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Reinier Janssen

Photo of Reinier Janssen


4800 Oak Grove Drive

Pasadena, CA 91109

Curriculum Vitae:

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Member of:

Interstellar and Heliospheric Physics


Reinier Janssen combines the study of active galactic nuclei (AGN) and their effect on galaxy evolution with the development of novel instrumentation based on superconducting detectors.

Reinier obtained his PhD at Delft, University of Technology, where he developed Kinetic Inductance Detectors made from NbTiN and Al and was the first to show photon noise limited performance at astronomically relevant loading. In addition, he identified an unusual population of radio-loud optically-quiet AGN in actively star forming galaxies. After his PhD, Reinier did a 2-year post-doc at the Institut d’Astrophysique Spatiale in Paris where he led an observational campaign using optical and mm-wave observations to study this population in detail. In parallel, he developed a system to test the effect of high-energy particles on new cryogenic detector technologies.

Since January 2019 Reinier has been at the Jet Propulsion Laboratory, first as a NASA Postdoctoral Program Fellow and now as a Scientist. He is leading the development of the focal plane arrays for the Terahertz Intensity Mapper balloon mission and contributing to the development of the focal planes for the PRIMA Probe-class mission concept.


  • BSc Applied Physics (Delft, University of Technology, 2007)
  • MSc Applied Physics (Delft, University of Technology, 2011)
  • MSc Astronomy (Leiden University, 2011)
  • PhD Applied Physics (Delft, University of Technology, 2017)

Professional Experience

  • Jan 2023 - now: Scientist (Jet Propulsion Laboratory)
  • Jan 2019 - now: Visiting Research Scholar (California Institute of Technology)
  • Jan 2019 - Jan 2023: NASA Postdoctoral Program Fellow (Jet Propulsion Laboratory)
  • Feb 2017 - Dec 2018: Postdoctoral researcher (Institut d'Astrophysique Spatiale, Université Paris-Sud XI)

Research Interests

  • Superconducting detectors for astronomical applications, in particular development of Kinetic Inductance Detectors instrumentation based on them.
  • Properties of actively accreting super massive black holes and their host galaxies
  • Active galactic nuclei feedback and their influence on galaxy evolution.

Selected Awards

JPL Postdoc Research Day – Best Poster Award (2021)

NASA Postdoctoral Program Fellowship (2018)

Selected Publications

  1. RMJ Janssen, et al., Single pixel performance of the kinetic inductance detectors for the Terahertz Intensity Mapper, Journal of Low Temperature Physics (2022)
  2. L-J Liu, RMJ Janssen, et al., Design of the kinetic inductance detector based focal plane assembly for the Terahertz Intensity Mapper, Journal of Low Temperature Physics, 209, 953 (2022)
  3. R Nie, RMJ Janssen, et al., Absorber design and optimization of Kinetic Inductance Detectors for the Terahertz Intensity Mapper, Journal of Low Temperature Physics, 209, 525 (2022)
  4. NPH Nesvadba, et al., Jet-driven AGN feedback on molecular gas and low star-formation efficiency in a massive local spiral galaxy with bright X-ray halo, Astronomy & Astrophysics 654, A8 (2021)
  5. JJA Baselmans, et al., A kilo-pixel imaging system for future space based far-infrared observatories, Astronomy & Astrophysics 601, A89 (2017)
  6. RMJ Janssen, et al., Equivalence of Optical and Electrical Noise Equivalent Power of Hybrid NbTiN-Al Microwave Kinetic Inductance Detectors, Applied Physics Letters 105, 193504 (2014)
  7. RMJ Janssen, et al., High optical efficiency and photon noise limited sensitivity of microwave kinetic inductance detectors using phase readout, Applied Physics Letters 103, 203503 (2013)
  8. RMJ Janssen, et al., The triggering probability of radio-loud AGN: A comparison of high and low excitation radio galaxies in hosts of different colors, Astronomy & Astrophysics 541, A62 (2012)