Physics with Neutrons 2 (Applications)

• Quasi-elastic neutron scattering
• Magnetic neutron scattering: structure
• Magnetic neutron scattering: magnons
• Neutron guides and super mirrors
• Neutron Polarization
• Ultra cold neutrons: production and applications
• Neutrons for medicine: radioisotopes and other medical applications
• Neutrons for industry, selected examples

After participation in the module the student is able to:

• understand magnetic scattering cross sections
• interpret elastic magnetic neutron scattering data
• measure and interpret dispersion curves from ferro- and antiferromagnetic magnons
• evaluate crystal electric fields
• interpret SANS-data from flux line lattices
• understand basics of polarization analysis

• Bachelor degree in physics

The learning outcomes of the module will be achieved via frontal lecture, written and verbal lecturing and powerpoint presentations. The lecture will be complemented by a weekly exercise class, where students will solve problems under supervision.

• lecture with PowerPoint presentation
• exercises
• books
• internet

1. A. Furrer, J. Mesot, T. Strässle: Neutron Scattering in Condensed Matter Physics, World Scientific, London (2009) .
2. G. L. Squires: Introduction to the Theory of Thermal Neutron Scattering, Dover Publications, N. Y. (1966).
3. S. W. Lovesey, Theory of Neutron Scattering from Condensed Matter I, II, Oxford Science Publ., Oxford (1984).
4. A. Furrer: Frontiers in Neutron Scattering, World Scientific, London (1999).
5. G. E. Bacon: Neutron Diffraction, Oxford (1962).
6. P. A. Egelstaff: Thermal Neutron Scattering, Acad. Press, London (1965).

There will be an oral exam of 30 minutes duration. Therein the achievement of the competencies given in section learning outcome is tested exemplarily at least to the given cognition level using comprehension questions, discussions of sketches and simple formulas.

For example an assignment in the exam might be:

• Quasielastic neutron scattering: What measures quasielastic incoherent neutron scattering? Which isotope has the largest incoherent cross section? How incoherent quasielastic scattering can distinguish long-range diffusive motion from localized motion?
• Magnetic scattering: Interaction of thermal neutrons with magnetic moment from electron spin and orbital? Formfactor for scattering of thermal neutrons at the magnetic moment of an atom? Condition for neutron spin-flip in a scattering event. Explain magnetic Bragg scattering. Examples of magnietc structures. Simple examples of magnon dispersion
• Neutron guides: Principle of a neutron guide? What are supermirrors for thermal neutrons
• Polarisation of neutrons: Definition of the degree of polarisation of a thermal neutron beam? Which methods to polarize a thermal neutron beam do you know? Explain their working principles.
• Ultra cold neutrons: Definition of ultra cold neutrons? Which physical quantities enter into the wall potential seen by thermal neutrons? What do we understand under “phase-space-density”? Describe the neutron decay. How to store UCNs? Examples of physical questions tackled by UCNs
• Neutrons for medicine: Which applications in medicine do you know, where neutrons play a vital role? For what purpose medicine needs radioisotopes? What tells you the expression „linear energy transfer“ with respect to cancer treatment?
• Industrial applications of neutrons: Which kind of applications of neutron beams for industry do you know? Please, categorize those with respect to competing methods

Participation in the exercise classes is strongly recommended since the exercises prepare for the problems of the exam and rehearse the specific competencies.