The Splitter field will bend the primary beam away from its incident direction. Since beam luminosity will be significantly increased for this experiment compared with the HNSS experiment, a local dump cannot be used. The beam has to be brought back to the Hall C main dump. Two BZ magnets will be used to merge the primary beam and the forward bremsstrahlung photons toward the main dump (figure 74). A standard BZ (gap 1.5'') will be used at the front and an enlarged gap (2.2'') BZ magnet will be placed at the back for merging the two lines. This is due to the consideration of beam size and the bending power of the BZ magnets. The entire system of beam line, dump lines, and the Splitter magnet will be under MCC control to ensure safe transport of the beam into the dump.
Necessary correction and monitoring systems will be installed by ACC in order to enable MCC to tune the beam into the dump. Correctors (minimum 4) will be mounted at necessary locations along the front dump lines chosen by ACC. A number of BPMs will also be installed at various locations by ACC. A BeO target should be prepared which will be inserted into the beam during beam tune by MCC for additional viewing of the beam position at the target. These additional control and monitoring systems ensure the safe beam delivery.
Trip locks will be used along the incoming and dump lines. As used for HNSS, trip lock will also be installed on the Splitter power supply. All these locks will be used to protect the lines and to transfer beam safely. All detailed locations are under ACC consideration. Discussions between the collaboration and ACC are undertaken on a regular basis.
Fast rastered beam will be used for the calibration run with the CH
target
to protect the target, however
the experiment requires the point beam for the standard operation as mentioned
above to achieve a high resolution.