Joris van Heijningen

Research scientist


Centre for Cosmology, Particle Physics and Phenomenology - CP3
Université catholique de Louvain
2, Chemin du Cyclotron - Box L7.01.05
B-1348 Louvain-la-Neuve

+32 10 473215


UCL member card
People responsibilities
PhD students
Ricardo Cabrita (IISN - virgo) (member since June 2021)
I am working in Gravitational Wave Interferometer instrumentation. Working in the optics lab to test the use of Phase Cameras (PC) for mode matching mitigation in optical cavities and also collaborating with the Phase Camera group at Virgo, contributing with optical simulations and trying to understand the PC generated amplitude and phase maps.
Morgane Zeoli (PDR) (member since August 2022)
My work is orientated toward gravitational wave (GW) instrumentation. It focuses on passive and active seismic sensing parts and isolation strategies for two gravitational wave detector projects: E-TEST, an almost 1x1 scaled prototype of the future ET (Einstein Telescope) GW detectors which will be built in the Euregio Meuse-Rhine sector, and LGWA (Lunar Gravitational Wave Antenna), a lunar GW detector. I am working on mode damping of the E-TEST cryogenic mirrors crystal compressive suspension using optomechanical dampers and on the characterization of horizontal and vertical Cryogenic Superconducting Inertial Sensors (CSISs) which will be part of the aforementioned projects.

Former members
Research directions:
Cosmology and General Relativity
Data analysis in HEP, astroparticle and GW experiments
Research and development of new detectors

Experiments and collaborations:

Active projects
E-TEST - Cryogenic inertial sensor development
Giacomo Bruno, Joris van Heijningen, Morgane Zeoli

On Feb 1, 2020 the R&D EU Interreg project E-TEST officially started. It involves 11 institutes from Belgium, Germany and Netherlands and will carry on crucial detector developments for the Einstein Telescope (ET) - a 3rd generation antenna of gravitational waves, related mostly to cryogenic operations of large mass mirrors and their suspensions, ultra-precise metrology and sensing, as well as to advanced geological studies in the region (the ET is a deep-underground detector). The CP3 group is a partner in this project and is working on work package 1 : "Ultra-cold vibration control" and in particular on a cryogenic superconducting inertial sensor.

Gravitational wave signals below a frequency of about 10 Hz are obscured by thermal noise in current detectors. Because temperature is the vibration of atoms in some respect, making the distance measurement between the mirror surfaces more challenging, the mirrors of future detectors will need to be cooled down to temperatures around 10 K. We need to control the motion of some of the cold objects, for which we develop inertial sensors that can survive this harsh environment. The interferometric readout of the inertial sensor also serves as to monitor a ringdown or the E-TEST mirror. After it is excited by a tiny hammer strike, the interferometer follows the ringdown and can determine the quality factor. Additionally, we are investigating an alternative suspension technique, where instead of long fibres under tension, we use short flexures under compression in combination with long, fat rods so we obtain good thermal conductivity and low stiffness suspension.

CP3 members collaborate mostly with KU Leuven (we are collaborating to develop cryogenic readout electronics for the sensor) and ULiège (we align our sensor efforts), RWTH Aachen (they are preparing a cryostat where we will test the inertial sensor).

External collaborators: C. Collette (Liege), S. Hild (Maastricht), A. Bertolini (Nikhef), A. Gatto (KULeuven) and E-TEST collaboration.
ETpathfinder - Bench top suspension design and fabrication
Giacomo Bruno, Nicolas Szilasi, Joris van Heijningen

The ETpathfinder is an R&D infrastructure for testing and prototyping innovative concepts and enabling technologies for the Einstein Telescope, the European concept for a new class of future gravitational wave observatories. ETpathfinder is funded by the interreg program of the EU. The ETpathfinder project broadly consists of six vacuum towers. Four towers are cryogenic and hold suspensions for the mirrors (or test masses) of the experiment. Two towers are operated at room temperature. They hold suspensions for optical tables which hold smaller optics that prepare the beams to be shot into both arms (mode cleaning, frequency stabilisation etc.) and hold the beamsplitters and detection optics.

Many of these optics are suspended individually with small bench top suspensions so they can be steered and additionally seismically isolated. This project concerns the design, prototyping and partial fabrication of >10 suspensions of order 75cm high.

External collaborators: S. Hild (Maastricht), A. Bertolini (Nikhef), Conor Mow-Lowry (Nikhef), Ken Strain (and other LIGO HRTS designers) and ETpathfinder collaboration.
Virgo - instrumentation - mode matching with phase cameras
Ricardo Cabrita, Joris van Heijningen

A gravitational wave detector consists of many coupled optical cavities, the shortest being centimeter scale with sub-millimeter beams and the longest being several kilometers long with several centimeter size beams. When an input beam’s shape is not matched to the cavity eigenmode (the preferred beam shape of the cavity), we speak of mode mismatch (MM). MM is a source of optical loss from the fundamental mode, shown in the top figure, into cylindrical higher order modes (HOMs) of which an example is shown in the bottom figure. Minimising optical losses in a gravitational wave detector is important if techniques such as squeezed light injection are to be more fruitful. At the moment, no gravitational wave detector has an automated way to control MM. We investigate error signal generation by detection of the cylindrical HOMs. These signals then serve as input for control of MM a coupled cavity set-up.

External collaborators: Nikhef.

Non-active projects
Publications in IRMP
All my publications on Inspire

Number of publications as IRMP member: 19
Last 5 publications


CP3-21-37: Constraints on cosmic strings using data from the third Advanced LIGO-Virgo observing run
Abbott, R. and others

[Abstract] [PDF] [Journal] [Dial]
Refereed paper. June 18.
CP3-21-36: Upper Limits on the Isotropic Gravitational-Wave Background from Advanced LIGO's and Advanced Virgo's Third Observing Run
Abbott, R. and others

[Abstract] [PDF] [Journal] [Dial]
Refereed paper. June 18.
CP3-21-35: Diving below the spin-down limit: Constraints on gravitational waves from the energetic young pulsar PSR J0537-6910
Abbott, R. and others

[Abstract] [PDF] [Journal] [Dial]
Refereed paper. June 18.
CP3-21-34: All-sky search in early O3 LIGO data for continuous gravitational-wave signals from unknown neutron stars in binary systems
Abbott, R. and others

[Abstract] [PDF] [Journal] [Dial]
Refereed paper. June 18.
CP3-21-33: GWTC-2: Compact Binary Coalescences Observed by LIGO and Virgo During the First Half of the Third Observing Run
Abbott, R. and others

[Abstract] [PDF] [Journal] [Dial]
Refereed paper. June 18.

More publications