquids to get this thing started. The fun part is that once it's at 4 K, we will feed current into the coils and that current will run in a circle for the life of the magnet without any further current source.. About two weeks ago, we drained the current out of the old magnet after 23 years of stalwart service. Take that, NASCAR.

NMR.jpg
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BrianS

Super Moderator
Apr 3, 2013
124
23 years- too funny. I bought my Pentium Pro Tower in '96. It still works perfectly, I still use it in the Lab. I used to control EDFA's with it, software feed-back loop. Running DOS means nobody gets between my code and the hardware. One of the command responses read out "SETTING LASER TO MAXIMUM" on an LCD panel, could not resist.

That's a lot of COLD in those containers!
 

drd1135

Zen Snapshooter
Jul 13, 2011
124
Lexington, Virginia
Steve
🤓 The nuclei of all atoms act as little magnets of different strengths which are specific to the element. We put a sample of a particular compound in the middle of this big (superconducting) magnet. The big magnet causes all these little magnets in the atoms that make up the molecules in the sample to line up with its magnetic field. If you give the little magnets the right energy, they will flip over to oppose the field of the big magnet. The energy needed to flip the little magnets depends on their magnetic strength, which is unique to each nucleus. Further, the little magnets also feel a magnetic field from all the little magnets around them. This means that field each feels depends on what is around them, i.e., how the atoms are connected together. We then hit the sample with a radio frequency (RF) field that provides the energy to flip the little magnets. We slowly scan the frequency of the RF field and as we hit the right frequency to flip a certain kind of little manget, we note a drop in the energy of the RF field and record the frequency. We know what kind of RF frequency is associated with each atom in each kind of molecular situation so we can easily work out the structure of the molecules. It's a very powerful method of analysis and is a sine qua non piece of equipment for any chemistry department. Modern NMRs can actually be used to work out the structures of proteins, which contain tens of thousands of atoms. They also cost about $350 K for a basic model, which we have. We bought our old one with a government grant, but you can only get one that way. This one came out of our pocket.🤑
 
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drd1135

Zen Snapshooter
Jul 13, 2011
124
Lexington, Virginia
Steve
23 years- too funny. I bought my Pentium Pro Tower in '96. It still works perfectly, I still use it in the Lab. I used to control EDFA's with it, software feed-back loop. Running DOS means nobody gets between my code and the hardware. One of the command responses read out "SETTING LASER TO MAXIMUM" on an LCD panel, could not resist.

That's a lot of COLD in those containers!
We ultimately had to replace the old NMR because the electronics was increasingly incompatible with newer operating systems and the company was phasing out support. 23 years is a very long lifetime for a scientific instrument so we bought the new one from the same company, JEOL.
 

tonyturley

Hall of Famer
Nov 24, 2014
124
Scott Depot, WV, USA
Tony
I'm not going to sleep tonight now; your above posts brought back long buried memories of sitting in ancient lecture halls with inadequate HVAC, trying to decipher what the prof was saying: "Covalent? Molarity? I thought a mole was those furry pests that dig up the lawn. What do you mean we have to memorize the Periodic Table! Aaaaaack!!"
 

agentlossing

Veteran
Mar 23, 2015
104
Andrew Lossing
Just to note, that used A7 with the Samyang 35 2.8 is now an office camera. It produces pretty good raw files that clean up nicely, as seen in the first post.
That is a cheap(ish) combo that I've thought about getting multiple times.
 

drd1135

Zen Snapshooter
Jul 13, 2011
124
Lexington, Virginia
Steve
It's a surprisingly small combination. It is oddly similar to the new Canon RF, their low end FF body, except the sensor is better at high iso and the AF is quicker. The shutter is loud however. I want to laugh every time I use it.
 

Derek

New Member
Jul 11, 2010
4
Minneapolis
Well, you've certainly got some fun toys at work! The best thing I've got in my current cube is a Godzilla. :laugh:

I'm just curious though, what kind of experiments are done with a supercooled magnet?
The most common use of a superconducting magnet that people would recognize is as an MRI (magnetic resonance imaging) machine. MRI is based on the same thing that Steve (@drd1135) explained, which is nuclear magnetic resonance (hence, NMR). Just like with cameras, the full-frame models used in medical centers are more expensive than the crop-sensor models referenced by Steve, generally having a cost of entry of about $1M US. And, just like with the original A7, the AF is kinda poky.... To add another longevity tale, the research machine I worked on in grad school was fired up in 1989, and was still running up until the research building was torn down in 2007; it was working just fine and probably would have kept on trucking if it weren't for the lack of, well, a building. It turns out superconductors work pretty well.

By the way, hi, everyone. I've actually been around since Amin started the Serious Compacts site (the original one, lost to the depths of internet time), but this is my first post here. I've contributed a bit over at mu-43, but generally just lurk. I have to say, though, that I've always really liked the small community feel of this place. We'll see if I can get myself to post some pics here some time....
 

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