[en] This report details some of the measurements made by Bechtel Nevada (BN) to characterize the Armando radiographic detection system and marks the completion of the R-306 Armando System Characterization milestone. The measurements, made in July 2003, utilized the Cygnus pulse power machine, which was assembled at the Los Alamos National Laboratory (LANL) Firing Site R-306. This report describes the test configuration used and the findings concerning the following Armando radiographic detection system issues for source spot size, mirror vs. pellicle performance, scintillator configuration evaluation, resolution and reproducibility, off-axis scatter contribution, and source spectra reproducibility

[en] This report presents results derived from a digital radiography study performed using x-rays from a 2.3 MeV, rod-pinch diode. Detailed is a parameter study of cerium-doped lutetium ortho-silicate (LSO) scintillator thickness, as it relates to system resolution and detection quantum efficiency (DQE). Additionally, the detection statistics of LSO were compared with that of CsI(Tl). As a result of this study we found the LSO scintillator with a thickness of 3 mm to yield the highest system DQE over the range of spatial frequencies from 0.75 to 2.5 mm^-1

[en] Long-wavelength liquid scintillators have been developed for fiber-optic plasma-diagnostic experiments. Relative system sensitivity and bandwidth data as a function of fiber length for several scintillator systems will be presented

[en] The use of fiber optics in plasma diagnostics has spurred the development of long wavelength scintillators with fast temporal characteristics. In this paper we describe several new liquid scintillator systems with fluorescent emissions maxima up to 730 nm. Subnanosecond scintillator FWHM response times have been obtained by the operation of liquid scintillators at elevated temperatures. Data on fiber system sensitivity versus fiber length and scintillator emission wavelength will be presented

[en] High nutrient concentrations despite mitigation measures and reduced inputs are a common problem in anthropogenically impacted catchments. To investigate how water and solutes of different ages are mixed and released from catchment storage to the stream, catchment-scale models based on water transit time from StorAge Selection functions (SAS) are a promising tool. Tracking fluxes of environmental tracers, such as stable water isotopes, allows to calibrate and validate these models. However, this requires collection of water samples with an adequate temporal and spatial resolution, while sampling in catchments at the management scale is often limited by the high costs of the instruments, maintenance and chemical analysis. Therefore, temporal and spatial interpolation techniques are needed. This study demonstrates how to deal with sparse tracer data in space and time, and evaluates if these data are valuable to constrain the subsurface mixing dynamics and transit time with SAS modelling. We simulated water isotope data in diverse sub-basins of the Bode catchment (Germany) and calibrated the SAS function parameters against the measured streamflow isotope data. We tested four different combinations of spatial and temporal interpolation of the measured precipitation isotope data. In terms of temporal interpolation, monthly oxygen isotopes in precipitation (δ18OP) collected between 2012 and 2015 were converted to a daily time step with a step function and sinusoidal interpolation. In terms of spatial interpolation, the model was tested with raw values of δ18OP collected at a specific sampling point and with δ18OP interpolated using kriging to gain the spatial pattern of precipitation. The effect of the spatial and temporal interpolation techniques on the modeled SAS functions was analyzed using different parameterizations of the SAS function (i.e., power law time-invariant, power law time-variant and beta law). The results show how tracer input data with different distribution in time and space affect the SAS parameterization and water transit time. Moreover, they reveal preference of the sub-basins to mobilize either younger or older water, which has implications on how water flows through a catchment and on the fate of solutes.

[en] There has been considerable work in recent years in the development of high-brightness, high-dose flash x-ray radiographic sources. Spot size is one of several parameters that helps characterize source performance and provides a figure of merit to assess the suitability of various sources to specific experimental requirements. Time-integrated spot-size measurements using radiographic film and a high-Z rolled-edge object have been used for several years with great success. The Advanced Radiographic Technologies program thrust to improve diode performance requires extending both modeling and experimental measurements into the transient time domain. A new Time Resolved Spot Detector (TRSD) is under development to provide this information. In this paper we report the initial results of the performance of a 148-element scintillating fiber array that is fiber-optically coupled to a gated streak camera. Spatial and temporal resolution results are discussed and the data obtained FR-om the Sand ia National Laboratories (SNL) RITS-3 (Radiographic Integrated Test Stand) accelerator are presented

[en] Progress is reported from efforts to develop radiation-to-light converters suitable for use with optical fibers as they are applied to the diagnostics of transient nuclear phenomena. Liquid and plastic fluors have been prepared which emit in the 550- to 600-nm region. Ternary liquid systems with decay times as short as 1.3 ns at 560 nm and plastic fluors with decay times less than 3 ns at 560 nm are reported. Other liquid and plastic fluors are reported with improved emission characteristics in the region of 600 nm. Conversion efficiences, on a pulse amplitude basis, are generally lower than that of a commercially available 570 nm-16 ns plastic fluor

[en] Fiber optics can provide a cost effective transmission medium for wide bandwidth radiation diagnostics. Passive systems have been investigated which allow conversion of radiation energy to optical energy with direct coupling to optical fibers. Organic scintillators have been developed which emit at wavelengths near 600 nm. The new scintillators yield a FWHM below 1.5 ns. The scintillator emission band is very broad, leading to the requirement of optical filtering to limit material dispersion in the fiber. Trade-offs involving fiber length, dynamic range, fiber radiation damage, scintillator radiation damage, bandwidth, and spectral filter width are discussed

No abstract available

[en] The application of low loss multimode optical fibers to nuclear diagnostics has been discussed in previous papers. Fiber requirements for this application differ substantially from those for normal communications use. The emphasis for nuclear measurements has been on development of high frequency analog fiber optic transmission line systems, which range from 100 MHz to > 500 MHz signals transmitted at 600 nm and 800 nm, respectively. Accordingly, specialized fiber characterization procedures over a wide spectral range have been developed. These techniques include measurement of material and modal dispersion, optical attenuation, and optical linearity. It is also important to know the prompt radiation response of optical fibers in nuclear diagnostics. Measurements of this type have been discussed in previous papers