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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Accelerator/Experiment Operations - FY 2016

This Technical Memorandum summarizes the Fermilab accelerator and experiment operations for FY 2016. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2016 NOvA, MINOS+ and MINERvA experiments using the Main Injector Neutrino Beam (NuMI), the MicroBooNE experiment and the activities in the SciBooNE Hall using the Booster Neutrino Beam (BNB), and the SeaQuest experiment, LArIAT experiment and Meson Test Beam activities in the 120 GeV external switchyard beam (SY120). Each section was prepared by the relevant authors, and was then edited for inclusion in this summary.

43 PARTICLE ACCELERATORS↗
DOE OSTI2018

Accelerator/Experiment Operations - FY 2018

This Technical Memorandum summarizes the Fermilab accelerator and experiment operations for FY 2018. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2018 NOvA and MINERvA experiments using the Main Injector Neutrino Beam (NuMI), the MicroBooNE experiment, LArIAT experiment, and Meson Test Beam activities in the 120 GeV external switchyard beam (SY120).

43 PARTICLE ACCELERATORS↗
DOE OSTI2017

Accelerator/Experiment Operations: FY17

This Technical Memorandum summarizes the Fermilab accelerator and experiment operations for FY 2017. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2017 NOvA, MINOS+ and MINERvA experiments using the Main Injector Neutrino Beam (NuMI), the MicroBooNE experiment and the activities in the SciBooNE Hall using the Booster Neutrino Beam (BNB), and the SeaQuest experiment, LArIAT experiment and Meson Test Beam activities in the 120 GeV external switchyard beam (SY120).

43 PARTICLE ACCELERATORS↗
DOE OSTI2018

Beam asymmetry for photoproduced omega mesons off bound protons in deuterons

Quantum chromodynamics (QCD) is the fundamental theory underlying the strong interaction. Great effort has been dedicated to explain hadron interactions and the hadron composition in terms of the QCD degrees of freedom (quarks and gluons). However, this task has been largely complicated by confinement, an intrinsic feature of QCD itself, which prevents us from a direct experimental study of the dynamics of quarks and gluons. Instead, QCD-inspired models have been developed to explain the hadron spectrum, and while there has been success in explaining important features of it, many of the states that have been predicted by these models have not been found experimentally. Furthermore, the hadronic spectrum is much more complicated to analyze than the atomic one because of a high number of excited states of the nucleon which have large widths that cause resonances to overlap. Also, these resonances may decay into a multitude of decay channels involving either mesons or baryons. Additionally, we will need measurements of observables, coming from polarized beam and polarized target experiments, to obtain a complete measurement of all the helicity amplitudes. My current research aims at contributing to a larger experimental program that seeks to shed light on the evolving status of the proton spectrum. I focus on the photoproduction of ω mesons off the bound proton, which is of great interest in providing information about N* resonances as ω is an isospin filter. I have extracted a preliminary quasi-free right-arrow gamma delta → ωp(n) photon beam asymmetry polarization observable from CLAS data. The ω meson was identified through its charged decay ω → π + π - π 0 where the π 0 subsequently decays in two photons. The data were taken during the E06-103 experiment with the CLAS detector in Hall B at the Thomas Jefferson National Accelerator Laboratory (JLab). The experiment used the Hall-B Coherent Bremsstrahlung Facility to provide a high quality beam of linearly-polarized photons in the energy range from 1.1 to 2.3 GeV.

Source record↗
DOE OSTI2026

Neutrino Beam Monitoring

Accelerator facilities produce neutrino beams from meson decays in a decay volume. Experiments measure event rates that depend on flux, cross sections, and detector response, so the flux is predicted using hadron production and beamline modeling and constrained by beam instrumentation, since near detectors alone cannot separate flux from cross section. Proton, hadron, and muon monitors can track the parent particle distributions and beam conditions, providing the inputs needed for flux predictions in long-baseline experiments such as NOvA, T2K, and DUNE. This talk reviews how beam monitors are used in practice to understand neutrino flux. Proton beam monitors tell where the beam hits the target and how stable it is. Farther downstream, hadron and muon monitors sample particles produced in meson decays. Because those muons come from the same parents as the neutrinos, their profiles reveal focusing, alignment shifts, and other changes in the beam, and they are routinely used to detect problems and guide flux predictions. The muon information can be used more quantitatively; for example, to infer the parent meson phase space, and fast radiation-hard timing detectors can add sensitivity to the momentum dependence of the focusing. These developments show both how tightly beam measurements can constrain the flux and where the current limits still lie. These approaches complement monitored-beam concepts, in which the decay region is instrumented to detect charged leptons from meson decays and to measure the neutrino flux directly.

Ganguly, Sudeshna [Fermilab] (ORCID:00000003163482↗
DOE OSTI2026

Neutrino Beam Monitoring

Accelerator facilities produce neutrino beams from meson decays in a decay volume. Experiments measure event rates that depend on flux, cross sections, and detector response, so the flux is predicted using hadron production and beamline modeling and constrained by beam instrumentation, since near detectors alone cannot separate flux from cross section. Proton, hadron, and muon monitors can track the parent particle distributions and beam conditions, providing the inputs needed for flux predictions in long-baseline experiments such as NOvA, T2K, and DUNE. This talk reviews how beam monitors are used in practice to understand neutrino flux. Proton beam monitors tell where the beam hits the target and how stable it is. Farther downstream, hadron and muon monitors sample particles produced in meson decays. Because those muons come from the same parents as the neutrinos, their profiles reveal focusing, alignment shifts, and other changes in the beam, and they are routinely used to detect problems and guide flux predictions. The muon information can be used more quantitatively; for example, to infer the parent meson phase space, and fast radiation-hard timing detectors can add sensitivity to the momentum dependence of the focusing. These developments show both how tightly beam measurements can constrain the flux and where the current limits still lie. These approaches complement monitored-beam concepts, in which the decay region is instrumented to detect charged leptons from meson decays and to measure the neutrino flux directly.

Ganguly, Sudeshna [Fermilab] (ORCID:00000003163482↗
DOE OSTI2017

Exploring Meson and Nucleon Structure with Tagged Structure Functions

Novel tagged beam and target techniques are being developed to create effective neutron, pion, and other targets from nucleon and nuclear targets and beams. The effective meson targets in particular open the opportunity to uniquely probe the structure and composition of mesons and the nucleon sea. This talk will discuss some results from the 6 GeV era at Jefferson Lab, approved and possible tagged deep inelastic scattering experiments at Jefferson Lab in the 12 GeV era, and look forward also to potential tagged experiments at the Electron Ion Collider.

Keppel, Cynthia↗
DOE OSTI2020

Mitigation of Beam Losses in LANSCE Linear Accelerator

Suppression of beam losses is essential for successful operation of high-intensity accelerator facility. The LANSCE accelerator started routine operation in 1972 as a 0.8 MW average proton beam power facility for meson physics research, and delivered highpower beam for a quarter century. The accelerator currently delivers 100 MeV proton beam to Isotope Production Facility (IPF) and 800 MeV H- beams to various experimental areas. The accelerator is equipped with two independent injectors for H + and H - beams, merging at the entrance of a 201.25 MHz Drift Tube Linac (DTL). The DTL performs acceleration up to the energy of 100 MeV. After the DTL, the Transition Region beamline directs a 100 MeV proton beam to the Isotope Production Facility, while the H - beam is accelerated up to the final energy of 800 MeV in an 805- MHz Coupled Cavity Linac. The H - beams, created with different time structure by a lowenergy chopper, are distributed in the Switch Yard (SY) to four experimental areas: the Lujan Neutron Scattering Center equipped with a Proton Storage Ring (PSR), the Weapons Neutron Research facility (WNR), the Proton Radiography facility (pRad), and the Ultra-Cold Neutron facility (UCN). Multi-beam operation requires careful control of accelerator tune to minimize beam losses. In this paper we review main effects affecting beam losses in LANSCE linear accelerator and discuss methods to reduce them.

43 PARTICLE ACCELERATORS↗
DOE OSTI2025

Dark photons and axion-like particles at the electron-ion collider in China

The Electron-Ion Collider in China (EicC), a proposed high-luminosity facility with advanced charged particle and photon detection capabilities, provides unique opportunities to uncover new physics beyond the Standard Model. We analyze its sensitivity to dark photons produced through electron bremsstrahlung in coherent scattering. Thanks to its beam energy settings, it has the potential to comprehensively probe the previously unexplored parameter space between the constraints from meson decays and beam dumps below $\mathcal{O}(1)$ GeV with displaced-vertex search. Additionally, the EicC has the potential to probe axion-like particles (ALPs) in the mass range 0.1 GeV ≲ m a ≲ 5 GeV, with a coupling reach of Λ ≲ 10 6 GeV, by combining the prompt-decay and displaced-vertex searches. The projected sensitivities to ALPs exceed the current bounds.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2019

Measurement of the Beam Asymmetry for the ETA and ETA Prime Mesons with the GlueX Experiment

The GlueX Experiment in Hall D at Jefferson Lab ultimately aims to provide evidence of hybrid mesons, quark-antiquark pairs with gluonic excitations, which are predicted by quantum chromodynamics calculations on the lattice. GlueX features a linearly-polarized photon beam incident on a liquid hydrogen target and a nearly-four-pi hermetic detector capable of measuring positions and momenta of both charged and neutral final state particles generated in the target. The short-term physics goals of GlueX are to measure observables and properties of the known particles, especially those that are likely decay products of hybrids, such as the eta and eta-prime mesons. An overview of the detector subsystems and the long-term physics goals of GlueX are presented, along with analyses on the Sigma beam asymmetry of the eta and eta-prime mesons. The measurements of Sigma are presented versus the four-momentum transfer squared using a photon beam energy of 8.2-8.8 GeV in the three main decay channels of the eta (eta -> 2gamma, eta -> pi+pi-pi0, and eta -> 3pi0) and the largest branching fraction decay channel of the eta-prime (eta-prime -> pi+pi-eta, with eta -> 2gamma). These are the first results for the beam asymmetry of the eta-prime measured at this beam energy. The results, which are in agreement with past published measurements for the eta by GlueX and with modern theory predictions for the eta and eta-prime, indicate a dominance of natural parity exchange in the resonance production mechanism.

Beattie, Tegan↗
DOE OSTI2019

Development of the Barrel Calorimeter Reconstruction and Measurement of the Beam Asymmetry (S) for Photoproduced π 0 and η Mesons with the GlueX Experiment

The GlueX experiment is located in Hall D at Jefferson Lab with the primary goal of mapping out the spectrum of hybrid mesons. GlueX features a nearly-4π hermetic detector capable of measuring neutral and charged particles produced by a 9 GeV linearly polarized photon beam incident on a liquid hydrogen target. A description of the detector is presented to give an overview of the experiment. A lot of effort has been put forth into analyzing the data recorded by the detector. Here I discuss improving the performance of the Barrel Calorimeter subdetector by calibrating the gains and improving the reconstruction software. The immediate physics goal of GlueX is to measure observables of known particles, especially those that are expected to be decay particles of hybrid mesons, such as π 0 and η. To understand the photoproduction mechanism of these two particles the beam asymmetry (S) observable is measured. The measurements of Σ are obtained as a function of the four-momentum transfer squared, -t, in the photon energy range of 8.2 GeV to 8.8 GeV in the three dominant decay modes of the η meson and in the dominant decay mode of the π 0 meson. These are the first results for the η meson at this beam energy in multiple decay modes. The results agree with previously published GlueX results for η and π 0 and are made with significantly higher statistical precision. There is also agreement between theory predictions and the results which indicates that the resonance production mechanisms of the π 0 and η mesons are dominated by natural parity exchange.

McGinley, William Edmund↗
DOE OSTI2019

Beam spin asymmetry in the electroproduction of a pseudoscalar meson or a scalar meson off the scalar target

In this paper, we discuss the electroproduction of a pseudoscalar (0⁻⁺) meson or a scalar (0⁺⁺) meson off the scalar target. The most general formulation of the differential cross section for the 0⁻⁺ or 0⁺⁺ meson process involves only one or two hadronic form factors, respectively, on a scalar target. The Rosenbluth-type separation of the differential cross section provides the explicit relation between the hadronic form factors and the different parts of the differential cross section in a completely model-independent manner. The absence of the beam spin asymmetry for the pseudoscalar meson production provides a benchmark for the experimental data analysis. The measurement of the beam spin asymmetry for the scalar meson production may also provide a unique opportunity not only to explore the imaginary part of the hadronic amplitude in the general formulation but also to examine the significance of the chiral-odd generalized parton distribution (GPD) contribution in the leading-twist GPD formulation.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗