Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “BEAM LINES”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 649 records · Page 36
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

X-ray absorption spectroscopy using a self-seeded soft X-ray free-electron laser

X-ray free electron lasers (XFELs) enable unprecedented new ways to study the electronic structure and dynamics of transition metal systems. L-edge absorption spectroscopy is a powerful technique for such studies and the feasibility of this method at XFELs for solutions and solids has been demonstrated. But, the required x-ray bandwidth is an order of magnitude narrower than that of self-amplified spontaneous emission (SASE), and additional monochromatization is needed. We compare L-edge x-ray absorption spectroscopy (XAS) of a prototypical transition metal system based on monochromatizing the SASE radiation of the linac coherent light source (LCLS) with a new technique based on self-seeding of LCLS. We demonstrate how L-edge XAS can be performed using the self-seeding scheme without the need of an additional beam line monochromator. Lastly, we show how the spectral shape and pulse energy depend on the undulator setup and how this affects the x-ray spectroscopy measurements.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2017

The Mu2e experiment at Fermilab: Design and status

The Mu2e experiment at Fermilab will search for coherent, neutrinoless conversion of negative muons into electrons in the field of an aluminum nucleus. The dynamics of such charged lepton flavour violating (CLFV) process is a twobody decay, resulting in a mono-energetic electron with an energy slightly below the muon rest mass. If no events are observed in three years of running, Mu2e will set an upper limit on the ratio between the conversion and the capture rates Rμe of ≤ 6 × 10 -17 (@90% C.L.). This will improve the current limit of four order of magnitudes with respect to the previous best experiment. Mu2e complements and extends the current search for μ → eγ decay at MEG as well as the direct searches for new physics at the LHC. Indeed, such a CLFV process probes new physics at a scale inaccessible to direct searches at either present or planned high energy colliders. Observation of a signal will be a clear evidence for new physics beyond the Standard Model. To search for the muon conversion process, a very intense pulsed beam of negative muons (~ 10 10 μ/s) is stopped on an aluminum target inside a very long solenoid where the detector is also located. The Mu2e detector is composed of a straw tube tracker and an electromagnetic calorimeter consisting of arrays of CsI crystals. An external veto for cosmic rays is surrounding the detector solenoid. In 2016, Mu2e has passed the final approval stage from DOE and has started its construction phase. Data collection is planned for the end of 2021. Lastly, an overview of the physics motivations for Mu2e, the current status of the experiment and design of the muon beam-line and the detector is presented.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2017

A Wedge Absorber Experiment at MICE

Emittance exchange mediated by wedge absorbers is required for longitudinal ionization cooling and for final transverse emittance minimization for a muon collider. A wedge absorber within the MICE beam line could serve as a demonstration of the type of emittance exchange needed for 6-D cooling, including the configurations needed for muon colliders, as well as configurations for low-energy muon sources. Parameters for this test are explored in simulation and possible experimental configurations with simulated results are presented.

43 PARTICLE ACCELERATORS↗
DOE OSTI2019

Magnetic Measurement With Single Stretched Wire Method on SuperKEKB Final Focus Quadrupoles

Superconducting-final-focus-quadrupole magnet system (QCS) were installed on an interaction region (IR) of SuperKEKB on Feb. 2017. The QCS consists of eight quadrupole magnets and four compensation solenoids; these magnets are contained in the two cryostats and are installed into Belle II detector which generates a solenoid field of 1.5 T. We determined the quadrupole centers with respect to accelerator beam lines with a single stretched wire (SSW) method. Here the results of the magnetic measurement with SSW are presented.

43 PARTICLE ACCELERATORS↗
DOE OSTI2021

Design of an RF-Dipole Crabbing Cavity System for the Electron-Ion Collider

The Electron-Ion Collider requires several crabbing systems to facilitate head-on collisions between electron and proton beams in increasing the luminosity at the interaction point. One of the critical rf systems is the 197 MHz crabbing system that will be used in crabbing the proton beam. Many factors such as the low operating frequency, large transverse voltage requirement, tight longitudinal and transverse impedance thresholds, and limited beam line space makes the crabbing cavity design challenging. The rf-dipole cavity design is considered as one of the crabbing cavity options for the 197 MHz crabbing system. The cavity is designed including the HOM couplers, FPC and other ancillaries. This paper presents the detailed electromagnetic design, mechanical analysis, and conceptual cryomodule design of the crabbing system.

De Silva, S. U.↗
DOE OSTI2022

RLAs WITH FFA ARCS FOR PROTONS AND ELECTRONS

Recirculating Linear Accelerators (RLAs) provide an efficient way of producing high-power, high-quality, continuous-wave hadron and lepton beams. However, their attractiveness had been limited by the cumbersomeness of multiple recirculating arcs and by the complexity of the spreader and recombiner regions. The latter problem sets one of the practical limitations on the maximum number of recirculations. We present an RLA design concept where the problem of multiple arcs is solved using the Fixed-Field Alternating gradient (FFA) design as in CBETA. The spreader/recombiner design is greatly simplified using an adiabatic matching approach. It allows for the spreader/recombiner function to be accomplished by a single beam line. The concept is applied to the designs of a high-power hadron accelerator being considered at ORNL and a CEBAF electron energy doubling project, FFA@CEBAF, being developed at Jefferson lab.

Morozov, V. S.↗
DOE OSTI2022

Electron Accelerator Lattice Design for LHeC with Permanent Magnets

We present a new ’green energy’ approach to the Energy Recovery Linac (ERL) the future Electron Ion Collider at LHeC using single beam line made of very strong focusing combined function permanent magnets and the Fixed Field Alternating Linear Gradient (FFA-LG) principle. We are basing our design on recent very successful commissioning results of the Cornell University and Brookhaven National Laboratory ERL Test Accelerator-CBETA.

Trbojevic, D.↗
DOE OSTI2023

Positron beams at Ce+BAF

Positron beams would provide a new and meaningful probe for the experimental program at the Thomas Jefferson National Accelerator Facility (JLab). The JLab Positron Working Group, formed in 2018 and now with over 250 members from 75 institutions, continues to develop an experimental program with high duty-cycle positron beams including but not limited to future hadronic physics and dark matter experiments. Critical requirements involve generating positron beams with a high degree of spin polarization, sufficient intensity and a continuous-wave (CW) bunch train compatible with acceleration to 12 GeV at the Continuous Electron Beam Accelerator Facility (CEBAF). In this presentation we describe a start-to-end layout for positron beams at 12 GeV CEBAF utilizing the Low Energy Research Facility (LERF) at Jefferson Lab to build two new injectors. A GaAs dc high voltage photo-gun first generates >1 mA of polarized electrons which are then accelerated to 80-150 MeV and directed to a high-power spinning W target for polarized bremsstrahlung and positron pair creation. A second injector then collects, bunches and accelerates the positrons to 123 MeV. The positron beams are transported by a new beam line and injected into the CEBAF acceptance for acceleration to the end stations with energies up to 12 GeV. The layout is optimized to provide Users with positron spin polarization >60% and intensity greater than >100 nA, and with higher intensities when polarization is not required.

Benesch, J.↗
DOE OSTI2024

ORBITAL ANGULAR MOMENTUM BEAMS RESEARCH USING A FREE-ELECTRON LASER OSCILLATOR

We present a Fixed-Field-Alternating (FFA) permanent magnet racetrack electron accelerator with energy range between 10-60 GeV for the future LHeC. Electron beam is brought back to the linac by the single beam line without requiring electric power REDUCING estimated wall power of 100 MW in the present LHeC design to a negligible power for arcs as the permanent magnets are used. The design is based on experience from the very successful commissioning of the Cornell University and Brookhaven National Laboratory Energy Recovery Test Accelerator ? ?CBETA?. The proposal supports sustainability efforts for LHeC by making a 'green' accelerator. It is an energy recovery linac with 99.9% energy efficiency and reduces the power consumption by using small permanent magnets. The FFA non-linear gradient design is a racetrack shape, where, as in the CBETA, the arcs are matched by adiabatic transition to the two (LHeC) or multiple straight sections. Two 10 GeV superconducting linacs are placed on both sides of the Interaction Region (IR) significantly reducing the power of synchrotron radiation loss.

Trbojevic, D.↗
DOE OSTI2020

Analysis of Allison Scanner Phase Portraits Using Action-Phase Coordinates

Allison scanners provide detailed information on the beam transverse phase space. An effective way for analyzing the beam distribution from these measurements is to use action-phase coordinates, where beam propagation in a linear lattice is reduced to advancing the phase. This report presents such analysis for measurements performed with a 2.1 MeV, 5 mA H⁻ beam in the MEBT of the PIP2IT test accelerator at Fermilab. In part, with the choice of calculating the Twiss parameters over the high intensity portion of the beam, the beam core is found to be phase-independent with intensity decreasing exponentially with action, while the beam tails exhibit a clear phase dependence that is stable over the beam line.

43 PARTICLE ACCELERATORS↗
DOE OSTI2012

Laser Cladding Modeling and Operation Applied to Plasma Facing Components (Final Report)

This report summarizes progress during the performance period of June 17, 2011 to March 17, 2012 for DOE Award number DE-SC0006270. Modeling of the LENS process to construct tungsten on both copper and Inconel substrates was performed and experimentally tested with good results. During the course of the Phase I effort Nanohmics, working collaboratively with Purdue University, modeled and experimentally confirmed that the Laser-Engineered Net Shaping (LENS) process can successfully clad tungsten to both Inconel and copper substrates. Early in Phase I, work was carried out using the LENS process on Inconel substrates that were previously clad to steel. In this regard, nine tungsten tracks were cladded onto an Inconel 625 substrate. The substrate consisted of several layers of Inconel 625 cladded onto a bar of steel 25.4 mm thick and 50.8 mm wide. The Inconel portion of the bar was then cut flat on a mill so that the layer was 2.2 mm thick. The powder was applied to the Inconel 625 surface using both pre-placed powder and blown powder techniques and the powder was melted onto the Inconel surface with varying laser powers and laser travel speeds. The laser used in these experiments is a 4000 W Nuvonyx diode laser (wavelength 808 nm) with a line beam profile 12 mm long and 0.5 mm wide. The laser travel direction was always perpendicular to the long direction of the beam so as to create a 12 mm wide clad track.

36 MATERIALS SCIENCE↗
DOE OSTI2012

Experimental and Theoretical Studies of Liquid-Solid and Liquid-Vapor Interfaces of Metals and Alloys

The research supported by ER46321 was designed to understand in microscopic detail the structures of the interfaces between liquid metals and alloys and solid media. The system chosen for study, because of detailed knowledge of the structure of the corresponding liquid alloy-vapor interface, was the interface between a Si crystal and a dilute alloy of Pb in Ga. Experimental study of the Si:PbGa interface was anticipated to be very difficult; it requires preparation of an interface between a liquid metal and a solid surface that is flat to better than a nanometer on the scale length of the x-ray coherence, alignment of the x-ray beam and the surface in the sub-micro radian regime, and the use of high energy x-rays to penetrate the window and reach the interface without disastrous loss of intensity. The experimental design was subject to compromises forced by the limit to the highest x-ray energy available at the ChemMatCARS beam-line, namely 30 keV, which reduced the scattered signal relative to what can be obtained with higher x-ray energy. Although considerable progress was achieved during the support period and its no-cost extension, the difficulties encountered prevented completion of the studies and the data collected are incomplete. These data hint at the existence of unexpected structural features of the interface, in particular that Pb dimers play an important role in the interfacial structure. These data provide a different picture of the interface from the pentagonal structure inferred to be present in the interface between pure Pb and Si 001 (Nature 408, 839 (2000)), but much like the Ga dimers in the interface between liquid Ga and the 100 face of diamond (Nature 390, 379 (1997), J. Chem. Phys. 123, 104703 (2005)). However, during the latter part of the support period significant progress was made in the theoretical description of the liquid metal-crystal interface. In particular, stimulated by the results of an experimental study of the interface between liquid Hg and the reconstructed (0001) face of sapphire, we developed an extension of the self-consistent quantum Monte Carlo scheme previously used to study the structure of the liquid metal-vapor interface.

36 MATERIALS SCIENCE↗
DOE OSTI2012

Progress in the Measurement of Prompt Neutron Output in Neutron-Induced Fission of 239 Pu: The Chi-Nu Project

Knowledge of the prompt neutron output from neutron-induced fission of 239 Pu is essential to nuclear defense and energy applications. Because the experimental data base is inadequate to constrain models of the spectrum of neutrons from fission, we have embarked on a multi-year program of new measurements of the prompt fission neutron spectrum as a function of the energy of the incident neutron that induces the fission. This is a joint LANL-LLNL project with participation by four university groups in advanced detector development. In the past year much progress has been achieved. The building housing the experiment has been completed and the flight paths including one for this experiment are now constructed. A parallel-plate avalanche counter (PPAC) containing 235 U is installed and working in the beam line. Neutron detectors for both low (<1 MeV) and high (> 0.5 MeV) neutrons have been assembled. The data acquisition system based on waveform digitizers has undergone extensive development and now can handle 10 PPAC channels and 10 neutron detectors simultaneously. In addition, a detector test station centered on a 252 Cf spontaneous fission chamber has been commissioned so that we can characterize our neutron detectors in a well understood experimental environment. Analysis of experiments at this facility has helped us understand the performance of several types of neutron detectors. In addition, the analysis work uncovered that the “standard” 252 Cf fission neutron spectrum in MCNPX disagrees significantly from that presently accepted by the international standards community. One year ago we submitted a report (LA-UR-11-05576) on the accuracies that could be reached under certain assumptions. Several sources of possible systematic uncertainties were identified, and procedures to control these uncertainties were suggested. This report is included as an appendix to this report. One element missing from these estimates was the contribution of backgrounds. It could not be quantified because, at that time, the building and flight path for the experiments had not been constructed. We now have made some measurements of the background and can now add this component to the accuracy projections. This report summarizes the progress in the past year. It also discusses measurements reported in the literature and some factors that should be considered when using these data to optimize parameters in nuclear model codes used in constructing evaluated nuclear data bases.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2012

Science Campaign-1 Pulsed Power Efforts [Slides]

The PHELIX portable pulsed-power driver is discussed. It is composed of two air-insulated, single Marx modules capable of storing 300 kJ of electrical energy. The Marx are cable coupled to a toroidal transformer with a 4:1 winding ratio. The experimental load is located at the center of the transformer. The components are mounted in a 8’x10’x18’ boxcar which can be moved in and out of the beam line at the LANL proton radiography facility and prevents EMI within the facility. PHELIX has successfully completed two liner implosion experiments with full diagnostic return from flash X-ray imaging, optical Faraday load current, and multi-channel PDV. Computational modeling with both the legacy 1D MHD code RAVEN and the LANL ASC-LAP FLAG code show good agreement with data.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2012

Precision Characterization of Gyrotron Window Materials

The response of dielectric material to electromagnetic waves in the millimeter wavelength range (30 to 300 GHz) has received relatively little study and the processes that give rise to absorption in this region are often poorly understood. Understanding the origin of absorption at these wavelengths has basic significance for solid state physics as well as importance for development of technology in this region of the RF spectrum. This project has provided high-quality data on the temperature dependence of the dielectric loss in high-purity, semi-insulating silicon carbide (HPSI SiC), a material that holds much promise for application, especially in devices that must operate in the high power and high frequency regime. Comparison of this experimental data with theoretical predictions for various loss processes provides convincing evidence that the loss in HPSI SiC arises almost entirely from intrinsic lattice loss (ILL) as described by Garin. Fitting the data to this model yields an accurate value for the Debye temperature that characterizes crystalline SiC. In addition, our results refute a previous study(2) which reported much higher loss, attributed to the presence of free charge. The quality of the data acquired in this project is clear evidence for the value of the experimental technique that was employed here. This technique combines the excitation of a high-quality open resonator by a phase-locked backward wave oscillator (BWO) with use of a spectrum analyzer to measure the change in the resonator response curve when the sample is inserted. This system has demonstrated consistent results for very challenging measurements and does not suffer from the artifacts that often arise when using other techniques that rely on thermal sources. The low absorption loss found in HPSI SiC, when combined with its other outstanding material properties, e.g. high thermal conductivity, high tensile strength, and high carrier mobility, should provide incentive for designers to utilize this material to solve the challenging problems that are encountered as devices are pushed to operate at higher frequencies and higher power levels. In particular, for the fusion energy program, it may provide an economical alternative to CVD diamond for certain gyrotron and beam line applications. In addition, the value obtained for the Debye temperature provides an important datum for modeling the crystalline structure of SiC. Clearly SiC is a unique material with few competitors and should see wider utilization.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2013

Investigation of uranium attenuation and release at column and pore scales in response to advective geochemical gradients

Column experiments were devised to investigate the role of changing fluid composition on mobility of uranium through a sequence of geologic media. Fluids and media were chosen to be relevant to the ground water plume emanating from the former S-3 ponds at the Oak Ridge Integrated Field Research Challenge (ORIFC) site. Synthetic ground waters were pumped upwards at 0.05 mL/minute for 21 days through layers of quartz sand alternating with layers of uncontaminated soil, quartz sand mixed with illite, quartz sand coated with iron oxides, and another soil layer. Increases in pH or concentration of phosphate, bicarbonate, or acetate were imposed on the influent solutions after each 7 pore volumes while uranium (as uranyl) remained constant at 0.1mM. A control column maintained the original synthetic groundwater composition with 0.1mM U. Pore water solutions were extracted to assess U retention and release in relation to the advective ligand or pH gradients. Following the column experiments, subsamples from each layer were characterized using microbeam X-ray absorption spectroscopy (XANES) in conjunction with X-ray fluorescence mapping and compared to sediment core samples from the ORIFC, at SSRL Beam Line 2-3.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2013

Development of a Positron Source for JLab at the IAC

We report on the research performed towards the development of a positron sour for Jefferson Lab's (JLab) Continuous Electron Beam Accelerator Facility (CEBAF) in Newport News, VA. The first year of work was used to benchmark the predictions of our current simulation with positron production efficiency measurements at the IAC. The second year used the benchmarked simulation to design a beam line configuration which optimized positron production efficiency while minimizing radioactive waste as well as design and construct a positron converter target. The final year quantified the performance of the positron source. This joint research and development project brought together the experiences of both electron accelerator facilities. Our intention is to use the project as a spring board towards developing a program of accelerator based research and education which will train students to meet the needs of both facilities as well as provide a pool of trained scientists.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2013

BACoN Cryostat Pressure Relief Calculations

Use this description: The BACoN cryostat is being constructed to determine the neutron energy spectrum of the LANSCE beam line at low rate (1 neutron per macropulse) in a liquid argon detector. It will utilize the scintillation light produced by nuclear recoils in argon to determine the energy via time of flight and provide data on the scintillation light yield for the CAPTAIN liquid argon TPC being designed and constructed now. The approximate volume of liquid argon contained within the cryostat is ~105 L.

42 ENGINEERING↗