Single stage coldheads

Compact, variable-speed GM coolers

The Coolstar single stage coldheads comprise the 0/12 and 0/40 models, respectively delivery cooling powers of 12 and 40 W at 77 K. These are some of the smallest GM coldheads available, and can be installed in systems where space is at a premium. Coolstar is the only commercially available range of Gifford-McMahon Cryocoolers offering complete control of the Coldhead speed; by using a variable speed stepper motor and proprietary control software, every cooler in the range can be operated at speeds of 40-90 rpm. 

The Coolstar range of coldheads may be used wherever a compact and variable speed head is desirable, in applications from laboratory cryostats to radio astronomy.

  • Prolonged service intervals: Decreased Coldhead speed during low demand periods reduces wear on Coldhead seals.
  • Cooling power control: Varying the cycle rate second-by-second offers complete control for integration into OEM systems.
  • Fast cooldown time: Increased Coldhead speed makes it possible to reach 77 K in as little as 11 minutes.


Technical specifications

Coolstar 0/12:

  • Nominal Cooling Power at 77 K : 12W @ 72 rpm, 17 W @ 90 rpm
  • Base temperature (unloaded): 30 K
  • Cooldown time of bare coldhead to 77 K: < 11 minutes

Coolstar 0/40:

  • Nominal Cooling Power at 77 K : 42W @ 72 rpm, 57 W @ 90 rpm
  • Base temperature (unloaded): 30 K
  • Cooldown time of bare coldhead to 77 K: < 11 minutes

The variable speed stepper motor found in a Coolstar coldhead is controlled through the Cryocontroller in the K450 compressor. There are three control modes – Auto Mode, Serial Mode and PCSP Mode – and these may be changed by the user at any time.

  • Auto Mode is commonly used with Cryopumps and is the simplest of the three modes; the K450 will start automatically when turned on and will command the coldhead stepper motor to run at a high speed for a set amount of time, then a lower speed indefinitely. The default is to run at 90 rpm for 60 minutes, then 60 rpm indefinitely.
  • Serial Mode is designed for control of the K450 through CryoConnector software. In Serial Mode, the K450 will not start until ordered to; the Power LED on the front of the K450 will flash if it is awaiting a command to start. Using Cryoconnector software via a PC connected via a serial line to the K450, allows the user to continuously change the coldhead speed in real time. OEM integration is easily achieved by using Cryoconnector software in Server mode.
  • PCSP (Parallel Command and Status Port) Mode is a specialised mode in which coldhead speeds are controlled using the 15-pin controller connection on the front of the K450. PCSP mode is included to allow backwards compatibility with older devices.

Coolstar 0/12: 185 x 123 x 150 mm, 2.4 kg

Coolstar 0/40: 219 x 155 x 207 mm, 5.6 kg

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We understand that when it comes to cooling systems, one size does not fit all. So contact us for a sensible discussion about your needs, without any pressure or commitment.

CryoConnector and Oxford Connect

Our free software and web portal for remote control, monitoring and logging of your Oxford Cryosystems device.