Present status and plans: Positron production system was successfully tested at designed parameters. Dumping ring is ready for commissioning with 500 MeV electron beam. 500 MeV electron beam will be available from linac in December MeV positron beam will be available from linac in December 2007.
Conventional positron production system layout. 1 electron source, 2 RF accelerating structure, 3 triplet of quadrupoles, 4 positron production target, 5 matching device, 6 first accelerating structure of positron linac, 7 quadrupole lens.
Phase space diagrams for positron beam (black contour lines): a) just after the target, b) after the matching device. White zone corresponds to the acceptance of further linear accelerator. These results of simulation were obtained for axial-symmetric magnetic field of matching device:
Part of injector complex is in operation now : 1 electron gun, 2 sub harmonic bunching system, 3 focusing coil, 4 accelerating structure, 5 solenoid coil, 6 quadrupole lens, 7 corrector, 8 spectrometer, 9 bending magnet, 10 positron production system and first accelerating structure of positron linac.
Positron bunch profile at different moments of time. Results of simulation.
Results of magnetic measurements for matching device of VEPP-5 Injection Complex: upper curve – longitudinal magnetic field on the geometrical axis of the device, lower curve – transverse component of magnetic field on the geometrical axis Z.
Examples of positron trajectories in matching device with axial symmetry of magnetic field:
Positron production test bench: 1 main DC solenoid, 2, 3, 4 quadrupole lenses, 5 steering magnet, 6 separating magnet. Positron beam intensity as a function of distance from the target in the positron production test bench. Designed positron beam intensity at the end of linac.
The dependence of positrons number upon the maximum field in FC. Driving electron beam energy MeV. Number of electrons in primary electron beam - Y=0.1 1/GeV
Image on the phosphor screen placed just after the output foil window of separating magnet (screen diameter is 34 mm). PositronsElectrons