Proposals

The constant presence of background radiation as an abiotic component of the Earth’s surface may have resulted in biophysical and biochemical effects derived from it being incorporated into fundamental cellular processes during the evolution of organisms living in near-surface environments. Reducing these radiation levels in underground laboratories has been shown to cause altered growth kinetics, differing between unicellular and multicellular organisms. This difference suggests that the state of cellular organisation may influence a different response to low background radiation.
The aim of this proposal is to study the contribution of cellular organisation in the response to low background radiation, investigating this response in unicellular near Metazoa models, which form multicellular structures during their life cycle or in response to environmental stimuli.

Radiation can cause severe DNA damage. However, some micro-organisms have developed resistance mechanisms to survive under extreme levels of radiation. Some of these micro-organisms have been extensively studied for the key to their radioresistance, which could have many applications in genetic engineering and space exploration. In addition, the absence of radiation has been shown to have a negative impact on certain micro-organisms, leading to the hypothesis that this absence may lead to inefficient DNA repair systems.
This proposal proposes to study the molecular basis of the effect of environmental radiation on the genomic integrity of model organisms (prokaryotes and eukaryotes), and in turn, the development of improved microorganisms for survival in extreme environments, using conditions similar to those of Mars or the International Space Station, to study their possible implications in the development of environments conducive to life.

Several studies have shown that experiments in underground laboratories with a low environmental radiation background consistently generate stressful conditions for all organisms tested so far (bacteria, fruit flies and human cells). This abiotic stress results in a change in the susceptibility of hosts to pathogen infection and a reduction of innate and adaptive immune responses, which drives the evolution of pathogens towards reduced virulence.
The aim of this experiment is to assess the effect of stress induced by low environmental radiation on the interaction between the model organism Caenorhabditis elengans and its natural pathogen, the nodavirus Orsay.

A world-wide consensus exists that deep geological disposal is the best option for the safe confinement of spent nuclear fuel and long-lived radioactive waste. This proposal is based on wireless transmission of geotechnical data through clay rocks. Through its works, it aims to achieve a wireless monitoring system capable of operating with the measurement instrumentation commonly used for monitoring the main geotechnical parameters that are relevant for the operation of the future nuclear waste repository.

The Canfranc Axion Detection Experiment (CADEx) collaboration is building a new experiment to detect axion particles in the mass range 330-460 μeV. CADEx is an ambitious and innovative project employing new technology to measure axion signatures with a frequency of 90 GHz. For this purpose, the experiment will employ a microwave resonant cavity haloscope in a magnetic field inside a dilution refrigerator (at K or mK temperatures). More details can be found on the presentation at the 29th LSC Scientific Committee meeting (Dec 1, 2021). Download here.

Recent studies suggest that cosmic rays, and in particular muons, which constitute the dominant flux of particles reaching the Earth’s surface, may play a very important role in evolution. Also, neutrons, another type of particle, may be the main cause of deleterious mutations during evolution. However, experimental work to quantitatively test these hypotheses to discover the role of cosmic radiation in the genomic mutation rate and, consequently, its role in evolutionary terms, is still lacking nowadays.
This project proposes to investigate this problem by means of a new version of the classic Luria and Delbrück experiment (fluctuation test) under different levels of cosmic radiation to evaluate its possible role in the mutation rate of bacteria, and in the directedness (Lamarckism) vs. randomness (Darwinism) of mutations.

This experiment aims to evaluate the effect of reduced cosmic radiation (ɣ-rays, muons, neutrons) on the viability of bacterial communities recovered from high purity D2O in the absence of externally added nutrients. To this end, the proposed experiments will take advantage of the low levels of ambient radiation that can be achieved in underground facilities in order to analyse microbial growth, and simultaneously determine by ICP-MS the possible metabolites present in the system. These studies will make it possible to address the effect of such radiation on the bacterial life cycle.

The fourth phase of the NEXT program is called NEXT-HD, for which several possible technologies are being studied, and a baseline concept has been outlined. The design goal of NEXT-HD is not only to increase the isotopic mass of 136Xe very substantially beyond that of NEXT-100, but also to achieve “Higher Definition” of the tracking technology by reducing electron diffusion using gaseous additives, or improving the granularity of the tracking system, or both. Exploration of gas mixtures involving either molecular or noble additives, and tracking technologies involving either dense SiPM planes or high-speed cameras, are ongoing for NEXT-HD within the NEXT collaboration.

This proposal aims to build and commission an underground facility to grow ultra-high radiopurity NaI(Tl) scintillators. The facility after commissioning will be used to make detectors to search for dark matter in a model-independent approach. The synergy between SABRE, ANAIS, and LSC is a unique opportunity to face the DAMA/LIBRA finding with an ultra-low background detector. As a matter of fact, it is understood that a conclusive verification of DAMA/LIBRA has to go beyond the present NaI(Tl) experiments. The goal is to deliver a facility which can make NaI(Tl) detectors with a background of the order of 0.1 dru (cpd/kg/keV) in the ROI of [2,6] keV electron-recoil.
The strategy is based on the work done at Princeton by the group of F. Calaprice [Phys.Rev.Res. 2 (2020) 1, 013223], in the framework of the SABRE experiment, which has carried out recent measurements at the Gran Sasso Laboratory.

This proposal was made in the context of the proposal ARQ (Abatement of Radioactivity for Qubits) which has been submitted to the FET Open call 2020, led by Instituto Nazionale di Fisica Nucleare (INFN). Project ARQ aims at developing a new technology to mitigate the effects of radiation on qubits, and an important part of the work is developed in underground laboratories, such as LSC.

Dark Matter in CCDs (DAMIC) has pioneered the detection of nuclear and electronic recoils induced by Dark Matter (DM) particles in charge-coupled devices (CCDs). Scientific CCDs are commonly used in the focal plane of astronomical telescopes for the digital imaging of faint astrophysical objects. Our non-standard use of CCDs was demonstrated at SNOLAB (Sudbury, Canada) where a 40-g prototype detector is currently operating. DAMIC-M is a 1 Kg detector to be installed at Laboratoire Souterrain de Modane (LSM) in France which profits from this experience and, at the same time, will greatly improve in sensitivity by further innovating the detector technology. CCDs show unique properties: a) unprecedented charge resolution, b) low leakage current, c) spatial resolution and 3D reconstruction, d) background identification and rejection.

Low-level γ spectroscopy with High Purity Germanium (HPGe) detectors has become an essential tool for material screening in rare event physics experiments, which demand the lowest radioactivity levels. Typical examples are searches for solar neutrinos, neutrinoless double beta decay and dark matter. Compared to other methods, such as mass spectrometry or neutron activation, spectroscopy provides a comprehensive method in a non-destructive way without complex sample treatment. The primordial radioisotopes ²³²Th, ²³⁸U and ⁴⁰K represent the main sources of contamination in common materials. Concerning the two former isotopes, only HPGE spectroscopy can verify secular equilibrium as it is capable of measuring the concentration of their progenies near the end of their respective decay chains – in particular ²⁰⁸Tl and ²¹⁴Bi.

In 2009 an Expression of Interest entitled “A Nuclear Astrophysics facility for LSC: The sources of neutrons in the stars and other reactions of astrophysical interest” (CUNA) was submitted to the LSC by Spanish groups and international partners. It was followed by a Letter of Intent, which was submitted in 2012. The idea was to install a high-current multi-MV accelerator at the LSC to measure reactions of importance in nuclear astrophysics.