Rensselaer Polytechnic Research Articles

Centrifuge modeling-of-models investigation on earthquake-induced excess pore pressure behavior of silty sand

Two centrifuge experiments conducted at Rensselaer Polytechnic Institute (RPI) aimed to evaluate the effectiveness of the used centrifuge scaling laws and validate results obtained within the project, related to the liquefaction behavior of silty sand soils under simulated field drainage conditions. These experiments, replicating a 5-m thick silty sand layer under 1 atm overburden pressure and featuring a double drainage condition, were performed at two different centrifugal accelerations. Due to the difficulties encountered in saturating silty sand, this paper presents a bottom-up saturation method, verified through assessments of remaining air volume after saturation. Despite differing g-levels, the tests consistently demonstrated similar behaviors in terms of acceleration, pore pressure buildup and dissipation, and stress-strain responses, validating the saturation and modeling technique for silty sand.

Museum Acoustics: Classification and auralization of design approaches

Architecture defines various aspects of museum spaces. Despite often being considered secondary importance by some deciders and designers, the acoustic environment significantly shapes the interpretation of exhibitions and human-building interactions. Focusing on enhancing museum acoustics, this study builds upon previous research that developed a methodology for simulating and evaluating museum soundscapes through psychophysical experiments in immersive environments, showing that participants preferred congruent soundscapes over generic noise maskers [J. Acoust. Soc. Am. 154, A257]. Expanding on these previous investigations, our current research involves cataloging and classifying design approaches currently used within museum contexts—architectural elements, acoustic characteristics, spatial distribution, exhibition strategies, multimodal approaches, etc. Subsequently, we present an auralization method for these museum spaces using the ray tracing method developed for collaborative virtual reality systems [J. Acoust. Soc. Am. 143, 1824]. This method is used within the CRAIVE-Lab at Rensselaer Polytechnic Institute to facilitate tangible analysis, enriching our understanding of these solutions to support future design efforts by guiding architects and acousticians to optimize the museum experience. It offers significant insights into current practices, emerging trends, or notable innovations, thereby promoting more experiential design approaches to shaping the acoustic impacts of the museum environment.

Design of an optimized nuclear fuel pellet

Background The design of an improved nuclear fuel pellet for use in the Westinghouse AP1000 reactor that is more powerful than existing pellets, is less expensive to manufacture, and meets Nuclear Regulatory Commission requirements for certification was undertaken to complete a senior design course in the ABET-certified nuclear engineering curriculum of Rensselaer Polytechnic Institute, Troy, NY. Methods The modeling team selected the Monte Carlo N-Particle (MCNP) program for assessing how well the pellet design achieves a k-effective value of 1, designed the base model consisting of a fuel pin inside a boron-water moderator with reflector, and ran MCNP tests on the base pellet. The design team modified the base pellet and tested it at different uranium-235 enrichments, with void spheres of varying volume and silicon carbide inclusions in the void volume. The simulation team selected K-code for testing the fuel pellets. The economics team analyzed the cost of manufacturing the improved pellet from cost of raw material through its tail assay in the form of Separative Work Unit (SWUs). The impacts team researched environmental, societal, governmental, political, and public affairs aspects of nuclear fuel production. Results Multiple configurations of uranium enrichment and silicon carbide volume inclusions in the nuclear fuel pellet achieved a k eff of 1, and the price per pellet, assuming fabrication costs comparable to existing manufacturing processes, was reduced by as much as about 50% when the volume of uranium oxide replaced by silicon carbide is 0.27 cm3. At smaller replacement volumes, the price per pellet is reduced by as little as 5%. Conclusions The goal of designing an optimized fuel pellet was met. Replacing a 0.27 cm3-volume sphere of uranium oxide with silicon carbide from the center of a pellet of 4%, 5%, or 6% uranium-235 enrichment reduced the cost of the pellet by approximately 50%.

Social innovation in working management practices to support facilities management at Malaysian polytechnics

Purpose Operation and maintenance (O&M) processes projects such as identification, assessment, planning and execution, embody a variety of standards such as technical (method of statement), environmental, economic (campus development) and social (health and wellbeing). Because these standards have proven to be challenging to integrate, local governments are increasingly experimenting with social innovation (SI) as a bottom-up form of standard integration. This study aims to apply the concept of SI to the O&M processes of facilities management at polytechnics in Malaysia to identify problems with conventional working practices in this area and to recommend potential solutions. Design/methodology/approach The paper reviews evidence that conventional working methods generate significant problems related to paper-based forms, improper database management and flawed decision-making processes. Because of the lack knowledge about different ways of how standard integration is achieved, the comparison of three polytechnic institutions which are Rensselaer Polytechnic Institute (RPI) and Southern Polytechnic College of Engineering and Engineering Technology (SPCEET) in USA as well as Seberang Perai Polytechnic, Pulau Pinang (PSP) in Malaysia shares the ambition to realise standard integration of O&M through SI. Findings The findings reveal that SI leads to four ways of standard integration: computerised maintenance management system, online customer complaint, electronic form and relational database. Application of the concept of SI reveals the need for more sophisticated management solutions in the O&M processes of facilities management. Originality/value These standard integration arrangements unfortunately seem to mainly contribute to greater alignment between standard rather than true standard integration. The concept of SI will guide future improvements and developments in maintenance management systems to fulfil requirements in this area.

Machine Learning Effectively Diagnoses Mandibular Deformity Using Three-Dimensional Landmarks

Jaw deformity diagnosis requires objective tests. Current methods, like cephalometry, have limitations. However, recent studies have shown that machine learning can diagnose jaw deformities in two dimensions. Therefore, we hypothesized that a multilayer perceptron (MLP) could accurately diagnose jaw deformities in three dimensions (3D). Examine the hypothesis by focusing on anomalous mandibular position. We aimed to: (1) create a machine learning model to diagnose mandibular retrognathism and prognathism; and (2) compare its performance with traditional cephalometric methods. An in-silico experiment on deidentified retrospective data. The study was conducted at the Houston Methodist Research Institute and Rensselaer Polytechnic Institute. Included were patient records with jaw deformities and preoperative 3D facial models. Patients with significant jaw asymmetry were excluded. The tests used to diagnose mandibular anteroposterior position are: (1) SNB angle; (2) facial angle; (3) mandibular unit length (MdUL); and (4) MLP model. The resultant diagnoses: normal, prognathic, or retrognathic. None. A senior surgeon labeled the patients' mandibles as prognathic, normal, or retrognathic, creating a gold standard. Scientists at Rensselaer Polytechnic Institute developed an MLP model to diagnose mandibular prognathism and retrognathism using the 3D coordinates of 50 landmarks. The performance of the MLP model was compared with three traditional cephalometric measurements: (1) SNB, (2) facial angle, and (3) MdUL. The primary metric used to assess the performance was diagnostic accuracy. McNemar's exact test tested the difference between traditional cephalometric measurement and MLP. Cohen's Kappa measured inter-rater agreement between each method and the gold standard. The sample included 101 patients. The diagnostic accuracy of SNB, facial angle, MdUL, and MLP were 74.3, 74.3, 75.3, and 85.2%, respectively. McNemar's test shows that our MLP performs significantly better than the SNB (P=.027), facial angle (P=.019), and MdUL (P=.031). The agreement between the traditional cephalometric measurements and the surgeon's diagnosis was fair. In contrast, the agreement between the MLP and the surgeon was moderate. The performance of the MLP is significantly better than that of the traditional cephalometric measurements.

Starting from Scratch: A Holistic Framework for Designing Digitally Delivered Graduate Programs for STEM Working Professionals

Provided the opportunity to create new, high-quality graduate programs from scratch, a framework was sought to help meet the intersecting needs of employers and employees, while cultivating a learning environment that honors the individuality of working professionals. Given Rensselaer Polytechnic Institute’s (RPI) nearly 200 years of engineering and research excellence, it was natural to leverage the engineering design process to develop a modern solution. Though there are many variations of the engineering design process, this paper presents it as a sequence of six steps: identify, explore, design, create, test, and improve. The first three steps (identify, explore, and design) are the focus of this work. From these emerged a series of strategic decisions in program logistics (face-to-face, online, hybrid, etc.), curriculum design, and learning interface informed by thorough consideration of employer and employee needs as well as the latest in learning science. Due to the abundance of variety in how graduate programs are designed, this paper provides a detailed description of the design process such that other institutions looking to develop quality, digitally delivered programs, may consider this work. Consequently, clear connections are made between the needs of employers and employees, learning science, and research design. In all, eight graduate certificates, 10 sets of learning goals and competencies (LG&Cs), 25 project-based courses, and more than 60 projects have successfully been designed, developed, and delivered using the described process as a framework for program development. Future papers will explore how these courses and projects were created, tested, and improved through course development and review and revision processes that incorporate regularly cadenced instructor and student feedback.

Effects of sounds on the visitors' experience in museums

Museums increasingly recognize the significance of acoustics for a high-quality visitor experience. Objective/physical parameters have been extensively studied, but there is a need for research focusing on user perception. This study addressed this gap by investigating visitors' soundscape preferences and the effects of different soundscapes on the museum experience. We hypothesized that exhibition-congruent sounds are more effective than conventional masking sounds in reducing distractions, enhancing engagement with artwork, and creating immersive experiences. The research utilized the Cognitive Immersive Room (CIR) at Rensselaer Polytechnic Institute, featuring a 360° visual display with a multi-channel loudspeaker system for spatial audio rendering to project panoramic photographs and ambisonic audio recordings recorded in 16 exhibitions in five relevant museums—for example, MASSMoca and the New York State Museum. Four scenarios were presented to the participants: originally recorded soundscape, recorded soundscape combined with a conventional sound masker, recorded soundscape combined with a congruent sound masker, and silence. After experiencing the immersive environment, 23 subjects responded to a questionnaire. The results showed congruent sounds increased focus and engagement and contributed to a more comprehensive and immersive experience. In 58% of cases, the participants preferred the congruent-sound scenario over the others.

Methodology for physics-informed generation of synthetic neutron time-of-flight measurement data

Accurate neutron cross section data are a vital input to the simulation of nuclear systems for a wide range of applications from energy production to national security. The evaluation of experimental data is a key step in producing accurate cross sections. There is a widely recognized lack of reproducibility in the evaluation process due to its artisanal nature and therefore there is a call for improvement within the nuclear data community. This can be realized by automating/standardizing viable parts of the process, namely, parameter estimation by fitting theoretical models to experimental data. There are numerous candidate methods to approach this type of problem, but many rely on large, labeled datasets that are not accessible to the nuclear data evaluator. For a reaction cross-section, there are usually just a handful of datasets, none of which can be considered labeled because evaluators never have access to the exact solution (cross section). This work leverages problem-specific physics, Monte Carlo sampling, and a general methodology for data synthesis to generate unlimited, labeled experimental cross-section data of high-utility. The synthesized data is said to be of high-utility because it is statistically similar to the observed data. Heuristic and, where applicable, rigorous statistical comparisons to observed data support this claim. The methodology is split into two generative models. The first generates a realization of an energy-differential cross section for a given isotope. The second takes the output from the first as a determined input and generates noisy experimental observables (radiation detector signals) from the determined cross section realization. The latter is the primary development of this article and is based/limited to transmission measurements at Rensselaer Polytechnic Institute (RPI). The former leverages an existing method for model parameter sampling in the resolved resonance region (RRR), thus limiting the current demonstration to the RRR of incident neutron energies. An open-source software is published alongside this article that executes the complete methodology to produce high-utility synthetic datasets. The goal of this work is to provide an approach and corresponding tool that will allow the evaluation community to begin exploring more data-driven, ML-based solutions to long-standing challenges in the field.

Spatially-aware group interaction design framework for collaborative room-oriented immersive systems

Room-oriented immersive systems are human-scale built environments that enable collective multi-sensory immersion in virtual space. Although such systems are currently seeing increasing applications in public realms, limited understanding remains regarding how humans interact with the virtual environments displayed within. Synthesizing virtual reality ergonomics and human-building interaction (HBI) knowledge allows us to investigate these systems meaningfully. In this work, we develop a model of content analysis based on hardware components of the Collaborative-Research Augmented Immersive Virtual Environment Laboratory (CRAIVE-Lab) and the Cognitive Immersive Room (CIR) at Rensselaer Polytechnic Institute. Situating ROIS as a joint cognitive system, this model consists of five categories of qualitative factors: 1) general design approach; 2) topological relationships; 3) features of tasks; 4) hardware-specific design modalities; and 5) interactive qualities. We probe the comprehensiveness of this model using existing design scenarios at the CRAIVE-Lab and the CIR featuring both application-based and experience-based designs. Through these case studies, the robustness of this model in its representation of design intention is observed, with limitations on temporal constraints. In creating this model, we establish foundations for more detailed assessments of the interactive qualities of systems alike.

Numerical Investigation on Pool Boiling Heat Transfer of Silica and Alumina Nanofluids

Surface modification through pool boiling of nanofluid is an efficient technique in delaying critical heat flux and attaining high heat flux at lower wall superheat temperature. The method of involving phase interaction, bubble evolving and dynamics phenomenon, and distribution of vapor void fraction altogether is the motivation behind current topic. The present work will contribute to the recovery and reuse of the wastewater and incinerator heat, cooling of high heat flux generating micro-electronics chips, and cooling of fast breeder test reactors. In the present study, the nucleate pool boiling of SiO2/water and Al2O3/water nanofluid are studied numerically and the effect of wall superheat temperature and heat flux on active nucleation site density, bubble departure diameter, and bubble waiting time are studied. The effect of various heater surface material and nanofluid concentration on wall superheat temperature and heat transfer coefficient are also investigated. A two-phase Eulerian approach, heat flux wall-partitioning model, and Rensselaer Polytechnic Institute boiling model are considered to simulate the current model. The pool boiling of nanofluids resulted in the formation of nano-porous layer on heater surface because of microlayer evaporation process that enhanced the heat transfer coefficient and reduced the wall superheat temperature.

Research on parameter extraction of thin‐film transistors based on swarm intelligence

AbstractThe development of integrated circuits for displays and other applications requires semiconductor device models and appropriate parameter extraction techniques to predict and understand the circuit behavior. These techniques are paramount in reducing design errors and shortening the product development cycle. This paper presents an algorithm that employed swarm intelligence in exploring an automated and accurate parameter extraction technology. First, an automatic parameter extraction of Rensselaer Polytechnic Institute (RPI) Model for polysilicon thin‐film transistor (Poly‐Si TFT) is achieved by genetic algorithm (GA) and particle swarm optimization (PSO) algorithm. Compared with the best solution of the GA algorithm for automatic parameter extraction, the PSO outperformed the GA. However, it still prematurely converges to the suboptimal solution henceforth cannot obtain the expected solution accuracy. Second, the mutual learning particle swarm optimization (MLPSO) algorithm is proposed that introduces the concept of “mutual learning.” The new algorithm aims to find the global optimum in getting suitable trade‐off between exploration and exploitation. In addition, the MLPSO algorithm implemented the novel random initialization and fitness function in simplifying the complex manual processes and the empirical calibration, and it led to achieving automatic and accurate parameters extraction.

Influence of pin-fin patterns and geometry on the effectiveness of jet impingement boiling – A computational study

Jet impingement combined with phase change in the form of boiling has been proven to enhance heat transfer in thermal management applications. When added to surface enhancement, a further increase in heat transfer can be envisaged. Surface enhancement in the form of pin-fins are investigated numerically for a confined single jet of HFE 7100 impinging on a copper surface under boiling conditions. ANSYS Fluent with the Rensselaer Polytechnic Institute boiling model embedded in the Eulerian multiphase framework is utilised. After validating the resulting boiling curve against experiments with an in-line arrangement of pin-fins, a parametric study to investigate the effect of pin geometry, and pattern was performed. Key parameters included Reynolds numbers, pin-fin heights, pin-fin spacing and a star pattern. The objective of the parametric analysis was to limit the dry-out regions in the domain. Finding that local dry-out is decreased through decreasing flow obstruction and heat transfer is mainly linked to surface augmentation. Our results show that for the experimental configuration, 17 % of the pin-fin area experienced dry-out at the 23.2 W/cm2 input heat flux. Dry-out was practically eliminated for low pin-fins spaced far apart as expected. But, when keeping the surface augmentation factor constant in a star pattern, the dry-out area was reduced from 17 % to 1 % at the same input heat flux without a significant change in the wall superheat. In addition, the star pattern distribution allowed for a substantial increase in the critical heat flux compared to the in-line arrangement. It was also demonstrated that the pressure drop over the domain was independent of the surface enhancement as it was dominated by the jet stagnation pressure.

Numerical simulation of subcooled flow boiling for nuclear engineering applications using OpenFOAM

Abstract This work is focused on the development and validation of models and methods for the simulation of wall boiling in nuclear engineering applications with the computational fluid dynamics (CFD) code OpenFOAM. The new chtMultiRegionReactingTwoPhaseEulerFoam solver was developed based on the reactingTwoPhaseEulerFoam solver of OpenFOAM Foundation version 7. The solver is used for the simulation of two-phase flow under consideration of wall boiling and conjugate heat transfer (CHT) between solid structure and two-phase fluid regions. The Euler–Euler approach for two-phase flows was used. The heat flux during wall boiling was calculated with the help of the extended Rensselaer Polytechnic Institute wall heat flux partitioning model, in which the convective heat flux between solid wall and two-phase flow with high void fractions was also considered. The solver was validated against experimental data from the OECD/NEA PWR Subchannel and Bundle Tests benchmark. This Nuclear Power Energy Corporation (NUPEC) database provides data for different fuel assembly subchannel geometries at different thermal-hydraulic conditions. 10 experimental runs with different boundary conditions of the benchmark exercise I-1 were simulated with the chtMultiRegionReactingTwoPhaseEulerFoam solver. The solver showed good numerical stability in all examined cases, which captured different boiling regimes with up to cross-section averaged void fractions of 0.6. The results were compared with measured data for the averaged over the cross-section of the investigated geometry void fractions. Good agreement with experimental data was observed.

Effect of U-bend on void fraction in subcooled boiling flow

U-bend is very common in heat exchangers to facilitate the pipe arrangement, whereas studies on boiling heat transfer in such a bend pipe flow are quite scare, hindering the accurate design of this heat exchanger type. This work studied subcooled boiling flow in U-bend pipes with emphasis on the point of net vapor generation (PNVG) and the void fraction distribution. A Eulerian−Eulerian two fluid numerical scheme was established and Rensselaer Polytechnic Institute wall boiling model was incorporated. After verifying the model by experimental data, numerical runs were conducted at 10.81 MPa, mass flux of 100–3000 kg/m2s, and heat flux of 100–3000 kW/m2. Results show that net vapor generation was postponed when PNVG located outside of bend section, while close to that of straight tube when it is within the bend. Compared with straight pipe, void fraction in U-bend pipe was initially smaller and eventually larger. This transition occurred at different axial positions as the location or curvature of U-bend varied. The delayed PNVG leading to reduction of void fraction. After PNVG, turbulent kinetic energy induced by secondary flow accelerated bubble departure from the wall thus yielded larger void fraction. A modified Saha-Zuber model was proposed by properly considering the bend influence on PNVG and distribution parameter. The modified model is competent to the prediction of void fraction distribution, and can serve the thermal-hydraulic design of heat exchanger involving U-bend.

Getting to yes: An interview with Igor Vamos

Patrick Burkart, Editor-in-Chief of Popular Communication: International Journal of Media and Culture, interviews Dr Igor Vamos, member of The Yes Men and Professor of Art at Rennselaer Polytechnic Institute, New York, USA. Dr Burkart and Dr Vamos discuss the formative years of experimentation with art and politics which informed Dr Vamos’s vision for The Yes Men's environmental activism and the prospects for an ecological politics.

Measurement of Photoneutron Yields Using the RPI LINAC and Assessment of Evaluated Photoneutron Data for Tantalum and Beryllium

A new experiment configuration was designed, developed, and implemented to measure photoneutron yields using the Rensselaer Polytechnic Institute (RPI) electron linear accelerator (LINAC) at the RPI Gaerttner LINAC Center. The experiment configuration includes a new target assembly that converts the LINAC electron beam into a high energy bremsstrahlung photon flux incident upon a sample material of interest. The photons excite nuclei in the sample of interest, which can subsequently emit neutrons (photoneutrons). The photoneutrons emitted in the direction of the detector system travel through a series of collimated vacuum pipes before reaching a pair of proton-recoil high-energy neutron detectors. The signals generated by the neutron detectors are processed using a digital data acquisition system and subsequently analyzed to determine the energy-dependent photoneutron yield from the sample of interest. The new experiment configuration was used to perform proof-of-concept experiments to measure the photoneutron yields from samples of tantalum and beryllium. The measured results were then compared against the results from Monte Carlo simulations of the detailed experiment configurations to perform preliminary assessments of evaluated photoneutron data libraries.

Computational investigation of single and multi-jet array impingement boiling

Jet impingement boiling has been studied extensively and has been identified as one of the most promising thermal management techniques for high heat flux applications. Unfortunately, only a few numerical studies have been reported in literature and they are mostly limited to single jets. In the present study, both submerged single round jets and confined multi-jet arrays are investigated numerically, using the Eulerian multiphase framework with the Rensselaer Polytechnic Institute (RPI) boiling model to predict heat transfer. The numerical results of the single jet case correlate well with reported experimental data and previously reported numerical results. The numerical results of the multi-jet array correlate well with experimental data reported in the literature, proving that the RPI boiling model can successfully predict the heat transfer of jet array boiling. The effect of conjugate heat transfer in jet impingement boiling heat transfer is also investigated for both single and multiple jet cases. The single-jet results agree with previous reported numerical studies. To improve numerical convergence, especially for higher heat fluxes, use was made of a hydrostatic pressure gradient at the outlet. This allowed for significant improvement in the convergence of the continuity equation. Finally, parametric analyses were conducted for both single and multi-jet arrays in the fully developed nucleate boiling regimes. Parameters included jet-to-surface spacing, Reynolds number and subcooling. The results for the single jet correlate well with the observations of experiments reported in the literature. The results for the multi-jet array showed less sensitivity to changes in jet velocity at low jet-to-surface spacing than the single-jet case. Both single and multi-jet cases showed that reducing the subcooling resulted in an onset of nucleate boiling at lower heat fluxes and that the boiling curve shifted to the left in the nucleate boiling regime.

Validation of S(α, β) thermal neutron scattering libraries using pulsed-neutron die-away experiments

Validation of the accuracy of S(α, β) thermal scattering law (TSL) evaluations for moderator materials is an important task for the development of high-performance nuclear engineering systems. Many recent thermal neutron scattering evaluations have had limited experimental validation. Like other nuclear data, validation of TSL libraries has historically been by integral criticality benchmarks. While sufficient for general study, these benchmarks often have limited sensitivity to the tested TSLs, and compounding uncertainties from other nuclear data can make validation ambiguous. In some cases, no criticality benchmarks exist that are sensitive to the TSLs of interest. With the development of high-performance next-generation thermal nuclear reactors, alternative validation of applicable TSLs is of high importance. By performing thermal neutron measurements via pulsed-neutron die-away (PNDA) experiments, along with parallel simulations, the integral performance of various TSL evaluations can be compared to measured experimental data. An experimental testbed using a D-T neutron generator, moderator sample, and thermal neutron detector was assembled at Rensselaer Polytechnic Institute. A Thermo Scientific D211 Deuterium-Tritium Neutron generator is used to generate 10 μs neutron pulses. Various targets of different sizes and geometries are used to moderate the neutrons. Multiple detector types and configurations were tested to optimize the experiment. The room-temperature polyethylene TSL evaluation is well vetted and is similar across different evaluations. This makes it an ideal evaluation to compare with the experimental results.

New Capabilities of the RPI γ-Multiplicity Detector to Measure γ-Production

Accurate modeling of γ-production in neutron capture reactions is critical for many applications including on-proliferation, safeguards and modeling nuclear reactors. To improve this work, the Rensselaer Polytechnic Institute (RPI) 16-segment γ-multiplicity NaI(Tl) detector at the Gaerttner Linear Accelerator (LINAC) Center has been upgraded by implementing a digital data acquisition system. The new digitized system records the γ-energy deposition distribution in each individual detector, and γ-multiplicity values as a function of neutron time-of-flight (TOF). With the new capabilities, high precision capture (and fission) yield measurements can be made, and the accuracy of simulation tools used to predict capture γ-cascades can be tested. To validate the updated system, an experiment was performed using a natural Ta sample to measure 181Ta and 180mTa resonance capture yield by detecting prompt γ-rays emitted from neutron capture interactions as a function of both neutron energy and measured γ-multiplicity of each capture event. The results confirm earlier measurements and agree with theoretical yield in the low energy resonance region from 1 to 20 eV. A 238U(n, γ) measurement was also performed to generate γ-spectra. For capture γ-cascades where the total γ-energy deposition is close to the neutron binding energy, γ-spectra were measured for individual resonance energies and observed γ-multiplicities. The results are comparable in shape to a recent measurement done using the Detector for Advanced Neutron Capture Experiments (DANCE) array at Los Alamos Neutron Science Center (LANSCE); however, differences need to be compared to Monte-Carlo n-particle simulations.

Neutron Capture and Transmission Measurements of 54Fe at the RPI LINAC

54Fe radiative capture cross section and transmission measurements were conducted at the Rensselaer Polytechnic Institute (RPI) Gaerttner Linear Accelerator (LINAC) Center using an enriched 54Fe sample in the keV energy region. 54Fe is a constituent of natural iron, which is present in a large variety of nuclear grade materials. Therefore, it is important to have an accurate understanding of the cross sections of 54Fe, which can be measured experimentally. In the time-of-flight measurements conducted at the LINAC, an array of four C6D6 detectors surrounded the sample and radiative capture data were collected using a digital data acquisition system. Additionally, a Li-glass detector was used to collect transmission data using an analog data acquisition system. The radiative capture yield of the 54Fe measurements were normalized to saturated resonances observed in Au and Ta to obtain an absolute capture yield. The preliminary capture yield and preliminary transmission obtained can be compared to evaluations and existing experimental data. Some disagreements were observed in prominent d-wave capture resonances observed in 54Fe in the low-keV neutron energy region. Both sets of experimental data along with pre-existing datasets will greatly enhance RPI’s ability to perform resonance evaluation for 54Fe up to roughly 1 MeV.