This is a closed-cycle refrigerator with a Joule-Thomson stage, it can reach a base temperature of 1.8 K. The cryostat's heating is controlled by a lakeshore 340 unit, and the temperature can be changed remotely via the spec window.

Single crystal samples are mounted on a cylindrical copper rod, 3 or 5 mm in diameter and 15 mm in length. Other sample mounts for powder/polycrystalline samples are available from the beamline. (See figure 2 for examples of sample mounts).

The cryostat is complex to operate and takes at least 3.5 hours to reach the base temperature.

It is therefore recommend to use the ST-15 whenever possible.

 

JT_1.jpg JT_2.jpg
Figure 1: Image of the J-T displex without Kapton or Be shields. Also included are some examples of sample mounts and a 10 cent coin and a 2 euro coin for scale. Figure 2: close up of the sample mounts shown in figure 1.

Temperature range:        1.8 K to 295 K

Cooling time to 1.8 K: > 3.5 hours

Samples: Solid, single crystal and powder.

Sample mount: 3mm or 5mm wide copper rods, length must be between 12 and 20 mm. (Sample mounts are available from the beamline).

Working orientation:      Reflection and transmission.

Entrance windows:        Up to three Be domes or 25 Mum kapton foils

Temperature control via beamline computer: Yes