The potential of photon activation and neutron activation techniques for fast soil characterization

Adrien Sari (1) , Sara Garti (1) , Frédéric Lainé (1) , Frédérick Carrel (1) , Jonathan Nicolas Dumazert (1) , Hamid Makil (1) , Nicolas Dufour (1) , Caroline Mougel (2) , Adeline Masset (2) , Lucile Mondon (3) , Laurent Boutillon (3) , Jean-Pierre Lejeune (3)

1 LCAE (CEA, LIST) - Laboratoire Capteurs et Architectures Electroniques (CEA, LIST)
2 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)
3 Vinci Construction France

In the frame of a partnership between CEA and VINCI, various measurement techniques are applied to soil analysis and tested in different laboratories located at CEA Saclay (France). This paper deals with two nuclear measurement techniques assessed in this project. More specifically, this paper presents the feasibility study carried out for two non-destructive active methods: photon activation and neutron activation. First, some atomic nuclides are activated either by photons or neutrons. Secondly, gamma-rays of specific energies are emitted by activated nuclides and gamma-ray spectrometry enables to identify these activated nuclides. Calibration of the full measurement system with reference samples would enable to quantify the mass of activated nuclides. Irradiations performed for photon activation measurements were conducted using a linear electron accelerator (linac) as the latter enables to generate high-energy photons by Bremsstrahlung thanks to its conversion target. Furthermore, irradiations performed for neutron activation measurements were also conducted with a linac. Indeed, photons may be converted to neutrons by photonuclear reactions using a secondary target. In the frame of this project, experiments were carried out at the SAPHIR platform (CEA Saclay) with a Linatron-M9 VARIAN linac. The electron energy was either 6 or 9 MeV. For neutron activation measurements, a secondary target made of heavy water has been used as neutron source and a polyethylene cell enabled to thermalize neutrons and increase the number of reactions of interest. In this paper, we present the different experimental setups and the measurement protocols established for this feasibility study. We show experimental results obtained with raw material samples coming from three construction sites.

Mots clés: instrumentation; nuclear instrumentation; nuclear measurement; feasibility study; non-destructive testing; photon activation; photons; neutron activation; neutrons; radioactivity; ionizing radiation; gamma-rays; gamma spectrometry; spectrometry; Calibration; Irradiation; linear electron accelerator; linac; Bremsstrahlung; photonuclear reactions; SAPHIR; neutron source; thermal neutrons; prompt gamma-rays; delayed gamma-rays; soil characterization

Domaines: Instrumentations et Détecteurs [physics.ins-det]; Physique Nucléaire Expérimentale [nucl-ex]

Adrien Sari, Sara Garti, Frédéric Lainé, Frédérick Carrel, Jonathan Nicolas Dumazert, et al.. The potential of photon activation and neutron activation techniques for fast soil characterization. 6th International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications (ANIMMA 2019), Jun 2019, Portoroz, Slovenia. 09001 (6 p.), ⟨10.1051/epjconf/202022509001⟩. ⟨cea-04560080⟩