W. C. Griffith
A5090667749- Atomic and Subatomic Physics Research
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Astrophysics and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Quantum, superfluid, helium dynamics
- Radiation Detection and Scintillator Technologies
- Carcinogens and Genotoxicity Assessment
- Cold Atom Physics and Bose-Einstein Condensates
- Radiation Dose and Imaging
- Air Quality and Health Impacts
- Nuclear Physics and Applications
- Radioactivity and Radon Measurements
- Particle Detector Development and Performance
- Radioactive contamination and transfer
- Radiopharmaceutical Chemistry and Applications
- Nuclear and radioactivity studies
- Advanced MRI Techniques and Applications
- Quantum optics and atomic interactions
- Advanced Frequency and Time Standards
- Air Quality Monitoring and Forecasting
- Veterinary Oncology Research
- Toxic Organic Pollutants Impact
- Medical Imaging and Pathology Studies
- Graphite, nuclear technology, radiation studies
University of Sussex
2015-2025
Sussex County Community College
2018-2024
Addenbrooke's Hospital
2017
California Institute of Technology
2017
University of Washington
2001-2016
Los Alamos National Laboratory
2013-2016
National Institute of Standards and Technology
2009-2012
National Institute of Standards
2009
Theodore Roosevelt High School
2004
Lovelace Respiratory Research Institute
1980-1997
We present the result of an experiment to measure electric dipole moment (EDM) neutron at Paul Scherrer Institute using Ramsey's method separated oscillating magnetic fields with ultracold neutrons (UCN). Our measurement stands in long history EDM experiments probing physics violating time reversal invariance. The salient features this were use a Hg-199 co-magnetometer and array optically pumped cesium vapor magnetometers cancel correct for field changes. statistical analysis was performed...
We report the results of a new experimental search for permanent electric dipole moment 199Hg utilizing stack four vapor cells. find d(199Hg)=(0.49+/-1.29_{stat}+/-0.76_{syst})x10;{-29} e cm, and interpret this as upper bound, |d(199Hg)|<3.1x10;{-29} cm (95% C.L.). This result improves our previous limit by factor 7, can be used to set constraints on CP violation in physics beyond standard model.
We present for the first time a detailed and comprehensive analysis of experimental results that set current world sensitivity limit on magnitude electric dipole moment (EDM) neutron. have extended enhanced our earlier to include recent developments in understanding effects gravity depolarizing ultracold neutrons (UCN); an improved calculation spectrum neutrons; conservative estimates other possible systematic errors, which are also shown be consistent with more measurements undertaken...
We report on a search for ultralow-mass axionlike dark matter by analyzing the ratio of spin-precession frequencies stored ultracold neutrons and 199Hg atoms an axion-induced oscillating electric dipole moment neutron axion-wind effect. No signal consistent with is observed axion mass range 10−24≤ma≤10−17 eV. Our null result sets first laboratory constraints coupling to gluons, which improve astrophysical limits up 3 orders magnitude, also improves previous nucleons factor 40.Received 29...
We present the first results of a new search for permanent electric dipole moment 199Hg atom using UV laser. Our measurements give d(199Hg) = -(1.06+/-0.49+/-0.40)x10(-28)e cm. interpret result as an upper limit absolute value [d(199Hg)]<2.1x10(-28)e cm (95% C.L.), which sets constraints on theta bar;(QCD), chromo-EDMs quarks, and CP violation in supersymmetric models.
We describe an optically pumped 87 Rb magnetometer with 5 fT/Hz 1/2 sensitivity when operated in the spin-exchange relaxation free (SERF) regime.The uses a microfabricated vapor cell consisting of cavity etched 1 mm thick silicon wafer anodically bonded Pyrex windows.The measurement volume is 3 , defined by overlap region circularly polarized pump laser and linearly probe laser, both near 795 nm.Sensitivity limitations unique to use cells are discussed.
Studies were completed in F344/N rats and B6C3F1 mice to determine the effect of dose, dose rate, route administration, rodent species on formation total individual benzene metabolites. Oral doses 50 mg/kg or higher saturated capacity for metabolism both mice, resulting an increased proportion administered being exhaled as benzene. The saturating air concentration during 6-hr exposures was between 130 900 ppm. At highest exposure concentration, approximately half internal retained at end...
We discuss in detail the search for a permanent electric dipole moment (EDM) of ${}^{199}\mathrm{Hg}$ atom reported by Griffith et al. [Phys. Rev. Lett. 102, 101601 (2009)]. The upper bound, $d{(}^{199}\text{Hg})<3.1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}29}$ $e$ cm (95$%$ C.L.), is factor 7 improvement over best previous EDM limit ${}^{199}$Hg, provides most sensitive probe to date EDMs diamagnetic atoms, and sets new limits on time-reversal symmetry violation extensions...
It has been proposed that there could be a mirror copy of the standard model particles, restoring parity symmetry in weak interaction on global level. Oscillations between neutral particle, such as neutron, and its counterpart potentially answer various standing issues physics today. Astrophysical studies terrestrial experiments led by ultracold neutron storage measurements have investigated to mirror-neutron oscillations imposed constraints theoretical parameters. Recently, further analysis...
We present the design of a next-generation experiment, n2EDM, currently under construction at ultracold neutron source Paul Scherrer Institute (PSI) with aim carrying out high-precision search for an electric dipole moment neutron. The project builds on experience gained previous apparatus operated PSI until 2017, and is expected to deliver order magnitude better sensitivity provision further substantial improvements. An overview experimental method setup given, requirements are derived, its...
Static electric dipole moments of nondegenerate systems probe mass scales for physics beyond the Standard Model well those reached directly at high energy colliders. Discrimination between different models, however, requires complementary searches in atomic-molecular-and-optical, nuclear and particle physics. In this report, we discuss current status prospects near future a compelling suite such experiments, along with developments needed encompassing theoretical framework.
Abstract High-precision searches for an electric dipole moment of the neutron (nEDM) require stable and uniform magnetic field environments. We present recent achievements degaussing equilibrating magnetically shielded room (MSR) n2EDM experiment at Paul Scherrer Institute. final configuration that will be used after numerous studies. The optimized procedure results in a residual has been reduced by factor two. ultra-low is achieved with full magnetic-field-coil system, large vacuum vessel...
We present a coil system designed to generate highly uniform magnetic field for the n2EDM experiment at Paul Scherrer Institute. It consists of main B0 and set auxiliary coils mounted on cubic structure with side length 273cm , inside large magnetically shielded room (MSR). have assembled this characterized its performances mapping robot. The apparatus is able 1μT vertical relative root mean square deviation σ(Bz)/Bz=3×10-5 over volume interest, cylinder radius 40cm height 30cm . This level...
High permeability magnetic flux concentrators are used to enhance the sensitivity of an atomic magnetometer operating in spin-exchange relaxation-free regime. The uses a millimeter scale Rb87 vapor cell and either mu-metal or Mn–Zn ferrite concentrators. measured gives excellent agreement with calculations thermal noise from concentrator material. allow 50fTHz−1∕2, limited by current noise. magnetization at low frequencies, reach 10fTHz−1∕2 for frequencies above 125Hz.
We compare the sensitivity performance of two optically pumped atomic magnetometers based on Mx and frequency-modulated bell-bloom configurations. The Cs are implemented using a millimeter-scale microfabricated vapor cell. It is found that Bell-Bloom magnetometer yields sensitivities similar to those when operated under equally optimized conditions. approach offers several attractive features over for chip-scale instrumentation.
OBJECTIVES: Animal inhalation studies and theoretical models suggest that the pattern of formation benzene metabolites changes as exposure to increases. To determine if this occurs in humans, urine samples collected part a cross sectional study occupationally exposed workers Shanghai, China were measured. METHODS: With organic vapour monitoring badges, 38 subjects monitored during their full workshift for benzene. The urinary phenol, catechol, hydroquinone, muconic acid measured with an...
We demonstrate a scalar Rb87 optical magnetometer that retains magnetic-field sensitivities below 10pT/√Hzover 3 dB bandwidths of 10 kHz in an ambient field Bo=11.4 μT and using measurement volume 1 mm3. The operates at high atomic densities where both the sensitivity bandwidth are limited by spin-exchange collisions between alkali atoms. By operating this regime, our measurements show can be increased without significant degradation its sensitivity.
Magnetic-field uniformity is of the utmost importance in experiments to measure electric dipole moment neutron. A general parametrization magnetic field terms harmonic polynomial modes proposed, going beyond linear-gradients approximation. We review main undesirable effects nonuniformities: depolarization ultracold neutrons and Larmor frequency shifts mercury atoms. The theoretical predictions for these were verified by dedicated measurements with single-chamber neutron...
We present the magnetically shielded room (MSR) for n2EDM experiment at Paul Scherrer Institute which features an interior cubic volume with each side of length 2.92m, thus providing accessible space 25m3. The MSR has 87 openings up to 220mm diameter operate experimental apparatus inside, and intermediate between layers sensitive signal processing electronics. characterization measurements show a remanent magnetic field in central 1m3 below 100pT, 600pT entire inner volume, 4\,cm walls....
SBND is the near detector of Short-Baseline Neutrino program at Fermilab. Its location to Booster Beam source and relatively large mass will allow study neutrino interactions on argon with unprecedented statistics. This paper describes expected performance photon detection system, using a simulated sample beam neutrinos cosmogenic particles. design dual readout concept combining system 120 photomultiplier tubes, used for triggering, 192 X-ARAPUCA devices, located behind anode wire planes....
Intact female Beagles from life-span studies in the Lovelace Respiratory Research Institute colony were examined for mammary tumor incidence. The breeding colony, founded 1963, produced five generations 28 founder females. After proportional hazards analysis, two maternal families shown to have markedly different phenotypes, one susceptible and resistant neoplasia, as compared with entire colony. When tumors subdivided into benign malignant based on local invasiveness, familial differences...
As part of long-term pulmonary carcinogenesis studies in dogs, it is important to analyze the incidence spontaneous lung neoplasia. Primary carcinoma was determined two control populations Beagle dogs observed for their life spans. One population comprised 216 (112 males and 104 females) that were controls span studies, another 182 (50 132 retirees from a breeding colony. Forty neoplasms noted 398 dogs; 35 carcinomas classified as papillary adenocarcinoma (20), bronchioloalveolar (9),...