PPT-2023 X-ray diffraction and Crystallography safety training

Xrays Xrays are a type of ionizing electromagnetic radiation Xrays are a valuable tool but there are associated health risks These risks can be minimized by adhering to certain principles and practices as explained in this presentation . g Basic Crystallography g Why Use Diffraction in the TEM? g Bragg’s Law g Selected Area Electron Diffraction 1 2 Crystal Structure  A crystal structure is defined as a regular arrang Wave Optics. The wave nature of light is needed to explain various phenomena. Interference. Diffraction. The . particle nature of light was the basis for ray (geometric) . optics. Light waves interfere with each other much like mechanical waves do. shape our . world. Crystals . —familiar to all in gemstones, glittering snowflakes or grains of salt— are everywhere in nature. Throughout history, people have been fascinated by their beauty and mystery. Two thousand years ago, the process of crystallizing sugar and salt was already known to the ancient . Grisel. Rivera Batista. Science Undergraduate Laboratory Internship Program. August 12, 2010.. Advantages of AXRD. Sensitive to:. N. eighboring elements in the periodic table.. Specific crystallographic phase.. History. 1895. Wilhelm Conrad R. ӧ. ntgen. discovered . X-rays. 1905 . Albert Einstein introduces the concept of photons (concept not accepted until 1922). 1913 . Max von . Laue, . Walter Friedrich . Diffraction of Light. Newton pointed . out in his 1704 book . Opticks. , that "Light is never known to follow crooked passages nor to bend into the shadow". . This concept is consistent with the particle theory, which proposes that light particles must always travel in straight lines.. Data Analysis. Scott A Speakman, Ph.D.. Center for Materials Science and Engineering at MIT. speakman@mit.edu. http://prism.mit.edu/xray. . An X-ray diffraction pattern is a plot of the intensity of X-rays scattered at different angles . Physics . 2212. Light. Light has Wave properties. Light can Diffract. Light can Interfere. Constructively. Destructively. Wave Fronts. Lines that are perpendicular to the motion of the wave, indicate the location of the crests in the waves that are traveling together.. Synchrotron radiation macromolecular crystallography: instrumentation, methods and applications. John R . Helliwell. Thank you to the ACA for this . Patterson Award!. I share your vision and world view . Resolution of SEMTransmissionelectronmicroscopy(TEM)isamicroscopytechniquewherebyabeamofelectronsistransmittedthroughanultrathinspecimen,interactingwiththespecimenasitpassesthrough.Animageisformedfrom 6-x. Au. x. system hosts the first known example of an elastic quantum critical point. Neutron and x-ray diffraction measurements were performed to study the structural properties as a function of temperature and Au-composition. First principle calculations confirm that the phase transition is driven by an elastic instability and is independent of electronic properties. Heat capacity measurements indicate the presence of quantum fluctuations at the critical composition. Different imaging modalities. This training presentation covers the following imaging modalities involving X-rays:. Radiography. Fluoroscopy (under-table and C-arm). Computed Tomography (CT). Intraoral Dental. FORMATION OF IUCR. The IUCr became a member of ICSU in April 1947.. Acta. . Crystallographica. . was launched in 1948.. The first General Assembly was held in 1948 in Cambridge, USA.. Four founding Adhering . (. XRD. ). . X. -. R. ay . P. hotoelectron . S. pectroscopy. (. XPS. ). By:. . Roya. . Ayazi. . Nasrabadi. What is X. -. ray. ?. X-ray . diffraction. (. XRD. ). Bragg’s Law. n . λ. =2dsin. θ.