Positrons are the antimatter version of electrons and so their fate in a matter world is ultimately to annihilate. However, prior to this, a positron may combine with an electron to form a matter-antimatter hybrid called positronium. This is akin to a hydrogen atom with the proton replaced by a positron. Fundamental to our understanding of the physical universe, positron and positronium are these days also acknowledged as being fantastically useful in practical applications such as probing material properties and medical diagnostics. However, there is still much that we do not know for sure about the details of the interactions of these particles with ordinary matter. For example if, in a collision with an atom or molecule, a positron captures an electron, in which directions is the positronium likely to travel and with what probability? More...
Published: Jun 17, 2015 12:35:19 PM
How light of different colours is absorbed by carbon dioxide (CO2) can now be accurately predicted using new calculations developed by a UCL-led team of scientists. This will help climate scientists studying Earth’s greenhouse gas emissions to better interpret data collected from satellites and ground stations measuring CO2. More...
Published: Jun 15, 2015 10:29:10 AM
New research from UCL has uncovered additional second laws of thermodynamics which complement the ordinary second law of thermodynamics, one of the most fundamental laws of nature. These new second laws are generally not noticeable except on very small scales, at which point, they become increasingly important. More...
Published: Feb 10, 2015 11:55:53 AM
Dr Philip Jones
|Telephone||+44 (0) 20 7679 3422 [Office]; +44 (0) 20 7679 2268 [Lab]|
I studied Natural Sciences at Cambridge University, followed by an MSc in Applied Optics at Imperial College, and a DPhil in Atomic & Laser Physics at Oxford University, working with Dr David Meacher on optical lattices. I followed David to UCL where I have remained, as a postdoc with Dr Ferruccio Renzoni, and then since 2004 as a Lecturer.
My research is on optical tweezers - a way of trapping and manipulating micron-sized particles using a single, strongly focussed laser beam - and in particular applications to soft matter and the physics/life science interface.
More information is on my website
PHAS3443 Lasers & Modern Optics website
PHAS2440 Practical Physics course website (restricted to UCL users)
Page last modified on 15 jun 11 18:11