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All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Nuclear Data Sheets for A=140☆

The 2006 evaluation of A=140 was updated using experimental results published before November 2018 from the various reaction and decay studies leading to the nuclei {sup 140}Sb, {sup 140}Te, {sup 140}I, {sup 140}Xe, {sup 140}Cs, {sup 140}Ba, {sup 140}La, {sup 140}Ce, {sup 140}Pr, {sup 140}Nd, {sup 140}Pm, {sup 140}Sm, {sup 140}Eu, {sup 140}Gd, {sup 140}Tb, {sup 140}Dy, {sup 140}Ho. These data are summarized and presented, together with adopted level schemes and properties.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2016

Inspection of a LOCA test rod at the Halden reactor project using gamma emission tomography

The LOCA test series IFA-650 conducted at the OECD Halden Reactor Project (HRP) has provided unique data on the performance of fuel rods during LOCA transients. One focus of the current investigations is the performance of the fuel in the ballooning stage of the LOCA transient. In this stage, relocation of fuel material is a possibility, in which case pellet fragments fall down to fill the void introduced by the increased volume of the ballooned cladding. This increases the heat load in that region, further promoting corrosion of the cladding. A special concern in the case of high-burnup fuels is the increasing number of small fuel fragments, which may be expected to cause a higher packing fraction in the ballooned region. In this work, a novel technique is presented for assessing the average density of the fuel material in the ballooned region of LOCA test rods. The investigation is based on non-destructive gamma emission tomography measurements, using the dedicated instrument recently developed at the HRP in collaboration with Westinghouse (Sweden) and Uppsala University. In this approach, the gamma radiation field surrounding the test rod has been measured with a narrowly collimated HPGe detector. Tomographic reconstruction of the data was performed, providing the radial gamma-ray source distribution within the measured volume, which reveals the fuel fragment distribution. From this, the density of the fuel in the measured volume (i.e., the packing fraction) may be calculated. The technique has been used to investigate a LOCA test rod of the Halden Reactor Project LOCA series. The LOCA experiment was carried out about one month prior to the gamma tomography examination. The results show that the distribution of the relocated fuel can be imaged using gamma rays from fission products. The reconstructions of the 662 keV rays from {sup 137}Cs and 1596 keV from {sup 140}Ba/La are demonstrated. In addition, the peaks of activation products offer valuable information on the location of the test rig structures, which may be utilized in a quantitative tomographic reconstruction to assess the spatially resolved packing fraction. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2024

The Mu2e Digitizer ReAdout Controller (DiRAC): characterization and radiation hardness

The Mu2e experiment at Fermilab will search for the neutrino-less coherent conversion of a muon into an electron in the field of a nucleus. Mu2e detectors comprise a straw tracker, an electromagnetic calorimeter and a veto for cosmic rays. The calorimeter employs 1348 Cesium Iodide crystals readout by silicon photo-multipliers and fast front-end, and digitization electronics. The digitization board is named DiRAC (Digitizer ReAdout Controller) and 140 cards are needed for the readout of the full calorimeter. The DiRACs are hosted in crates located on the external surface of calorimeter disks, inside the detector solenoid cryostat and must sustain very high radiation and magnetic field so it was necessary to fully qualify it. Several version of prototypes were validated for operation in a high-vacuum (10−4 Torr) and under a 1T magnetic field. An extensive radiation hardness qualification campaign, carried out with photons, 14 MeV neutron beams, and 200 MeV protons, certified the DiRAC design to sustain doses up to 12 Krad, neutron fluences up to ∼ 1011 1 MeV neq/cm2, and very low occurrences of single-event effects. The qualification campaigns and quality assurance procedures will be reviewed.

43 PARTICLE ACCELERATORS↗
DOE OSTI2017

Bottom up synthesis of boron-doped graphene for stable intermediate temperature fuel cell electrodes

The high surface area and electrical conductivity of few-layered graphene would make it an ideal catalyst support and electrode in fuel cells apart from its susceptibility to oxidative corrosion. Here we report the single-step, bottom-up synthesis of oxidation-resistant boron-doped graphene and show its increased stability in the aggressive electrochemical environment of intermediate temperature solid acid fuel cells (SAFCs). Boron was shown to alter the growth mode of single walled carbon nanohorns by laser vaporization to produce high yields of thin (<20 layer) boron-doped (2–3 at.%) crystalline flakes of turbostratic graphene (B-GLF). Alternatively, adding partial pressures of hydrogen less effectively shifted the growth mode of SWCNHs toward planar, turbostratic graphene-like flakes (GLFs). Thermogravimetric analysis indicates that boron-doping enhances the oxidation resistance of few-layer GLFs by >140 °C, with large fractions of multilayered B-GLFs surviving 10 °C/min ramps to 1000 °C. These B-GLFs provided a stable Pt catalyst support and electrode over 40 h operation in SAFCs with cesium dihydrogen phosphate electrolyte operating at 250 °C, as opposed to undoped GLFs or SWCNHs which were nearly completely consumed. Furthermore, the facile synthesis and oxidation-resistant properties of boron-doped GLF appear promising for graphene applications in oxidizing environments.

25 ENERGY STORAGE↗
DOE OSTI2017

Structural Investigation of Cesium Lead Halide Perovskites for High-Efficiency Quantum Dot Light-Emitting Diodes

We have investigated the effect of reaction temperature of hot-injection method on the structural properties of CsPbX3 (X: Br, I, Cl) perovskite nanocrystals (NCs) using the small- and wide-angle X-ray scattering. It is confirmed that the size of the NCs decreased as the reaction temperature decreased, resulting stronger quantum confinement. The cubic-phase perovskite NCs were formed despite the reaction temperatures increased from 140 to 180 °C. However, monodispersive NC cubes which are required for densely packing self-assembly film were only formed at lower temperatures. From the X-ray scattering measurements, the spin-coated film from more monodispersive perovskite nanocubes synthesized at lower temperatures resulted in more preferred orientation. This dense-packing perovskite film with preferred orientation yielded efficient light-emitting diode (LED) performance. Thus, the dense-packing structure of NC assemblies formed after spin-coating should be considered for high-efficient LEDs based on perovskite quantum dots in addition to quantum confinement effect of the quantum dots.

Le, Quyet Van↗
DOE OSTI2019

Evaluation of Low-cost, Full HD, CMOS Cameras for Use in the Calcine Retrieval Project - 19530

This paper describes results from radiation testing conducted on low-cost, commercial off-the-shelf, full high-definition (HD) resolution (1920 x 1080 p), complementary metal-oxide-semiconductor (CMOS) camera sensors. The purpose of the testing was to evaluate the sensors' suitability for use in the Calcine Retrieval Project by determining their image quality and life expectancy while operating in an ionizing radiation field of 20.0 Gy/h. The two camera sensors tested were the Axis FA1105 and Axis FA1125. These commercial camera sensors were designed for retail security surveillance and have no radiation-hardened (rad-hard) components. In addition to radiation testing, the sensors' field-of-view, resolution, and low-light image quality were tested at several target distances to ensure they meet project requirements. Testing was divided into two phases. During Phase 1, four FA1105 sensors and four FA1125 sensors were tested simultaneously without any shielding in radiation fields of 25.5 Gy/h and 49.3 Gy/h. In Phase 2, three FA1105 and five FA1125 sensors were shielded by 22.2 mm of lead and tested simultaneously in radiation fields of 26.8 Gy/h, 52.3 Gy/h, 143.0 Gy/h, 200.7 Gy/h, 404.6 Gy/h, and 2,317.5 Gy/h. Dose rate values were established using film dosimetry readings. Apertures in the shielding allowed for a 40-degree field of view while shielding all parts of the sensor except for directly in front of the CMOS sensor array. All testing was conducted at the Idaho Accelerator Center in Pocatello, Idaho, using a 450 keV X-ray generator. Sensor images were automatically captured at regular intervals throughout the testing for qualitative evaluation by the test team. Film dosimetry was placed near the sensors to record actual dose totals. The 450 keV setting generates X-ray radiation with an energy level close to the primary gamma energy level produced by the Cesium-137 isotope in the calcine, which is 662 keV. Results from Phase 1 indicate the sensors failed at an average cumulative dose of 226.3 Gy. For a given 20.0 Gy/h field this results in a mean time to failure (MTTF) of 11.3 hours. Recorded images from all sensors showed minimal image degradation due to radiation-induced noise. When the sensors finally failed, the failure mode was an abrupt loss of video. The image went black suggesting some other component in the sensor head besides the CMOS sensor array was responsible for the failure. During a portion of Phase 1 testing, a commercial, rad-hard camera was irradiated in the 25.5 Gy/h field along with the eight Axis FA series sensors. Image quality from the FA series sensors significantly outperformed the image quality of the rad-hard camera in radiation-induced noise tolerance, image resolution, and dynamic range. During Phase 2 testing, all sensors produced excellent images in radiation fields as high as 404.6 Gy/h. One FA1125 sensor was tested at the highest dose rate of 2,317.5 Gy/h. At this dose rate, the image was color shifted towards red and contained a significant amount radiation-induced noise. The sensor did not fail and was producing usable imagery after one hour, at which time the test was ended due to allotted beam-time at the test facility. Eighteen hours after X-rays were shut off, the sensor image returned to normal color and all eight sensors continued to operate without any visible, permanent image degradation. For Phase 2 testing, it was not possible to establish a MTTF since none of the shielded sensors failed during the allotted test time. However, given the highest cumulative dose of 4,142.1 Gy received by a shielded FA1125 sensor, a minimum life expectancy of 207 hours (8.6 days) is predicted while operating in a 20.0 Gy/h field. Test results indicate the radiation tolerance of the FA series sensor's CMOS array, along with the small form factor, full HD image quality, wide dynamic range, and Ethernet standard makes it suitable for short-term use in monitoring and visually documenting waste remediation efforts for the Calcine Retrieval Project at the INL. The sensor's low-cost of about $140 US, compared to commercial rad-hard cameras costing between $5,000 and $7,000 US each, allow them to be used as an affordable, disposable resource for many short-duration, radioactive waste remediation efforts where decontamination of an expensive, commercial rad-hard camera is undesirable or not possible. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

The Mu2e crystal calorimeter and improvements in the $\mu^-\mbox{N} \to e^-\mbox{N}$ search sensitivity

The Mu2e experiment will search for Charged Lepton Flavor Violation (CLFV) looking at the conversion of a muon into an electron in the field of an aluminum nucleus. About $7\cdot 10^{17}$ muons, provided by a dedicated muon beam line in construction at the Fermi National Accelarator Laboratory (Fermilab), will be stopped in 3 years in the Aluminum target. The corresponding single event sensitivity will be $2.5\cdot 10^{-17}$. The Standard Model of particle physics, even extendend to include the finite neutrino masses, predicts the ratio R μe between muon conversions and muon nuclear captures to be $\sim 10^{- 52}$. Several extensions of the Standard Model predict R μe to be in the range of $10^{-14} - 10^{-18}$. % The current best experimental limit, set by the SINDRUM II experiment is $7 \cdot 10^{-13}$ @ $90\%$ CL. The Mu2e experiment plans to improve this experimental limit by four order of magnitude to test many of the possible extensions of the Standard Model. To reach this ambitious goal, the Mu2e experiment is expected to use an intense pulsed muon beam, and rely on a detector system composed of a straw tube tracker and a calorimeter made of pure CsI crystals. The calorimeter plays a central role in the Mu2e measurement, providing particle identification capabilities that are necessary for rejecting two of the most dangerous background sources that can mimic the μ⁻N → e⁻N conversion electron: cosmic muons and $\bar{p}$ induced background. The calorimeter information allows also to improve the tracking performance. Thanks to a calorimeter-seeded track finder algorithm, it is possible to increase the track reconstruction efficiency, and make it more robust with respect to the occupancy level. Expected performances of the calorimeter have been studied in a beam test at the Beam Test Facility in Frascati (Rome, Italy). A reduced scale calorimeter prototype has been exposed to an electron beam, with energy varying from 80 to 140 MeV, for measuring the timing resolution and validate the Monte Carlo prediction. A timing resolution $\sigma_{\rm t}<200$ ps @ 100 MeV has been obtained. Combination of the background rejection performance, and the improvements in the track reconstruction, have then been used in the calculation of the expected Mu2e sensitivity.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

Application of Novel Adsorbent Prepared by Mucor hiemalis Biomass Impregnated with Calcium Alginate for Removal of Sr{sup 2+} from Aqueous Solutions

In this research, a novel biosorbent was prepared by Mucor hiemalis biomass combined with calcium alginate (Mucor hiemalis/Alg-Ca). The dead biomass was entrapped into alginate gel by curing method in the presence of Ca{sup 2+} ions. The synthesized biosorbent characterized by XRD, EDAX, BET, FTIR, and SEM techniques was used for removal of Sr{sup 2+} from aquatic streams under various experimental conditions and the optimized adsorption capacity of 140 mg g{sup −1} was obtained. The selectivity of the adsorbent towards Sr{sup 2+} studied in the presence of Na{sup +}, Cs{sup +}, Ca{sup 2+} and Mg{sup 2+} was reasonably high. The adsorption process was kinetically fast and the equilibrium was established within 60 min, and followed the pseudo-second order kinetics model. The equilibrium data was well described by Langmuir isotherm model. The thermodynamics parameters (∆G°, ∆H° and ∆S°) of the process were determined. Positive ∆H° and negative ∆G° were indicative of the endothermic and spontaneous nature of the adsorption process. Graphical Abstract: .

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗