PaperPanorama

Nuclear Experiment·nucl-ex

Fri·Mar 8, 2019

4 papers—2 primary·2 cross-listed·reconstructed*

All4Primary2Cross-lists2
  1. 01*

    The neutron electric dipole moment experiment at the Spallation Neutron Source

    K.K.H. Leung🇺🇸 · M. Ahmed🇺🇸 · R. Alarcon🇺🇸 · A. Aleksandrova🇺🇸 · S. Baeßler🇺🇸 · L. Barrón-Palos🇲🇽 · L. Bartoszek · D.H. Beck🇺🇸 · M. Behzadipour · J. Bessuille🇺🇸 · M.A. Blatnik🇺🇸 · M. Broering🇺🇸 and 81 other authors

    Novel experimental techniques are required to make the next big leap in neutron electric dipole moment experimental sensitivity, both in terms of statistics and systematic error control. The nEDM experiment at the Spallation Neutron Source (nEDM@SNS) will implement the scheme of Golub & Lamoreaux [Phys. Rep., 237, 1 (1994)]. The unique properties of combining polarized ultracold neutrons, polarized He, and superfluid He will be exploited to provide a sensitivity to . Our cryogenic apparatus will deploy two small () measurement cells with a high density of ultracold neutrons produced and spin analyzed in situ. The electric field strength, precession time, magnetic shielding, and detected UCN number will all be enhanced compared to previous room temperature Ramsey measurements. Our He co-magnetometer offers unique control of systematic effects, in particular the Bloch-Siegert induced false EDM. Furthermore, there will be two distinct measurement modes: free precession and dressed spin. This will provide an important self-check of our results. Following five years of "critical component demonstration," our collaboration transitioned to a "large scale integration" phase in 2018. An overview of our measurement techniques, experimental design, and brief updates are described in these proceedings.

    nucl-exphysics.ins-detEPJ Web Conf.(2019)·12 citations
  3. 03*

    Design and Operation of a Windowless Gas Target Internal to a Solenoidal Magnet for Use with a Megawatt Electron Beam

    S. Lee🇺🇸 · R. Corliss🇺🇸 · I. Friščić🇺🇸 · R. Alarcon🇺🇸 · S. Aulenbacher🇩🇪 · J. Balewski🇺🇸 · S. Benson🇺🇸 · J. C. Bernauer🇺🇸 · J. Bessuille🇺🇸 · J. Boyce🇺🇸 · J. Coleman🇺🇸 · D. Douglas🇺🇸 and 28 other authors

    A windowless hydrogen gas target of nominal thickness cm is an essential component of the DarkLight experiment, which is designed to utilize the megawatt electron beam at an Energy Recovery Linac (ERL). The design of such a target is challenging because the pressure drops by many orders of magnitude between the central, high-density section of the target and the surrounding beamline, resulting in laminar, transitional, and finally molecular flow regimes. The target system was assembled and operated at Jefferson Lab's Low Energy Recirculator Facility (LERF) in 2016, and subsequently underwent several revisions and calibration tests at MIT Bates in 2017. The system at dynamic equilibrium was simulated in COMSOL to provide a better understanding of its optimal operation at other working points. We have determined that a windowless gas target with sufficiently high density for DarkLight's experimental needs is feasible in an ERL environment.

    ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2019)·3 citations
  4. 04*

    Gravitational form factors of a spin one particle

    Maxim V. Polyakov🇷🇺 · Bao-Dong Sun🇨🇳

    We define the form factors of the quark and gluon symmetric energy-momentum tensor (EMT). The static EMT is related to the spatial distributions of energy, spin, pressure and shear forces. They are obtained in the form of a multipole expansion. The relations between gravitational form factors and the generalised parton distributions are given.

    ↳ hep-phnucl-exnucl-thPRD(2019)·71 citations

* 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.