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At least 1,765 records · Page 98
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

THE LINAC LASER NOTCHER FOR THE FERMILAB BOOSTER

In synchrotron machines, the beam extraction is accomplished by a combination of septa and kicker magnets which deflect the beam from an accelerator into another. Ideally the kicker field must rise/fall in between the beam bunches. However, in reality, an intentional beam-free time region (aka "notch") is created on the beam pulse to assure that the beam can be extracted with minimal losses. In the case of the Fermilab Booster, the notch is created in the ring near injection energy by the use of fast kickers which deposit the beam in a shielded collimation region within the accelerator tunnel. With increasing beam power it is desirable to create this notch at the lowest possible energy to minimize activation. The Fermilab Proton Improvement Plan (PIP) initiated an R&D project to build a laser system to create the notch within a linac beam pulse at 750 keV. This talk will describe the concept for the laser notcher and discuss our current status, commissioning results, and future plans.

43 PARTICLE ACCELERATORS↗
DOE OSTI2016

Field Quality Measurements in the FNAL Twin-Aperture 11 T Dipole for LHC Upgrades

FNAL and CERN are developing an 11 T Nb3Sn dipole suitable for installation in the LHC to provide room for additional collimators. Two 1 m long collared coils previously tested at FNAL in single-aperture dipole configuration were assembled into the twin-aperture configuration and tested including magnet quench performance and field quality. The results of magnetic measurements are reported and discussed in this paper.

43 PARTICLE ACCELERATORS↗
DOE OSTI2015

A Preliminary Comparison of Three Dimensional Particle Tracking and Sizing using Plenoptic Imaging and Digital In-line Holography

Digital in-line holography and plenoptic photography are two techniques for single-shot, volumetric measurement of 3D particle fields. Here we present a preliminary comparison of the two methods by applying plenoptic imaging to experimental configurations that have been previously investigated with digital in-line holography. These experiments include the tracking of secondary droplets from the impact of a water drop on a thin film of water and tracking of pellets from a shotgun. Both plenoptic imaging and digital in-line holography successfully quantify the 3D nature of these particle fields. This includes measurement of the 3D particle position, individual particle sizes, and three-component velocity vectors. For the initial processing methods presented here, both techniques give out-of-plane positional accuracy of approximately 1-2 particle diameters. For a fixed image sensor, digital holography achieves higher effective in-plane spatial resolutions. However, collimated and coherent illumination makes holography susceptible to image distortion through index of refraction gradients, as demonstrated in the shotgun experiments. On the other hand, plenotpic imaging allows for a simpler experimental configuration. Furthermore, due to the use of diffuse, white-light illumination, plenoptic imaging is less susceptible to image distortion in the shotgun experiments. Additional work is needed to better quantify sources of uncertainty, particularly in the plenoptic experiments, as well as develop data processing methodologies optimized for the plenoptic measurement.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2015

A Preliminary Comparison of Three Dimensional Particle Tracking and Sizing using Plenoptic Imaging and Digital In-line Holography [PowerPoint]

Digital in-line holography and plenoptic photography are two techniques for single-shot, volumetric measurement of 3D particle fields. Here we present a preliminary comparison of the two methods by applying plenoptic imaging to experimental configurations that have been previously investigated with digital in-line holography. These experiments include the tracking of secondary droplets from the impact of a water drop on a thin film of water and tracking of pellets from a shotgun. Both plenoptic imaging and digital in-line holography successfully quantify the 3D nature of these particle fields. This includes measurement of the 3D particle position, individual particle sizes, and three-component velocity vectors. For the initial processing methods presented here, both techniques give out-of-plane positional accuracy of approximately 1-2 particle diameters. For a fixed image sensor, digital holography achieves higher effective in-plane spatial resolutions. However, collimated and coherent illumination makes holography susceptible to image distortion through index of refraction gradients, as demonstrated in the shotgun experiments. On the other hand, plenotpic imaging allows for a simpler experimental configuration. Furthermore, due to the use of diffuse, white-light illumination, plenoptic imaging is less susceptible to image distortion in the shotgun experiments. Additional work is needed to better quantify sources of uncertainty, particularly in the plenoptic experiments, as well as develop data processing methodologies optimized for the plenoptic measurement.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2017

First indirect x-ray imaging tests with an 88-mm diameter single crystal

Using the 1-BM-C beamline at the Advanced Photon Source (APS), we have performed the initial indirect x - ray imaging point-spread-function (PSF) test of a unique 88-mm diameter YAG:Ce single crystal of only 100 - micron thickness. The crystal was bonded to a fiber optic plat e (FOP) for mechanical support and to allow the option for FO coupling to a large format camera. This configuration resolution was compared to that of self - supported 25-mm diameter crystals, with and without an Al reflective coating. An upstream monochromator was used to select 17-keV x-rays from the broadband APS bending magnet source of synchrotron radiation. The upstream , adjustable Mo collimators were then used to provide a series of x-ray source transverse sizes from 200 microns down to about 15-20 microns (FWHM) at the crystal surface. The emitted scintillator radiation was in this case lens coupled to the ANDOR Neo sCMOS camera, and the indirect x-ray images were processed offline by a MATLAB - based image processing program. Based on single Gaussian peak fits to the x-ray image projected profiles, we observed a 10.5 micron PSF. This sample thus exhibited superior spatial resolution to standard P43 polycrystalline phosphors of the same thickness which would have about a 100-micron PSF. Lastly, this single crystal resolution combined with the 88-mm diameter makes it a candidate to support future x-ray diffraction or wafer topography experiments.

43 PARTICLE ACCELERATORS↗
DOE OSTI2015

Precision mechanical structure of an ultra-high-resolution spectrometer for inelastic X-ray scattering instrument

A method and an ultrahigh-resolution spectrometer including a precision mechanical structure for positioning inelastic X-ray scattering optics are provided. The spectrometer includes an X-ray monochromator and an X-ray analyzer, each including X-ray optics of a collimating (C) crystal, a pair of dispersing (D) element crystals, anomalous transmission filter (F) and a wavelength (W) selector crystal. A respective precision mechanical structure is provided with the X-ray monochromator and the X-ray analyzer. The precision mechanical structure includes a base plate, such as an aluminum base plate; positioning stages for D-crystal alignment; positioning stages with an incline sensor for C/F/W-crystal alignment, and the positioning stages including flexure-based high-stiffness structure.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Gamma ray spectroscopy monitoring method and apparatus

The present invention relates generally to the field of gamma ray spectroscopy monitoring and a system for accomplishing same to monitor one or more aspects of various isotope production processes. In one embodiment, the present invention relates to a monitoring system, and method of utilizing same, for monitoring one or more aspects of an isotope production process where the monitoring system comprises: (A) at least one sample cell; (B) at least one measuring port; (C) at least one adjustable collimator device; (D) at least one shutter; and (E) at least one high resolution gamma ray spectrometer.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2016

Study Of Boosted W-Jets And Higgs-Jets With the SiFCC Detector

We study the detector performance in the reconstruction of hadronically-decaying W bosons and Higgs bosons at very high energy proton colliders using a full GEANT4 simulation of the SiFCC detector. The W and Higgs bosons carry transverse momentum in the multi-TeV range, which results in collimated decay products that are reconstructed as a single jet. We present a measurement of the energy response and resolution of boosted W-jets and Higgs-jets and show the separation of two sub-jets within the boosted boson jet.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Search for new resonances decaying into boosted W, Z and H bosons at CMS

An overview of the searches for new heavy resonances decaying to standard model (SM) bosons at the TeV mass scale is presented. Results are based on data corresponding to an integrated luminosity up to about $36\; \mathrm{fb}^{-1}$ recorded in proton-proton collisions at $\sqrt{s}=13$ TeV with the CMS detector at the Large Hadron Collider at CERN. The bosons coming from the resonance decay can be W, Z, or the SM Higgs. For very heavy resonances, bosons are produced with momentum considerably higher than their mass, modifying in a very appreciable way the event topology. The quarks originated from the hadronic decay of the SM bosons will be collimated into a smaller area such that they are clustered within a single large cone jet. Dedicated reconstruction techniques are used to distinguish the merged decay products of W, Z and H bosons produced with high transverse momentum, from jets that originate from single partons.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2018

High-speed volume measurement system

Disclosed is a volume sensor having a first axis, a second axis, and a third axis, each axis including a laser source configured to emit a beam; a parallel beam generating assembly configured to receive the beam and split the beam into a first parallel beam and a second parallel beam, a beam-collimating assembly configured to receive the first parallel beam and the second parallel beam and output a first beam sheet and a second beam sheet, the first beam sheet and the second beam sheet being configured to traverse the object aperture; a first collecting lens and a second collecting lens; and a first photodetector and a second photodetector, the first photodetector and the second photodetector configured to output an electrical signal proportional to the object; wherein the first axis, the second axis, and the third axis are arranged at an angular offset with respect to each other.

42 ENGINEERING↗
DOE OSTI2018

Radiation Safety Consideration for the Parasitic Final Focus Test Beam at SLAC

A low intensity electron beam parasitic to the operation of the Stanford Linear Collider (SLC) has been transported through the Final Focus Test Beam (FFTB) facility making secondary test beams available for users. Photons generated in collimation of the SLC electron and positron beams in the linac pass through a splitter magnet that deflects the primary beams away from the linac axis into the SLC beam lines. These photons are converted to electrons and positrons in a secondary production target located down beam on the hnac axis. The secondary electrons are then transported through the FFTB beam line onto experimental detectors. The average power of the parasitic beam is very low, thus, it presents no hazards. However, various accident scenarios involving failure of the splitter magnet and the active protection devices could send much more powerful SLC beams (up to 90 kilo-watts) into this zero-degree secondary beam line. For the accident case, the average power in the transmitted beam was calculated using the Monte Carlo programs EGS4 and TURTLE. Results from analysis of the radiation protection systems that assure safety during the parasitic operation are presented.

Rokni, S. H.↗
DOE OSTI2016

Remote Sampling of Failed Spallation Neutron Source Targets

The Spallation Neutron Source (SNS) is a unique high powered particle accelerator-based source of neutrons for research and development purposes. Protons are accelerated into a mercury-filled stainless steel target where they “spall” off neutrons that are then collimated into beams for use in multiple experiments simultaneously. The mercury targets are intended to last up to one year and then must be changed out remotely due to activation by the high intensity proton and neutron beams. In the recent past several of these million dollar targets have failed in a matter of weeks. A team was assembled to acquire samples that could be used for diagnostics of the failures. The team developed a remote sampling tool that was small, economical, simple, easy to use, and could be fabricated and deployed quickly.

Noakes, Mark↗
DOE OSTI2018

Design and Indoor Validation of DUSST: A Novel Low-Maintenance Soiling Station

This poster shows the design, and the indoor validation of 'DUSST' (Detector Unit for Soiling Spectral Transmittance), a new low-maintenance soiling station. DUSST projects a collimated monochromatic light through a glass surface and on to a light detector to measure the intensity of the transmitted light. As the glass surface naturally soils, the losses are quantified by comparing this soiled reading with a calibrated reading in the baseline clean condition.

14 SOLAR ENERGY↗
DOE OSTI2017

Direct SN Treatment of the Scattering Source with Phase Functions

In deterministic transport, the scattering operator is commonly expressed using a spherical harmonics (pn) expansion of the scattering source. Not only does this require minimal modifications if the problem dimensionality is changed, but it also contains little to no approximation whenever the scattering anisotropy degree is small. An alternative method relying on a discrete ordinates (sn) approach -- essentially computing the angular integral of the phase function with a finite number of weighted directions -- is theoretically possible and has shown some advantages. In particular, this method was introduced for neutron elastic scattering and was shown to be more accurate for highly anisotropic group-to-group transfer cross-sections. Benefits were further shown in the case of a collimated beam in highly forward peaked scattering media, particularly reducing the memory usage by storing an angle-to-angle collision matrix rather than a large number of angular moments. In addition, the scattering source was expressed using that same method, the phase function having been previously expanded using Legendre polynomials, in the context of achieving extreme precision while solving the 1D radiative transfer equation. Based on these previous works, we aim at exploring two questions. First, we wish to derive an expression of the phase function in reduced geometries that does not require any more angular quadrature points than for a standard sn calculation. This is particularly relevant in 2-D problems where the reduced phase function does not solely depend on the product of the incoming and outgoing directions. Second, we wish to better understand the relationship between the sn and pn treatments. We in particular show equivalence if the phase function in the former case is expanded Legendre polynomials. This equivalence is verified numerically and the computational costs of the methods are compared on a test problem involving a Dirac delta phase function.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2019

System and method for monitoring integrity of a wellbore

A detector assembly includes scintillators configured to generate a light signal in response to an impinging backscatter signal, where the scintillators are arranged in a first pattern, a plurality of first detectors, where each first detector is coupled to a scintillator and configured to receive a first portion of a light signal from that scintillator, and where the first detectors are arranged in a second pattern aligned with the first pattern, a plurality of second detectors, where each second detector is disposed adjacent a scintillator and configured to receive a second portion of the light signal from that scintillator, and where the plurality of second detectors is arranged in a third pattern, and a scintillator collimator including a plurality of openings and configured to selectively receive the backscatter signal, where the detector assembly is configured to provide depth resolution, azimuthal resolution, a defect type, a defect size, or combinations thereof.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Apparatus for GHz rate high duty cycle pulsing and manipulation of low and medium energy DC electron beams

An ElectroMagnetic-Mechanical Pulser can generate electron pulses at rates up to 50 GHz, energies up to 1 MeV, duty cycles up to 10%, and pulse widths between 100 fs and 10 ps. A modulating Transverse Deflecting Cavity (“TDC”) imposes a transverse modulation on a continuous electron beam, which is then chopped into pulses by an adjustable Chopping Collimating Aperture. Pulse dispersion due to the modulating TDC is minimized by a suppressing section comprising a plurality of additional TDC's and/or magnetic quadrupoles. In embodiments the suppression section includes a magnetic quadrupole and a TDC followed by four additional magnetic quadrupoles. The TDC's can be single-cell or triple-cell. A fundamental frequency of at least one TDC can be tuned by literally or virtually adjusting its volume. TDC's can be filled with vacuum, air, or a dielectric or ferroelectric material. Embodiments are easily switchable between passive, continuous mode and active pulsed mode.

Baryshev, Sergey V.↗
DOE OSTI2019

Spall and re-compaction in OFHC copper under high velocity impact

Copper spall and re-compaction experiments were performed with a single stage large bore (76.2 mm) light gas gun capable of planar impacts at low impact velocity. The experiments used PDV to capture the velocity history of the back surface of the target and the projectile velocity (collimating probes). The tilts for these experiments typically range from 1–2 mrad. A re-compaction wave was clearly observed using Photon Doppler Velocimetry (PDV) on the back surface of the copper target as well as identified using Electron Backscatter Diffraction (EBSD) in the recovered samples. The spall and re-compaction data are similar until re-compaction occurs; the time-resolved data show clear evidence for spall damage in the first case and spall followed by re-compaction in the second case. For the initial spall signature, ringing consistent with half the thickness of the target is observed in all cases; after re-compaction, ringing is observed that is consistent with the full sample thickness. Samples recovered using the soft catch system were analyzed, and the cross-sectional view from the spalled target clearly showed a spall plane with voids, whereas the re-compaction target showed an area of plastic deformation. It is hypothesized that the voids formed by spall close during re-compaction and leave behind a deformed area.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

AC Dipole Requirements for Beam Extinction for the Fermilab Mu2e Experiment

Mu2e experiment is a particle physics experiment which studies the muon-to-electron conversion without producing neutrinos. The experiment has very strict limits on the unwanted proton beam between pulses, so an extinction process to eliminate the unwanted beam is needed. The goal of our study is to simulate an extinction system with AC dipoles and a collimator and verify the 10-10 extinction requirement is fulfilled. We also analyze several sources of error to investigate the stability of our system.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗