Dr
Bernhard Lauss
(Paul Scherrer Institute)
16/10/2017, 09:45
" on behalf of the nEDM collaboration at PSI
The next big step in sensitivity improvement of the search for a possible electric dipole moment of the neutron at the Paul Scherrer Institute, Switzerland requires a new apparatus with several improvements with respect to the present setup. In a first step of the new apparatus – dubbed n2EDM -- a sensitivity improvement of a factor of 10 is...
Dr
David Morrissey
(TRIUMF)
16/10/2017, 10:45
CP violation presents two major puzzles for our understanding of fundamental physics. On one hand, we do not know the origin of the CP violation observed in quark mixing. On the other, the amount of CP violation that is seen is not enough to account for the excess of matter over antimatter and appears to be anomalously small compared to what is expected from the structure of the strong...
Dr
Brent Graner
(University of Washington)
16/10/2017, 11:25
This talk will cover the latest results on the permanent electric dipole moment (EDM) of neutral $^{199}$Hg atoms. The EDM is manifested as a small perturbation to the Larmor precession frequency due to the interaction energy of the electric dipole with a static electric field. The atoms are prepared in four separate glass vapor cells using optical pumping with resonant 254 nm laser light and...
Dr
Beatrice Franke
(TRIUMF)
16/10/2017, 12:00
The Japanese-Canadian Ultracold Neutron (UCN) Source is a new facility under
construction at TRIUMF. The distinct feature of TRIUMFs UCN facility is the combination of a neutron spallation source with a superfluid helium UCN converter - unique among all existing and planned UCN sources worldwide. The goal of the UCN project at TRIUMF is to provide a density of several hundreds of UCN per...
Prof.
Brad Filippone
(Caltech)
16/10/2017, 14:00
The SNS nEDM experiment plans to use a cryogenic central detector and magnet system along with a polarized 3He co-magnetometer to achieve neutron EDM
sensitivities < 3x10-28 e-cm. An overview of the experiment will be discussed including its present status, schedule and a summary of the technical progress on many of the key components.
Dr
Alexey Fomin
(PNPI NRC KI)
16/10/2017, 14:35
Use of ultracold neutrons (UCN) gives unique opportunities of a research of fundamental interactions in physics of elementary particles. Search of the electric dipole moment of a neutron (EDM) aims to test models of CP violation. Precise measurement of neutron lifetime is extremely important for cosmology and astrophysics. Considerable progress in these questions can be reached due to...
Dr
Ekaterina Korobkina
(NCSU)
16/10/2017, 15:10
Oral
Recently we completed cryogenic commissioning of the UCN source at PULSTAR reactor, located at NC State University campus. As part of the commissioning , we have studied growth of a solid deuterium crystal in situ using external camera and temperature probes. In addition, we did simulation of the pulsed heat input into walls of the cryostat, to simulate condition typical for the pulsed UCN sources.
Prof.
Dieter Ries
(Johannes Gutenberg Universität Mainz)
16/10/2017, 16:20
Currently, a new experiment aiming to measure the neutron EDM using a pulsed beam of cold neutrons is being commissioned at the University of Bern. The innovative measuring concept is ideally suited for high peak-flux and time-structure provided by next-generation pulsed spallation sources (e.g. the European Spallation Source ESS). The present design, technical challenges and solutions as well...
Doug Beck
(University of Illinois)
16/10/2017, 16:55
Oral
In the SNS experiment, polarized 3He is used to measure the neutron precession frequency as well as to serve as a co-magnetometer. The polarized 3He, from an atomic beam source, is injected into the system and then removed therefrom in each measurement cycle (using a ‘heat flush’ technique). I will discuss the current status of the system.
Skyler Degenkolb
(Institut Laue-Langevin)
17/10/2017, 09:00
The most severe difficulty in measuring the neutron EDM is low achievable density of ultracold neutrons; this is addressed by the new source SuperSUN, currently under construction at the Institut Laue-Langevin. The intense primary cold beam H523 will be shaped by a unique tapered guide geometry, and guided for a further three meters inside an 11-liter converter volume with circular...
Steven Clayton
(Los Alamos National Laboratory)
17/10/2017, 09:35
Research and development work at LANL towards a new neutron EDM experiment using the LANL UCN source with a sensitivity goal of several x 10-27 e-cm is currently ongoing. The initial focus of this effort was an upgrade of the UCN source and a demonstration that a sufficient number of UCN can indeed be stored in a nEDM measurement cell and was successfully completed. In this talk, the concept...
Dr
Robert Pattie
(Los Alamos National Laboratory)
17/10/2017, 09:55
The spallation-driven solid deutrium-based ultracold neutron (UCN) source at Los Alamos Neutron Science Center (LANSCE) has provided a facility for precision measurements of fundamental symmetries via the decay observables from neutron beta decay for over a decade. In preparation for a new room temperature neutron electric dipole moment (nEDM) search and to increase the statistical sensitivity...
Mr
Jacob Thorne
(University of Sussex)
17/10/2017, 10:25
We present details of the design, construction and initial tests of an apparatus for high voltage testing of a full-size cryogenic nEDM cell in liquid helium at 4.2K. The test cell is cylindrical and of 24 cm internal diameter with stainless steel electrodes and an insulating spacer. The cylinder axis of the cell is vertical and the insulator is located in grooves in the electrodes. The...
Dr
Philipp Schmidt-Wellenburg
(Paul Scherrer Institute)
17/10/2017, 11:10
At the Paul Scherrer Institute (PSI) in Switzerland a collaboration of 15 institutions is measuring the nEDM using ultracold neutrons (UCN).
In recent years a total of nearly 55000 cycles each with an average of approximately 11500 UCN were recorded. The pre-analysis sensitivity of the dataset is about 0.95×10E-26 ecm.
This talk will present the summary of the ongoing statistical analysis...
Dr
Tatsuya Kikawa
(TRIUMF)
17/10/2017, 11:40
We aim to search for the neutron EDM down to 1e-27e*cm by using ultracold neutrons at TRIUMF.
In order to achieve this goal, systematic errors of the neutron EDM measurement must be drastically reduced as well as the statistical error.
With this objective, we are developing a next generation EDM measurement system.
This talk will describe the current status and the future plans for the...
Dr
Ryohei Matsumiya
(TRIUMF)
17/10/2017, 19:00
We developed an intense ultracold neutron (UCN) source using superfluid helium (He-II) at the Research Center for Nuclear Physics (RCNP), in Japan. This UCN source uses He-II as a UCN converter to produce a high density of UCN. At the exit of the UCN source, a UCN density of 26 UCN/cm$^3$ at 90 neV critical energy was achieved with the 400 W proton beam of the ring cyclotron of RCNP in...
Dr
Guillaume Pignol
(LPSC)
17/10/2017, 19:25
Magnetic field non-uniformities generate important systematic effects on the neutron EDM, especially for experiments using an atomic comagnetometer.
Field gradients generate frequency shifts of UCNs and atoms, possibly dependent on the electric field, they also induce transverse depolarization of UCNs.
All these effects will be reviewed.
I will first present a polynomial...
Dr
Simon Slutsky
(Caltech)
17/10/2017, 19:50
A search for the neutron electric dipole moment (nEDM) will take place at the Spallation Neutron Source at Oak Ridge National Lab, aiming for a sensitivity of <$3\times10^{-28}$ e-cm. Polarized ultracold neutrons will precess in a 30 mG magnetic holding field inside a liquid helium cell, which will be doped with a minute amount of polarized He-3 to measure the precession frequency. Magnetic...
Dr
Edgard Pierre
(TRIUMF)
17/10/2017, 20:15
Transport and manipulation of ultra cold neutrons (materials, valves, polarization, spin transport, neutron detection)
Oral
We are currently developing a super-thermal Ultracold Neutron (UCN) source using phonon exchange in super-fluid helium. To take full advantage of the high density of UCNs from our source, high transmission guides for polarized UCNs are being developed. Statistical sensitivity is the main limiting factor for a neutron EDM measurement. Furthermore, this sensitivity also depends on the initial...
Mr
Shinsuke Kawasaki
(KEK)
18/10/2017, 09:00
Ultracold Neutrons (UCN) are extremely slow neutrons with a kinetic energy in the order of 100 neV. As a consequence, UCNs are totally reflected at the surface of certain materials and can be confined in a material bottle. Using this unique property, UCNs are used for various experiments such as neutron electric dipole moment searches, neutron lifetime measurements, gravity experiments, and...
Dr
Geza Zsigmond
(Paul Scherrer Institut)
18/10/2017, 09:35
In UCN physics experiments Monte Carlo simulation methods are very effective in the characterization and optimization of many-parameter systems, and when a detailed calculation of a geometry containing several sub-volumes is relevant. Exact analytic modeling is not feasible in many cases - for example because of gravity effects on UCN or because of UCN viewing several surface qualities at the...
Dr
Wolfgang Schreyer
(TRIUMF)
18/10/2017, 10:00
The TRIUMF Japanese-Canadian UCN Collaboration is planning a next-generation
ultracold-neutron source. To maximize the number of ultracold neutrons
available to experiments, Monte Carlo simulations of neutrons
over a wide energy range are needed. Additionally, heat deposit due to
neutron scattering, neutron capture, and gamma radiation is an important
design parameter.
This...
Georg Bison
(Paul Scherrer Institut)
18/10/2017, 10:50
Experiments searching for the electric dipole moment (EDM) of the neutron require a stable and homogeneous magnetic field. Statistical and systematic uncertainties in such experiments depend on magnetic field gradients and fluctuations of those gradients and the field itself. In order to monitor the different aspects of the magnetic field we developed a variety of special magnetometer systems...
Dr
Tomohiro Hayamizu (for the TRIUMF Japanese-Canadian UCN Collaboration)
(The University of British Columbia)
18/10/2017, 11:15
In support of the neutron electric dipole moment (EDM) experiment at TRIUMF, we are developing a $^{129}$Xe/$^{199}$Hg dual-comagnetometer that can monitor the magnetic field drift and reduce the uncertainties arising from geometric phase effects caused by inhomogeneous fields.
Using UV light sources, we will excite transitions in $^{129}$Xe and $^{199}$Hg suitable for detection of their spin...
Steven Clayton
(Los Alamos National Laboratory)
18/10/2017, 11:40
In the SNS nEDM experiment, liquid helium at around 0.4 Kelvin will fill and surround the measurement cells. In addition to its roles in superthermal production of ultracold neutrons and scintillator, the liquid helium has excellent dielectric strength, and the planned electric field in the cells is ~75 kV/cm. This field requires a voltage applied to the central electrode of ~650 kV. Instead...
Dr
Ekaterina Korobkina
(NCSU)
18/10/2017, 12:05
nEDM @SNS experiment is designed to be able to measure neutron EDM down to $10^{−28}$ range due to special technique for suppressing systematic effect arising from magnetic field gradients in presence of electric field. This technique requires cryogenic environment at about 0.5K and use of polarized $^3He$ in the same cell as trapped neutrons. We also plan to utilize simultaneous spin dressing...
Dr
Takeyasu Ito
(Los Alamos National Laboratory)
18/10/2017, 13:45
The SNS nEDM collaboration is developing an experiment to search for the neutron’s electric dipole moment (EDM), using ultracold neutrons (UCNs) stored in superfluid liquid helium, to be run at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. In this experiment, being able to achieve a strong and stable electric field in superfluid liquid helium in the region where UCNs...
Dr
Florian Kuchler
(TRIUMF)
18/10/2017, 14:10
The currently established best limit on the neutron EDM was obtained by eliminating and investigating main systematic effects using an atomic co-magnetometer inside the neutron storage volume.
The next generation neutron EDM search at TRIUMF aims to introduce 129-Xe as co-magnetometer due to its low neutron absorption cross section. An optical detection scheme of 129-Xe spin precession is...
Dr
Nguyen Phan
(Los Alamos National Laboratory)
18/10/2017, 14:35
Realization of large electric fields is an important goal for neutron electric dipole moment (nEDM) experiments. For a nEDM experiment performed in superfluid helium such as the SNS nEDM experiment, it is vital to understand the behavior of high electric fields in this medium. The electrical breakdown, which limits the applicable electric potential and field, in liquid helium is poorly...
Mr
Shomi Ahmed
(for the TRIUMF Japan-Canada UCN Collaboration)
18/10/2017, 15:00
The existence of a non-zero neutron electric dipole moment (nEDM) would violate parity and time-reversal symmetry. Extensions to the Standard Model predict the nEDM to be $10^{-26}$ -- $10^{-28}$ e-cm. The current best upper limit set by Sussex/RAL/ILL nEDM experiment is $3.0 \times 10^{-26}$ e-cm. The nEDM experiment at TRIUMF is aiming at the $10^{-27}$ e-cm sensitivity level . We are...
Emily Altiere
(University of British Columbia),
Eric Miller
(University of British Columbia)
18/10/2017, 15:00
Poster
The nEDM (neutron electric dipole moment) project at TRIUMF’s recently established ultra cold neutron (UCN) facility in Canada will introduce a dual co-magnetometer with cohabiting 129Xe and 199Hg for measuring precise magnetic fields within a neutron storage cell. By simultaneously incorporating two atomic species we can deduce both the magnitude and gradient of the magnetic fields, thereby...
Dr
arnaud leredde
(LPSC, Université Grenoble-Alpes)
18/10/2017, 15:00
Poster
In the scope of the n2EDM experiment, aiming for a sensitivity of $σ_{d_n }=1×10^{-27}$e.cm, the precise measurement of the magnetic field and its gradients is critical. Taking advantage of the gravitational shift between the neutrons and the mercury atoms of the co-magnetometer to correct for the false EDM induced by the relativistic motional field, this problem reduces to the knowledge of...
Ms
Solange Emmenegger
(ETH Zürich)
18/10/2017, 15:00
The nEDM experiment at the Paul Scherrer Institute (PSI) has finished data taking and preparations for the installation of the new n2EDM apparatus are in progress. This poster presents the best performances of the nEDM experiment in terms of the transverse spin relaxation time $T_2$, the visibility $\alpha$ and the best statistical sensitivity per day. We also show the best performances of the...
Steve Sidhu
(TRIUMF, SFU)
18/10/2017, 15:00
Poster
The newly installed vertical source at TRIUMF will enable the production of
neutrons with energies below 300~neV, referred to as ultracold neutrons (UCN).
A superfluid helium cryostat uses three cooling stages and a heat exchanger to
produce isopure He-II at <1K. Fast neutrons are produced through spallation
of a tungsten target by a proton beam from the TRIUMF 520~MeV cyclotron.
These...
Ms
Taraneh Andalib
(University of Manitoba/TRIUMF/University of Winnipeg)
18/10/2017, 15:00
Poster
The neutron EDM experiment at TRIUMF aims to measure the nEDM to the
precision of ~$10^{−27}$ e$\cdot$cm by using a new superfluid He ultracold
neutron (UCN) source. The Japan-Canada UCN source is unique in
combining a neutron spallation source with superfluid helium. The new
UCN source is expected to yield the highest density of UCNs
worldwide. The ongoing research on the present...
Mr
Nicholas Ayres
(University of Sussex)
18/10/2017, 15:45
**nEDM as a dark matter detector: constraints on axion-like dark matter from limits on an oscillating EDM**
N. J. Ayres for the nEDM collaboration at PSI
Axions and axion-like particles (ALPs) are popular dark matter candidates. Ultralight axion and ALP cold dark matter would manifest as a classical field, oscillating coherently on a galactic scale. Through their couplings to gluons,...
Peter Geltenbort
18/10/2017, 16:05
Neutron electric dipole moment (nEDM) research at the Petersburg Nuclear Physics Institute (PNPI) in Gatchina, Russia, is briefly reviewed and the present and near future programme led by PNPI at the Institut Laue Langevin (ILL) in Grenoble, France, outlined.
Prof.
Robert Golub
(NCSU)
18/10/2017, 16:35
The behavior of a spin undergoing Larmor precession in the presence of
fluctuating fields is of interest to workers in many fields. Particles making random walks in inhomogeneous fields see time fluctuating fields which cause frequency shifts and relaxation which are related to their power spectrum, which can be determined by taking the Fourier transform of the auto-correlation functions of...
Mr
Michał Rawlik
(ETH Zürich)
19/10/2017, 09:00
A measurement of the neutron electric dipole moment requires the magnetic field to be stable on a picotesla level. Yet in a typical experimental hall there are strong sources of magnetic field, nemeses of precise nEDM mesurements. A large-scale mapping, performed prior to the installation of the apparatus, can resolve the spatial distribution of the field. During the nEDM measurement the...
Prof.
Christopher Bidinosti
(University of Winnipeg)
19/10/2017, 09:25
The TRIUMF nEDM experiment employs a magnetically shielded Ramsey Resonance based EDM apparatus employing ultracold neutrons from a spallation based isopure Helium-II UCN source that is currently under construction at TRIUMF. Fluctuations and inhomogeneities of the roughly 1-uT measurement field are expected to be one of the leading sources of systematic errors in the experiment. This...
Mr
Pierrick Flaux
(LPC Caen)
19/10/2017, 09:50
This work presents a preliminary design of the coils system
developped for the neutron electric dipole moment experiment (n2EDM)
at the Paul Sherrer Institute (PSI). The goal of this experiment is to find
new sources of CP violation through the measurement of the neutron
electric dipole. The current best limit of the nEDM measurement, 2.9 $\times$ 10$^{ -26}$
e.cm (90% C.L.) was reached...
Mr
Reza Tavakoli-Dinani
(Department of Physics, Simon Fraser University)
19/10/2017, 10:40
It has long been proposed [1] that spin dressing [2] could be employed to realize a highly effective helium-3 nuclear precession co-magnetometer for a neutron electric dipole moment search. The proposal requires application of an intense, continuous, and far off-resonant oscillating magnetic field in such a way that the apparent Larmor precession frequency of both species is modified. Under...
Dr
Jochen Krempel
(ETH Zürich - Institute for Particle Physics and Astrophysics)
19/10/2017, 11:05
Psychological bias towards (or away from) a prior measurement or a theory prediction is an intrinsic threat to any data analysis. While various methods can be used to avoid the bias (e.g. actively not looking at the result), only data blinding is a traceable and thus trustworthy method to circumvent the bias and to convince the external audience that there is not even an accidental...
Mr
Sean Hansen-Romu
(University of Winnipeg)
19/10/2017, 11:30
Transport and manipulation of ultra cold neutrons (materials, valves, polarization, spin transport, neutron detection)
Oral
The Ultracold Neutron (UCN) source at TRIUMF is expected to produce a high density of UCN, and TRIUMF’s first experiment using this source will be a search for a neutron Electric Dipole Moment (nEDM). Tests of a lithium glass scintillator detector capable of meeting the expected high rate of UCN was tested at PSI in 2015, and the design of an apparatus to use four of these detectors is...
