主题：【求助】“低温射频探头能提高信噪比”是怎么一回事儿？

FT 又不是把样品放在20K  是线圈吧

Please read:

CryoProbe Mechanics
CryoProbe technology takes advantage of the fact that the radio frequency electronics will generate a higher signal and less noise at lower temperatures. By reducing the temperature of the NMR coil and preamplifier signal to noise ratio, enhancements of a factor of four or more can be achieved. This can easily translate into an order of magnitude higher throughput. The coil assembly and preamplifier are cooled using cold helium gas in a closed-loop cooling system. The closed-loop cooling system, in which helium gas is compressed in one chamber and then allowed to expand in a second chamber, produces the cold helium gas. Vacuum-insulated parts in the cooling system allow the coil assembly to reach very low temperatures. Thermal isolation in the probe is critical to allow samples to be measured at room temperature only a few millimeters from the cold coil assembly.

---------------------From Bruker's website-----------------------

谢谢释疑！！