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All sources NASA NTRS DOE OSTI

DOE OSTI2019

Performance evaluation of an energy tuning assembly for neutron spectral shaping

An energy tuning assembly (ETA) was designed here to be fielded at the National Ignition Facility (NIF) to modify the characteristic D-T fusion spectrum to include a prompt fission neutron spectral component. The ETA was characterized at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory to measure the shaped spectrum from an incident deuteron breakup neutron source, test the proposed neutron spectroscopy techniques used to inform the flux measurements at NIF, and validate the ability to predict ETA performance using a Monte Carlo Neutral Particle (MCNP) simulation. Activation foils (i.e., Ni, In, Au, Al) were exposed to a collimated 33-MeV deuteron-breakup beam originating from a tantalum breakup target. The source spectrum absent the ETA was characterized using a set of activation foils and the STAYSL unfolding code. Finally, the ETA-modified spectrum was obtained using activation foil unfolding with a χ 2 ν = 0 . 92 . The ETA-modified unfolded spectrum agreed with the MCNP-simulated prediction in the energy range of 0.1–14 MeV, but exhibited disagreements in the 10 eV–100 keV region. This work demonstrates shaping of the NIF neutron spectrum via the ETA to be a viable path forward for tailored neutron beams at NIF.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2023

Commissioning of the Second JLAB C75 Cryomodule & Performance Evaluation of Installed C75 Cavities

JLAB has long been a hub of SRF technology with the CEBAF accelerator as one of its first large scale adopters. As SRF technology has advanced, the C50 and C100 programs have allowed for the extension of CEBAF's total energy to 6 GeV and nearly 12 GeV respectively. Along with the increase in energy reach, rates of accelerating gradient degradation have been extracted for these cryomodule designs. A plan to mitigate these losses & maintain robust gradient headroom to deliver the 12 GeV program - the CEBAF Performance Plan - established a multi-year effort of cryomodule refurbishments and replacements. Part of this plan included a cost optimization of the C50 program with more modern processing techniques and the replacement of existing cavities with larger grain boundary cavities produced from ingot Niobium (dubbed C75 for 75 MeV gain). Reports have been made on the prototype pair of C75 cavities installed in a C50 cryomodule and the first full C75 cryomodule installed in 2017 and 2021. This paper reports on the results from the qualification of the cavities for the second C75 module in both a vertical cryostat and the commissioning results of the cryomodule in the CEBAF tunnel. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.

McCaughan, Michael↗

NASA NTRS1989

QM-8 final performance evaluation report: SEALS, volume 4

The Space Shuttle Redesigned Solid Rocket Motor (RSRM) static test of Qualification Motor-8 (QM-8) was conducted. The QM-8 test article was the fifth full-scale, full-duration test, and the third qualification motor to incorporate the redesigned case field joint and nozzle-to-case joint. This was the second static test conducted in the T-97 test facility, which is equipped with actuators for inducing external side loads to a 360 degree external tank (ET) attach ring during test motor operation, and permits heating/cooling of an entire motor. The QM-8 motor was cooled to a temperature which ensured that the maximum propellant mean bulk temperature (PMBT) of 40 F was achieved at firing. All test results are not included, but rather, the performance of the metal case, field joints, and nozzle-to-case joint is addressed. The involvement is studied of the Structural Applications and Structural Design Groups with the QM-8 test which includes: assembly procedures of the field and nozzle-to-case joints, joint leak check results, structural test results, and post-test inspection evaluations.

Nelsen, L. V.↗

DOE OSTI2017

Performance evaluation of a novel anaerobic digestion operation process for treating high-solids content chicken manure: Effect of reduction of the hydraulic retention time at a constant organic loading rate

Highlights: • A novel feeding strategy, keeping constant OLR but reducing HRT{sub CM} was adopted. • The effect of reducing HRT{sub CM} on CH{sub 4} fermentation of chicken manure was studied. •High content of ammonia was the main inhibition factor at HRT{sub CM} of 52 days. • Reduce in HRT{sub CM} relaxed the inhibition of high ammonia at OLR of 6.0 gVS/L/d. • The performance deterioration occurred as HRT{sub CM} decreased to 10 days. - Abstract: A novel feeding strategy was adopted in this study and the effect of reduction in hydraulic retention time (HRT) on the anaerobic digestion of chicken manure (CM) with a constant organic loading rate of 6.0 gVS/L/d was investigated. The lab-scale CSTR was operated at 38 °C and HRT{sub CM} was reduced from 52 days to 5 days. At HRT{sub CM} of 20–45 days, the reactor was relatively stable in terms of the volumetric biogas production rates and specific biogas production (SBP), which were 2.2–2.4 L/L/d and 338.3–418.7 mL/gVS{sub added}, respectively. However, process instability and VFA accumulation occurred when the HRT{sub CM} was reduced to 10 days due to excess microbes washout. The reduction in HRT{sub CM} to 5 days caused SBP to decrease to 198.7 mL/gVS{sub added} and the acetic acid content to exceed 6000 mg/L. The biomass balance model showed that the biomass concentration at HRT{sub CM} of 20–52 days (0.473–0.615 gVSS/L) was notably higher than that at HRT{sub CM} of 5–10 days (0.173 gVSS/L).

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2022

Dynamic characterization and performance evaluation of a 10-kW power take-off with mechanical motion rectifier for wave energy conversion

The power take-off (PTO) is a key component for wave energy converters. In this paper, a compact PTO with mechanical motion rectification rated at 10 kW is designed and prototyped, and characterized. A piecewise nonlinear dynamic model is established to describe its unique dynamic property. A linear hydraulic actuator is adopted in lab testing to drive the prototype and the unknown parameters of the dynamic model are identified. Further verification shows that the model can predict the dynamic performance of the PTO well. The test results show that the mechanical motion rectifier-based PTO can achieve overall energy transfer efficiency as high as 65% in regular waves even when the generator is working below the rated electric load and speed. In the irregular wave test, the PTO achieved the overall energy transfer efficiency of 54%, and the peak-to-average ratio acquired during the test is 12.5.

16 TIDAL AND WAVE POWER↗

NASA NTRS1980

Solar energy system performance evaluation report for IBM System 4 at Clinton, Mississippi

The IBM System 4 Solar Energy System is described and evaluated. The system was designed to provide 35 percent of the space heating and 63 percent of the domestic hot water preheating for a single family residence located within the United States. The system consists of 259 square feet of flat plate air collectors, a rock thermal storage containing 5 1/2 ton of rock, heat exchangers, blowers, a 52 gallon preheat tank, controls, and associated plumbing. In general, the performance of the system did not meet design expectations, since the overall design solar fraction was 48 percent and the measured value was 32 percent. Although the measured space heating solar fraction at 32 percent did agree favorably with the design space heating solar fraction at 35 percent, the hot water measured solar fraction at 33 percent did not agree favorably with the design hot water solar fraction of 63 percent. In particular collector array air leakage, dust covered collectors, abnormal hot water demand, and the preheat tank by pass valve problem are main reasons for the lower performance.

Source record↗

NASA NTRS1978

Thermal performance evaluation of the Calmac (liquid) solar collector

The procedures used and the results obtained during the evaluation test program on the S. N. 1, (liquid) solar collector are presented. The flat plate collector uses water as the working fluid. The absorber plate is aluminum with plastic tubes coated with urethane black. The glazing consists of .040 in fiberglass reinforced polyester. The collector weight is 78.5 pounds with overall external dimensions of approximately 50.3in. x 98.3in. x 3.8in. The following information is given: thermal performance data under simulated conditions, structural behavior under static loading, and the effects of long term exposure to natural weathering. These tests were conducted using the MSFC Solar Simulator.

Usher, H.↗

NASA NTRS1990

Performance evaluation of land mobile satellite system under vegetative shadowing using differential multiple TCM and QPSK

A comparative analysis by computer simulation of the land mobile satellite system (LMSS) is presented for the uncoded quadrature phase shift keying (QPSK), rate 2/3 8-PSK trellis coded modulation (TCM), and rate 4/6 multiplicity 2 8-PSK TCM schemes. An analytical model is used for simulating the fading channel. The simulation results show that under Rayleigh fades, the TCM designed for the fading channel is superior to uncoded QPSK and to the conventional TCM optimized for the additive white Gaussian noise (AWGN) channel. The performance of differentially detected TCM under AWGN and fading is examined based on the preliminary results. Results of the uncoded QPSK with fading channel modeled with the empirical fade data are given.

Kim, Junghwan↗

DOE OSTI2024

Performance evaluation of an RFSoC operating in a 1.25 Tesla magnetic field

Here, the Belle II experiment at the SuperKEKB collider is preparing for an upgrade after 2027–2028 to handle higher luminosity and increased background rates. A Radio Frequency System-on-Chip (RFSoC) has been identified as a potential candidate for a common front-end upgrade for subsystems requiring high-speed waveform digitization. The RFSoC's ADC and DAC channels were tested across various magnetic field strengths and a few different field orientations. Power consumption and boot memory functionality were also assessed. Results indicate stable operation with negligible performance degradation, suggesting the RFSoC's viability for high-speed digitization tasks in high magnetic field environments.

47 OTHER INSTRUMENTATION↗

NASA NTRS1991

A portable X-band front-end test package for beam-waveguide antenna performance evaluation. Part 2: Tests on the antenna

Results are given for an X-band (8.45 GHz) test package for testing the new 34-m beam-waveguide antenna at Goldstone in an 'on-the-antenna' configuration. Included are X-band zenith noise temperature values and tipping-curve data obtained at the Cassegrain focal point F1 as well as at the pedestal room focal point F3. Subreflector Z-defocus test results for both F1 and F3 are also presented. The X-band test package operated well in all of the different test configurations and exceeded expected performance.

Otoshi, T. Y.↗

DOE OSTI2013

Laboratory Report on Performance Evaluation of Key Constituents during Pre-Treatment of High Level Waste Direct Feed

The analytical capabilities of the 222-S Laboratory are tested against the requirements for an optional start up scenario of the Waste Treatment and Immobilization Plant on the Hanford Site. In this case, washed and in-tank leached sludge would be sent directly to the High Level Melter, bypassing Pretreatment. The sludge samples would need to be analyzed for certain key constituents in terms identifying melter-related issues and adjustment needs. The analyses on original tank waste as well as on washed and leached material were performed using five sludge samples from tanks 241-AY-102, 241-AZ-102, 241-AN-106, 241-AW-105, and 241-SY-102. Additionally, solid phase characterization was applied to determine the changes in mineralogy throughout the pre-treatment steps.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

NASA NTRS1991

A portable Ku-band front-end test package for beam-waveguide antenna performance evaluation

A 34-m beam-waveguide (BWG) antenna has been built a Deep Space Station 13 (DDS 13) in the Goldstone Deep Space Communications Complex. This antenna is designed to be efficient at X-, Ku-, and Ka-bands, and it is the first NASA tracking antenna to use a BWG design. The design of a Ku-band test package for the new BWG antenna at 11.7-12.2 GHz is presented. Results of linear polarization measurements with the test package on the ground are also presented. This report is the fifth in a series of articles concerned with test package design and performance.

Otoshi, T. Y.↗

DOE OSTI2014

Performance Evaluation of Lower-Energy Energy Storage Alternatives for Full-Hybrid Vehicles; NREL (National Renewable Energy Laboratory)

Automakers have been mass producing hybrid electric vehicles (HEVs) for well over a decade, and the technology has proven to be very effective at reducing per-vehicle fuel use. However, the incremental cost of HEVs such as the Toyota Prius or Ford Fusion Hybrid remains several thousand dollars higher than the cost of comparable conventional vehicles, which has limited HEV market penetration. The b b b b battery energy storage device is typically the component with the greatest contribution toward this cost increment, so significant cost reductions/performance improvements to the energy storage system (ESS) can correspondingly improve the vehicle-level cost/benefit relationship. Such an improvement would in turn lead to larger HEV market penetration and greater aggregate fuel savings. The United States Advanced Battery Consortium (USABC) and the U.S. Department of Energy (DOE) Energy Storage Program managers asked the National Renewable Energy Laboratory (NREL) to collaborate with a USABC Workgroup and analyze the trade-offs between vehicle fuel economy and reducing the decade-old minimum energy requirement for power-assist HEVs. NREL’s analysis showed that significant fuel savings could still be delivered from an ESS with much lower energy storage than the previous targets, which prompted USABC to issue a new set of lower-energy ESS (LEESS) targets that could be satisfied by a variety of technologies. With support from DOE, NREL has developed an HEV test platform for in-vehicle performance and fuel economy validation testing of the hybrid system using such LEESS devices. This presentation describes development of the vehicle test platform, and laboratory as well as in-vehicle evaluation results with alternate energy storage configurations as compared to the production battery system. The alternate energy storage technologies considered include lithium-ion capacitors -- i.e., asymmetric electrochemical energy storage devices possessing one electrode with battery-type characteristics (lithiated graphite) and one with ultracapacitor-type characteristics (carbon) -- and electrochemical double-layer capacitors.

33 ADVANCED PROPULSION SYSTEMS↗

DOE OSTI2019

Multi-rate OCDMA system BER performance evaluations for different ML-code sequences

This paper analyzes Bit Error Rate (BER) of Optical Code Division Multiple Access (OCDMA) networks for different class of services which are data, voice, and video; whereas Multi-Length Weighted Modified Prime Code (ML-WMPC) sequences are utilized as a spreading code in with respect to previously used ML-Optical Orthogonal codes. Due to variations in bit rates between the mentioned services, each of them assigns a different WMPC sequence length. In addition, the shot noise, thermal noise, and the Multiple Access Interference (MAI) are included and considered as sources of noise in the BER performance analysis. Furthermore, Pulse Position Modulation, Manchester encoding and MAI cancellation (MAIC) technique are utilized to improve the network performance at a higher number of active users. For analysis, the BER performance calculations are investigated for three types of OCDMA receivers such as simple receiver, receiver with MAIC technique, and receiver with MAIC and Manchester encoding. Moreover, the BER mathematical models have been introduced for different bit rates according to the type of service in the presence of the ML-WMPC and the last of three mentioned OCDMA receivers. Finally, these models and their results are compared with the other existing models, where the results show an improvement in BER performance in the proposed approach.

42 ENGINEERING↗

NASA NTRS1983

Performance evaluation and geologic utility of LANDSAT 4 TM and MSS scanners

Experiments using artificial targets (polyethylene sheets) to help calibrate and evaluate atmospheric effects as well as the radiometric precision and spatial characteristics of the NS-001 and TM sensor systems were attempted and show the technical feasibility of using plastic targets for such studies, although weather precluded successful TM data acquisition. Tapes for six LANDSAT 4 TM scenes were acquired and data processing began. Computer enhanced TM simulator and LANDSAT 4 TM data were compared for a porphyry copper deposit in Southern Arizona. Preliminary analyses performed on two TM scenes acquired in the CCT-PT format, show the TM data appear to contain a marked increase in geologically useful information; however, a number of instrumental processing artifacts may well limit the ability of the geologist to fully extract this information.

Paley, H. N.↗

NASA NTRS1988

Shuttle rendezvous radar performance evaluation and simulation

The US Space Shuttle's Ku-band system was specifically designed for communications and tracking functions which are required during on-orbit operations with other spacecraft. Operating modes permit search and acquisition to be accomplished by computer designation or under manual control by the astronaut. Ku-band system data channels drive on-board dedicated displays and are incorporated into state vector updates by Shuttle guidance and navigation computers. Radar-cross-section estimates were used in computer simulations to predict the range at which radar detection and acquisition can be expected. Validity of the simulationi model and the radar design and performance were verified by flight tests on the White Sands test range. It is concluded that results of the testing established confidence in the capability of the system to provide the relative position and rate information which is needed for Shuttle work involving other spacecraft.

Griffin, John W.↗

NASA NTRS1991

A portable Ka-band front-end test package for beam-waveguide antenna performance evaluation. Part 1: Design and ground tests

A unique experimental method was used to test the beam waveguide (BWG) antenna at Deep Space Station (DDS) 13 in the Goldstone Deep Space Communications Complex near Barstow, California. The methodology involved the use of portable test packages to make measurements of operating noise temperatures and antenna efficiencies (as functions of antenna pointing angles) at the Cassegrain focal point and the final focal point located in a subterranean pedestal room. Degradations caused by the BWG mirror systems were determined by making comparisons of the measured parameters at the two focal points of the antenna. Previous articles were concerned with the design, performance characteristics, and test results obtained with an X-band test package operating at 32 GHz. Noise temperature measurement results are presented for the Ka-band test package in an on-the-ground test configuration.

Otoshi, T. Y.↗

NASA NTRS1979

Thermal performance evaluation of the Semco (liquid) solar collector

Procedures used and results obtained during the evaluation test program on a flat plate collector which uses water as the working fluid are discussed. The absorber plate is copper tube soldered to copper fin coated with flat black paint. The glazing consists of two plates of Lo-Iron glass; the insulation is polyurethane foam. The collector weight is 242.5 pounds with overall external dimensions of approximately 48.8 in. x 120.8 in. x 4.1 in. The test program was conducted to obtain thermal performance data before and after 34 days of weather exposure test.

Source record↗