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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 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Cryogenic test of the 4 K / 2 K insert for the ARIEL e-Linac cryomodule

The ARIEL project at TRIUMF requires a 50 MeV superconducting electron linac consisting of five nine cell 1.3 GHz cavities divided into three cryomodules with one, two and two cavities in each module respectively. LHe is distributed in parallel to each module at 4 K and at ∼1.2 bar. Each module has a cryogenic insert on board that receives the 4 K liquid and produces 2 K into a cavity phase separator. The module combines a 4 K phase separator, a plate and fin heat exchanger from DATE and a J-T valve expanding into the 2 K phase separator. The unit also supplies 4 K liquid to thermal intercepts in the module in siphon loops that return the vaporized liquid to the 4 K reservoir. For testing purposes the unit is outfitted with a dummy 2 K phase separator and thermal intercepts with variable heaters that mimic the final heat loads in order to test the cryogenic performance. The design of the 4 K / 2 K insert, the results of the cold tests and a summary of the test infrastructure including cryogenics services will be presented.

43 PARTICLE ACCELERATORS↗
DOE OSTI2015

Design of Linear Accelerator (LINAC) tanks for proton therapy via Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) approaches

A homemade computer code for designing a Side- Coupled Linear Accelerator (SCL) is written. It integrates a simplified model of SCL tanks with the Particle Swarm Optimization (PSO) algorithm. The computer code main aim is to obtain useful guidelines for the design of Linear Accelerator (LINAC) resonant cavities. The design procedure, assisted via the aforesaid approach seems very promising, allowing future improvements towards the optimization of actual accelerating geometries. (authors)

43 PARTICLE ACCELERATORS↗
NASA NTRS2004

Test of the Equivalence Principle in an Einstein Elevator

The scientific goal of the experiment is to test the equality of gravitational and inertial mass (i.e., to test the Principle of Equivalence) by measuring the independence of the rate of fall of bodies from their compositions. The measurement is accomplished by measuring the relative displacement (or equivalently acceleration) of two falling bodies of different materials which are the proof masses of a differential accelerometer spinning about an horizontal axis to modulate a possible violation signal. A non-zero differential acceleration appearing at the signal frequency will indicate a violation of the Equivalence Principle. The goal of the experiment is to measure the Eotvos ratio og/g (differential acceleration/common acceleration) with a targeted accuracy that is about two orders of magnitude better than the state of the art (presently at several parts in 10(exp 13). The analyses carried out during this first grant year have focused on: (1) evaluation of possible shapes for the proof masses to meet the requirements on the higher-order mass moment disturbances generated by the falling capsule; (2) dynamics of the instrument package and differential acceleration measurement in the presence of errors and imperfections; (3) computation of the inertia characteristic of the instrument package that enable a separation of the signal from the dynamics-related noise; (4) a revised thermal analysis of the instrument package in light of the new conceptual design of the cryostat; (5) the development of a dynamic and control model of the capsule attached to the gondola and balloon to define the requirements for the leveling mechanism (6) a conceptual design of the leveling mechanism that keeps the capsule aligned before release from the balloon; and (7) a new conceptual design of the customized cryostat and a preliminary valuation of its cost. The project also involves an international cooperation with the Institute of Space Physics (IFSI) in Rome, Italy. The group at IFSI is in charge of prototyping the differential accelerometer and carrying out precursor laboratory measurements. During this grant year, our partners analyzed and then designed a new prototype of differential accelerometer that has several characteristics in common with the flight accelerometer at this point of the instrument development. The highlights of these activities are documented in a section of this report.

Shapiro, Irwin I.↗
DOE OSTI2019

Scanning Electrochemical Flow Cell with Online Mass Spectroscopy for Accelerated Screening of Carbon Dioxide Reduction Electrocatalysts

Electrochemical conversion of carbon dioxide into valuable chemicals or fuels is an increasingly important strategy for achieving carbon neutral technologies. The lack of a sufficiently active and selective electrocatalyst, particularly for synthesizing highly reduced products, motivates accelerated screening to evaluate new catalyst spaces. Traditional techniques, which couple electrocatalyst operation with analytical techniques to measure product distributions, enable screening throughput at 1–10 catalysts per day. In this paper, a combinatorial screening instrument is designed for MS detection of hydrogen, methane, and ethylene in quasi-real-time during catalyst operation experiments in an electrochemical flow cell. Coupled with experiment modeling, product detection during cyclic voltammetry (CV) enables modeling of the voltage-dependent partial current density for each detected product. Here, we demonstrate the technique by using the well-established thin film Cu catalysts and by screening a Pd–Zn composition library in carbonate-buffered aqueous electrolyte. The rapid product distribution characterization over a large range of overpotential makes the instrument uniquely suited for accelerating screening of electrocatalysts for the carbon dioxide reduction reaction.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

Production of high current proton beams using complex H-rich molecules at GSI

In this contribution, the concept of production of intense proton beams using molecular heavy ion beams from an ion source is described, as well as the indisputable advantages of this technique for operation of the GSI linear accelerator. The results of experimental investigations, including mass-spectra analysis and beam emittance measurements, with different ion beams (CH{sub 3}{sup +},C{sub 2}H{sub 4}{sup +},C{sub 3}H{sub 7}{sup +}) using various gaseous and liquid substances (methane, ethane, propane, isobutane, and iodoethane) at the ion source are summarized. Further steps to improve the ion source and injector performance with molecular beams are depicted.

2-METHYLPROPANE↗
DOE OSTI2012

Article on Trident Laser Facility for NA-11 Stockpile Stewardship Quarterly

The Trident Intermediate-Scale Laser Facility at Los Alamos National Laboratory is an extremely versatile Nd:glass laser system dedicated to high energy density laboratory physics and weapons physics research and fundamental laser-matter interactions. Trident is a three-beam, 200 J/beam at the second harmonic for glass (527 nm wavelength), facility with tremendous flexibility and high beam quality. Pulse durations varying over 6 orders of magnitude, from 0.5 picoseconds to 1.0 microsecs, can be directed to either of two different target chambers with changeable illumination geometries, including the ability to achieve near-diffraction limited focus. This provides a unique range of capability at one facility from sub-picosecond pulses (and high-intensity laser science) to nanosecond pulses (and LPI physics relevant to ICF) to microsecond pulses (and driving flyer plates for supported shock dynamic materials science.) When in short-pulse mode (less than picosecond pulse), a single beam can provide up to 200 TW of power with uniquely controllable and measured pre-pulse contrast of 10 orders of magnitude. A recent external capability review at Los Alamos concluded that "Trident is generating excellent, cutting edge science and is a leading intermediate scale laser system worldwide."

36 MATERIALS SCIENCE↗
DOE OSTI2024

An Improved Beam Position Monitor for Scorpius and the DARHT Multi-Pulse Test Line

Beam position monitors (BPMs) provide time-resolved measurements of the current and centroid position of high-current electron beams in linear induction accelerators (LIAs). A frequently used BPM detector is the B-dot loop, which generates a signal from the EMF generated by the time varying magnetic flux through the loop. We have developed a second generation BPM that avoids previously observed diffusion effects in earlier stainless steel through the use of exceptionally high conductivity copper alloy for its construction.

43 PARTICLE ACCELERATORS↗
DOE OSTI2013

Instrument performance study on the short and long pulse options of the second Spallation Neutron Source target station

The Spallation Neutron Source (SNS) facility at the Oak Ridge National Laboratory is designed with an upgrade option for a future low repetition rate, long wavelength second target station. This second target station is intended to complement the scientific capabilities of the 1.4 MW, 60 Hz high power first target station. Two upgrade possibilities have been considered, the short and the long pulse options. In the short pulse mode, proton extraction occurs after the pulse compression in the accumulator ring. The proton pulse structure is thus the same as that for the first target station with a pulse width of ∼0.7 μs. In the long pulse mode, protons are extracted as they are produced by the linac, with no compression in the accumulator ring. The time width of the uncompressed proton pulse is ∼1 ms. This difference in proton pulse structure means that neutron pulses will also be different. Neutron scattering instruments thus have to be designed and optimized very differently for these two source options which will directly impact the overall scientific capabilities of the SNS facility. In order to assess the merits of the short and long pulse target stations, we investigated a representative suit of neutron scattering instruments and evaluated their performance under each option. Our results indicate that the short pulse option will offer significantly better performance for the instruments and is the preferred choice for the SNS facility.

43 PARTICLE ACCELERATORS↗
NASA NTRSDate not supplied

TARDIS: Acelerating TVAC Transitions

"Large spacecraft components, including instruments, require long durations to transition between temperature plateaus during TVAC (Thermal Vacuum) testing. This is especially true for cryogenic instruments whose operating temperatures are extremely low. Due to the T4 relation, using radiative heat transfer alone for temperature transitions to cryogenic temperatures is extremely time consuming. The Wide Field Instrument (WFI) on the upcoming Roman Space Telescope (RST) is one such cryogenic instrument. The TARDIS (Thermal Acceleration Rate Device for Integrated Systems) is a heat switch device which will be used during the WFI TVAC test campaign in order to decrease WFI transition times. Over the course of the planned ___ week WFI instrument-level TVAC testing, TARDIS is being estimated to save ___ days of test time. By reducing the total TVAC duration, TARDIS is providing significant cost and schedule savings to the RST WFI project. Based on the successful design of the LUCY L’Ralph AZQ Heat Switch, TARDIS can provide both high conductivity for temperature transitions and low conductivity Zero-Q for thermal balances. This is achieved by use of a mechanical clamp heat switch and actively controlled cold plate. Using this method, TARDIS is estimated to be able to change its conductance from approximately 0.20 W/K to ¬¬0.002 W/K, for a turndown ratio of 100. This paper details the design, analysis, and testing of TARDIS. It also previews the operation of TARDIS in the upcoming WFI TVAC test campaign. "

TVAC, Heat Switch↗
DOE OSTI2013

The Tandem-ALPI-PIAVE accelerator complex of LNL

Heavy ion beams are delivered at the Laboratori Nazionali di Legnaro by the accelerator complex Tandem-ALPI-PIAVE. The Tandem XTU is a Van de Graaff accelerator normally operated at terminal voltages of up to about 15 MV. The Tandem accelerator can be operated in stand-alone mode or as an injector for the linac booster ALPI. The linear accelerator ALPI is built of superconducting resonant cavities and consists of a low-beta branch, particularly important for the acceleration of the heavier mass ions, a medium-beta branch, and a high-beta branch. ALPI can be operated also with the PIAVE injector that consists of a superconducting linac and an ECR source. The PIAVE source was mainly used for the acceleration of intense noble gas beams but most recently also a first metallic beam was delivered to the users. The accelerator complex delivers beams of ions from protons to gold in three experimental areas on 11 different beam lines. A rich scientific activity is ongoing at the Tandem-ALPI-PIAVE accelerator complex, beam time being shared between nuclear physics research and applied and interdisciplinary physics research. An overview of the present status and perspectives of the Tandem-ALPI-PIAVE complex and its physics program is given in the present paper.

43 PARTICLE ACCELERATORS↗
DOE OSTI2020

Nb 3 Sn multicell cavity coating system at Jefferson Lab

Superconducting radio frequency niobium cavities are the building blocks of modern accelerators for scientific applications. Lower surface resistance, higher fields, and high operating temperatures advance the reach of the future accelerators for scientific discovery as well as potentially enabling cost-effective industrial solutions. We describe the design and performance of an Nb 3 Sn coating system that converts the inner surface of niobium cavities to an Nb 3 Sn film. The niobium surface, heated by radiation from the niobium retort, is exposed to Sn and SnCl 2 vapor during the heat cycle, which results in about 2 μm Nb 3 Sn film on the niobium surface. Film composition and structure as well as radio frequency properties with 1-cell R&D cavities and 5-cell practical accelerator cavities are presented.

47 OTHER INSTRUMENTATION↗
DOE OSTI2013

Neutron production using a pyroelectric driven target coupled with a gated field ionization source

A palm sized, portable neutron source would be useful for widespread implementation of detection systems for shielded, special nuclear material. We present progress towards the development of the components for an ultracompact neutron generator using a pulsed, meso-scale field ionization source, a deuterated (or tritiated) titanium target driven by a negative high voltage lithium tantalate crystal. Neutron production from integrated tests using an ion source with a single, biased tungsten tip and a 3 Multiplication-Sign 1 cm, vacuum insulated crystal with a plastic deuterated target are presented. Component testing of the ion source with a single tip produces up to 3 nA of current. Dielectric insulation of the lithium tantalate crystals appears to reduce flashover, which should improve the robustness. The field emission losses from a 3 cm diameter crystal with a plastic target and 6 cm diameter crystal with a metal target are compared.

43 PARTICLE ACCELERATORS↗
DOE OSTI2013

Construction of a scattering chamber for ion-beam analysis of environmental materials in undergraduate physics research

We have developed a new scattering chamber for ion-beam analysis of environmental materials with the 1.1-MV Pelletron accelerator at the Union College Ion-Beam Analysis Laboratory. The chamber was constructed from a ten-inch, Conflat, multi-port cross and includes a three-axis target manipulator and target ladder assembly, an eight-inch turbo pump, an Amptek X-ray detector, and multiple charged particle detectors. Recent projects performed by our undergraduate research team include proton induced X-ray emission (PIXE) and Rutherford backscattering (RBS) analyses of atmospheric aerosols collected with a nine-stage cascade impactor in Upstate New York. We will describe the construction of the chamber and discuss the results of some commissioning experiments.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

Status of the RF-driven H{sup −} ion source for J-PARC linac

For the upgrade of the Japan Proton Accelerator Research Complex linac beam current, a cesiated RF-driven negative hydrogen ion source was installed during the 2014 summer shutdown period, with subsequent operations commencing on September 29, 2014. The ion source has been successfully operating with a beam current and duty factor of 33 mA and 1.25% (500 μs and 25 Hz), respectively. The result of recent beam operation has demonstrated that the ion source is capable of continuous operation for approximately 1100 h. The spark rate at the beam extractor was observed to be at a frequency of less than once a day, which is an acceptable level for user operation. Although an antenna failure occurred during operation on October 26, 2014, no subsequent serious issues have occurred since then.

43 PARTICLE ACCELERATORS↗
DOE OSTI2015

Monte Carlo simulations of photoneutron activation in a medical LINAC

The first step of the present study was to simulate the γ-radioactivity produced by photoneutrons in the treatment head of a decommissioned medical LINAC. These results, obtained with MCNPX and CINDER'90, are then compared with γ-ray spectrometric measurements of parts of the treatment head. Our ultimate objective is to simulate the associated production by photonuclear reactions of pure β-emitters, which are more difficult to access experimentally than the γ-ray emitters. (authors)

43 PARTICLE ACCELERATORS↗
DOE OSTI2024

Multipoint-BAX: a new approach for efficiently tuning particle accelerator emittance via virtual objectives

Abstract Although beam emittance is critical for the performance of high-brightness accelerators, optimization is often time limited as emittance calculations, commonly done via quadrupole scans, are typically slow. Such calculations are a type of multipoint query , i.e. each query requires multiple secondary measurements. Traditional black-box optimizers such as Bayesian optimization are slow and inefficient when dealing with such objectives as they must acquire the full series of measurements, but return only the emittance, with each query. We propose a new information-theoretic algorithm, Multipoint-BAX , for black-box optimization on multipoint queries, which queries and models individual beam-size measurements using techniques from Bayesian Algorithm Execution (BAX). Our method avoids the slow multipoint query on the accelerator by acquiring points through a virtual objective , i.e. calculating the emittance objective from a fast learned model rather than directly from the accelerator. We use Multipoint-BAX to minimize emittance at the Linac Coherent Light Source (LCLS) and the Facility for Advanced Accelerator Experimental Tests II (FACET-II). In simulation, our method is 20× faster and more robust to noise compared to existing methods. In live tests, it matched the hand-tuned emittance at FACET-II and achieved a 24% lower emittance than hand-tuning at LCLS. Our method represents a conceptual shift for optimizing multipoint queries, and we anticipate that it can be readily adapted to similar problems in particle accelerators and other scientific instruments.

43 PARTICLE ACCELERATORS↗
DOE OSTI2017

Radiation Testing at Sandia National Laboratories: Sandia – JPL Collaboration for Europa Lander

Sandia National Laboratories (SNL) is assisting Jet Propulsion Laboratory in undertaking feasibility studies and performance assessments for the Planetary Protection aspect of the Europa Lander mission. The specific areas of interest for this project are described by task number. This white paper presents the evaluation results for Task 2, Radiation Testing, which was stated as follows: Survey SNL facilities and capabilities for simulating the Europan radiation environment and assess suitability for: A. Testing batteries, electronics, and other component and subsystems B. Exposing biological organisms to assess their survivability metrics. The radiation environment the Europa Lander will encounter on route and in orbit upon arrival at its destination consists primarily of charged particles, energetic protons and electrons with the energies up to 1 GeV. The charged particle environments can be simulated using the accelerators at the Ion Beam Laboratory. The Gamma Irradiation Facility and its annex, the Low Dose Rate Irradiation Facility, offer irradiations using Co-60 gamma sources (1.17 and 1.33 MeV), as well as Cs-137 gamma (0.661 MeV) AmBe neutron (0-10 MeV) sources.

07 ISOTOPE AND RADIATION SOURCES↗