The positrons and electrons, which are produced at a metal plate in front of the bending magnet RTAGX by the photon beam, are provided at three beamlines in the GeV-γ experimental hall. The positrons and electrons are momentum-analyzed with RTAGX, and the energy spread of them is approximately 0.5% . The beam profile and intensity depend on the beam energy, and the diameter of the beam is roughly 20 mm, the intensity is roughly a few kHz. The positrons (or electrons) at the -30 deg beamline can be focused with a triplet quadrupole magnets thanks to a KEK cooperation. The polarity of the magnets can be changed. The details of the photon beam properties after the earthquake are under investigation. Information before can be obtained in a reference “A detailed test of a BSO calorimeter with 100-800 MeV positrons”,
Reference: T. Ishikawa et al., Nucl. Instr. and Meth. A 694, 348 (2012).
| Beam | Beam line | Maximum beam energy |
|---|---|---|
| Positron / Electron | ± 30 deg | ~840 MeV |
| Positron | -23 deg | ~1000 MeV |
Please contact to Dr. A. Tokiyasu (tokiyasu-at-lns.tohoku.ac.jp -at- should be replaced with @).
