We wish to pool our expertise to reinforce relations between theory and experiment, to develop new synergies and collaborations between research teams. The GDR DUPhy missions will be to facilitate the development and access of new players to European underground platforms (e.g. LSM, LNGS, LSC and BUL), to provide visibility for the French underground physics community, to favour the emergence of common projects, to promote the young generation of researchers working in the field, and to reflect on the needs of future experiments in this area.

Five topics in relation to Low Radioactivity Techniques have been identified which will be discussed in the form of round tables. Each round table will be dealt with over several sessions. Each session will last a maximum of 2 hours. The time between 2 sessions of the same topic will be at least 1 month but may go beyond. Several subjects can be carried out in parallel. The objective is to have 1 session every 4 to 6 weeks.

We will start with the NAA round table by the end of september 2021. The exact date will be sent by e-mail to the duphy-wp2 mailing list. If you want to attend these round tables and are not yet on the list send an email to gdr-duphy-wp2 at ip2i.in2p3.fr .

Any other topic that you would like to be treated in the scope of these round tables is welcome.

This technique necessitates a strong neutron source (e.g. a nuclear reactor) and a gamma spectrometer. According to the decay time of the studied isotope, the gamma spectrometry can be done in a laboratory distant from the neutron source. These different points will be discussed during the dedicated round tables.

• Monica Sisti Neutron Activation Analysis for low background experiments

In this section we will make an inventory of available facilities and techniques for α, β and γ spectrometry 

• Alpha and beta facilities (underground or/and shallow sites)
• Detection techniques for alpha and beta 
• …

• Pia Loaiza Screening activities with HPGe detectors 
• Hector Gomez-Maluenda BiPo: a dedicated radiopurity detector for planar samples

In this round table, we will make an inventory of the facilities and techniques available for ICP-MS, GD-MS,…  measurements of trace amounts of, for example, U and Th with very small samples in a short time.

• Frederic Perrot LA-ICPMS

In this section we will discuss the main problems related to the presence of radon in the experiments (emanation and transport) as well as the purification and trapping techniques.We will consider the facilities available for the measurement of emanation and diffusion, as well as existing or necessary developments for future experiments.

• Radon emanation : facilities, emanation studies 
• Radon transport : diffusion facilities, general studies
• Radon capture : anti-radon facilities, new adsorbents
• Surface contamination

• José Busto Radon 

In this section, we will discuss different underground facilities, from very deep, used for the study of very rare physical processes, to small laboratories of a few m.w.e. suitable for low-level radioactivity measurements.

• Silvia Scorza  Material@SNOLAB

• Cleaning techniques
• Cosmogenic activation