Abstract
The Deep Underground Neutrino Experiment (DUNE) is a leading-edge experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE-Dual ...Phase (DP) is a 6 × 6 × 6 m
3
liquid argon time-projection-chamber (LArTPC) operated at the CERN Neutrino Platform in 2019–2020 as a prototype of the DUNE far detector. In ProtoDUNE-DP, the scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, we present the performance of the ProtoDUNE-DP photon detection system, comparing different wavelength-shifting techniques and the use of xenon-doped LAr as a promising option for future large LArTPCs. The scintillation light production and propagation processes are analyzed and compared to simulations, improving understanding of the liquid argon properties.
Home parenteral nutrition (HPN) is increasingly prescribed for patients with advanced cancer. This therapy improves free-fat mass, quality of life and survival, but it is not free from complications, ...especially catheter-related bloodstream infections (CRBSIs). The use of commercial multichamber bags in HPN has not been extensively explored in oncologic patients and their association with complications is not well known. In this prospective cohort study, we included 130 patients with advanced cancer and HPN. We compared the effects of individual compounded bags (n = 87) vs. commercial multichamber bags (n = 43) on complications. There were no differences in any complication, including thrombosis (
> 0.05). There were 0.28 episodes of CRBSI per 1000 catheter days in the individual compounded bag group and 0.21 in the multichamber bag group (
> 0.05). A total of 34 patients were weaned off HPN, 22 with individual bags and 12 with multichamber bags (
= 0.749). Regarding survival when on HPN, the group with individual bags showed a median of 98 days (95% CI of 49-147), whereas those with multichamber bags showed a median of 88 days (95% CI of 43-133 (
= 0.913)). In conclusion, commercial multichamber bags for HPN in patients with advanced cancer are non-inferior when compared to individual compounded bags in terms of complications.
Neutrinos were assumed to be massless particles until the discovery of the neutrino oscillation process. This phenomenon indicates that the neutrinos have non-zero masses and the mass eigenstates ...(ν1, ν2, ν3) are mixtures of their flavour eigenstates (νe, νμ, ντ). The oscillations between different flavour eigenstates are described by three mixing angles (θ12, θ23, θ13), two differences of the squared neutrino masses of the ν2/ν1 and ν3/ν1 pairs and a charge conjugation parity symmetry violating phase δCP. The Double Chooz experiment, located near the Chooz Electricité de France reactors, measures the oscillation parameter θ13 using reactor neutrinos. Here, the Double Chooz collaboration reports the measurement of the mixing angle θ13 with the new total neutron capture detection technique from the full data set, yielding sin2(2θ13) = 0.105 ± 0.014. This measurement exploits the multidetector configuration, the isoflux baseline and data recorded when the reactors were switched off. In addition to the neutrino mixing angle measurement, Double Chooz provides a precise measurement of the reactor neutrino flux, given by the mean cross-section per fission 〈σf〉 = (5.71 ± 0.06) × 10−43 cm2 per fission, and reports an empirical model of the distortion in the reactor neutrino spectrum.The Double Chooz collaboration reports the neutrino oscillation parameter θ13 from a measurement of the disappearance of reactor anti-electron neutrinos with the total neutron capture technique.
ProtoDUNE-DP is a <inline-formula> <tex-math notation="LaTeX">6\times 6\times 6\,\,\text{m}^{3} </tex-math></inline-formula> liquid argon time-projection-chamber operated at the CERN Neutrino ...Platform in 2019-2020 as a prototype of the dual phase concept for the Deep Underground Neutrino Experiment (DUNE) far detector. The photon detection system (PDS) is based on 36 8-in photomultiplier tubes (PMTs) and allows triggering on the scintillation light signals produced by cosmic rays and other charged particles traversing the detector. The acquisition and calibration software specifically developed for the ProtoDUNE-DP PDS is described in this article. This software controls the high-voltage power supplies, the calibration system, and the PDS DAQ. It has been developed with Qt Creator and features different operation modes and a graphical user interface. This software has already been validated and used during the ProtoDUNE-DP operation.
The Deep Underground Neutrino Experiment (DUNE) is a dual-site experiment for long-baseline neutrino oscillation studies, and for neutrino astrophysics and nucleon decay searches. The far detector is ...a 40-kton underground liquid argon time-projection-chamber (LAr TPC), in which the photon detector system adds precise timing capabilities. The ProtoDUNE Dual-Phase detector will consist of a 6×6×6 m3 LAr TPC to be operated at the CERN Neutrino Platform and the photon detection system will be formed by 8-inch cryogenic photomultipliers from Hamamatsu. The PMT model (R5912-20Mod) performance at cryogenic temperature is studied including dark current, gain, and linearity with the light intensity and pulse rate. In addition, the PMT base design is validated. At cold, a decrease of the PMT amplification, or fatigue effect, is measured as the PMT output current increases, either, due to high gain, light intensity or rate. Also, the characterization results of the 40 photomultipliers to be used in ProtoDUNE Dual-Phase are presented.
Neoadjuvant chemotherapy (NT) followed by radical surgery is the standard treatment for locally advanced gastric cancer (GC). The incidence of sarcopenia in upper gastrointestinal tract malignancies ...is very high, and it may be increased after NT. This study aimed to evaluate the impact of NT on body composition. A retrospective study of patients with locally advanced GC undergoing gastrectomy who had received NT in a tertiary hospital between 2012 and 2019 was conducted. CT measured the skeletal muscle index, total psoas area, and visceral and subcutaneous adipose tissue before and after NT. Of the 180 gastrectomies for GC, 61 patients received NT. During NT, changes in body composition were observed with a decrease in the skeletal muscle mass index (SMMI −2.5%; p < 0.001), and these changes were significantly greater in men (SMMI −10.55%). Before surgery, patients who received NT presented 15% more sarcopenia than those without NT (p = 0.048). In conclusion, patients with locally advanced gastric cancer who receive NT have significant changes in body composition during chemotherapy. These changes, which are at the expense of a loss of muscle mass, lead to an increased incidence of pre-surgical sarcopenia.
Low-energy physics in neutrino LArTPCs Andringa, S; Asaadi, J; Bezerra, J T C ...
Journal of physics. G, Nuclear and particle physics,
01/2023, Letnik:
50, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Abstract
In this paper, we review scientific opportunities and challenges related to detection and reconstruction of low-energy (less than 100 MeV) signatures in liquid argon time-projection chamber ...(LArTPC) neutrino detectors. LArTPC neutrino detectors designed for performing precise long-baseline oscillation measurements with GeV-scale accelerator neutrino beams also have unique sensitivity to a range of physics and astrophysics signatures via detection of event features at and below the few tens of MeV range. In addition, low-energy signatures are an integral part of GeV-scale accelerator neutrino interaction final-states, and their reconstruction can enhance the oscillation physics sensitivities of LArTPC experiments. New physics signals from accelerator and natural sources also generate diverse signatures in the low-energy range, and reconstruction of these signatures can increase the breadth of Beyond the Standard Model scenarios accessible in LArTPC-based searches. A variety of experimental and theory-related challenges remain to realizing this full range of potential benefits. Neutrino interaction cross-sections and other nuclear physics processes in argon relevant to sub-hundred-MeV LArTPC signatures are poorly understood, and improved theory and experimental measurements are needed; pion decay-at-rest sources and charged particle and neutron test beams are ideal facilities for improving this understanding. There are specific calibration needs in the low-energy range, as well as specific needs for control and understanding of radiological and cosmogenic backgrounds. Low-energy signatures, whether steady-state or part of a supernova burst or larger GeV-scale event topology, have specific triggering, DAQ and reconstruction requirements that must be addressed outside the scope of conventional GeV-scale data collection and analysis pathways. Novel concepts for future LArTPC technology that enhance low-energy capabilities should also be explored to help address these challenges.
The Hamamatsu R5912-02Mod photomultiplier tube (PMT) will be used in the DUNE dual-phase module, a 10-kton fiducial volume liquid-argon time-projection chamber, which is one of the four projected ...far-detector modules of the DUNE long-baseline neutrino experiment. In the DUNE dual-phase module, the liquid argon places high pressure on the photo-detectors located at the bottom of the 14-m cryostat. Four Hamamatsu R5912-02Mod PMTs were tested at 4-bar absolute pressure and cryogenic temperature (in liquid nitrogen) for the first time. No mechanical or electrical damage is reported, validating the use of this PMT model in the DUNE dual-phase module and in other large scale cryogenic liquid detectors. The differences observed in their behavior are expected for the change in the PMT operating temperature.
This paper describes a procedure for the validation of alpha-particle sources (exempt unsealed sources) to be used in experimental setups with liquefied gases at cryogenic temperatures (down to ...−196 °C) and high vacuum. These setups are of interest for the development and characterization of neutrino and dark matter detectors based on liquid argon, among others. Due to the high purity requirements, the sources have to withstand high vacuum and cryogenic temperatures for extended periods. The validation procedure has been applied to 241Am sources produced by electrodeposition.
•A method to validate electrodeposited 241Am alpha-particle sources for use under high vacuum and cryogenic temperatures has been developed.•Electrodeposited alpha-particle sources from aqueous electrolytes containing sulphate ions were validated for use at cryogenic temperatures.•Electrodeposited alpha-particle sources from aqueous electrolytes containing sulphate ions were validated for use at high vacuum.
A LED-based fiber calibration system for the ProtoDUNE-Dual Phase (DP) photon detection system (PDS) has been designed and validated. ProtoDUNE-DP is a 6x6x6 m3 liquid argon time-projection-chamber ...(LAr TPC) currently being installed at the Neutrino Platform at CERN. The PDS is based on 36 8-inch photomultiplier tubes (PMTs) and will allow triggering on cosmic rays. The system serves as prototype for the PDS of the final DUNE DP far detector in which the PDS also has the function to allow the 3D event reconstruction on non-beam physics. For this purpose an equalized PMT response is desirable to allow using the same threshold definition for all PMT groups, simplifying the determination of the trigger efficiency. The light calibration system (LCS) described in this paper is developed to provide this and to monitor the PMT performance in-situ.
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