4 ms·
I used to do a lot of cryogenics work during my PhD. The statistic one of the professors often quoted was that "LN2 is cheaper than milk". Although LN2 is che
by jeffwass 10y ago
I used to do a lot of cryogenics work during my PhD.
The statistic one of the professors often quoted was that "LN2 is cheaper than milk".
Although LN2 is cheaper and more abundant, it's also 20 times warmer than LHe. That matters a lot for applications.
To get an idea of ability to restrict thermal excitations, LN2 at 77K is only 4x 'colder' than room temperature. But LHe (4.2K) is 18x 'colder' than LN2, or 72x 'colder' than room temperature!
- bryondowd 10y agoThe 4x 'colder' here really threw me. Took me a minute to realize you meant 1/4 the temperature. Strikes me as an odd phrasing, like saying "airplanes fly 23x 'lower' than LEO".
- witty_username 10y agoIt's odd but correct because temperature has a minimum. We're just used to Celsius/Fahrenheit temperatures where you can't say that.