Assembly of XENONnT Cleanroom at LNGS. Foto: Roberto Corrieri/XENON
The upcoming XENONnT detector, the next phase in our dark matter program, will have a dark matter target about three times larger than that of XENON1T. This means that all dimensions of the instruments are about 50% larger and thus require more space for the cleaning of the detector components and for detector assembly. For this reason, the class ISO-5/6 XENON cleanroom is currently being moved to a new above-ground space at LNGS, where it is re-built with a 50% increased footprint and a partially increased height.
The last action seen by the “old” cleanroom before its decommissioning were very successful tests of the TPC electrodes for XENONnT.
XENON1T results from a 1 ton-year dark matter exposure.
Our latest dark matter results from XENON1T, the most sensitive search for WIMPs with an unprecedented liquid xenon exposure of 1 ton-years and a world-record low background level is featured in the July/August 2018 edition of the CERN Courier, the International Journal of High-Energy Physics. Read the full article here.
In order to keep the liquid xenon inside XENON1T at a temperature of almost -100°C, the TPC is installed inside a double-wall cryostat. In fact, this cryostat consists of two independent shells (the “inner” and the “outer” cryostat), and the space in between is evacuated to block convective heat transfer between them. Both shells are made from stainless steel, carefully selected for its low intrinsic radioactive contaminations. The inner cryostat was already closed in Fall 2014, and is kept closed since then in order to keep its inner surface, and the cables and pipes which are already installed inside as clean as possible. It has now been wrapped in superinsulation (the shiny foil on the picture) which is used to block radiative heat transfer. Now, on February 24, 2015, the outer cryostat has been closed for the first time and the insulation vacuum in between is being pumped since then. This is the next step towards filling the first liquid xenon into the XENON1T cryostat.
Putting the gasket in the outer cryostat flange before closing it for evacuation. The inner cryostat can be seen wrapped in superinsulating foil.
The latest result from XENON100 on spin-independent WIMP-nucleon interactions, derived from 225 live days of data taking, is among the 20 most-cited particle physics papers of the year 2013. According to the new summary of INSPIRE, the high energy physics information system, our result from 2012, published in Physical Review Letters, is the only dark matter-related paper in the top 40, and is surrounded by high-impact results from ATLAS, CMS, Planck, WMAP, Daya Bay, etc.