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Cryo-Pulse 5 Plus Electrically Refrigerated Cryostat


The Cryo-Pulse® 5 is an electrically powered cryostat for use with HPGe radiation detectors. It utilizes a pulse tube cooler, a highly reliable technology originally used in military and space applications and which has proven its value for germanium detectors in the original Cryo-Pulse 5.

Like its predecessor, the Cryo-Pulse 5 Plus still consists of a cold head assembly, to which the detector is attached, and an external power controller. The basic external design and interface of the coldhead have been preserved to maximize interchangeability between the previous and the new version. However the coldhead internals and the controller have been completely redesigned and new features have been added to further improve the performance and reliability and to answer our customers’ requirements even better.

The cooler is integrated in a compact coldhead-assembly which is directly attached to the detector housing. The unit can operate in all orientations. The coldhead-assembly is connected to a bench-top power controller that produces the necessary output voltage to drive the compressor. The controller contains an auto ranging power supply at 100-240 V and 50 or 60 Hz. In addition to the relay output, the new controller is also equipped with a RS-232 serial interface to connect to a PC. A dedicated GUI allows remote control and status monitoring. Two BNC-connectors are located on the rear panel to combine the inhibit signal of the preamplifier and the controller for enhanced detector protection. The Cryo-Pulse 5 Plus controllers are backwards compatible with the previous Cryo-Pulse 5 model coldheads.

A pulse tube cooler operates with a pressure wave instead of a piston, virtually eliminating wear and vibrations. This means pulse tube coolers are extremely reliable (MTTF of about 3,000,000 hours) and have a demonstrated life time of over 100 000 hours or 11 years of operation. This life time estimation is documented in a paper that can be found under ‘Detectors’ in the Technical Literature section of the CANBERRA web site.

Although the compressor already produces very low vibration levels, all efforts are done to reduce these even more. Apart from shock mounts to isolate the compressor from the rest of the cooler and the detector housing, the Cryo-Pulse 5 Plus is equipped with an active vibration reduction system. An accelerometer inside the coldhead measures the vibrations generated by the compressor and feeds this signal back to the controller. The controller then adjusts the drive signal to the cooler so that vibrations are minimized. The system is even self-tuning such that it adapts to possible changes of the system’s vibration characteristics over time. It is currently the best available technology in the field and allows CANBERRA to offer the broadest range of detector models available with electric cooling and continue to provide high-quality detector solutions with no compromise on performance.

Our confidence in the Cryo-Pulse 5 Plus is demonstrated by the two year full warranty on the complete system (detector included) and additional pro-rated warranty on the coldhead. If the coldhead fails after the second year, it will be repaired or replaced at 40, 60 or 80% of the list price in year three to five respectively.

Cryo-Cycle II

Key Improvements

Active and passive vibration reduction:

  • Expanded range of HPGe detector models now available with electric cooling
  • Reduced audible noise
  • Improved heat sinking, allowing operation up to 40 ºC ambient temperature (up to +50 °C with water cooled heat sinks)
  • Graphical User Interface for remote control and status monitoring
  • Integrated HV-inhibit circuit

A pulse-tube cooler contains CFC free, non-flammable gas and is hermetically sealed, so no gas-refill is required. The compressor contains no oil or lubricant, so no contamination of the refrigerant occurs and no periodic filter exchange is required. This makes the Cryo-Pulse 5 Plus completely maintenance free.


  • Completely LN2 free
  • Non-CFC/non-flammable refrigerant
  • MTTF > 3,000,000 hours
  • No maintenance required
  • Low power demand
  • Low vibration/low noise
  • Compact and lightweight
  • No compromise on detector specifications
  • Remote read-out
  • Pulse-tube technology
  • 2-year full warranty + pro-rated warranty on the coldhead
  • Optional water-cooling for use up to +50 °C


  • Safety
  • Low operating cost
  • High availability
  • Expanded field of applications
  • Quiet: < 55 dB(A) at 1 m