"Magnetic fields that had been able to focus positrons into stable orbits were unable to control the wild antiprotons... Budker's idea was to pass the antiprotons through clouds of cold electrons. Although electrons are matter and antiprotons are antimatter, they are in no danger to one another: electrons are destroyed by their antiparticle, the positron, while the antiproton is at risk only from protons or neutrons. ...By 1974 Budker... succeeded in making and cooling antiprotons, but not in sufficient numbers to make an intense beam."