Centre members visit LNGS, Italy
Centre members William Melbourne, Zuzana Slavkovska and Ferdos Dastgiri travelled to the INFN node at LNGS (Laboratori Nazionali del Gran Sasso) to collaborate with the Dark Matter Centre’s partners, Ambra Mariani, Chiara Vignoli and Giuseppe DiCarlo between April 19 and May 5.
The aim of this research trip was to conduct characterisation measurements for the first SABRE South NaI(Tl) test crystal. This is important as some of the main background components cannot be measured as the concentrations are too small. Therefore, to measure the background, the crystals are put underground in a shielded location so that these problematic backgrounds can be measured. In this case, the priority was measuring the lead 210 activity as well as the Uranium and Thorium decay chains.
William describes his experience of the trip, the research the Centre members carried out and why it was so important to collaborate with the Centre’s international partners in person:
“The NaI(Tl) crystal was shipped to LNGS, and we met it there. Before the measurements, we set up a version of the data acquisition system for SABRE South and tested the photomultiplier tubes that would be used for the measurement. We then coupled the crystal and the photomultipliers together and sealed it all in a copper and lead castle to conduct the measurements which will take several months. We are now starting to analyse the data collected to make the final measurements.
“Aside from the main measurements (which are still in progress but looking promising), we learnt about the best ways to conduct ultra-low background characterisation measurements underground. We also had an important test of the data acquisition and processing systems for SABRE South on real data collected by low background NaI(Tl) detectors located underground. Essentially, it was a great exchange of experience with our colleagues at SABRE North, as we showed them some of the software we are developing for the final experiment, and we got some of their experience from previous crystal measurements and the proof of principle operation.
“It was a great experience. Being able to visit and work with our colleagues at SABRE North was a wonderful thing after two years of border closures. It was really great to see them in person again.
“The Gran Sasso region is a beautiful part of the world, and it is a very different experience working in an office with an uninterrupted view of snow-capped mountains, with also plenty of good food and wine when we were not working. In terms of the work, it was great to finally start working with a SABRE South crystal, after working on them for several years to finally have one of our own was very exciting. The results so far seem very promising, and we gained a great deal of experience on the best ways to work with these detectors underground.”