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•We present a new and simple design of an RF-only ion funnel.•Longitudinal ion transport is provided by the residual gas flow through the funnel thus no DC drag field is required.•The ...presented ion funnel allows for ion extraction from argon and xenon gas from up to 10bar to 10−3mbar in only one step with very high efficiency.•First experimental results of ion extraction from high-pressure noble gas have been performed and are compared with gas dynamic and ion trajectory calculations.
An RF ion-funnel technique has been developed to extract ions from a high-pressure (10bar) noble-gas environment into a vacuum (10−6mbar). Detailed simulations have been performed and a prototype has been developed for the purpose of extracting 136Ba ions from Xe gas with high efficiency. With this prototype, ions have been extracted for the first time from high-pressure xenon gas and argon gas. Systematic studies have been carried out and compared to simulations. This demonstration of extraction of ions, with mass comparable to that of the gas generating the high-pressure, has applications to Ba tagging from a Xe-gas time-projection chamber for double-beta decay, as well as to the general problem of recovering trace amounts of an ionized element in a heavy (m>40u) carrier gas.
We report on a comparison between the theoretically predicted and experimentally measured spectra of the first-forbidden nonunique β-decay transition 137Xe(7/2−) → 137Cs(7/2+). The experimental data ...were acquired by the EXO-200 experiment during a deployment of an AmBe neutron source. The ultralow background environment of EXO-200, together with dedicated source deployment and analysis procedures, allowed for collection of a pure sample of the decays, with an estimated signal to background ratio of more than 99 to 1 in the energy range from 1075 to 4175 keV. In addition to providing a rare and accurate measurement of the first-forbidden nonunique β-decay shape, this work constitutes a novel test of the calculated electron spectral shapes in the context of the reactor antineutrino anomaly and spectral bump.
An exclusive measurement of the decay η→π+π−γ has been performed at the WASA facility at COSY. The η mesons were produced in the fusion reaction pd→He3 X at a proton beam momentum of 1.7 GeV/c. ...Efficiency corrected differential distributions have been extracted based on 13960±140 events after background subtraction. The measured pion angular distribution is consistent with a relative p-wave of the two-pion system, whereas the measured photon energy spectrum was found at variance with the simplest gauge invariant matrix element of η→π+π−γ. A parameterization of the data can be achieved by the additional inclusion of the empirical pion vector form factor multiplied by a first-order polynomial in the squared invariant mass of the π+π− system.
Searches for double beta decay of Xe134 were performed with EXO-200, a single-phase liquid xenon detector designed to search for neutrinoless double beta decay of Xe136. Using an exposure of 29.6 ...kg·yr, the lower limits of T1/22νββ>8.7×1020 yr and T1/20νββ>1.1×1023 yr at 90% confidence level were derived, with corresponding half-life sensitivities of 1.2×1021 yr and 1.9×1023 yr. These limits exceed those in the literature for Xe134, improving by factors of nearly 105 and 2 for the two antineutrino and neutrinoless modes, respectively.
Searches for double beta decay of 134Xe were performed with EXO-200, a single-phase liquid xenon detector designed to search for neutrinoless double beta decay of 136Xe. Using an exposure of 29.6 kg ...· yr, the lower limits of T2νββ 1=2 > 8.7 × 1020 yr and T0νββ 1=2 > 1.1 × 1023 yr at 90% confidence level were derived, with corresponding half-life sensitivities of 1.2 × 1021 yr and 1.9 × 1023 yr. These limits exceed those in the literature for 134Xe, improving by factors of nearly 105 and 2 for the two antineutrino and neutrinoless modes, respectively.
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