Synchrotron Radiation Damage Mechanism of X-Ray Mask Membranes Irradiated in Helium Environment

1992 ◽  
Vol 31 (Part 1, No. 12B) ◽  
pp. 4459-4462 ◽  
Author(s):  
Tomiyuki Arakawa ◽  
Hiroshi Okuyama ◽  
Koichi Okada ◽  
Hiroyuki Nagasawa ◽  
Tsutomu Syoki ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Radiation Damage ◽  
Damage Mechanism ◽  
X Ray

X-ray topography of natural beryl using synchrotron and conventional sources

1983 ◽  
Vol 16 (1) ◽  
pp. 47-56 ◽  
Author(s):  
N. Herres ◽  
A. R. Lang
Keyword(s):  
Synchrotron Radiation ◽  
Radiation Damage ◽  
Continuous Spectrum ◽  
Lattice Defects ◽  
Growth Sector ◽  
X Ray ◽  
Diffraction Contrast

Continuous-spectrum synchrotron-radiation Laue transmission topographs of natural beryl have been compared with the corresponding projection topographs taken with conventional apparatus and Cu Kα 1 and Mo Kα 1 radiations in an analysis of configurations of grown-in lattice defects and of the diffraction contrast they produce. The natural defects studied included grown-in dislocations, impurity zoning and fault surfaces. A growth-sector map was constructed for the (0001) specimen slice examined. Differences of contrast among the various reflections appearing on the synchrotron-radiation topographs are discussed and it is demonstrated that the contrast characteristics of the synchrotron-radiation images which consist of a superimposition of 3{\bar 2\bar 1}1 and 6{\bar 4 \bar 2}2 reflections can be satisfactorily synthesized by a weighted superimposition of the 3{\bar 21}1 image recorded with Cu Kα 1 and the 6{\bar 4\bar 2}2 with Mo Kα 1. Synchrotron-radiation damage to the crystal manifested itself on the X-ray topographs both as area contrast and as contrast at the periphery of the irradiated area, yet no visual absorption or birefringence due to this damage was detected. Annealing at 770 K for 3 h completely removed the contrast due to radiation damage.

Effects of soft X-ray radiation damage on paraffin-embedded rat tissues supported on ultralene: a chemical perspective

2018 ◽  
Vol 25 (3) ◽  
pp. 848-856 ◽  
Author(s):  
Diana E. Bedolla ◽  
Andrea Mantuano ◽  
Arissa Pickler ◽  
Carla Lemos Mota ◽  
Delson Braz ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Radiation Damage ◽  
Structural Changes ◽  
Damage Mechanism ◽  
Exposure Dose ◽  
Rat Tissues ◽  
Structural Morphology ◽  
X Ray ◽  
Tissue Lipids ◽  
Embedding Medium

Radiation damage is an important aspect to be considered when analysing biological samples with X-ray techniques as it can induce chemical and structural changes in the specimens. This work aims to provide new insights into the soft X-ray induced radiation damage of the complete sample, including not only the biological tissue itself but also the substrate and embedding medium, and the tissue fixation procedure. Sample preparation and handling involves an unavoidable interaction with the sample matrix and could play an important role in the radiation-damage mechanism. To understand the influence of sample preparation and handling on radiation damage, the effects of soft X-ray exposure at different doses on ultralene, paraffin and on paraffin-embedded rat tissues were studied using Fourier-transform infrared (FTIR) microspectroscopy and X-ray microscopy. Tissues were preserved with three different commonly used fixatives: formalin, glutaraldehyde and Karnovsky. FTIR results showed that ultralene and paraffin undergo a dose-dependent degradation of their vibrational profiles, consistent with radiation-induced oxidative damage. In addition, formalin fixative has been shown to improve the preservation of the secondary structure of proteins in tissues compared with both glutaraldehyde and Karnovsky fixation. However, conclusive considerations cannot be drawn on the optimal fixation protocol because of the interference introduced by both substrate and embedding medium in the spectral regions specific to tissue lipids, nucleic acids and carbohydrates. Notably, despite the detected alterations affecting the chemical architecture of the sample as a whole, composed of tissue, substrate and embedding medium, the structural morphology of the tissues at the micrometre scale is essentially preserved even at the highest exposure dose.

scholarly journals Soft X-Ray Microscopy Radiation Damage On Fixed Cells Investigated With Synchrotron Radiation FTIR Microscopy

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
A. Gianoncelli ◽  
L. Vaccari ◽  
G. Kourousias ◽  
D. Cassese ◽  
D. E. Bedolla ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Radiation Damage ◽  
Ftir Microscopy ◽  
X Ray

scholarly journals Study on Microstructure and Fatigue Properties of FGH96 Nickel-Based Superalloy

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6298
Author(s):  
Yishan Bai ◽  
Shanglei Yang ◽  
Minqi Zhu ◽  
Cong Fan
Keyword(s):  
Synchrotron Radiation ◽  
Cleavage Fracture ◽  
Damage Mechanism ◽  
Propagation Path ◽  
Fatigue Properties ◽  
Second Phase ◽  
X Ray ◽  
Nickel Based Superalloy ◽  
Second Phase Particles ◽  
Cleavage Step

In this study, using synchrotron radiation X-ray imaging, the microstructure, tensile properties, and fatigue properties of FGH96 nickel-based superalloy were tested, and the fatigue damage mechanism was analyzed. An analysis of the experimental results shows that the alloy structure is dense without voids or other defects. It was observed that the primary γ′ phase is distributed on the grain boundary in a chain shape, and the secondary γ′ phase is found inside the crystal grains. The X-ray diffraction (XRD) pattern indicates that no other phases were seen except for the γ and γ′ phases. The tensile strength of the alloy is 1570 MPa and the elongation is 12.1%. Using data fitting and calculation, it was found that the fatigue strength of the alloy under the condition of 5 × 106 cycles is 620.33 MPa. A fatigue fracture has the characteristics of secondary crack, cleavage step, fatigue stripe, tire indentation, and dimple. The fracture is a mix of cleavage fracture and ductile fracture. Through a three-dimensional reconstruction of the alloy synchrotron radiation imaging area, it was found that the internal defects are small and mostly distributed at the edge of the sample. The dimple morphology is formed by cavity aggregation and cavity germination resulting from defects in the material itself, fracture of the second-phase particles, and separation of the second-phase particles from the matrix interface. By analyzing the damage mechanism of fatigue fractures, it is concluded that the cleavage step is formed by the intersection of cleavage planes formed by branch cracks, with the main crack of the confluence extending forward to form a cleavage fracture. The crack propagation path was also analyzed, and under the action of cyclic load and tip passivation, the crack shows Z-shaped propagation.

Experimental Absorption Coefficients of Resists and Biological Materials

1985 ◽  
Vol 43 ◽  
pp. 606-609
Author(s):  
D.M. Shinozaki ◽  
P.C. Cheng ◽  
K. Tan ◽  
J. Wm. McGowan
Keyword(s):  
Radiation Damage ◽  
Damage Mechanism ◽  
Biological Materials ◽  
Absorption Coefficients ◽  
X Ray ◽  
Long Wavelength ◽  
Image Recording ◽  
Direct Measurements ◽  
Using Data ◽  
Biological Component

The technique of soft x-ray contact imaging involves irradiating a polymer resist (the image recording medium) through a specimen with a microstructure of interest. The x-ray flux transmitted through the specimen is attenuated by the constituents of the microstructure, and the polymer resist and biological component and tissue suffer varying amounts of radiation damage. The amount of radiation damage in the resist depends on the absorbed energy and therefore is a function of the absorption coefficient of the resist and the flux incident on the resist. An understanding of the image formed in the resist, and the use of images for microchemical analysis depends on a quantitative measurement of absorption coefficients of both the resist and biological materials. It is possible to estimate the absorption behavior of materials using data from experiments on the gas phase of nitrogen, oxygen, etcetera. However direct measurements are particularly necessary near absorption edges such as at the carbon K edge where chemical effects are significant, and towards the long wavelength side of the soft x-ray region where the radiation damage mechanism is strongly affected by the molecular structure.

X-Ray Radiation Damage of Polymers in a Scanning Transmission X-Ray Microscope

1998 ◽  
Vol 4 (S2) ◽  
pp. 370-371
Author(s):  
T. Coffey ◽  
H. Ade ◽  
S. Urquhart ◽  
A.P. Smith
Keyword(s):  
Radiation Damage ◽  
Damage Mechanism ◽  
Polymer Structure ◽  
National Synchrotron Light Source ◽  
X Ray ◽  
Critical Dose ◽  
Scanning Transmission ◽  
Synchrotron Light ◽  
X Ray Absorption ◽  
The Continuum

We use the Scanning Transmission X-ray Microscope (STXM) at the National Synchrotron Light Source (NSLS) (1) to acquire images and spectra of polymers. To interpret data correctly, the effects X-ray radiation has on polymers must be understood. We have therefore started to characterize radiation damage in a variety of carbonyl containing polymers in two ways. First, we want to ascertain the critical dose for mass loss and the critical dose for the carbonyl in a variety of polymers and relate the critical dose to the polymer structure. (The critical dose is the radiation dose at which the optical density of the material is decreased by 1/e of its original value.) We also want to understand the damage mechanism. STXM acquires images and Near Edge X-ray Absorption Fine Structure (NEXAFS) spectra by using X-ray photons to excite inner shell electrons to unoccupied valence orbitals or to the continuum.

Studies of metaphase chromosomes in the scanning transmission x-ray microscope: Image fidelity, radiation damage and specimen preparation

1992 ◽  
Vol 50 (2) ◽  
pp. 1038-1039
Author(s):  
Shawn Williams ◽  
Xiaodong Zhang ◽  
Susan Lamm ◽  
Jack Van’t Hof
Keyword(s):  
Visible Light ◽  
Radiation Damage ◽  
Cross Section ◽  
Imaging Techniques ◽  
Dose Range ◽  
Specimen Preparation ◽  
X Rays ◽  
Metaphase Chromosomes ◽  
X Ray ◽  
Scanning Transmission

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.

Characterization of defects in tabular silver halide grains

1990 ◽  
Vol 48 (4) ◽  
pp. 1046-1047
Author(s):  
C. Goessens ◽  
D. Schryvers ◽  
J. Van Landuyt ◽  
A. Verbeeck ◽  
R. De Keyzer
Keyword(s):  
Radiation Damage ◽  
Silver Halide ◽  
Chemical Characteristics ◽  
X Ray ◽  
Free Region ◽  
Central Defect ◽  
Crystallographic Defects ◽  
Physical And Chemical ◽  
Two Sides

Silver halide grains (AgX, X=Cl,Br,I) are commonly recognized as important entities in photographic applications. Depending on the preparation specifications one can grow cubic, octahedral, tabular a.o. morphologies, each with its own physical and chemical characteristics. In the present study crystallographic defects introduced by the mixing of 5-20% iodide in a growing AgBr tabular grain are investigated. X-ray diffractometry reveals the existence of a homogeneous Ag(Br1-xIx) region, expected to be formed around the AgBr kernel. In fig. 1 a two-beam BF image, taken at T≈100 K to diminish radiation damage, of a triangular tabular grain is presented, clearly showing defect contrast fringes along four of the six directions; the remaining two sides show similar contrast under relevant diffraction conditions. The width of the central defect free region corresponds with the pure AgBr kernel grown before the mixing with I. The thickness of a given grain lies between 0.15 and 0.3 μm: as indicated in fig. 2 triangular (resp. hexagonal) grains exhibit an uneven (resp. even) number of twin interfaces (i.e., between + and - twin variants) parallel with the (111) surfaces. The thickness of the grains and the existence of the twin variants was confirmed from CTEM images of perpendicular cuts.

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