相关论文: Development and application of a $^3$He Neutron Sp…
Maintaining high levels of 3He polarization over long periods of time is important to many areas of fundamental and particle beam physics. Long measurement times are often required in such experiments and the data quality is a function of…
This article reviews the physics and technology of producing large quantities of highly spin-polarized, or hyperpolarized, $^3$He nuclei using spin-exchange (SEOP) and metastability-exchange (MEOP) optical pumping, and surveys applications…
We present the development of high-performance polarized $^3\mathrm{He}$ targets for use in electron scattering experiments that utilize the technique of alkali-hybrid spin-exchange optical pumping. We include data obtained during the…
Polarized eV neutrons can address interesting scientific questions in nuclear physics, particle physics, and astrophysics/cosmology. We present the first experiment to polarize the neutrons on the Back-n beamline at the Chinese Spallation…
Following the first experiment on three-body photodisintegration of polarized $^3$He utilizing circularly polarized photons from High Intensity Gamma Source (HI$\gamma$S) at Duke Free Electron Laser Laboratory (DFELL), a new high-pressure…
We present two recent projects which aim to improve the performance of polarized neutron scattering experiments using hyperpolarized $^{3}He$ spin filters at ISIS. The first is the optimization of a new compact magnetostatic cavity ("Magic…
The proposed polarized $^3$He$^{++}$ acceleration in RHIC and the future Electron-Ion Collider will require about $2\times10^{11}$ ions in the source pulse. A new technique had been proposed for production of high intensity polarized…
The Japan Proton Accelerator Research Complex (J-PARC) currently delivers a 1 MW, 3 GeV proton beam to the Materials and Life Science Experimental Facility (MLF). Power is expected to increase to 1.3 MW, driven by the needs of…
We have observed depolarization effects when high intensity cold neutron beams are incident on alkali-metal-spin-exchange polarized He-3 cells used as neutron spin filters. This was first observed as a reduction of the maximum attainable…
We report high steady-state nuclear polarization of 1 torr $^3$He gas nuclei via metastability-exchange optical pumping at magnetic fields above 2 T. The introduction of highly polarized $^3$He gas into Brookhaven's Electron Beam Ion Source…
Systematic studies on metastability exchange optical pumping of $^3$He nuclei have been performed at Jefferson Lab using a 1-torr sealed cell at magnetic fields from 2 to 4 T. The effects of the discharge intensity, pump laser power, and…
We report high nuclear polarization of 1.2 mbar 3He gas in a sealed cell in magnetic fields up to 5 T using Metastability Exchange Optical Pumping (MEOP). The creation of a highly polarized 3He gas target for use in the 5 T field of…
We present the conceptual design of a polarized $^3$He target to be used for high luminosity scattering experiments within high magnetic field environments. This two-cell target will take advantage of advancements in optical pumping…
Metastability exchange optical pumping (MEOP) is a widely used technique for producing polarized $^{3}$He. In connection with an experiment to search for the electric dipole moment of the neutron (nEDM) we have built a MEOP based $^{3}$He…
Since 2012, a BNL-MIT collaboration has worked to develop a polarized $^3$He ion source for the Relativistic Heavy Ion Collider (RHIC) using the existing Electron Beam Ionization Source (EBIS). $^3$He atoms are polarized using optical…
A spin-polarized triplet metastable helium (He*) beam has been used as a probe for surface magnetism, but changes in the spin state during scattering from a surface remain unclear. In the present study, we explored this issue by…
A laser-driven spin-polarized 3He2+ beam source for nuclear-physics experiments and for the investigation of polarized nuclear fusion demands a high-density polarized 3He gas-jet target. Such a target requires a magnetic system providing a…
After being hyperpolarized using the technique of Metastability Exchange Optical Pumping (MEOP), 3He can be used as a contrast agent for lung magnetic resonance imaging (MRI). MEOP is usually performed at low magnetic field (~ 1 mT) and low…
A method to measure a beam polarization with the use of polarized 3He gas is discussed. It is shown that special design of the Neutron Spin Filter cell allows for a fast and accurate measurement. The accuracy of this method is analyzed.
The capability of performing accurate measurements of neutron beam polarization opens a number of exciting opportunities in fundamental neutron physics and in neutron scattering. At the LANSCE pulsed neutron source we have measured the…