Status and New Ideas Regarding Liquid Argon Detectors

Abstract

Large (up to ∼ 100 kt) liquid argon time-projection chamber detectors are presently being considered for proton decay searches and neutrino astrophysics, as well as for far detectors for the next generation of longbaseline neutrino oscillation experiments that aim to determine neutrino mass hierarchy and search for CP violation in the leptonic sector. These detectors rely on the capabilities to assemble large volumes of LAr in ultrahigh-purity conditions, possibly in an underground environment, and to achieve relatively long drifts for the ionization charge. Several proposals have been developed, each of which takes a different approach to the design of the cryogenic vessels and has different scales of modularity to reach the final mass dictated by physics. New detector concepts, with innovative designs of readout electronics and novel methods for the readout of the ionization charge and scintillation light, have been proposed.

Developing the MeV potential of DUNE: Detailed considerations of muon-induced spallation and other backgrounds

“…For half of them, including some important ones such as 40 Cl, 38 Cl, 34 P, etc., we find a good agreement, within a factor of ≈ 2. For some rarely produced isotopes ( 37 P, 33 Cl, 35 Ar, etc. ), our yields are a factor ≈ 0.1 of theirs.…”

“…Another high-A isotope, 39 Ar (Q = 0.6 MeV), has a similar production rate, but its half-life is extremely long (268 yrs). We expect that 39 Ar made from spallation has a decay rate of only 3 per day after one year of operation, while it would increase to 30 per day once DUNE has run for 10 years, which is still insignificant compared to the rate (≈ 10 MHz) due to the pre-existing 39 Ar in the atmospheric argon that DUNE will use [35]. Low-A isotopes, the dominant source for the backgrounds at higher energies, are typically short-lived.…”

A multi-term solution of the space–time Boltzmann equation for electrons in gases and liquids

“…It is simple to address this issue by increasing the number of points in configuration-space but this is also significantly more computationally intensive. Argon Time Projection Chambers (LArTPC) which are currently being used for high energy particle detection [5]. Ionized electrons in liquid argon originating from the high energy particles are accelerated under the action of an electric field to generate a current and consequently reconstruct the path of the high energy particle.…”

Near-infrared scintillation of liquid argon: recent results obtained with the NIR facility at Fermilab

“…In recent years the technology of liquid noble gases (LNG) detectors [1] has come of age and is finding widespread use in experiments searching for dark matter (DM) [2] and in large liquid argon (LAr) time projection chambers (TPC) for neutrino physics [3]. In both cases (DM and neutrino physics) there are significant gains when detecting both the charge coming from the primary ionization as well as the scintillation light produced in an event through excitation mechanisms in the LNG medium.…”