Procedure to Select BB Shower Blocks

How to select BigBite Shower Blocks

1. After changed kinematics, turn on all the shower blocks in hvgui. Wait a while until all the showers blocks on the map display turn green.

2. Use LH2 target, check prescale . Take a 5 minutes run.

3. Do analysis, check the hits pattern on the shower blocks.

4. Turn off the other blocks, take another run.

5. Do analysis for the run after turning off the other blocks. Make sure the right blocks are on.

6. Check the physics replay, check the acceptance in HRS to ensure we keep the elastic events.

   The variables to look at: L.tr.tg_ph vs L.tr.tg_dp, L.tr.tg_y. L.tr.tg_ph:L.tr.tg_th.
   For further analysis, do a graphic cut on ph_dp to select the elastic events, calculate the ratio of event number
   before and after the cut. 

7. If evetything is OK, halog the hits pattern before and after turning off the shower blocks, and the HV map.