Tue·Dec 10, 2019Tuesday·December 10, 2019

1. 01*

   Projected sensitivity of the LUX-ZEPLIN experiment to the $0\nu \beta \beta$ decay of ${}^{136}$Xe

   D. S. Akerib🇺🇸 · C. W. Akerlof🇺🇸 · A. Alqahtani🇺🇸 · S. K. Alsum🇺🇸 · T. J. Anderson🇺🇸 · N. Angelides🇬🇧 · H. M. Araújo🇬🇧 · J. E. Armstrong🇺🇸 · M. Arthurs🇺🇸 · X. Bai🇺🇸 · J. Balajthy🇺🇸 · S. Balashov🇬🇧 and 180 other authors

   The LUX-ZEPLIN (LZ) experiment will enable a neutrinoless double beta decay search in parallel to the main science goal of discovering dark matter particle interactions. We report the expected LZ sensitivity to ${}^{136}$Xe neutrinoless double beta decay, taking advantage of the significant ($>$600 kg) ${}^{136}$Xe mass contained within the active volume of LZ without isotopic enrichment. After 1000 live-days, the median exclusion sensitivity to the half-life of ${}^{136}$Xe is projected to be 1.06$\times$10${}^{26}$ years (90% confidence level), similar to existing constraints. We also report the expected sensitivity of a possible subsequent dedicated exposure using 90% enrichment with ${}^{136}$Xe at 1.06$\times$10${}^{27}$ years.

   nucl-exPRC(2020)·63 citations
2. 02*

   Feasibility Study of a Laser-Based Approach for Diagnosing Deuterium Neutrals in the Edge of Fusion Devices

   David Feng · Ahmed Diallo · Mikhail N. Shneider

   In magnetically-confined plasmas of tokamaks, neutral deuterium/hydrogen (D/H) atoms play a role in energy, momentum, and particle balance, as well as the stabilization of plasma turbulence. One key important fusion performance parameter is the pedestal density. Understanding the pedestal density formation is critical for the development of predictive model of future fusion devices. Typically, measurements of the neutrals are obtained using optical emission spectroscopy of the Lyman alpha lines, which is a line-integrated measurement. The plasma in tokamaks is characterized by a high density of electrons and ions and a relatively low concentration of neutral hydrogen atoms, which could make direct measurement of density seemingly impossible at first. We propose a laser-based method that allows for accurate measurement of both the spatial and absolute magnitude of the neutral D/H with minimal knowledge of the radial profiles of electron temperatures and densities. This relies on the fact that the neutral spectral profile can have a larger peak than the electron spectral profile and thus make the neutral density signal resolvable. In practice, this method can be co-located with Thomson scattering systems and is referred to as laser Rayleigh scattering (LRS). More specifically, we assess and evaluate the LRS method for two test cases: in the midplane radii of the National Spherical Torus Experiment (NSTX), and in the small angle slot divertor configuration of DIII-D. Preliminary simulations and calculations will determine the feasibility of LRS in the presence of incoherent Thomson scattering under neutral densities ranging from $10^{13}$ to $10^{21}{\text{m}}^{-3}$. Wavelength dependence of LRS will be evaluated to determine the boost in the signal and photon generation capability.

   ↳ physics.app-phnucl-exphysics.plasm-ph0 citations
3. 03*

   The proton radius: From a puzzle to precision

   Hans-Werner Hammer🇩🇪 · Ulf-G. Meißner🇩🇪

   We comment on the status and history of the proton charge radius determinations.

   ↳ hep-phhep-exhep-latnucl-ex+1Sci.Bull.(2020)·59 citations
4. 04*

   An overview of the scientific contribution of Andrea Vitturi to Nuclear Physics (being an account of the recent TNP19 meeting held in Padova)

   L. Fortunato🇮🇹 · C.E. Alonso🇪🇸 · J.M. Arias🇪🇸 · J. Casal🇮🇹 · K. Hagino🇯🇵 · J.A. Lay🇪🇸 · E.G. Lanza🇮🇹 · S.M. Lenzi🇮🇹 · J. Lubian🇧🇷 · T. Oishi🇭🇷 · F. Pérez-Bernal🇪🇸

   We give an account of the main achievements of the scientific career of Andrea Vitturi so far, that have recently been discussed during the workshop "Theoretical Nuclear Physics in Padova" on the occasion of his retirement from full professor at the University of Padova. He has oftentimes been the driving force behind numerous contributions to nuclear structure and nuclear reactions that are here reviewed: giant resonances, pairing correlations, collective modes, algebraic models, inelastic excitations, electromagnetic response, break-up and transfer reactions, coupled-channel formalism, clustering, subbarrier fusion processes, etc. Among these topics several inspirational works and ideas can be found that we would like to highlight.

   ↳ nucl-thnucl-exEPJA(2020)·0 citations
5. 05*

   Development of a novel MPGD-based drift chamber for the NSCL/FRIB S800 spectrometer

   M. Cortesi🇺🇸 · J. Pereira🇺🇸 · D. Bazin🇺🇸 · Y. Ayyad🇪🇸 · G. Cerizza🇺🇸 · R. Fox · R.G.T. Zegers🇺🇸

   The performance of a novel tracking detector developed for the focal plane of the NSCL/FRIB S800 magnetic spectrometer is presented. The detector comprises a large-area drift chamber equipped with a hybrid Micro-Pattern Gaseous Detector (MPGD)-based readout. The latter consists of a position-sensitive Micromegas detector preceded by a two-layer M-THGEM multiplier as a pre-amplification stage. The signals from the Micromegas readout are processed by a data acquisition system based on the General Electronics for TPC (GET). The drift chamber has an effective area of around 60x30 cm^2, which matches to the very large acceptance of the S800 spectrometer. This work discusses in detail the results of performance evaluation tests carried out with a low-energy alpha-particles source and with high-energy heavy-ion beams with the detector installed at the S800 focal plane. In this latter case, the detector was irradiated with a 150 MeV/u 78Kr36+ beam as well as a heavy-ion fragmentation cocktail beam produced by the 78Kr36+ beam impinging on a thin beryllium target. Sub-millimeter position resolution is obtained in both dispersive and non-dispersive directions.

   ↳ physics.ins-dethep-exnucl-exJINST(2020)·10 citations
6. 06*

   Study of a Passive Gating Grid for Ion Back Flow Suppression

   Vladislav Zakharov🇺🇸 · Prakhar Garg🇺🇸 · Thomas Hemmick🇺🇸 · Klaus Dehmelt🇺🇸

   Space Charge (SC) distortions are some of the main issues for high-resolution Time Projection Chambers (TPC). The two main SC sources are those from primary ionizations and those that result from amplification stages. The gain stages are required to increase the electron signal above electronics noise levels, but this inevitably creates extra ions. These ions can enter the drift region and distort the electric field, and thus lower the detector performance. We will present a brief motivation for our Ion Back Flow (IBF) studies along with explanations of existing techniques and our simulation results to reduce IBF. We propose several mesh structures along with static bi-polar gating. Further, we discuss position distortions in electron trajectories due to a static bi-polar grid and use these distortions to compensate for non-linear responses of our Zig-Zag pad readout.

   ↳ physics.ins-detnucl-exJ.Phys.Conf.Ser.(2020)·1 citation

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.