Fermi Lab produces a 225‐GeV electron beam

The Fermi National Accelerator Laboratory has produced a 225‐GeV electron beam, a record energy for electrons. According to Thomas Nash, the NAL physicist responsible for the beam’s development, beam intensity in the 100–150‐GeV range was about ${\text{4×10}}^5\hspace{0.17em}\mathrm{electrons}$ per pulse, in agreement with predicted values for ${\text{2×10}}^{11}\hspace{0.17em}\mathrm{protons}$ injected per pulse. Intensity is expected to be over ${10}^7\hspace{0.17em}\mathrm{electrons}$ per pulse for a full intensity proton beam of over ${10}^{12}\hspace{0.17em}\mathrm{protons}$ per pulse. Of course, intensity at 225 GeV is much lower but is also within the range predicted. The electrons will be used as a source of “tagged” photons, rather than for themselves; NAL already has a muon beam for doing lepton physics, but the ability to produce photons of known energy is unique. Before the NAL beam was produced, the highest energy electron beams were at Serpukhov, USSR (35 GeV) and at the Stanford Linear Accelerator Center (20 GeV).