Integrated CO2 cooling system

The Integrated 2-Phase Accumulator Controlled Loop (2PACL) is a modification of the existing 2PACL system developed for the AMS-Tracker and LHCb-VELO CO2 cooling systems. The integrated 2PACL method is a different way of operating and control the original 2PACL concept. The modification makes the system simpler, more reliable, better to control and cheaper.

Figure 1 shows the integrated 2PACL principle. Here the accumulator cooling is integrated with the internal heat exchanger. The only remaining control of the system is a simple heater control in the accumulator. This makes the new principle easier to use and control. It will also be much cheaper to build.

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Advantages & Applications


Accurate thermal control of distant set-ups with small additional cooling hardware is a common goal in many hi-tech equipment. The easiness of using the Integrated 2PACL makes it ideal for experimental set-ups as its connection is as easy as the use of a normal thermostatic bath, which is often used now.


  • Clean and green technology
  • Small cooling tubes
  • Accurate (isothermal) and direct temperature control on distant experiments
  • CO2 is an inexpensive fluid
Patent application filed.
Patent application filed.