We (a small group of scientists from various LAr experiments) have measured the longterm stability of a Poly(ethylene 2,6-naphthalate)-based wavelength-shifting reflector as a potential candidate to substitute TPB in large LAr detectors in a 2 tonne-cryostat at CERN. The preprint is on the arXiv today: arXiv:2411.17934 and will be published as proceedings of the LIDINE 2024 conference.
Our paper Benchmarking the design of the cryogenics system for the underground argon in DarkSide-20k is on the arXiv today: http://arxiv.org/abs/2408.14071. The paper discusses the current design status of the system in view of the DarkSide-20k requirements, shows the benchmarking and testing efforts of its integral system components in a dedicated testing platform at CERN and LNGS, outlines implications of the results for the final system design and provides an outlook to ongoing activities. I am very proud that I was part of the team who pushed this project through, leading the benchmarking at LNGS and the paper writing. Congratulations to the entire team involved and thanks to those colleagues who spent their time reviewing the manuscript internally or who were involved in the editorial process.
This week I am participating in the 15th International Workshop on the Identification of Dark Matter at L’Aquila! I am thrilled to present the Underground Argon Cryogenics System of DarkSide-20k at this important conference. My poster contains the main results of a paper on that topic which is currently under Collaboration-internal review. Looking forward to this exciting event!
The Summer collaboration meeting took place at LNGS from 10–14 June. I presented two topics: Simulations on the distribution of internal calibration sources in the active volume and the results from the mockup cryogenics test at LNGS.
This week DarkSide had a meeting with the INFN Review Committee with fruitful discussions and good feedback. I presented the results of the first run of the UAr testbed for the DS-20k detector Mock-up in the UAr Cryogenics breakout session. We used our spare time to open the cryostat and to install the new heat exchanger geometry. After performing a couple of other upgrades and maintenance on the setup, we are on track to restart operations beginning of February!
Liquid argon is running through the veins of our UAr cryogenics test stand! The cryostat is fully filled and we commence the testing of the cooling control system and the system efficiency.
For the DS-20k Mockup TPC I am responsible for the design of the capacitive short level meters, the liquid level control and a cryogenic camera. The first parts are already finished. Thanks to the team of the Mechanical Workshop of the Physics Department of the University of Zurich for the incredible machining job! In the pictures we see the bubbler/boiler unit and parts of the level meters for the liquid level control.
This week we had a Collaboration Meeting at GSSI in L’Aquila, Italy. I presented the progress on the cryogenics test within the Mockup programme and gave an update on the UAr Working Group activities.
The run has started today and we are currently acquiring valuable data with gas argon at room temperature to characterise the compressor performance and the flow resistance of the recirculation circuit. Thanks to everybody involved – the reassembly of the system at LNGS after the transport from CERN was a huge amount of work and the start of the run is an important landmark.
This week we have installed the nitrogen phase separator on the cryogenics system test bed in Hall C at LNGS. This is the last major piece of the setup. The run can start soon!
