| Texto completo | |
| Autor(es): Mostrar menos - |
Neto, Pedro Bianchi
;
Soccol Junior, Renato
;
Blaszczyk, Flor de Maria
;
Koshelev, Sergey
;
Hahn, Alan
;
Correia, Daniel
;
Cardoso, Dilson
;
Doubnik, Roza
;
Adamowski, Mark
;
Montanari, David
;
Alegre, Thiago P. M.
;
Machado, Ana Amelia
;
Segreto, Ettore
;
Assaf, Jose Mansur
;
da Motta, Helio
;
Pagliuso, Pascoal G.
;
Noriler, Dirceu
Número total de Autores: 17
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Journal of Instrumentation; v. 20, n. 6, p. 8-pg., 2025-06-01. |
| Resumo | |
Liquefied ultrapure noble gases are typically the chosen target for neutrino and dark matter experiments. Commonly, the required grade of purity of such cryogenic liquids in terms of O-2 contamination is less than 100 ppt, which makes it necessary for the argon to circulate through adsorption columns filled, typically, with BASF Cu-0226S and Mol Sieve 4A for capturing O-2 and H2O. Another requirement that emerged during the design of LBNF-DUNE is the purity of the Liquid Argon (LAr) in terms of N-2 concentration, as it was observed that both N-2 and O-2 contaminations can cause the reduction of the LAr scintillation light emission. In particular, a decreasing behavior in the lifetime and the relative amplitude of the slow component is relevant from concentrations of 1 ppm of N-2 and 0.1 ppm of O-2. Recently, exploratory experiments performed in the Liquid Argon Purification Cryostat (PuLArC - similar to 90 L of LAr) had been successfully used to purify LAr from N-2 using an innovative solid adsorbent based on a Li-FAU Molecular Sieve. Here, we report experiments of N-2 capturing in LAr carried out at the ICEBERG Cryostat (similar to 3000 L of LAr) at Fermilab. For the experiments, several controlled injections of N-2 were made into the cryostat, and the impurity concentrations in the LAr (both for N-2 and O-2) were monitored using a calibrated gas analyzer during the purification process. The experimental data confirmed that the Li-FAU is capable of capturing the N-2 from the LAr. A numerical methodology based on the mass and energy balances of the system was applied to better understand the behavior of the adsorption process and to help with the scale-up of the process. A Pore Diffusion Model (PDM) coupled with parameter optimization was proposed to predict the N-2 concentration in the ICEBERG cryostat over time. The model parameters applied in this work were determined based on experimental data acquired in the PuLArC. The model was able to accurately reproduce the data from the ICEBERG, indicating that the mathematical model could be a valuable tool to design and operate the GAr/LAr system of LBNF-DUNE. It was possible to predict from simulations the necessary time to reach the required purity from an initial contamination concentration and also the number of purification cycles until solid saturation. (AU) | |
| Processo FAPESP: | 20/01609-2 - Otimização dos procedimentos de purificação, regeneração e condensação de argônio para instalações de grande escala |
| Beneficiário: | Pascoal Jose Giglio Pagliuso |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |