High resolution, high efficiency liquid scintillator capillary array for gamma imaging

2018 ◽  
Vol 89 (7) ◽  
pp. 073506
Author(s):  
Mei Zhang ◽  
Huasi Hu ◽  
Kuinian Li ◽  
Bodong Peng ◽  
Liang Sheng ◽  
...  
2020 ◽  
Vol 56 (8) ◽  
Author(s):  
F. Kandzia ◽  
G. Belier ◽  
C. Michelagnoli ◽  
J. Aupiais ◽  
M. Barani ◽  
...  

Abstract An active fission target has been developed for the FIPPS instrument at ILL, enabling for the first time an efficient suppression of $$\upbeta $$ β -delayed $$\upgamma $$ γ rays in high-resolution and high-efficiency $$\upgamma $$ γ -ray spectroscopy of fission fragments at a neutron beam. The target is based on a liquid scintillator in which the actinide is dissolved, resulting in a 4$$\pi $$ π fragment detection. Measurements have been performed with $$^{233, 235}$$ 233 , 235 U, with a fission tagging efficiency of 97.8(25)%. The high efficiency, together with the good time resolution of the scintillator target, provide high-selectivity data for $$\upgamma $$ γ -ray spectroscopy studies of fission fragments.


1988 ◽  
Vol 102 ◽  
pp. 41
Author(s):  
E. Silver ◽  
C. Hailey ◽  
S. Labov ◽  
N. Madden ◽  
D. Landis ◽  
...  

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.


Author(s):  
P. G. Kotula ◽  
D. D. Erickson ◽  
C. B. Carter

High-resolution field-emission-gun scanning electron microscopy (FESEM) has recently emerged as an extremely powerful method for characterizing the micro- or nanostructure of materials. The development of high efficiency backscattered-electron detectors has increased the resolution attainable with backscattered-electrons to almost that attainable with secondary-electrons. This increased resolution allows backscattered-electron imaging to be utilized to study materials once possible only by TEM. In addition to providing quantitative information, such as critical dimensions, SEM is more statistically representative. That is, the amount of material that can be sampled with SEM for a given measurement is many orders of magnitude greater than that with TEM.In the present work, a Hitachi S-900 FESEM (operating at 5kV) equipped with a high-resolution backscattered electron detector, has been used to study the α-Fe2O3 enhanced or seeded solid-state phase transformations of sol-gel alumina and solid-state reactions in the NiO/α-Al2O3 system. In both cases, a thin-film cross-section approach has been developed to facilitate the investigation. Specifically, the FESEM allows transformed- or reaction-layer thicknesses along interfaces that are millimeters in length to be measured with a resolution of better than 10nm.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Peipei Du ◽  
Jinghui Li ◽  
Liang Wang ◽  
Liang Sun ◽  
Xi Wang ◽  
...  

AbstractWith rapid advances of perovskite light-emitting diodes (PeLEDs), the large-scale fabrication of patterned PeLEDs towards display panels is of increasing importance. However, most state-of-the-art PeLEDs are fabricated by solution-processed techniques, which are difficult to simultaneously achieve high-resolution pixels and large-scale production. To this end, we construct efficient CsPbBr3 PeLEDs employing a vacuum deposition technique, which has been demonstrated as the most successful route for commercial organic LED displays. By carefully controlling the strength of the spatial confinement in CsPbBr3 film, its radiative recombination is greatly enhanced while the nonradiative recombination is suppressed. As a result, the external quantum efficiency (EQE) of thermally evaporated PeLED reaches 8.0%, a record for vacuum processed PeLEDs. Benefitting from the excellent uniformity and scalability of the thermal evaporation, we demonstrate PeLED with a functional area up to 40.2 cm2 and a peak EQE of 7.1%, representing one of the most efficient large-area PeLEDs. We further achieve high-resolution patterned perovskite film with 100 μm pixels using fine metal masks, laying the foundation for potential display applications. We believe the strategy of confinement strength regulation in thermally evaporated perovskites provides an effective way to process high-efficiency and large-area PeLEDs towards commercial display panels.


2021 ◽  
Author(s):  
Manyi Tao ◽  
Xiang Zhang ◽  
Fang Dong ◽  
Guangqing Hu ◽  
Xinjie Zhang ◽  
...  

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shi Zhao ◽  
Tien-Fu Lu ◽  
Larissa Statsenko ◽  
Benjamin Koch ◽  
Chris Garcia

Purpose In the mining industry, a run-of-mine (ROM) stockpile is a temporary storage unit, but it is also widely accepted as an effective method to reduce the short-term variations of ore grade. However, tracing ore grade at ROM stockpiles accurately using most current fleet management systems is challenging, due to insufficient information available in real time. This study aims to build a three-dimensional (3D) model for ROM stockpiles continuously based on fine-grained grade information through integrating data from a number of ore grade tracking sources. Design/methodology/approach Following a literature review, a framework for a new stockpile management system is proposed. In this system, near real-time high-resolution 3D ROM stockpile models are created based on dump/load locations measured from global positioning system sensors. Each stockpile model contains a group of layers which are separated by different qualities. Findings Acquiring the geometric shapes of all the layers in a stockpile and cuts made by front wheel loaders provides a better understanding about the quality and quality distribution within a stockpile when it is stacked/reclaimed. Such a ROM stockpile model can provide information on predicating ore blend quality with high accuracy and high efficiency. Furthermore, a 3D stockyard model created based on such ROM stockpile models can help organisations optimise material flow and reduce the cost. Research limitations/implications The modelling algorithm is evaluated using a laboratory scaled stockpile at this stage. The authors expect to scan a real stockpile and create a reference model from it. Meanwhile, the geometric model cannot represent slump or collapse during reclaiming faithfully. Therefore, the model is expected to be reconcile monthly using laser scanning data. Practical implications The proposed model is currently translated to the operations at OZ Minerals. The use of such model will reduce the handling costs and improve the efficiency of existing grade management systems in the mining industry. Originality/value This study provides a solution to build a near real-time high-resolution multi-layered 3D stockpile model through using currently available information and resources. Such novel and low-cost stockpile model will improve the production rates with good output product quality control.


2007 ◽  
Author(s):  
Marco Stampanoni ◽  
Amela Groso ◽  
Gunther Borchert ◽  
Rafael Abela

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