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
Professor Gaetana Laricchia
Born in Barletta (Italy), I was an undergraduate in Physics at UCL from 1980 to 1983 and then a postgraduate obtaining a PhD in positron physics in 1986. From 1986-88 I worked as a postdoctoral research assistant at UCL and Aarhus University in Denmark. In 1988, I was appointed to the UCL staff as a Lecturer. In 1994-1995 I held a Science Research Fellowship awarded by the Nuffield Foundation. I was promoted to Reader in 1996, to Professor in 2003 and appointed Head of the Atomic, Molecular, Optical and Positron Physics group in 2004.
+44 (0) 20 7679 3467
+44 (0) 20 7679 3470
My major research interests are in experimental studies of positron and
positronium interactions with simple atomic and molecular systems.
Particular attention has recently been given to positronium formation
and positron impact ionization (including threshold and differential
studies), annihilation, the production of positronium beams and
positronium scattering. More detail about this research can be found here.
Page last modified on 19 apr 08 22:35