A Ku -Band CMOS FMCW Radar Transceiver for Snowpack Remote Sensing

This paper presents a Ku -band (14-16 GHz) CMOS frequency-modulated continuous-wave (FMCW) radar transceiver developed to measure dry-snow depth for water management purposes and to aid in retrieval of snow water equivalent. An on-chip direct digital frequency synthesizer and digital-to-analog converter digitally generates a chirping waveform which then drives a ring oscillator-based Ku -Band phase-locked loop to provide the final Ku -band FMCW signal. Employing a ring oscillator as opposed to a tuned inductor-based oscillator (LC-VCO) allows the radar to achieve wide chirp bandwidth resulting in a higher axial resolution (7.5 cm), which is needed to accurately quantify the snowpack profile. The demonstrated radar chip is fabricated in a 65-nm CMOS process. The chip consumes 252.4 mW of power under 1.1-V supply, making its payload requirements suitable for observations from a small unmanned aerial vehicle

First Differential Measurement of the Single <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:msup> <mml:mrow> <mml:mi>π</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> Production Cross Section in Neutrino Neutral-Current Scattering

Since its first observation in the 1970s, neutrino-induced neutral-current single positive pion production ( NC 1 π + ) has remained an elusive and poorly understood interaction channel. This process is a significant background in neutrino oscillation experiments and studying it further is critical for the physics program of next-generation accelerator-based neutrino oscillation experiments. In this Letter, we present the first double-differential cross-section measurement of NC 1 π + interactions using data from the ND280 detector of the T2K experiment collected in ν -beam mode. The measured flux-averaged integrated cross section is σ = ( 6.07 ± 1.22 ) × 10 − 41     cm 2 / nucleon . We compare the results on a hydrocarbon target to the predictions of several neutrino interaction generators and final-state-interaction models. While model predictions agree with the differential results, the data show a weak preference for a cross-section normalization approximately 30% higher than predicted by most models studied in this Letter. </jats:p

First differential measurement of the single π+\mathbf{\pi}^+ production cross section in neutrino neutral-current scattering

International audienceSince its first observation in the 1970s, neutrino-induced neutral-current single positive pion production (NC1$\pi^+$) has remained an elusive and poorly understood interaction channel. This process is a significant background in neutrino oscillation experiments and studying it further is critical for the physics program of next-generation accelerator-based neutrino oscillation experiments. In this Letter we present the first double-differential cross-section measurement of NC1$\pi^+$ interactions using data from the ND280 detector of the T2K experiment collected in $\nu$-beam mode. We compare the results on a hydrocarbon target to the predictions of several neutrino interaction generators and final-state interaction models. While model predictions agree with the differential results, the data shows a weak preference for a cross-section normalization approximately 30% higher than predicted by most models studied in this Letter

Signal selection and model-independent extraction of the neutrino neutral-current single <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:msup> <mml:mi>π</mml:mi> <mml:mo>+</mml:mo> </mml:msup> </mml:math> cross section with the T2K experiment

This article presents a study of single π + production in neutrino neutral-current interactions ( NC 1 π + ) using the FGD1 hydrocarbon target of the ND280 detector of the T2K experiment. We report the largest sample of such events selected by any experiment, providing the first new data for this channel in over four decades and the first using a sub-GeV neutrino flux. The signal selection strategy and its performance are detailed together with validations of a robust cross section extraction methodology. The measured flux-averaged integrated cross-section is σ = ( 6.07 ± 1.22 ) × 10 − 41     cm 2 / nucleon , 1.3 σ above the NEUT v5.4.0 expectation. </jats:p

Signal selection and model-independent extraction of the neutrino neutral-current single π+\pi^+ cross section with the T2K experiment

International audienceThis article presents a study of single $\pi^+$ production in neutrino neutral-current interactions (NC1$\pi^+$) using the ND280 detector of the T2K experiment. We report the largest sample of such events selected by any experiment, providing the first new data for this channel in over four decades and the first using a sub-GeV neutrino flux. The signal selection strategy and its performance are detailed together with validations of a robust cross section extraction methodology. The measured flux-averaged integrated cross-section is $\sigma = (6.07 \pm 1.22 )\times 10^{-41} \,\, \text{cm}^2/\text{nucleon}$, 1.3~$\sigma~$ above the NEUT v5.4.0 expectation

First Measurement of the Electron Neutrino Charged-Current Pion Production Cross Section on Carbon with the T2K Near Detector

International audienceThe T2K Collaboration presents the first measurement of electron neutrino-induced charged-current pion production on carbon in a restricted kinematical phase space. This is performed using data from the 2.5$^{\deg}$ off-axis near detector, ND280. The differential cross sections with respect to the outgoing electron and pion kinematics, in addition to the total flux-integrated cross section, are obtained. Comparisons between the measured and predicted cross section results using the Neut, Genie and NuWro Monte Carlo event generators are presented. The measured total flux-integrated cross section is [2.52 $\pm$ 0.52 (stat) $\pm$ 0.30 (sys)] x $10^{-39}$ cm$^2$ nucleon$^{-1}$, which is lower than the event generator predictions

First measurement of neutron capture multiplicity in neutrino-oxygen neutral-current quasi-elastic-like interactions using an accelerator neutrino beam

International audienceWe report the first measurement of neutron capture multiplicity in neutrino-oxygen neutral-current quasi-elastic-like interactions at the gadolinium-loaded Super-Kamiokande detector using the T2K neutrino beam, which has a peak energy of about 0.6 GeV. A total of 30 neutral-current quasi-elastic-like event candidates were selected from T2K data corresponding to an exposure of $1.76\times10^{20}$ protons on target. The $\gamma$ ray signals resulting from neutron captures were identified using a neural network. The flux-averaged mean neutron capture multiplicity was measured to be $1.37\pm0.33\text{ (stat.)}$$(^{+0.17}_{-0.27})$, which is compatible within $2.3\,\sigma$ than predictions obtained using our nominal simulation. We discuss potential sources of systematic uncertainty in the prediction and demonstrate that a significant portion of this discrepancy arises from the modeling of hadron-nucleus interactions in the detector medium

First measurement of neutron capture multiplicity in neutrino-oxygen neutral-current quasielasticlike interactions using an accelerator neutrino beam

We report the first measurement of neutron capture multiplicity in neutrino-oxygen neutral-current quasielasticlike interactions at the gadolinium-loaded Super-Kamiokande detector using the T2K neutrino beam, which has a peak energy of about 0.6 GeV. A total of 30 neutral-current quasielasticlike event candidates were selected from T2K data corresponding to an exposure of 1.76×1020 protons on target. The γ ray signals resulting from neutron captures were identified using a neural network. The flux-averaged mean neutron capture multiplicity was measured to be 1.37±0.33 (stat.)−0.27+0.17 (syst.), which is compatible within 2.3 sigma than predictions obtained using our nominal simulation. We discuss potential sources of systematic uncertainty in the prediction and demonstrate that a significant portion of this discrepancy arises from the modeling of hadron-nucleus interactions in the detector medium.</jats:p