The commissioning of the CUORE experiment: the mini-tower run

CUORE is a ton-scale experiment approaching the data taking phase in Gran Sasso National Laboratory. Its primary goal is to search for the neutrinoless double-beta decay in 130Te using 988 crystals of tellurim dioxide. The crystals are operated as bolometers at about 10 mK taking advantage of one of the largest dilution cryostat ever built. Concluded in March 2016, the cryostat commissioning consisted in a sequence of cool down runs each one integrating new parts of the apparatus. The last run was performed with the fully configured cryostat and the thermal load at 4 K reached the impressive mass of about 14 tons. During that run the base temperature of 6.3 mK was reached and maintained for more than 70 days. An array of 8 crystals, called mini-tower, was used to check bolometers operation, readout electronics and DAQ. Results will be presented in terms of cooling power, electronic noise, energy resolution and preliminary background measurements

Precise lead isotope ratios measurements on Ebusus coins and on some Campanian imitations

Coin finds in Pompeii are characterised by a large amount of specimens from Ebusus e Massalia and by Campanian coins that imitate the types of those foreign productions.  Using mass spectrometry it was possible to get information useful to understand in a better way the differences between original issue and imitations; furthermore this study highlighted socio-economic reasons: on one hand, the arrival of a great deal of Ebusitan and Massalian coins in the ancient city, on the other, the need to mint imitation coins in ager vesuvianus. Data about the supply of different metals used to obtain alloys were identified and -also thanks to historical reflection- it can be considered important to discover connections between Ebusitan coinage and the people that introduced those foreign specimens and the Campanian imitations

Ultra-low radioactivity flexible printed cables

Abstract Flexible printed cables and circuitry based on copper-polyimide materials are widely used in experiments looking for rare events due to their unique electrical and mechanical characteristics. However, past studies have found copper-polyimide flexible cables to contain 400-4700 pg 238U/g, 16-3700 pg 232Th/g, and 170-2100 ng natK/g, which can be a significant source of radioactive background for many current and next-generation ultralow background detectors. This study presents a comprehensive investigation into the fabrication process of copper-polyimide flexible cables and the development of custom low radioactivity cables for use in rare-event physics applications. A methodical step-by-step approach was developed and informed by ultrasensitive assay to determine the radiopurity in the starting materials and identify the contaminating production steps in the cable fabrication process. Radiopure material alternatives were identified, and cleaner production processes and treatments were developed to significantly reduce the imparted contamination. Through the newly developed radiopure fabrication process, fully-functioning cables were produced with radiocontaminant concentrations of 20-31 pg 238U/g, 12-13 pg 232Th/g, and 40-550 ng natK/g, which is significantly cleaner than cables from previous work and sufficiently radiopure for current and next-generation detectors. This approach, employing witness samples to investigate each step of the fabrication process, can hopefully serve as a template for investigating radiocontaminants in other material production processes

Development of a multi-analytical approach for the characterization of ancient Roman lead ingots

In the present work the characterization of six ingots of ancient Roman Lead, found on the seabed near Mal Di Ventre Isle (Sardinia-Italy), is presented. The ingots come from three different foundries, defined by following codes found on the particular ingots selves: SOCPONTILIENORUMMF, QAPPCF and MCPONTILIENORUMMF. The foundries were active about 2000 years ago in Sierra de Cartagena (Spain) where some of the most important lead mines of the Roman Empire were located. In order to identify the provenance of the ingots and to shed some lights on their manufacturing we applied a multi-analytical method, based on instrumental neutron activation analysis and thermal ionization mass spectrometry. Coupling the two techniques it was possible to obtain an accurate multi-elemental and isotopical fingerprint of the different ingots, giving some important results in the field of archeo-metallurgy. The possibility to perform such measurements with a non-destructive approach satisfies a very important request of the cultural heritage authorities involved in the protection and conservation of similar goods

Lingots de plomb antique trouvés dans les eaux de Corse du Sud

International audienc