NFYK13013U Experimental X-ray Physics
X-rays are a remarkable tool in science: 20 Nobel prizes are based on the use of X-rays. With the recent development of synchrotron radiation sources (for Danish users primarly in Hamburg, Grenoble, Lund and near Zurich) the brilliance of X-ray sources has been increased by more than a billion times over the conventional X-ray tube! The purpose of this course is to prepare students, i.e. the scientists of the near future, to utilize this tool in physics, chemistry, biophysics, materials science, biology. Lectures are given on the basics of X-ray physics, exercises in the lab will provide "hands-on" experience, and the course concludes with a stay at the synchrotron facility MAXlab in Lund, where students will carry out a number of basic experiments with X-ray synchrotron radiation.
The student is expected to have the following skills after completing this course:
- Describe the X-ray radiation in the wave characteristic, its interaction with electrons and to establish the equation for Thompson scattering.
- Explain the scattering of atoms and molecules, and to establish formulas for the related scattering function.
- Being able to explain how X-rays are produced in the laboratory and at synchrotron X-ray facilities using bending magnets, wigglers and undulators, as well as the different characteristics of each source. In addition, the students must be able formulate how the X-ray beam is generated from a bending magnet and an undulator.
- Explain the fundamental optical properties of X-ray radiation interaction with solids. The students must be able to deduce the refractive index of X-rays and based on physical principles to provide the Fresnel equation and the Snell’s law within the X-ray regime. Finally, the student must be able to deduce the reflectivity of sharp as well as rough surfaces and layered systems.
- Explain the properties of the main optical elements such as monochromator, refractive lens, multilayer and mirrors as well as to calculate the focal length of a refractive lens system.
- Explain the spatial structure of simple crystals, especially the cubic structures such as fcc, bcc and diamant structure. Further explain the relationship between the reciprocal lattice, the Miller index and diffraction. The student must also be able to calculate the structure factors and the reflection from simple systems, including two-dimensional systems and to describe the effect of thermal fluctuations of diffraction.
- Explain the Ewald construction and powder diffraction
- Setup the basic equations for resonant scattering and the principle of Multiple Anomalous Diffraction, and to explain how to use this to solve the phase-problem when studying protein structures.
The course will describe the basic interaction between x-ray radiation and materials going from Thomson scattering from free electrons to the classical reciprocal space description of scattering from crystal. A fair part of the course will contain a discussion on new x-ray sources and the development of modern x-ray components, including optics using the refractive properties of materials. Finally, discussions of applications of X-rays will include the Extended X-ray Absorption and phasing of structure factors using anormalous scattering. The exercises will contain a discussion of detectors and anode x-ray sources as well as x-ray reflectometry. During the exercises at MAXlab in Lund, we will exploit the properties of synchtrotron radiation.
The student will be familiar with the application of X-Ray techniques in physics, chemistry, biophysics, materials science and biology and have "hands on" lab experience. The student will have insight into what type of information can be gained using X-ray methods, where such facilities exists, and which components are critical in the experiment.
"Elements of Modern X-ray Physics" by J. Als-Nielsen and D. McMorrow, (Wiley 2001)
PhD-students in chemistry or biology are welcome
Restricted elective for specialisations "Quantum Physics" and "Physics"
- 7,5 ECTS
- Type of assessment
- Oral examination, 30 minWithout time for preparation
- Exam registration requirements
- To participate in the oral exam the written reports handed in during the course must have been approved.
- Marking scale
- 7-point grading scale
- Censorship form
- No external censorship
More internal examiners
- Same as regular exam.
If the student participated in the experiments during the course but the reports were not approved, it will be possible to hand in new reports no later than 2 weeks before the re-exam.
For a student who did not participate in the experiments it will not be possible to take the re-exam, and the student must follow the course Again the following year.
Criteria for exam assesment
The grade 12 is given to the outstanding students who have an overview that will allow detailed explanation and extended formulating of the basic properties of the X-ray interaction with matter, as well as a detailed insight into the concept of diffraction. In addition, the excellent students have ability to derive details of all major equations and concepts. It is also required that the student has an overview of the order of magnitude of main physical concepts.