Improved reliability and flexibility of Thales RM2 rotary cooler

Trends at detector and system levels are mainly linked to reduced SWaP (Size, Weight and Power), higher availability and higher flexibility of integration. As a first example, originally, the detectors used to be cooled around 77K. More recently, depending on the detector technology, the required bandwidth, and the performance, detectors operating temperature may vary in a broader range between 60K to 170K. In order to avoid having to develop a cooler for each specific detector, it is therefore necessary to have coolers that are capable to operate on a wide range of conditions. This flexibility shall also improve the SWaP at system level by reducing the electronic driver size and by making easier the cooler integration in the system. Moreover, the cooler reliability is a major performance requested by customers, especially for 24h/7 applications, which are a growing market. Indeed, most of the time, coolers are one of the components dimensioning the lifetime of the system. Several improvements were made on rotary coolers in order to fill the reliability gap between linear and rotary coolers. It is important to continuously improve this key parameter. All of these trends were taken into account in Thales rotary coolers' road map in order to propose on the market coolers able to answer to these new users needs. The paper will focus on the last works made at Thales on rotary coolers in the frame of that target and more particularly on the RM2 cooler. Firstly, we will illustrate the latest reliability improvements made on this cooler with lifetime tests results. Then, we will describe a new option for this cooler allowing us to have better SWaP and flexibility.