Research Associate in Atomic Physics

Applications are invited for a three year postdoctoral research fellowship in the Atomic Physics research group in the Photon Science Institute, Department of Physics & Astronomy at the University of Manchester. This EPSRC funded research project is entitled ‘(e,gamma,2e) Threshold Spectroscopy - A new method to study collisional excitation of atoms using combined laser and electron beams’.

Project description:

Since the foundation of modern physics where Ernest Rutherford and collaborators discovered the structure of the atom in Manchester and Niels Bohr developed the first quantum theory, collision experiments between an incident particle and an atom have provided physicists with precise details on the nature of matter. Rutherford's experiments probed the nucleus using alpha particles, leading to modern nuclear physics. Franck and Hertz soon after used an electron beam to probe the structure of the electrons surrounding the nucleus. These experiments lead to the development of modern quantum theory and atomic physics. Since then our understanding of the atom and its structure, as developed through theory and sophisticated experiments, has paved the way to the development of almost all technologies that we use today.

Key to our understanding and development of new and emerging technologies is the close collaboration between experimentalists who measure the interactions to high precision and theoreticians who develop the quantum theories that describe these processes. By testing theory with experiment the models are refined and improved, so that they can predict what occurs in many areas of modern science and industry. Processes where the models have direct application include the development of new lasers, in Tokomaks for generation of fusion energy, in the earth's upper atmosphere (including the ozone layer and ionosphere) and in astrophysics, where they are used to model stellar atmospheres and the atmospheres of exo-planets.

Understanding excitation of atoms by electron impact plays an essential role in testing the models. Results from experiment and theory have converged in recent years, with the models agreeing well with experiment. The conventional experiments currently in use are however limited, due to the low efficiency of the detectors or due to limitations of the techniques that are adopted. They hence cannot measure excitation of a wide range of target states, including higher lying states with long lifetimes and metastable states where the atom effectively 'stores' energy impacted by the collision for a long time. Understanding excitation of these 'metastable' atoms hence is important in many different areas.

The new technique to be developed here will allow these interactions to be studied for the first time. This will use a very precise laser beam to further excite the atoms created by the collision to a highly excited Rydberg state that is very close to ionization. These 'Rydberg atoms' can be huge - we can make neutral atoms in our laboratory with diameters around 1/10th that of a human hair. Rydberg atoms are easily ionized by applying a small electric field that releases the electron from the atom, which we can then detect. By measuring the ionized electron in coincidence with the scattered electron that initially excited the atom and by changing the laser polarization, all information about the collision can be extracted in a unique way and with high efficiency. This new technique hence complements existing methods without suffering from the technological limitations that plague them. These new experiments will provide the first data to test the models, allowing them to be further refined, enhanced and improved.

References:

S Cvejanovic & F H Read J. Phys. B 7 1180 (1974)

G C King et al J. Phys. E 20 440 (1987)
A J Murray et al Phys Rev A 77 013409 (2008)

K L Nixon & A J Murray Phys Rev Lett 106 123201 (2011)

M Hussey et al Phys Rev A 86 042705 (2012)

K L Nixon & A J Murray Phys Rev Lett 112 023202 (2014)

M Patel et al Rev Sci Inst 91 103104 (2020)

The School/Department is strongly committed to promoting equality and diversity, including the Athena SWAN charter for gender equality in higher education. The School/Department holds a Silver Award which recognises their good practice in relation to gender; including flexible working arrangements, family-friendly policies, and support to allow staff achieve a good work-life balance. We particularly welcome applications from women for this post. All appointment will be made on merit. For further information, please visit:

 http://www.physics.manchester.ac.uk/about-us/equality-and-diversity/

Our University is positive about flexible working – you can find out more here

Blended working arrangements may be considered      

Please note that we are unable to respond to enquiries, accept CVs or applications from Recruitment Agencies.

Enquiries about the vacancy, shortlisting and interviews:

Name: Professor Andrew Murray

Email: [email protected]

General enquiries:

Email: [email protected]

Technical support:

https://jobseekersupport.jobtrain.co.uk/support/home

This vacancy will close for applications at midnight on the closing date.

Please see the link below for the Further Particulars document which contains the person specification criteria.