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At least 307 records · Page 17

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DOE OSTI2026

Laboratory Tests of Laser Control of Electron Beams for Future Colliders

Laser-driven Compton backscattering (CBS) has been proposed as method for controlling the intensity of colliding bunches in the FCC-ee so as to avoid the flip-flop instability caused by intensity asymmetry in colliding bunches. Laser-based collimation has also been proposed as an indestructible collimator for high-intensity electron beams. We have initiated a laboratory-based test program of these concepts with the E344 experiment at FACET-II. In this paper, we describe simulations of laser-beam interactions at FACET-II and the relevant scaling for FCC-ee. We also describe the experimental setup and diagnostics that will be used to make the measurements at FACET-II.

Accelerator Physics (physics.acc-ph)↗

DOE OSTI2017

Broadband unidirectional ultrasound propagation

A passive, linear arrangement of a sonic crystal-based apparatus and method including a 1D sonic crystal, a nonlinear medium, and an acoustic low-pass filter, for permitting unidirectional broadband ultrasound propagation as a collimated beam for underwater, air or other fluid communication, are described. The signal to be transmitted is first used to modulate a high-frequency ultrasonic carrier wave which is directed into the sonic crystal side of the apparatus. The apparatus processes the modulated signal, whereby the original low-frequency signal exits the apparatus as a collimated beam on the side of the apparatus opposite the sonic crystal. The sonic crystal provides a bandpass acoustic filter through which the modulated high-frequency ultrasonic signal passes, and the nonlinear medium demodulates the modulated signal and recovers the low-frequency sound beam. The low-pass filter removes remaining high-frequency components, and contributes to the unidirectional property of the apparatus.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2017

Spatially-resolved HPGe Gamma-ray Spectroscopy of Swipe Samples

Measurement of swipe samples is a critical element of the National Technical Nuclear Forensics (NTNF) mission. A unique, portable, germanium gamma imager (GeGI-s) from PHDS Co may provide complementary information to current techniques for swipe sample screening. The GeGI-s is a modified version of the commercial GeGI-4, a planar HPGe detector, capable of several million counts per second across the whole detector. The GeGI-s detector is a prototype of a commercial off-the-shelf high rate GeGI. The high rate capability allows high-activity samples be placed directly on the face of the detector. Utilizing the high energy resolution and pixelization of the detector, the GeGI-s can generate isotope specific spatial maps of the materials on the swipe sample. To prove this technology is viable for such mapping, the GeGI-s detector response to spatially distributed events must be well characterized. The detection efficiency as a function of location has been characterized to understand the non-uniformities presented as a collimated photon beam was rastered vertically and horizontally across the face of the detector. The detection efficiency as a function of location has been characterized to understand the non-uniformities presented as a collimated photon beam was rastered vertically and horizontally across the face of the detector. The response was found to be primarily uniform and symmetric, however two causes of non-uniformity were found. Both of these causes can ultimately be corrected for in off-line data analysis.

germanium gamma imager↗

DOE OSTI2018

DEVELOPMENT OF A NUCLEAR FUEL SAFEGUARDS VERIFICATION TECHNOLOGY FOR NEW FACILITY TYPES: Use of fast neutron emission tomography for spent fuel verification

With the buildup of spent fuel inventories around the world from decommissioning activities, a tool for the efficient and effective verification of a variety of fuel types for long-term disposition is needed. Fast neutron emission tomography is a promising imaging technology that can address this problem and has been under development at Oak Ridge National Laboratory for the past two years. The goal of this capability is to detect the removal or substitution of individual fuel pins in spent nuclear fuel assemblies for international safeguards applications. The present imaging technique is based on neutron emissions originating primarily from curium-244, which is produced predominantly at the end of the exposure cycle. As a result, this technique may be sensitive not only to fuel pins that are removed or substituted subsequent to all irradiation, but also to fuel pins that are substituted and subsequently irradiated. At present, a laboratory prototype imager is under construction. The purpose of the prototype is to demonstrate an imaging capabilitysufficient to resolve individual fuel pins using commercially available boron straw detectors that can withstand the high gamma ray dose from a typical spent fuel assembly. To achieve both practical measurement durations and sufficient resolution to discern individual pins, the prototype imager employs a novel collimator design where the slits of a parallel-slit collimator are rearranged to distribute them around a ring surrounding the target fuel assembly. This paper will report on simulations and experimental results undertaken to converge on a final design, image reconstruction of sample fuel types of interest, and challenges associated.

Iyengar, Anagha↗

DOE OSTI2019

X-ray beam alignment device and method

The present invention provides a bright, focused visible light source that is part of a visible light alignment assembly that is coupled to an X-ray generator. The visible light source projects a bright, focused visible light beam from the X-ray generator through a collimator and object or part to be radiographed and to a detector or film, just as a subsequent X-ray beam eventually is. This allows the operator to quickly and easily visually assess the eventual position and coverage or spread of the X-ray beam and align the X-ray generator, collimator, object or part to be radiographed, and/or detector or film, with a minimum of test radiographs.

Henry, Nathaniel Frederick↗

DOE OSTI2020

Modular low cost trackerless spectral sensor

A photodiode sensor device and systems. The photodiode sensor device includes a housing portion. The housing portion includes a cylindrical enclosure. A window is disposed at a first end of the housing portion. A filter wheel is within the housing portion. A motor positioned within the housing is adjacent the filter wheel opposite the window. The motor is attached to the filter wheel. A photodiode sensor within the housing portion intermediate the first photodiode sensor and the window. The first photodiode sensor receives filtered light incident on the window and transmit a signal associated with sensed parameters of the filtered light. Also, a hemispherical dome for diffusing the light to a collimating lens has a grating, a focusing lens, and a linear detector array. An exit port transmits light to the collimating lens. The sensor array is opposite the grating for sensing the diffused light.

14 SOLAR ENERGY↗

DOE OSTI2021

High-energy X-ray source and detector for wellbore inspection

A system, method, and apparatus for wellbore inspection comprise an electron accelerator to generate X-rays, a rotating collimator assembly configured to produce a cone of X-rays, and at least one detector assembly configured to collect backscattered X-rays. A position assembly can be provided to move the electron accelerator, rotating collimator assembly, and detector through a wellbore. A computer system is configured to receive data from the detector and generate an image of the wellbore.

Kroc, Thomas K.↗

DOE OSTI2021

System and method for passive assay of holdup deposits in nuclear piping

Disclosed herein are a method, apparatus, and software for passive, non-destructive assay of holdup deposits in nuclear piping by in-pipe apparatus. A detector deployed within a pipe is collimated to observe radiation impinging radially inward from decay of deposits that lie on the pipe wall. A radiation detector is centered in the pipe and collimated by a pair of coaxial shielding discs disposed equidistant from the detector. This arrangement causes radiation from a truncated cylinder of pipe deposit within a field of regard to impinge on the detector, while precluding radiation emanating from pipe walls beyond the field of regard from reaching the detector. Hence, observations are unique to a known cylindrical length of pipe. The detector assembly is translated through pipes by an autonomous mobile robotic apparatus. Computer software controls the robotic apparatus, logs data, and post-processes to assay deposits.

Whittaker, William Lawrence↗

DOE OSTI2022

Design and Validation of a Gammaray Scanning System for Measuring Irradiated Nuclear Fuel

A prototype gamma-ray scanning system was designed to perform post-irradiation measurements of nuclear fuel at Idaho National Laboratory (INL). The system is composed of a coaxial high-purity germanium (HPGe) detector, a collimator, and mechanical positioning stages that translate the fuel sample across the front of the collimator. This paper documents the design process, modeling and the laboratory characterization performed to validate the system. The modeling of the system was done using the Monte Carlo N-Particle code with vendor-supplied design specifications, dimensional measurements, and x-ray radiographs of the HPGe detector. The characterization included measurements of calibrated radiation sources in different geometries, and calculations for absolute efficiency and dead time. Benchmark measurements were performed by scanning an irradiated fuel rodlet containing ten pellets of 4.9% enriched UO2 in zirconium alloy. These results were compared to simulated spectra to further help characterize the detector model. One goal of the system is to determine the number of fissions per gram of UO2 in the fuel; comparison of the results from this prototype system's assay of the irradiated fuel rodlet are in agreement with previously estimated results.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2023

Irradiated Low-Enriched Uranium Fuel Measurements with a Gamma-Ray Scanning System

A gamma-ray scanning system was designed to perform post-irradiation measurements of nuclear fuel at Idaho National Laboratory (INL). The system is composed of a coaxial high-purity germanium (HPGe) detector, a collimator, and mechanical positioning stages that translate the fuel sample across the front of the collimator. A Monte Carlo N-Particle code simulation of the system and the fuel were created with vendor-supplied design specifications, dimensional measurements, and x-ray radiographs of the HPGe detector as well as all available fuel specifications. Benchmark measurements were performed by scanning an irradiated fuel rodlet containing eight pellets of 0.74% enriched UO2 in zirconium alloy. This fuel rodlet was part of the Static Environment Rodlet Transient Test Apparatus (SERTTA) testing campaign in the Transient Reactor Test Facility (TREAT). These results were compared to simulated spectra to help characterize the detector model and establish fidelity. A goal of the system is to determine the number of fissions per gram of UO2 in the fuel. This paper documents the modeling of the system and the calculation of the number of fissions per gram along the axial length of the SERTTA-C rodlet.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2023

Inspection system of wellbores and surrounding rock using penetrating X-rays

Kroc, Thomas K.↗

DOE OSTI2017

CdZnTe Detector Using for Characterization MR Water Cleanup System before Dismantling - 17005

The Kurchatov Institute's MR research reactor water cleanup system comprises 20 containers with ion-exchange resin. Each container is 25 cm in diameter and 130 cm high. These containers are placed under the floor with 50 cm concrete protection. Access to container is provided via technological hole with protective covers. A CdZnTe detector was chosen for spectrometric investigation due to high exposure dose level from containers. A collimated spectrometric system on the basis of a semiconductor detector CdZnTe (volume of a crystal of 20 mm{sup 3} or 60 mm{sup 3}) and a multichannel analyzer InSpector 2000 was developed. It was determined that 8 of the 20 containers were filled with the ion- exchange resin in aqueous solution. The main dose forming radionuclide was {sup 137}Cs. Specific activity was from 10{sup 7} Bq/kg to 10{sup 9} Bq/kg in different containers. Measurements were carried out in high radiation fields and the background radiation reached the detector even through the lead shield, which created difficulties in the interpretation of collected data. For verification of the results some samples of ion-exchange resin was taken from containers. The concentration of γ-ray radionuclides was estimated by the Canberra Company spectrometric complex that included a semi-conductor detector made of HP Germanium. Obtained data had good correlation with the data of the CdZnTe collimated spectrometer. Our investigation has shown that remote mechanisms must be used to remove the containers with ion-exchange resin. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2017

Recent Advancements in Tomographic Gamma Scanning for Non- Destructive Assay - 17321

Canberra Industries has recently designed and built a Tomographic Gamma Scanning (TGS) system for the deployment in a nuclear facility. The TGS technique combines high-resolution gamma spectroscopy with low spatial resolution 3- dimensional image reconstruction to provide increased accuracy over traditional approaches for the assay of non-uniform source distributions in low-to medium-density containers. The TGS system has been optimized to measure 120 liter drums and has the capability to measure containers of various sizes. Canberra has incorporated numerous enhancements and improvements to the latest system in both its hardware and software components. The signal processing chain and data analysis software have been configured to use either an electronic pulser or digital signal processing (DSP) electronics for dead time corrections. In the case of using the DSP electronics, the need to calibrate and maintain a pulser can be eliminated without sacrificing any performance. For the 120 liter container, the TGS system has been calibrated and validated with three different spatial resolutions, using two collimator aperture sizes, measuring 2.54 and 1.27 cm in width. The system has also been supplied and calibrated with a wide, rectangular collimator (25.4 cm W x 10.2 cm H) for scanning containers solely in the vertical axis. The TGS system also has an automated attenuator assembly, which has the capability to use a combination of attenuators to reduce the count rate for high activity samples. An extensive measurement campaign was performed in addition to the calibration verification to evaluate the accuracy of the system using rod sources, point sources, and a variety of matrices and source distributions. Improvements to the evaluation of the total measurement uncertainty based upon these studies have been incorporated into the analysis software package. Finally, the performance of this new TGS system will be demonstrated in the context of Canberra's previous TGS systems, including several 208 liter-based systems and a smaller, 20 liter container TGS system. (authors)

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2016

Evaluation of MSNDs for Fast-Neutron Detection and the TREAT Hodoscope

The need for next-generation, accident-tolerant fuels has generated significant interest in the restart of domestic fuels testing at the Transient Reactor Test (TREAT) facility. A key feature of the TREAT reactor core is an open, horizontal channel that allows line-of-sight viewing of test specimens using various instrumentation during steady-state and transient operation. This instrumentation includes the hodoscope, which consists of over 300 steel-collimated channels coupled to Hornyak buttons (and other detectors) for detection of fast neutrons emitted from fission of the test specimen. Posterior analysis can be used to reconstruct fuel motion and other properties from the collimated channel signals. A large-scale effort is underway to develop next generation instrumentation for transient testing at TREAT (and, potentially, other facilities). Work at KSU specifically aims to provide improved detection systems for hodoscope applications. It was initially proposed to adapt KSU-developed Microstructured Semiconductor Neutron Detectors (MSNDs) for use as fast-neutron detectors. The current generation of MSNDs is designed for thermal-neutron detection based on {sup 6}Li and can achieve intrinsic efficiencies nearing 30% owing to the large (n, t) cross section of {sup 6}Li and clever optimization of the geometry. In order to evaluate MSNDs for fast-neutron detection, two approaches were considered: (1) use of a hydrogenous material to thermalize neutrons to exploit the intrinsic efficiencies of current MSNDs, and (2) substitution of a fast-sensitive reactant for {sup 6}Li. The former approach is attractive because it makes use of proven, off-the-shelf technology and leads to reasonable time resolution and efficiency. Unfortunately, use of thermalization leads to prohibitive degradation of spatial resolution. The second approach will require further experimental efforts, but scoping analyses suggest {sup 235}U- or {sup 237}Th-loaded MSNDs may achieve sufficient efficiencies. The rest of this summary examines these issues in more detail. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2016

Computational Study of 15 MeV Linac Radiation Doses at the UNLV Accelerator Facility

Linear electron accelerators (linacs) are used to generate Bremsstrahlung photons through the interaction of an electron beam with a heavy metal target. These Bremsstrahlung photons with endpoint energy equal to that of the impinging electron beam are typically collimated into a desired beam shape (fan or cone beams). At electron energies larger than 10 MeV, the interaction of the newly produced photons with the linac component materials leads to the production of neutrons. These neutrons are often undesired and pollute the collimated photon beam while increasing the dose rates at the facility due to the linac operation. MCNPX 2.7.0 code was used to investigate the production of neutrons due to the normal operation of a 15 MeV linac. Dose rates within the UNLV accelerator facility were calculated for both photons and neutrons. Furthermore, the irradiation of several materials using the K15 linac was modeled; the resulting neutron fluxes and dose rates were determined. (authors)

43 PARTICLE ACCELERATORS↗

DOE OSTI2022

DESIGN AND VALIDATION OF A GAMMA-RAY SCANNING SYSTEM FOR MEASURING IRRADIATED NUCLEAR FUEL (ABSTRACT)

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2023

Measurements of Irradiated Low Enriched Fuel with a Gamma-Ray Scanning System (ANIMMA 2023 Conference Presentation)

A gamma-ray scanning system was designed to perform post-irradiation measurements of nuclear fuel at Idaho National Laboratory (INL). The system is composed of a coaxial high-purity germanium (HPGe) detector, a collimator, and mechanical positioning stages that translate the fuel sample across the front of the collimator. A Monte Carlo N-Particle code simulation of the system and the fuel were created with vendor-supplied design specifications, dimensional measurements, and x-ray radiographs of the HPGe detector as well as all available fuel specifications. Benchmark measurements were performed by scanning an irradiated fuel rodlet containing eight pellets of 0.74% enriched UO2 in zirconium alloy. This fuel rodlet was part of the Environment Rodlet Transient Test Apparatus (SERTTA) testing campaign in the Transient Reactor Test Facility (TREAT). These results were compared to simulated spectra to help characterize the detector model and establish fidelity. One goal of the system is to determine the number of fissions per gram of UO2 in the fuel. This article documents the modeling, benchmarking measurements, and the calculated number of fissions per gram in the SERTTA-A rodlet which was previously irradiated at TREAT.

11 - NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2026

Improvements to In-Canal Assay of High Specific Activity 60Co at the ATR

Improvements to the quality of measurements in the assaying of High Specific Activity (HSA) cobalt 60 produced at the Advanced Test Reactor at the Idaho National Laboratory are presented. Such assays are conducted regularly between cycles at the ATR, and due to the radiological safety concerns, they are performed within the ATR canal. A standard ion chamber detector was placed in a collimated assay tube within the canal. Another tube, parallel to the detector, was used to position various cobalt 60 standards and targets. The collimated port between these tubes allows for the targets to be pulled across via a winch system. Previous measurements were performed at discrete 1.5-inch steps using a hand-cranked winch system. Charge was collected and integrated for 10 seconds at each discrete step during a scan. Two substantial improvements to the assay include an electronically controlled, motor-driven winch system and a software controlled continuous charge collection. Combined, these changes improved the quality of measurements as well as streamline the assay process. Further examination of these charge profiles indicated a reasonable amount of photon scattering, or shine, before a line-of-sight is established. This created inaccuracies in the reported activity of the cobalt targets. A series of MCNP-6.3 calculations were performed in an effort to quantify and correct for this shine effect. The results of the calculations and how they were employed to a create shine correction factor for the in-canal cobalt assay at the ATR are presented. The overall bias showed an overestimation of the HSA cobalt 60 activity by around 7-8%.

07 - ISOTOPES AND RADIATION SOURCES↗