Development of ET technologies through two Interreg projects:

ETpathfinder & E-TEST

E-TEST & ETpathfinder – differences, synergies and complementarities

In the frame of the development of the full Einstein Telescope, E-TEST and ETpathfinder are two independent but very complementary building blocks. The focus of both projects is clearly different:

  • ETpathfinder (2019 – 2022): Construction of a long-term Infrastructure for testing future gravitational-wave detector technologies and concepts in a complete interferometer within an ET-like environment.
  • E-TEST (01.02.2020 – 31.07.2023): Development of technology for the Einstein Telescope in two separated domains:
    • 1- Geological exploration and analysis of EMR region and determining the optimal ET site.
    • 2- Development of advanced concepts for optics, cryogenics and seismic isolation.

Both initiatives can be seen as the development of expertise centers to make the links between gravitational-wave science, its technological aspects and the huge number of economical actors involved into such development, present in the EMR region.

The main difference between the two projects, apart from the geological part which is unique to E-TEST, is that ETpathfinder results in a full facility laser-interferometer that can be used by knowledge institutes and (SME) companies for developing and testing new technologies.  On the other side E-TEST will result in a prototype in a vacuum chamber and optical instruments working at 10 Kelvin (much colder than the 120 Kelvin foreseen for ETpathfinder in its initial phase). Knowledge institutes and companies can use E-TEST results to develop and test new products or gain new insights/knowledge.

Due to their complementarity, both projects will work in synergy. Moreover, at the end, the outputs of both will be merged and implemented into the ET. The region will gain a massive competitive edge in this field via E-TEST and ETpathfinder.

EMR based companies can use this advantage to create and deliver products and services to Einstein Telescope, even if Einstein Telescope could not be built in the Euregio Meuse-Rhine.


ET2SMEs, a new Interreg V-A project, aiming to maximise the economic and social impact of the implementation of the Einstein telescope in the Meuse-Rhine Euregio, is being submitted under Call 6 of the Interreg V-A EMR programme.

The final submission deadline is November 10 2020, with a possible start of the Project, if selected, on March 01 2021.