Muons going through MICE should –Have ISIS proton timing structure –Generate TOF signals –Satisfy ISIS and TOF trigger requirements MICE tracker DAQ will keep raw tracker data of appropriate ISIS bucket upon receipt of trigger (L1ACCEPT or Particle Trigger). Description of Trigger/Pipeline Issues

Trigger formation from ISIS and TOF signals takes ~ 1000 ns. When raw data arrive at AFE IIt boards, we don’t know immediately if this data corresponds to muon data. Solution: –Store data from each ISIS bucket in pipeline putting data into pipeline at bucket period. –When trigger is received, keep and process data from particular pipeline slot corresponding to trigger formation time. Note: slot number or pipeline depth ~ (trigger formation time)/(bucket period) Potential problems –Trigger formation time not multiple of proton bucket period –Proton bucket period varies from 345 ns to 324 ns over course of 1 ms wide spill

Start with ISIS bucket structure at end of spill with - bucket period = 324 ns - bucket width = 108 ns

A B Start with ISIS bucket structure with - bucket period = 324 ns - bucket width = 108 ns Suppose events A, B occur in bucket 1 at times t A = 50 ns, t B = 90 ns.

A B Trigger formation time = 1000 ns Start with ISIS bucket structure with - bucket period = 324 ns - bucket width = 108 ns Suppose events A, B occur in bucket 1 at times t A = 50 ns, t B = 90 ns. Assume it takes 1000 ns to form trigger.

Trigger formation time = 1000 ns Buckets are placed in pipeline: bucket 1 Bucket 1 added to pipeline. 1 A B

Trigger formation time = 1000 ns Buckets are placed in pipeline: bucket 2 Bucket 1 added to pipeline. Bucket 2 added to pipeline A B

Trigger formation time = 1000 ns Buckets are placed in pipeline: bucket 3 Bucket 1 added to pipeline. Bucket 2 added to pipeline. Bucket 3 added to pipeline A B

Trigger formation time = 1000 ns Buckets are placed in pipeline: bucket 4 Triggers for events A and B arrive before and after bucket 4 added to pipeline. This presents problem for setting pipeline depth for taking data out of pipeline. Bucket 1 added to pipeline. Bucket 2 added to pipeline. Bucket 3 added to pipeline. Bucket 4 added to pipeline A B

Before 4 th bucket added to pipeline, pipeline depth needs to be set to 3 for event A. Trigger formation time = 1000 ns Bucket 1 added to pipeline. Bucket 2 added to pipeline. Bucket 3 added to pipeline. Bucket 4 added to pipeline. A B Buckets are placed in pipeline: bucket 4 Triggers for events A and B arrive before and after bucket 4 added to pipeline. This presents problem for setting pipeline depth for taking data out of pipeline. After 4 th bucket added to pipeline, pipeline depth needs to be set to 4 for event B.

After 4 th bucket added to pipeline, pipeline depth needs to be set to 4 for events A and B. Trigger formation time = 1000 ns Bucket 1 added to pipeline. Bucket 2 added to pipeline. Bucket 3 added to pipeline. Bucket 4 added to pipeline. A B Solution: Add delay to trigger. In this case, a delay between 80 ns – 296 ns results in necessary pipeline depth of 4 for any event in bucket 1. Trigger formation delay = 80 ns

What About Variable ISIS Bucket Period? At beginning and end of spill, the trigger needs to be delayed so that the pipeline depth is 4 for any event occurring in bucket 1. Adding trigger delay of 80 ns – 296 ns works at end of spill –Bucket period = 324 ns –Bucket width = 108 ns Adding trigger delay of 150 ns – 380 ns works at start of spill –Bucket period = 345 ns –Bucket width = 115 ns Trigger formation time = 1000 ns

What About Variable ISIS Bucket Period? Adding trigger delay of 80 ns – 296 ns works at end of spill –Bucket period = 324 ns –Bucket width = 108 ns Adding trigger delay of 150 ns – 380 ns works at start of spill –Bucket period = 345 ns –Bucket width = 115 ns Satisfying both constraints done be setting trigger delay between 150 ns – 296 ns. Appropriate trigger delays can be determined for trigger formation times < ~3000 ns. Trigger formation time = 1000 ns