Micro 2.5 Probe

The Micro 2.5 probe has been developed for micro-imaging of small objects (max. diam. 30 mm) in wide bore magnets (89 mm ID). The probe is assembled without tools from its separate modular components: gradient system, probe body (with variable temperature fittings), and exchangeable rf-inserts.
 

The Micro 2.5 probe body contains the rf-cabling and mechanical tuning/matching controls for two channels as well as the standard fittings for variable temperature operation (heater dewar, gas inlet, thermocouple). When necessary, these fittings can be easily removed from the probe body to obtain a free-access bore of 22 mm dia. from the bottom to the top of the probe and into the rf-resonator.
 

Micro 2.5 gradient system, probe body and exchangeable resonator.
Micro 2.5 gradient system (top), probe body (bottom) and exchangeable resonator (middle).

Gradient System

The actively shielded Streamline design is the same as that used for the Micro 5 gradient system, however, the larger inner diameter of 40 mm means that the maximum gradient strength reaches 150 G/cm (@ 60 A).
 

RF Section

A variety of exchangeable rf-inserts are available for the Micro 2.5, including solenoid coils with inner diameters down to 1 mm and birdcage resonators with diameters up to 30 mm. Resonators can be provided for single- or double-frequency applications, and each insert is optimally tuned and matched with its own internal rf-tuning elements, which are manipulated via the mechanical control elements provided in the probe body. All rf-inserts are completely open on both ends, allowing for the insertion of long samples.
 

Applications

With a maximum sample diameter of 30 mm, the Micro 2.5 probe can accommodate a wider variety of samples than are possible with the Micro 5. In addition, flow experiments can be conveniently performed since the required tubing can pass through the probe body.

The Micro 2.5 with a 25 mm rf-resonator can be connected to an accessory for rheological nmr studies (Rheo NMR).
 

Micro 2.5 Probe and Gradient Specifications

Rf Coil Types (exchangeable):

solenoid, saddle, birdcage

Rf Coil Diameters:

1 - 30 mm

Nucleus:

1H and/or X

Gradients:

xyz

Gradient Strength:

2.5 G/cm/A

Linearity:

+/- 1.8% peak-peak
+/- 2.2% peak-peak
+/- 3.0% peak-peak

 

36 mm sphere
38 mm sphere
40 mm sphere

Inductance:

<= 100 µH

Resistance:

<= 400 mΩ

Rise Time, 0-40A, 120V:

< 110 µs

Cooling:

water

Maximum Current Tested:

60 A