Aug 7 2007
Physicists want to study antimatter much more closely and confirm beyond all doubt that it really is the exact opposite of the matter we observe in everyday existence, but there is a problem. Antimatter is very difficult to make, and even harder to store afterwards, making it more precious to scientists than gold. The moment it comes into contact with the normal matter surrounding us it annihilates within a trillionth of second, so it has to be isolated and manipulated indirectly. Until now this has only been possible in large expensive apparatus using electric or magnetic fields to contain the antimatter.
Enter Japanese EURYI Award winner Dr. Masaki Hori. His project was chosen for one of a valuable EURYI Awards because Hori aims to break new ground in handling and storing anti-matter, in this case sub-atomic particles called anti-protons. These are the exact opposite of the protons within the nucleus of every atom, having negative rather than positive charge. He has been cooperating with the Max-Planck-Institute in Germany on this research.
“The newness here is that I want to use radiofrequency (and not magnetic fields like other experimental groups) to store the antiprotons,” said Hori. “The advantage is that the gadget can then be made quite compact, maybe the size of an office wastebasket.” Hori calls this new basket, the "superconducting radiofrequency quadrupole trap".
The EURYI Award is organised by the European science Foundation (ESF) and the European Heads of Research Councils (EuroHORCS). The awards scheme, entering its fourth and final year, aims to attract outstanding young researchers from anywhere in the world to work in Europe for the further development of European science, contributing to building up the next generation of leading European researchers.
Hori then plans to exploit this new device to create new complete atoms comprising anti-matter and then conduct experiments that prove these really do behave exactly as physicists have predicted on the basis of being the exact opposite of matter. “Scientists believe that nature, at a very fundamental level, possesses a symmetry called "CPT" (Charge, Parity, and Time-reversal): this means, if we were to imagine an "antiworld", where all the matter in the universe were replaced with antimatter, the left and right directions inverted as if in a mirror, and the flow of time reversed, it would be completely indistinguishable from our real matter world,” said Hori. “Since this symmetry is of such crucial importance in our understanding of the world, it is of the first importance to test it at the highest possible precision.”
Hori has already laid the ground for this project in his previous research on the antiproton. “What I have done up till now has been to measure the mass and electric charge of the antiproton with a very high level of precision of several parts per billion,” said Hori. “We found that the antiproton did in fact have EXACTLY the same mass as the proton, and equal but opposite charge.”
To achieve this, Hori manufactured a special type of atom, called "antiprotonic helium", which is made of half matter and half antimatter. “I then measured this artificial atom's spectra using a laser beam, which yielded the above information on the antiproton,” said Hori, showing that antimatter obeys all the predictions about its symmetry up to this higher level of accuracy.
Antimatter is not just of academic interest, because it has already been applied with great success in medical diagnosis in the PET (Positron Emission Tomography) scanner, which has saved many lives. Positrons are the anti-matter opposite of electrons, carrying a positive rather than negative charge. In PET scanning, patients are injected with a radioactive isotope which decays in the body by emitting positrons. When these annihilate after coming into contact with electrons, a characteristic burst of light is produced, detected by the PET scanner.
Hori anticipates an exciting future for antimatter, with many potential applications, even though he doubted whether it could be used as a source of energy for powering space ships, as had been thought.
Hori is currently a postdoctoral fellow at the University of Tokyo, having won the 19th Inoue prize for young researchers in 2003. As well as submitting regularly to a number of publications, he is a reviewer for four international journals including the Comments in Atomic and Molecular Physics review..
EURYI is designed to attract outstanding young scientists from around the world to create their own research teams at European research centres and launch potential world-leading research careers. Most awards are between €1,000,000 and €1,250,000, comparable in size to the Nobel Prize. Hori will receive his award in Helsinki, Finland on 27 September 2007 with other 19 young researchers.