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FYST16
Modern Subatomic Physics, 7.5p ECTS
 
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  FYS246: Modern Subatomic Physics, 7.5p ECTS

What is subatomic physics?

The Wordsmyth English Dictionary-Thesaurus defines subatomic as an adjective meaning "of or pertaining to particles contained within or processes occurring within an atom." Subatomic physics is thus related to the inner workings of atomic nuclei, such as the interactions between the nucleons (protons and neutrons), or the properties of the fundamental building blocks of all matter - the elementary particles.

In a historical perspective, almost all we now know about atomic nuclei is the result of 100 years of scientific investigation. In this relatively short time, our picture of nuclear matter has been steadily refined. The early planetary model of an unsplittable atom has been replaced by a complex interconnected system where interactions between quarks and leptons are fundamentally responsible for the properties of the nuclei that make up our universe.

This impressive evolution of our knowledge has been possible because of the close cooperation of theorists and experimentalists. The need for actual measurements of nuclear and subatomic properties has led to the construction of large accelerators and complicated detector systems. The results of experiments have, in their turn, spurred on the development of sophisticated theoretical models and computer simulations.

Interestingly, our expanding knowledge about the very smallest particles has had a profound influence on the understanding of astrophysical phenomena, ranging from the Big Bang to the mechanisms governing the stars and the formation of the chemical elements.

How can we study subatomic phenomena?

In order to measure the properties of a subatomic system it must somehow be perturbed, for instance in a nuclear reaction. Depending on the projectile/target combination, the kinematics and the energy available, different aspects of the picture can be revealed. (Remember that from the simple formula of de Broglie, the wavelength of a particle is inversely proportional to its momentum. Thus the higher kinetic energy the particle has, the smaller objects can be probed.)

Studies of nuclear decays and reactions at low energy give information about the structure of the atomic nucleus in terms of the nucleons and their interactions. At higher excitation energies, the focus shifts to probing basic properties of nuclear matter, such as its compressibility. Very high energies are needed to study the inner structure of nucleons, the quarks and the gluons.

Only by carefully and as completely as possible detecting the particles and radiation emitted from a nuclear reaction, can it be correctly reconstructed and interpreted. The last decades has seen a rapid development of detectors dedicated to subatomic physics. New materials and the advances in experimental electronics and data evaluation has made it possible to examine the innermost building blocks of matter.

(Some scientists have suggested an alternative way to gain insight into the strange forces that rule subatomic behaviour. This method is very dangerous and can lead to severe side effects - don't try it at home!)

Subatomic research in Lund

Experimental research in subatomic physics is carried out at two Divisions of the Department of Physics. Amongst other issues, the Divisions of Nuclear Physics and High Energy Physics are engaged in a wide range of projects involving heavy ion- and photon-induced reactions. Presented in order of increasing energy, topics under investigation and relevant to the course include:

If you want to know more about the current research projects, follow the links above!

 

© Margareta Hellström | Department of Physics | Lund University.