Northwestern traps a single positron in first antimatter quantum cyclotron for months

Physicists at Northwestern University built the first one-positron quantum cyclotron, holding a single antiparticle in a Penning trap for months at about 300 millikelvins. The device aims to deliver the most precise test yet of CPT symmetry and possibly explain the universe's matter-antimatter imbalance.

• A single positron was trapped for months at roughly 300 millikelvins
• Loading one positron takes between 8 and 11 hours
• Positrons from sodium-22 decay are slowed in a tungsten moderator
• The goal is a record-precision test of CPT symmetry