G0 Forward Angle Measurement

• Electron beam energy = 3 GeV on 20 cm LH2 target

• Detect recoil protons (q ~ 62 - 78o corresponding to 15 - 5o electrons)

• Magnet sorts protons by Q2  in focal plane detectors

• Full desired range of Q2 (0.16 - 1.0 GeV2) obtained in one setting

• Beam bunches 32 nsec apart (31.25 MHz = 499 MHz/16)

• Flight time separates p (about 20 ns) and p+ (about 8 ns)

lowest Q2

highest Q2