• Optical combi cryostat (bath + continuous flow)

Sample in helium or nitrogen gas flow

The optCRYO105 is universal helium/nitrogen cryostat for the temperature region 1.8 – 273 K. The optCRYO105 is a combi cryostat based on the advantages of bath and continuous flow cryostats. Cooling agent is placed in a reservoir inside of the cryostat body and is flowing into the sample room through the capillary to cool the sample. The sample is placed in a helium gas flow, the temperature is stabilized by variations of the flow rate or resistive heater power. The low consumption of cryogenic liquids (< 0.1 l/h) enables long operation time typically more than 24 hours. The optCRYO105 can be used as a nitrogen cryostat on filling of liquid nitrogen in helium reservoir (modification optCRYO105N2).

All cryostats of the optCRYO105 family use tSTAT310x temperature controller and Manostat.

Operation

Inside the cryostat body are located the liquid nitrogen and helium reservoirs. The nitrogen bath cools the radiation screen. Liquid cooling agent flows through the capillary at the bottom of the sample room and evaporates on the heat exchanger. The temperature at the sample room is controlled by the gas flow rate and resistive heater power at the heat exchanger. The samples are placed in cryogen gas flow directed upwards. The gas flow rate is regulated by differential pressure regulator and electrical needle valve controlled by electronic unit outside of the cryostat. The simultaneous gas flow and heat exchanger temperature regulation results in high temperature stability and low consumption of the liquid He (N2). The temperatures below 4.2 to 1.8 K can be reached by helium vapor pumping. In this temperature region the samples are immersed in liquid helium. Samples are top loading by the use of sample holders.

Basic parameters and modifications of optCRYO105 cryostats

* – Temperature regulation system tSTAT310x is strongly recommended.

Scheme of the optical cryostat

Scheme of the optical cryostat with rectangular tail

Complete system

1. optCRYO105 cryostat.

2. Temperature controller tSTAT310x with Manostat.

3. Vacuum isolated transfer line.

4. Sample holder.

Optionally

1. Special windows configuration for spectroscopy.

2. Maximal number of windows in horizontal plane – 5.

3. Windows material

• Sapphire.

• A2B6 (ZnSe, ZnS, CdTe) and other materials on request.

4. Maximal aperture of an optic windows – 45° (4 windows).

5. Windows depolarization ratio less than 1%.

6. Additional window at the bottom of the cryostat.

7. Minimal distance outer window – sample 25 mm.

8. Asymmetric sample position in the sample holder. Maximal aperture of a window in the case of asymmetric sample position – 90°.

9. Angle between window axes is 45°, 90°, 180°.

10. Distance from windows to the cryostat bottom up to 400 mm.

11. Rectangular cryostat tail for experiments in magnetic field. Minimal distance between magnet poles is 40 mm.

12. Calibrated coal temperature sensors.

Additional equipment

1. Sample holder

• Sample rotation by 360° around the windows axis.

• X and XY shift of the sample.

• Asymmetric sample position.

• Up to 200 kg mechanical stress applied at helium temperatures.

2. He-transfer vacuum isolated line

• Hard connection.

• Flexible connection.

3. Sample rod with a universal flange.

4. Measuring heads, cassette heads.

5. Multipin electric connections on the top of the sample holder.

6. Helium or nitrogen storage dewar.

7. Dewar transport platform.

Key benefits

• Low cooling agent consumption.

• He and N2 operation modes of the system.

• Flexibility of the system.