Showing papers by "George M. Seidel published in 2019"
North Carolina Central University1, Duke University2, Arizona State University3, University of Kentucky4, University of Virginia5, Oak Ridge National Laboratory6, National Autonomous University of Mexico7, University of Illinois at Urbana–Champaign8, Massachusetts Institute of Technology9, California Institute of Technology10, Los Alamos National Laboratory11, Mississippi State University12, University of Tennessee13, North Carolina State University14, Simon Fraser University15, Tennessee Technological University16, Indiana University17, Yale University18, Thomas Jefferson National Accelerator Facility19, Lawrence Livermore National Laboratory20, Brown University21, Harvard University22, Valparaiso University23, Katholieke Universiteit Leuven24
TL;DR: In this paper, a new experiment, nEDM@SNS, is described that enables a major improvement in sensitivity compared to the existing limit in the search for a neutron Electric Dipole Moment (EDM), using superfluid 4He to produce a high density of ultra-cold Neutrons (UCN) which are contained in a suitably coated pair of measurement cells.
Abstract: A cryogenic apparatus is described that enables a new experiment, nEDM@SNS, with a major improvement in sensitivity compared to the existing limit in the search for a neutron Electric Dipole Moment (EDM). This apparatus uses superfluid ⁴He to produce a high density of Ultra-Cold Neutrons (UCN) which are contained in a suitably coated pair of measurement cells. The experiment, to be operated at the Spallation Neutron Source at Oak Ridge National Laboratory, uses polarized ³He from an Atomic Beam Source injected into the superfluid 4He and transported to the measurement cells where it serves as a co-magnetometer. The superfluid ⁴He is also used as an insulating medium allowing significantly higher electric fields, compared to previous experiments, to be maintained across the measurement cells. These features provide an ultimate statistical uncertainty for the EDM of 2−3× 10⁻²⁸ e-cm, with anticipated systematic uncertainties below this level.
32 citations
TL;DR: In this paper, a new experiment, nEDM@SNS, is described that enables a major improvement in sensitivity compared to the existing limit in the search for a neutron Electric Dipole Moment (EDM).
Abstract: A cryogenic apparatus is described that enables a new experiment, nEDM@SNS, with a major improvement in sensitivity compared to the existing limit in the search for a neutron Electric Dipole Moment (EDM). It uses superfluid $^4$He to produce a high density of Ultra-Cold Neutrons (UCN) which are contained in a suitably coated pair of measurement cells. The experiment, to be operated at the Spallation Neutron Source at Oak Ridge National Laboratory, uses polarized $^3$He from an Atomic Beam Source injected into the superfluid $^4$He and transported to the measurement cells as a co-magnetometer. The superfluid $^4$He is also used as an insulating medium allowing significantly higher electric fields, compared to previous experiments, to be maintained across the measurement cells. These features provide an ultimate statistical uncertainty for the EDM of $2-3\times 10^{-28}$ e-cm, with anticipated systematic uncertainties below this level.
11 citations
Durham University1, North Carolina State University2, North Carolina Central University3, Duke University4, Arizona State University5, University of Kentucky6, University of Virginia7, Oak Ridge National Laboratory8, National Autonomous University of Mexico9, University of Illinois at Urbana–Champaign10, Massachusetts Institute of Technology11, California Institute of Technology12, Los Alamos National Laboratory13, Mississippi State University14, University of Tennessee15, Simon Fraser University16, Yale University17, Indiana University18, Brown University19, Harvard University20, Valparaiso University21
TL;DR: The nEDM experiment at the Spallation Neutron Source (nEDM@SNS) as discussed by the authors was the first to implement the scheme of Golub & Lamoreaux [Phys. Rep., 237, 1 (1994).
Abstract: 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 3 He, and superfluid 4 He will be exploited to provide a sensitivity to ∼ 10−28 e · cm. Our cryogenic apparatus will deploy two small (3 L) 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 3 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.
6 citations
TL;DR: The nEDM experiment at the Spallation Neutron Source (nEDM@SNS) as discussed by the authors was the first to implement the scheme of Golub & Lamoreaux [Phys. Rep., 237, 1 (1994)].
Abstract: 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 $^3$He, and superfluid $^4$He will be exploited to provide a sensitivity to $\sim 10^{-28}\,e{\rm \,\cdot\, cm}$. Our cryogenic apparatus will deploy two small ($3\,{\rm L}$) 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 $^3$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.
3 citations