Cryocoolers¶

The cryocooler is manufactured by CYRO Industries of America, Inc..

Close-circle cryostats are installed in <QM>² allowing samples to be comprehensively studied in a wide range of temperatures from 12K to 500K. The cryocooler can operate both helium (12K to 300K) and nitrogen gas (300K to 500K ) using a single stream flow. In-house nitrogen and helium gas are used for cryocoolers. Just by switching the knob outside of the hutch, the gas supply can be altered.

The external tip-heater prevents frost and maintains a dry tip that helps to create an ice-free sample environment at low temperatures. A platinum temperature sensor is installed to control the low alarm setting temperature that triggers back the temperature controller to energize and maintain the ice-free environment.

The main component of the cryostat can be divided into five different components:

• (i) source : the refrigerator or the cryostat act as a source to cool a reliable cryogenic temperature for a long continuous periods
  

• (ii) compressor
  

• (iii) PID temperature controller : Cryogenic temperature controlled Model 336 manufactured by Lake Shore is used. The controller’s zone tuning feature allows you to measure and control temperatures seamlessly from 300 mK to over 1,500 K by automatically switching temperature sensor inputs [1].
  

• (iv) Power supply : 30 V digital and 24V DC are used
  

• (v) Gas flow controller : The digital flow automatically control and displays the flow rate

Gas flow parameters
Helium gas: Normal flow rate is between 8 – 12 liters/min, typically 11 l/min Nitrogen gas : Normal flow rate is between 8 – 12 liters/min, typically 9 l/min.

Safety

• Do not touch the cold helium and nitrogen gas stream. Exposure to the skin of the cold gas could result in severe injuries.
• The dewar system has pressure relief protection installed. Do not remove pressure reliefs or check valves.

Motors

To open the lakeshore¶

• Open terminal

• css

• The Lakeshore controller will open
• Output (1(input A): stage 1 heater, 2(input C): Sample temperature, 3 (input B): Stage 2 heater ), you can control.
• Change the Range : Rang3/High

Temperature change guideline