arXiv subjects

F. Duval

Publications and source records attributed to F. Duval.

4 recordsLinked to original sources

arXiv2020

Study of scintillation light collection, production and propagation in a 4 tonne dual-phase LArTPC

The $3 \times 1 \times 1$ m$^3$ demonstrator is a dual phase liquid argon time projection chamber that has recorded cosmic rays events in 2017 at CERN. The light signal in these detectors is crucial to provide precise timing capabilities. The performances of the photon detection system, composed of five PMTs, are discussed. The collected scintillation and electroluminescence light created by passing particles has been studied in various detector conditions. In particular, the scintillation light production and propagation processes have been analyzed and compared to simulations, improving the understanding of some liquid argon properties.

physics.ins-det↗

arXiv2018

A 4 tonne demonstrator for large-scale dual-phase liquid argon time projection chambers

A 10 kilo-tonne dual-phase liquid argon TPC is one of the detector options considered for the Deep Underground Neutrino Experiment (DUNE). The detector technology relies on amplification of the ionisation charge in ultra-pure argon vapour and oers several advantages compared to the traditional single-phase liquid argon TPCs. A 4.2 tonne dual-phase liquid argon TPC prototype, the largest of its kind, with an active volume of 3x1x1 $m^3$ has been constructed and operated at CERN. In this paper we describe in detail the experimental setup and detector components as well as report on the operation experience. We also present the first results on the achieved charge amplification, prompt scintillation and electroluminescence detection, and purity of the liquid argon from analyses of a collected sample of cosmic ray muons.

physics.ins-det↗

arXiv2011

The HST colours of high-redshift population III galaxies with strong Lyman alpha emission

Population III galaxies, made partly or exclusively of metal-free stars, are predicted to exist at high redshifts and may produce very strong Lya emission. A substantial fraction of these Lya photons are likely absorbed in the intergalactic medium at z>6, but recent simulations suggest that significant Lya emission may be detectable up to z~8.5, i.e. well into the reionization epoch. Here, we argue that high-redshift population III galaxies with strong Lya emission can be identified in Hubble Space Telescope imaging data because of their unusual colours. We quantify this effect in some of the filters used in Y-band dropout searches for galaxies at z~8 and find that population III galaxies with high Lya fluxes may exhibit much bluer J-H colours at z=8-10 than any normal type of galaxy at these redshifts. This colour signature can arise even if pop III stars account for as little as ~1e-3 to ~1e-2 of the stellar mass in these galaxies. Some of the anomalously blue objects reported in current Y-band dropout samples do in fact meet the colour criteria for Lya-emitting population III galaxies.

astro-ph.CO↗

arXiv2008

Paul trapping of radioactive 6He+ions and direct observation of their beta-decay

We demonstrate that abundant quantities of short-lived beta unstable ions can be trapped in a novel transparent Paul trap and that their decay products can directly be detected in coincidence. Low energy 6He+ (807 ms half-life) ions were extracted from the SPIRAL source at GANIL, then decelerated, cooled and bunched by means of the buffer gas cooling technique. More than 10^8 ions have been stored over a measuring period of six days and about 10^5 decay coincidences between the beta particles and the 6Li^{++} recoiling ions have been recorded. The technique can be extended to other short-lived species, opening new possibilities for trap assisted decay experiments.

nucl-ex↗