A magnetic bottle can be used to store charged particles, called ions, usually in the form of a plasma. But it is actually a very poor method of storing anything, even plasma, as leakage through the ends is fairly significant. It's just one of the easiest methods of storing plasma for research, as better storage methods are vastly more complicated and expensive.
Doriangrey said:
Oh, so hydrogen fuses with another hydrogen to become stable and get the configuration of helium or is there another mechanism?
Hydrogen is fused with itself to make helium, but we are usually talking about fusing dueterium and tritium, which are isotopes of hydrogen. That is, regular, plain, basic hydrogen is just a single proton with a single electron. Dueterium is a proton bonded to a neutron and tritium is a proton bonded to two neutrons. All three have a single electron and a single proton, making them chemically identical except for differences in mass. Plain hydrogen and dueterium are both entirely stable. Tritium is unstable and will undergo beta decay with a half-life of about 12 years.
Helium can be formed from the fusion of deuterium with itself or with tritium. Specifically helium-4, the most common isotope of helium. Another isotope of helium, helium-3, is created when tritium naturally decays. Both helium-3 and helium-4 are chemically identical, differing only by mass.
Doriangrey said:
They say that no other devices can store hydrogen, so how exactly is the magnetic bottle able to do so?
Just about any compressed gas cylinder can store hydrogen in gaseous form, though there will always be some leakage due to hydrogen's very small size. However these cylinders cannot store plasma. You need magnetic bottles or another magnetic-based storage device to handle plasma.