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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 541 records · Page 30
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Mixed nickel-gallium tellurides Ni{sub 3−x}GaTe{sub 2} as a matrix for incorporating magnetic cations: A Ni{sub 3−x}Fe{sub x}GaTe{sub 2} series

Using a high-temperature ampoule technique, a series of mixed nickel-iron-gallium metal-rich tellurides with layered structures, Ni{sub 3-x}Fe{sub x}GaTe{sub 2}, were prepared and characterized based on X-ray powder diffraction, energy-dispersive spectroscopy, and {sup 57}Fe Mössbauer spectroscopy data. These compounds may be regarded as a result of partial substitution of nickel by iron in the recently reported ternary Ni{sub 3-x}GaTe{sub 2} series, which are based on NiAs/Ni{sub 2}In type of structure. The compositional boundary for the substitution was found to be at x~1. According to the Mössbauer spectroscopy data, the substitution is not statistical, and iron atoms with the increase in x tend to preferentially occupy those nickel positions that are partially vacant in the initial ternary compound. Magnetic measurements data for the Ni{sub 3-x}Fe{sub x}GaTe{sub 2} series show dramatic change in behavior from temperature-independent paramagnetic properties of the initial matrix to a low-temperature (~75 K) ferromagnetic ordering in the Ni{sub 2}FeGaTe{sub 2}. - Graphical abstract: Ordered substitution of nickel by iron in the Ni{sub 3−x}GaTe{sub 2} series leading to ferromagnetic ordering. - Highlights: • A series of Ni{sub 3−x}Fe{sub x}GaTe{sub 2} compounds were synthesized. • They adopt the NiAs/Ni{sub 2}In type of structure with ordered iron distribution. • The distribution of iron was studied using {sup 57}Fe Mössbauer spectroscopy. • An increase in iron content leads to the strong ferromagnetic coupling.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2013

A chemical approach toward low temperature alloying of immiscible iron and molybdenum metals

Graphical abstract: - Highlights: • Low temperature pyrolysis of [Fe(bipy){sub 3}]Cl{sub 2} and [Mo(bipy)Cl{sub 4}] homogeneous powder. • Easy low temperature alloying of immiscible metals like Fe and Mo. • Uniform sized Fe–Mo nanoalloy with particle size of 48–68 nm. • Characterization by EDXRF, AFM, XRPD, magnetometery, {sup 57}Fe Mössbauer and impedance. • Alloy behaves as almost superparamagnetic obeying simple –R(CPE)– circuit. - Abstract: The present research is based on a low temperature operated feasible method for the synthesis of immiscible iron and molybdenum metals’ nanoalloy for technological applications. The nanoalloy has been synthesized by pyrolysis of homogeneous powder precipitated, from a common solvent, of the two complexes, trisbipyridineiron(II)chloride, [Fe(bipy){sub 3}]Cl{sub 2}, and bipyridinemolybedenum(IV) chloride, [Mo(bipy)Cl{sub 4}], followed by heating at 500 °C in an inert atmosphere of flowing argon gas. The resulting nanoalloy has been characterized by using EDXRF, AFM, XRD, magnetometery, {sup 57}Fe Mössbauer and impedance spectroscopies. These results showed that under provided experimental conditions iron and molybdenum metals, with known miscibility barrier, alloy together to give (1:1) single phase material having particle size in the range of 48–66 nm. The magnetism of iron is considerably reduced after alloy formation and shows its trend toward superparamagnetism. The designed chemical synthetic procedure is equally feasible for the fabrication of other immiscible metals.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Synthesis and characterization of O3-Na{sub 3}LiFeSbO{sub 6}: A new honeycomb ordered layered oxide

Highlights: • A new honeycomb ordered layered oxide Na{sub 3}LiFeSbO{sub 6} was synthesized. • This compound crystallizes in the C2/c space group. • Disorder in the honeycomb arrangement of Li and Fe is present. - Abstract: A new compound Na{sub 3}LiFeSbO{sub 6} has been synthesized by conventional solid state methods and investigated using X-ray diffraction, DC magnetic susceptibility, {sup 57}Fe Mössbauer spectroscopy and optical measurements. This compound crystallizes in a monoclinic unit cell and is related to a family of honeycomb ordered layered oxide materials where Na{sup +} fills octahedral interlayer sites between Li{sub 1/3}Fe{sub 1/3}Sb{sub 1/3}O{sub 2} slabs of edge sharing octahedra. Each SbO{sub 6} octahedron is surrounded by LiO{sub 6} and FeO{sub 6} octahedra creating a honeycomb arrangement within the slabs. Powder X-ray diffraction indicates the presence of stacking faults. This compound exhibits Curie–Weiss behavior at high temperatures and the effective magnetic moment verifies the presence of high spin Fe{sup 3+}. The {sup 57}Fe Mössbauer spectroscopy confirms Fe{sup 3+} in an octahedral position and indicates disorder in the arrangement of LiO{sub 6} and FeO{sub 6} octahedra in the Li{sub 1/3}Fe{sub 1/3}Sb{sub 1/3}O{sub 2} slabs.

36 MATERIALS SCIENCE↗
DOE OSTI2015

The formation and structure of mechano-synthesized nanocrystalline Sr{sub 3}Fe{sub 2}O{sub 6.4}: XRD Rietveld, Mössabuer and XPS analyses

Highlights: • The formation of mechano-synthesized nanocrystalline Sr{sub 3}Fe{sub 2}O{sub 7−δ} is investigated. • Pre-milling the reactants substantially lowers the formation temperature. • The core and surface structures were studied. • XRD and {sup 57}Fe Mössbauer spectroscopic analyses indicate the δ-value to be 0.60. • XPS shows a complex surface structure for the mechanosynthesized Sr{sub 3}Fe{sub 2}O{sub 7−δ} nanoparticles. - Abstract: The influence of ball milling and subsequent sintering of a 3:1 molar mixture of SrCO{sub 3} and α-Fe{sub 2}O{sub 3} on the formation of Sr{sub 3}Fe{sub 2}O{sub 7−δ} double perovskite is investigated with different analytical techniques. Milling the mixture for 110 h leads to the formation of SrCO{sub 3}-α-Fe{sub 2}O{sub 3} nanocomposites and the structural deformation of α-Fe{sub 2}O{sub 3} via the incorporation of Sr{sup 2+} ions. Subsequent sintering of the pre-milled reactants’ mixture has led to the partial formation of an SrFeO{sub 3} perovskite-related phase in the temperature range 400–600 °C. This was followed by the progressive development of an Sr{sub 3}Fe{sub 2}O{sub 7−δ} phase that continued to increase with increasing sintering temperature until a single-phased nanocrystalline Sr{sub 3}Fe{sub 2}O{sub 7−δ} phase was attained at 950 °C (12 h). This temperature is ∼350 °C lower than the temperature at which the material is prepared conventionally using the ceramic method. The evolution of different structural phases during the reaction process is discussed. Rietveld refinement of the X-ray diffraction data shows a value of 0.60 for the oxygen deficiency δ, in consistency with the Fe{sup 3+}/Fe{sup 4+} ratio derived from the {sup 57}Fe Mössbauer data recorded at both 300 K and 78 K. The Mössbauer data suggests that the Sr{sub 3}Fe{sub 2}O{sub 6.4} nanoparticles are superparamagnetic with blocking temperatures below 78 K. The surfaces of the Sr{sub 3}Fe{sub 2}O{sub 6.4} nanoparticles were shown to have a complex structure and composition relative to those of their cores with traces of SrCO{sub 3}, SrO and SrFeO{sub 3−δ} being detected.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

Fe–Ni solid solutions in nano-size dimensions: Effect of hydrogen annealing

Highlights: • Fe–Ni solid solution with nano-size dimensions were prepared and characterized. • Both as prepared and hydrogenated solid solutions have FCC structure of Ni. • Paramagnetic and ferromagnetic domains coexist in these samples. - Abstract: Nanoparticles of Ni{sub 0.50}Fe{sub 0.50} and Ni{sub 0.75}Fe{sub 0.25} alloys were prepared by chemical reduction in ethylene glycol medium. XRD and {sup 57}Fe Mössbauer studies have confirmed the formation of Fe–Ni solid solution in nano-size dimensions with FCC structure. These samples consist of both ferromagnetic and paramagnetic domains which have been attributed to the coexistence of large and small particles as confirmed by atomic force microscopic (AFM) and {sup 57}Fe Mössbauer spectroscopic studies. Improved extent of Fe–Fe exchange interaction existing in Ni{sub 0.50}Fe{sub 0.50} alloy compared to Ni{sub 0.75}Fe{sub 0.25} alloy explains the observed increase in the relative extent of ferromagnetic domains compared to paramagnetic domains in the former sample. Increase in the relative extent of ferromagnetic domains for hydrogenated alloys is due to increase in particle size brought about by the high temperature activation prior to hydrogenation.

36 MATERIALS SCIENCE↗
DOE OSTI2011

Preparation and Characterization of Ultrathin Stainless Steel Films

We report on the preparation of polycrystalline austenitic 310 ({sup 57}Fe{sub 0.55}Cr{sub 0.25}Ni{sub 0.20}) stainless steel (SS) thin films on Si substrates and the characterization of their residual magnetism via {sup 57}Fe conversion-electron Moessbauer spectroscopy (CEMS). The films were structurally characterized at room temperature by X-ray diffraction (XRD). The virgin films were found to be structurally disordered. Subsequent annealing at moderate temperatures in ultrahigh vacuum produces the ordered martensitic and austenitic SS phases. Further annealing at higher temperatures (up to temperatures where long-range diffusion into the substrate is still weak) transforms the films into the austenitic phase with no trace of a magnetic hyperfine interaction. However, when a 2 nm thick SS thin film is embedded between two carbon layers, the as prepared disordered SS film does not transform to the martensitic or austenitic SS phase irrespective of the annealing temperature, probably because the interdiffusion with C prohibits the formation of these phases.

36 MATERIALS SCIENCE↗
DOE OSTI2013

Optimal width of barrier region in X/{gamma}-ray Schottky diode detectors based on CdTe and CdZnTe

The spectral distribution of quantum detection efficiency of X- and {gamma}-ray Schottky diodes based on semi-insulating CdTe or Cd{sub 0.9}Zn{sub 0.1}Te crystals is substantiated and obtained in analytical form. It is shown that the width of the space charge region (SCR) of 6-40 {mu}m at zero bias in CdTe (Cd{sub 0.9}Zn{sub 0.1}Te) Schottky diode is optimal for detecting radiation in the photon energy range above 5-10 keV. Based on the Poisson equation, the relationship between the SCR width and the composition of impurities and the degree of their compensation are investigated. It is shown that the presence of deep levels in the bandgap leads to a considerable increase in space charge density and electric field strength near the crystal surface. However, this effect contributes a small error in the determination of the SCR width using the standard formula for the Schottky diode. It is also shown that the concentration of uncompensated impurities in CdTe and Cd{sub 0.9}Zn{sub 0.1}Te crystals within the 4 Multiplication-Sign 10{sup 11}-10{sup 13} cm{sup -3} range is optimal for the detection efficiency of X- and {gamma}-rays in the photon high-energy range. The record-high values of energy resolution have been obtained in the spectra of {sup 241}Am, {sup 57}Co, {sup 133}Ba and {sup 137}Cs isotopes measured using CdTe crystals with Schottky diodes because the concentration of uncompensated donors in the CdTe crystals (1-2) Multiplication-Sign 10{sup 12} cm{sup -3} falls on an interval of maximum detection efficiency. In the spectrum of {sup 57}Co isotope, the limiting energy resolution has been achieved.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2013

Setting temperature effect in polycrystalline exchange-biased IrMn/CoFe bilayers

We study the effect of atomic interdiffusion on the exchange bias of polycrystalline IrMn/({sup 57}Fe + CoFe) multilayers due to the thermal setting process of exchange coupling during field annealing. Depth-resolved {sup 57}Fe conversion electron Moessbauer spectroscopy was used to quantify atomic interdiffusion. Vibrating sample magnetometry was used to monitor the variation of exchange bias and magnetisation. It was found that interface sharpness is only affected above {approx}350 Degree-Sign C. Three different stages for the setting of exchange bias can be inferred from our results. At the lower setting temperatures (up to 350 Degree-Sign C), the effect of field annealing involves alignment of spins and interfacial coupling due to the setting of both antiferromagnetic (AF) bulk and interface without significant interdiffusion. At a second stage (350-450 Degree-Sign C), where AF ordering dominates over diffusion effects, atomic migration and increased setting of AF spins co-exist to produce a peak in exchange bias field and coercivity. On a third stage (>450 Degree-Sign C), severe chemical intermixing reduces significantly the F/AF coupling.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Mössbauer spectroscopy of Basal Ganglia

Chemical states, structural arrangement, and magnetic features of iron deposits in biological tissue of Basal Ganglia are characterized. The methods of SQUID magnetometry and electron microscopy are employed. {sup 57}Fe Mössbauer spectroscopy is used as a principal method of investigation. Though electron microscopy has unveiled robust crystals (1-3 μm in size) of iron oxides, they are not manifested in the corresponding {sup 57}Fe Mössbauer spectra. The latter were acquired at 300 K and 4.2 K and resemble ferritin-like behavior.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2015

The magnetic transition in ε-Fe{sub 2}O{sub 3} nanoparticles: Magnetic properties and hyperfine interactions from Mössbauer spectroscopy

The nanoparticles of ε-Fe{sub 2}O{sub 3} enriched with {sup 57}Fe isotope in amorphous silica matrix were prepared by sol-gel technique starting from a single molecular precursor for both Fe{sub 2}O{sub 3} and silica. From the X-ray powder diffraction pattern ε-Fe{sub 2}O{sub 3} was identified as the major phase and α-Fe{sub 2}O{sub 3} and β-Fe{sub 2}O{sub 3} were observed as minor iron oxide phases. Using the log-normal distribution for fitting the experimental data from the TEM micrographs, the characteristic size of particles d{sub 0} ∼ 25 nm was derived. The rather high coercivity of ∼2.1 T at room temperature was confirmed for our nanoparticle system. From the dependences of magnetization on temperature a two-step magnetic transition spread between 100 K and 153 K was indicated. From the {sup 57}Fe Mössbauer spectra measured in the temperature range of 4.2–300 K, the hyperfine parameters for one tetrahedral and three octahedral sites of ε-Fe{sub 2}O{sub 3} structure were identified. The in-field spectra in the external magnetic fields up to 6 T were taken both above and below the indicated two-step magnetic transition. Their dependence on temperature and external magnetic field suggests that the first step in the temperature range of 153 K–130 K is related to the spin reorientation of the local magnetic moments in the magnetic sublattices and the second step in temperatures 130 K–100 K may be associated with the intermediate spin–high spin state transition of Fe{sup 3+} cation in the tetrahedral sublattice expressed in the change of the hyperfine magnetic field.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

Magnetic, ferroelectric, and spin phonon coupling studies of Sr{sub 3}Co{sub 2}Fe{sub 24}O{sub 41} multiferroic Z-type hexaferrite

The magnetic, Raman, ferroelectric, and in-field {sup 57}Fe Mössbauer studies of polycrystalline multiferroic Sr{sub 3}Co{sub 2}Fe{sub 24}O{sub 41} are reported in this paper. From the magnetization studies, it is observed that the sample is soft magnetic in nature with low temperature magnetic spin transitions like longitudinal to transverse conical structure around 130 K and change in magnetic crystalline anisotropy from conical to planar structure at 250 K. Ferroelectric studies of the sample exhibit the spontaneous polarization at low temperature. Strong spin phonon and spin lattice coupling is observed through low temperature Raman spectroscopy. From the in-field {sup 57}Fe Mössbauer spectroscopy, spin up and spin down site occupations of Fe ions are calculated in the unit cell.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2017

Mössbauer study of the modulated magnetic structure of FeVO{sub 4}

Mössbauer spectroscopy is used to study the FeVO{sub 4} multiferroic, which undergoes two magnetic phase transitions at T{sub N1} ≈ 22 K and T{sub N2} ≈ 15 K. The first transition (T{sub N1}) is related to transformation from a paramagnetic state into a magnetically ordered state of a spin density wave, and the second transition (T{sub N2}) is associated with a change in the type of the spatial magnetic structure of the vanadate. The electric field gradient tensor at {sup 57}Fe nuclei is calculated to perform a crystal-chemical identification of the partial Mössbauer spectra corresponding to various crystallographic positions of Fe{sup 3+} cations. The spectra measured in the range T{sub N2} < T < T{sub N1} are analyzed on the assumption about amplitude modulation of the magnetic moments of iron atoms μ{sub Fe}. The results of model intersection of the spectra recorded at T < T{sub N2} point to a high degree of anharmonicity of the helicoidal magnetic structure of the vanadate and to elliptic polarization of μ{sub Fe}. These features are characteristic of type-II multiferroics. The temperature dependences of the hyperfine interaction parameters of {sup 57}Fe nuclei that were obtained in this work are analyzed in terms of the Weiss molecular field model on the assumption of orbital contribution to the magnetic moments of iron cations.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2013

Survival after Radiofrequency Ablation in 122 Patients with Inoperable Colorectal Lung Metastases

Purpose. To analyze the factors associated with favorable survival in patients with inoperable colorectal lung metastases treated with percutaneous image-guided radiofrequency ablation. Methods. Between 2002 and 2011, a total of 398 metastases were ablated in 122 patients (87 male, median age 68 years, range 29-90 years) at 256 procedures. Percutaneous CT-guided cool-tip radiofrequency ablation was performed under sedation/general anesthesia. Maximum tumor size, number of tumors ablated, number of procedures, concurrent/prior liver ablation, previous liver or lung resection, systemic chemotherapy, disease-free interval from primary resection to lung metastasis, and survival from first ablation were recorded prospectively. Kaplan-Meier analysis was performed, and factors were compared by log rank test. Results. The initial number of metastases ablated was 2.3 (range 1-8); the total number was 3.3 (range 1-15). The maximum tumor diameter was 1.7 (range 0.5-4) cm, and the number of procedures was 2 (range 1-10). The major complication rate was 3.9 %. Overall median and 3-year survival rate were 41 months and 57 %. Survival was better in patients with smaller tumors-a median of 51 months, with 3-year survival of 64 % for tumors 2 cm or smaller versus 31 months and 44 % for tumors 2.1-4 cm (p = 0.08). The number of metastases ablated and whether the tumors were unilateral or bilateral did not affect survival. The presence of treated liver metastases, systemic chemotherapy, or prior lung resection did not affect survival. Conclusion. Three-year survival of 57 % in patients with inoperable colorectal lung metastases is better than would be expected with chemotherapy alone. Patients with inoperable but small-volume colorectal lung metastases should be referred for ablation.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Lipiodol Trans-arterial Chemoembolization of Hepatocellular Carcinoma with Idarubicin: First Experience

BackgroundThere is still no consensus about the best chemotherapeutic agent for transarterial chemoembolization (TACE). A recent in vitro study demonstrated that idarubicin, an anthracycline, was by far the most cytotoxic drug on human hepatocellular carcinoma (HCC) cell lines. Idarubicin is much more lipophilic than doxorubicin, leading to higher cell penetration through lipidic membranes and greater accumulation of the drug in the lipiodol. Furthermore, idarubicin has the ability to overcome multidrug resistance. Therefore, we designed this pilot human study to evaluate the safety and efficacy of lipiodol TACE using idarubicin.MethodsIn 21 consecutive patients treated by lipiodol TACE with idarubicin (10 mg) for HCC, safety data, tumor response (Response Evaluation Criteria in Solid Tumors, mRECIST), time to treatment failure (TTTF), and overall survival were evaluated.ResultsPostembolization syndrome was observed after 30.9 % (17 of 55) of sessions. No patient died from a TACE-related complication. No hematological grade 3-5 adverse event was observed. At least one grade 3 or higher adverse event occurred in 19 % (4 of 21) of patients. On imaging, no progression was encountered; four patients (24 %) exhibited stable disease, 12 (57 %) exhibited a partial response, and five (19 %) exhibited a complete response. Median TTTF was 16.7 months (Kaplan-Meier analysis). At 6 months, 94.7 % (95 % confidence interval [CI] 68.1-99.2) of patients did not reach treatment failure, whereas treatment failure was not reached in 50.6 % (95 % CI 21.6-73.9) of patients at 1 year. Overall survival was 83.5 % (95 % CI 57-94.4) at 1 year.ConclusionIdarubicin seems safe and effective in lipiodol TACE of HCC. This warrants further study to determine the potential of this drug to replace doxorubicin for TACE.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2021

On the Strong Convergence of Forward-Backward Splitting in Reconstructing Jointly Sparse Signals

We consider the problem of reconstructing an infinite set of sparse, finite-dimensional vectors, that share a common sparsity pattern, from incomplete measurements. This is in contrast to the work (Daubechies et al., Pure Appl. Math. 57(11), 1413–1457, 2004), where the single vector signal can be infinite-dimensional, and (Fornasier and Rauhut, SIAM J. Numer. Anal. 46(2), 577613, 2008), which extends the aforementioned work to the joint sparse recovery of finite number of infinite-dimensional vectors. In our case, to take account of the joint sparsity and promote the coupling of nonvanishing components, we employ a convex relaxation approach with mixed norm penalty ℓ 2,1 . This paper discusses the computation of the solutions of linear inverse problems with such relaxation by a forward-backward splitting algorithm. However, since the solution matrix possesses infinitely many columns, the arguments of Daubechies et al. (Pure Appl. Math. 57(11), 1413–1457, 2004) no longer apply. As such, we establish new strong convergence results for the algorithm, in particular when the set of jointly sparse vectors is infinite.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2019

Evaluating the decisions of glioma patients regarding clinical trial participation: a retrospective single provider review

Clinical trial accrual is vital to advancing care. A single study elucidated demographic data correlating with glioma patients’ clinical trial enrollment. However, it did not investigate the underlying decision-making process for non-participation. In this study, we seek to understand this key aspect of patient accrual. All notes for glioma patients seen by a single neuro-oncologist from July 2010 to May 2017 were examined for mention of clinical trial offerings. When a trial was declined, the patient’s reasoning was recorded along with the following: diagnosis, KPS, extent of resection, age, gender, race, marital status, income group, religion, trial offered at initial visit versus subsequent, and distance from trial site. Of 279 consecutive glioma patients, 88 were eligible for and offered a clinical trial. Fifty-seven accepted (65%), and 31 (35%) declined participation (Fig. 1). Of those offered a clinical trial, patients with glioblastoma (GBM) were significantly more likely to accept (44 out of 57 (77%) vs. 13 out of 57 (23%), p =0.03). After we adjusted for gender and travel distance, GBM was the only significant predictor of clinical trial acceptance, with an odds ratio of 3.18 (95% CI 1.17, 8.61, p =0.02). Reasons cited for non-participation included: travel distance (39%), lack of interest (39%), visit frequency (16%), and fear of randomization (6%). This study clarified for the first time individual glioma patient rationale for non-participation and potential areas for improving enrollment. Allowing off-site treatment centers or telemedicine visits may entice rural patients to participate. Visit frequency should be carefully considered and minimized whenever possible. Further prospective study of rationale for non-participation may improve enrollment over time.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Activation product interpretation of structural material for fast critical assemblies

This work evaluates whether activation products in stainless steel components can be used to infer initial conditions (i.e. alloy composition, position within the fluence, etc.) and the associated uncertainties in a fast neutron irradiation. Activation measurements of stainless steel and elemental components were obtained through a Flattop critical assembly irradiation experiment. A forward model was developed, utilizing MCNP6.1 and FISPACT ii, to estimate activation product concentrations from several input parameters: alloy composition, source specifications, and foil positioning. While some of the calculated activation product concentrations agreed fairly well with measurements, some isotopics (i.e. 57 Co) had large discrepancies. It became clear that uncertainties in both measurements and nuclear data drove this divergence for select isotopics, and the quantification of this impact was needed. By treating both experimental measurement and nuclear data uncertainty in a Bayesian framework, it was possible to infer unknowns from given activation ratios. The developed approach showed promise in constraining mass parameters, but degeneracy existed when considering position within the neutron flux. Higher threshold reactions could potentially break the degeneracy, such as 57 Co, but uncertainty estimation needs to be better resolved for those isotopes.

36 MATERIALS SCIENCE↗