The detection coil and preamplifier are cooled to very low temperatures to minimize thermal noise, allowing for much more sensitive measurements than standard room temperature probes. They also feature automatic tuning and matching, making performing numerous continuous measurements easy.
JOEL provides three cryogenic probe types for solution NMR:
- SCC: SuperCOOL MARVEL Closed type
- SCO: SuperCOOL MARVEL Open type
- UC: UltraCOOL probe
All probes can regulate the temperature of the sample over a very large range, from -40 °C to +150 °C. To make probe exchange easier, the Probe Arm and Probe Lifter are available as optional add-ons.
Features
Source: JEOL USA, Inc.
| |
Type |
Cooling
by |
Sample Coil
Temperature |
Features |
| UltraCOOL |
UC |
He gas |
≒20 K |
Ultra-high sensitivity due to cryogenic capability |
SuperCOOL
MARVEL |
SCC |
He gas |
≒50 K |
About 1/4 of the running cost of UltraCOOL probe No need to fill the cooling system with liquid nitrogen
Higher sensitivity than the open type |
| SCO |
Liquid nitrogen |
≒77 K |
Reasonable installation and running costs Uses liquid nitrogen as coolant
Liquid nitrogen can be refilled during NMR measurement |
UltraCOOL probe
Image Credit: JEOL USA, Inc.
The UltraCOOL probe can perform stable high-temperature measurements required to analyze polymers and other materials and ultra-sensitive measurements characteristic of cryogenic probes. It also supports the novel high-speed automatic matching and tuning.
SuperCOOL MARVEL probe
SuperCOOL MARVEL Open. Image Credit: JEOL USA, Inc.
SuperCOOL MARVEL Closed. Image Credit: JEOL USA, Inc.
There are two cooling options for the SuperCOOL MARVEL probe: circulating type, which uses an air-cooled refrigerator, and open type, which uses a liquid nitrogen tank. The open type is better regarding operating costs because it does not require a refrigerator. In addition to having a higher continuous operating capacity, the circulating type does not require refrigerant replenishment and has a higher cooling capacity and better sensitivity.
29Si Background-Free
The 29Si background signal from the probe components is significantly reduced by JEOL cryogenic probes. Glass materials can be calculated utilizing background-free measurement. The background signal was significantly lower without the sample tube, as seen in the spectra below, indicating that the sample tube was the source of most background signals.
Image Credit: JEOL USA, Inc.
29Si NMR spectrum of 10w t% water glass/D2O. Image Credit: JEOL USA, Inc.
29Si NMR spectra were obtained using a 5 mm PTFE sample tube and the SuperCOOL MARVEL probe. The high magnetic field side signals are confirmed, as no background signal appears at -100 ppm.
Probe Arm and Probe Lifter
Cryogenic probes cannot be safely moved by hand when cold and may need to be warmed to room temperature before handling.
Replace the UltraCOOL or SuperCOOL MARVEL probes while they’re still cold using the Probe Arm or Probe Lifter.
Although these probes are heavier than room temperature ones due to their design, they can still be easily swapped out with the Probe Arm or Probe Lifter.
Probe Arm. Image Credit: JEOL USA, Inc.
Probe Lifter. Image Credit: JEOL USA, Inc.
Image Credit: JEOL USA, Inc.
Image Credit: JEOL USA, Inc.