Refrigerator/Cold heads of the COOLPOWERe series are gas cooling machines which operate on the basis of a thermodynamic cycle to produce cryogenic temperatures. The COOLPOWER e cold heads are the basic units for cryo pumps of the COOLVAC e series.

A refrigerator is a cooling machine which operates on the basis of a thermodynamic cycle (Carnot) to produce cryogenic temperatures (T ≤ 120 K).

Refrigerators operating according to the Gifford/McMahon principle have succeeded over other methods of cooling cryo pumps and cryogenic applications. Such coolers are produced and used by Leybold.

The cold heads consist essentially of three modules. A drive module, a displacement unit and the cold head stage(s).

The first stage of the cold head cools down to ~ 45 K to 80 K depending on the operating conditions and model, operating temperatures of down to 4 K are reached at the second stage. Both stages are made of copper with high thermal conductivity in order to optimally utilize the available refrigerating capacity.

For pneumatically driven cold heads the pneumatic drive system for the displacer consists of only two mechanically moving components: the rotating control valve and the stepper motor driving the control valve.

With mechanically driven cold heads, movement of the displacer unit is automatically controlled via a crank drive, which leads to low vibration levels.

The standard range of the single and double-stage COOLPOWER e cold heads matches a wide range of applications. Leybold is offering refrigerators with usable refrigerating powers from 20 W to 250 W at 80 K (single-stage). In two-stage systems, the refrigeration capacities of the second stage range in between 5 W and 20 W at 20 K. Helium compressors from the COOLPAK e range are used to drive the cold heads from the COOLPOWER e series with variable motor speed and thus increased cooling performance. In addition to the standard products, we also offer these cold heads, in custom designs in accordance with customer requirements.