These days, I am working again at the Neutrino Platform at the Prevessin Site. I am preparing a PIN diode box with LED illumination for a cold test which was shipped from my colleagues at Hawai’i.
I am attending my first in-person conference since 2019. Today I will present my work on the Xenon W-value during the fundamental measurements session in beautiful Coimbra! The slides can be found here.
This is the camera assembly that I quickly designed for the cryo-test. The off-the-shelf webcam is mounted inside an acrylic dome which is kept warm by a constant supply of warm GAr. A rotary feedthrough allows to look around during operation. It provides us with a view of the inside of the cryostat which is important to benchmark the evaporation performance of the heat exchanger assembly.
Yesterday, I successfully defended my thesis The Low-Energy and Large-Scale Frontier of Dual-Phase Xenon Time Projection Chambers for Dark Matter Search. The talk and the exam went really great and my committee recommended my work for distinction. I thank my supervisor Laura Baudis for the unique opportunity to work with her, for teaching and pushing me and giving me the freedom to develop. Thanks to her and the other committee members for the great guidance. Afterwards, we had a great party with my old group and my family. I will miss you folks! (The PhD hat in the picture is the result of the great and dedicated machining work of my friend Frédéric Girard.)
After many online safety training courses at CERN, I finally had a classroom course on safety with handling cryogenic liquids today. Although this was not my first one of this type and I have worked a lot with LN2 and LXe during my PhD, it was a really well presented course and a good recap for me. The picture shows a setup to demonstrate the condensation of oxygen from the air on surfaces at LN2 temperature.
These days I have some cable installation work at ProtoDUNE-SP on the agenda. The picture was taken inside the cryostat. This is a very impressive facility!
We are preparing the next benchmarking test of the DS-20k cryogenic setup. This includes the modification of a valve on the nitrogen vent that controls the cooling power based on the cryostat pressure – a fully mechanical and failsafe emergency cooling loop. The opening pressure can now be set by adjusting the counteracting spring force.
I was invited to give the Science Club Seminar of the XENON/DARWIN collaborations on our publication A measurement of the mean electronic excitation energy of liquid xenon, Eur. Phys. J. C 81, 1060 (2021). This is the second invitation after my online INPA seminar at LBNL Berkeley on this topic.
Although my contract with the University of Hawai’i started on New Year, my start as a User on-site CERN was a bit delayed due to the pandemic. I had an exciting first day, meeting my colleagues around Hanguo Wang and seeing the UAr Cryo-Setup of DS-20k for the first time.
The news page of my former group can be found here.