The Role of Sn, Zr and Hf in the Radiation Damage in II, III, IV and V Pyrochlores

2012 ◽  
Vol 1383 ◽  
Author(s):  
Karl R. Whittle ◽  
Massey de los Reyes ◽  
Mark G. Blackford ◽  
Nestor J. Zaluzec ◽  
Gregory R. Lumpkin

ABSTRACTCeramics based on the general compositions CaLnXNbO7 (where Ln = La, Nd and Sm, and X=Zr and Sn) have been prepared, and irradiated with 1 MeV Kr ions at the IVEM-TANDEM user facility. The radiation tolerance of these materials has been found to be less than Zr and Hf equivalents. The results also suggest that the amorphisation cross section for these materials is related to the Ln component, and is similar to those observed for Zr and Hf equivalents.

2012 ◽  
Vol 1475 ◽  
Author(s):  
Karl R. Whittle ◽  
Massey de los Reyes ◽  
Yan Gao ◽  
Mark G. Blackford ◽  
Nestor J. Zaluzec ◽  
...  

ABSTRACTPyrochlores based on the general composition CaLnZrNbO7 (where Ln = La, Nd, Sm, Gd and Ho) have been prepared, and irradiated through the crystalline-amorphous transition, with 1 MeV Kr ions at the IVEM-TANDEM user facility. The obtained critical temperatures show a decrease from La to Gd (∼680 K to ∼230 K), with Ho being resistant to amorphisation at 50K. The results suggest that the amorphisation cross section for these materials is directly related to the Ln component.


Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 887
Author(s):  
Minwoong Lee ◽  
Namho Lee ◽  
Jongyeol Kim ◽  
Younggwan Hwang ◽  
Seongik Cho

In the present study, the layout structure of an n-MOSFET, which is vulnerable to radiation, was designed in a different way to enhance its tolerance to radiation. Radiation damage assessment was conducted using modeling and simulation (M&S) techniques before actual semiconductor process fabrication and radiation tests to verify its tolerance properties. Based on the M&S techniques, the role of each layer was determined to improve the radiation tolerance of semiconductors, and the layout design of an n-MOSFET with enhanced radiation tolerance was optimized. The optimized radiation-tolerant n-MOSFET design was implemented in the 0.18-um CMOS bulk process, and radiation exposure tests were conducted on the device. A cumulative radiation dose up to 2 Mrad(Si) was applied to verify its radiation-tolerant performance. Developing new devices using M&S techniques for radiation damage assessment allows reliable estimates of their electrical and radiation-tolerant properties to be obtained in advance of the actual manufacturing process, thereby minimizing development costs and time.


Author(s):  
Xudong Weng ◽  
Peter Rez

In electron energy loss spectroscopy, quantitative chemical microanalysis is performed by comparison of the intensity under a specific inner shell edge with the corresponding partial cross section. There are two commonly used models for calculations of atomic partial cross sections, the hydrogenic model and the Hartree-Slater model. Partial cross sections could also be measured from standards of known compositions. These partial cross sections are complicated by variations in the edge shapes, such as the near edge structure (ELNES) and extended fine structures (ELEXFS). The role of these solid state effects in the partial cross sections, and the transferability of the partial cross sections from material to material, has yet to be fully explored. In this work, we consider the oxygen K edge in several oxides as oxygen is present in many materials. Since the energy window of interest is in the range of 20-100 eV, we limit ourselves to the near edge structures.


Author(s):  
Shawn Williams ◽  
Xiaodong Zhang ◽  
Susan Lamm ◽  
Jack Van’t Hof

The Scanning Transmission X-ray Microscope (STXM) is well suited for investigating metaphase chromosome structure. The absorption cross-section of soft x-rays having energies between the carbon and oxygen K edges (284 - 531 eV) is 6 - 9.5 times greater for organic specimens than for water, which permits one to examine unstained, wet biological specimens with resolution superior to that attainable using visible light. The attenuation length of the x-rays is suitable for imaging micron thick specimens without sectioning. This large difference in cross-section yields good specimen contrast, so that fewer soft x-rays than electrons are required to image wet biological specimens at a given resolution. But most imaging techniques delivering better resolution than visible light produce radiation damage. Soft x-rays are known to be very effective in damaging biological specimens. The STXM is constructed to minimize specimen dose, but it is important to measure the actual damage induced as a function of dose in order to determine the dose range within which radiation damage does not compromise image quality.


World ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 205-215
Author(s):  
Joshua Mullenite

In this article, I review a cross-section of research in socio-hydrology from across disciplines in order to better understand the current role of historical-archival analysis in the development of socio-hydrological scholarship. I argue that despite its widespread use in environmental history, science and technology studies, anthropology, and human geography, archival methods are currently underutilized in socio-hydrological scholarship more broadly, particularly in the development of socio-hydrological models. Drawing on archival research conducted in relation to the socio-hydrology of coastal Guyana, I demonstrate the ways in which such scholarship can be readily incorporated into model development.


2016 ◽  
Vol 25 (5) ◽  
pp. 055016 ◽  
Author(s):  
Annemie Bogaerts ◽  
Weizong Wang ◽  
Antonin Berthelot ◽  
Vasco Guerra

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