Amorphous radiator/harp ladder requirements
Amorphous ladder requirements
- Need an electron harp near the radiators with dynamic range of .
- We requested information from accelerator division regarding such a harp
- Such harp does not exist in the schedule.
- It would cost Hall D $15K to turn the IHA5C11A harp located a few meters upstream of the goniometer from the dynamic range wire-readout harp into a PMT-based harp with range.
- Since we are developing our own scanning procedure for the converter harp, we can put wires on the amorphous radiator located just behind the goniometer, and use very similar procedure to do the harp scan using the amorphous radiator stick and the halo counters.
- No extra hardware will be required since we already planned for the halo PMTs, VME crate with discriminators and the motion axis controls.
- Can design the amorphous radiator ladder based on the photon harp stick since the stages for the two insertion devices are going to be identical.
- Reduce the spacing for the wire along the stick by ~1" to allow for four amorphous targets and and harp wires.
- Question is if four or three wires are enough for the amorphous target stick.