-
Asked by anon-232563 to Mark, Liam, Laura, Kasia, Gina, Felix on 15 Nov 2019.
-
Mark Johnson answered on 15 Nov 2019: last edited 15 Nov 2019 1:58 pm
There are actually a few different ways of trapping atoms!
I work on an experiment where we trap anti-hydrogen atoms by putting them into a special kind of magnetic field. Antihydrogen atoms are slightly magnetic because of their own subatomic structure, with a positron (or anti-electron) orbiting around an anti-proton. About half of the atoms that we make will be attracted towards stronger magnetic fields, while the other half will move towards weaker magnetic fields. In our experiment, we use a special arrangement of very strong ‘superconducting’ magnets to produce a field that gets stronger in any direction that an atom might try to escape. Atoms that like to hang around in weak magnetic fields are constantly pulled towards the centre of our experiment, which keeps them trapped inside a small volume.
It’s also possible to trap some atoms using special arrangements of lasers, but the details of this are a bit complicated. Lots of scientists are trying to use trapped atoms to design powerful ‘quantum computers’ that might be very useful in the future!
-
-
Liam Gaffney answered on 15 Nov 2019:
Oooo, Mark is the best person to answer this, he uses traps all of the time for atoms.
In my laboratory, we knock off some electrons from the atom so that it has an overall positive electric charge. When you do this, you can hold them for a very long time using electric fields as long as you have a very good vacuum. To create the vacuum, you have to pump out all of the air from a sealed chamber and if you want to move them around then your chamber has to be very big. We connect many chambers together to create a “beam line” so the ions can travel along and even accelerate them in straight lines. If we want to bend them around corners, we have to use very powerful magnets, so we combine all of these things at the same time.
-
Laura Sinclair answered on 19 Nov 2019:
This is a good question. Mark and Liam answered it so well, I’ve learnt something!
-
Felix Warren answered on 19 Nov 2019:
We use strong magnetic fields to contain the plasma in our reactor as when heated it can reach temperatures many times hotter than that of the sun. On some experiments we have had plasma touch metal components in the reactor and melt them instantly requiring maintenance before we can resume testing.
Comments