A5007324714- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Quantum, superfluid, helium dynamics
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Nuclear Physics and Applications
- Magnetic confinement fusion research
- Cold Atom Physics and Bose-Einstein Condensates
- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Radiation Detection and Scintillator Technologies
- Plasma Diagnostics and Applications
- Nuclear physics research studies
- Dark Matter and Cosmic Phenomena
- Radioactive Decay and Measurement Techniques
- Scientific Research and Discoveries
- Physics of Superconductivity and Magnetism
- High-Energy Particle Collisions Research
- Thermal Analysis in Power Transmission
- Nuclear reactor physics and engineering
- Advanced Frequency and Time Standards
- Spacecraft and Cryogenic Technologies
- Electrostatics and Colloid Interactions
- Geothermal Energy Systems and Applications
- Quantum and electron transport phenomena
Montclair State University
2021-2024
North Carolina State University
2016-2022
Triangle Universities Nuclear Laboratory
2016-2022
North Central State College
2022
Duke University
2022
Institut Laue-Langevin
2009-2016
Technical University of Munich
2009-2015
University of Auckland
2009
Lawrence Berkeley National Laboratory
2000-2003
Supercon (United States)
1991-2002
A cryogenic apparatus is described that enables a new experiment, nEDM@SNS, with major improvement in sensitivity compared to the existing limit search for neutron Electric Dipole Moment (EDM). This uses superfluid 4He produce high density of Ultra-Cold Neutrons (UCN) which are contained suitably coated pair measurement cells. The be operated at Spallation Neutron Source Oak Ridge National Laboratory, polarized 3He from an Atomic Beam injected into and transported cells where it serves as...
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.
A new intense superthermal source for ultracold neutrons (UCN) was installed at a dedicated beam line the Institut Laue-Langevin. Incident with wavelength of 0.89 nm are converted to UCN in 5-liter volume filled superfluid $^{4}\mathrm{He}$ temperature about 0.7 K. The can be extracted room experiments. We present cryogenic setup source, characterization cold neutron beam, and production measurements, where density least 55 per ${\mathrm{cm}}^{3}$ determined.
Ultracold neutron (UCN) storage measurements were made in a trap constructed from 1.3-T Halbach octupole permanent (HOPE) magnet array aligned vertically, using the TES port of PF2 source at Institut Laue-Langevin. A mechanical UCN valve bottom was used for filling and emptying. This covered with Fomblin grease to induce nonspecular reflections combination movable polyethylene remover inserted top cleaning above-threshold UCNs. Loss depolarization suppressed minimum 2-mT bias field. Without...
Ultracold neutrons (UCNs) were produced in a 4 liter volume of superfluid helium using the PF1B cold neutron beam facility at Institut Laue-Langevin and then extracted to detector room temperature. With converter temperature 1.08 K number accumulated UCNs was counted be $91,\!700 \pm 300$. From this, we derive volumetric UCN production rate $(6.9 1.7)\,\mathrm{cm^{-3}\,s^{-1}}$, which includes correction for losses during extraction caused by short storage time, but not accounting transport...
We investigate experimentally the pressure dependence of production ultracold neutrons (UCNs) in superfluid helium range from saturated vapor to 20 bar. A neutron velocity selector allows separation underlying single-phonon and multiphonon processes by varying incident cold (CN) wavelength $3.5$ 10 \AA{}. The predicted UCN derived inelastic scattering data is confirmed for excitation. For multiphonon-based we found no significant on pressure, whereas calculations predict an increase 43(6)%...
Differential cross sections for Compton scattering from the proton have been measured at angles of 55°, 90°, and 125° in laboratory frame using quasimonoenergetic linearly (circularly) polarized photon beams with a weighted mean energy value 83.4 MeV (81.3 MeV). These measurements were performed High Intensity Gamma-Ray Source facility Triangle Universities Nuclear Laboratory. The results are compared to previous interpreted chiral effective field theory framework extract electromagnetic...
The physics model of a next-generation spallation-driven high-current ultracold neutron (UCN) source capable delivering an extracted UCN rate around an-order-of-magnitude higher than the strongest proposed sources, and three-orders-of-magnitude existing is presented. This UCN-current-optimized would dramatically improve cutting-edge measurements that are currently statistically limited. A novel "Inverse Geometry" design used with 40 L superfluid $^4$He (He-II), which acts as converter cold...
We analyze the spin flip loss for ultracold neutrons in magnetic bottles of type used experiments aiming at a precise measurement neutron lifetime, extending one-dimensional field model previously by Steyerl $\textit{et al.}$ [Phys.Rev.C $\mathbf{86}$, 065501 (2012)] to two dimensions cylindrical multipole fields. also develop general analysis applicable three dimensions. Here we apply it fields and bowl-type configuration Los Alamos UCN$\tau$ experiment. In all cases considered calculated...
Differential cross sections for elastic Compton scattering from $^4$He have been measured with high statistical precision at the High Intensity $\gamma$-ray Source laboratory angles of $55^\circ$, $90^\circ$, and $125^\circ$ using a quasi-monoenergetic photon beam weighted mean energy value $81.3$ MeV. The results are compared to previous measurements similar fore-aft asymmetry in angular distribution differential is observed. This experimental work expected strongly motivate development...
The authors describe the mechanical design of ends Superconducting Super Collider (SSC) dipole magnets to be constructed and tested at Fermilab. Coil end clamps, yoke configuration, plate are discussed. Loading by axial Lorentz forces is examined. Relevant data from 40 mm 50 aperture model built Fermilab presented. In particular, apparent influence clamp on quench behavior SSC dipoles described.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
The half-life of the nucleus $^{10}\mathrm{C}$ has been determined by detecting its decay positrons in an $E\ensuremath{-}\ensuremath{\Delta}E$ fast scintillator telescope and recording data event mode. Care was taken to exclude effects possible contaminant activities pileup linear electronic systems. A value 19.282(11) s obtained, which is good agreement with two three previous measurements, but not most recent.
Novel experimental techniques are required to make the next big leap in neutron electric dipole moment sensitivity, both terms of statistics and systematic error control. The nEDM experiment at Spallation Neutron Source (nEDM@SNS) will implement scheme Golub & Lamoreaux [Phys. Rep., 237, 1 (1994)]. unique properties combining polarized ultracold neutrons, 3 He, superfluid 4 He be exploited provide a sensitivity ∼ 10 −28 e · cm. Our cryogenic apparatus deploy two small (3 L) measurement...
We have experimentally studied growing a large (about 1 liter) ortho-deuterium crystal in real UCN source cryostat and recorded the process optically using camera. The best quality was observed when directly from vapor phase. grown at different mass flows of deuterium annealed temperatures. Optimum conditions were found for both, obtaining an transparent cooling it down with minimal damage. that quality, final shape changes during annealing are very much dependent on temperature profile walls.
This paper presents a new technique to study the adsorption and desorption of ions electrons on insulating surfaces in presence strong electric fields cryoliquids. The experimental design consists compact cryostat coupled with sensitive electro-optical Kerr device monitor stability fields. behavior nitrogen helium poly(methyl methacrylate) (PMMA) surface was compared PMMA coated mixture deuterated polystyrene polybutadiene. Ion accumulation removal these were unambiguously observed. Within...
This paper presents a new technique to study the adsorption and desorption of ions electrons on insulating surfaces in presence strong electric fields cryoliquids. The experimental design consists compact cryostat coupled with sensitive electro-optical Kerr device monitor stability fields. behavior nitrogen helium poly(methyl methacrylate) (PMMA) surface was compared PMMA coated mixture deuterated polystyrene polybutadiene. Ion accumulation removal these were unambiguously observed. Within...