arXiv subjects

Richard Milner

Publications and source records attributed to Richard Milner.

9 recordsLinked to original sources

arXiv2025

Polarizing 3He via Metastability Exchange Optical Pumping Using a 1.2 mbar Sealed Cell at Magnetic Fields up to 5 T

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 Jefferson Lab's CLAS12 spectrometer would enable new studies of spin-dependent asymmetries on the neutron. A systematic study was conducted to evaluate the effects of discharge intensity, pump laser power, and optical pumping transition schemes on nuclear polarization and pumping rates. Steady-state polarizations up to 86 % in magnetic fields between 2 and 5 T were achieved, with a discharge-on relaxation time of 898 s at 5 T. These results underscore the potential of MEOP for high-field applications in nuclear physics experiments.

physics.ins-det↗

arXiv2023

Measurement of $^3$He$^{++}$ Polarization at 5.3 MeV via Scattering with an Unpolarized $^4$He Target

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 pumping at high field and injected as neutral atoms into the EBIS. A critical issue is the demonstration that the polarization of the extracted $^3$He$^{++}$ ions from the source is high. In 2014, a concept to measure the nuclear polarization was developed in this paper. Since then, the development of the polarized $^3$He ion source has progressed, the polarimeter is under construction, and the demonstration experiment is expected to take place in the next several years.

physics.ins-det↗

arXiv2023

Scientific Opportunities at the ARIEL Electron Linac

This paper gives an overview of the scientific opportunities at the ARIEL electron accelerator identified in open discussion at the workshop, including applications in hadron structure, astrophysical processes, tests of quantum electrodynamics, dark matter and other BSM physics, and material science.

nucl-ex↗

arXiv2021

Neutron Spin Structure from e-3He Scattering with Double Spectator Tagging at the Electron-Ion Collider

The spin structure function of the neutron is traditionally determined by measuring the spin asymmetry of inclusive electron deep inelastic scattering (DIS) off polarized3He nuclei. In such experiments, nuclear effects can lead to large model dependencies in the interpretation of experimental data. Here we study the feasibility of suppressing such model dependencies by tagging both spectator protons in the process of DIS off neutrons in3He at the forthcoming Electron-Ion Collider (EIC). This allows reconstructing the momentum of the struck neutron to ensure it was nearly at rest in the initial state, thereby reducing sensitivity to nuclear corrections, and suppress contributions from electron DIS off protonsin3He. Using realistic accelerator and detector configurations, we find that the EIC can probe the neutron spin structure from xB of 0.003 to 0.651. We further find that the double spectator tagging method results in reduced uncertainties bya factor of 4 on the extracted neutron spin asymmetries over all kinematics, and by a factor of 10 in the low-xB region,thereby providing valuable insight to the spin and flavor structure of nucleons

nucl-ex↗

arXiv2021

A Concept for Polarized $^3$He Targets for High Luminosity Scattering Experiments in High Magnetic Field Environments

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 techniques at high magnetic field to create 60% longitudinally polarized $^3$He gas in a pumping cell within a uniform magnetic field above 1 T. By transferring the polarized gas to cryogenic target cell, the gas density is increased to create a target thickness suitable for high luminosity applications. We discuss the general design of this scheme, and plans for its application in Jefferson Lab's CLAS12 detector.

physics.ins-det↗

arXiv2020

CFNS Ad-Hoc meeting on Radiative Corrections Whitepaper

Current precision scattering experiments and even more so many experiments planed for the Electron Ion Collider will be limited by systematics. From the theory side, a fundamental source of systematic uncertainty is the correct treatment of radiative effects. To gauge the current state of technique and knowledge, help the cross-pollination between different direction of nuclear physics, and to give input to the yellow report process, the community met in an ad-hoc workshop hosted by the Center for Frontiers in Nuclear Science, Stony Brook University. This whitepaper is a collection of contributions to this workshop.

nucl-th↗

arXiv2019

Conceptual Design of a Polarized 3He Target for the CLAS12 Spectrometer

We present a conceptual design for a polarized $^3$He target for Jefferson Lab's CLAS12 spectrometer in its standard configuration. This two-cell target will take advantage of advancements in optical pumping techniques at high magnetic field to create 60\% longitudinally polarized $^3$He gas in a pumping cell inside the CLAS12 5 T solenoid. By transferring this gas to a 20 cm long, 5 K target cell, a target thickness of $3 \times 10^{21}$ $^3$He/cm$^2$ will be produced, reaching the detector's specified maximum luminosity with a beam current of 2.5 $\mu A$.

physics.ins-det↗

arXiv2018

Spin-Dependent DIS from Polarized $^3$He at EIC

A day-1 EIC detector should be prepared to carry out inclusive DIS measurements from electron collisions with nucleon and nuclear beams. Here I consider the scientific motivation for spin-dependent DIS measurements from a polarized $^3$He beam. Longitudinally polarized $^3$He ions can be used to measure $g^n_1(x,Q^2)$ in purely inclusive scattering. I also consider spin-dependent DIS from polarized $^3$He by tagging the spectator proton or deuteron in coincidence with the scattered electron. A calculation of high energy scattering from the polarized $^3$He nucleus in the EIC frame is motivated. Further, this type of measurement can be extended to other polarized few-body nuclei. High energy spin-dependent scattering from polarized $^3$He with tagged proton and deuteron could be studied experimentally ahead of EIC using spin-dependent proton-$^3$He scattering in RHIC, when polarized $^3$He ions become available.

nucl-ex↗

arXiv2005

Study of the Fundamental Structure of Matter with an Electron-Ion Collider

We present an overview of the scientific opportunities that would be offered by a high-energy electron-ion collider. We discuss the relevant physics of polarized and unpolarized electron-proton collisions and of electron-nucleus collisions. We also describe the current accelerator and detector plans for a future electron-ion collider.

hep-ph↗