Physicists trapped antimatter particle for months in landmark experiment
Northwestern physicists trapped a positron in a vacuum for months, solving a problem that has stymied research for decades.
Positrons are antimatter - the deadly opposite of electrons. When the two meet, they annihilate each other instantly.
Physicists have observed positrons since the 1930s but keeping one alive long enough to study has been nearly impossible. A positron ejected from radioactive decay shoots out at 88 percent the speed of light.
Northwestern University researchers solved this by passing positrons through a tungsten crystal, which slowed them down enough to enter a trap. The trap uses electric and magnetic fields to hold the particle in a vacuum cooled to nearly absolute zero.
For the first time, the team kept a single positron isolated for months. They could then use microwaves to nudge it between different energy levels and detect the changes without disturbing the particle itself.
This breakthrough opens the door to rigorous tests of fundamental physics.
- Northwestern University
- Institution
- Gerald Gabrielse
- Senior author
- 88 percent the speed of light
- Ejection speed
- months
- Isolation period
Why it mattersUnderstanding antimatter could answer why anything exists at all instead of the universe being empty space.
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