Available student project - Measuring electric quadrupole moments - the shapes of atomic nuclei

Research fields

CAESAR detector array schematic as used for quadrupole moment measurements

Project details

The quadrupole moments of short-lived nuclear quantum states (lifetimes of the order of 1 ns) will be measured by implanting excited nuclei into suitable crystalline hosts where they experience a hyperfine electric field gradient (EFG). This EGF causes the nuclear angular momentum to undergo a kind of precession, proportional to the quadrupole moment. The precession effect, from which the quadrupole moment can be deduced, is observed via changes in the pattern of the gamma-ray radiation that de-excites the state. We have preliminary data obtained as a by-product of another type of  measurement that proves the viability of the method. The next step is to design and implement experiments specifically to measure the quadrupole moment. The preliminary data were taken using the CAESAR array of Compton suppressed hyperpure germanium detectors. It will continue as the primary apparatus for the project.

Student projects can include developing the experimental method, designing apparatus and performing experiments, as well as the analysis of data and the theoretical interpretation of results. The experiment design requires theoretical work on the quantum mechanics of gamma-ray angular correlations and of the interactions between the nucleus and ints immediate electronic environment (i.e. hyperfine interactions).

Students will gain experience working with radiation detectors, electronics, data acquisition, accelerator operations, and develop data analysis skills. At PhD level participation in international experiments is likely.

Required background

Some quantum mechanics is useful. Proficiency in computing for modeling and data analysis (or willingness to learn) will be useful.

Project suitability

This research project can be tailored to suit students of the following type(s)

Contact supervisor

Stuchbery, Andrew profile

Other supervisor(s)

Mitchell, AJ profile
Lane, Gregory profile
Coombes, Ben profile