Nikhef physicist Paul Kuijer passed away

29 January 2025

To our great sorrow, we received the sad news of the passing of Paul Kuijer.

Although Paul had been retired for a number of months, he was undiminishedly active for Nikhef. For most of his career Paul was associated with the ALICE experiment at CERN; in recent years he dedicated himself to the ETpathfinder project in Maastricht.

But above all, we will greatly miss his friendly and warm personality. Paul leaves a great void in our community.

Our thoughts are with Paul’s family and friends, and with the immediate colleagues who are left behind in grief.

On behalf of Paul’s colleagues,

Jorgen D’Hondt
Director Nikhef

 

In memoriam, by Raimond Snellings and Frank Linde

Paul was a senior experimental physicist at Nikhef who had an important role in the ALICE experiment at CERN. During the last years of his career he played a significant role in the development of the ETpathfinder within the Gravitational Waves group.

Paul did his PhD work at the University of Amsterdam with the MARK-J experiment at the PETRA accelerator (DESY, Hamburg) where he performed a search for the top-quark and did a measurement of the strong coupling constant with electron-positron collisions. In 1987 he joined Utrecht University as an assistant professor and worked on the various experiments in the institute for nuclear physics. In 1994 he became a member of the ALICE experiment at CERN and worked on the proposal and technical design report of the Silicon Strip Detectors (SSD), a joint project realized with laboratories in Finland, France, Italy, The Netherlands, Russia and Ukraine. In 2008 he became the first ALICE run-coordinator and in 2009 he was selected as deputy spokesperson of the ALICE collaboration, which at that time consisted of about 1000 scientists worldwide.

After his role as deputy spokesperson, he again started working on silicon detectors at Nikhef, oversaw maintaining the SSD, and was until 2019 the project leader of the upgrade of the new ALICE Inner Tracking System.

In addition to working on hardware, Paul also had a strong passion for physics and during his whole career he supervised many PhD students. Everybody who has worked with Paul remembers him fondly and with respect. He was an excellent scientist and a gentle and reliable person who always would make time to discuss physics and help with all the practical problems a technician, PhD student or staff member would encounter during their daily work.

– Raimond Snellings

 

From 2019, Paul made a switch to gravitational wave research. The beginning of a very pleasant collaboration. Paul dove into the ETpathfinder R&D project with great enthusiasm. The ETpathfinder cleanroom tender was fantastically handled by Paul: on budget and on time. Paul also took on the monitoring of the cleanroom. Paul was incredibly skilled in software and computers. Paul also did all the calculations on whether or not our cleanroom would survive a major vacuum leak, and arranged for according adjustments to be installed in the cleanroom. Safety was in good hands with Paul. Paul always worked in a good mood, installing countless flanges, valves, pumps and not to forget: cable-trays. Up and down stairs/ramps countless times every day and without exaggeration, he fixed more than 1000 bolts/nuts. All this work was completed by the end of 2024 and from this year the  installation of the vibration dampers, optics, etc. will begin. Paul would have liked tremendously to have witnessed that. Unfortunately, it was not to be.

In addition to ETpathfinder, Paul has spent the past year, together with Matteo Tacca, working on a high-tech project: the phase camera. There again, he completely surprised me by delving into both the details of the software and the optical fine-tuning of the set-up itself.

Outside of Nikhef work, I remember a very nice trip to the ‘Marker Wadden’ on the occasion of Paul’s official retirement (Paul never really retired: he visited Nikhef weekly and also worked on Nikhef matters at home). Paul was a passionate bird photographer. I cherish his photos of Bearded Warblers on the ‘Marker Wadden’.

– Frank Linde