Optical specifications

 

Window thickness

 

0.5 mm

1.5 mm

Clear access diameter

10 mm

25 mm

Sample holder to window top surface

4.5 mm

5.5 mm

Angle of admittance (to surface of sample holder at centre)

102°

144°

Max sample thickness

5 mm

5 mm

Max sample diameter

20 mm

20 mm

 All dimensions are approximate and relate to the top window with plain sample holder in central position

 Product specifications

 

Description

Cooling medium

Liquid helium (can be used with liquid nitrogen)

Operating temperature range

2.2 K to 500 K (with EPS40 pump)

 

3.2 K to 500 K (with GF4 pump)

Temperature stability

± 0.1 K

Helium consumption

< 0.45 lhr-1 (at 4.2 K)

Cool down time

< 10 minutes from ambient to 4.2 K with transfer tube cold

Sample holder drift at constant temperature

±1 µm (typical – see note 1)*

Sample holder vibration

0.1 µm (typical – see note 2)*

Sample window material

Spectrosil B fused quartz

Other materials available on request

 

Standard temperature sensor

3-point calibrated rhodium iron (see note 3)

Sample change time

30 min (approx)

Weight

1.8 kg

* Approximate measurement. The stability is neither measured nor guaranteed and will be dependent upon the system’s final configuration and the environment that the equipment is used in.

1. Thermal drift of the sample position was measured after the cryostat temperature had stabilised for half an hour at base temperature. At temperatures above 4.2 K the time to reach thermal equilibrium is considerably longer. Typical values for the drift have been measured tube 1 µm in 5 minutes below 100 K and 1 µm in 1 minute above 100 K.

2. Vibration levels were measured with the cryostat, LLT600/13 transfer tube and a diaphragm pump. Room temperature measurements showed that in all directions the displacement due to mechanical vibration for frequencies greater than 500 Hz is negligible. For frequencies below 500 Hz vibration levels are less than 0.1 µm.

3. The cryostat is supplied with a temperature sensor mounted in the heat exchanger. The sample holder is in thermal contact with the heat exchanger. The temperature difference between the sample position and the heat exchanger has been measured to approximately 0.4 K.