Page History

...

• The geometry of the PS setup actually used is described very well by Stefan
• Other setups are in progress.

• • The requirements come from the following list:

• • Photon runs
    ------------
    2 cerenkov
    1 large plastic (1cm thick) for rate monitoring
    2 finger counters (2mm thickness, overlap of 1x1cm) for triggering
    1 large plastic (1cm thick) with a 24mm diameter hole centered on the
    beam for vetoing background
    2 XY silicon layers before the magnet
    1 magnet
    2 XY silicon layers after the magnet
    1 plastic (1cm thick) after the last silicon for triggering

...

• • *           Comment: we might deplete the 2nd cerenkov to reduce X0 if we realize

...

• • that the photon trigger is efficient
              Electron runs
              --------------
              2 cerenkov
              1 large plastic (1cm thick) for rate monitoring
              2 finger counters (2mm thickness, overlap of 1x1cm) for triggering
              1 large plastic (1cm thick) with a 24mm diameter hole centered on the
              beam for vetoing background
              1 XY silicon layers before the magnet
              1 magnet OFF

          comment: we might need a trigger scintillator in coincidence with the
          fingers just before the CU

          Positron runs
          --------------
          2 cerenkov
          1 large plastic (1cm thick) for rate monitoring
          2 finger counters (2mm thickness, overlap of 1x1cm) for triggering
          1 large plastic (1cm thick) with a 24mm diameter hole centered on the
          beam for vetoing background
          1 XY silicon layers before the magnet
          1 magnet ON
          1 EM CAL (40cm NaI) to veto gammas
          1 plastic after the annihilator before the CU to veto electron/positron

          Proton runs
          --------------
          2 cerenkov
          1 large plastic (1cm thick) for rate monitoring
          2 finger counters (2mm thickness, overlap of 1x1cm) for triggering
          1 large plastic (1cm thick) with a 24mm diameter hole centered on the
          beam for vetoing background
          1 XY silicon layers before the magnet
          1 magnet OFF

          comment: we might need a trigger scintillator in coincidence with the
          fingers just before the CU

         general comment: the veto counter (plastic with hole) might be removed
         if background is measured to be low enough